Dissertations / Theses on the topic 'Geographical distribution'

Models that are used for predicting species' potential distributions are important tools that have found applications in a number of areas of applied ecology. The majority of these models can be classified as correlative, as they rely on strong, often indirect, links between species distribution records and environmental predictor variables to make predictions. Correlative models are an alternative to more complex mechanistic models that attempt to simulate the mechanisms considered to underlie the observed correlations with environmental attributes. This study explores the influence of the type and quality of the data used to calibrate correlative models. In terms of data type, the most popular techniques in use are group discrimination techniques, those that use both presence and absence locality data to make predictions. However, for many organisms absence data are either not available or are considered to be unreliable. As the available range of profile techniques (those using presence only data) appeared to be limited, new profile techniques were investigated and evaluated. A new profile modelling technique based on fuzzy classification (the Fuzzy Envelope Model) was developed and implemented. A second profile technique based on Principal Components Analysis was implemented and evaluated. Based on quantitative model evaluation tests, both of these techniques performed well and show considerable promise. In terms of data quality, the effects on model performance of false absence records, the number of locality records (sample size) and the proportion of localities representing species presence (prevalence) in samples were investigated for logistic regression distribution models. Sample size and prevalence both had a significant effect on model performance. False absence records had a significant influence on model performance, which was affected by sample size. A quantitative comparison of the performance of selected profile models and group discrimination modelling techniques suggests that different techniques may be more successful for predicting distributions for particular species or types of organism than others. The results also suggest that several different model design! sample size combinations are capable of making predictions that will on average not differ significantly in performance for a particular species. A further quantitative comparison among modelling techniques suggests that correlative techniques can perform as well as simple mechanistic techniques for predicting potential distributions.

Angola is among the largest countries in Africa and due to its great geographical and climatic variety, presents a great diversity of biomes and habitats. However, is one of few biodiverse countries in Africa that remains highly incomplete in knowledge of vertebrate diversity. Data regarding the occurrence and geographical distribution of amphibians and reptiles in Angola are currently scattered across museum specimens housed in Natural History institutions and in a diversity of books and papers published since the second half of the nineteenth century, and there is no available distribution database or atlas. Considering the threats faced by amphibians and reptiles worldwide and consequently the need for an update overview of their diversity and distribution in Angola, we compiled a database with the available published bibliographical data on amphibian and reptile occurrences in Angola, updated the taxonomy and nomenclature for every citation and mapped the species occurrences in the country; Distribuição Geográfica dos Anfíbios e Répteis em Angola RESUMO: Angola está entre os maiores países de África e, devido à sua ampla variedade geográfica e climática, apresenta uma grande diversidade de biomas e habitats. É considerado um dos países mais ricos em biodiversidade, contudo o seu conhecimento encontra-se extremamente incompleto. Os dados relativos à distribuição de espécies de anfíbios e répteis em Angola encontram-se dispersos por todo o Mundo, em instituições como Museus de História Natural, bem como em livros e artigos publicados desde a segunda metade do século XIX, não se encontrando esta informação atualmente disponível em qualquer base de dados ou atlas. Considerando as ameaças globais enfrentadas por este grupo animal e a consequente necessidade de atualização do seu conhecimento para Angola, procedemos à compilação de uma base de dados atualizada sobre as suas ocorrências, atualizando o status taxonómico e nomenclatural para cada espécie e consequente criação de mapas de distribuição.

Objectives: The objectives of this study are 1) To study the epidemiology and geographical distribution of child abuse in Hong Kong. 2) To study the district differences in co-morbidities of child abuse. Methods: Children under 19 years old with diagnostic codes for child abuse and child maltreatment from 1st January 2001 to 31st December 2010 were retrieved from Hospital Authority database. Demographics, hospital admission data and co-morbidities diagnosis were retrieved. The data were further analyzed according to districts of Hong Kong. Results: A total of 8055 episodes of child abuse were retrieved. 4241 (52.7%) were female and 3814 (47.3%) were male. There was a significant increasing trend of child abuse steadily in the whole territory over the study period. There were significant differences in the number of child abuse cases among different districts (p = 0.0038). Yuen Long, followed by Tuen Mun, constituted the highest numbers of child abuse cases, with 970 cases (12%) and 896 cases (11.1%) identified respectively. The mean age of onset of child abuse was 8.5 years old, while the mean number of hospital admission was 2.3 episodes during the study period. For length of hospital stay, the overall mean was 6.5 days. There was no significant difference among the clusters. The overall rate of suicidal attempt was 1.6%. The rate of suicidal attempt in New Territory west cluster (2.5%) was 2.8 times of that of Hong Kong west cluster (0.9%) (p<0.0001). The number of injury diagnosis, mental health problem, developmental delay, behavioral problem, antisocial or conduct problem, were also significantly different among different clusters. (p<0.05). Conclusion: There was a significant increasing trend of child abuse in the past decade in Hong Kong. In addition, the present study demonstrated a significant geographical variation in the number of child abuse cases as well as their associated co-morbidities. The identification of areas with higher rates of child abuse and associated co-morbidities poses important implication on service planning and policy making.<br>published_or_final_version<br>Paediatrics and Adolescent Medicine<br>Master<br>Master of Medical Sciences

Prior to the year 2007, Eskom Distribution followed a method of load forecasting (now referred to as legacy method in this report) that was based on collecting customer applications, historical load trending, and relied on the planner’s knowledge of the area to a large extent. It was based in a conventional Microsoft Excel spreadsheet. On seeking to improve its load forecasting approach, the utility adopted a technique that was based on spatial forecasting. This new technique was called a geographical based load forecasting (GLF) technique which was performed by using a custom based tool, called PowerGLF. The aim of this research was to assess any improvements (or lack thereof) that were brought about by adopting the GLF method as compared to the legacy method that was used previously. The hypothesis to be tested was declared as: “The use of the GLF method that was introduced to Eskom Distribution Planning brings about the improvement on the planning process of infrastructure that is adequate, reliable and economic, when compared to the legacy method that was used before it.” To carry out this assessment, a case study method was followed. Real network studies that were compiled in 2006 and 2007 were used. These network studies were based on GLF method and the legacy method. The load forecasts from the case studies were evaluated on forecast accuracy, how they influenced the planning of adequate, reliable and economic (ARE) network infrastructure and their impact on the procurement and construction of the network infrastructure (which represent the actual utility expenditure on infrastructure). The statistical comparative analysis was done. The research results revealed that the legacy method was more accurate than the GLF method in both the case studies that were evaluated. However, regarding the ability of a load forecast method to support the planning process, the GLF method showed to be supporting the planning of adequate, reliable and economic infrastructure better than the legacy method. It was found that the forecast error for the GLF and legacy method do not affect the utility infrastructure procurement and construction. Based on the test results, the study reached a conclusion that the use of the GLF method that was introduced to Eskom Distribution Planning brings about the improvement in the planning process of infrastructure that is adequate, economic and reliable when compared to the legacy method that was used before it. The author wishes to express that the results of this study must not be taken as a generic conclusive finding regarding the evaluated load forecasting methods; they are applicable to the tested case studies. To get to a general conclusive result, more case studies would need to be carried out where clear and consistent evidence on performance of these load forecasting methods will be seen. The findings of this study can be used as part of a larger sample if such a larger population of case studies was to be evaluated. The methodology followed in this research can be repeated and followed when similar assessments are done in future.

The Agulhas Bank supports a speciose fish community, many of which are commercially important. Despite substantial research being conducted on aspects of their biology spatial aspects of their distribution and abundance in relation to environment parameters has been ignored. This study, therefore, addressed aspects related to the distribution and abundance of representative species on the Agulhas Bank within a Geographic Information System (GIS). Four candidate species were chosen due to their importance either in numbers or unit mass to the South African demersal trawl fishery. The species also shared morphological and taxonomic similarities. The candidate species chosen were the two Cape hake species, shallow-water hake Meluccius capensis, and deep-water hake Merluccius paradoxus, and the two pleuronectiform species being Agulhas sole Austroglossus pectoralis and redspotted tonguesole Cynoglossus zanzibarensis. The use of a GIS was appropriate and allowed for hidden spatial patterns be exposed and illustrated visually, while also facilitating the quantification of the relationships between distribution/abundance and certain environmental predictors using statistical methods The Department of Marine and Coastal Management, Cape Town, supplied biological data in the form of length frequency and biomass information from spring (AprillMay) and autumn (September/October) cruises conducted between 1986 and 1993 on the R. V. Africana. The Council for National Geoscience, Cape Town, supplied sediment data for the entire southern African coastline. Initial exploratory data analysis highlighted potential relationships between environmental variables and abundance for each specie's life-history stanzas. Variations in spatial distribution were found to be significantly different between each life-history stanzas within species. Fish density as a function of the additive effects of the various environmental parameters, including temperature, depth and sediment type, was assessed using a Poisson Generalized Additive Model (GAM), while distribution was analysed with a logistic GAM. A predictive logistic model was then created, taking into consideration the importance of the predictor variables for each species, allowing for predictive estimates to be made for each species by inputting environmental information within the study area. The importance of certain environmental variables influencing distribution and abundance were noted. General patterns indicated that sediment was the most important to both the distribution and abundance of the two pleuronectiform species and juvenile life-history stanzas, while the adult gadoids' distribution and abundance appeared to be depth dependent.

