637 research outputs found

    On chains in HH-closed topological pospaces

    Full text link
    We study chains in an HH-closed topological partially ordered space. We give sufficient conditions for a maximal chain LL in an HH-closed topological partially ordered space such that LL contains a maximal (minimal) element. Also we give sufficient conditions for a linearly ordered topological partially ordered space to be HH-closed. We prove that any HH-closed topological semilattice contains a zero. We show that a linearly ordered HH-closed topological semilattice is an HH-closed topological pospace and show that in the general case this is not true. We construct an example an HH-closed topological pospace with a non-HH-closed maximal chain and give sufficient conditions that a maximal chain of an HH-closed topological pospace is an HH-closed topological pospace.Comment: We have rewritten and substantially expanded the manuscrip

    MERS-CoV antibody responses 1 Year after symptom onset, South Korea, 2015

    Get PDF
    We investigated the kinetics of the Middle East respiratory syndrome coronavirus (MERS-CoV) neutralizing and spike protein antibody titers over the course of 1 year in 11 patients who were confirmed by reverse transcription PCR to have been infected during the outbreak in South Korea in 2015. Robust antibody responses were detected in all survivors who had severe disease; responses remained detectable, albeit with some waning, for <1 year. The duration of viral RNA detection (but not viral load) in sputum significantly correlated with the antibody response magnitude. The MERS S1 ELISA antibody titers correlated well with the neutralizing antibody response. Antibody titers in 4 of 6 patients who had mild illness were undetectable even though most had evidence of pneumonia. This finding implies that MERS-CoV seroepidemiologic studies markedly underestimate the extent of mild and asymptomatic infection. Obtaining convalescent-phase plasma with high antibody titers to treat MERS will be challenging.published_or_final_versio

    A Preference for a Sexual Signal Keeps Females Safe

    Get PDF
    Predation is generally thought to constrain sexual selection by female choice and limit the evolution of conspicuous sexual signals. Under high predation risk, females usually become less choosy, because they reduce their exposure to their predators by reducing the extent of their mate searching. However, predation need not weaken sexual selection if, under high predation risk, females exhibit stronger preferences for males that use conspicuous signals that help females avoid their predators. We tested this prediction in the fiddler crab Uca terpsichores by increasing females' perceived predation risk from crab-eating birds and measuring the attractiveness of a courtship signal that females use to find mates. The sexual signal is an arching mound of sand that males build at the openings of their burrows to which they attract females for mating. We found that the greater the risk, the more attractive were males with those structures. The benefits of mate preferences for sexual signals are usually thought to be linked to males' reproductive contributions to females or their young. Our study provides the first evidence that a female preference for a sexual signal can yield direct survival benefits by keeping females safe as they search for mates

    Comparison of serological assays in human Middle East respiratory syndrome (MERS)-coronavirus infection

    Get PDF
    Plaque reduction neutralisation tests (PRNT), microneutralisation (MN), Middle East respiratory syndrome (MERS)-spike pseudoparticle neutralisation (ppNT) and MERS S1-enzyme-linked immunosorbent assay (ELISA) antibody titres were compared using 95 sera from 17 patients with MERS, collected two to 46 days after symptom onset. Neutralisation tests correlated well with each other and moderately well with S1 ELISA. Moreover to compare antigenic similarity of genetically diverse MERS-CoV clades, the response of four sera from two patients sampled at two time periods during the course of illness were tested by 90% PRNT. Genetically diverse MERS-CoV clades were antigenically homogenous.published_or_final_versio

    Health Locus of Control and Assimilation of Cervical Cancer Information in Deaf Women

    Get PDF
    This study assessed the relationship between Deaf women's internal health locus of control (IHLC) and their cervical cancer knowledge acquisition and retention. A blind, randomized trial evaluated Deaf women's (N = 130) baseline cancer knowledge and knowledge gained and retained from an educational intervention, in relation to their IHLC. The Multidimensional Health Locus of Control scales measured baseline IHLC, and a cervical cancer knowledge survey evaluated baseline to post-intervention knowledge change. Women's IHLC did not significantly predict greater cervical cancer knowledge at baseline or over time. IHLC does not appear to be a characteristic that must be considered when creating Deaf women's cancer education programs

    Proteomic Analysis of Human Skin Treated with Larval Schistosome Peptidases Reveals Distinct Invasion Strategies among Species of Blood Flukes

    Get PDF
    Schistosome parasites are a major cause of disease in the developing world, but the mechanism by which these parasites first infect their host has been studied at the molecular level only for S. mansoni. In this paper, we have mined recent genome annotations of S. mansoni and S. japonicum, a zoonotic schistosome species, to identify differential expansion of peptidase gene families that may be involved in parasite invasion and subsequent migration through skin. Having identified a serine peptidase gene family in S. mansoni and a cysteine peptidase gene family in S. japonicum, we then used a comparative proteomic approach to identify potential substrates of representative members of both classes of enzymes from S. mansoni in human skin. The results of this study suggest that while these species evolved to use different classes of peptidases in host invasion, both are capable of cleaving components of the epidermis and dermal extracellular matrix, as well as proteins involved in the host immune response against the migrating parasite

