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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
191

Plži Přírodní rezervace Oheb / Gastropods of NR Oheb.

KADAVÁ, Jana January 2011 (has links)
This work was the processing of existing data from Culek, Brabenec and Juřičková. Mapping of a semiquantitative abundances of gastropods in Oheb Nature Reserve, as well as developing a list of species inventory and assessment of their habitat preferences, particularly with reference to a particular forest type. Regular monitoring helps in assessing the status and trends of populations and the entire reservation.
192

Influência da endometriose sobre a resposta ovariana em ciclos de reprodução assistida: provável associação com prejuízo do desenvolvimento folicular, mas não do pool de reserva / Endometriosis influence on ovarian response in assisted reproduction cycles: probable association with damage to follicular development, but not to follicular reserve.

Bruno Ramalho de Carvalho 13 October 2008 (has links)
Introdução: A avaliação da reserva ovariana em reprodução assistida (RA) busca identificar mulheres em que a exaustão folicular determine as dificuldades reprodutivas. Além da idade, a presença de causas outras de subfertilidade, como a endometriose (EDT), implica interferências negativas potenciais sobre a resposta ovariana. Objetivo: Avaliar a reserva folicular ovariana de mulheres subférteis portadoras de endometriose e determinar o melhor preditor de má resposta em RA. Métodos: Foram analisados 87 ciclos de RA em mulheres com idade inferior a 40 anos, ciclos menstruais regulares, sem patologias endócrinas e com ambos os ovários, sendo 30 ciclos em portadoras de EDT (casos) e 57 ciclos em mulheres subférteis por fator masculino exclusivo (controles). A reserva ovariana foi inferida pelas dosagens basais dos hormônios anti-mülleriano (AMH) e folículo estimulante (FSH), a contagem de folículos antrais pequenos (CFA) e a medida do volume ovariano médio (VOM). Curvas Receiver Operating Characteristic (ROC AUC) foram traçadas para avaliação da capacidade discriminatória de cada teste em identificar má resposta. Resultados: Pacientes com EDT apresentaram FSH basal significativamente maior em relação aos controles (9,13 ± 5,09 mUI/mL vs. 6,28 ± 2,45 mUI/mL; p < 0,05), sem diferenças para AMH, CFA e VOM. O número total de oócitos aspirados foi menor na EDT em relação aos controles (5,33 ± 3,43 vs. 8,28 ± 5,8; p < 0,05) e correlacionou-se significativamente com o AMH em ambos os grupos (EDT: r = 0,61; Controles: r = 0,58; p<0,0001). O FSH basal apresentou correlação significativa com o total de oócitos aspirados apenas na EDT (r = -0,48; p<0,01); também na EDT, o AMH basal foi o marcador individual com melhor potencial discriminatório para má resposta (AUC = 0,875), seguido de FSH basal (AUC = 0,682) e VOM (AUC = 0,665), enquanto no grupo controle, o AMH foi o melhor marcador (AUC = 0,8372), seguido do VOM (AUC = 0,709) e da CFA (AUC = 0,686). Conclusões: O FSH basal está significativamente maior nas pacientes subférteis com EDT e correlaciona-se com a resposta em RA apenas nas portadoras da doença. Já o AMH basal, é o marcador com o melhor potencial discriminatório de má resposta, independentemente da presença da endometriose. CFA e VOM não se apresentaram como bons preditores de má resposta. Sendo assim, a associação entre endometriose e subfertilidade deve estar vinculada a alterações do crescimento/desenvolvimento do folículo ovariano e não a prejuízos sobre a reserva folicular gonadal propriamente dita. / Introduction: Ovarian reserve evaluation in assisted reproduction (AR) aims to identify women in whom follicular exhaustion determines reproductive difficulties. More than age, the presence of other subfertility factors, such as endometriosis (EDT), implies potential negative interference on ovarian response. Objective: To evaluate follicular ovarian reserve in subfertile patients with endometriosis and determine the best predictor of poor response in AR. Methods: We evaluated 87 AR cycles of women presenting with less than 40 years of age, regular menses, no endocrine diseases and with both ovaries, divided in 30 EDT cycles (cases) and 57 cycles in women with subfertility associated to male factor (controls). Ovarian reserve was determined based on basal levels of anti-müllerian hormone (AMH) and follicle- stimulating hormone (FSH), small antral follicle count (AFC) and medium ovarian volume (MOV). Receiver Operating Characteristic curves (ROC AUC) were obtained for evaluation of discriminatory capacity of each test in identifying poor response. Results: EDT patients presented significantly higher basal FSH levels when compared to controls (9,13 ± 5,09 mUI/mL vs. 6,28 ± 2,45 mUI/mL; p < 0,05) and there were no differences in AMH, AFC and MOV between groups. The total number of oocytes retrieved was lower in endometriosis when compared to controls (5,33 ± 3,43 vs. 8,28 ± 5,8; p < 0,05) and significantly correlated with AMH in both groups (EDT: r = 0,61; Control: r = 0,58; p<0,0001). Basal FSH presented significant correlation with the number of oocytes retrieved only among EDT patients (r = - 0,48; p<0,01); in EDT patients, either, basal AMH was the individual marker with the best discriminatory potential for poor responders identification (AUC = 0,875), followed by basal FSH (AUC = 0,682) and MOV (AUC = 0,665), whereas among controls, AMH was the best marker (AUC = 0,8372), followed by MOV (AUC = 0,709) and AFC (AUC = 0,686). Conclusions: Basal FSH is significantly higher in subfertile patients with endometriosis and correlates with ovarian response in AR among these patients. Basal AMH, by the way, is the individual marker with the best discriminatory potential in determining poor response, which is not dependent on endometriosis presence. AFC and MOV did not presented as good predictors of poor response. The association between endometriosis and subfertility, therefore, may be linked to prejudice to growth/development of the ovarian follicle, but not to damage to the real ovarian follicular reserve.
193