A Geographic Information Systems (GIS) atlas of southern African freshwater fish was developed for the SADC countries from natural history collection specimens, hydrological, topographical and climatological data. The primary purpose of the development of the atlas of freshwater fish was the construction of a practical framework to transform vast amounts of existing biological data for use in research and management of aquatic resources. The database of freshwater fish collection specimens that was incorporated into the atlas, was developed in association with ALCOM (Aquatic Resources Management for Local Community Development Programme). The development of advanced computing and GIS technology has increased the scope of biological atlas projects by facilitating the integration of large amounts of spatial data to produce derived databases for specific applications. The atlas of freshwater fish was constructed using TNTmips GIS software as the most practical system available for managing and analysing biological data with a spatial component. The atlas contains 35 180 comprehensive distribution records of 735 species of fish. It has many applications as an inventory of ichthyofaunal spatial biodiversity, including those of conservation planning, environmental assessment and biogeographic research. Biogeographic studies have traditionally been subjective due to the logistical problems of working with large amounts of distribution data, although some small-scale quantitative research has been carried out in the past. The content of the atlas of freshwater fish is tested with respect to these previous studies, on known patterns of freshwater fish distributions, and the analytical capability of the atlas is tested and demonstrated with some new preliminary approaches to the analysis of freshwater fish distributions in southern Africa.

The importance of spatial variation in abundance for the assessment of climate change impacts was examined using the North American beaver ( Castor canadensis) in Quebec as a model species. A preliminary characterization of the beavers' range edge improved the core-sampling bias and revealed that beavers are present at low densities, in shrubby riparian habitats as far north as the communities of Tasiujaq and Umiujaq. Spatial variation in beaver abundance across the province follows a roughly logistic pattern, with abundance peaking in southern Quebec, declining steeply around 49°N, and remaining uniformly low as far as 58°N. Although climate sensitivity of beaver abundance and the greatest changes in future beaver density are predicted to occur near the middle of their range, beavers are expected to occupy most of the province by 2055. These results highlight the value of incorporating density estimates from across a species' range into climate envelope models.

The spatial distribution of four species of rorqual whales was studied along the north shore of the Gulf of St. Lawrence during the months of June to October from 1989 to 2000. A research effort of 6511 hours at sea yielded 849 sightings of blue whales (Balaenoptera musculus), 5291 of finback whales (Balaenoptera physalus), 3822 of humpback whales (Megaptera novaeangliae) and 6489 of minke whales (Balaenoptera acutorostrata). Spatial and behavioural data were collected at sea using inflatable boats, and Global Positioning Systems (GPS) were used to obtain accurate positions. These data were plotted and analysed using a Geographic Information System (GIS) to test the hypotheses that patterns of distribution were not random, were associated with bathymetry and reflected specific differences in habitat use. The resulting maps illustrated the clustered distribution of rorqual whales linked to sea-bottom topography, probably associated with areas of local upwelling and increased productivity. Blue and fin whales shared almost the same distribution, humpback whales were found in slightly deeper, offshore waters whereas minke whales were more abundant in shallower waters. Little attention has been given until now to local patterns of distribution in the area and such information can be useful for practical management considerations. The results emphasise the importance of scale in ecological studies of marine mammals and the need for further research using additional oceanographic parameters, in order to better understand habitat selection.

This dissertation deals with two aspects of the history of the Companions of the Prophet: the pattern of their geographical distribution and their political alignments---taking as its test case the Battle of S&dotbelow;iffin. Based on biographical dictionaries of the Companions written by selected Traditionists (i.e., Ibn Sa`d, Ibn `Abd al-Barr, Ibn al-Athir, al-Dhahabi and Ibn H&dotbelow;ajar), and on the Traditionist definition of what constitutes a Companion, an attempt will be made to identify on the one hand the Companions who settled in Iraq, Syria and Egypt, and on the other those Companions whose loyalties during the Battle of S&dotbelow;iffin are known. Based on an analysis of the background of the Companions appearing in each of these groups and on a comparison between the two, it is argued that religious ideals played a significant role both in the Companions' movements after the death of the Prophet and in their behavior during the Battle of S&dotbelow;iffin.

Thesis (MPH.) -- University of Limpopo, 2016<br>Introduction: During mid-November 2008, eleven acute watery diarrhoea cases with the suspicion of cholera like symptoms were detected by a diarrhoea surveillance system at Musina Hospital in Vhembe district - Limpopo Province, South Africa. These cases included eight Zimbabwean and three South African citizens. Laboratory test performed on stool specimens confirmed Vibrio cholerae serogroup 01 Ogawa as the causative pathogen for these reported acute watery diarrhoea cases. Within eight weeks of its onset, the outbreak spread to all the five districts of Limpopo. So far between 15 November 2008 and 01 June 2009, the cumulative number of cases of acute watery diarrhoea reported from five districts of Limpopo Province stands at 4634 including 30 confirmed cholera deaths with an overall case fatality rate of 0.65%. Of these reported cases, Vibrio cholerae has been laboratory confirmed in 656 samples. Methodology: A database was received from the Limpopo Department of Health having all reported cholera cases during the 2008 and 2009 outbreak in Limpopo Province. The data was analysed using STATA statistical software version 12 for windows (STATA Corporation, College Station, Texas). Results: The cholera affected all ages, but the geographic distribution of the disease was very heterogeneous in Limpopo Province. The highest and lowest numbers of cases were reported in Capricorn and Mopani districts, respectively. The majority of the cases 55% (N=2 542) were females. Children less than five years of age 14.2% (N=652) were less affected by the disease. About 73.8% of the cases were aged between O and 44 years. The first four weeks of cholera outbreak strictly included a day-to-day admixture of Zimbabweans and South Africans presenting in the health facilities. The outbreak then affected most South Africans after week five of the epidemic. Conclusion: The cholera outbreak has affected all the five districts of Limpopo Province in South Africa, and new cases continued to be reported until first week of June 2009. There was a link between the Zimbabwean and South African cholera outbreak in Limpopo province.

The results of a community survey of the rocky intertidal and subtidal reef ichthyofauna of the Tsitsikamma National Park and adjacent areas are presented. An updated species checklist is given, comprising 116 species of 46 families, including a new genus and species of Tripterygiid. Single species are shown to dominate, in terms of numbers, both the cryptic and subtidal components for all the areas sampled down the vertical profile. Species richness, evenness and diversity are found to increase with depth for both the cryptic and suprabenthic components. A community level feeding study shows an increase in trophic specialisation with depth and food availability is found to be an important factor delimiting littoral fish vertical distribution. The nursery function of the Tsitsikamma rocky littoral area is assessed and it is shown that shallow littoral areas as a whole are more important than intertidal pools alone in functioning as nurseries. The results of the study are found to fit into the existing trend of an increase in species richness and diversity, from west to east, along the South African coast. A significant difference is shown between the observed frequencies of species on exploited reefs outside the Park and unexploited reefs inside the Park. The density of the key reef predator Petrus rupestris is shown to be nine times more abundant on deep reef inside the park compared to deep reef outside the park (0.0045 fish/m² and 0.0005 fish/m² respectively) and a paucity of larger individuals of this species on exploited reefs is noted. Marked differences in the relative abundance of other species between exploited and unexploited reefs are evident and it is hypothesised that community disruption has occurred on exploited reefs, either directly or indirectly because of the removal of P. rupestris. These results are discussed in the context of marine reserves as a conservation strategy and a recommendation is made to extend the 5.6km seaward boundary of the Tsitsikamma National Park westwards to include the large concentration of presently exploited rocky reefs between the Blaaukrans river mouth and Natures Valley.

