2,379 research outputs found
On the highly reddened members in 6 young galactic star clusters - a multiwavelength study
The spectral and reddening properties of 211 highly reddened proper motion
members with mag in 6 young galactic star clusters are investigated
using low resolution spectroscopic, broad-band and mid-IR data. We
report emission features in CaII HK and HI lines for a sample of 29 stars
including 11 stars reported for the first time and also provide either a new or
more reliable spectral class for a sample of 24 stars. CaII triplet width
measurements are used to indicate the presence of an accretion disk for a dozen
stars and to hint luminosity for a couple of stars. On the basis of spectral
features, near-IR excesses, dereddened color-color diagrams and mid-IR spectral
indices we identify a group of 28 pre-main sequence cluster members including 5
highly probable Herbig Ae/Be and 6 classical T Tauri star. A total of 25
non-emission MS stars, amounting to 10 % early type MS members, appears
to show Vega-like characteristics or are precursors to such a phenomenon. The
various membership indicators suggest that 16% of the PM members are
non-members. A significant fraction (70%) of program stars in NGC 1976, NGC
2244, NGC 6530 and NGC 6611 show anomalous reddening with =
, , and , respectively,
indicating the presence of grain size dust larger than that typical to the
diffuse medium. A small number of stars in NGC 1976, NGC 2244 and NGC 6611 also
show normal behavior while the cluster NGC 6823 appears to have a normal
reddening. Three highly luminous late type giants, one in NGC 2244 and two in
NGC 6530, appears to be member and are in post-hydrogen-core-burning stages
suggesting a prolonged duration ( 25 Myrs) of star formation.Comment: 12 pages, 13 figures, submitted to MNRA
Recommended from our members
DFN-02, Sumatriptan 10 mg Nasal Spray with Permeation Enhancer, for the Acute Treatment of Migraine: A Randomized, Double-Blind, Placebo-Controlled Study Assessing Functional Disability and Subject Satisfaction with Treatment.
BackgroundThe commercial formulation of sumatriptan nasal spray is an effective option for migraine patients requiring or preferring a non-oral route of drug administration, but its utility is limited by poor absorption and tolerability issues. DFN-02, a new formulation of sumatriptan 10 mg nasal spray, is co-formulated with a permeation enhancer that gives it pharmacokinetics comparable to subcutaneous sumatriptan. As reported previously, DFN-02 was significantly better than placebo on multiple efficacy endpoints at 2 h postdose, including pain freedom, absence of the most bothersome symptom, and pain relief, and its safety and tolerability profiles were excellent.ObjectiveThe objective of this study was to assess the efficacy of acute treatment of migraine with DFN-02, including its effect on migraine-related functional disability and patient satisfaction with treatment.MethodsThis was a multicenter, randomized, double-blind, placebo-controlled efficacy and safety study of DFN-02 in adults with episodic migraine. Functional disability and subject satisfaction with treatment were prespecified endpoints, assessed in real-time by subjects, using an electronic diary.ResultsIn total, 107 subjects were randomized. DFN-02 was significantly superior to placebo for the reduction in functional disability score from predose level at 2 h after treatment (- 1.2 vs. - 0.6, p < 0.001). Subjects treated with DFN-02 were also more likely to be satisfied or very satisfied than subjects treated with placebo at 2 h postdose (70.0% vs. 44.2%, p = 0.027). Using the Patient Perception of Migraine Questionnaire-Revised at 24 h postdose, DFN-02 mean scores were significantly superior to placebo for the subscales of efficacy (65.2 vs. 42.5, p = 0.016) and function (68.9 vs. 42.1, p = 0.001), and for total score (71.0 vs. 56.6, p = 0.016); global medication effectiveness (p = 0.027); and overall satisfaction (p = 0.019). Placebo was significantly better than DFN-02 on the tolerability subscale (94.8 vs. 88.5, p = 0.026). At 24 h postdose, subjects reported significantly higher satisfaction with DFN-02 compared with satisfaction reported pre-randomization regarding their usual migraine medication (p = 0.012).ConclusionDFN-02 was superior to placebo for the relief of migraine-related functional disability, and provided greater satisfaction than placebo or subjects' usual acute treatment.Trial registrationClinicalTrials.gov identifier: NCT02856802
CCD photometric and mass function study of 9 young Large Magellanic Cloud star clusters
We present CCD photometric and mass function study of 9 young Large
Magellanic Cloud star clusters namely NGC 1767, NGC 1994, NGC 2002, NGC 2003,
NGC 2006, SL 538, NGC 2011, NGC 2098 and NGC 2136. The BVRI data reaching down
to V ~ 21 mag, are collected from 3.5-meter NTT/EFOSC2 in sub-arcsec seeing
conditions. For NGC 1767, NGC 1994, NGC 2002, NGC 2003, NGC 2011 and NGC 2136,
broad band photometric CCD data are presented for the first time. Seven of the
9 clusters have ages between 16 to 25 Myr while remaining two clusters have
ages Myr (NGC 2098) and Myr (NGC 2136). For 7 younger
clusters, the age estimates based on a recent model and the integrated spectra
are found to be systematically lower ( 10 Myr) from the present estimate.
