704 research outputs found

    Multi-epoch VLTI-PIONIER imaging of the supergiant V766 Cen: Image of the close companion in front of the primary

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    Context. The star V766 Cen (=HR 5171A) was originally classified as a yellow hypergiant but lately found to more likely be a 27−36 M⊙ red supergiant (RSG). Recent observations indicated a close eclipsing companion in the contact or common-envelope phase

    The role of an electronic alert system to detect acute kidney injury in hospitalized patients: DETECT-H Project

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    Background and aims: Acute kidney injury (AKI) is associated with higher mortality and length of stay (LOS) for hospitalized patients. To improve outcomes, an electronic detection system could be a useful tool for early diagnosis. Methods: A fully automated real-time system for detecting decreased glomerular filtration rate in adult patients was developed in our hospital, DETECT-H project. AKI was established according to KDIGO guidelines. Results: In six months, 1241 alerts from 11,022 admissions were issued. Overall incidence of AKI was 7.7%. Highest AKI stage reached was: stage 1 (49.8%), 2 (24.5%) and 3 (25.8%), in-hospital mortality was 10.9%, 22.7%, 33.9% respectively and 57.1% in AKI requiring dialysis; mortality in stable CKD was 4.3%. Median LOS was 8 days versus 5 days for all patients. AKI was associated with a mortality of 3.18 (95% CI 1.80–5.59) and a LOS 1.52 (1.11–2.08) times as high as that for admissions without AKI. Multivariate analysis indicated that a LOS higher than 8 days was associated with AKI. Previous CKD was noted in 31.9% and AKI in 45.3% at discharge. As compared to the use of the detect system, only one third of CKD patients and half of AKI episodes were identified. Conclusions: CKD and in-hospital AKI are under-recognized entities. Mortality and LOS are increased in-hospital patients with renal dysfunction. AKI severity was associated with higher mortality and LOS. An automated electronic detection system for identifying renal dysfunction would be a useful tool to improve renal outcomes. Resumen: Introducción y objetivos: El fracaso renal agudo (FRA) aumenta la mortalidad y la estancia hospitalarias (EH). El empleo de sistemas de detección electrónica podría ser una herramienta beneficiosa para mejorar estos resultados. Métodos: Se desarrolló un sistema de detección automático a tiempo real de pacientes ingresados con función renal alterada, denominado proyecto DETECT-H. El FRA se estableció de acuerdo con las guías KDIGO. Resultados: En 6 meses, 1.241 alertas fueron recogidas de 11.022 ingresos. La incidencia global del FRA fue del 7,7%. La distribución en función del estadio máximo del FRA alcanzado fue: estadio 1: 49,8%, estadio 2: 24,5% y estadio 3: 25,8%; con una mortalidad hospitalaria del 10,9, 22,7 y 33,9%, respectivamente. En el caso del FRA con necesidad de diálisis fue del 57,1%. La mortalidad en pacientes con enfermedad renal crónica (ERC) estable fue del 4,3%. La mediana de EH en pacientes detectados fue 8 vs. 5 días para todos los pacientes hospitalizados. El FRA se asoció con una mortalidad 3,18 (1,8-5,59) y una EH 1,52 (1,11-2,08) veces superior que aquellos ingresos sin FRA. El análisis multivariante indicó que el FRA se asociaba con la EH > 8 días.En los informes de alta, la presencia de ERC previa solo fue registrada en el 31,9% de los pacientes con ERC y el FRA hospitalario en el 45,3%. Conclusiones: La ERC y el FRA intrahospitalario son entidades infradiagnosticadas. La mortalidad y la EH están aumentadas en pacientes con disfunción renal. La gravedad del FRA se asoció con mayor mortalidad y EH. Un sistema de detección automático para identificarlos podría ser útil para mejorar estos resultados. Keywords: Acute kidney injury, Automated electronic detection system, Chronic kidney disease, Diagnosis, Health information technology, Mortality, Palabras clave: Fracaso renal agudo, Sistema de detección electrónica automática, Enfermedad renal crónica, Diagnóstico, Tecnología de información de la salud, Mortalida

