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The specification of shelter requirements of cattle requires knowledge of the complex interactions of climate, the enclosed animals and their enclosure. The modelling approach used in this research reduces this complexity by identifying the most significant components of the system. Four electrically heated physical thermal models of suckler cows with controlled internal temperatures and coverings of synthetic hair were used over two consecutive winter periods to simulate sensible heat losses from suckler cows kept in an unsheltered site and in three simple shelters. The measured reductions of unsheltered heat losses were (1) 2% (2) 6% and (3) 20% for shelters with respectively (1) just a roof (2) four solid walls, no roof and (3) a roof and four walls with ventilation openings. A mathematical model which predicts hourly and daily mean sensible heat losses from a suckler cow using measurements of air temperature, rainfall, windspeed and net radiation had previously been developed using a large thermal model. Climate modifying factors were derived for each shelter type by comparing hourly and daily mean measured heat losses with those predicted by the mathematical model. These factors were successfully validated using the second winter's data. The accuracies of heat loss predictions for the small thermal models in each shelter were similar to those for the original large thermal model. Examples are given for cattle sheltered by a forest and for calves sheltered by a creep to show how this model for prediction of heat losses in different shelters can be incorporated in a model of the whole system. Meteorological Office climate data was used to predict heat losses from cattle. This included a novel method for prediction of net radiation. The analysis indicated that predictions for a given site could be applied to a large area although this should be tested before any large scale analysis of records is undertaken.

Annual losses of nitrogen from existing glasshouse crop production substrate systems could be as high as 600 kg ha 1, using an average of 30% drainwater containing a nitrate-nitrogen concentration of 200 mg 1". The use of nutrient recirculation systems such as nutrient film technique (NFT) helped to reduce nutrient losses to the environment but the commercial area of NFT has decreasedd ue to high initial capital costs, concernso ver diseaset ransmissionw ithin the system and an absence of recent research and development. Most substrate systems rely on the provision of liquid nutrient feeds at every watering. This study examines clinoptilolite which is able to selectively store, supply and exchange cations with plant roots. The use of the naturally-occurring volcanic aluminosilicates pumice and clinoptilolite zeolite in the intensive production of edible and ornamental protected crops, tomatoes, sweet peppers and standard carnations was studied. Pumice from Sicily, Italy and clinoptilolite (84-87%) from Beli Plast, Bulgaria were used in the experiments. The management of the pumice and unloaded clinoptilolite systems involved provision of all the plant growth nutrients via a drip irrigation system. In comparison, the nutrient-loaded clinoptilolites were examined using only water in the irrigation cycles which allowed relatively unimpeded cation exchange to take place between the clinoptilolite and the surrounding solution, thus providing nutrients for plant roots. The total cation exchange capacity of clinoptilolite was measured as 132.0-158.3 meq 100g'', compared with 1.8 meq 100g-' for pumice. Unloaded clinoptilolite irrigated with nutrient-balanced liquid feeds gave yields and quality equivalent to those of tomatoes, peppers and standard carnations grown on rockwool, pumice and peat / peat alternatives. For the first nine months of an eighteen month experiment, the yield and quality of standard carnation flowers from high nutrient-loaded clinoptilolite matched those from pumice receiving liquid feeds at every watering. Thereafter, lower concentrations of available nitrogen and, to a lesser extent phosphorus, limited production by up to 25%. Drainwater nutrient concentrations were, however, extremely low and reduced the potential pollution risk to the surrounding environment. Drainwater nitrate-nitrogen concentrations of below 10 mg 1'' were measured, compared with 100-300 mg 1.1 for pumice. Drainwater potassium concentrations were also comparatively low at < 20 mg 1'' for clinoptilolite and 200 mg 1" for pumice. Phosphorus concentrationsi n the drainwater did not exceed1 2 mg 1.1c, omparedw ith a maximum of 70 mg 1'1 in drainwater from pumice. The inclusion of phosphate rock (apatite) in with the clinoptilolite provided a source of phosphorus available to plants and the dissolution of apatite was regulated by the rate of absorption of phosphorus and calcium by plants. In all the experiments, clinoptilolite adsorbed ammonium-nitrogen and potassium, releasing calcium and sodium. However, concentrations of sodium released into the root zone were not harmful to plant growth. The average nitrate-nitrogen concentration of new, fully-expanded carnation leaves was 51.7% lower than the target levels. The nutrient loading of nitrogen and phosphorus regulated the overall yield of the crops evaluated in the experiments. The use of nutrient-loaded clinoptilolite to produce commercial crops and reduce environmental pollution by regulating the concentration of nutrients in the drainwater over long periods of time is further explored in the study.

