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Design And Synthesis Of Cationic Steroid Antimicrobial Compounds, Synthesis Of Glycolipids Recognized By Natural Killer T Cells And Development Of Tlr-1, Tlr-6 Heterodimer Binders And Studies Of Their Immunology Activities, Yanshu Feng Dec 2011

Design And Synthesis Of Cationic Steroid Antimicrobial Compounds, Synthesis Of Glycolipids Recognized By Natural Killer T Cells And Development Of Tlr-1, Tlr-6 Heterodimer Binders And Studies Of Their Immunology Activities, Yanshu Feng

Theses and Dissertations

Cationic steroid antimicrobial agents (CSAs) are a family of bile acid derivatives. These compounds are amphiphilic and mimic endogenous antimicrobial peptides. The antimicrobial activities of CSA-13 have been investigated and due to portent bactericidal activities and low toxicity, a large amount of CSA-13 is demanded for clinic trails and other antimicrobial applications. During our studies, we optimized the synthetic route of CSA-13, so that it can be prepared at the kilogram, even in tons scale. We investigated three routes and one of them is suitable for industry, because only recrystallization is needed in the synthesis. Natural killer T cells (NKT …


A Floristic Survey Of The Lichens Of The Spring Mountains, Nevada, Usa, Monica W. Proulx Dec 2011

A Floristic Survey Of The Lichens Of The Spring Mountains, Nevada, Usa, Monica W. Proulx

Theses and Dissertations

This thesis is the culmination of a graduate research project involving a floristic survey of the lichens of the Spring Mountain National Recreation Area (SMNRA), Humboldt-Toiyabe National Forest, Nevada. The project was based on extensive collections made between 1997 and 2007 as part of an air pollution biomonitoring program and a baseline established by Larry St. Clair (BYU). The Spring Mountains are a sky island mountain range in the Mojave Desert located less than an hour northwest of Las Vegas. A floristic survey of the lichen communities in the Spring Mountains represents a major addition to our understanding of the …


Characterization Of The Role Nuclear Bmp2 (Nbmp2) Plays In Regulating Gene Expression, Fialka Grigorova Dec 2011

Characterization Of The Role Nuclear Bmp2 (Nbmp2) Plays In Regulating Gene Expression, Fialka Grigorova

Theses and Dissertations

The nBmp2 protein was first identified in a DNA affinity chromatography/mass spectrometry screen designed to detect proteins that interact with a cartilage-specific enhancer element (called D/E) from the type XI collagen gene Col11a2. The transcription factor SOX9, a protein from the Sox (SRY-related HMG box) family, binds to and activates gene expression from this enhancer. nBmp2 has no transcriptional activity of its own on this enhancer, but when co-transfected with SOX9 it increases SOX9's activation of D/E nearly 2-fold. SOX9 also activates cartilage-specific enhancer elements from the Col2a1, Col27a1, and Col9a1 genes. The purpose of this project …


Influence Of Weak Interactions On Supramolecular Binding: Characterization Of Cucurbituril Complexes With Alkylmonoammonium Ions Using Fourier Transform Ion Cyclotron Resonance Mass Spectrometry, Ruijan Shi Dec 2011

Influence Of Weak Interactions On Supramolecular Binding: Characterization Of Cucurbituril Complexes With Alkylmonoammonium Ions Using Fourier Transform Ion Cyclotron Resonance Mass Spectrometry, Ruijan Shi

Theses and Dissertations

This thesis focuses on using mass spectrometry-based techniques for characterizing the structure and behavior of cucurbituril complexes in the gas phase. Both solvent and counter ion effects can be completely eliminated in the gas phase and the intrinsic interactions in the system are directly shown in the experimental results. Chapter 1 introduces the structures, properties and host-guest chemistry of cucurbituril, and FTICR mass spectrometry including instrumentation, performance and working principles. Two mass spectrometry-based methods for supramolecular characterization, sustained off-resonance irradiation collision induced dissociation (SORI CID) and ion molecule equilibrium measurements, are also discussed in this chapter. Chapter 2 characterizes the …


Changes In Fruit And Vegetable Household Food Availability Among Low-Income Families Over A One-Month Period Of Time, Ann Alicia Wells Dec 2011

