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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.
1

Cougar Exploitation Levels in Utah: Implications for Demographic Structure, Metapopulation Dynamics, and Population Recover

Stoner, David C. 01 May 2004 (has links)
Presently, eleven western states and two Canadian provinces utilize sport hunting as the primary mechanism for managing cougar (Puma concolor) populations. However, the impacts of sustained harvest on population dynamics and demographic structure arc not well understood. Additionally, the lack of cost-effective enumeration techniques and strongly conflicting societal values complicate effective management of this species. Given these concerns, the primary goals of this study were (I) to determine the effects of sustained harvest on cougar populations, and (2) estimate the level and extent of cougar harvest statewide. I monitored cougar populations on Monroe Mountain in south-central Utah, and in the Oquirrh Mountains of north-central Utah from 1999 to 2003. Over this interval the Monroe population was subjected to heavy annual removals and was characterized demographically by a younger age structure. low survival and fecundity, and declining density. In contrast , the Oquirrh Mountain population was partially protected and exhibited an older age distribution, relatively high survival and fecundity, and static density. To examine the statewide distribution of sport hunting, I mapped the locations of all cougars legally harvested from I 996-200 I, and calculated harvest rates by watershed (# cougars killed I yr I I 00 km2) . Population trends derived on the st udy sites under known harvest regimes were used as benchmarks and compared with rates calculated for occupied cougar habitat across the state. This provided an index of where cougar populations were stable or declining as a result of hunting pressure. Results from this research suggest heavy, sustained harvest can have significant impacts on cougar population dynamics and demographics. Patterns of recruitment resemble a source-sink population structure due in part to spatially variable management strategies. Moreover, these results indicate during the later I 990s, most of the statewide population was exploited at levels equal to or surpass ing those measured on Monroe Mountain. Because cougar density and habitat characteristics vary across management units, the temporal scale of population recovery will most likely depend on the interaction of harvest regime, productivity of unexploited populations, and landscape connectivity.
2

Assessing Community Dynamics and Colonization Patterns of <i>Tritatoma dimidiata</i> and Other Biotic Factors Associated with Chagas Disease Prevalence in Central America

Orantes, Lucia Consuelo 01 January 2017 (has links)
Chagas disease is caused by the parasite Trypanosoma cruzi and transmitted by multiple triatomine vectors across the Americas. In Central America, the predominant vector is Triatoma dimidiata, a highly adaptable and genetically diverse Hemiptera. In this research, we used a novel reduced-representation DNA sequencing approach to discover community dynamics among multiple biotic factors associated with Chagas disease in Central America, and assess the infestation patterns of T. dimidiata after seasonal and chemical disturbances in Jutiapa, Guatemala. For our first study, we used a hierarchical sampling design to obtain multi-species DNA data found in the abdomens of 32 T. dimidiata specimens from Central America. We aimed to understand (1) the prevalence of T. cruzi infection, (2) the population genetics of the vector and parasite, (3) the blood meal history of the vector, and (4) gut microbial diversity. Our results indicated the presence of nine infected vectors harboring two distinct DTUs: TcI and possibly TcIV. We found significant clusters among T. dimidiata populations in countrywide and within-country levels associated with sylvatic ecotopes and diverse domestic genotypes. There was significantly higher bacteria species richness in infected T. dimidiata abdomens than those that were not infected, with further analysis suggesting that gut bacteria diversity relates to both T. cruzi infection and the local environment. We identified vertebrate blood meals from five T. dimidiata abdomens including chicken, dog, duck and human; however, additional detection methods are necessary to confidently identify blood meal sources. In our second study, we analyzed the GBS genotypes of 440 T. dimidiata specimens collected in two towns of Jutiapa, Guatemala. Our aim was to assess (1) the domestic population patterns that aid the recovery of T. dimidiata after an insecticide treatment in El Carrizal and (2) the seasonal changes that regulate the dispersal of the vector in the untreated communities of El Chaperno. Results showed that the insecticide application was effective at reducing the population abundance immediately after the application in El Carrizal; nevertheless, 18-month post-treatment the town-wide infestation and genetic diversity were recovering. Within-house relatedness among specimens recovered 18 months post-treatment, suggesting that the insecticide treatment failed to fully eliminate domiciliated colonies. In contrast, lack of change in abundance or genetic diversity in El Chaperno implied absence of dispersers from sources beyond the town periphery, while evidence of a decrease of relatedness among individuals implied dispersal among houses. After the insecticide treatment in El Carrizal, population reduction led to lack of genetic spatial autocorrelation; nevertheless, rapid dispersal into neighboring houses lead to autocorrelation 18 months after the insecticide treatment. This pattern was also observed in El Chaperno, where an increase in spatial autocorrelation during seasonal dispersal suggests spillover to close-by households. The creation of a novel genomics pipeline allowed us to understand community and dispersal patterns of T. dimidiata and other biotic factors important for the prevalence and transmission of Chagas disease at local and regional levels. Future studies should include complementary approaches for taxa verification (e.g. bacteria 16S barcoding, PCR-base detection), as well as expand the scope of local population analyses to peridomestic and sylvatic genotypes that could suggest a broader range of vector sources and region-wide patterns of temporal and spatial dispersion.
3

