• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 11
  • 1
  • 1
  • Tagged with
  • 32
  • 32
  • 11
  • 10
  • 10
  • 9
  • 5
  • 4
  • 4
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 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

Multicopy gene family evolution on primate Y chromosomes

Ghenu, Ana-Hermina 11 1900 (has links)
Unlike the autosomes, the Y chromosome in humans and other primates has few protein coding genes, with only a few dozen single-copy genes and several tandem duplicated gene families, called the "ampliconic" genes. The interaction of many biological and evolutionary factors is responsible for this structural heterogeneity among different parts of the genome. We sequenced and assayed the copy numbers of Y-linked, single-copy genes and ampliconic genes in a group of closely related macaque monkeys, then fit models of gene family evolution to this data along with whole genome data from human, chimpanzee, and rhesus macaque. Our results (i) recovered evidence for several novel examples of gene conversion in papionin monkeys, (ii) indicate that ampliconic gene families evolve faster than autosomal gene families and than single-copy genes on the Y chromosome, and that (iii) Y-linked singleton and autosomal gene families evolved faster in great apes than they do in other Old World higher Primates. These findings highlight the evolutionary eccentricity of duplicated genes on the Y chromosome and suggest an important role for natural selection and gene conversion in the evolution of Y-linked gene duplicates. / Thesis / Master of Science (MSc)
22

Segregation within afferent pathways in primate vision

Roy, Sujata January 2009 (has links)
The current knowledge of the visual pathways in primates includes the patterns of projection from the retina through the dorsal lateral geniculate nucleus (dLGN) to the striate cortex (V1) and the extra-striate projections towards the dorsal and ventral streams. Cells with short wavelength sensitive cone (S-cone) inputs in the dLGN have been studied extensively in New World marmosets but not in Old World macaques. This thesis presents results from studies in the macaque monkey which are more relevant to humans since humans are closer in evolution to Old World than New World monkeys. / The spatial, temporal, chromatic and orientation preferences of neurons in the dLGN of the macaque were investigated by electrophysiological methods. The physiological findings of cells with S-cone inputs were compared to cells with opponent inputs from the long and medium wavelength sensitive cones (L-cones & M-cones, respectively). The cells receiving S-cone inputs (blue-yellow or B-Y cells) preferred lower spatial frequencies than the cells with opponent L-cone and M-cone inputs (red-green or R-G cells). Orthodromic latencies from optic chiasm stimulation were measured where possible to distinguish differences in conduction velocity between the cell groups. Although the B-Y cells usually had longer latencies than R-G cells, there wasconsiderable overlap between the cell groups. / The recorded cells were localised through histological reconstruction of dLGN sections stained for Nissl substance. The distribution of B-Y cells within the dLGN was compared to the distribution of R-G cells. The majority of B-Y cells were located within the intercalated koniocellular layers as well as the koniocellular bridges (extensions of the koniocellular layers into the adjacent parvocellular layers). The B-Y cells were also largely segregated within the middle dLGN layers (K3, P3, K4 & P4). The R-G cells were mainly concentrated within the parvocellular layers (P3, P4, P5 & P6) and were evenly distributed throughout the middle and outer layers of the dLGN. / The study also included recordings from the extra-striate middle temporal area (MT) to determine whether a fast S-cone input exists from the dLGN to area MT which bypasses V1. The pattern of cone inputs to area MT neurons was investigated before and during inactivation of V1. The inactivation was done through reversible cooling with a Peltier thermocouple device or focal inactivation with y-amino butyric acid (GABA) iontophoresis. Precise inactivation of V1 to the topographically matching visual fields of the recording sites in area MT revealed a preservation of all three coneinputs in many cells. The subcortical sources of these preserved inputs are discussed with their relevance to blindsight, which is the limited retention of visual perception after V1 damage. Analysis of the latencies of area MT cells revealed a rough segregation into latencies faster or slower than 70 ms. Cells both with and without a significant change in response during V1 inactivation were present in each group. The findings reported in this thesis indicate that some of the preserved inputs in area MT during V1 inactivation may be carried by a direct input from the dLGN which bypasses V1.
23

Lokomoce guerézy pláštíkové Colobus gueresa caudatus-kikuyuensis (Thomas 1885 - Lonnberg 1912) v Zoologické zahradě Praha a Ústí nad Labem / Locomotion of mantled guereza Colobus gueresa caudatus-kikuyuensis (Thomas 1885 - Lonnberg 1912) in ZOO Prague and ZOO Usti nad Labem