Changes In Fruit And Vegetable Household Food Availability Among Low-Income Families Over A One-Month Period Of Time, Ann Alicia Wells

Theses and Dissertations

Objective: There is little evidence of how fruit and vegetable (FV) household food availability changes over a one-month period among low-income households. The objective of this study was to analyze how FV variety and sustainability changes over a 4-week period.
Design: Inventories were conducted in low-income family households (n=49) once a week over a 4-week period. Trained researchers gathered the weights of all FV, including legumes, within the home. Previously determined mean container weights were subtracted to obtain the estimated weight of the FV. All weights were then converted to edible cups of FV, taking into account the weight that …


Mechanism Of G Protein Beta-Gamma Assembly Mediated By Phosducin-Like Protein 1, Chun Wan Jeffrey Lai Dec 2011

Mechanism Of G Protein Beta-Gamma Assembly Mediated By Phosducin-Like Protein 1, Chun Wan Jeffrey Lai

Theses and Dissertations

G-protein coupled receptor signaling (GPCR) is essential for regulating a large variety of hormonal, sensory and neuronal processes in eukaryotic cells. Because the regulation of these physiological responses is critical, GPCR signaling pathways are carefully controlled at different levels within the cascade. Phosducin-like protein 1 (PhLP1) can bind the G protein βγ dimer and participate in GPCR signaling. Recent evidence has supported the concept that PhLP1 can serve as a co-chaperone of the eukaryotic cytosolic chaperonin complex CCT/TRiC to mediate G βγ assembly. Although a general mechanism of PhLP1-mediated G βγ assembly has been postulated, many of the details about …


Species Level Differences In The Ecology Of Two Neotropical Tadpole Species: Responses To Nonlethal Predators And The Roles Of Competition And Resource Use, Zacharia Costa Dec 2011

Species Level Differences In The Ecology Of Two Neotropical Tadpole Species: Responses To Nonlethal Predators And The Roles Of Competition And Resource Use, Zacharia Costa

Theses and Dissertations

Closely related species at the same trophic level are often considered to be ecologically equivalent. However, it is clear that individuals species can have unique functional roles that drive community and ecosystem processes. In this study we examine the growth responses of two Neotropical hylid tadpole species, Agalychnis callidryas and Dendropsophus ebraccatus, to intraspecific and interspecific competition. We also look at density-dependent effects of each on phytoplankton, periphyton and zooplankton, as well as their responses to a caged dragonfly predator through ontogeny. Intraspecific competition affected both species similarly, and their effects on resources were qualitatively similar but quantitatively different. Predators …


C-Met Initiates Epithelial Scattering Through Transient Calcium Influxes And Nfat-Dependent Gene Transcription, Peter R. Langford Dec 2011

C-Met Initiates Epithelial Scattering Through Transient Calcium Influxes And Nfat-Dependent Gene Transcription, Peter R. Langford

Theses and Dissertations

Hepatocyte growth factor (HGF) signaling drives epithelial cells to scatter by breaking cell-cell adhesions and migrating as solitary cells, a process that parallels epithelial-mesenchymal transition. HGF binds and activates the c-Met receptor tyrosine kinase, but downstream signaling required for scattering remains poorly defined. This study addresses this shortcoming in a number of ways.A high-throughput in vitro drug screen was employed to identify proteins necessary in this HGF-induced signaling. Cells were tested for reactivity to HGF stimulation in a Boyden chamber assay. This tactic yielded several small molecules that block HGF-induced scattering, including a calcium channel blocker. Patch clamping was used …


Geochemical Analysis Of Ancient Activities At Two Plazas In Cobá, Mexico, Eric G. Coronel Dec 2011

Geochemical Analysis Of Ancient Activities At Two Plazas In Cobá, Mexico, Eric G. Coronel

