97 research outputs found

    On generalized order statistics and maximal correlation as a measure of dependence

    Get PDF
    AbstractIn the first part of this review article some recent developments of maximal correlation coefficient, introduced by Gebelein (1941) [7], and its applications in various areas of statistics are discussed. The second part is devoted to find the distributions providing the maximal correlation coefficient between generalized order statistics (gos) and dual generalized order statistics (dgos), which are introduced by Kamps (1995) [8] and Burkschat et al. (2003) [4], respectively. Finally, in the third part, general theorems are presented, which give simple non-parametric criterion for the asymptotic independence between the different elements of gos, as well as dgos

    On the Digital Holographic Interferometry of Fibrous Material, I. Optical Properties of Polymer and Optical Fibers

    Full text link
    The digital holographic interferometry (DHI) was utilized for investigating the optical properties of polymer and optical fibers. The samples investigated here were polyvinylidene fluoride (PVDF) polymer fiber and graded-index (GRIN) optical fiber. The phase shifting Mach-Zehnder interferometer was used to obtain five phase-shifted holograms, in which the phase difference between two successive holograms is pi/2, for each fiber sample. These holograms were recorded using a CCD camera and were combined to gain a complex wavefield, which was numerically reconstructed using the convolution approach into amplitude and phase distributions. The reconstructed phase distribution was used to determine the refractive index, birefringence and refractive index profile of the studied samples. The mean refractive index has been measured with accuracy up to 4 {\times} 10-4. The main advantage of DHI is to overcome the manual focusing limitations by means of the numerical focusing. The results showed accurate measurements of the optical properties of fibers.Comment: abstract, reference

    Synthesis, characterization, antimicrobial activity and molecular docking studies of combined pyrazol-barbituric acid pharmacophores

    Get PDF
    Purpose: To synthesize, and determine the antibacterial activity and binding mode of new pyrazolbarbituric acid derivatives in a search for new antimicrobial agents.Methods: One-pot multi-component reaction of aldehyde derivatives, barbituric acid and 3-methyl-1- phenyl-1H-pyrazol-5(4H)-one in the presence of NHEt2 to afford Michael adduct was carried out. The reaction was carried out in water and afforded new heterocycles in a one-step fashion, with expedient work-up and high yield without extraction and purification steps. The synthesized compounds were evaluated for antimicrobial activity using agar disc diffusion. Molecular docking approach via MOE-Dock program was applied to predict the binding interactions of some of the new pyrazol-barbituric acid derivatives against six different target proteins downloaded from Protein Data Bank.Results: A series of pyrazole-barbituric acid derivatives were successfully synthesized and characterized. The synthesized compounds showed moderate to very good antibacterial activity against S. aureus ATCC 29213 and E. faecalis ATCC29212, as well as also antifungal activity against Candida albicans ATCC 10400Conclusion: A series of pyrazole-barbituric acid derivatives has been synthesized and some of them display antimicrobial activities.Keywords: Pyrazole, Barbituric acid, Pyrazole-barbituric acid derivatives, Antimicrobial activity, Molecular dockin

    Perioperative, postoperative, and long-term outcomes following open surgical repair of ruptured abdominal aortic aneurysm

    Get PDF
    We investigated factors that affected perioperative, postoperative, and long-term outcomes of patients who underwent open emergency surgical repair of ruptured abdominal aortic aneurysms (RAAA). All patients who underwent open emergency surgical repair from 1990 to 2011 were included (463 patients; 374 [81%] male; mean age 74.7 ± 8.7years). Logistic and Cox regression analyses were performed to explore the association of variables with outcomes. Preoperatively, median (interquartile range) hemoglobin was 11.2 (9.5-12.8) g/dL, and median creatinine level was 140 (112-177) µmol/L. Intraoperatively, the median operative time was 2.25 (2-3) hours, and median estimated blood loss was 1.5 (0.5-3) L; 250 (54%) patients required intraoperative inotropes, and a median of 6 (4-8) units of blood was transfused. Median length of hospital stay was 11 (7-20) days. In-hospital mortality rate was 35.6%, and 5-year mortality was 48%. Age, distance traveled, operation duration, postoperative myocardial infarction (MI), and multi-organ failure (MOF) were predictors of in-hospital mortality and long-term outcome. Additionally, postoperative acute renal failure predicted in-hospital mortality. In patients with RAAA undergoing open surgical repair, the strongest predictors of in-hospital mortality and long-term outcome were postoperative MOF and MI and operative duration

    Loss-of-function mutations in UDP-Glucose 6-Dehydrogenase cause recessive developmental epileptic encephalopathy

