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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.
41

Distribution and abundance of anurans in southeast Missouri

Vradenburg, John. January 2005 (has links)
Thesis (M.S.)--University of Missouri-Columbia, 2005. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (January 10, 2007) Includes bibliographical references.
42

Assessing the influence of anthropogenic disturbance on sympatric felids on Borneo with special reference to the Sunda clouded leopard

Hearn, Andrew James January 2016 (has links)
For decades, Borneo's once extensive and pristine forests have been increasingly exposed to a suite of anthropogenic disturbance and deforestation processes as a result of selective and illegal logging, hunting, droughts, fires and the conversion to plantations, chiefly oil palm. Such disturbance is likely impacting the Sunda clouded leopard, Neofelis diardi, and other threatened, sympatric Bornean felids, yet few studies have attempted to address these issues. In this thesis, I used data from intensive camera trap surveys throughout Sabah, Malaysian Borneo and high-resolution GPS data from tagged Sunda clouded leopards to examine the influence of forest disturbance on the abundance, distribution, movements and population connectivity of Sunda clouded leopards and other sympatric felids on Borneo, and to provide some of the first data regarding the ecological interactions and patterns of coexistence among this felid assemblage. I showed that Sunda clouded leopard movement was facilitated by forest cover with high canopy closure, and highly resisted by oil palm plantations with low canopy closure. Models of population connectivity across Sabah identified a number of isolated populations of these felids, which may be particularly threatened with extinction. Analysis of camera trap detection data revealed that the Bornean felids exhibit evidence of resource segregation along the temporal, spatial and prey niche axes, and showed that Sunda clouded leopards, bay cats, Catopuma badia, and marbled cats, Pardofelis marmorata exhibited broad scale avoidance of disturbed habitats but varied in their selection of optimal foraging habitat at fine scales. Conversely, leopard cats, Prionailurus bengalensis, were associated with forest disturbance and likely benefit from such changes. I developed some of the first estimates of population density for Sunda clouded leopards and the first such data for marbled cats. The results are discussed in the context of the conservation of these felids on Borneo.
43

Aspects of the ecology of leopards (Panthera Pardus) in the Little Karoo, South Africa

Mann, Gareth January 2014 (has links)
Leopards (Panthera pardus) are the most common large predators, free roaming outside of protected areas across most of South Africa. Leopard persistence is attributed to their tolerance of rugged terrain that is subject to less development pressure, as well as their cryptic behaviour. Nevertheless, existing leopard populations are threatened indirectly by ongoing transformation of natural habitat and directly through hunting and conflict with livestock farmers. Together these threats may further isolate leopards to fragmented areas of core natural habitat. I studied leopard habitat preferences, population density, diet and the attitudes of landowners towards leopards in the Little Karoo, Western Cape, South Africa, an area of mixed land-use that contains elements of three overlapping global biodiversity hotspots. Data were gathered between 2010 and 2012 using camera traps set up at 141 sites over an area of ~3100km², GPS tracking collars fitted to three male leopards, scat samples (n=76), interviews with landowners (n=53) analysed in combination with geographical information system (GIS) layers. My results reveal that leopards preferred rugged, mountainous terrain of intermediate elevation, avoiding low-lying, open areas where human disturbance was generally greater. Despite relatively un-fragmented habitat within my study area, the leopard population density (0.75 leopards/100km²) was one of the lowest yet recorded in South Africa. This may reflect low prey densities in mountain refuges in addition to historical human persecution in the area. Currently local landowners are more tolerant of leopards than other wildlife species with incidents of conflict involving leopards being rare relative to black-backed jackals (Canis mesomelas), baboons (Papio hamadryas), caracals (Caracal caracal) and porcupine (Hystrix africaeaustralis). Although current levels of conflict between leopards and stock farmers are low, leopards do depredate livestock, which constitute 10-15% of their diet. Improved livestock husbandry measures and co-operation between conservation authorities and farmers are necessary to mitigate such conflict and balance economic security with biodiversity conservation in the region. Leopards are the only remaining top predators throughout much of the Little Karoo and the Western Cape and as such are predicted to play a critical role in ecosystem structure and the survival of other species. Current high levels of connectivity between areas of suitable leopard habitat bode well for the conservation status of leopards within this region and future conservation efforts need to ensure that narrow corridors linking such habitat are preserved. The potential for leopards to serve as both an umbrella and a flagship species for biodiversity conservation suggests that long term monitoring of this population would be a conservation priority for the Little Karoo.
44

