2,072 research outputs found

    A peer-to-peer infrastructure for resilient web services

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    This work is funded by GR/M78403 “Supporting Internet Computation in Arbitrary Geographical Locations” and GR/R51872 “Reflective Application Framework for Distributed Architectures”, and by Nuffield Grant URB/01597/G “Peer-to-Peer Infrastructure for Autonomic Storage Architectures”This paper describes an infrastructure for the deployment and use of Web Services that are resilient to the failure of the nodes that host those services. The infrastructure presents a single interface that provides mechanisms for users to publish services and to find hosted services. The infrastructure supports the autonomic deployment of services and the brokerage of hosts on which services may be deployed. Once deployed, services are autonomically managed in a number of aspects including load balancing, availability, failure detection and recovery, and lifetime management. Services are published and deployed with associated metadata describing the service type. This same metadata may be used subsequently by interested parties to discover services. The infrastructure uses peer-to-peer (P2P) overlay technologies to abstract over the underlying network to deploy and locate instances of those services. It takes advantage of the P2P network to replicate directory services used to locate service instances (for using a service), Service Hosts (for deployment of services) and Autonomic Managers which manage the deployed services. The P2P overlay network is itself constructed using novel Web Services-based middleware and a variation of the Chord P2P protocol, which is self-managing.Postprin

    16S rRNA gene-based profiling of the human infant gut microbiota is strongly influenced by sample processing and PCR primer choice

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    Acknowledgements The authors acknowledge the assistance of Grietje Holtrop (RINH-BioSS) with the statistical analysis of the data and the Wellcome Trust Sanger Institute’s 454 pyrosequencing team for generating 16S rRNA gene data. AWW, PS and JP received core funding support from the Wellcome Trust [grant number 098051]. AWW, JCM, HJF and KPS are funded by the Scottish Government (SG-RESAS).Peer reviewedPublisher PD

    TPL-2 restricts Ccl24-dependent immunity to Heligmosomoides polygyrus

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    Funding: This work was supported by the Francis Crick Institute which receives its core funding from Cancer Research UK (FC001220), the UK Medical Research Council (FC001220), and the Wellcome Trust (FC001200). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Acknowledgments We are indebted to The Francis Crick Institute Flow Cytometry facility, and in particular Bhavik Patel, Graham Preece, Wayne Turnbull and Phil Hobson. We would also like to thank The Francis Crick Institute Procedural Service Section for production of GA lines and Biological Services, especially Trisha Norton, Keith Williams and Adebambo Adekoya for animal husbandry and technical support; to Riccardo Guidi for constructive discussions and technical assistance. We would like to thank Gitta Stockinger and AhR Immunity Laboratory for providing technical support and reagents throughout this study. We also thank Richard Rance and the Wellcome Trust Sanger Institute’s 454 pyrosequencing team for generating 16S rRNA gene data.Peer reviewedPublisher PD

    Molecular Line Emission from Gravitationally Unstable Protoplanetary Disks

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    In the era of high resolution submillimeter interferometers, it will soon be possible to observe the neutral circumstellar medium directly involved in gas giant planet (GGP) formation at physical scales previously unattainable. In order to explore possible signatures of gas giant planet formation via disk instabilities, we have combined a 3D, non-local thermodynamic equilibrium (LTE) radiative transfer code with a 3D, finite differences hydrodynamical code to model molecular emission lines from the vicinity of a 1.4 M_J self-gravitating proto-GGP. Here, we explore the properties of rotational transitions of the commonly observed dense gas tracer, HCO+. Our main results are the following: 1. Very high lying HCO+ transitions (e.g. HCO+ J=7-6) can trace dense planet forming clumps around circumstellar disks. Depending on the molecular abundance, the proto-GGP may be directly imageable by the Atacama Large Millimeter Array (ALMA). 2. HCO+ emission lines are heavily self-absorbed through the proto-GGP's dense molecular core. This signature is nearly ubiquitous, and only weakly dependent on assumed HCO+ abundances. The self-absorption features are most pronounced at higher angular resolutions. Dense clumps that are not self-gravitating only show minor self-absorption features. 3. Line temperatures are highest through the proto-GGP at all assumed abundances and inclination angles. Conversely, due to self-absorption in the line, the velocity-integrated intensity may not be. High angular resolution interferometers such as the Submillimeter Array (SMA) and ALMA may be able to differentiate between competing theories of gas giant planet formation.Comment: 10 pages, 13 figures; Accepted by Ap

    A non-endoscopic device to sample the oesophageal microbiota: a case-control study.