    Get PDF
    Developmental epileptic encephalopathies are devastating disorders characterized by intractable epileptic seizures and developmental delay. Here, we report an allelic series of germline recessive mutations in UGDH in 36 cases from 25 families presenting with epileptic encephalopathy with developmental delay and hypotonia. UGDH encodes an oxidoreductase that converts UDP-glucose to UDP-glucuronic acid, a key component of specific proteoglycans and glycolipids. Consistent with being loss-of-function alleles, we show using patients’ primary fibroblasts and biochemical assays, that these mutations either impair UGDH stability, oligomerization, or enzymatic activity. In vitro, patient-derived cerebral organoids are smaller with a reduced number of proliferating neuronal progenitors while mutant ugdh zebrafish do not phenocopy the human disease. Our study defines UGDH as a key player for the production of extracellular matrix components that are essential for human brain development. Based on the incidence of variants observed, UGDH mutations are likely to be a frequent cause of recessive epileptic encephalopathy

    EPIdemiology of Surgery-Associated Acute Kidney Injury (EPIS-AKI) : Study protocol for a multicentre, observational trial

    Get PDF
    More than 300 million surgical procedures are performed each year. Acute kidney injury (AKI) is a common complication after major surgery and is associated with adverse short-term and long-term outcomes. However, there is a large variation in the incidence of reported AKI rates. The establishment of an accurate epidemiology of surgery-associated AKI is important for healthcare policy, quality initiatives, clinical trials, as well as for improving guidelines. The objective of the Epidemiology of Surgery-associated Acute Kidney Injury (EPIS-AKI) trial is to prospectively evaluate the epidemiology of AKI after major surgery using the latest Kidney Disease: Improving Global Outcomes (KDIGO) consensus definition of AKI. EPIS-AKI is an international prospective, observational, multicentre cohort study including 10 000 patients undergoing major surgery who are subsequently admitted to the ICU or a similar high dependency unit. The primary endpoint is the incidence of AKI within 72 hours after surgery according to the KDIGO criteria. Secondary endpoints include use of renal replacement therapy (RRT), mortality during ICU and hospital stay, length of ICU and hospital stay and major adverse kidney events (combined endpoint consisting of persistent renal dysfunction, RRT and mortality) at day 90. Further, we will evaluate preoperative and intraoperative risk factors affecting the incidence of postoperative AKI. In an add-on analysis, we will assess urinary biomarkers for early detection of AKI. EPIS-AKI has been approved by the leading Ethics Committee of the Medical Council North Rhine-Westphalia, of the Westphalian Wilhelms-University Münster and the corresponding Ethics Committee at each participating site. Results will be disseminated widely and published in peer-reviewed journals, presented at conferences and used to design further AKI-related trials. Trial registration number NCT04165369

    Search for the Zγ decay mode of new high-mass resonances in pp collisions at √s = 13 TeV with the ATLAS detector

    Get PDF
    This letter presents a search for narrow, high-mass resonances in the Zγ final state with the Z boson decaying into a pair of electrons or muons. The √s = 13 TeV pp collision data were recorded by the ATLAS detector at the CERN Large Hadron Collider and have an integrated luminosity of 140 fb−1. The data are found to be in agreement with the Standard Model background expectation. Upper limits are set on the resonance production cross section times the decay branching ratio into Zγ. For spin-0 resonances produced via gluon–gluon fusion, the observed limits at 95% confidence level vary between 65.5 fb and 0.6 fb, while for spin-2 resonances produced via gluon–gluon fusion (or quark–antiquark initial states) limits vary between 77.4 (76.1) fb and 0.6 (0.5) fb, for the mass range from 220 GeV to 3400 GeV

    The ATLAS trigger system for LHC Run 3 and trigger performance in 2022

    Get PDF
    The ATLAS trigger system is a crucial component of the ATLAS experiment at the LHC. It is responsible for selecting events in line with the ATLAS physics programme. This paper presents an overview of the changes to the trigger and data acquisition system during the second long shutdown of the LHC, and shows the performance of the trigger system and its components in the proton-proton collisions during the 2022 commissioning period as well as its expected performance in proton-proton and heavy-ion collisions for the remainder of the third LHC data-taking period (2022–2025)

    Search for heavy Higgs bosons with flavour-violating couplings in multi-lepton plus b-jets final states in pp collisions at 13 TeV with the ATLAS detector

    Get PDF
    A search for new heavy scalars with flavour-violating decays in final states with multiple leptons and b-tagged jets is presented. The results are interpreted in terms of a general two-Higgs-doublet model involving an additional scalar with couplings to the top-quark and the three up-type quarks (ρtt, ρtc, and ρtu). The targeted signals lead to final states with either a same-sign top-quark pair, three top-quarks, or four top-quarks. The search is based on a data sample of proton-proton collisions at √s = 13 TeV recorded with the ATLAS detector during Run 2 of the Large Hadron Collider, corresponding to an integrated luminosity of 139 fb−1. Events are categorised depending on the multiplicity of light charged leptons (electrons or muons), total lepton charge, and a deep-neural-network output to enhance the purity of each of the signals. Masses of an additional scalar boson mH between 200 − 630 GeV with couplings ρtt = 0.4, ρtc = 0.2, and ρtu = 0.2 are excluded at 95% confidence level. Additional interpretations are provided in models of R-parity violating supersymmetry, motivated by the recent flavour and (g − 2)μ anomalies
    corecore