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2018

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Articles 301 - 330 of 428

Full-Text Articles in Microbiology

Investigation Into The Role Of Manganese In The Growth Of The Opportunistic Pathogen Streptococcus Sanguinis, Brittany Spivey Jan 2018

Investigation Into The Role Of Manganese In The Growth Of The Opportunistic Pathogen Streptococcus Sanguinis, Brittany Spivey

AUCTUS: The Journal of Undergraduate Research and Creative Scholarship

While Streptococcus sanguinis plays a beneficial role in the oral cavity as a competitor of Streptococcus mutans and Streptococcus sobrinus, the bacteria that produce dental caries, it can cause deadly infective endocarditis if given the opportunity to colonize the vegetations that form over damaged endocardial tissue. Pre-existing heart conditions, surgery, and intravenous drug use predispose individuals to endocarditis. S. sanguinis growth and consequential virulence is significantly impeded by restriction to manganese. This is due to the resulting overwhelming oxidative stress and formation of reactive oxygen species which damage DNA and other cellular components. Manganese is essential for S. sanguinis proteins …

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Biosynthetic Mechanism Of The Antibiotic Capuramycin, Erfu Yan Jan 2018

Biosynthetic Mechanism Of The Antibiotic Capuramycin, Erfu Yan

Theses and Dissertations--Pharmacy

A-102395 is a member of the capuramycin family of antibiotics which was isolated from the culture broth of Amycolatopsis sp. SANK 60206. A-102339 is structurally classified as a nucleoside antibiotic, which like all members of the capuramycin family, inhibits bacterial MraY (translocase I) with IC50 of 11 nM which is the lowest among the capuramycin family. A semisynthetic derivative of capuramycin is currently in clinical trials as an antituberculosis antibiotic, suggesting high potential for using A-102395 as a starting point for new antibiotic discovery. In contrast to other capuramycins, A-102395 has a unique arylamine-containing polyamide side chain. The biosynthetic …

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Insights Into Key Gene Regulatory Networks In Borrelia Burgdorferi, William Kenneth Arnold Jan 2018

Insights Into Key Gene Regulatory Networks In Borrelia Burgdorferi, William Kenneth Arnold

Theses and Dissertations--Microbiology, Immunology, and Molecular Genetics

Gene regulatory networks are composed of interconnected regulatory nodes created by regulatory factors of multiple types. All organisms finely tune gene expression in order to adapt to and survive within their current niche. Obligate parasitic bacteria are under extreme pressure to quickly and appropriately adapt their gene regulatory programs in order to survive within their given host. Borrelia burgdorferi is one such organism and persists in nature by alternating between two hosts; Ixodes spp. ticks and small vertebrate animals. These two hosts represent drastically different environments; requiring a unique gene regulatory program to survive and transmit between them. Microbiologists have …

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Sivcpz Closely Related To The Ancestral Hiv-1 Is Less Or Non-Pathogenic To Humans In A Hu-Blt Mouse Model, Zhe Yuan, Guobin Kang, Lance Daharsh, Wenjin Fan, Qingsheng Li Jan 2018

Sivcpz Closely Related To The Ancestral Hiv-1 Is Less Or Non-Pathogenic To Humans In A Hu-Blt Mouse Model, Zhe Yuan, Guobin Kang, Lance Daharsh, Wenjin Fan, Qingsheng Li

Nebraska Center for Virology: Faculty Publications

The HIV-1 pandemic is a consequence of the cross-species transmission of simian immunodeficiency virus in wild chimpanzees (SIVcpz) to humans. Our previous study demonstrated SIVcpz strains that are closely related to the ancestral viruses of HIV-1 groups M (SIVcpzMB897) and N (SIVcpzEK505) and two SIVcpz lineages that are not associated with any known HIV-1 infections in humans (SIVcpzMT145 and SIVcpzBF1167), all can readily infect and robustly replicate in the humanized-BLT mouse model of humans. However, the comparative pathogenicity of different SIVcpz strains remains unknown. Herein, we compared the pathogenicity of the above four SIVcpz strains with HIV-1 using humanized-BLT mice. …

