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Identification And Characterization Of Epp, The Secreted Processing Protease For The Vibrio Anguillarum Empa Metalloprotease, Maureen Varina, Steven M. Denkin, Andrew M. Staroscik, David R. Nelson

Cell and Molecular Biology Faculty Publications

The zinc metalloprotease EmpA is a virulence factor for the fish pathogen Vibrio anguillarum. Previous studies demonstrated that EmpA is secreted as a 46-kDa proenzyme that is activated extracellularly by the removal of an ∼10-kDa propeptide. We hypothesized that a specific protease is responsible for processing secreted pro-EmpA into mature EmpA. To identify the protease responsible for processing pro-EmpA, a minitransposon mutagenesis (using mini-Tn10Km) clone bank of V. anguillarum was screened for reduced protease activity due to insertions in undescribed genes. One mutant with reduced protease activity was identified. The region containing the mini-Tn10Km was …

Tailored Intervention To Increase Dual-Contraceptive Method Use: A Randomized Trial To Reduce Unintended Pregnancies And Sexually Transmitted Infections, Jeffrey F. Peipert, Colleen A. Redding, Jeffrey D. Blume, Jenifer E. Allsworth, Kristen A. Matteson, Faye Lozowski, Kenneth H. Mayer, Patricia J. Morokoff, Joseph S. Rossi

Cancer Prevention Research Center Faculty Publications

Objective: The objective of the study was to determine whether a transtheoretical model–tailored expert system intervention increases dual-method contraceptive use, compared with a nontailored educational intervention.

Study Design: We performed a randomized clinical trial of 542 women at high risk for sexually transmitted infections (STIs) and unintended pregnancy. The intervention group received computer-based tailored feedback using a multimedia program. The control group received general contraceptive information and nontailored advice.

Results: Participants in the intervention group were more likely to report use of dual contraceptive methods during follow-up (adjusted hazard rate ratio 1.70, 95% confidence interval 1.09, 2.66), compared with controls. …

Freshman Record : The University Of Rhode Island, The Interfraternity/Panhellenic Councils

Freshman Record

No abstract provided.

Fluid Dynamics Of Feeding Behaviour In White-Spotted Bamboo Sharks, Sandra Nauwelaerts, Cheryl Wilga, George V. Lauder, Christopher P. Sanford

Biological Sciences Faculty Publications

Although the motor control of feeding is presumed to be generally conserved, some fishes are capable of modulating the feeding behaviour in response to prey type and or prey size. This led to the ʻfeeding modulation hypothesisʼ, which states that rapid suction strikes are pre-programmed stereotyped events that proceed to completion once initiated regardless of sensory input. If this hypothesis holds true, successful strikes should be indistinguishable from unsuccessful strikes owing to a lack of feedback control in specialized suction feeding fishes. The hydrodynamics of suction feeding in white-spotted bamboo sharks (Chiloscyllium plagiosum) was studied in three behaviours: …

Suction Generation In White-Spotted Bamboo Sharks Chiloscyllium Plagiosum, Cheryl D. Wilga, Christopher P. Sanford

Biological Sciences Faculty Publications

After the divergence of chondrichthyans and teleostomes, the structure of the feeding apparatus also diverged leading to alterations in the suction mechanism. In this study we investigated the mechanism for suction generation during feeding in whitespotted bamboo sharks, Chiloscyllium plagiosum and compared it with that in teleosts. The internal movement of cranial elements and pressure in the buccal, hyoid and pharyngeal cavities that are directly responsible for suction generation was quantified using sonomicrometry and pressure transducers. Backward stepwise multiple linear regressions were used to explore the relationship between expansion and pressure, accounting for 60–96% of the variation in pressure among …

Revisiting The Classics: Considering Nonconsumptive Effects In Textbook Examples Of Predator–Prey Interactions, Barbara L. Peckarsky, Peter A. Abrams, Daniel I. Bolnick, Lawrence M. Dill, Jonathan H. Grabowski, Barney Luttberg, John L. Orrock, Scott D. Peacor, Evan L. Preisser, Oswald J. Schmitz, Geoffrey C. Trussell

