1,372 research outputs found
A Readout System for the STAR Time Projection Chamber
We describe the readout electronics for the STAR Time Projection Chamber. The
system is made up of 136,608 channels of waveform digitizer, each sampling 512
time samples at 6-12 Mega-samples per second. The noise level is about 1000
electrons, and the dynamic range is 800:1, allowing for good energy loss
() measurement for particles with energy losses up to 40 times minimum
ionizing. The system is functioning well, with more than 99% of the channels
working within specifications.Comment: 22 pages + 8 separate figures; 2 figures are .jpg photos to appear in
Nuclear Instruments and Method
Patient safety culture lives in departments and wards: Multilevel partitioning of variance in patient safety culture
<p>Abstract</p> <p>Background</p> <p>Aim of study was to document 1) that patient safety culture scores vary considerably by hospital department and ward, and 2) that much of the variation is across the lowest level organizational units: the wards. Setting of study: 500-bed Norwegian university hospital, September-December 2006.</p> <p>Methods</p> <p>Data collected from 1400 staff by (the Norwegian version of) the generic version of the Safety Attitudes Questionnaire (SAQ Short Form 2006). Multilevel analysis by MLwiN version 1.10.</p> <p>Results</p> <p>Considerable parts of the score variations were at the ward and department levels. More organization level variation was seen at the ward level than at the department level.</p> <p>Conclusions</p> <p>Patient safety culture improvement efforts should not be limited to all-hospital interventions or interventions aimed at entire departments, but include involvement at the ward level, selectively aimed at low-scoring wards. Patient safety culture should be studied as closely to the patient as possible. There may be such a thing as "hospital safety culture" and the variance across hospital departments indicates the existence of department safety cultures. However, neglecting the study of patient safety culture at the ward level will mask important local variations. Safety culture research and improvement should not stop at the lowest formal level of the hospital (wards, out-patient clinics, ERs), but proceed to collect and analyze data on the micro-units within them.</p
Association of perceived work pace and physical work demands with occupational accidents:a cross-sectional study of ageing male construction workers in Denmark
BACKGROUND: Occupational accidents continue to be a significant public health challenge worldwide. Construction workers in particular are at high risk of occupational accidents, and thus it is of major importance to identify possible predictors of occupational accidents among construction workers. We aimed to investigate the association between self-reported work pace and physical work demands and occupational accidents among ageing male construction workers in Denmark. METHODS: Data on perceived work pace, physical work demands, and occupational accidents was acquired from questionnaires sent to ageing construction workers in Denmark in 2016 as part of the ALFA project (ALdring og Fysisk Arbejde; Ageing and Physical Work). A sample of 1270 Danish male construction workers above 50âyears of age was included in the present study. Multiple logistic regression models were applied, with adjustments for age, smoking, body mass index, musculoskeletal disorders, occupation, work experience, and support at work. RESULTS: Of 1270 construction workers, 166 (13.1%) reported an occupational accident within the last 12âmonths. There was no significant association between perceived work pace and occupational accidents, but physical work demands were associated with higher odds for occupational accidents, with an odds ratio of 2.27 (95% confidence interval 1.26â4.10) for medium physical work demands and 2.62 (95% confidence interval 1.50â4.57) for high physical work demands. CONCLUSIONS: Ageing male construction workers with high physical work demands had statistically significant higher odds of having an occupational accident. By contrast, perceived work pace was not associated with occupational accidents in this large cross-sectional study. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12889-021-12461-6
Perfusion Changes in Acute Stroke Treated with Theophylline as an Add-on to Thrombolysis:AÂ Randomized Clinical Trial Subgroup Analysis
