Observation of R-Band Variability of L Dwarfs

We report, for the first time, photometric variability of L dwarfs in $R$ band. Out of three L1 dwarfs (2MASS 1300+19, 2MASS 1439+19, and 2MASS 1658+70) observed, we have detected R band variability in 2MASS 1300+19 and 2MASS 1439+19. The objects exhibit variability of amplitude ranging from 0.01 mag to 0.02 mag. Object 2MASS 1658+70, turns out to be non-variable in both $R$ and $I$ band. However, more observations are needed to infer its variability. No periodic behaviour in the variability is found from the two L1 dwarfs that are variable. All the three L1 dwarfs have either negligible or no $H_{\alpha}$ activity. In the absence of any direct evidence for the presence of sufficiently strong magnetic field, the detection of polarization at the optical favors the presence of dust in the atmosphere of L dwarfs. We suggest that the observed $R$ band photometric variability is most likely due to atmospheric dust activity.Comment: 13 pages (latex, aastex style) including 3 eps figures. Accepted for publication in The Astrophysical Journal Letter

In silico Characterization of Industrial Important Cellulases using Computational Tools

Cellulases refer to a class of enzymes produced majorly by fungi, bacteria and protozoans that catalyze cellulolysis. Cellulase enzyme is used extensively in various industries, especially in textile, food and in the bioconversion of lignocellulosic wastes to alcohol. The extensive use of cellulase in industries depends on the cost of the enzyme and hence considerable research is being carried out to isolate better microbial strains and also to develop new fermentation processes with the aim to reduce the product cost. Cellulases from different strains of Pseudomonas species were analyzed using computational tools. The physicochemical properties of the selected cellulases were analyzed by using ExPASy’s ProtParam tool and it was found that the molecular weight (M.Wt) ranges between 40927.4-100058.7 Da. Isoelectric Points (pI) of all the organisms were found to be acidic in nature. The aliphatic index infers that all the cellulases are stable. The negative value of GRAVY indicates that there will be better interaction with water. The secondary structure prediction was done by SOPMA which showed that random coils dominated all the other conformations. Multiple sequence analysis and evolutionary analysis of cellulases were carried out by CLC workbench. The Phylogenetic analysis was done using Neighbour joining method. The 3D structures of cellualses were obtained by ESyPred 3D server. Keywords: Cellulases, Enzymes, ProtParam, SOPMA, ESyPred 3D

A possible solution to the Hubble tension from quantum gravity

We investigate the relevance of quantum gravity during inflation to address the Hubble tension that arises from Planck 2018 and SH0ES data sets. We show that the effect of quantum gravity during inflation can increase the rate of change of $H_0$, thereby accounting for a wide range of observed $H_0$. Further, we show that due to the quantum gravity effect on inflation, the temperature at the onset of reheating can be lower than the standard case, causing delays in the reheating process. The role of quantum gravity is inevitable in settling the Hubble tension. The results of the present study may find use in resolving the Hubble tension, in validating inflationary model and quantum gravity.Comment: A new paragraph is added in the introduction part and fig. 7 is replaced with a new one. 19 pages, 10 figure

Drug utilization study in neonatal intensive care unit of a tertiary care teaching hospital

Background: Sick and pre-term neonates are admitted in neonatal intensive care units (NICU) and treated. A great care needs to be taken to use drugs in neonates due to the immaturity of their body functions. There is a lack of standard drug prescribing guideline in children, especially neonates because; safety and efficacy for a majority of drugs have not been established in them. The objectives of the study were to evaluate the drug utilization pattern in NICU of a teaching hospital and to identify problems in drug utilization and suggest measures, if needed.Methods: A prospective, observational study was carried out in NICU for duration of one year. Demographic details like age, sex, birth weight, duration of hospitalization was recorded from the case files of neonates. The morbid condition, treatment with drugs and other supportive modalities were recorded. The outcome of treatment was also noted. WHO drug utilization core indicators were also evaluated.Results: Out of 623 admissions in NICU, 56% were males. There were 56% of neonates who were born pre-term. The maximum used drugs were Vitamin K (73%) and antibiotics (64%). The antibiotics were mainly from penicillin and aminoglycoside groups. Respiratory distress syndrome (19%) and neonatal sepsis (16%) were the most common causes for admission. Out of total admissions, 64% were discharged following recovery, while, 12% had expired.Conclusions: Drugs usage in neonates should be minimal and should be prescribed from essential drug list. Antibiotic policy needs to be formulated for hospitals to minimize antibiotic usage and prevent development of resistance

Spectroscopic results of the recurrent nova RS ophiuchi

The recurrent nova RS Ophiuchi has had five outbursts in 1898, 1933, 1958, 1967 and 1985. We present here in brief the spectroscopic results of the 1985 outburst and subsequent quiescence, based on data obtained at the Vainu Bappu Observatory (VBO), Kavalur. Detailed results of the 1985 outburst appear in Anupama and Prabhu (1989). Spectra were recorded in the range 6200-8900 A at dispersion of 194 A mm−1 at four epochs: 32, 59 and 60; 89 and 91 and 108 days since the 1985 outburst maximum on January 27.5. In addition, spectra were recorded in the range 4300-5600 and 5000-7600 A at dispersion of 132 A mm−1on day 60, and in the range 5700-8000 A, at dispersion of 194 A mm−1, on days 89, 91 and 108

The nebular remnant and quiescent spectrum of Nova GK Persei

CCD images of the nebular shell of the old nova GK Per in [N II] and [O III] emission lines, and also the quiescent spectrum in the optical region, are presented. Proper motion measurements of the knots in [N II] over the baseline 1984–90 give a mean expansion rate of 0.31 ± 0.07 arcsec yr-1. This value agrees with models of the expansion of the ejecta into the ambient circumstellar medium. A correction for projection effects indicates that the ratio of the mass of the shell to the density of the circumstellar medium is a factor of 2 – 3 higher than estimated previously. The optical spectrum is decomposed into those of the secondary and the accretion disc. The estimate of MV = + 4.9 for the accretion disc implies a mass transfer rate of 3.5 × 10-9 M☉ yr-1 in the steady state. The H and He emission-line fluxes are used to infer that (i) the line-emitting region has a high density, (ii) the He/H abundance is near-solar, and (iii) the ionizing source has a Zanstra temperature of 1.3 × 105 K and an effective radius of 0.01 R☉, which are consistent with its being a white dwarf

H α variability in the quiescent spectrum of the recurrent nova T Coronae Borealis

The emission lines in the quiescent spectrum of the recurrent nova T Coronae Borealis are variable. Optical spectra recorded during the years 1985–90 show one full cycle of high and low states. After removing the slow variation, an orbital-phase-dependent variation becomes apparent in the H α line, with maxima around orbital phases 0 and 0.5. The slow variation indicates secular changes in the accretion disc possibly caused by a variable mass transfer rate. Orbital variations can be caused either by geometrical effects or a phase-modulated mass transfer rate. More detailed monitoring is needed to model the system