ABSTRACT On 2014 April 23, the Swift satellite responded to a hard X-ray transient detected by its Burst Alert Telescope, which turned out to be a stellar flare from a nearby, young M dwarf binary DG ...CVn. We utilize observations at X-ray, UV, optical, and radio wavelengths to infer the properties of two large flares. The X-ray spectrum of the primary outburst can be described over the 0.3-100 keV bandpass by either a single very high-temperature plasma or a nonthermal thick-target bremsstrahlung model, and we rule out the nonthermal model based on energetic grounds. The temperatures were the highest seen spectroscopically in a stellar flare, at TX of 290 MK. The first event was followed by a comparably energetic event almost a day later. We constrain the photospheric area involved in each of the two flares to be >1020 cm2, and find evidence from flux ratios in the second event of contributions to the white light flare emission in addition to the usual hot, T ∼ 104 K blackbody emission seen in the impulsive phase of flares. The radiated energy in X-rays and white light reveal these events to be the two most energetic X-ray flares observed from an M dwarf, with X-ray radiated energies in the 0.3-10 keV bandpass of 4 × 1035 and 9 × 1035 erg, and optical flare energies at EV of 2.8 × 1034 and 5.2 × 1034 erg, respectively. The results presented here should be integrated into updated modeling of the astrophysical impact of large stellar flares on close-in exoplanetary atmospheres.
In this work, the application of the bicoherence (a squared normalized version of the bispectrum) of the stray flux signal is proposed as a way of detecting faults in the field winding of synchronous ...motors. These signals are analyzed both under the starting and at steady state regime. Likewise, two quantitative indicators are proposed, the first one based on the maximum values of the asymmetry and the kurtosis of the bicoherence matrix obtained from the flux signals and the second one relying on an algorithm based on the bicoherence image segmentation of the obtained pattern for each analyzed state. The results are analyzed through a comparative study for the two considered motor regimes, obtaining satisfactory results that sustain the potential application of the proposed methodology for the automatic field winding fault detection in real applications.
The aim of this work was to develop a new unsupervised exploratory method of characterizing feature extraction and detecting similarity of movement during sleep through actigraphy signals. We here ...propose some algorithms, based on signal bispectrum and bispectral entropy, to determine the unique features of independent actigraphy signals. Experiments were carried out on 20 randomly chosen actigraphy samples of the Hispanic Community Health Study/Study of Latinos (HCHS/SOL) database, with no information other than their aperiodicity. The Pearson correlation coefficient matrix and the histogram correlation matrix were computed to study the similarity of movements during sleep. The results obtained allowed us to explore the connections between certain sleep actigraphy patterns and certain pathologies.
We evaluated the psychometric properties of the Spanish version of the European Organization for Research and Treatment of Multiple Myeloma (MM) specific quality-of-life (QoL) questionnaire module ...(QLQ-MY20) in relapsed/refractory MM (RRMM) patients. This was an observational, cross-sectional, multicenter study using EORTC QLQ-C30 and QLQ-MY20 in RRMM patients (ClinicalTrials.gov ID NCT03188536). We assessed the non-response rate, ceiling/floor effects, internal consistency, test-retest reliability, and validity. The study included 276 patients (53.3% males, mean SD age of 67.4 10.5 years). The EORTC QLQ-MY20 showed a low non-response rate, very low ceiling and floor effects, and good internal consistency. The test-retest reliability assessment revealed good temporary stability, the construct validity analysis stated four main factors similar to the ones of the original version, and the criterion validity assessment showed no differences between groups. In conclusion, the Spanish version of EORTC QLQ-MY20 is a reliable and valid tool for assessing QoL in RRMM patients.
Sparking is a common phenomenon in brushed DC motors. Early detection of sparks can prevent their aggravation and promptly adopt appropriate maintenance actions. In this work, we propose the ...application of a multifractal analysis to armature currents and stray flux signals to detect the presence of sparks in the commutation system of DC motors. Two methodologies are proposed in the paper, the first one using the spectral kurtosis of armature currents and the second one using the flux signal envelope. We apply this method to signals captured both under starting and at steady state to compare their suitability and analyze their feasibility to be used as the basis of the sparking detection method. Additionally, we also propose a quantitative indicator based on the variance of the complex cepstrum to determine the severity of the failure based on the cepstral analysis of both considered signals. The results demonstrate the potential of the approach for sparking detection and sparking level assessment in DC motors and its suitability for potential future incorporation into autonomous systems.
Carbapenem-resistant Enterobacteriaceae (CRE) infections have emerged as a serious threat to health worldwide. They are associated with increased morbidity and mortality and are capable of silently ...colonizing the gastrointestinal tract. Because of this, there is great interest to characterize the epidemiology of CRE carriage and acquisition in healthcare facilities. The aim of this study was to determine the prevalence and factors associated with CRE fecal carriage (CRE-fc), and risk factors for incident cases.
A cohort study was conducted at a tertiary care hospital from January 1st to April 30th, 2014 during a CRE outbreak. Weekly rectal swabs were performed in patients considered at risk until discharge. CRE-fc prevalence was 10.9% (CI 95% 7.7-14.7) among 330 patients. Treatment with carbapenems (OR 2.54, CI 95% 1.15-5.62); transfer from an institution (OR 2.16, CI 95% 1.02-4.59); multi-drug resistant infection within the previous six months (OR 2.81, CI 95% 1.47-5.36); intensive care unit admission (OR 0.42, CI 95% 0.20-0.88); hematologic malignancy (OR 4.02, CI 95% 1.88-8.06); invasive procedures (OR 2.18, CI 95% 1.10-4.32); and sharing a room with a known CRE carrier (OR 3.0, CI 95% 1.43-6.31) were independently associated factors for CRE-fc. Risk factors associated with CRE-fc incidence were determined for 87 patients initially negative and with subsequent screening; the incidence rate was 2.5 cases, per 1000 person-years (CI 95% 1.5-3.9). Independently associated risk factors were carbapenem treatment (HR 2.68, CI 95% 1.03-6.98), hematologic malignancy (HR 5.74, 95% CI 2.46-13.4) and a mean daily colonization pressure ≥10% (HR 5.03, IC 95% 1.77-14.28). OXA-48-like (OXA-232) and CTX-M-15 were the predominantly identified mechanisms of resistance.
