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Thermal Ecology Of Urosaurus Ornatus (Ornate Tree Lizard), In The Northern Chihuahuan Desert On Indio Mountains Research Station, Texas, Julia Sandoval Alva

Open Access Theses & Dissertations

The main goal of this study was to determine the thermal ecology of the small tree lizard Urosaurus ornatus in a Chihuahuan Desert landscape. The study site was located at Indio Mountains Research Station (IMRS), Hudspeth County, Texas. We obtained body temperature (Tb) data on 385 lizards collected from April 2007 to June 2014 during the active period using a cloacal thermometer. Additionally, we recorded air temperature (Ta) and substrate temperature (Ts) of lizard microhabitats at the time of capture, and the operative temperature of lizard models left in the sun and shade from May to September 2014. My results …

The Sumoylation Of The Non-Structural Protein 1 Of The Influenza A Virus Plays A Dual Role During Viral Infection, Jason Michael Chacon

Open Access Theses & Dissertations

The potential for a highly pathogenic influenza pandemic remains a concern for global health. The ability of the influenza virus to undergo antigenic shift and genetic drift give circulating strains of influenza the high probability of developing resistance to current antiviral therapies. Emerging strains of higher virulence, to which the infected person has not had any previous exposure to viral antigens, pose a greater threat of serious illness and death. Currently, there is no antiviral therapy that is effective against all strains of influenza, emphasizing the need to develop new strategies that target cellular systems required for viral replication to …

Glycine Transporter 2: Expression And Interactions In The Central Nervous System., Shweta Lavania

Open Access Theses & Dissertations

Glycine is an important inhibitory neurotransmitter that is localized in the caudal areas of the nervous system and plays an important role in mediating many important functions related to breathing, spinal reflexes, nociception etc. Termination of neurotransmission is achieved by the re-uptake of glycine back into the pre- synaptic neuron and neighboring glial cells by the two glycine transporters namely Glycine transporter 1 (GlyT1) and Glycine transporter 2 (GlyT2). These transporters play an essential role in regulating glycinergic inhibition in the central nervous system by controlling the duration and intensity of neurotransmission and therefore the efficacy of synaptic inhibition as …

Effects Of The Cellular Sumoylation System On The Influenza Nuclear Export Protein (Nep), Karla Prieto

Open Access Theses & Dissertations

The high genetic compatibility between the 2009 H1N1 pandemic "swine flu" and the highly pathogenic H5N1 "bird flu" viruses indicates that the odds of a deadly bird flu strain mingling its genetic material with a human virus and becoming easily transmissible among humans are at an all-time high. This fact stresses the urgent need for new treatment and prevention methods to combat influenza. Our current anti-influenza weapons include vaccination and two type of antivirals that

target specific viral components (the so-called M2 ion channel inhibitors and the neuraminidase inhibitors). However, the high genetic variability of the virus enables it to …

Identification And Characterization Of Novel Anti-Leukemia And Anti-Lymphoma Compounds, Yahaira Santiago

Open Access Theses & Dissertations

The anti-cancer properties of curcumin, the natural yellow pigment in the roots of turmeric (Curcuma longa), have been extensively described over the last century. It has been shown to interfere with multiple cell signaling pathways, including execution of apoptosis, anti-proliferation, anti-angiogenic, and anti-inflammatory properties. However, curcumin's cytotoxic potential is limited when administered in vivo. With the idea of preserving curcumin's characteristics, but improving its bioavailability, analogues have been developed and evaluated in the last decade. Most of the analogues have shown very good anti-cancer activity in various cell lines and one analogue is now in a clinical trial. Nonetheless, this …

Characterization Of The Disulfide In The Ectodomain Of Anthrax Toxin Receptor 2, Pedro Raymundo Jacquez

Open Access Theses & Dissertations

Anthrax toxin receptors act as molecular clamps or switches that control anthrax toxin entry, pH-dependent pore formation, and translocation of enzymatic moieties across the endosomal membranes. The ectodomain of anthrax toxin receptor 2 (ANTXR2) is composed of a von Willebrand factor A (VWA) domain that binds to anthrax toxin protective antigen (PA) and a newly defined immunoglobulin-like (Ig) domain, in which the disulfide bonds are required for PA pore formation and for the folding of ANTXR2. While the VWA domain has been well characterized, the structure and function of the whole ectodomain (VWA-Ig) are poorly defined, this is mainly due …

Two-Photon Microscopy For Biomedical Studies, Yassel Acosta

Open Access Theses & Dissertations

Fluorescence optical microscopy is one of the most important tools to investigate biological samples and to observe structures in living cells. Based on the principle of the simultaneous absorption of two-photons and subsequent emission of fluorescent light we have developed a Two-Photon Laser Scanning Fluorescence Microscope that allow us to perform optical sectioning and three-dimensional reconstructions of structures in biological samples such as dopaminergic clusters of neurons and tracheal branches in Drosophila brain. The spatial confinement of the excitation light to the focal plane combined with the temporal compression of photons into short packets during femtosecond pulses make our system …

