1,277 research outputs found

    Psychological stress reactivity and future health and disease outcomes: A systematic review of prospective evidence

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    Background Acute psychological stress activates the sympatho-adrenal medullary (SAM) system and hypothalamo-pituitary adrenal (HPA) axis. The relevance of this stress reactivity to long-term health and disease outcomes is of great importance. We examined prospective studies in apparently healthy adults to test the hypothesis that the magnitude of the response to acute psychological stress in healthy adults is related to future health and disease outcomes. Methods We searched Medline Complete, PsycINFO, CINAHL Complete and Embase up to 15 Aug 2019. Included studies were peer-reviewed, English-language, prospective studies in apparently healthy adults. The exposure was acute psychological stress reactivity (SAM system or HPA axis) at baseline. The outcome was any health or disease outcome at follow-up after ≄ 1 year. Results We identified 1,719 papers through database searching and 1 additional paper through other sources. Forty-seven papers met our criteria including 32,866 participants (range 30 – 4100) with 1- 23 years of follow-up. Overall, one third (32%; 83/263) of all reported findings were significant and two thirds (68%; 180/263) were null. With regard to the significant findings, both exaggerated (i.e. high) and blunted (i.e. low) stress reactivity of both the SAM system and the HPA axis at baseline were related to health and disease outcomes at follow-up. Exaggerated stress reactivity at baseline predicted an increase in risk factors for cardiovascular disease and decreased telomere length at follow-up. In contrast, blunted stress reactivity predicted future increased adiposity and obesity, more depression, anxiety and PTSD symptoms, greater illness frequency, musculoskeletal pain and regulatory T-Cell percentage, poorer cognitive ability, poorer self-reported health and physical disability and lower bone mass. Conclusion Exaggerated and blunted SAM system and HPA axis stress reactivity predicted distinct physical and mental health and disease outcomes over time. Results from prospective studies consistently indicate stress reactivity as a predictor for future health and disease outcomes. Dysregulation of stress reactivity may represent a mechanism by which psychological stress contributes to the development of future health and disease outcomes

    Combined effects of exogenous enzymes and probiotic on Nile tilapia (Oreochromis niloticus) growth, intestinal morphology and microbiome

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    A study was carried out to investigate the combined effect of exogenous enzymes and probiotic supplementation on tilapia growth, intestinal morphology and microbiome composition. Tilapia (34.56 ± 0.05 g) were fed one of four diets (35% protein, 5% lipid); one of which was a control and the remaining three diets were supplemented with either enzymes (containing phytase, protease and xylanase), probiotic (containing Bacillus subtilis, Bacillus licheniformis and Bacillus pumilus) or enz-pro (the combination of the enzymes and probiotic). Tilapia fed diet supplemented with enz-pro performed better (P < 0.05) than tilapia fed the control and probiotic supplemented diets in terms of final body weight (FBW), specific growth rate (SGR), feed conversion ratio (FCR) and protein efficiency ratio (PER). The dietary treatments did not affect somatic indices. The serum lysozyme activity was significantly higher (P < 0.05) in tilapia fed the probiotic supplemented diet than of those fed the remaining experimental diets. The intestinal perimeter ratio was higher (P < 0.05) in tilapia fed enz-pro supplemented diet when compared to those fed with the control and probiotic supplemented diets. Goblet cells abundance, microvilli diameter and total enterocyte absorptive surface was higher (P < 0.05) in tilapia fed diet supplemented with enz-pro than those fed the control diet. High-throughput sequencing revealed that majority of reads derived from the tilapia digesta belonged to members of Fusobacteria (predominantly Cetobacterium) distantly followed by Proteobacteria and Firmicutes. The alpha and beta diversities did not differ among dietary treatments indicating that the overall microbial community was not modified to a large extent by dietary treatment. In conclusion, supplementation of the diet with a combination of enzymes and probiotic is capable of improving tilapia growth and intestinal morphology without deleterious effect on the intestinal microbial composition

    High-Energy Cosmology: gamma rays and neutrinos from beyond the galaxy

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    Our knowledge of the high-energy universe is undergoing a period of rapid change as new astronomical detectors of high-energy radiation start to operate at their design sensitivities. Now is a boomtime for high-energy astrophysics, with new discoveries from Swift and HESS, results from MAGIC and VERITAS starting to be reported, the upcoming launches of the gamma-ray space telescopes GLAST and AGILE, and anticipated data releases from IceCube and Auger. A formalism for calculating statistical properties of cosmological gamma-ray sources is presented. Application is made to model calculations of the statistical distributions of gamma-ray and neutrino emission from (i) beamed sources, specifically, long-duration GRBs, blazars, and extagalactic microquasars, and (ii) unbeamed sources, including normal galaxies, starburst galaxies and clusters. Expressions for the integrated intensities of faint beamed and unbeamed high-energy radiation sources are also derived. A toy model for the background intensity of radiation from dark-matter annihilation taking place in the early universe is constructed. Estimates for the gamma-ray fluxes of local group galaxies, starburst, and infrared luminous galaxies are briefly reviewed. Because the brightest extragalactic gamma-ray sources are flaring sources, and these are the best targets for sources of PeV -- EeV neutrinos and ultra-high energy cosmic rays, rapidly slewing all-sky telescopes like MAGIC and an all-sky gamma-ray observatory beyond Milagro will be crucial for optimal science return in the multi-messenger age.Comment: 10 pages, 3 figs, accepted for publication in the Barcelona Conference on Multimessenger Astronomy; corrected eq. 27, revised Fig. 3, added 2 ref

