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Distribution And Site Selection Of Le Conte's And Crissal Thrashers In The Mojave Desert: A Multi-Model Approach, Dawn Marie Fletcher May 2009

Distribution And Site Selection Of Le Conte's And Crissal Thrashers In The Mojave Desert: A Multi-Model Approach, Dawn Marie Fletcher

UNLV Theses, Dissertations, Professional Papers, and Capstones

Information on the distribution and habitat requirements of a species are critical components to the development of meaningful conservation plans. Such knowledge, however, is particularly difficult to obtain for species that are elusive and occur at low densities, such as the Le Conte's ( Toxostoma lecontei ) and Crissal (Toxostoma crissale ) thrashers. In association with a regional conservation plan, I evaluated the distribution and habitat selection of these thrashers within Clark County, Nevada in the eastern Mojave Desert. I used a call-broadcast approach to sample 432 stratified random locations, detecting Le Conte's thrashers at 45 locations and Crissal …

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Arid Climate Decomposition And Decay: A Taphonomic Study Using Swine, James William Munkres May 2009

Arid Climate Decomposition And Decay: A Taphonomic Study Using Swine, James William Munkres

UNLV Theses, Dissertations, Professional Papers, and Capstones

The present project analyzes the taphonomic processes and variables involved in the decomposition and desiccation of animal remains in an arid/hyper-arid environment. The study and the derived data will assist in determining postmortem intervals for remains in modern contexts, inform judgments made regarding mortuary habits and techniques in archaeological contexts, and will improve our knowledge regarding taphonomic processes. Manner of deposition, the depositional surface/medium and arid-climate specific variables (temperature, water, insect activity, weathering, pH levels, and soil characteristics) were examined in this study. Reported observations are limited to the first ten months following death from early December through early October …

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Stress Responses To Salinity In A Native Fresh Water Snake (Nerodia Rhombifer), Joana A. Cordoba May 2009

Stress Responses To Salinity In A Native Fresh Water Snake (Nerodia Rhombifer), Joana A. Cordoba

Theses and Dissertations - UTB/UTPA

Salinity stress at 0 ppt, 9 ppt, 18 ppt, and 27 ppt was investigated in Nerodia rhombifer, a fresh water snake. The purpose of this study was to establish if exposure to salinity could elicit a hormonal response in the form of corticosterone. Salinity treatment 27 ppt was lethal for 50% of the snakes. Factors such as population and gender differences were not significant, p=0.748 and p=0.135, respectively. Exposure to the different salinities did not significantly affect the overall mass of the animal, p=0.951. A significant increase in circulating corticosterone was noted in salinity treatments 0 ppt and 18 ppt, …

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The Effects Of Stream Discharge And Channelization On The Macroinvertebrate Community In A Semi-Arid Landscape, Thomas L. Kennedy May 2009

The Effects Of Stream Discharge And Channelization On The Macroinvertebrate Community In A Semi-Arid Landscape, Thomas L. Kennedy

Biology ETDs

The Middle Rio Grande is the second largest watershed in the southwestern United States and is a vitally important component for the biodiversity in the region. Similar to many other rivers, the MRG is a temporally dynamic system that unfortunately, has been subjected to river regulation. As a result, the river has become channelised in many reaches disconnecting it from the surrounding floodplain. The effects of river regulation on the MRG and its surrounding riparian zone were largely unknown. I tested three main hypothesis with regards to the macroinvertebrates in the MRG: 1) Does flow variability structure the aquatic macroinvertebrate …

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Controls On Microbial Community Structure In Thermal Environments: Exploring Bacterial Diversity And The Relative Influence Of Geochemistry And Geography, Kendra Renee Mitchell May 2009

Controls On Microbial Community Structure In Thermal Environments: Exploring Bacterial Diversity And The Relative Influence Of Geochemistry And Geography, Kendra Renee Mitchell

