Biology Commons^™

Anthropogenic Disturbance Modulates Mammal Community Diversity, Assembly, & Abundance: Emerging Infectious Disease Risk In The Greater Yellowstone Ecosystem, Leticia Andrea Gutiérrez Jiménez

Dissertations

This dissertation examines the role of mammalian biodiversity in maintaining overall ecosystem health in the Greater Yellowstone Ecosystem (GYE). The study explores the pathways by which anthropogenic disturbance prevents or promotes the emergence of human infectious diseases. I studied two paramount research questions: Question 1: What are the direct effects of anthropogenic disturbance on rodent community assemblages and the consequent indirect effects on public health? I first surveyed the GYE rodent community and their pathogens by using land use as a measure of anthropogenic disturbance (e.g., human settlements, horseback ranches, pastures, undisturbed). I identified pathogens in rodent blood samples by …

Synthetic Ion Channels: A New Class Of Membrane Disruptor And Efflux Pump Inhibitor For The Recovery Of Antibiotic Potency, Mohit Bharatkumar Patel

Dissertations

Antibiotic resistance has become a world-wide health care crisis. In 2013 there were 50,000 deaths in U.S. and EU, associated with hospital acquired bacterial infections. This problem is exacerbated by the lack of new antibiotics in development. Here, we report that synthetic amphiphiles represent a new class of adjuvants that rescue antibiotic potency against multidrug resistant bacteria. Hydraphiles are amphiphiles, designed and synthesized in Gokel lab, that show many of the same properties as protein ion channels. Hydraphiles were previously shown to have antimicrobial activity against Escherichia coli, Bacillus subtilis and Saccharomyces cerevisiae. Here, we report that hydraphiles recover the …

Endogenous Small Interfering Rna: Insights Into Esirna Biogenesis And Their Precursors, Andrew White Harrington

Dissertations

Rarely in research is the path to an answer straightforward. Initial questions lead to more questions, many times doubling back to allow for greater insight into the original question. For example, discovery of interactions between previously unrelated pathways can lead to breakthroughs with regard to understanding of gene regulation. One such novel interaction and the subsequent discoveries this interaction spurred are discussed herein. Transposons, or “Jumping Genes” are mobile genetic elements found throughout all three major domains of life. Transposons comprise 44% of the human genome and possess the ability to move within the genome. This ability makes them an …

Color-Mediated Foraging By Pollinators: A Comparative Study Of Two Passionflower Butterflies At Lantana Camara, Gyanpriya Maharaj

Dissertations

Colorful floral signaling and resulting insect foraging behaviors have only been extensively examined in hymenopteran pollinators, especially bees, in comparison to flies, beetles, and butterflies regardless of their ecological importance. Therefore, my study provides novel information by focusing on foraging behaviors of adult passionflower butterflies, Heliconius melpomene and Dryas iulia, to the color changing flowers of Lantana camara. My dissertation which is divided into four chapters, aims to explore various aspects of color mediate foraging in passionflower butterflies by combining observations in the wild with controlled field and laboratory experiments. In the first chapter I reviewed flower color development and …

Historical Biogeography, Spatial Distribution, And Within-Host Interactions Of Avian Haemosporidian Parasites (Apicomplexa, Haemosporida), Leticia De Souza Soares

Dissertations

This dissertation addresses several aspects of the biogeography and evolution of avian malarial parasites (Haemosporida: Plasmodium and Haemoproteus), and the interactions of these pathogens with their hosts and other avian blood parasites. In Chapter 1, I investigate change in haemosporidian assemblages on the West Indies over millennial time scales, taking advantage of the historical isolation of islands by postglacial rising sea levels. I found that, the prevalence of parasite lineages is highly dynamic over periods from decades to thousands of years. Turnover of lineages requires more time than variation in lineage prevalence, suggesting that competitive exclusion of parasite lineages, likely …

Minority Middle And High School Students' Interest In Science: An Exploration Of Teachers' Perceptions, Caroline Makere

Dissertations

A high school teacher conducted a study about minority middle and high school students’ interest in science. The problem was to find out why African American and Hispanic students were showing very little interest in science. The researcher used four middle school science teachers and nine high school science teachers, all from inner city schools in a big city of the Midwest United States except for one middle school teacher from a nearby suburb. The participants answered a survey questionnaire followed with a face-to-face recorded interview. The findings of the study confirmed that students showed little interest in science due …

Examining The Combined Effects Of Dissolved Oxygen, Temperature, And Body Size On The Physiological Responses Of A Model Macrobenthic Polychaete Species, Capitella Teleta, Kelsey Burns Gillam

Dissertations

While the scientific community is in consensus that coastal systems are threatened by climate change, few climate change studies test the effects of more than one variable directly related to climate change. The dissolved oxygen (DO) levels of the ocean are currently subject to both global warming and eutrophication; 94% of all hypoxia zones are expected to experience >2°C increase by 2035. This dissertation aims to examine how a model organism responds to simultaneous thermal and DO stress involving four levels of DO (100%, 70%, 50%, and 20%) saturation and three temperatures (15°C, 20°C, and 25°C).