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    BACKGROUND: The strongest risk factor for oesophageal adenocarcinoma is reflux disease, and the rising incidence of this coincides with the eradication of Helicobacter pylori, both of which might alter the oesophageal microbiota. We aimed to profile the microbiota at different stages of Barrett's carcinogenesis and investigate the Cytosponge as a minimally invasive tool for sampling the oesophageal microbiota. METHODS: In this case-control study, 16S rRNA gene amplicon sequencing was done on 210 oesophageal samples from 86 patients representing the Barrett's oesophagus progression sequence (normal squamous controls [n=20], non-dysplastic [n=24] and dysplastic Barrett's oesophagus [n=23], and oesophageal adenocarcinoma [n=19]), relevant negative controls, and replicates on the Illumina MiSeq platform. Samples were taken from patients enrolled in the BEST2 study at five UK hospitals and the OCCAMS study at six UK hospitals. We compared fresh frozen tissue, fresh frozen endoscopic brushings, and the Cytosponge device for microbial DNA yield (qPCR), diversity, and community composition. FINDINGS: There was decreased microbial diversity in oesophageal adenocarcinoma tissue compared with tissue from healthy control patients as measured by the observed operational taxonomic unit (OTU) richness (p=0·0012), Chao estimated total richness (p=0·0004), and Shannon diversity index (p=0·0075). Lactobacillus fermentum was enriched in oesophageal adenocarcinoma (p=0·028), and lactic acid bacteria dominated the microenvironment in seven (47%) of 15 cases of oesophageal adenocarcinoma. Comparison of oesophageal sampling methods showed that the Cytosponge yielded more than ten-times higher quantities of microbial DNA than did endoscopic brushes or biopsies using quantitative PCR (p<0·0001). The Cytosponge samples contained the majority of taxa detected in biopsy and brush samples, but were enriched for genera from the oral cavity and stomach, including Fusobacterium, Megasphaera, Campylobacter, Capnocytophaga, and Dialister. The Cytosponge detected decreased microbial diversity in patients with high-grade dysplasia in comparison to control patients, as measured by the observed OTU richness (p=0·0147), Chao estimated total richness (p=0·023), and Shannon diversity index (p=0·0085). INTERPRETATION: Alterations in microbial communities occur in the lower oesophagus in Barrett's carcinogenesis, which can be detected at the pre-invasive stage of high-grade dysplasia with the novel Cytosponge device. Our findings are potentially applicable to early disease detection, and future test development should focus on longitudinal sampling of the microbiota to monitor for changes in microbial diversity in a larger cohort of patients. FUNDING: Cancer Research UK, National Institute for Health Research, Medical Research Council, Wellcome Trust, The Scottish Government (RESAS).Cancer Research UK, National Institute for Health Research, Medical Research Council, and Wellcome Trust.This is the author accepted manuscript. The final version is available from Elsevier via https://doi.org/10.1016/S2468-1253(16)30086-

    Elevated levels of inflammatory cytokines predict survival in idiopathic and familial pulmonary arterial hypertension

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    BACKGROUND: Inflammation is a feature of pulmonary arterial hypertension (PAH), and increased circulating levels of cytokines are reported in patients with PAH. However, to date, no information exists on the significance of elevated cytokines or their potential as biomarkers. We sought to determine the levels of a range of cytokines in PAH and to examine their impact on survival and relationship to hemodynamic indexes. METHODS AND RESULTS: We measured levels of serum cytokines (tumor necrosis factor-alpha, interferon-gamma and interleukin-1beta, -2, -4, -5, -6, -8, -10, -12p70, and -13) using ELISAs in idiopathic and heritable PAH patients (n=60). Concurrent clinical data included hemodynamics, 6-minute walk distance, and survival time from sampling to death or transplantation. Healthy volunteers served as control subjects (n=21). PAH patients had significantly higher levels of interleukin-1beta, -2, -4, -6, -8, -10, and -12p70 and tumor necrosis factor-alpha compared with healthy control subjects. Kaplan-Meier analysis showed that levels of interleukin-6, 8, 10, and 12p70 predicted survival in patients. For example, 5-year survival with interleukin-6 levels of >9 pg/mL was 30% compared with 63% for patients with levels < or = 9 pg/mL (P=0.008). In this PAH cohort, cytokine levels were superior to traditional markers of prognosis such as 6-minute walk distance and hemodynamics. CONCLUSIONS: This study illustrates dysregulation of a broad range of inflammatory mediators in idiopathic and familial PAH and demonstrates that cytokine levels have a previously unrecognized impact on patient survival. They may prove to be useful biomarkers and provide insight into the contribution of inflammation in PAH

    Identification of mildew resistance in wild and cultivated Central Asian grape germplasm