Biology ETDs

Community wide molecular surveys have revealed incredible hidden phylogenetic and metabolic diversity in microbial habitats. We have conducted the first microbial survey of Yellowstone National Park thermal environments, sampling 103 communities from across the park and across the range of conditions found. Yellowstone is particularly suited for this type of research because of the large number and wide variety of thermal springs, which are naturally occurring chemostats enabling examination of the factors that control microbes and drive community structure. In addition to samples for molecular microbial analysis, we collected water for extensive geochemical analysis in order to begin to deduce …

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Oceanic-Atmospheric Modes Of Variability And Their Effect On River Flow And Blue Crab (Callinectes Sapidus) Abundance In The Northcentral Gulf Of Mexico, Guillermo Humberto Sanchez-Rubio May 2009

Oceanic-Atmospheric Modes Of Variability And Their Effect On River Flow And Blue Crab (Callinectes Sapidus) Abundance In The Northcentral Gulf Of Mexico, Guillermo Humberto Sanchez-Rubio

Dissertations

Oceanic-atmospheric modes of variability occur on interdecadal, multidecadal, decadal, and interannual timescales and their influence on climate around the world has been confirmed. The present study investigates Mississippi River and Pascagoula River flows in response to the influence of one or more of the four oceanic-atmospheric modes of variability: the Pacific Decadal Oscillation (PDO), the Atlantic Multidecadal Oscillation (AMO), the North Atlantic Oscillation (NAO), and the El Nino Southern Oscillation (ENSO). These modes of variability are present in phases: PDO warm (PDOw) and cold (PDOc), AMO warm (AMOw) and cold (AMOc), NAO positive (NAOp) and negative (NAOn), and ENSO warm …

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Transcriptomic Analysis Of The Entomopathogenic Nematode Heterorhabditis Bacteriophora Tto1, Byron J. Adams, Xiaodong Bai, Todd A. Ciche, Sandra Clifton, Randy Gaugler, Parwinder S. Grewal, Saskia A. Hogenhout, John Spieth, Paul W. Sternberg, Richard K. Wilson Apr 2009

Transcriptomic Analysis Of The Entomopathogenic Nematode Heterorhabditis Bacteriophora Tto1, Byron J. Adams, Xiaodong Bai, Todd A. Ciche, Sandra Clifton, Randy Gaugler, Parwinder S. Grewal, Saskia A. Hogenhout, John Spieth, Paul W. Sternberg, Richard K. Wilson

Faculty Publications

Background: The entomopathogenic nematode Heterorhabditis bacteriophora and its symbiotic bacterium, Photorhabdus luminescens, are important biological control agents of insect pests. This nematode-bacterium-insect association represents an emerging tripartite model for research on mutualistic and parasitic symbioses. Elucidation of mechanisms underlying these biological processes may serve as a foundation for improving the biological control potential of the nematode-bacterium complex. This large-scale expressed sequence tag (EST) analysis effort enables gene discovery and development of microsatellite markers. These ESTs will also aid in the annotation of the upcoming complete genome sequence of H. bacteriophora. Results: A total of 31,485 high quality ESTs were generated …

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Bioinformatic Study Of Snps And Phenotypes In Patients With Smith-Magenis Syndrome, Tyler Andrew Cox Apr 2009

Bioinformatic Study Of Snps And Phenotypes In Patients With Smith-Magenis Syndrome, Tyler Andrew Cox

Departmental Honors & Graduate Capstone Projects

Smith-Magenis Syndrome (SMS) is a human genetic disorder that is caused by either a deletion within chromosomal region 17p11.2 or a mutation of a gene in that region –the RAI1 gene. The most prominent phenotypes observed with this disorder are mental retardation, distinctive craniofacial features, and sleep disorders caused by an inverted pattern of serotonin secretion. The current methods for molecular detection of Smith-Magenis Syndrome are reliable for the detection of the deletions within chromosomal region 17p11.2, but are not reliable in detecting mutations with the RAI1 gene. One way to enhance the detection of RAI1 mutations is with the …

