Tesis sobre el tema "Bird damage"
Siga este enlace para ver otros tipos de publicaciones sobre el tema: Bird damage.
Crea una cita precisa en los estilos APA, MLA, Chicago, Harvard y otros
Consulte los 24 mejores tesis para su investigación sobre el tema "Bird damage".
Junto a cada fuente en la lista de referencias hay un botón "Agregar a la bibliografía". Pulsa este botón, y generaremos automáticamente la referencia bibliográfica para la obra elegida en el estilo de cita que necesites: APA, MLA, Harvard, Vancouver, Chicago, etc.
También puede descargar el texto completo de la publicación académica en formato pdf y leer en línea su resumen siempre que esté disponible en los metadatos.
Explore tesis sobre una amplia variedad de disciplinas y organice su bibliografía correctamente.
1
Watkins, Nigel G. "Ecological correlates of bird damage in a Canterbury vineyard". Lincoln University, 1999. http://hdl.handle.net/10182/508.
Texto completoResumen
Birds are a major pest in vineyards both in New Zealand and overseas. There is a need for new behavioural research on birds' foraging habits and feeding preferences in vineyards, as much of the literature to date is anecdotal. Research on cues to birds' feeding will provide a basis on which new deterrent and control strategies can be devised. Spatial-and temporal bird damage in a small vineyard block was mapped to find if damage was correlated with grape maturity and environmental factors. Vineyard and field observations of bird behaviour using video technology combined with preference experiments aimed to establish the relative roles of grape sugar concentration and colour in avian selection. Proximity of vineyards to bird roosts affects damage levels, regardless of differing maturity between locations. The rate of damage tends to increase exponentially once grape maturity has passed a threshold of 13 °Brix. Bunches positioned closest to the ground receive more damage if blackbirds or song thrushes are the predominant pests. Both sugar concentration and grape colour were found to affect birds' feeding preference, but the importance of the two factors varied between years. Black and green grape varieties were differentially preferred by blackbirds (Turdus merula) and song thrushes (Turdus philomelos) while silvereyes (Zosterops lateralis) appeared to have no strong colour preference. It was apparent that there were other, not assessed, grape factors that also affect selection. In small unprotected vineyards that are adjacent to bird roosts the entire grape crop can be taken by bird pests. Besides removing the roosts, which can be beneficial shelterbelts in regions exposed to high winds, growers currently may have no alternative other than to use exclusion netting to keep crops intact. The differential preferences between bird species for variety characteristics suggest that any new deterrents and other strategies to deflect birds from grape crops may need to be species-specific.
2
Hui, Wun-fung y 許桓峰. "Bird damage to vegetable crops in Long Valley during winter". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2013. http://hdl.handle.net/10722/194581.
Texto completoResumen
Long Valley is the largest agricultural wetland in Hong Kong and supports a high level of biodiversity. The implementation of Management Agreement project in Long Valley has successfully enhanced its conservation value through habitat management and various eco-agricultural practices. However, the conflict between profitable agricultural yield and bird conservation in the area has also been intensifying as reflected by the increasing number of complaints of bird-related crop damage from local farmers in winter.
The study aimed to assess the extent and impact of crop damage caused by birds in Long Valley during winter. The first part of the study involved a transect survey in the area reported to be the most severely affected area of Long Valley to determine the bird diversity and abundance, also the environmental factors of individual farmland plots were collected for analysis of their relationship with bird distribution. The bird species responsible for crop damage (targeted species) were also identified. The second part of the study evaluated the impact of different targeted species by using the technique of focal animal sampling, which involved focused observation of individual bird’s behaviour in the field and to quantify its time budget spent on crop-damaging behaviour. In order to understand the perspectives from farmers, face-to-face interviews with farmers practicing in the area were also conducted.
The study identified five species to have crop-damaging behaviour, which can be further divided into two groups: the crop-consuming species causing actual crop damage included Chinese Bulbul (Pycnonotus sinensis), Crested Myna (Acridotheres cristatellus) and Eurasian Tree Sparrow(Passer montanus). The incidental crop-pecking species causing minimal crop damage included the White Wagtail (Motacilla alba)and Yellow Wagtail (Motacilla tschutschensis). Lettuce (Lactuca sativa) was the only type of crop suffering from bird damage. The intensity of crop-damaging behaviour of a species was estimated by the mean time allocated in crop consumption, and was found to be 66.7%±7.3% in Chinese Bulbul, 31.6%±29.1% in Eurasian Tree Sparrow and 8.9%±12.0% in Crested Myna. However, taking into account of the abundance, distribution and activity record of a species, Crested Myna showed the greatest overall impact to the vegetable crops. Chinese Bulbul showed a relatively focal but intensive damage to a few plots. It was found that having wires and a wet field nearby the plots were significant determinants of the presence of Eurasian Tree Sparrow. And the presence of Chinese Bulbul was significantly associated with the use of bird deterrents. Crested Myna was found in significantly higher numbers in late afternoon and was associated with plots having the seedling stage of lettuce growth.
