SARAS 2: A Spectral Radiometer for probing Cosmic Dawn and the Epoch of Reionization through detection of the global 21 cm signal

The global 21 cm signal from Cosmic Dawn (CD) and the Epoch of Reionization (EoR), at redshifts $z \sim 6-30$, probes the nature of first sources of radiation as well as physics of the Inter-Galactic Medium (IGM). Given that the signal is predicted to be extremely weak, of wide fractional bandwidth, and lies in a frequency range that is dominated by Galactic and Extragalactic foregrounds as well as Radio Frequency Interference, detection of the signal is a daunting task. Critical to the experiment is the manner in which the sky signal is represented through the instrument. It is of utmost importance to design a system whose spectral bandpass and additive spurious can be well calibrated and any calibration residual does not mimic the signal. SARAS is an ongoing experiment that aims to detect the global 21 cm signal. Here we present the design philosophy of the SARAS 2 system and discuss its performance and limitations based on laboratory and field measurements. Laboratory tests with the antenna replaced with a variety of terminations, including a network model for the antenna impedance, show that the gain calibration and modeling of internal additives leave no residuals with Fourier amplitudes exceeding 2~mK, or residual Gaussians of 25 MHz width with amplitudes exceeding 2~mK. Thus, even accounting for reflection and radiation efficiency losses in the antenna, the SARAS~2 system is capable of detection of complex 21-cm profiles at the level predicted by currently favoured models for thermal baryon evolution.Comment: 44 pages, 17 figures; comments and suggestions are welcom

EVALUATION OF GENOTOXICITY PROFILE OF JASADA BHASMA (A ZINC-BASED MINERAL FORMULATION) IN SWISS ALBINO MICE

  Objective: Genotoxicity is regarded as one of the potential risk factors for causing pathological diseases. It was confirmed that many chemicals have the mutagenic activity which leads to cancer. A compound which interacts with genetic material DNA and shows adverse effects by altering its structure or function is referred to as genotoxic.Methods: The present study involved 40 Swiss albino mice weighing between 25 and 30 g body weights categorized into four different groups. Group-I (normal control) received 0.5% carboxymethyl cellulose as vehicle. Group-II (toxicant control) received 40 mg/kg/body weight cyclophosphamide on the 28th day. Group-III and IV received test drug JB 15.6 mg/kg and 78 mg/kg, respectively, for 28 consecutive days. Blood samples were collected and processed for evaluating by comet assay. The animals were sacrificed and collected the bone marrow from both the femur for chromosomal aberration and micronuclei assay.Results: JB administered at two different dose levels did not show any significant changes in the comet assay parameters, no micronucleus was found and did not produce any chromosomal aberrations both numerically and structurally when compared to positive test control group.Conclusion: The genotoxicity evaluation of JB did not show any chromosomal aberrations and presence of micronucleus. Thus, the safety data will refine therapeutic utility of JB encouraging their rationale use and translate into greater and broader utilization of JB

A prospective, open label, randomized-controlled study to evaluate the efficacy and safety of MyVir tablets in mildly symptomatic COVID-19 patients

Background: Coronavirus can cause pneumonia, respiratory failure and death. The emergence of novel coronavirus has posed a challenging situation that warrants urgent global attention. Currently there was no effective therapy available for COVID-19 and hence antiviral and immune modulators are most sought after medicines to manage complications of COVID-19.Methods: In this study involving mild COVID-19 we randomized 42 patients to receive a MyVir tablets twice daily along with standard of care (SOC) or SOC alone in 1:1 ratio for 14 days. We evaluated the benefits of MyVir tablets by assessing clinical outcomes and improvement in immune markers (LDH, CRP, D-dimer, TLC).Results: At the end of the study the immune markers in MyVir group improved significantly compared to control group. In patients who received MyVir, CRP decreased from 3.3 mg/l to 1.7 mg/l (p=0.0171). D-dimer decreased from 0.589 on day 0 to 0.368 on day 14 (p=0.03) and LDH decreased from 224 U/l on day 0 to 158 U/l on day 14 in test group (p=0.05). TLC showed favorable improvement in study group compared to control group. Early recovery from COVID-19 symptoms was observed in patients on MyVir treated group. Patients treated with MyVir tablets reduced the duration of hospitalization when given along with standard of care.Conclusions: MyVir accelerated recovery of COVID-19 patients by early improvement in clinical symptoms and immune markers in this study and results clearly indicates that MyVir tablets has antiviral, immune booster activity. Hence this study provides evidence that MyVir has definitive role in the management of mild COVID-19 patients along with standard of care (funded by Mi Lab Life Sciences(P) Ltd. CTRI no. CTRI/2020/05/024967)

