2,619 research outputs found
Measurement of the ÎS=-ÎQ Amplitude from K_(e3)^0 Decay
We have measured the time distribution of the Ï^+e^-Îœ and Ï^-e^+Îœ modes from initial K^0's in a spark-chamber experiment performed at the Bevatron. From 1079 events between 0.2 and 7 K_S^0 lifetime, we find ReX=-0.069±0.036, ImX=+0.108_(-0.074)^(+0.092). This result is consistent with X=0 (relative probability = 0.25), but more than 4 standard deviations from the existing world average, +0.14 -0.13i
Measurement of the electron electric dipole moment using GdIG
A new method for the detection of the electron edm using a solid is
described. The method involves the measurement of a voltage induced across the
solid by the alignment of the samples magnetic dipoles in an applied magnetic
field, H. A first application of the method to GdIG has resulted in a limit on
the electron edm of 5E-24 e-cm, which is a factor of 40 below the limit
obtained from the only previous solid-state edm experiment. The result is
limited by the imperfect discrimination of an unexpectedly large voltage that
is even upon the reversal of the sample magnetization.Comment: 10 pages, 5 figures, v2:references corrected, submitted to PRL,
v3:added labels to figure
Factors Controlling Porosity and Permeability in the Curdsville Member of the Lexington Limestone
Factors controlling the porosity and permeability of the Curdsville Limestone Member of the Lexington Limestone of Middle Ordovician Age in the Blue Grass Region of Kentucky are geological.
Microstratigraphic analysis had led to the division of the lower Lexington Limestone, consisting principally of the Curdsville Member into three beds which may be subdivided into zones made up of several lithologic types and sub-types. Lower, middle, and upper bed characteristics are helpful in determining the regional depositional history in the progressively transgressing Curdsville sea. Paleogeography of Curdsville time has been determined by delineation of two local facies: (1) a carbonate bank--shoal area facies, and (2) a shelf--channel area facies.
Permeable carbonate bank--shoal facies are best developed on the structurally high Jessamine Dome Shoal Area where the Curdsville Limestone is found at shallow depth. Ground waters of meteoric origin have created sink holes, solution valleys, and caverns through solution enlargement of fractures comprising an extensive intersecting joint system.
Detailed examination of the Bryantsville Quadrangle on the Jessamine Dome Shoal Area indicates that fracture traces such as sink hole, solution valley, and stream channel alignments are controlled mainly by nearly vertical joints in the Curdsville and underlying Tyrone Limestones. High frequency and intersection of joint fractures may indicate the presence of permeable limestone aquifers at shallow depth, The hypothesis can be tested by drilling several wells in prospective areas
âIâm my own bossâŠâ: Active intermediation and âentrepreneurialâ worker agency in the Australian gig-economy
Platform firm in the gig-economy are disrupting work as a social practice, production systems and recasting capital-labour relations. This qualitative study examines worker agency in the Australian food-delivery sector; a segment where platforms actively intermediate both product and labour markets. Within this sector, worker agency poses a potential challenge to platform-organisations; however this study reveals how these platformsâ work organisation and market regulation constrain agency potential. Shaped by the workâs spatio-temporal features, organisational fixes and institutional context, it is shown how food-delivery workers, transiently attached to the labour market, predominantly engage in âentrepreneurial agencyâ â a low-level agency expression aimed at materially improving individual conditions and aligning with, rather than challenging, platformsâ business models
Disentangling the circumnuclear environs of Centaurus A: II. On the nature of the broad absorption line
We report on atomic gas (HI) and molecular gas (as traced by CO(2-1))
redshifted absorption features toward the nuclear regions of the closest
powerful radio galaxy, Centaurus A (NGC 5128). Our HI observations using the
Very Long Baseline Array allow us to discern with unprecedented sub-parsec
resolution HI absorption profiles toward different positions along the 21 cm
continuum jet emission in the inner 0."3 (or 5.4 pc). In addition, our CO(2-1)
data obtained with the Submillimeter Array probe the bulk of the absorbing
molecular gas with little contamination by emission, not possible with previous
CO single-dish observations. We shed light with these data on the physical
properties of the gas in the line of sight, emphasizing the still open debate
about the nature of the gas that produces the broad absorption line (~55 km/s).
First, the broad H I line is more prominent toward the central and brightest 21
cm continuum component than toward a region along the jet at a distance ~ 20
mas (or 0.4 pc) further from it. This suggests that the broad absorption line
arises from gas located close to the nucleus, rather than from diffuse and more
distant gas. Second, the different velocity components detected in the CO(2-1)
absorption spectrum match well other molecular lines, such as those of
HCO+(1-0), except the broad absorption line that is detected in HCO+(1-0) (and
most likely related to that of the H I). Dissociation of molecular hydrogen due
to the AGN seems to be efficient at distances <= 10 pc, which might contribute
to the depth of the broad H I and molecular lines.Comment: 17 pages, 9 figures, accepted for publication in Ap
Health system barriers and facilitators to medication adherence for the secondary prevention of cardiovascular disease: a systematic review
Background: Secondary prevention is cost-effective for cardiovascular disease (CVD), but uptake is suboptimal. Understanding barriers and facilitators to adherence to secondary prevention for CVD at multiple health system levels may inform policy.
