Biology Commons^™

A Computational Investigation Of The Biophysical Mechanisms Underlying Thermotaxis In The Afd Neurons Of Caenorhabditis Elegans, Zachary Mobille

Theses and Dissertations

Thermotaxis in the nematode Caenorhabditis elegans (C. elegans) is studied at the cellular scale of the amphid finger-like ciliated (AFD) neurons, which have previously been shown to be essential for thermoreception. The voltage and calcium signals of AFD during temperature stimuli are described with ordinary differential equations. The primary calcium model is a modified version of that published by Kuramochi and Doi in 2017 to explain the calcium responses of the chemosensitive amphid single-ciliated right (ASER) neuron to fluctuations in extracellular salt concentration. To account for the effects of temperature, changes to the stimuli conditions under which inactivation takes place …

The Reemergence Of Eradicated Disease Due To Ecological Impact Of Climate Change, Claudia Kolakowski

Theses and Dissertations

Global warming is radically changing aspects of the Earth. As scientists continue to research the effects, the ramifications of melting permafrost is coming to light. We build off of a previously existing Anthrax model in the hopes to include climate change as a factor in Anthrax spread. Chapter II develops a simplified version of an Anthrax model. Parameters for the model are found by using previous research and eigenvalues are analyzed in order to find thresholds and equilibria. Chapter III consider the general solutions of the model through eigenvalues and eigenvectors. This model is then extended to include a parameter …

Physiological Consequences Of Neuromodulation And The Cellular Properties That Underlie Them, Margaret Louise Demaegd

Theses and Dissertations

Neuronal activity is a product of more than the underlying neuronal connections. Modulatory influences like changes in the animal’s environment, the animals physiological state, or the release of neuromodulators can dramatically alter neuronal activity. Modulatory influences can be beneficial for the animal because they are a source of neuronal and behavioral plasticity, and they can provide neuronal circuits with the robustness needed to continue to function in new conditions, states, or tasks.However, malfunctions of the modulatory system can disrupt neuronal activity and lead to pathologies. Predicting how modulatory influences will alter neuronal activity is challenging because the underlying cellular and …

Bioinformatic Analysis Of Venom Proteins From Dasymutilla Occidentalis, Eva Gunawan

Theses and Dissertations

Venom proteins have been found in a wide range of species in the animal kingdom. These venoms serve various functions such as defense against predators, hunting for food, and parasitism for reproduction. Because of their diverse functions, venom proteins are utilized in agrochemical treatments for protection from pests as well as treatments to control human diseases. Venoms, including those coming from a range of insect species, have been manipulated for these purposes, but many remain uncharacterized. Currently, one of the orders that venom-based research is focusing on are parasitoids from the order Hymenoptera. The purpose of some venom proteins in …

Determination Of The Summer Origins Of American Kestrels ( Falco Sparverius ) Wintering In Northern And Central Illinois, Taylor P. Joray

Theses and Dissertations

The seasonal and interannual movements of the American Kestrel (Falco sparverius) are not fully understood. Although one of the most widespread and abundant raptors found in North America, information on where many populations summer and overwinter is lacking. We used stable hydrogen isotope values obtained from feathers (δ2Hf) of known origin to create age-specific calibration functions for juvenile and adult American Kestrels. We then used these calibration functions to determine the most likely summer origins of the American Kestrels that wintered in northern and central Illinois during 2015-16, classified these individuals as year-round residents or wintering migrants, and validated these …

Dissecting Dystrophin's Roles, Subcellular Organization, And Functional Network In Drosophila Oogenesis, Mina Amini Moghaddam

Theses and Dissertations

Mutations in the giant actin-membrane linker protein Dystrophin (Dys) are the cause of Duchenne Muscular Dystrophy (DMD). In the Drosophila model system, the highly conserved Dys protein is not required for viability but is required for proper wing and ovarian development. Dys mutations produce two visible phenotypes: posterior crossveins are detached from the longitudinal veins, and in oogenesis the developing eggs fail to elongate properly. This provides an opportunity to explore the less-understood cellular and developmental roles of Dys and gain a new insight into how tissues adopt their correct shapes.

