95 research outputs found
Polarimetry and the High-Energy Emission Mechanisms in Quasar Jets. The Case of PKS 1136-135
Since the discovery of kiloparsec-scale X-ray emission from quasar jets, the
physical processes responsible for their high-energy emission have been poorly
defined. A number of mechanisms are under active debate, including synchrotron
radiation, inverse-Comptonized CMB (IC/CMB) emission, and other Comptonization
processes. In a number of cases, the optical and X-ray emission of jet regions
are inked by a single spectral component, and in those, high- resolution
multi-band imaging and polarimetry can be combined to yield a powerful
diagnostic of jet emission processes. Here we report on deep imaging photometry
of the jet of PKS 1136135 obtained with the {\it Hubble Space Telescope.} We
find that several knots are highly polarized in the optical, with fractional
polarization . When combined with the broadband spectral shape
observed in these regions, this is very difficult to explain via IC/CMB models,
unless the scattering particles are at the lowest-energy tip of the electron
energy distribution, with Lorentz factor , and the jet is also
very highly beamed () and viewed within a few degrees of the
line of sight. We discuss both the IC/CMB and synchrotron interpretation of the
X-ray emission in the light of this new evidence, presenting new models of the
spectral energy distribution and also the matter content of this jet. The high
polarizations do not completely rule out the possibility of IC/CMB
optical-to-X-ray emission in this jet, but they do strongly disfavor the model.
We discuss the implications of this finding, and also the prospects for future
work.Comment: 14 pages, 8 figures, ApJ in pres
Optical- & UV-Continuum Morphologies of Compact Radio Source Hosts
We present the first systematic search for UV signatures from radio
source-driven AGN feedback in Compact Steep Spectrum (CSS) radio galaxies.
Owing to their characteristic sub-galactic jets (1-20 kpc projected linear
sizes), CSS hosts are excellent laboratories for probing galaxy scale feedback
via jet-triggered star formation. The sample consists of 7 powerful CSS
galaxies, and 2 galaxies host to radio sources >20 kpc as control, at low to
intermediate redshifts (z<0.6). Our new HST images show extended UV continuum
emission in 6/7 CSS galaxies; with 5 CSS hosts exhibiting UV knots co-spatial
and aligned along the radio-jet axis. Young (5 M)
stellar populations are likely to be the dominant source of the blue excess
emission in radio galaxies at these redshifts. Hence, the radio-aligned UV
regions could be attributed to jet-induced starbursts. Lower near-UV SFRs
compared to other indicators suggests low scattered AGN light contribution to
the observed UV. Dust attenuation of UV emission appears unlikely from high
internal extinction correction estimates in most sources. Comparison with
evolutionary synthesis models shows that our observations are consistent with
recent (~1-8 Myr old) star forming activity likely triggered by current or an
earlier episode of radio emission, or by a confined radio source that has
frustrated growth due to a dense environment. While follow-up spectroscopic and
polarized light observations are needed to constrain the activity-related
components in the observed UV, the detection of jet-induced star formation is a
confirmation of an important prediction of the jet feedback paradigm.Comment: Submitted to Ap
XMM-NEWTON Detection of X-ray Emission from the Compact Steep Spectrum Radio Galaxy 3C303.1
Using XMM we detect faint unresolved X-ray emission from the Compact Steep
Spectrum radio galaxy 3C303.1. We detect a thermal component at kT = 0.8 keV
which seems likely to be produced in the ISM of the host galaxy. There is
evidence for a second component in the spectrum whose nature is currently
ambiguous. Plausible hypotheses for the second component include (1) hot gas
shocked by the expansion of the radio source, and (2) Synchrotron self-Compton
emission from the southern radio lobe if the magnetic field is below the
equipartition value by a factor of about 3.5
A multicentre, randomised, double-blind, single-dose study assessing the efficacy of AMC/DCBA Warm lozenge or AMC/DCBA Cool lozenge in the relief of acute sore throat
<p>Abstract</p> <p>Background</p> <p>Clinically proven over-the-counter (OTC) treatment options are becoming increasingly important in the self-management of acute sore throat. The aim of this study was to determine the analgesic and sensorial benefits of two different amylmetacresol/2,4-dichlorobenzyl alcohol (AMC/DCBA) throat lozenge formulation variants, AMC/DCBA Warm lozenge and AMC/DCBA Cool lozenge, compared with an unflavoured, non-medicated placebo lozenge in the relief of acute sore throat due to upper respiratory tract infections.