398 research outputs found

    Simulation of the response of a silicon pixel detector

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    A model to simulate the response of a silicon pixel detector is described. The effects of geometrical charge sharing, electronic noise threshold dispersion, capacitive coupling between pixel channels and d -rays production have been taken into account. The model has been tested on the Omega3chip, which is the direct predecessor of the ALICE pixel detector, to be used in the inner tracking system of the ALICE experiment. The model is able to reproduce the experimental data and the resulting parameters are consistent with the measurements made on the Omega3chip. Key words:silicon pixel, simulation PACS:07.05.T,29.40.

    Impairment of the CD8+ T cell response in lungs following infection with human respiratory syncytial virus is specific to the anatomical site rather than the virus, antigen, or route of infection

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    <p>Abstract</p> <p>Background</p> <p>A subset of the virus-specific CD8+ cytotoxic T lymphocytes (CTL) isolated from the lungs of mice infected with human respiratory syncytial virus (RSV) is impaired in the ability to secrete interferon γ (IFNγ), a measure of functionality. It was suggested that the impairment specifically suppressed the host cellular immune response, a finding that could help explain the ability of RSV to re-infect throughout life.</p> <p>Results</p> <p>To determine whether this effect is dependent on the virus, the route of infection, or the type of infection (respiratory, disseminated, or localized dermal), we compared the CTL responses in mice following intranasal (IN) infection with RSV or influenza virus or IN or intradermal (ID) infection with vaccinia virus expressing an RSV CTL antigen. The impairment was observed in the lungs after IN infection with RSV, influenza or vaccinia virus, and after a localized ID infection with vaccinia virus. In contrast, we observed a much higher percentage of IFNγ secreting CD8+ lymphocytes in the spleens of infected mice in every case.</p> <p>Conclusion</p> <p>The decreased functionality of CD8+ CTL is specific to the lungs and is not dependent on the specific virus, viral antigen, or route of infection.</p

    Approximate Bayesian Computation of radiocarbon and paleoenvironmental record shows population resilience on Rapa Nui (Easter Island).

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    Examining how past human populations responded to environmental and climatic changes is a central focus of the historical sciences. The use of summed probability distributions (SPD) of radiocarbon dates as a proxy for estimating relative population sizes provides a widely applicable method in this research area. Paleodemographic reconstructions and modeling with SPDs, however, are stymied by a lack of accepted methods for model fitting, tools for assessing the demographic impact of environmental or climatic variables, and a means for formal multi-model comparison. These deficiencies severely limit our ability to reliably resolve crucial questions of past human-environment interactions. We propose a solution using Approximate Bayesian Computation (ABC) to fit complex demographic models to observed SPDs. Using a case study from Rapa Nui (Easter Island), a location that has long been the focus of debate regarding the impact of environmental and climatic changes on its human population, we find that past populations were resilient to environmental and climatic challenges. Our findings support a growing body of evidence showing stable and sustainable communities on the island. The ABC framework offers a novel approach for exploring regions and time periods where questions of climate-induced demographic and cultural change remain unresolved

    Performance of single-photon-counting PILATUS detector modules

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    Characterization of PILATUS single-photon-counting X-ray detector modules regarding charge sharing, energy resolution and rate capability is presented. The performance of the detector was tested with surface diffraction experiments at the synchrotron

    EROS 2.0 study: evaluation of two interventional radiotherapy (brachytherapy) schedules for endometrial cancer: a comparison of late vaginal toxicity rates

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    Background To compare the late toxicity rates after two different high dose rate (HDR) adjuvant intravaginal interventional radiotherapy (IRT-brachytherapy) dose schedules in stage I-II endometrial cancer. Methods Stage I-II patients with endometrial cancer treated with surgery (with or without lymphadenectomy) and adjuvant HDR-IRT between 2014 and 2020 were included in this analysis. Patients were treated with two schedules. In the first cohort (C1), 21 Gy were delivered in three weekly fractions (7 Gy) prescribed 0.5 cm from the applicator surface. In the second cohort (C2), 24 Gy were delivered in four weekly fractions (6 Gy). The clinical target volume was the upper third of the vagina for C1 and the upper 3 cm for C2. HDR-IRT technique and point prescription (5 mm depth from the applicator surface) were the same for all patients. Vaginal toxicity was scored according to the CTCAE 5.0 scale in terms of the presence versus absence of any toxicity grade. The correlation among toxicity and clinical covariates (age, lymphadenectomy, fractionation, stage) was tested by Pearson correlation test (univariate) and by logistic regression (multivariable). Results 114 stage I and three stage II patients, median age 62 (range: 32-85) years, were included in this analysis. The mean follow-up was 56.3 months in C1 (40-76) and 20 months in C2 (8-42). Vaginal late toxicity was recorded in 40 and 15 patients in C1 and 2, respectively. Age, lymphadenectomy, and fractionation were significantly correlated with toxicity at univariate analysis (p value = 0.029, 0.006, and 0.002, respectively), while stepwise logistic regression confirmed only age and fractionation as significantly correlated parameters (p value = 0.02 and 0.001, respectively). Three-year local relapse-free, distant metastasis-free and cause-specific survival rates were 96.6%, 94.8%, and 99.1%, respectively. Conclusions This analysis showed lower vaginal late toxicity rate in C2 compared to C1
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