Academic literature on the topic 'Other chemical sciences not elsewhere classified'

BackgroundThe diet of the koala (Phascolarctos cinereus) is comprised almost exclusively of foliage from the genusEucalyptus(family Myrtaceae).Eucalyptusproduces a wide variety of potentially toxic plant secondary metabolites which have evolved as chemical defences against herbivory. The koala is classified as an obligate dietary specialist, and although dietary specialisation is rare in mammalian herbivores, it has been found elsewhere to promote a highly-conserved but low-diversity gut microbiome. The gut microbes of dietary specialists have been found sometimes to enhance tolerance of dietary PSMs, facilitating competition-free access to food. Although the koala and its gut microbes have evolved together to utilise a low nutrient, potentially toxic diet, their gut microbiome has not previously been assessed in conjunction with diet quality. Thus, linking the two may provide new insights in to the ability of the koala to extract nutrients and detoxify their potentially toxic diet.MethodThe 16S rRNA gene was used to characterise the composition and diversity of faecal bacterial communities from a wild koala population (n = 32) comprising individuals that predominately eat either one of two different food species, one the strongly preferred and relatively nutritious speciesEucalyptus viminalis, the other comprising the less preferred and less digestible speciesEucalyptus obliqua.ResultsAlpha diversity indices indicated consistently and significantly lower diversity and richness in koalas eatingE. viminalis. Assessment of beta diversity using both weighted and unweighted UniFrac matrices indicated that diet was a strong driver of both microbial community structure, and of microbial presence/absence across the combined koala population and when assessed independently. Further, principal coordinates analysis based on both the weighted and unweighted UniFrac matrices for the combined and separated populations, also revealed a separation linked to diet. During our analysis of the OTU tables we also detected a strong association between microbial community composition and host diet. We found that the phyla Bacteroidetes and Firmicutes were co-dominant in all faecal microbiomes, with Cyanobacteria also co-dominant in some individuals; however, theE. viminalisdiet produced communities dominated by the generaParabacteroidesand/orBacteroides, whereas theE. obliqua-associated diets were dominated by unidentified genera from the family Ruminococcaceae.DiscussionWe show that diet differences, even those caused by differential consumption of the foliage of two species from the same plant genus, can profoundly affect the gut microbiome of a specialist folivorous mammal, even amongst individuals in the same population. We identify key microbiota associated with each diet type and predict functions within the microbial community based on 80 previously identifiedParabacteroidesand Ruminococcaceae genomes.

This article offers an approach through administrative and cultural history to the problems associated with gathering and processing data for the Spanish national census of 1920, and by implication for earlier Spanish censuses. It focuses on the Basque province of Guipúzcoa, making use of correspondence between the central statistical office in Madrid, the provincial jefe de estadística and the localities, and of reports on three problematic towns within the province. The issues that emerge regarding ‘undercounting’, the definition of administrative boundaries and the classification of demographic characteristics are set in the wider context of census-taking practices and problems elsewhere in Spain and in other cultures.

AbstractObjectivesTo estimate the dietary intakes of heterocyclic amines (HCAs), to examine the intakes in relation to socio-economics, lifestyle and other dietary factors and to compare the classification of subjects by intake of HCA versus intake of meat and fish.DesignCross-sectional analysis within the Malmö Diet and Cancer (MDC) cohort. Data were obtained from a modified diet history, a structured questionnaire on socio-economics and lifestyle, anthropometric measurements and chemical analysis of HCAs. HCA intake was cross-classified against meat and fish intake. The likelihood of being a high consumer of HCAs was estimated by logistic regression analysis. Dietary intakes were examined across quintiles of HCA intake using analysis of variance.SettingBaseline examinations conducted in 1991–1994 in Malmö, Sweden.SubjectsA sub-sample of 8599 women and 6575 men of the MDC cohort.ResultsThe mean daily HCA intake was 583 ng for women and 821 ng for men. Subjects were ranked differently with respect to HCA intake compared with intake of fried and baked meat and fish (κ = 0.13). High HCA intake was significantly associated with lower age, overweight, sedentary lifestyle and smoking. Intakes of dietary fibre, fruits and fermented milk products were negatively associated with HCA intake, while intakes of selenium, vegetables, potatoes, alcohol (among men) and non-milk-based margarines (among women) were positively associated with HCA intake.ConclusionsThe estimated daily HCA intake of 690 ng is similar to values obtained elsewhere. The present study suggests that lifestyle factors (e.g. smoking, physical activity, fruit and vegetable intakes, and types of milk products and margarines) may confound associations between HCA intake and disease. The poor correlation between HCA intake and intakes of fried meat and fish facilitates an isolation of the health effects of HCAs.