The study shows that birds do cause localized and patchy damage to vegetable crops in Long Valley. Individual farmlands may exhibit variations in severity of the damage due to the difference in species distribution and environmental factors. The management of bird damage must therefore be individualized from plot to plot. Also education and engagement with local farmers are indispensable to maintaining sustainable agricultural development while conserving avifauna in Long Valley.published_or_final_version
Environmental Management
Master
Master of Science in Environmental Management
3
Kale, Manoj Ashokrao. "Bird Species in Urban and Agricultural Landscapes : Bird diversity patterns along an urbanisation gradient and crop damage caused by birds on the Deccan Plateau, India". Doctoral thesis, KTH, Hållbar utveckling, miljövetenskap och teknik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-154421.
Texto completoResumen
The major human activities that have transformed the Earth include agriculture and urbanization. The present study was conducted to contribute to a description of the effect on birds of urbanization and agriculture in an Indian region. Terrestrial bird assemblages were censused along a five-stage urbanisation gradient between January and April 2010-2013 near the city of Amravati, on the Deccan Plateau, Central India. Altogether, 89 species of birds were recorded, with the highest species richness in the rural areas (67 species) and lowest in the urban stage (29 species). The assemblages were significantly nested in all the five stages. Maximum cumulative species abundance (12 399 individuals over four years) was found in the urban stage, and was due to the constant presence of large groups of Rose-ringed Parakeets (Psittacula krameri). The lowest bird abundance was found in the industrial zone (4837 in total), where there was also a nearly two-fold decrease from 2010 to 2013. Thirty-six species demonstrated significant variation in their densities at least in one stage and between at least two months (p<0.05). Densities of 13.9% (n=5) of those species varied significantly in two stages, that of Copsychus saularis in three stages, and of Phoenicurus ochruros, in all five stages. Urban, suburban, periurban and forest stages were characterised by relatively stable species densities (significant changes observed only for 17.2% (n=5), 17.1% (n=6), 12.9% (n=7), and 17.8% (n=16) species, respectively). The additive diversity partitioning indicated that of the overall diversity (gamma-diversity), alpha diversity (within transects located within one stage) contributed 50.1% to the total diversity, and the controbution of within-stage variability was small (2.7%). Additionally, censuses on cultivated fields were taken. In two areas under mixed cropping systems, 53 bird species were identified in the two years period between June and December, 2011 and 2012. Out of the 53 detected species, only 14 were common (recorded at ≥50% of visits). Twenty-one species were recorded at Zadgaon in crops of tur (Cajanus cajan), cotton (Gossypium arboreum) and soybean (Glycine max). Nineteen species were recorded at Bhankhed in jawar (Sorghum bicolor), cotton and mung bean (Phaseolus aureus). At Zadgaon, territorial activity was observed in four species: the House Sparrow (Passer domesticus), Jungle Babbler (Turdoides striata), Yellow-eyed Babbler (Chrysomma sinense) and Red-wattled Lapwing (Vanellus indicus). The study indicated that four bird species were found under high risk, thirteen species at medium risk and eight species at low risk due to pesticide applications in croplands. The extent of crop damage in fields of groundnut, pearl millet, peas, sorghum, and sunflower was assessed by doing actual field censuses. The sustainable solution for reducing crop damage is a need for the farmers and such techniques will help to avoid direct or indirect effects of use of lethal bird control techniques on bird species diversity.QC 20141022
4
Tedrow, Christine Atkins. "Bird Strike Risk Assessment for United States Air Force Airfields and Aircraft". Thesis, Virginia Tech, 1998. http://hdl.handle.net/10919/40926.
Texto completoResumen
Analysis of strike data is critical to determine the true economic costs of bird strikes, determine the magnitude of safety issues, and develop preventive measures. Analysis of USAF bird-strike data identified trends and indicated suggested relationships among factors contributing to damaging strikes. From FY 1988 through FY 1997, the annual mean was 2,668 bird strikes with peaks evident in fall and spring. Daylight and dusk were hazardous for bird strikes. More bird strikes occurred during airfield operations - aircraft are at low altitudes and soaring birds are more numerous. Aircraft speed, phase of flight, taxonomic group, bird mass and aircraft group were the strongest predictors of damaging bird strikes. Bird strike rates were calculated for USAF aircraft and selected USAF airfields. Bomber aircraft had the highest strike rate; these aircraft frequently fly long missions at low altitudes where they are likely to encounter birds. Logistic regression analyses estimated odds of occurrence for damaging bird strikes during airfield operations. General statistics, odds for a damaging airfield strike, and airfield strike rates, were used to identify USAF airfields with higher bird strike risks. Howard AFB, Panama, had a higher number and rate of bird strikes, and greater odds for a damaging bird strike than other airfields analyzed.
This study allows recommendations for improving reporting of bird strikes and data management. Results will enable USAF to better estimate bird strike risks aircraft, better focus research on preventing bird strikes, and assess the effectiveness of bird management programs.Master of Science
5
Dignon, Niki. "Quantifying bird damage to wine grapes in the Western Cape of South Africa : a questionnaire-based approach". Bachelor's thesis, University of Cape Town, 2013. http://hdl.handle.net/11427/14121.
