Dissertationen: „Veterinary and Environmental Sciences“

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ElSayed, Eman. „Fate and transport of agricultural herbicides and veterinary antibiotics in the presence of a non ionic surfactant“. Thesis, McGill University, 2013. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=119479.

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Many parts of the world, and especially developing countries, are experiencing severe water shortage problems. This is causing increased use of untreated or partially-treated wastewater for irrigation. Consequently, many pollutants such as surfactants, present in wastewaters, could influence fate and transport of agricultural chemicals in soils. Therefore, a field lysimeter study was undertaken to investigate the effect of non-ionic surfactant, Brij 35, on the fate and transport of two commonly used antibiotics, oxytetracycline (OTC) and monensin (MON), and an herbicide, metribuzin. Twenty seven PVC lysimeters, 1.0 m long x 0.45 m diameter, were packed with a sandy soil to a bulk density of 1.35 Mg m-3. Cattle manure, containing these compounds, was applied at the surface of the lysimeters at the recommended rate of 10 t/ha. Three types of wastewaters, i.e., good, poor, and very poor, were simulated by using three aqueous Brij 35 concentrations of 0, 0.5 and 5.0 g L 1, respectively, and applied to lysimeters, in triplicate, for each compound. Over a 90-day period, soil and leachate samples were collected and analyzed. Sorption experiments were also conducted for all compounds in the laboratory in the presence and absence of surfactant. Overall, the OTC and monensin mobility in the lysimeter study significantly increased in the presence of the surfactant (p<0.01). The maximum OTC concentration in the leachate was 102.72 µg L-1 for the surfactant concentration of 0.5 g L-1, which was higher than both control and the high surfactant concentration treatment. Unlike OTC, monensin leaching increased significantly with increasing surfactant concentration (p<0.01), and the maximum detected concentration in the leachate was 5.83 µg L-1 for the surfactant concentration of 5.0 g L-1. The laboratory study also showed that the sorption coefficient of OTC significantly reduced in the presence of the surfactant (p<0.05); it changed from 23.55 mL g-1 in the aqueous medium to 19.49, 12.49 and 14.53 mL g-1, respectively, in the presence of the surfactant at concentrations of 0.25, 2.5 and 5 g L-1. It may, however, be noted that the sorption coefficient was higher for the highest surfactant concentration used. However, in the case of monensin, the sorption coefficient reduced significantly (p<0.01) from 120.22 mL g-1 in the aqueous medium to 112.20, 100 and 63.09 mL g-1 with surfactant concentrations of 0.25, 2.5 and 5 g L-1, respectively. Herbicide movement may also be affected by surfactants; therefore, the mobility of a commonly-used herbicide, metribuzin, was investigated. In the presence of the surfactant, a significant increase in metribuzin movement (p<0.05) in the soil profile was observed. The highest metribuzin concentration in the leachate was 84.80 µg L-1 for the 5.0 g L-1 surfactant treatment. However, no significant differences on mobility were observed for the two treatments with differing surfactant concentrations. The laboratory sorption study showed that the sorption coefficient of metribuzin significantly decreased with increasing surfactant concentration (p<0.05). It can be concluded that nonionic surfactants may increase the mobility of agricultural pollutants, including antibiotics and herbicides, in soil. Therefore, irrigation with poor quality water can potentially cause ground water contamination.
Plusieurs régions du monde, particulièrement celles en voie de développement, souffrent d'une pénurie d'eau. Afin de composer avec l'augmentation de la demande en produits alimentaires et la pauvreté au sein d'une population croissante, des eaux usées partiellement- ou non-traitées servent souvent a l'irrigation. Il en survient que plusieurs polluants, incluant des agents de surface, peuvent être présents dans ces eaux d'irrigation et influencer le devenir et le transport de pesticides et antibiotiques dans les sols agricoles. Une étude lysimétrique au champ visa à évaluer l'effet de l'agent de surface non-ionique, Brij 35, sur le devenir et le transport de deux antibiotiques, l'oxytétracycline (OTC) et le monensin (MON), ainsi qu'un herbicide le metribuzin. Vingt-sept lysimètres en PVC, hauteur 1.0 m  diamètre intérieur 0.45 m, furent remplis d'un sol sablonneux à une densité apparente de 1.35 Mg m-3. Du fumier de vache, contenant les composés sous étude fut épandu à la surface des lysimètres au taux recommandé de 10 Mg ha-1. Pour chaque polluant, chacun des trois lysimètres répliquats fut arrosé d'une des trios solutions aqueuses de l'agent de surface Brij 35 (0, 0.5 ou 5 g L 1), représentant une qualité d'eau d'irrigation 'bonne,' 'mauvaise' ou 'très mauvaise'. Sur une durée de 90 jours, des échantillons de sol et de lixiviat furent obtenus et analysés. Des expériences en laboratoire additionnelles furent conduites en réacteur pour évaluer le potentiel de sorption des composés à l'étude. La présence de l'agent de surface non-ionique Brij 35 diminua de façon significative (p<0.05) le coefficient de sorption de l'OTC, soit de 23.55 ml g-1 en milieu aqueux, à 19.49, 12.49 et 14.53, respectivement, en la présence de 0.25, 2.5 et 5 g L-1 de Brij 35. La mobilité de l'OTC fut significativement moindre en présence de 0.5 g L-1 vs. 5.0 g L 1 de Brij 35. La concentration maximale en OTC du lixiviat fut de 102.72 µg L-1. Le coefficient de sorption du MON diminua de façon significative (p<0.05) de 120.22 mL g-1 en milieu aqueux, à 112.20, 100 et 63.09 mL g-1, respectivement, en présences de 0.25, 2.5 et 5 g L-1 de Brij 35. Si la demi-vie (t½) du MON fut de 5.72 jours en eau du robinet, elle augmenta à 9.62 et 11 jours, respectivement, en presence de 0.5 et 5.0 g L-1 Brij 35. La concentration maximale de MON détecté dans le lixiviat fut de 5.83 µg L-1. Dans le laboratoire, la sorption/désorption de l'OTC fut comparé à celle du sulfachloropyidazine (SCP) en présence et en absence d'un agent de surface non-ionique. En contraste à l'OTC, la présence d'un agent de surface augmenta de façon significative le potential de sorption du SCP au sol, tel qu'en témoigne le coefficient de sorption coefficient (KF) pour le SCP qui augmenta de 19.95 mL g-1 en absence de Brij 35, à 95.49 mL g-1 et 66.06 mL g-1 en présence de Brij 35 à des concentrations de 2.5 g L-1 et 5 g L-1, respectivement. Le coefficient de désorption de l'OTC en l'absence d'agent de surface fut de 61.58 mL g-1, tandis qu'en présence de 2.5 g L-1 Brij 35 elle diminua à 50.35 mL g-1. Comparativement, pour le SCP, les valeurs correspondantes furent de 1.24 and 1.38 mL g-1. Un phénomène d'hystérèse dans le cas du SCP en présence vs. absence de Brij 35 indiqua le bas potentiel de lixiviation du SCP en présence d'un agent de surface. Cependant, l'OTC se montra facilement désorbée en présence de Brij 35 en forme micellaire. Vu les inquiétudes quant a l'utilisation constante d'herbicides dans la production agricole actuelle, le potentiel d'une mobilité accrue de l'herbicide métribuzine en présence d'agents de surface s'avéra digne d'attention. La métribuzine présenta une mobilité accrue et une moindre affinité de sorption au sol et t½ en présence de micelles de Brij35 comparé à en leur absence. Les agents de surface ont augmenté la mobilité en sol des polluants étudiés. L'irrigation avec des eaux de mauvaise qualité peut donc poser un risque de contamination des eaux souterraines.

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Hooper, Paul Nicholas. „The resistance of liquid extended boar semen to environmental stress encountered during air transport“. Thesis, University of Reading, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.333488.

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Kongara, Kavitha. „Studies on renal safety and preventive analgesic efficacy of tramadol and parecoxib in dogs : thesis in fulfilment of the degree of Doctor of Philosophy in Veterinary Clinical Science, Institute of Veterinary Animal and Biomedical Sciences, College of Sciences, Massey University, Palmerston North, New Zealand“. Massey University, 2008. http://hdl.handle.net/10179/864.

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Ovariohysterectomy and castration are common surgical procedures in small animal practice that can result in clinically significant postoperative pain. One way of controlling postoperative pain is administration of a single analgesic or a combination of different classes of analgesics prior to the onset of noxious stimuli. A constraint to the perioperative use of traditional opioids and non-steroidal anti-inflammatory drugs (NSAIDs) is their undesirable side effects. In this series of experiments, the preventive (pre-emptive) analgesic efficacy of two popular human analgesics, tramadol (an ?atypical? opioid) and parecoxib (a NSAID with selective COX-2 inhibition) was evaluated in dogs. Initially, the efficacy and renal safety of parecoxib, tramadol and a combination of parecoxib, tramadol and pindolol (a -adrenoceptor blocker and 5-HT1A/1B antagonist) were screened in anaesthetised healthy dogs. These analgesics increased the dogs? nociceptive threshold to mechanical stimuli, without causing significant alterations in the dogs? glomerular filtration rate (GFR) estimated by plasma iohexol clearance. Subsequently, the efficacy of tramadol was compared with morphine, in dogs undergoing ovariohysterectomy or castration. The Glasgow composite measure pain scale-short form score (CMPS-SF) and changes in intraoperative electroencephalogram (EEG) responses were used to assess the efficacy of analgesics. Of the three treatment groups (preoperative morphine, 0.5 mg kg-1; preoperative tramadol, 3 mg kg-1; a ?combination? of preoperative low-dose morphine, 0.1 mg kg-1, and postoperative tramadol 3 mg kg-1), dogs given the ?combination? had significantly lower pain scores after ovariohysterectomy. In castrated dogs, preoperative tramadol (3 mg kg-1) and morphine (0.5 mg kg-1) were tested and no significant difference in the CMPS-SF score were observed between them. Changes in EEG variables were not specific between the treatment groups in ovariohysterectomised dogs. Finally, the efficacy of test drugs was evaluated against acute noxious electrical stimulation in anaesthetised dogs, using EEG. Median frequency of the EEG, a reliable indicator of nociception, increased significantly in tramadol and parecoxib groups, compared to morphine, after electrical stimulation. These studies demonstrated that tramadol and parecoxib can produce analgesia in dogs with insignificant side effects. The efficacy of tramadol appears to vary with the type of noxious stimulus. A complete prevention of noxious input by administration of analgesics pre- and post-operatively could have important clinical applications.

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Swan, Kathie Lanette. „Sorption Characteristics of Veterinary Ionophore Antibiotics Monensin and Lasalocid and Soil Clay Constituents Kaolinite, Illite and Montmorillonite“. University of Toledo / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1344958732.

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Turner, Susan Jane. „Microbiological Indicators of Faecal Contamination in Aquatic Environments“. Thesis, University of Auckland, 1996. http://hdl.handle.net/2292/2375.

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1. The aim of this research was to determine appropriate microbial indicator systems for use in monitoring the occurrence and source of faecal contamination in aquatic environments. Particular emphasis has been placed on the identification of indicators which might enable faecal contamination of human origin to be distinguished from that of non-human derivation. Two lines of investigation have been pursued; the use of alternative microbial indicator systems for water quality monitoring, and the development of diagnostic molecular methods for identifying the origin of faecal organisms. 2. Field and treatment plant studies were undertaken to investigate the utility of three indicator systems for monitoring water quality impacts in the coastal area surrounding the discharge from Auckland's North Shore City wastewater treatment plant. F-specific bacteriophage (F-phage) and ratios of F-phage to enterococci and faecal coliforms were examined over a twelve month period in which indicator levels at various stages of the wastewater treatment process were measured. These indicators and levels of Clostridium perfringens spores in sediment were measured in four outfall impact studies. 3. F-phage levels in effluent from the treatment plant (median=2.5 x 102 cfu/l00 ml) were too low to enable their use as source-specific tracers of effluent dispersion. However, higher F-phage levels in raw sewage (median=6.2 x l05 cfu/l00 ml) suggested that phage may be an appropriate indicator of raw sewage contamination in the receiving environment. F-phage was detected in coastal waters remote from the sewage outfall, providing presumptive evidence of sewage contamination entering the sea from sources other than the outfall discharge itself. 4. F-phage/enterococci and F-phage/faecal coliform ratios that were determined for sewage and treated effluent derived from the North Shore plant proved to be highly variable and were therefore unreliable for determining the source faecal contamination. 5. The concentration of Clostridium perfringens spores in sediments did not provide a useful means for tracing the distribution of faecal contaminants in the coastal system because the spore levels were found to be similar throughout the study area. This widespread occurrence of C. perfringens spores prevented identification of defined impact zones for any of the potential sources of faecal contaminants examined. 6. Randomly Amplified Polymorphic DNA (RAPD) analysis was used to investigate whether genetic markers could be identified for Escherichia coli isolates derived from different sources. RAPD profiling was found to be a highly discriminative method able to subtype E. coli strains present in both sewage and in the wastewater stream of a mechanical wood-pulping operation. In the pulp mill effluent, RAPD analysis indicated the presence of a restricted range of E. coli strains compared to the range found in the water intake and sewage effluent discharges. The results obtained provide presumptive evidence for the multiplication of E. coli strains within the wastewater stream. 7. Comparison of RAPD profiles derived from a range of human and environmental E. coli isolates led to the identification of a 1.6-kb marker. present in a subset of human isolates, but found only infrequently in isolates from animal origin. Primers based on sequence information obtained from this region of the genome yielded a direct PCR assay for the 'human' marker. The reliability and utility of the assay was improved when fluorescently-labelled primers and an automated DNA detection system was employed for the analysis of the amplified PCR products. 8. The diagnostic polymorphism was localised to the region immediately downstream of the gene encoding the glycine decarboxylase P-protein (gcvP). Comparison of DNA sequences from this region in 'marker-positive' and 'marker-negative' E. coli isolates revealed an abrupt loss of homology immediately downstream of the transcription termination point of the gcvP gene. The region of non-homology extends for at least 130 base pairs beyond the gcvP transcription terminator. Sequences spanning this region in marker-negative isolates exhibited a high level homology with that determined for E. coli K-12. The origin of the sequence for the same region in marker-positive isolates was unable to be identified. 9. The utility of the marker for environmental monitoring was investigated in a field study of a rural stream receiving bacterial contamination of both human and animal origin. The marker was consistently detected both in isolates derived from sewage effluents and in those found immediately downstream from sewage inputs-despite the presence of a high background of E. coli of animal origin. However the utility of the marker as a sewage-specific tracer was limited by the relatively low numbers of marker-positive d. coli in sewage effluents (approximately 8%). 10. In summary, the work described in this thesis has confirmed the need for multiple indicator systems in water quality monitoring and has identified appropriate areas for further research. The most promising area for future research is in the development of molecular tools which might provide both a better understanding of genetic variation in indicator organisms and enable methods to be developed for the detection of host-specific strains. Location of other polymorphisms likely to be present in the E. coli genome should enable further host-specific markers to be identified which could complement the 'human' marker identified in this study.
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Stanley, Karen Nicola. „Seasonal varation of the thermophilic campylobacters in farm animals and the farm environment“. Thesis, Lancaster University, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.337461.

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Erceg, Vicki Heather. „Detection of behavioural and cognitive dysfunction in mucopolysaccharidosis IIIA affected dogs : a thesis presented in partial fulfilment of the requirements for the degree of Master of Veterinary Science at Massey University, Palmerston North, New Zealand“. Massey University, 2009. http://hdl.handle.net/10179/1053.

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This study investigated whether behavioural and cognitive dysfunction caused by mucopolysaccharidosis (MPS) IIIA can be detected early in affected dogs’ lives, and to describe the behaviours of these dogs. No other scientific papers have been published on this topic and the population of dogs examined in this study are the only MPS IIIA affected dog colony available worldwide for study. Three main tests were performed on the population of MPS IIIA affected dogs. Physical behavioural assessment tests were performed at six and eight weeks of age and from twenty weeks of age a cognitive function task was taught and then tested to measure the dogs’ performance. A previously validated questionnaire, the canine behavioural assessment and research questionnaire (C-BARQ), was completed at three, six and twelve months of age. The researchers in these studies were blinded to the MPS IIIA status of the dogs examined. The behaviours shown by the MPS IIIA puppies at six and eight weeks of age were not significantly different from the behaviours of the unaffected puppies. This finding supported the research of other MPS IIIA studies and suggests that clinical behavioural changes do not occur at such a young age. The behaviours shown by the MPS IIIA affected puppies appeared to be normal puppy behaviours similar to those described in previous research on puppies. The C-BARQ measured the behaviours shown by the MPS IIIA affected and unaffected dogs. Most of the MPS IIIA affected dogs’ behaviours were not significantly different from the unaffected dogs’ behaviours, but MPS IIIA affected dogs did retrieve significantly more than unaffected dogs at three months of age, and were less distractible at twelve months of age. It would be worth investigating these findings further to decide whether it suggests a subtle alteration in brain functioning. The cognitive function test showed a significant decrease in the success of the MPS IIIA affected dogs in the final maze test. This is the first study on dogs affected with MPS IIIA to find a decline in cognitive function before the occurrence of cerebellar clinical signs and this new knowledge may lead to future developments measuring therapy response and disease progression. The T-shaped maze testing may be valuable in future research on cognitive function in dogs with other diseases such as epilepsy. Thus this thesis provides valuable information on canine MPS IIIA and provides a foundation for future disease investigations.

