Biology Commons^™

Homoplastic Microinversions And The Avian Tree Of Life, E. L. Braun, R T. Kimball, K. L. Han, N. R. Luhasz-Velez, A. J. Bonilla, Jena L. Chojnowski, J. V. Smith, R. C. Bowie, M. J. Braun, S. J. Hackett, J. Harshman, C. J. Huddleston, B. D. Marks, W. S. Moore, S. Reddy, F. H. Sheldon, C. C. Witt, T. Yuri

Natural Sciences Faculty Publications

BACKGROUND:

Microinversions are cytologically undetectable inversions of DNA sequences that accumulate slowly in genomes. Like many other rare genomic changes (RGCs), microinversions are thought to be virtually homoplasy-free evolutionary characters, suggesting that they may be very useful for difficult phylogenetic problems such as the avian tree of life. However, few detailed surveys of these genomic rearrangements have been conducted, making it difficult to assess this hypothesis or understand the impact of microinversions upon genome evolution.

RESULTS:

We surveyed non-coding sequence data from a recent avian phylogenetic study and found substantially more microinversions than expected based upon prior information about vertebrate …

Range-Expanding Populations Of A Globally Introduced Weed Experience Negative Plant-Soil Feedbacks, Krikor Andonian, José L. Hierro, Liana Khetsuriani, Pablo Becerra, Grigor Janoyan, Diego Villarreal, Lohengrin Cavieres, Laurel R. Fox, Ragan M. Callaway

Biological Sciences Faculty Publications

Background: Biological invasions are fundamentally biogeographic processes that occur over large spatial scales. Interactions with soil microbes can have strong impacts on plant invasions, but how these interactions vary among areas where introduced species are highly invasive vs. naturalized is still unknown. In this study, we examined biogeographic variation in plant-soil microbe interactions of a globally invasive weed, Centaurea solstitialis (yellow starthistle). We addressed the following questions (1) Is Centaurea released from natural enemy pressure from soil microbes in introduced regions? and (2) Is variation in plant-soil feedbacks associated with variation in Centaurea's invasive success? Methodology/Principal Findings: We conducted greenhouse …

Pcr Amplification Of Trypanosoma Cruzi - Specific Dna From Raccoon Blood Samples, Colin Moss

Mahurin Honors College Capstone Experience/Thesis Projects

The parasitic protist Trypanosoma cruzi is the causative agent of Chagas Disease. Chagas Disease causes greater than 15,000 deaths each year, and nearly 28 million people are believed to be at risk of infection in Central and South America. This parasite has been described in many mammalian host species and has also been described in the United States. The purpose of this study was to attempt to use PCR to amplify T. cruzi-specific DNA directly from blood samples obtained from raccoons (Procyon lotor) trapped in Warren and Barren Counties of Kentucky in 2007 and 2008. DNA was …

Mitochondrial Dna Inheritance In Bivalves: A Comparative Study Involving The Unique System Of Doubly Uniparental Inheritance, Sarah Heishman

Honors Theses

A comparative study of Doubly Uniparental Inheritance (DUI) in the bivalve mollusks Mytilus edulis and Geukensia demissa has yielded unanticipated results. Around the world, it has been reported that members of the taxonomic family Mytilidae (along with the families of Unionidae and Veneridae) consistently exhibit DUI. However, the hard-to-place Geukensia demissa, which is a member of this family, has had varying reports of its DUI status. Most reports involving G. demissa vary with the location in which it is being studied, which prompts more questions than it answers. Due to many months of unsuccessful DNA purification attempts, sequencing and an …

Recovery Of The Long-Spine Sea Urchin, Diadema Antillarum, In Discovery Bay, Jamaica, 27 Years After Its Mass Mortality, Jessica Keller

Honors Theses

The long-spined sea urchin, Diadema antillarum, is a well-studied keystone herbivore on Caribbean coral reefs. The sea urchin controls benthic algae populations by grazing on macroalgae. Destruction caused by Hurricane Allen in 1980, along with the mass mortality of this urchin in 1983, greatly impacted Caribbean reef systems. In Discovery Bay, Jamaica, Diadema densities have been heavily studied over the years, allowing a review of their recovery and a prediction of their future. In Discovery Bay, densities were recorded to be up to 9.3 and 13.9 ± 2.8 m-2 at 5 m depth on the forereef before the mass mortality. …

Effects Of Exposure To Low, Ecologically Relevant Doses Of Atrazine On Somatic And Gonadal Development In American Toad (Bufo Americanus) Tadpoles, Tyler Davis Hoskins

