The LOFT (Large Observatory for X-ray Timing) background simulations

The Large Observatory For X-ray Timing (LOFT) is an innovative medium-class mission selected for an assessment phase in the framework of the ESA M3 Cosmic Vision call. LOFT is intended to answer fundamental questions about the behaviour of matter in the very strong gravitational and magnetic fields around compact objects. With an effective area of ~10 m^2 LOFT will be able to measure very fast variability in the X-ray fluxes and spectra. A good knowledge of the in-orbit background environment is essential to assess the scientific performance of the mission and to optimize the instrument design. The two main contributions to the background are cosmic diffuse X-rays and high energy cosmic rays; also, albedo emission from the Earth is significant. These contributions to the background for both the Large Area Detector and the Wide Field Monitor are discussed, on the basis of extensive Geant-4 simulations of a simplified instrumental mass model.Comment: Proceedings of SPIE, Vol. 8443, Paper No. 8443-209, 201

Simulations of the X-ray imaging capabilities of the Silicon Drift Detectors (SDD) for the LOFT Wide Field Monitor

The Large Observatory For X-ray Timing (LOFT), selected by ESA as one of the four Cosmic Vision M3 candidate missions to undergo an assessment phase, will revolutionize the study of compact objects in our galaxy and of the brightest supermassive black holes in active galactic nuclei. The Large Area Detector (LAD), carrying an unprecedented effective area of 10 m^2, is complemented by a coded-mask Wide Field Monitor, in charge of monitoring a large fraction of the sky potentially accessible to the LAD, to provide the history and context for the sources observed by LAD and to trigger its observations on their most interesting and extreme states. In this paper we present detailed simulations of the imaging capabilities of the Silicon Drift Detectors developed for the LOFT Wide Field Monitor detection plane. The simulations explore a large parameter space for both the detector design and the environmental conditions, allowing us to optimize the detector characteristics and demonstrating the X-ray imaging performance of the large-area SDDs in the 2-50 keV energy band.Comment: Proceedings of SPIE, Vol. 8443, Paper No. 8443-210, 201

Impaired Reproductive Development in Sons of Women Occupationally Exposed to Pesticides during Pregnancy

OBJECTIVES: The aim of this prospective study was to investigate whether occupational pesticide exposure during pregnancy causes adverse effects on the reproductive development in the male infants. DESIGN AND MEASUREMENTS: Pregnant women employed in greenhouses in Denmark were consecutively recruited, and 113 mother–son pairs were included. The mothers were categorized as occupationally exposed (91 sons) or unexposed (22 sons) to pesticides during pregnancy. Testicular position and volume, penile length, and position of urethral opening were determined at 3 months of age using standardized techniques. Concentrations of reproductive hormones in serum from the boys were analyzed. RESULTS: The prevalence of cryptorchidism at 3 months of age was 6.2 % [95 % confidence interval (CI), 3.0–12.4]. This prevalence was considerably higher than among Danish boys born in the Copenhagen area (1.9%; 95 % CI, 1.2–3.0) examined by the same procedure. Boys of pesticideexposed mothers showed decreased penile length, testicular volume, serum concentrations of testosterone, and inhibin B. Serum concentrations of sex hormone-binding globulin, follicle-stimulating hormone, and the luteinizing hormone:testosterone ratio were increased compared with boys of nonexposed mothers. For individual parameters, only the decreased penile length was statisticall