Glutamate is the main excitatory neurotransmitter in the CNS and at the neuromuscular junctions (NMJs) of invertebrate. The characteristic similarities to CNS glutamatergic synapses in vertebrate and the anatomical simplicity of invertebrate NMJs favor the investigation of glutamatergic synaptic functions in this system. This dissertation mainly aimed to physiologically separate two functional vesicle groups, the reserve pool (RP) and readily releasable pool (RRP) within presynaptic nerve terminals of Procambarus Clarkii and Drosophila melanogaster. This was addressed in part by blocking the vesicular glutamate transporter (VGlut) with bafilomycin A1. Various frequencies of motor nerve stimulation, exposure time, and concentration of bafilomycin A1 were examined. The low-output tonic opener NMJs in crayfish exposed to 4μM bafilomycin A1 and 20Hz continuous stimulation decreased the EPSP amplitude to 50% in ∼30min with controls lasting 3h. After activity and bafilomycin A1-induced synaptic depression, the EPSPs were rapidly revitalized by serotonin (5-HT, 1μM) in the crayfish preparations. The 5-HT action can be blocked almost completely with a PLC inhibitor, but partially with a cAMP activator. The higher output synapses of the larval Drosophila NMJ when stimulated at 1Hz or 5Hz and exposed to 4μM of bafilomycin A1 showed a depression rate of 50% within ∼10min with controls lasting ∼40min. After low frequency depression and/or exposure to bafilomycin A1 a burst of higher frequency (10Hz) can recruit vesicles from the RP to the RRP. Physiological differences in low- (tonic like) and high-output (phasic like) synapses match many of the expected anatomical features of these terminals, part of this dissertation highlights physiological differences and differential modulation and/or extent of the vesicles in a RP for maintaining synaptic output during evoked depression of the RRP in crayfish abdomen extensor preparation. With the use of bafilomycin A1, the tonic terminal is fatigue resistant due to a large RRP, whereas the phasic depresses rapidly upon continuous stimulation. Upon depression of the tonic terminal, 5-HT has a large RP to act on to recruit vesicles to the RRP; whereas, the phasic terminal, 5-HT can recruit RP vesicles to the RRP prior to synaptic depression but not after depression.

The focus of this study is the effect of environmental conditions on the social relationships among females in a free-ranging troop of chacma baboons (Papio cynocephalus ursinus), in a southern woodland habitat. The female dominance hierarchy, rank related differential costs and benefits to individuals, and the nature of special relationships between females, were followed. The study was conducted for a total of 18 months during three years, at Mkuzi Game Reserve, Zululand, South-Africa. The study troop occupy a rich woodland habitat with abundant food resources. Visibility under these conditions is poor and the baboons are subjected to leopard predation. Intra-troop competition for food among female primates and its effect on lifetime reproductive success, has been widely stressed to be a major cost for low ranking females. No evidence of competition for food was found among females at Mkuzi. It is suggested that the main cause for mortality may be predation by leopards, and that females compete mainly over a safe spatial position. The following characteristics of female sociality at Mkuzi may support this suggestion: 1. While no indication of rank related feeding behaviour, reproductive success, or 'attractiveness' to others was found, the higher ranking females had more access to central, and thus better protected, spatial positions in the troop. 2. The importance of social associations among females at Mkuzi seems to lie in mutual grooming and protection from predation by the vicinity to each other, and not in coalitionary support. Female associates were thus not necessarily adjacent ranking and probably not kin. 3. Although female dominance hierarchy was usually stable, the lowest ranking adult female has promoted her rank independently, following the disappearance of her only female associate and during her pregnancy, when she was probably subjected to high risk of predation. 4. Following troop fission, most females chose to improve their own rank position by adopting the AYS strategy (Abandon Your immediate Superior in rank), rather than joining associates. It is suggested that the resident males were responsible for the initiation of troop fission, in order to decrease the high cost of sexual competition to them, by reducing the number of males in each daughter troop. High intensity of competition between males was the result of the high female reproductive success. Risk of predation, and therefore the cost to individual females, increased after fission. This study may present an additional accumulating behavioural evidence on adaptations environmental conditions. the of flexibility primates example to of social and to various environmental conditions. / Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 1993.

Įvertinti Raudonosios knygos augalų paplitimą, būklę, bei kaitą ir pasiūlyti priemones jų būklei ir paplitimui pagerinti. / To assess the distribution of plants of red list, their condition and changes in Vištytgiris botanical-zoological rezerve; and identify measures to improve their condition and spread.

While few people would say that Canada has done a good job of housing its poor citizens, this discussion goes beyond problems of housing the poor. In this dissertation I draw from government records to uncover how, between the 1930s and 1990s, the Indian Department created and oversaw a failed housing system on reserves across the country - one decision at a time. While housing is usually seen to be a result of poverty I argue that during this time the practices and policies of the Indian Department were active participants in making Indigenous people and First Nations communities poor. As a consequence of the persistent housing crisis on reserves in Canada Indigenous people suffered not only from living in substandard dwellings but also from the indignity and shame that comes from the association Canadians have made between the poor conditions of on-reserve housing and the personal characteristics of its occupants. What most people do not know is how it is that on-reserve housing remained in crisis for so long. On-reserve housing is something we have done not something we have studied. While federal government reports have charted the number of houses on reserves and their physical condition, no one has examined the history of government programs or how they were delivered until now. Recognizing that my study was not designed to recommend solutions, but believing that we cannot fix a problem until we know it, I am convinced that this dissertation provides the background information future academics will need to tell a different story about housing on reserves. And with a different story we will be better prepared to make fundamental changes needed to the way housing is delivered on reserves. / Graduate