A revolução demográfica dos povos indígenas do Brasil: a experiência dos Kaiabi do Parque Indígena do Xingu - Mato Grosso - 1970-1999 / The demographic revolution of the Brazilian Indians: the experience of the Kaiabi a indigenous people of the Xingu river (Mato Grosso), 1970-1999

Pagliaro, Heloisa 15 August 2002 (has links)
Objetivo. Nesta investigação, analisa-se a dinâmica demográfica dos índios Kaiabi do Parque Indígena do Xingu (PIX), Mato Grosso, Brasil, no período 1970-1999. Métodos. Análise transversal e longitudinal da dinâmica demográfica, com base em nas informações do registro de eventos vitais da população das aldeias Kaiabi do PIX, gerados pelo programa de saúde da UNIFESP no Xingu, apoiados por levantamento histórico e etnográfico. Resultados. O contato com a sociedade nacional, nas décadas de 1920 a 1950, na região do rio Teles Pires, deu origem à depopulação das aldeias por confrontos e epidemias e à migração de parte dos Kaiabi para o Xingu. Em 1970, havia 204 no Parque e em 1999, 758. O crescimento da população foi de 4,5% ao ano, a taxas bruta de natalidade é alta ( 53,7 por mil habitantes) e de mortalidade baixa (8,1 por mil habitantes). Na população, 56,2% são menores de 15 anos de idade, sendo a taxa de mortalidade infantil de 15,2 por mil nascimentos vivos, em razão de um programa de saúde indígena existente na área desde 1965. A recuperação demográfica desta população se assemelha a do conjunto da população do Xingu, também atendida pelo programa de saúde. Destaca-se a analise da fecundidade por coortes acompanhadas por períodos de 35 anos, e a importância da coleta sistemática de dados demográficos para populações indígenas. / Objective. This study analyses the demographic dynamic of the Kaiabi a indigenous people of the Xingu river, Mato Grosso, Brazil, from 1970 to 1999. Methods. The demographic survey included cohort and period analyse, with vital statistics from the health service of the Xingu Indigenous Park. Results. Contact with Brazilian national society, established in the 1920 and 1950, in the Teles Pires river region, caused a population drop due to clashes and epidemics. In 1952, a part of the Kaiabi group start to migrate to the Xingu region where they live at present. In 1970 there where 204 individuals in the Xingu villages and in 1999, 758. The crude birth rate is higth (53,7 per thousand inhabitants) and the death crude rate low (8,1 per thousand inhabitants). The majority of the population is under 15 years of age (56,2%) and the infant mortality rate is low or moderate (15,2 per thousands live births ), considering indigenous communities on general, because a health indigenous program is installed on the area before 1965. The demographic recovery starts at 1975 and is similar to that others indigenous Xingu groups. The research highlights the importance of a analyse of fertility cohorts about 35 years.
4

A revolução demográfica dos povos indígenas do Brasil: a experiência dos Kaiabi do Parque Indígena do Xingu - Mato Grosso - 1970-1999 / The demographic revolution of the Brazilian Indians: the experience of the Kaiabi a indigenous people of the Xingu river (Mato Grosso), 1970-1999

