Digital Commons Network^™

Microbial Communities Colonizing Leaves During Early Decomposition Stages, Stephanie Harper

College of Graduate Studies: Theses & Dissertations

Microbial communities associated with decaying leaves play an important role in the cycling of nutrients in stream ecosystems. In headwater streams that are deemed as heterotrophic, bacteria and fungi are main drivers of organic matter decomposition and thus partly responsible for facilitating the cycling of nutrients from leaves that fall into the stream. The main objective of this study was to compare microbial community composition between different leaf types during breakdown in stream ecosystems. To achieve this objective, I used a combination of field and laboratory trials. Field experiments were performed at the Luquillo Experimental Forest using Dacryodes excelsa and …

Water Column Ammonium Concentration And Salinity Influence Nitrogen Uptake And Growth Of Spartina Alterniflora, Rachel Mactavish

College of Graduate Studies: Theses & Dissertations

Salt marsh macrophytes, such as Spartina alterniflora, play a critical role in uptake and transformation of inorganic nitrogen before it reaches coastal waters, thereby reducing the potential for eutrophication. Although nitrogen availability typically limits S. alterniflora growth, it may be possible to exceed the nitrogen uptake capacity of S. alterniflora. Increasing either nitrogen concentrations or salinity are key factors regulating S. alterniflora nitrogen uptake. Investigating the effects of nutrients and salinity on S. alterniflora is important given that increases in inorganic nitrogen supply to surface waters from agriculture and urbanization occur simultaneously with freshwater withdrawals that reduce flow and increase …

Investigation Of Angiogenic Effects Of Bioactive Borate Glass Microfibers And Beads In A Rodent Model, Richard Jeffrey Watters

Masters Theses

"The primary objective of this research project was to evaluate the effects of three different compositions of bioactive glass microfibers (45S5, 13-93B3, and 13-93B3Cu) and bioactive glass beads (13-93, 13-93B3, and 13-93B3Cu) on angiogenesis in subcutaneous tissue in the SKH1 'hairless' mouse. Microvascular responses to the bioactive glass implants were investigated via three experimental approaches: noninvasive vital imaging of microvasculature in dorsal skin windows; quantitative histomorphometry of microvascular densities; and quantitative PCR measurements of mRNA expression of pro-angiogenic cytokines VEGF and FGF-2. The live imaging of dorsal skin window preparations in the hairless SKH1 showed the formation of a halo-like …

Relative Importance Of Male Song On Female Mate Selection In The Zebra Finch (Taeniopygia Guttata), Casey Sprague

Scripps Senior Theses

In the zebra finch (Taeniopygia guttata), song and its social context play an important role in female mate selection. The song of the zebra finch is unique in that it can only be produced by males, which makes the species ideal for analyzing the components of male song that influence female song preference and mate selection. There are three consistent features of zebra finch song that affect female mate preference: 1) the amount of time a male sings, 2) the size and complexity of his song repertoire, and 3) the structural conformation to species or population norms (reviewed …

The Impact Of Sea Surface Temperature On Outbreaks Of Acanthaster Planci On The Great Barrier Reef, Laura A. Grossman

Scripps Senior Theses

The causes of increasing outbreaks of Acanthaster planci on the Great Barrier Reef have been a point of hot debate in recent years. It is unknown whether the increased success is due to nutrient runoff, salinity levels, or a decrease in predation, among other possibilities. In this paper I argue that the primary influence on outbreak status is sea surface temperature. From existing literature, I demonstrate that sea surface temperature in the Great Barrier Reef has increased by 0.4°C per year over the past three decades. I attempt to tie this increase with an increase in frequency of A. planci …

The Ecology, Assembly, And Evolution Of Gypsophile Floras, Michael J. Moore, Juan F. Mota, Norman A. Douglas, Hilda Flores-Olvera, Helga Ochoterena

Faculty & Staff Scholarship

Gypsum (CaSO4·2H2O) exposures and gypseous soils occupy over 100 million ha worldwide, primarily in arid and semiarid regions, with particularly large areas of surface gypsum in southwestern Asia, the Mediterranean region, the Horn of Africa and southwestern North America. Each of these areas hosts a diverse assemblage of gypsum endemic plant taxa, known as gypsophiles. Although plant biologists have been interested in the causes of gypsophily for well over a century, it has only been over the past few decades that gypsophile floras have received sustained ecological and evolutionary study. Recent work, principally in Spain, has revealed that both physical …