M. Com. (Financial Economics) / The success of a monetary policy framework depends mostly on whether economic agents, especially the financial market participants, understand monetary policy decisions and are able to predict them in advance. Academics and practitioners agree that a successful Central Bank should be “boring” such that surprises about monetary policy should not arise in the announcements and the actions of the Bank, but rather in the macroeconomic developments. Thus policies that enhance clarity, transparency and communication between a Central Bank and the market can contribute to strengthening monetary policy predictability and improve the effectiveness of monetary policy itself. This dissertation assesses the predictability of the South African Reserve Bank’s (SARB) interest rate decisions since the adoption of the inflation targeting monetary policy framework in February 2000. Firstly, in order to evaluate predictability, money market forward rates are used to test whether the financial market is able to forecast the future level of policy rates, using the unbiased forward rate hypothesis. Then, using an event study methodology, changes in the money market forward rates following a monetary policy announcement are used to test whether the financial market participants were surprised by the SARB’s monetary policy decisions. The results of the unbiased forward rate hypothesis (UFRH) and the event study analysis indicate that, at least in the short term, specifically on a one-month-forward period, financial market participants have been able to predict the SARB’s monetary policy decisions with a high degree of accuracy. Moreover, the results of the event study analysis show that the South African financial market is at least semi-strong efficient, in the sense that monetary policy decisions are quickly incorporated in the market interest rates following the announcements. The event study analysis also provided some evidence that volatility in financial markets at the time of interest rate decisions has been declining over time.

South Africa's adherence to the Gold Standard while many other countries abandoned it, placed the country in a difficult position. This was exacerbated by the worldwide economic depression that resulted in the sharp decline of primary commodity prices, a decrease in demand and unemployment. The commercial banks in South Africa were obviously also affected by the prevailing circumstances and the position of one of them, Barclays Bank (Dominion, Colonial and Overseas) will be the focus of this study. One of the most important questions that will receive attention is to what extent the bank was affected by the gold standard crisis. Linked closely to this is the question of the nature of the problems encountered by the bank and the measures, if any, it took to overcome these difficulties. In this regard it will be necessary to investigate the most important areas of the imperial banks' business and the type of customers they served. Another question or issue to be investigated is the relationship between the two British banks on the one hand and the South African Reserve Bank and the government on the other. The establishment of the Reserve Bank was not openly welcomed by the imperial banks as they feared competition from the Bank while, with their considerable balances overseas, they were not convinced that there existed a need for a central bank in South Africa. In this respect, the question of co-operation between the two banks will also receive attention. / Prof. G Verhoef

A preliminary purpose of this study in the area of business communications was that of determining the status of correspondence improvement in stock life insurance companies in Dallas. However, the major purpose, which stemmed from the preliminary one, was to study intensively the approach used in Great American.

The purpose of this study is to determine whether oil and gas producing companies smooth their ending reserve quantities. Smoothing is defined as a reduction in variance in the trend of ending reserve quantities over time compared to the trend of ending reserve quantities less the hypothesized smoothing variable over time. This study focuses on two variables that are most susceptible to manipulation—revisions of previous estimates and additions. This study also examines whether revisions are positively or negatively biased and the variability of the revisions. The sample consists of 70 companies chosen from oil & Gas Reserve Disclosures: 1980-1984 Survey of 400 Public Companies by Arthur Andersen and Company. For each company, ending reserve quantities for the years 1978-1984 were regressed over time, and the standard deviation of the estimate (SDE) was calculated. Then the ending reserve quantities less the hypothesized smoothing variable were regressed over time, and the SDE was calculated. A linear model and a semi-logarithmic model were used. A smoothing ratio (SR) was determined by dividing the SDE of reserves less the hypothesized smoothing variable by the SDE of ending reserve quantities. An SR greater than one indicates smoothing, and an SR less than one indicates that smoothing did not occur. The mean percentage revision and a t-test were used to test for positive or negative bias in the revisions. The mean absolute percentage revision was used to assess the relative variability of revisions. The number of companies classified as smoothers of oil reserves was statistically significant for the semi-logarithmic model but not for the linear model. Under both models the number of companies classified as smoothers of gas reserves was statistically significant. Few companies had mean percentage revisions that were significantly different from zero. The majority of companies had mean absolute revisions of under ten percent.

Title: Munich chain ladder method Author: Bc. Veronika Janáková Department: Department of probability and mathematical statistic Supervisor: Mgr. Martin Pleška Supervisor's e-mail address: martin.pleska@cz.pwc.com Abstract: The insurance company is obliged to create technical reserves to cover the risk from insurance activities. One of the main reserves in non-life insurance is the IBNR reserve - the reserve to cover the damages that already exist, but that have not been reported to the insurance company yet. The content and the general aim of this thesis is to provide a better orientation in the method used in the estimation of the reserve IBNR - the Munich Chain Ladder Method. Munich Chain Ladder Method was created as a modification of the standard Chain Ladder calculation - one of the most used methods in the estimation of the IBNR reserve. The thesis focuses on the reasons that led to the modification of standard Chain Ladder calculation and explains the calculation of the modified method. It presents the application ot the method on the real data as well as the comparison with the results of the classical and less complicated Chain Ladder method. Keywords: IBNR reserve, chain ladder, Munich chain ladder 1

This text describes wide variety of models for IBNR reserve estimation, among them we can find chain ladder, Munich chain ladder, Cape Cod or regression methods. Especially, it aims at identification of model assumptions, its verification, impacts of their non-fulfillment and resulting model modification. Moreover, this work deals with anomalies and specificity of historical data and tries to suggest solutions for this problems. The last part of the thesis is dedicated to real analysis of motor third party liability.