<b>TRES TRABAJOS SOBRE LA DISTRIBUCIÓN GEOGRÁFICA DE LA ACTIVIDAD REAL DE LAS EMPRESAS Y ESTRUCTURAS EN LA RENTABILIDAD DE SUS ACCIONES</b><br/><br/>La creciente integración internacional de los mercados financieros ha propiciado la realización de una serie de trabajos empíricos cuyo objeto es analizar los mecanismos a través de los cuales los movimientos de precios se transmiten de un mercado financiero a otro. Además, esos trabajos estudian las implicaciones de esa transmisión para la valoración de activos financieros, de cara a la aplicación de estrategias de cobertura y de inversión. Desde que Grubel (1969) resaltó los beneficios de la diversificación internacional se tiene un mayor interés en aplicar estrategias de cobertura y de inversión utilizando activos financieros cotizados en diferentes mercados financieros.<br/>Por otra parte, esos estudios también analizan las implicaciones de esa transmisión en las políticas reguladoras de cada mercado financiero. En Octubre de 1987 hubo una gran crisis financiera que se propagó a una gran parte de los mercados financieros del mundo. A raíz de esa crisis se aplicaron varias regulaciones y reglas institucionales con el objeto frenar el impacto de los shocks financieros internacionales. Aun así, se siguen produciendo shocks financieros internacionales que se propagan de mercado en mercado. Por ejemplo, la crisis asiática de 1998 tuvo un gran impacto negativo en los mercados financieros Latino Americanos.<br/>Por lo tanto, parece clara la importancia de detectar la existencia de transmisión de movimientos entre mercados financieros, lo cual está bien documentado en la literatura. Pero, dando un paso más, también es importante analizar las causas de esa transmisión de movimientos. Un ejemplo documentado, que pone de manifiesto esa importancia, es el caso de la bolsa de Toronto. En 1988 la bolsa de Nueva York puso límites a las caídas de precios que puede haber en un día, implantó los llamados circuit breakers. Seguidamente la bolsa de Toronto implantó estos límites, de forma tal que siempre que el índice Dow Jones bajaba en una cierta cantidad se suspendía la negociación en una serie de activos cotizados en la bolsa de Toronto. Esta medida se basaba en la creencia de que había una fuerte transmisión de movimientos entre Toronto y Nueva York. Más adelante Karolyi (1995) estudia la transmisión entre Toronto y Nueva York utilizando técnicas econométricas más sofisticadas que las utilizadas anteriormente, y llega a la conclusión de que la transmisión es menor de lo que se creía, y que ha ido disminuyendo con el tiempo, con lo cual lo más racional es ligar los circuit breakers de la bolsa de Toronto a un índice que recoja la evolución del mercado de Toronto y no al Dow Jones. En este caso, si se hubieran conocido los fundamentos económicos que hay detrás de la transmisión de movimientos entre Nueva York y Toronto, se habría podido detectar antes esa menor transmisión y se habría podido aplicar una regulación más adecuada.<br/>En la literatura hay varias contribuciones sobre las causas de esa transmisión de<br/>movimientos entre mercados financieros. Una primera explicación está basada en el modelo APT de Ross (1976), donde se supone que hay factores que influyen en la valoración de activos de varios mercados y que son los que provocan la transmisión de movimientos entre esos mercados. En esta línea está el trabajo de King, Sentana y Wadhwani (1994) en el que suponen que hay factores observables y factores no observables: encuentran que la mayor parte de la transmisión de movimientos está explicada por los factores no observables. Otra explicación, mencionada por Engle, Ito y Lin (1990), es que podrían existir técnicas de análisis chartista que causaran transmisión de movimientos de un mercado a otro. Sin embargo, esta explicación contradice la hipótesis de eficiencia del mercado y por esa razón no analizan su relevancia. Finalmente, se ha argumentado que la coordinación estocástica de políticas económicas de diferentes países podría causar transmisión de movimientos entre los mercados financieros de esos países. Ito Engle y Lin (1992) estudian la relevancia<br/>de esta explicación en el mercado de divisas y llegan a la conclusión de que esta razón no es muy importante. En el mercado de acciones, Francis y Leachman (1996) plantean la posibilidad de que la competencia entre políticas económicas también cause transmisión de movimientos entre mercados, pero no estudian la relevancia de esta posibilidad. <br/>A la primera de las explicaciones anteriores, la de los factores comunes, le falta la completa identificación de esos factores comunes que explicarían la transmisión de movimientos, y aun así parece ser la explicación más aceptada. Por ejemplo, King y Wadhwani (1990) presentan un modelo de contagio basado en esta teoría de los factores comunes. En ese modelo suponen dos mercados en los que el precio de las acciones viene determinado por dos factores, uno común y otro específico de cada mercado. Los agentes de un mercado solamente pueden observar los movimientos en el precio del mercado extranjero, y al tratar de inferir que parte de ese movimiento se debe al factor común pueden incurrir en una sobrevaloración del movimiento de ese factor, y este es el origen de contagio. <br/>Toda esta literatura sobre transmisión de movimientos entre mercados financieros solamente tiene en cuenta una parte de la globalización, la globalización financiera. Efectivamente, cada vez hay mas empresas cotizadas en diferentes mercados, con la tecnología de la información actual se pueden realizar movimientos de capitales entre mercados financieros de forma casi instantánea, etc... Sin embargo, no se ha prestado atención a la otra parte de la globalización, la que hace referencia a aspectos más reales de la economía. Hay un número creciente de empresas multinacionales que tienen sus mercados distribuidos en todo el mundo. Por ejemplo, la mayoría de empresas Japonesas que cotizan en Nueva York también realizan mucha actividad real en Estados Unidos. En 1998, Honada Motors realizó el 46,6% de sus ventas en Estados Unidos, Sony el 29,9%, Kyrocera el 21,3%, etc... Además las empresas multinacionales tienden a localizar sus centros de producción allí donde haya más ventajas en costes. Nuestra intuición es que para comprender la globalización financiera se debe tener en cuenta la otra cara de la globalización, la globalización real.<br/>Esta tesis intenta ser el primer paso de una investigación sobre la relación entre la<br/>globalización de la economía real y la globalización de la economía financiera. Todavía no se entienden bien los mecanismos a través de los cuales las fluctuaciones en los precios se transmiten de mercado financiero en mercado financiero. Nuestra investigación intenta estudiar si teniendo en cuenta la globalización en la economía real podemos entender mejor la globalización financiera. En esta tesis presentamos tres trabajos empíricos que estudian la importancia de la distribución geográfica de los negocios de las empresas para explicar algunas estructuras en la rentabilidad de las acciones. Esta tesis está organizada de la siguiente forma. En el capitulo 2 estudiamos el efecto de la actividad de las empresas multinacionales en la persistencia que suele detectarse en la volatilidad de la rentabilidad de las acciones. Utilizamos series de rentabilidades de acciones de empresas multinacionales cotizadas en los dos mercados financieros mas importantes del mundo: La bolsa de Nueva York y la bolsa de Tokio. Con estas acciones construimos dos carteras: i) Una con acciones de empresas que tienen una proporción significativa de negocios en las zonas horarias de Nueva York y de Tokio (empresas globales), y ii) otra con acciones de empresas que solamente tienen una proporción significativa de negocios en una de las zonas horarias (empresas no globales). Y encontramos que la transmisión de volatilidad de un mercado financiero al otro, o lo que es lo mismo, persistencia en la volatilidad lo suficientemente grande como para causar esa transmisión, es significativamente mayor en las empresas globales que en las no globales. Las principales causas para explicar esta persistencia en la volatilidad son: a) Dinámica de mercado o b) procesos generadores de información. Nuestros resultados sugieren que la principal causa de la persistencia en la volatilidad encontrada son los procesos generadores de información relacionados con la actividad comercial que realizan las empresas globales alrededor del mundo.<br/>Para interpretar los resultados del capitulo 2 suponemos que en el muy corto plazo hay información relacionada con la actividad del día a día de cada empresa que se introduce en el precio de su acción. Sin embargo, por lo que nosotros conocemos, la literatura no proporciona explicación teórica ni evidencia empírica que justifique nuestra suposición. Por lo tanto, la segunda parte de nuestra investigación, presentada en el capitulo 3, se centra en estudiar la validez de esta suposición. Para realizar esta investigación, la bolsa española constituye una buena muestra. La mayoría de las empresas multinacionales cotizadas en la bolsa española tiene concentrada su actividad multinacional extraeuropea en Sudamérica. Podemos, entonces, dividir el período de negociación en Madrid en dos subperíodos, uno cuando todavía es de noche en América (por la mañana en Madrid), y otro cuando ya es de día en América (por la tarde en Madrid). En este estudio, si en el muy corto plazo hay información relacionada con la actividad del día a día de las empresas que se introduce en los precios de las acciones, esperamos encontrar que las empresas con una proporción significativa de negocios en América tengan una mayor parte de su volatilidad diaria concentrada en el período en que todos sus negocios están en funcionamiento, es decir cuando es de día en América. Y esos son los resultados que encontramos.<br/><br/>Si en el muy corto plazo hay información relacionada con la actividad del día a día de una empresa que se introduce en el precio de su acción, podemos esperar que todas las acciones de empresas con negocios en una región económica se muevan por informaciones genéricas que afectan a esa región. Podríamos pensar en factores regionales que incorporaran esa información. Esos factores serian comunes a todas las empresas con actividad en esa región y podrían provocar transmisión de movimientos entre mercados financieros con empresas que realizan actividades en esa región. En el capitulo 4 trabajamos con esta posibilidad. Intentamos contribuir en la identificación de esos factores comunes que podrían causar la transmisión de movimientos entre mercados financieros. En este trabajo estudiamos los comovimientos entre la bolsa española y el mercado de acciones estadounidense. Para la realización de este estudio, esos dos mercados constituyen una buena muestra porque: i) Las multinacionales españolas tienen concentrada su actividad internacional (fuera de Europa) en Sudamérica. ii) Hay grandes empresas estadounidenses con actividad en Sudamérica (muchas de las cuales están incluidas en índices del mercado de acciones estadounidense, como el S&P 500). iii) La mayoría de las exportaciones sudamericanas se dirige a Estados Unidos.<br/>Por una parte, esperamos que las acciones de todas las empresas con actividad en<br/>Sudamérica estén movidas por factores que reflejen información relevante para<br/>Sudamérica, de manera que deberíamos encontrar un mayor comovimiento del mercado<br/>estadounidense con las empresas españolas con actividad en Sudamérica que con las que no tienen actividad allí. Por otra parte, esperamos que la evolución de la economía<br/>estadounidense se refleje en el mercado de acciones estadounidense y que tenga un efecto significativo en las empresas con actividad en Sudamérica, y este es un segundo mecanismo a través del cual esperamos encontrar que las empresas españolas con actividad en Sudamérica tengan un mayor comovimiento con el mercado de acciones estadounidense.<br/>En la investigación que presentamos en el capitulo 4 encontramos que efectivamente las<br/>empresas españolas con actividad en Sudamérica tienen un mayor comovimiento con el<br/>mercado de acciones estadounidense.<br/>En resumen, la evidencia empírica presentada en esta tesis sugiere que: i) Hay procesos generadores de información, relacionados con la actividad comercial que realizan las empresas globales alrededor del mundo, que constituyen un determinante importante de la persistencia en la volatilidad encontrada en la rentabilidad de las acciones. ii) Esos procesos generadores de información, también constituyen un determinante importante de los patrones intradia que presenta la volatilidad de la rentabilidad de las acciones. Parece haber información relacionada con la actividad del día a día de las empresas que se incorpora en el precio de las acciones en el muy corto plazo. iii) Hay indicios de que puede haber factores regionales que influyen en el precio de las empresas que realizan actividades en esas regiones, y estos factores podrían explicar una parte de la transmisión entre mercados financieros con acciones de empresas que realizan actividades en una misma región económica. Y por último, la evidencia empírica presentada en esta tesis sugiere que la globalización de la economía real afecta a algunas estructuras presentes en la rentabilidad de las acciones, por lo tanto, futuras investigaciones sobre la integración de mercados financieros teniendo en cuenta la globalización real deberían ser provechosas.<br/>La investigación que se presenta en esta tesis puede mejorarse en varios aspectos, que se dejan como futuras extensiones del trabajo. Por ejemplo: i) en el capitulo 2, realizamos todo el análisis con modelos de volatilidad autoregresiva univariantes, por lo tanto, una posibilidad seria repetir el análisis con modelos multivariantes y comprobar si obtenemos los mismos resultados. Por otra parte podríamos realizar el análisis con acciones de la misma nacionalidad para comprobar la relevancia de la nacionalidad en los resultados obtenidos. ii) En el capitulo 3, se deja para un futuro análisis, estudiar si teniendo en cuenta la distribución geográfica de los negocios de las empresas se obtienen resultados diferentes en trabajos relacionados como los de Chan et al (1994) o Werner y Kleidon (1997). iii) Y en los capítulos 3 y 4 se deja para un futuro trabajo, estudiar si los inversores españoles recogen esa información relevante para las empresas españolas con actividad en Sudamérica, directamente desde Sudamérica o bien si infieren esa información a través de los movimientos del mercado de acciones estadounidense.

