Life Sciences Commons^™

D-Glucose-6-Phosphate Stimulates Sags-Dependent Biofilm Formation In Pseudomonas Aeruginosa, Madison Gowett

Undergraduate Honors Theses

The SagS protein is a two-component regulatory system in Pseudomonas aeruginosa that works to independently regulate biofilm formation and antibiotic tolerance. Previous work found that these two pathways are controlled by two distinct sets of amino acids within the sensory domain of SagS that are thought to be potential ligand binding sites. Despite the extensive research done on the structure and function of SagS, the signals that activate this protein have yet to be identified. In this study we aimed to identify ligands that stimulate SagS-dependent biofilm formation. To do this we utilized ΔsagS mutants, one harboring wild-type sagS under …

Immune System Detection Of Pseudomonas Aeruginosa Persister Cells, Grace Elizabeth Himmler

Undergraduate Honors Theses

Persister cells are a subpopulation of bacterial cells known to be tolerant to antimicrobials. Their reduced susceptibility to antimicrobials allows them to be the source of recurrence of many chronic bacterial infections. As a result, it is vital to understand the mechanisms that allow these cells to be able to evade further treatment. Furthermore, it is currently unknown whether the persister cells are detected and killed by the host immune response. In this work I explored the host-pathogen interactions between Pseudomonas aeruginosa cells, both persister and regular, and human macrophages. I hypothesized that persister cells would be engulfed at a …

Characterization Of Urban Wetland Vegetation And Management Practices, Megan Anne Larson

Graduate Dissertations and Theses

Urban wetlands are important ecosystems that moderate flooding risks and improve water quality. Vegetation is a key component of urban wetlands; plants promote sedimentation, play critical roles in biogeochemical cycling, and provide food and habitats for other organisms. My research focuses on the standing vegetation and seed banks of urban wetland plant communities. Urban wetlands in south-central New York had a higher percent cover of invasive species in the standing vegetation and significantly lower species richness; however, native species were also common in urban flora. These sites had a high percentage of obligate wetland species, and most closely resembled emergent …

Functional Variation In The Mitochondrial Genome Of The Yeast Saccharomyces Cerevisiae, John F. Wolters

Graduate Dissertations and Theses

Mitochondrial haplotypes contribute to functional diversity in natural populations. Uniparental inheritance makes it difficult to characterize the genetic architecture of mitochondrially driven phenotypes. In this work I explored the natural diversity of mitochondrial genomes in the yeast Saccharomyces cerevisiae. Few complete mitochondrial genomes were available for S. cerevisiae owing to challenges in high-throughput sequencing. I developed sequencing strategies using new technologies to generate complete high quality yeast mitochondrial genomes. Comparisons of 100 complete yeast mitochondrial genomes demonstrated extensive variation between populations in coding sequences and variable introns.

I demonstrated that these mitochondrial variants directly caused growth differences in strains with …

Interaction Graphs Derived From Activation Functions And Their Application To Gene Regulation, Simon Joyce

Graduate Dissertations and Theses

Interaction graphs are graphic representations of complex networks of mutually interacting components. Their main application is in the field of gene regulatory networks, where they are used to visualize how the expression levels of genes activate or inhibit the expression levels of other genes.

First we develop a natural transformation of activation functions and their derived interaction graphs, called conjugation, that is related to a natural transformation of signed digraphs called switching isomorphism. This is a useful tool for the analysis of interaction graphs used throughout the rest of the dissertation.

We then discuss the question of what restrictions, if …

Nitrogen Biogeochemistry In Binghamton, Ny, A Medium-Sized Urban Ecosystem, Stephanie Craig

Graduate Dissertations and Theses

Humans have altered nitrogen (N) cycling on a global scale, and elevated nitrogen levels are characteristic of urban ecosystems. The major reasons that N is higher in cities include imports of food, fuel and fertilizer. High N export from both point- and nonpoint-sources is common in large cities. While N cycling has been studied in large urban areas, less is known about its cycling in medium-sized cities, such as Binghamton, N.Y. We found that point-source N exported from the Binghamton-Johnson City Wastewater Treatment Plant (B-JC WWTP) was greater than nonpoint-source N exported from eight urban streams to the Susquehanna River, …