Texto completoResumen
Bird-wine grape damage is a globally acknowledged problem that has been the subject of considerable research in many wine growing regions. However, despite the Western Cape of South Africa being a major wine grape growing region, very little research has quantified bird damage in this region and very little is known about the extent of the problem. This research aimed to quantify bird damage to wine grapes in four grape growing regions of the Western Cape, through questionnaires. It also aimed to determine the factors that might explain the patterns of damage observed. 102 questionnaires were sent to the wine farms, and 52 were returned. Of the respondents, 71% reported bird grape damage. The amount of damage per wine farm ranged between 0% and 15% of the total rows of vines across a farm. When exploring the factors associated with whether a wine farm experienced bird damage, it was found that the border habitat of a farm was a significant factor. The composition of the border habitat greatly influenced the probability of bird damage. The PCA showed that tall trees, Fynbos and residential areas specifically increased the probability of bird damage. Within farms that experienced damage, it was found that in different vineyard blocks the areas closer to the edge of a vineyard and to trees were significantly more susceptible to bird damage. The most common reported damage-causing bird species were Red-Winged Starlings (Onycognathus morio) and White-Eyes (Zosterops lateralis). Damage was reported to occur mostly one month before harvest and at harvest time. This research provides a baseline for understanding the nature of bird damage in these regions and will aid future quantitative studies aimed at the management of the problem.
6
Saxton, Valerie Patricia. "Influence of ripening grape compounds on behavioural responses of birds". Phd thesis, Lincoln University. Agriculture and Life Sciences Division, 2004. http://theses.lincoln.ac.nz/public/adt-NZLIU20061207.121738/.
Texto completoResumen
Vineyards in New Zealand suffer bird damage caused by several avian species, including blackbirds and silvereyes. The introduced European Blackbird takes whole grapes which reduces yield. The self-introduced Australasian Silvereye pecks on grapes, leaving them on the vine to be further attacked by fungi and bacteria, and the subsequent off-odours can cause grapes to be refused by the winery or to suffer a price-reduction. Bird control methods remain primitive and largely ineffective during the long ripening period of wine grapes. An ecologically sound method to manage and reduce bird pressure requires deeper understanding of why some birds eat grapes, especially since grapes are not particularly nutritious.
This work investigated the extent to which blackbirds and silvereyes are attracted by various compounds in ripening grapes. Since in natural grapes these compounds develop and change simultaneously, I developed an artificial grape in which a single parameter could be investigated. Artificial grapes (and sometimes nectar) were presented on a bird feeder table and the responses of birds to hexose sugars, the aromas 2-3-isobutylmethoxypyrazine and geraniol, tartaric and malic acids, grape tannins, and purple and green colour were recorded on timelapse video and analysed.
7
Wohlfarth, Hasle Inger-Marie. "Tranors förekomst på fält kring Tåkern påverkas av vägar, vatten, byggnader, träd och buskage". Thesis, Linköpings universitet, Biologi, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-129776.
Texto completoResumen
Every year the Eurasian crane travel from northern Africa to northern Europe and Asia. On their migration route they need to rest and often choose places around shallow lakes in agriculture landscapes. During their time in these resting sites the cranes forage in agriculture fields surrounding the lakes, which often cause crop-damage and thereof also financial loses. The last 30 years the population has increased radically, resulting in more extensive crop-damage. This study was set out to gain a better understanding how these migrating cranes choose sites to forage, based on four environment factors: roads, water, buildings, trees and shrub. A study-area in north of Lake Tåkern was selected and during six days in the spring all the cranes in the area were counted and marked on a map. The results showed that the factors affected the occurrence of cranes in the fields. They wanted to be close to shallow water and keep a distance to buildings, roads, trees and shrub. The cranes often spend the night in shallow water and search for food in the area close by to not lose too much energy, which probably was the main reason for the birds to stay close to the water. The distance to buildings and roads suggests that the cranes want to avoid interference from humans and the distance to trees and shrub that they want to have a good awareness of their surroundings. Through this understanding, areas with higher risk to attract groups of cranes can more easily be identified.
8
Song, Yangkun. "Development of Comprehensive Dynamic Damage Assessment Methodology for High-Bypass Air Breathing Propulsion Subject to Foreign Object Ingestion". Diss., Virginia Tech, 2016. http://hdl.handle.net/10919/93960.
Texto completoResumen
Foreign object ingestion (FOI) into jet engines is a recurring scenario during the operation life of aircraft. Objects can range from as small as a pebble on the tarmac to the size of a large bird. Among the potential ingestion scenarios, damage caused by smaller objects may be considered to be negligible. Alternatively, larger objects can initiate progressive damage, potentially leading to catastrophic failure, compromising the integrity of the structure, and endangering the safety of passengers. Considering the dramatic increase in air traffic, FOI represents a crucial safety hazard, and must be better understood to minimize possible damage and structural failure.
The main purpose of this study is to develop a unique methodology to assess the response and dynamic damage progression of an advanced, high-bypass propulsion system in the event of an FOI during operation. Using a finite element framework, a unique modeling methodology has been proposed in order to characterize the FOI response of the system. In order to demonstrate versatility of the computational analysis, the impact characteristics of two most common foreign object materials, bird and ice, were investigated. These materials were then defined in finite element domain, verified computationally, and then validated against the existing physical experiments. In addition to the mechanics of the two FOI materials, other material definitions, used to characterize the structures of the high-bypass propulsion system, were also explored. Both composite materials and rate dependent definitions for metal alloys were investigated to represent the damage mechanics in the event of an FOI.