The concept of logistics, which until the mid-50 was limited to physical distribution - transport docks and warehouses due to its beginnings in the great empires and armies, has become much more complex and comprehensive. Nowadays it integrates processes involving the entire geographic scope, encompassing material flows, information and products from the point of origin (suppliers) to the point of consumption (client), among several companies throughout the supply chain. Thus, this chain management has become essential for survival, where the changes occur within a dynamic, unstable and evolving scenario. Consumers are increasingly demanding and product life cycles are shrinking. Companies seek to optimize their processes by creating a competitive advantage with perceived value, reducing operational costs, managing effectively and efficiently throughout the flow to exceed the customers expectations. This thesis aims to investigate whether the geographic information system (GIS) supports the distribution centers in the physical distribution logistics decisions. The study is based on literature review and field research covering 36 distribution centers in the region of Greater Sao Paulo that interact with the region of Vale do Paraíba Paulista, distribution centers that use geographic information system (GIS) as strategy in the physical distribution chain and 12 distribution centers that do not use this system. The research result allows the discussion of the advantages of using Geographic Information System (GIS) in the physical distribution logistics decisions in the distribution centers studied. It is concluded that the use of GIS can support and facilitate the decision making of Physical Distribution Logistics positive influence on reducing logistics costs, the risk of lack of materials and delivery lead time, extending its benefits to an improvement in their performance resulting in an increase in market share. The use of GIS can also be useful and valuable for analysis and decision making in Public Transport Sector in order to improve the infrastructure of Brazilian modal transportation and create more efficient multimodal networks, ensuring the flow of materials for domestic and foreign markets.<br>O conceito de Logística, que até meados dos anos 50 restringia-se à distribuição física armazéns e docas de transporte, em razão da prática nos seus primórdios, à época dos grandes impérios e exércitos da Antiguidade, tornou-se hoje muito mais complexo e abrangente. O conceito atual integra os processos, em todo o escopo geográfico, decorrente dos fluxos de materiais, produtos e informações, desde o ponto de origem (fornecedores) até o ponto de consumo (cliente) e entre as diversas empresas de toda a cadeia de suprimentos. Assim, a gestão dessa cadeia tornou-se fundamental para a sobrevivência das empresas, em um cenário dinâmico, instável e evolutivo. Os consumidores estão cada vez mais exigentes e os produtos com ciclos de vida cada vez menores, o que faz com que as empresas busquem otimizar seus processos criando uma vantagem competitiva com valor percebido, reduzindo os custos operacionais, controlando de forma eficaz e eficiente todo o fluxo, a fim de superar as expectativas de seus clientes. Esta dissertação tem como objetivo investigar se o Sistema de Informação Geográfica (GIS) apoia os Centros de Distribuição nas decisões logísticas de distribuição física. O estudo tem como base a revisão bibliográfica, a pesquisa de campo englobando 36 Centros de Distribuição da região da Grande São Paulo que interagem com a região do Vale do Paraíba Paulista, Centros de Distribuição que utilizam o sistema de informação geográfica (GIS) como estratégia na cadeia de distribuição física e, 12 Centros de Distribuição que não utilizam esse sistema. O resultado da pesquisa indica haver vantagens na utilização do Sistema de Informação Geográfica (GIS) nas decisões logísticas de distribuição física nos Centros de Distribuição estudados. Conclui-se que a utilização do GIS pode apoiar e facilitar a tomada de decisão logística de Distribuição Física influenciando positivamente na redução de custos logísticos, do risco da falta de materiais e no lead time de entrega, estendendo seus benefícios para uma melhoria em seu desempenho, resultando em um crescimento da participação de mercado. O uso do GIS pode, ainda, ser útil e valioso para a análise e tomada de decisão em Políticas Públicas do Setor de Transportes com o objetivo de melhorar a infraestrutura de modais de transportes Brasileira e criar redes multimodais mais eficientes, garantindo o escoamento de materiais para o mercado interno e externo.

The aim of this thesis has been to develop a water quality model, suitable for Brazilian conditions and that is capable of estimating the effects of future land use scenarios on water quality. The model is designed to be consistent with the availability of data in less developed countries and one of its major advantages is that the parameters involved are easily defined in terms of physical characteristics. A methodology is presented which has been designed specifically to support the determination of water quality changes resulting from point and non-point sources in a large river basin with varied land use, taking into account both the magnitude and spatial distribution of the loads produced. The methodology is capable of implementation on land surfaces having heterogeneous distribution of water pollution sources. The model is based on a cellular configuration where information on land use, topography, soil type and rainfall is manipulated using geographical information systems (GIS). Information on land use in each cell is obtained by classifying remotely sensed satellite data. Topographic parameters for each cell are derived from digital elevation models (DEM). Rainfall values for each cell are obtained from the interpolation of point data derived from meteorological stations. Other more conventional data are acquired by digitising maps. Using this cellular structure, runoff, and chemical outputs from the individual cell, are routed through the catchment using a physically based mixing model to provide input to the drainage network. The network, derived automatically from a digital elevation model (DEM), defines the river system in the model. The link between the catchment and the river network defines a river 'buffer' zone where point and non-point sources are stored. The model enables spatial relationships between point and non-point sources to be investigated and the consequences to the river system can then be modelled using the river network topology.

This thesis investigates the combination of changes in the population and employment into sectors in rural Sweden for the period 1960-2010. The aim is to describe and analyze the demographic changes together with the labour market changes, and to account for the spatial outcome of these changes by considering the heterogeneity of rural areas. The analysis departs from the framework of rural restructuring, where changes in employment and population in rural Sweden are interpreted as local products of the global processes of technological development, social modernization and globalization. Empirically, the analysis is based on a combination of longitudinal censuses and register data on the Swedish population covering the period 1960-2010. The first part of the aim is achieved by applying a life-course perspective and exploiting the longitudinal nature of the data. The life-course perspective distinguishes between historical time and the age of individuals, making it possible to situate changes in employment and migration on the individual level. The second part of the aim is achieved through developing a typology of rural Sweden by doing a cluster analysis on SAMS-areas. The results show that rural change after 1980 was characterized by de-industrialization and the rise of the urban service sector. The period was also characterized by regional urbanization rather than local urbanization. Peripheral urban and rural areas based on industrial employment found themselves with a declining economic motor, which meant that people had to find their source of income elsewhere. The migration stream in this period was thus increasingly directed towards metropolitan or large city centers, and their rural surroundings within commuting distance. However, the more fine-tuned spatial typology reveals that also a few areas in the rural periphery have experienced growth, these areas are mainly attractive places based on various kinds of tourism. It can thus be concluded that different rural areas have experienced, and will continue to experience, the shift from manufacturing to services differently, where some areas have grown in both demographic and employment terms while others have declined. In this sense the heterogeneity of rural areas are a product of both growth and decline – of old development paths that is reaching their end and of new development paths that will continue into the future.

Mobile, rocky shore species often exhibit distinct but dynamic spatial distribution patterns, such as the occupation of microhabitats and formation of aggregations. These patterns are likely to be influenced by the behavioural patterns of a species, their population dynamics and the consequent benefits of adopting particular patterns at certain times of the year. Using Planaxis sulcatus (Planaxidae) as a model species, this thesis documented spatial and temporal variation in the spatial patterns of this species, and attempted to identify the causes and consequences of these behaviours in the seasonally variable Hong Kong intertidal zone. Activity patterns and snail behaviour during activity influenced the locations and types of spatial patterns formed. Planaxis was active and foraged whilst awash, with activity initiated by the ebbing or rising tides. Activity continued until the rock dried on an ebbing tide, or until snails were submerged by the rising tide. Snails were more active and moved for longer durations in summer than winter. When inactive, Planaxis occupied microhabitats such as cracks and crevices in summer and winter, but in the cooler months snails also formed aggregations on open rock surfaces and around microhabitats such as crevices. The extent of aggregation and number of snails in each aggregation showed strong seasonal variation, being greater in the transition period between summer and winter, and differed between sites, being the greatest at one site at Stanley. Seasonal differences in aggregation patterns may be linked with concurrent variation in Planaxis populations which, as a result of life histories events, had a greater abundance of snails and a larger number of recruits in the summer-winter transition, potentially increasing the chances and likelihood of aggregation formation. Microhabitat occupation in the summer provided physiological benefits to the snails. Compared with snails on open rock surfaces during summer low tides, those in crevices remained cooler and suffered less osmotic stress; while individuals in rock pools experienced lower osmotic but not thermal stress. In summer, aggregated snails suffered higher thermal and osmotic stresses than solitary individuals. The winter aggregations, however, showed little physiological benefits; with aggregations of different sizes having no effect on snail body temperatures, and only weak indications of large aggregations relieving osmotic stress. Winter aggregations, therefore, may be linked to minimizing dislodgement risks due to increased wave action at this time. A computer simulation incorporating seasonal differences in population densities, the likelihood and duration of activity, different topographies and three behavioural “rules” produced spatial patterns similar to those on the shore in terms of aggregation sizes, and the proportions of aggregating and crevice-occupying snails. These variables, therefore, play a role in determining the spatial patterns seen in Planaxis. This simple model did not, however, completely match field observations, suggesting that seasonal and spatial differences in distribution patterns involved more complex processes such as variation in local environmental conditions (temperature, wave action, shore topography) and/or biological factors (population densities, size structures, behavioural variation). Further investigations of these processes may better resolve our understanding of how these patterns form and their potential benefits.<br>published_or_final_version<br>Biological Sciences<br>Doctoral<br>Doctor of Philosophy