Undergraduate Honors Thesis Collection

Atrazine is the most commonly used herbicide in the United States, with 80 million pounds applied annually, making it the most common contaminant of ground and surface water nationwide. It has been shown to act as a potent endocrine disrupter in amphibians, causing altered somatic and gonadal development in the ecologically relevant part per billion range; as a result, it has been hypothesized that atrazine may be a major factor behind amphibian declines. However, responses of different species to the chemical vary widely, and have made predicting susceptibility difficult. Recently, it has been shown that life history can serve as …

The Proliferation Of Vascular Smooth Muscle Cells Depends On Thioredoxin 1 Protein In A Model Of Pulmonary Hypertension, Viktoria Nelin

Mahurin Honors College Capstone Experience/Thesis Projects

Pulmonary hypertension (PH) is a disease which manifests itself in the lungs of both adults and children. Vascular proliferation and remodeling are the hallmarks of PH and are found mainly in the pulmonary arterial smooth muscle cells (PASMC). The cause of PASMC proliferation and vascular remodeling in PH is poorly understood. Hypoxia, or low oxygen content, underlies many forms of PH. Hypoxia results in alterations in the redox balance of the PASMC. Therefore, the aim of this study was to examine the role of the thioredoxin system, an antioxidant system in the cell, in hypoxia-induced proliferation in PASMC. Protein was …

Assessing Social Benefits Of Domestic Rainwater Harvesting In Southern Kenya, Lindsey M. Filiatreau

Mahurin Honors College Capstone Experience/Thesis Projects

In the Kasigau location of the Voi District of Kenya, severe rainwater shortages closed fourteen water collection stations in 2008 and 2009, leaving ten water sources to service 15,000 people in the region. Few families in the area have domestic rainwater harvesting systems which are an easily implemented, low-cost means of water collection. I investigated the ability of rainwater catchment systems to modify family time budgets (by reducing water collection time) and lessen the severity of water scarcity (by supplying families a significant amount of water). Forty families participated in the research, 20 of whom received free installation of a …

Once On The Dark Continent, Katrina Alexandria Bidwell

Mahurin Honors College Capstone Experience/Thesis Projects

Set in the fictional village of Buguta in post-genocide Rwanda, Once on the Dark Continent follows the experiences of a young doctor working for the Doctors Without Borders Program. Dr. Erica Davis unwittingly finds herself in a country where the past has continued to repeat itself a decade after a devastating civil war, unbeknownst to most of the outside world. Their history isn’t the only thing plaguing the villagers like a parasite: Erica’s careful attention to the patients at the Buguta clinic leads her to diagnose them with toxoplasmosis, a revelation that has the potential to begin solving the myriad …

Transcriptional Regulation Of Nitrogenase And Identification Of A Fructose Transport System In Anabaena Variabilis, Justin Lynn Ungerer

Dissertations

Little is known about the regulation of nitrogenase genes in cyanobacteria. Transcription of the nifH1 and vnfH genes, encoding dinitrogenase reductases for the heterocyst-specific Mo-nitrogenase and the alternative V-nitrogenase, respectively, was studied using a lacZ reporter. Two promoters were found to be responsible for expression of nifHDK; a weak promoter within nifU1 and a strong promoter upstream of nifB (the nifB1 promoter). The region immediately upstream of vnfH did not drive expression of lacZ, however the region that included the promoter for the upstream gene, ava4055 did. Characterization of the previously reported nifH1 and vnfH transcriptional start sites by 5' …

Avian Abundance And Diversity In Crep And Fescue Fields In The Summer And Winter Related To Vegetation Structure In The Upper Green River Watershed, Ky, Thomas A. Hulsey

Mahurin Honors College Capstone Experience/Thesis Projects

Grassland bird populations have been undergoing dramatic declines in the last fifty years due to loss and degradation of habitat. The Conservation Reserve Enhancement Program (CREP) was initiated in the upper Green River Watershed of south-central Kentucky to improve water quality and provide wildlife habitat. Many studies have previously examined how similar programs in other states have contributed to grassland bird populations; in this study we are examining how the Kentucky CREP program is influencing bird populations, particularly grassland birds, and contributing to the conservation of these species. Bird and vegetation surveys were conducted during the summer of 2008 and …

Dna Sequence Variation In The Wingless Gene Product In Buckeye Butterflies (Genus Junonia), Bonnie Mccullagh