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Sheldon-Sayer, Lynne. „The vegetation of Maud Island, Marlborough, New Zealand“. Lincoln University, 2006. http://hdl.handle.net/10182/1707.

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Maud Island (Te Hoiere - "a long paddle or mighty pull") is a moderately sized island of 309 hectares, located in the Pelorus Sound (41°, 02 'S, 173° 54 'E) Marlborough, at the north-east end of the South Island of New Zealand. It has a long history of human modification and impacts since its colonisation by Maori and early Europeans. The vegetation of Maud Island has been studied in the 1980's and again in the early 1990's. The objectives of this study were to (1) describe how the vascular plant communities vary in species composition across Maud Island, (2) determine which environmental factors are important predictors of the variation in species composition of Maud Island plant communities, and (3) describe the pattern of succession of the plant communities on Maud Island over the last twenty years. In this 2001 study, I comprehensively sampled the vegetation on Maud Island using a Reconnaissance Description Procedure in a total of 158 plots across the island and compared these results to previous descriptions. I also retook photos at permanent photo points to provide a visual comparison of vegetation change. In total, 219 plant species were identified; 177 species occurred within the plots and 42 additional species were observed while walking around the coastline and walking tracks. Six dominant plant species occurred in over 70% of the plots. They were Pteridium esculentum, Pseudopanax arboreus, Hebe stricta var. stricta, Melicytus ramiflorus, Ozothamnus leptophylla and Coprosma robusta. Two-Way Indicator Species Analysis resulted in the description of eight different plant communities on the island. Detrended correspondence analysis showed a high degree of turnover in species composition among these communities. Canonical correspondence analysis showed that slope and moisture were particularly important predictors of variation in plant species composition. The environmental factors that best predicted to variation communities were slope, moisture, and a gradient in historical disturbance. Comparisons of present and past vegetation maps and photos (ground and aerial) showed, in terms of the successional pathways of the vegetation on Maud Island, that over time, the vegetation is reverting from short stature grassland and scrub to predominantly forest scrub and young secondary forest.

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Puig, Virginia Moreno. „Conservation issues for Hochstetter's frog (Leiopelma hochstetteri): monitoring techniques and chytridiomycosis prevalence in the Auckland region, New Zealand : a thesis presented in partial fulfillment of the requirements for the degree of Master of Science in Conservation Biology at Massey University, Auckland, New Zealand“. Massey University, 2009. http://hdl.handle.net/10179/1132.

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Amphibians are suffering extinctions and range contractions globally. This is caused by numerous factors and most of them are related to human activities. The overall aim of this thesis was to make a significant contribution to the conservation of the endemic amphibian Leiopelma hochstetteri through research. This was achieved by focusing in two of the main conservation issues for this species, the need for standardised and robust monitoring techniques to detect trends and changes in populations, and the determination of the prevalence of chytridiomycosis, caused by the amphibian chytrid fungus (Batrachochytrium dendrobatidis). Two populations of the Auckland Region were selected for this study, one on the mainland (Waitakere Ranges) and the only known offshore island population of this species (Great Barrier Island). For both study sites different monitoring methods were used to obtain some population parameters. Site occupancy models of MacKenzie et al. (2002) gave reliable site-specific estimations of occupancy and detection probability using covariate information and presence-absence data collected from 50 sites in the Waitakere Ranges and four repeated visits during 2008. Elevation and distance searched were found to have an important effect on occupancy levels, while time taken to search the site was important variable determining detection probabilities. Also, parameters were estimated for three age classes separately. Statistical models were used to infer abundance from occupancy analysis, and results were compared with the distribution of relative abundances obtained from repeated transect counts and an established sight/re-sight criterion. In addition, the use of surrogate measures for relative abundance was explored. Detection probability and the distance to first frog found were found to have a significant correlation with relative abundance. These measures can be used to infer relative abundance in future site occupancy surveys. Two surveys and a pilot site occupancy survey were conducted on Great Barrier Island, and presence of frogs was confirmed atthe northern block, and in a small seepage in the central block. No new locations were found. Waitakere Ranges and Great Barrier Is. populations were tested for the presence of chytridiomycosis, and all frogs sampled tested negative (n = 124) which means that if present chytridiomycosis prevalence is lower than 5% with a 95% confidence interval. This and previous evidence suggests that L. hochstetteri may be resistant or immune to the disease. However, to confirm this additional studies are needed.

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Bates, Andrew John. „Effects of grazing management and pasture composition on the nitrogen dynamics of a dairy farm : a simulation analysis : a thesis submitted in partial fulfilment of the requirements for the degree of Doctor of Philosophy at Lincoln University /“. Diss., Lincoln University, 2009. http://hdl.handle.net/10182/1360.

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There is an extensive debate on the potential environmental impact of dairy farms and in particular the effect of dairy farms on the nitrogen cycle and the effect that this has on ecosystems. Within New Zealand and in particular in the South Island, the expansion of dairying and the adoption of new dairy systems has led to this becoming an increasingly important issue, locally through its effect on water quality and the environment and nationally and internationally through the production of green house gases. Increases in nitrogen usage at the expense of clover nitrogen fixation, irrigation, stocking rate and the introduction of dairy cows onto light free draining soils previously the preserve of arable or sheep farming has led to concern as to the effect intensive pastoral dairying may have on the nitrogen dynamics of the farm and the environment. This study is designed to assess how changes in grazing management in particular changes in pre-grazing and post-grazing residuals alter the clover/ryegrass balance on the farm and the effect that this has on the farm’s nitrogen dynamics. The effects of qualitative changes in grazing management on pasture composition are well established but little is known of the effect of quantitative changes in pasture management on composition, in particular the effect of grazing residuals. There are a number of detailed models of the physiological processes in the energy and nutrient cycling in plants, animals and the soil. There are a smaller number of whole farm models that through integration and simplification of component models attempt to represent the flux of nutrients though a dairy farm. None of these whole farm models is currently able to model the nitrogen flux through a dairy farm at a sufficient level of resolution to capture differences in pasture composition as these occur spatially, temporally and in response to grazing management. This project sought to better understand the nitrogen dynamics on a dairy farm by constructing and then linking component models – a pasture composition and growth model, a cow model, an excretal return model, a soil model and a water balance model – within a whole farm management schedule. The formal null hypothesis is that the mechanistic, mathematical model constructed for this PhD cannot capture and explain the full range of the changes in soil water content, soil nitrogen status, pasture production and composition and animal production, following the alteration in management of the dairy farm between 2002 and 2004. Individual component models were constructed by the author using the computer software package (Matlab) and validated against data extracted from the literature. The models were then converted into one simulation package using C-sharp as the source code language by Elizabeth Post, Senior Computer Scientist at Lincoln Ventures Ltd, Lincoln, New Zealand and the author. This model was then used to investigate the nitrogen dynamics of a dairy farm: the relationship with pasture composition and whether small changes in pasture residuals make a difference to pasture composition and nitrogen dynamics. Two different simulations were run based on the management practice of Lincoln University Dairy farm (LUDF) over two dairy seasons (2002-03 and 2003-04) and validated against the data recorded on this farm. In 2002-03, 50 cows were over wintered and 580 cows were subsequently milked on 200ha. Post grazing residuals where maintained at 1600-1750KgDM/ha. In 2003-04, 125 cows were overwintered and 635 cows were milked on 200ha with post grazing residuals maintained at 1400KgDm/ha. All models operate on a daily time step. Within the pasture model composition is described by 9 state variables describing different components of the pasture and pasture growth is modelled mechanistically from a calculation of component photosynthesis. A further 9 state variables describe the nitrogen composition of the pasture components. The soil model is a variable two layer, mechanistic representation, parametised for the shallow, stony soils of LUDF. Soil water status is an input for the pasture model while water uptake by the growing plants affects the soil water balance within the soil model. Animal intake and production are modelled mechanistically with model cows described in terms of their age, genetic merit, body weight, breed, pregnancy status, conception date and body condition score. Each cow type produces a different quantity of urinary and faecal excretion which varies with dry matter intake, milk yield and the sodium and potassium status of the pasture. Excretal nitrogen composition is predicted within a separate model which calculates daily nitrogen excretion in faeces, urine and milk. Excretions are deposited randomly over the grazed area and account is taken of overlapping excretions that are created on the same day and overlaps that occur with older excretal patches deposited in previous grazing rounds. Each excretal patch has its own associated pasture, water and soil model reflecting the differences in nitrogen status between patches. Grazing preference is expressed within the model between different classes of excretal patch and between excretal patches and the base pasture and between clover and grass. Supplementary silage is conserved and fed according to the management schedule of LUDF. Cows calve, become pregnant and are dried off within the model according to the relevant records from LUDF. Cows are deemed to arrive on the farm on the day of calving and to leave on the day that drying off is finished (a 5 day procedure within the model), except for those cows that are overwintering which remain on the farm. The soil model has multiple nitrogen/carbon pools and is dynamically linked to all the other models. External nitrogen losses from the system are modelled as volatilisation, leaching and denitrification, with pasture nitrogen uptake from the soil model and fixation by clover from the atmosphere. Both the individual component models and the final assembled composite model were successful in matching the available data in terms of pasture and animal production, pasture composition, soil water balance and nitrogen status and external losses. The model indicates that the low residual, high stocking rate farm returns more excreta to the soil. However, this is countered by a reduction in the amount of dead material returned to the paddock and this reduces the relative size of the pool of nitrogen in the dead organic matter. This produces a relative lack of substrate for the soil microbes which are thus unable to exploit all of the nitrogen in the available pool. Soil ammonium and nitrate pools are also increased from the increase in faecal and urinary return so precipitating an immobilising flux from these larger pools to the smaller pool of nitrogen available to the soil microbes. However, the relative inability of the soil bacteria to fully exploit this means that the production of soil organic live matter and the resulting mineralising flux from the dead organic matter pool through the available pool to the ammonium and nitrate pools is reduced. The larger ammonium and nitrate pools will also be associated with increased external losses from the system as denitrification, leaching and volatilisation are increased. The increase in the clover percentage within the sward in 2003-04 led to greater nitrogen fixation and the model suggests that some of the extra nitrogen is effectively captured by the animals in increased production. However, the reduction in the return of dead matter coupled with an increase in excretal return and the consequent increase in the mineral nitrogen pools within the soil lead to greater losses of nitrogen from the soil.

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Lopez, Juan Carlos. „The effect of environmental stressors on the immune response to avian infectious bronchitis virus“. Lincoln University, 2006. http://hdl.handle.net/10182/643.

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The first aim of this research was to determine the prevalence of IBV in broilers within the Canterbury province, New Zealand, in late winter and to search for associations with management or environmental factors. The second aim was to study how ambient stressors affect the immune system in birds, their adaptive capacity to respond, and the price that they have to pay in order to return to homeostasis. In a case control study, binary logistic regression analyses were used to seek associations between the presence of IBV in broilers and various risk factors that had been linked in other studies to the presence of different avian pathogens: ambient ammonia, oxygen, carbon dioxide, humidity and litter humidity. Pairs of sheds were selected from ten large broiler farms in Canterbury. One shed (case) from each pair contained poultry that had a production or health alteration that suggested the presence of IBV and the other was a control shed. Overall, IBV was detected by RT-PCR in 50% of the farms. In 2 of the 5 positive farms (but none of the control sheds) where IBV was detected there were accompanying clinical signs that suggested infectious bronchitis (IB). Ambient humidity was the only risk factor that showed an association (inverse) with the prevalence of IBV (p = 0.05; OR = 0.92). It was concluded within the constraints of the totally enclosed management systems described, that humidity had an influence on the presence of IBV, but temperature, ammonia, carbon dioxide, oxygen or litter humidity had no effect. In another study environmental temperatures were changed in order to affect the biological function and adaptive capacity of chickens following infection with IBV. The 'affective states' of the animal were assessed by measuring levels of corticosterone (CORT) in plasma and tonic immobility (TI). It was found that low (10 +/- 2°C) and high (30 +/- 2°C) temperatures exacerbated the respiratory signs and lesions in birds infected with IBV as compared to those housed at moderate (20 +/- 2°C) temperatures. The chickens housed at high temperatures showed significantly decreased growth, a higher proportion of hepatic lesions (principally haemorrhages) and a longer tonic immobility period, but there was no significant alteration in the plasma levels of CORT. The birds housed at low temperatures developed a higher proportion of heart lesions (hydropericardium, ventricular hypertrophy) and had significantly higher levels of plasma CORT than birds housed under moderate and/or high temperatures. The specific antibody response to IBV decreased in birds housed under high temperatures. Interestingly the birds housed at high temperatures developed significantly higher levels of haemagglutinin antibodies to sheep red blood cells (SRBC) than those birds housed under low or moderated temperatures. Cell mediated immunity was not significantly affected by heat or cold stress in the first 13 days of treatment but at 20 days the levels of interferon gamma in the birds subjected to low temperatures were lower than in the high temperature group. In other trials, the exogenous administration of low physiological doses of oral CORT (as compared to high pharmacological doses typically used in such experiments) to birds resulted in suppression or enhancement of the immune response depending on duration of treatment and/or dose and nature of the antigen. To our knowledge, this is the first study to show that exogenous CORT can produce an enhancement in the immune response in chickens. iv In conclusion, environmental stressors such as high or low temperatures do affect the physiology of the fast-growing broiler. The adjustments the birds have to make to maintain homeostasis impacts on the course of common infectious diseases, such as IB, that normally is mild in the New Zealand poultry industry. The administration of exogenous CORT showed that this hormone may be part of the physiological stress response and acts as a messenger to prepare the immune system for potential challenges (e.g., infection).

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Fisher, P. M. „Residual concentrations and persistence of the anticoagulant rodenticides brodifacoum and diphacinone in fauna“. Lincoln University, 2009. http://hdl.handle.net/10182/930.

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Brodifacoum is a highly effective anticoagulant rodenticide that presents a secondary hazard to some non-target wildlife. The high acute toxicity of brodifacoum to mammals and birds, and its prolonged persistence in liver predicates secondary risk to predators and scavengers of poisoned rodents. Hence there is a need to improve ability to monitor and predict hazards of brodifacoum to non-targets, and optimise use patterns accordingly. Use of a less persistent anticoagulant rodenticide, diphacinone, is an alternative approach currently under investigation in New Zealand. This thesis describes a series of laboratory and pen studies that address information gaps relevant to the assessment of non-target hazards in continued use of brodifacoum, and of using diphacinone as an alternative. Non-lethal techniques for determining sublethal brodifacoum exposure in birds was investigated in chickens. Elevation of prothrombin time was a less reliable index than residual concentrations in tissues. Samples requiring less invasive procedures, such as dried blood spots or faeces, have potential to detect recent sublethal brodifacoum exposure and refinement of these indices could be useful in proactive monitoring of avian wildlife. Residual brodifacoum in eggs of sublethally-exposed hens raised further questions regarding wider non-target hazard and adverse effects on development of fertile eggs or chicks. A laboratory trial with rats found a positive correlation between residual brodifacoum concentrations in liver and the amount of brodifacoum ingested as bait. An estimated 14-22% of ingested brodifacoum was excreted in rat faeces in the period between ingestion of a lethal dose and death, indicating another potentially significant environmental pathway for brodifacoum transfer. In considering diphacinone as a less persistent alternative rodenticide to brodifacoum, evaluation of residual concentrations and persistence in pig tissues was required to estimate secondary hazard to human consumers and adequate with-holding periods for hunting feral pigs in areas where diphacinone was applied. A pen trial showed that domestic pigs were more susceptible to diphacinone toxicity, and thus primary poisoning risk, than previously estimated. Hepatic half-life of diphacinone in pigs was approximately 14 days, indicating reduced persistence in comparison to brodifacoum and enabling estimates of with-holding periods for hunting feral pigs from areas where diphacinone baits were applied. To investigate potential hazards of diphacinone use to invertebrates a trial using tree weta, a native New Zealand invertebrate, was undertaken. Weta readily ate diphacinone wax block baits with no mortality or weight loss evident, indicating low susceptibility. Residual whole-body diphacinone concentrations did not increase with the amount of diphacinone bait eaten. A simple, deterministic risk assessment suggested that, as a single secondary exposure, the maximum diphacinone concentration measured in weta would present a low risk to non-target birds. Given international recognition of the high secondary hazard and corresponding restrictions on use of brodifacoum, continued availability of brodifacoum to non-licensed users and sustained field applications for possum and rodent control in New Zealand is an exceptional use pattern. New data in this thesis suggest that baiting strategies that minimise the amount of brodifacoum available in the environment are important and regulatory review of some New Zealand brodifacoum applications should address this. In parallel, development of diphacinone as an alternative to brodifacoum should continue, as new data here confirms lower persistence in mammalian liver than brodifacoum, and also indicates low toxicity to invertebrates. However further investigation of multiple-exposure hazard and potential sublethal effects of diphacinone on non-target mammals and birds is warranted before extensive and sustained field applications of diphacinone are undertaken.