This study is concerned with the geographical distribution of the provision of nursery education in England and Wales from 1981 to 1994. It examines the extent to which the provision of nursery education is related to the need for the service. Davies's (1968) concept of territorial justice implies a positive correlation between need and provision. This interpretation of territorial justice is well established in the academic literature on the distribution of public services. Boyne and Powell (1991) have questioned whether a positive correlation between need and provision is always required for territorial justice. The key issue, it has been argued, is the requirement to consider the dimensions of need and service provision. This study assesses the validity of Boyne and Powell's (1991) analysis and builds substantially on its foundation A new set of criteria for the assessment of territorial justice is developed. These are presented as the alternative to the Davies (1968) criterion of territorial justice. Territorial justice is more appropriately concerned with 'equal provision for relevant dimensions of need'. The criteria for the evaluation of territorial justice developed in this study are applied to nursery education. The correlations provide a mixture of evidence of territorial justice and injustice in the quantity of service provision, together with territorial injustice in the quality of service. The Davies (1968) criterion of territorial justice would have indicated greater territorial justice in the provision of nursery education than that found using the new criteria. This study contributes at two levels to previous literature on territorial justice: a new method is used to assess territorial justice and new evidence on territorial justice within nursery education provision in England and Wales is presented. Further studies using the criteria developed in this study are required in other areas of public policy.

Thesis (PhD)--Macquarie University, Division of Environmental & Life Sciences, Dept. of Biological Sciences, 2004.<br>Bibliography: p. 599-618 (pt. 1).<br>Introduction -- Materials and methods -- Taxonomic studies -- Species descriptions and keys to genera and species -- Tardigrades from cryptograms and leaf litter on soil and from a sand island -- The distribution of terrestrial tardigrades in eastern Australia.<br>The terrestrial tardigrade fauna of Australia has been given scant attention in the past. This study was undertaken to collect and identify terrestrial tardigrade species from a wide a variety of habitats in Australia. This new taxonomic data set was then used to explore zoogeographic patterns and processes in eastern Australia. -- The first part of this study is concerned with the clarification of some taxonomic problems which arose during the course of the study, the solution of which was essential in order to delineate species boundaries. In the family Macrobiotidae, two genera, Minibiotus and Calcarobiotus, are remarkable for the high number of species recorded in Australia relative to other parts of the world. Within the genus Macrobiotus many new species within two groups, hufelandi and harmsworthi, are described and it is concluded that the nominal species in each case is not part of the Australian fauna. A new genus, Haptobiotus, is described in the family Macrobiotidae. -- In order to clarify species within the Diphascon (D.) pingue group, populations were subjected to multivariate analysis. The analysis resulted in the conclusion that only two species in that group, D. pingue and D. pinguiforme, have so far been found in Australia. The study also resulted in the synonymisation with D. pingue and D. pinguiforme of two previously described species from Australia. -- The discovery of a new genus, Milnesioides, provides an insight into the structure and function of the buccal apparatus of the rare monotypic genus Limmenius within the family Milnesiidae. A new genus. Lexia, is described in the subfamily Itaquasconinae along with other members of this group which has been under-recorded in Australia. The descriptions of three species in the genus Antechiniscus provides new morphological detail for this genus and provides additional evidence that the genus is found only in cool temperate regions in the southern hemisphere. -- The 161 species in 34 genera found in this study are described and line drawings provided. Of the 161 species, 59 are new to science and a further 16 have been published as new species during the course of the project. Also included are descriptions of an additional 21 species, recorded from Australia by other authors but not found in this study. Eleven of these species are probably misidentified. Keys to genera and species are supplied. -- A small but revealing study provides some preliminary data on tardigrade species associated with cryptogams or leaf litter on soil and sand. The detection of a rich fauna suggests that such habitats need to be examined if the full tardigrade fauna of Australia is to be documented. -- Data from 36 sites in eastern Australia containing 141 species were subjected to multivariate analysis in order to elucidate zoogeographic patterns of tardigrade communities. The study, although preliminary in many ways, showed a high correlation between tardigrade communities and core zoogeographic subregions in eastern Australia, e.g., a northern monsoonal, a nontropical south-eastern and a dry central-western subregion. Two distinct habitat types within the south-eastern subregion, cool temperate rainforest and limestone sites also support distinct species communities. Each tardigrade community consists of cosmopolitan, pantropical, oriental, southern hemisphere and Australian species. The degree to which each of these types contribute to each community is discussed in terms of the evolutionary history and the climatic regime (primarily temperature and length of dry periods) of each subregion and, to a limited extent by passive dispersal.<br>Mode of access: World Wide Web.<br>2 parts (xxvi, 618 leaves (pt. 1), 182 leaves (pt. 2) ill

Wireless networks are useful in many different scenarios. They allow to create emergency networks for catastrophe response, wide area surveillance networks in hostile environments, or simply permit users to share information, play on-line games, and surf the Web. Mobile ad hoc networks are a particular case of wireless networks characterised by the absence of a supporting infrastructure.The thesis addresses the problem of building middleware services that permit to fully exploit the opportunities offered by mobile ad hoc networks. For that purpose, it is required to design algorithms that account for the limitations of mobile devices and that make a careful use of the scarce resources available in ad hoc networks. A central middleware service for mobile applications is data sharing. The thesis addresses the use of data replication as a technique to improve data availability and resource savings in mobile ad hoc networks. In particular, the thesis proposes the use of epidemic protocols to achieve these goals. In this context, the thesis presents the following contributions. It presents and evaluates $\i)$ an algorithm to reduce the number of transmissions required in a broadcast, $\ii)$ an algorithms for the geographical distribution of replicas of data items, and $\iii)$ algorithms to attenuate the impact of node movement in the geographical distribution. Finally, the thesis describes an application of the algorithms to build a concrete application, a version of the Session Initiation Protocol for wireless networks

This thesis investigated the distribution of community-based crime prevention programs across 223 suburbs in Brisbane, Australia. It aimed to problematise the implementation and funding of services and examine whether the number and type of programs implemented were related to crime rates, community capacity, community perceptions of collective efficacy or other community characteristics. The thesis addressed two research questions. First, what types of community-based crime prevention programs are most prevalent in the Brisbane Statistical Division? Secondly, how are resident demographics, community cohesion, community levels of collective efficacy and community crime rates related to the distribution of community-based crime prevention programs across the Brisbane Statistical Division? Community-based crime prevention programs were defined as those that might impact one or more crime risk factors. This broad definition includes not just programs targeting crime and harm prevention, but also programs with aims such as safeguarding against social isolation and providing welfare support. I used four main data sources. The first was an audit I conducted of all community-based crime prevention programs in Greater Brisbane, active at some point from 2000 to 2005 inclusive. I found 8,894 programs, funded by a variety of organisations, and coded the crime prevention approach of each: 1. problem-focused, 2. developmental (modifying individual pathways), or 3. social-community (strengthening the community). The second data source was the Australian Research Council Community Capacity Survey: Wave One, a survey of 82 randomly selected communities in Greater Brisbane. This survey captured each community’s perceptions of their levels of cohesion, disorder, social activism, and collective efficacy. The third dataset consisted of community characteristics and demographics from the Australian Bureau of Statistics (ABS) 2001 Census. The fourth dataset was Queensland Police Service data on annual crime rates, by crime type and community. I examined the theoretical construct of collective efficacy to determine whether there was a relationship between program density and a community’s belief in a common sense of trust and cohesion and willingness to solve local problems. I found no statistically significant relationship. Interestingly, program density instead had a strong positive correlation with civic engagement – the extent to which people involve themselves in activities for their community’s benefit. Due to this correlation with civic engagement, but not collective efficacy, I propose that it is not residents initiating an intervention, but residents participating in an intervention, that impacts program density. Organisations can analyse the needs of a community and develop and organise interventions, but to keep a program running it is necessary to engage community residents willing to participate in those interventions. By comparison, I investigated whether there was a link between low program density and residents’ fear of participating. My research supported this hypothesis, finding an inverse relationship between program density and resident perceptions of crime levels. Specifically, program density had moderate or strong inverse relationships with community perceptions of community violence, alcohol and drug problems, community problems and community divisions. The relationships between program density and actual crime rates were not strong, but were positive, the opposite to the relationship of program density with perceptions of crime. Program density had a moderate positive relationship with property crime and weak positive relationships with drug, violent, and public nuisance crimes. In summary, this thesis had two major findings. The first finding was that it was not the perceived level of collective efficacy but the level of civic engagement in a community that had a significant relationship with program density. The second finding was that the mix of program types did not differ greatly across communities; this was potentially due to programs being implemented without investigation of community needs, as well as being implemented broadly. I argue that it is important to understand that programs are not implemented in isolation; communities often already have multiple co-existing crime prevention and other programs. A regularly updated and searchable database of existing programs, like the one constructed for this thesis, would be a useful resource for both government and communities interested in developing and evaluating programs.<br>Thesis (PhD Doctorate)<br>Doctor of Philosophy (PhD)<br>School of Crim & Crim Justice<br>Arts, Education and Law<br>Full Text

A simulation matrix population model of a small population of wrens (Troglodytes troglodytes) is presented. The field work methods used to obtain and analyse the demographic rates are provided. This includes a description of the use of miniature radio tags to track juvenile (post-fledging) survival and dispersal, and capture mark recapture analysis of an eight year dataset to estimate adult survival rates, taking into account environmental variation and density dependence. Age related reproductive rates were obtained from detailed nest surveys. Using these demographic rates (means and variances), and information on density dependence in survival and breeding, a simulation matrix model was developed using Matlab (The MathWorks, Inc.). The operation of this model and its outputs are explained in detail, with particular reference to the methods employed to incorporate both density dependent survival and reproduction and environmental and demographic stochasticity. This model is then used to illustrate how, under plausible conditions of density dependence and stochasticity, large discrepancies are obtained between the deterministic, density independent elasticities of the population growth rate (λ) and the stochastic, density dependent elasticities of the equilibrium population size, extinction probability and invasion exponent. Since the elasticities of λ are often used to guide the management of endangered species, these results are particularly relevant to workers in the field of rare species conservation. While the importance of including environmental variation in the form of stochastic population simulations seems to now be generally accepted, the role of density dependent population regulation is still infrequently considered. Since one of the most common causes of population decline is habitat destruction, leading to an increase in population density within the remaining areas of habitat, this omission may rarely be justified. It is recommended that when elasticity analysis is conducted as part of species conservation efforts, both density dependence and stochasticity are included. Failure to do so may result in the misguided management of endangered species.

