Life Sciences Commons^™

Investigating Nectar Rhythms In Squash (Cucurbita Pepo): Effects On Honey Bee (Apis Mellifera) Foraging Behavior., Samuel David Boyd

Electronic Theses and Dissertations

Experiments were performed to investigate the influence of water availability on the diel patterns of nectar secretion (volume, concentration, sugar production) in male squash flowers as well as to discover what physical component of nectar honey bees use to trigger their time-memory. Squash plants were grown in the greenhouse and in the field under both constant and variable watering regimes. Throughout anthesis, nectar volume and sugar concentration were recorded. In the field, the temporal distribution of arrivals to squash was observed with and without blossoms present. In the greenhouse and in the field, squash flowers exhibit a consistent diel pattern …

Dopamine D2 Receptor Priming Enhances Dopaminergic Response To Amphetamine In The Nucleus Accumbens: Role Of The D1 And D2 Receptors., Kimberly Norris Huggins

Electronic Theses and Dissertations

In past work, we have shown neonatal quinpirole (dopamine D₂/D₃ agonist) treatment produces a significant increase in dopamine D₂ receptor sensitivity, a phenomenon known as D₂ receptor priming. Dopamine D₂ receptor priming is common in psychosis. Male and female rats were administered quinpirole (1mg/kg) or saline from postnatal days 1-11 and raised to adulthood (P60). As adults, rats were administered d-amphetamine sulfate (1mg/kg) or saline every other day for 14 days. Approximately 10 min before each amphetamine or saline injection, animals were administered the D1 antagonist SCH 23390 (0.1 mg/kg), the D2 antagonist eticlopride …

Genetic Structure Of Yonahlossee Salamander Populations., Joshua Andrew Rudd

Electronic Theses and Dissertations

Plethodon yonahlossee is the largest eastern Plethodontid salamander. It has been classified as a species of greatest conservation need by the Tennessee Wildlife Resources Agency (TWRA). Found only in mountainous areas along the borders of Tennessee, North Carolina, and Virginia, populations of the yonahlossee are considered to be rare and local throughout their range. Genetic differentiation among populations of any species is usually attributable to long-standing, extrinsic barriers to gene flow. Because of their disjunct population structure and some observed morphological variation, genetic differentiation among yonahlossee populations is expected. A genetic structure study of yonahlossee was conducted to identify any …

Reproductive Success Of American Kestrels (Falco Sparverius) Nesting In Boxes Along An Interstate In Northeastern Tennessee., Jennifer Robertson Powers

Electronic Theses and Dissertations

Nest box programs provide supplemental nest sites for American Kestrels, Falco sparverius. When the availability of nest sites is a limiting factor, the addition of nest boxes can increase local breeding populations. These programs also facilitate the collection of data on breeding kestrels.

This study focuses on an American Kestrel (Falco sparverius) nest box trail along Interstate 26 in northeastern Tennessee during the breeding seasons of 1998, 1999, 2000, 2003, 2004, 2006, and 2009. Productivity measures and reproductive success of nesting birds are provided and compared to other programs. The data are analyzed across years and by …

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

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 …

The Effect Of Heavy Handrail Support On Blood Pressure Response In Normotensive Adults During Treadmill Walking, Kevin Brian Reid

Masters Theses, 2010-2019

Physiological and hemodynamic responses to handrail support during treadmill walking have shown a blunted response when compared to non-handrail support. The effects of treadmill walking, with the inclusion of “heavy” upper limb and torso activation through handrail support is yet unreported. The effect of “heavy” support through side handrail support (SHRS) and front console support (C) versus no handrail support (NHRS) treadmill walking was studied utilizing both slow/low (2.5 mph & 3% elevation) and high/fast (3.5 mph & 11% elevation) energy expenditure levels. Seventeen healthy adults (43.89 +/- 6.07 years) completed trials at both energy expenditure levels incorporating all three …

The Effects Of Different Doses Of Caffeine On A 40 Kilometer Cycling Time Trial: A Dose-Response Study, Michael Martin

Masters Theses, 2010-2019

Abstract The purpose of this study was to determine the ergogenic response to different caffeine doses of 3 mg/kg and 6 mg/kg consumed by trained cyclists 1 hour prior to a 40 kilometer cycling time trial. It was hypothesized that there would not be a difference in time trial performance following caffeine supplementation of a 3 mg/kg dose as compared to a 6 mg/kg dose. Sixteen male subjects, age 18-40, were initially assessed via a VO2max test on an indoor cycle trainer. Subjects then reported to the lab on 4 separate occasions following a 10 hour fast and a 24 …