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Identification Of Unequally Represented Founder Viruses Among Tissues In Very Early Siv Rectal Transmission, Jian Chen, Yanqin Ren, Lance Daharsh, Lu Liu, Guobin Kang, Qingsheng Li, Qiang Wei, Yanmin Wu, Jianqing Xu Jan 2018

Identification Of Unequally Represented Founder Viruses Among Tissues In Very Early Siv Rectal Transmission, Jian Chen, Yanqin Ren, Lance Daharsh, Lu Liu, Guobin Kang, Qingsheng Li, Qiang Wei, Yanmin Wu, Jianqing Xu

Nebraska Center for Virology: Faculty Publications

Characterizing the transmitted/founder (T/F) viruses of multi-variant SIV infection may shed new light on the understanding of mucosal transmission.We intrarectally inoculated six Chinese rhesus macaques with a single high dose of SIVmac251 (3.1 × 104 TCID50) and obtained 985 full-length env sequences from multiple tissues at 6 and 10 days post-infection by single genome amplification (SGA). All 6 monkeys were infected with a range of 2 to 8 T/F viruses and the dominant variants from the inoculum were still dominant in different tissues from each monkey. Interestingly, our data showed that a cluster of rare T/F viruses …

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Analytical Performance Of A Low‐Cost Multiplex Polymerase Chain Reaction Human Papillomavirus Genotyping Assay For Use In Sub‐Saharan Africa, Kandali Samwel, Crispin Kahesa, Julius Mwaiselage, Daniela Gonzalez, John T. West, Charles Wood, Joel Palefsky, Peter C. Angeletti Jan 2018

Analytical Performance Of A Low‐Cost Multiplex Polymerase Chain Reaction Human Papillomavirus Genotyping Assay For Use In Sub‐Saharan Africa, Kandali Samwel, Crispin Kahesa, Julius Mwaiselage, Daniela Gonzalez, John T. West, Charles Wood, Joel Palefsky, Peter C. Angeletti

Nebraska Center for Virology: Faculty Publications

We have tested a multiplex polymerase chain reaction (PCR) human papillomavirus (HPV) genotyping assay to fill the need for rapid and low‐cost HPV detection in Sub‐ Saharan Africa. This method allows high throughput genotyping and simultaneous detection of 14 high‐risk and two low‐risk HPV types, by PCR amplification of HPV DNAs in a single reaction tube. In this study, we describe stepwise experiments to validate the multiplex HPV PCR assay for determination of HPV genotypes from 104 cervical brush samples from Tanzanian women. Assay performance was evaluated by determination of intra‐laboratory reproducibility, sensitivity, and specificity. Further performance was assessed by …

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Discovery Of A Non-Nucleoside Rna Polymerase Inhibitor For Blocking Zika Virus Replication Through In Silico Screening, Aryamav Pattnaik, Nicholas Palermo, Bikash R. Sahoo, Zhe Yuan, Duoyi Hu, Arun S. Annamalai, Hiep L. X. Vu, Ignacio Correas, Pavan Kumar Prathipati, Christopher J. Destache, Qingsheng Li, Fernando A. Osorio, Asit K. Pattnaik, Shi-Hua Xiang Jan 2018

Discovery Of A Non-Nucleoside Rna Polymerase Inhibitor For Blocking Zika Virus Replication Through In Silico Screening, Aryamav Pattnaik, Nicholas Palermo, Bikash R. Sahoo, Zhe Yuan, Duoyi Hu, Arun S. Annamalai, Hiep L. X. Vu, Ignacio Correas, Pavan Kumar Prathipati, Christopher J. Destache, Qingsheng Li, Fernando A. Osorio, Asit K. Pattnaik, Shi-Hua Xiang

