462 research outputs found
Wind from the black-hole accretion disk driving a molecular outflow in an active galaxy
Powerful winds driven by active galactic nuclei (AGN) are often invoked to
play a fundamental role in the evolution of both supermassive black holes
(SMBHs) and their host galaxies, quenching star formation and explaining the
tight SMBH-galaxy relations. Recent observations of large-scale molecular
outflows in ultra-luminous infrared galaxies (ULIRGs) have provided the
evidence to support these studies, as they directly trace the gas out of which
stars form. Theoretical models suggest an origin of these outflows as
energy-conserving flows driven by fast AGN accretion disk winds. Previous
claims of a connection between large-scale molecular outflows and AGN activity
in ULIRGs were incomplete because they were lacking the detection of the
putative inner wind. Conversely, studies of powerful AGN accretion disk winds
to date have focused only on X-ray observations of local Seyferts and a few
higher redshift quasars. Here we show the clear detection of a powerful AGN
accretion disk wind with a mildly relativistic velocity of 0.25c in the X-ray
spectrum of IRAS F11119+3257, a nearby (z = 0.189) optically classified type 1
ULIRG hosting a powerful molecular outflow. The AGN is responsible for ~80% of
the emission, with a quasar-like luminosity of L_AGN = 1.5x10^46 erg/s. The
energetics of these winds are consistent with the energy-conserving mechanism,
which is the basis of the quasar mode feedback in AGN lacking powerful radio
jets.Comment: Revised file including the letter, methods and supplementary
information. Published in the March 26th 2015 issue of Natur
Effectiveness of dry needling on reducing pain intensity in patients with myofascial pain syndrome: a Meta-analysis
AbstractObjectiveTo summarize the literature about the effectiveness of dry needling (DN) on relieving pain and increasing range of motion (ROM) in individuals with myofascial pain syndrome (MPS).MethodsPapers published from January 2000 to January 2013 were identified through an electronic search in the databases MEDLINE, Dialnet, Cochrane Library Plus, Physiotherapy Evidence Database (PEDro) and Spanish Superior Council of Scientific Research (CSIC). The studies included were randomized controlled trials written in English and/or Spanish about the effectiveness of DN on pain and ROM in individuals with MPS.ResultsOut of 19 clinical trials that were potentially relevant, a total of 10 were included in the Meta-analysis. Regarding pain intensity reduction when measured before and immediately after the intervention, DN achieved improvement compared with the placebo treatment [d = − 0.49; 95% CI (− 3.21, 0.42)] and with the control group [d = − 9.13; 95% CI (− 14.70, − 3.56)]. However, other treatments achieved better results on the same variable compared with DN, considering the measurements for pre-treatment and immediately after [d = 2.54; 95% CI (− 0.40, 5.48)], as well as the pre-treatment and after 3-4 weeks [d = 4.23; 95% CI (0.78, 7.68)]. DN showed a significantly increased ROM when measured before the intervention and immediately after, in comparison with the placebo [d = 2.00; 95% CI (1.60, 2.41)]. However, other treatments achieved a significant better result regarding ROM when it was measured before the intervention and immediately after, as compared with DN [d = −1.42; 95% CI (− 1.84, − 0.99)].ConclusionDN was less effective on decreasing pain comparing to the placebo group. Other treatments were more effective than DN on reducing pain after 3-4 weeks. However, on increasing ROM, DN was more effective comparing to that of placebo group, but less than other treatments
Real-space mapping of tailored sheet and edge plasmons in graphene nanoresonators
Plasmons in graphene nanoresonators have many potential applications in photonics and optoelectronics, including room-temperature infrared and terahertz photodetectors, sensors, reflect arrays or modulators1, 2, 3, 4, 5, 6, 7. The development of efficient devices will critically depend on precise knowledge and control of the plasmonic modes. Here, we use near-field microscopy8, 9, 10, 11 between λ0 = 10–12 μm to excite and image plasmons in tailored disk and rectangular graphene nanoresonators, and observe a rich variety of coexisting Fabry–Perot modes. Disentangling them by a theoretical analysis allows the identification of sheet and edge plasmons, the latter exhibiting mode volumes as small as 10−8λ03. By measuring the dispersion of the edge plasmons we corroborate their superior confinement compared with sheet plasmons, which among others could be applied for efficient 1D coupling of quantum emitters12. Our understanding of graphene plasmon images is a key to unprecedented in-depth analysis and verification of plasmonic functionalities in future flatland technologies.Peer ReviewedPostprint (author's final draft
Reaction rates and transport in neutron stars
Understanding signals from neutron stars requires knowledge about the
transport inside the star. We review the transport properties and the
underlying reaction rates of dense hadronic and quark matter in the crust and
the core of neutron stars and point out open problems and future directions.Comment: 74 pages; commissioned for the book "Physics and Astrophysics of
Neutron Stars", NewCompStar COST Action MP1304; version 3: minor changes,
references updated, overview graphic added in the introduction, improvements
in Sec IV.A.
