403 research outputs found
Non-perturbative renormalization of overlap quark bilinears on 2+1-flavor domain wall fermion configurations
We present renormalization constants of overlap quark bilinear operators on
2+1-flavor domain wall fermion configurations. This setup is being used by the
chiQCD collaboration in calculations of physical quantities such as strangeness
in the nucleon and the strange and charm quark masses. The scale independent
renormalization constant for the axial vector current is computed using the
Ward Identity. The renormalization constants for scalar, pseudoscalar and
vector current are calculated in the RI-MOM scheme. Results in the MS-bar
scheme are also given. The step scaling function of quark masses in the RI-MOM
scheme is computed as well. The analysis uses, in total, six different
ensembles of three sea quarks each on two lattices with sizes 24^3x64 and
32^3x64 at spacings a=(1.73 GeV)^{-1} and (2.28 GeV)^{-1}, respectively.Comment: 26 pages, 17 figures. More discussions on O(4) breaking effects, and
on the perturbative running and a^2p^2 extrapolation of Zs. A subsection for
the calculation of the step scaling function of quark mass is added.
References added. Version to appear in PR
Two Photon Decays of from Lattice QCD
We present an exploratory lattice study for the two-photon decay of
using twisted mass lattice QCD gauge configurations generated by the
European Twisted Mass Collaboration. Two different lattice spacings of
fm and fm are used in the study, both of which are of
physical size of 2. The decay widths are found to be KeV for the
coarser lattice and KeV for the finer lattice respectively where the
errors are purely statistical. A naive extrapolation towards the continuum
limit yields KeV which is smaller than the previous
quenched result and most of the current experimental results. Possible reasons
are discussed.Comment: 13 pages, 7 figures; matches the published versio
Individual differences in schizophrenia
Background: Whether there are distinct subtypes of schizophrenia is an important issue to advance understanding and treatment of schizophrenia. Aims: To understand and treat individuals with schizophrenia, the aim was to advance understanding of differences between individuals, whether there are discrete subtypes, and how fist-episode patients (FEP) may differ from multiple episode patients (MEP). Method: These issues were analysed in 687 FEP and 1880 MEP with schizophrenia using the Positive and Negative Syndrome Scale for (PANSS) schizophrenia before and after antipsychotic medication for 6 weeks. Results: The seven Negative Symptoms were correlated with each other and with P2 (conceptual disorganisation), G13 (disturbance of volition), and G7 (motor retardation). The main difference between individuals was in the cluster of seven negative symptoms, which had a continuous unimodal distribution. Medication decreased the PANSS scores for all the symptoms, which were similar in the FEP and MEP groups. Conclusions: The negative symptoms are a major source of individual differences, and there are potential implications for treatment
Knowledge and attitudes of healthcare workers in Chinese intensive care units regarding 2009 H1N1 influenza pandemic
<p>Abstract</p> <p>Background</p> <p>To describe the knowledge and attitudes of critical care clinicians during the 2009 H1N1 influenza pandemic.</p> <p>Methods</p> <p>A survey conducted in 21 intensive care units in 17 provinces in China.</p> <p>Results</p> <p>Out of 733 questionnaires distributed, 695 were completed. Three hundred and fifty-six respondents (51.2%) reported their experience of caring for H1N1 patients. Despite the fact that 88.5% of all respondents ultimately finished an H1N1 training program, only 41.9% admitted that they had the knowledge of 2009 H1N1 influenza. A total of 572 respondents (82.3%) expressed willingness to care for H1N1 patients. Independent variables associated with increasing likelihood to care for patients in the logistic regression analysis were physicians or nurses rather than other professionals (odds ratio 4.056 and 3.235, p = 0.002 and 0.007, respectively), knowledge training prior to patient care (odds ratio 1.531, p = 0.044), and the confidence to know how to protect themselves and their patients (odds ratio 2.109, p = 0.001).</p> <p>Conclusion</p> <p>Critical care clinicians reported poor knowledge of H1N1 influenza, even though most finished a relevant knowledge training program. Implementation of appropriate education program might improve compliance to infection control measures, and willingness to work in a pandemic.</p
Limits on Light Weakly Interacting Massive Particles from the First 102.8 kg day Data of the CDEX-10 Experiment
We report the first results of a light weakly interacting massive particles
(WIMPs) search from the CDEX-10 experiment with a 10 kg germanium detector
array immersed in liquid nitrogen at the China Jinping Underground Laboratory
with a physics data size of 102.8 kg day. At an analysis threshold of 160 eVee,
improved limits of 8 and 3 cm at a
90\% confidence level on spin-independent and spin-dependent WIMP-nucleon cross
sections, respectively, at a WIMP mass () of 5 GeV/ are
achieved. The lower reach of is extended to 2 GeV/.Comment: 5 pages, 4 figure
Efficacy and safety of combination therapy with vildagliptin and metformin versus metformin up-titration in Chinese patients with type 2 diabetes mellitus: study design and rationale of the vision study