PURPOSE: Theophylline has been suggested to have a neuroprotective effect in ischemic stroke; however, results from animal stroke models and clinical trials in humans are controversial. The aim of this study was to assess the effect of theophylline on the cerebral perfusion with multiparametric magnetic resonance imaging (MRI). METHODS: The relative cerebral blood flow (rCBF), relative cerebral blood volume (rCBV), and relative mean transit time (rMTT) in the infarct core, penumbra, and unaffected tissue were measured using multi-parametric MRI at baseline and 3âh follow-up in patients treated with theophylline or placebo as an add-on to thrombolytic therapy. RESULTS: No significant differences in mean rCBF, rCBV, and rMTT was found in the penumbra and unaffected tissue between the theophylline group and the control group between baseline and 3âh follow-up. In the infarct core, mean rCBV increased on average by 0.05 in the theophylline group and decreased by 0.14 in the control group (pâŻ<â0.04). Mean rCBF and mean rMTT in the infarct core were similar between the two treatment groups. CONCLUSION: The results indicate that theophylline does not change the perfusion in potentially salvageable penumbral tissue but only affects the rCBV in the infarct core. In contrast to the penumbra, the infarct core is unlikely to be salvageable, which might explain why theophylline failed in clinical trials. SUPPLEMENTARY INFORMATION: The online version of this article (10.1007/s00062-021-01029-x) contains supplementary material, which is available to authorized users
The BATSE-Swift luminosity and redshift distributions of short-duration GRBs
We compare the luminosity function and rate inferred from the BATSE short
hard bursts (SHBs) peak flux distribution with the redshift and luminosity
distributions of SHBs observed by Swift/HETE II. While the Swift/HETE II SHB
sample is incompatible with SHB population that follows the star formation
rate, it is compatible with a SHB rate that reflect a distribution of delay
times after the SFR. This would be the case if SHBs are associated with binary
neutron star mergers. The available data allows, however, different
interpretations. For example, a population whose rate is independent of the
redshift fits the data very well. The implied SHB rates that we find range from
to Gpcyr. This is a much higher rate
than what was previously estimated. A detailed (2 dimensional) look at the best
fit models shows, however, some discrepancy between the four Swift/HETE II SHBs
and the models based on BATSE SHBs. This could be a statistical fluke. It could
also arise from wrong estimates of the triggering criteria or from selection
effects. If real it may indicate the existence of two SHB populations with
different luminosity functions and redshift distributions.Comment: Revised version includes additional bursts and revised redshift of
older burst
Larval dispersal in a changing ocean with an emphasis on upwelling regions
Dispersal of benthic species in the sea is mediated primarily through small, vulnerable larvae that must survive minutes to months as members of the plankton community while being transported by strong, dynamic currents. As climate change alters ocean conditions, the dispersal of these larvae will be affected, with pervasive ecological and evolutionary consequences. We review the impacts of oceanic changes on larval transport, physiology, and behavior. We then discuss the implications for population connectivity and recruitment and evaluate life history strategies that will affect susceptibility to the effects of climate change on their dispersal patterns, with implications for understanding selective regimes in a future ocean. We find that physical oceanographic changes will impact dispersal by transporting larvae in different directions or inhibiting their movements while changing environmental factors, such as temperature, pH, salinity, oxygen, ultraviolet radiation, and turbidity, will affect the survival of larvae and alter their behavior. Reduced dispersal distance may make local adaptation more likely in well-connected populations with high genetic variation while reduced dispersal success will lower recruitment with implications for fishery stocks. Increased dispersal may spur adaptation by increasing genetic diversity among previously disconnected populations as well as increasing the likelihood of range expansions. We hypothesize that species with planktotrophic (feeding), calcifying, or weakly swimming larvae with specialized adult habitats will be most affected by climate change. We also propose that the adaptive value of retentive larval behaviors may decrease where transport trajectories follow changing climate envelopes and increase where transport trajectories drive larvae toward increasingly unsuitable conditions. Our holistic framework, combined with knowledge of regional ocean conditions and larval traits, can be used to produce powerful predictions of expected impacts on larval dispersal as well as the consequences for connectivity, range expansion, or recruitment. Based on our findings, we recommend that future studies take a holistic view of dispersal incorporating biological and oceanographic impacts of climate change rather than solely focusing on oceanography or physiology. Genetic and paleontological techniques can be used to examine evolutionary impacts of altered dispersal in a future ocean, while museum collections and expedition records can inform modern-day range shifts