Animals from worms to flies to humans express multiple …

Investigating The Regulation And Role Of P38 Mapk In Collagen-Related Limb Girdle Muscular Dystrophy, Briseida Oceguera-Perez

Theses and Dissertations

Aging is an expected and normal process across living organisms. It is characterized as a loss of stress resistance, degeneration of tissues, and decline in motor function that happen gradually across lifespan. Susceptibility to neurodegenerative and dystrophic conditions also increase, and unlike aging, are not a normal aspect of lifespan. Discerning the difference between normal and aberrant aging states will give insight into the mechanisms behind the progressive dysfunction shared among organisms. Previous work in our lab has shown that the aging gene p38 MAPK in Drosophila melanogaster plays a significant role in the aging process through its downstream effects …

Elucidating The Role Of The High Aliphatic Glucosinolate ( Hag ) Genes In Pennycress ( Thlaspi Arvense L. ) Glucosinolate Production, Dalton Williams

Theses and Dissertations

Pennycress (Thlaspi arvense L.) is a Brassica species being developed into an oilseed-producing winter cash cover crop. Similar to its relatives, rapeseed (Brassica napus L.) and camelina (Camelina sativa L.), pennycress seeds produce high levels of oil and protein (~34% oil and ~19% protein dry weight). For pennycress to be economically viable and environmentally sustainable as a crop, both the oil and seed meal must be utilized. Pennycress like other Brassicaceae, produces high levels of glucosinolates in the seed coat. Glucosinolates taste bitter and can be metabolized by the enzyme, myrosinase, into toxic isothiocyanates, nitriles, and epithionitriles. Seed meal containing …

Characterizing The Transport Of Parasitoid Wasp Genaspis Hookeri Venom Serca Into Host Drosophila Hemocytes, Christopher Lark

Theses and Dissertations

The female endoparasitoid wasps introduce venom accompanied by an egg into

the larval hosts’ body cavity during oviposition. The venom contains a mixture of

proteins that exploit the host’s biological processes, such as, regulating gene

expression, disrupting immune signaling pathways, or inducing immune cell death to

give a decided advantage to the incipient wasp to develop unchallenged. Drosophila

possesses a highly conserved innate immune response that recognizes and neutralizes

foreign microbes and macroparasites. The venom of Ganaspis hookeri (strain G1)

endoparasitoid wasp has co-evolved to suppresses the humoral phase Drosophila’s

innate immune response by inhibiting Ca2+ bursts needed to induce …

Reconsidering Undergraduate Anatomy And Physiology Curriculum, Eric Michael Walsh

Theses and Dissertations

In the past 50 years several convergent factors have spurred unprecedented change in anatomy and physiology (A&P) instruction. An explosion of biomedical knowledge, an increased demand for students well-versed in A&P, and decreased resources for the course has provoked a vast array of research. However, most studies employ one of three strategies to enact change: testing the effectiveness of new pedagogies, exploring the utility of new technologies, or documenting learning in new contexts. By comparison, a much smaller body of research focuses on changing the A&P curriculum to improve student learning. To address this gap, the musculoskeletal curriculum for an …

Overcompensation In Aedes Mosquitoes Populations: Field Tests On Likelihood And An Agent-Based Model To Investigate The Influence Of Cohort Structure, Katherine G. Evans

Theses and Dissertations

The number of individuals in a competitive environment can affect the growth rate, survival, size, and fecundity of those individuals, which is known as density-dependent effects. Overcompensation may occur if few juveniles survive to adulthood in a high-density environment. Overcompensation arises when density dependent survival interacts with extrinsic sources of mortality, such that more juveniles survive to adulthood than if no extrinsic mortality had occurred.