Biological Sciences Faculty Publications

Predator effects on prey dynamics are conventionally studied by measuring changes in prey abundance attributed to consumption by predators. We revisit four classic examples of predator–prey systems often cited in textbooks and incorporate subsequent studies of nonconsumptive effects of predators (NCE), defined as changes in prey traits (e.g., behavior, growth, development) measured on an ecological time scale. Our review revealed that NCE were integral to explaining lynx–hare population dynamics in boreal forests, cascading effects of top predators in Wisconsin lakes, and cascading effects of killer whales and sea otters on kelp forests in nearshore marine habitats. The relative roles of …

Cis-Regulatory Organization Of The Pax6 Gene In The Ascidian Ciona Intestinalis, Steven Q. Irvine, Vera C. Fonseca, Michael A. Zompa, Rajee Antony

Biological Sciences Faculty Publications

The Pax6 gene has attracted intense research interest due to its apparently important role in the development of eyes and the central nervous system (CNS) in many animal groups. Pax6 is also of interest for comparative genomics since it has not been duplicated in tetrapods, making for a direct orthology between the Ciona intestinalis gene CiPax6 and Pax6 in mammals. CiPax6 has been shown to be expressed in the anterior brain, caudal nerve cord, and in parts of the brain associated with the photoreceptive ocellus. This information was extended here using in-situ hybridization, and shows that CiPax6 transcripts mark the …

Dec1, A Basic Helix-Loop-Helix Transcription Factor And A Novel Target Gene Of The P53 Family, Mediates P53-Dependent Premature Senescence, Yingjuan Qian, Jin Zhang, Bingfang Yan, Xinbin Chen

Biomedical and Pharmaceutical Sciences Faculty Publications

Cellular senescence plays an important role in tumor suppression. p53 tumor suppressor has been reported to be crucial in cellular senescence. However, the underlying mechanism is poorly understood. In this regard, a cDNA microarray assay was performed to identify p53 targets involved in senescence. Among the many candidates is DEC1, a basic helix-loop-helix transcription factor that has been recently shown to be up-regulated in K-ras-induced premature senescence. However, it is not clear whether DEC1 is capable of inducing senescence. Here, we found that DEC1 is a novel target gene of the p53 family and mediates p53-dependent premature senescence. …

Rapid Activation Of Erk1/2 And Akt In Human Breast Cancer Cells By Cadmium, Zhiwei Liu, Xinyuan Yu, Zahir A. Shaikh

Biomedical and Pharmaceutical Sciences Faculty Publications

Cadmium (Cd), an endocrine disruptor, can induce a variety of signaling events including the activation of ERK1/2 and AKT. In this study, the involvement of estrogen receptors (ER) in these events was evaluated in three human breast caner cell lines, MCF-7, MDA-MB-231, and SK-BR-3. The Cd-induced signal activation patterns in the three cell lines mimicked those exhibited in response to 17β-estradiol. Specifically, treatment of MCF-7 cells, that express ERα, ERβ and GPR30, to 0.5–10 μM Cd for only 2.5 min resulted in transient phosphorylation of ERK1/2. Cd also triggered a gradual increase and sustained activation of AKT during the 60 …

Gender And Women's Studies Newsletter For Winter 2008, Uri Gender And Women's Studies Department

Gender and Women's Studies Publications

The Winter 2008 issue of Gender and Women’s Studies Newsletter, a periodical with articles written by faculty members and some related to events within the Gender and Women’s Studies program.

A Randomized, Placebo-Controlled Trial Of Repeated Iv Antibiotic Therapy For Lyme Encephalopathy, B. A. Fallon, J. G. Keilp, K. M. Corbera, E. Petkova, C. B. Britton, E. Dwyer, I. Slavov, J. Cheng, David R. Nelson, H. A. Sackeim

Cell and Molecular Biology Faculty Publications

Background: Optimal treatment remains uncertain for patients with cognitive impairment that persists or returns after standard IV antibiotic therapy for Lyme disease.

