345 research outputs found

    Endomicroscopic and transcriptomic analysis of impaired barrier function and malabsorption in environmental enteropathy

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    Introduction: Environmental enteropathy (EE) is associated with growth failure, micronutrient malabsorption and impaired responses to oral vaccines. We set out to define cellular mechanisms of impaired barrier function in EE and explore protective mechanisms. Methods: We studied 49 adults with environmental enteropathy in Lusaka, Zambia using confocal laser endomicroscopy (CLE); histology, immunohistochemistry and mRNA sequencing of small intestinal biopsies; and correlated these with plasma lipopolysaccharide (LPS) and a zinc uptake test. Results: CLE images (median 134 for each study) showed virtually ubiquitous small intestinal damage. Epithelial defects, imaged by histology and claudin 4 immunostaining, were predominantly seen at the tips of villi and corresponded with leakage imaged in vivo by CLE. In multivariate analysis, circulating log-transformed LPS was correlated with cell shedding events (β = 0.83; P = 0.035) and with serum glucagon-like peptide-2 (β = -0.13; P = 0.007). Zinc uptake from a test dose of 25mg was attenuated in 30/47 (64%) individuals and in multivariate analysis was reduced by HIV, but positively correlated with GLP-2 (β = 2.72; P = 0.03). There was a U-shaped relationship between circulating LPS and villus surface area. Transcriptomic analysis identified 23 differentially expressed genes in severe enteropathy, including protective peptides and proteins. Conclusions: Confocal endomicroscopy, claudin 4 immunostaining and histology identify epithelial defects which are probably sites of bacterial translocation, in the presence of which increased epithelial surface area increases the burden of translocation. GLP 2 and other protective peptides may play an important role in mucosal protection in EE

    Fluids in cosmology

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    We review the role of fluids in cosmology by first introducing them in General Relativity and then by applying them to a FRW Universe's model. We describe how relativistic and non-relativistic components evolve in the background dynamics. We also introduce scalar fields to show that they are able to yield an inflationary dynamics at very early times (inflation) and late times (quintessence). Then, we proceed to study the thermodynamical properties of the fluids and, lastly, its perturbed kinematics. We make emphasis in the constrictions of parameters by recent cosmological probes.Comment: 34 pages, 4 figures, version accepted as invited review to the book "Computational and Experimental Fluid Mechanics with Applications to Physics, Engineering and the Environment". Version 2: typos corrected and references expande

    Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

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    Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente

    A Complete Skull of an Early Cretaceous Sauropod and the Evolution of Advanced Titanosaurians

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    Advanced titanosaurian sauropods, such as nemegtosaurids and saltasaurids, were diverse and one of the most important groups of herbivores in the terrestrial biotas of the Late Cretaceous. However, little is known about their rise and diversification prior to the Late Cretaceous. Furthermore, the evolution of their highly-modified skull anatomy has been largely hindered by the scarcity of well-preserved cranial remains. A new sauropod dinosaur from the Early Cretaceous of Brazil represents the earliest advanced titanosaurian known to date, demonstrating that the initial diversification of advanced titanosaurians was well under way at least 30 million years before their known radiation in the latest Cretaceous. The new taxon also preserves the most complete skull among titanosaurians, further revealing that their low and elongated diplodocid-like skull morphology appeared much earlier than previously thought

    Tracking the spatial diffusion of influenza and norovirus using telehealth data: A spatiotemporal analysis of syndromic data

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    Background: Telehealth systems have a large potential for informing public health authorities in an early stage of outbreaks of communicable disease. Influenza and norovirus are common viruses that cause significant respiratory and gastrointestinal disease worldwide. Data about these viruses are not routinely mapped for surveillance purposes in the UK, so the spatial diffusion of national outbreaks and epidemics is not known as such incidents occur. We aim to describe the geographical origin and diffusion of rises in fever and vomiting calls to a national telehealth system, and consider the usefulness of these findings for influenza and norovirus surveillance. Methods: Data about fever calls (5- to 14-year-old age group) and vomiting calls (≥ 5-year-old age group) in school-age children, proxies for influenza and norovirus, respectively, were extracted from the NHS Direct national telehealth database for the period June 2005 to May 2006. The SaTScan space-time permutation model was used to retrospectively detect statistically significant clusters of calls on a week-by-week basis. These syndromic results were validated against existing laboratory and clinical surveillance data. Results: We identified two distinct periods of elevated fever calls. The first originated in the North-West of England during November 2005 and spread in a south-east direction, the second began in Central England during January 2006 and moved southwards. The timing, geographical location, and age structure of these rises in fever calls were similar to a national influenza B outbreak that occurred during winter 2005–2006. We also identified significantly elevated levels of vomiting calls in South-East England during winter 2005–2006. Conclusion: Spatiotemporal analyses of telehealth data, specifically fever calls, provided a timely and unique description of the evolution of a national influenza outbreak. In a similar way the tool may be useful for tracking norovirus, although the lack of consistent comparison data makes this more difficult to assess. In interpreting these results, care must be taken to consider other infectious and non-infectious causes of fever and vomiting. The scan statistic should be considered for spatial analyses of telehealth data elsewhere and will be used to initiate prospective geographical surveillance of influenza in England.