Mahurin Honors College Capstone Experience/Thesis Projects

Wingless is a highly conserved gene important to cell determination in development. In Drosophila, the wingless gene product has been identified as responsible for wing patterning. In Bicyclus anynana and Junonia coenia, wingless gene product is expressed in a fashion that suggests that it is involved in butterfly wing color pattern development. The wingless gene product has been implicated as a potential focal signal for patterning the eyespot of Junonia butterflies. I have shown that extensive DNA sequence variation (26.04% of the sequenced region) exists in 402 bp of wingless coding sequence among 338 specimens of Junonia from …

Screening Rnai Transformants Of Chlamydomonas For Reduced Expression Of The Photoreceptor Cryptochrome, Jeremy Webb

Mahurin Honors College Capstone Experience/Thesis Projects

Chlamydomonas reinhardtii is a unicellular green alga. In C. reinhardtii, three types of photoreceptors are known to be present: rhodopsins, phototropins, and cryptochromes. The single cryptochrome is the most likely photoreceptor for adjusting the circadian clock to the daily light/dark cycles, because cryptochromes are involved in clock entrainment in higher plants and insects. In this segment of the research, C. reinhardtii strains, which were genetically modified through transformation with a RNA interference construct, were screened for reduction in cryptochrome compared to the control strain. After C. reinhardtii cultures were harvested in complete darkness, all soluble proteins were extracted from the …

Assessment Of Prenatal Care And Perinatal Outcomes In Kasigau, Kenya, Allison Smith

Mahurin Honors College Capstone Experience/Thesis Projects

The World Health Organization (WHO) implemented the Millennium Declaration in 2000 to establish global health goals to be achieved by 2015. Two of these Millennium Development Goals (MDG’s) are directly related to maternal, neonatal and child health. Healthcare during the prenatal period can help achieve the WHO MDG’s for maternal health and child mortality. Evidence has shown that women in Kenya have limited access to prenatal care. This study focused on the prenatal care and postnatal outcome trends of the women in Kasigau, Kenya. Participants were surveyed in three villages (Rukanga, Makwasinyi, and Bhuguta) to determine if prenatal care was …

Role Of Stress In The Onset Of Diabetes Mellitus In Mice., Lindsey Brianne Mcamis

Undergraduate Honors Theses

This study investigated the effects of stress on the onset of chemically-induced diabetes mellitus in mice. Sixty male ICR mice were randomly divided into 6 groups of 10 mice. A factorial arrangement of 2 factors (streptozotocin (STZ) and stress) was used to produce 6 treatments. Three levels of STZ (0, 25 and 50 mg/kg bodyweight) and 2 levels of stress (stress and no-stress) were used. Stressed groups were exposed to restraint stress 6 hours daily for 18 days. Mice bodyweight, feed consumption and blood glucose levels were recorded regularly during the study period. At the end of the study period, …

A Bioaugmentation Approach To The Prevention Of Chytridiomycosis, Carly Muletz

Masters Theses, 2010-2019

Symbiosis is defined as two species living together. This association between organisms is present at all taxonomic levels making it a ubiquitious phenomenon in ecology and evolution. I studied symbiosis among three species: a mutualistic bacterium, a parasitic fungus and an amphibian host. The first goal of my research was to examine how the mutualistic bacteria of amphibians’ skin are acquired. I demonstrated that a cutaneous mutualistic bacterial species, Janthinobacterium lividum, was transmitted environmentally, via soil, to the skin of an amphibian species, Plethodon cinereus. These results indicate that amphibians’ mutualistic bacteria can be acquired from the environment. Based upon …

Influence Of Estradiol And Exercise On Foot Laxity, Ankle Laxity, And Plantar Loading In College Athletes, Kristina Teri Silke

Masters Theses, 2010-2019

As female participation in athletics has increased, it has become apparent that sex differences exist in sports-related injury types and frequencies. The purpose of this study is to examine the effects of exercise and the sex hormone estradiol on sex differences in foot and ankle laxity and plantar pressure. We measured serum estradiol, pre- and post-fatigue ankle and toe laxity, and pre- and post-fatigue plantar pressure in 47 subjects (34 female, 13 male) once a week for 12 weeks. We compared laxity and plantar pressure in females not using oral contraceptive (NOC) to females using oral contraceptives (OC) and males. …

Ontogeny Of Postcranial Morphology And Locomotor Behavior In Propithecus Verreauxi Coquereli And Lemur Catta, Stephanie Ann Wolf