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Molecular Characterization Of The Human Rai1 Promoter, Rose Irene Salzberg Apr 2009

Molecular Characterization Of The Human Rai1 Promoter, Rose Irene Salzberg

Departmental Honors & Graduate Capstone Projects

Smith-Magenis syndrome (SMS) is a type of mental retardation disorder associated with a deletion of DNA from chromosome 17p11.2. It affects approximately18,000 individuals in the US alone. Major phenotypes are associated with a mutation in the Retinoic Acid-Inducible gene-1 (RAI1) and include: developmental delay, repetitive behaviors, short stature, and hoarse voice. Studying the molecular mechanisms that lead to SMS will help promote earlier detection of the disorder and will help develop a better treatment plan for patients. The purpose of this project was to characterize the promoter of RAI1. Studying the promoter of RAI1 will help determine the normal expression …

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Analyzing The Interconnectedness Between Space, Place, And Human Interaction With The Natural Environment: "Ecological Reawakening: Organic Dna And Evolution", Sarah Moos Apr 2009

Analyzing The Interconnectedness Between Space, Place, And Human Interaction With The Natural Environment: "Ecological Reawakening: Organic Dna And Evolution", Sarah Moos

Scripps Senior Theses

I have organized this paper into four chapters: "The Environmental Situation," "Space and Place," "Art and the Natural Environment," and "Creating Work of My Own." Chapter 1 explains human beings' intrinsic interconnection to the natural environment, outlining why humans should be concerned about the current degraded state of the natural world. Chapter 2 discusses the concepts of space and place. It analyzes how human beings interact with and experience spaces, developing their sense of place - within physical, theoretical, and spiritual realms. It finally illustrates the importance that spaces and places have in humans' lives. Chapter 3 describes the Land …

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An Analysis Of The Environmental And Hormonal Effects On The Growth And Development Of The Moss Ceratodon Purpureus, Megan Knight Apr 2009

An Analysis Of The Environmental And Hormonal Effects On The Growth And Development Of The Moss Ceratodon Purpureus, Megan Knight

Undergraduate Honors Thesis Collection

Ceratodon has not been documented in scientific literature as thoroughly as other species of moss such as Funaria or Tortula. Commonly known as fire moss or purple horned moss, Ceratodon is often reddish or yellow-brown and the spore capsules are usually purple (Crum, 1983). A picture of the species growing in its natural habitat is shown in Figure 4. Ceratodon often grows in tufts and is considered a weed, often thriving in polluted or disturbed areas and frequently invading after a fire (Crum 1983). Ceratodon belongs to the class Bryopsida, which also contains the previously mentioned Funaria and Tortula species. …

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Lead Bullet Fragments In Venison From Rifle-Killed Deer: Potential For Human Dietary Exposure, W. Grainger Hunt, Richard T. Watson, J. Lindsay Oaks, Chris N. Parish, Kurt K. Burnham, Russell L. Tucker, James R. Belthoff, Garret Hart Apr 2009

Lead Bullet Fragments In Venison From Rifle-Killed Deer: Potential For Human Dietary Exposure, W. Grainger Hunt, Richard T. Watson, J. Lindsay Oaks, Chris N. Parish, Kurt K. Burnham, Russell L. Tucker, James R. Belthoff, Garret Hart

Biology Faculty Publications and Presentations

Human consumers of wildlife killed with lead ammunition may be exposed to health risks associated with lead ingestion. This hypothesis is based on published studies showing elevated blood lead concentrations in subsistence hunter populations, retention of ammunition residues in the tissues of hunter-killed animals, and systemic, cognitive, and behavioral disorders associated with human lead body burdens once considered safe. Our objective was to determine the incidence and bioavailability of lead bullet fragments in hunter-killed venison, a widely-eaten food among hunters and their families. We radiographed 30 eviscerated carcasses of White-tailed Deer (Odocoileus virginianus) shot by hunters with standard …

