Biology Commons^™

Tritrophic Interactions In Forests: Direct And Indirect Interactions Between Birds, Insect Herbivores, And Oaks, Nicholas Anthony Barber

Dissertations

This study examines direct and indirect relationships between three trophic levels to determine effects on plant damage, herbivore abundance and community structure, and bird distribution in forest ecosystems. Exclusion experiments on white oak (Quercus alba) revealed that bird predation effects to not vary spatially despite variation in abundance of both birds and insects. Using a leaf quality manipulation, I demonstrated that bird impacts do not differ with host plant quality. Rather, birds and plant traits had additive effects on herbivore damage. Bottom-up effects of leaf quality were also more important than top-down effects of birds in structuring the insect herbivore …

Effects Of Estrogen On Muscle Damage In Response To An Acute Resistance Exercise Protocol, Megan R. Wolf

Honors Scholar Theses

Creatine Kinase (CK) is used as a measure of exercise-induced muscle membrane damage. During acute eccentric (muscle lengthening) exercise, muscle sarcolemma, sarcoplasmic reticulum, and Z-lines are damaged, thus causing muscle proteins and enzymes to leak into the interstitial fluid.

Strenuous eccentric exercise produces an elevation of oxygen free radicals, which further increases muscle damage. Muscle soreness and fatigue can be attributed to this membrane damage. Estradiol, however, may preserve membrane stability post-exercise (Brancaccio, Maffulli, & Limongelli, 2007; Carter, Dobridge, & Hackney, 2001; Tiidus, 2001). Because estradiol has a similar structure to Vitamin E, which is known to have antioxidant properties, …

Towards A New Developmental Synthesis: Adaptive Developmental Plasticity And Human Disease, P. D. Gluckman, M. A. Hanson, P. Bateson, A. S. Beedle, C. M. Law, Z. A. Bhutta, K. V. Snokhin, P. Bougneres, G. R. Chandak, P. Dasgupta, G. D. Smith, P. T. Ellison, T. E. Forrester, Scott F. Gilbert, E. Jablonka, H. Kaplan, A. M. Prentice, S. J. Simpson, R. Uauy, M. J. West-Eberhard

Biology Faculty Works

The Lancet has rightly drawn attention to the goals of reducing the burden of maternal and childhood undernutrition,¹ focusing mainly on short-term outcomes such as infant survival and stunting.² However, the longer term effects on adult health³ of a poor start to life suggest a further perspective. Developmental effects have been viewed traditionally in the context of major disruptions such as caused by teratogens, prematurity and growth retardation, but there is increasing appreciation of the role of developmental plasticity, which provides individuals with the flexibility to adjust their trajectory of development to match their environment.

An Examination Of The Correlation Between Shoot Apical Meristem Size And Leaf Heterophylly In Pisum Sativum, Cynthia Mary Halfman

Undergraduate Honors Thesis Collection

This study is a quantitative examination of the ramifications of leaf development as influenced by the size of the shoot apical meristem. I wish not to delve into a genetic examination of the shoot apical meristem but rather into the possible correlation between the apical meristem size and leaf heterophylly. If changes in shoot apical meristem size influence heterophylly in leaves, then as shoot apical meristem changes, leaf characteristics will change. This change may result from two different relationships.

Apicomplexan Parasites Co-Opt Host Calpains To Facilitate Their Escape From Infected Cells, Rajesh Chandramohanadas, Paul H. Davis, Daniel P. Beiting, Michael B. Harbut, Claire Darling, Geetha Velmourougane, Ming Yeh Lee, Peter A. Greer, David S. Roos, Doron C. Greenbaum

Biology Faculty Publications

Apicomplexan parasites, including Plasmodium falciparum and Toxoplasma gondii (the causative agents of malaria and toxoplasmosis, respectively), are responsible for considerable morbidity and mortality worldwide. These pathogenic protozoa replicate within an intracellular vacuole inside of infected host cells, from which they must escape to initiate a new lytic cycle. By integrating cell biological, pharmacological, and genetic approaches, we provide evidence that both Plasmodium and Toxoplasma hijack host cell calpain proteases to facilitate parasite egress. Immunodepletion or inhibition of calpain-1 in hypotonically lysed and resealed erythrocytes prevented the escape of P. falciparum parasites, which was restored by adding purified calpain-1. Similarly, efficient …

Analysis And Classification Of Sounds Produced By Asian Elephants (Elephas Maximus), Sharon Stuart Glaeser

Dissertations and Theses

Relatively little is known about the vocal repertoire of Asian elephants (Elephas maximus), and a categorization of basic call types and modifications of these call types by quantitative acoustic parameters is needed to examine acoustic variability within and among call types, to examine individuality, to determine communicative function of calls via playback, to compare species and populations, and to develop rigorous call recognition algorithms for monitoring populations.