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Calder, Keith Wallace. „A LEEP forward : biodiversity futures for New Zealand : a thesis in partial fulfilment of the requirements for the Master of Resource and Environmental Planning at Massey University, Palmerston North, New Zealand“. Massey University, 2007. http://hdl.handle.net/10179/741.

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Loss of indigenous biodiversity continues in New Zealand. Despite admirable goals in the NZBS 2000 to the contrary, efforts at improved biodiversity conservation have been insufficient to halt loss of significant amounts of indigenous forest and wildlife habitat. Increasing numbers of native species are moving towards critically endangered and extinction. Whatever we are doing in New Zealand, it is not effective enough. The aim of this study is to firstly identify factors contributing to the failure, “to halt the decline of indigenous biodiversity” in New Zealand and to then consider opportunities to overcome these barriers. In considering opportunities, this study then reviews the emerging discipline of landscape ecology as an answer to, at least, some of those factors and the recurring calls from New Zealand ecologists for a more integrated and holistic approach to biodiversity conservation. Recent advances in the planning framework and particularly provisions for biodiversity conservation in England are explored as a model of practical application of landscape ecological principles to land-use planning. From this review, the study proposes a new ‘LEEP’ model for strategic biodiversity conservation that produces a regional-scale spatial conservation map and accompanying policy and implementation guide. Together they provide an integrated and holistic approach to restoring or creating functional landscapes that also recognises and provides for human activities and development. Application of the LEEP model is demonstrated through a case study of the Wellington region. Benefits and potential uses of the map and policy outputs are canvassed. Interviews with leading New Zealand and international ecologists provide an assessment of the current status of landscape ecology and interviewees also act as an expert ‘test panel’ against which the Wellington maps and guides produced from the ‘LEEP’ model are assessed. Finally, suggestions are provided for development of the new model and future research needs towards fuller and more effective implementation of this approach to biodiversity conservation in the New Zealand context.

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Willems, Nancy. „Forest structure and regeneration dynamics of podocarp/hardwood forest fragments, Banks Peninsula, New Zealand“. Lincoln University, 1999. http://hdl.handle.net/10182/1301.

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Although species maintenance in small forest fragments relies on successful regeneration and recruitment, few studies have examined the effects of fragmentation on regeneration processes. New Zealand's podocarp species rely on large disturbance openings operating across a vegetated landscape to stimulate regeneration. Clearance of vegetation that results in small fragments of forest removes regeneration opportunities for podocarps by destroying the intact vegetation mosaic, and as a result may exclude disturbances of the scale necessary for podocarp regeneration. Fragmentation alters the disturbance regime of the landscape, with important implications for the regeneration of podocarps on Banks Peninsula. The four remaining lowland podocarp-hardwood fragments on Banks Peninsula were sampled to determine the structure and regeneration patterns of podocarps and to assess their long term viability. Density, basal area, and size and age class distributions were used to examine current composition, and in conjunction with spatial analysis, to identify past regeneration patterns and infer likely future changes in composition and population structure. Podocarp size and age class structures for three of the four fragments were characteristically even-sized and relatively even-aged (eg; Prumnopitys taxifolia c. 350 to 600 years), with little or no regeneration for approximately the last 200 years (old-growth fragments). Regeneration of the current podocarp canopy in the old-growth fragments may have been stimulated by flooding. The fourth younger fragment showed much more recent regeneration with Prumnopitys taxifolia, Podocarpus totara and Dacrycarpus dacrydioides mostly 80-160 years old, and substantial populations of seedlings and saplings, probably as a result of anthropogenic fire. In the absence of major disturbance the podocarp component in forest fragments on Banks Peninsula is likely to decline with composition shifting towards dominance by hardwood species. There is some evidence to suggest that canopy collapse will stimulate some podocarp regeneration within the fragments, however it appears to be unlikely that podocarps will persist on Banks Peninsula indefinitely within the fragments studied. There is an urgent need for more quantitative research in New Zealand fragmentation literature, and a need for more emphasis on processes. Banks Peninsula offers potential for a more landscape scale approach in forest management, and the maintenance of regenerating scrub in pockets about the Peninsula may offer the regeneration opportunities for podocarps that are lacking within protected fragments. My study took a quantitative approach in examining the effects of forest fragmentation on the demographics of podocarps and compositional change in forest fragments on Banks Peninsula.

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Dittmer, Keren Elizabeth. „Inherited rickets in Corriedale sheep : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy at Massey University, Palmerston North, New Zealand“. Massey University, 2008. http://hdl.handle.net/10179/882.

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Inherited rickets of Corriedale sheep is a newly discovered skeletal disease of sheep with simple autosomal recessive inheritance. The clinical signs resemble rickets in other species and include decreased growth rate, thoracic lordosis and angular limb deformities. Radiographic features include physeal thickening, blurred metaphyseal trabeculae and thickened porous cortices. Computed tomography scanning of long bones reveals increased bone mineral content and cortical area, but decreased bone mineral density. Gross lesions include segmental thickening of physes, growth arrest lines, collapse of subchondral bone of the humeral head, thickened cortices and enthesophytes around distal limb joints. Microscopically there is persistence of hypertrophic chondrocytes at sites of endochondral ossification, inappropriate and excessive osteoclastic resorption, microfractures and wide, unmineralised osteoid seams lining trabeculae and filling secondary osteons. Affected sheep are persistently hypophosphataemic and hypocalcaemic. Normal serum 25-hydroxyvitamin D3 concentration accompanied by a two-fold elevation in 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) suggested a defect in endorgan responsiveness to vitamin D as a likely mechanism, but this was not supported by in vitro studies using cultured skin fibroblasts. These studies revealed normal vitamin D receptor function and the presence of 24- hydroxylase mRNA in cells from affected sheep, even without induction by 1,25(OH)2D3. Inappropriate overexpression of 25-hydroxyvitamin D3-24- hydroxylase, the enzyme that breaks down active vitamin D, is therefore considered the probable cause of inherited rickets in Corriedale sheep. Such a mechanism has not previously been described as a cause of inherited rickets in humans or other animal species. Treatment of affected sheep with high oral doses of vitamin D3 weekly for 3 months showed a trend towards increased bone mineral density, thus supporting an intact vitamin D receptor. Preliminary studies on immune function revealed reduced numbers of CD4+ and CD8+ lymphocytes and reduced interferon-? production by lymphocytes stimulated with parasite antigen. This new form of inherited rickets may be widespread in

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Stella, Judith Lynn. „An Investigation of Environmental Factors that Affect the Behavior and Welfare of Domestic Cats (Felis sylvestris catus)“. The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1364486788.

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17

O'Connor, Katrina Marie. „The ecological footprint of international tourists in New Zealand : a thesis presented in partial fulfilment for the degree of Master of Applied Science in Natural Resource Management at Massey University, Palmerston North, New Zealand“. Massey University, 2009. http://hdl.handle.net/10179/1124.

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Ecological Footprint Analysis (EFA) is a technique that was first developed by Wackernagel as a Ph.D. thesis in 1994, then further developed in combination with Rees and published (Rees & Wackernagel, 1995). EFA is employed in this study to assess the resource utilisation of international tourists visiting New Zealand. Tourism is one of the fastest growing industries in the world and the ecological sustainability of tourism is becoming more important term for managing tourism. This is becoming increasingly important with tourism identified as particularly as a significant contributor to carbon emissions. This study uses EFA to assess whether international tourists visiting New Zealand behave in a sustainable manner. Tourists are surveyed and classed into high, mid and low budget tourist types to gain a detailed account of their behaviour with particular reference to food, accommodation, transport, services, activities attractions, goods and waste. The EFA helps to identify areas of a tourist’s trip that have the greatest impact on the environment, thereby identifying ways to improve the sustainability of tourism in New Zealand. It was found that tourists generally consume more whilst on holiday than they do at home and more than New Zealand residents. The results show that international tourists’ behaviour is sustainable and New Zealand has the ecological carrying capacity to allow the number of international tourists to increase without incurring any significant ecological costs to the country. It was found that there is a positive relationship between ‘high’ income tourists and their ecological footprint and that independent travellers have a larger ecological footprint than the package travellers; however, package travellers have a larger food and housing ecological footprint than independent travellers. The energy footprint was the largest out of the six land types of a tourist’s ecological footprint. Food is the consumption category that is the largest contributor to a tourist’s ecological footprint.

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Ford, Colleen D. „The fate of nitrogen in lactose-depleted dairy factory effluent irrigated onto land“. Lincoln University, 2008. http://hdl.handle.net/10182/837.

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A two-year lysimeter study was undertaken to compare the environmental effects (e.g. nitrate leaching and nitrous oxide emissions) of soil applied lactose-depleted dairy factory effluent (LD-DFE) with lactose-rich DFE. The aim of this experiment was to determine the fate of nitrogen from LD-DFE and dairy cow urine applied to a Templeton fine sandy loam soil (Udic Ustrochrept), supporting a herbage cover of ryegrass (Lolium perenne) and white clover (Trifolium repens). Measurements were carried out on the amount of nitrogen lost from the soil via leaching, lost by denitrification, removed by the pasture plants, and immobilized within the soil organic fraction. Further, a comparison between the fate of nitrogen in LD-DFE irrigated onto land under a "cut and carry" system, as opposed to a "grazed" pasture system was undertaken. Lactose-depleted dairy factory effluent was applied at three-weekly intervals during the summer months at rates of 25 and 50 mm, until nitrogen loading targets of 300 and 600 kg N ha⁻¹ yr⁻¹ had been achieved. Measured leaching losses of nitrogen averaged 2 and 7 kg N ha⁻¹ yr⁻¹ for Control 25 and Control 50 treatments; 21, 20 and 58 kg N ha⁻¹ yr⁻¹ for 25 and 50 mm "cut and carry" treatments respectively; and 96 kg N ha⁻¹ yr⁻¹ for the 25 mm "grazed" treatment. The range of nitrate-N leaching loss from LD-DFE plus urine is no different from the lactose-rich DFE nitrate leaching loss. Uptake of nitrogen by the growing pasture averaged 153, 184,340,352,483, and 415 kg N ha⁻¹ yr⁻¹ for Control 25, Control 50, LD-DFE 25 and LD-DFE 50 mm "cut and carry" treatments, and the LD-DFE 25 mm "grazed" treatment, respectively. Denitrification losses were 0.06, 4.4, 1.69, 19.70, and 7.4 kg N ha⁻¹ yr⁻¹ for Control 25, the LD-DFE 25 "cut and carry" treatments, the LD-DFE 25 mm "grazed" treatment, and calculated "paddock losses", respectively. Isotopic nitrogen studies found that 29.4 and 25.8% of applied LD-DFE nitrogen was immobilised in the LD-DFE 25 and LD-DFE 50 "cut and carry" treatments. The results of this experiment confirm the findings of the previous lactose-rich DFE study, in that the effects of grazing stock are of greater environmental concern than the removal of lactose from the effluent waste stream.

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Hill, Andrew Gordon. „An investigation of Leucocytozoon in the endangered yellow-eyed penguin (Megadyptes antipodes) : a thesis presented in partial fulfilment of the requirements for the degree of Master of Veterinary Science at Massey University, Turitea, Palmerston North, New Zealand“. Massey University, 2008. http://hdl.handle.net/10179/1063.

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Yellow-eyed penguins have suffered major population declines and periodic mass mortality without an established cause. On Stewart Island a high incidence of regional chick mortality was associated with infection by a novel Leucocytozoon sp. The prevalence, structure and molecular characteristics of this leucocytozoon sp. were examined in the 2006-07 breeding season. In 2006-07, 100% of chicks (n=32) on the Anglem coast of Stewart Island died prior to fledging. Neonates showed poor growth and died acutely at approximately 10 days old. Clinical signs in older chicks up to 108 days included anaemia, loss of body condition, subcutaneous ecchymotic haemorrhages and sudden death. Infected adults on Stewart Island showed no clinical signs and were in good body condition, suggesting adequate food availability and a potential reservoir source of ongoing infections. A polymerase chain reaction (PCR) survey of blood samples from the South Island, Stewart and Codfish Island found Leucocytozoon infection exclusively on Stewart Island. The prevalence of Leucocytozoon infection in yellow-eyed penguin populations from each island ranged from 0-2.8% (South Island), to 0-21.25% (Codfish Island) and 51.6-97.9% (Stewart Island). The high prevalence on Stewart Island represented the infection of 100% of chicks and 83% of adult yellow-eyed penguins when tested by PCR. Sequencing of Leucocytozoon sp. DNA found similarities between infections in yellow-eyed penguin adults and chicks, but differences to Leucocytozoon sp. DNA obtained from Fiordland crested penguins. These findings support the suggestion of cross infection between adults and chicks, and indicate that endemic infection in yellow-eyed penguins is unrelated to that in Fiordland crested penguins. Examination by histology and electron microscopy showed tissue megaloschizonts and circulating round gametocytes. Megaloschizonts up to 440µm diameter showed an affinity for hepatic and splenic tissue and were observed releasing occasional intact cytomeres. Round gametocytes were observed within leucocytes in visceral sections, but not peripheral blood smears. The morphology of Leucocytozoon sp. in yellow-eyed penguins showed similarities to the pathogenic species L. simondi and L. sakharoffi but not L. tawaki. A successful treatment protocol for leucocytozoonosis has not been established, although treatment in a Fiordland crested penguin was able to suppress parasitaemia. The role of Leucocytozoon in yellow-eyed penguins as a cause of morbidity and mortality remains unclear. Further investigation into direct pathogenicity, and the interaction of concurrent disease and environmental influences is required. The findings of this thesis provide potential management recommendations and highlight areas requiring further investigation.

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Donaldson, Laura Patricia Constance. „The distribution of fatty acids and presence of environmental contaminants in the blubber of the New Zealand sea lion (Phocarctos hookeri) : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Conservation Biology at Massey University, Palmerston North, New Zealand“. Massey University, 2008. http://hdl.handle.net/10179/887.

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The conservation of marine mammals relies on the knowledge of species ecology in order to assess the impacts of anthropogenic activites and make appropriate species management decisions. Blubber biopsies are a relatively non-invasive sampling protocol to provide ecological information; two particular uses are for dietary analysis via fatty acid signature analysis (FASA) and investigating the uptake of organochlorine (OC) and polychlorinated biphenyl (PCB) environmental contaminants. Blubber composition and structure may vary according to body site and depth due to its dynamic functioning. This may result in the vertical stratification and heterogenous distribution of blubber FAs, OCs and PCBs between body sites, giving variable interpretations of diet and contaminant levels depending on biopsy sample site and depth. The aim of this thesis is to determine the FA distribution of blubber from two body sample sites (dorsal pelvic and ventral thoracic) currently used for FASA of the New Zealand sea lion, Phocarctos hookeri (NZSL) and to determine the level of OCs and PCBs in the blubber of healthy NZSLs for comparison to diseased NZSLs recorded in the 1997/98 epidemic. Blubber samples were collected from 29 by-caught NZSLs incidentally captured by the squid fishery around the Auckland Islands (50º42’S, 166º5’E) during the years 2005 to 2007 (not all NZSLs were able to be analysed for each chapter). Full blubber cores from both sample sites were collected from 18 NZSLs. Both sites showed a relative homogeneity of FA profiles, indicating the similar deposition and mobilisation of FAs at the two sample sites. To determine if FA stratification occurred, full blubber cores from both sample sites of 20 NZSLs were divided into inner and outer halves. Both sites displayed the same pattern of vertical stratification or biochemical layering of FAs between the two divisions, indicating that stratification of FAs occurs in the blubber of the NZSL. A range of OCs and PCBs were then determined in full thoracic blubber cores of seven NZSLs. The levels were higher than those previously recorded in NZSLs affected by disease during a 1997/98 epidemic. The SPCB in NZSLs was 0.034-0.192 mg/kg lipids, below the suggested threshold of 17 mg/kg for adverse health affects in marine mammals. From the results of this study I can support current blubber biopsy sampling techniques for FASA in NZSL. Obtaining full blubber cores from either the thoracic or pelvic sample site will give a comparable interpretation of diet. The low levels of blubber OCs and PCBs suggest a minor role of contaminants acting as a possible causative agent toward disease outbreaks in the NZSL. This research provides important information for developing correct and consistent blubber sampling techniques for NZSL and other pinniped species. This will ensure more accurate interpretations of ecological information obtained from blubber biopsies and therefore improved species management and conservation decisions that may be based on such research.

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Newcombe, Vernon Claude. „Mercury use in the goldmining industry : a retrospective examination of elemental mercury use in the gold mining industry of the West Coast of New Zealand in the period 1984-1988 : a thesis submitted in partial fulfilment of the requirement for the degree of Master of Philosophy (Science) at Massey University, Wellington, New Zealand“. Massey University, 2008. http://hdl.handle.net/10179/832.

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Chappell, Esta Monique. „Morphology, phylogeography and drumming behaviour of a New Zealand ground weta, Hemiandrus pallitarsis : a thesis presented in partial fulfillment of the requirements for the degree of Master of Science in Conservation Biology at Massey University, Palmerston North, New Zealand“. Massey University, 2008. http://hdl.handle.net/10179/828.

