Biology Commons^™

Algae Living In Salamanders, Friend Or Foe?, John Burns, Ryan R. Kerney

Biology Faculty Publications

Roughly speaking, our bodies use energy from the sun, but we can't use sunlight directly. Instead, plants and algae collect sunlight and store it as chemical energy through the process of photosynthesis. We can access that fuel directly when we eat plants, or indirectly when we eat other animals that eat plants.

However, in some invertebrate animals (those without a backbone) the relationships to algae are more intimate. Tiny single-celled algal "symbionts" can actually live inside the cells of living corals and small animals like hydra that live in water. The algae live in a safe environment inside animal …

Association Of P53 Polymorphisms, Pah-Like Fluorescence, And Developmental Trends In Caught Gulf Menhaden To Crude Oil Exposure Post-Deepwater Horizon Oil Spill: A Holistic Approach, Kevin Luiz Frisina

Capstone Projects/Undergraduate Honors Theses

Environmental pollution is of great concern in the United States. Of special concern is the chronic effects from the exposure to potentially carcinogenic compounds released from episodic environmental disasters (e.g. 911 twin-towers, oil spills). Disasters like the British Petroleum (BP) Deepwater Horizon oil spill in the Gulf of Mexico (GOM), affected many marine organisms, exposing them to crude oil polycyclic aromatic hydrocarbons (PAHs), some of which are known carcinogenic. Despite many marine-based consumer products (e.g. fish oil, animal feed, fertilizer) were known affected by the BP oil spill, bioaccumulation and chronic toxicity of the crude oil PAHs into marine organisms …

The Physiological Effects Of Exercise On California Yellowtail (Seriola Dorsalis) White Muscle, Julie Giannini

Undergraduate Honors Theses

California yellowtail (Seriola dorsalis) is a species of ray-finned fish that demonstrates a significant increase in muscle mass in response to sustained exercise at optimal swimming speed. In this study, three groups of yellowtail have been analyzed for a 6-month period to determine if the length of exercise affects white muscle fiber development and if these changes persist when the exercised fish have been returned to a normal “resting” condition. Gene analysis was performed to test if MyoD, a myogenic regulatory factor, was upregulated in response to exercise. To test these questions, the groups compared included a control …

Effect Of Adult Chemical Cues On Molting Of Fiddler Crab Megalopae In Low Salinity Seawater, Sydney Rilum

Undergraduate Honors Theses

Three species of fiddler crabs, Uca minax, U. pugnax, and U. pugilator, are commonly found in estuaries along the Atlantic coast, each with distinct adult habitats differing in salinity and sediment grain size. Prior research has found evidence for larvae exhibiting selective settlement; however, the degree to which and the method by which they choose their species-appropriate habitat to settle in is still unknown. Additionally, a recent study determined that chemical cues from adult crabs stimulate molting in field-caught fiddler crab megalopae, as previously determined in lab-reared megalopae; however, in 35 ppt seawater, few U. minax molted. …

Zero Textbook Cost Syllabus For Env 1004 (Fundamentals Of Ecology-Lab), Aleksandra Kravtsova

Open Educational Resources

Fundamentals of Ecological Research is a hands-on course designed to teach students the basic concepts and methodologies used in the field of ecology. The significance of ecological research to current environmental issues, both local and global, will be stressed throughout the course.

Parasite Rearing And Infection Temperatures Jointly Influence Disease Transmission And Shape Seasonality Of Epidemics, Marta S. Shocket, Daniela Vergara, Andrew J. Sickbert, Jason M. Walsman, Alexander T. Strauss, Jessica L. Hite, Meghan A. Duffy, Carla E. Caceres, Spencer R. Hall

School of Biological Sciences: Faculty Publications

Seasonal epidemics erupt commonly in nature and are driven by numerous mechanisms. Here, we suggest a new mechanism that could determine the size and timing of seasonal epidemics: rearing environment changes the performance of parasites. This mechanism arises when the environmental conditions in which a parasite is produced impact its performance—independently from the current environment. To illustrate the potential for “rearing effects”, we show how temperature influences infection risk (transmission rate) in a Daphnia-fungus disease system through both parasite rearing temperature and infection temperature. During autumnal epidemics, zooplankton hosts contact (eat) fungal parasites (spores) reared in a gradually cooling environment. …

