1,722 research outputs found

    THE CRITICAL EXPONENTS OF THE DECONFINEMENT TRANSITION IN SU(2) LATTICE GAUGE-THEORY

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    Engels J, JERSAK J, KANAYA K, et al. THE CRITICAL EXPONENTS OF THE DECONFINEMENT TRANSITION IN SU(2) LATTICE GAUGE-THEORY. NUCLEAR PHYSICS B. 1987;280(4):577-598

    MALT1 is an intrinsic regulator of regulatory T cells

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    Regulatory T cells (Tregs) are crucial for the maintenance of immunological self-tolerance and their absence or dysfunction can lead to autoimmunity. However, the molecular pathways that govern Treg biology remain obscure. In this study, we show that the nuclear factor-ÎșB signalling mediator mucosa-associated lymphoid tissue lymphoma translocation protein 1 (MALT1) is an important novel regulator of both Tregs originating in the thymus (‘natural’ or nTregs) and Tregs induced to differentiate from naive thymocyte helper (Th) cells in the periphery (‘induced’ or iTregs). Our examination of mice deficient for MALT1 revealed that these mutants have a reduced number of total Tregs. In young Malt1−/− mice, nTregs are totally absent and iTreg are diminished in the periphery. Interestingly, total Treg numbers increase in older Malt1−/− mice as well as in Malt1−/− mice subjected to experimentally induced inflammation. iTregs isolated from WT and Malt1−/− mice were indistinguishable with respect to their ability to suppress the activities of effector T cells, but Malt1−/− iTregs expressed higher levels of Toll-like receptor (TLR) 2. Treatment of WT and Malt1−/− Th cells in vitro with the TLR2 ligand Pam3Cys strongly enhanced the induction and proliferation of Malt1−/− iTregs. Our data suggest that MALT1 supports nTreg development in the thymus but suppresses iTreg induction in the periphery during inflammation. Our data position MALT1 as a key molecule that contributes to immune tolerance at steady-state while facilitating immune reactivity under stress conditions.This work was supported by grants by the Canadian Institutes of Health Research (to TWM). DB is supported by the ATTRACT Programme of the National Research Fund Luxembourg (FNR).This study was further supported by the Alexander von Humboldt Foundation (SKA2010) and the German Research Council (LA2558/3-1)

    A morphometric analysis of the infant calvarium and dura

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    Literature addressing the anatomic development of the dura and calvarium during childhood is limited. Nevertheless, histological features of a subdural neomembrane (NM), including its thickness and vascularity, developing in response to an acute subdural hematoma (SDH) have been compared to the dura of adults to estimate when an injury occurred. Therefore, we measured the morphometric growth of the calvarium and dura and the vascular density within the dura during infancy. The mean thicknesses of the calvarium and dura as a function of occipitofrontal circumference (OFC), as well as the mean number of vessels per 25× field, were determined from the right parasagittal midparietal bone lateral to the sagittal suture of 128 infants without a history of head trauma. Our results showed that as OFC increased, the mean thicknesses of the calvarium and dura increased while the vascular density within the dura decreased. Our morphometric data may assist in the interpretation of subdural NM occurring during infancy. We recommend future investigations to confirm and extend our present data, especially by evaluating cases during later infancy and beyond as well as by sampling other anatomic sites from the calvarium. We also recommend morphometric evaluation of subdural NM associated with SDH in infancy and childhood

