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Influence Of Soil Water Repellency On Post-Fire Revegetation Success And Management Techniques To Improve Establishment Of Desired Species, Matthew D. Madsen Dec 2009

Influence Of Soil Water Repellency On Post-Fire Revegetation Success And Management Techniques To Improve Establishment Of Desired Species, Matthew D. Madsen

Theses and Dissertations

The influence of soil water repellency (WR) on vegetation recovery after a fire is poorly understood. This dissertation presents strategies to broaden opportunities for enhanced post-fire rangeland restoration and monitoring of burned piñon and juniper (P-J) woodlands by: 1) mapping the extent and severity of critical and subcritical WR, 2) determining the influence of WR on soil ecohydrologic properties and revegetation success, and 3) evaluating the suitability of a wetting agent composed of alkylpolyglycoside-ethylene oxide/propylene oxide block copolymers as a post-fire restoration tool for ameliorating the effects of soil WR and increasing seedling establishment. Results indicate that:

• Post-fire patterns …


Inferring Dispersal Of Aquatic Invertebrates From Genetic Variation: A Comparative Study Of An Amphipod (Talitridae Hyalella Azteca) And Mayfly (Baetidae Callibaetis Americanus) In Great Basin Springs, Heather Lynn Stutz Dec 2009

Inferring Dispersal Of Aquatic Invertebrates From Genetic Variation: A Comparative Study Of An Amphipod (Talitridae Hyalella Azteca) And Mayfly (Baetidae Callibaetis Americanus) In Great Basin Springs, Heather Lynn Stutz

Theses and Dissertations

Whether active or passive, dispersal accompanied by gene flow shapes the population genetics and evolutionary divergence of species. Indirect methods which use genetic markers have the ability to assess effective dispersal—that which resulted in gene flow. My objective was to see if an aquatic insect and an obligate aquatic invertebrate show similar phylogeographic patterns and genetic uniqueness. Hyalella azteca and Callibaetis americanus were collected from 4-5 springs in each of six basins in the Great Basin of western North America. No dispersal or genetic studies of C. americanus have been conducted to date. However, several studies focusing on mtDNA diversity …


Comparison Of Single-Use And Multiple-Use Electrodes For Sensory, Motor Threshold Amplitudes And Force Production, Lucia Maloy Dec 2009

Comparison Of Single-Use And Multiple-Use Electrodes For Sensory, Motor Threshold Amplitudes And Force Production, Lucia Maloy

Theses and Dissertations

Context: Electrodes play an important role in interfacing tissue with electrical stimulation devices. Manufacturers recommend that adhesive metallic mesh cloth electrodes be used no more than 10 times before they are discarded, however, clinically the electrodes are often used up to 30 times. Another concern is sanitation. When electrodes are used on different patients, there is a chance for cross-contamination and bacterial growth on the electrode. Objective: To compare amplitudes of perceived sensation, motor twitch and force produced at specific amplitudes using single-use electrodes that run no risk of cross-contamination, and multiple-use electrodes. Design: Mixed model ANOVA with the subject …


Progress Toward The Total Synthesis Of Lyconadin A, Yu Zhang Dec 2009

Progress Toward The Total Synthesis Of Lyconadin A, Yu Zhang

Theses and Dissertations

Lyconadin A is a pentacyclic Lycopodium alkaloid isolated from the club moss Lycopodium complanatum with antitumor properties. We have developed a novel 7-exo/6-exo acyl radical cascade cyclization as a method of making the bicyclo[5.4.0]undecane ring system of lyconadin A. The model products are trans-fused ring systems, while a cis-fused ring system is needed in lyconadin A. We have discovered a method to convert the trans-fused model cascade cyclization product into the desired cis isomer. Based on Donohoe's pyridone synthesis, we developed a method for the construction of 5-alkyl and 3,5-dialkyl-6-carbomethoxy-2-pyridones, the former of which …


The Ecological Importance Of Extrinsic And Intrinsic Drivers Of Animal Movement, Josh Earl Rasmussen Dec 2009