Kyoto University (京都大学)<br>0048<br>新制・課程博士<br>博士(農学)<br>甲第9639号<br>農博第1267号<br>新制||農||846(附属図書館)<br>学位論文||H14||N3671(農学部図書室)<br>UT51-2002-G397<br>京都大学大学院農学研究科地域環境科学専攻<br>(主査)教授 櫻谷 哲夫, 教授 大西 近江, 教授 矢澤 進<br>学位規則第4条第1項該当

Zooplankton samples were collected from 166 Oregon lakes. The lakes included a wide range in size, trophic status, and water quality. Lakes were located throughout the state. Zooplankton were identified using standard taxonomic keys and counted. Seventy-four species were identified from the 200 total samples, including 32 species of cladocera, 22 copepods, and 11 rotifers. Two species of copepod were recorded for the first time in Oregon: Diaptomus mississippiensis and Diaptomus pallidus. Seven species had widespread distributions throughout most of the watersheds in the state. Seventeen other species had distributions restricted to eastern, central, or western Oregon. The remaining species were either rare or had random distributions.

Individuals within a species often compete for resources in both space and time. In dominance hierarchies individuals with the greatest competitive ability will occupy prime locations during optimal periods to increase efficiency in gathering a resource. Subdominant individuals with low competitive abilities may be forced to reside in habitats of poor quality relative to dominant individuals. In this study I examined the long term patterns of giant kokopu distribution, movement, growth, habitat use, and social interaction between fish in relation to invertebrate drift (food supply). The habitat quality and abundance of food along a one km section of Alex�s Creek was monitored for a two year period. Though the physical structure of Alex�s Creek was relatively homogenous there were significant spatial differences in the density of drifting invertebrates sampled between riffles and pools over this long temporal period. In general, more drifting invertebrates were sampled in riffles of relatively long length and area. Within Alex�s Creek the distribution of giant kokopu, Galaxias argenteus, was determined by patchy distributions of food supply, specific physical factors of pools, and interactions between fish in dominance hierarchies. Over the 20 month study period, the most important biotic factor determining fish biomass was the total number of drifting invertebrates within pools while the most important abiotic factor determining fish abundances within pools was the pool size (surface area). The growth rate of individual fish correspondingly varied between fish residing within pools of different quality. Growth rates were higher for individual fish residing in pools with a relatively high density of drifting invertebrates. The differences in individual growth rates of giant kokopu may determine when fish leave a particular habitat patch (pool) and move to a new one. Fish that moved had lower growth rates (before moving) than fish that remained resident within home pools. Overall the movement of giant kokopu within Alex�s Creek was very restricted due to a relatively consistent distribution of food, however there were differences in the mobility of giant kokopu among different social ranks. The most dominant fish in pools were largely sedentary while fish ranked directly below fish 1 (i.e. fish 2 and 3 in social hierarchies) were relatively mobile. The ability of dominant fish to exclude subdominant fish from the most preferred feeding positions during optimal feeding times had consequences for overall giant kokopu activity. Under normal food supply conditions dominant fish were predominantly nocturnal and maintained large home ranges at night. Conversely subdominant fish occupied large home ranges by day, but were generally not observed at night. When the food supply was limited the utilization of pools was determined by social rank. Dominant fish from each pool increased daytime activity, home range size, aggressiveness, and the capture of food items offered by day while simultaneously reducing the spatial and temporal activity and habitat use of subdominant fish. These results indicate that behavioral changes in large dominant fish influence and reduce the amount of resources available to subdominant fish.

Using SCUBA and an in situ method of quantifying substrate characteristics, I describe patterns of zebra mussel (Dreissena polymorpha) distribution along the St. Lawrence and Hudson Rivers and in Oneida Lake, New York, and develop empirical models for their abundance. Calcium-poor waters originating from rivers draining the Canadian Shield resulted in a lack of zebra mussel along the north shore of the St. Lawrence River east of Montreal until Portneuf despite an abundance of suitable substrate. Calcium concentrations of 15 mg/L or less were found to limit the distribution of zebra mussel. The entire south shore from Cornwall, Ontario to Ile d'Orleans, Quebec was colonized by zebra mussel wherever suitable substrate was found. In the Hudson River, along the south shore of the St. Lawrence River and in Oneida Lake variability in density was primarily related to substrate type which explained between 38% and 91% of the variance. Other factors such as Secchi depth, calcium concentration of the water, the presence of crayfish, native unionid abundance and the maximum width of the river at the site increased the amount of explained variance across the different systems. The influence of substrate type on zebra mussel density and the predictions of the model were also tested using data from the literature, where substrate type explained 75% of the variability in density. The scatter of the literature data above the predictions of the empirical model suggests that North American zebra mussel populations may continue to grow before reaching equilibrium levels. While water chemistry parameters may be useful predictors of the presence or absence of zebra mussel in a given water body, physical factors play a far greater role in determining local abundance.

Unsustainable use of wildlife is a global conservation challenge. Understanding ecosystem specific patterns of wildlife exploitation is key to addressing this challenge. This thesis explores the nature of wildlife exploitation in and around Ugalla Game Reserve in western Tanzania. The reserve is divided into Ugalla east and Ugalla west tourist hunting blocks. First, I assessed the status of wildlife in the hunting blocks. Overall, estimates of wildlife population parameters suggested that Ugalla west was somewhat more exploited than Ugalla east. Second, I looked at the degree to which the hunting blocks experienced illegal wildlife hunting (poaching) and factors behind this. The spatial distribution of poaching signs and household interviews revealed that poaching was widespread, more so in Ugalla west than Ugalla east. Proximity to the reserve encouraged poaching, although bushmeat consumption increased with distance from the reserve. A wide range of bushmeat species was favoured, but the common species were impala Aepyceros melampus, dik-dik Madoqua kirkii and common duiker Sylvicapra grimmia. Availability of alternative sources of animal protein, agricultural production and income had significant influences on poaching. Different forms of poaching were specialist activities largely independent of each other. To address poaching, the main focus of attention has been on creating wildlife management areas (WMAs) along with allowing legal subsistence hunting by the communities around the reserve. Third, I assessed the impact of legal subsistence hunting on the wildlife species, and showed that it is not well managed and wildlife populations are contracting. This leaves WMAs as a potentially viable option for the conservation of Ugalla. Therefore, lastly, I identified and recounted some options for promoting the sustainability of WMAs. This thesis presents the first detailed assessment of wildlife exploitation in Ugalla, thus contributing to the existing body of knowledge on tackling the bushmeat crisis in Africa.