Masters Theses, 2010-2019

Despite living under the same environmental pressures and sympatrically in many cases, Propithecus verreauxi and Lemur catta have evolved very different strategies for survival in stochastic environmental conditions. P. verreauxi show slow somatic growth, low maternal investment, and rapid dental growth while L. catta show faster somatic growth, high maternal investment, and slower dental growth. P. v. coquereli are highly specialized for vertical clinging and leaping (VCL) among lemurs, while L. catta, the most terrestrial of lemurs, use a wider variety of locomotor types including quadrupedalism, climbing, and leaping. P. v. coquereli have unusually long legs and muscular thighs while …

Interleukin-3 Promotes Susceptibility In A Mouse Model Of Cutaneous Leishmaniasis, Bryan Lewis Saunders

Masters Theses, 2010-2019

Cutaneous leishmaniasis (CL), a vector-borne infectious disease caused by protozoan parasites of the genus Leishmania, is one of the most important neglected infectious diseases worldwide. Currently, 10 million people in 82 (mostly developing) countries are infected. Those infected develop ulcerative skin lesions on exposed parts of the body, causing serious disability and permanent scarring. All mice are susceptible to infection with Leishmania major, however, the outcome of infection is different depending on the mouse strain. For example, resistant C57BL/6 mice develop lesions, which like in humans, ultimately heal. In contrast, lesions in susceptible BALB/c mice progressively worsen, ultimately resulting in …

A Taxonomic Revision Of The Endemic Members Of Varronia P. Br. (Cordiaceae) In The Galápagos Islands, Julia Kathryn Stutzman

Masters Theses, 2010-2019

The Galápagos Islands have long been an arena for biological diversity, scientific discovery, and conservation. Accurate identification and documentation of the flora of the Galápagos continue to aid conservation efforts. The purpose of this study was to conduct a taxonomic revision of the endemic members genus Varronia (Cordiaceae) on the Islands: V. revoluta (Hook. f.) Andersson, V. leucophlyctis (Hook. f.) Andersson, V. canescens Andersson, and V. scouleri (Hook. f.) Andersson. Taxonomic uncertainty among these species has resulted in difficult evaluation of their potential for conservation status by the International Union for the Conservation of Nature. The present taxonomic study concludes …

Human-Wildlife Conflict On Small, Subsistence Farms In Kenya, Christopher B. Colonna

Mahurin Honors College Capstone Experience/Thesis Projects

As human populations expand, wildlife suddenly competes with humans for resources and confrontation arises as a result. Rural Africa is typical of this problem. We surveyed local owners of small farms within the five villages surrounding Mount Kasigau in Southeast Kenya to quantify losses due to wildlife depredation on both subsistence and cash crops as well as to discover the patterns and variables influencing farmer-wildlife confrontations in the region. We found no statistically significant correlations among the value of damage per acre, the distance from the bush, or the distance to the nearest water source. We did find statistical significance …

Characterization Of Expression Of The Kcne Gene Family In Zebrafish, Danio Rerio, Lauren Vernlund

Honors Senior Capstones and Theses

The KCNE gene family codes for five transmembrane accessory proteins, "minK related peptides" or Mirps, involved in the modification of voltage-gated potassium (Kv) channels, K+ selective pores vital in the regulation of membrane potential and repolarization in all organisms. In mammals, all five KCNE gene members are conserved and active in the heart. In the zebrafish Danio rerio, there are no apparent orthologs for KCNE2 or KCNE5, yet they contain Kv channels with homologous structure, function, and Mirp regulatory behavior to other organisms. Sequence analysis of wildtype zebrafish KCNE1, 3 and 4, and rtPCR on RNA from zebrafish tissues …

Prescribed Fire Effects On The Summer And Fall Herbs Of Mesic Deciduous Forests, Margaret Wilder

Mahurin Honors College Capstone Experience/Thesis Projects

After years of fire suppression, high intensity forest fires were destructive to surrounding areas. Historically, fire was common in the eastern United States, but was suppressed over the past century, and recently has become a major tool in forest management. But to date, there have been no studies on the influence of fire on mesic sites in the eastern United States. Because fire is being reintroduced as a management practice, it is critical to know the influence of fire in this region. This study seeks to understand the influences of fire on summer and fall herbs in the western mesophytic …

Variation In The Branching Pattern Of The Four Major Caudal Vessels Emerging From The External Carotid Artery, Sara B. Heltzel

Masters Theses, 2010-2019

The branching pattern of vessels emerging from the external carotid artery (ECA) displays considerable variation. Knowledge of this variation is of particular interest to clinicians. There are few reports in the literature assessing these differences with regard to sex and sidedness (i.e., branching patterns of the right vs. left neck). The objective of this study was to assess the origin of the four primary caudal branches of the external carotid artery: the superior thyroid (STA), lingual (LA), facial (FA), and occipital (OA) arteries, in addition to the level of common carotid artery bifurcation (CB), with regard to sex, and side. …

