EFFECT OF SODIUM VALPROATE AND DOCOSAHEXAENOIC ACID ON INFLAMMATION IN RATS

Objective: To evaluate the anti-inflammatory activity of sodium valproate and docosahexaenoic acid (DHA) supplementation using various experimental models in albino Wistar rats.Method: A total of 48 adult Wistar albino male rats were divided into 8 groups of 6 rats each. Group I was control (distilled water 1 ml/kg), Group II received intraperitoneal (i.p.) injection of indomethacin (10 mg/kg), Groups III-V were injected (i.p.) with sodium valproate 100, 200, and 400 mg/kg water, and Groups VI-VIII were given sodium valproate 100, 200, and 400 mg/kg plus DHA 300 mg/kg (i.p.), respectively. Anti-inflammatory activity was assessed using carrageenan induced paw edema and the cotton pellet granuloma models.Results: We found that higher doses of sodium valproate (400 mg/kg) used either alone or with a combination of DHA (300 mg/kg) showed a significant anti-inflammatory activity when compared to control in both the models of inflammation.Conclusion: Combination of sodium valproate along DHA has shown promising anti-inflammatory activity.Keywords: Anti-inflammatory drugs, Sodium valproate, Rat model

The age of the Milky Way inner stellar spheroid from RR Lyrae population synthesis

The central kiloparsecs of the Milky Way are known to host an old, spheroidal stellar population, whose spatial and kinematical properties set it apart from the boxy/peanut structure that constitutes most of the central stellar mass. The nature of this spheroidal population, whether a small classical bulge, the innermost stellar halo or a population of disk stars with large initial velocity dispersion, remains unclear. This structure is also a promising candidate to host some of the oldest stars in the Galaxy. Here we address the topic of the inner stellar spheroid age, using spectroscopic and photometric metallicities for a sample of 935 RR Lyrae stars that are constituents of this component. By means of stellar population synthesis, we derive an age-metallicity relation for RR Lyrae populations. We infer, for the RR Lyrae stars in the bulge spheroid, an extremely ancient age of $13.41 \pm 0.54$ Gyr and conclude they were among the first stars to form in what is now the Milky Way galaxy. Our age estimate for the central spheroid shows remarkable agreement with the age profile that has been inferred for the Milky Way stellar halo, suggesting a connection between the two structures. However, we find mild evidence for a transition in the halo properties at $r_{\rm GC} \sim 5$~kpc. We also investigate formation scenarios for metal-rich RR Lyrae stars, such as binarity and helium variations, and whether they can provide alternative explanations for the properties of our sample. We conclude that, within our framework, the only viable alternative is to have younger, slightly helium-rich, RR Lyrae stars, a hypothesis that would open intriguing questions for the formation of the inner stellar spheroid.Comment: Accepted for publication in Astronomy & Astrophysics. 17 pages, 15 figure

The Galactic Bulge exploration I.: The period-absolute\,magnitude-metallicity relations for RR~Lyrae stars for GBPG_{\rm BP}, VV, GG, GRPG_{\rm RP}, II, JJ, HH, and KsK_{\rm s} passbands using GaiaGaia DR3 parallaxes

We present a new set of period-absolute magnitude-metallicity (PMZ) relations for single-mode RR Lyrae stars calibrated for the optical $G_{\rm BP}$, $V$, $G$, $G_{\rm RP}$, near-infrared $I$, $J$, $H$, and $K_{\rm s}$ passbands. We compiled a large dataset (over $100$ objects) of fundamental and first-overtone RR~Lyrae pulsators consisting of mean intensity magnitudes, reddenings, pulsations properties, iron abundances, and parallaxes measured by the \textit{Gaia} astrometric satellite in its third data release. Our newly calibrated PMZ relations encapsulate the most up-to-date ingredients in terms of both data and methodology. They are aimed to be used in conjunction with large photometric surveys targeting the Galactic bulge, including the Optical Gravitational Lensing Experiment (OGLE), the Vista Variables in the V\'ia L\'actea Survey (VVV), and the \textit{Gaia} catalog. In addition, our Bayesian probabilistic approach provides accurate uncertainty estimates of the predicted absolute magnitudes of individual RR Lyrae stars. Our derived PMZ relations provide consistent results when compared to benchmark distances to Globular clusters NGC\,6121 (also known as M4), NGC\,5139 (also known as omega Cen), and Large and Small Magellanic Clouds, which are stellar systems rich in RR~Lyrae stars. Lastly, our $K_{\rm s}$-band PMZ relations match well with the previously published PMZ relations based on Gaia data and accurately predict the distance toward the prototype of this class of variables, the eponymic RR~Lyr itself.Comment: Accepted for publication in A&

