Life Sciences Commons^™

Native Plant Establishment Success Influenced By Centaurea Stoebe Control Method, Laurelin Marie Martin

Masters Theses

Invasive species frequently hinder restoration efforts. While the effectiveness of differing control methods are often reported, the impacts these methods have on the establishment of a native plant community are often unknown. To determine methods that effectively reduce spotted knapweed (Centaurea stoebe) while enhancing native species establishment, we tested 12 treatment combinations consisting of an initial site preparation (mowing, mowing + clopyralid, or mowing + glyphosate), with combinations of annual adult knapweed hand pulling, and/or burning. We established 48 plots and applied site preparation treatments during summer 2008, seeded 23 native forbs and grasses during spring 2009, pulled …

Climate Change And Metapopulation Implications For Species Re/Introductions: A Spatial Analysis Of Suitable Habitat For The American Marten (Martes Americana) In Northern Michigan, Joshua Michael Green

Masters Theses

The American marten (Martes americana), which was extirpated from Michigan by 1939 due to logging and trapping, has cultural significance as a clan animal to Great Lakes Native American Tribes and ecological significance as a forest health indicator. Sleeping Bear Dunes National Lakeshore (SBD) is considering reintroduction, but several factors must first be considered in assessing the habitat suitability. The goals of this study were to 1) enhance an existing habitat suitability model by including additional relevant variables, 2) conduct a spatial analysis of the habitat within the study area using a metapopulation perspective and 3) incorporate climate …

Small Scale Population Structure Of Pityopsis Ruthii And P. Graminifolia Var. Latifolia, Sarah Lynn Boggess

Masters Theses

Pityopsis graminifolia var. latifolia (Michx.) Small var. latifolia (Fern.) or narrowleaf silkgrass is an herbaceous perennial native to the southeastern United States and northern Central America. Pityopsis ruthii (Small) Small is an endangered plant endemic to the Hiwassee and Ocoee Rivers in Polk County, Tennessee. Little is known about the genetic diversity and population structure of both Pityopsis species as well as the phylogenic relationships between the species. In this study, 16 microsatellite loci were used to assess genetic diversity and population structure of 261 individuals of P. ruthii (n=167) and P. graminifolia var. latifolia (n=76). Pityopsis ruthii is …

Population Demographics And Genetic Structure Of Black Bears In Coastal Louisiana, Jesse Charles Troxler

Masters Theses

The range and abundance of the Louisiana black bear (Ursus americanus luteolus) were greatly diminished during the 20th century. This subspecies was reduced to 3 small, isolated subpopulations in Louisiana as bottomland hardwood habitat was converted to agriculture. These bears were listed as threatened by the U.S. Fish and Wildlife Service in 1992 and a recovery plan was published in 1995. Recovery requires estimates of population parameters to evaluate current population status and future viability. I conducted a mark-recapture study from 2010 to 2012 to estimate demographic parameters of the coastal population of Louisiana black bears. Because inbreeding …

Studies On Solo Working Mechanism In The Meiosis Of Drosophila Melanogaster, Qian Ma

Masters Theses

In eukaryotes, sister chromatids are closely aligned due to cohesion, a process essential for chromosome pairing and segregation during both mitosis and meiosis. A conserved cohesin complex in a ring structure is composed of four subunits, including each of these four members or their homologs, SMC1, SMC3, SCC1/RAD21/REC8, and SCC3/SA. Up to now, no REC8 homolog has been identified in the meiosis of Drosophila. SOLO is a meiotic protein required for accurate chromosome segregation, centromere cohesion, and cohesin complex localization in Drosophila meiosis. In addition, SOLO is required for synapsis and recombination in Drosophila female meiosis.

In this study, …

Trends In Borrelia Spp. Prevalence In Ixodes Spp. Ticks From The Southeastern Coastal United States, Lauren Paul Maestas

Masters Theses

The Lyme borreliosis (LB) cycle, involving Ixodes scapularis and Borrelia burgdorferi sensu stricto (Bbss), is well documented in the northeastern US, where LB is becoming increasingly prevalent. In coastal North Carolina, I. affinis has been shown to have a higher incidence of Bbss than I. scapularis. My objectives were, to assess changes in prevalence of Bbss in Ixodes spp. along a transect from Virginia to Florida, and to assess the value of dogs and mesomammals as sentinels for spread of Borrelia burgdorferi sensu lato.