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Species are one of the fundamental components of biology and the accurate delimitation of species is important in evolutionary, systematic and ecological studies, yet there is still confusion over how species can be recognised. Examining different characters allows multiple lines of evidence for successful and accurate species delimitation and identification. In this thesis, morphological, genetic and behavioural variation is investigated within an endemic species of ground weta, Hemiandrus pallitarsis, in the North Island, New Zealand. Twelve morphological characters were measured, and mitochondrial cytochrome oxidase I DNA sequences were analysed from populations across the distributional range of H. pallitarsis. Both methods provide no evidence of a species complex within H. pallitarsis. Instead, the morphometric results suggest females are significantly larger than males, and ground weta in Palmerston North are significantly smaller than weta further north. Additionally, genetic analyses found substantial population structuring, large genetic distances, and an historical south to north pattern of movement in the North Island. The pattern of vibratory drumming behaviour followed that predicted by morphology and geographic proximity – drumming signals were more similar between geographically close populations and did not match the patterns of genetic isolation. Overall, this thesis was able to show that H. pallitarsis is morphologically, genetically and behaviourally variable across the North Island.

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Chakraborty, Manas. „Spatial pattern in macroinvertebrate communities in headwater streams of New Zealand and a multivariate river classification system : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Ecology at Massey University, Palmerston North, New Zealand“. Massey University, 2008. http://hdl.handle.net/10179/1067.

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Macroinvertebrate data collected from 120 headwater streams in New Zealand were used to test the ability of the Freshwater Environments of New Zealand River Classification (FWENZ) to explain spatial variation in unimpacted stream invertebrate communities. FWENZ is a GIS based multivariate river environment classification of the sections of national river network. The classification performance of the FWENZ was examined to determine the optimum classification level which could be used for the purpose of conservation and biomonitoring of New Zealand rivers and streams. The classification performance of the FWENZ was also compared to those of two other river classification systems, the ecoregions and the River Environment Classification (REC). Results of the analysis of similarity (ANOSIM) test showed that discrimination of the study sites based on interclass differences in macroinvertebrate community composition was optimal at FWENZ 100 class level which classifies the New Zealand rivers and streams into 100 different groups. The FWENZ 100 class level distinguished the biological variation of the study sites at a finer spatial scale than the REC Geology level. Although performance of the ecoregions classification was stronger than both the river environmental classifications, the REC and the FWENZ, but it was unable to explain the variation in local assemblage structures. Multivariate analyses of the macroinvertebrate abundance data and the associated environmental variables at three different spatial scales (upstream catchment, segment, and reach) were used to identify environmental predictors of assemblage patterns. Catchmentscale measures of climatic, topographic and landcover factors were more strongly correlated with macroinvertebrate community structures than segment scale measures, whereas reachscale measures of instream physicochemical factors and riparian characteristics had the least association with assemblage patterns. Despite the strong influences of cathment-scale factors on macroinvertebrate communities, local factors like water temperature, stream velocity, reach elevation, percent canopy cover and percent moss cover were also involved in explaining the within-region variation in assemblage patterns, which indicates the importance of considering regional as well as local factors as surrogates of stream invertebrate communities to provide a base for stream bioassessment programmes at multiple scales.

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Jimenez-Castro, Claudia. „Management of a marine protected area by a local NGO in Honduras: its implications for local communities“. Lincoln University, 2008. http://hdl.handle.net/10182/1237.

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This study explores the factors that influence the management of a protected area situated on private land as well as the implications of these factors in the interaction between the NGO and the communities associated with this area. The protected area, Marine National Monument Cayos Cochinos, is an archipelago surrounded by reefs in the Honduran Caribbean. This area is home to a highly heterogeneous population of fisherfolk communities –most are members of the Garifuna ethnic group– and wealthy Honduran and foreign landowners. This case study also comprises three fisherfolk communities outside the protected area who fish in Cayos Cochinos. Local fishermen in Cayos Cochinos are settled in community-owned areas; however, these settlements started by the occupation of private lands. Wealthy landowners have either individual land titles or shares of a firm owning four of the islands. The protected area was established through the initiative of this firm to protect the natural resources. This area is nominally co-managed by a local nongovernmental organisation (NGO) and two government agencies; however in practice it is managed solely by the NGO. This study discusses the influence of the nature of the Honduran legislation regarding protected areas and of the co-management agreement on the management of Cayos Cochinos. This research also shows that the management priorities of this protected area are only partially based on the Honduran government’s laws and regulations and the guidelines specific for this area. Lack of government participation in the co-management of the area, financial constraints, influences on the NGO of stakeholders in higher positions of power with respect to it, personal preferences of the NGO managers and issues regarding the communities’ leadership, have all had an influence on the management priorities of the protected area since its constitution. The combined effect of these factors has influenced the management of the NGO towards prioritising the natural resource conservation. This area is managed under a ‘people-out’ conservation paradigm. The adoption of this paradigm has disadvantaged the fisherfolk communities inside and outside the protected area by restricting their access to the natural resources on which their livelihoods are highly dependent. However, the same situation has favoured the private landowners by limiting the access of the fisherfolk communities to the land owned by the former. The privileging of one community sector over another has created conflicts between the NGO and the fisherfolk communities. However, these conflicts have been fuelled by other factors such as the steady contesting of the land titles over the territories occupied by the latter, and by the support that external organisations have given to the latter at the expense of the original owners of the land. This research suggests that local NGOs in charge of the management of natural protected areas might have limited capacity to abide by national conservation and sustainable development priorities due to the likelihood to be influenced by external forces with different priorities.

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Mojsilovic, Ognjen. „Estimating bioaccessibility, phytoavailability and phytotoxicity of contaminant arsenic in soils at former sheep dip sites“. Lincoln University, 2009. http://hdl.handle.net/10182/1142.

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Recognition that the bioavailability of soil As (As) is influenced by its soil dynamics has initiated research into development of more accurate, site-specific soil guideline values, departing from the assumption that the total soil As content is bioavailable. With the aim of deriving predictive models, the relationship between soil properties and As bioavailability (bioaccessibility and phytotoxicity) was examined on a set of naturally contaminated sheep dip soils (n = 30). Sampled soils were extensively characterised, bioaccessibility was estimated through an in vitro procedure, and soil As toxicity and availability to plants were evaluated using an early growth wheat bioassay. The in vitro bioaccessibility was consistently less than the total soil As content. Arsenic bioaccessibility was negatively correlated to soil iron (Fe), manganese (Mn) and aluminium (Al) contents, and it was positively related to the soil As loading. The in vitro extractable soil As concentrations were successfully modelled using linear combinations of soil As content, soil Fe and Mn determinations and soil pH. Differences in As phytotoxicity, expressed in terms of effective toxic concentration (EC50), between soils were directly related to soil Fe, Mn and Al contents. Available soil phosphorous (P) exerted an ameliorating effect on As toxicity, with the available soil As/P ratio representing the single best predictor of plant growth suppression. Plant P nutrition appeared to influence the relative selectivity for As and P by wheat, with greater selectivity for P demonstrated under P deficient conditions. Plant As uptake, its distribution, and also the plant nutrient status were all adversely affected by increasing soil As exposure. Co-contamination by Zn corresponded to a substantial elevation in proportion of the plant As allocated in shoots. Plant As levels exhibited a saturation-dependent relationship with increasing soil As. The best linear predictors of plant As levels in the non-toxic range were RHIZO-extractable and effective soil As concentrations, the latter based on the diffusive gradients in thin films (DGT) technique. Despite the complexity of soil As dynamics, large proportions in the variances exhibited by the two measures of bioavailability were explained using a small set of readily-available soil properties.

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Robertson, Louise Mary. „Anthelmintic treatment and digestive organ morphology of captive-reared kaki (Himantopus novaezelandiae) released to the wild : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Conservation Biology at Massey University, Palmerston North, New Zealand“. Massey University, 2009. http://hdl.handle.net/10179/1001.

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The continued existence of New Zealand’s critically endangered and endemic black stilt or kakï (Himantopus novaezelandiae) relies on an intensive captive management programme. While this is successful at rearing large numbers of birds for release to the wild, poor survivability of these birds is limiting significant increases in the wild population. Predation and starvation are suspected to be the most common causes of death in released birds, but underlying contributing factors to these mortalities have not been fully evaluated. This research investigates the possible contribution of gastrointestinal (GI) helminth burdens and suboptimal digestive organ development to the high mortality rates of released kakï. Emphasis is placed on evaluating the methods used to assess the importance of these factors and to make informed recommendations for future management. The efficacy of the anthelmintic regime used for kakï was assessed by dosing half of the 80 captive birds with praziquantel (PZQ) prior to release in 2007. Faecal samples were collected before and after anthelmintic treatment, and before and after release to the wild. Post mortem worm counts were conducted on 11 birds that died following release and historical worm count records dating back to 1997 were accessed. The main findings were: PZQ had high efficacy against trematodes; treatment did not prevent re-infection; birds were exposed to helminths at release site; and there was no advantage of treatment for survival. Overall, the results suggest that anthelmintic treatment is an unnecessary cost. Consequently, recommendations were made to cease anthelmintic treatment or reduce its intensity, continue health screening, and incorporate annual efficacy testing to monitor the emergence of anthelmintic resistance. The reliability of faecal screening for GI helminths was evaluated. Faecal egg counts (FECs) were found to be poor indicators of worm burden. The two modified sedimentation methods used to detect trematodes provided relatively low egg recovery rates. Trematode egg shedding varied between days but not by hour of the day or temperature. The collection and analysis of pooled faecal samples proved to be more cost and time-effective than samples from individual birds and the larger masses collected resulted in greater sensitivity. In conclusion, faecal analysis of pooled samples is a useful qualitative indicator of helminth presence or absence but is quantitatively unreliable. In order to assess the importance of digestive organ development to captive-reared and released kak?, the digestive organs of healthy and emaciated captive, released and wild Himantopus sp. were compared. Captive and released kak? had generally smaller digestive organs than wild birds, released birds did not increase digestive organ size to match the high fibre wild diet, and emaciated birds did not have atrophied organs. However, the greatest mortality rates occur soon after release, while the birds were still being supplementary fed. These results suggest that reduced digestive efficiency is probably not contributing significantly to mortality rates and the direct impacts of the translocation are probably greater risk factors. The continued provision of supplementary food to released birds and an increased focus on habitat enhancement and predator control at release sites were recommended. The reliability of comparing fresh and formalin fixed Himantopus sp. gut specimens was evaluated. Significant differences in fresh and formalin fixed organ dry masses and variation in preserved organ lengths indicate that this variation should be considered in future studies. In conclusion, current management practices appear to be successful in ensuring that GI helminths and reduced digestive efficiency do not significantly lower the survivorship of captive-reared and released kakï. There is a need for further research into developing a more direct physiological assessment of the impacts of GI helminths and gut morphology as well as considering the role that starvation may have on poor survivability.

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Muir, Paul David. „Studies on the growth and compositional development of antlers in red deer (Cervus elaphus)“. Lincoln College, University of Canterbury, 1985. http://hdl.handle.net/10182/1178.

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The experiments described in this thesis investigated nutritional and physiological aspects of antler growth in red deer stags. The initial experiment (Section 3) examined the effects of winter nutrition on subsequent antler casting date and velvet antler weight. Mature stags on two different farm types (hill country, Farm H and irrigated lowland, Farm L) were offered three levels of winter nutrition, two levels of a concentrate supplement (ad libitum pellets and 1/2 ad libitum pellets) and a basal hay ration. On both properties liveweight gains occurred in supplemented groups and liveweight losses in unsupplemented groups. At antler casting there were significant differences in liveweight of approximately 10 kg between fully supplemented and unsupplemented groups. Realimentation of winter liveweight losses subsequently occurred so that by the following rut the effects of winter undernutrition had been eliminated. On Farm H poor winter nutrition (hay only) resulted in a significant delay in casting date (13 days) and lower velvet antler yields (0.24 kg), than in stags offered the ad libitum concentrate ration. Stags on Farm H were 13 kg lighter at commencement of the trial than at Farm L and the differences in treatment effects obtained between farms may have been due to differences in body condition at commencement of the trial. An association was demonstrated between liveweight and date of antler casting, with heavier stags casting earlier than lighter stags. There was no effect of age of stag on casting date. Of the liveweights recorded, liveweight prior to the rut showed the best relationship with casting date, possibly because the seasonal nature of liveweight change meant that a weight recorded at this time gave the best indicator of the true frame size of a stag. Both age and liveweight significantly affected velvet antler weight, with increases of velvet antler weight of 0.26 kg between 3 and 4-year-old stags and of 0.30 kg between 4 and 5-year-old stags at the same liveweight. Within an age group velvet weight increased by 0.12 kg for each 10 kg increase in pre-rut liveweight. The experiments described in Section 4 comprised studies on antler growth and composition. In order to obtain data on antler growth and composition individual antlers were removed sequentially from mature red deer stags between 28 and 112 days after casting of hard antlers. Contralateral antlers were removed after stripping of velvet. Wide variation occurred in antler casting date (53 days) compared to date of velvet stripping (24 days). The duration of the period of antler growth may therefore be governed more by date of casting than by date of velvet stripping. Mean duration of the antler growth period was 164 days. Growth in length of the antler appeared to follow a sigmoid curve. However, between 28 and 112 days after casting, rates of elongation were close to linear. Mean length of hard stripped antlers was 0.71 m and between 28 to 112 days after casting mean rate of antler elongation was 0.62 cm/day. Over this period indivdual antlers increased in fresh weight at a rate of 13.7 g/d, with heaviest weight recorded 112 days after antler casting, at approximately 130% of final hard antler weight. Between 28 and 91 days of growth, volume of blood in the antler increased linearly at a rate of 194 ml/kg. Three phases of mineralization were demonstrated in developing antlers. Tips of growing antlers were cartilaginous and poorly mineralized. A zone of mineralization occurred 5.0 to 7.5 cm behind the antler tip which corresponded histologically to the transition from mineralized cartilage to trabecular bone. The second phase of mineralization occurred through continued accretion of trabecular bone in the antler shaft. The third phase, described as "terminal mineralization" in this study, appeared to be associated with a rapid increase in density of cortical bone in the periphery of the antler shaft. Terminal mineralization (between 91 and 112 days after casting of hard antlers) coincided with the slowing of growth in length, a decrease in relative blood volume in the antler and an increase in levels of plasma testosterone. These events occurred close to the summer solstice. At velvet stripping individual antlers had a mean weight of 1.12 kg and contained 81.1% dry matter (DM). Fat free organic matter (FFOM) and ash concentration in DM were 36.6 and 60.0%, respectively. Peak daily rates of FFOM and ash deposition occurred between 91 days and 112 days after casting, at rates of 1.4% of hard antler FFOM and 1.6% of hard antler ash. For a stag producing 2.24 kg of hard antler mean rates of FFOM and ash deposition over this period were 9.3 and 18.3 g/d, respectively. On a whole antler basis calcium concentration in antler ash remained constant, at around 35%. Therefore peak rate of antler calcium deposition would be 6.4 g/d. In the final experiment (Section 5) mature stags were offered a maintenance ration of greenfeed oats during the period of peak calcium requirement for antler growth and the kinetics of calcium metabolism were examined using a radio-isotope (⁴⁵Ca). Rates of faecal endogenous loss were low and at approximately 6.4 mg/kg BW per were half the estimated requirements of ARC (1980) for sheep and cattle. Availability of calcium from greenfeed oats was low (mean, 37%) and less than 30% of total calcium requirements were derived from the diet. Poorly mineralized skeletal bones indicated that the shortfall in antler calcium was derived from the skeleton. In spite of a severely negative calcium balance stags were capable of maintaining high and apparently normal rates of antler calcium deposition (mean, 44 mg/kg BW per day). Antlers appear to be acting as a sink with calcium being irreversibly deposited in the antler and lost to the animal's body. On the assumption therefore that antler calcium behaves like calcium lost during lactation a kinetic model of calcium metabolism in the stag was developed.

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Hedley, Carolyn B. „The development of proximal sensing methods for soil mapping and monitoring, and their application to precision irrigation : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Soil Science at Massey University, Palmerston North, New Zealand“. Massey University, 2009. http://hdl.handle.net/10179/1217.