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Influence Of Salinity Variations On The Desorption And Lability Of Soil Organic Carbon Associated With Tidal Freshwater Marshes, Lindsey Michelle Koren Apr 2009

Influence Of Salinity Variations On The Desorption And Lability Of Soil Organic Carbon Associated With Tidal Freshwater Marshes, Lindsey Michelle Koren

Theses and Dissertations

Tidal freshwater marshes (TFMs) are unique ecosystems that bridge the gap between terrestrial and aquatic ecosystems and are important in the sequestration of soil organic carbon. With the ever changing global climate, TFMs are left vulnerable to downstream effects of rising sea level and salt water intrusion due to increases in flooding by saline waters. These changes often act over large spatial and temporal scales resulting in significant impacts to local and regional environments. This multidisciplinary study assessed the amount and lability of desorbed organic carbon in tidal freshwater marsh soils from the Waccamaw River Marsh, South Carolina and Sweet …

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Developmental Changes In Zebrafish Embryos Exposed To Bisphenol A Leeched From Commonly Used Plastics, David L. Ortiz Apr 2009

Developmental Changes In Zebrafish Embryos Exposed To Bisphenol A Leeched From Commonly Used Plastics, David L. Ortiz

Senior Honors Theses

Bisphenol A, an estrogen mimicker, is found in the commonly used plastic, polycarbonate. Zebrafish embryos were raised in water that had been heated in polycarbonate water bottles by either microwaving for 5 minutes, or boiling for one hour. Near total mortality was seen in 7 days for the embryos growing in bottle-microwaved water, and 9 days for those raised in bottle-boiled water. Zebrafish embryos were also grown in the following known concentrations of BPA: 2mg/l, 14mg/l, 16mg/l, 50mg/l, 135mg/l, and 235mg/l. A stepwise relationship between concentration of BPA and embryo lifespan was seen, and the lowest observed adverse effect level …

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Engineering An Anaerobic Derivative Of The Obligately Aerobic Thermophile Thermus Thermophilus Hb27 For The Purposes Of Studying Thermophilic Aerobic Respiratory Chain Proteins, Prajit Limsirichai Apr 2009

Engineering An Anaerobic Derivative Of The Obligately Aerobic Thermophile Thermus Thermophilus Hb27 For The Purposes Of Studying Thermophilic Aerobic Respiratory Chain Proteins, Prajit Limsirichai

Biology Honors Theses

The thermophilic bacterium Thermus thermophilus (Tth) is an obligate aerobe with many important biotechnological applications and products. Thermostable proteins isolated from Thermus species have proven important in understanding adaptation to thermophilic environments. Thermophilic adaptations of respiratory electron transport chains (ETC) are not well characterized. Conventional homology-based, genetic, and biochemical techniques are limited in their ability to identify thermophilic Tth homologues of mesophilic respiratory ETC proteins due to the lack of a mutable facultative platform. We are attempting to generate this platform by increasing glycolytic flux through metabolic engineering techniques. Based on physiological studies, Tth HB27 demonstrates a low affinity for …

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Consequences Of Shrub Encroachment: Linking Changes In Canopy Structure To Shifts In The Resource Environment, Steven Brantley Apr 2009

Consequences Of Shrub Encroachment: Linking Changes In Canopy Structure To Shifts In The Resource Environment, Steven Brantley

Theses and Dissertations

Shrub expansion in herbaceous ecosystems is emerging as an important ecological response to global change, especially in mesic systems where increases in canopy biomass are greatest. Two consequences of woody encroachment are increases in belowground resources, such as carbon and nitrogen, and reductions in above-ground resources such as light, which affect diversity, community trajectory, and ecosystem function. My objective was to determine how expansion of the nitrogen-fixing shrub Morella cerifera affected the resource environment across a chronosequence of shrub expansion on a Virginia barrier island. I quantified changes in carbon (C) and nitrogen (N) cycling, canopy structure and understory light …