Nebraska Center for Virology: Faculty Publications

Zika virus (ZIKV), an emerging arbovirus, has become a major human health concern globally due to its association with congenital abnormalities and neurological diseases. Licensed vaccines or antivirals against ZIKV are currently unavailable. Here, by employing a structure-based approach targeting the ZIKV RNA-dependent RNA polymerase (RdRp), we conducted in silico screening of a library of 100,000 small molecules and tested the top ten lead compounds for their ability to inhibit the virus replication in cell-based in vitro assays. One compound, 3-chloro-N-[({4-[4-(2-thienylcarbonyl)-1-piperazinyl]phenyl}amino)carbonothioyl]-1-benzothiophene-2-carboxamide (TPB), potently inhibited ZIKV replication at submicromolar concentrations. Molecular docking analysis suggests that …

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Expression And Function Of Nuclear Receptor Coactivator 4 Isoforms In Transformed Endometriotic And Malignant Ovarian Cells, Stephanie Rockfield, Idhaliz Flores, Meera Nanjundan Jan 2018

Expression And Function Of Nuclear Receptor Coactivator 4 Isoforms In Transformed Endometriotic And Malignant Ovarian Cells, Stephanie Rockfield, Idhaliz Flores, Meera Nanjundan

Molecular Biosciences Faculty Publications

Iron is proposed to contribute to the transition from endometriosis to specific subtypes of ovarian cancers (OVCAs). Regulation of intracellular iron occurs via a ferritinophagic process involving NCOA4 (Nuclear Receptor Coactivator 4), represented by two major isoforms (NCOA4α and NCOA4β), whose contribution to ovarian cancer biology remains uninvestigated. We thus generated transformed endometriotic cells (via HRASV12A, c-MYCT58A, and p53 inactivation) whose migratory potential was increased in response to conditioned media from senescent endometriotic cells. We identified elevated NCOA4 mRNA in transformed endometriotic cells (relative to non-transformed). Knockdown of NCOA4 increased ferritin heavy chain (FTH1) and p21 …

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Mbd2-Cp2c Loop Drives Adult-Type Globin Gene Expression And Definitive Erythropoiesis, Min Young Kim, Ji Sook Kim, Seung Han Son, Chang Su Lim, Hea Young Eum, Dae Hyun Ha, Mi Ae Park, Eun Jung Baek, Buom-Yong Ryu, Ho Chul Kang, Vladimir N. Uversky, Chul Geun Kim Jan 2018

Mbd2-Cp2c Loop Drives Adult-Type Globin Gene Expression And Definitive Erythropoiesis, Min Young Kim, Ji Sook Kim, Seung Han Son, Chang Su Lim, Hea Young Eum, Dae Hyun Ha, Mi Ae Park, Eun Jung Baek, Buom-Yong Ryu, Ho Chul Kang, Vladimir N. Uversky, Chul Geun Kim

Molecular Biosciences Faculty Publications

During hematopoiesis, red blood cells originate from the hematopoietic stem cell reservoir. Although the regulation of erythropoiesis and globin expression has been intensively investigated, the underlining mechanisms are not fully understood, including the interplay between transcription factors and epigenetic factors. Here, we uncover that the Mbd2-free NuRD chromatin remodeling complex potentiates erythroid differentiation of proerythroblasts via managing functions of the CP2c complexes. We found that both Mbd2 and Mbd3 expression is downregulated during differentiation of MEL cells in vitro and in normal erythropoiesis in mouse bone marrow, and Mbd2 downregulation is crucial for erythropoiesis. In uninduced MEL cells, the Mbd2-NuRD …

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Yeast Lifespan Variation Correlates With Cell Growth And Sir2 Expression, Jessica T. Smith, Jill W. White, Huzefa Dungrawala, Hui Hua, Brandt L. Schneider Jan 2018

Yeast Lifespan Variation Correlates With Cell Growth And Sir2 Expression, Jessica T. Smith, Jill W. White, Huzefa Dungrawala, Hui Hua, Brandt L. Schneider

Molecular Biosciences Faculty Publications

Isogenic wild type yeast cells raised in controlled environments display a significant range of lifespan variation. Recent microfluidic studies suggest that differential growth or gene expression patterns may explain some of the heterogeneity of aging assays. Herein, we sought to complement this work by similarly examining a large set of replicative lifespan data from traditional plate assays. In so doing, we reproduced the finding that short-lived cells tend to arrest at senescence with a budded morphology. Further, we found that wild type cells born unusually small did not have an extended lifespan. However, large birth size and/or high inter-generational growth …