We found an elevated incidence and prevalence of CRE-fc in our hospital. Hematologic patients need to be considered a population at risk, and antibiotic stewardship along with infection control programs need to be improved to avoid nosocomial spread.
Quienes nos adscribimos al realismo metafísico y tenemos a Robert Spaemann como uno de nuestros filósofos de referencia, celebramos que Comares haya editado una “introducción a la ética de Robert ...Spaemann”, elaborada por la profesora de la Universidad Católica de Ávila y de la Universidad Pontificia de Salamanca Mª Luisa Pro Velasco (Pro Velasco, 2021).
En su introducción, la autora señala que su estudio viene a cubrir el vacío provocado por la escasez de trabajos sobre el filósofo alemán. Y ciertamente lo hace. Por eso, no se trata tanto de un ensayo dirigido a quienes ya conocemos a Spaemann, cuanto de una síntesis orientada a seducir a un público culto de amplio espectro, interesado por la filosofía y cansado de las propuestas éticas idealistas (e ideológicas), para que descubra la obra de este gran filósofo y se adhiera a su idea de que la verdad, por más que sea perspectivista y se deje decir desde múltiples ubicaciones, es siempre verdad y se asienta sobre la realidad.
En lo que sigue, ofrecemos una breve recensión del contenido del libro, al objeto de ayudar a los lectores a decidirse en favor de su lectura.
Resynchronization of the Asynchronous Polar CD Ind Myers, Gordon; Patterson, Joseph; Miguel, Enrique de ...
Publications of the Astronomical Society of the Pacific,
04/2017, Letnik:
129, Številka:
974
Journal Article
Recenzirano
Odprti dostop
CD Ind is one of only four confirmed asynchronous polars (APs). APs are strongly magnetic cataclysmic variables of the AM Herculis subclass with the characteristic that their white dwarfs rotate a ...few percent out of synchronism with their binary orbit. Theory suggests that nova eruptions disrupt previously synchronized states. Following the eruption, the system is expected to rapidly resynchronize over a timescale of centuries. The other three asynchronous polars-V1432 Aql, BY Cam, and V1500 Cyg-have resynchronization time estimates ranging from 100 to more than 3500 years, with all but one being less than 1200 years. We report on the analysis of over 46,000 observations of CD Ind taken between 2007 and 2016, combined with previous observations from 1996, and estimate a CD Ind resynchronization time of 6400 800 years. We also estimate an orbital period of 110.820(1) minutes and a current (2016.4) white dwarf spin period of 109.6564(1) minutes.
Mycobacterium tuberculosis causes the majority of tuberculosis (TB) cases in humans; however, in developing countries, human TB caused by M. bovis may be frequent but undetected. Human TB caused by ...M. bovis is considered a zoonosis; transmission is mainly through consumption of unpasteurized dairy products, and it is less frequently attributed to animal-to-human or human-to-human contact. We describe the trends of M. bovis isolation from human samples and first-line drug susceptibility during a 15-year period in a referral laboratory located in a tertiary care hospital in Mexico City.
Data on mycobacterial isolates from human clinical samples were retrieved from the laboratory's database for the 2000-2014 period. Susceptibility to first-line drugs: rifampin, isoniazid, streptomycin (STR) and ethambutol was determined. We identified 1,165 isolates, 73.7% were M. tuberculosis and 26.2%, M. bovis. Among pulmonary samples, 16.6% were M. bovis. The proportion of M. bovis isolates significantly increased from 7.8% in 2000 to 28.4% in 2014 (X(2)trend, p<0.001). Primary STR resistance was higher among M. bovis compared with M. tuberculosis isolates (10.9% vs.3.4%, p<0.001). Secondary multidrug resistance (MDR) rates were 38.5% and 34.4% for M. bovis and M. tuberculosis, respectively (p = 0.637). A rising trend of primary STR monoresistance was observed for both species (3.4% in 2000-2004 vs. 7.6% in 2010-2014; p = 0.02).
There is a high prevalence and a rising trend of M. bovis isolates in our region. The proportion of pulmonary M. bovis isolates is higher than in previous reports. Additionally, we report high rates of primary anti-tuberculosis resistance and secondary MDR in both M. tuberculosis and M. bovis. This is one of the largest reports on drug susceptibility of M. bovis from human samples and shows a significant proportion of first-line anti-tuberculosis drug resistance.
Orbital Period Increase in ES Ceti Miguel, Enrique de; Patterson, Joseph; Kemp, Jonathan ...
Astrophysical journal/The Astrophysical journal,
01/2018, Letnik:
852, Številka:
1
Journal Article
Recenzirano
Odprti dostop
We report a long-term study of the eclipse times in the 10 minute helium binary ES Ceti. The binary period increases rapidly, with years. This is consistent with the assumption that gravitational ...radiation (GR) drives the mass transfer, and it appears to be the first dynamical evidence that GR is indeed the driver of evolution in this class of very old cataclysmic variables-the AM Canum Venaticorum stars.
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