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The potential of proximal soil sensing methods for high resolution investigation of soils in the landscape has been investigated. This addresses the need for improved environmental monitoring and management of soils within their environs. On-the-go electromagnetic (EM) mapping has been used to map soils, providing a high resolution (< 10m) spatially defined soil apparent electrical conductivity (ECa) datalayer. Vis-NIR field spectroscopy has been trialled for in situ analysis of soil carbon, nitrogen and moisture. The portable spectroradiometer has been used at 6 sites in the Taupo-Rotorua region for rapid, field analysis of soil carbon (R2 calibration = 0.95, R2 prediction = 0.75,) soil nitrogen (R2 calibration = 0.95, R2 prediction = 0.86) and moisture (R2 calibration = 0.96, R2 prediction = 0.70) by collecting reflectance spectra from the flat surface of a soil core; and at one Manawatu site for soil moisture (R2 calibration = 0.79, R2 prediction = 0.71), where the reflectance spectra were collected directly from a freshly cut in situ soil surface. EM mapping and Vis-NIR field spectroscopy were used in combination to spatially characterize soil moisture patterns at the Manawatu site. Soil available water-holding capacity (AWC) of ECa-defined zones has been assessed at six irrigated production farming sites. Two methods (predicted AWC v ECa; estimated AWC v ECa) have been used to relate soil ECa to soil AWC to predict spatial AWC (R2 = 0.8 at 5 sites). Site-specific soil water balance models have been developed at all sites; and a wireless real-time soil moisture monitoring network has been trialled at two sites, to be used with the ECa-AWC prediction model for the development of daily soil water status maps, for variable rate irrigation (VRI) scheduling. This digital, spatially defined soil water status information is available for upload to a sprinkler system modified for variable rate application. The calculated water savings with VRI were 926% with equivalent energy savings and improved irrigation water use efficiency. Drainage and runoff were reduced by 055% during the period of irrigation, with the accompanying reduced risk of nitrogen leaching. The reduction in virtual water content of product has also been assessed for VRI and compared with uniform rate irrigation (URI) at three study sites. This study suggests that these proximal sensing methods provide a new improved way of monitoring and mapping soils. This facilitates soil inventory mapping, for example soil moisture and carbon mapping. In addition, these high resolution environmental monitoring and mapping techniques provide the information required for optimizing site-specific management of natural resources at the farm scale. On-the-go electromagnetic (EM) mapping has enabled a step change in the pedological investigation of New Zealand soils. Resulting soil ECa maps provide a tool for improving traditional soil map boundaries because they delineate soil zones primarily on a basis of soil texture and moisture in non-saline soils. In this study the maps have been used for site-specific irrigation management at the farm-scale, aiming to increase the energy efficiency of this land management operation. The study has developed a method for improved use of freshwaters by more accurate irrigation scheduling, based on high resolution characterization of spatial and temporal soil differences.

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Robertson, M. S. T. „Riparian management guides : are they meeting the needs of the interested public?“ Diss., Lincoln University, 2008. http://hdl.handle.net/10182/601.

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In New Zealand, there are many published guidelines about the management of riparian areas. The question needs to be asked, are these guides useful? This research thesis investigates the extent to which riparian management guides meet the needs of the users. This research also considers the importance of riparian management (with regards to the appropriateness of educational guides) in assisting practitioners and the interested public in the management of riparian areas. The main way of investigating this topic was with the help of discussion groups. Discussion groups were held with interested organisations. These groups fell into three categories; Urban groups, Rural groups and Interest groups. The groups were asked to define what would make a guide most useful and desirable to them under three major categories: 1) what the guide looked like, 2) what information was contained, and 3) how was the information accessed. An opportunity was also provided for any further comments. This information was used to create a list of the most popular criteria that existing guides and further publications could be examined against. Eleven criteria were identified as follows: Information should be available online; Have pictures; Include diagrams; Is simple and easy to understand; Contains how to and appropriate methods; Has a plant list; Considers maintenance issues; Identifies where to locate further information; How to contact experts; Is available in libraries; Is in booklet form. The availability of existing information was investigated and its suitability assessed against the criteria. A list of all regional, territorial and unitary councils as well as 'other organisations' that were regarded as sources of environmental knowledge were investigated to see how many had produced information on riparian and wetland management issues. In terms of sources of information, 'other organisations' produce the greatest rate of riparian management information, followed by regional/unitary authorities. Two guides from Canterbury best meet the criteria identified by the interested parties, for the Canterbury region. Each scored 10/11 and failed on different criteria. This led to the conclusion that riparian management guides in Canterbury, while obviously still having room for improvement, are very close to meeting what interested parties feel is most important. Finally, a prototype (model) based on the research is provided for anyone who might be considering preparing a riparian management guide.

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Black, Amanda. „Bioavailability of cadmium, copper, nickel and zinc in soils treated with biosolids and metal salts“. Lincoln University, 2010. http://hdl.handle.net/10182/1561.

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It is widely accepted that bioavailability, rather than total soil concentration, is preferred when assessing the risk associated with metal contamination. Despite this, debate continues on what constitutes a bioavailable pool and how to best predict bioavailability, especially in relation to crop plants. The overall aim of this thesis was to assess and validate measures of cadmium (Cd), copper (Cu), nickel (Ni) and zinc (Zn) bioavailability in a range of soils amended with metal salts and biosolids. Six potential measures of bioavailability were investigated and compared: total metal; 0.04 M EDTA extraction; 0.05 M Ca(NO₃)₂ extraction; soil solution extracted using rhizon probes; effective solution concentration (CE) determined using diffusive gradients in thin films (DGT); and modelled free ion activities (WHAM 6.0). These were compared to shoot metal concentrations obtained from plants grown in three soils with contrasting properties treated with biosolids and metal salts. The first study involved a wheat seedling (Triticum aestivum) assay carried out under controlled environmental conditions on incubated soils treated with metal salts and biosolids. Results showed that the presence of biosolids resulted in increases of DOC, salinity, Ca and Mg in soil solution as well as total concentrations of Cu and Zn, dry matter was also adversely affected by increased levels of salinity. The addition of biosolids did not significantly alter the extractability or solubility of Cd, Cu, Ni and Zn although concentrations of Cd in shoots were significantly lower in plants grown in biosolids amended soils compared with unamended soils. The second study involved a field experiment that used 20 cm diameter by 30 cm deep soil monoliths of the same three soils treated with metals and biosolids, and perennial ryegrass (Lolium perenne) was grown for 24 months. Results revealed the addition of biosolids significantly increased the amount of DOC, salinity, Ca and Mg in solution. The presence of biosolids also significantly altered the bioavailability of Cd, Cu, Ni and Zn, as measured by soil solution, CE and free ion activity. However, this change had little effect on plant metal uptake. The length of time following treatment application had the greatest effect on soil chemistry and metal availability, resulting in pH decreases and increases in DOC, soil solution salinity, Ca and Mg. The free ion activities of each metal increased with time, as did soil solution Cd and Zn and CE-Cu, with results for Zn indicative of migration through the soil profile with time. Plant uptake of Ni and Zn also changed with time. Nickel concentrations in shoots decreased, while concentrations of Zn in shoots increased. The findings from the two studies demonstrated that biosolids increased the amount of DOC, salinity, Ca and Mg present in soil solution. In the lysimeter study measures of metal availability were affected in soils amended with biosolids, but this did not effect shoot concentrations. The overall predictive strengths of the six potential measures of bioavailability was investigated using results from the previously described experiments and related studies carried out by ESR and Lincoln University using nine different soils amended with combinations of biosolids and metal salts. Of the four metals Ni provided the strongest correlations between metal bioavailability and shoot concentrations, with 0.05 M Ca(NO₃)₂ extraction giving the strongest relationship for Ni concentrations in shoots (r² = 0.73). This suggests that the solubility of Ni is highly indicative of shoot concentrations and that Ca(NO₃)₂ is a robust measure of Ni bioavailability. In addition Ca(NO₃)₂ provided the best estimate of Zn bioavailability (r² = 0.65), and CE-Cd provided the best measure of Cd bioavailability, although it could only describe 47 % of shoot Cd concentration. Results for Cu were typical of previously described studies as assays of Cu availability are almost always poorly correlated with shoot concentrations, with total Cu having the strongest relationship (r² = 0.34). Methods based on the extractability and solubility of Cu in soils were poor indicators of Cu concentration in shoots. Overall, the addition of biosolids did not alter the outcome of these bioavailability assays, and results indicated that total metal concentrations present in the soils and biosolids matrix, plus length of time since soil treatment, had a greater affect on metal bioavailability.

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Thomas, Craig W. „Current practices and future possibilities of performance recording extensively-grazed commercial beef herds in New Zealand“. Diss., Lincoln University, 2008. http://hdl.handle.net/10182/844.

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There is little evidence that the productivity of New Zealand beef herds has improved over time. Data from the NZ Meat and Wool Board’s Economic Service (2006) suggest that the average national calving percentage has declined over the last two decades. During the same period cattle carcass weights have increased but so too has the average cow live-weight which has resulted in increased maintenance costs of the cow herds. It is unclear whether production efficiency in the industry has improved or declined over time. The aim of this research was to develop means of improving productivity in commercial beef herds through practical methods of performance recording. The objectives were firstly to establish current management practices in commercial herds and secondly to develop an objective system for cow selection and culling which would have practical application in commercial herds. Beef management survey Ninety two commercial beef producers with more than 100 breeding cows from the greater Canterbury region of New Zealand were surveyed. Pasture control was the main reason given for owning a beef herd. Size and conformation were the main selection criteria for choosing replacement heifers and bulls. Over 80% of herds retained their own heifers as replacements and >60% mated yearling heifers to first calve at two years of age. Fertility was poor in the surveyed herds. In-calf rates at pregnancy testing averaged 88% for maiden heifers, 92% for rising second calvers and 93% for mixed age (m.a.) cows. There was no significant difference between in-calf rates of maiden heifers mated to first calve at two or three years of age; nor was there any significant difference between the re-breeding success of the two groups. Heifers mated at least one week earlier than m.a. cows, achieved a re-breeding success 4.7% greater (P<.01) than those mated at the same time. Reasons for cows not weaning a calf included wet dry (9.3% of pregnant cows wintered), pregnancy tested not-in-calf (7.4%) and dam death (2.6%). Only 87.9% of pregnant females wintered weaned a calf (89.4% of m.a. cows and 84.9% of heifers). Reasons why cows exited the herds included diagnosed empty (37.2% of all exits), involuntary culls (25.4%), sold wet dry (16.2%), deaths (13.1%) and poor calf production (5.1%). Vaccination was infrequent with clostridial vaccines the most common in m.a. cows (15.2%) and in calves (40.7%); vaccination against Leptospirosis was much less common. Very few of the surveyed farms used any system of performance recording; as a result there was very little performance-based selection or culling practiced. Evaluation of alternative measures of cow productivity Data from four performance recording beef herds were used to compare alternative measures of cow productivity with the industry standard which is calf weaning weight adjusted for sex (SOC) and age of calf and age of dam (AOD), i.e. the “200 day weight.” None of the alternative measures evaluated required knowledge of calving date and all were relatively easily obtainable in extensively managed beef herds. The assessment of cows was based not on their estimated breeding values but instead on their most probable producing ability which, as the sum of all of the permanent, repeatable aspects of the calf-rearing ability of the cow, explains considerably more of the variance of weaning weight than does breeding value alone. SOC and AOD-adjusted marking weight, weaning weight and average daily gain (ADG) between marking and weaning were the traits mostly highly correlated with the 200d wt of calves (r = 0.68, 0.90 and 0.74. respectively). An Extensively- Grazed-Cow-Weaning-Index of these three indicator traits was found to be more highly correlated than any of the individual traits on their own (r = 0.94). Index weights for the three indicator traits were calculated within each herd and then those within-herd index weights were regressed on readily obtainable herd descriptive variables to obtain a regression equation that could predict index weights for any herd. When the model was applied to data from two additional herd years not included in the original model, the EGCW Index was highly correlated with the 200d weights (r>0.90). Performance-based culling of previously unselected commercial beef herds based on the EGCW Index will result in improved productivity due to the moderately high repeatability of calf weaning weight. Objective data from extensively grazed commercial herds will also make possible the use of commercial herd data in genetic evaluations of herd sires.

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Whitwell, Sarah Margaret. „The impact of isolation from mammalian predators on the anti-predator behaviours of the North Island robin (Petroica longipes) : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Conservation Biology at Massey University, Auckland, New Zealand“. Massey University, 2009. http://hdl.handle.net/10179/1142.

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Conservation in New Zealand has begun to focus heavily on the restoration of degraded mainland ecosystems and the reintroduction of native species that have become locally extinct. In many cases the individuals that are selected for reintroduction are harvested from ‘mammal-free’ offshore islands. This thesis examines the effects of isolation from mammalian predators on the predator avoidance behaviours and predator recognition abilities of New Zealand birds using the North Island robin as a model. It also investigates whether any effects of isolation from mammalian predators has a lasting impact on mainland populations founded by individuals from offshore islands. Nest site selection behaviours were compared across three populations that are exposed to different suites of predators and have differing translocation histories; Benneydale, Tiritiri Matangi and Wenderholm. Point height intercept and point-centred quarter surveys were used to compare habitat availability between the sites and to compare nest sites with the available habitat. Eight nest characteristic variables were also compared across the three sites using a principle component analysis. Benneydale nests were located higher in the trees and were more concealed than nests at the other two sites. Nests on Tiritiri Matangi were supported by large numbers of thin branches and were located toward the periphery of the nest tree. Unfortunately these differences are very difficult to interpret due to a high degree of variation in the habitat types present at the three sites. The anti-predator behaviours initiated in response to a model stoat, model morepork and control were used to test the ability of nesting robins to recognise the threat that each of these treatments might pose to nest success. Behavioural variables were compared between Benneydale, Tiritiri Matangi and Wenderholm using a response intensity scoring system and a principle component analysis. The results indicated that isolation from mammalian predators on Tiritiri Matangi has suppressed the ability of robins on the island to recognise the predatory threat posed by a stoat. They also suggest that the intense mammal control carried out at Wenderholm may have inhibited the ability of local robins to produce strong anti-predator responses when faced with a stoat.

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Gibson, Troy John. „Electroencephalographic responses of calves to the noxious sensory input of slaughter by ventral neck incision and its modulation with non-penetrative captive bolt stunning : a thesis presented in partial fulfilment of the requirements of the degree of Doctor of Philosophy in Physiology, Massey University, Palmerston North, New Zealand“. Massey University, 2009. http://hdl.handle.net/10179/1010.

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Slaughter by ventral neck incision (VNI) is performed on some animals without prior stunning in New Zealand and other countries. A single incision with a razor sharp blade is made in the ventral aspect of the neck, sectioning both carotid arteries and jugular veins, though, not the vertebral arteries. There are a number of potential welfare concerns surrounding slaughter by VNI including pain due to the incision, which may lead to distress during the time before loss of consciousness. The aims of this thesis were to identify cortical responses indicative of noxious stimulation due to slaughter by VNI using analysis of the electroencephalogram (EEG) power spectrum and to investigate the effects of non-penetrative captive bolt (NPCB) stunning on these cortical responses. The studies utilised adaptations of a minimal anaesthesia model, which has been validated in a range of mammalian species. Surgical dehorning was used as a validation technique for this methodology in cattle and demonstrated a ‘typical’ EEG response to noxious stimulation. Cattle slaughtered by VNI without prior stunning produced specific responses in the EEG that strongly indicated responses to noxious stimulation. Causation was investigated in cattle where blood flow through the brain remained intact during neck tissue incision (NTI) or the major blood vessels of the neck were isolated and transected independently of other neck tissues (BVT). The response to neck incision in intact animals was principally due to the noxious sensory input due to incision of neck tissues and not mainly as a result of loss of blood flow through the brain. NPCB stunning produced states of cortical activity that were incompatible with the maintenance of sensibility and pain perception. Experimental examination of the time to onset of undoubted insensibility was attempted in cattle subsequent to a pilot study in sheep. The generation of somatosensory-evoked potentials was problematic in cattle. The conclusions of this thesis are that incision of neck tissues during slaughter without prior stunning constitutes a substantial noxious stimulus. Were an animal conscious, this stimulus would be perceived as painful until the onset of hypoxiainduced insensibility. This would represent a significant compromise to animal welfare.

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Wilkinson, Roger Lindsay. „Population dynamics and succession strategies of rural industry producers“. full-text, 2009. http://eprints.vu.edu.au/1943/1/Roger_Wilkinson_PhD_thesis.pdf.

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Sheep farming in Australia has a long tradition, built up over several generations, of inheritance of the family farm, the occupation of sheep farming and the personal identity around being a sheep farmer. This tradition appears to be under threat, due to a combination of hard times and the long-term and inexorable decline in the terms of trade. I examined this threat to the continuation of family farming in Australia’s sheep industry by describing the demographic structure of the industry, documenting the structural changes and questioning whether the changes actually matter. The work involved demographic analysis of data from recent censuses of population and housing and in-depth interviews with sheep farming families. The average age of Australia’s sheep farmers is increasing, caused mainly by the decrease in entry of young people to the industry. This phenomenon is not confined to Australia’s sheep industry but is widespread and long-term through the industrialised world. Also, as some areas focus on agricultural production and others on amenity consumption, the rural landscape is changing. The changes to the structure of Australia’s sheep industry and the nation’s rural landscapes are driven by substantial forces that cannot be resisted easily. This has implications for policy-makers, extension agents and farm families.

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Justice-Allen, Anne E. „Survival of Mycoplasma Species in Recycled Bedding Sand and Possible Implications for Disease Transmission to Ruminants“. DigitalCommons@USU, 2010. https://digitalcommons.usu.edu/etd/730.

