1,412 research outputs found

    Cosmic Dawn and Epoch of Reionization Foreground Removal with the SKA

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    The exceptional sensitivity of the SKA will allow observations of the Cosmic Dawn and Epoch of Reionization (CD/EoR) in unprecedented detail, both spectrally and spatially. This wealth of information is buried under Galactic and extragalactic foregrounds, which must be removed accurately and precisely in order to reveal the cosmological signal. This problem has been addressed already for the previous generation of radio telescopes, but the application to SKA is different in many aspects. In this chapter we summarise the contributions to the field of foreground removal in the context of high redshift and high sensitivity 21-cm measurements. We use a state-of-the-art simulation of the SKA Phase 1 observations complete with cosmological signal, foregrounds and frequency-dependent instrumental effects to test both parametric and non-parametric foreground removal methods. We compare the recovered cosmological signal using several different statistics and explore one of the most exciting possibilities with the SKA --- imaging of the ionized bubbles. We find that with current methods it is possible to remove the foregrounds with great accuracy and to get impressive power spectra and images of the cosmological signal. The frequency-dependent PSF of the instrument complicates this recovery, so we resort to splitting the observation bandwidth into smaller segments, each of a common resolution. If the foregrounds are allowed a random variation from the smooth power law along the line of sight, methods exploiting the smoothness of foregrounds or a parametrization of their behaviour are challenged much more than non-parametric ones. However, we show that correction techniques can be implemented to restore the performances of parametric approaches, as long as the first-order approximation of a power law stands.Comment: Accepted for publication in the SKA Science Book 'Advancing Astrophysics with the Square Kilometre Array', to appear in 201

    Reasons for Resubmission of Research Projects to the Research Ethics Committee of a University Hospital in SÃO Paulo, Brazil

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    INTRODUCTION: It is important to know the reasons for resubmitting research projects to the Research Ethics Committee in order to help researchers to prepare their research projects, informed consent forms and needed research documentation. OBJECTIVES: To verify the reasons for resubmitting projects that were previously rejected by the Ethics Committee. METHOD: This is a cross-sectional study that evaluated research projects involving human beings. Research projects were submitted in 2007 to the Research Ethics Committee of the Hospital das Clínicas, Faculdade de Medicina da Universidade de São Paulo. RESULTS: One thousand two hundred and fifty six research projects were submitted to the ethics committee and the average time for evaluating the research projects and related documents until a final decision was reached was 49.95 days. From the total, 399 projects were reviewed in 2 or more meetings until a final decision was reached. Of these, 392 research projects were included in the study; 35 projects were subsequently excluded for involving animals. Among the research projects included, 42.5% concerned research with new drugs, vaccines and diagnostic tests, 48.5% consisted of undergraduate students' research projects, 68.9% of the research had no sponsorship, and 97.5% were eventually approved. The main reasons for returning the projects to the researchers were the use of inadequate language and/or difficulty of understanding the informed consent form (32.2%), lack of information about the protocol at the informed consent form (25.8%), as well as doubts regarding methodological and statistical issues of the protocol (77.1%). Other reasons for returning the research projects involved lack of, inaccuracy on or incomplete documentation, need of clarification or approval for participation of external entities on the research, lack of information on financial support. CONCLUSION: Among the research projects that were returned to the researchers for additional clarification, the main reasons were inadequacies or doubts about the terms used in the informed consent form as well as lack of information regarding the research at the informed consent form and methodological and statistical issues regarding the protocol

    Datacenter in a box: Test your sdn cloud-datacenter controller at home

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    Abstract-In the last years, the widespread of Cloud computing as the main paradigm to deliver a large plethora of virtualized services significantly increased the complexity of Datacenters management and raised new performance issues for the intra-Datacenter network. Providing heterogeneous services and satisfying users' experience is really challenging for Cloud service providers, since system (IT resources) and network administration functions are definitely separated. As the Software Defined Networking (SDN) approach seems to be a promising way to address innovation in Datacenters, the paper presents a new framework that allows to develop and test new OpenFlow-based controllers for Cloud Datacenters. More specifically, our framework enhances both Mininet (a well-known SDN emulator) and POX (a network controller written in python), with all the extensions necessary to experiment novel control and management strategies of IT and network resources

    The impact of deep-sea fisheries and implementation of the UNGA Resolutions 61/105 and 64/72. Report of an international scientific workshop

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    The scientific workshop to review fisheries management, held in Lisbon in May 2011, brought together 22 scientists and fisheries experts from around the world to consider the United Nations General Assembly (UNGA) resolutions on high seas bottom fisheries: what progress has been made and what the outstanding issues are. This report summarises the workshop conclusions, identifying examples of good practice and making recommendations in areas where it was agreed that the current management measures fall short of their target