Kost, Lukáš January 2013 (has links)
Summary: This dissertation is focused on observation of locomotion two groups of mantled guereza in ZOO Prague and ZOO Usti nad Labem. The observation took place in the summer of 2011. The locomotion behavior is for better clarity presented by tables, diagrams and detailed description of the breeding facilities of both groups. The work contains list of all species of guereza, including all subspecies of mantled guereza. Key words: primates, old world monkeys, Colobinae, black and white colobus monkey, mantled guereza, threat, behavior, breeding in the zoo.
24

Variation in Dental Microwear Textures and Dietary Variation in African Old World Monkeys (Cercopithecidae)

January 2015 (has links)
abstract: Dietary diversity is an important component of species’s ecology that often relates to species’s abundance and geographic distribution. Additionally, dietary diversity is involved in many hypotheses regarding the geographic distribution and evolutionary fate of fossil primates. However, in taxa such as primates with relatively generalized morphology and diets, a method for approximating dietary diversity in fossil species is lacking. One method that has shown promise in approximating dietary diversity is dental microwear analyses. Dental microwear variance has been used to infer dietary variation in fossil species, but a strong link between variation in microwear and variation in diet is lacking. This dissertation presents data testing the hypotheses that species with greater variation in dental microwear textures have greater annual, seasonal, or monthly dietary diversity. Dental microwear texture scans were collected from Phase II facets of first and second molars from 309 museum specimens of eight species of extant African Old World monkeys (Cercopithecidae; n = 9 to 74) with differing dietary diversity. Dietary diversity was calculated based on food category consumption frequency at study sites of wild populations. Variation in the individual microwear variables complexity (Asfc) and scale of maximum complexity (Smc) distinguished groups that were consistent with differences in annual dietary diversity, but other variables did not distinguish such groups. The overall variance in microwear variables for each species in this sample was also significantly correlated with the species’s annual dietary diversity. However, the overall variance in microwear variables was more strongly correlated with annual frequencies of fruit and foliage consumption. Although some variation due to seasonal and geographic differences among individuals was present, this variation was small in comparison to the variation among species. Finally, no association was found between short-term monthly dietary variation and variation in microwear textures. These results suggest that greater variation in microwear textures is correlated with greater annual dietary diversity in Cercopithecidae, but that variation may be more closely related to the frequencies of fruit and foliage in the diet. / Dissertation/Thesis / Doctoral Dissertation Anthropology 2015
25

The Effects of Fire on Spore Viability of Lygodium microphyllum (Old World Climbing Fern)

Sebesta, Nicole 02 July 2015 (has links)
Lygodium microphyllum, native to the Old World tropics, has invaded central and southern Florida, destroying native habitats, reducing biodiversity and altering fire regimes. Prescribed fire, one of several methods used to manage L. microphyllum infestations, reduces fern biomass over large areas, but its effects on spore viability are unknown. To provide tools to evaluate whether fire-dispersed spores are viable, this research determined how heat affects spore viability. Spores were exposed to temperatures of 50°C to 300°C for durations of 5 seconds to 1 hour, then allowed to germinate on agar in petri plates. Percent germination was assayed after two weeks. Temperatures of 50°C had little effect; 300°C killed spores for all durations. Results indicate that while viability of unburnt spores decreases with increasing temperature and duration of heat exposure, spores are killed when exposed to relatively low temperatures compared to those in fires.
26

Landscape preservation and biodiversity planning : the Kino Heritage Fruit Trees Project and beyond

Yaquinto, Robert Giacomo 01 October 2014 (has links)
This report argues that historic landscape preservation efforts need to embrace biodiversity planning. Historic landscape preservation sites need to develop biodiversity plans because they are uniquely qualified to provide the continuous monitoring that successful biodiversity planning requires. Not only will biodiversity monitoring at various historic landscape sites contribute to a nationwide collection of biodiversity planning data, but it will also provide a rich source of information that can be presented to draw a wider audience into the biodiversity discussion. After considering three precedents: Old Sturbridge Village, Old World Wisconsin, and Tucson Botanical Gardens, the report focuses on the Kino Heritage Fruit Trees Project and its real and potential impacts on biodiversity planning in southern Arizona and more broadly. Finally, the report considers how seed libraries and seed swaps might serve a similar purpose in other parts of the country. / text
27

To Market: Representations of the Marketplace by New Zealand Expatriate Artists 1900-1939