This study was carried out to ascertain the characterization and classification of soils along river Donga in Donga local government area of Taraba State. Three profile pits were dug on the flat terrain for the physio-chemical properties of the soils. The pits were described and samples were collected for routine laboratory analysis for the selected physio-chemicals properties. Data collected were analyzed statistically using analysis of variance (ANOVA) The result of the laboratory analysis of the physical and chemical properties indicated that particle size distribution of sand particle dominated other fraction of fine earth materials. This can be attributed to the parent materials that gave rise to the soils.The pH (H2O) was slightly acidic in reaction in all the pedons studied (6.44, 5.82 and 5.67). The organic carbon content ranges from very low to low compared to the maximum level (5%) for tropical soils. Available phosphorus obtained exceeded the critical limits of 8.0 to >18mg/kg, which indicates that the available phosphorus were high. The exchangeable bases (Ca, Mg, K & Na) as indicated in the table 3 that Ca, Mg, K & Na were low in all the pedons studied. The results obtained from analyzed profile samples showed that percentage (%) base saturation values for all the pedons were high. The Correlation was done to determine non-significant and significant values among soil physio-chemical properties studied at 5% and 1% probability level. In addition, after the profile description and examination of the soil properties of the study area, the soils were classified using USDA soil taxonomy (2014). Pedons 1 and 2 are classified into the order of Alfisols and sub-group of Typical Haplustalf while pedon 3 is also classified into Alfisols but sub-group of Arenickandiustals (Hypereuticlixisels).

Although well over 1000 journal articles, conference papers, books, technical notes and theses have been written on the subject of information technology (IT) evaluation, only a relatively small subset of this literature has been concerned with the core issues of what precisely is meant by the term ‘value’ and with the process of making (specifically) IT investment decisions. All too often, the problem and highly complex issue of value is either simplified, ignored or assumed away. Instead the focus of much of the research to date has been on evaluation methodologies and, within this literature, there are different strands of thought which can be classified as partisan, composite and meta approaches to evaluation. Research shows that a small number of partisan techniques are used by most decision makers with a minority using a single technique and a majority using a mixture of such techniques of whom a substantial minority use a formal composite approach. It is argued that, in mapping the set of evaluation methodologies on to what is termed the investment opportunity space, that there is a limit to what can be achieved by formal rational evaluation methods. This limit becomes evident when decision makers fall back on ‘gut feel’ and other non-formal/rigorous ways of making decisions. It is suggested that an understanding of these more complex processes and decision making, in IT as elsewhere, needs tools drawn from philosophy and psychology.

Winter wheat is one of the major cereal crops in China. The spatial distribution of winter wheat planting areas is closely related to food security; however, mapping winter wheat with time-series finer spatial resolution satellite images across large areas is challenging. This paper explores the potential of combining temporally aggregated Landsat-8 OLI and Sentinel-2 MSI data available via the Google Earth Engine (GEE) platform for mapping winter wheat in Shandong Province, China. First, six phenological median composites of Landsat-8 OLI and Sentinel-2 MSI reflectance measures were generated by a temporal aggregation technique according to the winter wheat phenological calendar, which covered seedling, tillering, over-wintering, reviving, jointing-heading and maturing phases, respectively. Then, Random Forest (RF) classifier was used to classify multi-temporal composites but also mono-temporal winter wheat development phases and mono-sensor data. The results showed that winter wheat could be classified with an overall accuracy of 93.4% and F1 measure (the harmonic mean of producer’s and user’s accuracy) of 0.97 with temporally aggregated Landsat-8 and Sentinel-2 data were combined. As our results also revealed, it was always good to classify multi-temporal images compared to mono-temporal imagery (the overall accuracy dropped from 93.4% to as low as 76.4%). It was also good to classify Landsat-8 OLI and Sentinel-2 MSI imagery combined instead of classifying them individually. The analysis showed among the mono-temporal winter wheat development phases that the maturing phase’s and reviving phase’s data were more important than the data for other mono-temporal winter wheat development phases. In sum, this study confirmed the importance of using temporally aggregated Landsat-8 OLI and Sentinel-2 MSI data combined and identified key winter wheat development phases for accurate winter wheat classification. These results can be useful to benefit on freely available optical satellite data (Landsat-8 OLI and Sentinel-2 MSI) and prioritize key winter wheat development phases for accurate mapping winter wheat planting areas across China and elsewhere.