The polychaete, Capitella teleta …

A Microbiomic Approach To The Characterization Of The Impacts And Influences Of Viral, Bacterial, And Harmful Algal Bloom Toxins On The Bottlenose Dolphin, Corey David Russo

Dissertations

As apex predators that display high site fidelity Tursiops truncatus (bottlenose dolphin) are indicators of marine ecosystem health. Bottlenose dolphins, additionally, display pathogenesis and immune response similar to that of humans. Humans and coastal bottlenose dolphins, in particular, are constantly exposed to the same industrial, agricultural and domestic toxins and pathogens, contaminants and pollutants. Thus, studies on the bottlenose dolphin are also valuable in bridging the gap between ocean and human health. Bottlenose dolphins are susceptible to viral bacterial and toxin infection. Infection in the bottlenose dolphin manifests itself in the form of mass stranding events, unusual mortality events, chronic …

Investigations Of Storage Root Development In Cassava (Manihot Esculenta Crantz), Yeetoh Chaweewan

Dissertations

The tropical root crop cassava is cultivated for its large starchy storage roots. Understanding critical processes in root tuberization is essential if improvement programs are to secure future yields for farmers. Studies were undertaken to identify critical components of storage root development at the anatomical and gene expression levels. Two types of roots were identified from greenhouse-grown stem cuttings: basal roots, which develop from the stem cut end and are prolific in nature, and nodal roots, which originate from the region of the buried axillary bud. Only nodal roots develop to produce storage organs. Anatomical sectioning was performed to determine …

The Effect Of Auditory Stimulation On Sleep Disruption In West Indian Manatee (Trichechus Manatus Latirostris), Natalija Lace

Dissertations

Florida manatees inhabit waterways where motorized boats are common. Although manatee mortalities resulting from boat strikes are well documented, the effect of boat noise on some manatee behaviors, including rest, has not been investigated. This study focuses on rest behavior and used a playback experiment with four manatees at the Lowry Park Zoo in Florida. We tested their responses to playback stimuli of either boat noise, silence, or manatee calls. A playback trial was initiated when the focal animal showed behavioral characteristics of rest.

Results showed that rest was interrupted in response to the playback of boat noise for each …

Effects Of Human Disturbance On Physiology, Behavior, And Ornamentation In The Eastern Bluebird, Lauren Marjorie Gillespie

Dissertations

Overall, few studies have focused on anthropogenic disturbance on wildlife physiology. Research has typically focused on how environmentally contaminated areas or anthropogenic disturbance (e.g. noise, human activity) influences biodiversity, community structure and behavior of individual animals. However, understanding how disturbance influences some aspects of physiology can require sacrifice of the animal, prohibiting ecologically relevant measures of behavior and reproductive success. This research strives to examine covariation between testosterone (T) and corticosterone (CORT), plumage ornamentation, and behavior in two populations of eastern bluebirds (Sialia sialis) that differ in degree to which their habitat is modified by human activity.

In …

Supplemental Action Learning Workshops: Understanding The Effects Of Independent And Cooperative Workshops On Students’ Knowledge, Kathryn M. Morris

Dissertations

Community colleges enroll more than half of the undergraduate population in the United States, thereby retaining students of varying demographics with extracurricular demands differing from traditional four-year university students. Often in a collegiate lecture course, students are limited in their abilities to absorb and process information presented by their instructors due to content-specific cognitive gaps between the instructor and the student (Preszler, 2009). Research has shown implementation of instructor-facilitated action learning workshops as supplemental instruction may help bridge these cognitive gaps allowing better student conceptualization and dissemination of knowledge (Drake, 2001; Fullilove & Treisman, 1990; Preszler, 2009; Udovick et al., …

Transition Between Phases Of The Annual Cycle: Spring Migration To Breeding In Nearctic-Neotropical Songbirds, Kristen Marie Covino

Dissertations

Appropriate timing of each life-history stage is crucial for seasonally migratory species. The temporal constraints faced by migratory songbirds require that they overlap preparation for breeding with spring migration. However, previous work has focused primarily on male birds and has produced inconsistent results regarding the degree of overlap between these two life-history stages. I study the degree to which migrating male and female songbirds prepare for breeding throughout spring migration as they move towards their breeding grounds. Overall, male migrants show a significant degree of breeding preparation during spring migration as determined by circulating testosterone levels and their ability to …

A Comparative Study Of Isolation In Headwater Fishes, Bjorn Victor Schmidt

Dissertations

Headwater resident fishes may be prone to a high rate of population fragmentation within river networks because large streams have habitat conditions outside of their preferred ecological niche and may limit gene flow in the dendritic ecological network. To investigate patterns of population structure, asymmetrical gene flow, and influences on genetic distance and isolation from connecting habitat pathways, species specific ecological traits, and basin scale characteristics, a multi-species, multi-regional study was performed. Six headwater species of fish from four taxonomic groupings were sampled for genetic material in three regions of paired neighbor drainages and then genotyped for eight microsatellite loci. …