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Radx Modulates Rad51 Activity To Control Replication Fork Protection, Kamakoti P. Bhat, Archana Krishnamoorthy, Huzefa Dungrawala, Edwige B. Garcin, Mauro Modesti, David Cortez Jan 2018

Radx Modulates Rad51 Activity To Control Replication Fork Protection, Kamakoti P. Bhat, Archana Krishnamoorthy, Huzefa Dungrawala, Edwige B. Garcin, Mauro Modesti, David Cortez

Molecular Biosciences Faculty Publications

RAD51 promotes homologous recombination repair (HR) of double-strand breaks and acts during DNA replication to facilitate fork reversal and protect nascent DNA strands from nuclease digestion. Several additional HR proteins regulate fork protection by promoting RAD51 filament formation. Here, we show that RADX modulates stalled fork protection by antagonizing RAD51. Consequently, silencing RADX restores fork protection in cells deficient for BRCA1, BRCA2, FANCA, FANCD2, or BOD1L. Inactivating RADX prevents both MRE11- and DNA2-dependent fork degradation. Furthermore, RADX overexpression causes fork degradation that is dependent on these nucleases and fork reversal. The amount of RAD51 determines the fate of stalled replication …

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Septal Secretion Of Protein A In Staphylococcus Aureus Requires Seca And Lipoteichoic Acid Synthesis, Wenqi Yu, Dominique Missiakas, Olaf Schneewind Jan 2018

Septal Secretion Of Protein A In Staphylococcus Aureus Requires Seca And Lipoteichoic Acid Synthesis, Wenqi Yu, Dominique Missiakas, Olaf Schneewind

Molecular Biosciences Faculty Publications

Surface proteins of Staphylococcus aureus are secreted across septal membranes for assembly into the bacterial cross-wall. This localized secretion requires the YSIRK/GXXS motif signal peptide, however the mechanisms supporting precursor trafficking are not known. We show here that the signal peptide of staphylococcal protein A (SpA) is cleaved at the YSIRK/GXXS motif. A SpA signal peptide mutant defective for YSIRK/GXXS cleavage is also impaired for septal secretion and co-purifies with SecA, SecDF and LtaS. SecA depletion blocks precursor targeting to septal membranes, whereas deletion of secDF diminishes SpA secretion into the cross-wall. Depletion of LtaS blocks lipoteichoic acid synthesis and …

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The Bi-Directional Relationship Between Gut Microbiota And Autoimmunity, Trevor O. Kirby Jan 2018

The Bi-Directional Relationship Between Gut Microbiota And Autoimmunity, Trevor O. Kirby

EWU Masters Thesis Collection

Humans serve as a major reservoir for a vast number of microbiota. These microbes have evolved symbiotic relationships with humans due to their close proximity with their host. As a result, the immune system adapts to the microbiota thus modulating immunological function. Autoimmunity is a state in which there are aberrant immune responses produced against host tissue. Intestinal bacteria are directly impacted by instances of inflammation brought on by autoimmunity. The complicated nature between autoimmunity and bacterial modulation demonstrates a bi-directional relationship. Here, we utilize experimental autoimmune encephalomyelitis, a model for multiple sclerosis, to explore the bi-directional relationship that disease …

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Trends In Antibiotic Resistance And Correlations Of Antibiotic Use And Antibiotic Resistance In A Small Hospital In El Paso, Texas 2013-2015, Christopher Olivas Jan 2018

Trends In Antibiotic Resistance And Correlations Of Antibiotic Use And Antibiotic Resistance In A Small Hospital In El Paso, Texas 2013-2015, Christopher Olivas

