1,187 research outputs found
Blindly detecting orbital modulations of jets from merging supermassive black holes
In the last few years before merger, supermassive black hole binaries will
rapidly inspiral and precess in a magnetic field imposed by a surrounding
circumbinary disk. Multiple simulations suggest this relative motion will
convert some of the local energy to a Poynting-dominated outflow, with a
luminosity 10^{43} erg/s * (B/10^4 G)^2(M/10^8 Msun)^2 (v/0.4 c)^2, some of
which may emerge as synchrotron emission at frequencies near 1 GHz where
current and planned wide-field radio surveys will operate. On top of a secular
increase in power on the gravitational wave inspiral timescale, orbital motion
will produce significant, detectable modulations, both on orbital periods and
(if black hole spins are not aligned with the binary's total angular momenta)
spin-orbit precession timescales. Because the gravitational wave merger time
increases rapidly with separation, we find vast numbers of these transients are
ubiquitously predicted, unless explicitly ruled out (by low efficiency
) or obscured (by accretion geometry f_{geo}). If the fraction of
Poynting flux converted to radio emission times the fraction of lines of sight
accessible is sufficiently large (f_{geo} \epsilon > 2\times 10^{-4}
for a 1 year orbital period), at least one event is accessible to future blind
surveys at a nominal 10^4 {deg}^2 with 0.5 mJy sensitivity. Our procedure
generalizes to other flux-limited surveys designed to investigate EM signatures
associated with many modulations produced by merging SMBH binaries.Comment: Submitted to ApJ. v1 original submission; v2 minor changes in
response to refere
Constraints on the environment and energetics of the Broad-Line Ic SN2014ad from deep radio and X-ray observations
Broad-line type Ic Supernovae (BL-Ic SNe) are characterized by high ejecta
velocity ( km s) and are sometimes associated with the
relativistic jets typical of long duration ( s) Gamma-Ray Bursts
(L-GRBs). The reason why a small fraction of BL-Ic SNe harbor relativistic jets
is not known. Here we present deep X-ray and radio observations of the BL-Ic
SN2014ad extending from to days post explosion. SN2014ad was not
detected at either frequency and has no observational evidence of a GRB
counterpart. The proximity of SN2014ad ( Mpc) enables very deep
constraints on the progenitor mass-loss rate and on the total energy
of the fast ejecta . We consider two synchrotron emission scenarios for a
wind-like circumstellar medium (CSM): (i) uncollimated non-relativistic ejecta,
and (ii) off-axis relativistic jet. Within the first scenario our observations
are consistent with GRB-less BL-Ic SNe characterized by a modest energy budget
of their fast ejecta ( erg), like SNe 2002ap and 2010ay.
For jetted explosions, we cannot rule out a GRB with erg
(beam-corrected) with a narrow opening angle ()
observed moderately off-axis () and
expanding in a very low CSM density ( M
yr). Our study shows that off-axis low-energy jets expanding in a
low-density medium cannot be ruled out even in the most nearby BL-Ic SNe with
extensive deep observations, and might be a common feature of BL-Ic SNe.Comment: 9 pages, 5 figures, accepted in Ap
DEVELOPMENT OF SIMPLE HPLC METHOD TO ESTIMATE THE BLOOD PLASMA CONCENTRATION OF EFAVIRENZ IN RAT AFTER ORAL ADMINISTRATION
Objective: The present study was design with an objective of developing a simple and rapid high performance liquid chromatography (HPLC) method for the determination of Efavirenz (EFA) in rat plasma.Methods: Chromatographic separation was achieved on C18 column using acetonitrile-50 mM potassium phosphate (55:45 v/v) as mobile phase at a flow rate of 1 ml/min and UV detection at 250 nm.Results: The retention time of EFA was found to be 13.2 min. The developed method was validated for linearity, limit of quantification (LOQ), limit of detection (LOD), Stability and selectivity. Linearity studies were found to be acceptable over the range of 5-50 μg/ml.Conclusion: The present analytical method was found to be specific, sensitive, accurate and precise for quantification of EFA in rat plasma. It can be successively applied for pharmacokinetics studies also.Â
New Report On AMF Colonization in Root Parasite Striga gesnerioides and its Host Lepidagathis hamiltoniana from High Altitude Region of Maharashtra
Present paper deals with in-depth analysis of AMF colonization reported in root parasite Striga gesnerioides (Willd) Vatke. Oester, Var gesnerioides and its host Lepidagathis hamiltoniana Wall. ex Nees collected from from Alang, and Madan Forts situated at high altitude region of Maharashtra. Although AM fungal colonization in S. gesnerioides and its host L. cuspidata has been recently reported, this is the new report with reference to host- parasite system of S. gesnerioides - L. hamiltoniana from high altitude region of Maharashtra
Rupture of Heart in a Cannabis Addict: an Autopsy Case Report
Background: Cannabis sativa or indica also known as Indian hemp is most widely used illicit drug in the world in its various forms such as bhang, majoon, ganja, charas or hashis. It affects various systems of human body on virtue of its active principle i.e. delta-9 tetrahydrocannabinol (THC). Its effect on cardiovascular system such as dose dependant increase in heart rate, arrhythmia and increased occurrence of myocardial infarction are well known.Case Report: In present case, a 42 years old male, addicted to ingestion of ‘bhang’ and suffering from psychiatric illness was brought to the hospital with history of headache and vomiting since last 12 hours. There was history of his violent behaviour, hence he was kept locked in a room for few hours and then relieved. He was treated for few hours and succumbed to death. On autopsy, patent coronaries and rupture of anterior wall of heart, in the vicinity of inter-ventricular septum was revealed.Conclusion: To the best of our knowledge, no such case was found in the literature. Treatment of patients with history of cannabis addiction must be focused in the view of acute cardiac conditions