Thesis (PhD)--University of Stellenbosch, 2003.<br>ENGLISH ABSTRACT: The geographic genetic population structure and evolutionary history of the African four-striped mouse, Rhabdomys pumilio, was investigated using mitochondrial (mtDNA) cytochrome b gene (1140 bp) and control region (994 bp) sequences and a combination of cytogenetic banding techniques (G- and C-banding), and fluorescence in situ hybridization. Two cytotypes (2n = 46 and 2n = 48) were identified by cytogenetic analysis. No evidence of diploid number variation within populations was found nor were there differences in gross chromosome morphology, or subtle interchromosomal rearrangements at levels detected by ZOO-FISH. The comparative painting data (using the complete suite, N = 20, of Mus musculus chromosome specific painting probes) show that 10 mouse chromosomes have been retained as chromosomal arms, or intact chromosome blocks within the R. pumilio genome, six produced double signals, while the remaining four hybridized to three or more R. pumilio chromosomes. In total, the 20 mouse chromosome paints detected 40 segments of conserved synteny. Their analysis revealed eight R. pumilio specific contiguous segment associations, a further two that were shared by R. pumilio and other rodents for which comparable data are available, the Black (Rattus rattus) and Norwegian (Rattus nONegicus) rats, but not by the Chinese hamster, Cricetulus grise us. The results suggest that mouse chromosomes 1, 10, and 17 have undergone extensive rearrangements during genome evolution in the murids and may be useful markers for enhancing our understanding of the mode and tempo of chromosome evolution in rodents. Following initial studies using control region sequences, the phylogeographic appraisal of R. pumilio was done using cytochrome b gene sequences. Analyses based on a variety of analytical procedures resulted in the detection of two major mtDNA lineages that correspond roughly to the xeric and mesic biotic zones of southern Africa. One clade comprises specimens with 2n = 48, and the other representatives of two cytotypes (2n = 48 and 2n = 46). The mean sequence divergence (12.0%, range 8.3% -15.6%) separating the two mtDNA clades is comparable to among-species variation within murid genera suggesting their recognition as distinct species, the prior names for which would be R. dilecfus and R. pumilio. Low sequence divergences and the diploid number dichotomy within the mesic lineage support the recognition of two subspecies corresponding to R. d. dilecfus (2n = 46) and R. d. chakae (2n = 48). The data do not support subspecific division within the nominate, R. pumilio. Molecular dating places cladogenesis of the two putative species at less than 5 million years, a period characterised by extensive climatic oscillations which are thought to have resulted in habitat fragmentation throughout much of the species' range.<br>AFRIKAANSE OPSOMMING: Die geografiesebevolkingsstruktuur en evolusionêre verwantskappe binne die Afrika streepmuis, Rhabdoys pumilio, is ondersoek deur middel van mitochondriale ONS volgordebepaling van die geenfragment sitochroom b (1140 basispare) en die reguleerstreek (994 bp) in kombinasie met sitogenetiese tegnieke (G- en Cbandkleuring en f1uoreseerende in situ hibridisasie). Twee sitotipes (2n = 46 en 2n = 48) is geidentifiseer deur sitogenetiese analasie. Geen bewys van variasie in die 2n chromosoomgetal binne bevolkings is gevind nie. Verder is daar ook geen verskil in die morfologies struktuur van chromosome aanwesig binne bevolkings nie. Vergelykende data (verkry met behulp van die N = 20 Mus musculus chromosoomspesifiekepeilers) dui daarop dat 10 muis chromosome behoud gebly het as chromosoomarms of chromosoomblokke binne die R. pumilio genoom. Ses peilers het dubbel seine gelewer terwyl die oorblywende vier peilers gehibridiseer het aan drie of meer R. pumilio chromosome. In totaal het die 20 muischromosoomverwe 40 konserwatiewe segmente geidentifiseer. Die analise dui agt R. pumilio spesifieke aaneenlopende segmentassosiasies aan, met 'n addisionele twee wat deur R. pumilio en ander muisagtiges vir wie vergelykende data beskikbaar is, byvoorbeeld die swart (Rattus rattus) en Noorweegse (R. norvegicus) rot maar nie die Chinese hamster, Cricetulus grise us, gedeel word. Die resultate stel voor dat muischromosoom 1, 10 en 17 ekstensiewe herrangskikkings ondergaan het gedurende die genoom evolusie binne die Muridae en dat hulle waarskynlik waardevolle merkers kan wees om beide die patroon en tempo van chromosome evolusie in muisagtiges verder te kan verstaan. Die filogeografiese verwantskappe binne R. pumilio is ondersoek deur middel van ONS volgordebepalings van die reguleerstreek asook sitochroom b. Die resultate van hierdie studie het twee divergente mitochondriale ONS eenhede ontdek wat gekorreleer kan word met xeriese en mesiese klimaatsones binne suidelike Afrika. Een groep bestaan uit diere met 2n = 48, terwyl die ander genetiese groep twee sitotipes (2n = 46 en 2n= 48) insluit. 'n Gemiddelde genetiese divergensie van 12.0% (varieer tussen 8.3% - 15.5%) verdeel die twee mtDNS-groepe en is vergelykbaar met tussenspesievariasie binne ander muisagtige genera, wat moontlik daarop dui dat twee verskillende spesies teenwoordig is; die voorgestelde name is R. di/ectus en R. pumilio. Lae genetiese divergensie binne die mesiese groep versterk die moontlike teenwoordigheid van twee subspesies, R. d. di/ectus (2n = 46) en R. d. chakae (2n = 48). Die data verleen egter nie steun aan die divisie binne R. pumilio nie. Molekulêre datering van die twee spesies dui daarop dat die divergensie ten minste 5 miljoen jaar gelede plaasgevind het. Die periode was gekarakteriseer deur ekstensiewe klimaatsossilasies, wat gely het tot habitat fragmentasie in die spesie se verspreidingsgebied.

Geographical variation in taxa must be considered in evolutionary studies. The purpose of the present study is to demonstrate how geographical variation can be measured and documented for a taxon for one slice of time. Future evolutionary studies should document geographical variation for the entire geographical range of the species involved at several points of time throughout its total stratigraphic range. Thus the variation that is present at one time horizon may be separated from the variation that occurs through time. This work consists of a study of geographical variation in the genus Astarte (Phylum Mollusca: Class Bivalvia) from the Yorktown and Jackson Bluff Formations (early Pliocene) of the Atlantic Coastal Plain. Factor analysis, multivariate analysis of variance, and discriminant analysis were performed on measurements of specimens of Astarte from ten localities. There are significant differences in the morphologies of individuals among localities. These differences are due to the presence of different species of Astarte and to variation in size and external ornamentation within the same species. Seven species recognized from literature on Pliocene Astarte were identified among the individuals of the ten localities, but the statistical results indicate that these seven species may be grouped into three "types" that mayor may not represent species. The three types occur together in some localities, suggesting that they are distinct species living in sympatry. Factors influencing geographical variation include larval dispersal strategy and the effect of the environment.<br>Master of Science

Biological invasions threaten the stability and biodiversity of freshwater ecosystems worldwide. The impacts of an invading species often vary across systems, making their prediction difficult. When data from multiple invaded sites are available, statistical models can be developed to correlate an invader's distribution and abundance with local environmental variables; such models could then provide managers with useful tools to help prioritize efforts to control the invader. The introduction of the zebra mussel (Dreissena polymorpha) and quagga mussel (D. bugensis) to North America ranks among the most ecologically and economically disruptive aquatic invasions ever documented. While some attempts have been made to predict zebra mussel occurrence and abundance, none have been made for quagga mussels. Furthermore, few studies have been based on river systems, which possess the bulk of North American freshwater biodiversity. I related zebra and quagga mussel occurrence and biomass to physical habitat variables (calcium concentration, substrate size and depth) in the St. Lawrence River. I then developed predictive models of abundance for each species from combinations of these variables. Each variable explained a significant amount of variation in mussel biomass, but different combinations of variables were obtained for each species. Although these models do not account for all of the variation in abundance, they do provide a useful basis for predicting dreissenid distribution and abundance in other invaded river systems.

Ecological research aimed at the conservation of useful plants has rarely considered the spatial distribution of resources nor the potential implications for management. In this thesis I examined the spatial patterning of a group of 23 useful plant species on the 3,500 ha territory of a Kuna community in Darien, Panama. A systematic random sampling scheme was used to survey the distribution and abundance of the species, as well as the physical environment. A series of canonical analyses was conducted to evaluate the species-environment relationships and to identify spatial structures in the species distributions left unexplained by the environmental variables. Four distinct distribution patterns were identified among the species; these were most strongly explained by land-use, the degree of canopy closure and topography. Significant spatial structures, independent of the environmental variables, were related to anthropogenic pressures and an edaphic gradient. The habitat associations of the individual species are described and data on one species, Sabal mauritiiformis , is used to illustrate the utility of these data in the management of plant resources on human landscapes.

Meningococcal disease, caused by the bacterium Neisseria meningitidis, is an important cause of morbidity and mortality in young children and adolescents worldwide. There are 12 serogroups with most disease due to meningococci expressing one of five capsular polysaccharide antigens corresponding to serogroups A, B, C, Y and W135. In Europe, the majority of disease-causing strains are of serogroups B and C. No comprehensive vaccine is available against the bacterium due to the difficulty in producing serogroup B vaccines. A number of countries, e.g. UK and the Republic of Ireland have implemented routine meningococcal conjugate C (MCC) vaccine strategies. Due to the high proportion of disease accounted for by serogroup B in Europe and other developed countries, much research is currently being carried out to unearth vaccine candidates that would be protective and give as wide coverage as possible. Such candidates include the antigens PorA, FetA and factor H-binding protein. Potential drawbacks with antigens such as these which are under immune selection are high degrees of variability and lack of cross-immunity. Determination of the distribution, both geographically and temporally, of antigens and their association with clonal complex can aid in the formulation of novel vaccines and assess their potential coverage across Europe. Serological typing schemes involving characterisation of the polysaccharide capsule (serogroup) and outer membrane proteins such as PorA (serosubtype) and PorB (serotype) have been used for a number of years with some success. However, drawbacks associated with these methods include insufficient discrimination, limitations in panels of monoclonal antibodies used in the typing procedures and difficulty in comparison of results among labs. Consequently, in recent years genotypic methods such as multi-locus enzyme electrophoresis (MLEE) and subsequently multi-locus sequence typing (MLST) have been developed. These methods measure the variation in slowly evolving housekeeping genes whereas serological methods measure variation in antigens which are under immune pressure and are therefore more diverse. Combination of phenotypic and genotypic typing methods can offer high levels of discrimination. Molecular studies into meningococcal diversity have offered many important insights into its population biology, which have implications for prevention and control of meningococcal disease. These have included the identification of hyperinvasive lineages and the correlation of genetic type with antigenic type and disease epidemiology. The EU-MenNet programme was established as a pan-European infrastructure for the research and surveillance of European meningococcal disease. Its aim was to coordinate and disseminate the latest molecular isolate characterisation techniques (MLST) and electronic data transfer via the Internet to exploit epidemiological and population genetic studies. Within the EU-MenNet, the European Meningococcal MLST Centre (EMMC) was set up to carry out molecular typing — MLST, PorA and FetA — of European disease isolates from 18 countries over three years 2000, 2001 and 2002. The output of this project will be the largest representative molecular epidemiological study of meningococcal disease in Europe. Assessment of the data produced will give insights into the geographic and temporal distribution and structuring of disease-associated clonal complexes and antigens and their associations. This will give an indication of the meningococcal disease population in Europe and will be invaluable for the current, and ongoing, development and introduction of new meningococcal vaccines.