    Uso de fĂĄrmacos psicoestimulantes en drogodependencias

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    El uso de medicamentos estimulantes es una cuestiĂłn de plena actualidad en psiquiatrĂ­a, aunque su utilizaciĂłn y prescripciĂłn es controvertida . FĂĄrmacos como el metilfenidato, las anfetaminas, o el modafinilo estĂĄn siendo utilizados y estudiados en distintas enfermedades psiquiĂĄtricas como el trastorno por dĂ©ficit de atenciĂłn e hiperactividad (TDAH), la dependencia de cocaĂ­na, en trastornos del sueño y en la depresiĂłn resistente. Todos estos fĂĄrmacos tienen en comĂșn, igual que las drogas de abuso, que son medicamentos que actĂșan sobre el sistema dopaminĂ©rgico, que constituye la base neurobiolĂłgica del refuerzo fisiolĂłgico. Los estimulantes como el metilfenidato o el modafinilo son fĂĄrmacos eficaces en el TDAH y han sido estudiados en el tratamiento de la dependencia de cocaĂ­na. En niños con TDAH el metilfenidato es un factor protector para el desarrollo de fĂĄrmaco en la dependencia de cocaĂ­na, aunque son estudios preliminares, por lo que no se debe considerar que este totalmente demostrado que los fĂĄrmacos psicoestimulantes sean eficaces en el tratamiento de esta dependencia. Aunque no son conocidos todos los mecanismos fisiopatolĂłgicos, parece crĂ­tico que el refuerzo, y por lo tanto el riesgo de dependencia, aparece cuando se producen incrementos rĂĄpidos dopaminĂ©rgicos y que los efectos terapĂ©uticos aparecen cuando son lentos y mantenidos. Las caracterĂ­sticas de uso a dosis bajas administradas por vĂ­a oral disminuyen el riesgo de abuso. Para realizar una adecuada prescripciĂłn es necesario aclarar, definitivamente, los mecanismos neuroquĂ­micos en los que intervienen, y sus indicaciones en drogodependenciasStimulant drugs prescription is a controversial and current topic in psychiatry. Drugs such as methylphenidate, amphetamine compounds and modafinil have been trialed and used in attention deficit hyperactivity disorder (ADHD), sleep conditions, cocaine dependence and as an adjunct to antidepressants for depression. All these drugs, like stimulant drugs abuse, increase extracellular dopamine in the brain.This effect is associated with reinforcing as well as therapeutic effects. Methylphenidate and modafinil treatment of ADHD are associated with a reduced risk for later substance abuse among ADHD patients. There is evidence of the beneficial effects of the use of modafinil in cocaine dependence, altough there isn't conclusive evidence for the stimulants' efficacy in treatment of the stimulants' dependence. At this time, the physiopathology of drug abuse and dependence is unknown, but it's known that the very critical point is that the reinforcing effects are associated with rapid changes in dopamine increases, whereas the therapeutic effects are associated with slowly and smoothly rising dopamine levels, such as are achieved with low doses and oral administration. Due to this, it's necessary to study the neurobiological bases on which stimulants drugs are related, and their clinical use in dependence treatment

    Environmental risk assessment of genetically modified plants - concepts and controversies

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    Background and purpose: In Europe, the EU Directive 2001/18/EC lays out the main provisions of environmental risk assessment (ERA) of genetically modified (GM) organisms that are interpreted very differently by different stakeholders. The purpose of this paper is to: (a) describe the current implementation of ERA of GM plants in the EU and its scientific shortcomings, (b) present an improved ERA concept through the integration of a previously developed selection procedure for identification of non-target testing organisms into the ERA framework as laid out in the EU Directive 2001/18/EC and its supplement material (Commission Decision 2002/623/EC), (c) describe the activities to be carried out in each component of the ERA and (d) propose a hierarchical testing scheme. Lastly, we illustrate the outcomes for three different crop case examples. Main features: Implementation of the current ERA concept of GM crops in the EU is based on an interpretation of the EU regulations that focuses almost exclusively on the isolated bacteria-produced novel proteins with little consideration of the whole plant. Therefore, testing procedures for the effect assessment of GM plants on non-target organisms largely follow the ecotoxicological testing strategy developed for pesticides. This presumes that any potential adverse effect of the whole GM plant and the plant-produced novel compound can be extrapolated from testing of the isolated bacteriaproduced novel compound or can be detected in agronomic field trials. This has led to persisting scientific criticism. Results: Based on the EU ERA framework, we present an improved ERA concept that is system oriented with the GM plant at the centre and integrates a procedure for selection of testing organisms that do occur in the receiving environment. We also propose a hierarchical testing scheme from laboratory studies to field trials and we illustrate the outcomes for three different crop case examples. Conclusions and recommendations: Our proposed concept can alleviate a number of deficits identified in the current approach to ERA of GM plants. It allows the ERA to be tailored to the GM plant case and the receiving environment

    Very Cold Gas and Dark Matter

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    We have recently proposed a new candidate for baryonic dark matter: very cold molecular gas, in near-isothermal equilibrium with the cosmic background radiation at 2.73 K. The cold gas, of quasi-primordial abundances, is condensed in a fractal structure, resembling the hierarchical structure of the detected interstellar medium. We present some perspectives of detecting this very cold gas, either directly or indirectly. The H2_2 molecule has an "ultrafine" structure, due to the interaction between the rotation-induced magnetic moment and the nuclear spins. But the lines fall in the km domain, and are very weak. The best opportunity might be the UV absorption of H2_2 in front of quasars. The unexpected cold dust component, revealed by the COBE/FIRAS submillimetric results, could also be due to this very cold H2_2 gas, through collision-induced radiation, or solid H2_2 grains or snowflakes. The Îł\gamma-ray distribution, much more radially extended than the supernovae at the origin of cosmic rays acceleration, also points towards and extended gas distribution.Comment: 16 pages, Latex pages, crckapb macro, 3 postscript figures, uuencoded compressed tar file. To be published in the proceeedings of the "Dust-Morphology" conference, Johannesburg, 22-26 January, 1996, D. Block (ed.), (Kluwer Dordrecht