</p> <p>Methods</p> <p>In this multicentre, randomised, double-blind, single-dose study, 225 adult patients with acute sore throat were randomly assigned to receive either one AMC/DCBA Warm lozenge (n = 77), one AMC/DCBA Cool lozenge (n = 74) or one unflavoured, non-medicated lozenge (matched for size, shape and demulcency; n = 74). After baseline assessments, patients received their assigned lozenge and completed four rating assessments at 11 timepoints from 1 to 120 minutes post dose. Analgesic properties were assessed by comparing severity of throat soreness and sore throat relief ratings. Difficulty in swallowing, throat numbness, functional, sensorial and emotional benefits were also assessed.</p> <p>Results</p> <p>Both the AMC/DCBA Warm and AMC/DCBA Cool lozenge induced significant analgesic, functional, sensorial and emotional effects compared with the unflavoured, non-medicated lozenge. Sore throat relief, improvements in throat soreness and difficulty in swallowing, and throat numbness were observed as early as 1-5 minutes, and lasted up to 2 hours post dose. Sensorial benefits of warming and cooling associated with the AMC/DCBA Warm and AMC/DCBA Cool lozenge, respectively, were experienced soon after first dose, and in the case of the latter, it lasted long after the lozenge had dissolved. Emotional benefits of feeling better, happier, less distracted and less frustrated were reported in those taking either of the AMC/DCBA throat lozenge variants, with no differences in adverse events compared with the unflavoured, non-medicated lozenge.</p> <p>Conclusions</p> <p>AMC/DCBA Warm and AMC/DCBA Cool lozenges are well-tolerated and effective OTC treatment options, offering functional, sensorial and emotional benefits to patients with acute sore throat, over and above that of the rapid efficacy effects provided.</p> <p>Trial registration</p> <p>ISRCTN: <a href="http://www.controlled-trials.com/ISRCTN00003567">ISRCTN00003567</a></p
Genome-wide association study identifies a variant in HDAC9 associated with large vessel ischemic stroke
Genetic factors have been implicated in stroke risk but few replicated associations have been reported. We conducted a genome-wide association study (GWAS) in ischemic stroke and its subtypes in 3,548 cases and 5,972 controls, all of European ancestry. Replication of potential
signals was performed in 5,859 cases and 6,281 controls. We replicated reported associations between variants close to PITX2 and ZFHX3 with cardioembolic stroke, and a 9p21 locus with large vessel stroke. We identified a novel association for a SNP within the histone deacetylase 9(HDAC9) gene on chromosome 7p21.1 which was associated with large vessel stroke including additional replication in a further 735 cases and 28583 controls (rs11984041, combined P =
1.87×10−11, OR=1.42 (95% CI) 1.28-1.57). All four loci exhibit evidence for heterogeneity of effect across the stroke subtypes, with some, and possibly all, affecting risk for only one subtype. This suggests differing genetic architectures for different stroke subtypes
Formations of European modernity: a historical and political sociology of Europe
This book seeks to provide an interpretation of the idea of Europe through an analysis of the course of European history. It aims to discover the structure of qualitative shifts in the relation between state, society and individual, how they occurred and what were their consequences for the formation of social and culture structures for European history. The book makes a major contribution to the debate on the idea of Europe and offers an interdisciplinary approach drawing especially from history, sociology and political theory, but also from geography and anthropology. The theoretical objective of is to make sense of the course of European history through an account of the formation of a European cultural model that emerges out of the legacies of the inter-civilizational background. It considers how in relation to this cultural model a societal structure takes shape. The tension between both gives form to Europe’s path to modernity and defines the specificity of its heritage. The structuring process that has shaped Europe made possible a model of modernity that has placed a strong emphasis on the values of social justice and solidarity. These values have been reflectively appropriated in different periods to produce different interpretations, societal outcomes and a multiplicity of projects of modernity
Variants at APOE influence risk of deep and lobar intracerebral hemorrhage
Objective Prior studies investigating the association between APOE alleles ε2/ε4 and risk of intracerebral hemorrhage (ICH) have been inconsistent and limited to small sample sizes, and did not account for confounding by population stratification or determine which genetic risk model was best applied. Methods We performed a large-scale genetic association study of 2189 ICH cases and 4041 controls from 7 cohorts, which were analyzed using additive models for ε2 and ε4. Results were subsequently meta-analyzed using a random effects model. A proportion of the individuals (322 cases, 357 controls) had available genome-wide data to adjust for population stratification. Results Alleles ε2 and ε4 were associated with lobar ICH at genome-wide significance levels (odds ratio [OR] = 1.82, 95% confidence interval [CI] = 1.50–2.23, p = 6.6 × 10 −10 ; and OR = 2.20, 95%CI = 1.85–2.63, p = 2.4 × 10 −11 , respectively). Restriction of analysis to definite/probable cerebral amyloid angiopathy ICH uncovered a stronger effect. Allele ε4 was also associated with increased risk for deep ICH (OR = 1.21, 95% CI = 1.08–1.36, p = 2.6 × 10 −4 ). Risk prediction evaluation identified the additive model as best for describing the effect of APOE genotypes. Interpretation APOE ε2 and ε4 are independent risk factors for lobar ICH, consistent with their known associations with amyloid biology. In addition, we present preliminary findings on a novel association between APOE ε4 and deep ICH. Finally, we demonstrate that an additive model for these APOE variants is superior to other forms of genetic risk modeling previously applied. ANN NEUROL 2010Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78478/1/22134_ftp.pd