This study defines an acoustic repertoire of Asian elephants based on acoustic parameters, compares repertoire usage among groups and individuals, and validates structural distinction among call types through comparison of manual and automated …

Isolation And Characterization Of A Spontaneously Immortalized Bovine Retinal Pigmented Epithelial Cell Line, Thomas E. Liggett, T. Daniel Griffiths, Elizabeth R. Gaillard

Biological Sciences Faculty Research and Publications

Background

The Retinal Pigmented Epithelium (RPE) is juxtaposed with the photoreceptor outer segments of the eye. The proximity of the photoreceptor cells is a prerequisite for their survival, as they depend on the RPE to remove the outer segments and are also influenced by RPE cell paracrine factors. RPE cell death can cause a progressive loss of photoreceptor function, which can diminish vision and, over time, blindness ensues. Degeneration of the retina has been shown to induce a variety of retinopathies, such as Stargardt's disease, Cone-Rod Dystrophy (CRD), Retinitis Pigmentosa (RP), Fundus Flavimaculatus (FFM), Best's disease and Age-related Macular Degeneration …

The Rise Of The Classical Gene: A Review Of In Pursuit Of The Gene: From Darwin To Dna, Michael Dietrich

Dartmouth Scholarship

Review of The rise of the classical gene: a review of In Pursuit of the Gene: From Darwin to DNA by James Schwartz, 2008.

Comparative Vegetative Anatomy And Systematics Of Laeliinae (Orchidaceae), William Stern, Barbara Carlsward

Faculty Research & Creative Activity

Laeliinae are one of the most prominent orchid subtribes, with c. 40 genera and nearly 1500 species, and contain a disparate group of taxa with widely varying morphological features. There does not appear to be a complex of characters to which one can refer in order to delineate the subtribe as a whole. Thus, it was thought that vegetative anatomy might provide clues to the monophyly of the group. The microscopic structure of the leaves, stems and roots of representatives of most of the genera was studied. It was concluded that the anatomy lacks overall uniformity and that vegetative characters …

Comparative Vegetative Anatomy And Systematics Of Laeliinae (Orchidaceae), William Louis Stern, Barbara S. Carlsward

Faculty Research & Creative Activity

Laeliinae are one of the most prominent orchid subtribes, with c. 40 genera and nearly 1500 species, and contain a disparate group of taxa with widely varying morphological features. There does not appear to be a complex of characters to which one can refer in order to delineate the subtribe as a whole. Thus, it was thought that vegetative anatomy might provide clues to the monophyly of the group. The microscopic structure of the leaves, stems and roots of representatives of most of the genera was studied. It was concluded that the anatomy lacks overall uniformity and that vegetative characters …

Thyroid Hormone Regulation Of Mrnas Encoding Thyrotropin Β-Subunit, Glycoprotein Α-Subunit, And Thyroid Hormone Receptors Α And Β In Brain, Pituitary Gland, Liver, And Gonads Of An Adult Teleost, Pimephales Promelas, Sean C. Lema, Jon T. Dickey, Irvin R. Schultz, Penny Swanson

Biological Sciences

Thyroid hormones (THs) regulate growth, morphological development, and migratory behaviors in teleost fish, yet little is known about the transcriptional dynamics of gene targets for THs in these taxa. Here, we characterized TH regulation of mRNAs encoding thyrotropin subunits and thyroid hormone receptors (TRs) in an adult teleost fish model, the fathead minnow (Pimephales promelas). Breeding pairs of adult minnows were fed diets containing 3,5, 3^,-triiodo-_L-thyronine (T₃) or the goitrogen methimazole for 10 days. In males and females, dietary intake of exogenous T₃ elevated circulating total T₃, while methimazole …

A Comparative Ecological Study Of Two Sister Species Of Darters In Kentucky, Etheostoma Kantuckeense And Etheostoma Lawrencei, Bjorn Victor Schmidt

