Fading hard X-ray emission from the Galactic Centre molecular cloud Sgr B2

The centre of our Galaxy harbours a 4 million solar mass black hole that is unusually quiet: its present X-ray luminosity is more than 10 orders of magnitude less than its Eddington luminosity. The observation of iron fluorescence and hard X-ray emission from some of the massive molecular clouds surrounding the Galactic Centre has been interpreted as an echo of a past flare. Alternatively, low-energy cosmic rays propagating inside the clouds might account for the observed emission, through inverse bremsstrahlung of low energy ions or bremsstrahlung emission of low energy electrons. Here we report the observation of a clear decay of the hard X-ray emission from the molecular cloud Sgr B2 during the past 7 years thanks to more than 20 Ms of INTEGRAL exposure. The measured decay time is compatible with the light crossing time of the molecular cloud core . Such a short timescale rules out inverse bremsstrahlung by cosmic-ray ions as the origin of the X ray emission. We also obtained 2-100 keV broadband X-ray spectra by combining INTEGRAL and XMM-Newton data and compared them with detailed models of X-ray emission due to irradiation of molecular gas by (i) low-energy cosmic-ray electrons and (ii) hard X-rays. Both models can reproduce the data equally well, but the time variability constraints and the huge cosmic ray electron luminosity required to explain the observed hard X-ray emission strongly favor the scenario in which the diffuse emission of Sgr B2 is scattered and reprocessed radiation emitted in the past by Sgr A*. Using recent parallax measurements that place Sgr B2 in front of Sgr A*, we find that the period of intense activity of Sgr A* ended between 75 and 155 years ago.Comment: Accepted for publication in ApJ. 10 pages, 5 figure

CCAAT/enhancer binding protein β expression is increased in the brain during HIV-1-infection and contributes to regulation of astrocyte tissue inhibitor of metalloproteinase-1

Human immunodeficiency virus (HIV)-1-associated neurocognitive disorders (HAND) associated with infection and activation of mononuclear phagocytes (MP) in the brain, occur late in disease. Infected/activated MP initiate neuroinflammation activating glial cells and ultimately disrupting neuronal function. Astrocytes secrete tissue inhibitor of metalloproteinase (TIMP)-1 in response to neural injury. Altered TIMP-1 levels are implicated in several CNS diseases. CCAAT enhancer-binding protein ß (C/EBPß), a transcription factor, is expressed in rodent brains in response to neuroinflammation, implicating it in Alzheimer’s, Parkinson’s, and HAND. Here, we report that C/EBPß mRNA levels are elevated and its isoforms differentially expressed in total brain tissue lysates of HIV-1-infected and HIV-1 encephalitis patients. In vitro, HAND-relevant stimuli additively induce C/EBPß nuclear expression in human astrocytes through 7 days of treatment. Over-expression of C/EBPß increases TIMP-1 promoter activity, mRNA, and protein levels in human astrocytes activated with interleukin-1ß. Knockdown of C/EBPß with siRNA decreases TIMP-1 mRNA and protein levels. These data suggest that C/EBPß isoforms are involved in complex regulation of astrocyte TIMP-1 production during HIV-1 infection; however, further studies are required to completely understand their role during disease progression