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Structural Basis For Inhibition Of Mammalian Adenylyl Cyclase By Calcium, Tung-Chung Mou, Nanako Masada, Dermot M. Cooper, Stephen R. Sprang Apr 2009

Structural Basis For Inhibition Of Mammalian Adenylyl Cyclase By Calcium, Tung-Chung Mou, Nanako Masada, Dermot M. Cooper, Stephen R. Sprang

Biological Sciences Faculty Publications

Type V and VI mammalian adenylyl cyclases (AC5, AC6) are inhibited by Ca(2+) at both sub- and supramicromolar concentration. This inhibition may provide feedback in situations where cAMP promotes opening of Ca(2+) channels, allowing fine control of cardiac contraction and rhythmicity in cardiac tissue where AC5 and AC6 predominate. Ca(2+) inhibits the soluble AC core composed of the C1 domain of AC5 (VC1) and the C2 domain of AC2 (IIC2). As observed for holo-AC5, inhibition is biphasic, showing "high-affinity" (K(i) = approximately 0.4 microM) and "low-affinity" (K(i) = approximately 100 microM) modes of inhibition. At micromolar concentration, Ca(2+) inhibition is …

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The Presence Of Amphibian Ranavirus In Virginia Warm Water Fish Hatchery Ponds, Elizabeth Nelson Apr 2009

The Presence Of Amphibian Ranavirus In Virginia Warm Water Fish Hatchery Ponds, Elizabeth Nelson

Theses and Dissertations

Amphibian declines have been occurring world wide over the past several decades. Infectious disease and environmental changes have been implicated as the causative agents in these declines. Fish stocking from hatcheries provides a unique opportunity for organisms, including infectious diseases, to travel over long distances. Ranavirus was previously found in two ponds at Harrison Lake National Fish Hatchery in Charles City County, Virginia. Therefore, the primary objective of this study was to determine if ranavirus is present in tadpoles from four warm water fish hatcheries in Virginia. A secondary objective of this study was to determine if there are relationships …

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Generation Of Macrophage Chemotactic Factors By Spla2, Andria Chambers Apr 2009

Generation Of Macrophage Chemotactic Factors By Spla2, Andria Chambers

Theses and Dissertations

Removal of apoptotic cells by macrophages is required in order to prevent autoimmune responses. Previous studies have reported that group IIA secretory phospholipase A2 (sPLA2) preferentially binds to apoptotic cells and induces a chemotactic factor which promotes the migration of macrophages to apoptotic cells. Based on these observations, we hypothesized that the pool of sPLA2 trapped on apoptotic cells produces chemoattractant lipids that recruit macrophages to phagocytose the apoptotic cells. To test this hypothesis, Jurkat cells were cultured under normal conditions and induced to undergo early apoptosis through treatment with D,L-threo-dihydrosphingosine. Live and early apoptotic cells were incubated with catalytically …

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The Furman Lake Restoration Plan, Wade Worthen Apr 2009

The Furman Lake Restoration Plan, Wade Worthen

Furman Lake Restoration Book Gallery

A presentation with text and images providing information on the history of the Furman Lake, it's environmental health decline throughout the years, and the lake's restoration. The presentation details the Furman Lake's problems, causes of these problems, and solutions. It describes Furman's progress in the restoration project, as well as it's goals for the future.

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From In-Vitro To In-Vivo: Corporate Development And Efficacy Of A Topical Hair Growth Agent Derived From Natural Extracts, Kelly Michael Glynn Apr 2009

From In-Vitro To In-Vivo: Corporate Development And Efficacy Of A Topical Hair Growth Agent Derived From Natural Extracts, Kelly Michael Glynn