Differential adipokine DNA methylation and gene expression in subcutaneous adipose tissue from adult offspring of women with diabetes in pregnancy
Abstract Background Offspring of women with diabetes in pregnancy are at increased risk of type 2 diabetes mellitus (T2DM), potentially mediated by epigenetic mechanisms. The adipokines leptin, adiponectin, and resistin (genes: LEP, ADIPOQ, RETN) play key roles in the pathophysiology of T2DM. We hypothesized that offspring exposed to maternal diabetes exhibit alterations in epigenetic regulation of subcutaneous adipose tissue (SAT) adipokine transcription. We studied adipokine plasma levels, SAT gene expression, and DNA methylation of LEP, ADIPOQ, and RETN in adult offspring of women with gestational diabetes (O-GDM, Nâ=â82) or type 1 diabetes (O-T1DM, Nâ=â67) in pregnancy, compared to offspring of women from the background population (O-BP, Nâ=â57). Results Compared to O-BP, we found elevated plasma leptin and resistin levels in O-T1DM, decreased gene expression of all adipokines in O-GDM, decreased RETN expression in O-T1DM, and increased LEP and ADIPOQ methylation in O-GDM. In multivariate regression analysis, O-GDM remained associated with increased ADIPOQ methylation and decreased ADIPOQ and RETN gene expression and O-T1DM remained associated with decreased RETN expression after adjustment for potential confounders and mediators. Conclusions In conclusion, offspring of women with diabetes in pregnancy exhibit increased ADIPOQ DNA methylation and decreased ADIPOQ and RETN gene expression in SAT. However, altered methylation and expression levels were not reflected in plasma protein levels, and the functional implications of these findings remain uncertain
Geometrical structure effect on localization length of carbon nanotubes
The localization length and density of states of carbon nanotubes are
evaluated within the tight-binding approximation. By comparison with the
corresponding results for the square lattice tubes, it is found that the
hexagonal structure affects strongly the behaviors of the density of states and
localization lengths of carbon nanotubes.Comment: 7 pages, 4 figures, revised version to appear in Chin. Phys. Lett.
The title is changed. Some arguments are adde
Collapse and recovery of forage fish populations prior to commercial exploitation
We use a new, wellâcalibrated 500 year paleorecord off southern California to determine collapse frequency, cross correlation, persistence, and return times of exploited forage fish populations. The paleorecord shows that âcollapseâ (defined as <10% of the mean peak biomass) is a normal state repeatedly experienced by northern anchovy, Pacific hake, and Pacific sardine which were collapsed 29â40% of the time, prior to commercial fishing exploitation. Mean (± SD) persistence of âfishable biomassâ (defined as one third mean peak biomass from the paleorecord) was 19 ± 18, 15 ± 17, and 12 ± 7 years for anchovy, hake, and sardine. Mean return times to the same biomass was 8 years for anchovy but 22 years for sardine and hake. Further, we find that sardine and anchovy are positively correlated over 400 years, consistent with coherent declines of both species off California. Persistence and return times combined with positive sardineâanchovy correlation indicate that on average 1â2 decades of fishable biomass will be followed by 1â2 decades of low forage. Forage populations are resilient on the 500 year time scale, but their collapse and recovery cycle (based on the paleorecord) are suited to alternating periods of high fishing mortality and periods of little or no fishing.Key PointsThe paleorecord shows that âcollapseâ is a normal state repeatedly experienced by northern anchovy, Pacific hake, and Pacific sardineMean return times to âfishableâ biomass was 8 years for anchovy, but 22 years for sardine and hake, and persistence was of the same orderSardine and anchovy are positively correlated over 400 years, consistent with coherent declines of both species off CaliforniaPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/136405/1/grl55551.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136405/2/grl55551_am.pd
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