Biology Commons^™

Paleoenvironmental Implications Of Small-Animal Fossils From The Black Mountain Turtle Layer And Associated Layers, Eocene Of Wyoming, Jeremy Mclarty

Master's Theses

The Bridger Formation is an Early Middle Eocene deposit in southwestern Wyoming that preserves a rich record of life from North America. Some horizons within the Bridger Formation contain abundant fossil turtle shells, but turtle skulls are rarely found. Previous research focused on one of these fossil-rich horizons, the Black Mountain turtle layer, to develop a model for the abundance and taphonomic condition of the fossil turtles. The proposed model begins with a limestone layer deposited in a lake. Then, an influx of fine-grained volcanic ash (forming the Black Mountain turtle layer) was rapidly deposited into this lake likely causing …

The Use Of Multiple Sensory Modalities By The Antillean Manatee (Trichechus Manatus Manatus) To Locate Food In Their Natural Environments, Amanda Marie Moore

Master's Theses

Manatees are herbivorous aquatic mammals found in the coastal and inland waters of the Atlantic Ocean. All three manatee species are currently listed as vulnerable on the IUCN red list and there still remains much unknown about their ecology. It is currently unknown what sensory modalities manatees use to locate their food in the wild. A literature review of the Paenungulata clade (sirenians, proboscideans, and hyracoideans) was conducted in order to compare and contrast what is known about the sensory modalities of the clade, to better understand the sensory modalities of manatees, particularly the ones they use to locate their …

Investigating Dispersal Ability To Infer Diversification In The Birds Of Madagascar, Robert D. Lauer

Master's Theses

The objective of this study was to investigate whether dispersal ability, as measured by a proxy of hand-wing index 2, influenced diversification of the birds of Madagascar at two scales. Madagascar is home to several avian lineages that have diversified greatly while other lineages are only represented by a single species. a key question in evolutionary biology is why some of these lineages diversified while others did not. One way to address this is to examine what features of these lineages promotes their diversification. Recent studies have focused on the relative importance of dispersal ability to diversification at the continental …

Investigating The Relationship Between Hormone Receptors Dax-1 And Estrogen Receptor Within Prostate Cancer Cell Lines, Meghana G. Vijayraghavan

Master's Theses

Prostate cancer (PCa) is estimated to be the second leading cause of cancer-related deaths among men in the United States in 2019. While most prostate tumors rely on androgens for growth signaling, there are subsets of tumors that become androgen-resistant, therefore resisting conventional androgen-depravation therapy. Consequently, research has focused on targeting different hormone receptors for novel therapeutics. One such receptor is Dosage-sensitive sex reversal, adrenal hypoplasia critical region, on chromosome X, gene 1 (DAX-1). DAX-1 is known to interact with other hormone receptors, such as androgen receptor (AR) and estrogen receptors (ERs) to suppress the proliferative effects …

Effects Of Water Table Depth And Edaphic Characteristics On Plant Diversity In A Southern Mississippi Pitcher Plant Bog, Patrick Kirby

Master's Theses

This study examined the effects that water table depth and soil characteristics have on plant species richness and species composition within pitcher plant bogs across seasons. Eight piezometers were installed at random distances to monitor long-term water table depth and pressure fluctuations along a ~710-meter line transect traversing upland and bog habitats. Vegetation sampling quadrats (n=128) were set up near each piezometer. Cover data and water table depths were collected in spring and late summer. Soil samples collected from each treatment group were used to obtain soil texture and nutrient data. The summer collection period yielded a total gdiversity of …

Evaluation Of Pheromone Mating Disruption For California Red Scale Control In Commercial California Citrus, Joel Timothy Leonard

Master's Theses

California red scale (CRS), Aonidella aurantii, is an increasingly injurious insect pest for the California citrus industry due to insecticide resistance, changing weather patterns, and shifting trade regulations. The presence of the insect on fruit, damages the rind of the fruit and high populations can cause dieback of branches as well as lower yields. Pheromone mating disruption of CRS has the potential to alleviate population control concerns and reduce insecticide use. The efficacy of the pheromone mating disruption technique for pest management of CRS was determined using the products CheckMate® CRS and Semios CRS Plus. CheckMate® CRS was evaluated …

Effects Of Intertidal Position On Metabolism And Behavior In The Acorn Barnacle, Balanus Glandula, Kali Horn