Methods: Patients had well-documented Lyme disease, with at least 3 weeks of prior IV antibiotics, current positive IgG Western blot, and objective memory impairment. Healthy individuals served as controls for practice effects. Patients were randomly assigned to 10 weeks of double-masked treatment with IV ceftriaxone or IV placebo and then no antibiotic therapy. The primary outcome was neurocognitive performance at week 12—specifically, memory. Durability of benefit was evaluated at week 24. Group differences were estimated according …

Glycogen And Maltose Utilization By Escherichia Coli O157:H7 In The Mouse Intestine, Shari A. Jones, Mathias Jorgensen, Fatema Z. Chowdhury, Rosalie Rodgers, James Hartline, Mary P. Leatham, Carsten Struve, Karen A. Krogfelt, Paul S. Cohen, Tyrrell Conway

Cell and Molecular Biology Faculty Publications

Mutant screens and transcriptome studies led us to consider whether the metabolism of glucose polymers, i.e., maltose, maltodextrin, and glycogen, is important for Escherichia coli colonization of the intestine. By using the streptomycin-treated mouse model, we found that catabolism of the disaccharide maltose provides a competitive advantage in vivo to pathogenic E. coli O157:H7 and commensal E. coli K-12, whereas degradation of exogenous forms of the more complex glucose polymer, maltodextrin, does not. The endogenous glucose polymer, glycogen, appears to play an important role in colonization, since mutants that are unable to synthesize or degrade glycogen have significant colonization defects. …

Comparison Of Carbon Nutrition For Pathogenic And Commensal ,Escherichia Coli Strains In The Mouse Intestine, Andrew J. Fabich, Shari A. Jones, Fatema Z. Chowdhury, Amanda Cernosek, April Anderson, Darren Smalley, J. Wesley Mchargue, G. Aaron Hightower, Joel T. Smith, Steven M. Autieri, Mary P. Leatham, Jeremy J. Lins, Regina L. Allen, David C. Laux, Paul S. Cohen, Tyrrell Conway

Cell and Molecular Biology Faculty Publications

The carbon sources that support the growth of pathogenic Escherichia coli O157:H7 in the mammalian intestine have not previously been investigated. In vivo, the pathogenic E. coli EDL933 grows primarily as single cells dispersed within the mucus layer that overlies the mouse cecal epithelium. We therefore compared the pathogenic strain and the commensal E. coli strain MG1655 modes of metabolism in vitro, using a mixture of the sugars known to be present in cecal mucus, and found that the two strains used the 13 sugars in a similar order and cometabolized as many as 9 sugars at a time. We …

Identification And Characterization Of A Repeat-In-Toxin Gene Cluster In Vibrio Anguillarum, Ling Li, Jessica L. Rock, David R. Nelson

Cell and Molecular Biology Faculty Publications

Vibrio anguillarum is the causative agent of vibriosis in fish. Hemolysins of V. anguillarum have been considered virulence factors during infection. One hemolysin gene, vah1, has been previously identified but does not account for all hemolytic activity. The mini-Tn10Km mutagenesis performed with a vah1 mutant resulted in a hemolysin-negative mutant. The region surrounding the mutation was cloned and sequenced, revealing a putative rtx operon with six genes (rtxACHBDE), where rtxA encodes an exotoxin, rtxC encodes an RtxA activator, rtxH encodes a conserved hypothetical protein, and rtxBDE encode the ABC transporters. Single mutations in rtx genes …

Alzheimer's Disease (Ad)-Like Pathology In Aged Monkeys After Infantile Exposure To Environmental Metal Lead (Pb): Evidence For A Developmental Origin And Environmental Link For Ad, Jinfang Wu, Md. Riyaz Basha, Brian Brock, David P. Cox, Fernando Cardozo-Pelaez, Christopher A. Mcpherson, Jean Harry, Deborah C. Rise, Brian Maloney, Demaio Chen, Debomoy K. Lahiri, Nasser H. Zawia

