97 research outputs found

    Speciation of common Gram-negative pathogens using a highly multiplexed high resolution melt curve assay

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    The identification of the bacterial species responsible for an infection remains an important step for the selection of antimicrobial therapy. Gram-negative bacteria are an important source of hospital and community acquired infections and frequently antimicrobial resistant. Speciation of bacteria is typically carried out by biochemical profiling of organisms isolated from clinical specimens, which is time consuming and delays the initiation of tailored treatment. Whilst molecular methods such as PCR have been used, they often struggle with the challenge of detecting and discriminating a wide range of targets. High resolution melt analysis is an end-point qPCR detection method that provides greater multiplexing capability than probe based methods. Here we report the design of a high resolution melt analysis assay for the identification of six common Gram-negative pathogens; Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, Pseudomonas aeruginosa, Salmonella Sp, and Acinetobacter baumannii, and a generic Gram-negative specific 16S rRNA control. The assay was evaluated using a well characterised collection of 113 clinically isolated Gram-negative bacteria. The agreement between the HRM assay and the reference test of PCR and sequencing was 98.2% (Kappa 0.96); the overall sensitivity and specificity of the assay was 97.1% (95% CI: 90.1–99.7%) and 100% (95% CI: 91.78–100%) respectively

    Predicting RNA-Protein Interactions Using Only Sequence Information

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    <p>Abstract</p> <p>Background</p> <p>RNA-protein interactions (RPIs) play important roles in a wide variety of cellular processes, ranging from transcriptional and post-transcriptional regulation of gene expression to host defense against pathogens. High throughput experiments to identify RNA-protein interactions are beginning to provide valuable information about the complexity of RNA-protein interaction networks, but are expensive and time consuming. Hence, there is a need for reliable computational methods for predicting RNA-protein interactions.</p> <p>Results</p> <p>We propose <b><it>RPISeq</it></b>, a family of classifiers for predicting <b><it>R</it></b>NA-<b><it>p</it></b>rotein <b><it>i</it></b>nteractions using only <b><it>seq</it></b>uence information. Given the sequences of an RNA and a protein as input, <it>RPIseq </it>predicts whether or not the RNA-protein pair interact. The RNA sequence is encoded as a normalized vector of its ribonucleotide 4-mer composition, and the protein sequence is encoded as a normalized vector of its 3-mer composition, based on a 7-letter reduced alphabet representation. Two variants of <it>RPISeq </it>are presented: <it>RPISeq-SVM</it>, which uses a Support Vector Machine (SVM) classifier and <it>RPISeq-RF</it>, which uses a Random Forest classifier. On two non-redundant benchmark datasets extracted from the Protein-RNA Interface Database (PRIDB), <it>RPISeq </it>achieved an AUC (Area Under the Receiver Operating Characteristic (ROC) curve) of 0.96 and 0.92. On a third dataset containing only mRNA-protein interactions, the performance of <it>RPISeq </it>was competitive with that of a published method that requires information regarding many different features (e.g., mRNA half-life, GO annotations) of the putative RNA and protein partners. In addition, <it>RPISeq </it>classifiers trained using the PRIDB data correctly predicted the majority (57-99%) of non-coding RNA-protein interactions in NPInter-derived networks from <it>E. coli, S. cerevisiae, D. melanogaster, M. musculus</it>, and <it>H. sapiens</it>.</p> <p>Conclusions</p> <p>Our experiments with <it>RPISeq </it>demonstrate that RNA-protein interactions can be reliably predicted using only sequence-derived information. <it>RPISeq </it>offers an inexpensive method for computational construction of RNA-protein interaction networks, and should provide useful insights into the function of non-coding RNAs. <it>RPISeq </it>is freely available as a web-based server at <url>http://pridb.gdcb.iastate.edu/RPISeq/.</url></p