Masters Theses & Specialist Projects

Etheostoma kantuckeense and E. lawrencei are former members of the wide ranging E. spectabile species complex. Etheostoma kantuckeense is endemic to the Barren River Basin in Southern Kentucky and Northern Tennessee, while E. lawrencei occurs in the Green River, Salt River, and Cumberland River Basins of Central and Eastern Kentucky. Isolation of populations within these drainages has allowed for a relatively recent evolutionary divergence, leading to slight differences in morphology. This study was conducted to address if geographical isolation has led to measurable differences in the ecology of these two species. In particular, habitat preference across three spatial scales and …

The Effect Of Breeding Herd Parity Structure On Genetic Improvement Of The Sow Herd, Caitlyn E. Abell

Mahurin Honors College Capstone Experience/Thesis Projects

This study focuses on the value of the genetic lag associated with maintaining sows for additional parities in a commercial swine herd. Three traits were included in this study: number born alive (NBA), 21 day litter weight (W21), and days to market (D250). The economic values assigned to these traits were $22.00/pig, $0.70/lb., and $0.17/day, respectively. The genetic improvement per generation made for each trait was assumed to be 0.3 pigs, 3.0 lbs., and 3.0 days, respectively. It was estimated that the value of the genetic lag associated with retaining a sow to P3, P5, and P7 was $24.80, $46.89, …

Empirical Testing Of 16s Rrna Gene Pcr Primer Pairs Reveals Variance In Target Specificity And Efficacy Not Suggested By In Silico Analysis, Sergio E. Morales, William E. Holben

Biological Sciences Faculty Publications

Phylogenetic and "fingerprinting" analyses of the 16S rRNA genes of prokaryotes have been a mainstay of microbial ecology during the last two decades. However, many methods and results from studies that rely on the 16S rRNA gene for detection and quantification of specific microbial taxa have seemingly received only cursory or even no validation. To directly examine the efficacy and specificity of 16S rRNA gene-based primers for phylum-, class-, and operational taxonomic unit-specific target amplification in quantitative PCR, we created a collection of primers based solely on an extensive soil bacterial 16S rRNA gene clone library containing similar to 5,000 …

Intersubunit Interactions Modulate Ph-Induced Activation Of Membrane Fusion By The Junín Virus Envelope Glycoprotein Gpc, Joanne York, Jack H. Nunberg

Biological Sciences Faculty Publications

The mature arenavirus envelope glycoprotein GPC is a tripartite complex comprising a stable signal peptide (SSP) in addition to the receptor-binding (G1) and transmembrane fusion (G2) subunits. We have shown previously that SSP is a key element in GPC-mediated membrane fusion, and that GPC sensitivity to acidic pH is modulated in part through the lysine residue at position 33 in the ectodomain loop of SSP (J. York and J. H. Nunberg, J. Virol. 80: 7775-7780, 2006). A glutamine substitution at this position stabilizes the native GPC complex and thereby prevents the induction of pH-dependent membrane fusion. In efforts to identify …

Common Garden Comparisons Of Native And Introduced Plant Populations: Latitudinal Clines Can Obscure Evolutionary Inferences, Robert I. Colautti, John L. Maron, Spencer C.H. Barrett

Biological Sciences Faculty Publications

Common garden studies are increasingly used to identify differences in phenotypic traits between native and introduced genotypes, often ignoring sources of among-population variation within each range. We re-analyzed data from 32 common garden studies of 28 plant species that tested for rapid evolution associated with biological invasion. Our goals were: (i) to identify patterns of phenotypic trait variation among populations within native and introduced ranges, and (ii) to explore the consequences of this variation for how differences between the ranges are interpreted. We combined life history and physiologic traits into a single principal component (PC_ALL) and also compared …

Do Hypothermic Tissue Tolerances Limit Torpor Expression?, Clark J. Cotton, Henry J. Harlow

Biology Faculty Publications

1. Arrest temperatures and Q₁₀ values for extensor digitorum longus (EDL), soleus, trabecula, and jejunum muscle twitch strength, contraction time, and 0.5 relaxation time were calculated for a deep torpor hibernator, white-tailed prairie dog (WTPD) (Cynomys leucurus), a shallow torpor hibernator, black-tailed prairie dog (BTPD) (Cynomys ludovicianus), and a non-hibernator, lab rat (Rattus norvegicus) to test the hypothesis that tissue temperature tolerances limit the depth of expressed torpor.