Subsequently, damage sequence of high-bypass propulsion systems subject to FOI was developed and assessed, using a uniquely devised Fluid-Structure Interaction (FSI) technique. Using advanced finite element formulation, this approach enabled the accurate simulation of the comprehensive damage progression of the propulsion systems by including aerodynamic interaction. Through this strategy, fluid mechanics was combined with structural mechanics in order to simulate the mutual interaction between both continua, allowing the interpretation of both the additional damage caused by the fluid flow and disrupted aerodynamics induced by the dynamic deformation of the fan blade. Subsequently, this multidisciplinary-multiphysics computational approach, in the framework of the comprehensive analysis methodology introduced, enabled the effective determination of details on the overall progressive impact damage, not traditionally available to propulsion designers.PHD
9
Saxton, V. P. "Influence of ripening grape compounds on behavioural responses of birds". Diss., Lincoln University, 2004. http://hdl.handle.net/10182/28.
Texto completoResumen
Vineyards in New Zealand suffer bird damage caused by several avian species, including blackbirds and silvereyes. The introduced European Blackbird takes whole grapes which reduces yield. The self-introduced Australasian Silvereye pecks on grapes, leaving them on the vine to be further attacked by fungi and bacteria, and the subsequent off-odours can cause grapes to be refused by the winery or to suffer a price-reduction. Bird control methods remain primitive and largely ineffective during the long ripening period of wine grapes. An ecologically sound method to manage and reduce bird pressure requires deeper understanding of why some birds eat grapes, especially since grapes are not particularly nutritious. This work investigated the extent to which blackbirds and silvereyes are attracted by various compounds in ripening grapes. Since in natural grapes these compounds develop and change simultaneously, I developed an artificial grape in which a single parameter could be investigated. Artificial grapes (and sometimes nectar) were presented on a bird feeder table and the responses of birds to hexose sugars, the aromas 2-3-isobutylmethoxypyrazine and geraniol, tartaric and malic acids, grape tannins, and purple and green colour were recorded on timelapse video and analysed.
10
Bílek, Tomáš. "Vliv doby znečistění karoserie vozidla ptačím trusem na míru poškození laku". Master's thesis, Vysoké učení technické v Brně. Ústav soudního inženýrství, 2017. http://www.nusl.cz/ntk/nusl-318548.
Texto completoResumen
This diploma thesis deals with the issue of the degree of damage done to the vehicle‘s body paint varnish by bird droppings; with respect to the influence of the pollution time on the thickness of the layer of lacquer. The first chapter deals with the importance of varnish and other layers of body protection, types of body varnish damage, painting technology, lacquer defects, bird droppings and its effects on the varnish of the vehicle‘s body. The second chapter is dedicated exclusively to the description, planning and measurement of the coated layers on the vehicle’s body contaminated with bird feces.
11
Furness, Lindsay Jayne. "Energetics, oxidative damage and ageing in birds". Thesis, Available from the University of Aberdeen Library and Historic Collections Digital Resources, 2009. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?application=DIGITOOL-3&owner=resourcediscovery&custom_att_2=simple_viewer&pid=25473.
Texto completo
12
Coulthard, Julie. "Parental incarceration and the ties that bind: children of offenders as collateral damage". Thesis, McGill University, 2010. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=95023.
Texto completoResumen
The children of offenders have often been referred to as the "hidden victims of crime," with parental incarceration shown to have a negative and profound impact on the children. However, despite pressing concerns regarding the welfare of these children, significant gaps exist in our understanding of their well-being, of the way in which certain factors impact their well-being, and of the relationship between the condition of the children's well-being and their deviant and criminal behaviour. In addition, there is a significant paucity of research addressing the topic of children of incarcerated parents from a Canadian perspective. Therefore, the goal of this study is to address these limitations in the literature and to provide greater insight into the experiences of the children of offenders in Canada. The data for this study is drawn from in-person semi-structured interviews conducted with three groupings of individuals, including: practitioners who had experience with children of incarcerated parents in a professional capacity; the legal guardians of children with an incarcerated parent; and the children of an incarcerated parent. The study includes a sample size of 47 participants in Kingston, Ontario. Based on an index comprised of four key indicators of well-being (emotional, behavioural, academic, and social), analyses of the data indicated that the majority of the children were doing poorly across multiple dimensions. It was further evident that there were some prominent factors that impacted upon the well-being of the children of incarcerated parents, including the children's quality of care, the stigma surrounding parental incarceration, and available social support networks. Lastly, in investigating the relationship between the condition of the children's overall well-being and their participation in deviant and criminal behaviour, it is determined that, while overall well-being may provide a partial predictor for these negative outcomes, it is angerOn réfère aux enfants de parents criminels comme étant les « victimes cachées du crime » puisque l'incarcération de leurs parents a un impact négatif profond sur eux. Pourtant, malgré les inquiétudes pressantes concernant la qualité de vie de ces enfants, il existe des lacunes sérieuses entre notre compréhension de leur bien-être, la façon dans laquelle certains facteurs peuvent affecter leur bien-être et la relation entre la condition de vie des enfants et leurs comportements déviants et criminels. De plus, il y a un grand manque de recherches axées sur les enfants de parents incarcérés qui offrent une perspective Canadienne. C'est la raison pour laquelle cette étude a comme but d'adressé les lacunes dans la littérature actuelle en permettant un aperçu plus complet des expériences de vie des enfants de parents criminels au Canada. Les données pour cette étude proviennent d'entrevues en personne semi-structuré avec trois groupes d'individus, incluant : des professionnels qui avaient de l'expérience avec des enfants de parents incarcérés ; les tuteurs légales d'enfants dont un parent est incarcéré ; et les enfants de parents incarcérés. L'étude comprend un échantillon de 47 participants de Kingston, Ontario. Quatre indicateurs ont été utilisés pour évaluer le bien-être (émotionnel, comportemental, académique, et social) et l'analyse des données indique que la majorité des enfants avaient des difficultés à plus qu'un niveau. Il était aussi évident que certains facteurs avaient un impacte plus important sur le bien-être des enfants de parents incarcérés, incluant : la qualité des soins offerts aux enfants, le stigma qui existe envers l'incarcération parental, ainsi que le réseaux de soutien social disponibles. Finalement, en investiguant les relations entre le bien-être des enfants et leur participation dans des comportements déviants and criminels, une détermination peut être faite que malgré les pr
13
Sitzlar, Megan Annette. "P450 aromatase alterations and DNA damage as avian pollution biomarkers in cliff and cave swallow breeding near the Rio Grande region, Texas". Texas A&M University, 2005. http://hdl.handle.net/1969.1/3223.