Master's Theses

The intertidal zone is characterized by persistent, tidally-driven fluctuations in both abiotic (e.g., temperature, [O₂], salinity) and biotic (e.g., food availability, predation) conditions, which makes this a very physiologically challenging habitat for resident organisms. The magnitude and degree of variability of these environmental stressors differs between intertidal zones, with the most extreme physiological stress often being experienced by organisms in the high intertidal. Given that many of the fluctuating conditions in this environment are primary drivers of metabolic rate (e.g., temperature, [O₂], food availability), we hypothesized that sessile conspecifics residing in different tidal zones would exhibit …

Heat Activation Of Bacillus Anthracis Persists Over A Seven Day Period, Nathan T. Ross

Master's Theses

Bacteria of the Bacillus genera are capable of forming dormant and resilient cells called spores in response to starvation. Spores can break dormancy in the presence of nutrients in a process called germination. Historically, spores are exposed to sublethal heat treatments to increase the extent and rate of germination. This process is known as heat activation (HA). Previous studies on Bacillus species indicate the effects of HA are reversible after 72 hours. After this time period, the spores must be reactivated. However, spores of Bacillus anthracis, a member of the Bacillus family, have not been tested to see how long …

Development Of A Prolyl Endopeptidase Expression System In Lactobacillus Reuteri To Reduce The Clinical Manifestation Of Celiac Disease, Kara Lynn Jew

Master's Theses

Celiac Disease (CD) is an autoimmune disorder that emerges due to the ingestion of gluten, a protein found in a variety of common grains such as wheat, rye, and barley. Approximately 1 in 100 individuals in the US suffer from CD, making it the most commonly diagnosed gastrointestinal disorder (Ciclitira et. al., 2005). These proline-rich gluten peptides are resistant to proteolysis and accumulate in the duodenum of the small intestine. Once in the duodenum, these peptides illicit an autoimmune response resulting in villous atrophy. Current treatment for CD requires a rigorous adherence to a gluten-free diet. Nevertheless, gluten-containing grains are …

Dna And Protein Sequence Analysis Of Neuronal Markers Neuronal Nuclei (Neun) And Doublecortin (Dcx) In The Northern Pacific Rattlesnake (Crotalus Oreganus) And Western Fence Lizard (Sceloporus Occidentalis)., Brett M. Vassar

Master's Theses

Neuronal Nuclei (NeuN) and Doublecortin (DCX) are neuron specific proteins that are used in histological studies of brain structure in a variety of vertebrate taxa.Antibodies against NeuN (anti-NeuN) bind to the Fox-3 protein, an RNA binding protein common in mature neurons. Anti-DCX labels a microtubule-associated protein expressed in actively dividing neural progenitor cells and migrating neurons. The DCX gene encodes a protein that is well conserved across mammalian, avian, and a few reptilian species, therefore anti-DCX staining has been used successfully across a range of vertebrate taxa. Successful neuronal staining using anti-NeuN has been demonstrated in mammals, birds, and the …

Development Of A Pediatric Model Of Nafld In Neonatal Iberian Pigs, Gabriella Veronica Hernandez, Victoria Alice Smith, Morgan Coffin, Daniel Columbus, Matthew Burd, Kimberly Sprayberry, Mark Edwards, Daniel Peterson, Darin Bennett, Robert Fanter, Christopher Kitts, Michael La Frano, Margaret Rice, Douglas Burrin, Magdalena Maj, Rodrigo Manjarin

Master's Theses

The prevalence of non-alcoholic fatty liver disease (NAFLD) in children has increased over the past decades, creating a need for animal models that recapitulate the features of the pediatric disease. Iberian pigs have a leptin-resistant phenotype characterized by hyperleptinemia, hyperphagia, and extreme adipogenesis. We hypothesized that neonatal Iberian pigs fed a high fat high-fructose (HFF) diet will develop a pattern of liver injury resembling pediatric NAFLD. In addition, we sought to determine if a mixture of probiotics would prevent the disease. Animals were fed 1 of 4 diets containing (g/kg body weight × d) 0 g fructose, 11 g fat …

The Development Of Diving Capabilities In Weddell Seal (Leptonychotes Weddellii) Pups Throughout Early Ontogeny, Emma Weitzner

Master's Theses

Weddell seals (Leptonychotes weddellii) are among the deepest diving pinnipeds (i.e., seals, sea lions, and walrus) and one of the best studied marine mammals in the world; as such, these seals are considered a model species for the study of diving physiology and behavior. Adult Weddell seal dive physiology is rather comprehensively understood, yet previous research has excluded an examination of pups’ initial independent diving attempts, beginning instead with the diving capabilities of near-weaning individuals at four to five weeks of age. This is beyond the point many pups have attempted their first independent dives; pups begin to …

