125 research outputs found
The balance of power: accretion and feedback in stellar mass black holes
In this review we discuss the population of stellar-mass black holes in our
galaxy and beyond, which are the extreme endpoints of massive star evolution.
In particular we focus on how we can attempt to balance the available accretion
energy with feedback to the environment via radiation, jets and winds,
considering also possible contributions to the energy balance from black hole
spin and advection. We review quantitatively the methods which are used to
estimate these quantities, regardless of the details of the astrophysics close
to the black hole. Once these methods have been outlined, we work through an
outburst of a black hole X-ray binary system, estimating the flow of mass and
energy through the different accretion rates and states. While we focus on
feedback from stellar mass black holes in X-ray binary systems, we also
consider the applicability of what we have learned to supermassive black holes
in active galactic nuclei. As an important control sample we also review the
coupling between accretion and feedback in neutron stars, and show that it is
very similar to that observed in black holes, which strongly constrains how
much of the astrophysics of feedback can be unique to black holes.Comment: To be published in Haardt et al. Astrophysical Black Holes. Lecture
Notes in Physics. Springer 201
Azimuthal asymmetry in the risetime of the surface detector signals of the Pierre Auger Observatory
The azimuthal asymmetry in the risetime of signals in Auger surface detector
stations is a source of information on shower development. The azimuthal
asymmetry is due to a combination of the longitudinal evolution of the shower
and geometrical effects related to the angles of incidence of the particles
into the detectors. The magnitude of the effect depends upon the zenith angle
and state of development of the shower and thus provides a novel observable,
, sensitive to the mass composition of cosmic rays
above eV. By comparing measurements with predictions from
shower simulations, we find for both of our adopted models of hadronic physics
(QGSJETII-04 and EPOS-LHC) an indication that the mean cosmic-ray mass
increases slowly with energy, as has been inferred from other studies. However,
the mass estimates are dependent on the shower model and on the range of
distance from the shower core selected. Thus the method has uncovered further
deficiencies in our understanding of shower modelling that must be resolved
before the mass composition can be inferred from .Comment: Replaced with published version. Added journal reference and DO
An NLO QCD analysis of inclusive cross-section and jet-production data from the ZEUS experiment
The ZEUS inclusive differential cross-section data from HERA, for charged and
neutral current processes taken with e+ and e- beams, together with
differential cross-section data on inclusive jet production in e+ p scattering
and dijet production in \gamma p scattering, have been used in a new NLO QCD
analysis to extract the parton distribution functions of the proton. The input
of jet data constrains the gluon and allows an accurate extraction of
\alpha_s(M_Z) at NLO;
\alpha_s(M_Z) = 0.1183 \pm 0.0028(exp.) \pm 0.0008(model)
An additional uncertainty from the choice of scales is estimated as \pm
0.005. This is the first extraction of \alpha_s(M_Z) from HERA data alone.Comment: 37 pages, 14 figures, to be submitted to EPJC. PDFs available at
http://durpdg.dur.ac.uk/hepdata in LHAPDFv
Identification of novel genetic markers associated with clinical phenotypes of systemic sclerosis through a genome-wide association strategy
The aim of this study was to determine, through a genome-wide association study (GWAS), the genetic components contributing to different clinical sub-phenotypes of systemic sclerosis (SSc). We considered limited (lcSSc) and diffuse (dcSSc) cutaneous involvement, and the relationships with presence of the SSc-specific auto-antibodies, anti-centromere (ACA), and anti-topoisomerase I (ATA). Four GWAS cohorts, comprising 2,296 SSc patients and 5,171 healthy controls, were meta-analyzed looking for associations in the selected subgroups. Eighteen polymorphisms were further tested in nine independent cohorts comprising an additional 3,175 SSc patients and 4,971 controls. Conditional analysis for associated SNPs in the HLA region was performed to explore their independent association in antibody subgroups. Overall analysis showed that non-HLA polymorphism rs11642873 in IRF8 gene to be associated at GWAS level with lcSSc (P = 2.32×10−12, OR = 0.75). Also, rs12540874 in GRB10 gene (P = 1.27 × 10−6, OR = 1.15) and rs11047102 in SOX5 gene (P = 1.39×10−7, OR = 1.36) showed a suggestive association with lcSSc and ACA subgroups respectively. In the HLA region, we observed highly associated allelic combinations in the HLA-DQB1 locus with ACA (P = 1.79×10−61, OR = 2.48), in the HLA-DPA1/B1 loci with ATA (P = 4.57×10−76, OR = 8.84), and in NOTCH4 with ACA P = 8.84×10−21, OR = 0.55) and ATA (P = 1.14×10−8, OR = 0.54). We have identified three new non-HLA genes (IRF8, GRB10, and SOX5) associated with SSc clinical and auto-antibody subgroups. Within the HLA region, HLA-DQB1, HLA-DPA1/B1, and NOTCH4 associations with SSc are likely confined to specific auto-antibodies. These data emphasize the differential genetic components of subphenotypes of SSc.This work was supported by the following grants: J Martin was funded by GEN-FER from the Spanish Society of Rheumatology, SAF2009-11110 from the Spanish Ministry of Science, CTS-4977 from Junta de Andalucı´a, Spain, and in part by Redes Tema´ticas de Investigacio´n Cooperativa Sanitaria Program, RD08/0075 (RIER) from Instituto de Salud Carlos III (ISCIII), Spain. TRDJ Radstake was funded by the VIDI laureate from the Dutch Association of Research (NWO) and Dutch Arthritis Foundation (National Reumafonds). J Martin and TRDJ Radstake were sponsored by the Orphan Disease Program grant from the European League Against Rheumatism (EULAR). BPC Koeleman is supported by the Dutch Diabetes Research Foundation (grant 2008.40.001) and the Dutch Arthritis Foundation