Texto completoResumen
The endocrine system, specifically relating to sex hormones, and genetic material
can be targets of environmental contaminants. Environmental contaminants in the Rio
Grande region may originate from industrial or agricultural processes and growing
populations lacking proper water and sewage infrastructure. Cliff (Petrochelidon
pyrrhonota) and cave (P. fulva) swallows breeding near the Rio Grande were selected to
monitor aromatase activity alterations and DNA damage. Swallows were sampled at six
sites along the Rio Grande from Brownsville to Laredo, and a reference site (Somerville)
350 miles north of the Rio Grande. DNA damage, based on nuclear DNA content, was
determined by flow cytometry. A significantly larger mean half peak coefficient of
variation (HPCV) of DNA content in contaminated sites compared to a reference site
reflects possible chromosomal damage. No detectable HPCV differences were observed
in cave swallows among locations, notwithstanding the presence of mutagenic
contaminants. Selenium may provide a protective role against genetic damage.
However, cliff swallows from Laredo had significantly higher HPCV values than those
from Somerville. DNA damage could be attributed to metals and polycyclic aromatic hydrocarbons released near Laredo. Brains and gonads, two estrogen-dependent organs,
were tested for aromatase activity with a tritiated water method. Brain aromatase
activity was higher, though not always statistically, for male cave and male and female
cliff swallows. Dichlorodiphenyldichloroethylene (DDE) may play a role in the
increased activity. Female cave swallows in Llano Grande appeared to have a greatly
depressed brain aromatase activity, possibly attributed to past human use of toxaphene.
Testicular and ovarian aromatase activity in cliff and cave swallows from Rio Grande
was higher than in those from Somerville, though not always significantly. DDE,
atrazine, sewage treatment plant contaminants (phthalates, alkylphenols,
ethynylestradiol), metals, or other pollutants could play a role in the increased gonadal
activity. Increased aromatase activity, in association with contaminants, may be easier
to detect in testes of male birds which normally exhibit low levels of estrogen. Siterelated
contaminants may be playing a role in DNA damage and aromatase alterations.
This is the first known study which uses aromatase activity as an endocrine disruptor
indicator in wild birds.
14
Nalapareddy, Padmavathi Devi [Verfasser]. "Role of bid in liver injury following BDL and CCl4-induced liver damage / Padmavathi Devi Nalapareddy". Hannover : Technische Informationsbibliothek und Universitätsbibliothek Hannover, 2010. http://d-nb.info/1004974523/34.
Texto completo
15
Musquiz, Daniel. "Cave and cliff swallows as indicators of exposure and effects of environmental contaminants on birds from the Rio Grande, Texas". Thesis, Texas A&M University, 2003. http://hdl.handle.net/1969.1/1154.
Texto completoResumen
Cave (Petrochelidon fulva) and cliff swallows (Petrochelidon pyrrhonota) were collected along the Rio Grande and evaluated as potential indicators of environmental contamination. The Rio Grande receives toxic substances from agricultural, industrial, municipal, and non-point sources; consequently, high levels of contaminants have been detected in birds, mammals, fishes and sediments. Swallows were obtained from 8 sites between Brownsville and El Paso, as well as from a reference site in Burleson County, 320 miles north of the nearest site of the Rio Grande. Blood samples were analyzed by flow cytometry, a technique that allows the detection of DNA damage in blood and other tissues. Plasma samples were analyzed for thyroid hormones using a radioimmunoassay technique. Organochlorines and trace metal analysis was limited to a few samples. DDE and PCB levels were below levels known to cause reduced hatching, embryo mortality, and deformities, Hg, Pb, and As were below detection, and Se, Ni and Cr concentrations were lower than levels known to cause harm in birds. Neither species showed sex-related differences in chromosome damage. Cave swallows from the Del Rio area had the highest levels of DNA variation, which may be indicative of DNA damage, possibly from PAHs exposure. Previous studies indicate that sediment samples from tributaries near Del Rio have high levels of chromium compared to other sites along the Rio Grande. A significant increase in DNA variation between sampling years was detected in cave swallows from Llano Grande Lake. Wildlife samples collected from Llano Grande Lake have recorded high levels of DDE and PCBs; in addition, this urban/agricultural contaminant sink appears to be affected by PAH exposure. T3 levels were below the detection limit of the radioimmunoassay. There were no gender related differences in T4 levels in cave swallows. Cave swallows sampled from Laredo had significantly higher T4 levels than those from birds at other sites during 1999. It was not possible to determine thyroid hormone disruption in plasma samples. Thyroid hormone and flow cytometry data were useful in establishing baseline data. Areas of concern based on genotoxic data include Llano Grande Lake, Del Rio, and El Paso.
