659 research outputs found
Bayesian evidence for two companions orbiting HIP 5158
We present results of a Bayesian analysis of radial velocity (RV) data for
the star HIP 5158, confirming the presence of two companions and also
constraining their orbital parameters. Assuming Keplerian orbits, the
two-companion model is found to be e^{48} times more probable than the
one-planet model, although the orbital parameters of the second companion are
only weakly constrained. The derived orbital periods are 345.6 +/- 2.0 d and
9017.8 +/- 3180.7 d respectively, and the corresponding eccentricities are 0.54
+/- 0.04 and 0.14 +/- 0.10. The limits on planetary mass (m \sin i) and
semimajor axis are (1.44 +/- 0.14 M_{J}, 0.89 +/- 0.01 AU) and (15.04 +/- 10.55
M_{J}, 7.70 +/- 1.88 AU) respectively. Owing to large uncertainty on the mass
of the second companion, we are unable to determine whether it is a planet or a
brown dwarf. The remaining `noise' (stellar jitter) unaccounted for by the
model is 2.28 +/- 0.31 m/s. We also analysed a three-companion model, but found
it to be e^{8} times less probable than the two-companion model.Comment: 5 pages, 4 figures, 3 tables. Added a couple of figures showing the
residuals after one and two companion fits. Accepted for publication in MNRAS
Letter
QSAR studies on Withanolide analogs for anticancer activity
Withanolides are a group of pharmacologically active compounds present in most prodigal amounts in roots and leaves of Withania somnifera (Indian ginseng), one of the most important medicinal plants of Indian systems of medicine. Withanolides are basically steroidal lactones (highly oxygenated C-28 phytochemicals) and similar to ginsenosides activity. Some of the withanolides that have been reported possess immunomodulatory, and anticancer activities. In the present investigation, a quantitative structure activity relationship (QSAR) model based on forward stepwise multiple linear regression (MLR) has been developed against the MCF7, MCF7/BUS, and SK-Br-3 human solid tumor breast cancer cell lines. Relationship correlation coefficient (r2) and cross validation correlation coefficient (r2CV) of QSAR model were 0.77 and 0.73 for MCF7, 0.91 and 0.85 for MCF7/BUS, 0.93 and 0.90 for SK-Br-3 respectively. Developed QSAR model was also evaluated for prediction accuracy through internal, external and randomization validation methods. The QSAR study indicates that chemical descriptors viz., atom count (all atoms), connectivity index (order 2, standard), for MCF7, Connectivity Index (order 0, standard), Dipole Vector X (debye), Molar Refractivity, Shape Index (basic kappa, order 2) for SK-Br-3 and Atom Count (all atoms), Dielectric Energy (kcal/mole), Total Energy (Hartree), Heat of Formation (kcal/mole) for MCF7/BUS are correlate well with the breast cancer activity, Moreover, on the basis of screening for oral bioavailability, in silico ADME and toxicity risk assessment, we concluded that compounds W3, W4, W8 have markedly higher anticancer activity compared to control. These results can offer useful references for directing the molecular design of lead compound(s) based on withanolide or analogous template with improved activity
Classifying LISA gravitational wave burst signals using Bayesian evidence
We consider the problem of characterisation of burst sources detected with
the Laser Interferometer Space Antenna (LISA) using the multi-modal nested
sampling algorithm, MultiNest. We use MultiNest as a tool to search for
modelled bursts from cosmic string cusps, and compute the Bayesian evidence
associated with the cosmic string model. As an alternative burst model, we
consider sine-Gaussian burst signals, and show how the evidence ratio can be
used to choose between these two alternatives. We present results from an
application of MultiNest to the last round of the Mock LISA Data Challenge, in
which we were able to successfully detect and characterise all three of the
cosmic string burst sources present in the release data set. We also present
results of independent trials and show that MultiNest can detect cosmic string
signals with signal-to-noise ratio (SNR) as low as ~7 and sine-Gaussian signals
with SNR as low as ~8. In both cases, we show that the threshold at which the
sources become detectable coincides with the SNR at which the evidence ratio
begins to favour the correct model over the alternative.Comment: 21 pages, 11 figures, accepted by CQG; v2 has minor changes for
consistency with accepted versio
Recommended from our members
Lysosomal oxidation of LDL alters lysosomal pH, induces senescence and increases secretion of pro-inflammatory cytokines in human macrophages
Objective
We have shown that aggregated low density lipoproteins (LDL) is internalised by macrophages and oxidised in lysosomes by redox-active iron. We have now investigated if the lysosomal oxidation of LDL impairs lysosomal function and if a lysosomotropic antioxidant can prevent these alterations.