Biomedical and Pharmaceutical Sciences Faculty Publications

The sporadic nature of Alzheimer's disease (AD) argues for an environmental link that may drive AD pathogenesis; however, the triggering factors and the period of their action are unknown. Recent studies in rodents have shown that exposure to lead (Pb) during brain development predetermined the expression and regulation of the amyloid precursor protein (APP) and its amyloidogenic β-amyloid (Aβ) product in old age. Here, we report that the expression of AD-related genes [APP, BACE1 (β-site APP cleaving enzyme 1)] as well as their transcriptional regulator (Sp1) were elevated in aged (23-year-old) monkeys exposed to Pb as infants. Furthermore, developmental exposure …

Liver Receptor Homolog 1 Transcriptionally Regulates Human Bile Salt Export Pump Expression, Xiulong Song, Rajani Kaimal, Bingfang Yan, Ruitang Deng

Biomedical and Pharmaceutical Sciences Faculty Publications

The metabolic conversion of cholesterol into bile acids in liver is initiated by the rate-limiting cholesterol 7α-hydroxylase (CYP7A1), whereas the bile salt export pump (BSEP) is responsible for the canalicular secretion of bile acids. Liver receptor homolog 1 (LRH-1) is a key transcriptional factor required for the hepatic expression of CYP7A1. We hypothesized that LRH-1 was also involved in the transcriptional regulation of BSEP. In support of our hypothesis, we found that overexpression of LRH-1 induced, whereas knockdown of LRH-1 decreased, BSEP expression. Consistent with its role in transcriptional regulation, LRH-1 dose-dependently transactivated the BSEP promoter. In addition, such transactivation …

Metapopulation Dynamics Override Local Limits On Long‐Term Parasite Persistence, Karthik Ram, Evan L. Preisser, Daniel S. Gruner, Donald R. Strong

Biological Sciences Faculty Publications

A simple null model, particularly germane to small and vulnerable organisms such as parasites, is that local conditions set a stage upon which larger‐scale dynamics play out. Soil moisture strongly influences survival of entomopathogenic nematodes (EPN), which in turn drive trophic cascades by protecting vegetation from root‐feeding herbivores. In this study, we examine the mechanisms responsible for patchy occurrence of an entomopathogenic nematode, Heterorhabditis marelatus, in a California coastal prairie. One hypothesis proposes that biotic factors such as competition and natural enemies could regulate occurrence of EPN populations. We found that fungi and other enemies of EPN, although locally potent, …

From Individuals To Ecosystem Function: Toward An Integration Of Evolutionary And Ecosystem Ecology, Oswald J. Schmitz, Jonathan H. Garbowski, Barbara L. Peckarsky, Evan L. Preisser, Geoffrey C. Trussell, James R. Vonesh

Biological Sciences Faculty Publications

An important goal in ecology is developing general theory on how the species composition of ecosystems is related to ecosystem properties and functions. Progress on this front is limited partly because of the need to identify mechanisms controlling functions that are common to a wide range of ecosystem types. We propose that one general mechanism, rooted in the evolutionary ecology of all species, is adaptive foraging behavior in response to predation risk. To support our claim, we present two kinds of empirical evidence from plant‐based and detritus‐based food chains of terrestrial and aquatic ecosystems. The first kind comes from experiments …

A Bac-Based Integrated Linkage Map Of The Silkworm Bombyx Mori, Kimiko Yamamoto, Junko Nohata, Keiko Kadono-Okuda, Junko Narukawa, Motoe Sasanuma, Shun-Ichi Sasanuma, Hiroshi Minami, Michihiko Shimomura, Yoshitaka Suetsugu, Yutaka Banno, Kazutoyo Osoegawa, Pieter J. De Jong, Marian R. Goldsmith, Kazuei Mita

Biological Sciences Faculty Publications

Background: In 2004, draft sequences of the model lepidopteran Bombyx mori were reported using whole-genome shotgun sequencing. Because of relatively shallow genome coverage, the silkworm genome remains fragmented, hampering annotation and comparative genome studies. For a more complete genome analysis, we developed extended scaffolds combining physical maps with improved genetic maps.