Interrelationships between the larger carnivores of the Klaserie private nature reserve with special reference to the leopard Pantera pardus (Linnaeus, 1758) and the cheetah Acinonyx jubatus (Schreber, 1775)

Kruger, John Ernst 03 October 2007 (has links)
Please read the abstract in the section 00front of this document / Dissertation (MSc (Wildlife Management))--University of Pretoria, 2007. / Zoology and Entomology / MSc / Unrestricted
45

Assessing the diet of the Cape leopard (panthera pardus) in the Cederberg and Gamka mountains, South Africa

Rautenbach, Therèsè January 2010 (has links)
As limited prey availability and persecution by humans in response to livestock predation are key conservation concerns for the Cape leopard (Martins & Martins 2006), the present study aimed to provide more information regarding their feeding habits. The first objective was to determine whether the Cape leopard was subject to a change in their prey base and how they responded to the change. This was established by comparison of their current diet in the Cederberg and Gamka Mountains, determined by using scat analysis techniques, with a previous dietary assessment (Norton et al. 1986). The second aim was to provide a preliminary assessment of the prey preference of the Cape leopard and examine the utility of camera trap surveys to determine leopard prey preference. Leopard diet in the Cederberg and Gamka Mountains consisted largely of small- (1-10 kg) and medium-sized (10-40 kg) mammals; rock hyraxes (Procavia capensis) and klipspringers (Oreotragus oreotragus) were key prey items. In terms of regional variation in leopard diet, there was a significant difference in the average weight of prey utilized in the Cederberg and Gamka Mountains. Despite the importance of prey availability of suitable size, their flexibility in terms of prey size utilization reflected their ability to switch to smaller prey to fulfil their dietary requirements, when prey is limited. The study suggested a dietary shift, with significant variation in prey species utilization in both regions. The shift did not appear to be in response to prey scarcity, but rather a reduction in key prey species, particularly the rock hyrax. The shift involved an increase in the number of species utilized, and only a very small increase in livestock predation in both areas. There was however no significant variation in prey size category utilization. This demonstrated their dietary flexibility, as well as the importance of suitable prey sizes rather than the presence of specific prey species to fulfil their dietary requirements. The camera trap survey revealed a strong correlation between the number of camera trap days and the number of photographs taken of identifiable species. Variation of this correlation between different habitats supported the notion that individual images are a better unit to determine sampling efficiency than trap days. The camera trap survey also showed that small rodent availability was underestimated by camera trap surveillance, which resulted in poor prey preference estimation. It was therefore suggested that camera trap surveys be restricted to the surveillance of larger prey species (> 1 kg). By excluding small rodents from the analysis, prey preference could be estimated for other species and prey size categories. Small- and medium-sized mammals were significantly preferred, whereas large mammals were significantly avoided by the Cape leopard.
46

Étude prospective des manifestations dermatologiques des RASopathies / Prospective study of dermatological manifestations of the RASopathies