An evaluation of the veld management practices of Mabula Game Reserve, Limpopo Province

Serfontein, Daniel Johannes 04 May 2009 (has links)
M.Sc. / Mabula Game Reserve initiated an extensive grass-monitoring programme ten years ago. At the same time, management kept records of factors such as rainfall, burning, game numbers and game composition that might have an influence on grass production. They also conducted an extensive mapping programme over a number of years to familiarise themselves with the physical phenomena of Mabula, namely geology, soils, slope and aspect, that influence grass growth. The most important aspect of their mapping programme was to divide the reserve into different vegetation communities. The objective of the study is to supply Mabula Game Reserve with clear-cut evidence of the condition of the grazing resources at Mabula. The aim of the study is to assist the management of Mabula with future guidelines in the veld management of the reserve. The overall purpose of this study was to investigate the veld management efficiency of Mabula Game Reserve by establishing whether the ecological status of the grazing had been degraded or improved over the study period. This researcher analysed the grass monitoring data to determine veld condition indices, grazing values, perenniality and to establish the amount of climax and pioneer grass. He sequenced his research by: • classifying grass species in terms of the ecological index method to determine whether grass had been utilised in a sustainable manner or over-utilised;. • calculating the grazing capacity for each vegetation community over the past ten years; • highlighting those grass species in the analyses that showed abnormal growth or decline over the ten years; and • interpreting the results in terms of the ecological status of the relevant area.. The study was conducted firstly by categorising the grass monitoring stations into different vegetation communities. Ecological indices for each vegetation community was determined. The grass species that showed the biggest increase/decrease in the ten years of monitoring were seperated to determine the ecological significance of the increase/decrease. The ecoloical indices of the different vegetation communities were compared with each other to determine the overall improvement or deterioration of the veld quality. By re-calculating the game numbers for every year, this researcher was able to determine the Game Livestock Unit for the area. With this figure, he was able to differentiate between the grass utilisers, comparing them from year to year in terms of their grazing capacity. The study revealed that in order to obtain an objective view of the condition of the veld, it is necessary to evaluate the condition of the veld in terms of each vegetation community, as well as the total area. Such an approach would enable the manager to plan according to a specific vegetation community. The study also made it clear that it is necessary to reduce the number of game, but that this must be done by culling the appropriate group of utilisers. The necessity of introducing a browsing monitoring programme soon became evident. The study showed how the grass and game monitoring analyses for the area can be applied in association with the rainfall figures in forward planning in order to manage the sustainable utilisation of biological resources and to minimise the effects of drought conditions. The researcher concluded this study by highlighting the shortfalls of the ecological index method in determining the condition of the veld, and recommended other methods i.e. the Benchmark Method, Key Species Method, and the Weighted Key Species Method to supplement the present method. Another recommendation was to collect two different sets of data during monitoring to avoid conflicting results, as was the case with the 2004 survey. One data set should include herbs and forbs while the other set should only contain grass species.
194