    Probe-level linear model fitting and mixture modeling results in high accuracy detection of differential gene expression

    Get PDF
    BACKGROUND: The identification of differentially expressed genes (DEGs) from Affymetrix GeneChips arrays is currently done by first computing expression levels from the low-level probe intensities, then deriving significance by comparing these expression levels between conditions. The proposed PL-LM (Probe-Level Linear Model) method implements a linear model applied on the probe-level data to directly estimate the treatment effect. A finite mixture of Gaussian components is then used to identify DEGs using the coefficients estimated by the linear model. This approach can readily be applied to experimental design with or without replication. RESULTS: On a wholly defined dataset, the PL-LM method was able to identify 75% of the differentially expressed genes within 10% of false positives. This accuracy was achieved both using the three replicates per conditions available in the dataset and using only one replicate per condition. CONCLUSION: The method achieves, on this dataset, a higher accuracy than the best set of tools identified by the authors of the dataset, and does so using only one replicate per condition

    Informing the design of a national screening and treatment programme for chronic viral hepatitis in primary care: qualitative study of at-risk immigrant communities and healthcare professionals

    Get PDF
    n Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise statedThis paper presents independent research funded by the National Institute for Health Research (NIHR) under the Programme Grants for Applied Research programme (RP-PG-1209-10038).

    Rudra Interrupts Receptor Signaling Complexes to Negatively Regulate the IMD Pathway

    Get PDF
    Insects rely primarily on innate immune responses to fight pathogens. In Drosophila, antimicrobial peptides are key contributors to host defense. Antimicrobial peptide gene expression is regulated by the IMD and Toll pathways. Bacterial peptidoglycans trigger these pathways, through recognition by peptidoglycan recognition proteins (PGRPs). DAP-type peptidoglycan triggers the IMD pathway via PGRP-LC and PGRP-LE, while lysine-type peptidoglycan is an agonist for the Toll pathway through PGRP-SA and PGRP-SD. Recent work has shown that the intensity and duration of the immune responses initiating with these receptors is tightly regulated at multiple levels, by a series of negative regulators. Through two-hybrid screening with PGRP-LC, we identified Rudra, a new regulator of the IMD pathway, and demonstrate that it is a critical feedback inhibitor of peptidoglycan receptor signaling. Following stimulation of the IMD pathway, rudra expression was rapidly induced. In cells, RNAi targeting of rudra caused a marked up-regulation of antimicrobial peptide gene expression. rudra mutant flies also hyper-activated antimicrobial peptide genes and were more resistant to infection with the insect pathogen Erwinia carotovora carotovora. Molecularly, Rudra was found to bind and interfere with both PGRP-LC and PGRP-LE, disrupting their signaling complex. These results show that Rudra is a critical component in a negative feedback loop, whereby immune-induced gene expression rapidly produces a potent inhibitor that binds and inhibits pattern recognition receptors

    Gene selection with multiple ordering criteria

    Get PDF
    BACKGROUND: A microarray study may select different differentially expressed gene sets because of different selection criteria. For example, the fold-change and p-value are two commonly known criteria to select differentially expressed genes under two experimental conditions. These two selection criteria often result in incompatible selected gene sets. Also, in a two-factor, say, treatment by time experiment, the investigator may be interested in one gene list that responds to both treatment and time effects. RESULTS: We propose three layer ranking algorithms, point-admissible, line-admissible (convex), and Pareto, to provide a preference gene list from multiple gene lists generated by different ranking criteria. Using the public colon data as an example, the layer ranking algorithms are applied to the three univariate ranking criteria, fold-change, p-value, and frequency of selections by the SVM-RFE classifier. A simulation experiment shows that for experiments with small or moderate sample sizes (less than 20 per group) and detecting a 4-fold change or less, the two-dimensional (p-value and fold-change) convex layer ranking selects differentially expressed genes with generally lower FDR and higher power than the standard p-value ranking. Three applications are presented. The first application illustrates a use of the layer rankings to potentially improve predictive accuracy. The second application illustrates an application to a two-factor experiment involving two dose levels and two time points. The layer rankings are applied to selecting differentially expressed genes relating to the dose and time effects. In the third application, the layer rankings are applied to a benchmark data set consisting of three dilution concentrations to provide a ranking system from a long list of differentially expressed genes generated from the three dilution concentrations. CONCLUSION: The layer ranking algorithms are useful to help investigators in selecting the most promising genes from multiple gene lists generated by different filter, normalization, or analysis methods for various objectives
    corecore