Identification of Showers with Cores Outside the ARGO-YBJ Detector

In any EAS array, the rejection of events with shower cores outside the detector boundaries is of great importance. A large difference between the true and the reconstructed shower core positions may lead to a systematic miscalculation of some shower characteristics. Moreover, an accurate determination of the shower core position for selected internal events is important to reconstruct the primary direction using conical fits to the shower front, improving the detector angular resolution, or to performe an efficient gamma/hadron discrimination. In this paper we present a procedure able to identify and reject showers with cores outside the ARGO-YBJ carpet boundaries. A comparison of the results for gamma and proton induced showers is reported.Comment: 4 pages, to be published in the Proceedings of the 28th International Cosmic Ray Conference (Tsukuba, Japan 2003

Expected sensitivity of ARGO-YBJ to detect point gamma-ray sources

ARGO-YBJ is a full coverage air shower detector currently under construction at the Yangbajing Laboratory (4300 m a.s.l., Tibet, China). First data obtained with a subset of the apparatus will be available in summer 2003 while the full detector operation is expected in 2005. One of the main aims of ARGO-YBJ is the observation of gamma-ray sources, at an energy threshold of a few hundreds GeV. In this paper we present the expected sensitivity to detect point gamma ray sources, with particular attention to the Crab Nebula. According to our simulations a Crab-like signal could be detected in one year of operation with a statistical significance of 10 standard deviations, without any gamma/hadron discrimination.Comment: 4 pages, 2 Postscript figure

Update of the search for Gamma Ray Bursts with ARGO-YBJ in scaler mode

We report an update of the search for emission from Gamma Ray Bursts (GRBs) in the energy range 1−100 GeV in coincidence with the prompt emission detected by satellites, using the large field of view (about 2 sr) air shower detector ARGO-YBJ, appropriate to monitor unpredictable and short duration events like GRBs. The search has been carried out using the single particle technique in time coincidence with satellite detections both for single events and by stacking GRBs in time and phase. Between December 2004 and April 2011, 131 GRBs detected by different satellites occurred in the ARGO-YBJ field of view (zenith angle within 45 degrees). For 110 of these we searched for a high energy counterpart in the ARGO-YBJ data, finding no statistically significant signal. The resulting fluence upper limits between 1 and 100 GeV reach values as low as 10^(−5) erg/cm2, and in one case (GRB090902B) can be compared with observations by the LAT instrument on the Fermi satellite

Sistema de alerta da ferrugem do cafeeiro: resultado de um processo de mineração de dados.

Resumo. Este artigo apresenta o sistema de alerta de doença de plantas desenvolvido para realizar a predição da taxa de progresso da ferrugem do cafeeiro, que utiliza modelos preditivos criados a partir de dados meteorológicos e da cultura, fornecidos pela Fundação Procafé. O sistema de alerta desenvolvido visa auxiliar, através do resultado da predição, o técnico da Fundação Procafé a elaborar boletins mensais de recomendação de tomada de decisão no controle da ferrugem do cafeeiro.SBIAgro 2013

Sistema de alerta da ferrugem do cafeeiro.

RESUMO: Este trabalho apresenta um sistema de alerta Web para a ferrugem do cafeeiro, demonstrando suas funcionalidades e características. O sistema incorpora modelos para predizer se a taxa de progresso da ferrugem será maior ou igual a 5 ou 10 pontos percentuais em relação ao mês anterior. A modelagem utilizou dados meteorológicos e de cultura fornecidos pela Fundação Procafé e coletados nas cidades de Boa Esperança, Carmo de Minas e Varginha, em Minas Gerais. Dados similares são utilizados para a predição. A emissão de alerta positivo ou negativo é obtida através de um sistema de votação entre as saídas dos modelos. Caso a maioria indique aumento na taxa de progresso superior ao valor estipulado, o alerta é positivo; caso contrário, é negativo. O intuito do sistema é auxiliar na elaboração de boletins mensais de avisos fitossanitários distribuídos aos cafeicultores e demais interessados na cultura do café, com informações úteis para o controle da ferrugem, procurando indicar os momentos oportunos para a aplicação de fungicidas

Chagas disease at the crossroad of international migration and public health policies: why a national screening might not be enough

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