13,045 research outputs found
Evidence of Environmental Quenching at Redshift z ~ 2
We report evidence of environmental quenching among galaxies at redshift ~ 2,
namely the probability that a galaxy quenches its star formation activity is
enhanced in the regions of space in proximity of other quenched, more massive
galaxies. The effect is observed as strong clustering of quiescent galaxies
around quiescent galaxies on angular scales \theta < 20 arcsec, corresponding
to a proper(comoving) scale of 168 (502) kpc at z = 2. The effect is observed
only for quiescent galaxies around other quiescent galaxies; the probability to
find star-forming galaxies around quiescent or around star-forming ones is
consistent with the clustering strength of galaxies of the same mass and at the
same redshift, as observed in dedicated studies of galaxy clustering. The
effect is mass dependent in the sense that the quenching probability is
stronger for galaxies of smaller mass () than for more
massive ones, i.e. it follows the opposite trend with mass relative to
gravitational galaxy clustering. The spatial scale where the effect is observed
suggests these environments are massive halos, in which case the observed
effect would likely be satellite quenching. The effect is also redshift
dependent in that the clustering strength of quiescent galaxies around other
quiescent galaxies at z = 1.6 is ~ 1.7 times larger than that of the galaxies
with the same stellar mass at z = 2.6. This redshift dependence allows for a
crude estimate of the time scale of environmental quenching of low-mass
galaxies, which is in the range 1.5 - 4 Gyr, in broad agreement with other
estimates and with our ideas on satellite quenching.Comment: 12 pages, 9 figures, Accepted for publication in Ap
How do Doctors Decide When to Prescribe Antibiotics in Upper Respiratory Tract Infections?
Purpose: To examine the predictive features which doctors use when prescribing antibiotics in upper respiratory tract infections (URTIs). Method: This is a cross sectional, prospective study done in a teaching university primary care centre in Kuala Lumpur from June to August 2000. Twelve primary care practitioners participated in the study. Each practitioner was asked to record clinical data and prescriptions given to twenty consecutive patients with URTIs using a structured questionnaire for each patient
Metabolism of ticagrelor in patients with acute coronary syndromes.
© The Author(s) 2018Ticagrelor is a state-of-the-art antiplatelet agent used for the treatment of patients with acute coronary syndromes (ACS). Unlike remaining oral P2Y12 receptor inhibitors ticagrelor does not require metabolic activation to exert its antiplatelet action. Still, ticagrelor is extensively metabolized by hepatic CYP3A enzymes, and AR-C124910XX is its only active metabolite. A post hoc analysis of patient-level (n = 117) pharmacokinetic data pooled from two prospective studies was performed to identify clinical characteristics affecting the degree of AR-C124910XX formation during the first six hours after 180 mg ticagrelor loading dose in the setting of ACS. Both linear and multiple regression analyses indicated that ACS patients presenting with ST-elevation myocardial infarction or suffering from diabetes mellitus are more likely to have decreased rate of ticagrelor metabolism during the acute phase of ACS. Administration of morphine during ACS was found to negatively influence transformation of ticagrelor into AR-C124910XX when assessed with linear regression analysis, but not with multiple regression analysis. On the other hand, smoking appears to increase the degree of ticagrelor transformation in ACS patients. Mechanisms underlying our findings and their clinical significance warrant further research.Peer reviewedFinal Published versio
Do Primary Care Doctors Behave the Same in Antibiotic Prescribing for Upper Respiratory Tract Infections?
Purpose: To compare the extent of using an evidence-based approach in managing upper respiratory tract infections (URTIs) among primary care doctors from two different government clinic settings in Malaysia. Method: This is a cross sectional, prospective study carried out in a teaching university primary care centre in Kuala Lumpur (KL) where doctors are constantly exposed to continuing medical education (CME) and seven health clinics in Seremban, Malaysia where doctors have less exposure to CME in the year 2000. Twelve primary care practitioners in KL and 13 in Seremban participated in the study. Each practitioner was asked to record clinical data and prescriptions given to twenty consecutive patients with URTIs using a structured questionnaire for each patient. The extent of usage of an evidence-based approach in managing URTIs among practitioners was assessed
Are Doctors in the University-Based Primary Care Clinic More Evidence-Based?