Masters Theses

Androgenetic alopecia (male pattern baldness) affects up to 50% of the world’s population, propelling the development for a possible treatment. The hair follicle is influenced by several genetic and physiologic factors, which, when gone awry, lead to androgenetic alopecia. Vascular endothelial and keratinocyte growth factors are believed to be promoters of hair growth, as is inhibition of the proteasome complex. The cytokine IL-1α is also known to regulate follicle dynamics. The research objective described herein was an attempt to develop a botanical blend, which could mediate the above biomarkers, be successfully incorporated into a safe topical product and be evaluated …

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Factors Affecting Dissolved Oxygen Metabolism In Coastal Plain Streams Of Virginia, Julie Frank Apr 2009

Factors Affecting Dissolved Oxygen Metabolism In Coastal Plain Streams Of Virginia, Julie Frank

Theses and Dissertations

I investigated seasonal and inter-site variation in factors influencing diel dissolved oxygen (DO) metabolism at four streams in the Virginia Coastal Plain. Data were collected monthly from January to August 2008 to characterize DO metabolism (diel DO amplitude, production, respiration), incident solar radiation (PAR), dissolved nutrients, fine benthic materials (mass, C:N, Chlα) and hydrology (discharge, water transit time, transient storage). Reach-scale metabolism estimates were determined using the one-station diurnal DO technique and transit time and transient storage were determined by conservative tracer additions. Incident solar radiation was the primary determinant of DO metabolism as streams experiencing higher light levels (Herring …

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Molecular Systematics Of Spiny Pocket Mice (Subfamily Heteromyinae) Inferred From Mitochondrial And Nuclear Sequence Data, Melina Crystal Williamson Apr 2009

Molecular Systematics Of Spiny Pocket Mice (Subfamily Heteromyinae) Inferred From Mitochondrial And Nuclear Sequence Data, Melina Crystal Williamson

Theses and Dissertations

This study aims to determine species-level relationships within the genus Heteromys, as well as generic-level relationships among members of the subfamily Heteromyinae using a phylogenetic framework. Molecular sequence data were generated from two mitochondrial genes (cytochrome b and cytochrome oxidase I) and three nuclear gene segments (β-fibrinogen, engrailed protein II, and myosin heavy chain II), and analyzed under maximum parsimony, maximum likelihood, and Bayesian optimality criteria to infer relationships. Chapter 1 focuses on the phylogenetic and taxonomic implications for Heteromys from the analyses of sequence data. Phylogenies also provided a framework for delimiting species boundaries within the wide-ranging Heteromys desmarestianus …

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Coupling Of Autotrophic And Heterotrophic Plankton Food Web Components In The Tidal-Freshwater James River, Usa, Matthew Beckwith Apr 2009

Coupling Of Autotrophic And Heterotrophic Plankton Food Web Components In The Tidal-Freshwater James River, Usa, Matthew Beckwith

Theses and Dissertations

Empirical studies have shown that algal- and detrital-based food web components are coupled in many pelagic systems as algal carbon enhances bacterioplankton production and growth efficiencies. Such phyto-bacterioplankton coupling impacts carbon flow through plankton food webs, yet the extent of coupling is poorly understood in systems receiving large amounts of allochthonous carbon. To investigate this issue, bacterioplankton abundance (BA) and community composition were compared to chlorophyll a concentrations and phytoplankton production in the tidal-freshwater James River (VA). BA averaged 107 cells mL-1 and was significantly related to chlorophyll a, phytoplankton production, and DOC concentrations. Analysis of DOC quality using fluorescence …

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Common-Path Multimodal Optical Microscopy, Marla Tipping, Chandra S. Yelleswarapu, Sri-Rajasekhar Kothapalli, Alexey Veraksa, D.V.G.L.N. Rao Apr 2009

Common-Path Multimodal Optical Microscopy, Marla Tipping, Chandra S. Yelleswarapu, Sri-Rajasekhar Kothapalli, Alexey Veraksa, D.V.G.L.N. Rao

