87 research outputs found
Time-integrated luminosity recorded by the BABAR detector at the PEP-II e+e- collider
This article is the Preprint version of the final published artcile which can be accessed at the link below.We describe a measurement of the time-integrated luminosity of the data collected by the BABAR experiment at the PEP-II asymmetric-energy e+e- collider at the ϒ(4S), ϒ(3S), and ϒ(2S) resonances and in a continuum region below each resonance. We measure the time-integrated luminosity by counting e+e-→e+e- and (for the ϒ(4S) only) e+e-→μ+μ- candidate events, allowing additional photons in the final state. We use data-corrected simulation to determine the cross-sections and reconstruction efficiencies for these processes, as well as the major backgrounds. Due to the large cross-sections of e+e-→e+e- and e+e-→μ+μ-, the statistical uncertainties of the measurement are substantially smaller than the systematic uncertainties. The dominant systematic uncertainties are due to observed differences between data and simulation, as well as uncertainties on the cross-sections. For data collected on the ϒ(3S) and ϒ(2S) resonances, an additional uncertainty arises due to ϒ→e+e-X background. For data collected off the ϒ resonances, we estimate an additional uncertainty due to time dependent efficiency variations, which can affect the short off-resonance runs. The relative uncertainties on the luminosities of the on-resonance (off-resonance) samples are 0.43% (0.43%) for the ϒ(4S), 0.58% (0.72%) for the ϒ(3S), and 0.68% (0.88%) for the ϒ(2S).This work is supported by the US Department of Energy and National Science Foundation, the Natural Sciences and Engineering Research Council (Canada), the Commissariat à l’Energie Atomique and Institut National de Physique Nucléaire et de Physiquedes Particules (France), the Bundesministerium für Bildung und Forschung and Deutsche Forschungsgemeinschaft (Germany), the Istituto Nazionale di Fisica Nucleare (Italy), the Foundation for Fundamental Research on Matter (The Netherlands), the Research Council of Norway, the Ministry of Education and Science of the Russian Federation, Ministerio de Ciencia e Innovación (Spain), and the Science and Technology Facilities Council (United Kingdom). Individuals have received support from the Marie-Curie IEF program (European Union) and the A.P. Sloan Foundation (USA)
Observation of the baryonic decay B \uaf 0 \u2192 \u39bc+ p \uaf K-K+
We report the observation of the baryonic decay B\uaf0\u2192\u39bc+p\uafK-K+ using a data sample of 471
7106 BB\uaf pairs produced in e+e- annihilations at s=10.58GeV. This data sample was recorded with the BABAR detector at the PEP-II storage ring at SLAC. We find B(B\uaf0\u2192\u39bc+p\uafK-K+)=(2.5\ub10.4(stat)\ub10.2(syst)\ub10.6B(\u39bc+))
710-5, where the uncertainties are statistical, systematic, and due to the uncertainty of the \u39bc+\u2192pK-\u3c0+ branching fraction, respectively. The result has a significance corresponding to 5.0 standard deviations, including all uncertainties. For the resonant decay B\uaf0\u2192\u39bc+p\uaf\u3c6, we determine the upper limit B(B\uaf0\u2192\u39bc+p\uaf\u3c6)<1.2
710-5 at 90% confidence level
Search for Darkonium in e+e- Collisions
Collider searches for dark sectors, new particles interacting only feebly with ordinary matter, have largely focused on identifying signatures of new mediators, leaving much of dark sector structures unexplored. In particular, the existence of dark matter bound states (darkonia) remains to be investigated. This possibility could arise in a simple model in which a dark photon (A0 ) is light enough to generate an attractive force between dark fermions. We report herein a search for a JPC ¼ 1−− darkonium state, the ϒD, produced in the reaction eþe− → γϒD, ϒD → A0 A0 A0 , where the dark photons subsequently decay into pairs of leptons or pions, using 514 fb−1 of data collected with the BABAR detector. No significant signal is observed, and we set bounds on the γ − A0 kinetic mixing as a function of the dark sector coupling constant for 0.001 < mA0 < 3.16 GeV and 0.05 < mϒD < 9.5 GeV.publishedVersio
EuFeAs under high pressure: an antiferromagnetic bulk superconductor
We report the ac magnetic susceptibility and resistivity
measurements of EuFeAs under high pressure . By observing nearly
100% superconducting shielding and zero resistivity at = 28 kbar, we
establish that -induced superconductivity occurs at ~30 K in
EuFeAs. shows an anomalous nearly linear temperature dependence
from room temperature down to at the same . indicates that
an antiferromagnetic order of Eu moments with ~20 K persists
in the superconducting phase. The temperature dependence of the upper critical
field is also determined.Comment: To appear in J. Phys. Soc. Jpn., Vol. 78 No.
