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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.
221

Ovlivnění genetické diverzity rákosových porostů strukturou říčních systémů / Impact of river system structure on the genetic diversity of reed populations

Fuxová, Gabriela January 2011 (has links)
Many plant species are closely related to river biotopes or to biotopes influenced by rivers. River systems create important linear corridors in ecosystems and directly or non-directly influence spatial spread of species in these environments. This offer many questions about species spread in this system. We can answer these questions by using molecular methods. Using 10 microsatellite (SSRs) primers, 202 individuals of Phragmites australis from 60 populations were analysed. Those analyses allowed reveal kinship of individuals, obtain information about spatial spread of populations and about spreading of common reed. Phragmites australis creates both - monoclonal and polyclonal - populations. Dependence of rate of clonality on environment was revealed. Populations from river banks are more monoclonal, populations from pond shores are more polyclonal. Populations are isolated. The highest percentage of variability was explained on among-population level. This is common for anemochoric species. Communication between populations is present, more on shorter distances. Evidence for vegetative spread was found on short distance. Generative spread is much more common. Long-distance spreading is mediated by generative diaspores - seeds. This spreading includes within-river spread, among-river spread and spreading...
222

Going the distance : a description of commuter couples in Jos, Nigeria

Kumswa, Sahmicit Kankemwa 01 1900 (has links)
Includes bibliographical references (leaves 193-206) / This thesis describes a family variation among urban Nigerian couples called a commuter marriage. A commuter marriage in this study is defined as a union between a dual earner/dual career couple where the husband and wife have decided to live apart from each other due to work commitments until such a time as is convenient for them to live continuously together again. This separation is mainly undertaken to improve their financial and career prospects. The study seeks to understand what dynamics are involved in a commuter marriage in Jos, Plateau State. The Life Course Perspective, with a focus on the gendered life course perspective, serves as a theoretical framework for this study. The perspective assumes that families undergoing the same transitions are likely to display the same characteristics which may not be necessarily relevant for all families in the same life stage, while the gendered life course perspective acknowledges the gendered context. At the same time the cultural context of the Nigerian society in terms of family norms are taken into account. An overview of commuter marriages, including characteristics of commuter marriages and non-traditional marriages linked to commuter marriages are provided. The differences between established and adjusting couples were repeatedly underlined. The research has an underlying interpretivist paradigm, therefore a qualitative research methodology was deemed best for the study. A semi-structured interview guide and time diaries were used to obtain data from seventeen participants. It was found that a commuter marriage is costly financially, socially and emotionally. An emphasis on the male provider and the wife as the manager of the resources was highlighted. Commuter couples report that their greatest support system constitute their family members who show the most understanding to their situation. Commuter fathers were generally passionate about their fatherly roles, but had conflicting feelings about balancing work and family, feeling the family is losing out. Generally, commuter couples in this study showed a sincere desire for the commuting relationship not to span an indefinite amount of time. / Sociology / D. Phil. (Sociology)
223

Vliv dlouhých optovláknových tras na polarizační stav světla a jejich využití pro napájení polarizačních senzorů / Long optical fibre routes influence on the polarizing state of light and uses it for powering polarization sensors

Panascí, Marco January 2021 (has links)
This diploma thesis deals with the influence of long fiber optic paths on the polarization state of light and their use for powering polarization sensors. The aim of the diploma thesis was to design the arrangement of optical fiber components so that the polarization properties of light at the end of the path are further usable for sensory purposes. Four partial measurements with a long path (in a laboratory setting, laying in the ground, on a curtain, under the influence of external influence) and one measurement without a path under the influence of external influence were designed. The overall measurement results demonstrate that for the functional power supply of long-distance sensor systems, an existing single-mode fiber can be used (laid by laying in the ground), into which a light source for a given sensor system would be multiplexed. In the discussion, all types of measurements are analyzed and compared with each other. Finally, the overall result is summarized and applications are described in which such a sensor system could be used.

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