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Full-Text Articles in Microbiology

A Population Genetic Study Of Middle Eastern Populations Using Dys 458 Microvariants And Cohen Modal Haplotypes, Enass Nabeel Tinah Dec 2008

A Population Genetic Study Of Middle Eastern Populations Using Dys 458 Microvariants And Cohen Modal Haplotypes, Enass Nabeel Tinah

Theses and Dissertations

A comprehensive population study in the Middle East was conducted using different genetic markers in order to establish a wider genetic profile of the Middle Eastern populations. The main goal of this study was to analyze DNA from samples collected from different locations, and produce genetic motifs and patterns that could be used to identify and distinguish the target populations. This information will allow us to analyze the ancestry of these populations, their interactions through time and space, and the effects these interactions have on the populations' structure. We have collected around 1300 individual samples from different populations in the …


Evolution Of Picornaviruses: Impacts Of Recombination And Selection, Nicole Noel Lewis-Rogers Nov 2008

Evolution Of Picornaviruses: Impacts Of Recombination And Selection, Nicole Noel Lewis-Rogers

Theses and Dissertations

Picornaviruses are responsible for some of the most common and debilitating diseases affecting humans and animals worldwide. The objectives of this dissertation research were (1) estimate phylogenetic relationships among 11 picornavirus genera and within three species: foot-and-mouth disease virus (FMDV: Aphthovirus) which afflicts cloven-hoofed animals and human rhinovirus A and B (HRV: Enterovirus) which cause the common cold; (2) better understand the impact recombination has on genomic organization and evolution; (3) characterize where positive and purifying selection has occurred in proteins and how selection has influenced phenotype. The dissertation includes four studies. The first chapter provides an overview of the …


Specific Compartmentalization Of Iga Ascs In Mouse Salivary Glands Via Differential Expression Of Chemokines And Chemokine Receptors, Yuet Ching Law Nov 2008

Specific Compartmentalization Of Iga Ascs In Mouse Salivary Glands Via Differential Expression Of Chemokines And Chemokine Receptors, Yuet Ching Law

Theses and Dissertations

The mucosal system, which forms a barrier between internal organ systems and the external environment, is frequently exposed to pathogenic microorganisms. Immunoglobulin A (IgA) antibody secreting cells (ASCs) localize in the lamina propria, and produce IgA antibodies which help protect mucosal tissues. The concept of a common mucosal immune system in which IgA ASCs have the ability to populate any mucosal site has been proposed (1, 2). However, recent research has suggested that IgA ASCs primed in different mucosal sites might possess different sets of chemokine receptors, and therefore migrate specifically to particular mucosal locations (3). In this study, the …


The Antioxidant Defense Network: Synergistic Combinations To Prevent Oxidative Damage, Amy Marie Clement Aug 2008

The Antioxidant Defense Network: Synergistic Combinations To Prevent Oxidative Damage, Amy Marie Clement

Theses and Dissertations

One of the matchless ironies of the human body is its requirement for the highly reactive oxygen molecule, which has been clearly implicated in many diseases and the aging processes. Oxidants produced by metabolic processes damage cells by starting chemical chain reactions including oxidation of DNA and proteins as well as lipid peroxidation. Damage to DNA can cause mutations and lead to cancer if not reversed by DNA repair mechanisms. Damage to proteins causes enzyme inhibition, denaturation and protein degradation. Lipid peroxidation can cause cell lysis as well as creating mutagenic and carcinogenic by-products. The human body contains antioxidants and …


Decline In A Dominant Invertebrate Species Contributes To Altered Carbon Cycling In A Low-Diversity Soil Ecosystem, Byron J. Adams, J. E. Barrett, Ross A. Virginia, Diana H. Wall Aug 2008

Decline In A Dominant Invertebrate Species Contributes To Altered Carbon Cycling In A Low-Diversity Soil Ecosystem, Byron J. Adams, J. E. Barrett, Ross A. Virginia, Diana H. Wall

Faculty Publications

Low-diversity ecosystems cover large portions of the Earth's land surface, yet studies of climate change on ecosystem functioning typically focus on temperate ecosystems, where diversity is high and the effects of individual species on ecosystem functioning are difficult to determine. We show that a climate-induced decline of an invertebrate species in a low-diversity ecosystem could contribute to significant changes in carbon © cycling. Recent climate variability in the McMurdo Dry Valleys of Antarctica is associated with changes in hydrology, biological productivity, and community composition of terrestrial and aquatic ecosystems. One of the greatest changes documented in the dry valleys is …


Comparative Phylogeography Of Codistributed Species Of Chilean Liolaemus (Squamata: Tropiduridae) From The Central-Southern Andean Range, Byron J. Adams, Pedro F. Victoriano, Juan Carlos Ortiz, Edgar Benavides, Jack W. Sites May 2008

Comparative Phylogeography Of Codistributed Species Of Chilean Liolaemus (Squamata: Tropiduridae) From The Central-Southern Andean Range, Byron J. Adams, Pedro F. Victoriano, Juan Carlos Ortiz, Edgar Benavides, Jack W. Sites

Faculty Publications

In this study, we used a recently developed supertrees method to test for shared phylogeographical signal in partially overlapping geographical ranges of lizards of the genus Liolaemus from the Andean Range in south-central Chile. We reconstruct mtDNA gene trees for three partially codistributed species (Liolaemus tenuis, L. lemniscatus and L. pictus), and our sampling effort is sufficient to allow statistical tests of shared signal between the combinations L. tenuis-L. pictus, and L. tenuis-L. lemniscatus. For both combinations, standardized maximum agreement subtrees scores showed statistically significant signal for shared pattern in regions of overlap, as evaluated by randomization tests (P < 0.001 and < 0.05, respectively). The matrix representation with parsimony tree obtained from the combination of the three different gene trees revealed concordant phylogeographical associations of all species, and was consistent with the geographical association of intraspecific haploclades with three Chilean bioclimatic zones. A multidimensional scaling analysis of several climate variables showed highly significant differences among these zones, which further suggests that they may have contributed to similar patterns of intraspecific divergence across all three species. In the mesomorphic zone in Central Chile, the species L. tenuis and L. lemniscatus may have codiverged in response to shared orogenic vicariant events, which likely predominated over climatic events associated with cycles of glacial advance and retreat. In the hygromorphic zone in southern Chile, however, glacial cycles likely predominated in structuring the phylogeographical histories of L. tenuis and L. pictus, although important ecological differences between these two caution against broad generalizations at this point.