In the mass range of , the MF slopes for 8 out of nine
clusters were found to be similar with the value of ranging from
to . For NGC 1767 it is flatter with . Mass segregation effects are observed for NGC 2002, NGC 2006,
NGC 2136 and NGC 2098. This is consistent with the findings of Kontizas et al.
for NGC 2098. Presence of mass segregation in these clusters could be an
imprint of star formation process as their ages are significantly smaller than
their dynamical evolution time. Mean MF slope of
derived for a sample of 25 young ( Myr) dynamically unevolved LMC
stellar systems provide support for the universality of IMF in the intermediate
mass range .Comment: To appear in MNRA
A retrospective study of 50 cases of lower limb soft tissue infection and its different modalities of presentation and its management
Background: Soft tissue infections are common in everyday practice. They show great variations in their severity. Skin and soft tissue infections are usually preceded by minor traumatic events. Among them soft tissue bacterial infections of lower limbs are more common. Patients having diabetes makes the scenario even worst. Diagnosis, intervention and treatment of these infections are very important. This study aims at understanding the pathology involved for lower limb soft tissue infections, spectrum of organisms and different treatment modalities in various age group and gender.Methods: 50 cases of lower limb soft tissue infections were included in this study. Detailed history, clinical examination, investigations, pre-operative preparation, intraoperative details and post-operative management were included.Results: 94% patients were having history of trauma.88% patients were having history of diabetes. Staphylococcus aureus was the most common (43%) organism cultured from swabs followed by pseudomonas (36%) out of total cases. Minimum stay in hospital was of 4 days to a maximum of 34 days. Most of the patients were managed with regular dressing and debridement.Conclusions: The patients sought treatment only when they had extensive lesions which affect their daily living. Health education regarding foot care forms an integral part of surgical management of lower limb soft tissue infections. Readmissions are mainly due to inadequate local control or fluctuating blood sugar levels and improper foot care due to illiteracy, poverty, ignorance and lack of adequate primary care facilities
Modeling a high mass turn down in the stellar initial mass function
Statistical sampling from the stellar initial mass function (IMF) for all
star-forming regions in the Galaxy would lead to the prediction of ~1000 Msun
stars unless there is a rapid turn-down in the IMF beyond several hundred solar
masses. Such a turndown is not necessary for dense clusters because the number
of stars sampled is always too small. Here we explore several mechanisms for an
upper mass cutoff, including an exponential decline of the star formation
probability after a turbulent crossing time. The results are in good agreement
with the observed IMF over the entire stellar mass range, and they give a
gradual turn down compared to the Salpeter function above ~100 Msun for normal
thermal Jeans mass, M_J. The upper mass turn down should scale with M_J in
different environments. A problem with the models is that they cannot give both
the observed power-law IMF out to the high-mass sampling limit in dense
clusters, as well as the observed lack of supermassive stars in whole galaxy
disks. Either there is a sharper upper-mass cutoff in the IMF, perhaps from
self-limitation, or the IMF is different for dense clusters than for the
majority of star formation that occurs at lower density. Dense clusters seem to
have an overabundance of massive stars relative to the average IMF in a galaxy.Comment: 19 pages, 2 figures, Astrophysical Journal, Vol 539, August 10, 200
Complete Genome Sequence of Pelosinus fermentans JBW45, a Member of a Remarkably Competitive Group of Negativicutes in the Firmicutes Phylum.
The genome of Pelosinus fermentans JBW45, isolated from a chromium-contaminated site in Hanford, Washington, USA, has been completed with PacBio sequencing. Nine copies of the rRNA gene operon and multiple transposase genes with identical sequences resulted in breaks in the original draft genome and may suggest genomic instability of JBW45
Context Free Grammar (CFG) Analysis for simple Kannada sentences
When Computational Linguistic is concerns Kannada is lagging far behind compared to Telugu and Tamil. Writing the grammar production for any south Indian language is bit difficult. Because the languages are highly inflected with three gender forms and two number forms. This paper is an effort to write Context Free Grammar for simple Kannada sentences. Kannada Language being one of the major Dravidian languages of India and it has 27th place in most spoken language in the world. But still it does not yet have computerized grammar checking methods for a given Kannada sentence. Thus, this paper highlights the process of generating context free grammar for simple Kannada sentences
A Late-Time Flattening of Afterglow Light Curves
We present a sample of radio afterglow light curves with measured decay
slopes which show evidence for a flattening at late times compared to optical
and X-ray decay indices. The simplest origin for this behavior is that the
change in slope is due to a jet-like outflow making a transition to
sub-relativistic expansion. This can explain the late-time radio light curves
for many but not all of the bursts in the sample. We investigate several
possible modifications to the standard fireball model which can flatten
late-time light curves. Changes to the shock microphysics which govern particle
acceleration, or energy injection to the shock (either radially or azimuthally)
can reproduce the observed behavior. Distinguishing between these different
possibilities will require simultaneous optical/radio monitoring of afterglows
at late times.Comment: ApJ, submitte
Optical and Radio observations of the bright GRB010222 afterglow: evidence for rapid synchrotron cooling?
We report photometric observations of the optical afterglow of GRB010222 in
V,R and I passbands carried out at UPSO, Naini Tal between 22-27 Feb 2001. We
determine CCD Johnson BV and Cousins RI photometric magnitudes for 31 stars in
the field of GRB010222 and use them to calibrate our measurements as well as
other published BVRI photometric magnitudes of GRB010222 afterglow. We
construct the light curve in V,R,I passbands and from a broken power-law fit
determine the decay indices of 0.74+/-0.05 and 1.35+/-0.04 before and after the
break at 0.7 days. Using reported X-ray flux measurements at 0.35 and 9.13 days
after the burst we determine X-ray to opt/IR spectral index of 0.61+/-0.02 and
0.75+/-0.02 on these two days. We also report upper limits to the radio flux
obtained from the RATAN-600 telescope and the GMRT, and millimeter-wave upper
limits obtained from the Plateau de Bure Millimeter interferometer. We argue
that the synchrotron cooling frequency is below the optical band for most of
the observing period. We also estimate an initial jet opening angle of about
2.0n^(1/8) degrees, where n is the number density of the ambient medium.Comment: 16 pages, 4 postscript figures, minor revisions according to
referee's comments, millimeter upper limit added, accepted for publication in
Bulletin of the Astronomical Society of Indi
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