Nickel laterite deposits developed on ultramafic rocks have traditionally been a significant source of Ni and Co and recently of Sc. Although the Loma de Hierro deposit (Venezuela) has been in operation for more than 50 years, it lacks detailed studies on the mineralogical and geochemical composition of the lateritic profile. In this study, we present a geochemical and mineral description of the main carrier phases of Ni and Co in a complete profile of the deposit. The selected weathering profile has been developed from a partially serpentinized harzburgitic protolith and has a well-developed saprolitic horizon covered by a thin limonitic horizon. The geochemical signature of the profile is characterized by a significant Mg and Si decrease towards the top of the saprolite, with a clearly visible Mg discontinuity. The main Ni-bearing minerals are secondary serpentine (1–4 wt.% NiO) and kerolite-pimelite-dominated garnierite mixtures with serpentine (18–22 wt.% NiO). Limonite is rich in goethite (0–1.85 wt. % NiO), gibbsite, and Mn-oxy-hydroxides. The latter have intermediate compositions between lithiophorite and asbolane (2–13 wt.% CoO). The highest Sc grades (40–68 ppm) were observed in the limonite with amounts positively correlated with Fe content. Rare earth elements are mainly concentrated in the upper part of the saprolite horizon (60–80 ppm), while they have a lower content in the limonite (7–45 ppm). In this horizon, rare earth elements are clearly associated with Fe, indicating adsorption and/or coprecipitation. This association was not observed in the saprolite, suggesting that other minerals (e.g., clay minerals) are controlling their concentration; more information is needed to identify the rare earth element-bearing minerals. The lateritic profile of Loma de Hierro can be classified as representative of hydrated Mg silicate deposits, and was formed in a context of continuous tectonic uplift and a low water table conditions favoring the development of a thick saprolitic horizon and the precipitation of kerolite-pimelite-dominated garnierites.

Signet-ring cell carcinoma of the prostate gland (SRCCP) an uncommon and aggressive malignant tumour of the prostate gland which is characterized by histopathology examination features of compression of the nucleus into the form of a crescent by a large cytoplasmic vacuole. SRCCPs that have so far been reported have been either (a) primary tumours, metastatic tumours with the primary tumour elsewhere with the gastro-intestinal tract being the site of the primary tumour but the primary tumour could originate elsewhere, and additionally some reported SRCCPs have been classified as carcinoma of unknown primary. SRCCP could be a pure tumour or a tumour that is contemporaneously associated with other types of tumour including various variants of adenocarcinoma. SRCCP can manifest in various ways including: Incidental finding following prostatectomy that has been undertaken for a presumed benign prostatic hyperplasia, lower urinary tract symptoms, visible and non-visible haematuria, raised levels of serum PSA but some SRCCPs have been diagnosed with normal / low levels of serum PSA, there may be a history of dyspepsia in cases of metastatic signet-ring cell carcinoma in association with contemporaneous primary signet-ring cell carcinoma of the stomach or there may be a past history of surgical treatment for signet-ring cell carcinoma of the gastrointestinal tract, or bleeding from the gastrointestinal tract in cases of upper gastrointestinal tract and rectal bleeding as well as change in bowel habit for primary tumours of the anorectal region, retention of urine, and rarely a rectal mass in the case of SRCCP with an anorectal primary tumour. In order to exclude a primary signet ring cell carcinoma elsewhere, a detailed past medical history is required as well as radiology imaging including contrast – enhanced computed tomography (CECT) scan and contrast-enhanced magnetic resonance imaging (CEMRI) scan as well as upper gastrointestinal endoscopy and colonoscopy to exclude a primary lesion within the gastrointestinal tract. Diagnosis of SRCCP requires utilization of the histopathology and immunohistochemistry examination features of prostate biopsy, prostatic chips obtained from trans-urethral resection of prostate specimen or radical prostatectomy specimen. SRCCPs upon immunohistochemistry staining studies tend to show tumour that tend to exhibit positive staining for the following tumour markers as follows: PSA – positive staining for PSA has been variable in some studies, AE1/AE3, CAM 5.2, Ki-67 with a mean of 8%, PAS-diastase, Mucicarmine (50%), Alcian blue (60%), Alpha-methyl-acyl coenzyme A racemase (P504S), and Cytokeratin 5/6. SRCCPs also tend to exhibit negative staining for: Bcl2 (rare positive), and CEA (80%). Traditionally the treatment of Primary Signet-Ring Cell Carcinoma of the Prostate Gland has tended to be similar to the treatment of the traditional adenocarcinoma of the prostate gland which does include: hormonal treatment, radiotherapy, and surgery. Nevertheless, considering that primary SRCCPs and metastatic SRCCPs that have been reported in the literature have generally tended to be associated with an aggressive biological behaviour, even though there is no consensus opinion on the treatment of the disease it would be strongly recommended that these tumours that tend to be associated with rapid progress of the disease and poor survival there is an urgent need to treat all these tumours with aggressive surgery including radical prostatectomy plus adjuvant therapies including: radical radiotherapy, combination chemotherapy, selective prostatic angiography and super-selective embolization of the artery feeding the tumour including intra-arterial infusion of chemotherapy agents directly to the tumour, radiofrequency ablation of the tumour as well as irreversible electroporation of the tumour which should form part of a global multicentre study of various treatment options. With regard to metastatic signet-ring cell carcinomas of the prostate gland with a contemporaneous primary tumour elsewhere the primary tumour should also be treated by radical and complete excision of the primary tumour plus radical surgery and aggressive adjuvant therapy. Considering that SRCCPs have tendered not to respond well to available chemotherapy agents, there is need for urologists, oncologists, and pharmacotherapy research workers to identify new chemotherapy medicaments that would more effectively and safely destroy signet-ring cell tumours in order to improve upon the prognosis.