Play Behavior And The Development Of Boldness And Caution In Juvenile Belding’S Ground Squirrels (Urocitellus Beldingi), Madelene Shehan

Master's Theses

The ubiquity of play among juvenile mammals suggests it provides adaptive benefits, potentially through influences on the development of temperament in young animals. Juvenile Belding’s ground squirrels (Urocitellus beldingi) must balance competing demands for boldness and caution imposed by the fundamental trade-off between their short active season and their vulnerability to predation. In this study, I evaluated whether play helps to facilitate the development of an appropriate balance between boldness and caution in juvenile U. beldingi.I observed the play behavior of juvenile U. beldingiand conducted flight-initiation distance tests to measure boldness-caution at the beginning and toward …

Comparative Thermal Ecology Of Coastal And Inland Pacific Rattlesnakes (Crotalus Oreganus), Hayley Layne Crowell

Master's Theses

Global biodiversity is declining as a direct result of anthropogenic climate change. Ectothermic species have become focal organisms for studying the ecological effects of altered climates due to the clear relationship between environmental temperatures and ectotherms’ basic physiological functions. Historically, examinations of these effects have focused heavily on heliothermic lizards, and most others have tended to focus on single populations or sympatric species within a single community. Addressing the longterm energetic implications of environmental temperature variation will provide valuable insight into the cascading physiological effects that certain populations or species may experience as a result of altered climates.

In this …

Methylation-Specific Differentiation Of Vaginal Epithelial Cells For Forensic Tissue Typing By Bisulfite Conversion And Pyrosequencing, Elise Pood

Master's Theses

The identification of bodily fluids and tissues is often applied to criminal investigations to clarify events that may or may not have taken place. Current forensic techniques can identify blood, saliva, seminal fluid, and spermatozoa, but there is a clear absence of reliable testing to identify vaginal epithelial tissue. Though there are serological tests available for this purpose, tissue-specific methylation markers have recently been investigated as a candidate for the identification of blood, saliva, and spermatozoa.

In this study, tissue-specific methylation markers were analyzed to identify a set of markers for the differentiation of vaginal fluid from blood, saliva, and …

Role Of Daxx As A Predictive Biomarker In Breast Cancer, Michelle Lucia Fernandez

Master's Theses

Breast cancer is the most commonly diagnosed form of cancer in women, besides skin cancer, and second only to lung cancer for cause of mortality. It is divided into three subtypes, depending on different molecular or pathologic characteristics, including estrogen or progesterone receptor-positive (ER/PR+), human epidermal growth factor receptor-2-positive (HER2+) and triple negative breast cancer (TNBC). There are several therapies used to target these subtypes, but there is still a chance that the cancer will recur into a more aggressive, resistant form even if the therapies were successful before. This recurrence is believed to be due to the Cancer Stem …

Seasonal Diet Variation In Thirteen-Lined Ground Squirrel (Ictidomys Tridecemlineatus) In Southernwestern Michigan, Austin Menzmer

Master's Theses

Thirteen-lined ground squirrels (Ictidomys tridecemlineatus) are omnivorous ground squirrels that range from Texas to Alberta and from Michigan to Utah. The amount and type of both animal and plant matter in their diet may vary both geographically and seasonally. The present study was motivated by prior work, based on δ13C analysis of incisor enamel of thirteen-lined ground squirrels from a colony in southwestern Michigan, suggesting that these animals underwent a pronounced, late-season shift in diet from predominantly C3 to C4 plants. However, this inferred dietary shift was not directly demonstrated. Here, I tracked diet of thirteen-lined ground squirrels in southwestern …

Investigating The Anti-Cancer Properties Of Novel Hybrid 1,4-Dihydropyridine Derivatives In U-87mg Glioblastoma Cell, Tendai Hunyenyiwa

Master's Theses

Glioblastoma is the most devastating of brain cancers with a very high death rate and a low survival rate of less than 15 months after diagnosis. Glioblastoma is a cancer of astrocytes which are the majority of the brain glial cells that support neurons and help create the blood-brain barrier among other functions. The current approach to treating this disease is surgical removal of the main tumor, followed by radiotherapy and limited chemical intervention by the use of temozolomide (TMZ). This disease is characterized by high invasion and recurrence after surgical removal of the main tumor as a result of …