Theses and Dissertations

Two plazas at Cobá, Mexico, may have been the place of market activity during the classic Maya period. The intense decomposition in the warm, moist soils of the Yucatan Peninsula precludes the identification of organic artifacts in archaeological contexts, but phosphorus and trace elements accumulation in soils may provide evidence of marketing activities. The spatial patterns of P and trace element concentrations were used to elucidate the types of ancient Maya activities that took place in those plazas. Phosphorus concentrations are highly correlated (p-value <0.01) with Fe, Mn, and Zn levels in both Plaza B and D. Although the soil geochemistry of Plaza B does not show a marketplace pattern in comparison with previous studies, the elemental concentrations and distributions within Plaza D join other lines of evidence to support the premise that marketplace activities took place at that location. Soil samples were analyzed using DTPA extraction, Mehlich II, Olsen, and Portable X-Ray Fluorescence (PXRF). Experiments were performed to study the suitability of PXRF for field studies. Aspects that were studied include granule size, soil moisture content, protective plastic films that could interfere with the X-Ray signal when placing the samples on top of the analyzer, and a comparison of certified soil standards to the PXRF elemental concentration readings. The results suggest that a field laboratory could be set up to air-dry and sieve soil samples to a minimum mesh size of #10 (> 2 mm).


Seasonal Habitat Selection By Greater Sage Grouse In Strawberry Valley Utah, Riley D. Peck Dec 2011

Seasonal Habitat Selection By Greater Sage Grouse In Strawberry Valley Utah, Riley D. Peck

Theses and Dissertations

This study examined winter habitat use and nesting ecology of greater sage grouse (Centrocercus urophasianus) in Strawberry Valley (SV), Utah located in the north-central part of the state. We monitored sage grouse with the aid of radio telemetry throughout the year, but specifically used information from the winter and nesting periods for this study. Our study provided evidence that sage grouse show fidelity to nesting areas in subsequent years regardless of nest success. We found only 57% of our nests located within the 3 km distance from an active lek typically used to delineate critical nesting habitat. We …


Stable Isotope Diet Reconstruction Of Feral Horses (Equus Caballas) On The Sheldon National Wildlife Refuge, Nevada, Usa, Megan Kathleen Nordquist Dec 2011

Stable Isotope Diet Reconstruction Of Feral Horses (Equus Caballas) On The Sheldon National Wildlife Refuge, Nevada, Usa, Megan Kathleen Nordquist

Theses and Dissertations

Feral horse management has become a subject of significant controversy in the United States. This is because of differing opinions and minimal recent empirical data on feral horses. In recent years, numbers of feral horses have increased due to governmental horse removal restrictions (specifically the Wild Horse and Burro act of 1971). With increasing numbers of feral horses on rangelands, land managers are challenged with identifying the appropriate course of action for satisfying groups with differing opinions. The purpose of this study is to characterize diet consumption through the use of stable isotope dietary analysis (δ15N and δ13C). We did …


Neuromechanical Alterations Due To Induced Knee Pain And Effusion During Functional Movements, Jihong Park Dec 2011

Neuromechanical Alterations Due To Induced Knee Pain And Effusion During Functional Movements, Jihong Park

Theses and Dissertations

Purpose: Examine neuromechanical alterations due to isolated and/or combined knee pain and effusion in functional movements. Methods: A 4X3 randomised controlled laboratory study with repeated measures was used. Nineteen, healthy volunteers (age: 22.4 ± 2.4 years) underwent four different treatments (control, effusion, pain, and pain/effusion) with a week wash out period. Ten near-infrared cameras with 43 reflective markers, 12 surface EMG electrodes, and two ground-embedded force platforms were used to record neuromechanical changes during functional movements (walking and drop landing). To induce pain, 5% sodium chloride (1 ml) was injected into the infrapatellar fat pad. To induce effusion, 0.9% sodium …


The Effects Of Whole Body Vibration On Dorsiflexion In Chronic Ankle Instability, Lesley Abigail Thalman Dec 2011

The Effects Of Whole Body Vibration On Dorsiflexion In Chronic Ankle Instability, Lesley Abigail Thalman

Theses and Dissertations

BACKGROUND: Whole body vibration (WBV) platforms are currently used as adjunctive training devices for exercise programs, and have been shown to facilitate flexibility. One of the biggest contributing factors to chronic ankle instability (CAI) is the lack of dorsiflexion after lateral ankle sprains and WBV may be an effective way to increase range of motion in this population. PURPOSE: Determine if WBV done concurrently with static stretching (SS) is more effective then SS alone in improving dorsiflexion ROM in subjects with CAI. METHODS: Subjects were divided into 3 groups (control, static stretch, and static stretch and vibrate). Subjects stretched 4 …