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Mycoplasmas are a group of bacteria which are small in size, lack a cell wall, and have small genomes in comparison to other bacteria. The members of the group that are pathogenic utilize several mechanisms to evade the host's immune system. These processes affect surveillance and control mechanisms such as serologic testing and vaccination. Many of these organisms cause diseases of livestock, which heavily impact production parameters such as weight gain, milk yield, and egg production. Mycoplasmas also cause disease in people. Mycoplasma spp. can cause mastitis, metritis, pneumonia, and arthritis. The currently documented routes of transmission of Mycoplasma spp. are through fomites and by direct animal contact. The existence of environmental sources for Mycoplasma spp. and their role in transmission are poorly characterized. Mycoplasma spp. (confirmed as M. bovis using PCR) was found in recycled bedding sand from a dairy experiencing an outbreak of mycoplasma mastitis. The possibility of a persistent environmental source of Mycoplasma spp. in recycled bedding sand was further investigated using recycled sand from the dairy. Study objectives included determining factors associated with the persistence of Mycoplasma spp. in recycled bedding sand and the duration of survival of mycoplasmas in the sand. We also evaluated 2 disinfectants at 2 different concentrations each for the elimination of Mycoplasma spp. from contaminated sand. Mycoplasma spp. survived in the sand pile intermittently over a period of 8 months. The concentration of Mycoplasma spp. within the sand pile was directly related to temperature and precipitation. The survival of Mycoplasma spp. at a greater than expected range of temperatures suggests the formation of a biofilm. Ideal temperatures for replication of Mycoplasma spp. occurred between 15 °C and 20 °C. Moisture in the sand and movement of the sand pile also appeared to play a role in replication of mycoplasmas. Sodium hypochlorite (0.5%) and chlorhexidine (2%) were efficacious in eliminating Mycoplasma spp. from contaminated bedding sand. Recycled bedding sand could be an environmental source of Mycoplasma spp. infections, including M. bovis, in dairy cows. Future studies should investigate the contribution of this environmental source to the epidemiology of mycoplasma infections in dairy cattle and other ruminants.

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Page, Girija. „An environmentally-based systems approach to sustainability analyses of organic fruit production systems in New Zealand : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Sustainable Agricultural Systems at Massey University, Palmerston North, New Zealand“. Massey University, 2009. http://hdl.handle.net/10179/825.

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An environmentally-based systems approach to sustainability analyses of organic fruit production systems in New Zealand. This research introduces an approach for the assessment of the sustainability of farming systems. It is based on the premises that sustainability has an environmental bottom line and that there is very limited substitutability between natural capital and other forms of capital. Sustainability assessment is undertaken through analyses of energy and material flows of the system and their impacts on the environment. The proposed sustainability assessment approach is based on two high level criteria for sustainability: efficient use of energy and non-degradation of the environment from energy and material use. Sustainability assessment of organic orchard systems in New Zealand was undertaken to demonstrate this approach. Five indicators which address the two criteria for the sustainability of the orchard systems are the energy ratio, the CO2 ratio, changes in the soil carbon level, nutrient balances, and the leaching of nitrogen. Organic kiwifruit and organic apple systems are modelled based on their key energy and material flows and their interactions with the natural environment. The energy and material flows are converted into appropriate energy and matter equivalents based on coefficients taken from the published literature. Sustainability indicators are estimated over one growing season using two computer modelling tools, Overseer® and Stella®, in a life cycle approach. Sustainability assessment of the organic orchard systems suggests that the approach is useful for evaluating energy use and key environmental impacts that occur in soil, water and atmosphere. The results indicate that the model organic orchard systems are sustainable in terms of energy use and are a net sink of CO2-equivalent emissions. The implication of this result is that organic orchard systems potentially could trade carbon credits under the Kyoto Protocol. The findings also suggest that the sustainability assessment approach is capable of identifying the trade-offs within the sustainability indicators associated with particular management practices. Further research to improve and validate the proposed approach is essential, before it can be practically used for decision making at the orchard level and for policy making at the national level.

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Di, Hong J. „Application of isotopic dilution methods to the study of the dissolution of phosphate fertilisers of differing solubility in the soil“. Lincoln University, 1991. http://hdl.handle.net/10182/1792.

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An injection technique, in which undisturbed soil cores are labelled with ³²P to study dissolution of phosphate fertilisers in the soil, was evaluated in field and glasshouse trials. When ³²P was injected between 0-150 mm depths of the undisturbed soil columns and fertilisers applied at the surface, the amounts of fertiliser P dissolved, as measured by the increases in the exchangeable P pools, were overestimated. Three possible reasons were suggested: (i) the interaction between surface-applied fertiliser, ³²P injected through the whole soil column, and the vertical decline in root density, (ii) the decline of specific activity in the exchangeable P pool due to losses of ³²P to nonexchangeable P pools and continuous addition of P from fertiliser dissolution, and (iii) non-uniform distribution of ³²P vis-a-vis ³¹P phosphate. The injection technique may be employed to assess the effectiveness of phosphate fertilisers by introducing a concept, the fertiliser equivalent (FE). The FE is a measure of the amounts of soil exchangeable P that the fertilisers are equivalent to in supplying P to plants, when applied at the specific location. Soluble single superphosphate (SSP) applied at the surface of undisturbed grassland soil cores (Tekapo fine sandy loam), was much more effective than surface-applied unground North Carolina phosphate rock (NCPR) and 30% acidulated NCPR with phosphoric acid (NCPAPR) within the 56 day period of plant growth. An isotopic dilution method, based on tracer kinetic theory, was developed to study the rates of dissolution (F in) and retention (F out) of phosphate fertilisers in the soil in growth chamber experiments. The estimation of F in and F out required labelling of the soils with carrier-free ³²P and determination of the corresponding values of the specific activities of the exchangeable P pools, SA₁ and SA₂, and the sizes of the exchangeable P pools, Q₁ and Q₂, at times t₁ and t₂. Most of the phosphate in the monocalcium phosphate (MCP) solution entered the exchangeable P pool immediately after addition to the soils (Tekapo fine sandy loam and Craigieburn silt loam), and there was little further phosphate input. With increasing periods of incubation, the phosphate was quickly transformed to less rapidly exchangeable forms. In the soils treated with ground North Carolina phosphate rock (<150 µm, NCPR) or partially acidulated (30%) NCPR with phosphoric acid (NCPAPR), the initial exchangeable P pools were not as large as those in the soils treated with MCP, but were maintained at relatively stable concentrations for extended periods, due to the continuous dissolution of PR materials and to lower rates of pretention. An increase in P-retention caused a slight rise in the rate of PR dissolution, but also a rise in the rate of P-retention by the soil. The rate of dissolution was higher at a lower application rate in relative terms, but smaller in absolute terms. The trends in the changes of plant-available P in the soils, measured by the water extractable P, Bray I P and Olsen P, correspond to those predicted by the F in and F out values. The average rates of dissolution between 1-50 and 50-111 days estimated by the F in, however, were higher than those estimated by extractions with 0.5 M NaOH followed by 1 M HCl, and with 0.5 M BaCl₂/TEA. This is partly because the Fin values reflect a plant growth effect on PR dissolution. The relative agronomic effectiveness of NCPR and NCPAPR with respect to MCP was higher after 50 and 111 days of incubation than after 1 day. The F in values were included in all the two-variable models constructed by stepwise regression to describe the relationship between plant P uptake and soil measurements. The amounts of variation in plant P uptake accounted for by the regression model was significantly improved by including F in in the model. This indicates the importance of fertiliser dissolution rates in affecting soil P supply, when phosphate fertilisers differing in solubility are applied.

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Dobson-Hill, Brenna Catherine. „Uterine involution in the dairy cow : comparative study between organic and conventional dairy cows : a thesis presented in partial fulfilment of the requirements for degree of Masters of Science in Animal Science, Massey University, Palmerston North“. Massey University, 2009. http://hdl.handle.net/10179/1272.

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Organic dairying is growing in popularity in New Zealand and the demand for knowledge is ever increasing. Many more farmers are considering organics as an alternative to their current conventional system. However, limited information is available on organic dairying in a New Zealand pastoral situation particularly in relation to its effect on fertility. The New Zealand dairy industry requires the dairy cow to become pregnant every year at the same time to maximise milk production and utilise the high pasture production in spring. A cow requires 40 to 60 days for uterine involution to occur and for resumption of oestrous cycles. It is critical that the cow becomes pregnant within the six to eight week mating period, however, this can be difficult for late calvers or those cows that had or still have a uterine infection, to undergo uterine involution and be successfully mated. These cows will often not become pregnant and as a consequence be culled for infertility. During the first few weeks postpartum, the bacterial composition of the uterus fluctuates as a result of spontaneous contamination, elimination and recontamination. Most cows are able to eliminate these bacteria, however, 10 to 17% of cows are unable to do this. In these cows, the bacteria persist, cause infection and inflammation, and delay uterine involution. The main objective of this present study was to investigate the effect of different management systems (Organic and Conventional) on productivity and reproduction, particularly the process of uterine involution and its relationship with reproductive outcomes. Uterine involution will be studied through the following measurements: cervical diameter as assessed by measurement per rectum, plasma concentrations of glucocorticoids and bacteriology of the uterus. Lactation characteristics: milk yield, cumulative milk yield, milksolids production and somatic cell count will also be investigated. From the results, it can be concluded that Organic cows have reduced milk yield (P=0.05) and milksolids production (P<0.01) through there were no major differences at peak lactation or in the rate of decline after. However, overall somatic cell count was not affected by management system though the Conventional cows had high somatic cell counts in early lactation (P=0.925). Cervical diameter was affected by the management system with the difference between Organic and Conventional cows almost significant (P=0.06). Cortisol concentrations were significantly higher in Organic cows (0.68 ± 0.08 ng/ml) when compared to Conventional cows (0.95 ± 0.06 ng/ml) (P=0.01). Cortisol concentrations decreased over time postpartum (P<0.01). Additionally Organic cows had a shorter interval from calving to AI (P=0.017). However, none of the other reproductive outcomes were affected by management system. Simple correlations established that reproductive outcomes and bacterial counts, reproductive outcomes and cortisol at Day seven, and cortisol and milk production characteristics, were not independent of each other. Aerobic bacterial counts on Day 28 and the interval from calving to AI were found to be significantly correlated (r= 0.615). Stepwise partial regression analysis, plus analysis of variance calculated on the relationships between uterine involution parameters and reproductive outcomes found multiple weak correlations. It found that cervical diameter, and aerobic and anaerobic bacterial counts on Day 28 were significantly correlated with the interval from calving to first AI (P=0.018). The differences in lactation characteristics are related to the lower pasture production on the organic farmlet reducing the maximal potential milk production and the possibly earlier calving dates of the Conventional cows. The differences in bacterial counts and almost significant difference in cervical diameter may be related to the lower cortisol levels and thus suggest that the Organic cows may be less stressed. As stress suppresses the immune system, it may be possible that the higher bacterial counts are indicitative of a less efficient or slightly weakened immune system which takes longer to eliminate bacteria in the uterus; however this is open to conjecture. The shorter interval from calving to AI suggests that Organic cows may be exhibiting oestrus behaviour earlier postpartum or the Conventional cows are having “silent heats” but this difference is possibly related to human factors. The correlation between parameters of uterine involution and interval from calving to AI, and the lower values for uterine involution parameters in Organic cows suggest the possibility of faster uterine involution and this may result in better fertility in the Organic cows. More research needs to be carried out to further investigate the effect of organic dairying on uterine involution and reproduction outcomes but organic dairying at the very least does not negatively impact on uterine involution and fertility.

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Muswema, Aubrey Patrick. „An audit of veterinary waste management in Durban“. Thesis, 2003. http://hdl.handle.net/10413/4163.

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Since 1994, there have been sweeping changes made to South African policy and legislation, including environmental rights for all people, environmental protection and the consideration of sustainability in all activities. A national policy for medical waste management is being developed and guidelines for the South African Veterinary Council are currently being revised. By auditing contemporary veterinary waste management in one of South Africa's largest cities, this study sought to provide appropriate input into these initiatives. As a study area, the Durban Unicity provided the opportunity to audit a large population of veterinary clinics within a relatively short distance of each other arid also the opportunity to ascertain whether waste management practices were dependent on the socio-economic status of the clinics catchment area. A pilot study was used to inform the design of a questionnaire, which was then administered to thirty-two clinics sampled to represent a range in size of clinic, predominant type of patient treated and catchment socio-economic status. Another questionnaire was administered to four waste disposal companies and one veterinary diagnostics laboratory that removed waste for disposal from veterinary practices. The main findings suggest that there is a health risk to staff and the public, due to the incorrect separation, storage, handling and disposal of sharps, anatomical, contaminated domestic and infectious material. Staff at 6.3% of clinics sampled are not provided with any safety equipment. Most veterinarians (63%) as well as two of the five waste disposal companies audited were not aware of their responsibilities in terms of waste management policy and legislation. Sixty nine percent of the practices sampled reported that employees have either never been trained or have not received training in waste management in the past five years. Domestic waste contaminated with other potentially hazardous waste forms 12% of the total waste stream reported by practices. Even though the results indicate that a, few veterinary practices are mismanaging their waste this has the potential negative impact on staff, the public and the environment. The findings of the study would suggest a need for well communicated, enforceable guidelines outlining sustainable veterinary waste management for practices and waste disposal companies. The study highlights the similarities between veterinary and medical waste and the need to consider this in planning an effective waste management strategy. It also provides guidelines for a sustainable approach to veterinary waste management.
Thesis (M.Sc.)-University of Natal, Durban, 2003.

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Peixoto, Patricia Lisandri de Souza. „Micro and Nano-flow approaches for monitoring the fate and environmental impacts of veterinary antibiotics“. Doctoral thesis, 2017. https://hdl.handle.net/10216/109990.

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Peixoto, Patricia Lisandri de Souza. „Micro and Nano-flow approaches for monitoring the fate and environmental impacts of veterinary antibiotics“. Tese, 2017. https://hdl.handle.net/10216/109990.

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Park, Buem-Seek. „Responses of an Environmental Gram-negative Bacterium to Pollutant Stress“. 2002. http://eprints.vu.edu.au/226/1/02whole.pdf.

