In 2006, a baseline survey for the UNEP/GEF-IAS Project was conducted in BFR to assess the status of IAS in the area. Findings indicated that extensive forest parts had severe S. spectabilis encroachment which appeared to interfere with the normal functioning and productivity of the forest. This study was motivated by the magnitude of S. spectabilis invasion in BFR, the level of public and government concern about the invasion, and the magnitude of the IAS problem across East Africa. This study was thus undertaken to address a specific need of the research and capacity building components of the UNEP/GEF-IAS Project. The study1 was carried out to assess the impacts of S. spectabilis invasion on the productivity of BFR and the socio-economic implications on the livelihoods of the dependent stakeholders (local resident population, timber suppliers and the tourism sector). The study used descriptive statistics to assess the levels of awareness of S. spectabilis invasion, perceptions and knowledge of the conservation values of BFR, knowledge on the benefits and costs of living with S. spectabilis and impacts of S. spectabilis on the flow of quantities and revenues from the benefits it generates. The impact on financial profitability and efficiency of timber firms was assessed using Gross margin analysis (GMA) and financial efficiency ratio analysis respectively. The impact on the population structure of chimpanzees was studied using mean differentials and focused group discussions. Results indicate that the level of awareness about S. spectabilis invasion and the knowledge of the conservation values of BFR were high among all the three stakeholder groups. GMA revealed that S. spectabilis invasion increases variable costs in timber production thus reducing profit margins and financial efficiency of timber firms. Alteration of habitat environment occasioned by S. spectabilis invasion was advanced, though with uncertainty, as a possible reason for the difference in chimpanzee numbers between the infested and non infested forest conditions. Like other IAS, S. spectabilis was found to have both benefits and costs though the distribution of the same differs. S. spectabilis can be considered a net benefit to the local dependent communities whereas it may be a net loss to both the timber and tourism sectors. Conflict of interest in S. spectabilis management is discussed and possible solutions suggested. It was recommended that the threat of invasive species should be tackled through a multisectoral approach. / Dissertation (MSc)--University of Pretoria, 2009. / Agricultural Economics, Extension and Rural Development / unrestricted

Author comes with a new product concept, which extends the current offering of life insurance. He wants to encourage a target group of potential customers who are not satisfied with ordinary life insurance products to enter into life insurance. The reason is an effort to prevent people from economic consequences of population aging. The new life insurance product is based on a specific use of profit shares from life insurance premium reserve in a form of charitable component. For insurance companies the new product represents an opportunity to cooperate with non-commercial charitable subjects especially in the area of marketing. On the other hand the charities obtain by this cooperation a long-term income for their activities.

Anthrax was associated with the death of a large number of animals in the Selous Game Reserve. The significance of this disease to the populations of these animals was of concern to the reserve's management. Models are presented of the evolutionary effects of four host-pathogen relationships. Based on a demographic study of the wildebeest and a study of the characteristics of the disease, the anthrax-wildebeest relationship was compared with the models. The results of the study indicate that even though anthrax was responsible for the death of approximately 10% of the wildebeest, it had a balanced relationship with the population. The pathogen was probably an asset to its host population's continued existence rather than a hazard, as its mortality was associated with animals that appeared to be a disadvantage to the wildebeest population. If the management of the reserve wished to reduce the occurrence of anthrax, it is suggested that they reduce the number of wildebeest older than calves. In addition to maintaining a stable age configuration, this would improve the quality of the habitat, reduce the number of animals in poor condition, and thus reduce the number dying of anthrax. In addition, I deal with several other topics in Appendices. / Science, Faculty of / Zoology, Department of / Graduate

An ecological assessment of the vegetation was conducted in the south-eastern part of the Kalahari. Detailed classification of the vegetation of Witsand Nature Reserve to determine small scale plant communities for a Nature Reserve management plan – 44 Braun-Blanquet plots revealed 7 detailed plant communities. One hundred and twenty six (126) sample plots, making up 45 sites, were used for the TWINSPAN classification, refined by Braun-Blanquet procedures, illustrated in a dendrogram, revealed 3 broad plant communities. A description of the communities is given and a vegetation map of the study area is provided. The step-point method was used and data collected at each sample plot in such a way that different degradation stages could be identified, an ordination technique (multivariate analytical procedures) was used to define the grazing gradient. Species abundance curves were statistically fitted to the grazing gradient and used to classify the species objectively into categories. Ecological index values were determined for each of the significant species within each community. Copyright / Dissertation (MSc)--University of Pretoria, 2009. / Plant Science / unrestricted