Bessis, Didier 26 November 2018 (has links)
Les RASopathies avec phénotype Noonan associent le syndrome de Noonan (SN), le syndrome cardio-facio-cutané (SCFC) et le syndrome de Costello (SC). Leurs manifestations dermatologiques restent peu étudiées.Objectifs Colliger les différentes manifestations dermatologiques des SN, SCFC et SC afin d’établir leur nature et leur prévalence, et définir d’éventuelles corrélations phénotype/génotype au sein de chacune de ces affections.Méthodes Les patients atteints d’un SN, SCFC et SC confirmé sur le plan moléculaire par la présence d’une mutation germinale pathogène étaient inclus dans une étude menée durant 5 ans dans les départements de Génétique, Dermatologie et Pédiatrie des CHU de Bordeaux, Marseille, Montpellier, Nancy, Nantes, Paris AP-HP (Hôpital Robert-Debré et Hôpital Necker-Enfants Malades), Rennes, Saint-Pierre (La Réunion) et Toulouse.Résultats Cent quatre-vingt-quatorze patients atteints de SN, SCFC et SC étaient inclus. Cent-vingt et un patients atteints de SN étaient inclus. La tendance aux hématomes était la manifestation la plus fréquente au cours du SN-PTPN11 (53.8%). Les ML et les tâches café-au-lait atypiques (≥3) étaient observés respectivement dans 94% et 80% des SNML liés à des mutations spécifiques de PTPN11. Des formes atypiques de SNML étaient associées au SN-RAF1 et SN-NRAS. En analyse univariée, les patients sans mutation PTPN11 présentaient (i) un risque de troubles de la kératinisation augmenté (P=0.001), dont la kératose pilaire (KP) (P=0.005), l’ulerythema ophryogenes (UO) (P=0.0001) et la kératodermie palmoplantaire (KPP) (P=0.06), et (ii) un risque augmenté d’alopécie du scalp (P=0.035) et des cils (P=0.06) par rapport aux patients sans mutation PTPN11.Quarante-cinq patients atteints de SCFC étaient inclus, parmi lesquels 77,8% avec mutation BRAF. Les anomalies pilaires étaient constantes, incluant une alopécie du scalp et des sourcils et des cheveux frisés ou bouclés respectivement dans 73% et 69% des cas. Une KP, un UO, une KPP et de multiples naevi (MN >50) étaient observés respectivement dans 82%, 44%, 27% et 29% des cas. L’alopécie des sourcils, l’association UO et KPP, la KP diffuse, et les MN constituaient des signes pertinents de différenciation du SCFC avec le SN et le SC. L’acitrétine orale permettait de traiter avec succès la KPP, tandis que le traitement de l’UO par sirolimus à 1% en topique échouait. Aucune corrélation phénotype-génotype n’était notée.Vingt-et-un patients atteints de SC étaient inclus, parmi lesquels 60% avec la mutation p.G12S-HRAS. Les anomalies pilaires étaient constantes, comprenant des cheveux frisés ou bouclés et une alopécie du scalp respectivement dans 70% and 60% des cas. Un acanthosis nigricans, des papillomes, une KPP, et une cutis laxa acrale étaient notés respectivement dans 65%, 65%, 55% et 80% des cas. Des papules linéaires à disposition pavimenteuse de la lèvre supérieure étaient présentes dans 55% des cas, tandis que l’alopécie des sourcils ou le lymphoedème n’étaient pas observés. Aucune corrélation phénotype-génotype n’était notée. Un patient avec SC atypique avec mutation c187_207dup21/p.Glu63_Asp69dup-HRAS présentait un phénotype cutané distinct associant des MN, un lymphoedème et des manifestations dermatologiques de SC, évoquant une nouvelle forme phénotypique de chevauchement entre un SC et un SN et/ou un SCFC.Conclusion La connaissance précise des manifestations dermatologiques des RASopathies et l’identification de thérapeutiques permet une optimisation de leur prise en charge. / Background Data on dermatological manifestations of RASopathies with Noonan phenotype including Noonan syndrome (NS), cardiofaciocutaneous syndrome (CFCS) and Costello syndrome (CS) remain heterogeneous and based on little dermatological expertise.Objectives To describe the dermatological manifestations of NS, CFCS and CS compare them with the literature findings, and test for dermatological phenotype-genotype correlations with or without the presence of PTPN11, BRAF and pG12S-HRAS mutations respectively for NS, CFCS and CS.Methods We performed a large, 5-year, prospective, multicentric, collaborative dermatological and genetic study.Results A total of 194 patients with NS, CFC and CS were included. One hundred and twenty-nine patients with NS were enrolled, including 65 with PTPN11-NS, 34 with PTPN11-NS with multiple lentigines (NSML), and 30 without PTPN11-NS. Easy bruising was the most frequent dermatological finding in PTPN11-NS, present in 53.8%. Multiple lentigines and café-au-lait macules (≥3) were present in, respectively, 94% and 80% of NSML linked to specific mutations of PTPN11. Atypical forms of NSML could be associated with NS with RAF1 or NRAS mutations. In univariate analysis, patients without a PTPN11 mutation showed (i) a significantly higher frequency of keratinization disorders (P=0.001), including keratosis pilaris (P=0.005), ulerythema ophryogenes (P=0.0001) and palmar and/or plantar hyperkeratosis (P=0.06, trend association), and (ii) a significantly higher frequency of scarce scalp hair (P=0.035) and scarce or absent eyelashes (P=0.06, trend association) than those with PTPN11 mutations. Forty-five patients with CFCS were enrolled with mutations in BRAFin 77.8%. Hair abnormalities were ubiquitous, including scarcity or absence of eyebrows and wavy or curly hair respectively in 73% and 69%. Keratosis pilaris (KP), ulerythema ophryogenes (UO), palmo-plantar hyperkeratosis (PPHK), and multiple melanocytic naevi (MMN; MN >50) were noted respectively in 82%, 44%, 27% and 29%. Scarcity or absence of eyebrows, association of UO and PPHK, diffuse KP, and MMN best differentiated CFCS from NS and CS. Oral acitretin may be highly beneficial for therapeutic management of PPHK, whereas treatment of UO by topical 1% sirolimus failed. No significant dermatological phenotype-genotype correlation was determined. Twenty-one patients with CS were enrolled with p.G12S mutation of HRAS identified respectively in 60%. Hair abnormalities were ubiquitous, including wavy or curly hair and scalp alopecia respectively in 70% and 60%. Acanthosis nigricans with pachydermatoglyphia, papillomas with periorificial location, PPHK, and acral cutis laxa were noted respectively in 65%, 65%, 55% and 80%. Cobblestone papillomatous linear papules of the upper lip was present in 55%, while scarcity of eyebrows and lymphedema were almost absent. No significant dermatological phenotype-genotype correlation was determined. One patient with CS with c187_207dup21/p.Glu63_Asp69dup mutation of HRAS had a new distinct cutaneous phenotype including MMN and severe lymphedema similar to NS and/or CFCS findings.Conclusions A thorough knowledge of RASopathies skin manifestations would help in making a positive diagnosis.
47