Výpočetní prostředky stanovení IBNR rezerv neživotního pojištění / Computational tools for IBNR reserves calculation

Gregor, Štěpán January 2010 (has links)
Title: Computational tools for IBNR reserves calculation Author: Bc. Štěpán Gregor Department: Department of Probability and Mathematical Statistics Supervisor: Mgr. Helga Krafferová, UNIQA pojišťovna, a.s. Supervisor' s e-mail address: Helga.Krafferova@uniqa.cz Abstract: Technical provisions represent the liability of the insurance company to its clients. In this work we focus on the computational tools of incurred but not reported claims. The most popular calculation method is probably the chain-ladder method which will be in detail analyzed in this thesis. Finally, by applying the theory in this work we will demonstrate the calculation in the own developed software. Keywords: Insurance, IBNR reserve, chain-ladder
195

An investigation of human activity and vegetation change around Mkuze Game Reserve, South Africa

Burgoyne, Christopher Nicholas 26 June 2014 (has links)
M.A. (Geography) / In the last century, the establishment of protected areas has become an important part of managing South Africa’s wilderness and wildlife. The notion of untouched protected areas is becoming contested in a time when developing nations are seeking to improve quality of life for their citizens. With the promulgation of the NEM: PAA of 2003, resource sharing with local rural communities has become an important policy guideline for protected area management authorities. An example of a protected area where management has sought to facilitate resource access in neighbouring rural communities is Mkuze Game Reserve (MGR), now part of the greater Isimangaliso Wetland Park. This study uses a mixed methods approach to combine local rainfall records, census archives, and remotely sensed data with qualitative interview data in order to investigate spatial, social and quantitative aspects of anthropogenic land-cover change between 1979 and 2008. If the proposed balance between development and conservation is to be achieved in this ecologically diverse locale, a deeper understanding of contextual relationships between human activity and environmental change will be vital. Results showed that while rainfall was cyclic, natural land-cover decreased consistently in densely populated rural areas. In contrast, protected areas such as MGR showed little change in land-cover indicating that human activity and cattle have a significant impact on the land surface in the Mkuze Region. While many local residents in the rural communities living adjacent to MGR recognise their role in the achievement of development-conservation objectives, a history of exclusion from MGR has left a legacy of negative perceptions towards MGR in these communities. In order to mitigate natural land-cover loss, local communities must have positive perceptions about MGR and become involved in its management. Useful inferences have been made from the results regarding the management of human population and activities around the borders of protected areas in South Africa.
196

The impact of repeated mild traumatic brain injuries (concussions) on the cognitive and academic functioning of early adolescent rugby union players: A controlled, longitudinal, prospective study

Alexander, Debbie January 2007 (has links)
Philosophiae Doctor - PhD / This study investigated, within the context of Brain Reserve Capacity (BRC) theory, whether repeated concussions resulted in residual deficits in cognitive and academic functioning of early adolescent rugby players relative to non-contact sports controls. / South Africa
197

The cheetahs of the Northern Tuli Game Reserve, Botswana: population estimates, monitoring techniques and human-predator conflict