I tested the hypothesis that density dependent effects are common and strong in the field for three mosquito species: Aedes aegypti, Aedes albopictus, and Aedes triseriatus. I surveyed naturally occurring densities in novel and established …

A Male-Female Genotype-By-Genotype Interaction Mediates The Effect Of Mating On Female Immunity In Decorated Crickets, Kylie J. Hampton

Theses and Dissertations

Sexually antagonistic coevolution should lead to the rapid divergence of male and female genotypes related to the effects of ejaculatory substances on female physiology. Hence, the outcome of mating should depend on an interaction between male and female genotypes. Although mating has been shown to influence female immune responses in diverse insect taxa, a male-female genotype-by-genotype effect on female immunity post-mating remains largely unexplored. Here, we investigate both the effects of mating on female immunity and the potential for a male-by-female genotype interaction on the form and magnitude of this response in decorated crickets. Females from three distinct genotypic backgrounds …

Regulation Of The Microtubule Cytoskeleton And Cell Wall Development In Arabidopsis Thaliana, Christy J. Fornero

Theses and Dissertations

Regulation of the cortical microtubule cytoskeleton is critical for organized plant cell division. Arabidopsis ton1 and ton2 mutants display random cell division plane placement and lack the plant-specific cortical microtubule array that encircles the nucleus prior to mitosis. In wild type plants, this preprophase band (PPB) of cortical microtubules precisely marks the future division plane. The specific roles of TON1 and TON2 in PPB formation are not yet known. It is suspected that TON1 Recruiting Motif (TRM) proteins may be involved in TON1 and TON2 recruitment to the PPB. Here we describe results for the targeted disruption of a group …

Connecting The Dots: Exploring The Relationship Between Avian Eggshell Pigmentation And Paternal Provisioning Effort, Kara E. Hodges

Theses and Dissertations

In a number of bird species, eggs laid by females breeding in the same population can vary extensively in the extent of their eggshell pigmentation, but the adaptive significance of this intraspecific variation remains unknown. One hypothesis posits that shell pigmentation is an honest signal of female quality that reflects her level of oxidative stress, one that is used by males to inform their subsequent paternal investment. We employed a reciprocal clutch cross-fostering design to test whether provisioning by male house wrens (Troglodytes aedon) responds to the clutch pigmentation of their mates. In experimental replicates, dark clutches were swapped with …

Effects Of Electrical Stimulation On Glioma Cells In Vitro With Implications For Treating Chronic Pain: Development Of A Model System, David C. Platt

Theses and Dissertations

Glial cells comprise over 70% of the central nervous system cells and exhibit diverse functions including regulation of synaptic transmission, neuron protection/repair, maintenance of neuronal metabolism, and are implicated in the development of persistent neuropathic pain. In addition, a perturbation in the concentration of intracellular reactive oxygen species (ROS) and reactive nitrogen species (RNS) has likewise been associated with the development of a chronic pain state. This perturbation in ROS/RNS creates an environment of oxidative stress. However, the mechanism by which the pain signal transmission is modulated, and the roles ROS play in the perpetuation of the pain state are …

Determining The Relationship Between Aging And Oxidative Stress In A Drosophila Melanogaster P38 Kb Framework, Aleksandra J. Majewski

Theses and Dissertations

Aging is inevitable for all organisms and can be characterized by degeneration of tissue, adecrease in motor function, and impaired stress response. In humans, it is often accompanied by an increased propensity for age related diseases. While all adults experience biological aging (senescence) not all adults experience age-associated disease. Thus, we claim these are not normal prospects of aging. Although the implications of aging are well understood, the molecular underpinnings for these processes remain elusive. As advances in medical science have been successful at prolonging lifespan, they concurrently extend the amount of time spend in diseased states. If we wish …

A Combinatorial Premotor Neural Code: Transformation Of Sensory Information Into Meaningful Rhythmic Motor Output By A Network Of Heterogeneous Modulatory Neurons, Christopher John Goldsmith

Theses and Dissertations

The goal of the following research was to investigate the contributions of neural networks in selecting distinct variants of rhythmic motor activity. We used the premotor commissural ganglion (CoG) in the stomatogastric nervous system of the Jonah crab to understand how this network effectively controls the rhythms produced in downstream motor circuits. Prior research determined that individual CoG neurons are necessary to mediate sensory-induced variation in the effected motor patterns. However, single premotor neuron inputs to the STG are not sufficient to recreate the patterns induced by the selective activation of sensory pathways. Thus, it was hypothesized that the CoG-mediated …

Learning And Behavior In Hatchling Trachemys Scripta Exposed To Bisphenol-A During Embryonic Development, Justin E. Dillard