The Ecological Importance Of Extrinsic And Intrinsic Drivers Of Animal Movement, Josh Earl Rasmussen

Theses and Dissertations

The movement of individuals is foundational to many ecological processes. For example, the movement of an organism from one place to another alters population density at both sites and has potential for affecting the genetic dynamics within the new population. Individual movement events may be in synchrony with overall trends in populations, e.g. spawning migrations, or may be atypical (asynchronous). This latter movement type can affect population and metapopulation dynamics, depending on its prevalence within a population. Nevertheless, given the complexity of interactions, the causative factors of movement are understood vaguely, much less for aquatic organisms. Drivers of movement are …


Influence Of Cardiac Output On Oxygen Uptake Kinetics, Crystelle Kiyoko Grant Dec 2009

Influence Of Cardiac Output On Oxygen Uptake Kinetics, Crystelle Kiyoko Grant

Theses and Dissertations

The purpose of this study was to evaluate increased cardiac output (Q) on oxygen kinetics at exercise intensities above and below the lactate threshold (LT). We hypothesized the increase in Q using head-out water immersion (HOI) while treadmill running would reduce the rate constant of the fast component and reduce the amplitude of the slow component of oxygen kinetics compared with land treadmill running. Subjects (n=10) performed two 6 min exercise bouts at a 15% below and above the LT on a land and underwater treadmill following rest. A single exponential equation [VO2(t) = VO2(b) + A1•(1-e-t/TC1] was used to …


Cocaine And Mefloquine-Induced Acute Effects In Ventral Tegmental Area Dopamine And Gaba Neurons, David Wilbanks Allison Dec 2009

Cocaine And Mefloquine-Induced Acute Effects In Ventral Tegmental Area Dopamine And Gaba Neurons, David Wilbanks Allison

Theses and Dissertations

The aim of the two studies presented here was to evaluate the effects of cocaine and mefloquine (MFQ) on γ-aminobutyric acid (GABA) and dopamine (DA) neurons in the ventral tegmental area (VTA). Cocaine: In vivo, lower doses of intravenous cocaine (0.25-0.5 mg/kg), or methamphetamine (METH), enhanced VTA GABA neuron firing rate via D2/D5 receptor activation. Higher cocaine doses (1.0-2.0 mg/kg) inhibited their firing rate. Cocaine and lidocaine inhibited the firing rate and spike discharges induced by stimulation of the internal capsule (ICPSDs) at dose levels 0.25-2 mg/kg (IC50 1.2 mg/kg), but neither DA nor METH reduced ICPSDs. In VTA …


Zooplankton Abundance, Community Composition And Grazing In The James River Estuary (Virginia, Usa), Laura E. Barry Dec 2009

Zooplankton Abundance, Community Composition And Grazing In The James River Estuary (Virginia, Usa), Laura E. Barry

Theses and Dissertations

This study examined the extent to which zooplankton in the James River Estuary (Virginia, USA) exploit the available algal-food resources. Zooplankton abundance, community composition and grazing rates were assessed at three locations which included a site with high algal production (near the VCU Rice Center) and two sites where algal production was lower. Grazing rates were measured by determining the rate of phytoplankton decline (as chlorophyll a) during 48-hour incubation experiments in the presence and absence of zooplankton. Significant differences in zooplankton abundance were observed among the three sites, with the greatest average zooplankton density (434 ± 69 ind/L) occurring …


Ecophysiological Mechanisms Underlying Aspen To Conifer Succession, William J. Calder Dec 2009

Ecophysiological Mechanisms Underlying Aspen To Conifer Succession, William J. Calder

Theses and Dissertations

This thesis includes three studies. The first study examined how reductions in light availability and changes in soil chemistry that occur as conifers establish in aspen stands, differentially affects the regeneration success of aspen and conifers. We found that aspen were more sensitive to changes in light and soil then subalpine fir. For aspen, reduced light and conifer influenced soils significantly reduced height, biomass, photosynthesis and the production of secondary defense compounds. Subalpine fir seedlings were significantly reduced in photosynthesis, biomass and R:S under lower light conditions but showed no differences in physiology or growth when grown on the contrasting …


