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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.
21

Distribution and abundance of swamp rabbits and bats in fragmented wetland forests of southeast Missouri

Warwick, J. Adam. January 2003 (has links)
Thesis (M.S.)--University of Missouri-Columbia, 2003. / Typescript. Includes bibliographical references. Also available on the Internet.
22

Green frog (Rana clamitans) movement behavior and terrestrial habitat use in fragmented landscapes in central Missouri /

Birchfield, Gayle Livingston, January 2002 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 2002. / Typescript. Vita. Includes bibliographical references. Also available on the Internet.
23

Green frog (Rana clamitans) movement behavior and terrestrial habitat use in fragmented landscapes in central Missouri

Birchfield, Gayle Livingston, January 2002 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 2002. / Typescript. Vita. Includes bibliographical references. Also available on the Internet.
24

Habitat loss and fragmentation under urbanization: the spatio-temporal dynamics of causes, processes andconsequences at landscape level

Xie, Yujing., 谢玉静. January 2013 (has links)
Landscape modification, especially those human-dominated changes, has been widely considered as one of the key drivers inducing the degradation of environment and ecosystem. The consequent habitat loss and fragmentation, which are closely related to ecological process, have attracted much scholarly attention. However, very few studies have systematically examined their causes and consequences at the landscape level. Integrating human activities into consideration in a holistic way remains poorly understood in particular. This thesis reports a systematic study of habitat loss and fragmentation under urbanization. This research distinguishes itself from previous works in its investigation of the spatio-temporal dynamics of causes and consequences of habitat loss and fragmentation, and its endeavor to disentangle habitat fragmentation from simple habitat loss in terms of their processes and effects. The Shenzhen River cross-border watershed, shared by Hong Kong Special Administrative Region and Shenzhen, is used as a case to illustrate how these ideas can work in practice. The study period spans from 1988 to 2008.The main contents of the study include analysis of the processes and causes of habitat loss and fragmentation, and dynamic consequences on water quality and ecosystem services for biodiversity conservation at spatial and temporal scales. Various methods are employed, mainly including conventional and newly developed landscape metrics (such as the Urbanization Isolation Effect (UIE) and Habitat Isolation Degree (HID)), a spatial statistical approach based on the Geographically Weighted Regression (GWR) model, spatio-temporal analyses and cross-border comparison. Major findings of the research are highlighted as follows. First, habitat loss and fragmentation show great spatial heterogeneity as well as temporal variation due to extensive and rapid urban sprawl in the study area. Second, by adopting the GWR model, it is found that human-related factors have played a significant role in determining not only the “amount” but also the “location” of habitat loss. Third, by using two new landscape metrics, namely the UIE and HID, both the extent (urban sprawl) and intensity (population density) of urbanization are suggested to have significant influences in habitat isolation. Fourth, water quality in the watershed is recognized to be closely correlated with habitat loss and fragmentation, and the correlations show major discrepancies between the Hong Kong and the Shenzhen sides. Moreover, by proposing a compound indicator (NP/MPS) for measuring habitat fragmentation (independent of simple habitat loss), it is found that habitat loss has exerted a bigger influence on water quality degradation than habitat fragmentation. Fifth, by integrating habitat connectivity into the evaluation of ecosystem services for biodiversity conservation, both the habitat size and connectivity are recognized to be important in explaining the degradation of ecosystem services value. Habitat size has played a dominant role in the overall change of ecosystem services value, whereas the role of connectivity (fragmentation) is more critical when the “stepping stones” sites are lost. The study provides a new framework to examine the habitat loss and fragmentation under urbanization at the landscape level. The efforts show great effectiveness in providing sound and useful information for future landscape planning, biodiversity conservation and watershed management. / published_or_final_version / Geography / Doctoral / Doctor of Philosophy
25

Assessment of genetic diversity in Asarum canadense L. using amplified fragment length polymorphism (AFLP)

Quadri, Asima January 2007 (has links)
Forest fragmentation poses a serious danger to population diversity in plants and animals by increasing species isolation, thus reducing the population size and genetic diversity. However, little information is available concerning how fragmentation impacts plant diversity. AFLP fingerprinting was used to assess genetic diversity within and between populations of Asarum canadense L. (Canadian Wild Ginger) across 11 different populations in East-Central Indiana. AFLP fingerprints using two primer pairs generated 51 distinct bands with an average of 25.5 bands per primer. Forty-eight low molecular weight distinct polymorphic bands were observed (50-200 bp range). The percentage of polymorphism was low (0-25%) indicating low levels of genetic diversity within each population studied. NTSYSpc Numerical Taxonomy Analysis Software generated aphenogram that revealed high levels of homologies within populations (75-100%), with individuals from the same population typically clustered. The genetic diversity between populations ranged from 10-50%. The populations from Jay, Randolph and Henry Counties clustered together exhibiting -54% homology, while populations from Mien, Madison, and Huntington counties shared approximately 64% homology. The populations from Adams, Blackford, Delaware, and Grant counties shared approximately 66% homology. However, within this last group Blackford and Delaware counties shared 90% homology. There were no apparent effects of the size of the forest fragments on the observed diversity measures. A possible relationship between genetic diversity and spatial distance was observed between populations moving from east to west. Possible reasons for this observation may be due to forest types, age of forests, climatic factors, soil types, and/or anthropogenic activities. Overall, the low level of average diversity within the populations strongly suggests that the individuals inhabiting isolated forests primarily propagate by asexual means.Ball State UniversityMuncie, IN 47306 / Department of Biology
26

