Search results for "LSA"
showing 10 items of 832 documents
Discovery of a soft X-ray 8 mHz QPO from the accreting millisecond pulsar IGR J00291+5934
2016
In this paper, we report on the analysis of the peculiar X-ray variability displayed by the accreting millisecond X-ray pulsar IGR J00291+5934 in a 80 ks-long joint NuSTAR and XMM-Newton observation performed during the source outburst in 2015. The light curve of the source was characterized by a flaring-like behavior, with typical rise and decay time scales of ~120 s. The flares are accompanied by a remarkable spectral variability, with the X-ray emission being generally softer at the peak of the flares. A strong quasi periodic oscillation (QPO) is detected at ~8 mHz in the power spectrum of the source and clearly associated with the flaring-like behavior. This feature has the strongest po…
Are pulsars born with a hidden magnetic field?
2015
The observation of several neutron stars in the center of supernova remnants and with significantly lower values of the dipolar magnetic field than the average radio-pulsar population has motivated a lively debate about their formation and origin, with controversial interpretations. A possible explanation requires the slow rotation of the proto-neutron star at birth, which is unable to amplify its magnetic field to typical pulsar levels. An alternative possibility, the hidden magnetic field scenario, considers the accretion of the fallback of the supernova debris onto the neutron star as responsible for the submergence (or screening) of the field and its apparently low value. In this paper …
Observation of TeV gamma rays from the Cygnus region with the ARGO-YBJ experiment
2012
We report the observation of TeV gamma-rays from the Cygnus region using the ARGO-YBJ data collected from 2007 November to 2011 August. Several TeV sources are located in this region including the two bright extended MGRO J2019+37 and MGRO J2031+41. According to the Milagro data set, at 20 TeV MGRO J2019+37 is the most significant source apart from the Crab Nebula. No signal from MGRO J2019+37 is detected by the ARGO-YBJ experiment, and the derived flux upper limits at 90% confidence level for all the events above 600 GeV with medium energy of 3 TeV are lower than the Milagro flux, implying that the source might be variable and hard to be identified as a pulsar wind nebula. The only statist…
Noticias del caos
2007
Non-thermal radiation from a pulsar wind interacting with an inhomogeneous stellar wind
2017
Binaries hosting a massive star and a non-accreting pulsar are powerful non-thermal emitters due to the interaction of the pulsar and the stellar wind. The winds of massive stars are thought to be inhomogeneous, which could have an impact on the non-thermal emission. We study numerically the impact of the presence of inhomogeneities or clumps in the stellar wind on the high-energy non-thermal radiation of high-mass binaries hosting a non-accreting pulsar. We compute the trajectories and physical properties of the streamlines in the shocked pulsar wind without clumps, with a small clump, and with a large one. This information is used to compute the synchrotron and inverse Compton emission fr…
Activity from the Be/X-ray binary system V0332+53 during its intermediate-luminosity outburst in 2008
2015
Aims: We present a study of the Be/X-ray binary system V 0332+53 with the main goal of characterizing its behavior mainly during the intermediate-luminosity X-ray event on 2008. In addition, we aim to contribute to the understanding of the global behavior of the donor companion by including optical data from our dedicated campaign starting on 2006. Methods: V 0332+53 was observed by RXTE and Swift during the decay of the intermediate-luminosity X-ray outburst of 2008, as well as with Suzaku before the rising of the third normal outburst of the 2010 series. In addition, we present recent data from the Spanish ground-based astronomical observatories of El Teide (Tenerife), Roque de los Muchac…
Determination of phenytoin in plasma by molecularly imprinted solid-phase extraction.
2001
Abstract A molecularly imprinted polymer (MIP) using phenytoin as template and methacrylamide as the functional monomer was prepared. The selectivity was measured by comparing capacity factors of phenytoin and other structurally related compounds. The polymer was evaluated as a selective sorbent in molecularly imprinted solid-phase extraction (MISPE). Several washing solvents were tested to study their ability to disrupt the non-specific interactions occurring between the sample and the polymer matrix and the role of water in the recognition process was also investigated. It was shown that the key step of successful sample extraction is the right choice of the washing solvent. Plasma sample…
Sexual Dysfunction and Mood Stabilizers in Long-Term Stable Patients With Bipolar Disorder.
2020
Abstract Background In addition to factors intrinsic to bipolar disorder (BD), sexual functioning (SF) can be affected by extrinsic causes, such as psychotropic drugs. However, the effect of mood stabilizers on SF and quality of life (QoL) is an underexplored research area. Aim To analyze SF in BD outpatients in euthymia for at least 6 months treated only with mood stabilizers and the association between SF and QoL. Methods A multicenter cross-sectional study was conducted in 114 BD outpatients treated with (i) lithium alone (L group); (ii) anticonvulsants alone (valproate or lamotrigine; A group); (iii) lithium plus anticonvulsants (L+A group); or (iv) lithium plus benzodiazepines (L+B gro…
Influence of dietary fat and carbohydrates proportions on plasma lipids, glucose control and low-grade inflammation in patients with type 2 diabetes—…
2015
Purpose: The optimal macronutrient composition of the diet for the management of type 2 diabetes is debated, particularly with regard to the ideal proportion of fat and carbohydrates. The aim of the study was to explore the association of different proportions of fat and carbohydrates of the diet—within the ranges recommended by different guidelines—with metabolic risk factors. Methods: We studied 1785 people with type 2 diabetes, aged 50–75, enrolled in the TOSCA.IT Study. Dietary habits were assessed using a validated food-frequency questionnaire (EPIC). Anthropometry, fasting lipids, HbA1c and C-reactive protein (CRP) were measured. Results: Increasing fat intake from <25 to ≥35 % is …