    Analysis of the EIAV Rev-Responsive Element (RRE) Reveals a Conserved RNA Motif Required for High Affinity Rev Binding in Both HIV-1 and EIAV

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    A cis-acting RNA regulatory element, the Rev-responsive element (RRE), has essential roles in replication of lentiviruses, including human immunodeficiency virus (HIV-1) and equine infection anemia virus (EIAV). The RRE binds the viral trans-acting regulatory protein, Rev, to mediate nucleocytoplasmic transport of incompletely spliced mRNAs encoding viral structural genes and genomic RNA. Because of its potential as a clinical target, RRE-Rev interactions have been well studied in HIV-1; however, detailed molecular structures of Rev-RRE complexes in other lentiviruses are still lacking. In this study, we investigate the secondary structure of the EIAV RRE and interrogate regulatory protein-RNA interactions in EIAV Rev-RRE complexes. Computational prediction and detailed chemical probing and footprinting experiments were used to determine the RNA secondary structure of EIAV RRE-1, a 555 nt region that provides RRE function in vivo. Chemical probing experiments confirmed the presence of several predicted loop and stem-loop structures, which are conserved among 140 EIAV sequence variants. Footprinting experiments revealed that Rev binding induces significant structural rearrangement in two conserved domains characterized by stable stem-loop structures. Rev binding region-1 (RBR-1) corresponds to a genetically-defined Rev binding region that overlaps exon 1 of the EIAV rev gene and contains an exonic splicing enhancer (ESE). RBR-2, characterized for the first time in this study, is required for high affinity binding of EIAV Rev to the RRE. RBR-2 contains an RNA structural motif that is also found within the high affinity Rev binding site in HIV-1 (stem-loop IIB), and within or near mapped RRE regions of four additional lentiviruses. The powerful integration of computational and experimental approaches in this study has generated a validated RNA secondary structure for the EIAV RRE and provided provocative evidence that high affinity Rev binding sites of HIV-1 and EIAV share a conserved RNA structural motif. The presence of this motif in phylogenetically divergent lentiviruses suggests that it may play a role in highly conserved interactions that could be targeted in novel anti-lentiviral therapies

    Stable carbon and nitrogen isotope enrichment in primate tissues

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    Isotopic studies of wild primates have used a wide range of tissues to infer diet and model the foraging ecologies of extinct species. The use of mismatched tissues for such comparisons can be problematic because differences in amino acid compositions can lead to small isotopic differences between tissues. Additionally, physiological and dietary differences among primate species could lead to variable offsets between apatite carbonate and collagen. To improve our understanding of the isotopic chemistry of primates, we explored the apparent enrichment (ε*) between bone collagen and muscle, collagen and fur or hair keratin, muscle and keratin, and collagen and bone carbonate across the primate order. We found that the mean ε* values of proteinaceous tissues were small (≤1‰), and uncorrelated with body size or phylogenetic relatedness. Additionally, ε* values did not vary by habitat, sex, age, or manner of death. The mean ε* value between bone carbonate and collagen (5.6 ± 1.2‰) was consistent with values reported for omnivorous mammals consuming monoisotopic diets. These primate-specific apparent enrichment values will be a valuable tool for cross-species comparisons. Additionally, they will facilitate dietary comparisons between living and fossil primates

    Neutrinos

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    229 pages229 pages229 pagesThe Proceedings of the 2011 workshop on Fundamental Physics at the Intensity Frontier. Science opportunities at the intensity frontier are identified and described in the areas of heavy quarks, charged leptons, neutrinos, proton decay, new light weakly-coupled particles, and nucleons, nuclei, and atoms

    QCD and strongly coupled gauge theories : challenges and perspectives

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    We highlight the progress, current status, and open challenges of QCD-driven physics, in theory and in experiment. We discuss how the strong interaction is intimately connected to a broad sweep of physical problems, in settings ranging from astrophysics and cosmology to strongly coupled, complex systems in particle and condensed-matter physics, as well as to searches for physics beyond the Standard Model. We also discuss how success in describing the strong interaction impacts other fields, and, in turn, how such subjects can impact studies of the strong interaction. In the course of the work we offer a perspective on the many research streams which flow into and out of QCD, as well as a vision for future developments.Peer reviewe