She’S A Femme Fatale: Low-Density Larval Development Produces Good Disease Vectors, Steven A. Juliano, Gabriel Sylvestre Ribeiro, Rafael Maciel-De-Freitas, Márcia G. Castro, Claudia Codeço, Ricardo Lourenço-De-Oliveira, L Philip Lounibos

Faculty Publications – Biological Sciences

Two hypotheses for how conditions for larval mosquitoes affect vectorial capacity make opposite predictions about the relationship of adult size and frequency of infection with vector-borne pathogens. Competition among larvae produces small adult females. The competition-susceptibility hypothesis postulates that small females are more susceptible to infection and predicts frequency of infection should decrease with size. The competition-longevity hypothesis postulates that small females have lower longevity and lower probability of becoming competent to transmit the pathogen and thus predicts frequency of infection should increase with size. We tested these hypotheses for Aedes aegypti in Rio de Janeiro, Brazil, during a dengue …

Energy Tradeoffs Between Food Assimilation, Growth, Metabolism And Maintenance, Lihong Jiao

Masters Theses

"The effect of metabolic rate (MR) on organisms' health maintenance is a long-standing puzzle and empirical data on this issue is contradictory. A theoretical model was developed for understanding animal's energy budget under the food condition of Ad libitum (AL) and food restriction. This model offers a framework for understanding the role of MR and health maintenance mechanism from the perspective of energy tradeoff between food assimilation, growth, metabolism and maintenance. Hornworm (Manduca sexta larva) has been selected as an model to test the energetic tradeoff under different food supply and ambient temperatures. The changes in energy budget can …

Homocysteine Intensifies Embryonic Lim3 Expression In Migratory Neural Crest Cells: A Quantitative Confocal Microscope Study, Jordan Naumann

Dissertations and Theses @ UNI

Elevated levels of homocysteine in maternal blood and amniotic fluid are associated with cardiovascular, renal, skeletal, and endocrine diseases and also with embryonic malformations related to neural crest cells. Neural crest cells are necessary for the formation of tissues and organs throughout the body of vertebrate animals. The migration of neural crest cells is essential for proper development of the target tissues. When migration is disrupted, abnormalities may occur. Migration is affected by transcriptional factor LIM3 protein, which regulates the dynamic components of the neural crest cell cytoskeleton. The objective of this study was to test the hypothesis that exogenous …

Steps Towards Successful Cryopreservation Of Fish Gametes: Improving Laboratory Protocols In The Zebrafish Model To Increase Gamete Viability And Efficiency, Megan Chastain

EWU Masters Thesis Collection

Cryopreserervation is a powerful tool for the long term storage of genetic material from endangered species. While mammalian gametes have long been freezable, eggs and embryos from fish have yet to be successfully frozen. Furthermore, protocols for freezing fish sperm have low success rates. In an effort to overcome the limitations in gamete manipulation currently impeding successful fish gamete cryopreservation, I outline two experiment using zebrafish (Danio rerio) as a model for freshwater fish species. First, I attempted to extend working time in both eggs and sperm by incubating the gametes in rainbow trout oviductal fluid (RTOF), RTOF + HEPES, …

Transcriptional Co-Repressor Response Of Arabidopsis Thaliana To Different Abiotic Stress, Bhuwan Guragain

LSU New Orleans Theses and Dissertations

Plants adapt to the complex environmental challenges by regulating their gene expression. Analyses of plant genomes have identified many genes that are either expressed or repressed during environmental stress. However we do not have much information on gene repression. Transcriptional repression in Arabidopsis thaliana is caused by co-repressors that lack the DNA binding domain and are recruited by transcription factors to regulate target gene expression. The Sridhar lab has identified co-repressors SLK1, SLK2, and LUH, which prevent the expression of stress response genes under non-stress conditions. Arabidopsis transgenic lines expressing the GUS under the control of co-repressor’s promoter were created, …

Mitochondrial Dysfunction And Reactive Oxygen Species In Neurodegeneration, Leah Farina

