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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.
511

The role of piscivores in a species-rich tropical river

Layman, Craig Anthony 15 November 2004 (has links)
Much of the world's species diversity is located in tropical and sub-tropical ecosystems, and a better understanding of the ecology of these systems is necessary to stem biodiversity loss and assess community- and ecosystem-level responses to anthropogenic impacts. In this dissertation, I endeavored to broaden our understanding of complex ecosystems through research conducted on the Cinaruco River, a floodplain river in Venezuela, with specific emphasis on how a human-induced perturbation, commercial netting activity, may affect food web structure and function. I employed two approaches in this work: (1) comparative analyses based on descriptive food web characteristics, and (2) experimental manipulations within important food web modules. Methodologies included monthly sampling of fish assemblages using a variety of techniques, large-scale field experiments, extensive stomach content and stable isotope analyses. Two themes unite the information presented: (1) substantial spatial and temporal variability in food web structure, and (2) how body-size can be used to generalize species-interactions across this complexity. Spatial variability occurred at various scales, from among small fish assemblages on seemingly homogeneous sand banks, to differences among landscape scale units (e.g. between lagoons and main river channel). Seasonal variability was apparent in predation patterns, with relative prey availability and body size primarily resulting in decreasing prey sizes with falling water levels. Body size was also related to functional outcomes of species interactions, for example, a size-based response of prey fishes to large-bodied piscivore exclusion. This pattern was further substantiated at the landscape-scale, as differences in assemblage structure among netted and un-netted lagoons were largely size-based. Trophic position of fish and body size was not found to be related, likely due to the diversity of prey available to consumers, and may signify that commercial netting activity will not decrease food chain lengths. In sum, by describing human impacts within a food web context, I endeavor to provide predictive power regarding a specific human-induced environmental problem, yet still allowing for generality that will broaden the theoretical foundations and applications of food web ecology.
512

Voices of four African American and European American female principals and their leadership styles in a recognized urban school district

Turner, Clara Thompson 15 November 2004 (has links)
This research study was conducted as a case study method on four African American and European American female educational administrators. The qualitative research framework was adopted to gain an understanding of how these administrators in secondary educational leadership positions exercised and (re)interpreted (Dillard, 1995) their leadership. The intent of my case study was to broaden the limited research base relating to the lived stories and experiences of the principalship from those whose voices can inform others about pertinent issues of leadership through diversity. In order to develop a clearer understanding of the administrators' perceptions on diverse leadership as it related to student academic performance, this study investigated constructed meanings of the relationship between their lived experiences and the way they led, by employing the feminist and interpretive lenses. This qualitative study used the actual words of the participants to tell their story, as it provided a rich representation of the ideas presented. Data was collected through in-depth, open-ended interviews, and semi-structured face-to-face interviews through which the events, beliefs, and perceptions shaped the phenomenon under study. Analysis of the data occurred immediately after each interview and observation. Analytic conclusions were formulated by unitizing, coding, and then categorizing ideas or statements of experiences from the data to ensure that important constructs, themes, and patterns emerged. The results of this study yielded the following as it related to the voices of four African American and European American female principals and their leadership styles in a recognized urban school district: (1) many forms or ways of leading were practiced by the administrators; (2) their upbringing or developmental pathways were different, however, they were determined to positively impact the lives of others throughout their educational career; (3) mentoring played an instrumental part in the administrators' leadership practices; (4) high student academic achievement was a result of effective professional development initiatives for their faculties; (5) they held themselves accountable for the outcomes of student academic performance; (6) they viewed diversity in leadership as critical; and (7) three of the four administrators identified their belief in a higher being as significant in their way of leading.
513

Perceptions Of Texas Agricultural Education Teachers Regarding Diversity Inclusion In Secondary Agricultural Education Programs

Lavergne, Douglas D. 14 January 2010 (has links)
While our schools across the United States evidently are witnessing an influx of students from diverse backgrounds, the need to address the issue of diversity among public school teachers is critical for inclusive and equitable schools. The purpose of this study was to explore and analyze Texas secondary agricultural education teachers' attitudes toward diversity inclusion in Texas secondary agricultural education programs. Using a web-based questionnaire, the researcher employed a nonproportional stratified random sampling technique, and 232 secondary agricultural education teachers participated in the study. Descriptive statistics were used for reporting the demographic and personal characteristics of respondents. Mean scores were used to assess teachers' perceptions of the benefits of diversity inclusion, perceptions of the barriers of diversity inclusion, and perceptions of proposed solutions to increase diversity inclusion in Texas secondary agricultural education programs. The sample consisted of 170 males and 45 females. The ethnic distribution of the sample was 90.5% White/European American, 6.2% Hispanic/Latino American, 1.9% Native American, 0.9% African American, and 0.5% Asian American. Respondents agreed that secondary agricultural education programs can benefit students of color and students with disabilities. Respondents also agreed that some of the barriers that prevent diversity inclusion in agricultural education include the lack of information about agricultural education, negative parental attitudes about agricultural education, and not being accepted by peers. Respondents indicated that the following is needed for all students to achieve in school: (a) educators, parents, and policymakers must develop strategies to address the different learning styles of all students; (b) agricultural educators should encourage and strive to increase students? of color membership in FFA; (c) teachers should become familiar with students of color represented in their classrooms in order to promote an atmosphere of acceptance and cooperation; and (d) agricultural educators should increase recruitment efforts to promote diversity inclusion must occur. The study also indicated that statistically significant differences in means scores existed based upon certain personal characteristics in regards to the Benefits, Barriers, and Solutions scales.
514

Angular and Temporal Diversity Combining in CDMA systems

Lee, Hung-yang 15 August 2009 (has links)
none
515

Sustainability and biodiversity : the impact, alternative design and prospects of restoration of channelized lowland streams in Hong Kong /

Chan, Pui-lok, Bosco. January 2001 (has links)
Thesis (Ph. D.)--University of Hong Kong, 2001. / Includes bibliographical references (leaves 325-365).
516

METPRO a case study in diversity and newspaper economics /

Fernandez Venard, Lourdes. Perry, Earnest L. January 2009 (has links)
The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Title from PDF of title page (University of Missouri--Columbia, viewed on January 20, 2010). Thesis advisor: Dr. Earnest L. Perry. Includes bibliographical references.
517

Interkulturelle Kompetenz in Arbeitssituationen eine handlungstheoretische Analyse individueller und kollektiver Fähigkeiten

Gröschke, Daniela January 2009 (has links)
Zugl.: Bochum, Univ., Diss., 2009
518

Workplace discrimination against gay & lesbian employees are state and local governments responding? /

Terrible, Heather A. January 2003 (has links)
Thesis (M.P.A.)--Kutztown University of Pennsylvania, 2003. / Source: Masters Abstracts International, Volume: 45-06, page: 2963. Typescript. Abstract precedes thesis as 2 preliminary leaves. Includes bibliographical references (leaves 61-63).
519

The role of science in the creation of endangered species law and policy the case of the West Indian manatee /

Goedeke, Theresa L. January 2003 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 2003. / Typescript. Vita. Includes bibliographical references (leaves 520-556). Also available on the Internet.
520

The role of science in the creation of endangered species law and policy : the case of the West Indian manatee /

Goedeke, Theresa L. January 2003 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 2003. / Typescript. Vita. Includes bibliographical references (leaves 520-556). Also available on the Internet.

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