    Using Lightweight Activity Diagrams for Modeling and Generation of Web Information Systems

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    The development process of web information systems nowadays improved a lot regarding effectiveness and tool support, but still contains many redundant steps for similar tasks. In order to overcome this, we use a model-driven approach to specify a web information system in an agile way and generate a full- edged and runnable application from a set of models. The covered aspects of the system comprise data structure, page structure including view on data, page- and workflow within the system as well as overall application structure and user rights management. Appropriate tooling allows transforming these models to complete systems and thus gives us opportunity for a lightweight development process based on models. In this paper, we describe how we approach the page- and workflow aspect by using activity diagrams as part of the agile modeling approach MontiWIS. We give an overview of the defined syntax, describe the supported forms of action contents and finally explain how the behavior is realized in the generated application.Comment: 12 pages, 6 figure

    Dietary fat restriction increases fat taste sensitivity in people with obesity

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    OBJECTIVE: Individuals with obesity may be less sensitive to the taste of fat, and it is hypothesized that this is due to excess dietary fat intake. This study assessed the effect of a 6-week low-fat (LF) or portion control (PC) diet matched for weight loss on fat taste thresholds, fat perception, and preference in people with overweight/obesity. METHODS: Participants (n&thinsp;=&thinsp;53) completed a randomized dietary intervention and consumed either a LF diet (25% fat) or PC diet (33% fat) for 6 weeks. Fat taste thresholds (lowest detectable fat concentration), fat perception (discrimination ability), preference, and anthropometry were assessed at baseline and week 6. RESULTS: Consumption of a LF diet (n&thinsp;=&thinsp;26) and PC diet (n&thinsp;=&thinsp;27) reduced participants\u27 weight (P&thinsp;&lt;&thinsp;0.001), with no significant differences between groups (LF, -2.9%, PC, -2.7%). Both diets resulted in a decrease in fat taste thresholds (P&thinsp;=&thinsp;0.014), and the effect tended to be stronger in the LF diet vs. the PC diet (P&thinsp;=&thinsp;0.060). The ability to perceive different fat concentrations in foods was increased after the LF diet only (P&thinsp;=&thinsp;0.017); however, food preference did not change on either diet. CONCLUSIONS: A PC and LF diet both increase fat taste sensitivity in people with overweight/obesity, with the strongest effect after the LF diet

    Physico-Chemical and structural interpretation of discrete derivative indices on N-tuples atoms

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    This report examines the interpretation of the Graph Derivative Indices (GDIs) from three different perspectives (i.e., in structural, steric and electronic terms). It is found that the individual vertex frequencies may be expressed in terms of the geometrical and electronic reactivity of the atoms and bonds, respectively. On the other hand, it is demonstrated that the GDIs are sensitive to progressive structural modifications in terms of: size, ramifications, electronic richness, conjugation effects and molecular symmetry. Moreover, it is observed that the GDIs quantify the interaction capacity among molecules and codify information on the activation entropy. A structure property relationship study reveals that there exists a direct correspondence between the individual frequencies of atoms and HĂŒckel’s Free Valence, as well as between the atomic GDIs and the chemical shift in NMR, which collectively validates the theory that these indices codify steric and electronic information of the atoms in a molecule. Taking in consideration the regularity and coherence found in experiments performed with the GDIs, it is possible to say that GDIs possess plausible interpretation in structural and physicochemical terms. © 2016 by the authors; licensee MDPI, Basel, Switzerland.Pharmaceutical Preparation

    Niche partitioning by three Pterodroma petrel species during non-breeding in the equatorial Pacific Ocean

