Biology Commons^™

Role Of Eukaryotic Sel-1 Like Repeat Containing Genes In Helicobacter Pylori Evolution And Pathogenesis., Kalyani Putty

Electronic Theses and Dissertations

Background: Helicobacter pylori (Hp) establishes life-long gastric infection in billions of humans, and is often responsible for diseases such as peptic ulcer and gastric cancer. Cumulative actions of genetic drift and natural selection over several millennia sculpted the present Hp population structure, which is characterized by extreme genetic diversity and striking geographic clustering of genotypes. Natural selection is more commonly imprinted in DNA sequences of Hp proteins that interact with host components; however, in most instances biological relevance of selection during Hp infection remains unknown. Here, I attempted to elucidate the consequence of natural selection in two different contexts: (1) …

Impacts Of Predation Risk And Development On Susceptibility Of North American Anurans To Ranaviruses, Nathan Alden Haislip

Masters Theses

For over three decades, amphibian populations have been declining across the globe. Emerging infectious diseases are responsible for some of these declines. Ranaviruses have caused die-offs in wild amphibian populations on 4 continents, in 5 Canadian provinces, and in over 25 U.S. states. In order to understand host-pathogen dynamics, it is critical to establish baseline information on species susceptibility and the effects of natural stressors. The goal of my thesis research was to quantify the effects of anuran development and exposure to invertebrate predators on species-specific susceptibility to ranavirus. My experiments were designed in factorial arrangements, and consisted of exposure …

Hsp70 And Hsp40 Functionally Interact With Soluble Mutant Huntingtin Oligomers In A Classic Atp-Dependent Reaction Cycle, Gregor P. Lotz, Justin Legleiter, Rebecca Aron, Emily M. Sontag, Shao-Yi Huang, Cheping Ng, Charles G. Glabe, Leslie M. Thompson, Paul J. Muchowski

Biological Sciences Faculty Research and Publications

Inclusion bodies of aggregated mutant huntingtin (htt) fragments are a neuropathological hallmark of Huntington disease (HD). The molecular chaperones Hsp70 and Hsp40 colocalize to inclusion bodies and are neuroprotective in HD animal models. How these chaperones suppress mutant htt toxicity is unclear but might involve direct effects on mutant htt misfolding and aggregation. Using size exclusion chromatography and atomic force microscopy, we found that mutant htt fragments assemble into soluble oligomeric species with a broad size distribution, some of which reacted with the conformation-specific antibody A11. Hsp70 associated with A11-reactive oligomers in an Hsp40- and ATP-dependent manner and inhibited their …

Structure And Expression Of Two Nuclear Receptor Genes In Marsupials: Insights Into The Evolution Of The Antisense Overlap Between The Α-Thyroid Hormone Receptor And Rev-Erbα, Brandon C. Rindfleisch, M. Scott Brown, John L. Vandeberg, Stephen Munroe

Biological Sciences Faculty Research and Publications

Background: Alternative processing of α-thyroid hormone receptor (TRα, NR1A1) mRNAs gives rise to two functionally antagonistic nuclear receptors: TRα1, the α-type receptor, and TRα2, a non-hormone binding variant that is found only in mammals. TRα2 shares an unusual antisense coding overlap with mRNA for Rev-erbα (NR1D1), another nuclear receptor protein. In this study we examine the structure and expression of these genes in the gray short-tailed opossum, Monodelphis domestica, in comparison with that of eutherian mammals and three other marsupial species, Didelphis virginiana, Potorous tridactylus and Macropus eugenii, in order to understand the evolution and regulatory …

Depth And Time Related Variations Of Microbial Communiites In An Emergent Freshwater Wetland, Amy Jenkins

Theses and Dissertations

Soils, and the microbial communities contained within them, are vital for most chemical, physical, and biological processes. This study investigated how microbial community structure responded to environmental changes, such as hydrology, across vertical space (depth) and time in an emergent fresh water wetland. Research was conducted in a non-tidal freshwater wetland along the James River (Charles City County, Virginia) by establishing plots in two areas that experienced different hydrologic regimes and plant communities. Soil cores (30 cm) were collected monthly from January 2008 to February 2009, and then every two to three months thereafter until October 2009, for a total …