A draft human pangenome reference
Here the Human Pangenome Reference Consortium presents a first draft of the human pangenome reference. The pangenome contains 47 phased, diploid assemblies from a cohort of genetically diverse individuals. These assemblies cover more than 99% of the expected sequence in each genome and are more than 99% accurate at the structural and base pair levels. Based on alignments of the assemblies, we generate a draft pangenome that captures known variants and haplotypes and reveals new alleles at structurally complex loci. We also add 119 million base pairs of euchromatic polymorphic sequences and 1,115 gene duplications relative to the existing reference GRCh38. Roughly 90 million of the additional base pairs are derived from structural variation. Using our draft pangenome to analyse short-read data reduced small variant discovery errors by 34% and increased the number of structural variants detected per haplotype by 104% compared with GRCh38-based workflows, which enabled the typing of the vast majority of structural variant alleles per sample
Prevention of bone loss with risedronate in glucocorticoid-treated rheumatoid arthritis patients
The aim of the study was to assess risedronate's effect on bone mineral density in postmenopausal women with rheumatoid arthritis receiving glucocorticoids. We carried out a two center, 2 year, double-masked, placebo-controlled trial with a third year of nontreatment follow-up. We studied 120 women requiring long-term glucocorticoid therapy at > 2.5 mg/day prednisolone randomized to treatment with daily placebo; daily 2.5 mg risedronate; or cyclical 15 mg risedronate (2 out of 12 weeks). At 97 weeks, bone mineral density was maintained at the lumbar spine (+1.4%) and trochanter (+0.4%) in the daily 2.5 mg risedronate group, while significant bone loss occurred in the placebo group (-1.6%, p = 0.03; and 4.0%, p < 0.005, respectively). At the femoral neck, there was a nonsignificant bone loss in the daily 2.5 mg risedronate group (-1.0%) while in the placebo group bone mass decreased significantly (-3.6%, p < 0.001). The difference between placebo and daily 2.5 mg risedronate groups was significant at the lumbar spine (p = 0.009) and trochanter (p = 0.02) but did not reach statistical significance at the femoral neck. Although not significantly different from placebo at the lumbar spine, the overall effect of the cyclical regimen was similar to that of the daily 2.5 mg risedronate regimen. Treatment withdrawal led to bone loss in the risedronate groups that was significant at the lumbar spine. A similar number of patients experienced adverse events (including upper gastrointestinal events) across treatment groups and risedronate was generally well tolerated. Thus risedronate preserves bone mass in postmenopausal women with rheumatoid arthritis receiving glucocorticoids while patients receiving a placebo have significant bone loss
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Lipid and lipoprotein levels remain stable in acute ischemic stroke: the Northern Manhattan Stroke Study
Serum lipoproteins including lipoprotein(a), Lp(a), are emerging as possible biological markers for cerebrovascular disease. Existing data on Lp(a) and serum lipids levels following acute ischemic stroke (AIS) are however equivocal. To determine whether serum Lp(a) and other lipid levels obtained within 24 h of acute ischemic stroke onset changed over the ensuing 4 weeks and whether these levels are related to an acute phase response, acquired nutritional deficiency, and neurovascular data, we conducted repeated measurement analyses among 19 subjects (mean age 65.0±12.1 years; 32% women) presenting with AIS (evaluated within 9.7±12.7 h). Eleven of the subjects had a moderate-to-severe stroke, defined by NIH stroke severity scale, and seven patients had a large cerebral infarction. Seven serial measurements of Lp(a), total cholesterol, high density lipoprotein cholesterol, low density lipoprotein cholesterol, and other lipoproteins, major acute phase reactants and albumin levels were collected for each subject over 4 weeks. The mean initial levels, (mg/dl), of total cholesterol, LDL cholesterol, HDL cholesterol, triglycerides, Lp(a), apolipoproteins A-I and B were: 225±57.6, 154±56.0, 40±10.4, 181±93.7, 52±28.6, 130±24.6, and 141±46.1, respectively. There were no significant changes in mean serum lipid, apolipoprotein or Lp(a) levels over the 4-week study period, analyzed by a random effects model to test for time trend. In addition, there were no significant changes in established acute phase or nutritional markers (C-reactive protein, alpha 1-glycoprotein, haptoglobin or serum albumin). Our findings suggest that serum lipid, apolipoprotein and Lp(a) levels remain stable following AIS, consistent with the absence of acute phase response or nutritional deficiency
LFU-K: An Effective Buffer Management Replacement Algorithm
Abstract. This paper introduces a new approach to database disk buffering, called the LFU-K method. The LFU-K page replacement algorithm is an im-provement to the Least Frequently Used (LFU) algorithm. The paper proposes a theoretical-probability model for formal description of LFU-K algorithm. Us-ing this model we evaluate estimations for the LFU-K parameters. This paper also describes an implementation of LFU-2 policy. As we demonstrate by trace-driven simulation experiments, the LFU-2 algorithm provides significant improvement over conventional buffering algorithms for the shared-nothing da-tabase systems.
[Overactive bladder syndrome: the social and economic perspective]
Overactive bladder syndrome (OAB) is a highly prevalent condition associated with a significant impairment of patients' Quality of Life (QoL) because of its adverse effects on social, sexual, interpersonal, and professional functions. Cost-of-illness analyses showed the huge economic burden related to OAB for patients, public healthcare systems, and society, secondary to both direct and indirect costs. These types of cost analyses, however, exclude intangible costs related to QoL impairment. Recently, many novel therapies have been introduced, arising the need to apply the modern methodology of Health Technology Assessment (HTA) to new therapies in order to evaluate objectively their value in terms of both improvement in length/Quality of Life and costs. By producing information on the clinical, economic, organizational, social and ethical impact of health technologies, HTA has been used worldwide to inform decision makers at different levels in health systems. The HTA approach demonstrated, worldwide, to be a useful approach to increase the level of appropriateness in the use of medical technology and, as a consequence of that, of resources. Health utilities are instruments that allow a measurement of QoL and its integration in the economic evaluation using the Quality-of-life-Adjusted-Life-Years (QALYs) model and cost-utility analysis. The development of suitable instruments for quantifying utility in the specific group of OAB patients is vitally important to extend the application of cost-utility analysis in OAB and to guide healthcare resources allocation for this disorder. Studies are required to define the cost-effectiveness of available pharmacological and non-pharmacological therapy options
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