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

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

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

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

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

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 …

Analyzing Spatial Patterns In Reefscape Ecology Via Remote Sensing, Benthic Habitat Mapping, And Morphometrics, Shanna K. Dunn

HCNSO Student Theses and Dissertations

A growing number of scientists are investigating applications of landscape ecology principles to marine studies, yet few coral reef scientists have examined spatial patterns across entire reefscapes with a holistic ecosystem-based view. This study was an effort to better understand reefscape ecology by quantitatively assessing spatial structures and habitat arrangements using remote sensing and geographic information systems (GIS).

Quantifying recurring patterns in reef systems has implications for improving the efficiency of mapping efforts and lowering costs associated with collecting field data and acquiring satellite imagery. If a representative example of a reef is mapped with high accuracy, the data derived …

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

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

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 …

Identification Of A Conserved Cluster In The Rh Domain Of Grk Critical For Activation By Gpcrs, Faiza Baameur

Dissertations & Theses (Open Access)

One of the most critical aspects of G Protein Coupled Receptors (GPCRs) regulation is their rapid and acute desensitization following agonist stimulation. Phosphorylation of these receptors by GPCR kinases (GRK) is a major mechanism of desensitization. Considerable evidence from studies of rhodopsin kinase and GRK2 suggests there is an allosteric docking site for the receptor distinct from the GRK catalytic site. While the agonist-activated GPCR appears crucial for GRK activation, the molecular details of this interaction remain unclear. Recent studies suggested an important role for the N- and C-termini and domains in the small lobe of the kinase domain in …

Biological Simulations And Biologically Inspired Adaptive Systems, Edgar Alfredo Duenez-Guzman

Doctoral Dissertations

Many of the most challenging problems in modern science lie at the interface of several fields. To study these problems, there is a pressing need for trans-disciplinary research incorporating computational and mathematical models. This dissertation presents a selection of new computational and mathematical techniques applied to biological simulations and problem solving: (i) The dynamics of alliance formation in primates are studied using a continuous time individual-based model. It is observed that increasing the cognitive abilities of individuals stabilizes alliances in a phase transition-like manner. Moreover, with strong cultural transmission an egalitarian regime is established in a few generations. (ii) A …

Morphological And Molecular Systematics Of Psychodidae (Diptera), Gregory Russel Curler

Doctoral Dissertations

A general overview of family Psychodidae is given. Genus Eurygarka Quate is revised to include three species. Genus Gondwanoscurus Jezek is revised to include seven species. The status of genus Stupkaiella Vaillant is revised. Eight new Nearctic species: Eurygarka cyphostylus sp. nov., E. nelderi sp. nov., Stupkaiella lasiostyla sp. nov., S. robinsoni sp. nov., S. capricorna sp. nov., Trichomyia rostrata sp. nov., Australopericoma delta sp. nov., and Threticus thelyceratus sp. nov., and two new Oriental species: Gondwanoscurus cruciferus sp. nov. and G. ornithostylus sp. nov. are described. Two Nearctic species: Eurygarka helicis (Dyar) and Stupkaiella bipunctata (Kincaid), and four Oriental …

Formation Of Multiple Dimer Interfaces In The Active And Inactive States Of A Model G Protein-Coupled Receptor, Hee Jung Kim

Doctoral Dissertations

G protein-coupled receptors (GPCRs) are a class of integral membrane receptor proteins that are characterized by seven-transmembrane (7TM) domains connected by intracellular and extracellular loops, an extracellular N-terminus, and an intracellular Cterminus. GPCRs recognize neurotransmitters, sensory molecules and chemotactic agents and are involved in the control of many aspects of metabolism. Since GPCRs play important roles in diverse processes such as pain perception, growth and blood pressure regulation, and viral pathogenesis, GPCRs became important target for therapeutic agents. The tridecapeptide α-factor pheromone (W₁H₂W₃L₄Q₅L₆K₇P₈G_{9 …}

Laboratory Models Of Infection And Transmission Of Mycobacterium Ulcerans; Causative Agent Of Buruli Ulcer Disease, Lydia Mosi