(Reumafonds, grant NR 09-1-408). BZ Alizadeh is supported by the Netherlands Organization for Health Research and Development (ZonMW grant 016.096.121). Genotyping of the Dutch control samples was sponsored by US National Institutes of Mental Health funding, R01 MH078075 (ROA). The German controls were from the PopGen biobank (to BPC Koeleman). The PopGen project received infrastructure support through the German Research Foundation excellence cluster ‘‘Inflammation at Interfaces.’’ The USA studies were supported by NIH/NIAMS Scleroderma Family Registry and DNA Repository (N01-AR-0-2251), NIH/NIAMS-RO1-AR055258, NIH/NIAMS Center of Research Translation in Scleroderma (1P50AR054144), and the Department of Defense Congressionally Directed Medical
Research Programs (W81XWH-07-01-0111). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript
Bronchoscopist's perception of the quality of the single-use bronchoscope (Ambu aScope4™) in selected bronchoscopies: a multicenter study in 21 Spanish pulmonology services
Background: The disposable bronchoscope is an excellent alternative to face the problem of SARS-CoV-2 and other cross infections, but the bronchoscopist's perception of its quality has not been evaluated.
Methods: To evaluate the quality of the Ambu-aScope4 disposable bronchoscope, we carried out a cross-sectional study in 21 Spanish pulmonology services. We use a standardized questionnaire completed by the bronchoscopists at the end of each bronchoscopy. The variables were described with absolute and relative frequencies, measures of central tendency and dispersion depending on their nature. The existence of learning curves was evaluated by CUSUM analysis.
Results: The most frequent indications in 300 included bronchoscopies was bronchial aspiration in 69.3% and the median duration of these was 9.1 min. The route of entry was nasal in 47.2% and oral in 34.1%. The average score for ease of use, image, and aspiration quality was 80/100. All the planned techniques were performed in 94.9% and the bronchoscopist was satisfied in 96.6% of the bronchoscopies. They highlighted the portability and immediacy of the aScope4TM to start the procedure in 99.3%, the possibility of taking and storing images in 99.3%. The CUSUM analysis showed average scores > 70/100 from the first procedure and from the 9th procedure more than 80% of the scores exceeded the 80/100 score.
Conclusions: The aScope4™ scored well for ease of use, imaging, and aspiration. We found a learning curve with excellent scores from the 9th procedure. Bronchoscopists highlighted its portability, immediacy of use and the possibility of taking and storing images
Polarimetry of binary systems: polars, magnetic CVs, XRBs
Polarimetry provides key physical information on the properties of
interacting binary systems, sometimes difficult to obtain by any other type of
observation. Indeed, radiation processes such as scattering by free electrons
in the hot plasma above accretion discs, cyclotron emission by mildly
relativistic electrons in the accretion shocks on the surface of highly
magnetic white dwarfs and the optically thin synchrotron emission from jets can
be observed. In this review, I will illustrate how optical/near-infrared
polarimetry allows one to estimate magnetic field strengths and map the
accretion zones in magnetic Cataclysmic Variables as well as determine the
location and nature of jets and ejection events in X-ray binaries.Comment: 26 pages, 16 figures; to be published in Astrophysics and Space
Science Library 460, Astronomical Polarisation from the Infrared to Gamma
Rays, Editors: Mignani, R., Shearer, A., S{\l}owikowska, A., Zane,
CD40: Novel Association with Crohn's Disease and Replication in Multiple Sclerosis Susceptibility
Background: A functional polymorphism located at 21 from the start codon of the CD40 gene, rs1883832, was previously
reported to disrupt a Kozak sequence essential for translation. It has been consistently associated with Graves’ disease risk in
populations of different ethnicity and genetic proxies of this variant evaluated in genome-wide association studies have
shown evidence of an effect in rheumatoid arthritis and multiple sclerosis (MS) susceptibility. However, the protective allele
associated with Graves’ disease or rheumatoid arthritis has shown a risk role in MS, an effect that we aimed to replicate in
the present work. We hypothesized that this functional polymorphism might also show an association with other complex
autoimmune condition such as inflammatory bowel disease, given the CD40 overexpression previously observed in Crohn’s
disease (CD) lesions.
Methodology: Genotyping of rs1883832C.T was performed in 1564 MS, 1102 CD and 969 ulcerative colitis (UC) Spanish
patients and in 2948 ethnically matched controls by TaqMan chemistry.
