6,184 research outputs found

    Particle acceleration and the origin of gamma-ray emission from Fermi Bubbles

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    Fermi LAT has discovered two extended gamma-ray bubbles above and below the galactic plane. We propose that their origin is due to the energy release in the Galactic center (GC) as a result of quasi-periodic star accretion onto the central black hole. Shocks generated by these processes propagate into the Galactic halo and accelerate particles there. We show that electrons accelerated up to ~10 TeV may be responsible for the observed gamma-ray emission of the bubbles as a result of inverse Compton (IC) scattering on the relic photons. We also suggest that the Bubble could generate the flux of CR protons at energies > 10^15 eV because the shocks in the Bubble have much larger length scales and longer lifetimes in comparison with those in SNRs. This may explain the the CR spectrum above the knee.Comment: 5 pages, 4 figures. Expanded version of the contribution to the 32nd ICRC, Beijing, #0589. To appear in the proceeding

    Spinal muscular atrophy (SMA) - natural history and functional status in Hong Kong children

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    OBJECTIVE: To study the natural history and current functional status of children with SMA in Hong Kong. METHODS: A SMA Registry had been collected since 1984 in Duchess of Kent Children’s Hospital. Families of SMA (FSMA) has been established in 2000. A total 102 SMA cases had been collected. We analyzed 81 SMA cases (34 males; 47 females) with clinical information available in September 2002. SMA cases were classified according to classification of the International SMA Consortium. SMA type III was further 
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    Influence of Humidity on the NO₂ Sensing Properties of SrCo₀.₁Ti₀.₉O₃

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    Strontium Cobalt Titanate (SCT) was synthesized via solid state route. Phase formation was analyzed using X-ray diffraction (XRD) technique. Resistive sensors were made using screen printing technique and corresponding sensing properties were investigated in dry as well as humid environment (RH 50%). Experimental results demonstrated that sensors displayed least humidity interference at 400 °C. The operating temperature of the sensor was optimized for best responsiveness. These type of sensors can be effectively used in environmental monitoring of NO2 gas at low ppm

    Outcomes in Trials for Management of Caries Lesions (OuTMaC):protocol

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    Background Clinical trials on caries lesion management use an abundance of outcomes, hampering comparison or combination of different study results and their efficient translation into clinical practice. Core outcome sets are an agreed standardized collection of outcomes which should be measured and reported in all trials for a specific clinical area. We aim to develop a core outcome set for trials investigating management of caries lesions in primary or permanent teeth conducted in primary or secondary care encompassing all stages of disease. Methods To identify existing outcomes, trials on prevention and trials on management of caries lesions will be screened systematically in four databases. Screening, extraction and deduplication will be performed by two researchers until consensus is reached. The definition of the core outcome set will by based on an e-Delhi consensus process involving key stakeholders namely patients, dentists, clinical researchers, health economists, statisticians, policy-makers and industry representatives. For the first stage of the Delphi process, a patient panel and a separate panel consisting of researchers, clinicians, teachers, industry affiliated researchers, policy-makers, and other interested parties will be held. An inclusive approach will be taken to involve panelists from a wide variety of socio-economic and geographic backgrounds. Results from the first round will be summarized and fed back to individuals for the second round, where panels will be combined and allowed to modify their scoring in light of the full panel’s opinion. Necessity for a third round will be dependent on the outcome of the first two. Agreement will be measured via defined consensus rules; up to a maximum of seven outcomes. If resources allow, we will investigate features that influence decision making for different groups. Discussion By using an explicit, transparent and inclusive multi-step consensus process, the planned core outcome set should be justifiable, relevant and comprehensive. The dissemination and application of this core outcome set should improve clinical trials on managing caries lesions and allow comparison, synthesis and implementation of scientific data. Trial registration Registered 12 April 2015 at COMET (http://www.comet-initiative.org

    Azimuthal anisotropy of jet quenching at LHC

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    We analyze the azimuthal anisotropy of jet spectra due to energy loss of hard partons in quark-gluon plasma, created initially in nuclear overlap zone in collisions with non-zero impact parameter. The calculations are performed for semi-central Pb-Pb collisions at LHC energy.Comment: Talk given at Fourth International Conference "Physics and Astrophysics of Quark-Gluon Plasma", November 26-30, 2001; 4 pages including 4 eps-figure

    De-Excitation Gamma-ray Line Emission from the Galactic Center

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    International audienceA future detection of de-excitation gamma-ray lines from the Galactic center region would provide unique information on the high-energy processes induced by the the central black hole and the physical conditions of the emitting region. We analyse the intensity of nuclear de-excitation lines in the direction of the Galactic center produced by subrelativistic protons, which are generated by star capture by the central black hole. With the metallicity two times higher than the solar one the total flux in gamma-ray lines of energies below 8 MeV is about 10−4 cm−2 s−1. The most promising lines for detection are those at 4.44 and 6.2 MeV, with a predicted flux in each line of 10−5 photons cm−2 s−1. We also analyze the possibility of detection of these lines by INTEGRAL and future missions