Examining The Effects Of Penning On Juvenile Eastern Box Turtles (Terrapene Carolina Carolina), Nicolas Frederick Dec 2009

Examining The Effects Of Penning On Juvenile Eastern Box Turtles (Terrapene Carolina Carolina), Nicolas Frederick

Theses and Dissertations

Box turtle (Terrapene carolina) populations have been declining over the last several decades, and one major cause is increasing urbanization. As a result of habitat fragmentation, wildlife managers are frequently turning to new and alternative management strategies. Traditional box turtle management has included relocation, which has been met with limited success. This study aims to combine these strategies with another less-studied one: forcing turtles to overwinter on site by penning them in an outdoor enclosure. Two sets of juvenile box turtles were released at the Virginia Commonwealth University Rice Center: one penned on site in a pen for one year, …


Genetic Dissection Of Triterpenoid Saponin Production In Chenopodium Quinoa Using Microarray Analysis, Derrick James Reynolds Dec 2009

Genetic Dissection Of Triterpenoid Saponin Production In Chenopodium Quinoa Using Microarray Analysis, Derrick James Reynolds

Theses and Dissertations

Quinoa (Chenopodium quinoa Willd.) is an important food crop for subsistence farmers in the Altiplano (high plains) of Peru, Bolivia, and Argentina. Saponins are part of a diverse family of secondary metabolites that are found in high concentrations in the pericarp of many varieties of quinoa. Due to their bitter taste and anti-nutritive properties, saponins must be removed before the quinoa grain is consumed. There are ‘sweet’ varieties of quinoa that have significantly reduced levels of saponin. Previous research suggests saponin production is controlled by a single locus. The major objective of this research was to elucidate the genetic …


A Family Home Evening Based Method For Improving Physical Activity Levels In Families, Megan Maughan Wyatt Dec 2009

A Family Home Evening Based Method For Improving Physical Activity Levels In Families, Megan Maughan Wyatt

Theses and Dissertations

The prevalence of physical inactivity has been recognized as a risk factor for multiple chronic disease conditions in both adults and children. Recently efforts to increase healthy behaviors have been promoted through religious groups (Ken Resnicow et al., 2002). The Church of Jesus Christ of Latter-day Saints (LDS) has a unique program called Family Home Evening (FHE) that could be used to teach and potentially improve physical activity. Six FHE lessons were designed to be taught in 6 consecutive weeks within a family environment. A total of 84 families (parents and children) were recruited for participation. Participating families were randomized …


Prothonotary Warbler (Protonotaria Citrea) Plumage As An Indicator For Infection: The Relationship Between Haemosporidia Infection And Breast Feather Reflectance In A Neotropical Migrant Passerine, Robert Fithian Nov 2009

Prothonotary Warbler (Protonotaria Citrea) Plumage As An Indicator For Infection: The Relationship Between Haemosporidia Infection And Breast Feather Reflectance In A Neotropical Migrant Passerine, Robert Fithian

Theses and Dissertations

Yellow avian plumage is a direct result of carotenoid pigments obtained in a bird’s diet and may act as an indicator for individual health, parasite resistance, and status. This study describes breast feather reflectance of adult Prothonotary Warblers (Protonotaria citrea) (n=169), insectivorous Neotropical migrant passerines, throughout the Ultraviolet (UV) and human visible light spectra and examines the relationship between Haemosporidia (pathogen causing Avian Malaria) infection and feather reflectance (n=41). Reflectance was characterized using a Principle Component Analysis evaluating Intensity, Brightness, Hue, UV Intensity, UV Brightness, and UV Chroma. UV and visible light reflectance was higher in birds sampled earlier in …


Examination Of Platelet Adhesion By Streptococcus Sanguinis, Brian Mahoney Nov 2009