Metallicity Distribution Functions, Radial Velocities, and Alpha Element Abundances in Three Off-Axis Bulge Fields

We present radial velocities and chemical abundance ratios of [Fe/H], [O/Fe], [Si/Fe], and [Ca/Fe] for 264 red giant branch (RGB) stars in three Galactic bulge off-axis fields located near (l,b)=(-5.5,-7), (-4,-9), and (+8.5,+9). The results are based on equivalent width and spectrum synthesis analyses of moderate resolution (R~18,000), high signal-to-noise ratio (S/N~75-300) spectra obtained with the Hydra spectrographs on the Blanco 4m and WIYN 3.5m telescopes. The targets were selected from the blue side of the giant branch to avoid cool stars that would be strongly affected by CN and TiO; however, a comparison of the color-metallicity distribution in literature samples suggests our selection of bluer targets should not present a significant bias against metal-rich stars. We find a full range in metallicity that spans [Fe/H]\approx-1.5 to +0.5, and that, in accordance with the previously observed minor-axis vertical metallicity gradient, the median [Fe/H] also declines with increasing Galactic latitude in off-axis fields. The off-axis vertical [Fe/H] gradient in the southern bulge is estimated to be ~0.4 dex/kpc. The (+8.5,+9) field exhibits a higher than expected metallicity, with a median [Fe/H]=-0.23, that might be related to a stronger presence of the X--shaped bulge structure along that line-of-sight. All fields exhibit an identical, strong decrease in velocity dispersion with increasing metallicity that is consistent with observations in similar minor-axis outer bulge fields. Additionally, the [O/Fe], [Si/Fe], and [Ca/Fe] versus [Fe/H] trends are identical among our three fields, and are in good agreement with past bulge studies. [abridged]Comment: Accepted for Publication in the Astrophysical Journal; 120 pages (main text ends on page 24); 22 figures (figures end on page 46); 6 tables; electronic versions of the tables can be made available upon request to author C. Johnso

A Photometric Study of the Outer Halo Globular Cluster NGC 5824

Multi-wavelength CCD photometry over 21 years has been used to produce deep color-magnitude diagrams together with light curves for the variables in the Galactic globular cluster NGC 5824. Twenty-one new cluster RR Lyrae stars are identified, bringing the total to 47, of which 42 have reliable periods determined for the first time. The color-magnitude diagram is matched using BaSTI isochrones with age of $13$~Gyr. and reddening is found to be $E(B-V) = 0.15 \pm0.02$; using the period-Wesenheit relation in two colors the distance modulus is $(m-M)_0=17.45 \pm 0.07$ corresponding to a distance of 30.9 Kpc. The observations show no signs of populations that are significantly younger than the $13$~Gyr stars. The width of the red giant branch does not allow for a spread in [Fe/H] greater than $\sigma = 0.05$ dex, and there is no photometric evidence for widened or parallel sequences. The $V, c_{UBI}$ pseudo-color magnitude diagram shows a bifurcation of the red giant branch that by analogy with other clusters is interpreted as being due to differing spectral signatures of the first (75\%) and second (25\%) generations of stars whose age difference is close enough that main sequence turnoffs in the color-magnitude diagram are unresolved. The cluster main sequence is visible against the background out to a radial distance of $\sim17$ arcmin. We conclude that NGC 5824 appears to be a classical Oosterhoff Type II globular cluster, without overt signs of being a remnant of a now-disrupted dwarf galaxy.Comment: 26 pages, 15 figures, 4 tables, accepted for publication in Astronomical Journa