Evaluation Of Brook Trout (Salvelinus Fontinalis) Introductions And Re-Introductions Into Four Virginia Blue Ridge Mountain Streams, Michael Isel Iii Dec 2011

Evaluation Of Brook Trout (Salvelinus Fontinalis) Introductions And Re-Introductions Into Four Virginia Blue Ridge Mountain Streams, Michael Isel Iii

Theses and Dissertations

Approximately 100 brook trout were transplanted into each of four Virginia streams in September 2008. Garth Run and Kinsey Run were re-introductions, and Wildcat Hollow and Sweet Run were new introductions. Single pass electrofishing (EF) surveys were conducted with a backpack electrofisher five times during the study. Selected trout > 70 mm but < 100 mm and all trout > 100 mm received a Biomark® 134.2 kHz passive integrated transponder (PIT) tag to identify individual fish upon recapture. Trout were present in all streams almost three years post introductions. Catches decreased across the first four surveys. Young of year catch rates severely decreased from June 2009 (n = …


Factors Controlling Dissolved Organic Carbon Lability And Ecological Fate In The East Branch Swift River, Massachusettes, Hall Eric Dec 2011

Factors Controlling Dissolved Organic Carbon Lability And Ecological Fate In The East Branch Swift River, Massachusettes, Hall Eric

Theses and Dissertations

Fluvial systems have been estimated to transform, transport, or store 2.75 petagrams (Pg) of Organic Carbon (OC) per year. Although approximately 1Pg per year of terrestrial carbon is fluxed to the atmosphere through inland waters, little is known about the factors regulating its eventual ecological fate. 28 day lability incubations were conducted concurrent with the measurement of several environmental parameters including discharge, nutrient concentration, DO13C, and DOC:DON at several sites along Bigelow Brook and the East Branch of the Swift River, Massachusetts. Temporal and spatial variation of DOC, DOC:DON and DO13C were explored. Two distinct DOC consumption rates, short and …


Characterizing The Phosphorylation State Of Tie2 Using Sh2 Domain Fusion Proteins, Kenneth Yuth Dec 2011

Characterizing The Phosphorylation State Of Tie2 Using Sh2 Domain Fusion Proteins, Kenneth Yuth

Theses and Dissertations

The cardiovascular system develops through two distinct processes in embryogenesis: vasculogenesis, whereby the primary plexus in the heart is formed along with embryonic and extraembryonic vasculature, and angiogenesis, which begins after vasculogenesis and results in the refinement and maturation of the branched vessel system. In pathological angiogenesis, tumors expand by releasing pro-angiogenic factors in response to hypoxic conditions. The Tie receptors, Tie1 and Tie2, are receptor tyrosine kinases that are integral to angiogenic pathways. A family of Angiopoietins, Ang1-4, have been shown to act as ligands for Tie2, of which Ang1 and Ang2 are best characterized. Activation of the receptor …


Woody Encroachment Mechanisms Of A Symbiotic N-Fixing Shrub: Ecophysiology, Facilitation, And Resource Use Efficiency, Jaclyn Vick Dec 2011

Woody Encroachment Mechanisms Of A Symbiotic N-Fixing Shrub: Ecophysiology, Facilitation, And Resource Use Efficiency, Jaclyn Vick

Theses and Dissertations

Causes and consequences of woody encroachment into grass dominated systems have been widely studied, however functional mechanisms which promote encroachment are largely unknown. Many expansive woody species are shrubs with rhizobial or actinorhizal N-fixing symbiotic associations. Morella cerifera L. (Myricaceae) is an actinorhizal N-fixing shrub which rapidly expands into grasslands on the barrier islands off the coast of Virginia, USA. The objective of this research was to determine physiological drivers of woody encroachment resulting in increased woody cover of M. cerifera on Southeastern, US barrier islands. Variations in physiology and resource use efficiencies (RUE) of M. cerifera and co-occurring shrubs …


Part I, Unified Pharmacophore Protein Models Of The Benzodiazepine Receptor Subtypes ; Part Ii, Subtype, Terrill S. Clayton Dec 2011