    ANALISIS REPRESENTASI TRADISI KEMATIAN PADA NOVEL PUYA KE PUYA KARYA FAISAL ODDANG

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    Death tradition is a ceremonial process that is done from generation to generation as the delivery of died people before actually going to another world (immortality).One of death traditions in Indonesia that is still done and well-known to foreign countries is Rambu Solo’ in Toraja. Rambu Solo’ is done as the process of perfecting died people. Death tradition is depicted in Puya Ke Puya novel by Faisal Oddang. Based on that thing, the problem formulation in this research, are (1) how is the representation of death ceremony stages in Puya Ke Puya novel by Faisal Oddang, (2) how are the meanings of death ceremony stages in Puya Ke Puya novel by Faisal Oddang. The method used in this research is descriptive method of analysis using literary anthropology approach. The source of data in this study is Puya Ke Puya novel by Faisal Oddang by concerning data quotations, sentences, as well as units of stories in the novel. Data found in this researh is processed through several stages, such as (1) collecting data, (2) classifying data, (3) data assessment, (4) drawing conclusion. The result of the analysis and discussion shows that in Puya Ke Puya novel by Faisal Oddang, it is found two processes of ceremonial stages and the meaning of process stages as representation of death tradition in Rambu Solo '. Death ceremony stages are (1) before death ceremony process and (2) during death ceremony process. Before the ceremony, there are several things that are need to be done and prepared by the family including holding big family meeting to determine when the Rambu Solo’ ceremony will be held, determining the level of death ceremony, preparing or buying buffaloes and pigs, preparing the necessary equipments. The next stage is the process of death ceremony. In this stage which includes Mappassulu ', Mangriu' Batu, Mapopengkaloa, Ma'pasonglo, Tau-tau, Lantang, Mappasilaga Tedong, Mantunu Tedong and ipalao. The meaning of Rambu Solo’ ceremony stage is a process of completion of died people so that they can get to puya. If it is not celebrated, thw aoul of died people will be stuck between heaven and earth in uncertain fate or become ghosts. It is also believed that it brings misfortune for families of died people. This is the belief of Toraja people

    Natural environments, ancestral diets, and microbial ecology: is there a modern “paleo-deficit disorder”? Part II

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    Surgical activity in England and Wales during the COVID-19 pandemic: a nationwide observational cohort study

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    Objectives To report the volume of surgical activity and the number of cancelled surgical procedures during the COVID-19 pandemic. Design and setting Analysis of electronic health record data from the National Health Service (NHS) in England and Wales. Methods We used hospital episode statistics for all adult patients undergoing surgery between 1st January 2020 and 31st December 2020. We identified surgical procedures using a previously published list of procedure codes. Procedures were stratified by urgency of surgery as defined by NHS England. We calculated the deficit of surgical activity by comparing the expected number of procedures from the years 2016-2019 with the actual number of procedures in 2020. We estimated the cumulative number of cancelled procedures by 31st December 2021 according patterns of activity in 2020. Results The total number of surgical procedures carried out in England and Wales in 2020 was 3,102,674 compared to the predicted number of 4,671,338. This represents a 33.6% reduction in the national volume of surgical activity. There were 763,730 emergency surgical procedures (13.4% reduction), compared to 2,338,944 elective surgical procedures (38.6% reduction). The cumulative number of cancelled or postponed procedures was 1,568,664. We estimate that this will increase to 2,358,420 by 31st December 2021. Conclusions The volume of surgical activity in England and Wales was reduced by 33.6% in 2020, resulting in over 1,568,664 cancelled operations. This deficit will continue to grow in 2021
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