One of most major concerns from both cost-effective and technical point of view in membrane process industry is membrane cleaning. The aim of the project was to investigate the variations in membrane surface properties and separation efficiency of reverse osmosis membrane. Compativtive analysis have to be performed on four RO membrane before and after exposing the virgin membrane into chemical cleaning to identify and analysis the impact of the chemical cleaning on the performance of RO membrane. Commerical chemical cleaning used in this project were caustic and acidic cleaning agent. The project’s aim is the investigation of simulation software’s precision for the four membranes performance projection at different conditions of the feed water. The assessment of the membranes performance was done in the Innovation Cluster at pilot plant that was industrial in size. The main commercial elements used were the thin-film composite membranes with a spiral-wound of 8-inch polyamide. Ultrafiltration (UF) and seawater RO membrane pretreatment process was done for the red sea sourced feed water. A pressure vessel dimensioned at 8-inch was operated in conjunction with an individual element at 8 -20 m3/hr feed flow rate, with an 8 to 12 % recovery and an average 35,000-42,000 mg/L of total dissolved solids (TDS) composition for the feed water. To achieve the project’s aim in assessing the membranes, three phase experimental stages were completed. The membranes performance was assessed in terms of their water flux, salt rejection, boron rejection, bicarbonate rejection and permeate quality. In addition, the membrane surfaces were characterized after exposing the fresh membranes with a chemical cleaning reagent. The experimental results showed an increase in both permeate flow and salt passage for all studied elements. The changes in the membranes performance were systematically explained based on the changes in the charge density and chemical structure of the membranes surface. The experimental results showed that both the physical and chemical surface properties of the membranes do not significantly alter under standard industrial conditions. These results shed some light on the effects of chemical cleaning in a pilot-scale RO plant and improve our understanding to provide a potential research direction for cleaning methods of membranes.

La chimiothérapie induit une baisse de la fertilité en exerçant une toxicité directe sur les ovaires entrainant une diminution du stock ovocytaire. Couramment utilisé dans le traitement du cancer du sein, le cyclophosphamide (Cy) est une des drogues reconnue comme la plus gonadotoxique. Récemment, il a été proposé que le Cy provoquait une déplétion folliculaire par une entrée en croissance massive des follicules au repos. L’Hormone Anti-Müllérienne (AMH) étant un des facteurs régulant la sortie des follicules primordiaux de la réserve ovarienne, nous avons émis l’hypothèse que cette hormone pourrait limiter la gonadotoxicité du Cy. Nous avons montré qu’un traitement par AMH recombinante chez des souris pubères traitées par Cy, permettait effectivement de limiter la déplétion folliculaire. Sur le plan fondamental, nous avons mis en évidence que l’autophagie pouvait être un des mécanismes impliqués dans l’inhibition du recrutement folliculaire exercée par l’AMH. Enfin, la méthode de référence consistant à évaluer la réserve ovarienne chez la souris étant particulièrement longue et fastidieuse, nous avons développé une technique de comptage folliculaire automatisé en utilisant des méthodes d’intelligence artificielle, et plus particulièrement une approche de « deep learning». / Chemotherapy induces infertility by exerting a direct toxicity on the ovaries, resulting in a depletion of the follicular stockpile. Cyclophosphamide (Cy), widely used for breast cancer, is recognized as one of the most gonadotoxic agent. Recently, it has been proposed that Cy gives rise to follicular depletion by a massive growth of resting follicles which are then destroyed. Since Anti-Müllerian Hormone (AMH) is one of the factors regulating primordial follicles activation, we hypothesized that this hormone might limited Cy-induced gonadotoxicity. We have shown in pubertal mice that recombinant AMH injections are able to preserve primordial follicle loss Cy-induced and might improve fertility outcome after treatment. In addition, we provide evidence that autophagy could be one of the mechanisms involved in the inhibition of follicular recruitment by AMH. At least, nowadays, the “gold standard” method of evaluating ovarian reserve in mouse is a process particularly time-consuming and tedious. We developed a new methodology of automatic primordial follicles detection and counting within mouse ovaries, using modern artificial intelligence methods, especially deep learning approach.