Rapid rates of coastal wetland loss in Louisiana are widely recognized. One important question of wetland sustainability is how volumetric contributions of roots to wetland soils vary under the influence of different hydrologic regimes. The research presented here specifically investigates the spatial and temporal relationships among the specific gravity of live roots, soil chemistry, and flooding regime for the macrophyte Spartina alterniflora Loisel. in natural, salt marsh, field settings located across southeastern coastal Louisiana. The results of this research propose the existence of a stress-tolerance threshold (beyond which root specific gravity modifications are observed), and highlight the importance of micro-scale factors over macro-scale regional characteristics in determining environmental stresses and the subsequent impact on root specific gravity. A conceptual model is developed linking the interactions of relevant environmental variables, root specific gravity, and the idea of a stress-tolerance threshold.

Thesis for Master of Science in Medicine at the School of Anatomical Sciences 5/11/2015 / In forensic anthropology, the estimation of sex is important for eliminating half of the possible identities the skeletal remains may have, as a result, sexing standards were set from fully dentate mandibles. Edentulous mandibles were excluded from studies that set these standards. Thus, this study intended to determine the effect of tooth loss on accurately estimating sex from the mandibular morphology of black South Africans. The mandibles sampled included 79 (31 males and 48 females) full dentition and 117 (57 males and 60 females) variable degrees of tooth loss mandibles from the Raymond A. Dart Collection of Human Skeletons. Outlines of the non-alveolar regions of the mandibles were digitised. The alveolar regions were rated according to the level of resorption that had occurred. A two block partial least square was performed to determine the effect of tooth loss on the mandibular morphology and a two sample permutation test was conducted to determine the sexing accuracies from all sampled mandibles. Tooth loss had a significant effect on the mandibular morphology. The overall accuracies determined were 85.5% from mandibles with tooth loss and 63.3% from full dentition mandibles. The overall mandible morphology is sexually dimorphic irrespective of the presence of tooth loss. The main factor that may affect the outcome was the mandibular mechanics in males and females. The results suggest that mandibles with high levels of tooth loss could be used in studies of identification. Further studies may want to set sexing standards from both dentate and edentate mandibles.

The decision regarding cochlear implantation is complex and involves the consideration of a multitude of factors that will influence the future of a hearing impaired child. Parents are often faced with the task of making this decision urgently during a period when they dealing with the diagnosis of a hearing loss. To date, there is sparse literature available on parental readiness for cochlear implantation. An understanding of parental experiences during the decision making process will help professionals involved in the cochlear implant teams to help parents through this difficult decision making time and hence have significant clinical implications for future practice. This is particularly relevant in South Africa where there is very little literature to guide both parents and professionals with regard to decision making. The objective of this study was to determine parental descriptions of their experiences with regard to the decision of cochlear implantation for their young children with hearing loss as well as the factors that needed to be considered by the parents for the child when deciding on a cochlear implant. Semi structured interviews were conducted with 13 parents at a Learning Facility in South Africa. The results revealed that the decision for cochlear implantation was based on two critical factors which were the sense of urgency and the future of the child. Other considerations such as the financial consideration, surgical risk, aesthetics, communicative outcomes, family consensus, and parental readiness were identified. The power of professionals during this time when decisions are being made in the context of ignorance and within an oral environment was revealed. This finding raised the question of the ethical and moral practice of professionals involved in cochlear implantation.

Thesis (PhD) — Boston College, 1984. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Economics.

Thesis (M. Phil.)--Chinese University of Hong Kong. / Bibliography: leaves 37-38.