Life Sciences Commons^™

Effects Of Parasitism And Mite Control Methods On European Starling Development, Aderinsola Oluwasikemi Odetunde

Theses and Dissertations

Certain developmental stressors can lead to developmental trade-offs in young organisms. Hematophagous ectoparasites are a common stressor experienced by European starlings, and we wished to explore what aspects of an ectoparasite infestation drove trade-offs. The first part of this study was to test the hypothesis that blood loss was the sole mediator of trade-offs due to hematophagous ectoparasite infestation. We used nestlings that were exposed to mites in the nests, nestlings in mite-reduced nests experiencing supplementary blood loss, and nestlings in mite reduced nests with no supplementary blood loss. We also used a new heat treatment to reduce mites in …

Takeover On The Tallgrass Prairie: How Lespedeza Cuneata Establishes Dominance, Morgan Rae Walder

Theses and Dissertations

Invasion ecology aims to study mechanisms by which invasive species are able to enter, establish, and spread within an ecosystem. This study analyzed Darwin’s naturalization and the biotic resistance hypotheses as the most likely explanations for invasion by an exotic legume, Lespedeza cuneata, into a tallgrass prairie. Darwin’s naturalization hypothesis posits that exotic species are less able to establish in communities that have related species, because similarity in morphology and function promotes intense competition for resources. The biotic resistance hypothesis states that competitors, herbivores, and pathogens already present in the community limit the colonization, naturalization, and persistence of invaders, therefore …

Membrane Biophysics Of Listeria Monocytogenes: Analysis Of An Alternate Pathway Of Branched-Chain Fatty Acid Biosynthesis And Elasticity Of Fatty Acid Utilization, Laura E. Kuczek

Theses and Dissertations

The membrane homeostasis of the psychrotolerant foodborne pathogen Listeria monocytogenes involves maintaining fluidity in a range of different conditions by incorporation of specific branched-chain fatty acids (BCFAs). BCFAs are synthesized through a well-characterized pathway from branched-chain amino acids into short branched-chain acyl-CoAs followed by elongation by the FAS II system. Branched-chain alpha-keto acid dehydrogenase (Bkd) is a major player in this pathway. MOR401 is a transposon insertion mutant deficient in Bkd and has decreased membrane BFCAs. Low levels of BCFAs in L. monocytogenes are linked to diminished growth, less resistance to antimicrobials, and a severe reduction in virulence. Rescued growth …

A Gis Analysis Of Land Cover Effects On Water Systems: Nutrients And Algae In Stormwater Ponds, Nicole Lee Kappel

Theses and Dissertations

Anthropogenic land conversion is occurring rapidly and has the potential to impact our water quality. This study aims to explore the effect of watershed land characteristics on water quality within stormwater ponds (SWPs). Rapid land conversion is known to affect water quality of receiving water bodies, however not much is known about the effect of urbanization on SWPs. Geographic informational systems (GIS) was used to determine areas of land that drain into ponds. Water samples were collected and analyzed for total phosphorous, dissolved reactive phosphorous, nitrate, and ammonia. Algal pigment and percent cover measurements were taken in the field and …

Why Are Students Doing Research? Examining The Motivation Of Students Involved In Undergraduate Research Programs, Andrew Layne Mcdevitt

Theses and Dissertations

Use of self-determination theory (SDT) within the science classroom focuses primarily on ways to integrate intrinsic motivation into students' identity. Experiential learning plays a large role in promoting learning by shaping students' interests, identity, and intrinsic aspirations. This phenomenological research study sought to understand how experiential learning experiences helped influence career aspirations of graduate students within ecological disciplines. By determining how their experiences met three basic psychological needs outlined by SDT (competence, autonomy, and relatedness), we were able to examine which regulators drove motivation.

In the qualitative pilot study, participants developed a genuine enjoyment and appreciation for their discipline as …

An Investigation Into B Cells In Peripheral Blood And Gut Associated Lymphoid Tissues In The Red Eared Slider Turtle, Trachemys Scripta, Sarah Marie Marrochello

Theses and Dissertations

As in endotherms, immunity in ectotherms is vital to survival and contributes to the overall fitness of an organism. For reptilians, there are a number of environmental factors, such as temperature, season, and pathogen prevalence, which are known to influence both innate and adaptive immunity. Of particular interest, is the effect of these factors on B cells, a component of adaptive immunity. Reptilian B cells are reported to secrete antibodies, much like their mammalian counterparts, and undergo phagocytosis. The work reported here primarily focused on understanding the effect of environmental temperature, incubation temperature, and nesting season on B cells in …

Î?- Lactam-Induced Changes In Cell Wall Composition And Autolytic Properties Of Daptomycin Resistant Staphylococcus Aureus, Michael Krzyskowski

Theses and Dissertations

Staphylococcus aureus is a major human pathogen that is well known for its ability to develop resistance to antimicrobial therapies. Recent studies have identified a combination of β-lactam antibiotic and daptomycin (DAP) to be highly effective at killing single and multi-drug-resistant S. aureus. Of particular interest is this drug combinationâ??s efficiency with which it kills strains classified as DAP-resistant methicillin-resistant Staphylococcus aureus (DAP-R MRSA). The goals of the present study were two-fold: to provide a physiological profile of a DAP-R S. aureus strain undergoing beta-lactam treatment by observing changes in autolytic rate, susceptibility to lytic enzymes, levels of peptidoglycan O-acetylation, …