Brassine, Eleanor I January 2015 (has links)
Remaining viable cheetah (Acinonyx jubatus) populations in Africa are threatened by direct persecution through conflict with farmers and habitat degradation and fragmentation. Botswana is considered a stronghold for free roaming cheetahs in Africa, yet the country has had relatively limited research on its cheetahs, and information from the east of the country is lacking. Data on the current status of populations is thus required to make informed management decisions. My study provides estimates of population density, abundance, distribution and status for the demographically open cheetah population of the Northern Tuli Game Reserve (NOTUGRE) in Botswana. The effectiveness of two population monitoring methods, namely camera trapping and a photographic survey, were also investigated. Moreover, I report on the level of conflict between livestock farmers and predators on rural communal farmlands within and adjacent to NOTUGRE. Data were collected between May 2012 and November 2013. Results indicate a low population density of 0.61 ± 0.18 adult cheetahs per 100 km² and a minimum population size of 10 individuals (nine adults and one cub). Camera traps placed at cheetah scent-marking posts increased detection rates and provided ideal set up locations. This approach, together with Spatial Explicit Capture- Recapture (SECR) models, is recommended for future studies. The long-term studies that are required to better understand the status of cheetahs in Botswana do not exist. Thus, photographic surveys may provide an alternative method for providing baseline data on population numbers, distribution and demography. The third aspect of my study gathered information on levels of livestock loss and human tolerance of predators through the use of interviews (n = 80). Conflict with subsistence farmers is a concern as livestock depredation is relatively high (9.1% of total livestock owned) and farmers had an overall negative attitude towards conservation of large predators. My results suggest that human-predator conflict in this area is more complex than the direct financial loss from depredation. Hence, reducing depredation rates alone is unlikely to change farmer tolerance of wildlife on farmlands. Improved, responsible farm management, including self-responsibility for livestock rearing, and positive appreciation for wildlife are necessary. The NOTUGRE cheetah population requires further research to understand possible threats to the population. Furthermore, a better understanding of the connectivity between cheetahs of NOTUGRE, South Africa and Zimbabwe is required. The number of cheetahs within NOTUGRE is too small to sustain a viable population, hence conserving cheetahs outside of the protected area should be a priority for the conservation of the population. This can only be achieved through assistance and involvement from national authorities, local people and conservation organisations.
198

Population estimates and spatial ecology of brown hyaenas in Kwandwe private game reserve

Welch, Rebecca Jane January 2015 (has links)
During the last 25 years, the Eastern Cape Province of South Africa has seen the establishment of many small to medium sized (≤ 440km2) game reserves. These reserves have reintroduced many of the larger indigenous wildlife that had been extirpated by the early 20th century. As such, these reserves and wildlife introductions have created many research opportunities, including investigations on the ecology of reintroduced carnivores in the Thicket biome. Brown hyaenas (Hyaena brunnea) are one of the large carnivore species that have been reintroduced into the area. As these animals have predominantly been studied in more open, arid systems, their reintroduction has provided an excellent opportunity to study the species in an alternate natural habitat. Information gathered from such investigations adds to our knowledge of the species and also provides information for the management of brown hyaenas within small, enclosed reserves. Data were collected over the period of one calendaryear, from February 2013 to February 2014 at Kwandwe Private Game Reserve in the Eastern Cape, South Africa. Brown hyaena population estimates were calculated using capture-recapture methods from individually identifiable images captured during a three month camera trapping survey. Images of brown hyaenas were separated into left- and right-side profiles. Twenty-eight individuals were positively identified from left-side images and 27 from right-side images. Non-spatial and spatially explicit capture-recapture analyses were both run in the program DENSITY 5.0. Density estimates ranged from 14 to 20 individuals/100km2 (equivalent to a total abundance of 26-37 individuals) depending on the method used. Despite the range of estimates, all are considerably higher than in other areaswhere densities have been calculated. Satellite/GPS collars were fitted to three individual brown hyaenas (two males and one female) to measure their home range size and use of space. Home range size was calculated using two different methods, Kernel utilisation distributions and Brownian bridges. Home range estimates were similar using both methods; however Brownian bridge methods appeared to exaggerate the use of space by individuals. Kernel home range sizes for the three individuals ranged between 42.62km2 and 79.88km2. These estimates are considerably smaller than previous findings from other parts of Africa and suggest that sufficient resources may be available within this enclosed system. The results from this study suggest that brown hyaenas are successful generalists in this enclosed system and are able to persist at high densities and occupy relatively small home ranges. This information is important for the managers of small reserves who wish to reintroduce brown hyaenas. Should brown hyaenas be introduced into reserves in the Thicket biome with sufficient resources, the numbers are likely to increase rapidly. If high numbers are not desired then preventative measures (e.g. contraception) should be investigated before release.
199

Ontogeny of the ovarian follicular reserve of the African elephant (Loxodonta africana)

