Life Sciences Commons^™

Stress Response Mechanisms Of Listeria Monocytogenes, Oindrila Paul

Dissertations

Listeria monocytogenes is a Gram-positive, facultative intracellular food-borne pathogen that causes the disease listeriosis. In order to establish an infection, L. monocytogenes must survive multiple stressors encountered within the gastrointestinal tract, including alterations in pH, bile, salt, and oxygen availability. This dissertation focused on understanding the stress response of L. monocytogenes to bile. Bile acts as a bactericidal agent by disrupting the membrane integrity and causing instability to macromolecules like DNA. Thus, a bacterium must be able to maintain its membrane architecture, composition and integrity.

Often times, bacteria will modulate their fatty acid composition in the membrane to cope with …

The Influence Of The Educational Environment On College Student Activity Behaviors, Helen M. Ziegler

Dissertations

Healthy Campus 2020, an initiative that provides a framework to support campuses in improving the health of their students, staff, and faculty, recognizes physical activity as one of the top eleven priorities for positively influencing health risk behaviors in college populations (American College Health Association, 2012). However, there is not much research to support the best way to influence physical activity behaviors and what types of programs and facilities can provide the greatest impact. The purpose of this study was to investigate which components or programs within the higher education environment have the greatest influence on college students’ intention to …

Divergent Rnai Biology In Mites And Development Of Pest Control Strategies, Md Mosharrof Hossain Mondal

Dissertations

RNA interference (RNAi) has transformed genetics research by revolutionizing reverse genetics in the nearly three decades that have passed since its discovery. ~19-31 nt small non-coding RNAs play a central role in RNAi biology, and are found in all multicellular eukaryotes. In these animals, three major classes of small RNAs have been described: microRNA (miRNA), small interfering RNA (siRNA), and Piwi interacting RNA (piRNA), which are produced in distinct yet occasionally overlapping pathways. While miRNAs are involved in tuning endogenous gene expression, piRNAs and siRNAs are essential for defense against viruses and transposons. Argonaute proteins are the main effectors in …

The Effect Of An Historical Geology Course On Students’ Attitudes Towards Science And Their Knowledge Of Deep Time As A Threshold To Their Knowledge Of Evolution, Allan Nolan

Dissertations

In America there exists a conflict between a small group of its citizens and the concept of evolution. Researchers have studied this conflict and the ways in which teachers might approach educational methodologies that not only address evolution in a sensitive manner, but also remain legally acceptable.

This research was designed to address teaching evolution in the context of deep time – the concept that time is vast and that geology and biology operate in a timescale of hundreds of millions to billions of years. In previous peer-reviewed works, it has been stated that deep time acts as a threshold …

Root Dynamics Of Crop Plants In A High Carbon Dioxide World: Effects Of Elevated Versus Ambient Carbon Dioxide Levels And No-Till Versus Conventional Agricultural Management, Charlotte Barker

Dissertations

Due to the continuing increases is atmospheric carbon dioxide levels and its potential effect on food sources, there is an interest in evaluating the effect of elevated CO₂ concentration versus ambient CO₂ concentration in agricultural crop plants although more studies have focused on the aboveground portions of plants rather than the roots. Additionally, the conservation agricultural method, no-till, has been widely suggested as a possible method of increasing soil organic carbon and increasing soil moisture in a hotter world.

This research involves two major agricultural plants, Sorghum bicolor (sorghum), and Glycine max (soybean) grown under four conditions including …

Personality In California Sea Lions (Zalophus Californianus) And Harbor Seals (Phoca Vitulina): Methodological Convergence And Species-Specific Emotional Repertoires, Amber De Vere

Dissertations

Despite the wide acceptance of animal personality as a valid area of study, research on marine mammal personality remains remarkably scarce. What literature does exist predominantly focuses on bottlenose dolphins (Frick, 2016; Highfill & Kuczaj, 2007; Kuczaj, Highfill & Byerly, 2012; Lilley, de Vere, Yeatre & Kuczaj, 2018; Moreno, Highfill & Kuczaj, 2017). There is also strong evidence for individual differences in grey seals (Robinson et al., 2015; Twiss & Franklin, 2010; Twiss, Culloch & Pomeroy, 2011; Twiss, Cairns, Culloch, Richards & Pomeroy, 2012), and preliminary research has provided evidence of broad personality factors in pinniped species using behavioral coding …

A Mechanistic Understanding Of Self-Propagating Amyloid-Β Oligomer Conformations In Alzheimer Disease, Dexter Nathanael Dean

Dissertations

Alzheimer disease (AD) is a fatal neurodegenerative disorder characterized by the widespread deposition of proteinaceous plaques abundant in amyloid-β (Aβ) aggregates. Although the plaques mainly contain high molecular weight, insoluble Aβ fibrils, the low molecular weight soluble aggregates called oligomers have been shown as the primary toxic species responsible for synaptic dysfunction and neuronal loss in AD. The process of aggregation is nucleation-dependent, but also highly stochastic and inhomogeneous resulting in biophysically diverse assemblies. Recent advances in the field indicate a potential correlation between the phenotypic diversity observed in AD subtypes and aggregate polymorphism. Therefore, understanding the molecular mechanisms which …

The Influence Of Conservation Tillage And Conventional Tillage On Soil Bacterial Diversity In Southern Illinois, Nasser Syed

Dissertations

Agriculture in the Midwest United States (Illinois, Indiana, Iowa, Michigan, Minnesota, Ohio, and Wisconsin) is a critically important component of the United States economy and also for world exports of food grain. This is well reflected in the 2012 Census of Agriculture which showed that these states had a market value of crop and livestock products sold in excess of $80,000,000,000 (USDA, 2012). Within the U.S. the three Midwest states, Illinois, Iowa, and Minnesota are ranked 2nd, 3rd, and 4th for the economic value of crops sold. This economic value of agriculture in the Midwest encompasses not only corn, soybeans, …

The Characterization Of The Transcription Factor Msab And Its Role In Staphylococcal Virulence, Justin Batte

Dissertations

Staphylococcus aureus is a common human pathogen that is responsible for a wide range of infections, ranging from relative minor skin infections to life-threatening disease such as bacteremia, septicemia, and endocarditis. S. aureus possesses many different virulent factors that aid in its ability to cause this wide array of infections. One major virulence factor includes the production of capsular polysaccharide (CP). The production of CP plays a major role in the virulence response during infection specifically by providing S. aureus an antiphagocytic mechanism that allows the pathogen to evade phagocytosis during an infection. S. aureus has developed complex genetic regulatory …