Letter to the editor
Exploring the Dust Content of Galactic Winds with Herschel. I. NGC 4631
We present a detailed analysis of deep far-infrared observations of the
nearby edge-on star-forming galaxy NGC 4631 obtained with the Herschel Space
Observatory. Our PACS images at 70 and 160 um show a rich complex of filaments
and chimney-like features that extends up to a projected distance of 6 kpc
above the plane of the galaxy. The PACS features often match extraplanar
Halpha, radio-continuum, and soft X-ray features observed in this galaxy,
pointing to a tight disk-halo connection regulated by star formation. On the
other hand, the morphology of the colder dust component detected on larger
scale in the SPIRE 250, 350, and 500 um data matches the extraplanar H~I
streams previously reported in NGC 4631 and suggests a tidal origin. The PACS
70/160 ratios are elevated in the central ~3.0 kpc region above the nucleus of
this galaxy (the "superbubble"). A pixel-by-pixel analysis shows that dust in
this region has a higher temperature and/or an emissivity with a steeper
spectral index (beta > 2) than the dust in the disk, possibly the result of the
harsher environment in the superbubble. Star formation in the disk seems
energetically insufficient to lift the material out of the disk, unless it was
more active in the past or the dust-to-gas ratio in the superbubble region is
higher than the Galactic value. Some of the dust in the halo may also have been
tidally stripped from nearby companions or lifted from the disk by galaxy
interactions.Comment: Accepted for publication in The Astrophysical Journa
Experimental quantum "Guess my Number" protocol using multiphoton entanglement
We present an experimental demonstration of a modified version of the
entanglement-assisted "Guess my Number" protocol for the reduction of
communication complexity among three separated parties. The results of
experimental measurements imply that the separated parties can compute a
function of distributed inputs by exchanging less classical information than by
using any classical strategy. And the results also demonstrate the advantages
of entanglement-enhanced communication, which is very close to quantum
communication. The advantages are based on the properties of
Greenberger-Horne-Zeilinger states.Comment: 4 pages, 2 figure
A New Viscosity Equation For Bin Aqueous Solutions.
An equation for the viscosity of binary aqueous solutions has been derived based on the Power law equation and Erying's absolute rate theory. The concentration dependent equation for viscosities of binary aqueous systems is derived using additive contribution from water and solute component. The equation has sufficient degree of freedom to represent the' whole range of concentration. The equation has been applied to 12 nonelectrolyte aqueous systems and 10 electrolyte systems at various temperatures. An average absolute deviation percentage error' (AAD%) of 0.2856% is reported for electrolyte systems: For non-electrolyte systems an average AAD% of 0.7843% is reported. Overall, the equation is found to have yielded an AAD% of 0.5576%
Famine Early Warning Systems Network (FEWS NET) Land Data Assimilation System (LDAS) and Other Assimilated Hydrological Data at NASA GES DISC
The NASA Goddard Earth Sciences Data and Information Services Center (GES DISC) provides science support for several data sets relevant to agriculture and food security, including the Famine Early Warning Systems Network (FEWS NET) Land Data Assimilation System (LDAS), or FLDAS data set. The GES DISC is one of twelve NASA Earth Observing System (EOS) data centers that process, archive, document, and distribute data from Earth science missions and related projects. The GES DISC hosts a wide range of remote sensing and model data, and provides reliable and robust data access and other services to users worldwide. Beyond data archive and access, the GES DISC offers many services to visualize and analyze the data. This presentation provides a summary of the hydrological data available at the GES DISC, along with an overview of related data services. Specifically, the FLDAS data set has been adapted to work with domains, data streams, and monitoring and forecast requirements associated with food security assessment in data-sparse, developing country settings. The FLDAS global monthly data have a 0.1 x 0.1 degree spatial resolution covering the period from January 1982 to present. Global FLDAS monthly anomaly and monthly climatology data are also available at the GES DISC to evaluate how current conditions compare to averages over the FLDAS 35-year period. Several case studies using the FLDAS soil moisture, evapotranspiration, rainfall, runoff, and surface temperature data will be presented
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