Examination Of Platelet Adhesion By Streptococcus Sanguinis, Brian Mahoney

Theses and Dissertations

Streptococcus sanguinis is a leading cause of infective endocarditis. Bacterial adhesion to platelets is likely important in the pathogenesis of infective endocarditis. Bacterial cell wall-anchored (Cwa) proteins may mediate this adhesion. To begin to test this hypothesis, S. sanguinis adhesion to platelets was examined in vitro. The requirement of 12 Cwa proteins for S. sanguinis-platelet adhesion was individually assessed, measuring adhesion of purified platelets to polystyrene wells coated with S. sanguinis strain SK36 or 12 isogenic Cwa protein mutants. Significantly fewer platelets adhered to wells coated with one mutant strain, VT1614. However, results of a whole-cell enzyme-linked immunosorbent assay (ELISA) …


The Role Of Cannabinoids And Cannabinoid Receptors In Enteric Neuronal Survival, Yan Li Nov 2009

The Role Of Cannabinoids And Cannabinoid Receptors In Enteric Neuronal Survival, Yan Li

Theses and Dissertations

The Endocannabinoid system has been found in the gastrointestinal tract, where it plays an important role in gut under both physiological and pathological conditions. Although the major effects of cannabinoids in the gut are mediated through effects on enteric neurons, the role of cannabinoids in the enteric nervous system is poorly understood. In the present study, we have used the primary cultures of myenteric ganglia and a newly developed fetal enteric neuronal cell line to identify whether the endocannabinoid, anandamide, affects ganglionic and neuronal survival and the pathways involved. Anandamide had a biphasic effect on ganglionic survival, increasing survival at …


Bpv Entry And Trafficking In Ebtr Cells, Enkhmart Dudleenamjil Nov 2009

Bpv Entry And Trafficking In Ebtr Cells, Enkhmart Dudleenamjil

Theses and Dissertations

Bovine Parvovirus (BPV) belongs to the genus Bocavirus, family Parvoviridae. BPV is the leading etiologic agent among the pathogens that cause primary gastroenteritis of cattle. Many of the intracellular events associated with virus replication are unknown. In this research project, we investigated BPV internalization into the host cell and trafficking in the cytosol. Preliminarily, EBTr cells had abundant clathrin, virus attached to purified clathrin, and EM micrographs revealed virus in endocytic vacuoles. Assays detecting virus infectivity (i.e. viral protein synthesis), virus production (completion of the replication cycle), and quantitative PCR (qPCR) to detect viral transcripts were used to evaluate …


Synthesis And Evaluation Of N6,5'-Bis-Ureido-5'-Amino-5'-Deoxyadenosine Derivatives: Novel Nucleosides With Antiproliferative And Protein Kinase Binding Activities, Marcelio Oliveira Nov 2009

Synthesis And Evaluation Of N6,5'-Bis-Ureido-5'-Amino-5'-Deoxyadenosine Derivatives: Novel Nucleosides With Antiproliferative And Protein Kinase Binding Activities, Marcelio Oliveira

Theses and Dissertations

A new series of N6,5'-bis-ureido-5'-amino-5'-deoxyadenosine derivatives was prepared and evaluated for anticancer activities using the NCI 60 panel of human cancers. Certain of the derivatives showed promising activities (low micromolar GI50's) against several of the representative cancers. These included cell lines from the following general cell types in the NCI 60: Leukemia, Breast, Central Nervous System, Non-Small Cell Lung, Ovarian, Prostate, Renal, and Colon cancers. Select compounds were also screened for their affinities for protein kinases. The synthesis of the compounds was straightforward and involved N6 acylation with arylisocyanates, preceded by activation and nucleophilic substitution of the 5'-position to give …


Predictive Modeling Of Sulfur Flower Buckwheat (Erigonum Umbellatum Torrey) Using Non-Parametric Multiplicative Regression Analysis, David B. Davis Nov 2009

Predictive Modeling Of Sulfur Flower Buckwheat (Erigonum Umbellatum Torrey) Using Non-Parametric Multiplicative Regression Analysis, David B. Davis