    Tolerância ao calor em cavalos Pantaneiros sob diferentes regimes de exercício

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    The objective of this work was to determine how different types of gait affect the physiological and thermographic responses of Pantaneiro horses (Equus ferus caballus) subjected to field conditions under high environmental temperatures. Ten horses were evaluated in a double 5x5 Latin square experimental design, with five gait types: walk, trot, extended trot, gallop, and extended gallop. The following physiological measures were determined immediately after exercise: heart and respiratory rates, blood lactate content, and rectal temperature. Body surface temperatures were evaluated using an infrared camera. The walk, trot, and extended trot were the most adequate gaits for Pantaneiro horses to maintain thermoregulation within the physiological norms under conditions with a high air temperature. The temperatures obtained in the eye and elbow regions show the best predictive capacity for physiological parameters.O objetivo deste trabalho foi determinar como os diferentes tipos de andamento afetam as respostas fisiológicas e termográficas de cavalos Pantaneiro (Equus ferus caballus) submetidos a condições ambientais com alta temperatura. Dez cavalos foram avaliados em delineamento experimental de quadrado latino 5x5 duplo, com cinco andamentos: passo, trote, trote estendido, galope e galope estendido. As seguintes medidas fisiológicas foram determinadas logo após os exercícios: taxas cardíaca e respiratória, teor de lactato sanguíneo e temperatura retal. As imagens termográficas foram avaliadas por meio de câmera de infravermelho. O passo, o trote e o trote estendido foram os andamentos mais adequados para os cavalos Pantaneiros manterem a termorregulação dentro das normas fisiológicas em condições de alta temperatura do ar. As temperaturas obtidas nas regiões da área do olho e da axila mostram maior capacidade preditiva para os parâmetros fisiológicos

    A apneia obstrutiva do sono impede a esperada diferença de crescimento cranofacial de meninos e meninas

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    OBJECTIVES: It was to compare cephalometric measures of mouth-breather boys and girls and with the cephalometric pattern observed in obstructive sleep apnea syndrome (OSAS) patients. METHODS: Craniofacial measurements of lateral cephalometric radiographs obtained from 144 children aged 7-14 years were compared between boys and girls, and both were compared to cephalometric pattern of OSAS patients. RESULTS: Mouth-breather boys and girls had no gender differences regarding to craniofacial morphology while nose-breather boys and girls showed those expected differences. Nose-breather boys presented a more retruded mandible and proinclined upper incisor when compared to nose-breather girls, but mouth-breather boys and girls had no differences. The measure NS.GoGn was the only variable with an interaction with gender and breathing. CONCLUSIONS: There were no cephalometric difference in mouth breather-boys and girls related to normal growth, suggesting that oral breathing make the same craniofacial morphology and both have craniofacial morphology close to that of OSAS patients.OBJETIVOS: Foi comparar medidas cefalométricas entre meninos e meninas respiradores bucais com o padrão cefalométrico de pacientes com síndrome da apneia obstrutiva do sono (SAOS). MÉTODOS: Medidas craniofaciais de radiografias cefalométricas laterais de 144 crianças com idade entre 7 e 14 anos foram comparadas entre meninos e meninas, e estas comparadas com o padrão cefalométrico de pacientes com SAOS. RESULTADOS: Meninos e meninas respiradores bucais não apresentaram diferenças em relação à morfologia craniofacial, enquanto meninos e meninas respiradores nasais mostraram as diferenças fisiologicamente esperadas. Meninos respiradores nasais apresentaram mandíbula mais retraída e incisivos superiores inclinados para frente quando comparados com meninas respiradoras nasais, mas os respiradores bucais não apresentaram diferenças. A medida NS.GoGn foi a única variável com interação entre gênero e tipo de respiração. CONCLUSÕES: Não houve diferença cefalométrica entre os respiradores bucais em relação ao crescimento craniofacial, sugerindo que a respiração bucal determina a mesma morfologia, e ambos os gêneros têm morfologia craniofacial semelhante àquela dos pacientes com SAOS.Universidade Federal de Sào Paulo São Paulo Hospital Department of NeurologySciEL

    Bruxaria e Normalização: a perseguição às mulheres e ao conhecimento tradicional frente à hegemonia do discurso médico.

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    O presente artigo visa abordar os desdobramentos político-sociais do discurso médico, não raro apresentado como “neutro” e aquém de disputas discursivas. Além disso, será traçada a sua relação com o apagamento e colonização dos saberes tradicionais produzidos pelas mulheres, e a passagem dessas de sujeito de terminado conhecimento para meros objetos. Por fim, será analisado como tais tecnologias formam um discurso que se anuncia como “verdade”, especificamente, relacionando-o com o fenômeno da caça às bruxas, sendo este tratado não apenas como mero fato histórico, mas como prática recorrente de controle

    Realistic Simulations of the Galactic Polarized Foreground: Consequences for 21-cm Reionization Detection Experiments

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    Experiments designed to measure the redshifted 21~cm line from the Epoch of Reionization (EoR) are challenged by strong astrophysical foreground contamination, ionospheric distortions, complex instrumental response and other different types of noise (e.g. radio frequency interference). The astrophysical foregrounds are dominated by diffuse synchrotron emission from our Galaxy. Here we present a simulation of the Galactic emission used as a foreground module for the LOFAR- EoR key science project end-to-end simulations. The simulation produces total and polarized intensity over 10×1010^\circ \times 10^\circ maps of the Galactic synchrotron and free-free emission, including all observed characteristics of the emission: spatial fluctuations of amplitude and spectral index of the synchrotron emission, together with Faraday rotation effects. The importance of these simulations arise from the fact that the Galactic polarized emission could behave in a manner similar to the EoR signal along the frequency direction. As a consequence, an improper instrumental calibration will give rise to leakages of the polarized to the total signal and mask the desired EoR signal. In this paper we address this for the first time through realistic simulations.Comment: 14 pages, 8 figures, published in MNRA
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