Biology Faculty Publications

We have developed a common-path multimodal optical microscopy system that is capable of using a single optical source and a single camera to image amplitude, phase, and fluorescence features of a biological specimen. This is achieved by varying either contrast enhancement filters at the Fourier plane and/or neutral density/fluorescence filters in front of the CCD camera. The feasibility of the technique is demonstrated by obtaining brightfield, fluorescence, phase-contrast, spatially filtered, brightfield + fluorescence, phase +fluorescence, and edge-enhanced+fluorescence images of the same Drosophila embryo without the need for image registration and fusion. This comprehensive microscope has the capability of providing both …

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Identification Of Binding Partners Of A Novel P. Falciparum Exported Protein, Monica Zapata Apr 2009

Identification Of Binding Partners Of A Novel P. Falciparum Exported Protein, Monica Zapata

Theses and Dissertations

Plasmodium falciparum is the causative agent of the most severe form of malaria. This parasite drastically modifies its host cell, the erythrocyte, to create a hospitable environment for its growth and reproduction. In order for these modifications to occur, the parasite secretes proteins into the erythrocyte. While the secretion machinery is still unknown, many secreted proteins have been found to have a hydrophobic signal sequence and a novel host-targeting signal downstream of the hydrophobic sequence. A novel P. falciparum protein has been shown to be secreted from the parasitophorous vacuole, yet it lacks both a hydrophobic signal sequence and a …

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The Role Of Mitogen-Activated Protein Kinases In The Regulation Of Plant Development, Erica Satterfield Apr 2009

The Role Of Mitogen-Activated Protein Kinases In The Regulation Of Plant Development, Erica Satterfield

Theses and Dissertations

Mitogen-activated protein kinases are part of an evolutionarily conserved protein phosphorylation cascade which serves essential regulatory functions in eukaryotic organisms. Although the role of MAPKs in the regulation of a plant’s response to environmental stress and plant defense has been well established, very little is known about their role in the regulation of plant developmental processes. In order to examine the role of MAPKs in plant growth and development, a strong mammalian MAPK phosphatase (MKP-1), which is known to inactivate MAPKs in plants, was introduced into tobacco plants. In tobacco plants, MKP-1 overexpression altered plant responses to the phytohormones, ethylene …

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Rap1 Is Essential For Silencing Telomeric Variant Surface Glycoprotein Genes In Trypanosoma Brucei, Xiaofeng Yang, Luisa M. Figueiredo, Amin Espinal, Eiji Okubo, Bibo Li Apr 2009

Rap1 Is Essential For Silencing Telomeric Variant Surface Glycoprotein Genes In Trypanosoma Brucei, Xiaofeng Yang, Luisa M. Figueiredo, Amin Espinal, Eiji Okubo, Bibo Li

Biological, Geological, and Environmental Faculty Publications

Trypanosoma brucei expresses variant surface glycoprotein (VSG) genes in a strictly monoallelic fashion in its mammalian hosts, but it is unclear how this important virulence mechanism is enforced. Telomere position effect, an epigenetic phenomenon, has been proposed to play a critical role in VSG regulation, yet no telomeric protein has been identified whose disruption led to VSG derepression. We now identify tbRAP1 as an intrinsic component of the T. brucei telomere complex and a major regulator for silencing VSG expression sites (ESs). Knockdown of tbRAP1 led to derepression of all VSGs in silent ESs, but not VSGs located elsewhere, and …

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Stem Cell Order Was Immoral And Unnecessary, Nicanor Austriaco Apr 2009

Stem Cell Order Was Immoral And Unnecessary, Nicanor Austriaco

Theology Faculty Publications

No abstract provided.

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My 20-Year Research Journey For A New Species Of Spiders, Or How To Come To A New Discovery, Vladimir Ovtcharenko Apr 2009

My 20-Year Research Journey For A New Species Of Spiders, Or How To Come To A New Discovery, Vladimir Ovtcharenko

Touchstone

From time to time students ask me whether it is difficult to discover new species of organisms on our planet. To answer this question, I have decided to tell my story of how I discovered a new species of spider that I have dedicated to Eugenio María de Hostos.

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