    Harmonic Sums and Mellin Transforms up to two-loop Order

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    A systematic study is performed on the finite harmonic sums up to level four. These sums form the general basis for the Mellin transforms of all individual functions fi(x)f_i(x) of the momentum fraction xx emerging in the quantities of massless QED and QCD up to two--loop order, as the unpolarized and polarized splitting functions, coefficient functions, and hard scattering cross sections for space and time-like momentum transfer. The finite harmonic sums are calculated explicitly in the linear representation. Algebraic relations connecting these sums are derived to obtain representations based on a reduced set of basic functions. The Mellin transforms of all the corresponding Nielsen functions are calculated.Comment: 44 pages Latex, contract number adde

    Detection of variable VHE gamma-ray emission from the extra-galactic gamma-ray binary LMC P3

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    Context. Recently, the high-energy (HE, 0.1-100 GeV) γ\gamma-ray emission from the object LMC P3 in the Large Magellanic Cloud (LMC) has been discovered to be modulated with a 10.3-day period, making it the first extra-galactic γ\gamma-ray binary. Aims. This work aims at the detection of very-high-energy (VHE, >100 GeV) γ\gamma-ray emission and the search for modulation of the VHE signal with the orbital period of the binary system. Methods. LMC P3 has been observed with the High Energy Stereoscopic System (H.E.S.S.); the acceptance-corrected exposure time is 100 h. The data set has been folded with the known orbital period of the system in order to test for variability of the emission. Energy spectra are obtained for the orbit-averaged data set, and for the orbital phase bin around the VHE maximum. Results. VHE γ\gamma-ray emission is detected with a statistical significance of 6.4 σ\sigma. The data clearly show variability which is phase-locked to the orbital period of the system. Periodicity cannot be deduced from the H.E.S.S. data set alone. The orbit-averaged luminosity in the 1101-10 TeV energy range is (1.4±0.2)×1035(1.4 \pm 0.2) \times 10^{35} erg/s. A luminosity of (5±1)×1035(5 \pm 1) \times 10^{35} erg/s is reached during 20% of the orbit. HE and VHE γ\gamma-ray emissions are anti-correlated. LMC P3 is the most luminous γ\gamma-ray binary known so far.Comment: 5 pages, 3 figures, 1 table, accepted for publication in A&

    The Effect of Insecticide Synergists on the Response of Scabies Mites to Pyrethroid Acaricides

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    Synergists are commonly used in combination with pesticides to suppress metabolism-based resistance and increase the efficacy of the agents. They are also useful as tools for laboratory investigation of specific resistance mechanisms based on their ability to inhibit specific metabolic pathways. To determine the role of metabolic degradation as a mechanism for acaricide resistance in human scabies, PBO (piperonyl butoxide), DEF (S,S,S-tributyl phosphorotrithioate) and DEM (diethyl maleate) were used with permethrin as synergists in a bioassay of mite killing. A statistically significant difference in survival time of permethrin-resistant Sarcoptes scabiei variety canis was noted when any of the three synergists were used in combination with permethrin compared to survival time of mites exposed to permethrin alone (p<0.0001). These results indicate the potential utility of synergists in reversing tolerance to pyrethroid-based acaricides (i.e. the addition of synergists to permethrin-containing topical acaricide cream commonly used to treat scabies). To further verify specific metabolic pathways being inhibited by these synergists, enzyme assays were developed to measure esterase, glutathione S-transferase (GST) and cytochrome P450 monooxygenase activity in scabies mites. Results of in vitro enzyme inhibition experiments showed lower levels of esterase activity with DEF; lower levels of GST activity with DEM and lower levels of cytochrome monooxygenase activity with PBO. These findings indicate a metabolic mechanism as mediating pyrethroid resistance in scabies mites

    First observations of separated atmospheric nu_mu and bar{nu-mu} events in the MINOS detector