Principal Findings: The observed effect of the minor allele rs1883832T was replicated in our independent Spanish MS
cohort [p= 0.025; OR (95% CI)= 1.12 (1.01–1.23)]. The frequency of the minor allele was also significantly higher in CD
patients than in controls [p= 0.002; OR (95% CI)= 1.19 (1.06–1.33)]. This increased predisposition was not detected in UC
patients [p= 0.5; OR (95% CI)= 1.04 (0.93–1.17)].
Conclusion: The impact of CD40 rs1883832 on MS and CD risk points to a common signaling shared by these autoimmune
conditions.Peer reviewe
Protein tyrosine phosphatase non-receptor 22 and C-Src tyrosine kinase genes are down-regulated in patients with rheumatoid arthritis
Several protein tyrosine phosphatase non-receptor 22 (PTPN22) single-nucleotide polymorphisms (SNPs) have been significantly related with rheumatoid arthritis (RA) susceptibility. Nevertheless, its potential influence on PTPN22 expression in RA has not been completely elucidated. Furthermore, PTPN22 binds to C-Src tyrosine kinase (CSK) forming a key complex in autoimmunity. However, the information of CSK gene in RA is scarce. In this study, we analyzed the relative PTPN22 and CSK expression in peripheral blood from 89 RA patients and 43 controls to determine if the most relevant PTPN22 (rs2488457, rs2476601 and rs33996649) and CSK (rs34933034 and rs1378942) polymorphisms may influence on PTPN22 and CSK expression in RA. The association between PTPN22 and CSK expression in RA patients and their clinical characteristics was also evaluated. Our study shows for the first time a marked down-regulation of PTPN22 expression in RA patients carrying the risk alleles of PTPN22 rs2488457 and rs2476601 compared to controls (p?=?0.004 and p?=?0.007, respectively). Furthermore, CSK expression was significantly lower in RA patients than in controls (p?<?0.0001). Interestingly, a reduced PTPN22 expression was disclosed in RA patients with ischemic heart disease (p?=?0.009). The transcriptional suppression of this PTPN22/CSK complex may have a noteworthy clinical relevance in RA patients
Association of smoking with amyotrophic lateral sclerosis risk and survival in men and women: a prospective study
<p>Abstract</p> <p>Background</p> <p>Previous epidemiologic studies have examined the association of smoking with amyotrophic lateral sclerosis (ALS) incidence, but their results have been inconsistent. Moreover, limited information exists on the association between smoking and survival in ALS patients. We evaluated the association of smoking with ALS incidence and survival in a population-based cohort.</p> <p>Methods</p> <p>We conducted a case-control study nested in the General Practice Research Database, a computerized clinical database in the United Kingdom. Cases were 1143 individuals with a diagnosis of ALS; 11,371 matched controls were selected among GPRD participants free of ALS. Predictors of survival were determined in the ALS cases. Smoking information was obtained from the computer database.</p> <p>Results</p> <p>Smoking was not associated with the risk of ALS in this population. The rate ratio (RR) of ALS comparing ever versus never smokers was 1.04, 95% confidence interval (CI) 0.80-1.34. In analysis stratified by gender, however, ever smoking was associated with ALS in women (RR 1.53, 95% CI 1.04-2.23) but not in men (RR 0.75, 95% CI 0.53-1.06). Mortality was 71% after 2.1 average years of follow-up. Old age and female sex were associated with lower survival. Smoking was a predictor of mortality only in women. Comparing ever versus never smokers, RR (95% CI) of death was 1.31 (1.04-1.65) in women, and 0.90 (0.72-1.11) in men.</p> <p>Conclusion</p> <p>In this large population-based study, smoking was associated with ALS risk and worse survival in women but not in men.</p
Bronchoscopist's perception of the quality of the single-use bronchoscope (Ambu aScope4™) in selected bronchoscopies: a multicenter study in 21 Spanish pulmonology services
Background: The disposable bronchoscope is an excellent alternative to face the problem of SARS-CoV-2 and other
cross infections, but the bronchoscopist’s perception of its quality has not been evaluated.
Methods: To evaluate the quality of the Ambu-aScope4 disposable bronchoscope, we carried out a cross-sectional
study in 21 Spanish pulmonology services. We use a standardized questionnaire completed by the bronchoscopists at
the end of each bronchoscopy. The variables were described with absolute and relative frequencies, measures of cen‑
tral tendency and dispersion depending on their nature. The existence of learning curves was evaluated by CUSUM
analysis.
Results: The most frequent indications in 300 included bronchoscopies was bronchial aspiration in 69.3% and the
median duration of these was 9.1 min. The route of entry was nasal in 47.2% and oral in 34.1%. The average score for
ease of use, image, and aspiration quality was 80/100. All the planned techniques were performed in 94.9% and the
bronchoscopist was satisfed in 96.6% of the bronchoscopies. They highlighted the portability and immediacy of the
aScope4TM to start the procedure in 99.3%, the possibility of taking and storing images in 99.3%. The CUSUM analysis showed average scores>70/100 from the frst procedure and from the 9th procedure more than 80% of the scores
exceeded the 80/100 score
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