909 research outputs found

    Prospects for Gamma-Ray Bursts detection by the Cherenkov Telescope Array

    Get PDF
    The first Gamma-Ray Burst (GRB) catalog presented by the Fermi-Large Area Telescope (LAT) collaboration includes 28 GRBs, detected above 100 MeV over the first three years since the launch of the Fermi mission. However, more than 100 GRBs are expected to be found over a period of six years of data collection thanks to a new detection algorithm and to the development of a new LAT event reconstruction, the so-called "Pass 8." Our aim is to provide revised prospects for GRB alerts in the CTA era in light of these new LAT discoveries. We focus initially on the possibility of GRB detection with the Large Size Telescopes (LSTs). Moreover, we investigate the contribution of the Middle Size Telescopes (MSTs), which are crucial for the search of larger areas on short post trigger timescales. The study of different spectral components in the prompt and afterglow phase, and the limits on the Extragalactic background light are highlighted. Different strategies to repoint part of - or the entire array - are studied in detail.Comment: In Proceedings of the 34th International Cosmic Ray Conference (ICRC 2015), The Hague, The Netherland

    Manufacturing and Characterization of AlSi Foams as Core Materials

    Get PDF
    AbstractAlSi alloys and their foaming properties have been studied in this paper. For adequate comparison it has been necessary to define process parameters and optimal chemical composition of the Al alloys. Such foams have been evaluated in terms of structure and mechanical properties, in particular in the use of foams as cores materials of cylindrical massive skins

    Pyridostigmine in pediatric Intestinal pseudo-obstruction. case report of a 2-year old girl and literature review

    Get PDF
    Pediatric chronic intestinal pseudo-obstruction is a rare disorder characterized by a severe impairment of gastrointestinal motility leading to intestinal obstruction symptoms in the absence of mechanical causes. The diagnosis is usually clinical and diagnostic work is usually aimed to rule out mechanical obstruction and to identify any underlying diseases. Treatment is challenging and requires a multidisciplinary effort. In this manuscript we describe the youngest child successfully treated with the orally administrable, longacting, reversible anti-cholinesterase drug, pyridostigmine. Like other drugs belonging to cholinesterase inhibitors, pyridostigmine enhances gut motility by increasing acetylcholine availability in the enteric nervous system and neuro-muscular junctions. Based on the direct evidence from the reported case, we reviewed the current literature on the use of pyridostigmine in severe pediatric dysmotility focusing on intestinal pseudo-obstruction. The overall data emerged from the few published studies suggest that pyridostigmine is an effective and usually well tolerated therapeutic options for patients with intestinal pseudo-obstruction. More specifically, the main results obtained by pyridostigmine included marked reduction of abdominal distension, reduced need of parenteral nutrition, and improvement of oral feeding. The present case and review on pyridostigmine pave the way for eagerly awaited future randomized controlled studies testing the efficacy of cholinesterase inhibitors in pediatric severe gut dysmotility

    Prospects for Gamma-Ray Bursts detection by the Cherenkov Telescope Array

    Get PDF
    The first Gamma-Ray Burst (GRB) catalog presented by the Fermi-Large Area Telescope (LAT) collaboration includes 28 GRBs, detected above 100 MeV over the first three years since the launch of the Fermi mission. However, more than 100 GRBs are expected to be found over a period of six years of data collection thanks to a new detection algorithm and to the development of a new LAT event reconstruction, the so-called "Pass 8." Our aim is to provide revised prospects for GRB alerts in the CTA era in light of these new LAT discoveries. We focus initially on the possibility of GRB detection with the Large Size Telescopes (LSTs). Moreover, we investigate the contribution of the Middle Size Telescopes (MSTs), which are crucial for the search of larger areas on short post trigger timescales. The study of different spectral components in the prompt and afterglow phase, and the limits on the Extragalactic background light are highlighted. Different strategies to repoint part of - or the entire array - are studied in detail

    Surrogate modeling of the aeroacoustics of an NM80 wind turbine

    Get PDF
    Wind turbines play a major role in the European Green Deal for clean energy transition. Noise is a critical aspect among open technological issues, as it determines the possibility of onshore installations near inhabited places and the possible detrimental effects on wildlife when offshore. This paper assesses the accuracy of different approaches to predicting the sound pressure level (SPL) of a wind turbine. The 2.75 MW Neg Micon NM80 horizontal axis wind turbine (HWAT) was simulated in OpenFOAM, modeling the turbine with the actuator line method (ALM) implemented in the turbinesFoam library. Two different inflow conditions were considered: a stationary inflow with a typical atmospheric boundary layer profile and a time-dependent inflow derived from a precursor channel with fully turbulent conditions. The surrogate model for noise prediction used for this work is based on the synthetic/surrogate acoustics models (SAMs) of Amiet and Brooks-Pope-Marcolini (BPM). This approach allows for blade motion modeling and the prediction of the SPL of the URANS postprocessing results. The SPL spectrum obtained was then compared to the results from the other aeroacoustic solvers of IEA Task 39 participants, showing the best performance in the fully turbulent case. The results demonstrate that coupling between the ALM and surrogate acoustics provides more accurate results than the blade element momentum (BEM) approach

