169 research outputs found

    Multi-messenger observations of a binary neutron star merger

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    On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta

    Access to healthcare for children with Congenital Zika Syndrome in Brazil: perspectives of mothers and health professionals.

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    The Congenital Zika Syndrome (CZS) epidemic took place in Brazil between 2015 and 2017 and led to the emergence of at least 3194 children born with CZS. We explored access to healthcare services and activities in the Unified Health Service (Sistema Único de Saúde: SUS) from the perspective of mothers of children with CZS and professionals in the Public Healthcare Network. We carried out a qualitative, exploratory study, using semi-structured interviews, in two Brazilian states-Pernambuco, which was the epicentre of the epidemic in Brazil, and Rio de Janeiro, where the epidemic was less intense. The mothers and health professionals reported that healthcare provision was insufficient and fragmented and there were problems with follow-up care. There was a lack of co-ordination and an absence of communication between the various specialized services and between different levels of the health system. We also noted a public-private mixture in access to healthcare services, resulting from a segmented system and related to inequality of access. High reported household expenditure is an expression of the phenomenon of underfunding of the public system. The challenges that mothers and health professionals reported exposes contradictions in the health system which, although universal, does not guarantee equitable and comprehensive care. Other gaps were revealed through the outbreak. The epidemic provided visibility regarding difficulties of access for other children with disabilities determined by other causes. It also made explicit the gender inequalities that had an impact on the lives of mothers and other female caregivers, as well as an absence of the provision of care for these groups. In the face of an epidemic, the Brazilian State reproduced old fashioned forms of action-activities related to the transmitting mosquito and to prevention with an emphasis on the individual and no action related to social determinants

    Optimising experimental design for high-throughput phenotyping in mice: a case study

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    To further the functional annotation of the mammalian genome, the Sanger Mouse Genetics Programme aims to generate and characterise knockout mice in a high-throughput manner. Annually, approximately 200 lines of knockout mice will be characterised using a standardised battery of phenotyping tests covering key disease indications ranging from obesity to sensory acuity. From these findings secondary centres will select putative mutants of interest for more in-depth, confirmatory experiments. Optimising experimental design and data analysis is essential to maximise output using the resources with greatest efficiency, thereby attaining our biological objective of understanding the role of genes in normal development and disease. This study uses the example of the noninvasive blood pressure test to demonstrate how statistical investigation is important for generating meaningful, reliable results and assessing the design for the defined research objectives. The analysis adjusts for the multiple-testing problem by applying the false discovery rate, which controls the number of false calls within those highlighted as significant. A variance analysis finds that the variation between mice dominates this assay. These variance measures were used to examine the interplay between days, readings, and number of mice on power, the ability to detect change. If an experiment is underpowered, we cannot conclude whether failure to detect a biological difference arises from low power or lack of a distinct phenotype, hence the mice are subjected to testing without gain. Consequently, in confirmatory studies, a power analysis along with the 3Rs can provide justification to increase the number of mice used

    Fyn Mediates Leptin Actions in the Thymus of Rodents

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    BACKGROUND:Several effects of leptin in the immune system rely on its capacity to modulate cytokine expression and apoptosis in the thymus. Surprisingly, some of these effects are dependent on signal transduction through the IRS1/PI3-kinase, but not on the activation of JAK2. Since all the well known effects of leptin in different cell types and tissues seem to be dependent on JAK2 activation, we hypothesized that, at least for the control of thymic function, another, unknown kinase could mediate the transduction of the leptin signal from the ObR towards the IRS1/PI3-kinase signaling cascade. METHODOLOGY/PRINCIPAL FINDINGS:Here, by employing immunoblot, real-time PCR and flow citometry we show that the tyrosine kinase, Fyn, is constitutively associated with the ObR in thymic cells. Following a leptin stimulus, Fyn undergoes an activating tyrosine phosphorylation and a transient association with IRS1. All these effects are independent of JAK2 activation and, upon Fyn inhibition, the signal transduction towards IRS1/PI3-kinase is abolished. In addition, the inhibition of Fyn significantly modifies the effects of leptin on thymic cytokine expression. CONCLUSION/SIGNIFICANCE:Therefore, in the thymus, Fyn acts as a tyrosine kinase that transduces the leptin signal independently of JAK2 activation, and mediates some of the immunomodulatory effects of leptin in this tissue

    Influência do perfil nutricional e da atividade física na postura de crianças e adolescentes

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    O objetivo do estudo foi verificar o efeito do perfil nutricional e da atividade física na postura de crianças e adolescentes. Foram avaliados 60 indivíduos de ambos os sexos, com idade entre 5 e 14 anos. A postura foi avaliada por meio da fotogrametria. Para determinar o nível de atividade física foi utilizado o Questionário de Atividade Física para Crianças (PAQ-C). A classificação do perfil nutricional foi realizada por meio do Índice de Massa Corporal por idade e com relação ao sexo. Os resultados mostraram que a atividade física exerceu efeito sobre os ângulos assimetria do ombro (AO) e assimetria corporal (ACO) (p<0,05). O grupo ativo apresentou maior assimetria nos ângulos de AO e ACO comparado ao grupo sedentário (p<0,05). O perfil nutricional não influenciou nenhum ângulo postural (p&gt;0,05). Também não houve efeito interativo entre os parâmetros avaliados sobre os ângulos posturais (p&gt;0,05). É importante o desenvolvimento de ações preventivas e intervencionistas, como atividade física controlada e acompanhamento nutricional, no alinhamento postural de crianças e adolescentes em idade escolar
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