Phylogenetics And Diversification Of Escallonia (Escalloniaceae), Felipe Zapata

Dissertations

Despite a large accumulation of evidence on the high richness of plant species in the mountains of South America, little is known about the historical underpinnings of this diversity. To contribute to our understanding of the origin and diversification of plant species in these mountains, I analyzed geographic patterns of variation in molecular and phenotypic characters for the genus Escallonia L.f. (Escalloniaceae), a group of shrubs widespread in montane habitats in South America. Molecular phylogenetic analyses using chloroplast and nuclear loci revealed i) that Escallonia is monophyletic, ii) a remarkable level of geographical phylogenetic structure, and iii) a widespread absence …

Septin Filaments Exhibit A Dynamic, Paired Organization That Is Conserved From Yeast To Mammals, Bradley S. Demay, Xiaobo Bai, Louisa Howard, Patricia Occhipinti, Rebecca A. Meseroll, Elias T. Spiliotis, Rudolf Oldenbourg, Amy S. Gladfelter

Dartmouth Scholarship

The septins are conserved, GTP-binding proteins important for cytokinesis, membrane compartmentalization, and exocytosis. However, it is unknown how septins are arranged within higher-order structures in cells. To determine the organization of septins in live cells, we developed a polarized fluorescence microscopy system to monitor the orientation of GFP dipole moments with high spatial and temporal resolution. When GFP was fused to septins, the arrangement of GFP dipoles reflected the underlying septin organization. We demonstrated in a filamentous fungus, a budding yeast, and a mammalian epithelial cell line that septin proteins were organized in an identical highly ordered fashion. Fluorescence anisotropy …

The History Of Zoological Gardens And The State, Federal And International Laws That Govern Them, Morgan Maxwell

Mahurin Honors College Capstone Experience/Thesis Projects

The history of zoos in North America can be traced back through 18th century Europe to ancient civilizations such as the Romans. The menageries of ancient Rome were far different from modern zoos that stress conservation, education, and research as primary objectives. Zoos are still evolving and changing to become more suitable for captive animals and to ensure their animals’ health and well-being. An examination of state wildlife laws reveals that there are more laws that pertain to wildlife at the state and local level than at any other level of government. Federal wildlife laws are few in number and …

Changes In Leaf Morphology, Photosynthesis And Nitrogen Content In Two Coastal Shrubs, Elizabeth Kost

Theses and Dissertations

It is important to understand mechanisms that facilitate expansion of two common shrubs, Morella cerifera and Baccharis halimifolia in coastal environments. The purpose of my study was to investigate the physiological and structural changes that occur as leaves age. Photosynthesis, incident light, chlorophyll, and leaf C:N ratios were quantified for young, intermediate, and old leaves (distal, central and proximal leaves, respectively). Leaf structural differences were also compared. Leaves did not change morphologically with age. Light decreased with leaf age and during winter months. Photosynthesis showed no seasonal or age related patterns. Chlorophyll increased initially and then declined with age due …

Effective And Affordable Novel Arsenic Removal Technology, Benadin Varajic

Mahurin Honors College Capstone Experience/Thesis Projects

Arsenic contaminated drinking water is a serious worldwide issue faced by millions of people every day. Long term exposure to arsenic levels above the World Health Organization’s (WHO) standard of 10 ppb has been associated with severe detrimental health effects including cardiovascular disease and cancer. Although current water purification technologies exist, their implementation is an unrealistic goal by many third world nations for a variety of reasons, the most common being the cost associated with what are typically complicated procedures. This study strives to discover an effective and affordable novel arsenic removal technology.

The first step of this study was …

Ecosystem Management Of The Missouri River From Gavins Point Dam To Ponca State Park, Nebraska, Robert S. Nebel

Biology Faculty Publications

•Authorized by a 1978 amendment to the National Parks and Recreation Act (PL 95- 625) which amended the Wild and Scenic Rivers Act of 1968 (PL 90-542)

• Corps is authorized to construct recreational development, bank stabilization, and other recreational river features as necessary to support the values for which the river was designated

• Life-of-project funding ceiling of $21 million; approximately $3.2 million spent to date

• The Corps and National Park Service signed a 1980 Cooperative Agreement outlining each agency's responsibilities

• The General Management Plan has recently been updated (1999) with an environmental emphasis