Honors Theses

Neurodegeneration leads to the loss of normal anatomy and physiology of the neuronal system in a human body. The hallmark of most neurodegenerative diseases is abnormal folding and accumulation of proteins within neuronal cell bodies that is not present in healthy people. These changes in normal protein metabolism often lead to neuronal cell death and failure of the affected regions of the central nervous system. Abnormal protein accumulation may be attributed to dysfunctional mitochondria and damage by reactive oxygen species. In addition to causing altered protein accumulation, dysfunctional mitochondria and an excess of reactive oxygen species also lead to errors …

Vibrio Cholerae As A Predator: Lessons From Evolutionary Principles, Stefan Pukatzki, Daniele Provenzano

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

Diarrheal diseases are the second-most common cause of death among children under the age of five worldwide. Cholera alone, caused by the marine bacterium Vibrio cholerae, is responsible for several million cases and over 120,000 deaths annually. When contaminated water is ingested, V. cholerae passes through the gastric acid barrier, penetrates the mucin layer of the small intestine, and adheres to the underlying epithelial lining. V. cholerae multiplies rapidly, secretes cholera toxin, and exits the human host in vast numbers during diarrheal purges. How V. cholerae rapidly reaches such high numbers during each purge is not clearly understood. We propose …

Ua66 Ogden College Of Science & Engineering Newsletter, Cheryl Stevens, Dean

Ogden College of Science & Engineering Publications

No abstract provided.

Stairway To Heaven: Evaluating Levels Of Biological Organization Correlated With The Successful Ascent Of Natural Waterfalls In The Hawaiian Stream Goby Sicyopterus Stimpsoni, Richard W. Blob, Heiko L. Schoenfuss, Takashi Maie, Kristine N. Moody, Kelsey E. Lesteberg, Tonya C. Schoenfuss

Publications

Selective pressures generated by locomotor challenges act at the level of the individual. However, phenotypic variation among individuals that might convey a selective advantage may occur across any of multiple levels of
biological organization. In this study, we test for differences in external morphology, muscle mechanical advantage, muscle fiber type and protein expression among individuals of the waterfall climbing Hawaiian fish Sicyopterus stimpsoni collected from sequential pools increasing in elevation within a single freshwater stream. Despite predictions from previous laboratory studies of morphological selection, few directional morphometric changes in
body shape were observed at successively higher elevations. Similarly, lever arm …

Smokeless Tobacco Use: A Risk Factor For Hyperhomocysteinemia In A Pakistani Population, Mohammad Perwaiz Iqbal, Mohsin Yakub

Department of Biological & Biomedical Sciences

Background

Smokeless tobacco (ST) use is highly prevalent in the South Asian populations. While there have been a number of reports on association of ST consumption with cancer, very few studies have been conducted to investigate its relationship with cardiovascular disease. Hyperhomocysteinemia is a well-recognized risk factor for cardiovascular disease; however, its association with ST use has never been investigated. The objective of this study was to evaluate the relationship of ST use with hyperhomocysteinemia in an urban Pakistani population.

Methodology/Principal Findings

In a cross-sectional study for assessment of risks of hyperhomocysteinemia, 872 healthy adults (355 males and 517 females …

Changes In Tissue-Specific Fatty Acid Composition Of The Freshwater Alewife (Alosa Pseudoharengus) In Response To Temperature, William D. Schregel

Biology Theses

Ectotherms are known to alter the composition of the cell membrane in response to changes in environmental temperature. Tissue-specific fatty acid composition in the alewife (Alosa pseudoharengus) was examined in response to both warm and cold temperature challenges administered over an approximate one month period. Gill, muscle, and liver tissues were analyzed prior to the start of the temperature challenge (initial), following the temperature challenges (survivors), and on those fish that did not survive the temperature challenges (mortalities). Significant differences were found between fatty acid composition of initial fish and survivors for membrane-incorporated fatty acids (polar) and for …

East Coast Salt Marsh Response To Sea Level Rise: Microbial Community Function And Structure, Matt R. Simon

All Theses And Dissertations

Coastal salt marshes are under stress from anthropogenic climate change-induced sea level rise (SLR). Sediment microbial decomposition is a major driver of marsh subsidence and any impact of SLR on this biotic process would have a direct effect on marsh surface elevation relative to sea level. Furthermore, sensitivity to SLR of microbial community composition may play a role in the functional response. I collected sediment from six coastal marshes on the United States Atlantic East coast, exposed it to simulated sea level rise and measured total respired carbon over a three week period. My results indicated that SLR caused a …