Heloisa Pagliaro 15 August 2002 (has links)
Objetivo. Nesta investigação, analisa-se a dinâmica demográfica dos índios Kaiabi do Parque Indígena do Xingu (PIX), Mato Grosso, Brasil, no período 1970-1999. Métodos. Análise transversal e longitudinal da dinâmica demográfica, com base em nas informações do registro de eventos vitais da população das aldeias Kaiabi do PIX, gerados pelo programa de saúde da UNIFESP no Xingu, apoiados por levantamento histórico e etnográfico. Resultados. O contato com a sociedade nacional, nas décadas de 1920 a 1950, na região do rio Teles Pires, deu origem à depopulação das aldeias por confrontos e epidemias e à migração de parte dos Kaiabi para o Xingu. Em 1970, havia 204 no Parque e em 1999, 758. O crescimento da população foi de 4,5% ao ano, a taxas bruta de natalidade é alta ( 53,7 por mil habitantes) e de mortalidade baixa (8,1 por mil habitantes). Na população, 56,2% são menores de 15 anos de idade, sendo a taxa de mortalidade infantil de 15,2 por mil nascimentos vivos, em razão de um programa de saúde indígena existente na área desde 1965. A recuperação demográfica desta população se assemelha a do conjunto da população do Xingu, também atendida pelo programa de saúde. Destaca-se a analise da fecundidade por coortes acompanhadas por períodos de 35 anos, e a importância da coleta sistemática de dados demográficos para populações indígenas. / Objective. This study analyses the demographic dynamic of the Kaiabi a indigenous people of the Xingu river, Mato Grosso, Brazil, from 1970 to 1999. Methods. The demographic survey included cohort and period analyse, with vital statistics from the health service of the Xingu Indigenous Park. Results. Contact with Brazilian national society, established in the 1920 and 1950, in the Teles Pires river region, caused a population drop due to clashes and epidemics. In 1952, a part of the Kaiabi group start to migrate to the Xingu region where they live at present. In 1970 there where 204 individuals in the Xingu villages and in 1999, 758. The crude birth rate is higth (53,7 per thousand inhabitants) and the death crude rate low (8,1 per thousand inhabitants). The majority of the population is under 15 years of age (56,2%) and the infant mortality rate is low or moderate (15,2 per thousands live births ), considering indigenous communities on general, because a health indigenous program is installed on the area before 1965. The demographic recovery starts at 1975 and is similar to that others indigenous Xingu groups. The research highlights the importance of a analyse of fertility cohorts about 35 years.
5

Genetic structure of the brown bears (<em>Ursus arctos</em>) in Northern Europe

Kopatz, A. (Alexander) 15 April 2014 (has links)
Abstract Wild populations of large carnivores in Europe were almost wiped out during the last centuries. Nowadays, the number of brown bears in North and Eastern Europe has increased, and the current situation suggests that these populations have recovered or are in the process of recovery. Knowledge of the population genetic consequences of demographic recovery in large carnivores, especially across national borders and on broader geographical scales, is still limited. In this study, we collected 3,757 fecal and hair samples as well as 881 tissue samples from brown bears across Northern Europe, with a focus on the Finnish population and neighboring areas, to investigate the population structure, connectivity, and genetic diversity on a spatial as well as a temporal scale. Bayesian clustering analysis of the population structure suggested the division of brown bears in Northern Europe into several genetic clusters, and the subdivision of the Finnish population into a northern and southern subpopulation. The estimation of gene flow pointed to better connectivity of the bears between Southern Finland and Western Russia, while migration between Scandinavia and Northern Finland as well as between Scandinavia and Southern Finland/Western Russia appeared to be restricted. Genetic clusters identified in Finland, Russia and Northern Norway displayed high genetic diversity, which was among the highest reported in wild brown bears. Recovery of the Finnish population has been accompanied by a detected range expansion towards the north, while genetic differentiation between clusters has decreased and genetic diversity has increased in the southern population, suggesting expansion from the south. Our results demonstrated that the immigration of bears from Russia still plays a major role in the Finnish bear population; however, connectivity between the Finnish-Russian population and Scandinavian bears appears to be restricted and should be improved, as well as regularly monitored. / Tiivistelmä Suurpetojen luonnonpopulaatiot hävisivät Euroopasta melkein kokonaan viimeisten vuosisatojen aikana. Ruskeakarhujen määrä on viime aikoina kasvanut Pohjois- ja Itä-Euroopassa, ja karhupopulaatiot ovat toipuneet tai toipumassa. Tieto demografisen toipumisen geneettisistä seurauksista populaatioissa on varsin rajoittunutta etenkin laajemmassa maantieteellisessä mittakaavassa, yli valtiorajojen. Keräsimme tätä tutkimusta varten 3757 uloste- ja karvanäytettä ja 881 kudosnäytettä Suomesta ja sen lähialueilta. Tarkoituksenamme oli kartoittaa Pohjois-Euroopan karhupopulaatioiden geneettistä rakennetta ja monimuotoisuutta, sekä populaatioiden välisiä yhteyksiä huomioiden ajallinen ja maantieteellinen ulottuvuus. Bayesiläisen ryhmittelyanalyysin perusteella Pohjois-Euroopan karhut jakaantuvat useaan geneettiseen ryhmään. Suomen populaatiossa erottuivat eteläinen ja pohjoinen alapopulaatio. Analyysit geenivirran määrästä osoittivat, että Etelä-Suomen ja Länsi-Venäjän karhupopulaatiot ovat yhteneväisemmät, kun taas migraatio Skandinavian ja Pohjois-Suomen sekä Etelä-Suomen ja Länsi-Venäjän välillä vaikuttaisi olevan rajoittunutta. Suomesta, Venäjältä ja Pohjois-Norjasta tunnistetut alaryhmät olivat geneettisesti hyvin monimuotoisia, ja muuntelu oli korkeampaa kuin koskaan aiemmin karhuilla havaittu. Suomen karhupopulaation toipuessa ja levitessä pohjoiseen, geneettinen erilaistuminen maan sisällä on vähentynyt ja eteläisen alapopulaation monimuotoisuus kasvanut. Tämä viittaa populaation laajentumiseen etelästä käsin. Tulosten perusteella karhujen tulomuutto Venäjältä on yhä tärkeää Suomen populaatiolle. Suomen ja Venäjän karhupopulaatioiden yhteyttä Skandinavian karhupopulaatioihin tulisi seurata ja parantaa.
6

