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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

Validating Body Condition Indices As Indicators Of Individual Quality: Does Condition Explain Intraspecific Variation In Reproductive Success And Survival Among Crimson Finches (Neochmia Phaeton)?

Milenkaya, Olga 05 November 2013 (has links)
Body condition is expected to reflect individual quality because high quality individuals should be better at acquiring and using resources, resulting in higher fitness. However, the hypothesis that condition indices are meaningful indicators of individual quality has been questioned. I monitored a population of crimson finches (Neochmia phaeton) for reproductive success and survival over four breeding seasons. My study population is well suited for this research because individuals forage in common areas and do not hold territories such that variation in condition between individuals is not confounded by differences in habitat quality. Because little is known about crimson finches in the wild, I first describe their breeding biology and life-history traits (Chapter I). Next, I sampled them for commonly used condition indices including mass adjusted for body size, muscle and fat scores, packed cell volume, hemoglobin concentration, total plasma protein, and heterophil to lymphocyte ratio. I describe the variation in these indices and find that many vary by sex and breeding stage, and to a lesser extent by year, age and time of day, concluding that these covariates need to be controlled for when examining intraspecific variation in condition (Chapter II). If condition indices reflect inherent individual quality, then condition indices should be (a) repeatable within individuals, and (b) predictors of realized fitness. I test these two predictions in Chapters III and IV, respectively, and I find that condition indices are repeatable within individuals over short, but not long, time periods and that some indices predict reproductive success, while others do not, and that none predict survival. Both findings only partially support the hypothesis that condition indices are meaningful indicators of individual quality, raising concerns over this common interpretation. In Chapter V, I glean insights from the ecological and poultry science literature and discuss further complications with the use of condition indices as proxies for individual quality and fitness. I conclude that condition indices indicate how well an individual is currently acquiring resources as well as its likely physiological state over the next few months, but that they do not reflect individual quality and are not reliable proxies for fitness. / Ph. D.
22

Life History And Secondary Production Of Cheumatopsyche Lasia Ross (Trichoptera: Hydropsychidae) With Respect To A Wastewater Treatment Facility In A North Texas Urban Stream

Paul, Jenny Sueanna 12 1900 (has links)
This study represents the first shift in multivoltine life history of Cheumatopsyche species from a wastewater treatment plant (WWTP) in North America. Populations of C. lasia were examined upstream and downstream of the Denton’s Pecan Creek WWTP August 2009 through November 2010. C. lasia is multivoltine in Pecan Creek with three cohorts observed upstream of the WWTP and four possible cohorts downstream. A fourth generation was possible downstream as thermal inputs from WWTP effluent resulted in elevated water temperatures that allowed larval development to progress through the winter producing a cohort ready to emerge in spring. Production of C. lasia was 5 times greater downstream of the WWTP with secondary production estimates of 1.3 g m-2 yr-1 and 4.88- 6.51 g m-2 yr-1, respectively. Differences in abundance were due to increased habitat availability downstream of the WWTP in addition to continuous stream flow from inputs of wastewater effluent. Results also suggest that C. lasia is important for energy transfer in semiarid urban prairie streams and may serve as a potential conduit for the transfer of energy along with emergent contaminants to terrestrial ecosystems. These finding highlight the need for more quantitative accounts of population dynamics (voltinism, development rates, secondary production, and P/B) of aquatic insect species to fully understand the ecology and energy dynamics of urban systems.
23

Comparisons of Secondary Production, Life History, and Mouthpart Functional Morphology Between Two Populations of the Amphipod Gammarus minus

Haley, Carol J. 21 January 1997 (has links)
In this study, features of ecology, behavior, and functional morphology related to feeding activity of two populations of the amphipod Gammarus minus were compared. The two populations occupied different habitats, and I attempted to determine whether differences observed between the two populations were related to habitat. Annual production and life history of the populations were compared and their relationship to factors such as temperature, water-chemistry, and quantity of available organic matter were examined. Mouthpart and foregut morphology were compared between the two populations and between immature and mature amphipods with light and scanning electron microscopy. Measurements of structure were analyzed by linear regression. A behavioral study, comparing feeding of immature and mature G. minus, was conducted in the laboratory. Annual production of G. minus occupying a habitat characterized by the presence of watercress, gravel substrate, and constant temperature (Site 1) was 3.9 g/m² (95% C.I.: 3.2- 4.5), while that in the habitat characterized by leaf detritus and fluctuating temperatures (Site 2) was 1.8 g/m² (95% C.I.: 1.6-2.1). Breeding occurred throughout the year at Site 1, but there was a yearly cycle at Site 2. The greatest numbers of the smallest size classes of amphipod were present at Site 2 when the quantity of ash-free dry mass (AFDM) of wood and bark was greater than AFDM of leaf detritus. Of nine mouthpart and foregut structures studied, three, the number of cuspidate setae on outer plates of maxillipeds, the length of the dactyl on maxilliped palps, and the number of hook setae on the foregut ampullae, were found to be correlated with body length. Of these, rates of increase in maxilliped setae numbers and hook setae numbers were greater for immature than mature animals, and the number of hook setae for a given sized animal was generally greater for animals at Site 1 than Site 2. Animals presented with ground-up leaf material in the laboratory exhibited twenty-one recognizable behaviors. The frequencies of six behaviors were found to be statistically different between immature and mature animals. The differences suggest that immatures may prefer a food type or size other than that provided in the experiment. / Ph. D.
24