Results: We mapped 1,755 single nucleotide polymorphism (SNP) markers from bacterial artificial chromosome (BAC) end sequences onto 28 linkage groups using a recombining male backcross population, yielding an average inter-SNP distance of 0.81 cM (about 270 kilobases). We constructed 6,221 contigs by fingerprinting clones from three BAC libraries digested …

Unsupervised Learning In Detection Of Gene Transfer, Lutz Hamel, Neha Nahar, M. S. Poptsova, O. Zhaxybayeva, J. P. Gogarten

Computer Science and Statistics Faculty Publications

The tree representation as a model for organismal evolution has been in use since before Darwin. However, with the recent unprecedented access to biomolecular data, it has been discovered that, especially in the microbial world, individual genes making up the genome of an organism give rise to different and sometimes conflicting evolutionary tree topologies. This discovery calls into question the notion of a single evolutionary tree for an organism and gives rise to the notion of an evolutionary consensus tree based on the evolutionary patterns of the majority of genes in a genome embedded in a network of gene histories. …

Reduce, Reuse, Recycle: Revamping A Freshman Seminar Information Literacy Program, Amanda Izenstark, Mary C. Macdonald

Public Services Faculty Publications

Describes the process of redesigning the information literacy component of the University of Rhode Island's first year experience program, URI 101, using a library-based scavenger hunt, student worksheets, hands-on exploration of the Library's web site, and in-class discussion.

Growth Trajectories Of Preterm Infants: Birth To 12 Years, Mary C. Sullivan, Margaret M. Mcgrath, Katheleen Hawes, Barry M. Lester

College of Nursing Faculty Publications

Introduction: Birth weight often is used to predict how preterm infants will grow, but scant attention has been paid to the effect of neonatal morbidities on growth trajectories. We investigated birth weight and neonatal morbidity in preterm infants’ growth to age 12 years.

Method: A five-group, prospective, longitudinal study was conducted with 194 infants: 46 full term; 29 healthy preterm without morbidity; 56 preterm with medical illness (MPT); 34 preterm with neurologic illness; and 29 preterm small for gestational age (SGA). Height, weight, and body mass index were measured at six ages.

Results: The full-term group had greater height than …

In Vitro And In Vivo Evidence For Lack Of Endovascular Remodeling By Third Trimester Trophoblasts, S. Kalkunte, Z. Lai, N. Tewari, Clinton O. Chichester Iii, R. Romero, J. Padbury, S. Sharma

Biomedical and Pharmaceutical Sciences Faculty Publications

The placental–decidual interaction through invading trophoblasts determines whether a physiological transformation of the uterine spiral arteries is established or not. Trophoblast-orchestrated artery remodeling is central to normal placentation. Dysregulated uteroplacental interaction and vascular remodeling are thought to be associated with the molecular events underlying the pathology of late pregnancy anomalies including preeclampsia. Although the exact gestational age at which trophoblast invasion ceases is not known, it remains unclear whether late pregnancy trophoblasts retain the ability to transform the uterine arteries. Here, we have developed a dual cell, in vitro culture system that mimics the vascular remodeling events during …

Framing, Symmetry, And Contrast In Edmond De Goncourt's Aesthetic Interior, Pamela J. Warner

Art and Art History Faculty Publications

No abstract provided.

The Growth And Tumor Suppressors Nore1a And Rassf1a Are Targets For Calpain-Mediated Proteolysis, Sergey Kuznetsov, Andrei V. Khokhlatchev

Physics Faculty Publications

Background: NORE1A and RASSF1A are growth and tumour suppressors inactivated in a variety of cancers. Methylation of NORE1A and RASSF1A promoters is the predominant mechanism for downregulation of these proteins; however, other mechanisms are likely to exist.