Theses and Dissertations

Steroids play an integral role in orchestrating embryonic development, and can affect a suite of phenotypic traits, including learning and memory. Endocrine disrupting compounds (EDCs) can mimic the effects of steroids and can affect the same suites of phenotypic traits during embryonic development. Bisphenol-A (BPA) is an EDC that mimics the action of estrogen, and recent work is beginning to implicate BPA in effects on learning and behavior similar to those caused by estrogen treatment studies. Red-eared slider turtles (Trachemys scripta) are a good system to investigate the effects of BPA on learning and behavior, both because the molecular underpinnings …

Exploring The Biogeography Of South American Rainforest Understory Birds Using Morphological Variation In The Wedge-Billed Woodcreeper ( Glyphorynchus Spirurus ), Gregory Tito

Theses and Dissertations

Tropical rainforests in the Amazon Basin show an extraordinarily high degree of biodiversity, the reasons for which are poorly understood. A number of biogeographical models have been proposed to account for the variation present within and among species, including birds. This study tests the predictive ability of six major historical vicariant biogeographical models (Andean uplift, marine incursion, Amazonian lake, river barrier, refuge, and river refuge) using a large data set of morphological characters in the Wedge-billed Woodcreeper (Glyphorynchus spirurus), a small understory songbird found mostly in terra firme tropical rain forest. It also characterizes variation in key morphological characters and …

Identification Of Novel Nuclear Proteins Required For Meiotic Silencing By Unpaired Dna In Neurospora Crassa, Dilini Ralalage

Theses and Dissertations

A fundamental step that occurs during sexual reproduction is meiosis, which is a specialized type of cell division. During meiosis, pairs of chromosomes exchange genetic information via recombination. At this point, the genome is particularly susceptible to viruses and other foreign genetic invasions. Therefore, it is important to protect the genome to prevent the transmission of foreign genetic materials to the offspring. There are several mechanisms work together to protect host genome from foreign genetic materials. These are known as “genome defense mechanisms”.

The fungus Neurospora crassa is one of the best organisms for genome defense studies due to the …

Altered Na, K- Atpase Isoform Expression In Artemia Franciscana In Response To Hypersaline Environments, Jessica Drenth

Theses and Dissertations

The Na,K-ATPase (NKA) is an essential membrane pump that helps to establish cell ion gradients, and regulate intracellular salt in many organisms. One such species, Artemia franciscana (brine shrimp), extreme halophiles which live in hypersaline environments, expresses 2 distinct α-catalytic subunits of the NKA. One of these subunits, α2-(KK), has two key lysine substitutions located within the cation binding sites. Prior work has demonstrated this specific subunit may be directly involved in brine shrimp adaptation to their extreme environments. However, the precise molecular and physiological effects of α2-(KK) have not been entirely elucidated. I determined through immunohistochemistry that my initial …

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, …

The Effects Of Modafinil And Atomoxetine On Dopamine Signaling In The Striatal Subregions Of The Rat, Martin Bobak

Theses and Dissertations

In an effort to combat diseases and disorders that impede our health, comfort and well-being, an abundance of prescription drugs have emerged in the past 60 years. Many prescription drugs have remarkable efficacy for treating the primary symptoms of these diseases and disorders; however, some drugs carry negative side effects that impose their own adverse symptoms, albeit, often to a lesser degree than the primary symptoms. Thus, one of the main objectives of the pharmaceutical industry is to innovate and develop novel therapeutics, which remediate the primary symptoms of disease and lack undesirable negative side effects. However, in order to …

Bacterially-Based Immune Challenges And Trauma Elicit Terminal Investment In Male Aedes Aegypti, Molly K. Schumacher

Theses and Dissertations

Investment in life history traits such as immune function and reproduction is constrained by finite available resources. A cost-of-immunity trade-off may occur in response to infection when resources are diverted away from reproductive effort and into an immune response. Alternatively, an infected individual may enhance reproductive effort to maximize terminal reproductive success in response to the survival threat inherent to infection (terminal investment). We measured male Aedes aegypti reproductive behavior following inoculations with: living bacteria; killed bacteria as an immune elicitor; and a sham control. Mating competitiveness relative to naïve males was also determined through a binary mate choice experiment …