Besides the introduction and conclusion, this thesis is comprised of six independent chapters. In this thesis we provide an in-sample and out-of-sample assessment of how the South African Reserve Bank (SARB) sets its policy rate, post 2000 inflation targeting regime, in the context of both linear and nonlinear Taylor-type rule models of monetary policy.<p. Chapter 2 provides the theoretical foundations and the case study discussion. The literature has shown that the Taylor (1993) rule has gone through many modifications since the last decade of the 20th century. The modifications of the Taylor rule include interest rate smoothing, backward and forward looking versions, and nonlinear approximations. Furthermore, there has been increasing debate on whether central banks should respond to asset prices and financial variables. Despite some disagreements, economists seem to agree on the role of the financial market in determining inflation and economic performance. As far as South Africa is concerned, a stable financial system is one of the mandates of the central bank. Chapter 3 discusses the research methods used in the thesis. First, the chapter provides an overview on the Hodrick-Prescott Filter used to detrend some series. Second, more focus is oriented on a class of estimators, used in this thesis, called Generalized Method of Moments (GMM) estimators. GMM is important in that it can be applied to several estimation contexts besides the linear model. In fact, GMM can provide a simple alternative to other estimators, especially when it is difficult to write down the maximum likelihood estimator. Chapter 4 is aimed to provide the source of data, to show the transformation made to some of them and to explore the data for preliminary results. The Augmented Dickey- Fuller (ADF), Phillips-Perron (PP), GLS transformed Dickey-Fuller (DFGLS) and Kwiatkowski, et. Al. (KPSS) tests suggest that all the series follow a stationary process. The chapter also reveals that the financial conditions index measured as an equal weight average of its components yields a smallest AIC than other alternative suggested herein. Furthermore, the chapter shows that the models that consider coincident business cycle indicator, rather than industrial production, perform better in terms of goodness of fit. Given the controversial debate on whether central banks should target asset prices for economic stability, chapter 5 investigates whether the SARB pays close attention to asset and financial markets in their policy decisions. The main findings are that the SARB policy-makers pay close attention to the financial conditions index when setting interest rate. In the same chapter, it is also found that nonlinear Taylor rule improves its performance with the advent of the financial crisis, providing the best description of insample SARB interest rate setting behaviour. The 2007-2009 financial crisis witnesses an overall increased reaction to inflation and financial conditions. In addition, the financial crisis saw a shift from output stabilisation to inflation targeting and a shift, from a symmetric policy response to financial conditions, to a more asymmetric response depending on the state of the economy. Although one could have expected that the SARB’s response of monetary policy to output during the crisis to increase, the response has dropped significantly. These results show the concern over the high level of inflation observed during the second semester of 2008.<p. In chapter 6, we test the concept of Opportunistic Approach to monetary policy. The findings support the two features of the opportunistic approach. First, we find that the models that include an intermediate target that reflects the recent history of inflation rather than a simple inflation target improve the fit of the models. Second, the data supports the view that the South African Reserve Bank (SARB) behaves with some degree of non-responsiveness when inflation is within the zone of discretion but react aggressively otherwise. Recursive estimates from the preferred model reveal that overall there has been a subdued reaction to inflation, output and financial conditions amidst the increased economic uncertainty of the 2007-2009 financial crisis. Chapter 7 compares forecast performance of linear and nonlinear monetary policy rules estimated in the two previous chapters but rewritten in their backward looking versions. Recursive forecasts values are computed for 1- to 12-step ahead for the out-of-sample period 2006:01 to 2010:12. For the nonlinear models we use bootstrap method for multi-step ahead forecasts as opposed to point forecasts approach used for linear models. The aim is to evaluate the performance of three competing models in an out of-sample forecasting exercise. Overall ranking reveals the superiority of the nonlinear model that distinguishes between downward and upward movements in the business cycles in closely matching the historical record. As such, forecasting performance tests reveal that the SARB pays particular attention to business cycles movements when setting its policy rate. / Thesis (PhD)--University of Pretoria, 2011. / Economics / unrestricted

Between 1970 and 1975 Natal Parks Board hel .icopter counts of waterbuck ( Kobus ellipsiprymnus) in the Umfolozi Game Reserve (UGR) declined from 1 098 to 494. The purpose of this project was to study the ecology of waterbuck with an emphasis on population regulating mechanisms, so that the reality and significance of this decline could be assessed. Density estimates for 1976-1977 were over twice the 1976 helicopter count of 319, but the population was confirmed to be declining. The ecological density of waterbuck represented 11,9 per cent of the metabolic biomass of grazers, which compared well with data from other areas. However, the other species' proportionate contributions to biomass were far from optimal, with an excess of short grass feeders. High juvenile mortality (80,7 per cent), attributable mainly to severe tick (Rhipicephalus appendiculatus) infestations, was the principal cause of the present decline. These severe infestations were probably symptomatic of poor condition of the whole waterbuck population, which meant that the ultimate cause of juvenile mortality lay elsewhere. The hypothesis that the waterbuck population was in a stressed condition was supported by their habitat utilization patterns, their feeding ecology and aspects of their behaviour. The dynamics of interspecific associations suggested that the primary habitat of Waterbuck was that now occupied by nyala (Tragelaphus angasi) and what had been recorded were the results of competition pushing waterbuck into an unfavourable habitat. Feeding studies indicated that nutritious food for herbivores represented a limited resource in UGR during winter, for which waterbuck may be largely outcompeted and that nyala and impala ( Aepyceros melampus) were the rnain competitors . Interspecific competition was the probable ultimate cause of the decline of waterbuck in UGR. It was recommended that the numbers of nyala and impala be reduced and that this action be integrated into a more precise management plan for UGR than exists at present. / Thesis (DSc)--University of Pretoria, 1978. / gm2014 / Zoology and Entomology / unrestricted