    Identification of novel Y chromosome encoded transcripts by testis transcriptome analysis of mice with deletions of the Y chromosome long arm.

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    BACKGROUND: The male-specific region of the mouse Y chromosome long arm (MSYq) is comprised largely of repeated DNA, including multiple copies of the spermatid-expressed Ssty gene family. Large deletions of MSYq are associated with sperm head defects for which Ssty deficiency has been presumed to be responsible. RESULTS: In a search for further candidate genes associated with these defects we analyzed changes in the testis transcriptome resulting from MSYq deletions, using testis cDNA microarrays. This approach, aided by accumulating mouse MSYq sequence information, identified transcripts derived from two further spermatid-expressed multicopy MSYq gene families; like Ssty, each of these new MSYq gene families has multicopy relatives on the X chromosome. The Sly family encodes a protein with homology to the chromatin-associated proteins XLR and XMR that are encoded by the X chromosomal relatives. The second MSYq gene family was identified because the transcripts hybridized to a microarrayed X chromosome-encoded testis cDNA. The X loci ('Astx') encoding this cDNA had 92-94% sequence identity to over 100 putative Y loci ('Asty') across exons and introns; only low level Asty transcription was detected. More strongly transcribed recombinant loci were identified that included Asty exons 2-4 preceded by Ssty1 exons 1, 2 and part of exon 3. Transcription from the Ssty1 promotor generated spermatid-specific transcripts that, in addition to the variable inclusion of Ssty1 and Asty exons, included additional exons because of the serendipitous presence of splice sites further downstream. CONCLUSION: We identified further MSYq-encoded transcripts expressed in spermatids and deriving from multicopy Y genes, deficiency of which may underlie the defects in sperm development associated with MSYq deletions.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

    Biofield Therapies: Helpful or Full of Hype? A Best Evidence Synthesis

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    Biofield therapies (such as Reiki, therapeutic touch, and healing touch) are complementary medicine modalities that remain controversial and are utilized by a significant number of patients, with little information regarding their efficacy. This systematic review examines 66 clinical studies with a variety of biofield therapies in different patient populations. We conducted a quality assessment as well as a best evidence synthesis approach to examine evidence for biofield therapies in relevant outcomes for different clinical populations. Studies overall are of medium quality, and generally meet minimum standards for validity of inferences. Biofield therapies show strong evidence for reducing pain intensity in pain populations, and moderate evidence for reducing pain intensity hospitalized and cancer populations. There is moderate evidence for decreasing negative behavioral symptoms in dementia and moderate evidence for decreasing anxiety for hospitalized populations. There is equivocal evidence for biofield therapies' effects on fatigue and quality of life for cancer patients, as well as for comprehensive pain outcomes and affect in pain patients, and for decreasing anxiety in cardiovascular patients. There is a need for further high-quality studies in this area. Implications and future research directions are discussed

    At the bottom of the differential diagnosis list: unusual causes of pediatric hypertension

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    Hypertension affects 1–5% of children and adolescents, and the incidence has been increasing in association with obesity. However, secondary causes of hypertension such as renal parenchymal diseases, congenital abnormalities and renovascular disorders still remain the leading cause of pediatric hypertension, particularly in children under 12 years old. Other less common causes of hypertension in children and adolescents, including immobilization, burns, illicit and prescription drugs, dietary supplements, genetic disorders, and tumors will be addressed in this review

    Stochastic backgrounds of relic gravitons: a theoretical appraisal

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    Stochastic backgrounds or relic gravitons, if ever detected, will constitute a prima facie evidence of physical processes taking place during the earliest stages of the evolution of the plasma. The essentials of the stochastic backgrounds of relic gravitons are hereby introduced and reviewed. The pivotal observables customarily employed to infer the properties of the relic gravitons are discussed both in the framework of the Λ\LambdaCDM paradigm as well as in neighboring contexts. The complementarity between experiments measuring the polarization of the Cosmic Microwave Background (such as, for instance, WMAP, Capmap, Quad, Cbi, just to mention a few) and wide band interferometers (e.g. Virgo, Ligo, Geo, Tama) is emphasized. While the analysis of the microwave sky strongly constrains the low-frequency tail of the relic graviton spectrum, wide-band detectors are sensitive to much higher frequencies where the spectral energy density depends chiefly upon the (poorly known) rate of post-inflationary expansion.Comment: 94 pages, 32 figure

    Architectures and biogenesis of non-flagellar protein appendages in Gram-negative bacteria

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    Bacteria commonly expose non-flagellar proteinaceous appendages on their outer surfaces. These extracellular structures, called pili or fimbriae, are employed in attachment and invasion, biofilm formation, cell motility or protein and DNA transport across membranes. Over the past 15 years, the power of molecular and structural techniques has revolutionalized our understanding of the biogenesis, structure, function and mode of action of these bacterial organelles. Here, we review the five known classes of Gram-negative non-flagellar appendages from a biosynthetic and structural point of view
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