259 research outputs found
Carbonaceous material fractions in sediments and their effect on the sorption and persistence of organic pollutants in small urban watersheds
U.S. Department of the InteriorU.S. Geological SurveyOpe
Interplay of Dirac nodes and Volkov-Pankratov surface states in compressively strained HgTe
Preceded by the discovery of topological insulators, Dirac and Weyl
semimetals have become a pivotal direction of research in contemporary
condensed matter physics. While easily accessible from a theoretical viewpoint,
these topological semimetals pose a serious challenge in terms of experimental
synthesis and analysis to allow for their unambiguous identification. In this
work, we report on detailed transport experiments on compressively strained
HgTe. Due to the superior sample quality in comparison to other topological
semimetallic materials, this enables us to resolve the interplay of topological
surface states and semimetallic bulk states to an unprecedented degree of
precision and complexity. As our gate design allows us to precisely tune the
Fermi level at the Weyl and Dirac points, we identify a magnetotransport regime
dominated by Weyl/Dirac bulk state conduction for small carrier densities and
by topological surface state conduction for larger carrier densities. As such,
similar to topological insulators, HgTe provides the archetypical reference for
the experimental investigation of topological semimetals.Comment: 8 pages, 7 figures, accepted in PRX, added kp calculation and
supplementar
Feasibility of the Manchester Acute Coronary Syndromes (MACS) decision rule to safely reduce unnecessary hospital admissions: a pilot randomised controlled trial
Background Observational studies suggest that the Manchester Acute Coronary Syndromes (MACS) decision rule can effectively rule out' and rule in' acute coronary syndromes (ACS) following a single blood test. In a pilot randomised controlled trial, we aimed to determine whether a large trial is feasible. Methods Patients presenting to two EDs with suspected cardiac chest pain were randomised to receive care guided by the MACS decision rule (intervention group) or standard care (controls). The primary efficacy outcome was a successful discharge from the ED, defined as a decision to discharge within 4 hours of arrival providing that the patient did not have a missed acute myocardial infarction (AMI) or develop a major adverse cardiac event (MACE: death, AMI or coronary revascularisation) within 30 days. Feasibility outcomes included recruitment and attrition rates. Results In total, 138 patients were included between October 2013 and October 2014, of whom 131 (95%) were randomised (66 to intervention and 65 controls). Nine (7%) patients had prevalent AMI and six (5%) had incident MACE within 30 days. All 131 patients completed 30-day follow-up and were included in the final analysis with no missing data for the primary analyses. Compared with standard care, a significantly greater proportion of patients whose care was guided by the MACS rule were successfully discharged within 4 hours (26% vs 8%, adjusted OR 5.45, 95% CI 1.73 to 17.11, p=0.004). No patients in either group who were discharged within 4 hours had a diagnosis of AMI or incident MACE within 30 days (0.0%, 95% CI 0% to 20.0% in the intervention group). Conclusions In this pilot trial, use of the MACS rule led to a significant increase in safe discharges from the ED but a larger, fully powered trial remains necessary. Our findings seem to support the feasibility of that trial. Trial registration number ISRCTN 86818215. Research Ethics Committee reference 13/NW/0081. UKCRN registration ID 14334
Recital Christa Ludwig
Programa de mà del recital dut a terme per Christa Ludwig i Charles Spencer el 30 de novembre del 1991 i on es van intepretar les següents peçes: Geheimnis, Im Abendrot, Auf der Donau, Sehnsucht, Der Lindenbaum i Der Musensohn de Schubert ; Ich gign mit Lust, Rheinlegendchen, Das irrdische Leben, Ich bin der Welt abhanden gedommen i Um Mitternacht de Gustav Mahler ; Freudvoll und leidvoll, Du bist wie eine Blume i Die drei Zigeuner, de Franz Liszt ; Dein blaues Auge, An eine Äolsharfe, St¨ndchen i Immer leiser wird mein Schlummer, de Johannes Brahms ; Du meines Herzens Krönelein, Begegnung, Die Nacht, Ruhe, meine Seele i Morgen, de Richard Straus
Beyond the Ultra-deep Frontier Fields And Legacy Observations (BUFFALO): a high-resolution strong + weak-lensing view of Abell 370
The HST treasury program BUFFALO provides extended wide-field imaging of the
six Hubble Frontier Fields galaxy clusters. Here we present the combined strong
and weak-lensing analysis of Abell 370, a massive cluster at z=0.375. From the
reconstructed total projected mass distribution in the 6arcmin x 6arcmin
BUFFALO field-of-view, we obtain the distribution of massive substructures
outside the cluster core and report the presence of a total of seven
candidates, each with mass . Combining the
total mass distribution derived from lensing with multi-wavelength data, we
evaluate the physical significance of each candidate substructure, and conclude
that 5 out of the 7 substructure candidates seem reliable, and that the mass
distribution in Abell 370 is extended along the North-West and South-East
directions. While this finding is in general agreement with previous studies,
our detailed spatial reconstruction provides new insights into the complex mass
distribution at large cluster-centric radius. We explore the impact of the
extended mass reconstruction on the model of the cluster core and in
particular, we attempt to physically explain the presence of an important
external shear component, necessary to obtain a low root-mean-square separation
between the model-predicted and observed positions of the multiple images in
the cluster core. The substructures can only account for up to half the
amplitude of the external shear, suggesting that more effort is needed to fully
replace it by more physically motivated mass components. We provide public
access to all the lensing data used as well as the different lens models.Comment: 29 pages, 17 figures, 3 table
Cardiorespiratory fitness, adiposity and incident asthma in adults
Available large-scale prospective studies on adiposity and asthma used body mass index as an
indicator of adiposity.