    The contribution of CXCL12-expressing radial glia cells to neuro-vascular patterning during human cerebral cortex development

    Get PDF
    This study was conducted on human developing brain by laser confocal and transmission electron microscopy (TEM) to make a detailed analysis of important features of blood-brain barrier (BBB) microvessels and possible control mechanisms of vessel growth and differentiation during cerebral cortex vascularization. The BBB status of cortex microvessels was examined at a defined stage of cortex development, at the end of neuroblast waves of migration, and before cortex lamination, with BBB-endothelial cell markers, namely tight junction (TJ) proteins (occludin and claudin-5) and influx and efflux transporters (Glut-1 and P-glycoprotein), the latter supporting evidence for functional effectiveness of the fetal BBB. According to the well-known roles of astroglia cells on microvessel growth and differentiation, the early composition of astroglia/endothelial cell relationships was analyzed by detecting the appropriate astroglia, endothelial, and pericyte markers. GFAP, chemokine CXCL12, and connexin 43 (Cx43) were utilized as markers of radial glia cells, CD105 (endoglin) as a marker of angiogenically activated endothelial cells (ECs), and proteoglycan NG2 as a marker of immature pericytes. Immunolabeling for CXCL12 showed the highest level of the ligand in radial glial (RG) fibers in contact with the growing cortex microvessels. These specialized contacts, recognizable on both perforating radial vessels and growing collaterals, appeared as CXCL12-reactive en passant, symmetrical and asymmetrical, vessel-specific RG fiber swellings. At the highest confocal resolution, these RG varicosities showed a CXCL12-reactive dot-like content whose microvesicular nature was confirmed by ultrastructural observations. A further analysis of RG varicosities reveals colocalization of CXCL12 with Cx43, which is possibly implicated in vessel-specific chemokine signaling

    Postoperative laryngeal symptoms in a general surgery setting. Clinical study.

    Get PDF
    INTRODUCTION: Vocal cord injuries (VI), postoperative hoarseness (PH), dysphonia (DN), dysphagia (DG) and sore throat (ST) are common complications after general anesthesia; there is actually a lack of consensus to support the proper timing for post-operative laryngoscopy that is reliable to support the diagnosis of laryngeal or vocal fold lesions after surgery and there are no valid studies about the entity of laryngeal trauma in oro-tracheal intubation. Aim of our study is to evaluate the statistical relation between anatomic, anesthesiological and surgical variables in the case of PH, DG or impaired voice register. MATERIALS AND METHODS: 50 patients (30 thyroidectomies, 8 videolaparoscopic cholecistectomies, 2 right emicolectomies, 2 left emicolectomies, 1 gastrectomy, 1 hemorrhoidectomy, 1 nefrectomy, 1 diagnostic videothoracoscopy, 1 superior right lung lobectomy, 1 appendicectomy, 1 incisional hernia repair, 1 low anterior rectal resection, 1 radical hysterectomy) underwent clinical evaluation and direct laryngoscopy before surgery, within 6 hours, after 72 hours and after 30 days, to evaluate motility and breathing space, phonatory motility, true and false vocal folds and arytenoids oedema. We evaluated also mean age (56.6 ± 3.6 years), male:female ratio (1:1.5), cigarette smoke (20%), atopic comorbidity (17/50 = 34%), Mallampati class (32% 1, 38% 2, 26% 3, 2% 4), mean duration of intubation (159 minutes, range 50 - 405 minutes), Cormack-Lehane score (34% 1, 22% 2, 22% 3, 2% 4), difficult intubation in 9 cases (18%). No complication during the laryngoscopy were registered. We investigated the statistic relationship between pre and intraoperative variables and laryngeal symptoms and lesions. RESULTS: In our experience, statistically significant relations were found in prevalence of vocal folds oedema in smokers (p < 0.005), self limiting DG and DN in younger patients (p < 0.005) and in thyroidectomy (p < 0.01), DG after thyroidectomy (p < 0.01). The short preoperative use of steroids and antihistaminic to prevent allergic reactions appears not related to reduction or prevention of DN, DG, PH and ST. No statistical relation in incidence of postoperative complications was found for the prolonged intubation, gastro-esophageal reflux, BURP manoeuvre (backward upward right sided pressure) and Mallampati and Cormack-Lehane class more than 2, maintenance with sevoflurane 2% and use of stilet. CONCLUSIONS: Direct laryngoscopy is essential for the detection of arytenoid lesions after orotracheal intubation for general anesthesia. In our opinion, a part of temporary post-operative DN or PH is due to monolateral or bilateral arytenoids oedema, secondary to prolonged or difficult orotracheal intubation, valuable with laryngoscopy 72 hours after surgery. Is necessary to adjunct these complications in the surgical informed consensus scheme
    corecore