Global Sphingolipid Profile Of Giardia Lamblia During Stage Differentiation: The Influence Of Sphingomyelin Abundance On Viable Cyst Production, Trevor Thomas Duarte

Open Access Theses & Dissertations

Giardia lamblia is a protozoan parasite and a major cause of the waterborne-illness, giardiasis, worldwide. Giardiasis is endemic in developing countries and is a leading cause of non-viral- and non-bacterial-associated intestinal disorders. Acute symptoms of giardiasis include diarrhea, cramps, and malabsorption. The disease is often self-limiting, although the infection can result in long-term disorders such as chronic fatigue, stunted cognitive skills, and failure to thrive even after the parasite has been cleared.

This parasite exists in two morphologic forms--infective trophozoites and transmissible, water-resistant cyst, which is passed by the fecal-oral route and is likely to be spread by contaminated drinking …

Revision Of The Ant Genus Bothroponera (Hymenoptera: Formicidae: Ponerinae) From The African Continent, Abdulmeneem Joma

Open Access Theses & Dissertations

Abstract (chapter 1)

The Afrotropical ants in the genus Bothroponera include the pumicosa, talpa, and sulcata species complexes. Species in the Bothroponera pumicosa species complex are mainly distributed in the southern part of Africa. This group of ants is characterized by having coarsely foveolate sculpture and by having either a raised a "v" or "u" shaped anterior medial area of the clypeus (anteclypeus), with or without a carina. The mandibles have 7 teeth in the majority of species and 8 teeth in the others. The eyes are relatively large. The scapes usually do not reach the posterior lateral corner of …

Characterization Of Membrane Interaction Of Mycobacterium Tuberculosis Esat-6, Yue Ma

Open Access Theses & Dissertations

Mycobacterium tuberculosis (Mtb) targets alveolar macrophages and has a high tolerance to the macrophage's antimicrobial effectors, such as low pH, reactive oxygen species, and reactive nitrogen species. It has been reported and widely accepted that Mtb disarms macrophages through arresting the normal maturation process of the phagosomes. Inhibition of phagosome-lysosome fusion and phagosome acidification is an effective survival strategy at the early stage of infection. This behavior allows Mtb to remain and replicate within the phagosomes of macrophages. At the later stage of infection, the pathogen translocates from the phagolysosomal compartments into the cytosol of host cells by phagolysosomal rupture. …

Spingolipid Metabolism In A Reptillian Protozoan, Entamoeba Invadens, Duran Dogan Debons

Open Access Theses & Dissertations

Entamoeba invadens (hereinafter E. invadens) is an anaerobic parasitic protozoan that can be found in water and soil. Although the host organisms for this parasite are snakes, lizards, and other reptile species, the parasite is morphologically identical to Entamoeba histolytica, a causative agent of human amebiasis. Entamoeba inavdens exists in two morphological forms--(1) a replicative trophozoite, and (2) a relatively dormant cyst. While the transformation of cyst to trophozoites (called "excystation") takes place in the stomach, the differentiation of trophozoites to cyst (known as "encystation"), occurs in the small intestine. Unlike the cyst, a trophozoite is unable to survive …

Il-2rβ T450 Phosphorylation Is A Positive Regulator For Receptor Complex Stability And Activation Of Signaling Molecules, Blanca Estela Ruiz-Medina

Open Access Theses & Dissertations

Homeostasis of the immune system is required for proper defense against pathogenic insult. Cells of the innate and adaptive compartments provide a strictly regulated response to clear infections while allowing for self-tolerance. Dysregulation of the components of the immune system can lead to immunodeficiency, autoimmunity, and cancer. Key players of the immune response are T, B, and NK cells, which become strongly activated by IL2 through its receptor. The β subunit of the receptor becomes tyrosine, serine, and threonine phosphorylated upon induction with IL2. Phosphorylation of tyrosine residues has been extensively studied, however, the putative regulatory role of serine and …

An Avian Survey Conducted At Five Water Sources Within The Northern Chihuahuan Desert On Indio Mountains Research Station, Texas, Geoffrey Hugh Wiseman

Open Access Theses & Dissertations

The objective of this study was to conduct an avian survey of five water sources (four ephemeral former cattle tanks and one perennial spring), determine how many species inhabit or use Indio Mountains Research Station, and show a hierarchal similarity between the survey sites. This survey was conducted in a Chihuahuan Desert scrub landscape on Indio Mountains Research Station (IMRS) in Hudspeth County, Texas. There have been no previous formal studies of the avifauna at IMRS. All species accounts or sightings have been from casual sightings.

Eighty-five avian species were recorded during this project bringing the total of avian species …