Stansfield, Fiona Jane 17 September 2012 (has links)
The aim of this study was to define the ovarian follicular reserve of wild African elephants in terms of its type of small follicles (SF), its establishment and distribution throughout the ovaries, and the change in numbers of SF in the embryo and fetus as well as throughout prepubertal and adult life. The large elephant population in Zimbabwe provided the opportunity to collect ovaries from elephants culled for management reasons and hunted professionally. In total, gross morphological and histological studies were done on the gonadal ridges from 5 embryos (76–96 days post conception) and ovaries from 11 fetuses (4.8–22.2 months), 29 prepubertal females (2 months–10 years), 24 adult females (11–55 years) and 7 aged females (56–70 years). Specimens were fixed in 4% buffered formalin before a series of 25 ìm thick sections were cut and examined using stereological protocols to count SF numbers in each section and thereby calculate the follicle reserve of the whole ovary. Prior to counting SF numbers, their distribution throughout the ovary was studied and the repeatability of counts was validated. Numbers of SF were highest in mid-term fetuses, lower in fetuses during the second half of gestation, even lower in calves younger than 4½ years, whereas the numbers in calves aged 4½–9 years were significantly higher than those in younger calves, and similar to what they were in late-term fetuses. The numbers of SF were substantially and highly significantly lower in elephant 10–15 years in age compared to calves aged 4½9 years, suggesting a reduction around puberty. Thereafter the ovarian reserve fell steadily until depletion around the age of 70 years. During adult life the ovarian reserve was composed of early-primary (EP) and true-primary (TP) follicles. By 45 years of age only TP follicles remained although these enabled oestrous cyclical activity for many more years; of 7 sets of ovaries recovered from females aged 57–70 years, 6 showed evidence of cyclical activity or pregnancy within the preceding 6 years. The study shows that EP and TP form the follicular reserve from before birth until 45 years, with TP forming the reserve thereafter, which depletes in some old elephants and persists to maximum life span in others. / Thesis (PhD)--University of Pretoria, 2012. / Production Animal Studies / unrestricted
200

A socio-economic assessment of the impacts of invasive alien plant species on forestry production : the case of Senna spectabilis in Budongo forest reserve, Uganda

Ahimbisibwe, Beine Peter 30 November 2009 (has links)
In 2006, a baseline survey for the UNEP/GEF-IAS Project was conducted in BFR to assess the status of IAS in the area. Findings indicated that extensive forest parts had severe S. spectabilis encroachment which appeared to interfere with the normal functioning and productivity of the forest. This study was motivated by the magnitude of S. spectabilis invasion in BFR, the level of public and government concern about the invasion, and the magnitude of the IAS problem across East Africa. This study was thus undertaken to address a specific need of the research and capacity building components of the UNEP/GEF-IAS Project. The study1 was carried out to assess the impacts of S. spectabilis invasion on the productivity of BFR and the socio-economic implications on the livelihoods of the dependent stakeholders (local resident population, timber suppliers and the tourism sector). The study used descriptive statistics to assess the levels of awareness of S. spectabilis invasion, perceptions and knowledge of the conservation values of BFR, knowledge on the benefits and costs of living with S. spectabilis and impacts of S. spectabilis on the flow of quantities and revenues from the benefits it generates. The impact on financial profitability and efficiency of timber firms was assessed using Gross margin analysis (GMA) and financial efficiency ratio analysis respectively. The impact on the population structure of chimpanzees was studied using mean differentials and focused group discussions. Results indicate that the level of awareness about S. spectabilis invasion and the knowledge of the conservation values of BFR were high among all the three stakeholder groups. GMA revealed that S. spectabilis invasion increases variable costs in timber production thus reducing profit margins and financial efficiency of timber firms. Alteration of habitat environment occasioned by S. spectabilis invasion was advanced, though with uncertainty, as a possible reason for the difference in chimpanzee numbers between the infested and non infested forest conditions. Like other IAS, S. spectabilis was found to have both benefits and costs though the distribution of the same differs. S. spectabilis can be considered a net benefit to the local dependent communities whereas it may be a net loss to both the timber and tourism sectors. Conflict of interest in S. spectabilis management is discussed and possible solutions suggested. It was recommended that the threat of invasive species should be tackled through a multisectoral approach. / Dissertation (MSc)--University of Pretoria, 2009. / Agricultural Economics, Extension and Rural Development / unrestricted

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