Population dynamics of the threatened staghorn coral, Acropora cervicornis, and the development of a species-specific monitoring protocol

Goergen, Elizabeth 03 May 2018 (has links)
Historically, Acropora cervicornis was found in high densities on many Caribbean, Florida, and Gulf of Mexico reefs. A disease outbreak in the late 1970s and 80s caused up to 99% loss of A. cervicornis cover at some sites, leaving populations sparsely distributed throughout its range and typically found as isolated colonies. Even though populations are depauperate causing a decrease in sexual reproduction, its fast growth rate and ability to reproduce through asexual fragmentation affords this species the potential for quick recovery and population growth. However, limited to no natural recovery has been documented. Many of these populations are poorly studied because most monitoring programs are not designed to capture A. cervicornis’ unique life history characteristics. Its patchy distribution, complex growth form, frequent fragmentation, and dislodgment present a challenge for long term tracking. Furthermore, its ability to exist from small isolated colonies to semi-continuous patches spanning hectares makes defining individuals to assess abundance, survival, health, and growth a difficult task. The aim of this dissertation was to develop a species-specific monitoring protocol to describe the abundance and cover of A. cervicornis and the effects of disease, predation, and disturbance events across space and time. The monitoring protocol was developed and used across three sub-regions of the Florida Reef Tract (Broward County, Middle Keys, and Dry Tortugas). Several permanent 3.5 m radial plots were installed across multiple sites in each sub-region. A species census, percent cover, and demographic data of a sub-set of colonies were collected three times per year (winter, summer, and fall) from 2008-2016. These results were then used to assist in designing and testing optimal outplant strategies. Outplanting occurred at seven sites in Broward County, FL between 2012- 2015. Experiments were designed to assess the effects outplant colony density, host genotype, colony size, and attachment technique had on colony survival, growth, and health. The monitoring protocol was successfully used for identifying spatial and temporal patterns and trends in cover, disease, and predation on A. cervicornis across a range of population sizes. Percent cover of living A. cervicornis declined significantly during the duration of the project. Disease prevalence and occurrence was highest during the summer. Colony size and volume increased with depth and were the largest in the Broward County sub-region. Disease caused the most mortality, however fireworms were the most prevalent cause of recent mortality. Disease and predation were more prevalent on masses (individuals larger than 1.5 m in diameter). The outplant experiments showed that colony survival and health were greatest when colonies had greater than 15 cm in total tissue and in densities less than 1 col/m2. Host genotype and outplant site had variable effects on survival and growth. Outplanted colonies quickly acclimated to their environment and increased colony abundance within sites by fragmentation. Prevalence of disease and predation were lower on outplanted colonies than wild colonies. Frequent disturbances such as tropical storms, hurricanes, and disease events caused increased, prolonged, and widespread mortality and fragmentation, however periods void of disturbances resulted in recovery and growth. Therefore, reducing the effects of climate change and determining and decreasing the causes of disease could promote species recovery. In the meantime, population enhancement by outplanting is a viable way to assist species conservation and recovery.

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