Lamprophyres are minor intrusions with atypical sources and crystallisation sequences. Among lamprophyres, the calc-alkaline (CAL) type on which this study focuses has the least distinctive chemistry and petrology. CAL correspond to small-volume mafic intrusions characterised by the early fractionation of amphibole and (or) biotite. In the Archean Superior Province (Canada), CAL are temporally and spatially related to several gold deposits and may thus be relevant to mineral exploration. This study focuses on several altered and metamorphosed intrusions of the Abitibi and La Grande subprovinces, which were designated lamprophyres based on field observations. Several criteria established from thin sections, whole-rock chemical analyses, and SEM data are applied to the studied rocks to distinguish CAL from other types of magma. As a result, only one of the studied dykes has the morphology, chemistry, and petrology typical of CAL, while the other intrusions are either too altered to be classified or may correspond to metamorphosed and metasomatized gabbro and diorite. This study shows that thin sections and whole-rock chemical analyses are not always sufficient to unequivocally classify an altered and metamorphosed intrusion as a CAL. Also, intrusions as challenging to recognise as CAL should not be used by exploration geologists to prospect for orogenic gold deposits. Much remains to be done to document the distribution and volume represented by lamprophyres in Archean greenstone belts and to confirm their spatial dependence with gold deposits.

Melagranites (colour index > 20, with biotite > garnet > cordierite) constitute ∼0.1% of the area of the 7300 km2 peraluminous South Mountain Batholith (SMB), Nova Scotia. The melagranites occur as small bodies showing sharp to gradational contacts against the Meguma Supergroup country rocks, and coeval mingling contacts against other facies of the batholith. They also occur as elliptical or blocky metre-scale enclaves elsewhere in the SMB. Characteristic petrological features of the melagranites include high modal abundances of sulphide minerals, strongly reacted metasedimentary xenoliths, mafic mineral-rich clots, apparent porphyritic textures with highly variable proportions of alkali feldspar megacrysts, and allotriomorphic-granular textures. Chemically and isotopically, melagranite rocks have wide compositional variations. In most major-element, trace-element, and isotopic variation diagrams, the melagranites lie on mixing lines between the more abundant granodioritic and monzogranitic phases of the SMB and the metasedimentary rocks of the Meguma Supergroup. Textural evidence, supported by published experimental evidence, suggests that the garnet, cordierite, and K-feldspar are peritectic phases resulting from incongruent melting of the pelitic fraction of the Meguma metasedimentary country rocks. The field relations, mineral assemblages, textural features, and chemical compositions of the melagranites all point to the melagranites as highly concentrated contamination zones in the SMB, representing small portions of the batholith that have failed either to complete the assimilation process or to disperse their contaminants widely in the batholith. As such, these rarely preserved melagranites provide petrogenetic information disproportionate in importance to their abundance in the batholith, especially about the significant role of contamination and assimilation in determining the physical and chemical composition of the SMB. Without preservation of melagranites in the SMB, and by extension all granite bodies, the petrogenetic importance of contamination is difficult to assess, even with trace-element and isotopic data. The present study shows that high quality field observations are as important in deciphering petrogenesis as chemical data.

The behaviour of waste biomass materials, specifically bagasse* and sawdust, in deep fluidized beds was investigated. The bagasse used was dry (less than 1% moisture by mass). Sawdust was from mixed eucalyptus hardwoods with moisture contents up to 25% by mass. A series of cold flow visualisation tests were completed in a bed of 190mm diameter using graded river sand of surface mean particle diameters of 180 and 490 microns. Bagasse was added to the bed in various quantities and the ingestion and mixing phenomena observed. The influence of distributor design, cones, and draft tubes on mixing rates were investigated for use in the combustor design. Combustion Tests using Sawdust and Bagasse were completed in a Combustor of 489mm diameter with graded river sands of surface mean particle diameters of 300,490 and 530 microns. Various configurations were tested including a shallow bed of depth 130mm, deep beds of depths up to 460mm, a Reverse Circulation Bed, and Modified Spouted Beds of depths up to 740mm. Fuel feeding systems included above bed chutes, an ingestor tube, a direct bed wall screw feeder, and a pressurised screw feeder fitted to the air supply of a Modified Spouted Bed. Bagasse was not successfully fed through the screw feeder systems used. Sawdust, which has similar fluidized bed combustion characteristics to bagasse, was used in screw feeders to indicate the possible results that could be obtained from bagasse using below bed feed systems. Configurations utilising direct below bed surface screw feed, Ingestor tube feed, and pressurised screw feed to the fluidizing air were all successful in increasing the percentage of combustion occurring below the bed surface. The best results were obtained from pre-mixed air and fuel particles entering the modified spouted bed giving combustion efficiencies of up to 60% comparable to coal. Higher efficiencies would be possible with further optimisation of the design. The results of the investigation open several avenues of development including partial gasification/combustion systems and further development of the ingestor tube, reverse circulation bed and modified spouted bed concepts. The problems encountered with the combustion of lightweight, particulate biomass fuels are now reduced to finding practical methods of fuel feeding and rate control. *Bagasse is the cellulose residue from sugar cane stalks which remains after crushing.It is particulate, fibrous, tangled and irregular in size, length and aspect ratio.

