63 research outputs found

    Transient activation of mucosal effector immune responses by resident intestinal bacteria in normal hosts is regulated by interleukin-10 signalling

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    Interleukin-10 (IL-10) is a key regulator of mucosal homeostasis. In the current study we investigated the early events after monoassociating germ-free (GF) wild type (WT) mice with an E. coli strain that we isolated previously from the cecal contents of a normal mouse housed under specific pathogen free (SPF) conditions. Our results show that IFN-Îł secreted by mesenteric lymph node (MLN) cells from both IL-10 deficient mice and WT mice, stimulated ex vivo with E. coli lysate, was dramatically higher at day 4 after monoassociation compared to IFN-Îł secreted by cells from GF mice without E. coli colonization. Production of IFN-Îł rapidly and progressively declined after colonization of WT but not IL-10 deficient mice. E. coli lysate-stimulated WT MLN cells also produced IL-10 that peaked at day 4 and subsequently declined, but not as precipitously as IFN-Îł. WT cells that express CD4, CD8, and NKp46 produced IFN-Îł; WT CD4-positive cells and B cells produced IL-10. Recombinant IL-10 added to E. coli-stimulated MLN cell cultures inhibited IFN-Îł secretion in a dose-dependent fashion. MLN cells from WT mice treated in vivo with neutralizing anti-IL-10 receptor antibody produced more IFN-Îł compared with MLN cells from isotype control antibody-treated mice. These findings show that a resident E. coli that induces chronic colitis in monoassociated IL-10 deficient mice rapidly but transiently activates the effector immune system in normal hosts, in parallel with induction of protective IL-10 produced by B cells and CD4(+) cells that subsequently suppresses this response to mediate mucosal homeostasis. This article is protected by copyright. All rights reserved

    Incorporating Uncertainties in Atomic Data Into the Analysis of Solar and Stellar Observations: A Case Study in Fe XIII

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    Information about the physical properties of astrophysical objects cannot be measured directly but is inferred by interpreting spectroscopic observations in the context of atomic physics calculations. Ratios of emission lines, for example, can be used to infer the electron density of the emitting plasma. Similarly, the relative intensities of emission lines formed over a wide range of temperatures yield information on the temperature structure. A critical component of this analysis is understanding how uncertainties in the underlying atomic physics propagates to the uncertainties in the inferred plasma parameters. At present, however, atomic physics databases do not include uncertainties on the atomic parameters and there is no established methodology for using them even if they did. In this paper we develop simple models for the uncertainties in the collision strengths and decay rates for Fe XIII and apply them to the interpretation of density sensitive lines observed with the EUV Imagining spectrometer (EIS) on Hinode. We incorporate these uncertainties in a Bayesian framework. We consider both a pragmatic Bayesian method where the atomic physics information is unaffected by the observed data, and a fully Bayesian method where the data can be used to probe the physics. The former generally increases the uncertainty in the inferred density by about a factor of 5 compared with models that incorporate only statistical uncertainties. The latter reduces the uncertainties on the inferred densities, but identifies areas of possible systematic problems with either the atomic physics or the observed intensities.Comment: in press at Ap

    Service Orientation and the Smart Grid state and trends

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    The energy market is undergoing major changes, the most notable of which is the transition from a hierarchical closed system toward a more open one highly based on a “smart” information-rich infrastructure. This transition calls for new information and communication technologies infrastructures and standards to support it. In this paper, we review the current state of affairs and the actual technologies with respect to such transition. Additionally, we highlight the contact points between the needs of the future grid and the advantages brought by service-oriented architectures.

    Essential versus accessory aspects of cell death: recommendations of the NCCD 2015

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    Cells exposed to extreme physicochemical or mechanical stimuli die in an uncontrollable manner, as a result of their immediate structural breakdown. Such an unavoidable variant of cellular demise is generally referred to as ‘accidental cell death’ (ACD). In most settings, however, cell death is initiated by a genetically encoded apparatus, correlating with the fact that its course can be altered by pharmacologic or genetic interventions. ‘Regulated cell death’ (RCD) can occur as part of physiologic programs or can be activated once adaptive responses to perturbations of the extracellular or intracellular microenvironment fail. The biochemical phenomena that accompany RCD may be harnessed to classify it into a few subtypes, which often (but not always) exhibit stereotyped morphologic features. Nonetheless, efficiently inhibiting the processes that are commonly thought to cause RCD, such as the activation of executioner caspases in the course of apoptosis, does not exert true cytoprotective effects in the mammalian system, but simply alters the kinetics of cellular demise as it shifts its morphologic and biochemical correlates. Conversely, bona fide cytoprotection can be achieved by inhibiting the transduction of lethal signals in the early phases of the process, when adaptive responses are still operational. Thus, the mechanisms that truly execute RCD may be less understood, less inhibitable and perhaps more homogeneous than previously thought. Here, the Nomenclature Committee on Cell Death formulates a set of recommendations to help scientists and researchers to discriminate between essential and accessory aspects of cell death