2. There were no temperature tolerance differences between the tissues of the two species of hibernators. Both hibernating species had arrest temperatures and Q_{10 …}

Seed Banks Of Sagebrush Communities Seeded With Crested Wheatgrass, Kevin L. Gunnell

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Crested wheatgrass (Agropyron cristatum [L.] Gaertn.) is one of the most commonly seeded exotic species in the western United States. Although many degraded Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis) plant communities have been seeded with crested wheatgrass during rehabilitation efforts, seed banks of these communities have not been characterized. I sought to characterize and explain the variation among 33 seeded communities in the northeastern Great Basin. Hierarchical clustering and principal components analysis identified four possible seed bank categories in these communities. Seed bank categories varied from high to low crested wheatgrass dominance. The crested wheatgrass-dominated category …

An Investigation Of Postzygotic Reproductive Isolation And Phenotypic Divergence In The Bark Beetle Dendroctonus Ponderosae, Ryan R. Bracewell

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Understanding reproductive isolation and divergence is the focus of speciation research. Recent evidence suggested that some Dendroctonus ponderosae populations produced hybrids with reproductive incompatibilities, a reproductive boundary undetected by phylogeographic analyses using molecular markers. Additionally, the unique bifurcated distribution of D. ponderosae and the proposed isolation-by-distance gene flow pattern around the Great Basin Desert provided a unique opportunity to investigate the evolution of postmating (postyzygotic) isolation while also understanding phenotypic divergence along latitudinal (climatic) gradients. First, I characterized the strength, biological pattern, and geographic pattern of postzygotic isolation in D. ponderosae by crossing increasingly divergent populations in a common garden …

Consumer-Driven Nutrient Recycling In Arctic Alaskan Lakes: Controls, Importance For Primary Productivity, And Influence On Nutirient Limitation, Cody R. Johnson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In lakes, fish and zooplankton can be both sources and sinks of nitrogen (N) and phosphorus (P) through the consumption of organic N and P, and subsequent excretion of bioavailable inorganic forms. These source/sink dynamics, known as consumer-driven nutrient recycling (CNR), may, in turn, control the availability of potentially limiting nutrients for algal primary production. In this dissertation I investigate the importance and controls of CNR as a source of inorganic N and P for primary production (Chapter 2). I then examine zooplankton CNR as a mechanism for increasing nutrient mean resident time (MRT) in the mixed layer of lakes …

Mechanisms Of Induced Cell Death In Bluetongue Virus Challenged Human Cell Lines, Justin Darrel Hoopes

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Bluetongue virus (BTV) is a pathogenic member of the Reoviridae family. BTV does not cause disease in humans, but is capable of selectively infecting and killing certain transformed human cell lines. Understanding BTV's oncotrophism may lead to new therapeutics for treating cancer. This study focused on the underlying mechanisms of BTV-induced cell death in carcinoma cell lines. It was our hypothesis that BTV infects human carcinoma transformed cells, produces mRNA and protein, induces a strong inflammatory response, induces mitogen activated protein kinase (MAPK)-based pro-apoptotic signaling, inhibits PKB-based signaling, and eventually kills the cell by inducing apoptosis.

Three carcinoma cell lines …

Consequences Of Vegetation Change On The Dynamics Of Labile Organic Matter And Soil Nitrogen Cycling In A Semiarid Ecosystem, Toby D. Hooker

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Sagebrush-dominated ecosystems are being transformed by wildfire, rangeland improvement techniques, and exotic plant invasions. These disturbances have substantial effects on the composition and structure of native vegetation, but the effects on ecosystem C and N dynamics are poorly understood. To examine whether differences in dominant vegetation affect the quantity and quality of plant organic matter inputs to soil, ecosystem C and N pools and rates of plant turnover were compared among historically grazed Wyoming big sagebrush, introduced perennial crested wheatgrass, and invasive annual cheatgrass communities. Since low soil moisture during the summer may inhibit the microbial colonization of plant detrital …

The Bioactive Properties Of Syringomycin E-Rhamnolipid Mixtures And Syringopeptins, Mekki F. Bensaci

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The need for new antimicrobial agents has become important in the last decade due to emerging resistance to a number of conventional antimicrobial agents. New approaches and sources are needed to generate novel and effective antimicrobials. For example, synergistic combinations between two or more agents may lead to new antimicrobial therapies. Furthermore, the increase in health problems caused by the exposure to agricultural crop pesticides and synthetic fungicides and the emerging development of organic farming has increased the necessity to develop natural products than can be used safely in controlling crop diseases.