HIPERTENSIÓN ARTERIAL EN NIÑOS ESCOLARES CON SOBREPESO Y OBESIDAD

Se realizó un estudio transversal con el objetivo de determinar la relación del sobrepeso y obesidad, estimada a través de índice de masa corporal, y la hipertensión arterial en niños escolares de una escuela primaria urbana de Guadalajara, Jalisco. Participaron 144 estudiantes de 9 a 12 años de edad. El sobrepeso y la obesidad  se determinaron a través del IMC utilizando los criterios del CDC. La hipertensión arterial se clasificó en base los valores de la Task Force Blood Pressure Control in Children and Adolescents.  Los datos fueron analizados en Epi Info 6 versión 6.04, mediante la prueba X2, explorando la asociación de variables a través de OR e IC al 95%. La prevalencia de HTA de los escolares evaluados fue de 13-19%, mientras que de obesidad y sobrepeso fue de 36.8% y 15.28%, respectivamente. La asociación de obesidad e HTA fue de 28.3%, siendo esto significativo (OR 5.28: IC 95%= 1.63, 22.6), concentrándose en niños de sexo masculino.  Los escolares con sobrepeso no tuvieron HTA, pero 4.55% ellos presentaron prehipertensión. Abstract Cross-sectional study aimed at determining the relationship between obesity and overweight, estimated through the body mass index (BMI), and high blood pressure on schoolchildren from an elementary school of Guadalajara, Jalisco. In which 144 from 9 to 12 years old students participated. Overweight and obesity were determined with BMI using the Centers of Disease Control and Prevention (CDC) criterio. Hypertension was classified based on the values of the Task Force Blood Pressure Control in Children and Adolescents. Data were analyzed at Epi info 6 version 6.04, through X2 test, exploring variables association through OR and IC at 95%. The prevalence of HBP from evaluated schoolchildren was 13-19%, whereas obesity and overweight were 36.8% y 15.28%, respectively. The association of obesity and HBP was 28.3%, being this significant (OR 5.28: CI 95%= 1.63, 22.6), focusing on male children. Schoolchildren with overweight did not have hypertension, but 4.55% from them presented pre high blood pressure. Palabras clave: sobrepeso, obesidad, hipertensión arterial, índice de masa corporal, escolares.

Recommendations for a core outcome set for measuring standing balance in adult populations: a consensus-based approach

Standing balance is imperative for mobility and avoiding falls. Use of an excessive number of standing balance measures has limited the synthesis of balance intervention data and hampered consistent clinical practice.To develop recommendations for a core outcome set (COS) of standing balance measures for research and practice among adults.A combination of scoping reviews, literature appraisal, anonymous voting and face-to-face meetings with fourteen invited experts from a range of disciplines with international recognition in balance measurement and falls prevention. Consensus was sought over three rounds using pre-established criteria.The scoping review identified 56 existing standing balance measures validated in adult populations with evidence of use in the past five years, and these were considered for inclusion in the COS.Fifteen measures were excluded after the first round of scoring and a further 36 after round two. Five measures were considered in round three. Two measures reached consensus for recommendation, and the expert panel recommended that at a minimum, either the Berg Balance Scale or Mini Balance Evaluation Systems Test be used when measuring standing balance in adult populations.Inclusion of two measures in the COS may increase the feasibility of potential uptake, but poses challenges for data synthesis. Adoption of the standing balance COS does not constitute a comprehensive balance assessment for any population, and users should include additional validated measures as appropriate.The absence of a gold standard for measuring standing balance has contributed to the proliferation of outcome measures. These recommendations represent an important first step towards greater standardization in the assessment and measurement of this critical skill and will inform clinical research and practice internationally

Uma Proposta de Solução Abordando o Contexto de Notícias Falsas em Países de Língua Portuguesa

Fake news é uma expressão utilizada atualmente, que ganhou uma maior visibilidade ao ser utilizado por Donald Trump durante a campanha eleitoral à presidência dos Estados Unidos da América, em 2016. Durante o estudo realizado foi possível identificar problemas generalizados sobre esta temática, como por exemplo impacto que apresentam na sociedade. A partir desses problemas foi possível identificar outros mais específicos, tais como a origem e fonte da notícia, a pessoa que a partilha e/ou cria e a relação interpessoal existente. Com a identificação destes subproblemas supracitados foi possível desenvolver um modelo taxonómico com o objetivo de implementar uma ferramenta que auxilie na deteção de fake news, identificando se uma notícia é verdadeira, falsa ou se o utilizador deve estar atento (quando não é possível identificar se a notícia é verdadeira ou falsa). Foi também possível verificar que a probabilidade estava corretamente calculada e que a ferramenta se revia no estudo realizado.info:eu-repo/semantics/publishedVersio

The ATLAS3D project - XXIX : The new look of early-type galaxies and surrounding fields disclosed by extremely deep optical images