New synthetic methods are explored for the synthesis of protoberberines using carbanionimine (CAI) cycloaddition, aza Diels-Alder (DA) cycloaddition.. Protoberberine alkaloids are widely distributed in numerous plant families, and commonly found as active components in many folklore medicines in Asia, Europe and North America. Due to their broad diversity of biological activities, there are great efforts about chemical, biogenetic and enzymatic synthesis, transformation, pharmacology, and culture development studies of these alkaloids. In this thesis, new synthetic methods are explored for the synthesis of protoberberines using the following approaches a) carbanionimine (CAI) cycloaddition, b) aza Diels-Alder (DA) cycloaddition. The structure elucidation of products using various analytical techniques, such as IR, UV-vis., MS, NMR and X-ray, are broadly discussed. Detailed stereostructure and conformation analysis have been studied using various one and two dimensional NMR techniques, which show great advantage for structure analysis in the liquid state, and give the consistent conclusion as the solid state structure as determined by the single crystal X-ray diffraction method. The carbanion-cyclic imine approach has been most successful in the synthesis of protoberberines, which contain a four-ring system (ABCD). Cycloaddition of 3,4-dihydroisoquinoline (DHIQ, eg A-I) with phthalide anion (eg A-2) gives stereo and regia selective 13-hydroxy protoberberines (eg A-3) with single diastereomers observed and isolated, which are transformed to various functionalised derivatives. The novel reaction of 3-methoxyphthalide anion (A-4) with DHIQ, where a 2+1 adduct (A-6) is formed, is broadly studied. The mechanisms are studied in details and highly suggestive via tandem nucleophilic condensation of the anion, in which the 8,13-dioxo intermediate (eg A-5) plays an important role. The geometry change due to the replace of angular 13a-H with methyl group accounts for the different facial selectivity of 13-keto to nucleophiles in A-5a A-5b. These are supported by theoretical AMl calculation and Surface Probe Analysis on model compounds (A-8). The phthalide anion-acyclic imine approach has been used to provide open chain products (eg A-10 and A-11). NMR and AMl calculation prove trans stereochemistry of major isomers (eg A-10). The conclusion is in contrast to previous assignments by MacLean, Cushman, and Prager on similar compounds. The direct asymmetric synthesis is also explored by using a chiral o-toluamide anion (eg A-12) instead of a phthalide counterpart. A series of chiral amine auxiliary agents have been studied and the tertiary o-toluamide with a bulky cyclohexyl group in addition to the chiral substituent on the amide nitrogen atom (A-12) gives the highest enantioselectivity (>96% ee). This approach established a new, fast entry to both enantiomers of protoberberines and exhibits predictable regiochemistry. This is an obvious advantage in all anion-imine cycloaddition reactions in our study and others. DA methodology is also studied, however only the reaction between DHIQ (AB synthon) and phthalazine (A-14, CD synthon) works. This reaction is the first example of aza DA reaction with phthalazine as an aza diene with an aza dienophile. The other AB+CD approaches with DHIQ (AB) as dienophile allowed to react with different dienes (CD), such as isobenzofuran and cyclopentadienone, do not give any adducts under thermal, Lewis acid catalyst or high pressure conditions. While the first step of an AB+C+D approach which involves sequential DA reaction of DHIQ with s-tetrazine (A-16) was successful, the second step involving benzyne or cyclic enamine cycloaddition failed.