16
Van, Niekerk Mark Harry. "Quantifying crop damage by Grey crowned crane balearica regulorum regulorum and evaluating changes in crane distribution in the North Eastern Cape, South Africa". Thesis, Rhodes University, 2011. http://hdl.handle.net/10962/d1005436.
Texto completoResumen
Complaints of crop damage by cranes on planted maize in the North Eastern Cape, South Africa, have been increasing since the mid-1990‘s, and in some instances severe losses have been reported. Crop damage by the Grey Crowned Crane Balearica regulorum regulorum near the town of Maclear (31º04´S 28º22´E), has been quantified over two growing seasons, and assessed relative to losses caused by foraging Cape Crows Corvus capensis and other feeding damage assumed to be caused by insects. Twelve fields were selected based on previous patterns of crop depredation. Maize seed in seven of the fields was treated with the chemical ‗Gaucho‘ and five fields were planted with untreated maize. In order to determine the source of losses, twenty quadrats (4 m x 4 m) randomly distributed within each field were visited on average every second day, for a period of up to twenty eight days. Results indicate that seed treatments do act as a deterrent to feeding by both cranes and crows, however crane damage is generally insignificant compared to other sources of damage. My study also reviewed past sightings data of the Grey Crowned Crane in an effort to determine if the conversion of former grassland to plantations in this region may have increased foraging activity in maize fields. The data did not allow for clear-cut conclusions regarding changes in distribution or population trends. Conclusions provide direct input into the management of agricultural areas by enabling landowners to take steps to mitigate crop damage. These mitigation measures may either involve the application of seed treatments, or the planting of low risk crops in high risk areas. Future studies should consider the ppossible detrimental effects of chemical seed treatments on crane biology.
17
Jelinek, Anja Maria [Verfasser] y Carsten [Akademischer Betreuer] Culmsee. "A key role for BID-mediated mitochondrial damage in oxidative cell death / Anja Maria Jelinek ; Betreuer: Carsten Culmsee". Marburg : Philipps-Universität Marburg, 2018. http://d-nb.info/1153881500/34.
Texto completo
18
Roset, i. Huguet Ramon. "Study of the regulation and signalling of cdk2-Cyclin o complexes during apoptosis". Doctoral thesis, Universitat Pompeu Fabra, 2008. http://hdl.handle.net/10803/7199.
Texto completoResumen
The aim of this thesis is the characterization of a protein involved in apoptosis. Our group has identified an early step common to different forms of intrinsic apoptosis stimuli. This step requires de novo synthesis of a novel Cyclin, Cyclin O, that upon apoptosis induction in lymphoid cells forms active complexes, primarily with Cdk2. Cyclin O expression precedes glucocorticoid and gamma radiation-induced apoptosis in vivo in mouse thymus and its overexpression induces apoptosis in cultured cells. Knocking down the endogenous expression of Cyclin O by shRNA leads to the inhibition of glucocorticoid and DNA damage-induced apoptosis while leaving CD95 death receptor mediated apoptosis intact. This data demonstrates that apoptosis induction in lymphoid cells is one of the physiological roles of Cyclin O and it does not act by perturbing a normal cellular process such as the cell cycle. In addition we have identified c-Myb a substrate of Cdk2-Cyclin O complexes and we show that c-Myb is downregulated during apoptosis of lymphoid cells.L'objectiu d'aquesta tesi és la caracterització d'una proteïna involucrada en l'apoptosi. El nostre grup ha identificat un pas primerenc comú en diversos estímuls apoptòtics de la ruta intrínseca. Aquest pas requereix la síntesi de novo d'una nova Ciclina, Ciclina O, que quan s'indueix apoptosi en cèl·lules limfoides forma complexes actius majoritàriament amb Cdk2. L'expressió de la Ciclina O és prèvia a l'apoptosi induïda per glucocorticoids i radiació gamma i la seva sobreexpressió indueix apoptosi en cultius cel·lulars. La baixada dels nivells d'expressió de la Ciclina O endògena amb shRNA provoca una inhibició de l'apoptosi induïda per glucocorticoids o agents que danyen el DNA, mentre que l'apoptosi mediada pel receptor CD95 es manté intacta. Aquests resultats demostren que la inducció d'apoptosi en cèl·lules limfoides és una de les funcions fisiològiques de la Ciclina O i que no es deu a una pertorbació de processos cel·lulars normals com ara el cicle cel·lular. A més a més, hem identificat c-Myb com a substrat dels complexes Cdk2-Ciclina O i demostrem que els nivells de c-Myb baixen durant l'apoptosis de cèl·lules limfoides.
19
Fang, Yi-Ching y 方薏菁. "Bird Communities and Bird Damage". Thesis, 2007. http://ndltd.ncl.edu.tw/handle/21849976870182823247.