Early Clinical Detection of Pharmacologic Response in Insulin Action in a Nondiabetic Insulin-Resistant Population

AbstractBackgroundInsulin resistance heightens the risk for type 2 diabetes mellitus and cardiovascular disease. Amelioration of insulin resistance may reduce this risk. The thiazolidinedone class of insulin sensitizers improves insulin action in individuals with insulin-resistant diabetes and nondiabetic individuals. However, there are few reports on the time of onset of such effects independent of reversal of glucotoxicity.ObjectiveThe goal of our study was to test whether the thiazolidinedione pioglitazone has prominent early metabolic effects that can be detected in an obese, nondiabetic, insulin-resistant population.MethodsWe conducted a randomized, double-blind, placebo-controlled, parallel-group trial in men with nondiabetic insulin resistance using a hyperinsulinemic euglycemic clamp technique (at low and high doses of insulin at 10 and 40 mU/m2/min, respectively). The patients were given 30 mg daily oral pioglitazone or placebo for 28 days. Patients underwent a baseline clamp before initiation of treatment, and again at 14 and 28 days of treatment.ResultsCompared with placebo, under high-dose hyperinsulinemia, pioglitazone led to significant increases in glucose disposal rates (GDR) of 1.29 mg/kg/min (90% CI, 0.43–2.15; 39%; P=0.008) that were detectable at 2 weeks of treatment and persisted at 4 weeks of treatment. Under low-dose hyperinsulinemia, significant increases in GDR of 0.40 mg/kg/min (90% CI, 0.17–0.62; 95%; P=0.003) were observed at 4 weeks of treatment. These responses were accompanied by robust suppression of free fatty acids under hyperinsulinemic conditions, and by significant increases in circulating basal total adiponectin at 2 and 4 weeks of treatment.ConclusionsSignificant changes in insulin action across multiple insulin-sensitive tissues can be detected within 2 weeks of initiation of insulin-sensitizing therapy with pioglitazone in obese patients with nondiabetic insulin resistance. ClinicalTrials.gov identifier: NCT01115712

Procrastination among basic science undergraduate medical students in a Caribbean medical school

Abstract Purpose: The study was conducted to study procrastination behavior among basic science undergraduate medical students using the previously validated procrastination assessment scale students (PASS). Frequency of and reasons for procrastination were compared among different subgroups of respondents. Methods: The study was conducted during the first two weeks of February 2017 using PASS. Gender, nationality and semester of study of the respondents were noted. PASS explores areas of and frequency of procrastination, reasons for procrastination and interest in changing the behavior. The frequency of procrastination, fear of failure, risk aversiveness, laziness and rebellion against control scores were compared among different subgroups using appropriate statistical tests. Results: A total of 107 students (84.9%) participated in the study. The mean frequency of procrastination score was 32.9 (maximum score 60). The score was significantly correlated with the respondents' gender. With regard to the percentage of students who nearly always or always procrastinated on a task, the percentages with regard to completing assignments, studying for exams, completing reading assignments, academic administrative tasks, attendance tasks and school activities in general were 25.2, 19.7, 25.2, 19.6, 18.7 and 17.7. The mean score for 'fear of failure' and 'aversiveness of task' as described by Solomon and Rothblum was 2.29 and 2.83. The mean scores for fear of failure, risk taking, and laziness were 26.17, 13.76 and 14.32. The median rebellion against control score was 6. Risk taking score was higher among respondents of other nationalities compared to Americans. Conclusions: Procrastination was regarded as a greater problem with regard to studying for exams and completing reading assignments and preparing for problem-based learning sessions. Only 42% of students were interested in attending a program to overcome procrastination. Similar studies among students during the clinical years are required. A study correlating self-reported procrastination with behavior can be carried out. Procrastination can als