Neanderthal Hand And Foot Remains From Moula-Guercy, Ardèche, France, Ben Mersey, Rebecca S. Jabbour, Kyle Brudvik, Alban Defleur

School of Science Faculty Works

The hand and foot remains from Moula-Guercy cave (Ardèche, France) comprise 24 specimens of Eemian age (ca. 120 ka). The specimens include primarily complete elements, which are rare among the Moula-Guercy postcrania. The hand remains have several characteristic Neanderthal traits including a laterally facing (parasagittally oriented) second metacarpal-capitate articulation, a short styloid process, a wide proximal articular surface on the third metacarpal, and absolutely expanded apical tuberosities on the distal hand phalanges relative to modern humans. The foot remains include several incomplete elements along with an antimeric pair of naviculars, a medial cuneiform and cuboid, and a single complete element …

Distribution And Abundance Of Anopheles Spp. In The Lower Rio Grande Valley, South Texas, Norma Hermelinda Martinez

Theses and Dissertations - UTB/UTPA

This study investigated the relationship between Anopheles abundance, collection sites and environmental variables in the Lower Rio Grande Valley, South Texas. In addition, species composition in the Lower Rio Grande Valley was determined in 2011. A total of 6772 female mosquitoes were identified to six genera and 27 species. The most prevalent genera collected were Culex (53.9%), Ochlerotatus (25.6%) and Aedes (13.6%). Anopheles mosquitoes were collected using resting boxes during summer 2012 at multiple locations along the Lower Rio Grande Valley. ArcGIS was used to identify land cover characteristics and nearest water sources at mosquito collection sites. Estero Llano Grande …

Greater Sage-Grouse (Centrocercus Urophasianus) Habitat Selection In Northwestern Wyoming And Stable Isotope Analysis Of Fecal Material, Andrea Renee Green

Graduate Theses and Dissertations

Dramatic range-wide declines in Greater Sage-Grouse populations have prompted efforts to determine habitat characteristics that are selected by sage-grouse for foraging, nesting and brood-rearing areas in an effort to conserve this species. Managers at Heart Mountain and Y U Bench in northwestern Wyoming expressed the need to quantify various habitat characteristics and to determine key use areas at both study sites. Data were collected on a variety of habitat variables in spots selected by grouse for foraging, nesting, and brood-rearing activities. These variables were compared to the same variables measured at random points at both study sites. Significant differences existed …

The Glucose Signaling Network In Yeast, Jeong-Ho Kim, Adhiraj Roy, David Jouandot Ii, Kyu Hong Cho

Faculty Publications

Background

Most cells possess a sophisticated mechanism for sensing glucose and responding to it appropriately. Glucose sensing and signaling in the budding yeast Saccharomyces cerevisiae represent an important paradigm for understanding how extracellular signals lead to changes in the gene expression program in eukaryotes.

Scope of review

This review focuses on the yeast glucose sensing and signaling pathways that operate in a highly regulated and cooperative manner to bring about glucose-induction of HXT gene expression.

Major conclusions

The yeast cells possess a family of glucose transporters (HXTs), with different kinetic properties. They employ three major glucose signaling pathways—Rgt2/Snf3, …

Can A Flea See? An Investigation Of Flea Opsin (Flopsin), Sean David Taylor, Dr. Michael F. Whiting

Journal of Undergraduate Research

Visual pigments are responsible for conferring visual perceptual abilities to animals. Various pigments are tuned to absorb light of different wavelengths and to provide contrast and movement perception. All pigments consist of an opsin protein and a chromophore molecule, usually a carotene derivative. Interactions between the chromophore and amino acid residues of opsin fine-tune visual pigments for the absorption of different wavelengths. Opsin variants can tune visual pigments to absorb wavelengths in the ultraviolet, blue, green, and red regions of the spectrum (Briscoe and Chittka 2001).

