Digital Commons Network^™

The Influence Of Hydrogeomorphology, Soil Redox Conditions, And Salinity On The Spatial Zoning Of Saltgrass, Salt Rush, And Cattails In Scotts Creek Marsh, Swanton Pacific Ranch, Ca, Mark D. Gormley

Master's Theses

Scotts Creek Marsh (SCM) is a small coastal wetland ecosystem in Davenport, CA. The vegetation of SCM is dominated by three halophytic zones comprised of saltgrass, salt rush, cattails. The objectives of the study were (i) to investigate the variables that influence the zoning of the three dominant halophyte communities in SCM and (ii) to the test the effectiveness of Indicator of Reduction in Soil (IRIS) tubes to indicate the reduction of S. The study examined the following parameters from April 6 to July 21, 2013: (i) the HGM of Scotts Creek Marsh, (ii) soil oxidation and reduction (redox) conditions, …

Hcmv Promotes Breast Cancer Metastasis: Impacts Of Cmvil-10 In The Tumor Microenvironment, Robin Bishop

Master's Theses

Human cytomegalovirus (HCMV) is a highly species-specific, common human pathogen. While a large majority of people are infected with HCMV worldwide, infection is typically asymptomatic in immune competent individuals. To enhance virus persistence and avoid immune detection by the host, HCMV exploits the strategy of encoding homologs of cellular cytokines. One factor produced by HCMV-infected cells is the viral cytokine cmvIL-10, which acts through the cellular IL-10 receptor to induce downstream cell signaling. In instances where HCMV-infected cells infiltrate the tumor microenvironment, the presence of cmvIL-10 in may initiate events that promote a more invasive tumor phenotype. Cancer cells that …

Characterizing The Persistence Of Sewage Enterococci In Mississippi Coastal Waters, Kimberly Anne-Marie Lewis

Master's Theses

Enterococci are microbiological indicators of marine recreation water quality.
Their reliability as fecal indicators is questioned as they are shown to persist in the environment. Multiple laboratory studies on their persistence have been done but few under natural environmental conditions. The purpose of this study was to investigate how long sewage enterococci and enterococcal DNA persist in beach water and to determine whether there is a difference in the genetic diversity and hardiness of sewage vs. environmental isolates. To study persistence, sewage was diluted with beach water, placed in microcosms, and deployed at a beach site in Longbeach and Pass …

Molecular Detection Of Tick-Borne Pathogens Associated With Ixodid Tick Species Infesting Migratory Songbirds And Ruminants, Nabanita Mukherjee

Master's Theses

Ticks are hematophagous arthropods and capable of inoculating various infectious agents to their vertebrate hosts. Ticks attached to birds and ruminants are capable of carrying tick-transmitted microorganisms. In our study, the prevalence of tick-borne pathogens was examined in ticks infesting migratory songbirds and Pakistani ruminants. During spring migration seasons, ticks were removed from northward-migrating songbirds in Louisiana and identified as Amblyomma Jongirostre, Amblyomma nodosum, Amb/yomma ca/caratum, Amblyomma maculatum, and Haemaphysalis species, all are considered as Neotropical ticks. Ticks removed from ruminants were identified as Hya/omma anatolicum, Hyalomma dromedarii, Rhipicephalus microplus, and Rhipicephalus sanguineus. A total of 112 and 72 bacterial …

Escherichia Coli Strain Diversity In Humans: Effects Of Sampling Effort And Methodology, Emily R. Neal

Master's Theses

Studies investigating Escherichia coli strain diversity and demographics in human hosts are frequently inconsistent regarding sampling effort and methodology while current strain typing methods are often expensive or laborious. To rectify these inconsistencies, sampling effort was investigated by comparing the diversity of 15-isolate collections to 100-isolate collections from 3 human subjects. Temporal variation in E. coli strain diversity was also studied by collecting 15 isolates once every 6 months. Additionally, strain identification and diversity collected by different sampling methods (fecal swabs vs. anal swabs collected at different times around defecation) were compared to identify any inherent biases in sampling method. …

Assessing The Effects Of Titanium Dioxide Nanoparticles On Microbial Communities In Stream Sediment Using Artificial Streams And High Throughput Screening, Alexandra Ozaki

Master's Theses

Nano-titanium dioxide (nano-TiO2) is an engineered nanomaterial used in a wide array of commercial products. The production and use of large amounts of nano-TiO2 is resulting in the unintended release to the environment. Nano-TiO2 is known to be cytotoxic due primarily to its ability to generate reactive oxygen species, and negative impacts on a variety of organisms have been demonstrated, but the effects of nano-TiO2 on complex microbial communities under ecologically relevant conditions have rarely been tested. We conducted a controlled manipulative experiment using recirculating model streams dosed with a one-time amendment of 1mg L-1 nano-TiO2 (specifically P25). Within one …

Antibodies To Inhibit Clostridium Difficile Adhesion To Human Gut Epithelial Cell Line, Wonbeom Paik

Master's Theses

Clostridium difficile infection (CDI) is a major hospital-acquired diarrhea that can cause life-threatening complications such as pseudomembranous colitis. CDI is caused by colonization of host with C. difficile, a Gram positive, anaerobic bacterium known to produce toxins that cause disease. Normally, the gut microbiota protects the host from CDI, but disruption of the microbial composition through antibiotic treatment can leave one vulnerable for CDI. To date, no vaccines for preventing CDI are available.

In this study, the potential of antibodies directed against specific surface molecules of C. difficile to block bacterial adherence to host gut epithelial cells was studied, in …

Exosomes: Antiviral Agents In The Human Lung, Jennifer Alexandra Novak

Master's Theses

Hundreds of interferon effectors comprise the immediate host response to virus infection. One family of interferon stimulated genes is the IFITM (Interferon-Induced Transmembrane) proteins. IFITM3, in particular, has been shown to block virus cell entry of Influenza A Virus, SARS Coronavirus, and West Nile Virus, among others. IFITM3 has also been identified as an essential factor for host protection against Influenza A Virus in mice and humans. However, the mechanism by which IFITM3 functions remains unclear.

IFITM3 may function both intracellularly and extracellularly to block virus infection in the human lung. The extracellular milieu contains microscopic vesicles termed exosomes which …

Identifying And Characterizing The Degradative Pathway Of The Retroviral Restriction Factor Rhtrim5Α, Rachel Nelson

Master's Theses

Human immunodeficiency virus 1 (HIV-1) is a lentivirus that progresses to acquired immunodeficiency syndrome (AIDS). The protein TRIM5alpha from rhesus macaques (rhTRIM5alpha) restricts HIV-1 by blocking infection after entry of the virion into cells. Treatment of rhTRIM5alpha expressing cells with inhibitors to a cellular degradation pathway, the proteasome, partially relieves restriction but does not inhibit rhTRIM5alpha protein turnover. The role of a second degradation pathway, the autophagy-lysosomal pathway, in TRIM5alpha mediated restriction has not been explored.

In the present study, we demonstrate that rhTRIM5alpha is degraded by chaperone mediated autophagy (CMA). Inhibition of CMA alters rhTRIM5alpha localization and turnover, while …