Date of Acceptance: 25/09/2014Galactic archaeology based on star counts is instrumental to reconstruct the past mass assembly of Local Group galaxies. The development of new observing techniques and data reduction, coupled with the use of sensitive large field of view cameras, now allows us to pursue this technique in more distant galaxies exploiting their diffuse low surface brightness (LSB) light. As part of the ATLAS3D project, we have obtained with the MegaCam camera at the Canada-France-Hawaii Telescope extremely deep, multiband images of nearby early-type galaxies (ETGs). We present here a catalogue of 92 galaxies from the ATLAS3D sample, which are located in low- to medium-density environments. The observing strategy and data reduction pipeline, which achieve a gain of several magnitudes in the limiting surface brightness with respect to classical imaging surveys, are presented. The size and depth of the survey are compared to other recent deep imaging projects. The paper highlights the capability of LSB-optimized surveys at detecting new prominent structures that change the apparent morphology of galaxies. The intrinsic limitations of deep imaging observations are also discussed, among those, the contamination of the stellar haloes of galaxies by extended ghost reflections, and the cirrus emission from Galactic dust. The detection and systematic census of fine structures that trace the present and past mass assembly of ETGs are one of the prime goals of the project. We provide specific examples of each type of observed structures - tidal tails, stellar streams and shells - and explain how they were identified and classified. We give an overview of the initial results. The detailed statistical analysis will be presented in future papers.Peer reviewedFinal Accepted Versio

Single-crosslink microscopy in a biopolymer network dissects local elasticity from molecular fluctuations

Polymer networks are fundamental from cellular biology to plastics technology but their intrinsic inhomogeneity is masked by the usual ensemble-averaged measurements. Here, we construct direct maps of crosslinks-symbolic depiction of spatially-distributed elements highlighting their physical features and the relationships between them-in an actin network. We selectively label crosslinks with fluorescent markers, track their thermal fluctuations, and characterize the local elasticity and cross-correlations between crosslinks. Such maps display massive heterogeneity, reveal abundant anticorrelations, and may contribute to address how local responses scale up to produce macroscopic elasticity. Single-crosslink microscopy offers a general, microscopic framework to better understand crosslinked molecular networks in undeformed or strained states

High Energy Activity of the Super-Massive Black Hole at the Galactic Center

The centre of our galaxy hosts the nearest super-massive black hole to the solar system, identified to the compact radio source Sgr A*. High energy experiments have tried in the past to detect the X/gamma-ray emission expected from the accretion of the surrounding material into this super-massive black hole. Only recently however, thanks to the new generation of telescopes, it has been possible to reveal high energy radiation associated with Sgr A* or its close environment. I will review and discuss in particular the results on the Sgr A* X-ray flares discovered with Chandra and XMM-Newton, on the central soft gamma-ray source detected with INTEGRAL and on the galactic centre TeV emission revealed by HESS.Comment: 10 pages, 6 figures. Published in Comptes Rendus Physique, Volume 8, Issue 1, January 2007, Pages 35-44, "Observation of black holes and extreme gravitational events", Academie des Sciences, Elsevier Science. Available online 2 February 200

When language gets emotional: irony and the embodiment of affect in discourse

Although there is increasing evidence to suggest that language is grounded in perception and action, the relationship between language and emotion is less well understood. We investigate the grounding of language in emotion using a novel approach that examines the relationship between the comprehension of a written discourse and the performance of affect-related motor actions (hand movements towards and away from the body). Results indicate that positively and negatively valenced words presented in context influence motor responses (Experiment 1), whilst valenced words presented in isolation do not (Experiment 3). Furthermore, whether discourse context indicates that an utterance should be interpreted literally or ironically can influence motor responding, suggesting that the grounding of language in emo- tional states can be influenced by discourse-level factors (Experiment 2). In addition, the finding of affect-related motor responses to certain forms of ironic language, but not to non-ironic control sentences, suggests that phrasing a message ironically may influence the emotional response that is elicited