Objectives: To conduct a systematic review of barriers and facilitators to adherence/persistence to secondary CVD prevention medications at health system level.
Methods: Included studies reported effects of health system level factors on adherence/persistence to secondary prevention medications for CVD (coronary artery or cerebrovascular disease). Studies considered at least one of ÎČ blockers, statins, angiotensinârenin system blockers and aspirin. Relevant databases were searched from 1 January 1966 until 1 October 2015. Full texts were screened for inclusion by 2 independent reviewers.
Results: Of 2246 screened articles, 25 studies were included (12 trials, 11 cohort studies, 1 cross-sectional study and 1 caseâcontrol study) with 132â
140 individuals overall (smallest n=30, largest n=63â
301). 3 studies included upper middle-income countries, 1 included a low middle-income country and 21 (84%) included high-income countries (9 in the USA). Studies concerned established CVD (n=4), cerebrovascular disease (n=7) and coronary heart disease (n=14). Three studies considered persistence and adherence. Quantity and quality of evidence was limited for adherence, persistence and across drug classes. Studies were concerned with governance and delivery (n=19, including 4 trials of fixed-dose combination therapy, FDC), intellectual resources (n=1), human resources (n=1) and health system financing (n=4). Full prescription coverage, reduced copayments, FDC and counselling were facilitators associated with higher adherence.
Conclusions: High-quality evidence on health system barriers and facilitators to adherence to secondary prevention medications for CVD is lacking, especially for low-income settings. Full prescription coverage, reduced copayments, FDC and counselling may be effective in improving adherence and are priorities for further research
The orphan germinant receptor protein GerXAO (but not GerX3b) is essential for L-alanine induced germination in Clostridium botulinum Group II
Clostridium botulinum is an anaerobic spore forming bacterium that produces the potent botulinum neurotoxin that causes a severe and fatal neuro-paralytic disease of humans and animals (botulism). C. botulinum Group II is a psychrotrophic saccharolytic bacterium that forms spores of moderate heat resistance and is a particular hazard in minimally heated chilled foods. Spore germination is a fundamental process that allows the spore to transition to a vegetative cell and typically involves a germinant receptor (GR) that responds to environmental signals. Analysis of C. botulinum Group II genomes shows they contain a single GR cluster (gerX3b), and an additional single gerA subunit (gerXAO). Spores of C. botulinum Group II strain Eklund 17B germinated in response to the addition of L-alanine, but did not germinate following the addition of exogenous Ca2+-DPA. Insertional inactivation experiments in this strain unexpectedly revealed that the orphan GR GerXAO is essential for L-alanine stimulated germination. GerX3bA and GerX3bC affected the germination rate but were unable to induce germination in the absence of GerXAO. No role could be identified for GerX3bB. This is the first study to identify the functional germination receptor of C. botulinum Group II
The Circumnuclear Molecular Gas in the Seyfert Galaxy NGC4945
We have mapped the central region of NGC 4945 in the transition of
CO, CO, and CO, as well as the continuum at 1.3 mm, at an
angular resolution of 5\farc \times 3\farc with the Submillimeter Array. The
relative proximity of NGC 4945 (distance of only 3.8 Mpc) permits a detailed
study of the circumnuclear molecular gas and dust in a galaxy exhibiting both
an AGN (classified as a Seyfert 2) and a circumnuclear starburst in an inclined
ring with radius 2\farcs5 (50 pc). We find that all three molecular
lines trace an inclined rotating disk with major axis aligned with that of the
starburst ring and large-scale galactic disk, and which exhibits solid-body
rotation within a radius of 5\farc (95 pc). We infer an inclination
for the nuclear disk of , somewhat smaller than the
inclination of the large-scale galactic disk of . The
continuum emission at 1.3 mm also extends beyond the starburst ring, and is
dominated by thermal emission from dust. If it traces the same dust emitting in
the far-infrared, then the bulk of this dust must be heated by star-formation
activity rather than the AGN. We discover a kinematically-decoupled component
at the center of the disk with a radius smaller than 1\farcs4 (27 pc), but
which spans approximately the same range of velocities as the surrounding disk.
This component has a higher density than its surroundings, and is a promising
candidate for the circumnuclear molecular torus invoked by AGN unification
models.Comment: 13 pages, 10 figures,accepted by Ap
Evolution of South Atlantic density and chemical stratification across the last deglaciation
The cause of the rise in atmospheric pCO2 over the last deglaciation has been a puzzle since its discovery in the early 1980s. It is widely believed to be related to changes in carbon storage in the deep ocean, but the exact mechanisms responsible for releasing CO2 from the deep-ocean reservoir, including the role of ocean density stratification, remains an open question. Here we reconstruct changes in the intermediate-deep density gradient in the South Atlantic across the last deglaciation and find evidence of an early deglacial chemical destratification and a late deglacial density destratification These results suggest that other mechanisms, besides deep-ocean density destratification, were responsible for the oceanâatmosphere transfer of carbon over the deglacial period
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