Deals with the preparation, characterisation and testing of a series of new and improved synthetic anion exchange resins for selective absorption of the precious metals gold and silver, over the base metals, iron, copper, cobalt, zinc, nickel and aluminium, from an industrial leach solution.. The major method employed by industry, over the last thirty years, to abstract gold from low grade ore or tailings has been cyanide leaching followed by activated carbon concentration. The inherent problems with carbon prompted investigations into alternative methods for the concentration and abstraction of the metal cyano complexes. Ion exchange resins were employed for this purpose due to their versatility towards derivatisation and inertness to chemical and physical attack. The aims of this study were three-fold. The first aim was to design, synthesise and characterise a series of precious metal selective, strong and mixed base, anion exchange resins, where the cationic active site of each is sterically hindered to the approach of the base metal complexes. This aim also included development of the synthetic procedure to yield a resin with the highest degree of substitution possible. The second aim involved the synthesis of each resin on a variety of solid supports, from Merrifield (gel) type resins with different percentage crosslinking to highly crosslinked macroreticular (macroporous) matrices, and comparison of the degree of substitution, precious metal selectivity, equilibrium loading and loading rate achieved with each. This would then allow the identification and use of the most suitable resin base for this study. The final objective of this research involved an investigation into the performance of each resin employing both synthetic and industrial metal cyanide solutions. These investigations were performed under varying chemical and physical conditions (pH, temperature and concentration, etc.) and various kinetic models applied to each resin to mimic its loading characteristics. The selectivity and loading properties of the prepared resins were compared to those of commercial anion exchange resins, industrial activated carbon and other specific gold selective resins. Twenty-four resins were prepared by attaching tertiary amines to blank, chloromethylated poly-styrene/divinylbenzene copolymer resin matrices via seven day reactions in DMF at temperatures of 110°C, thus forming the strong base, quaternary ammonium anion exchanging active site. If required, the resins were then further functionalised to form the respective gold selective species. The degrees of substitution for the novel resins ranged from 0.2 meq/g to 2.5 meq/g depending upon the nature of the starting amine. As some resins are mixed base anion exchange, having one strong base site and one or more (up to four) weak/moderate base sites, gold loadings were obtained in the range 40 000 g Au/ton resin to 1 110 000 g Au/ton resin, or 4 % Au w/w to 110 % Au w/w. No obvious differences in substitution were noted between the different resin matrices trialed. The structure of these function-alised groups on the synthesised resins were characterised by microanalysis, difference infra-red and solid state nuclear magnetic resonance spectroscopy, atomic absorption spectrophotometry, and by comparison with model compounds. Similarities between the NMR spectral properties of the resins and model compounds as well as differences in these properties between the unattached amines and the resins were sought and inferences made as to the success of either the attachment or derivatisation reactions. Microanalysis and anion exchange were also employed to confirm the existence of each functionality and the type of novel resin formed. All the resins prepared show good to excellent selectivity for the precious metal cyano complexes, with four - NOTREN, TIPA, TIPAAPS and TEA-BE resins - displaying extra-ordinary discrimination at all pH values. The pH of the solution was observed to have no effect on the loading of strong base resins, however the equilibrium loading on the mixed base resins was limited by the acidity of the solution. Variation in solution temperature results in an almost linear increase in initial loading rate, indicating a first order process, with an average rate constant of 2 x 10-³sec-¹and activation energy of 55 kJ/mol. At 30 C the reactions were complete in about six hours, while at 80 C the resins were fully loaded in approximately 45 minutes. An increase in temperature also resulted in a linear decrease in equilibrium loading, indicating an exothermic process, with an average Hextraction of - 35 kJ/mol. Change in ionic strength of the solution resulted in a decrease in the final loading due to increased competition for the active site. Variation of resin matrix had little effect on the gold selectivity or loading of the respective resin. Each of the resins tested with the metal cyanide solutions (both synthetic and industrial) could be easily regenerated to their full capacity. The thiocyanate and thiourea elution procedures proved to be the most efficient for recovery of the precious metals with these selective resins. Rate constants of approximately 5 x 10-³sec-¹(first order process) for the thiourea method and 1.55 L/mol/sec (second order process) for the thiocyanate method were measured. The resins were recycled many times through loading, elution and regeneration cycles employing industrial leachate solutions for loading without any loss of selectivity or gold loading ability. There was also no evidence of the resins being poisoned by non-eluting metal cyano complexes during this trial. This reported research has thus led to the preparation of a series of resins which display a high selectivity for the precious metal cyano complexes while limiting the abstraction of the base metal cyano complexes. The performance of these resins compares favourably with that of other gold selective resins (some of which are being employed commercially as gold selective extractants ) and as a result show enormous potential to industry for use as selective auro- and argento-cyanide concentrators from cyanidation leachates.