Methodology/Principal Findings: Here we describe a proteolysis of NORE1A and RASSF1A by calpains as alternative mechanism of their downregulation. Extracts of H358 cell line, a human bronchoalveolar carcinoma, and H460, a large cell carcinoma, were capable of proteolysis of NORE1A protein in the calpain-dependent manner. Likewise, RASSF1A tumor suppressor was proteolyzed by the H358 cell extract. Addition of calpain inhibitor to …

Natural Products Chemistry And Taxonomy Of The Marine Cyanobacterium Blennothrix Cantharidosmum, Benjamin R. Clark, Niclas Engene, Margaret E. Teasdale, David C. Rowley, Teatulohi Matainaho, Frederick A. Valeriote, William H. Gerwick

Biomedical and Pharmaceutical Sciences Faculty Publications

A Papua New Guinea field collection of the marine cyanobacterium Blennothrix cantharidosmum was investigated for its cytotoxic constituents. Bioassay-guided isolation defined the cytotoxic components as the known compounds lyngbyastatins 1 and 3. However, six new acyl proline derivatives, tumonoic acids D−I, plus the known tumonoic acid A were also isolated. Their planar structures were defined from NMR and MS data, while their stereostructures followed from a series of chiral chromatographies, degradation sequences, and synthetic approaches. The new compounds were tested in an array of assays, but showed only modest antimalarial and inhibition of quorum sensing activities. Nevertheless, these are the …

Examination Of Spot, Rpos And Rpon Gene Expression In Response To Fatty Acid Starvation In Borrelia Burgdorferi, The Lyme Disease Spirochete, Wendy Meredith Coy

Open Access Dissertations

The purpose of the present investigation is to examine the regulation and expression of the B. burgdorferi spoT/rpoS pathway under normal growth conditions and during serum starvation in wild-type strains and in spoT, rpoS and rpoN mutant strains. Additionally the expression of B. burgdorferi's rpoN gene has been examined within a surrogate Escherichia coli system by using a GFP reporter construct in order to determine if SpoT, RpoS or RpoN affect rpoN expression. In this study, we examined the affects of mutating the spoT, rpoS and rpoN genes. These genes are known to be both affected by starvation and to …

Effect Of Varying Inclusion Levels Of Linseed Oil On Growth, Fatty Acid Profile, Membrane Fluidity And Epa/Dha Production In Atlantic Salmon (Salmo Salar), Mary Anne Eaton

Open Access Dissertations

Fish oil accounts for approximately 26.8% of the operating costs of salmon aquaculture. To compensate for the increasing demand in fish oil, alternative plant and animal oils have been used to replace the fish oil. The goal of this study was to formulate a cost-effective fish feed which supports adequate growth of salmon and is less susceptible to oxidative damage while maintaining the characteristic beneficial fatty acid profile. Experiments were undertaken to assess the growth, fatty acid profile, erythrocyte membrane fluidity, and ability of liver hepatocytes to convert linolenic acid to EPA and DHA in Atlantic salmon with inclusion of …

Sediment Transport In A Dynamic, Tidally-Influenced Coastal Embayment Exemplified By Pleasant Bay And Chatham Harbor, Cape Cod, Massachusetts, Mark Borrelli

Open Access Dissertations

Sediment transport in a coastal embayment was documented on multiple spatial and temporal scales. An inlet formed in Chatham Harbor in 1987 and as a result the primary flood-tidal delta began to migrate. The relationship between the evolution of the tidal inlet and the flood-tidal delta was documented using field studies and spatial analyses of georeferenced aerial photographs. A feedback mechanism was documented such that the migrating flood-tidal delta increases in surface area, which causes the ebb-tidal flow to become more channelized, which in turn allows more intertidal area to be created by flood-tidal currents and further channelizing ebb-tidal flow. …

An Examination Of The Relationships Between The Peptide Hormone Ghrelin And Appetite, Plasma Biomarkers Of Satiety And Metabolic Response In Humans, Daniel Lee Kresge

Open Access Dissertations

The peripherally circulating peptide hormone ghrelin is purported to stimulate hunger and feeding in humans, and is affected by the energy storage state as reflected in body mass index and body composition, and by macronutrient content of the diet. There have been few studies in humans that have measured both ghrelin, in its various isoforms, and appetite. To address this, Manuscript #1 of this dissertation examined fasting and postprandial ghrelin and ratings of appetite, in addition to anthropometric and fitness measures in 50 college-age student. There were no significant correlations between fasting or postprandial ghrelin and appetite or anthropometric measures …