Texto completoResumen
碩士國立嘉義大學
生物資源學系研究所
95
Rice is the most important crop with widest cultivated area in Taiwan. The rice fields in Chianan Plain often mixed with some artificial forests, non-tillage grasslands and other crops areas, etc. To understand whether there are any differences in the bird compositions between the rice field and edge, we set up 7 sites in the rice field near by different edge types, and 7 sites in the edge, including 3 woodland sites and 4 mixed sites with other crops and grasses. We investigated bird species and abundances with counting flocks and point count methods. The results show that there were significant differences in bird compositions between the rice field and the margin. The bird species richness and abundance of edge were higher than those in the rice field. It shows that edge could provide habitats for more different kinds of farmland birds. We also studied the activity patterns and the distribution of crop damaging species, including tree sparrow (Passer montanus), scaly-breasted munia (Lonchura punctulata), red turtle dove (Streptopelia tranquebarica) and spooted dove (Streptopelia chinensis) in the study sites. The densities of the four pest bird species in the edge were higher than those in the rice field except scaly-breasted munia, and the bird densities in the rice field had no difference among different edge types. According to the investigation in the maturing period of rice, we found that sparrows (tree sparrow and scaly-breasted munia) had higher activity frequency in the early morning and evening and doves (red turtle dove and spooted dove) had higher activity frequency around noon. The population sizes of sparrows were higher in the early part of maturing period than those in the late period, but the population sizes of doves show no significant difference. In addition, we evaluated the effects of cotton thread, plastic tape, flag, reflecting tape and hawk eyeball on controlling the bird pests by counting the number of bird and estimating the loss of rice. The results of the two methods were not the same. It maybe can increase the expelling effects, if we use these methods in the highest population sizes of pest birds in the different part of maturing period and different time of a day.
20
Lee, Charles D. "Innovative techniques to control bird damage at feedlots". 1988. http://hdl.handle.net/2097/22299.
Texto completo
21
Jiang, Fu-Jen y 江富仁. "Effect of Bag Thickness and Color on the Control of Bird Damage and the Quality of Grape(Vitis vinifera ''Kyoho '') Fruits". Thesis, 2017. http://ndltd.ncl.edu.tw/handle/05563980601760845578.
Texto completoResumen
碩士國立中興大學
園藝學系所
105
Summary In Taiwan,Vitis vinifera ''Kyoho'',gained the popularity among Taiwanese for their rich fruit color, however, they are vulnerable when bird damage occur. People love grapes and birds as well. To solve the costly problem, we tried to improve the bags used for grape bagging to make them capable of preventing bird damage. We have tried four kinds of bags in the experiment; they are green double-layered bags, green single-layered bags, white double-layered bags and white single-layered bags. White single-layered bags are common bags used for grape bagging in Taiwan.Three trials were conducted in total, the first and the third were conducted in winter; the second was conducted in summer. The experiment included the effect of bagging to prevent bird damage and its concerned effect on fruit quality. When summer grapes were harvested, grapes bagged by green double-layered bags, were still green, and the quality were much lower than white double-bagged grapes. On the other hand, the grapes bagged by white double-layered bags seems almost the same to white single-layered ones. However, if we postponed harvest time of the green double-layered ones, we can observed not only anthocyanin content increased significantly from 0.31 μmol / g to 1.81 μmol / g and the soluble tannin content decreased from 2143 ppm to 641 ppm, but also an increase in soluble solids content and the decrease in the titratable acid content. Unfortunately, the quality of green double-layered grapes is still slightly worse than others. In the experiment of effect of preventing bird damage green double-layered bags shows the best effect, followed by white double bagging, but the double-layered white bagging ones are just slightly better than the normal bags. According to the test results, the green bags are better than white ones; and double-layered are better than the single-layered ones when it comes to the effect of prevention bird damage. But we recommend using white double-layered bags in summer, because the temperature is high, if we use green bags will make the temperature in bags higher and effect fruit quality negatively, green bags are more suitable for winter harvest; on the other hand, white double-layered bags are recommended to prevent bird damage and only have slightly influence on fruit quality.
22
Saheed, Sefiu Adekilekun, Christiaan Edward Johannes Botha, Lin Liu y Lisbeth Jonsson. "Comparison of structural damage caused by Russian wheat aphid (Diuraphis noxia Mordvilko) and Bird cherry-oat aphid (Rhopalosiphum padi L.) in a susceptible barley cultivar, Hordeum vulgare L. cv Clipper". 2007. http://hdl.handle.net/10962/d1005981.