A small subset of individuals that have experienced mild traumatic brain injury (mTBI) may experience persistent cognitive deficits more than a year following the head injury. Neuroimaging studies reveal structural and functional changes in frontal areas of the brain, exacerbated when loss of consciousness is experienced, and indicate that these changes may be progressive in nature for some people. Social support and social participation have, however, been suggested to confer cognitive reserve - neurocognitive protection against cognitive decline. Analyses were run on Canadian Longitudinal Study on Aging (CLSA) neuropsychological data, consisting of individuals who experienced mTBI with loss of consciousness (n = 536 for less than 1 minute, and n = 435 for unconsciousness between 1 and 20 minutes) more than a year prior, and 13,163 no-head injury comparisons. These same individuals were re-assessed three years later. The results presented in this thesis suggest that at a year or more after a single mTBI with loss of consciousness, a small subset of individuals are more likely to be impaired on prospective memory and other executive functioning tasks, relative to comparisons. In addition, when examined at three-year follow-up, those who experienced mTBI with longer duration of unconsciousness were more likely to exhibit cognitive decline relative to those who experienced less unconsciousness or comparisons. Moreover, greater social participation over the past year, and more perceived social support were predictive of lessened cognitive deterioration in those individuals.

This dissertation studies topics in international finance and central bank policy. In the first chapter, "Common idiosyncratic volatility and carry trade returns", I provide new evidence that incomplete consumption risk sharing across countries is an important determinant of carry trade returns. I show that there is a strong co-movement in idiosyncratic volatilities over time, and that shocks to the common idiosyncratic volatility (CIV) factor, defined as the equally weighted average of the idiosyncratic volatilities in the cross-section, are priced. I find that high-interest rate currencies deliver low returns when the CIV increases, which are bad times for investors. Low-interest rate currencies provide a hedge by yielding positive returns. CIV shocks remain an empirically powerful risk factor in explaining the cross-section of carry trade returns after controlling for global foreign exchange (FX) volatility risk. Furthermore, CIV risk is correlated with cross-country income risk faced by households. My findings are consistent with a heterogeneous-agent model with persistent, uninsurable idiosyncratic shocks in consumption growth. The calibrated model quantitatively accounts for the cross-sectional differences in average returns across CIV-beta sorted portfolios for plausible market prices of CIV risk. In the second chapter, "Fed-implied market conditions", we propose a novel text processing technique to extract views of market conditions that are implicit in the Fed's policy statements and minutes. The method is easy to apply and addresses several problems inherent in the use of changes in interest rates as a proxy for central bank policy. First, we project market variables into the text of FOMC statements and minutes (separately) using support vector regressions (SVRs) to predict the levels of 10-year yields, 3-month yields, 2s10s, DXY index, VIX, high-yield (HY) and investment-grade (IG) spreads. We then define measures of monetary policy (``FDIF'' variables) as the Fed-implied deviation away from the market variable: the out-of-sample value of the market variable implied by the SVR minus the corresponding value of the market variable the day before the statement (minutes) release. We show that different markets respond differently to monetary policy news in the short-run, in a way that has independent and complementary implications for market movements in the long-run. Fed news also has important long-run implications for macroeconomic outcomes. Our Fed measures outperform Bernanke-Kuttner and changes in 2-year yields for forecasting macro and financial outcomes in the future. Finally, we show that there are Fed-risky and Fed-hedging industries, and these earn risk premia on Fed statement days. Finally, in the third chapter, "Does the counterparty of central banks in derivatives-based foreign exchange interventions matter?", we study how the central bank counterparty in foreign exchange interventions affect the supply of hedge against FX risks to the private sector. We use Brazilian data where derivatives-based interventions have been used in tandem for almost two decades. The analysis finds evidence of a link between central bank counterparties in FX swap operations and the supply of hedge through FX futures contracts. The main central bank counterparty in foreign exchange interventions uses the liquidity provided by the central bank to increase the supply of hedge to the private sector. Other counterparties use the US dollars provided by the central bank to reduce their own foreign exchange exposure.