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    The complete 5.4 kton MINOS far detector has been taking data since the beginning of August 2003 at a depth of 2070 meters water-equivalent in the Soudan mine, Minnesota. This paper presents the first MINOS observations of nuµ and [overline nu ]µ charged-current atmospheric neutrino interactions based on an exposure of 418 days. The ratio of upward- to downward-going events in the data is compared to the Monte Carlo expectation in the absence of neutrino oscillations, giving Rup/downdata/Rup/downMC=0.62-0.14+0.19(stat.)±0.02(sys.). An extended maximum likelihood analysis of the observed L/E distributions excludes the null hypothesis of no neutrino oscillations at the 98% confidence level. Using the curvature of the observed muons in the 1.3 T MINOS magnetic field nuµ and [overline nu ]µ interactions are separated. The ratio of [overline nu ]µ to nuµ events in the data is compared to the Monte Carlo expectation assuming neutrinos and antineutrinos oscillate in the same manner, giving R[overline nu ][sub mu]/nu[sub mu]data/R[overline nu ][sub mu]/nu[sub mu]MC=0.96-0.27+0.38(stat.)±0.15(sys.), where the errors are the statistical and systematic uncertainties. Although the statistics are limited, this is the first direct observation of atmospheric neutrino interactions separately for nuµ and [overline nu ]µ

    Critical appraisal of technologies to assess electrical activity during atrial fibrillation: a position paper from the European Heart Rhythm Association and European Society of Cardiology Working Group on eCardiology in collaboration with the Heart Rhythm Society, Asia Pacific Heart Rhythm Society, Latin American Heart Rhythm Society and Computing in Cardiology

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    We aim to provide a critical appraisal of basic concepts underlying signal recording and processing technologies applied for (i) atrial fibrillation (AF) mapping to unravel AF mechanisms and/or identifying target sites for AF therapy and (ii) AF detection, to optimize usage of technologies, stimulate research aimed at closing knowledge gaps, and developing ideal AF recording and processing technologies. Recording and processing techniques for assessment of electrical activity during AF essential for diagnosis and guiding ablative therapy including body surface electrocardiograms (ECG) and endo- or epicardial electrograms (EGM) are evaluated. Discussion of (i) differences in uni-, bi-, and multi-polar (omnipolar/Laplacian) recording modes, (ii) impact of recording technologies on EGM morphology, (iii) global or local mapping using various types of EGM involving signal processing techniques including isochronal-, voltage- fractionation-, dipole density-, and rotor mapping, enabling derivation of parameters like atrial rate, entropy, conduction velocity/direction, (iv) value of epicardial and optical mapping, (v) AF detection by cardiac implantable electronic devices containing various detection algorithms applicable to stored EGMs, (vi) contribution of machine learning (ML) to further improvement of signals processing technologies. Recording and processing of EGM (or ECG) are the cornerstones of (body surface) mapping of AF. Currently available AF recording and processing technologies are mainly restricted to specific applications or have technological limitations. Improvements in AF mapping by obtaining highest fidelity source signals (e.g. catheter–electrode combinations) for signal processing (e.g. filtering, digitization, and noise elimination) is of utmost importance. Novel acquisition instruments (multi-polar catheters combined with improved physical modelling and ML techniques) will enable enhanced and automated interpretation of EGM recordings in the near future

    High-Throughput High-Resolution Class I HLA Genotyping in East Africa

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    HLA, the most genetically diverse loci in the human genome, play a crucial role in host-pathogen interaction by mediating innate and adaptive cellular immune responses. A vast number of infectious diseases affect East Africa, including HIV/AIDS, malaria, and tuberculosis, but the HLA genetic diversity in this region remains incompletely described. This is a major obstacle for the design and evaluation of preventive vaccines. Available HLA typing techniques, that provide the 4-digit level resolution needed to interpret immune responses, lack sufficient throughput for large immunoepidemiological studies. Here we present a novel HLA typing assay bridging the gap between high resolution and high throughput. The assay is based on real-time PCR using sequence-specific primers (SSP) and can genotype carriers of the 49 most common East African class I HLA-A, -B, and -C alleles, at the 4-digit level. Using a validation panel of 175 samples from Kampala, Uganda, previously defined by sequence-based typing, the new assay performed with 100% sensitivity and specificity. The assay was also implemented to define the HLA genetic complexity of a previously uncharacterized Tanzanian population, demonstrating its inclusion in the major East African genetic cluster. The availability of genotyping tools with this capacity will be extremely useful in the identification of correlates of immune protection and the evaluation of candidate vaccine efficacy
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