Texto completoResumen
The Russian wheat aphid (RWA, (Diuraphis noxia Mordvilko) and the Bird cherry-oat aphid (BCA, (Rhopalosiphum padi L.) cause severe damage to grain crops, including barley. An investigation of the effects of these aphids on a susceptible cultivar revealed that BCA-infested barley plants remained healthy-looking for two weeks after feeding commenced. In contrast, signs of stress and damage, including chlorosis and leaf necrosis were evident in RWA infested plants. Our study suggests that damage to the vascular tissue due to sustained feeding by BCA, was not as extensive as that caused by RWA. In addition, there is a marked difference in the salivary secretion pattern within xylem elements punctured by aphids tapping the xylem for water. RWA deposit electron-dense, amorphous to smooth saliva, which completely encases the inner walls of affected elements, and saliva encases pit membranes between xylem elements, and between xylem vessels and xylem parenchyma. Xylem tapped by BCA, contained more granular saliva, which apparently does not occlude vessel wall apertures or the pit membranes to the same extent as was observed with RWA. Damage to phloem tissue, including phloem parenchyma elements, sieve tube-companion cell (CC-ST) complexes as well as thick-walled sieve tubes, was extensive. Plasmodesmata between phloem parenchyma elements as well as pore-plasmodesmata between the CC-ST were occluded by callose. We conclude that severe, perhaps permanent damage to conducting elements in RWA infested leaves may be responsible for the detrimental chlorosis and necrosis symptoms. These symptoms are absent in BCA-infested plants.
23
Hoogduijn, Martin J., Eduardo Cemeli, K. Ross, Diana Anderson, Anthony J. Thody y John M. Wood. "Melanin protects melanocytes and keratinocytes against H2O2-induced DNA strand breaks through its ability to bind Ca2+". 2004. http://hdl.handle.net/10454/2311.
Texto completoResumen
NOReactive oxygen species (ROS) such as hydrogen peroxide (H2O2) are produced in the skin under the influence of UV radiation. These compounds are highly reactive and can induce DNA lesions in epidermal cells. Melanin is considered to protect human skin against DNA damage by absorbing UV radiation. We have investigated whether melanin can, in addition, offer protection against the effects of H2O2 in human melanocytes and HaCaT keratinocytes. In the present study, it was shown that 40 and 100 μM H2O2 increased the number of DNA strand breaks as measured using the comet assay, in melanocytes of Caucasian origin. In melanocytes of the same origin in which melanin levels were increased by culturing in presence of 10 mM NH4Cl and elevated l-tyrosine, H2O2-induced DNA damage was reduced compared to that in control melanocytes. Similarly, HaCaT cells that were loaded with melanin were better protected against H2O2-induced DNA strand breaks than control HaCaT cells. These protective effects of melanin were mimicked by the intracellular Ca2+-chelator BAPTA. Thus, BAPTA reduced the level of H2O2-induced DNA strand breaks in melanocytes. Like BAPTA, melanin is known to be a potent chelator of Ca2+ and this was confirmed in the present study. It was shown that melanin levels in melanocytic cells correlated directly with intracellular Ca2+ binding capacity and, in addition, correlated inversely with H2O2-induced increases in intracellular Ca2+. Our results show that melanin may have an important role in regulating intracellular Ca2+ homeostasis and it is suggested that melanin protects against H2O2-induced DNA strand breaks in both melanocytes and keratinocytes and through its ability to bind Ca2+.
24
Chen, Po-An y 陳柏安. "The study of habitat utilization for granivorous birds and their impacts on the rice grain damage in a natural farming field at Wufeng District in Taichung City". Thesis, 2018. http://ndltd.ncl.edu.tw/handle/67468u.
Texto completoResumen
碩士國立中興大學
生命科學系所
106
Food safety issue has been a great concern recently. Therefore, non-toxic farming practices have been valued in agricultural fields. These types of farming enrich the feeding habitats for birds. However, it also brings some damage cost for the growers. In order to study the impact of the natural farming practice on the feeding habitats of the birds, we monitored the population size of bird species, community structure and percentage of rice spikes damage at a natural farming rice field at Wufeng District in Taichung City. The results indicated that granivorous birds such as tree sparrow (Passer montanus) and scaly-breasted munia (Lonchura punctulata) used rice fields as foraging habitats and fed on the raw grain out of the rice plants. Although we found the exotic bird species such as white-vented myna (Acridotheres javanicus) and common myna (A. tristis) in the rice fields, there is no evidence to show they consume rice grain at the study site. We found more birds activities in the first rice cropping season than the second rice cropping season. The mean number of granivorous birds and percentage of rice spikes damage at the first rice cropping season are 3.61 ± 0.23 and 25.01％ ± 0.99％, which were significantly higher than those of the second rice cropping season (0.84 ± 0.21 and 6.51％ ± 1.02％ respectively). The mean number of granivorous birds at milky stage and yellow-ripe stage were 3.99 ± 0.35 and 4.79 ± 0.33, which were significantly higher than the population mean of the reproductive growth stage (1.47 ± 0.31). In addition, the percentage of rice spikes damage had significantly increased during the yellow-ripe stage. We also found the different bird population distribution and percentage of rice grain lost by birds with various landscape types and levee weed management patterns in the rice plantation area. The granivorous birds preferred the feeding sites closed to buildings and trees with a mean population size of 4.19 ± 0.38, which is significantly higher than the mean population sizes of the sampling sites from the center of the rice fields (3.70 ± 0.25) and the sites closed to aqueducts (2.93 ± 0.33). The granivorous birds also preferred the habitat sites with cement levee than the sites with soil levee and having long weeds. We found birds consume more rice grain from the edge areas such as the sites closed to buildings, trees and aqueducts than the central area of the rice plantation. The soil levee with weed control also attracted more birds to consume rice grain than the soil levee without weed control. This study concludes that it is critical to have a proper landscape management such as levee weed control and bird prevention practices in the first rice cropping season to lower the risk of rice grain loss in the natural farming practice for rice plantation in Taichung.