Physiological Implications Of Natural Versus Induced Arousal From Torpor, Jenifer C. Utz

UNLV Theses, Dissertations, Professional Papers, and Capstones

During the hibernation season, animals oscillate between periods of torpor and periods of interbout arousal (IBA). During torpor, body temperature is often near 0° C and metabolism is severely depressed. Oxygen consumption, a proxy for aerobic metabolism, may fall to 1% of active values. Many physiological processes including cardiovascular, respiratory, and cellular functions nearly cease. During the IBA, euthermic body temperature is restored and most systemic and cellular processes function at fully active levels. The transition period between these two physiologically dissimilar states is called arousal.

The rate of rewarming (RRW) during arousal was previously expected to progressively increase until …

Environmental Influence On Brain, Behavior, And Gene Expression In Drosophila, Xia Wang

UNLV Theses, Dissertations, Professional Papers, and Capstones

Brain development and behavior are sensitive to environmental stimuli. To gain an understanding of how and to what extent environmental variations, particularly with regard to thermal stress and sensory input, affect brain development, function, and genomic activity, in this dissertation, three interrelated studies were conducted in Drosophila melanogaster.

The first study examined the effects of ecologically-relevant hyperthermia stress on development of the Drosophila mushroom body (MB), a conserved sensory integration and associative center in the insect brain. A daily hyperthermic episode throughout larval and pupal development was shown to severely disrupt MB anatomy by reducing intrinsic Kenyon cell neuron …

The First Hypogean Dipluran From Portugal: Description Of A New Species Of The Genus Litocampa (Diplura: Campodeidae), Ana Reboleira, Alberto Sendra, Fernando Gonçalves, Pedro Oromí

Ana Sofia P.S. Reboleira

A new species of subterranean Campodeid Dipluran of the genus Litocampa mendesi n. sp. is described. Despite the presence of this genus in Spain, this is the first record in Portugal, and it is also the first Portuguese species of hypogean Diplura. The new species combines unique characters absent in the European and American species of the genus. Litocampa mendesi n. sp. was collected only in one part of a cave of the Jurassic karstic massif of Algarve, the southwesternmost part of the Iberian Peninsula. The morphological features of this species show some adaptations to hypogean life but not a …

Science As A Human Right: Esa And The Aaas Science And Human Rights Coalition, Clifford S. Duke, George Middendorf, Jessica Wyndham

George Middendorf

No abstract provided.

Excision Dynamics Of Vibrio Pathogenicity Island-2 From Vibrio Cholerae: Role Of A Recombination Directionality Factor Vefa, Salvador Almagro-Moreno, Michael G. Napolitano, E. Fidelma Boyd

Dartmouth Scholarship

Vibrio Pathogenicity Island-2 (VPI-2) is a 57 kb region present in choleragenic V. cholerae isolates that is required for growth on sialic acid as a sole carbon source. V. cholerae non-O1/O139 pathogenic strains also contain VPI-2, which in addition to sialic acid catabolism genes also encodes a type 3 secretion system in these strains. VPI-2 integrates into chromosome 1 at a tRNA-serine site and encodes an integrase intV2 (VC1758) that belongs to the tyrosine recombinase family. ntV2 is required for VPI-2 excision from chromosome 1, which occurs at very low levels, and formation of a non-replicative circular intermediate.

Molecular Cloning And Characterization Of The Porcine Fto Promoter And Coding Regions.Pdf, Jinming Huang, Yunzhou Yang, Gang Liu, Jibin Zhang, Xinxing Dong, Ying Bai, Meiying Fang

Jibin Zhang

Antimicrobial And Anticancer Activity Of Essential Oils From Guatemalan Medicinal Plants, Andrew B. Miller

Theses and Dissertations

Guatemalan medicinal plants were collected and screened for the presence of essential oils using steam distillation. Oil was found in 63 species from 24 families and was tested in tube dilution assays for activity against Escherichia coli, Staphylococcus aureus, Streptococcus mutans, Lactobacillus acidophilus and Candida albicans. Several essential oils were highly active with 20 instances of oils inhibiting the microbes at an MIC of 0.31 µl/ml. Oils were also tested against cancerous and established cell lines using a 15% (v/v) agar-media which was developed to improve essential oil solubility. Assays were performed against three cancer lines: …