Approach and Results
LDL aggregated by sphingomyelinase (SMase-LDL) caused increased lysosomal lipid peroxidation in human monocyte-derived macrophages or THP-1 macrophage-like cells, as shown by a fluorescent probe, Foam-LPO. The pH of the lysosomes was increased considerably by lysosomal LDL oxidation as shown by Lysosensor Yellow/Blue and LysoTracker Red. SMase-LDL induced senescence-like properties in the cells as shown by β-galactosidase staining and levels of p53 and p21. Inflammation plays a key role in atherosclerosis. SMase-LDL treatment increased the LPS-induced secretion of TNF-α, IL-6 and MCP-1. The lysosomotropic antioxidant, cysteamine inhibited all of the above changes.
Conclusions
Targeting lysosomes with antioxidants, such as cysteamine, to prevent the intralysosomal oxidation of LDL might be a novel therapy for atherosclerosis
Distributional patterns of brachyuran larvae in Manora Channel (Karachi, Pakistan) collected during 1995
This study gives an account of distributional patterns of Brachyuran larvae in the Manora Channel from January to November 1995. The planktonic sampling was carried out during day time from surface and sub-surface waters of station I and II (certain sites) at shallow depths (15'-20') using Bongo net of 300 micron mesh size. In all 19527 larvae were obtained through fourteen sampling. These brachyuran larvae belonged to nine families and twenty four species: Ebalia sagittifera, Philyra sp., Philyra scabriuscula (Leucosiidae), Schizophyris aspera (Majidae), Charybdis annulata, Charybdis sp. (Portunidae), Xanthid sp A., B. and C. (Xanthidae), Pilumnus karachiensis, Pilumnus sp. (Pilumnidae), Menippe rumphii (Oziidae), Pinnotheres sp. A, and B. (Pinnotheridae), Nasima dotilliforme, Serenella indica, Macrophthalmus (Mareotis) depressus, Macrophthalmus sp., Dotilla blanfordi, Ocypodid sp. A., B. and C. (Ocypodidae), Metopograpsus thukuhar and Clistocoeloma lanatum (Grapsidae). This study is based on identification, occurrence, distributional patterns along Manora Channel and percentage composition of brachyuran larvae in the area, collected during 1995
Occurrence and abundance of brachyuran larvae in the Manora Channel (Karachi, Pakistan) during 1993
The present paper investigates the occurrence and abundance of
brachyuran larvae in the Manora Channel during August- December 1993. The fortnightly planktonic sampling was carried out in Manora Channel which is bordered by mangroves, during day time from surface and subsurface waters at shallow depth using Bongo net of 300 micron mesh size. Analysis of samples revealed presence of brachyuran larvae of 12 species belonging to 6 families. Of these 4 species are confirmed: Serenella indica, Dotilla blanfordi,
Metopograpsus thukuhar and Clistocoeloma lanatum, 2 provisionally identified species are: Pilumnus ?karachiensis and Pinnotheres ?pisum, 2 species are identified upto generic level: Philyra sp. and Pinnotheres sp., and 1 Ocypodid species and 3 Xanthid species are identified upto family level.
This study based on identification, occurrence and abundance of brachyuran larvae in the area, also gives percentage composition of brachyuran larvae collected during 1993, in the Manora Channel
CARMA observations of massive Planck-discovered cluster candidates at z>0.5 associated with WISE overdensities: Breaking the size-flux degeneracy
We use a Bayesian software package to analyze CARMA-8 data towards 19
unconfirmed Planck SZ-cluster candidates from Rodriguez-Gonzalvez et al.
(2015), that are associated with significant overdensities in WISE. We used two
cluster parameterizations, one based on a (fixed shape) generalized-NFW
pressure profile and another based on a beta-gas-density profile (with varying
shape parameters) to obtain parameter estimates for the nine CARMA-8
SZ-detected clusters. We find our sample is comprised of massive,
Y_{500}=0.0010 \pm 0.0015 arcmin^2, relatively compact, theta_{500}= 3.9 \pm
2.0 arcmin systems. Results from the beta model show that our cluster
candidates exhibit a heterogeneous set of brightness-temperature profiles.