The sustainability of leopard panthera pardus sport hunting in Niassa Reserve, Mozambique.

Jorge, Agostinho A. January 2012 (has links)
Leopard Panthera pardus are an economically valuable asset and when used in sustainable consumptive use programs can provide tangible benefits to communities to improve human livelihoods and the conservation of the species. Sport hunting is increasingly proposed as a tool to generate funds to support the conservation of leopard and other large carnivores. However, to assess the value of sport hunting as a conservation tool it is critical to understand its economic impact and ensure that the off-takes are sustainable. In this study I assessed the conservation status of leopard and the ecological sustainability of legal and illegal off-take in Niassa National Reserve (NNR) the largest protected area, 42,000 km2, in Mozambique, which is inhabited by 35,000 people. I also investigated whether the revenues from leopard sport hunting off-set the costs of depredation on livestock in local communities and individual benefits from poaching by local hunters. To perform this study, I interviewed hunting operators and villagers, collected camera trapping data, and analyzed long-term leopard sport hunting data. Leopard had high value for sport hunters, however, the economic benefits from the legal hunting did not off-set the costs from livestock depredation and did not compete with benefits from the illegal hunting which accrued to individuals at the household level. Leopard population densities in Niassa Reserve were comparable with the study sites in central and southern Africa. The numbers of leopard legally hunted in NNR appear to be ecologically sustainable, however a high percentage of the leopard taken as trophies were under the recommended age of seven years. The illegal off-take was unsustainable and resulting in high turnover and combined with the operators’ off-take is likely to be negatively affecting leopard populations. For the future ecological and economic sustainability of leopard quotas, I recommend improvements in the distribution of economic benefits and creating economic incentives to encourage villagers not to engage in the illegal hunting and quantification and inclusion of the illegal off-take in the annual quotas. My study also indicates the need to zone community and wildlife areas in NNR to reduce the anthropogenic effects on leopard and other carnivore populations. / Thesis (M.Sc.)-University of KwaZulu-Natal, Westville, 2012.
48