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Several strains of pseudomonads which are normally found in natural water and soil environments, including Pseudomonas fluorescens, Pseudomonas aeruginosa, and strains initially identified as Pseudomonas paucimobilis and Pseudomonas maltophilia, were used in this thesis and their stress responsive proteins were surveyed at the physiological level. Additionally, 16S rRNA gene comparison was employed to classify the pseudomonads and related species at the genetic level. In order to see to what extent the pseudomonads and related species responded to heat shock, cells were initially subjected to temperature upshift from 28 to 37 deegree centegrade then disrupted by sonication or cells lysed by boiling in sample buffer, and the extracted total proteins were resolved on 1-D or 2-D SDS-PAGE. Their growth characteristics in different media (varying from rich to minimal) were determined and the physiological impacts on growth were examined at various concentrations of selected chemicals (metal ions, phenolics), to establish toxic and sub-lethal levels for use in determining stress responses. Production of novel proteins or elevated levels of normal proteins following exposure to different concentrations of toxicants was examined in detail in strain VUN10,077 (formerly Ps. paucimobilis) by sampling throughout the growth cycle and using 35S-methionine incorporation into newly synthesized proteins. Indigenous strain VUN10,077 presented abnormal rRNA pattern in standard RNA gels and 16S-like rRNA was analysed using Northern blot associated with 16S rRNA gene analysis which confirmed the identity of the known pseudomonads. An bands of MW 2.5 kb (faint), 1.38 kb, 1.2 kb and 0.1 kb were detected in RNA gels. The 1.38 kb band corresponded to 16S rRNA gene analysis, as shown by Northern blot analysis. 16S rRNA gene sequencing homology showed that strain VUN10,077 was a Brevundimonas species. The pseudomonads and related species accumulated a GroEL-like protein under heat stress when cells were grown in LB broth and disrupted by sonication, and 2-D SDS-PAGE conditions were established using sonically disrupted cells of Stenotrophomonas maltophilia (formerly Ps. maltophilia). Cells lysed by boiling represented the total protein profile and included particulate or membrane-associated proteins, 70 kDa-like and 44-46 kDa proteins for strain VUN10,077. Selected pollutants impacted on the cell viability and sub-lethal levels of these were determined as follows; 2.0 gL-1 for CdCl2, 2.0 gL-1 for CuCl2.2H2O, 2.0 gL-1 for NiCl2.6H2O, 1.0 gL-1 for CoCl2.6H2O, 0.025 gL-1 for HgCl2, 0.25 gL-1 for SDS, 0.2 gL-1 for NaAsO2 and 0.5 gL-1 for phenol, from A600 readings and viable counts. Major HSPs were present at relatively lower levels or were barely increased compared to controls, whereas low molecular weight proteins were significantly changed. A 20 kDa protein was commonly found in cadmium, copper, cobalt, nickel, arsenite and phenol stresses. However, a DnaK-like protein strongly reacted against commercially available DnaK antibodies on Western blot analysis and a visibly increased signal was seen for heat, cadmium, zinc, cobalt, phenol stresses and control, where represents in that order, whereas changes in the GroEL-like protein were less specific. Several minimal or defined minimal media were developed and used in heat stress and different protein profiles were seen. Medium (2) contained M9 salts medium (supplemented with glucose) plus casamino acids and medium (5) contained M9 salts medium (supplemented with glucose), vitamin solution, trace elements solution and casamino acids. Media (2) and (5) were found to be suitable for studying the physiological changes in strain VUN10,077, but growth rates in medium (2) were much less than seen in medium (5). Strain VUN10,077 presented major HSPs (70, 58 and 18 kDa proteins) in medium (5), similar to seen in Brain Heart Infusion (BHI) media. Pulse-chase 35S-methionine labelling methods were established and known major HSPs were newly synthesised by strain VUN10,077 under heat and cadmium stresses, and these proteins gradually declined while 55 kDa, 50 kDa and 18 kDa proteins were detected under ongoing stress conditions. Presumptive groEL gene analysis was attempted and partial conserved groEL sequences were determined in the pseudomonads and related species, where similarity was 98-100%. In parallel, a water-based lux system was established to examine physiological impacts of selected pollutants at the cellular level. Lux genes cloned from a marine bacterium were introduced into the background of the indigenous strain VUN10,077, providing a potentially sensitive tool for toxicity screening for terrestrial and fresh water samples. To show the use of bioluminescence in the indigenous (naturally non-bioluminescent) organism, research was performed on stable marking and optimisation of light output including marking of the organisms with luxAB or the whole lux cassette, which necessitated establishing gene transfer systems using available transposition vectors, optimisation of conditions for light output and stability. This approach would alleviate the requirement for salt or osmotic stabilizers in the test system to maintain bioluminescence or viability, which currently is a requirement of the Microtox (TM) system which employs Photobacterium phosphoreum. Expression of bioluminescence genes in the indigenous strain employed the luminescence system of Vibrio species which is encoded by a gene cluster with a divergent transcriptional pattern. As strain VUN10,077 was a genetically uncharacterised natural isolate, this work was achieved by establishing the parameters necessary for introducing genes after determining antibiotic sensitivity to determine which marker genes could be used in these backgrounds. The genes for two polypeptides (LuxA, LuxB) which form luciferase were transferred into strain VUN10,077. Introduction of the luxAB bioluminescence genes into a range of bacteria has been facilitated by using plasmid, pUT::Tn5-luxAB (de Lorenzo et al., 1990), which carries a tetracycline resistance gene. The plasmid was introduced by bi- and tri-parental conjugation employing a helper plasmid pRK2013, if necessary, so that antibiotic resistance can occur in the transconjugants if transposition occurs. Alternatively, electroporation was used to introduce bioluminescence lux genes into strain VUN10,077 when cells were harvested at early-log and stationary phase. One of the engineered water-based luxAB-marked strain (VUN3,600) was used to detect the presence of toxic substances (determining selectivity and sensitivity). This bacterial luciferase system produces bioluminescence when supplied with an aliphatic aldehyde substrate, where the luxAB genes were expressed on the chromosome. The substrate delivery system and preparation of cells for bioluminescence toxicity test were achieved by diluting ndecyl aldehyde 10 (3)-fold in Milli-Q water and resuspending cells in tap-water after mild centrifugation, when cells were harvested at A600 1.0-1.2. When a variety of common pollutants were tested in the water-based monitoring system, cells of VUN3,600 responded sensitively, rapidly and differentially to Cd, Pb, Hg, Zn, Co ions and SDS, and with less sensitivity to Ni, and As; responses were also dose-related in a short-term assay. DMF, a solvent used to dissolve or extract several organic compounds in environmental testing, stimulated light output but in a controlled fashion. Selected substituted heterocyclic compounds tested and phenol, d- nitrophenol and strontium failed to cause dose-related inhibition, whereas di-, tri-, tetra- and penta-chlorophenol decreased light output in a long-term assay. DMF-dissolved PAH compounds were tested in the long-term assay and naphthalene, phenanthrene, fluorene, fluoranthene and benzo[a]pyrene presented dose-related responses while benz[a] anthracene and di-benzo[a]anthracence were not suitable for use in this type of assay. Although there is need to investigate extensive toxicity assays to gain broad acceptance, the water-based monitoring system showed repeatable and reliable toxicity assessment and has great possibility of usage in aquatic samples in either water-soluble or DMF-soluble forms. This study allowed explanation of the stress responses of strain VUN10,077 to be examined at a variety of levels. Bioluminescence was the most sensitive approach to determining the lowest concentrations of pollutants which affected cell physiology, as this was obvious at concentrations lower than required to cause changes in viability or induce stress responses.

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Alistair, Phillips. „A method for replacing serrated tussock (Nassella trichotoma) with kangaroo grass (Themeda triandra) in lowland native grassland remnants“. 1999. http://eprints.vu.edu.au/218/1/Alistair%2C_Phillips.pdf.

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A 'spray and hay' method was developed which replaces the noxious weed serrated tussock (Nassella trichotoma (Nees) Arech.) with indigenous kangaroo grass (Themeda triandra Forrsk.) in partly disturbed remnants of western (basalt) plains indigenous grassland, a community listed as vulnerable to extinction. Investigations were carried out on Melbourne's north-west urban fringe. Refinements of the 'spray and hay' method resulted in low densities of other weeds amongst the newly established T. triandra swards. First steps in the method involved removal of weeds by slashing and follow-up treatment with either of the herbicides, glyphosate (as Monsanto RoundupÂ®) or atrazine (as Nufarm NutrazineÂ®). These steps resulted in close to 100% kill of mature N. trichotoma plants. Greater than 98% replacement of N. trichotoma with T. triandra was achieved by thatching over herbicide-treated plots with seed-bearing T. triandra hay harvested from remnant grasslands and then removal of the hay several months later by either burning or physical removal. The type and timing of herbicide application, thatching and removal of thatch were found to be central for successfully establishing competitive densities of T. triandra seedlings and minimizing re-establishment of N. trichotoma and other weed seedlings. A treatment set involving: slashing weed biomass in summer (January), herbicide application in autumn (April) followed by thatching with seed-bearing T. triandra hay in winter (July) and removal of thatch in spring (October) produced the best results. Assessing the seed content of hay and germinability of seed prior to revegetation were also important for calculating the amount of hay laid and subsequent seedling densities established. The seed content and germinability of seed-bearing hay was found to vary markedly in samples harvested in three different years, across discrete remnant grassland sites and even within undisturbed grassland sites. Reasons for the success of the method, and why other variations are less successful are discussed, as is the wider application of the method for weed control and replacement with indigenous grasses in lowland grassland remnants.

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Candy, SG. „Predictive models for integrated pest management of the leaf beetle Chrysophtharta bimaculata in Eucalyptus nitens plantations in Tasmania“. 2000. http://eprints.utas.edu.au/224.

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The Tasmanian Eucalyptus leaf beetle, Chrysophtharta bimaculata (Coleoptera: Chrysomelidae) is the most important phytophagous insect pest of eucalypts in Tasmania regularly defoliating new season’s growth over large areas of forest. An integrated pest management (IPM) system is currently in operation to minimise economic losses from defoliation of Eucalyptus nitens plantations due to browsing by larvae. However, the utility of the IPM system has been limited by the lack of : (a) an efficient sampling scheme for population monitoring, (b) the ability to predict an ‘action threshold’ (i.e. the population density for which it is profitable to apply insecticide at a standard rate), and (c) the ability to predict C. bimaculata population phenology. This study attempted to rectify this situation by developing predictive models that were calibrated using data from a number of sources including that obtained from a caged-shoot, larval feeding trial and from stage-frequency sampling carried out by the author. Sampling schemes for monitoring egg populations were investigated using (i) counts of the number of leaves occupied by one or more egg batches for a sample of shoots and trees where the total number of leaves on each shoot was unknown [‘occupied leaf count’ (OLC) sampling], (ii) counts of the number of occupied trees for a known total sample size (binomial sampling), and (iii) double sampling using a combination of both (i) and (ii). Novel statistical methods were employed in developing these sampling schemes. For OLC sampling, the current multi-stage technique for modelling the variance of the counts using either Taylor’s power law (TPL) or Iwao’s regression was compared to single-stage modelling using generalised linear mixed models (GLMMs). To do this, GLMMs were extended to incorporate a negative binomial variance function. Efficiency of estimation of TPL was improved by using a more accurate approximation to the variance of the marginal mean. For binomial sampling, William’s method III of handling over-dispersion in a binomial generalised linear model is shown to have theoretical and practical advantages over current methods that use simple linear regression. Models of the growth of E. nitens, with and without browsing by larvae, were developed at the leaf, shoot, tree, and stand level. The models included (i) a leaf expansion model, (ii) a process model of the impact of larval browsing on total shoot leaf area incorporating (i) above and calibrated using data from the caged-shoot feeding trial, and (iii) a model of the impact of defoliation level on the growth of tree diameter and height calibrated using data from artificial defoliation trials. A method of predicting action thresholds for insecticide application from inputs of initial stand conditions, silvicultural regime, cost of control, stumpage value, and cash discount rate was developed. This involved the comparison of growth predicted from existing stand and tree growth models for E. nitens with that obtained by combining those models with the browsing and defoliation impact models (ii) and (iii). Models of (i) egg and larval development rate as a function of ambient field temperature and (ii) the progression of the population through key life stages (egg to final instar larvae) were constructed. Maximum likelihood estimation was used for (i) based on interval-censored development times. Continuation ratio models for (ii), incorporating physiological time based on the models for (i) and calibrated using the stage-frequency data, were used to estimate time of peak occurrence of each of first, second, and third instar larvae. The models and estimation methods used are shown to have advantages over those currently used in population studies. Finally, the practical application of this suite of predictive models for decision support within the leaf beetle IPM system was demonstrated. For a typical 15-year rotation pulpwood regime on a site of average quality with a discount rate of 8%, a cost of control of $35/ha, and a stumpage of $30/m3, a value of 0.3 occupied leaves per shoot was the recommended action threshold. In addition, since approximately 90% of defoliation is caused by the last two (i.e. third and fourth) larval instars any application of insecticide should not be delayed past the time of the peak in the number of second instar larvae. The time from the start of mass oviposition to this peak was predicted to be approximately 175 DD[5] where DD[5] is the day-degrees calculated with a 5 lower threshold.

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Gillies, Craig. „Aspects of the ecology and management of small mammalian predators in northern New Zealand“. 1998. http://hdl.handle.net/2292/1942.

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Each chapter in this thesis has been written as a separate paper intended for later publication. Rather than write one summary, an abstract for each chapter has been given in the order they are presented in the thesis. Chapter I. The prey species of domestic cats (Felis catus) in two suburbs of Auckland city, New Zealand. The prey brought in by 80 cats (Felis catus), over a year was monitored in two suburbs of Auckland New Zealand. The survey technique followed that of Churcher & Lawton (1987) where cat owners were asked to record (and if possible keep) the prey their cats brought in. The results for the year indicated that there were distinct differences in the type of prey taken by cats in each area. Rodents were the most important prey brought in by domestic cats in an urban / forest fringe habitat and invertebrates were the main prey brought in by domestic cats in a fully urban habitat. Birds and lizards were the second and third most important prey groups in both study areas. Rat and mouse snap trap indexes which were run at each study location, did not detect rodents in the urban habitat. The results from the urban/forest fringe concurred more with studies of feral cat diet in New Zealand whilst those from the urban area compared more to studies of domestic and stray cat diet in urban areas overseas. There were seasonal trends in the prey captured in each area and in both areas cats hunted less over the winter months. Chapter II. Diets of coexisting alien mammalian carnivores in Northern New Zealand. 120 feral cats, 85 stoats (Mustela erminea), 28 weasels (M. nivalis) and 16 ferrets (M. furo) were caught over three years, in Northland, New Zealand. The gut contents of these animals were examined and their food habits described. The main prey groups of cats were (in order of importance by weight), lagomorphs, rodents (Rattus spp & Mus musculus), other mammals, birds and invertebrates. The main prey of stoats were rodents, birds, lagomorphs, skinks (Cyclodina spp) and invertebrates. Skinks, followed by mice, were the main prey of weasels. Rabbits (Oryctolagus cuniculus) were the most commonly occurring prey item in the ferret guts. The food habits for cats and stoats were compared between different habitats within the Northland region where these animals were collected from. There was little difference between habitats, but invertebrates occurred more frequently and lagomorphs less frequently in the diet of animals from forest habitats compared to those from forest / pasture and coastal habitats. No differences were found in the prey of male and female cats, but invertebrates occurred more frequently in the guts of sub-adult cats compared to adult cats. Skinks occurred more frequently in the guts of female stoats, which tended to take smaller prey items than males. Chapter III. Home range of introduced mammalian carnivores, feral cats (Felis catus), stoats (Mustela erminea) and a ferret (M. furo) at Trounson Kauri Park, Northland, New Zealand. The minimum home ranges of eleven feral cats, four stoats and one male ferret were examined by radio telemetry at Trounson Kauri Park in Northland New Zealand. The average minimum home range of male feral cats was 305 ± 74ha. This was not significantly larger than the 122 ± 35 ha minimum average home range of female cats. The minimum average home range of three male stoats was 108 ± 19 ha and the minimum home range of one female stoat was 50 ha. The male ferret had a minimum home range of 179 ha. There was no overlap spatially, in the home range of three adult male cats. There was also very little spatial overlap in the home range of four female cats. There was substantial home range overlap with four sub-adult male cats. The home ranges of these sub-adult male cats also overlapped spatially with those of the adjacent females and adult males. The home ranges of two male stoats overlapped spatially to some degree and the home range of another male stoat overlapped that of the female stoat substantially. The home range of the male ferret overlapped the home ranges of all of the cats occupying similar areas of the park. The home ranges of two male stoats overlapped the home ranges of the adjacent cats but not into the "core" areas of those cats ranges. Chapter IV. Secondary poisoning of introduced mammalian carnivores during possum and rodent control operations at Trounson Kauri Park, Northland New Zealand. Predatory mammals were monitored by radio telemetry through a 1080 then brodifacoum poison baiting operation at Trounson Kauri Park in Northland, New Zealand to target possums (Trichosurus vulpecula) and rodents (Rattus rattus, Rattus norvegicus & Mus musculus). All six feral cats (Felis catus), and the single stoat (Mustela erminea) and ferret (Mustela furo) being monitored at the beginning of the operation died of secondary poisoning following the 1080 operation. A further two cats and four stoats were radio tagged and monitored through the ongoing poisoning campaign using brodifacoum in a continuous baiting regime. None of these radio tagged carnivores died of secondary poisoning. However, tissue analysis of additional carnivores trapped at Trounson found that cats, weasels (Mustela nivalis) and to a lesser extent stoats did contain brodifacoum residues. The duration that the radio tagged predators were alive in and around Trounson Kauri Park suggested that the secondary poisoning effect was much reduced under the continuous baiting strategy, compared to the initial 1080 poison operation. Chapter V. Managing alien mammals in mainland New Zealand: The implications for predator/prey interactions in complex communities. Recent advancements in alien pest mammal control technologies have enabled conservation managers to attempt long term, large scale, predator and browser control programmes at mainland sites in New Zealand. At Trounson Kauri Park (in Northland, New Zealand) feral cats, ferrets, stoats and weasels plus rodents and possums were controlled for two and a half years. Early results from Trounson suggested that some native birds and plants responded positively and quickly to the control of these alien pest mammals. However, the management also affected the predator-prey and predator-predator interactions, within the mammalian community, with changes in the predator guild and some prey species increasing in abundance. The long term effects of these responses within the mammalian community to control efforts are unclear. A review of the international literature served only to confirm the view that managing alien mammals where re-invasion is constant will be a complex task. Conservation management at mainland sites like Trounson Kauri Park, may in effect be acting as crude mammalian predator removal experiments. Monitoring changes in predator-prey interactions and predator-predator interactions at this and other intensive management sites over sufficient time frames could provide scientists with the critical ecological data required to construct useful predictive models. The ability of managers to target specific pests at critical times would represent a significant advancement in controlling predatory mammals on the New Zealand mainland.

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Ito, Masayoshi 1967. „Non-filterable metals (NFM) in the atmosphere“. 2003. http://hdl.handle.net/2292/1954.

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A new air sampler, the Mist-UV sampling system, has been developed to trap and detect metals and metal compounds present in atmospheric samples, as non-filterable metal (NFM). The Mist-UV system is based on the combination of two ideas, mixing the filtrated air sample with nitric acid mist and simultaneous ultraviolet irradiation of the mist. Atmospheric NFM in the introduced air samples, which were first passed through a 0.2 µm filter, were oxidised by UV irradiation and dissolved in the nitric acid mist. The trapped metals resulting from the NFM in nitric acid were quantitatively determined using ICP-MS. Using the Mist-UV system, measurements of atmospheric NFM concentrations were carried out to obtain their temporal and spatial trends in Auckland, New Zealand. Five metals (Mg, Al, Cu, Ba and Sr) were detected as NFM in ambient air. Elevated atmospheric concentrations of Mg, Cu, and Ba were detected in midsummer and in daytime samples. The UV oxidisable fraction dominated the NFM and high enrichment factors (EFcrust) were found for these metals. This suggested that natural emissions of organometals or reduced metals were responsible for the elevated atmospheric concentrations. Meteorological factors, particularly air temperature, light irradiation and rainfall, promoted biogenic activity and resultant NFM emissions. Remarkably high concentrations of Al and Sr as NFM were discovered in several air samples and were dominated by the non-oxidisable compounds. This implies that the sources of Al and Sr were mainly from inorganic or oxidised metals associated with fine particulates. Wet and dry soils appeared to be the sources of Mg+Ba and Al+Sr, respectively. Plant emissions are recognised as important sources of Mg, Cu and Ba as NFM in ambient air, whereas the suspension of fine particulates derived from road dust and soil enriched with non-oxidisable compounds are seen as the major sources of Al and Sr. The emissions from automobiles and seawater samples were found to be unimportant NFM sources. The NFM concentrations were found to be significantly higher than concentrations of particulate metals, therefore the atmospheric importance and role of NFM cannot be ignored in the estimation of global metal circulation and budgets.