Open Access Theses & Dissertations

Antibiotic resistance is a serious public health threat, primarily, resulting from the excess and inappropriate use of antibiotics. Antibiotic resistance and antibiotic consumption trends may differ along the U.S-Mexico border from the rest of the U.S. due to geographical and cultural differences unique to the border region. The objectives of this study were: 1.) To examine the trends in antibiotic resistance among E. coli, ESBL producing E. coli, P. aeruginosa, S. aureus, and MRSA over a 3-year period (2013, 2014, 2015) in a U.S.-Mexico border area hospital; 2.) To examine the trends in antibiotic consumption among aztreonam, cefazolin, cefepime, ceftriaxone, …

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Tripartite Interactions Of Legumes With Arbuscular Mycorrhizal Fungi And Rhizobial Bacteria: Insight Into Plant Growth, Seed Yield, And Resource Exchange, Arjun Kafle Jan 2018

Tripartite Interactions Of Legumes With Arbuscular Mycorrhizal Fungi And Rhizobial Bacteria: Insight Into Plant Growth, Seed Yield, And Resource Exchange, Arjun Kafle

Electronic Theses and Dissertations

Under natural conditions, legumes, such as alfalfa (Medicago) and soybean (Glycine max) are colonized with arbuscular mycorrhizal (AM) fungi and rhizobial bacteria forming tripartite interactions. Legumes are important crop species due to their high nutritional and economic values. Most of the previous literatures focused on experiments with an individual symbiont: either AM fungi or rhizobial bacteria, but not with both symbionts at the same time, thus our current understanding of resource exchange in tripartite interactions is limited. It has been reported that AM fungi primarily provide phosphate (P), nitrogen (N), and other nutritional and non-nutritional benefits while rhizobial bacteria solely …

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Diversity Of Free – Living Nitrogen – Fixing Bacteria In Soil Of Sioux Prairie Of South Dakota, Nabilah Ali Alshibli Jan 2018

Diversity Of Free – Living Nitrogen – Fixing Bacteria In Soil Of Sioux Prairie Of South Dakota, Nabilah Ali Alshibli

Electronic Theses and Dissertations

There are only two natural ways by which molecular nitrogen can be available to support life, either by free-living or by symbiotic nitrogen fixing bacteria. The best studied diazotrophs form symbiotic associations with plants, primarily legumes and certain tree species, but little is known about how non-leguminous plants such as grasses obtain nitrogen in their environment. Natural prairies have few legumes, thus have less symbiotic nitrogen fixer interaction. This indicates presence of free-living nitrogen (FLN) fixation activity towards the balance of the N cycle. The objective of this study was to characterize the culturable diversity of free-living diazotrophs in native …

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Gtpase-Activating Protein-Binding Protein 1 Plays An Antiviral Role In Porcine Epidemic Diarrhea Virus (Pedv) Replication, Kabita Pandey Jan 2018

Gtpase-Activating Protein-Binding Protein 1 Plays An Antiviral Role In Porcine Epidemic Diarrhea Virus (Pedv) Replication, Kabita Pandey

Electronic Theses and Dissertations

Porcine Epidemic Diarrhea Virus (PEDV) is a non-segmented virus which uses one-stranded, positive-sense RNA as genetic material. PEDV falls under Coronaviridae family and extensive diarrhea and dehydration in nursing piglets are the major clinical signs. This emerging disease leads to huge economic loss in the pig farming. Very less studies are done towards the role of innate immunity in PEDV infection. The formation of Stress granules (SGs) are seen when cells are introduced to different stressful conditions, which also includes viral infections. SGs are formed when one of the four kinases: doublestranded RNA (dsRNA)-dependent protein kinase (PKR), PKR-like endoplasmic reticulum …

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Universal Swine Influenza Antigen And Vaccine, Zhao Wang Jan 2018

Universal Swine Influenza Antigen And Vaccine, Zhao Wang

Electronic Theses and Dissertations

Swine influenza A viruses pose a serious concern for global health and worldwide swine industry considering their evasion from vaccine-induced immune responses. Formulation of effective influenza vaccines can be complicated by both antigenic shift to a different subtype of hemagglutinin (HAs) and antigenic drift within a particular HA subtype. To address these concerns, we employed a systematic approach to determine the antigenic determinants of swine influenza A viruses by focusing on H1 and H3 subtypes. In parallel, we used a cross-disciplinary approach including structural biology and modeling, virology, and immunology to identify swine influenza A virus-derived HA fusion intermediates broadly …