Part I, Unified Pharmacophore Protein Models Of The Benzodiazepine Receptor Subtypes ; Part Ii, Subtype, Terrill S. Clayton

Theses and Dissertations

Part I. New models of unified pharmacophore/receptors have been constructed guided by the synthesis of subtype selective compounds in light of recent developments both in ligand synthesis and structural studies of the binding site itself. The evaluation of experimental data in combination with comparative models of the α1β2γ2, α2β2γ2, α3β2γ2 and α5β2γ2 GABA(A) receptors has led to an orientation of the pharmacophore model within the benzodiazepine binding site (Bz BS). These results not only are important for the rational design of new selective ligands, but also for the identification and evaluation of possible roles which specific residues may have within …


Dietary Fiber Consumption And Insulin Resistance: The Role Of Body Fat And Physical Activity, Charity B. Breneman Nov 2011

Dietary Fiber Consumption And Insulin Resistance: The Role Of Body Fat And Physical Activity, Charity B. Breneman

Theses and Dissertations

Background: This study was conducted to determine the association between fiber intake and insulin resistance in 264 women using a cross-sectional design. Methods: Insulin resistance was indexed using HOMA-IR (fasting insulin (μU/mL)×fasting glucose (mg/dL)/405). HOMA-IR values were log transformed. Fiber and energy consumption were assessed using 7-day weighed food records. Fiber was expressed as grams per 1000 kilocalories. Body fat percentage (BF%) was measured using the BOD POD and physical activity (PA) was ascertained using Actigraph accelerometers worn for 7 consecutive days. Results: (Mean±SD) age: 40.1±3.0 years, glucose: 86.7±5.9 mg/dL; insulin: 7.1±4.3 μU/mL; HOMA-IR: 1.5±1.0; fiber intake …


Shrubs As Sentinels Of Ordnance Contamination: Using Plant Physiology And Remote Sensing To Detect Tnt In Soils, Kathryn Rubis Nov 2011

Shrubs As Sentinels Of Ordnance Contamination: Using Plant Physiology And Remote Sensing To Detect Tnt In Soils, Kathryn Rubis

Theses and Dissertations

Methods for rapid, safe and effective detection of unmapped buried ordnance are vital to the protection of humans and environmental quality throughout the world. This study aimed to investigate the use of phytosensing and to understand the physiological response of woody plants to 2,4,6-trinitrotoluene (TNT) contamination. Baccharis halimifolia were potted in soils containing various concentrations of TNT and physiological responses were observed over a 9-week experimental period. Measurements included the collection of remotely sensed data, such as hyperspectral reflectance and chlorophyll fluorescence, and traditional plant-level physiological data. In accordance with the hypothesis, low levels of TNT improved physiological response in …


Effect Of Experimentally-Induced Anterior Knee Pain On Postural Control, Emily Elizabeth Falk Nov 2011

Effect Of Experimentally-Induced Anterior Knee Pain On Postural Control, Emily Elizabeth Falk

Theses and Dissertations

Context: Knee pain is experienced by many people. Because of this, authors have started researching the effects of pain on lower extremity mechanics and also on static and dynamic postural control. However, the effects of pain are difficult to study due to associated confounding variables. Objective: We asked: (1) Will experimentally-induced anterior knee pain alter perceived pain using the visual analogue scale? ; (2) will perceived pain affect postural control as measured by center-of-pressure during static and dynamic movement? Design: Crossover. Setting: Biomechanics laboratory. Participants: Fifteen healthy subjects. Intervention: Each subject participated in single leg quiet stance, landing, and walking …


The Effect Of An Acute Bout Of Exercise On Food Motivation, Energy Intake, And Total Physical Activity In Normal-Weight And Obese Woman: An Event-Related Potential Study, Nonie Erin Bliss Hanlon Nov 2011

The Effect Of An Acute Bout Of Exercise On Food Motivation, Energy Intake, And Total Physical Activity In Normal-Weight And Obese Woman: An Event-Related Potential Study, Nonie Erin Bliss Hanlon