Muscle Receptor Organs In The Crayfish Abdomen: A Student Laboratory Exercise In Proprioception, Bonnie Leksrisawat, Ann S. Cooper, Allison B. Gilberts, Robin L. Cooper

Biology Faculty Publications

The primary purpose of this experiment is to demonstrate primary sensory neurons conveying information of joint movements and positions as proprioceptive information for an animal. An additional objective of this experiment is to learn anatomy of the preparation by staining, dissection and viewing of neurons and sensory structures under a dissecting microscope. This is performed by using basic neurophysiological equipment to record the electrical activity from a joint receptor organ and staining techniques. The muscle receptor organ (MRO) system in the crayfish is analogous to the intrafusal muscle spindle in mammals, which aids in serving as a comparative model that …

Evaluation Of Harassment Of Migrating Double-Crested Cormorants To Limit Depredation On Selected Sport Fisheries In Michigan, Brian S. Dorr, Ashley Moerke, Michael Bur, Chuck Bassett, Tony Aderman, Dan Traynor, Russell D. Singleton, Peter H. Butchko, Jimmy D. Taylor

Brian S Dorr

No abstract provided.

Physiological Recordings Of High And Low Output Nmjs On The Crayfish Leg Extensor Muscle, Wenhui Wu, Robin L. Cooper

Biology Faculty Publications

We explain in detail how to expose and conduct electrophysiological recordings of synaptic responses for high (phasic) and low (tonic) output motor neurons innervating the extensor muscle in the walking leg of a crayfish. Distinct differences are present in the physiology and morphology of the phasic and tonic nerve terminals. The tonic axon contains many more mitochondria, enabling it to take a vital stain more intensely than the phasic axon. The tonic terminals have varicosities, and the phasic terminal is filiform. The tonic terminals are low in synaptic efficacy but show dramatic facilitated responses. In contrast, the phasic terminals are …

Drosophila Vitelline Membrane Assembly: A Critical Role For An Evolutionarily Conserved Cysteine In The “Vm Domain” Of Sv23, T. Wu, Anita L. Manogaran, J. M. Beauchamp, Gail L. Waring

Biological Sciences Faculty Research and Publications

The vitelline membrane (VM), the oocyte proximal layer of the Drosophila eggshell, contains four major proteins (VMPs) that possess a highly conserved “VM domain” which includes three precisely spaced, evolutionarily conserved, cysteines (CX⁷CX⁸C). Focusing on sV23, this study showed that the three cysteines are not functionally equivalent. While substitution mutations at the first (C123S) or third (C140S) cysteines were tolerated, females with a substitution at the second position (C131S) were sterile. Fractionation studies showed that sV23 incorporates into a large disulfide linked network well after its secretion ceases, suggesting that post-depositional mechanisms are in place to …

Impact Of Aging On Morphine Analgesia And Associated Changes In Μ-Opioid Receptor Binding And Expression In The Ventrolateral Periaqueductal Gray, Richard L. Hanberry Iv

Biology Theses

Chronic pain in the aged is a widespread phenomenon, and morphine is the most commonly used narcotic analgesic for treatment. Despite that fact, there are relatively few published studies examining the impact of advanced age on morphine analgesia. We hypothesized that aged rats would be less sensitive to morphine than adults, and that aged animals would have reduced mu-opioid receptor (MOR) binding and expression in the ventrolateral periaqueductal gray, a brain region responsible for morphine analgesia. Using a model of persistent inflammatory pain, we found that morphine was significantly less effective in aged males compared to adult males, and that …

Investigating The Spectrum Of Biological Activity Of Ring-Substituted Salicylanilides And Carbamoylphenylcarbamates, Jiahui Guo, Aidan Coffey, Et. Al.