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Serological Evidence For The Co-Circulation Of Two Lineages Of Influenza D Virus In Equine Populations Of The Midwest United States, Hunter Theodore Nedland Jan 2018

Serological Evidence For The Co-Circulation Of Two Lineages Of Influenza D Virus In Equine Populations Of The Midwest United States, Hunter Theodore Nedland

Electronic Theses and Dissertations

Influenza D virus (IDV) is a newly described lineage of the Orthomyxoviridae virus family that was first isolated from diseased swine in 2011 and has subsequently been detected in cattle around the world in 2014. In addition, serological evidence for IDV infection in humans has been recently established. Despite all the progress, the full range of susceptible hosts for this novel virus has yet to be determined, but includes swine, bovine, small ruminants and human. This study was designed to determine if equine is a possible host to this newly emerging influenza virus. 364 equine serum samples were collected in …

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Improving The Nutritional Characteristics Of Plant Feedstuff By-Products Using Fungal Metabolism, Jacob Zahler Jan 2018

Improving The Nutritional Characteristics Of Plant Feedstuff By-Products Using Fungal Metabolism, Jacob Zahler

Electronic Theses and Dissertations

Plant feedstuff by-products such as soy processing wastewater, guar korma meal, and sorghum hominy are very different, however, all possess a rich nutrient profile. Lessening their value is the presence of lignocellulose, plant anti-nutritional factors, and unfavorable protein profiles. Fungal conversion processes are an attractive approach to improving the value of these by-products by degrading detrimental fractions of each while simultaneously creating nutrient-rich cell mass. The aim of this research was to improve the value of each by-product for potential application in monogastric diets such as fish. Fungal organisms, both yeast and filamentous fungi, were examined for their ability to …

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Cell Fragmentation And Permeabilization By A 1 Ns Pulse Driven Triple-Point Electrode, Enbo Yang, Joy Li, Michael Cho, Shu Xiao Jan 2018

Cell Fragmentation And Permeabilization By A 1 Ns Pulse Driven Triple-Point Electrode, Enbo Yang, Joy Li, Michael Cho, Shu Xiao

Bioelectrics Publications

Ultrashort electric pulses (ns-ps) are useful in gaining understanding as to how pulsed electric fields act upon biological cells, but the electric field intensity to induce biological responses is typically higher than longer pulses and therefore a high voltage ultrashort pulse generator is required. To deliver 1 ns pulses with sufficient electric field but at a relatively low voltage, we used a glass-encapsulated tungsten wire triple-point electrode (TPE) at the interface among glass, tungsten wire, and water when it is immersed in water. A high electric field (2MV/cm) can be created when pulses are applied. However, such a high electric …

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Ictv Virus Taxonomy Profile: Chrysoviridae, Said A. Ghabrial, José R. Castón, Robert H. A. Coutts, Bradley I. Hillman, Daohong Jiang, Dae-Hyun Kim, Hiromitsu Moriyama, Ictv Report Consortium Jan 2018

Ictv Virus Taxonomy Profile: Chrysoviridae, Said A. Ghabrial, José R. Castón, Robert H. A. Coutts, Bradley I. Hillman, Daohong Jiang, Dae-Hyun Kim, Hiromitsu Moriyama, Ictv Report Consortium

Plant Pathology Faculty Publications

The Chrysoviridae is a family of small, isometric, non-enveloped viruses (40 nm in diameter) with segmented dsRNA genomes (typically four segments). The genome segments are individually encapsidated and together comprise 11.5–12.8 kbp. The single genus Chrysovirus includes nine species. Chrysoviruses lack an extracellular phase to their life cycle; they are transmitted via intracellular routes within an individual during hyphal growth, in asexual or sexual spores, or between individuals via hyphal anastomosis. There are no known natural vectors for chrysoviruses. This is a summary of the International Committee on Taxonomy of Viruses (ICTV) Report on the taxonomy of the Chrysoviridae, which …