Theses and Dissertations

Impacts of humans on ecosystems in western United States have necessitated ecological restoration, which includes the development of native seed that can be used for revegetation efforts. Development of such seed sources are costly and time consuming. This study describes the use of non-parametric multiplicative regression analysis (NPMR) to develop a predictive model for occurrence of sulfur-flower buckwheat (Eriogonum umbellatum Torrey) population seed collection. This perennial forb species is of interest for seed source development in the western United States. Presence and absence data for E. umbellatum was taken from the Utah Division of Wildlife Resources Big Game Range …


Part 1: Screening Of Thirty-One Medicinal Plant Species Against Herpes Simplex Virus, Acetone And Methanol Extracts From The Root Tissue Of Kalanchoe Pinnata Interferes With Hsv Types 1 And 2 Dna Replication And Early And Late Gene Expression Preventing The Spread Of Hsv In Vitro. Part 2: Professional Development Curriculum: Integrating Molecular Biology And Microbiology Into The Existing Secondary Biology Curricula, Mary Ruth Greer Nov 2009

Part 1: Screening Of Thirty-One Medicinal Plant Species Against Herpes Simplex Virus, Acetone And Methanol Extracts From The Root Tissue Of Kalanchoe Pinnata Interferes With Hsv Types 1 And 2 Dna Replication And Early And Late Gene Expression Preventing The Spread Of Hsv In Vitro. Part 2: Professional Development Curriculum: Integrating Molecular Biology And Microbiology Into The Existing Secondary Biology Curricula, Mary Ruth Greer

Theses and Dissertations

PART 1: Thirty-one medicinal plant species from Hawaii, Morocco, and the Sonoran Desert, USA have been shown in past studies to be highly inhibitory to pathogenic bacteria, fungi, and certain cancer cell lines. However, none were tested for antiviral activity. Acetone and methanol extracts from these species were bio-assayed for antiviral activity against herpes simplex virus types 1 and 2 (HSV 1 and HSV 2) and for cytotoxicity to the Vero C1008 cell line. Extracts from these species were tested in vitro for antiviral activity using an immunoperoxidase mini-plaque reduction assay to detect viral structural protein synthesis. Sulforhodamine B and …


Intraspecific Phylogeography Of Cycladenia Humilis (Apocynaceae), Mariana P. Last Nov 2009

Intraspecific Phylogeography Of Cycladenia Humilis (Apocynaceae), Mariana P. Last

Theses and Dissertations

Cycladenia humilis (Apocynaceae) is a rare perennial herb native to western North America and has a fragmented distribution in California, Utah, and Arizona. Populations in Utah and Arizona are federally listed as threatened, while there is no conservation status applied to California populations. Using genetic (three chloroplast and two nuclear DNA loci) and morphological characters, intraspecific variation between populations of C. humilis and current taxonomic conventions were assessed. Nested Clade Phylogeographic Analysis and Bayesian phylogenies were used to assess patterns within C. humilis and supported three main population groupings: a northern California, southern California, and Colorado Plateau group. The northern …


Systematics And Biogeography Of The Didymopanax Group Of Schefflera (Araliaceae), Pedro Fiaschi Oct 2009

Systematics And Biogeography Of The Didymopanax Group Of Schefflera (Araliaceae), Pedro Fiaschi

Theses and Dissertations

Schefflera is the largest genus in the angiosperm family Araliaceae, with about 900 species, of which c. 300 belong to five subgeneric groups in the Neotropical region. Previous phylogenetic studies of Schefflera have been limited to a small number of species from this region, and very little is know about phylogenetic relationships in the Brazilian-centered Didymopanax group of this genus. Therefore, to gain a better understanding of the diversity and evolution of the Didymopanax group of Schefflera, I investigated the systematics of these plants in the broader context of the entire Neotropical clade. The main goals were (1) to investigate …


Sphingolipid-Induced Activation Of The Volume-Sensitive Cl− Current Is Mediated By Mitochondrial Reactive Oxygen Species, Frank Raucci Oct 2009