Independent Acoustic Stimulation of the Amphibian and Basilar Papillae of Rana pipiens

Parker, Mark 07 July 1995 (has links)
This study attempted to selectively stimulate and record from either the amphibian or basilar papillae of Rana pipiens. Computer-generated, frequency-specific clicks were used to elicit BSER's from either amphibian or basilar papillae. Narrowband noise fatiguers were presented in the frequency region of which each papillae are tuned. It was expected that a threshold shift would be elicited in the papillae that received the acoustic trauma, and that no threshold shift would be observed from the collateral papilla. The results of this experiment indicated that there was no overall difference between the threshold shift of either papilla. Furthermore, the amount of AP threshold shift was relatively constant regardless of whether the fatiguer bandwidth was overloading the amphibian or basilar papillae. By contrast, the amount of BP threshold shift was greater when proceeded by a fatiguer with a bandwidth corresponding to the BP tuning region than by a fatiguer with a bandwidth corresponding to the AP tuning region. Additionally, curare maximized the amount of BP threshold shift following fatiguing noise presented with a bandwidth to which the AP is tuned.
49

The susceptibility of leopards Panthera pardus to trophy hunting : the trophy hunting of leopards

Braczkowski, Aleksander Ryszard January 2013 (has links)
The trophy hunting of African leopards Panthera pardus pardus may generate revenue to help foster their conservation. However, leopards are sensitive to hunting and populations decline if overharvested. The practice therefore requires careful management grounded in robust estimates of population density/status. Camera-trap surveys are commonly used to establish leopard numbers, and may guide harvest quotas. However, such surveys are limited over wide spatial scales and many African governments lack resources to implement them. In this thesis I explore the potential use of a harvest composition scheme applied to puma Puma concolor in North America, to monitor leopards. The method hinges on the susceptibility of different leopard cohorts to hunting and if this varies, then predictions can be made about harvest composition. Susceptibility is likely to be governed by space use, encounter rates with bait lures (a common method used to attract leopards to hunting hides) and hunter selectivity. Thus in this thesis I explore leopard susceptibility to these factors using a protected leopard population in northern Zululand, South Africa. In my first chapter I examine using scent lures in camera-trapping. Against a backdrop of a passive survey I show adult males, females and sub-adults are captured at similar rates compared to a passive survey using lures. The use of lures does not appear to violate closure assumptions or affect spatio-temporal patterning, but their use appears limited as density estimate precision is not improved. My second chapter examines ecological (likelihood of encountering a hunter) and anthropogenic (attractiveness to hunters) susceptibility of leopards to trophy hunting. I show that adult males are the most susceptible cohort to hunting (sub-adults least susceptible). I then take the incident rates from ecological and anthropogenic models and create a theoretical harvest composition using population parameters of protected leopards. My third data chapter departs from hunting susceptibility and examines determinants of leopard trophy package price across Africa. I show that factors such as trophy quality, outfitter leopard hunting reputation and hunt success have little impact on price determination. Instead, overall outfitter reputation and the number of charismatic species in a package are positively correlated with price. These results have important consequences on several sustainable leopard hunting schemes proposed in the literature.
50

Effects of Sublethal Copper Exposure on Escape Behavior and Growth of Rana pipiens Tadpoles

Redick, Melinda 05 1900 (has links)
This research is designed to test how sublethal exposure to copper affects tadpole predator-escape behavior and how quickly tadpoles recover. After exposure, tadpoles were separated. Escape behavior was recorded for two-thirds of exposed tadpoles while one-third of the exposed population was measured weekly to determine growth and recovery. Control tadpoles were consumed within 15 minutes whereas those exposed to higher concentrations were consumed at a slower rate, which does not support the hypotheses. Although the rate of predation was lower, tadpoles exposed to higher Cu concentrations were on average, 1.47 cm in total body length. Those exposed to 0.93 mg/L averaged 0.86 cm. After being placed into clean water, treatment tadpoles recovered after 20 days.

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