Thermoregulatory Dysfunction In Multiple Sclerosis, Dustin R. Allen

Applied Physiology and Wellness Theses and Dissertations

Multiple sclerosis (MS) is a progressive neurological disease of the central nervous system (CNS) affecting an estimated 2.3 million people worldwide. Marked by lesions in the brain and spinal cord, MS leads to conduction abnormalities in the CNS. Evidence suggests ~60% of individuals with MS experience temporary worsening of their symptoms upon exposure to heat. Adding complexity, observational evidence suggests these individuals exhibit reduced thermoregulatory responses in upon increases in core temperature. Consequently, these individuals face a vicious cycle of heat sensitivity and thermoregulatory dysfunction, substantially impacting their quality of life. With this in mind, our lab is dedicated to …

Radical Social Ecology As Deep Pragmatism: A Call To The Abolition Of Systemic Dissonance And The Minimization Of Entropic Chaos, Arielle Brender

Student Theses 2015-Present

This paper aims to shed light on the dissonance caused by the superimposition of Dominant Human Systems on Natural Systems. I highlight the synthetic nature of Dominant Human Systems as egoic and linguistic phenomenon manufactured by a mere portion of the human population, which renders them inherently oppressive unto peoples and landscapes whose wisdom were barred from the design process. In pursuing a radical pragmatic approach to mending the simultaneous oppression and destruction of the human being and the earth, I highlight the necessity of minimizing entropic chaos caused by excess energy expenditure, an essential feature of systems that aim …

Song Recognition And Heterospecific Associations Between 2 Fairy-Wren Species (Maluridae), Allison E. Johnson, Christina Masco, Stephen Pruett-Jones

School of Biological Sciences: Faculty Publications

Although heterospecific associations beneficial to one or both species involved (e.g. commensalisms or mutualisms) are common, it is generally assumed that interactions between species are transient and not particular to individuals. However, long-term interactions between individuals of different species do occur. In such heterospecific social groups, discrimination between heterospecific individuals may be beneficial, allowing individuals to direct beneficial or aggressive behaviors towards appropriate targets. Here, we describe heterospecific groups composed of splendid and variegated fairy-wrens (Malurus splendens and M. lamberti) and provide the first experimental evidence that recognition of heterospecific group members occurs across species. In these species, …

Social Play Predicts Docility In Juvenile Ground Squirrels, James Hurst-Hopf, Scott L. Nunes

Undergraduate Honors Theses

We evaluated the hypothesis that social play behavior influences the development of temperament in young animals, using docility as a measure of temperament. We observed the play behavior of juvenile Belding’s ground squirrels (Urocitellus beldingi) during the developmental period in which play primarily occurs, and conducted behavioral tests measuring docility at the beginning and end of the play interval. Tests involved handling squirrels and recording their responses. Body mass was a reliable predictor of docility at the beginning of the play period. Rates of social play and maximum distances traveled from the natal burrow during the play interval …

The Indestructible Insect: Velvet Ants From Across The United States Avoid Predation By Representatives From All Major Tetrapod Clades, Brian G. Gall, Kari L. Spivey, Trevor L. Chapman, Robert J. Delph, Edmund D. Brodie Jr., Joseph S. Wilson

Biology Faculty Publications

Velvet ants are a group of parasitic wasps that are well known for a suite of defensive adaptations including bright coloration and a formidable sting. While these adaptations are presumed to function in antipredator defense, observations between potential predators and this group are lacking. We conducted a series of experiments to determine the risk of velvet ants to a host of potential predators including amphibians, reptiles, birds, and small mammals. Velvet ants from across the United States were tested with predator’s representative of the velvet ants native range. All interactions between lizards, free-ranging birds, and a mole resulted in the …

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 …

Understanding The Impacts Of Urbanization On The Avian Community Of Portland Oregon And Evaluation Of The Portland Oregon Backyard Habitat Certification Program, Andrew Daniel Gibbs