Background and aim: Limitations of the currently recommended stepwise treatment pathway for type 2 diabetes mellitus (T2DM), especially the failure of monotherapies to maintain good glycemic control, have prompted use of early, more aggressive combination therapies. The VISION study is designed to explore the efficacy and safety of vildagliptin as an add-on to metformin therapy compared with up-titration of metformin monotherapy in Chinese patients with T2DM. Methods: VISION, a 24-week, phase 4, prospective, randomized, multicenter, open-label, parallel-group study, will include 3312 Chinese T2DM patients aged >= 18 years who are inadequately controlled (6.5% >HbA1c <= 9%) by metformin (750-1000 mg/day). Eligible patients will be randomized to receive either vildagliptin plus metformin or up-titration of metformin monotherapy (5: 1). Patients will also be subgrouped (1: 1: 1: 1) based on their age and body mass index (BMI): <60 years and <24 kg/m(2); <60 years and >= 24 kg/m(2); >= 60 years and <24 kg/m(2); and >= 60 years and >= 24 kg/m(2). Conclusion: The VISION study will test the hypothesis that early use of combination therapy with vildagliptin and metformin will provide good glycemic control and will be better tolerated than up-titration of metformin monotherapy. The study will also correlate these benefits with age and BMI.Cardiac & Cardiovascular SystemsEndocrinology & MetabolismSCI(E)PubMed1ARTICLE1181
A Unified Approach to the Classical Statistical Analysis of Small Signals
We give a classical confidence belt construction which unifies the treatment
of upper confidence limits for null results and two-sided confidence intervals
for non-null results. The unified treatment solves a problem (apparently not
previously recognized) that the choice of upper limit or two-sided intervals
leads to intervals which are not confidence intervals if the choice is based on
the data. We apply the construction to two related problems which have recently
been a battle-ground between classical and Bayesian statistics: Poisson
processes with background, and Gaussian errors with a bounded physical region.
In contrast with the usual classical construction for upper limits, our
construction avoids unphysical confidence intervals. In contrast with some
popular Bayesian intervals, our intervals eliminate conservatism (frequentist
coverage greater than the stated confidence) in the Gaussian case and reduce it
to a level dictated by discreteness in the Poisson case. We generalize the
method in order to apply it to analysis of experiments searching for neutrino
oscillations. We show that this technique both gives correct coverage and is
powerful, while other classical techniques that have been used by neutrino
oscillation search experiments fail one or both of these criteria.Comment: 40 pages, 15 figures. Changes 15-Dec-99 to agree more closely with
published version. A few small changes, plus the two substantive changes we
made in proof back in 1998: 1) The definition of "sensitivity" in Sec. V(C).
It was inconsistent with our actual definition in Sec. VI. 2) "Note added in
proof" at end of the Conclusio
Failure to prescribe pneumocystis prophylaxis is associated with increased mortality, even in the cART era: results from the Treat Asia HIV observational database
<p>Abstract</p> <p>Background</p> <p>Pneumocystis jiroveci pneumonia (PCP) prophylaxis is recommended for patients with CD4 counts of less than 200 cells/mm<sup>3</sup>. This study examines the proportion of patients in the TREAT Asia HIV Observational Database (TAHOD) receiving PCP prophylaxis, and its effect on PCP and mortality.</p> <p>Methods</p> <p>TAHOD patients with prospective follow up had data extracted for prophylaxis using co-trimoxazole, dapsone or pentamidine. The proportion of patients on prophylaxis was calculated for each calendar year since 2003 among patients with CD4 counts of less than 200 cells/mm<sup>3</sup>. The effect of prophylaxis on PCP and survival were assessed using random-effect Poisson regression models.</p> <p>Results</p> <p>There were a total of 4050 patients on prospective follow up, and 90% of them were receiving combination antiretroviral therapy. Of those with CD4 counts of less than 200 cells/mm<sup>3</sup>, 58% to 72% in any given year received PCP prophylaxis, predominantly co-trimoxazole. During follow up, 62 patients developed PCP (0.5 per 100 person-years) and 169 died from all causes (1.36/100 person-years). After stratifying by site and adjusting for age, CD4 count, CDC stage and antiretroviral treatment, those without prophylaxis had no higher risk of PCP, but had a significantly higher risk of death (incident rate ratio 10.8, p < 0.001). PCP prophylaxis had greatest absolute benefit in patients with CD4 counts of less than 50 cells/mm<sup>3</sup>, lowering mortality rates from 33.5 to 6.3 per 100 person-years.</p> <p>Conclusions</p> <p>Approximately two-thirds of TAHOD patients with CD4 counts of less than 200 cells/mm<sup>3 </sup>received PCP prophylaxis. Patients without prophylaxis had significantly higher mortality, even in the era of combination ART. Although PCP may be under-diagnosed, these data suggest that prophylaxis is associated with important survival benefits.</p
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