Sphingolipid-Induced Activation Of The Volume-Sensitive Cl− Current Is Mediated By Mitochondrial Reactive Oxygen Species, Frank Raucci

Theses and Dissertations

Swelling-activated Cl− current (ICl,swell) is an outwardly-rectifying current that plays an important role in cardiac electrical activity, cellular volume regulation, apoptosis, and acts as a potential effector of mechanoelectrical feedback. Persistent activation of ICl,swell has been observed in a number of models of cardiovascular disease. Previously we showed that angiotensin II (Ang II), endothelin-1 (ET-1), endothelial growth factor receptor (EGFR), and reactive oxygen species (ROS) produced by NADPH oxidase (NOX) and mitochondria are involved in the activation of ICl,swell by both osmotic swelling and Beta1 integrin stretch. Sphingolipid metabolism is modulated in several cardiopathologies and because sphingolipids are bioactive lipids …


The Regulation Of Alternative Splicing By Oncogenic Signaling Pathways., Jacqueline Shultz Sep 2009

The Regulation Of Alternative Splicing By Oncogenic Signaling Pathways., Jacqueline Shultz

Theses and Dissertations

In the presented study, we demonstrate that the alternative splicing of caspase 9 was dysregulated in a large percentage of NSCLC tumors and cell lines. These findings led to the hypothesis that survival pathways activated by oncogenic mutation regulated this mechanism. Indeed, the oncogenic PI3-Kinase/Akt pathway was demonstrated to regulate the alternative splicing of caspase 9. Further mechanistic studies demonstrate that multiple Akt isoforms can regulate the alternative splicing of caspase 9 in NSCLC. Akt was additionally shown to mediate the exclusion of the exon 3,4,5,6 cassette of caspase 9 via the phospho-state of the RNA trans-factor, SRp30a. Mutagenesis studies …


Pore Size Characterization Of Monolithic Capillary Columns Using Capillary Flow Porometry, Yan Fang Sep 2009

Pore Size Characterization Of Monolithic Capillary Columns Using Capillary Flow Porometry, Yan Fang

Theses and Dissertations

A simple capillary flow porometer (CFP) was assembled for pore structure characterization of monolithic capillary liquid chromatography columns based on ASTM standard F316-86. Determination of differential pressures and flow rates through dry and wet samples provided the necessary information to determine the through-pore throat diameter, bubble point pore diameter, mean flow pore diameter, and pore distribution. Unlike measurements in bulk using traditional techniques to provide indirect information about the pore properties of monolithic columns, monoliths can be characterized in their original chromatographic forms with this system. The performance of the new CFP was first evaluated by characterizing the pore size …


Gas Phase Chiral Recognition, Characterization Of Porous Polymer Monolith Nanospray Ionization, And The Negative Mode Crafti Method Using Fourier Transform Ion Cyclotron Resonance Mass Spectrometry, Nannan Fang Sep 2009

Gas Phase Chiral Recognition, Characterization Of Porous Polymer Monolith Nanospray Ionization, And The Negative Mode Crafti Method Using Fourier Transform Ion Cyclotron Resonance Mass Spectrometry, Nannan Fang

Theses and Dissertations

Our group has been studying chiral recognition in gas phase using mass spectrometry for more than 10 years. We are interested in gas phase studies of fundamental interactions because the gas phase avoids complications and masking effects that may arise upon solvation. Therefore, the results of gas phase experiments can be directly compared with those of high-level computational studies. In chapter 2, I studied the roles of hydrogen bonding and pi stacking in gas phase chiral recognition between aromatic crown molecules and aromatic amines. High affinity between host and guest doesn't necessarily result in better recognition. If the affinity is …


The Role Of Porphyromonas Gingivalis Lysine Specific Protease, Kgp In Hemin Transport And Pigment Accumulation, Anuj Phull Aug 2009

The Role Of Porphyromonas Gingivalis Lysine Specific Protease, Kgp In Hemin Transport And Pigment Accumulation, Anuj Phull