Department of Biological Sciences Publications

In this study, a series of twelve ring-substituted salicylanilides and carbamoylphenylcarbamates were prepared and characterized. The compounds were analyzed using RP-HPLC to determine lipophilicity. They were tested for their activity related to the inhibition of photosynthetic electron transport (PET) in spinach (Spinacia oleracea L.) chloroplasts. Moreover, their site of action in the photosynthetic apparatus was determined. Primary in vitro screening of the synthesized compounds was also performed against mycobacterial, bacterial and fungal strains. Several compounds showed biological activity comparable with or higher than the standards 3-(3,4-dichlorophenyl)-1,1-dimethylurea, isoniazid, penicillin G, ciprofloxacin or fluconazole. The most active compounds showed minimal anti-proliferative activity …

Micrornas Reveal The Interrelationships Of Hagfish, Lampreys, And Gnathostomes And The Nature Of The Ancestral Vertebrate, Alysha M. Heimberg, Richard Cowper-Sal{Middle Dot}Lari, Marie Semon, Philip C. J. Donoghue, Kevin J. Peterson

Dartmouth Scholarship

Hagfish and lampreys are the only living representatives of the jawless vertebrates (agnathans), and compared with jawed vertebrates (gnathostomes), they provide insight into the embryology, genomics, and body plan of the ancestral vertebrate. However, this insight has been obscured by controversy over their interrelationships. Morphological cladistic analyses have identified lampreys and gnathostomes as closest relatives, whereas molecular phylogenetic studies recover a monophyletic Cyclostomata (hagfish and lampreys as closest relatives). Here, we show through deep sequencing of small RNA libraries, coupled with genomic surveys, that Cyclostomata is monophyletic: hagfish and lampreys share 4 unique microRNA families, 15 unique paralogues of more …

Diatoms As Indicators Of Water-Level Change In Freshwater Lakes, Julie A. Wolin, Jeffrey R. Stone

Biological, Geological, and Environmental Faculty Publications

Water-level changes result from a variety of geological, biological, and/or climatic processes. Many of these changes occur over long periods; others may be rapid or result from catastrophic events. In aquatic environments, diatoms are highly sensitive indicator organisms and their microfossils, deposited in lake sediments, can be used to infer environmental changes (Smol, 2008). Unambiguous diatom signals can be reconstructed from lakes isolated from marine or brackish waters (e.g. Fritz et al., this volume; Horton & Sawai, this volume). However, in freshwater systems lake-level changes are often recorded as increases in planktonic (free-floating) diatoms – although as discussed below, interpretation …

Arctic Ecosystem Responses To Changes In Water Availability And Warming: Short And Long-Term Responses, Paulo C. Olivas

FIU Electronic Theses and Dissertations

Arctic soils store close to 14% of the global soil carbon. Most of arctic carbon is stored below ground in the permafrost. With climate warming the decomposition of the soil carbon could represent a significant positive feedback to global greenhouse warming. Recent evidence has shown that the temperature of the Arctic is already increasing, and this change is associated mostly with anthropogenic activities. Warmer soils will contribute to permafrost degradation and accelerate organic matter decay and thus increase the flux of carbon dioxide and methane into the atmosphere. Temperature and water availability are also important drivers of ecosystem performance, but …

The Lotus Japonicus Cytokinin Receptor Gene Family And Its Role In Nitrogen-Fixing Symbiosis, Mark A. Held

Electronic Thesis and Dissertation Repository

Nitrogen is the most abundant element in our atmosphere, yet has become increasingly limited in agricultural lands. Legume plants offer a possible solution to this problem due to their innate ability to symbiotically interact with nitrogen-fixing bacteria called rhizobia. In particular, a histidine kinase cytokinin receptor from the model legume Lotus japonicus (LHK1) has been clearly placed at the core of these interactions. Loss-of-function mutants in LHK1 fail to initiate timely cortical cell divisions in response to abundant bacterial infection, and gain-of-function mutations in the same locus cause L. japonicus plants to form spontaneous nodules in the absence of rhizobia, …

Using Critical-Thinking Skills To Substantiate Or Challenge Controversial Claims Endorsing A Myriad Of Weight-Loss Products, Teresa F. Degolier

Biological Sciences Faculty Publications

This exercise engages students in critically evaluating weight-loss products and programs. Specific objectives are to investigate, analyze, and substantiate claims made by the weight-loss industry and interpret how these claims may be fraudulent, misleading, or perhaps even truthful.