    The phase diagram of Yang-Mills theory with a compact extra dimension

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    We present a non-perturbative study of the phase diagram of SU(2) Yang-Mills theory in a five-dimensional spacetime with a compact extra dimension. The non-renormalizable theory is regularized on an anisotropic lattice and investigated through numerical simulations in a regime characterized by a hierarchy between the scale of low-energy physics, the inverse compactification radius, and the cutoff scale. We map out the structure of the phase diagram and the pattern of lines corresponding to fixed values of the ratio between the mass of the fifth component of the gauge field and the non-perturbative mass gap of the four-dimensional modes. We discuss different limits of the model, and comment on the implications of our findings.Comment: 17 pages, 9 figure

    Alzheimer's disease phospholipase C-gamma-2 (PLCG2) protective variant is a functional hypermorph

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    BACKGROUND: Recent Genome Wide Association Studies (GWAS) have identified novel rare coding variants in immune genes associated with late onset Alzheimer's disease (LOAD). Amongst these, a polymorphism in phospholipase C-gamma 2 (PLCG2) P522R has been reported to be protective against LOAD. PLC enzymes are key elements in signal transmission networks and are potentially druggable targets. PLCG2 is highly expressed in the hematopoietic system. Hypermorphic mutations in PLCG2 in humans have been reported to cause autoinflammation and immune disorders, suggesting a key role for this enzyme in the regulation of immune cell function. METHODS: We assessed PLCG2 distribution in human and mouse brain tissue via immunohistochemistry and in situ hybridization. We transfected heterologous cell systems (COS7 and HEK293T cells) to determine the effect of the P522R AD-associated variant on enzymatic function using various orthogonal assays, including a radioactive assay, IP-One ELISA, and calcium assays. RESULTS: PLCG2 expression is restricted primarily to microglia and granule cells of the dentate gyrus. Plcg2 mRNA is maintained in plaque-associated microglia in the cerebral tissue of an AD mouse model. Functional analysis of the p.P522R variant demonstrated a small hypermorphic effect of the mutation on enzyme function. CONCLUSIONS: The PLCG2 P522R variant is protective against AD. We show that PLCG2 is expressed in brain microglia, and the p.P522R polymorphism weakly increases enzyme function. These data suggest that activation of PLCÎł2 and not inhibition could be therapeutically beneficial in AD. PLCÎł2 is therefore a potential target for modulating microglia function in AD, and a small molecule drug that weakly activates PLCÎł2 may be one potential therapeutic approach

    Detection of emphysema progression in alpha 1-antitrypsin deficiency using CT densitometry; Methodological advances

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    <p>Abstract</p> <p>Background</p> <p>Computer tomography (CT) densitometry is a potential tool for detecting the progression of emphysema but the optimum methodology is uncertain. The level of inspiration affects reproducibility but the ability to adjust for this variable is facilitated by whole lung scanning methods. However, emphysema is frequently localised to sub-regions of the lung and targeted densitometric sampling may be more informative than whole lung assessment.</p> <p>Methods</p> <p>Emphysema progression over a 2-year interval was assessed in 71 patients (alpha 1-antitrypsin deficiency with PiZ phenotype) with CT densitometry, using the 15<sup>th </sup>percentile point (Perc15) and voxel index (VI) -950 Hounsfield Units (HU) and -910 HU (VI -950 and -910) on whole lung, limited single slices, and apical, central and basal thirds. The relationship between whole lung densitometric progression (ΔCT) and change in CT-derived lung volume (ΔCT<sub>Vol</sub>) was characterised, and adjustment for lung volume using statistical modelling was evaluated.</p> <p>Results</p> <p>CT densitometric progression was statistically significant for all methods. ΔCT correlated with ΔCT<sub>Vol </sub>and linear regression indicated that nearly one half of lung density loss was secondary to apparent hyperinflation. The most accurate measure was obtained using a random coefficient model to adjust for lung volume and the greatest progression was detected by targeted sampling of the middle third of the lung.</p> <p>Conclusion</p> <p>Progressive hyperinflation may contribute significantly to loss of lung density, but volume effects and absolute tissue loss can be identified by statistical modelling. Targeted sampling of the middle lung region using Perc15 appears to be the most robust measure of emphysema progression.</p

    Critical Dietetics and Sustainable Food Systems

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    In this chapter, we invite readers to consider a food system that is based on values where individual health, the health of the society (social system) and ecosystem health are of equal importance. With this as a lens, there is a clear need to move beyond the biosciences to consider transdisciplinary approaches as important for nutrition and Dietetic in today and tomorrow’s reality
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