Dempsey, Adrienne M. January 2012 (has links)
New Zealand expatriate artists working in England, Europe and North Africa in the early twentieth century painted a wide variety of market scenes. The subject features in the oeuvre of Frances Hodgkins, Maud Sherwood, Sydney Lough Thompson, Maude Burge, Owen Merton, Robert Procter and John Weeks and made a significant contribution to their artistic development. Like their contemporaries in the artists’ colonies and sketching grounds of England and Europe, New Zealand artists were often drawn to traditional rural and fishing villages and sought to capture the nostalgia of the ‘old world.’ Early exploratory works by New Zealand expatriates have often been dismissed merely as nostalgic visions of colonials, without any real artistic merit. This research offers a re-evaluation of these works, recognising their value as transitional works which illustrate New Zealand expatriate artists experimenting with early modernist trends, as well as revealing prevalent contemporary tastes among the New Zealand public. This study offers a comprehensive examination of the market theme and highlights the aspirations and achievements of New Zealand expatriate artists. This is reflected in both their choice of subjects and in the way in which these were depicted. A key finding of this research is that New Zealand expatriate artists developed a distinctive response towards the market subject. The vibrant atmosphere and activity of the market and colourful views of canvas booths, awnings and costume provided the perfect means of expression for these artists to explore a variety of painterly concerns and techniques, among them plein-air and impressionist painting, watercolour techniques and a modern treatment of colour and light. The hypothesis of a ‘female gaze’ is explored with specific reference to depiction of the market subjects by Frances Hodgkins and Maud Sherwood. Placed within a wider art historical context of images of female market vendors, their market works offer an original interpretation of the female milieu of the European market. Finally, the expatriates’ vision of the exotic and colourful markets in North Africa and Egypt is investigated. They offered an alternative response to more traditional Orientalist interpretations and their Maghrebian explorations were the catalyst for key stylistic developments in colour and form.
28

The Old World Journey : National Identity in Four American Novels from 1960 to 1973

Zetterberg Pettersson, Eva January 2005 (has links)
<p>A commonly held assumption among literary critics is that the motif of the European journey is exhausted in American literature in the post-World-War-II period. Challenging this view, the present study claims that the Old World journey narrative lives on, but in new guises, and that it continues to be a forum for the discussion of American national identity. Studying four novels about Americans traveling to Europe – William Styron’s Set This House on Fire (1960), Mary McCarthy’s Birds of America (1971), John A. Williams’s The Man Who Cried I Am (1967) and Erica Jong’s Fear of Flying (1973) – this thesis examines the ways in which the European journey is utilized for a questioning of “America.” Informed by the political debates of their time, which lead, for example, to the displacement of hegemonic ideologies such as nationalism, they share a critical stance vis-à-vis the conventional construction of national identity. They represent, however, different strands of the contemporary political counterculture; while the first two texts view national identity from the center of American society, addressing a moral and an ideological/intellectual critique, respectively, the last two represent marginal perspectives, that of the African American and feminist protest movements. The function of the European setting in the four novels is also scrutinized: in all of them the European setting provides the backdrop for a story that deals, almost exclusively, with American culture; it serves in a variety of ways, for example as a many-facetted stage, an experimental ground, or a zone of liberation. The Coda sketches recent developments in the 1980s and 1990s, finding the motif of initiation and the figure of the independent warm-hearted American girl to persist and the myth of American innocence to continue to be contested. </p>
29

The Old World Journey : National Identity in Four American Novels from 1960 to 1973

Zetterberg Pettersson, Eva January 2005 (has links)
A commonly held assumption among literary critics is that the motif of the European journey is exhausted in American literature in the post-World-War-II period. Challenging this view, the present study claims that the Old World journey narrative lives on, but in new guises, and that it continues to be a forum for the discussion of American national identity. Studying four novels about Americans traveling to Europe – William Styron’s Set This House on Fire (1960), Mary McCarthy’s Birds of America (1971), John A. Williams’s The Man Who Cried I Am (1967) and Erica Jong’s Fear of Flying (1973) – this thesis examines the ways in which the European journey is utilized for a questioning of “America.” Informed by the political debates of their time, which lead, for example, to the displacement of hegemonic ideologies such as nationalism, they share a critical stance vis-à-vis the conventional construction of national identity. They represent, however, different strands of the contemporary political counterculture; while the first two texts view national identity from the center of American society, addressing a moral and an ideological/intellectual critique, respectively, the last two represent marginal perspectives, that of the African American and feminist protest movements. The function of the European setting in the four novels is also scrutinized: in all of them the European setting provides the backdrop for a story that deals, almost exclusively, with American culture; it serves in a variety of ways, for example as a many-facetted stage, an experimental ground, or a zone of liberation. The Coda sketches recent developments in the 1980s and 1990s, finding the motif of initiation and the figure of the independent warm-hearted American girl to persist and the myth of American innocence to continue to be contested.
30

Social and Physical Cognition in Old World Monkeys - A Comparative Perspective / Soziale und Physikalische Kognition bei Altweltaffen - eine vergleichende Perspektive

Schmitt, Vanessa 13 April 2012 (has links)
No description available.

Page generated in 0.5053 seconds