Assessment Of Eastern Massasauga Rattlesnakes (Sistrurus Catenatus) In Berrien County Historical Sites, Roshelle M. Hall

Master's Theses

The Eastern Massasauga rattlesnake (Sistrurus catenatus; EMR) is a small robust pit viper currently found in nine states and the province of Ontario, Canada. Wetland habitats have experienced significant destruction and fragmentation by humans; as a result, the current distribution of the EMR is a fraction of its historic distribution. For this reason, the EMR has been federally listed as threatened. In general, little is known about the current distribution of this rattlesnake (in the southwest corner of Michigan, the size of local populations or their stability and genetic diversity. Much of this knowledge is based upon historical data. My …

Synthesis And Screening Of Novel Hybrid Benzothiazoles In U-87 Mg Glioblastoma Cell Line, Priscilla Kyi

Master's Theses

Benzothiazole is a heteroaromatic compound known for its wide range of bioactivities including anti-cancer, anti-viral, anti-microbial, anti-inflammatory, anti-convulsant, anti-diabetic, anti-helminthic, and anti-tubercular activities. Research has shown that derivatives of benzothiazole exhibit inhibition of proliferation via apoptosis in various human cancer cell lines, such as liver cancer (Wang, et. al., 2011). In this study, a series of novel hybrid benzothiazole α-cyanostilbene derivatives and styrylbenzothiazole derivatives containing boronic acid and non-boronic acid pharmacophores were synthesized. The anti-cancer and anti-invasive properties of selected benzothiazole α-cyanostilbene derivatives on U-87MG glioblastoma cells were investigated in vitro.

U-87MG cells were incubated with synthesized novel hybrid compounds …

Cold Acclimation Response Of Non-Native Italian Wall Lizard (Podarcis Siculus) Populations From New York And California, Daniel Haro

Master's Theses

Understanding how organisms respond to climatic variability and novel conditions is becoming an increasingly important task for ecologists. For ectotherms in the northern hemisphere, the response to cold is of special interest, considering that poleward range expansion events and increasing variability of temperatures during winter are already being observed as consequences of a warming planet. Though direction of change in physiological variables in response to cold is well studied in ectotherms, the extent to which traits can change and the rate at which they can change is not.

We compared the extent and rate of change in cold tolerance (CT …

Indirect Food Web Interactions: Sea Otter Predation Linked To Invasion Success In A Marine Fouling Community, Maggie F. Jenkins

Master's Theses

Humans have caused grave ecological and economic damage worldwide through the introduction of invasive species. Understanding the factors that influence community susceptibility to invasion are important for controlling further spread of invasive species. Predators have been found to provide biotic resistance to invasion in both terrestrial and marine systems. However, predators can also have the opposite effect, and facilitate invasion. Therefore, recovery or expansion of native predators could facilitate the spread of invasive species. Needles et al. (2015) demonstrated that the threatened southern sea otter (Enhydra lutris nereis) facilitated the invasion of an exotic bryozoan, Watersipora subatra. …

The Thermal Ecology Of Sceloporus Occidentalis, Luis Patricio Burgos

Master's Theses

With temperatures rising globally, assessing the possible impacts of the changing climate becomes more and more urgent. Ectotherms are excellent indicators of potential climatic ramifications on biodiversity because of their heavy reliance on the environment for their thermoregulation. Studies have historically looked at thermal tolerance values to establish predictive models for population and species extinctions.

In chapter 1, we looked at recent studies that suggest that thermal tolerance may be a plastic trait and test the effects empirically. Most studies are based on captive lizards acclimated to laboratory conditions that do not necessarily reflect natural environments, and if thermal tolerance …

The Roles Of Tid1, Ndj1, And Spo16 In Distributive Segregation During Saccharomyces Cerevisiae Meiosis, Ethan Atticus Shaw

Master's Theses

Meiosis is a specialized form of cell division in sexually reproducing eukaryotes. Crossovers are physical connections formed between homologous chromosomes during meiosis; these connections help ensure normal segregation of homologous chromosomes at meiosis I. However, the yeast Saccharomyces cerevisiae and other eukaryotes can still segregate homologs properly even in the absence of some crossovers. This is due to a backup mechanism known as distributive segregation, which correctly segregates non-crossover chromosomes at a higher rate than if segregation were completely random. To study distributive segregation, we have generated diploid yeast with one homeologous chromosome pair consisting of a Saccharomyces cerevisiae chromosome …