In this work, I present the first studies …

Watershed-Scale Analysis Of Riparian Buffer Function, Molly Van Appledorn

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The ability of riparian buffers to filter undesirable nutrients from upland sources has long been recognized as an important ecosystem service for maintaining or improving water quality, and as a result, many land management strategies have been built around the preservation or restoration of buffer zones. Newly derived flow-path metrics have shown great promise as a way to assess riparian buffer function at the watershed scale but a thorough investigation of metric performance was necessary. The goals of this study were to: 1) test the independence of flow-path metrics from traditional metrics using a spatially extensive, independent sample of watersheds, …

The Regulation Of Epithelial Sodium Channels In Mammalian Taste Receptor Cells, Arian F. Baquero Gonzalez

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Nutrient recognition is one of the main physiological roles of the gustatory system. In mammals, it is well established that the taste of sodium salts is primarily mediated by sodium influx through the epithelial sodium channel. The epithelial sodium channel is a sodium-specific ion channel that is expressed across a wide range of transporting epithelia such as colon, kidney, and taste. In addition to its role as a salt taste receptor, sodium influx through the epithelial sodium channel is important systemically for maintaining sodium balance and blood pressure. Following our earlier work on the endocrine regulation of salt taste at …

Targeting Fat-Sensitive Pathways In Enteroendocrine Cells Using Nanoparticle-Mediated Drug Delivery, Bhavik P. Shah

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The current epidemic of obesity has been linked to an increase in fat intake associated with the Western diet. Nutrient-induced stimulation of enteroendocrine cells in the small intestine leads to the release of hormones that contribute to satiety and the control of food intake. In particular, ingested fat, specifically in the form of free fatty acids, is potent activator of enteroendocrine cells in the proximal small intestine. However, the underlying signaling cascade that free fatty acids initiate in these enteroendocrine cells, which leads to secretion of satiety hormones, is not known. In general, my research is focused on identifying nutrient-responsive …

Punta Toro Virus Infection In Mice: Strain Differences In Pathogenesis And Regulation Of Interferon Response Pathways, Michelle Mendenhall

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Adames strain of Punta Toro virus (PTV-A) causes acute hepatic disease in hamsters and mice similar to that seen in natural Rift Valley fever virus (RVFV) infection, while the Balliet strain (PTV-B) is apathogenic. The ability of PTV-A to suppress the interferon (IFN) response has been demonstrated in hamsters and is thought to be a contributing factor to PTV-A's pathogenicity in hamsters. PTV-B is not assumed to exhibit this IFN-antagonistic activity, as it stimulates production of significantly higher IFN-β levels. To elucidate the role of IFN in resistance of mice to PTV-B infection, we utilized mice deficient in a …

Inducing A Normal Phenotype In Breast Epithelial Cells Using A Three-Dimensional Basement Membrane Extract Culture System: A Study On The Reversion Of Cancer, Ross H. Booth

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Experimentally, traditional developmental models and transgenic animals consistently underscore the importance of studying cell behavior in the correct tissue context. However, live animal experimentation is inherently complex, and systematic assessment of the effects of individual variables, such as cell shape and matrix compliance on cell behavior, is extremely difficult at best. Two-dimensional monolayer culture of key individual cell types has provided abundant, fundamental information on cell response, but cannot be used to show the normal phenotype of breast epithelial cells. Furthermore, their results often fail to translate into in vivo and clinical studies. It has been previously established that normal …

The Use Of Reverse Genetics To Clone And Rescue Infectious, Recombinant Human Parainfluenza Type 3 Viruses, Jason Peter Roth

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Reverse genetics is a discipline that involves the use of genetic manipulation and modification to study an organism's altered phenotype. In this study, infectious recombinant viruses were rescued from altered cDNA clones encoding the antigenome of human parainfluenza virus type 3 and the resulting phenotypes were examined. In one clone, the gene for the enhanced green fluorescent protein was inserted into the virus antigenome to be expressed during viral replication, resulting in infected cells emitting green fluorescence. Viral titers, mRNA replication, and genomic replication for the virus expressing the enhanced green fluorescent protein were reduced when compared to the human …

Greater Sage-Grouse And Energy Development In Northeastern Utah: Implications For Management, Leah Suzanne Smith

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Concern regarding the effect of energy development on greater sage-grouse (Centrocercus urophasianus) is increasing as the search for fossil fuel intensifies. Sage-grouse may be especially sensitive to energy development because they require large, diverse areas of sagebrush (Artemisia spp.) habitat to complete their life cycle. Additionally, the network of pipelines, roads, and wells required by energy development may fragment sagebrush habitat isolating populations and contributing to genetic drift, inbreeding, local extinction, or rapid divergence.

Seep Ridge, located in northeastern Utah, is one area where sage-grouse habitat and energy development plans overlap. Approved leases call for the construction …