Comparison of Planck and CARMA-8 measurements showed good agreement in Y_{500}
and an absence of obvious biases. We estimated the total cluster mass M_{500}
as a function of z for one of the systems; at the preferred photometric
redshift of 0.5, the derived mass, M_{500} \approx 0.8 \pm 0.2 \times 10^{15}
Msun. Spectroscopic Keck/MOSFIRE data confirmed a galaxy member of one of our
cluster candidates to be at z=0.565. Applying a Planck prior in Y_{500} to the
CARMA-8 results reduces uncertainties for both parameters by a factor >4,
relative to the independent Planck or CARMA-8 measurements. We here demonstrate
a powerful technique to find massive clusters at intermediate z \gtrsim 0.5
redshifts using a cross-correlation between Planck and WISE data, with
high-resolution follow-up with CARMA-8. We also use the combined capabilities
of Planck and CARMA-8 to obtain a dramatic reduction by a factor of several, in
parameter uncertainties.Comment: 26 pages, 8 figures, appearing in MNRAS (responded to referee report
Bayes-X: a Bayesian inference tool for the analysis of X-ray observations of galaxy clusters
We present the first public release of our Bayesian inference tool, Bayes-X,
for the analysis of X-ray observations of galaxy clusters. We illustrate the
use of Bayes-X by analysing a set of four simulated clusters at z=0.2-0.9 as
they would be observed by a Chandra-like X-ray observatory. In both the
simulations and the analysis pipeline we assume that the dark matter density
follows a spherically-symmetric Navarro, Frenk and White (NFW) profile and that
the gas pressure is described by a generalised NFW (GNFW) profile. We then
perform four sets of analyses. By numerically exploring the joint probability
distribution of the cluster parameters given simulated Chandra-like data, we
show that the model and analysis technique can robustly return the simulated
cluster input quantities, constrain the cluster physical parameters and reveal
the degeneracies among the model parameters and cluster physical parameters. We
then analyse Chandra data on the nearby cluster, A262, and derive the cluster
physical profiles. To illustrate the performance of the Bayesian model
selection, we also carried out analyses assuming an Einasto profile for the
matter density and calculated the Bayes factor. The results of the model
selection analyses for the simulated data favour the NFW model as expected.
However, we find that the Einasto profile is preferred in the analysis of A262.
The Bayes-X software, which is implemented in Fortran 90, is available at
http://www.mrao.cam.ac.uk/facilities/software/bayesx/.Comment: 22 pages, 11 figure
A Study on Dispensing Pattern of OTC (Over the Counter) Medication among Community Pharmacist in Kalaburagi City
Purpose: Over the counter drugs (OTC) are sold without the prescription of a registered medical practitioner. There are reports that OTC drug market in India is on the rise. This is attributed to the rising cost of healthcare, difficulty in accessing healthcare, and an alarming tendency to self-manage symptoms. The outcome of this is OTC related adverse effects, abuse and hospitalizations.
Subjects and Methods: The primary objective was to assess the knowledge of drug dispensing pattern of community pharmacists. The secondary objective was to assess the knowledge regarding drug related problems of over the counter medication. The tertiary objective was to find out whether the pharmacists involving in counselling activities. A community based, observational study was conducted among community pharmacist in Kalaburagi city, to find out knowledge on dispensing pattern of OTC medication. All the community pharmacist participated in the study were provided with a data collection form including self -structured questionnaires. One week after pre-test all the community pharmacist were educated regarding OTC drugs by means of providing information leaflets about OTC drugs. Post-test has been taken after 15 days of education by means of same questionnaires. Data were entered into Excel and analyzed using SPSS software. Pre and post intervention data were compared using student’s t-test.
Results: Among 110 pharmacist, males 98 (89.1%) were more compared to females 12(10.9%). The mean knowledge scores on drug dispensing pattern of community pharmacist in pre-test were 57.0% and post test is 87.6%.
Conclusions: Among 110 pharmacist, males 98 (89.1%) were more compared to females 12(10.9%). The mean knowledge scores on drug dispensing pattern of community pharmacist in pre-test were 57.0% and post test is 87.6%
Constraining Light Gravitino Mass from Cosmic Microwave Background
We investigate the possibilities of constraining the light gravitino mass
m_{3/2} from future cosmic microwave background (CMB) surveys. A model with
light gravitino with the mass m_{3/2}<O(10) eV is of great interest since it is
free from the cosmological gravitino problem and, in addition, can be
compatible with many baryogenesis/leptogenesis scenarios such as the thermal
leptogenesis. We show that the lensing of CMB anisotropies can be a good probe
for m_{3/2} and obtain an expected constraint on m_{3/2} from precise
measurements of lensing potential in the future CMB surveys, such as the
PolarBeaR and CMBpol experiments. If the gravitino mass is m_{3/2}=1 eV, we
will obtain the constraint for the gravitino mass as m_{3/2} < 3.2 eV (95%
C.L.) for the case with Planck+PolarBeaR combined and
m_{3/2}=1.04^{+0.22}_{-0.26} eV (68% C.L.) for CMBpol. The issue of Bayesian
model selection is also discussed.Comment: 22 pages, 6 figures, 7 tables, references are added, accepted for
publication in JCA
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