Investigating Connections between Lateral Enamel Formation and Life History in New World Monkeys

Clark, Allison N. 10 October 2014 (has links)
No description available.
25

Women activists : lives of commitment and transformation

Hanson, Laurel Marie 26 January 2007
This thesis is based on a life history study of two women involved in activism for social change. Broadly guided by life history methodology and feminist and constructivist postmodern theories and approaches, this inter-disciplinary research explores experiences and stories in the lives of these women that evoke the transformative journeys of womens long-term commitments to social change activism, and that portray ways in which personal and social transformation interweave. The stories illuminate how individual courses of action both resonate with and diverge from meta-narratives of social movements, and how they reflect and resist the contexts in which those courses evolve. Reflection on the process of constructing the stories reveals the effects on the participants and the researcher of the inter-subjective realm from which life history arises. The studys practical purpose relating activism, transformative education and postmodernism also leads to experimentation with creative texts that at once provide educational tools and invite participation in the interpretive process. Overall the thesis melds more traditional approaches with more unconventional ones. The study is both provocative and supportive of those working for social change through transformative education and activism.
26

Women activists : lives of commitment and transformation

Hanson, Laurel Marie 26 January 2007 (has links)
This thesis is based on a life history study of two women involved in activism for social change. Broadly guided by life history methodology and feminist and constructivist postmodern theories and approaches, this inter-disciplinary research explores experiences and stories in the lives of these women that evoke the transformative journeys of womens long-term commitments to social change activism, and that portray ways in which personal and social transformation interweave. The stories illuminate how individual courses of action both resonate with and diverge from meta-narratives of social movements, and how they reflect and resist the contexts in which those courses evolve. Reflection on the process of constructing the stories reveals the effects on the participants and the researcher of the inter-subjective realm from which life history arises. The studys practical purpose relating activism, transformative education and postmodernism also leads to experimentation with creative texts that at once provide educational tools and invite participation in the interpretive process. Overall the thesis melds more traditional approaches with more unconventional ones. The study is both provocative and supportive of those working for social change through transformative education and activism.
27

The community of Saint Cuthbert : its properties, rights and claims from the ninth century to the twelfth

Hall, David John January 1984 (has links)
Symeon of Durham's history of the church of Durham, a number of earlier narratives and the fine collection of twelfth century Durham charters formed the basis for this history of the Community of Saint Cuthbert before 1150. They generally concentrated upon the acquisition and maintenance of the community's lands, the changes in which reflected the major events in northern history. The survival of the sources and the story they tell bear witness to the remarkable resilience and continuity of the community. At no time did it suffer the destruction characteristic of northern monasticism, often flourishing at times of upheaval, as during the Scandinavian and Norman Conquests. In its first days the acquisition of land was, predictably, associated with early Anglian settlement, especially royal sites. Throughout the period the growth of the patrimony was largely dependent upon royal patronage, though some bishops were also avid acquirers of land. Royal and other lay patronage can be directly associated with the need to gather support in the north. Rulers secure in the north, as native northern earls, or strong enough to subdue the area were unlikely to be great benefactors and were inclined to despoil the church. For the Cuthbertine community jurisdictional rights were important and there is evidence to suggest that there existed a substantial jurisdictional immunity within the patrimony by the tenth century. The rights of sanctuary of a mother church and the immunities of church land in the seventh century seem to have been important factors in its establishment, rather than, as has generally been suggested, the alienation of comital rights to Durham in the late eleventh century. The combination of landed wealth, jurisdictional privilege and survival accounts for the immense power of the community in the north from the seventh century onwards.
28

Demography, Biomass Production and Effects of Harvesting Giant Kelp Macrocystis pyrifera (Linnaeus) in Southern New Zealand.

