Search results for "Flare"

Accretion disk coronae of intermediate polar cataclysmic variables

2017

Context. Intermediate polar cataclysmic variables (IPCV) contain a magnetic, rotating white dwarf surrounded by a magnetically truncated accretion disk. To explain their strong flickering X-ray emission, accretion has been successfully taken into account. Nevertheless, observations suggest that accretion phenomena might not be the only process behind it. An intense flaring activity occurring on the surface of the disk may generate a corona, contribute to the thermal X-ray emission, and influence the system stability. Aims. Our purposes are: investigating the formation of an extended corona above the accretion disk, due to an intense flaring activity occurring on the disk surface; studying t…

Accretion disk coronae of Intermediate Polar Cataclysmic Variables: 3D MagnetoHydroDynamic modeling and thermal X-ray emission

Intermediate Polar Cataclysmic Variables (IPCVs), also known as DQ Her stars after their prototype, are cataclysmic variable stars characterized by the presence of an accreting, magnetic, rapidly rotating white dwarf surrounded by an accretion disk magnetically truncated by the inner magnetosphere of the star. These objects exhibit a magnetic field of the order of few MG, able to disrupt the inner part of the disk but not strong enough to inhibit the formation of a disk. These stars show a strong X-ray emission with a stochastic pulsation that in some cases arise in the inner part of the disk. However, the observations of the X-ray luminosity for these objects do not match the expected valu…

Effects of different physical therapy programs on perceived health status in acute exacerbation of chronic obstructive pulmonary disease patients: a …

2017

To evaluate the repercussion of different physical therapy interventions on the perceived health status of chronic obstructive pulmonary disease (COPD) patients during acute exacerbation.Randomized controlled trial. Patients were assigned to: control group (standard medical treatment), controlled breathing + range of motion exercises group or Resistance exercises group. Perceived health status was assessed at baseline and discharge using the EuroQol-5D (EQ-5D) questionnaire. Clinical profile of patients was evaluated at baseline for descriptive purposes.Ninety patients were randomized into the groups. Perceived health status improved significantly in all groups. Significant differences were…

High flow nasal therapy versus noninvasive ventilation as initial ventilatory strategy in COPD exacerbation: a multicenter non-inferiority randomized…

2020

Abstract Background The efficacy and safety of high flow nasal therapy (HFNT) in patients with acute hypercapnic exacerbation of chronic obstructive pulmonary disease (AECOPD) are unclear. Our aim was to evaluate the short-term effect of HFNT versus NIV in patients with mild-to-moderate AECOPD, with the hypothesis that HFNT is non-inferior to NIV on CO2 clearance after 2 h of treatment. Methods We performed a multicenter, non-inferiority randomized trial comparing HFNT and noninvasive ventilation (NIV) in nine centers in Italy. Patients were eligible if presented with mild-to-moderate AECOPD (arterial pH 7.25–7.35, PaCO2 ≥ 55 mmHg before ventilator support). Primary endpoint was the mean di…

Quality standards for the management of bronchiectasis in Italy: A national audit

2016

Although historically considered a neglected disease, bronchiectasis has become a disease of renewed interest over recent decades in light of an increase in prevalence and a substantial burden on healthcare systems. In 2010, the British Thoracic Society (BTS) published guidelines on the management of bronchiectasis in adults, along with specific quality standards. To date, these represent the only quality standards available in Europe. These have been tested over a number of years in the UK with progressive improvements in the standard of care. No national guidelines are available in Italy and no indications on which guideline should be followed have been given by the Italian Society of Res…

Characteristics of patients with an unplanned admission to an acute palliative care unit

2016

The aim of this cohort study is to compare the symptom burden of patients who have an unplanned admission to an acute palliative care unit (APCU) with patients who have a regular planned admission. A consecutive sample of advanced cancer patients who were admitted to an APCU was prospectively assessed. The reasons and the kind of admission were recorded (unplanned, UP, or planned, P). Anticancer treatments, whether patients were on/off treatment or uncertain, previous care setting, and who referred the patient to the unit were also recorded. The Edmonton Symptom Assessment Scale (ESAS) was used at admission and at time of discharge, as well as the Memorial Delirium Assessment Scale. Analges…

The cool Galactic R Coronae Borealis variable DY Persei

2005

Results of first CCD photometry during the recent deep light decline, and high-resolution spectroscopy, are presented for DY Persei. The spectra show variable blueshifted features in the sodium D lines. The C  lines are strong whereas neutron- capture elements are not enhanced. The isotopic 13 CN(2, 0) lines relative to 12 CN are of similar strength with those for the carbon star U Hya. All these confirm the RCB nature of DY Per and the existence of ejected clouds. At least two clouds are revealed at −197.3 and −143.0 km s −1 . A star was detected about 0. 4t o the west and 2 . 5 to the north from DY Per. This anonymous companion, with observed colour indices (B − V) = 0.68 and (V − R) � 1…

Gamma-ray burst afterglow light curves from realistic density profiles

2011

The afterglow emission that follows gamma-ray bursts (GRBs) contains valuable information about the circumburst medium and, therefore, about the GRB progenitor. Theoretical studies of GRB blast waves, however, are often limited to simple density profiles for the external medium (mostly constant density and power-law R^{-k} ones). We argue that a large fraction of long-duration GRBs should take place in massive stellar clusters where the circumburst medium is much more complicated. As a case study, we simulate the propagation of a GRB blast wave in a medium shaped by the collision of the winds of O and Wolf-Rayet stars, the typical distance of which is d /sim 0.1 - 1 pc. Assuming a spherical…

Reconnection nanojets in the solar corona

2020

P.A. acknowledges STFC support from grant numbers ST/R004285/2 and ST/T000384/1 and support from the International Space Science Institute, Bern, Switzerland to the International Teams on ‘Implications for coronal heating and magnetic fields from coronal rain observations and modeling’ and ‘Observed Multi-Scale Variability of Coronal Loops as a Probe of Coronal Heating’. This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement no. 647214). P.T. was also supported by contracts 8100002705 and SP02H1701R from Lockheed-Martin to the Smithsonian Astrophysical Observatory (SAO), and NASA c…

A statistical analysis of X-ray variability in pre-main sequence objects of the Taurus Molecular Cloud

2006

This work is part of a systematic X-ray survey of the Taurus star forming complex with XMM-Newton. We study the time series of all X-ray sources associated with Taurus members, to statistically characterize their X-ray variability, and compare the results to those for pre-main sequence stars in the Orion Nebula Cluster and to expectations arising from a model where all the X-ray emission is the result of a large number of stochastically occurring flares. We find that roughly half of the detected X-ray sources show variability above our sensitivity limit, and in ~ 26 % of the cases this variability is recognized as flares. Variability is more frequently detected at hard than at soft energies…