Theses and Dissertations

This study examined the effect of acute exercise on food motivation, energy intake, and total physical activity in normal-weight and obese women. Participants of both groups were matched (except for Body Mass Index) and conditions (exercise vs. non-exercise) were randomized and counter-balanced. Eighteen normal-weight and 17 obese women completed an exercise and non-exercise day, each performed on the same day of the week. Exercise was performed on a motor-driven treadmill at 3.8 mph and 0% grade for 45 continuous minutes. To test for food motivation, participants were shown a continuous stream of pictures of food and flowers (control) while neural …


Computational Modeling And Simulation Study Of Dermal Wound Healing Proliferative Phase, Le Yang Nov 2011

Computational Modeling And Simulation Study Of Dermal Wound Healing Proliferative Phase, Le Yang

Theses and Dissertations

Dermal wound healing proliferative phase is a complicated physiological process in which many growth factors, cell types and matrix components participate. The process must be well coordinated to restore the structural and functional integrity of tissue injured. Many disorders interrupting healing process result in abnormal healing such as chronic wounds or excessive scarring. Mathematical modeling has been used to investigate many aspects of wound healing. Angiogenesis is pertinent for dermal wound healing since the cellular activities involved in tissue repair requires oxygen and nutrients to be delivered to the wound site. By using a hybrid agent-based model, we investigated the …


Maternal, Neonatal And Feeding Type Factors Associated With Severity Of Necrotizing Enterocolitis, Cheryl Ann Miner Nov 2011

Maternal, Neonatal And Feeding Type Factors Associated With Severity Of Necrotizing Enterocolitis, Cheryl Ann Miner

Theses and Dissertations

Objective: To identify statistical associations with necrotizing enterocolitis (NEC) severity as dichotomized into cases with Bell stage II and III disease.
Study Design: We conducted a retrospective study using eight consecutive years of data from a multihospital healthcare system analyzed NEC severity (Bell stage II vs. III).
Results: We identified 220 neonates with stage ≥ II who had 225 separate episodes of NEC (157 stage II and 68 stage III). Those with stage III were born at earlier gestational age (P<0.0001) and lower birth weight (P<0.0001). Diagnosis of NEC occurred on about the same day of life in stage II and stage III cases. Those who developed stage III had significantly higher C-reactive protein (P<0.0001), I/T ratio (P= 0.0005), mean platelet volume (MPV) (P= 0.0001) and lower pH (P<0.0001) and platelet counts (P<0.0001). Transfusions were more common to those who progressed to stage III (P<0.0001). Regression analysis indicated higher odds of stage III in relationship to the volume of RBC transfusions (OR 2.41, {CI 1.85 to 3.11}, P<0.0001) and pasteurized human milk (PHM) (OR 1.32, {CI 1.07 to 1.62}, P = 0.0089). In contrast, feeding early mother's own milk (colostrum) for five days reduced the odds for stage III (OR 0.802, {CI 0.67 to 0.96}, P=0.0170). Those with small bowel resection were less likely to have received mother's own milk before NEC (OR 0.94, {CI 0.89 to 0.99}, P = 0.019) and factors predicting death from NEC were a low pH (OR 2.21, {CI 1.27 to 3.85}, P = 0.0005) and less colostrum (OR 0.96, {CI 0.94 to 0.99}, P = 0.003).
Conclusions: RBC transfusions and PHM increased the odds for stage III NEC, whereas early mother's own milk five days …


Total Synthesis Of 4'-Ester Resveratrol Analogs And 8.9-Amido Geldanamycin Analog And Toward The Total Synthesis Of (-)-Englerin A, Yong Wang Oct 2011

Total Synthesis Of 4'-Ester Resveratrol Analogs And 8.9-Amido Geldanamycin Analog And Toward The Total Synthesis Of (-)-Englerin A, Yong Wang

Theses and Dissertations

Total Synthesis of 4'-ester Resveratrol Analogs and 8, 9-amido Geldanamycin Analog and toward the Total Synthesis of (-)-Englerin A Yong Wang Department of Chemistry and Biochemistry, BYU Doctor of Philosophy The phytoalexin resveratrol and its 4'-ester analogs have been prepared with a decarbonylative Heck reaction. The deprotecting step has been modified and improved to increase yield and avoid chromatography. A set of resveratrol analogs and resveratrol have been tested with melanoma and pancreatic cell assays. The 8, 9-amido Geldanamycin analog has been synthesized with a convergent route, involving 28 simplified steps in its longest linear sequence. Synthetic methodologies, such as …