Origin And Differential Selection Of Allelic Variation At Tas2r16 Associated With Salicin Bitter Taste Sensitivity In Africa, Michael Campbell

Department of Biology Faculty Publications

Bitter taste perception influences human nutrition and health, and the genetic variation underlying this trait may play a role in disease susceptibility. To better understand the genetic architecture and patterns of phenotypic variability of bitter taste perception, we sequenced a 996 bp region, encompassing the coding exon of TAS2R16, a bitter taste receptor gene, in 595 individuals from 74 African populations, and in 94 non-Africans from 11 populations. We also performed genotype-phenotype association analyses of threshold levels of sensitivity to salicin, a bitter anti-inflammatory compound, in 296 individuals from Central and East Africa. In addition, we characterized TAS2R16 mutants in …

Sequestration And Scavenging Of Iron In Infection, Nermi Lee Parrow, Robert E. Fleming, Michael F. Minnick

Biological Sciences Faculty Publications

The proliferative capability of many invasive pathogens is limited by the bioavailability of iron. Pathogens have thus developed strategies to obtain iron from their host organisms. In turn, host defense strategies have evolved to sequester iron from invasive pathogens. This review explores the mechanisms employed by bacterial pathogens to gain access to host iron sources, the role of iron in bacterial virulence, and iron-related genes required for the establishment or maintenance of infection. Host defenses to limit iron availability for bacterial growth during the acute-phase response and the consequences of iron overload conditions on susceptibility to bacterial infection are also …

Colorful Displays Signal Male Quality In A Tropical Anole Lizard, E. G. Cook, Troy G. Murphy, Michele A. Johnson

Biology Faculty Research

Parasites influence colorful ornaments and their behavioral display in many animal hosts. Because coloration and display behavior are often critical components of communication, variation in these traits may have important implications for individual fitness, yet it remains unclear whether such traits are signals of quality in many taxa. We investigated the association between ectoparasitic mite load and the color and behavioral use of the throat fan (dewlap) by male Anolis brevirostris lizards. We found that heavily parasitized lizards exhibited lower body condition, duller dewlaps, and less frequent dewlap displays than less parasitized individuals. Our results thus suggest that highly parasitized …

Comt1 Gene Fiber-Specific Promoter Elements From Poplar, Chung-Jui Tsai, Edward Odhiambo Anino

Michigan Tech Patents

Polynucleotide constructs contain fiber-specific elements which are used to target expression of polynucleotides and polypeptides to the vascular fibers of a plant. The constructs can be contained within a vector. Transgenic plants transformed with the fiber-specific elements can e made which have expression of polynucleotide or polypeptide directed to the plant fibers.

The Use Of 13c/12c And 15n/14n Stable Isotope Ratio Analysis To Determine Carnivory Level In Gender Identified Free-Ranging Utah American Black Bears (Ursus Americanus), Eric Olsen, Beverly Roeder

Journal of Undergraduate Research

Stable isotope analysis of carbon (13C/12C or d13C) and nitrogen (15N/14N or d15N) has been shown to provide a more accurate estimate of overall diet in various mammalian species (Sponheimer et al. 2003). This technique was used to determine the amount of vegetation and animal protein in the nutritional uptake of free ranging Utah black bears (Ursus americanus). Samples were obtained from harvested bears taken during the fall 2005 and spring 2006 hunt from various regions of Utah via the Utah Division of Wildlife Resources (UDWR). Gender was reported by the hunters at time of harvest. Age was determined by …

Tilapia Fish: Feast Or Famine?, Laura Scott, Dr. Jerald B. Johnson

Journal of Undergraduate Research

Tilapia is a commonly farmed fish throughout the world because of its nutritional value, reproductive efficiency, high resistance to disease, and the low-cost of production. However, despite such commercial benefits, there are some characteristics of this fish that are being overlooked. Previous field research in Costa Rica suggests that when tilapia escape from local farms into nearby streams, they negatively impact native fishes, both in terms of abundance and diversity (unpubl. data). The native fish most notably affected are small, livebearing poecealiids.

Watering Snakes, Samuel Hirt, Kent Hatch

Journal of Undergraduate Research

Stable isotope research is a relatively new and innovative tool in ecology. Studies have been done with stable isotopes to determine migration patterns, diet, and evidence for nutritional stress and much more. Little has been done with stable isotopes and reptiles. We conducted a stable isotope, pilot study that will help us understand what happens with snakes in relation to temperature and oxygen and hydrogen turnover ratios in water.