    Acute and delayed sulfur mustard toxicity; novel mechanisms and future studies

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    Sulfur mustard (SM), also known as mustard gas, has been the most widely used chemical weapon. The toxicity of SM as an incapacitating agent is of much greater importance than its ability to cause lethality. Acute toxicity of SM is related to reactive oxygen and nitrogen species, DNA damage, poly(ADP-ribose) polymerase activation and energy depletion within the affected cell. Therefore melatonin shows beneficial effects against acute SM toxicity in a variety of manner. It scavenges most of the oxygen- and nitrogen-based reactants, inhibits inducible nitric oxide synthase, repairs DNA damage and restores cellular energy depletion. The delayed toxicity of SM however, currently has no mechanistic explanation. We propose that epigenetic aberrations may be responsible for delayed detrimental effects of mustard poisoning. Epigenetic refers to the study of changes that influence the phenotype without causing alteration of the genotype. It involves changes in the properties of a cell that are inherited but do not involve a change in DNA sequence. It is now known that in addition to genetic mutations, epimutations can also involve in the pathogenesis of a variety of human diseases. Several actions of melatonin are now delineated by epigenetic actions including modulation of histone acetylation and DNA methylation. Future studies are warranted to clarify whether epigenetic mechanisms are involved in pathogenesis of delayed sulfur mustard toxicity and melatonin alleviates delayed toxicity of this warfare agent

    Wastewater Sequencing Reveals Community and Variant Dynamics of the Collective Human Virome

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    Wastewater is a discarded human by-product, but its analysis may help us understand the health of populations. Epidemiologists first analyzed wastewater to track outbreaks of poliovirus decades ago, but so-called wastewater-based epidemiology was reinvigorated to monitor SARS-CoV-2 levels while bypassing the difficulties and pit falls of individual testing. Current approaches overlook the activity of most human viruses and preclude a deeper understanding of human virome community dynamics. Here, we conduct a comprehensive sequencing-based analysis of 363 longitudinal wastewater samples from ten distinct sites in two major cities. Critical to detection is the use of a viral probe capture set targeting thousands of viral species or variants. Over 450 distinct pathogenic viruses from 28 viral families are observed, most of which have never been detected in such samples. Sequencing reads of established pathogens and emerging viruses correlate to clinical data sets of SARS-CoV-2, influenza virus, and monkeypox viruses, outlining the public health utility of this approach. Viral communities are tightly organized by space and time. Finally, the most abundant human viruses yield sequence variant information consistent with regional spread and evolution. We reveal the viral landscape of human wastewater and its potential to improve our understanding of outbreaks, transmission, and its effects on overall population health

    The EXPRES Stellar Signals Project II. State of the Field in Disentangling Photospheric Velocities

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    Measured spectral shifts due to intrinsic stellar variability (e.g., pulsations, granulation) and activity (e.g., spots, plages) are the largest source of error for extreme-precision radial-velocity (EPRV) exoplanet detection. Several methods are designed to disentangle stellar signals from true center-of-mass shifts due to planets. The Extreme-precision Spectrograph (EXPRES) Stellar Signals Project (ESSP) presents a self-consistent comparison of 22 different methods tested on the same extreme-precision spectroscopic data from EXPRES. Methods derived new activity indicators, constructed models for mapping an indicator to the needed radial-velocity (RV) correction, or separated out shape- and shift-driven RV components. Since no ground truth is known when using real data, relative method performance is assessed using the total and nightly scatter of returned RVs and agreement between the results of different methods. Nearly all submitted methods return a lower RV rms than classic linear decorrelation, but no method is yet consistently reducing the RV rms to sub-meter-per-second levels. There is a concerning lack of agreement between the RVs returned by different methods. These results suggest that continued progress in this field necessitates increased interpretability of methods, high-cadence data to capture stellar signals at all timescales, and continued tests like the ESSP using consistent data sets with more advanced metrics for method performance. Future comparisons should make use of various well-characterized data sets—such as solar data or data with known injected planetary and/or stellar signals—to better understand method performance and whether planetary signals are preserved
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