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Ictv Virus Taxonomy Profile: Partitiviridae, Eeva J. Vainio, Sotaro Chiba, Said A. Ghabrial, Edgar Maiss, Marilyn Roossinck, Sead Sabanadzovic, Nobuhiro Suzuki, Jiatao Xie, Max Nibert, Ictv Report Consortium Jan 2018

Ictv Virus Taxonomy Profile: Partitiviridae, Eeva J. Vainio, Sotaro Chiba, Said A. Ghabrial, Edgar Maiss, Marilyn Roossinck, Sead Sabanadzovic, Nobuhiro Suzuki, Jiatao Xie, Max Nibert, Ictv Report Consortium

Plant Pathology Faculty Publications

The Partitiviridae is a family of small, isometric, non-enveloped viruses with bisegmented double-stranded (ds) RNA genomes of 3–4.8 kbp. The two genome segments are individually encapsidated. The family has five genera, with characteristic hosts for members of each genus: either plants or fungi for genera Alphapartitivirus and Betapartitivirus, fungi for genus Gammapartitivirus, plants for genus Deltapartitivirus and protozoa for genus Cryspovirus. Partitiviruses are transmitted intracellularly via seeds (plants), oocysts (protozoa) or hyphal anastomosis, cell division and sporogenesis (fungi); there are no known natural vectors. This is a summary of the International Committee on Taxonomy of Viruses (ICTV) …

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Haloferax Volcanii For Carotenoid Production, Erika Smith Jan 2018

Haloferax Volcanii For Carotenoid Production, Erika Smith

Honors Theses

Carotenoids are used as natural colorants and have been shown to have numerous health benefits, making these molecules highly desirable in the aquaculture, pharmaceutical, and nutraceutical markets. There is increasing consumer demand for the natural synthesis of carotenoids, but current methods are limited by the cost and difficulty of extraction from organisms. The halophilic archaeon Haloferax volcanii is amenable to extraction and has an endogenous carotenoid biosynthetic pathway that culminates in the accumulation of the carotenoid bacterioruberin; however, H. volcanii also synthesizes important precursors that can be converted into more highly-desired carotenoids, such as β-carotene and astaxanthin, in the presence …

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The Effects Of Nutrient Limitation On Toxin Production For The Harmful Algal Bloom Species, Pseudo-Nitzschia, In The Gulf Of Maine, Julia M. Park Jan 2018

The Effects Of Nutrient Limitation On Toxin Production For The Harmful Algal Bloom Species, Pseudo-Nitzschia, In The Gulf Of Maine, Julia M. Park

Honors Theses

Pseudo-nitzschia is a pennate marine diatom that produces the neurotoxin domoic acid (DA). Domoic acid accumulates in the digestive tract of filter feeders and becomes concentrated at higher trophic levels. When DA concentrations reach critical levels, consumption of toxic shellfish can induce a condition known as Amnesic Shellfish Poisoning (ASP), which has been responsible for the deaths of marine mammals, seabirds and humans. This study worked to respond to a toxic Pseudo-nitzschia bloom in the Gulf of Maine during the fall of 2016, with the goal of quantifying and identifying Pseudo-nitzschia spp. in the bloom region and to determine the …

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Biotransformation Of Oxo-Bile Acids Derivatives By Human Gut Bacteria, Laina Sallam Jan 2018

Biotransformation Of Oxo-Bile Acids Derivatives By Human Gut Bacteria, Laina Sallam

Masters Theses

Bile acids are one group of steroids that can be metabolically transformed by human gut anaerobes. One of these transformations is the conversion of primary bile acids to secondary bile acids by 7α-dehydroxylating gut bacteria such as Clostridium scindens, Clostridium hylemonae, and Clostridium hiranonis. These anaerobes metabolize bile acid derivatives via 3α- and 7α-hydroxysteroid dehydrogenases (HSDH). Studies to date have not reported if these organisms are capable of converting 12-oxolithocholic acid (12-oxoLCA) to deoxycholic acid (DCA). The emphasis of this study was to determine the ability of C. scindens ATCC 35704, C. hiranonis DSM 13275, and C. …