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    BACKGROUND: Cultivated grapevines, Vitis vinifera subsp. sativa, evolved from their wild relative, V. vinifera subsp. sylvestris. They were domesticated in Central Asia in the absence of the powdery mildew fungus, Erysiphe necator, which is thought to have originated in North America. However, powdery mildew resistance has previously been discovered in two Central Asian cultivars and in Chinese Vitis species. RESULTS: A set of 380 unique genotypes were evaluated with data generated from 34 simple sequence repeat (SSR) markers. The set included 306 V. vinifera cultivars, 40 accessions of V. vinifera subsp. sylvestris, and 34 accessions of Vitis species from northern Pakistan, Afghanistan and China. Based on the presence of four SSR alleles previously identified as linked to the powdery mildew resistance locus, Ren1, 10 new mildew resistant genotypes were identified in the test set: eight were V. vinifera cultivars and two were V. vinifera subsp. sylvestris based on flower and seed morphology. Sequence comparison of a 620 bp region that includes the Ren1-linked allele (143 bp) of the co-segregating SSR marker SC8-0071-014, revealed that the ten newly identified genotypes have sequences that are essentially identical to the previously identified mildew resistant V. vinifera cultivars: ‘Kishmish vatkana’ and ‘Karadzhandal’. Kinship analysis determined that three of the newly identified powdery mildew resistant accessions had a relationship with ‘Kishmish vatkana’ and ‘Karadzhandal’, and that six were not related to any other accession in this study set. Clustering procedures assigned accessions into three groups: 1) Chinese species; 2) a mixed group of cultivated and wild V. vinifera; and 3) table grape cultivars, including nine of the powdery mildew resistant accessions. Gene flow was detected among the groups. CONCLUSIONS: This study provides evidence that powdery mildew resistance is present in V. vinifera subsp. sylvestris, the dioecious wild progenitor of the cultivated grape. Four first-degree parent progeny relationships were discovered among the hermaphroditic powdery mildew resistant cultivars, supporting the existence of intentional grape breeding efforts. Although several Chinese grape species are resistant to powdery mildew, no direct genetic link to the resistance found in V. vinifera could be established

    ARK: Aggregation of Reads by K-Means for Estimation of Bacterial Community Composition.

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    MOTIVATION: Estimation of bacterial community composition from high-throughput sequenced 16S rRNA gene amplicons is a key task in microbial ecology. Since the sequence data from each sample typically consist of a large number of reads and are adversely impacted by different levels of biological and technical noise, accurate analysis of such large datasets is challenging. RESULTS: There has been a recent surge of interest in using compressed sensing inspired and convex-optimization based methods to solve the estimation problem for bacterial community composition. These methods typically rely on summarizing the sequence data by frequencies of low-order k-mers and matching this information statistically with a taxonomically structured database. Here we show that the accuracy of the resulting community composition estimates can be substantially improved by aggregating the reads from a sample with an unsupervised machine learning approach prior to the estimation phase. The aggregation of reads is a pre-processing approach where we use a standard K-means clustering algorithm that partitions a large set of reads into subsets with reasonable computational cost to provide several vectors of first order statistics instead of only single statistical summarization in terms of k-mer frequencies. The output of the clustering is then processed further to obtain the final estimate for each sample. The resulting method is called Aggregation of Reads by K-means (ARK), and it is based on a statistical argument via mixture density formulation. ARK is found to improve the fidelity and robustness of several recently introduced methods, with only a modest increase in computational complexity. AVAILABILITY: An open source, platform-independent implementation of the method in the Julia programming language is freely available at https://github.com/dkoslicki/ARK. A Matlab implementation is available at http://www.ee.kth.se/ctsoftware

    Risdiplam for the Use of Spinal Muscular Atrophy

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    Spinal muscular atrophy (SMA) is one of the leading causes of death in infants related to the degeneration of neurons. Currently, there are no curative treatment options for SMA, and many options available may not be feasible. This review presents the background, clinical studies, and indications for the use of Risdiplam in treating SMA. SMA causes a decrease in the production of survival motor neuron proteins (SMN) and current treatments target to increase the expression of SMN. Risdiplam is the first and only oral medication to be approved to treat SMA. As an SMN2 splicing modifier, it has provided stronger systemic therapies than previous intrathecal and gene replacement therapies. There have been many efforts to treat SMA with multidisciplinary approaches. These include intrathecal injections to gene replacement therapies. However, these have been faced with limitations such as reaching a good therapeutic dose in systemic tissues, route of administration, and price. Risdiplam is currently the only orally administered drug approved by the FDA for the treatment of SMA. It not only provides a good therapeutic window to systemic tissues but allows for a non-invasive approach in infants. Further investigation and comparison on the safety profile of Risdiplam due to its broader systemic effect should be considered with other available therapies

    Microwave and Millimeter Wave Techniques

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    Contains reports on four research projects.Joint Services Electronics Program (Contract DAAB07-74-C-0630)National Science Foundation (Grant MPS-73-05043-A01
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