Currently, when dextranase is used in the sugar factory, modifications are required to normal factory operating conditions in order to achieve cost effective dextran 'removal'. The major change involves the decrease in primary heater temperature from 75°C to about 60°C. A number of processing problems result from this temperature change. Therefore, it was proposed to develop a thermostable dextranase which was active and stable at 75°C. The use of a high temperature dextranase would also overcome the problems associated with operating the primary heater at the lower temperature. Existing culture collections, thermal environments and sites within raw sugar factories were used as the sources of microbial isolates screened for thermostable dextranase producers. Based on the amount of enzyme produced at elevated temperatures, five bacterial strains ( SRI 2125, SRI 2128, AB11A, RT364 and DP17) were selected as the most promising sources of thermostable dextranases.These isolates were grown to pure strain using standard microbial techniques. Thereafter, broth culture of these strains was undertaken to produce sufficient crude extracellular dextranase for liquid assay. However, compared to fungal isolates, the amount of dextranase produced by the bacterial isolates was low. Several assays to measure micro-quantities of dextranase activity were developed or modified to assess the thermal stability of the enzymes. Temperature and pH profiles of the crude extracts were determined using the PAHBAH assay to obtain a rapid and sensitive measure of optimal conditions required for enzymic activity. The subsequent development of the micro-haze test allowed the thermal stability and activity to be reliably assessed under simulated factory conditions. Both new and existing enzymic assays were utilised to determine the activity and thermal stability of the most cost-effective commercial dextranase currently available i.e. the C. gracile dextranase. This enzyme was found to exhibit optimum activity at 55-60°C (pH 5.0) under all assay conditions. However, thermal stability at temperatures above 65°C was very low. A comparative assessment of the commercial potential of new thermostable dextranases was possible using the C. gracile dextranase as the 'bench mark'. In addition, detailed studies on the C. gracile dextranase were performed to determine the physico-chemical characteristics of the enzyme(s) in the commercial preparation. The dextranase was separated into five distinct components by electrophoresis of the native enzyme. However, each of these components were found to possess a similar (if not identical) molecular size. Partial separation of these components was achieved using chromatofocusing. Each fraction obtained exhibited endo-dextranase activity..Crude preparations of the five bacterial dextranases were found to exhibit optimal activity between 63 and 75°C (depending on the assay conditions and the method employed for activity measurement). The specific activities of these crude dextranase preparations were very low (0.021 to 0.68 mole min-¹mg-¹) compared to the crude extracts obtained from fungal sources such as C. gracile. The presence of endo-dextranase activity was confirmed by determining the activity against cane dextran under simulated factory conditions. The dextranase produced by the RT364 isolate was selected for purification investigations as it was the most active in the crude form. Several standard techniques for protein purification were utilised and the purity of the resulting preparations established by electrophoretic analysis. The active dextranase in the fraction of highest purity and activity was shown to represent in excess of 50 per cent of the protein in the preparation. Using this estimate, a final specific activity for the purified thermostable dextranase from RT364 was calculated to be about 20 mo1e min-¹mg-¹. At this level, the specific activity of the RT364 enzyme is approximately 150 times less than that of the commercial C..gracile dextranase measured its optimum at temperature of 55°C. On this basis, the commercial potential of the thermostable dextranase from the RT364 isolate appears to be limited. To date, the specific activities of purified forms of the remaining four thermostable dextranases have not been determined. It is possible that one of these isolates may be the source of a thermo-stable dextranase with greater commercial potential. However, further investigations with these enzymes to establish their commercial viability would require high developmental costs in relation to the very small market (the Australian sugar industry) currently available for these enzymes.

"The Central Queensland University developed an on-site wastewater treatment and reuse technology. Septic tanks were used for primary treatment and the discharged effluent was then pumped though a series of contained channels. The channels were designed to be a modified evapotranspiration trench; they were comprised of an aggregate layer and a soil layer in which were planted a variety of plants. The aggregate and the soil provided physical filtration, the microorganisms within the effluent, aggregate and soil provided nutrient reuse and transformation and the plants also used the nutrients and reused the treated effluent through evapotranspiration. Any effluent that was not transpired was returned to a holding tank and pumped through the evapotranspiration again. The treatment technology was assessed in relation to its ability to treat effluent in a sustainable manner. The water and soil was examined for concentrations of nutrients, heavy metals, salts, sodium, and organic carbon %. The pH, temperature and number of colony forming units of certain microorganism potential pathogens were also inspected in the soil and the water. The plants grown within the evapotranspiration channels were assessed in regards to their health, water usage, and in some cases potential pathogens on fruit. The infrastructure that was used to construct the wastewater treatment and reuse system was also evaluated in regards to reliability and maintenance. Certain limiting factors, in particular sodicity and salinity were identified, but the trial was successful and a sustainable form of on-site wastewater treatment and reuse technology was developed." --abstract

The research presented here analyses and compares textual narratives generated within policy, scholarly and popular media to discern how the sexuality or intimacy needs of people categorised as ‘learning disabled’ have been historically and more recently managed in Australia and the United Kingdom. The research uses a modified critical discourse analytical approach which, in order to clarify the distinct role of power in the construction of discourses of sexuality, is mediated by the more recent ideas of progressive phronesis offered by Flyvbjerg (1998a; 2001). The analysis identifies three broad stages in the historical development of the discourses about the sexuality of learning disabled people. The first phase was prior to the 1800s, when these people were labelled non-derogatorily as ‘idiots’, and perceived as childlike, innocent and asexual. The second stage was in the 1800s when, with the emergence of scientific rationality and medicalisation, so-called idiots became medicalised and categorised as ‘feeble-minded’ or ‘moral imbeciles’. This thesis demonstrates that, during this period, an emphasis on sexual self-denial, anxieties about venereal disease and non-procreative erotic pleasure helped to inform discourses of eugenics and learning disabled people became perceived as a sexual threat to the society. This underpinned policies of sexual control through institutionalisation, gender segregation and sterilisation. The third period in the development of discourses relating to the sexuality of learning disabled people paralleled the ‘sexual revolution’ of the late- 1900s and the move towards deinstitutionalisation and human rights. This analysis shows that, although the principle of ‘sexual freedom’ was ostensibly incorporated in modern policy discourse, the sexuality of learning disabled people continues to be influenced by significant barriers of sexual intolerance, demonstrated by continuing practices of sexual segregation, sterilisation, criminal labelling and imprisonment. The analysis indicates that a discourse of sexuality, which has legitimised the control and management of learning disabled people in varying forms since the Enlightenment, continues to be encountered in policy and popular narratives. Robust sexuality awareness and education programs for carers of these people, and society in general, are necessary so that intimacy and/or sexual desires are accepted as a normal need for all human beings.