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Distiphallus Morphology And Its Role In Copulation Dynamics In Anastrepha Suspensa (Loew), Taylor J. Inboden Jan 2018

Distiphallus Morphology And Its Role In Copulation Dynamics In Anastrepha Suspensa (Loew), Taylor J. Inboden

Masters Theses

Anastrepha suspensa (Diptera; Tephritidae) is an agricultural pest species causing severe economic damage and is controlled, in part, by applying knowledge of this species' reproduction (e.g., disrupting fertile copulations by SIT). During copulation, males transfer sperm as well as protein rich fluids through an aedeagus and distiphallus, which females then store in three spermathecae and one ventral receptacle. Within the female reproductive tract, the ventral receptacle and the three spermathecae are strategically separated from each other. I hypothesized males' ability to direct sperm transfer within the female reproductive tract is through the structures found in the distiphallus. Utilizing scanning electron …

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Assessment Of A Predicted Diguanylate Cyclase In Treponema Denticola, Dhara T. Patel Jan 2018

Assessment Of A Predicted Diguanylate Cyclase In Treponema Denticola, Dhara T. Patel

Theses and Dissertations

Periodontal disease is a progressive inflammatory condition that is characterized by the reabsorption of alveolar bone, the destruction of connective tissue, and edentulism. It is caused by a dysbiosis in the oral microbiome as a result of a shift from a Gram-positive aerobic bacterial population, to one that becomes more Gram-negative and anaerobic. Treponema denticola is thought to drive this diseased state based on its role as a keystone periopathogen. A major component of T.denticola’s invasiveness is its motility, which allows the spirochete to penetrate and disseminate through tissues. This motility, which has been seen to be crucial to …

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Nevada Desert Dust With Heavy Metals Suppresses Igm Antibody Production, Deborah E. Keil, Brenda J. Buck, Dirk Goossens, Brett Mclaurin, Lacey Murphy, Mallory Leetham-Spencer, Yuanxin Teng, James E. Pollard, Russell Gerads, Jamie C. Dewitt Jan 2018

Nevada Desert Dust With Heavy Metals Suppresses Igm Antibody Production, Deborah E. Keil, Brenda J. Buck, Dirk Goossens, Brett Mclaurin, Lacey Murphy, Mallory Leetham-Spencer, Yuanxin Teng, James E. Pollard, Russell Gerads, Jamie C. Dewitt

Geoscience Faculty Research

Systemic health effects from exposure to a complex natural dust containing heavy metals from the Nellis Dunes Recreation Area (NDRA) near Las Vegas, NV, were evaluated. Several toxicological parameters were examined following lung exposure to emissive dust from three geologic sediment types heavily used for recreational off-road activities: yellow sand very rich in arsenic (termed CBN 5); a shallow cover of loose dune sand overlying a gravelly subsoil bordering dune fields (termed CBN 6); and brown claystone and siltstone (termed CBN 7). Adult female B6C3F1 mice were exposed by oropharyngeal administration to these three types of geogenic dusts at 0.01–100 …

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Role Of Bovine Ileal Sub-Epithelial Myofibroblasts And Epithelial Cells In Innate Immunity, Tirth Uprety Jan 2018

Role Of Bovine Ileal Sub-Epithelial Myofibroblasts And Epithelial Cells In Innate Immunity, Tirth Uprety

Electronic Theses and Dissertations

Gastro-intestinal (GI) tract harbors largest number of microbiota as well as the largest number of immune cells for a given tissue. The host needs to mount an effective immune response against invading pathogens and tolerance against commensals. Thus, regulatory mechanism and barrier function of the GI tract are of utmost importance for appropriate host microbe interaction and gut homeostasis. Intestinal epithelial cells (IECs) act as the first line of defense against invading pathogens. IECs recognize pathogens and commensals and mount an effective innate immune response. Such recognition of pathogens is mediated through germ line encoded pattern recognition receptors (PRRs). Intestinal …

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