Spatial Distribution And Stock-Recruitment Analysis Of The Atlantic Surfclam, Spisula Solidissima, In The Mid-Atlantic Bight And On Georges Bank, Jeremy Timbs

Master's Theses

Atlantic surfclams, Spisula solidissima, are long-lived bivalve molluscs with dispersive larval stages. Surfclam patchiness throughout the U.S. Exclusive Economic Zone (EEZ) has declined from the 1980’s to the present in all assessed regions (Delmarva, New Jersey, Long Island, Southern New England, and Georges Banks). Warming of Mid-Atlantic bottom waters is driving the surfclam stock into new habitat and extirpating the surfclams from nearshore areas. Based on a species distribution function model, the small surfclams appear to inhabit a greater area than the large market-size surfclams across the entire stock. The wider distribution of recent recruits relative to the fishable …

Coastal Wetland Dynamics Under Sea-Level Rise And Wetland Restoration In The Northern Gulf Of Mexico Using Bayesian Multilevel Models And A Web Tool, Tyler Hardy

Master's Theses

There is currently a lack of modeling framework to predict how relative sea-level rise (SLR), combined with restoration activities, affects landscapes of coastal wetlands with uncertainties accounted for at the entire northern Gulf of Mexico (NGOM). I developed such a modeling framework – Bayesian multi-level models to study the spatial pattern of wetland loss in the NGOM, driven by relative RSLR, vegetation productivity, tidal range, coastal slope, and wave height – all interacting with river-borne sediment availability, indicated by hydrological regimes. These interactions have not been comprehensively investigated before. I further modified this model to assess the efficacy of restoration …

Zinc Sunscreens Affect Development Of Strongylocentrotus Purpuratus Embryos, Brittany E. Cunningham, Nikki L. Adams

Master's Theses

The growing popularity of physical sunscreens will also lead to an increased release of the ingredients from zinc oxide (ZnO) sunscreens into marine environments. Though zinc (Zn) is a necessary micronutrient in the ocean, greater than natural Zn concentrations are being released into marine environments by use of sunscreens. The extent of the consequences of the addition of Zn to the ocean are not fully understood. We investigated effects of materials released by zinc oxide (ZnO) sunscreens on the development of California purple sea urchin, Strongylocentrotus purpuratus. Embryos developed in various concentrations of Zn, the sources of which included …

Foraging Ecology Of Parrotfishes In The Greater Caribbean: Impacts Of Specialization And Dietary Preferences On Marine Benthic Communities, Madelyn V. Roycroft

Master's Theses

Coral reefs are one of the world’s most diverse yet heavily impacted marine ecosystems. As a result of many direct and indirect stressors, coral reefs have experienced major degradation over the last several decades. Declines in coral reefs in the Caribbean have been particularly acute and generally associated with the loss of key herbivores and an increase in algae. Herbivorous fishes such as parrotfishes can positively impact coral reefs by removing algae that compete with corals for light and space. However, many parrotfishes are also important coral predators. Predation on corals, known as corallivory, can adversely affect coral growth, reproduction …

Seeing Red: Analyzing Iucn Red List Data Of South And Southeast Asian Amphibians, Alexandra Gonzalez

Master's Theses

In the midst of the sixth mass extinction event which is currently underway, it appears that amphibians are one of the most impacted vertebrates. Over 6,500 amphibian species are listed on the IUCN Red List (an assessment tool which provides species’ conservation status, perceived threats, and distribution range). While it is well-known that populations under multiple stressors are more likely to undergo significant declines, there are little to no resources available for visualizing how these threats may work synergistically and interact within a species’ range. This is especially the case for Southeast Asian amphibians, which much less attention has been …

The Role And Contribution Of Saprotrophic Fungi During Standing Litter Decomposition Of Two Perennial Grass Species, Schizachyrium Scoparium And Schizachyrium Tenerum, Matthew Lodato

Master's Theses

In terrestrial ecosystems, most of the plant biomass produced enters the detrital pool, where microbial decomposers colonize, enzymatically degrade, and assimilate plant litter carbon and nutrients in amounts sufficient to bring about the decomposition of plant litter. Here, I estimated the biomass and production of fungi and microbial respiration associated with decaying Schizachyrium scoparium and Schizachyrium tenerum leaf litter, and constructed a partial organic matter budget estimating C flow into and through fungal decomposers. Significant losses in S. scoparium (57%) and S. tenerum (68%) leaf mass was observed during litter decomposition along with concomitant increases in fungal biomass, which reached …