    ERBlox: Combining Matching Dependencies with Machine Learning for Entity Resolution

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    Entity resolution (ER), an important and common data cleaning problem, is about detecting data duplicate representations for the same external entities, and merging them into single representations. Relatively recently, declarative rules called matching dependencies (MDs) have been proposed for specifying similarity conditions under which attribute values in database records are merged. In this work we show the process and the benefits of integrating three components of ER: (a) Classifiers for duplicate/non-duplicate record pairs built using machine learning (ML) techniques, (b) MDs for supporting both the blocking phase of ML and the merge itself; and (c) The use of the declarative language LogiQL -an extended form of Datalog supported by the LogicBlox platform- for data processing, and the specification and enforcement of MDs.Comment: To appear in Proc. SUM, 201

    X-Ray and Gamma-Ray Emission from the Galactic Center

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    We discuss the origin of continuum and line X-ray emission observed in the direction the Galactic Center. We predict a significant flux of de-excitation gamma-ray lines in this direction, which can be produced by subrelativistic protons generated by accretion processes.Comment: 5 pages, Contributed talk for the proceedings of the Galactic Center Workshop 2009, "The Galactic Center: A Window to the Nuclear Environment of Disk Galaxies", in 19-21 October, Shanghai China, 19-21 October, 200

    Susceptibility of influenza B viruses to neuraminidase inhibitors: findings from the first 4 years (2008–2012) of the global Influenza Resistance Information Study (IRIS)

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    Poster Session: Antiviral Drugs and ResistanceBackground: Type B influenza virus infections continue to account for a substantial proportion of clinical illness. Little is known about comparative disease profiles by virus lineage. A global observational trial (the Influenza Resistance Information Study or IRIS; NCT00884117) was initiated to study neuraminidase inhibitor (NAI) susceptibility and the clinical and virological course of influenza in treated and untreated patients. Materials and Methods: Patients in the northern and southern hemispheres (USA, France, Germany, Poland, Norway, Hong Kong, Australia) with influenza-like illness and/or a positive rapid influenza test result were enrolled. Throat/nasal swabs were performed on Days 1, 3 (self-swab), 6 and 10 and tested for influenza A and B viruses by RT-PCR. Influenzapositive samples collected on Days 1, 6 or 10 were cultured and subsequently sequenced (HA and NA) and phenotypically tested for NAI susceptibility. The lineage of B viruses was determined from sequencing. Clinical information, including the scoring of seven influenza symptoms (scale: 0 [absent], 1 [mild], 2 [moderate], 3 [severe]), was recorded on diary cards by the patient or the patient’s legal guardian (Days 1–12). Symptoms were also assessed by the investigator at each visit. The decision to prescribe an NAI was left to the physician’s discretion. Results: In the first 4 years of IRIS (December 2008 to March 2012), 2262 influenza-positive (RT-PCR) patients were enrolled, of whom 697 presented with a type B influenza virus infection (564 Victoria, 98 Yamagata, 35 undetermined lineage). Most type B patients (402; 58%) were children aged < 13 years. A total of 330 (47%) type B patients were treated with oseltamivir (as monotherapy) within 2 days of symptom onset; a further 26 started oseltamivir 2 days after symptom onset. Eleven patients received zanamivir, one received amantadine and another received rimantidine. A total of 328 (47%) did not receive any influenza antiviral. Symptoms were mild to moderate on Day 1 (mean total score: 12.8, treated; 12.9, untreated), and the mean temperature on Day 1 was 38.2°C. All viruses obtained at baseline or postbaseline were susceptible to NAIs: mean (SD) IC50 values for oseltamivir were 4.8 nM (2.5 nM) and 5.5 nM (2.3 nM) for the Victoria and Yamagata viruses, respectively; the corresponding values for zanamivir were 2.0 nM (1.4 nM) and 2.9 nM (1.6 nM), respectively. No known NAI resistance mutations were detected by NA or HA population sequencing. The proportion of RT-PCR–positive patients on Day 6 was 130/309 (42.1%) for patients treated with oseltamivir and 152/312 (48.7%) for untreated patients. In Kaplan–Meier analyses, no significant differences in median time to influenza RNA clearance were found between oseltamivir-treated and -untreated patients, either in adults or children. The time to symptom resolution (all symptom scores ≀ 1) was 5 days (95% CI, 4–5 days) in oseltamivir-treated children and 6 days (95% CI, 5–6 days) in untreated children (P = .026), but no significant difference in symptom resolution time was found in adults (Kaplan–Meier analysis). Conclusions: Analysis of type B influenza viruses obtained globally between 2008 and 2012 showed that all pre-treatment B/Victoria and B/Yamagata viruses were susceptible to oseltamivir and zanamivir. Moreover, no resistant viruses were detected during treatment. Given the non-randomised design of this study, no definitive conclusions can be drawn with regard to the clinical benefit of oseltamivir in patients infected with type B influenza viruses.published_or_final_versio
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