Dissertations and Theses

Over fifty percent of humans live in cities. The environmental cost of this is massive, as is the potential for utilizing privately held yards as an integral part of conservation in urban areas. The Backyard Habitat Certification Program (BHCP) in Portland, Oregon, was established to reduce invasive plants, support wildlife, and promote conservation. The program involves > 3000 yards certified at three tiers. While onsite inspections are required to verify compliance, there has never been an assessment of the value of these yards to wildlife. Chapter 1 examined the relationships between the urban landscape and bird distributions outside of yards. Chapter …

Target Sequence Capture Of Nuclear-Encoded Genes For Phylogenetic Analysis In Ferns, Paul G. Wolf, Tanner A. Robison, Matthew G. Johnson, Michael A. Sundue, Weston L. Testo, Carl J. Rothfels

Biology Faculty Publications

Premise of the Study

Until recently, most phylogenetic studies of ferns were based on chloroplast genes. Evolutionary inferences based on these data can be incomplete because the characters are from a single linkage group and are uniparentally inherited. These limitations are particularly acute in studies of hybridization, which is prevalent in ferns; fern hybrids are common and ferns are able to hybridize across highly diverged lineages, up to 60 million years since divergence in one documented case. However, it not yet clear what effect such hybridization has on fern evolution, in part due to a paucity of available biparentally inherited …

A Comparison Of Salinity Effects From Hurricanes Dolly (2008) And Alex (2010) In A Texas Lagoon System, Joseph L. Kowalski, Hudson R. Deyoe, Gilbert H. Boza Jr., Donald L. Hockaday, Paul V. Zimba

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

A comparison of salinity effects from hurricanes Dolly (2008) and Alex (2010) in a Texas lagoon system.Hurricanes are not uncommon along the Gulf of Mexico coast, but there are few studies of the effects they have on coastal embayments. Hurricanes Dolly (2008) and Alex (2010) were both Category 2 storms affecting the Lower Laguna Madre (LLM) of Texas. Surveys were performed to assess poststorm water quality after landfall of both storms at up to 18 sample stations. The main difference between storm effects was salinity reduction because of stormwater input from the watershed. Effects from Hurricane Dolly were of short …

Bio Buzz Newsletter, Issue 15, May 2018, Department Of Biology

Biology Buzz Newsletter

Denison University, Department of Biology newsletter for Spring 2018.

Population Structure, Demographic History, And Environmental Niche Of The Sand Fly Disease Vector Lutzomyia Shannoni (Dyar) (Diptera: Psychodidae) In The U.S., Mexico, And Colombia, Matthew E. Wolkoff

Biology Theses

Lutzomyia shannoni (Dyar, 1929) (Diptera: Psychodidae) is the only known sand fly vector of vesicular stomatitis virus, a putative leishmaniasis vector, and also boasts the widest distribution of any sand fly in the New World. Research on Lu. shannoni in Central and South America has revealed genetically divergent subpopulations; however, tentative analysis of Lu. shannoni in the U.S. has failed to detect any significant population structure, even between specimens collected from highly disparate localities.

The present study used four molecular markers to more closely investigate the population structure of Lu. shannoni in the U.S., and assess the species’ relationships with …

Development And Function Of Retinal Ganglion Cell Circuits, Nai-Wen Tien

Arts & Sciences Graduate Student Theses and Dissertations

The function of our nervous system relies on specific patterns of synaptic connections between diverse neuronal cell types. My thesis research addressed how cell-type-specific patterns of connectivity emerge in the developing mouse retina and how they enable mature retinal neurons to detect specific sensory stimuli.Spike trains of the approximately 40 retinal ganglion cell (RGC) types in mammals encode specific features and events in the visual world, and are the sole source of visual information to the brain. Recent studies have begun to dissect the presynaptic circuits underlying diverse RGC light responses, but how cell-type-specific retinal circuits emerge during development is …

Host Determinants Of Protection And Pathogenesis During Chikungunya Virus Infection, Lindsey Elaine Cook

Arts & Sciences Graduate Student Theses and Dissertations

Chikungunya virus (CHIKV) is a mosquito-transmitted alphavirus that causes acute and chronic polyarthritis. The virus has rapidly emerged over the last decade, and in 2013, CHIKV spread to the Western Hemisphere for the first time, infecting more than 1.8 million people. CHIKV targets the joints and musculoskeletal tissues, resulting in severe myalgia and symmetric polyarthritis that clinically mimics rheumatoid arthritis. Currently, no approved treatment is effective in preventing or controlling CHIKV infection or disease. Pathogenesis of CHIKV is still poorly understood but is thought to reflect an interplay between viral replication and detrimental immune responses. CHIKV patients have increased numbers …