Maternal Serum Meteorin Levels and the Risk of Preeclampsia
BACKGROUND: Meteorin (METRN) is a recently described neutrophic factor with angiogenic properties. This is a nested case-control study in a longitudinal cohort study that describes the serum profile of METRN during different periods of gestation in healthy and preeclamptic pregnant women. Moreover, we explore the possible application of METRN as a biomarker. METHODS AND FINDINGS: Serum METRN was measured by ELISA in a longitudinal prospective cohort study in 37 healthy pregnant women, 16 mild preeclamptic women, and 20 healthy non-pregnant women during the menstrual cycle with the aim of assessing serum METRN levels and its correlations with other metabolic parameters. Immunostaining for METRN protein was performed in placenta. A multivariate logistic regression model was proposed and a classifier model was formulated for predicting preeclampsia in early and middle pregnancy. The performance in classification was evaluated using measures such as sensitivity, specificity, and the receiver operating characteristic (ROC) curve. In healthy pregnant women, serum METRN levels were significantly elevated in early pregnancy compared to middle and late pregnancy. METRN levels are significantly lower only in early pregnancy in preeclamptic women when compared to healthy pregnant women. Decision trees that did not include METRN levels in the first trimester had a reduced sensitivity of 56% in the detection of preeclamptic women, compared to a sensitivity of 69% when METRN was included. CONCLUSIONS: The joint measurements of circulating METRN levels in the first trimester and systolic blood pressure and weight in the second trimester significantly increase the probabilities of predicting preeclampsia
Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC
The uncertainty on the calorimeter energy response to jets of particles is
derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the
calorimeter response to single isolated charged hadrons is measured and
compared to the Monte Carlo simulation using proton-proton collisions at
centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009
and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter
response to specific types of particles (positively and negatively charged
pions, protons, and anti-protons) is measured and compared to the Monte Carlo
predictions. Finally, the jet energy scale uncertainty is determined by
propagating the response uncertainty for single charged and neutral particles
to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3%
for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table,
submitted to European Physical Journal
Constraints on the braneworld from compact stars
According to the braneworld idea, ordinary matter is confined on a three-dimensional space (brane) that is embedded in a higher-dimensional space-time where
gravity propagates. In this work, after reviewing the limits coming from general relativity, finiteness of pressure and causality on the brane, we derive observational constraints on the braneworld parameters from the existence of stable compact stars. The analysis is carried out by solving numerically the brane-modified Tolman–Oppenheimer–Volkoff equations, using different representative equations
of state to describe matter in the star interior. The cases of normal dense matter, pure quark matter and hybrid matter are considered.info:eu-repo/semantics/publishedVersio
Measurement of the production cross section for W-bosons in association with jets in pp collisions at s=7 TeV with the ATLAS detector
Association of common ATM variants with familial breast cancer in a South American population
Background: The ATM gene has been frequently involved in hereditary breast cancer as a low-penetrance susceptibility gene but evidence regarding the role of ATM as a breast cancer susceptibility gene has been contradictory.
Methods: In this study, a full mutation analysis of the ATM gene was carried out in patients from 137 Chilean breast cancer families, of which 126 were BRCA1/2 negatives and 11 BRCA1/2 positives. We further perform a case-control study between the subgroup of 126 cases BRCA1/2 negatives and 200 controls for the 5557G > A missense variant and the IVS38-8T > C and the IVS24-9delT polymorphisms.
Results: In the full mutation analysis we detected two missense variants and eight intronic polymorphisms. Carriers of the variant IVS24-9delT, or IVS38-8T > C, or 5557G > A showed an increase in breast cancer risk. The higher significance was observed in the carriers of IVS38-8T > C (OR = 3.09 [95% CI 1.11-8.59], p = 0.024). The IVS24-9 T/(-T), IVS38-8 T/C, 5557 G/A composite genotype confered a 3.19 fold increase in breast cancer risk (OR = 3.19 [ 95% CI 1.16-8.89], p = 0.021). The haplotype estimation suggested a strong linkage disequilibrium between the three markers (D' = 1). We detected only three haplotypes in the cases and control samples, some of these may be founder haplotypes in the Chilean population.
Conclusion: The IVS24-9 T/(-T), IVS38-8 T/C, 5557 G/A composite genotype alone or in combination with certain genetic background and/or environmental factors, could modify the cancer risk by increasing genetic inestability or by altering the effect of the normal DNA damage response
Calculating Ensemble Averaged Descriptions of Protein Rigidity without Sampling
Previous works have demonstrated that protein rigidity is related to thermodynamic stability, especially under conditions that favor formation of native structure. Mechanical network rigidity properties of a single conformation are efficiently calculated using the integer body-bar Pebble Game (PG) algorithm. However, thermodynamic properties require averaging over many samples from the ensemble of accessible conformations to accurately account for fluctuations in network topology. We have developed a mean field Virtual Pebble Game (VPG) that represents the ensemble of networks by a single effective network. That is, all possible number of distance constraints (or bars) that can form between a pair of rigid bodies is replaced by the average number. The resulting effective network is viewed as having weighted edges, where the weight of an edge quantifies its capacity to absorb degrees of freedom. The VPG is interpreted as a flow problem on this effective network, which eliminates the need to sample. Across a nonredundant dataset of 272 protein structures, we apply the VPG to proteins for the first time. Our results show numerically and visually that the rigidity characterizations of the VPG accurately reflect the ensemble averaged properties. This result positions the VPG as an efficient alternative to understand the mechanical role that chemical interactions play in maintaining protein stability
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