New approaches in landscape genetics and niche modeling for understanding limits to anuran distributions

Murphy, Melanie April, January 2008 (has links) (PDF)
Thesis (Ph. D.)--Washington State University, August 2008. / Includes bibliographical references.
27

Biogeographic and experimental evidence for local scale dispersal limitation in central Panamanian forest birds /

Moore, Randall Phillips, January 1900 (has links)
Thesis (Ph. D.)--Oregon State University, 2006. / Printout. Includes bibliographical references (leaves 98-104). Also available on the World Wide Web.
28

Fragmented Cities and the Potential of Fallow Spaces: Finding Connectivity Through Architecture

Kryspin, Kelsey M. 15 July 2021 (has links)
No description available.
29

Interactions between habitat fragmentation and invasions : factors driving exotic plant invasions in native forest remnants, West Coast, New Zealand : a thesis submitted in partial fulfillment of the requirements of the degree of Doctor of Philosophy in Ecology, School of Biological Sciences, University of Canterbury /

Hutchison, Melissa Alice Sarah. January 2008 (has links)
Thesis (Ph. D.)--University of Canterbury, 2008. / Typescript (photocopy). Includes bibliographical references (leaves 148-172). Also available via the World Wide Web.
30

Fragmentação do sono e adaptação ao trabalho noturno / Sleep fragmentation and adaptation to night work

Moreno, Claudia Roberta de Castro 30 April 1998 (has links)
Este estudo é parte de um projeto mais amplo que investiga as diferenças individuais no processo de adaptação de trabalhadores aos esquemas temporais de trabalho a que estão submetidos. As diferentes estratégias dos trabalhadores para se adaptar ao trabalho noturno têm sido amplamente investigadas com o objetivo de se conhecer modos de lidar melhor com a organização temporal do trabalho. Neste trabalho foi realizado um estudo de uma possível estratégia de adaptação ao débito de sono provocado pelo trabalho noturno em uma população de mulheres: a fragmentação do sono, ou seja, a realização de mais de um episódio de sono ao longo das 24 horas. A princípio, foram identificadas trabalhadoras que se auto-avaliaram como bem adaptadas ao esquema de trabalho. A avaliação da adaptação foi realizada através de um formulário construído a partir dos depoimentos das próprias trabalhadoras acerca do impacto do trabalho noturno. O acompanhamento do ciclo vigília-sono das trabalhadoras, por dez semanas consecutivas, através de protocolos de atividades preenchidos por elas, permitiu identificar aquelas que fragmentavam o sono e posteriormente confrontar esse resultado com a autoavaliação da adaptação das trabalhadoras. Nessa última etapa, a amostra desse estudo consistia de 24 mulheres que trabalhavam em uma indústria farmacêutica de segunda a sexta-feira das 22:00 às 06:00. Na ocasião da pesquisa elas tinham entre 20 e 40 anos de idade. Para verificar a influência da fragmentação regular do sono foi realizado um segundo estudo, em laboratório, onde foi possível controlar a fragmentação do sono. Neste estudo foram avaliados sujeitos submetidos a um regime simulado de emergência de trabalho, envolvendo drástica redução do sono. Esta avaliação foi realizada com voluntários submetidos a uma fragmentação forçada de sono. Os resultados do estudo em laboratório mostraram que a fragmentação regular do sono não causa sonolência maior do que um único episódio de sono. O estudo no campo revelou que para a maioria das trabalhadoras que dormem mais de um episódio de sono ao longo das 24 horas e que se auto-avaliaram como bem-adaptadas, a fragmentação do sono pode ser interpretada como uma estratégia de adaptação. Entretanto, há trabalhadoras que apesar de se auto-avaliarem como bem-adaptadas não fragmentam o sono. Conclue-se, portanto, que não há um único padrão de sono adequado para todos os trabalhadores e a variabilidade individual deve ser levada em consideração antes de propor uma específica estratégia de sono como estratégias de adaptação ao trabalho. / This work is part of a larger project designed to search for individual differences relevant to adaptation of workers submitted to unusual work schedules. The different strategies of adaptation have been investigated in order to improve coping with nightwork. In this present study we report an investigation about sleep fragmentation (more than one sleep episode a day) as a strategy of adaptation to the sleep deficit caused by work schedule in female nightworkers. First of all, female nightworkers who evaluated themselves as well adapted were identified. This evaluation was made through a form based on interviews. The follow-up of workers\' sleep-wake cycle with sleep logs filled out by themselves for ten consecutive weeks permitted the identification of workers who showed sleep fragmentation. This result was compared with the adaptation\' scores obtained from the forms. In this last part of the study the sample was composed by 24 females who worked at a pharmaceutical plant from Monday to Friday from 22:00 to 06:00. They were between 20 and 40 years old. To verify the influence of regular sleep fragmentation on work adaptation a lab study was carried out. In this study we analyzed subjects submitted to a simulation of an emergency work condition with sleep reduction. This evaluation was done with volunteers submitted to a forced sleep fragmentation. The results from this lab study showed that the sleepiness caused by regular sleep fragmentation is not greater than when it is caused by a single sleep episode. The field study showed that sleep fragmentation can be understood as an adaptation strategy for women who both fragmented their sleep and identified themselves as well adapted. However, there were women who in spite of considering themselves well adapted, did not show sleep fragmentation. It can be concluded that there is not an ideal sleep pattern for all of the subjects and that individual variability should be taken in to account before proposing a specific sleep strategy as recommendation to cope with nightwork.

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