Novel Approaches To Studying The Effects Of Cis-Regulatory Variants In The Central Nervous System, Susan Shen

Arts & Sciences Graduate Student Theses and Dissertations

For decades, studies of the genetic basis of disease have focused on rare coding mutations that disrupt protein function, leading to the identification of hundreds of genes underlying Mendelian diseases. However, many complex diseases are non-Mendelian, and less than 2% of the genome is coding. It is now clear that non-coding variants contribute to disease susceptibility, but the precise underlying mechanisms are generally unknown. Cis-regulatory elements (CREs) are transcription factor (TF)-bound genomic regions that regulate gene expression, and variants within CREs can therefore modify gene expression. The putative locations of CREs in a variety of cell types have been identified …

Discovering Rare Hematopoietic Clones Harboring Leukemia-Associated Mutations Using Error-Corrected Sequencing, Andrew Lee Young

Arts & Sciences Graduate Student Theses and Dissertations

Cancer is a heterogeneous group of diseases that currently takes over half a million lives per year in the United States alone. Our understanding of cancer has improved dramatically over the last forty years, beginning with the discovery that cancer is a disease of the genome. Currently, the set of somatic mutations found in malignancy are largely known. The specific somatic mutations driving an individual’s disease can be readily assessed at clinical presentation. Additionally, the functional consequences for many of these mutations are known as well as their role in tumorigenesis. Despite this understanding, a cure for cancer remains elusive.Acute …

Effect Of Bmp Treatment On Periostin Gene Expression In Pre-Osteoblastic Mc3t3-E1 Mouse Cells, Vincent Lee Khang

UNLV Theses, Dissertations, Professional Papers, and Capstones

Periostin is a secreted, extracellular matrix (ECM) protein widely expressed within collagen-rich fibrous connective tissues of the body including the periodontal ligament (PDL), bone, skin, heart, and cornea. Periostin has been shown to serve many important regulatory functions including cell adhesion, cell motility, wound healing and of particular importance to the dental field, differentiation of osteoblasts. The deletion of periostin compromises osteoblast attachment to bone matrix and induces a reduction in mineralization and expression of bone markers, including type I collagen, osteocalcin, osteopontin and alkaline phosphatase. Periostin has also been shown to play a significant role in collagen fibrillogenesis by …

Digging Biomechanics In Geomyoid Rodents, Alexis Moore Crisp

UNLV Theses, Dissertations, Professional Papers, and Capstones

Subterranean digging behaviors provide opportunities for protection, access to prey, and predator avoidance for a diverse array of vertebrates, yet studies of the biomechanics of burrowing have been limited by the technical challenges of measuring kinetics and kinematics of animals moving within a substrate. Prior studies of burrowing have recorded a single axis of x-ray video and/or force. However, empirical observations show that burrowing is not restricted to a single axis or plane. I describe a new system called a ‘tunnel-tube’ for measuring 3D reaction force during burrowing. This tunnel-tube has two separate tubes, one ‘entry tube’ that has no …

Prevalence Of Cariogenic Microbial Flora Among Scardovia Wiggsiae-Positive And Negative Patients, Amy Tam

UNLV Theses, Dissertations, Professional Papers, and Capstones

The formation of dental caries (cavities) is a complex, multi-dimensional process that necessarily involves many risk factors – including the acquisition and colonization of cariogenic oral bacteria. The most frequently associated oral pathogens are the acid-producing and acid-tolerant oral streptococcus species, such as Streptococcus mutans (S. mutans or SM). Many studies have established and confirmed the critical role of the formation of biofilm in the virulence of S. mutans, and the critical role this may play in determining the balance of the oral microbiome towards health or disease.