Ixodes spp. were collected at sites from 37.4^o N to 30.0^{o …}

Prevalence And Transmission Potential Of Borrelia Burgdorferi In Three Species Of Wildcaught Plestiodon Spp. Skinks Of The Southeastern United States, Teresa Dianne Moody

Masters Theses

In the southeastern United States, blue-tailed skinks (Plestiodon spp.) are important hosts for Ixodes scapularis ticks, the principal vector of Lyme disease (LD) in this region. Skinks and other southeastern lizards are not thought to be reservoir competent for Borrelia burgdorferi sensu stricto (Bbss), the etiological agent of LD in the United States. . Lizard-feeding by southeastern I. scapularis may tend to suppress sylvatic cycles of B. burgdorferi, and thus may be an important reason why LD case rates in the Southeast are much lower than in the Northeast and upper Midwest. Nevertheless, some skinks …

Use Of A Specific Alpha7 Nicotinic Acetylcholine Receptor Agonist Can Prevent Loss Of Retinal Ganglion Cells In An In Vivo Rat Glaucoma Model, David Mata

Masters Theses

Acetylcholine (ACh) has been shown to have a neuroprotective effect against glutamate-induced excitotoxicity in cultured retinal ganglion cells (RGCs) through activation of α7 nicotinic ACh receptors (nAChRs). In this study, the neuroprotective effects of the α7 nAChR agonist, PNU-282987, were investigated using an in vivo model of glaucoma in adult Long Evans rats. Hypertonic saline injections were used to induce a glaucoma model. After one month, retinas were removed, flat mounted, fixed and labeled with an antibody against Thy 1.1 to label RGCs and fluorescently tagged for visualization. Eye drop application of PNU-282987 resulted in neuroprotection against RGC loss in …

Microarray Analysis Of Mrna Translation State In Arabidopsis Thaliana, Bayu Sisay Tiruneh

Masters Theses

The synthesis of proteins – translation – is one of the cellular processes that consume a great deal of energy. Genome-wide assays performed in Arabidopsis and other organisms have revealed that the translation status of mRNAs responds dramatically to different stresses and environmental and growth signals. Similar assays have revealed how translation of specific mRNAs is perturbed by genetic mutations in eukaryotic translation initiation factors (eIFs). I performed genome-wide analyses of translation state in A. thaliana seedlings with mutant genotypes for a specific eIF (subunit h of eIF3) and the large ribosomal protein, L24 (RPL24B). Using data from prior microarray …

Isolation Of A Dosage Dependent Suppressor Using Saccharomyces Cerevisiae As A Model System, Rachel Chimner

Masters Theses

Human pathogenic Yersinia use a type three secretion system to deliver various effector proteins into host cells. Once these effector proteins are within the cell, they elicit a cascade of events that disrupt the normal immune response. One of these effectors, YopT, is known to disrupt actin distribution but it is currently unknown what YopT targets within the host cell. To investigate the cellular targets of the YopT effector, we use a yeast model system and a dosage-dependent suppression screen. The dosage-dependent suppression screen isolated three plasmids able to suppress YopT induced lethality within yeast. One of them, 2T9, was …

Production Of 1,3-Propanediol From Glycerol Under Haloalkaline Conditions By Halanaerobium Hydrogeniformans, Daniel William Roush

Masters Theses

"With increased demands around the world to make modern lifestyles more environmentally friendly, the chemical commodity market has rapidly shifted. Through new technologies in chemical production, certain high value products have oversaturated the market and have become high-volume, low value waste products. The expansion of biodiesel production offers a prime example; high volumes of glycerol byproduct from this process have shifted glycerol from a high priced commodity to a common waste product. A number of microorganisms are known to synthesize the polymeric precursor 1,3-propanediol from glycerol; however, crude glycerol from biodiesel production creates a harsh environment for most microbes, and …

Wetting And Drying Cycles And The Fungal Communities On Leaf Litter In Streams, Kele Qwinn Thrailkill

Masters Theses

"Leaf litter is a major source of energy for streams in deciduous forests. Fungi play a critical role by converting the leaves into nutritional material for the rest of the food web. The breakdown of leaf litter and associated biota, including invertebrates and fungi, have been proposed as measures of stream health in systems affected by anthropogenic activity. Rates of leaf breakdown can be depressed in streams affected by acidity, metals, organic contaminants, and other stressors. Climate change may lead to alterations in stream hydrology such that streams experience more frequent floods as well as drying episodes. Fungal communities can …

Broad-Spectrum Antibacterial Properties Of Metal-Ion Doped Borate Bioactive Glasses For Clinical Applications, Megan Ottomeyer

Masters Theses

"Bioactive glasses with antimicrobial properties can be implemented as coatings on medical devices and implants, as well as a treatment for tissue repair and prevention of common hospital-acquired infections such as MRSA A borate-containing glass, B3, is also undergoing clinical trials to assess wound-healing properties. The sensitivities of various bacteria to B3, B3-Ag, B3-Ga, and B3-I bioactive glasses were tested. In addition, the mechanism of action for the glasses was studied by spectroscopic enzyme kinetics experiments, Live-Dead staining fluorescence microscopy, and luminescence assays using two gene fusion strains of Escherichia coli.

It was found that gram-positive bacteria were more …