Doctoral Dissertations

Identification of the environmental reservoir of Mycobacterium ulcerans, the etiological agent of Buruli ulcer, within the aquatic ecosystem has been a salient research area within the last five years. Based on extensive environmental sampling and elegant laboratory models, associations have been made between the bacterial DNA and aquatic invertebrates, biofilms, plants, fish and detritus material captured on 0.2μm pore filters. These studies have suggested that M. ulcerans is widely distributed within many functional feeding groups and may be concentrated through different trophic links; however, the specific route of transmission to humans remains a mystery. In this study we have …

“Saccharomyces Cerevisiae G Protein Coupled Receptor, Ste2p Interactions With Its Ligand, Α-Factor And Cognate Gα Protein, Gpa1p, George Kwabena Essien Umanah

Doctoral Dissertations

The Saccharomyces cerevisiae alpha-factor receptor, Ste2p, belongs to the G proteincoupled receptors (GPCRs), a class of integral membrane proteins that are characterized by seven-transmembrane (TM) domains. Ste2p-alpha-factor pair has been used extensively as a paradigm for investigating GPCRs structure and function. Upon binding of alpha-factor to Ste2p, a signal is transduced via an associated guanine-nucleotide binding protein, Gpa1p, initiating a cascade of events similar to those for mammalian GPCRs signal transduction. GPCRs are essential in many physiological processes associated with human diseases. Many aspects of structure and function are highly conserved across GPCRs, irrespective of primary amino acid sequence. This …

Nontarget Host Utilization Of Thistle Species By Introduced Biological Control Agents And Spatial Prediction Of Non-Target Feeding Habitats, Gregory J. Wiggins

Doctoral Dissertations

Rhinocyllus conicus Fröelich and Trichosirocalus horridus (Panzer) were introduced from Europe into North America as biological control agents of the exotic weed species Carduus nutans L. Concern exists over the feeding of these weevils on at least 25 species of native Cirsium thistles. Research was conducted to 1) estimate phenological synchrony of the eight thistle species in Tennessee with R. conicus and T. horridus, 2) investigate naturally-occurring populations of the five native Cirsium thistle species for non-target activity by R. conicus and T. horridus, 3) quantify the impacts to plants of each thistle species to feeding of R. …

Organic Carbon Content In Surface And Subsurface Soil On A Toposequence On The Peterson Ranch In Poly Canyon, San Luis Obispo, Renee Michelle Nall

Earth and Soil Sciences

Soil organic carbon (SOC) is directly related to soil organic matter (SOM), and is important in the functionality and stability of terrestrial ecosystems. Soil organic carbon is also an important pool for C storage and small changes of SOC may cause significant gains and losses in the large scale carbon cycle. The mechanisms by which SOC is transported and stored however are not widely studied. This study was conducted to determine if there is a relationship between toposequence and SOC in a small watershed on the Peterson Ranch, San Luis Obispo, CA. Nine soil pits were dug on various hillslope …

Relationship Between Tissue Carotenoid Concentrations In The Pacific Mole Crab, Emerita Analoga, And Parasitism By The Acanthocephalan, Profilicollis Altmani, Whitney Melroy

Biological Sciences

Acanthocephalan worms infect two hosts to reach full development. Some species have been demonstrated to change their intermediate host’s behavior or coloration to increase the likelihood they will reach the final host. The pacific mole crab, Emerita analoga, is commonly parasitized by Profilicollis altmani along the Pacific coast of North and South America, but the impact of parasitism on the crab intermediate host is unclear. We investigated whether P. altmani alters the concentration of dietary carotenoids present in E. analoga tissues and if the parasite may also acquire pigments normally allocated to the host. Fifty eight gravid female crabs were …

Attempted Cloning Of A Wnt Gene From Botrylloides Violaceus, Manasa Chandra, James Tumulak

Biological Sciences

Botrylloides violaceus is a colonial ascidian with the ability to undergo sexual and asexual reproduction as well as regeneration. The canonical pathway starts with the extracellular protein Wnt and ends with β-catenin, a transcription factor, which also functions in cell adhesion. The Wnt signaling pathway is involved in embryogenesis and regeneration in a variety of other species. In our studies we attempt to isolate and sequence both a Wnt gene and from Botrylloides via degenerate primer design and PCR. Using bioinformatic methods we aligned sequences from other organisms, as the Botrylloides genome has not yet been sequenced. Using mouse, Ciona, …

Overexpression And Partial Purification Of Serine Hydroxymethyltransferase, Kimberly Rose Stevens

Chemistry and Biochemistry

No abstract provided.

Dairy Cow Grouping, Allison Mcmillan

Dairy Science

No abstract provided.