Studies involving more accurate measures of adiposity, such as body
fat percentage (BF%), are needed to confirm or contrast body mass index - related results.
Cardiorepiratory fitness is a strong predictor of morbidity and mortality,
and the available
literature suggests that moderate-high cardiorespiratory fitness reduces many of the health
hazards associated with obesity.
The present study aimed: 1) to examine whether
cardiorespiratory fitness and/or BF% are associated with subsequent acquisition of asthma in
adults; and 2) to test the hypothesis that a high cardiorespiratory fitness level can reduce the
risk of incident asthma in individuals with excess adiposity
BUFFALO/Flashlights: Constraints on the abundance of lensed supergiant stars in the Spock galaxy at redshift 1
In this work, we present a constraint on the abundance of supergiant (SG) stars at redshift z ≈ 1, based on recent observations of astrongly lensed arc at this redshift. First we derived a free-form model of MACS J0416.1-2403 using data from the Beyond Ultradeep Frontier Fields and Legacy Observations (BUFFALO) program. The new lens model is based on 72 multiply lensed galaxies thatproduce 214 multiple images, making it the largest sample of spectroscopically confirmed lensed galaxies on this cluster. The largercoverage in BUFFALO allowed us to measure the shear up to the outskirts of the cluster, and extend the range of lensing constraintsup to ∼1 Mpc from the central region, providing a mass estimate up to this radius. As an application, we make predictions for thenumber of high-redshift multiply lensed galaxies detected in future observations with the James Webb Space Telescope (JWST).Then we focus on a previously known lensed galaxy at z = 1.0054, nicknamed Spock, which contains four previously reportedtransients. We interpret these transients as microcaustic crossings of SG stars and explain how we computed the probability of suchevents. Based on simplifications regarding the stellar evolution, we find that microlensing (by stars in the intracluster medium) ofSG stars at z = 1.0054 can fully explain these events. The inferred abundance of SG stars is consistent with either (1) a numberdensity of stars with bolometric luminosities beyond the Humphreys-Davidson (HD) limit (Lmax ≈ 6 × 105 L for red stars), whichis below ∼400 stars kpc−2, or (2) the absence of stars beyond the HD limit but with a SG number density of ∼9000 kpc−2 for starswith luminosities between 105 L and 6 × 105 L. This is equivalent to one SG star per 10 × 10 pc2. Finally, we make predictions forfuture observations with JWST’s NIRcam. We find that in observations made with the F200W filter that reach 29 mag AB, if cool red SG stars exist at z ≈ 1 beyond the HD limit, they should be easily detected in this arc
BUFFALO/Flashlights: Constraints on the abundance of lensed supergiant stars in the Spock galaxy at redshift 1
We present a constraint on the abundance of supergiant (SG) stars at redshift
z approx. 1, based on recent observations of a strongly lensed arc at this
redshift. First we derive a free-form model of MACS J0416.1-2403 using data
from the BUFFALO program. The new lens model is based on 72 multiply lensed
galaxies that produce 214 multiple images, making it the largest sample of
spectroscopically confirmed lensed galaxies on this cluster. The larger
coverage in BUFFALO allows us to measure the shear up to the outskirts of the
cluster, and extend the range of lensing constraints up to ~ 1 Mpc from the
central region, providing a mass estimate up to this radius. As an application,
we make predictions for the number of high-redshift multiply-lensed galaxies
detected in future observations with JWST. Then we focus on a previously known
lensed galaxy at z=1.0054, nicknamed Spock, which contains four previously
reported transients. We interpret these transients as microcaustic crossings of
SG stars and compute the probability of such events. Based on simplifications
regarding the stellar evolution, we find that microlensing (by stars in the
intracluster medium) of SG stars at z=1.0054 can fully explain these events.
The inferred abundance of SG stars is consistent with either (1) a number
density of stars with bolometric luminosities beyond the Humphreys-Davidson
(HD) limit (L ~ ) that is below 400 stars per sq. kpc,
or (2) the absence of stars beyond the HD limit but with a SG number density of
~ 9000 per sq. kpc for stars with luminosities between and
. This is equivalent to one SG star per 10x10 pc. We finally
make predictions for future observations with JWST's NIRcam. We find that in
observations made with the F200W filter that reach 29 mag AB, if cool red SG
stars exist at z~1 beyond the HD limit, they should be easily detected in this
arcComment: 24 pages & 18 figure
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