Maple Syrup: A Sweet Springtime Lesson, Stephen G. Saupe, Sarah Gainey

Biology Faculty Publications

No abstract provided.

Regulation Of Integrin Αiibβ3 Ligand Binding And Signaling By The Metal Ion Binding Sites In The Β I Domain, Joel Raborn

Honors Theses

No abstract provided.

A Novel Totivirus And Piscine Reovirus (Prv) In Atlantic Salmon (Salmo Salar) With Cardiomyopathy Syndrome (Cms), Torstein Tengs

Dr. Torstein Tengs

BACKGROUNDCardiomyopathy syndrome (CMS) is a severe disease affecting large farmed Atlantic salmon. Mortality often appears without prior clinical signs, typically shortly prior to slaughter. We recently reported the finding and the complete genomic sequence of a novel piscine reovirus (PRV), which is associated with another cardiac disease in Atlantic salmon; heart and skeletal muscle inflammation (HSMI). In the present work we have studied whether PRV or other infectious agents may be involved in the etiology of CMS.RESULTSUsing high throughput sequencing on heart samples from natural outbreaks of CMS and from fish experimentally challenged with material from fish diagnosed with CMS …

Optimising Maternal Sources Of Breastfeeding During The First Six Weeks Of Postpartum, Roslyn Tarrant, Katherine Younger, Margaret Sheridan-Pereira, John M. Kearney

Conference Papers

No abstract provided.

Hidden Consequences Of Living In A Wormy World: Nematode‐Induced Immune Suppression Facilitates Tuberculosis Invasion In African Buffalo, Vanessa O. Ezenwa, Rampal S. Etienne, Gordon Luikart, Albano Beja-Pereira, Anna E. Jolles

Biological Sciences Faculty Publications

Most hosts are infected with multiple parasites, and responses of the immune system to co-occurring parasites may influence disease spread. Helminth infection can bias the host immune response toward a T-helper type 2 (Th2) over a type 1 (Th1) response, impairing the host’s ability to control concurrent intracellular microparasite infections and potentially modifying disease dynamics. In humans, immune-mediated interactions between helminths and microparasites can alter host susceptibility to diseases such as HIV, tuberculosis (TB), and malaria. However, the extent to which similar processes operate in natural animal populations and influence disease spread remains unknown.We used cross-sectional, experimental, and genetic studies …

Hidden Consequences Of Living In A Wormy World: Nematode-Induced Immune Suppression Facilitates Tuberculosis Invasion In African Buffalo, Vanessa O. Ezenwa, Rampal S. Etienne, Gordon Luikart

Biological Sciences Faculty Publications

Most hosts are infected with multiple parasites, and responses of the immune system to co occurring parasites may influence disease spread. Helminth infection can bias the host immune response toward a T-helper type 2 Th2) over a type 1 Th1) response, impairing the host's ability to control concurrent intracellular microparasite infections and potentially modifying disease dynamics. In humans, immune-mediated interactions between helminths and microparasites can alter host susceptibility to diseases such as HIV, tuberculosis TB), and malaria. However, the extent to which similar processes operate in natural animal populations and influence disease spread remains unknown. We used cross-sectional, experimental, and …

Variation In Nutrient Resorption By Desert Shrubs, Rebecca E. Drenovsky, Jeremy J. James, James H. Richards

Biology

Plant nutrient resorption prior to leaf senescence is an important nutrient conservation mechanism for aridland plant species. However, little is known regarding the phylogenetic and environmental factors influencing this trait. Our objective was to compare nitrogen (N) and phosphorous (P) resorption in a suite of species in the Asteraceae and Chenopodiaceae and assess the impact of soil salinity on nitrogen resorption. Although asters and chenopods did not differ in N resorption proficiency, chenopods were more proficient than asters at resorbing P. Plant responses to salinity gradients were species-specific and likely related to different salt-tolerances of the species. During the three …