Identification And Characterization Of A Novel Thermohalophilic Esterase From The Red Sea: Atlantis Ii Brine Pool, Yasmine Mustafa Mohamed Oct 2011

Identification And Characterization Of A Novel Thermohalophilic Esterase From The Red Sea: Atlantis Ii Brine Pool, Yasmine Mustafa Mohamed

Theses and Dissertations

Industrial (white) biotechnology poses an increasing demand for novel biocatalysts that are robust under a wide range of conditions. Traditionally, biocatalysts were isolated from cultured isolates, however, less than 1% of microorganisms are culturable. Therefore, it became evident that the unculturable majority holds a great potential for the discovery of novel biocatalysts. Metagenomics is an invaluable tool for accessing the genomes of the uncultured majority and has led to the isolation of a large number of biocatalysts from various environments. Extreme environments such as hydrothermal vents, brine pools and glaciers, are an attractive source for biocatalysts. Biocatalysts from these environments …


Composition Of Suspended And Benthic Particulate Matter In The Tidal Freshwater James River, Anne Schlegel Sep 2011

Composition Of Suspended And Benthic Particulate Matter In The Tidal Freshwater James River, Anne Schlegel

Theses and Dissertations

Investigating linkages between the compositions of suspended (seston) and benthic particulate matter is important to the understanding of organic matter (OM) cycling and nutrient retention in aquatic systems. We compared the quantity and quality of the truly suspended (TS) and settleable (SB) fractions of seston as well as benthic particulate matter in the tidal freshwater James River, Virginia. The mass of seston and OM was consistently higher in the TS fraction compared to the SB fraction. OM was preferentially retained in the TS fraction relative to seston. The proportional contribution of OM constituents (chlorophyll a, particulate organic carbon and nitrogen) …


Characterization Of Hpk2-Rrp2, Two-Component Regulatory System In Treponema Denticola, Sarkar Juni Sep 2011

Characterization Of Hpk2-Rrp2, Two-Component Regulatory System In Treponema Denticola, Sarkar Juni

Theses and Dissertations

Treponema denticola levels in the gingival crevice become elevated as periodontal disease develops. Oral treponemes may account for as much as 40% of the total bacterial population in the periodontal pocket. The stimuli that trigger enhanced growth of T. denticola and the mechanisms associated with the transmission of these signals remain to be defined. A hypothesis was set that the T. denticola ORFs tde1970 (histidine kinase) and tde1969 (response regulator) constitute a functional two component regulatory system that regulates, at least in part, responses to the changing environmental conditions associated with the development of periodontal disease. The results presented demonstrate …


Follicular Dendritic Cells, Resting Cd4+ T Cells And Human Immunodeficiency Virus Expression, Changna Wang Sep 2011

Follicular Dendritic Cells, Resting Cd4+ T Cells And Human Immunodeficiency Virus Expression, Changna Wang

Theses and Dissertations

Many events associated with Human Immunodeficiency Virus (HIV) infection/replication occur in and around the germinal centers (GCs) of secondary lymphoid tissues where follicular dendritic cells (FDCs) reside, suggesting that this microenvironment may contribute unique signaling that is important to viral progression. My research focused on characterizing signaling, both positive and negative, contributed by FDCs that affects HIV infection and replication. Specifically, I determined if FDC signals could induce the expression of latent HIV in T cells and if so, to characterize the signaling pathways involved. Moreover, I also examined the ability of FDCs to produce inhibitory signals that might block …


Gene Expression In The Right Ventricle During Development Of Pulmonary Hypertension, Jennifer Drake Sep 2011

Gene Expression In The Right Ventricle During Development Of Pulmonary Hypertension, Jennifer Drake

Theses and Dissertations

Pulmonary arterial hypertension (PAH) is a disease of the lung vessels that causes severe effects on the right ventricle of the heart; ultimately, most patients with severe PAH die as a result of right heart failure. However, little is known about the causes of right heart failure. Here, we describe a pattern of gene expression that differs between the normal rat left ventricle (LV) and right ventricle (RV). These genes are known to be involved in the development of the heart as well as adaptations to the heart during stress. This gene expression pattern is used as a baseline to …