Pirker, John Georg January 2002 (has links)
This study examined the demography of giant kelp Macrocystis pyrifera (Linnaeus) and its interactions with understorey algae and invertebrates in southern New Zealand over two and a half years. Most of the study was done at two sites within Akaroa Harbour (Banks Peninsula) but ancillary sites at Tory Channel (Marlborough Sounds) were used for parts of the study. The kelp forests within Akaroa Harbour were generally highly productive, with a high annual turnover of giant kelp. Macrocystis plants were mostly annual and rarely reached ages greater than 12 months. Peak recruitment occurred in spring (November) during 1995-97, but lesser recruitment episodes occurred throughout the year. The maximum growth rates of Macrocystis fronds were comparable to rates reported elsewhere in southern hemisphere populations (22 mm - 24.5 mmlday), but considerably lower than those in northern hemisphere populations. The major experiment incorporated in the study tested the effects of the Macrocystis canopy and the understorey canopy of the stipitate laminarian Ecklonia radiata on macroalgae and invertebrates. The experiment was structured so that the effects of clearances at different times could be determined. One impetus for this experiment was the need to address issues relating to the commercial harvesting of giant kelp, its sustainability and its effects on other species. The effects of canopy removals on understorey algae, mostly juvenile Macrocystis, Ecklonia and Carpophyllum spp, were highly dependent on the timing of canopy removals and the combinations of canopies removed. For example, winter harvests of the Macrocystis canopy alone enhanced the survival of post-settlement Macrocystis recruits, but had little effect on Ecklonia recruitment. However, when both Macrocystis and Ecklonia canopies were removed in spring, there was heavy recruitment of Ecklonia that grew to dominate the understorey. Strong inter and intraspecific interactions from the Macrocystis surface canopy appeared to have been reduced by physical factors including water turbidity, sedimentation and the deterioration of the surface canopy during summer. These physical factors were not as limiting in Tory Channel. Fine scale extrinsic factor effects including nutrients, light and grazing on the early life history of Macrocystis were investigated in small experiments. Results suggest that recruitment may be nutrient limited even at moderately low temperatures, and that small herbivorous gastropods are an important source of mortality in the early life stages of Macrocystis. Culturing and transplantation cultivation techniques were also examined as a means of supplementing algal supplies. Macrocystis was cultured successfully through its life cycle onto culture ropes, but generally failed to produce visible sporophytes when placed in the field. Cultured plants did grow in Tory Channel, however. Juvenile plants transplanted to ropes for on-farm cultivation showed little growth during summer, but the addition of nutrients significantly enhanced growth rates of these plants during warmer months when natural nutrient levels were low. Increased growth rates at the onset of winter and with the addition of nutrients during summer confirmed that low nutrient levels during summer are growth limiting. Akaroa Harbour kelp forests exhibited considerable variation in Macrocystis canopy biomass through time. For example, the 32,000 m2 kelp forest at Wainui had a biomass of 144 t in October 1995, which then decreased to 21 t in October 1996. Canopies tended to deteriorate during summer. Thus, at Ohinepaka Bay kelp forest had a biomass of 31 t during winter 1997, which decreased to 0.06 t the following summer. The greatest reduction in biomass, however, coincided with a period of hugely increased sediment, which smothered blades in the sea-surface canopy, covered the substratum, and prevented successful recruitment of kelp for over a year. Nutrient depletion was one of several factors thought to cause the summer deterioration of the Macrocystis sea-surface canopy, which has important ramifications for the commercial harvesting of Macrocystis pyrifera in summer. Management considerations and options are discussed in relation the commercial harvesting of Macrocystis in New Zealand. The major conclusion of this study is that although Macrocystis was able to form dense surface canopies during winter its ability to dominate kelp forests was constrained by physical factors, especially sedimentation, high turbidity, nutrients, and storms. The lack of strong interactions between Macrocystis and Ecklonia are also largely a result of their different life history characteristics. Overall, there appear to be no significant negative flow-on effects resulting from kelp harvesting and it appears that Macrocystis can be harvested sustainably.
29

Sociosexual Development: Infusing the Belsky, Steinberg, and Draper Model with Sexual Selection

Jackson, Jenee James January 2010 (has links)
Life history theory attempts to explain between- and within-species variation in maturational and reproductive patterns, whereas sexual selection attempts to explain between- and within-sex differences in intersexual mate choice and intrasexual competition for members of the opposite sex. These two expansive evolutionary theories have been used by developmental scientists and social/personality psychologists to explain the variation observed in human reproduction, including the timing of reproductive events and individual differences in orientation toward mating and parenting. In Part I of the following paper, I review research related to life history theory and sexual selection in humans. I then show how integrating the principles of sexual selection with life history models of human reproductive strategies can address existing limitations. In Part II, I empirically examine many of the unique propositions that emerge from theoretical integration using a longitudinal dataset on adolescent development. Under investigation is an expanded model of sociosexual development that incorporates key principles from Belsky, Steinberg, and Draper's (BSD) psychosocial theory and sexual selection theory. I specifically examine the role of early rearing conditions within the home, as specified by BSD, and self-perceived mate value, as highlighted by a sexual selection perspective, on timing of sexual debut and sexual risk taking. The current study combines variable-centered and person-centered methods to assess specialized developmental trajectories. In total, the study provides novel support for BSD theory, while also highlighting needed revisions to account for the role of self-perceived mate value on adolescent sexual behavior.
30

Immature development in wild Assamese macaques (Macaca assamensis)

Berghänel, Andreas 03 February 2016 (has links)
No description available.

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