Gaia DR2 Distances and Peculiar Velocities for Galactic Black Hole Transients

We report on a first census of Galactic black hole X-ray binary (BHXRB) properties with the second data release (DR2) of {\em Gaia}, focusing on dynamically confirmed and strong candidate black hole transients. DR2 provides five-parameter astrometric solutions including position, parallax and proper motion for 11 of a sample of 24 systems. Distance estimates are tested with parallax inversion as well as Bayesian inference. We derive an empirically motivated characteristic scale length of $L$=2.17$\pm$0.12 kpc for this BHXRB population to infer distances based upon an exponentially decreasing space density prior. Geometric DR2 parallaxes provide new, independent distance estimates, but the faintness of this population in quiescence results in relatively large fractional distance uncertainties. Despite this, DR2 estimates generally agree with literature distances. The most discrepant case is BW Cir, for which detailed studies of the donor star have suggested a distant location at >~25 kpc. A large DR2 measured parallax and relatively high proper motion instead prefer significantly smaller distances, suggesting that the source may instead be amongst the nearest of XRBs. However, both distances create problems for interpretation of the source, and follow-up data are required to resolve its true nature. DR2 also provides a first distance estimate to one source, MAXI J1820+070, and novel proper motion estimates for 7 sources. Peculiar velocities relative to Galactic rotation exceed $\sim$ 50 km s$^{-1}$ for the bulk of the sample, with a median system kinetic energy of peculiar motion of $\sim$ 5 $\times$ 10$^{47}$ erg. BW Cir could be a new high-velocity BHXRB if its astrometry is confirmed. A putative anti-correlation between peculiar velocity and black hole mass is found, as expected in mass-dependent BH kick formation channels, but this trend remains weak in the DR2 data.Comment: MNRAS in pres

NEUROPROTECTIVE AND COGNITIVE ENHANCING EFFECT OF METHANOLIC MORUS ALBA LEAF FRACTION IN U87MG CELL LINES AND EXPERIMENTAL RAT MODEL

Objective: The present study aims to investigate the protective effect of methanol fraction of Morus alba (MEMA) leaves against hydrogen peroxide (H2O2)-induced U87MG cell toxicity and aluminum fluoride (ALF)-induced rat toxicity. Methods: The study was divided into in vitro and in vivo sections. U87MG cell lines were pre-treated with different fractions of MEMA for 20 h and further tested against 1000 ϻM of H2O2. The best fraction from in vitro studies was used to study the protective effects against ALF-induced neurotoxicity. Rats were divided i nto five different groups, and MEMA (200 and 400 mg/kg p.o) was administered for 14 days to the animals with α-tocopherol as the standard drug treatment. Behavioral studies were assessed using Barnes maze. The major biochemical measurements included catalase, superoxide dismutase and glutathione reductase, lipid peroxidation (LPO), and acetylcholinesterase (AchE) levels. Results: In vitro studies indicated MEMA as a potential candidate followed by AQMA and ethyl acetate. The MEMA fraction was able to ameliorate ALF-induced neurotoxicity in the behavioral assessment. The higher antioxidant content in the fraction decreased the LPO levels from 250±4.07 to 115±3.22 as well as elevated the levels of most of the endogenous antioxidant enzyme levels. AchE levels were also decreased to 33.89±0.71 from 38.94±0.64. Conclusion: Although the results obtained indicate that MEMA could significantly suppress oxidative stress-induced central neuronal damage both in vitro and in vivo, further mechanistic studies are required to delineate its neuroprotective pathway

NIPAH VIRUS INFECTION-A REVIEW

Nipah viral disease is a zoonotic infection caused by Nipah virus (NiV), a paramyxovirus belonging to the genus Henipavirus of the family Paramyxoviridae. First emerged in Malaysia in 1998 and has sinces caused outbreaks in other parts of south and south east Asia. It is an emerging bat-borne pathogen. It causes severe neurological and respiratory disease which is highly lethal. Nipah virus is associated with ingestion of contaminated date palm sap and human-to-human transmission. Bats are the main reservoir for this virus, which can cause disease in humans and animals. Rapid diagnosis and implementation of infection control measures are essential to contain outbreaks. Different types of enzyme-linked immunosorbent assays along with molecular methods based on polymerase chain reaction (PCR) have been developed for diagnostic purposes. A number of serological and molecular diagnostic techniques have been developed for diagnosis and management arise when a new area is affected. However, no effective treatment or prophylaxis is readily available, though several approaches show promise