Student-centered pedagogies have become increasingly popular in higher education. Research on flipped learning, in particular, has shown that collaborative problem-solving environments are able to better support effective learning than lecture alone. However, the effects of this format on students’ interests and motivations in chemistry remain unknown. For this study, students and graduate teaching assistants who participated in a flipped learning, second-semester general chemistry course were selected to participate in a focus group discussion and individual interviews that explored their experiences and perceptions of the features of the course (affordances) that supported and thwarted their sense of motivation.

This phenomenographic study mapped eight students’ experiences of the course and used qualitative data from interviews with the graduate teaching assistants (TAs) to compare and contrast with students’ claims. Self-determination theory was used to frame these experiences and the results were discussed using other relevant theories of motivation, including, but not limited to expectancy-value theory and achievement goal theories.

It was found that there are several features of the course that support students’ motivations according to the basic psychological needs of relatedness, autonomy, and competency in self-determination theory. The study also revealed many features of the course that thwarted students’ motivations. Features that students described as motivating left them feeling connected to their peers and other agents in the course, capable of efficiently interacting with their environments as a result of the course tasks, and a sense that their performance was related to their efforts. Features that students’ described as demotivating left them feeling helpless, incompetent, alone, and without a sense of control over their performance in the course.

The results of this study shed light on students’ perceptions of the environment in a flipped learning chemistry course. These findings can be used to improve students’ experiences, and consequently their motivation when taking a flipped learning chemistry course. Specific assertions developed from these results and recommendations for these improvements are further discussed.

The poultry industry has rapidly grown in the last few years with a focus in improving growth and productivity of broiler chickens, with performance assessed on measures such as feed conversion ratio, body weight gain and good immunity. The incorporation of antibiotics and feed additives in poultry diets, have been implemented for years to ensure the maintenance of poultry health with a focus on the control and reduction of zoonotic pathogens. In the last few years, however, key issues surrounding the antimicrobial resistance of antibiotics have urged for alternative supplementations. Nanoparticles (NPs) of silver and other metals have been heavily used in the poultry industry to improve the growth and performance of birds. Whilst successful, metal NPs exhibited higher toxicity at the higher surface to volume ratio, especially with the use of silver. This study proposes the use of NPs of essential metals and natural compounds to safely deliver nutrients, resulting in positive impacts on health and productivity with little to no toxic effects. Selenium is an essential mineral, required for the proper functioning of the immunity and is an important element in the first cell line of defence in the body. The work described in this thesis explores the ability of selenium NPs to improve the health and growth of broiler chickens by modulating their gut microbiome and metabolome, without the toxic effects observed with silver. Selenium NPs were synthesised using a simple chemical reduction method and a full characterisation was performed, assessing the physicochemical properties of the NP. Selenium NPs were then compared in an animal trial against two commonly used selenium additives in the poultry industry, sodium selenite (inorganic selenium) and selenomethionine (organic selenium). The performance of the birds was assessed based on body weight gain, the gut microbial composition and metabolite production. The toxicity of NPs was further investigated by quantifying selenium concentration in various tissues, along with a detailed histopathological assessment. Results show selenium NPs completely altered the gut microbial ecology at high concentration, with a strong correlation observed between Faecalibacterium prausnitzii abundance and increasing concentration of selenium NPs. Selenium NPs additionally increased villus height/crypt ratio associated with enhanced absorption in the small intestine and an overall increase of healthy colonic metabolites. Finally, an in vitro study demonstrated the ability of selenium NPs to reduce emerging pathogenic Enterococcus cecorum species. This thesis demonstrates the prospective ability of selenium NPs as alternatives to antibiotics and bulk supplementation, resulting in an improvement of health and performance of broiler chickens in the poultry industry.

Contamination of aquatic environments by pollutants of emerging concern (PEC) creates new public health and environmental threats. Over the years, Africa has struggled to adequately treat wastewater before discharged into the environment. The situation is expected to be worsened by the more challenging to treat PEC like pharmaceuticals, endocrine disrupters, microplastics, surfactants, cyanotoxins, radioactive and flame retardants. Generally, the pollution of aquatic environments will have serious negative impacts on organisms that depend on the affected sources. Elsewhere, a number of research studies have reported the occurrence of these pollutants and in some cases exceeding the recommended levels. However, in Africa and other developing countries, a few studies have focused on PEC in aquatic resources. In this review, discussions are centered on the: (i) occurrence of PEC in African aquatic environments, (ii) potential risks to aquatic ecosystems and human health, and (iii) current chemical and biological monitoring techniques. There is need to include PEC in the research studies and routine environmental monitoring programmes particularly before the urban wastewater is discharged into the environment. Passive biomonitoring through using biomarkers like oxidative stress proteins and gonadal histopathology may be more informative and cheaper way of monitoring PEC than chemical analysis.