On the density profile of the globular cluster M92

We present new number density and surface brightness profiles for the globular cluster M92 (NGC 6341). These profiles are calculated from optical images collected with the CCD mosaic camera MegaCam at the Canada-France-Hawaii-Telescope and with the Advanced Camera for Surveys on the Hubble Space Telescope. The ground-based data were supplemented with the Sloan Digital Sky Survey photometric catalog. Special care was taken to discriminate candidate cluster stars from field stars and to subtract the background contamination from both profiles. By examining the contour levels of the number density, we found that the stellar distribution becomes clumpy at radial distances larger than about 13 arcminutes, and there is no preferred orientation of contours in space. We performed detailed fits of King and Wilson models to the observed profiles. The best-fit models underestimate the number density inside the core radius. Wilson models better represent the observations, in particular in the outermost cluster regions: the good global agreement of these models with the observations suggests that there is no need to introduce an extra-tidal halo to explain the radial distribution of stars at large radial distances. The best-fit models for the number density and the surface brightness profiles are different, even though they are based on the same observations. Additional tests support the evidence that this fact reflects the difference in the radial distribution of the stellar tracers that determine the observed profiles (main sequence stars for the number density, bright evolved stars for the surface brightness).Comment: 18 pages, 10 figures, Accepted by A

Constraints on the Formation of the Globular Cluster IC 4499 from Multi-Wavelength Photometry

We present new multiband photometry for the Galactic globular cluster IC 4499 extending well past the main sequence turn-off in the U, B, V, R, I, and DDO51 bands. This photometry is used to determine that IC4499 has an age of 12 pm 1 Gyr and a cluster reddening of E(B-V) = 0.22 pm 0.02. Hence, IC 4499 is coeval with the majority of Galactic GCs, in contrast to suggestions of a younger age. The density profile of the cluster is observed to not flatten out to at least r~800 arcsec, implying that either the tidal radius of this cluster is larger than previously estimated, or that IC 4499 is surrounded by a halo. Unlike the situation in some other, more massive, globular clusters, no anomalous color spreads in the UV are detected among the red giant branch stars. The small uncertainties in our photometry should allow the detection of such signatures apparently associated with variations of light elements within the cluster, suggesting that IC 4499 consists of a single stellar population.Comment: accepted to MNRA

Chemical abundances in a high-velocity RR Lyrae star near the bulge

Low-mass variable high-velocity stars are interesting study cases for many aspects of Galactic structure and evolution. Until recently, the only known high- or hyper-velocity stars were young stars thought to originate from the Galactic center. Wide-area surveys such as APOGEE and BRAVA have found several low-mass stars in the bulge with Galactic rest-frame velocities higher than 350 km s-1. In this study we present the first abundance analysis of a low-mass RR Lyrae star that is located close to the Galactic bulge, with a space motion of ~–400 km s-1. Using medium-resolution spectra, we derived abundances (including upper limits) of 11 elements. These allowed us to chemically tag the star and discuss its origin, although our derived abundances and metallicity, at [Fe/H] =−0.9 dex, do not point toward one unambiguous answer. Based on the chemical tagging, we cannot exclude that it originated in the bulge. However, its retrograde orbit and the derived abundances combined suggest that the star was accelerated from the outskirts of the inner (or even outer) halo during many-body interactions. Other possible origins include the bulge itself, or the star might have been stripped from a stellar cluster or the Sagittarius dwarf galaxy when it merged with the Milky Way

A RARE INSTANCE OF LEVOSULPIRIDE–INDUCED GALACTORRHOEA

Antipsychotics are well known to affect prolactin secretion, resulting in hyperprolactinemia and its consequent manifestations like amenorrhoea, galactorrhoea, gynaecomastia, etc. Levosulpiride is a novel antipsychotic drug with additional antidepressant, antiemetic and antidyspeptic actions. The authors report a case of levosulpiride-induced hyperprolactinemia, presenting as galactorrhoea in a female patient with dyspepsia at Kasturba Hospital, Manipal, in South India.Keywords: Hyperprolactinemia, Prolactin, Dyspepsia, Antipsychotic, Dopamin