Genetic overlap between diagnostic subtypes of ischemic stroke
Background and Purpose: Despite moderate heritability, the phenotypic heterogeneity of ischemic stroke has hampered gene discovery, motivating analyses of diagnostic subtypes with reduced sample sizes. We assessed evidence for a shared genetic basis among the 3 major subtypes: large artery atherosclerosis (LAA), cardioembolism, and small vessel disease (SVD), to inform potential cross-subtype analyses. Methods: Analyses used genome-wide summary data for 12 389 ischemic stroke cases (including 2167 LAA, 2405 cardioembolism, and 1854 SVD) and 62 004 controls from the Metastroke consortium. For 4561 cases and 7094 controls, individual-level genotype data were also available. Genetic correlations between subtypes were estimated using linear mixed models and polygenic profile scores. Meta-analysis of a combined LAA-SVD phenotype (4021 cases and 51 976 controls) was performed to identify shared risk alleles. Results: High genetic correlation was identified between LAA and SVD using linear mixed models (rg=0.96, SE=0.47, P=9×10-4) and profile scores (rg=0.72; 95% confid
COL4A2 is associated with lacunar ischemic stroke and deep ICH: Meta-analyses among 21,500 cases and 40,600 controls
Objective: To determine whether common variants in familial cerebral small vessel disease (SVD) genes confer risk of sporadic cerebral SVD. Methods: We meta-analyzed genotype data from individuals of European ancestry to determine associations of common single nucleotide polymorphisms (SNPs) in 6 familial cerebral SVD genes (COL4A1, COL4A2, NOTCH3, HTRA1, TREX1, and CECR1) with intracerebral hemorrhage (ICH) (deep, lobar, all; 1,878 cases, 2,830 controls) and ischemic stroke (IS) (lacunar, cardioembolic, large vessel disease, all; 19,569 cases, 37,853 controls). We applied data quality filters and set statistical significance thresholds accounting for linkage disequilibrium and multiple testing. Results: A locus in COL4A2 was associated (significance threshold p , 3.5 3 1024) with both lacunar IS (lead SNP rs9515201: odds ratio [OR] 1.17, 95%confidence interval [CI] 1.11-1.24, p 56.62 31028) and deep ICH (lead SNP rs4771674: OR 1.28, 95%CI 1.13-1.44, p 55.76 3 1025). A SNP in HTRA1 was associated (significance threshold p , 5.5 3 1024) with lacunar IS (rs79043147: OR 1.23, 95%CI 1.10-1.37, p 5 1.90 3 1024) and less robustly with deep ICH. There was no clear evidence for association of common variants in either COL4A2 or HTRA1 with non-SVD strokes or in any of the other genes with any stroke phenotype
No additional prognostic value of genetic information in the prediction of vascular events after cerebral ischemia of arterial origin
Background: Patients who have suffered from cerebral ischemia have a high risk of recurrent vascular events. Predictive models based on classical risk factors typically have limited prognostic value. Given that cerebral ischemia has a heritable component, genetic information might improve performance of these risk models. Our aim was to develop and compare two models: one containing traditional vascular risk factors, the other also including genetic information. Methods and Results: We studied 1020 patients with cerebral ischemia and genotyped them with the Illumina Immunochip. Median follow-up time was 6.5 years; the annual incidence of new ischemic events (primary outcome, n=198) was 3.0%. The prognostic model based on classical vascular risk factors had an area under the receiver operating characteristics curve (AUC-ROC) of 0.65 (95% confidence interval 0.61-0.69). When we added a genetic risk score based on prioritized SNPs from a genome-wide association study of ischemic stroke (using summary statistics from the METASTROKE study which included 12389 cases and 62004 controls), the AUC-ROC remained the same. Similar results were found for the secondary outcome ischemic stroke. Conclusions: We found no additional value of genetic information in a prognostic model for the risk of ischemic events in patients with cerebral ischemia of arterial origin. This is consistent with a complex, polygenic architecture, where many genes of weak effect likely act in concert to influence the heritable risk of an individual to develop (recurrent) vascular events. At present, genetic information cannot help clinicians to distinguish patients at high risk for recurrent vascular events
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