More recent efforts have discovered a novel cariogenic pathogen, Scardovia wiggsiae (S. …

The Caspase Cascade During Hibernation In The Golden-Mantled Ground Squirrel, Spermophilus Lateralis, Michael David Treat

UNLV Theses, Dissertations, Professional Papers, and Capstones

In several human pathologies like heart attack, stroke, neurodegenerative diseases, and autoimmune disorders, widespread cell death, or apoptosis, is a major cause of organ dysfunction and death. Hibernating golden-mantled ground squirrels, Spermophilus lateralis, experience numerous conditions during the winter that are known to be pro-apoptotic in other mammal systems (e.g. extreme hypothermia, ischemia and reperfusion, acidosis, increased reactive oxygen species, bone and muscle disuse). However, studies suggest that hibernators may invoke a protective phenotype to limit widespread cell damage and loss during the hibernation season. Could regulating apoptosis provide protection against the harmful conditions experienced during the hibernation season? Could …

Screening For The Novel Cariogenic Pathogen Scardovia Wiggsiae Among Orthodontic Patients, Adam Whiteley

UNLV Theses, Dissertations, Professional Papers, and Capstones

Screening for the Novel Cariogenic Pathogen Scardovia wiggsiae among Orthodontic Patients

by

Adam Whiteley

Dr. Karl Kingsley, Examination Committee Chair Professor of Biomedical Sciences University of Nevada, Las Vegas School of Dental Medicine

The recent discovery of a novel cariogenic pathogen Scardovia wiggsiae has led many scientists and oral health researchers to re-evaluate and re-examine existing saliva repositories to determine the prevalence among patient populations. Recent efforts at this institution have used existing saliva samples to determine the prevalence among both adults and pediatric patients. These studies have revealed this organism may be found in approximately one-quarter of all samples …

Understanding Stroke In The Connected Human Brain, Joshua Sarfaty Siegel

Arts & Sciences Graduate Student Theses and Dissertations

Although structural damage from stroke is focal, remote dysfunction can occur in regions of the brain distant from the area of damage. Lesions in both gray and white matter can disrupt the flow of information in areas connected to or by the area of infarct. This is because the brain is not an assortment of specialized parts but an assembly of distributed networks that interact to support cognitive function. Functional connectivity analyses using resting functional magnetic resonance imaging (fMRI) have shown us that the cortex is organized into distributed brain networks. The primary goal of this work is to characterize …

Negative Regulators Of Colonic Peripheral Regulatory T Cell Development, Teresa Lei Ai

Arts & Sciences Graduate Student Theses and Dissertations

Peripheral Treg cells (pTreg cells) maintain immune homeostasis at mucosal interfaces, where they can develop upon activation of naïve CD4+ T cells by bacteria antigen. However, the cellular and molecular requirements that govern their differentiation in inflamed and homeostatic contexts require further elucidation. To circumvent uncertainties in existing methods of distinguishing pTreg cells from thymic Treg cells (tTreg cells), we analyzed monoclonal cell populations of CT2 and CT6 transgenic (Tg) cells that develop into pTreg cells in response to different species of endogenously presented Helicobacter antigen. In our comprehensive assessment of multiple intestinal inflammatory models, including infections and physical injury, …

Correlated Variability And Adaptation In Orbitofrontal Cortex During Economic Choice, Katherine E. Conen

Arts & Sciences Graduate Student Theses and Dissertations

Economic decision-making requires the computation and comparison of subjective values. Several lines of evidence suggest that these processes are mediated by circuits in orbitofrontal cortex (OFC). Neurons in OFC encode the subjective values of choice options and outcomes, and damage to this area leads to selective deficits in value-guided behavior. To understand the nature of choice more thoroughly, it is useful to consider the features of OFC circuits that can limit or enhance information processing. In this document, I present work examining two factors that influence encoding in OFC: noise correlation and value adaptation. In the first study, I show …

Integration Of Local And Regional Regulatory Information In The Human Genome, Hemangi Govind Chaudhari

Arts & Sciences Graduate Student Theses and Dissertations

Gene regulation involves the integration of different sources of information at multiple levels. The action of transcription factors is integrated at cis-regulatory sequences (CRSs). Information from many CRSs is combined to drive spatiotemporally regulated gene expression. Prediction of CRS activity from DNA sequence is challenging because most occurrences of transcription factor binding sites (TFBS) are not functional. I assayed the activity of thousands of genomic sequences with Activator Protein 1 (AP-1) binding sites in K562 cells to identify features in flanking sequences that distinguish functional from non-functional TFBS. I find that sequence features directly adjacent to the AP-1 core motif, …