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    Niche divergence is expected for species that compete for shared resources, including migrants that occupy similar regions during the non-breeding season. Studies of temperate seabirds indicate that both spatial and behavioural segregation can be important mechanisms for reducing competition, but there have been few investigations of resource partitioning by closely related taxa in low productivity, tropical environments. We investigated niche partitioning in 3 gadfly petrel taxa, Pterodroma leucoptera leucoptera (n = 22), P. leucoptera caledonica (n = 7) and P. pycrofti (n = 12), during their non-breeding season in the eastern tropical Pacific Ocean by combining tracking data from geolocator-immersion loggers with remotely sensed environmental data in species distribution models (SDMs), and by comparing feather stable isotope ratios. The 3 taxa showed spatial partitioning: two foraged in the North Equatorial Counter Current and one in the South Equatorial Current. This reflected differences in their realised habitat niches, with significant taxon-specific responses to thermocline depth, sea surface temperature and bathymetry. There were also differences among taxa in activity patterns, and all birds spent a much larger proportion of time in flight at night than during the day, suggesting predominance of nocturnal foraging behaviour. Comparison of stable isotope ratios in feathers suggests that P. l. leucoptera and P. pycrofti mainly consume vertically migrating mesopelagic fishes, whereas the diet of P. l. caledonica also includes some lower trophic levels including crustaceans and squid. Unique insights can be gained from studies of the foraging ecology of tropical pelagic seabirds, in comparison with temperate and polar waters, and are urgently required for understanding and protecting tropical avifauna in key marine habitats

    Type Checking Liveness for Collaborative Processes with Bounded and Unbounded Recursion

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    We present the first session typing system guaranteeing request-response liveness properties for possibly non-terminating communicating processes. The types augment the branch and select types of the standard binary session types with a set of required responses, indicating that whenever a particular label is selected, a set of other labels, its responses, must eventually also be selected. We prove that these extended types are strictly more expressive than standard session types. We provide a type system for a process calculus similar to a subset of collaborative BPMN processes with internal (data-based) and external (event-based) branching, message passing, bounded and unbounded looping. We prove that this type system is sound, i.e., it guarantees request-response liveness for dead-lock free processes. We exemplify the use of the calculus and type system on a concrete example of an infinite state system.Comment: Accepted for publication in Logical Methods in Computer Scienc

    Demystifying an unidentified EGRET source by VHE gamma-ray observations

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    In a novel approach in observational high-energy gamma-ray astronomy, observations carried out by imaging atmospheric Cherenkov telescopes provide necessary templates to pinpoint the nature of intriguing, yet unidentified EGRET gamma-ray sources. Using GeV-photons detected by CGRO EGRET and taking advantage of high spatial resolution images from H.E.S.S. observations, we were able to shed new light on the EGRET observed gamma-ray emission in the Kookaburra complex, whose previous coverage in the literature is somewhat contradictory. 3EGJ1420-6038 very likely accounts for two GeV gamma-ray sources (E>1 GeV), both in positional coincidence with the recently reported pulsar wind nebulae (PWN) by HESS in the Kookaburra/Rabbit complex. PWN associations at VHE energies, supported by accumulating evidence from observations in the radio and X-ray band, are indicative for the PSR/plerionic origin of spatially coincident, but still unidentified Galactic gamma-ray sources from EGRET. This not only supports the already suggested connection between variable, but unidentified low-latitude gamma-ray sources with pulsar wind nebulae (3EGJ1420-6038 has been suggested as PWN candidate previoulsy), it also documents the ability of resolving apparently confused EGRET sources by connecting the GeV emission as measured from a large-aperture space-based gamma-ray instrument with narrow field-of-view but superior spatial resolution observations by ground-based atmospheric Cherenkov telescopes, a very promising identification technique for achieving convincing individual source identifications in the era of GLAST-LAT.Comment: 4 pages, 5 figures, Accepted for publication in Astrophysics and Space Science, Proc. of "The Multi-Messenger Approach to High-Energy Gamma-ray Sources (Third Workshop on the Nature of Unidentified High-Energy Sources)", Barcelona, July 4-7, 2006, one typo correcte

    Atomic X-ray Spectroscopy of Accreting Black Holes

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    Current astrophysical research suggests that the most persistently luminous objects in the Universe are powered by the flow of matter through accretion disks onto black holes. Accretion disk systems are observed to emit copious radiation across the electromagnetic spectrum, each energy band providing access to rather distinct regimes of physical conditions and geometric scale. X-ray emission probes the innermost regions of the accretion disk, where relativistic effects prevail. While this has been known for decades, it also has been acknowledged that inferring physical conditions in the relativistic regime from the behavior of the X-ray continuum is problematic and not satisfactorily constraining. With the discovery in the 1990s of iron X-ray lines bearing signatures of relativistic distortion came the hope that such emission would more firmly constrain models of disk accretion near black holes, as well as provide observational criteria by which to test general relativity in the strong field limit. Here we provide an introduction to this phenomenon. While the presentation is intended to be primarily tutorial in nature, we aim also to acquaint the reader with trends in current research. To achieve these ends, we present the basic applications of general relativity that pertain to X-ray spectroscopic observations of black hole accretion disk systems, focusing on the Schwarzschild and Kerr solutions to the Einstein field equations. To this we add treatments of the fundamental concepts associated with the theoretical and modeling aspects of accretion disks, as well as relevant topics from observational and theoretical X-ray spectroscopy.Comment: 63 pages, 21 figures, Einstein Centennial Review Article, Canadian Journal of Physics, in pres
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