283 research outputs found
AstroSat view of MAXI J1535-571: broadband spectro-temporal features
We present the results of Target of Opportunity (ToO) observations made with
AstroSat of the newly discovered black hole binary MAXI J1535-571. We detect
prominent C-type Quasi-periodic Oscillations (QPOs) of frequencies varying from
1.85 Hz to 2.88 Hz, along with distinct harmonics in all the AstroSat
observations. We note that while the fundamental QPO is seen in the 3 - 50 keV
energy band, the harmonic is not significant above ~ 35 keV. The AstroSat
observations were made in the hard intermediate state, as seen from state
transitions observed by MAXI and Swift. We attempt spectral modelling of the
broadband data (0.7-80 keV) provided by AstroSat using phenomenological and
physical models. The spectral modelling using nthComp gives a photon index in
the range between 2.18-2.37 and electron temperature ranging from 21 to 63 keV.
The seed photon temperature is within 0.19 to 0.29 keV. The high flux in 0.3 -
80 keV band corresponds to a luminosity varying from 0.7 to 1.07 L_Edd assuming
the source to be at a distance of 8 kpc and hosting a black hole with a mass of
6 M. The physical model based on the two-component accretion flow
gives disc accretion rates as high as ~ 1 and halo rate ~ 0.2
respectively. The near Eddington accretion rate seems to be the
main reason for the unprecedented high flux observed from this source. The
two-component spectral fitting of AstroSat data also provides an estimate of a
black hole mass between 5.14 to 7.83 M.Comment: 15 pages, 9 figures, MNRAS (Accepted on 2019 May 10
Nonleptonic two-body charmless B decays involving a tensor meson in ISGW2 model
Nonleptonic charmless B decays into a pseudoscalar (P) or a vector (V) meson
accompanying a tensor (T) meson are re-analyzed. We scrutinize the hadronic
uncertainties and ambiguities of the form factors which appear in the
literature. The Isgur-Scora-Grinstein-Wise updated model (ISGW2) is adopted to
evaluate the relevant hadronic matrix elements. We calculate the branching
ratios and CP asymmetries for various decay processes. With the
ISGW2 model, the branching ratios are enhanced by about an order of magnitude
compared to the previous estimates. We show that the ratios \calB(B\to
VT)/\calB(B\to PT) for some strangeness-changing processes are very sensitive
to the CKM angle ().Comment: 23 pages, REVTEX; minor clarifications included; to appear in Phys.
Rev.
Hadronic decays of B involving a tensor meson through a transition
We re-analyze hadronic decays of B mesons to a pseudoscalar (P) and a tensor
meson (T), or a vector meson (V) and a tensor meson, through a
transition. We discuss possible large uncertainties to branching ratios (BR's)
of the relevant modes, mainly arising from uncertainties to the hadronic form
factors for the transition. The BR's and CP asymmetries for and VT decays are then calculated by using the form factors given in the
ISGW2 model (the improved version of the original Isgur-Scora-Grinstein-Wise
(ISGW) model). We find that the estimated BR's of many modes are increased by
an order of magnitude, compared to the previous results calculated within the
ISGW model.Comment: 22 pages, LaTex; minor clarifications included; to appear in Phys.
Rev.
Hadronic B Decays Involving Even Parity Charmed Mesons
Hadronic B decays containing an parity-even charmed meson in the final state
are studied. Specifically we focus on the Cabibbo-allowed decays and , where denotes generically a p-wave charmed meson.