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47

Adeeb, Farah. „A Study of near-surface ozone concentrations in the city of Auckland, New Zealand“. 2006. http://hdl.handle.net/2292/2571.

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This research provides insight into large-scale spatial variation of ozone (O3) distribution in the Auckland region and was designed to increase our understanding of O3 behaviour and distribution in a coastal-urban situation. The research was also carried out with a view to assisting regulatory agencies optimize future monitoring networks, and to help identify locations where human health and natural resources could be at risk in the future. Although the research was limited to one region, the results are valuable for improving the conceptual understanding of formation of high ozone concentrations in a more general sense in the New Zealand and Southern Hemisphere. The work reported in this thesis is aimed at studying O3 concentrations and the influence of the most relevant meteorological variables on an average coastal New Zealand city where precursor emissions are mainly due to traffic exhaust. It deals with the use of Principal Component Analysis method for determining O3 concentrations as a function of meteorological parameters. The study region includes the entire Auckland isthmus, and extends from Whangaparaoa in the North to Pukekohe in the South. Surface O3 data from four sites (Whangaparaoa, Musick Point, the Sky Tower and Pukekohe) for a 4-year period(October 1997 to October 2001) for the Auckland region were examined. Ambient concentration of O3 was characterized in terms of diurnal, weekday/weekend, seasonal and spatial variations in concentration using O3 measurements from the four air quality sites. The monthly average ambient background O3 concentrations at the monitoring sites during this study ranged from 16-30 ppb, much lower than those found in the Northern Hemisphere. The measured seasonal O3 record in the Auckland region, in common with many other remote sites in the Southern Hemisphere, exhibited a summer minimum and a winter maximum. Background concentrations of O3 (as seen in air of marine origin) made a significant contribution to the observed ambient concentrations. A unique feature of Auckland's air quality was the dilution of polluted city air due to the mixing of east coast air into the cleaner west coast circulation leading to overall lower average O3 concentrations in summer. The magnitude, frequency and spatial extent of maximum O3 concentrations were identified, and the observed patterns linked to the prevailing meteorological, topographic, and emission characteristics of the region. However, at no time at any site or season did the O3 concentration exceed the l-hour New Zealand Ministry for the Environment guideline of 75 ppb. O3 depletion was observed to occur at the urban sites, with O3 scavenging by nitric oxide believed to be the dominant depletion mechanism. The seasonal cycle was characterized by elevated O3 concentrations in the winter (nighttime level >24 ppb) and low mixing ratios in the summer (nighttime levels in the range 14-20 ppb). The afternoon O3 maxima found at the three low elevation sites under the impact of "Auckland city" plume were on average, 1.5 to 1.7 times higher than those associated with the "marine sector". A state of the art diagnostic meteorological model, namely CALMET, was used to generate wind fields for the Auckland region. These wind fields were then used to construct backward trajectories on days when high O3 concentrations (episodes up to 6l ppb) were observed. The un-even distribution of the meteorological monitoring sites provided justification for running the diagnostic model CALMET and exploring the utility of using such a model when topography/land use prohibits monitoring sites in certain sections of the domain. It was found that the high O3 events recorded at the monitoring sites during the study period coincided with transport episodes originating from Auckland's urban and industrial areas. For the occurrence of high O3 concentrations at downwind sites, it was found that not only wind direction from the urban areas of Auckland, but that high solar radiation was important as well. On four out of the five cases when photochemical production of O3 was found to occur, high O3 concentrations were associated with a particular type of diurnal evolution of wind direction wind fields associated with the sea breezes. In addition to the analysis of ambient o3 concentrations and O3 episodes, field measurements were carried out in an attempt to detect and subsequently understand the interaction between particulate matter and O3 in the Auckland region, a multivariate statistical analysis approach was utilized. Particulate matter in the size range 2.75-6.25 μm accounted for over 70% of the total aerosol concentration at all sampling sites. Surface area of particulate matter variable (especially in the size class 2.75-4.25 μm) was statistically significant in explaining variation in O3 concentration. However, the net change in the adjusted R2 indicated that the effect of adding particulate matter in the multiple regression model for the present dataset was relatively minor except at Musick Point.

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Park, Buem-Seek. „Responses of an Environmental Gram-negative Bacterium to Pollutant Stress“. Thesis, 2002. https://vuir.vu.edu.au/226/.

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Several strains of pseudomonads which are normally found in natural water and soil environments, including Pseudomonas fluorescens, Pseudomonas aeruginosa, and strains initially identified as Pseudomonas paucimobilis and Pseudomonas maltophilia, were used in this thesis and their stress responsive proteins were surveyed at the physiological level. Additionally, 16S rRNA gene comparison was employed to classify the pseudomonads and related species at the genetic level. In order to see to what extent the pseudomonads and related species responded to heat shock, cells were initially subjected to temperature upshift from 28 to 37 deegree centegrade then disrupted by sonication or cells lysed by boiling in sample buffer, and the extracted total proteins were resolved on 1-D or 2-D SDS-PAGE. Their growth characteristics in different media (varying from rich to minimal) were determined and the physiological impacts on growth were examined at various concentrations of selected chemicals (metal ions, phenolics), to establish toxic and sub-lethal levels for use in determining stress responses. Production of novel proteins or elevated levels of normal proteins following exposure to different concentrations of toxicants was examined in detail in strain VUN10,077 (formerly Ps. paucimobilis) by sampling throughout the growth cycle and using 35S-methionine incorporation into newly synthesized proteins. Indigenous strain VUN10,077 presented abnormal rRNA pattern in standard RNA gels and 16S-like rRNA was analysed using Northern blot associated with 16S rRNA gene analysis which confirmed the identity of the known pseudomonads. An bands of MW 2.5 kb (faint), 1.38 kb, 1.2 kb and 0.1 kb were detected in RNA gels. The 1.38 kb band corresponded to 16S rRNA gene analysis, as shown by Northern blot analysis. 16S rRNA gene sequencing homology showed that strain VUN10,077 was a Brevundimonas species. The pseudomonads and related species accumulated a GroEL-like protein under heat stress when cells were grown in LB broth and disrupted by sonication, and 2-D SDS-PAGE conditions were established using sonically disrupted cells of Stenotrophomonas maltophilia (formerly Ps. maltophilia). Cells lysed by boiling represented the total protein profile and included particulate or membrane-associated proteins, 70 kDa-like and 44-46 kDa proteins for strain VUN10,077. Selected pollutants impacted on the cell viability and sub-lethal levels of these were determined as follows; 2.0 gL-1 for CdCl2, 2.0 gL-1 for CuCl2.2H2O, 2.0 gL-1 for NiCl2.6H2O, 1.0 gL-1 for CoCl2.6H2O, 0.025 gL-1 for HgCl2, 0.25 gL-1 for SDS, 0.2 gL-1 for NaAsO2 and 0.5 gL-1 for phenol, from A600 readings and viable counts. Major HSPs were present at relatively lower levels or were barely increased compared to controls, whereas low molecular weight proteins were significantly changed. A 20 kDa protein was commonly found in cadmium, copper, cobalt, nickel, arsenite and phenol stresses. However, a DnaK-like protein strongly reacted against commercially available DnaK antibodies on Western blot analysis and a visibly increased signal was seen for heat, cadmium, zinc, cobalt, phenol stresses and control, where represents in that order, whereas changes in the GroEL-like protein were less specific. Several minimal or defined minimal media were developed and used in heat stress and different protein profiles were seen. Medium (2) contained M9 salts medium (supplemented with glucose) plus casamino acids and medium (5) contained M9 salts medium (supplemented with glucose), vitamin solution, trace elements solution and casamino acids. Media (2) and (5) were found to be suitable for studying the physiological changes in strain VUN10,077, but growth rates in medium (2) were much less than seen in medium (5). Strain VUN10,077 presented major HSPs (70, 58 and 18 kDa proteins) in medium (5), similar to seen in Brain Heart Infusion (BHI) media. Pulse-chase 35S-methionine labelling methods were established and known major HSPs were newly synthesised by strain VUN10,077 under heat and cadmium stresses, and these proteins gradually declined while 55 kDa, 50 kDa and 18 kDa proteins were detected under ongoing stress conditions. Presumptive groEL gene analysis was attempted and partial conserved groEL sequences were determined in the pseudomonads and related species, where similarity was 98-100%. In parallel, a water-based lux system was established to examine physiological impacts of selected pollutants at the cellular level. Lux genes cloned from a marine bacterium were introduced into the background of the indigenous strain VUN10,077, providing a potentially sensitive tool for toxicity screening for terrestrial and fresh water samples. To show the use of bioluminescence in the indigenous (naturally non-bioluminescent) organism, research was performed on stable marking and optimisation of light output including marking of the organisms with luxAB or the whole lux cassette, which necessitated establishing gene transfer systems using available transposition vectors, optimisation of conditions for light output and stability. This approach would alleviate the requirement for salt or osmotic stabilizers in the test system to maintain bioluminescence or viability, which currently is a requirement of the Microtox (TM) system which employs Photobacterium phosphoreum. Expression of bioluminescence genes in the indigenous strain employed the luminescence system of Vibrio species which is encoded by a gene cluster with a divergent transcriptional pattern. As strain VUN10,077 was a genetically uncharacterised natural isolate, this work was achieved by establishing the parameters necessary for introducing genes after determining antibiotic sensitivity to determine which marker genes could be used in these backgrounds. The genes for two polypeptides (LuxA, LuxB) which form luciferase were transferred into strain VUN10,077. Introduction of the luxAB bioluminescence genes into a range of bacteria has been facilitated by using plasmid, pUT::Tn5-luxAB (de Lorenzo et al., 1990), which carries a tetracycline resistance gene. The plasmid was introduced by bi- and tri-parental conjugation employing a helper plasmid pRK2013, if necessary, so that antibiotic resistance can occur in the transconjugants if transposition occurs. Alternatively, electroporation was used to introduce bioluminescence lux genes into strain VUN10,077 when cells were harvested at early-log and stationary phase. One of the engineered water-based luxAB-marked strain (VUN3,600) was used to detect the presence of toxic substances (determining selectivity and sensitivity). This bacterial luciferase system produces bioluminescence when supplied with an aliphatic aldehyde substrate, where the luxAB genes were expressed on the chromosome. The substrate delivery system and preparation of cells for bioluminescence toxicity test were achieved by diluting ndecyl aldehyde 10 (3)-fold in Milli-Q water and resuspending cells in tap-water after mild centrifugation, when cells were harvested at A600 1.0-1.2. When a variety of common pollutants were tested in the water-based monitoring system, cells of VUN3,600 responded sensitively, rapidly and differentially to Cd, Pb, Hg, Zn, Co ions and SDS, and with less sensitivity to Ni, and As; responses were also dose-related in a short-term assay. DMF, a solvent used to dissolve or extract several organic compounds in environmental testing, stimulated light output but in a controlled fashion. Selected substituted heterocyclic compounds tested and phenol, d- nitrophenol and strontium failed to cause dose-related inhibition, whereas di-, tri-, tetra- and penta-chlorophenol decreased light output in a long-term assay. DMF-dissolved PAH compounds were tested in the long-term assay and naphthalene, phenanthrene, fluorene, fluoranthene and benzo[a]pyrene presented dose-related responses while benz[a] anthracene and di-benzo[a]anthracence were not suitable for use in this type of assay. Although there is need to investigate extensive toxicity assays to gain broad acceptance, the water-based monitoring system showed repeatable and reliable toxicity assessment and has great possibility of usage in aquatic samples in either water-soluble or DMF-soluble forms. This study allowed explanation of the stress responses of strain VUN10,077 to be examined at a variety of levels. Bioluminescence was the most sensitive approach to determining the lowest concentrations of pollutants which affected cell physiology, as this was obvious at concentrations lower than required to cause changes in viability or induce stress responses.

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Lizarraga-Madrigal, Ignacio. „Spinal analgesic interaction between non-steroidal anti-inflammatory drugs and N-methyl-D-aspartate receptor systems : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Veterinary Science, Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Palmerston North, New Zealand“. 2006. http://hdl.handle.net/10179/1466.

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Activation of spinal N-methyl-D-aspartate (NMDA) receptors stimulates cyclooxygenase and nitric oxide pathways. Compounds that block the activity of these NMDA receptor systems reduce pain hypersensitivity. However, their usefulness is limited by the side effects they produce. One way of reducing side effects is by combining drugs that produce the same overt effect by different mechanisms, which hopefully increase the net effect. In these series of studies, drugs that interact with NMDA receptor systems and their combinations were screened in vitro to identify spinal antinociceptive synergistic combinations that could be assessed in vivo. Based on developmental changes in thresholds, conduction velocities and blocking actions of the local anaesthetic lignocaine in neonatal rat L4/L5 dorsal root potentials, it was decided to use spinal cord in vitro preparation from 5- to 7-day-old rat pups. In single drug studies, the NMDA receptor channel blocker ketamine (1-50 µM) and the non-steroidal anti-inflammatory drug (NSAID) ketoprofen (200-600 µM), but not the NSAID salicylate (1000 µM) and the nitric oxide synthase inhibitor Nω-nitro-L-arginine methyl ester (L-NAME; 1-100 µM), reduced spinal NMDA receptor-mediated transmission. Ketamine also depressed non-NMDA receptor-mediated transmission. Using isobolographic and composite additive line analyses, fixed-ratio combinations of ketamine and ketoprofen, ketamine and L-NAME, and ketopofen and L-NAME synergistically depressed NMDA receptor-mediated transmission. The two former combinations had a subadditive effect on non-NMDA receptor-mediated transmission, and the latter had no significant effect. These studies identified that all combinations synergistically reduced both nociceptive transmission and potential side effects. In free-moving sheep implanted with indwelling cervical intrathecal catheters, 100 µ1 subdural administration of ketamine (25-400 µM) and ketoprofen (200-3200 µM) alone and in a fixed-ratio combination (873.95-3350.78 µM, 0.045:0.955) did not raise nociceptive thresholds as assessed by mechanical stimulation of one foreleg. Subdural administration of NMDA (2 mM) decreased mechanical nociceptive thresholds, and this was prevented by the highest concentrations of ketamine and ketoprofen alone and in combination. These findings demonstrated that NMDA receptor channel blockers and NSAIDs alone or in combination had no direct hypoalgesic effects when given onto the spinal cord of sheep, but they prevented NMDA-induced pain hypersensitivity. Simultaneous blockade of NMDA receptor systems could have important clinical implications.

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Sandiford, Anna. „Palynology and tephrostratigraphy of Quaternary coverbed sequences of the Auckland area, New Zealand“. 2001. http://hdl.handle.net/2292/2218.

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This thesis presents the results of detailed palynological and tephrostratigraphic investigations of five sites around the Auckland Isthmus, which collectively contain a fragmented record spanning approximately the last 1.2 million years. A range of additional methods were applied including, radiometric dating, palaeomagnetism, identification of other palynomorphs and fossil wood, and calculation of deposition rates. Study of two late Quaternary sites provided information on the Last Glacial Maximum (LGM) environment of the Auckland Isthmus. This suggested LGM forest was spatially restricted, dominated by beech forest with minor podocarp elements and contained within extensive shruband grassland. Late Quaternary sites were more easily studied than early to mid Quaternary sites because the depositional environment in which they were found provided greater palynological and tephrostratigraphic detail. Detailed published late Quaternary tephrostratigraphy also allowed for tight chronological control, accurate interpolation of ages of uncorrelated tephra and assessment of the accuracy of radiocarbon dates. Forty late Quaternary tephra layers were identified, adding to the record of eruptions sourced from the Auckland Volcanic Field, Taupo Volcanic Zone and Taranaki Volcano. Since c. 24 ka the frequency of Late quaternary tephraforming events of significant volume to be recorded in the sediments on the Auckland Isthmus is 1 every 600 years. Study of early to mid Quaternary sites was hampered by lack of published tephrostratigraphic records for correlation. Last appearance data for four extinct taxa were tentatively extended. Significant depositional hiatuses were noted; the period between c. 1.0 Ma and c. 44 ka was particularly unsatisfactorily recorded. Three key tephra markers and nine previously undocumented tephra layers were documented. Spatial variation and alternating vegetation structure characterised cooler and warmer environments of the early to mid quaternary record. Extensive high diversity conifer-angiosperm forest occurred during warmer periods while reduced diversity beech-dominated forest contained within extensive shrub/grassland characterised the cooler periods. Certain combinations of taxa occurred during glacial/stadial and interglacial/interstadial periods and an attempt was made to generalise these. It was apparent the extremes of the LGM were not reached during this time, and-that climate oscillated between cool and warm periods sometimes characterised by vegetation assemblages without modem analogue. Extensive depositional hiatuses at one site, deposition of extremely thick, reworked, homogenous marine silt at a second site, and dipping bedding planes at a third site suggest sea level variation and/or tectonism were influential in the Quaternary depositional history of the Auckland Isthmus. However, not enough evidence was present to quantify this.

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Dissertationen zum Thema „Veterinary and Environmental Sciences“

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