This study identified the need to provide a proof of concept of the use and disaggregation of existing health data in order to study the cross-sectional and spatial distribution of HIV, tuberculosis and noncommunicable disease multimorbidity and the association with socioeconomic disadvantage at a South African, Western Cape Province and urban/intra-urban scale for 2008 and 2012. This study was framed within a health geography context and draws attention to the reality of health variations which are influenced by place-based effects, including the surrounding social, cultural and economic structural factors and mechanisms that, together, constitute the social determinants of health. However, in order to identify and understand these variations in health, access to health data that is able to be disaggregated by key characteristic and spatial scales, is essential. Therefore, this study utilised existing health data from the National Income Dynamics Study, a longitudinal study with a sample of approximately 28 000 people, to perform secondary data analysis using a positivist approach to research. This study found that the coupling of geospatial and health data is able to produce new health information and the graphical representation of data provides unique insights in health variations. Secondly, the burden of disease is not consistent between spatial scales which suggests variations in epidemiological profiles between sub-national geographies, thereby supporting the argument for the need of data disaggregation. Finally, the cross-sectional analysis of this study found multimorbidity to be associated with age, socioeconomic deprivation, obesity and urban areas, while the spatial analysis showed clusters (hot spots) of higher multimorbidity prevalence in parts of KwaZulu-Natal and the Eastern Cape, which compared with the socioeconomic disadvantage spatial pattern. Therefore, this study provides an example of the research needed to provide information to support policy improvement and enable the urban planning and public health professions to work together.

Durvillaea, a kelp genus occurring only in the Southern Hemisphere, presents an ideal system for studies of marine connectivity and postglacial recolonisation. Durvillaea contains five currently-recognised species, four of which are non-buoyant. Whereas all non-buoyant species are restricted to the south-western Pacific, the sole buoyant species (D. antarctica) has a far wider, circumpolar distribution, strongly suggesting that long-distance dispersal in D. antarctica is achieved by rafting. This contrast in predicted dispersal ability among Durvillaea species provides an opportunity for natural phylogeographic comparisons, thereby assessing the effectiveness of rafting as a long-distance dispersal mechanism. Additionally, the inability of D. antarctica to survive in ice-affected areas, combined with its broad distribution, make it an ideal candidate for studies of postglacial recolonisation. Phylogenetic and biogeographic relationships within Durvillaea were here assessed using sequence data from mitochondrial (COI), chloroplast (rbcL) and nuclear (18S) DNA. Genetic data were obtained from more than 500 specimens, including representatives from across the geographic range of each recognised species of Durvillaea. Mitochondrial data for Durvillaea were found to be highly phylogenetically informative, with 117 variable sites observed over a 629 bp fragment of COI. Chloroplast and nuclear markers, on the other hand, showed less variation than COI, but nonetheless contributed useful phylogenetic information. Phylogenetic analyses were performed using both Maximum Likelihood and Bayesian approaches. Contrasting patterns of genetic diversity were observed across the range of D. potatorum in Australia, with genetic homogeneity throughout western sites versus relatively high levels of diversity in eastern populations. Based on these results, I hypothesise that D. potatorum recolonised much of the western part of its range postglacially, perhaps being entirely eliminated from western Tasmania during the last glacial period by altered oceanographic systems. Additionally, 'western' and 'eastern' D. potatorum haplotypes formed deeply-divergent clades, likely reflecting geographic isolation on either side of the Bassian Isthmus during Pleistocene marine regressions. Substantial genetic diversity was observed across the range of the circumpolar species D. antarctica. Within New Zealand, phylogenetic and morphological analyses of D. antarctica indicate that two morphotypes ('cape' and 'thonged' forms) likely represent reproductively isolated species, with the 'cape' lineage apparently restricted to southern New Zealand. Whereas the 'cape' lineage showed little genetic variation throughout its range, the 'thonged' lineage exhibited marked phylogeographic structure, with high genetic diversity and a clear north - south genetic disjunction delineated by the Canterbury Bight. On a broader, circumpolar scale, D. antarctica showed contrasting patterns of genetic diversity, with high levels of variation in low-latitude regions (e.g., continental coasts of New Zealand and Chile), versus near-homogeneity at high, subantarctic latitudes. These phylogeographic contrasts strongly suggest that D. antarctica recolonised much of the subantarctic region only recently, most plausibly following extirpation by ice scour at the Last Glacial Maximum (LGM). Locations of putative recolonised islands relative to 'refugial' areas indicate that Antarctic sea ice was likely more extensive at the LGM than previous studies have suggested. Latitudinal contrasts in genetic diversity were also observed among Chilean populations of D. antarctica, with a single mitochondrial haplotype detected throughout Chilean Patagonia versus high diversity in central Chile (32�-42�S). The Patagonian populations appear to have recolonised the region postglacially, following recession of the Patagonian Ice Sheet after the LGM. These populations show transoceanic ancestry, with a closer relationship to populations in the subantarctic and southern New Zealand regions than to those in central Chile. Substantial phylogeographic structure was evident across small spatial scales in central Chile, and the correspondence of major genetic disjunctions among central Chilean sites with the presence of long stretches of unsuitable substrate (beaches) strongly suggests that habitat discontinuity drives genetic isolation in this dispersive species. Broad-scale molecular phylogenetic analyses indicate that the current taxonomy of Durvillaea species requires substantial revision. Previously-recognised 'morphotypes' of Durvillaea (of D. potatorum in Australia, and D. antarctica in New Zealand), for example, were here found to be genetically distinct, likely representing reproductively-isolated species. This phylogeographic research on Durvillaea kelp sheds new light on the historical impacts of climate change on Southern Hemisphere marine environments, and on the processes driving evolution in a marine macroalga.

Members of the genus Packera (Asteraceae) are widespread in North America, but most are found in western regions of the continent where extensive morphological integradation is common. Previous molecular systematic studies found that four species in southwestern Alberta, a region proposed to be at the interface of the Cordilleran and Laurentide ice sheets during the last advance of Pleistocene glaciation, showed unusually high levels of inter- and intrapopulational chloroplast DNA variation. The present study analyzed chloroplast haplotype phylogeny, frequency variation, and geographic distribution patterns in Packera contermina and closely related species P. pseudaurea, P. cana, and P. cymbalarioides from southwestern Alberta, nothern Montana, and northwestern Wyoming. Restriction site analyses of chloroplast DNA from 730 individuals across 34 populations of the four species revealed fifteen haplotypes, of which seven are commonly found in other North American Packera species. Three haplotypes were detected in P. cymbalarioides, seven in P. cana, eight in P. pseudaura, and twelve in P. contermina. The level of ahplotype frequency variation among populations was high in P. cymbalarioides (0=I) moderate to low in P. contermina (0=0.333) and P.cana (0=0.261), and very low in P.pseudaurea (0=0.085), possibly reflecting differences in the species' history. Phylogenetic analyses revealed 2 groups of haplotypes, one of which is found mainly in populations from the Great Basin of North America and the second in populations of more coastal and northern regions. The presence of haplotypes from both groups of Packera species suggests that the cpDNA diversity in southern Alberta arisen through hybridization/introgression events that have involved a number of species from outside of the region.<br>x, 81 leaves : ill., maps ; 28 cm.

The distribution of vervets in Barbados was not uniform across the island, vervets being more abundant in parishes with high vegetative cover and low human population density. Ranging patterns for 4 troops of vervets in Barbados were shown to be influenced by the maximum daily temperature and the mean daily humidity. The frequency of use of an area decreased with increasing distance from the sleeping site, and the duration of use increased with increasing distance from the sleeping site. An interpopulation comparison of home range size and ranging patterns of vervet populations from Africa and St. Kitts, showed a positive correlation between home range size and group size and a negative correlation between home range size and population density.<br>The genetic structure of the Barbados population was characterized by relatively high levels of heterozygosity and gene diversity at the group level, and small genetic distances between groups indicating adequate gene flow between groups. Three of the 6 polymorphic loci investigated showed differences in allele frequency between east and west sub-populations of vervets, indicating some genetic differentiation.

Despite increasing publicity, habitat loss and fragmentation remain a serious threat to biodiversity. The main objectives of this research were (i) to study the effects of forest fragmentation on the distribution and abundance of resident birds in the fragmented littoral forests of southeastern Madagascar and temperate woodlands of southeastern Australia at three spatial scales (patch, landscape and regional) and (ii) to place the results of these case studies within the realms of the equilibrium theory of island biogeography and its descendent theories, to ascertain whether it is appropriate to use these theories to derive conservation scenarios within these threatened regions. Deforestation of Madagascar's remaining forests is considered a global concern due to both its current high intensity and the small amount of forest claimed to be remaining on the island. Surprisingly, very few studies have considered the impacts of forest fragmentation on bird diversity in Madagascar. A multi-scale study on the effects of littoral forest fragmentation and degradation on birds is therefore a major step forward for bird conservation on the island. Furthermore, prior to this study no known work has been conducted on the avifauna within the threatened littoral forests of eastern Madagascar. My results indicated that (i) the littoral forests contained bird species assemblages that were unique when compared to neighbouring forest habitats, (ii) many forest-dependent bird species were significantly affected by habitat structure and especially proximity to forest edge and (iii) many forest-dependent species were affected by landscape factors such as remnant shape and remnant size. No relationship was found between measures of landscape composition, remnant 'isolation' and bird distribution within littoral forest remnants.

Thesis (M.S.)--Northwest Missouri State University, 2008.<br>The full text of the thesis is included in the pdf file. Title from title screen of full text.pdf file (viewed on July 25, 2008) Includes bibliographical references.

Two and a half years of data were collected from the Great Fish River and estuary using seine nets and gill nets to determine the fish species composition within these regions. The head region of the Great Fish River estuary was found to have a rich fish fauna, with the euryhaline marine fish component totally dominating the catch in all three regions. Gilchristella aesiuaria was the single most common species and several euryhaline marine species were captured in freshwater for the first time. Physical parameters were also measured in an effort to ascertain the possible factors which may affect the distribution and length frequency of the most common species within this area. Salinity was found to be the single most important factor affecting the species composition, and the sampling area was consequently divided into three regions, viz. river (< I ‰), head (1-4 ‰) and estuary (> 4 ‰). In addition, it was determined that river flow rate during the month prior to sampling also had a profound effect on species composition in all three regions. Based on the available evidence it is suggested that for most species this is related to conductivity levels rather than flow per se.