The transition form factors are studied in the improved version
of the Isgur-Scora-Grinstein-Wise quark model. We apply heavy quark effective
theory and chiral symmetry to study the strong decays of p-wave charmed mesons
and determine the magnitude of the mixing angle. Except
the decay to the predictions for agree
with experiment. The sign of mixing angle is found to be
positive in order to avoid a severe suppression on the production of
. The interference between color-allowed and color-suppressed
tree amplitudes is expected to be destructive in the decay . Hence, an observation of the ratio
can be used to test the relative signs of
various form factors as implied by heavy quark symmetry. Although the predicted
at the level of exceeds the
present upper limit, it leads to the ratio
as expected from the factorization
approach and from the ratio . Therefore, it is
crucial to have a measurement of this mode to test the factorization
hypothesis. For decays, it is expected that \bar
D_{s0}^*D\gsim \bar D_{s1}D as the decay constants of the multiplet
become the same in the heavy quark limit.Comment: 27 pages, Belle's new data on DD_s^{**} productions in B decays and
on the radiative decay D_{s1}-> D_s\gamma are updated and discussed. Add two
reference
Family-led rehabilitation after stroke in India (ATTEND): a randomised controlled trial
Background:
Most people with stroke in India have no access to organised rehabilitation services. The effectiveness of training family members to provide stroke rehabilitation is uncertain. Our primary objective was to determine whether family-led stroke rehabilitation, initiated in hospital and continued at home, would be superior to usual care in a low-resource setting.
Methods:
The Family-led Rehabilitation after Stroke in India (ATTEND) trial was a prospectively randomised open trial with blinded endpoint done across 14 hospitals in India. Patients aged 18 years or older who had had a stroke within the past month, had residual disability and reasonable expectation of survival, and who had an informal family-nominated caregiver were randomly assigned to intervention or usual care by site coordinators using a secure web-based system with minimisation by site and stroke severity. The family members of participants in the intervention group received additional structured rehabilitation training—including information provision, joint goal setting, carer training, and task-specific training—that was started in hospital and continued at home for up to 2 months. The primary outcome was death or dependency at 6 months, defined by scores 3–6 on the modified Rankin scale (range, 0 [no symptoms] to 6 [death]) as assessed by masked observers. Analyses were by intention to treat. This trial is registered with Clinical Trials Registry-India (CTRI/2013/04/003557), Australian New Zealand Clinical Trials Registry (ACTRN12613000078752), and Universal Trial Number (U1111-1138-6707).
Findings:
Between Jan 13, 2014, and Feb 12, 2016, 1250 patients were randomly assigned to intervention (n=623) or control (n=627) groups. 33 patients were lost to follow-up (14 intervention, 19 control) and five patients withdrew (two intervention, three control). At 6 months, 285 (47%) of 607 patients in the intervention group and 287 (47%) of 605 controls were dead or dependent (odds ratio 0·98, 95% CI 0·78–1·23, p=0·87). 72 (12%) patients in the intervention group and 86 (14%) in the control group died (p=0·27), and we observed no difference in rehospitalisation (89 [14%]patients in the intervention group vs 82 [13%] in the control group; p=0·56). We also found no difference in total non-fatal events (112 events in 82 [13%] intervention patients vs 110 events in 79 [13%] control patients; p=0·80).
Interpretation:
Although task shifting is an attractive solution for health-care sustainability, our results do not support investment in new stroke rehabilitation services that shift tasks to family caregivers, unless new evidence emerges. A future avenue of research should be to investigate the effects of task shifting to health-care assistants or team-based community care.
Funding:
The National Health and Medical Research Council of Australia
EMERGING QUALITY CONTROL PERSPECTIVES FOR AYURVEDIC DRUG
Ayush system of medicines based Herbal Pharmaceutical industry (ASU & H drug mfg) is having great potential and opportunities in India for development in future because of global acceptability of the medicinal plants & their value added products in Domestic & International Market as Ayurvedic, Unani and Siddha medicines, Herbal Nutraceuticals, Herbal Cosmoceutical, Herbal Health drinks, Dietary Health Supplements, Medicinal Plants / Crude Drugs, Herbal Extracts / Concentrates, Veterinary Medicines, Health Foods. India is rich with 771468 registered Ayush practitioners, 8667 licensed Ayurvedic drug manufacturing units. Quality Control/Assurance is the department, which controls all activities at various level of manufacturing as National & International standard. Ministry of Ayush continues to lay emphasis on up gradation of AYUSH educational standards, Quality control and standardisation of drugs, improving the availability of medicinal plant material, research and development and awareness generation about the efficacy of the system domestically and internationally. There are various issues & challenges related to drug quality for ASU&H Pharmaceutical Industries in India. It needs proper attention of policy makers and regulator & academia. Complete Implementation of GMP (schedule T) norm/guidelines and quality control/assurance procedure and activities is a big challenge for ensuring quality of drug
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