Theses and Dissertations

Porphyromonas gingivalis, a gram-negative anaerobic bacterium, is implicated as a major etiological agent in the initiation and progression of severe forms of periodontal disease. It has been reported that gingivitis and periodontal disease affect roughly 50.3% and 35% of the adult population, respectively. Therefore, approximately over 85% of the adult population may suffer from some form of gingival disease. Porphyromonas gingivalis, an established periodontopathogen, requires hemin for growth. Although multiple hemin uptake systems appear to be present in this organism, their specific role in hemin uptake and virulence remains unknown. Pigmentation is thought to result from the accumulation of iron …


Identification And Manipulation Of Resistance To Tomato Spotted Wilt Virus Derived From Solanum Peruvianum, Luis F. Gordillo Jr. Aug 2009

Identification And Manipulation Of Resistance To Tomato Spotted Wilt Virus Derived From Solanum Peruvianum, Luis F. Gordillo Jr.

Theses and Dissertations

The domesticated tomato Solanum lycopersicum (L.), formerly known as Lycopersicon esculentum is a genetically well-studied crop species with high-density linkage and molecular maps based on crosses done between cultivated tomato and its distant related wild species. Wild tomato species harbor a wealth of resistance to many pathogens that have been introgressed into domesticated tomato for genetic control of diseases and pests and for improvement of many agronomic traits. The wild tomato S. peruvianum (L.) is the source of the Sw-5 gene, characterized and mapped to chromosome 9 of the tomato genome and introgressed into elite tomato germplasm, providing resistance to …


Total Synthesis Of (-)-Acutumine, Fang Li Aug 2009

Total Synthesis Of (-)-Acutumine, Fang Li

Theses and Dissertations

Acutumine is a tetracyclic alkaloid isolated from the Asian vine Menispermum dauricum with selective T-cell cytotoxicity and antiamnestic properties. We have developed a total synthetic route to this congested alkaloid, during which we also found a novel, stereoselective radical-crossover reaction that combines an intramolecular radical conjugate addition with a subsequent enolate hydroxylation. Key features of this synthesis also include a reagent-controlled diastereoselective ketone allylation, an anionic oxy-Cope rearrangement to form a congested quaternary sterocenter, a pyridine-mediated selective ozonolysis, and a Lewis acid promoted Michael-type cyclization.


Ion Channel Modulation By Photocaged Dioctanoyl Pip2, Junghoon Ha Aug 2009

Ion Channel Modulation By Photocaged Dioctanoyl Pip2, Junghoon Ha

Theses and Dissertations

Phosphatidylinositol bisphosphate (PIP2) directly regulates electrophysiological activity in a diverse family of ion channels whether the effect is stimulatory or inhibitory. Much has been unveiled about the apparent affinity and modulatory function of PIP2 using a chemically modified dioctanoyl PIP2 (diC8), a membrane delimited cytosolic co-factor in inside-out macropatch experiments. Yet, the scarcity of molecular tools that permit fine external control in whole-cell systems has precluded future studies from probing the physiological role of PIP2 in cells in the presence of a fully intact cytoplasm. Here we introduce light as an external control for PIP2 through photocaging of diC8, and …


Development Of Biocompatible Polymer Monoliths For The Analysis Of Proteins And Peptides, Yun Li Aug 2009

Development Of Biocompatible Polymer Monoliths For The Analysis Of Proteins And Peptides, Yun Li

Theses and Dissertations

Biocompatibility is an important issue for the development of chromatographic stationary phases for the analysis of biomolecules (including proteins and peptides). A biocompatible stationary phase material is a material that resists nonspecific adsorption of biomolecules and does not interact with them in a way that would alter or destroy their structures or biochemical functions. The monolithic column format is a good alternative to typical spherical particle packed columns for capillary liquid chromatography of biomacromolecules. Several novel anion-exchange polymer monoliths for the analysis of proteins were synthesized for improved biocompatibility. Two novel polymeric monoliths were prepared in a single step by …