A Case for Renewed Activity in the Giant Radio Galaxy J0116-473

We present ATCA radio observations of the giant radio galaxy J0116-473 at 12 and 22 cm wavelengths in total intensity and polarization. The images clearly reveal a bright inner-double structure within more extended edge-brightened lobe emission. The lack of hotspots at the ends of the outer lobes, the strong core and the inner-double structure with its edge-brightened morphology lead us to suggest that this giant radio galaxy is undergoing a renewed nuclear activity: J0116-473 appears to be a striking example of a radio galaxy where a young double source is evolving within older lobe material. We also report the detection of a Mpc-long linear feature which is oriented perpendicular to the radio axis and has a high fractional polarization.Comment: 25 pages, 10 figures, appeared in 2002 ApJ, 565, 25

Neuropathology of HIV/AIDS with an overview of the Indian scene

Neurological manifestations of HIV infection and AIDS are being recognized with a frequency that parallels the increasing number of AIDS cases. Next to sub-Saharan Africa, India has the second largest burden of HIV related pathology, essentially caused by HIV-1 clade C in both the geographic locales, in contrast to USA and Europe. But the true prevalence of HIV related neuroinfections and pathology is not available due to inadequate medical facilities, social stigma and ignorance that lead to underdiagnosis. Neurotuberculosis, followed by cryptococcosis and toxoplasmosis in various combinations are the major neuropathologies reflecting the endemicity and manifesting clinically by reactivation of latent infection. Discordance in the clinical prevalence of various infections, when compared to pathological studies highlight similarities in clinical, radiological modalities of diagnosis and inherent problems in establishing definitive diagnosis. Viral infections appear to be relatively rare. Inspite of heavy burden of HIV/AIDS, HIV associated neoplasia is infrequent, including primary CNS lymphomas. HIV encephalitis and HIV associated dementia are considered infrequent, though systematic studies have just been initiated in various centres. Peripheral neuropathy characteristically manifests with vasculitic neuropathy while diffuse infiltrative lymphocytosis syndrome (DILS) involving nerves has not been reported from India. Spinal cord pathology including vacuolar myelopathy is rare, even in asymptomatic cases. Till now the AIDS cases in India were drug naÏve but a new cohort of cases following initiation of HAART therapy as a national policy is soon emerging, altering the biology and evolution of HIV/AIDS in India. Lacunae in the epidemiology, diagnosis and study of biology of HIV/AIDS are outlined for future research

Renewed activity in the radio galaxy PKS B1545-321: twin edge-brightened beams within diffuse radio lobes

Australia Telescope Compact Array (ATCA) images of the giant radio galaxy PKS B1545-321 show a pair of oppositely directed beams emerging from a radio core and ending in bright components that are symmetrically located on either side. These inner beams are embedded within edge-brightened outer lobes of lower surface brightness and the bright ends of the inner beams are well recessed from the ends of the outer lobes. The inner beams and diffuse surrounding lobes share a common central core and radio axis. We propose that the observed inner beams are double lobes which have been created within relic outer lobes as a consequence of a restarting of the central activity; therefore, PKS B1545-321 is a rare opportunity for examining the development of restarted beams within a relic synchrotron plasma cocoon. The inner double representing the new episode has among the highest axial ratios found in typical edge-brightened radio galaxies. The low radio luminosity of the inner double, the narrow and constant transverse extent of its cocoon and the relatively low brightness of the hotspots at its ends are consistent with the almost ballistic propagation expected for a beam that has a low density contrast and is advancing within a relatively light ambient medium.Comment: 30 pages, 12 figures, to appear in ApJ June, 200