6,184 research outputs found
Particle acceleration and the origin of gamma-ray emission from Fermi Bubbles
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
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 Childrenâs 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 âŠpublished_or_final_versio
Influence of Humidity on the NOâ Sensing Properties of SrCoâ.âTiâ.âOâ
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
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 panelâs 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
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
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 10â4 cmâ2 sâ1. The most promising lines for detection are those at 4.44 and 6.2 MeV, with a predicted flux in each line of 10â5 photons cmâ2 sâ1. 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
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
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 (2008â2012) of the global Influenza Resistance Information Study (IRIS)
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 patientâs
legal guardian (Days 1â12). Symptoms were also assessed by the investigator at each visit. The
decision to prescribe an NAI was left to the physicianâs 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-PCRâpositive
patients on Day 6 was 130/309 (42.1%) for patients treated with oseltamivir and 152/312 (48.7%) for
untreated patients. In KaplanâMeier 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, 4â5 days) in
oseltamivir-treated children and 6 days (95% CI, 5â6 days) in untreated children (P = .026), but no
significant difference in symptom resolution time was found in adults (KaplanâMeier 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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