Application of improved you only look once model in road traffic monitoring system
The present research focuses on developing an intelligent traffic management solution for tracking the vehicles on roads. Our proposed work focuses on a much better you only look once (YOLOv4) traffic monitoring system that uses the CSPDarknet53 architecture as its foundation. Deep-sort learning methodology for vehicle multi-target detection from traffic video is also part of our research study. We have included features like the Kalman filter, which estimates unknown objects and can track moving targets. Hungarian techniques identify the correct frame for the object. We are using enhanced object detection network design and new data augmentation techniques with YOLOv4, which ultimately aids in traffic monitoring. Until recently, object identification models could either perform quickly or draw conclusions quickly. This was a big improvement, as YOLOv4 has an astoundingly good performance for a very high frames per second (FPS). The current study is focused on developing an intelligent video surveillance-based vehicle tracking system that tracks the vehicles using a neural network, image-based tracking, and YOLOv4. Real video sequences of road traffic are used to test the effectiveness of the method that has been suggested in the research. Through simulations, it is demonstrated that the suggested technique significantly increases graphics processing unit (GPU) speed and FSP as compared to baseline algorithms
Isolation, identification and screening of potential cellulase-free xylanase producing fungi and its production
In order to isolate cellulase-free xylanase producing fungi, screening and isolation was done using composting soil as microbial source. Eight fungal species were selected for further study based on clearing zones formation on agar media containing covalently linked xylan with dye cibacron brilliant red-3BA. Both solid state and submerged fermentations were done with eight fungal isolates to identify strain that could produce highest amount of cellulase-free xylanase at a pH of 5.5 and at 28 ± 2°C temperature. Under solid state conditions, 50% of the strains produced xylanase (45.78 to 923 U gds-1) and lower amount of cellulase (20 to 33 U gds-1). The amount of soluble protein was also determined which ranged between 67 to 99 mg gds-1. In submerged conditions, 25% strains produced xylanase (45 to 205 U mL-1) and negligible amount of cellulase (12 to 13 U mL-1). The amount of soluble protein was determined which ranged between 45 and 85 U ml-1 in submerged conditions. Growth was determined in terms of mycelial dry weight which ranged between 0.70 and 2.90 mg mL-1.Keywords: Cellulase-free xylanase, xylan, solid state fermentation, submerged fermentatio
Strain-Rate Frequency Superposition in Large-Amplitude Oscillatory Shear
In a recent work, Wyss, {\it et.al.} [Phys. Rev. Lett., {\bf 98}, 238303
(2007)] have noted a property of `soft solids' under oscillatory shear, the
so-called strain-rate frequency superposition (SRFS). We extend this study to
the case of soft solids under large-amplitude oscillatory shear (LAOS). We show
results from LAOS studies in a monodisperse hydrogel suspension, an aqueous
gel, and a biopolymer suspension, and show that constant strain-rate frequency
sweep measurements with soft solids can be superimposed onto master curves for
higher harmonic moduli, with the {\it same} shift factors as for the linear
viscoelastic moduli. We show that the behavior of higher harmonic moduli at low
frequencies in constant strain-rate frequency sweep measurements is similar to
that at large strain amplitudes in strain-amplitude sweep tests. We show
surface plots of the harmonic moduli and the energy dissipation rate per unit
volume in LAOS for soft solids, and show experimentally that the energy
dissipated per unit volume depends on the first harmonic loss modulus alone, in
both the linear and the nonlinear viscoelastic regime.Comment: 10 pages, 25 figures, accepted for publication in Physical Review E.
Incorporates referee comment
EVALUATION OF CYTOTOXIC ACTIVITY OF ETHYL ACETATE EXTRACT OF PIGMENT FROM PSEUDOMONAS AERUGINOSA
Objective: Bacterial pigments have promising applications in food, cosmetics, textile, and therapeutics. Pigments from microbial origin are stable, safer, cost effective, easy production, and extraction and thus preferred over other natural sources. Under this backdrop, isolation and characterization of pigment-producing bacteria and analysis of bioactivity of the pigment were the aim of the study. From the literature studies, the pigment production was found to be influenced by various physical factors which directed the study toward optimization of physical parameters for pigment production.
Methods: Isolation of pigment-producing bacteria from water sample, cultural, and microscopic identification was done as per the standard protocol. Extraction of pigment by solvent extraction was carried out and its antibacterial and cytotoxic activity was assayed.
Results: Molecular characterization of the bacteria resembled the query sequence of the isolate to 99% with Pseudomonas aeruginosa strain. Extraction of pigment by solvent extraction method resulted in crude pigment extract with antibacterial activity against Gram-negative bacteria (17 mm zone of inhibition) at 100 μg/ml concentration. Pigment showed dose-dependent inhibition on proliferation of HeLa cells at the concentration of 345.83 μg/mL.
Conclusion: From the above results, it was evident that the pigment extracted from the bacterial isolate Pseudomonas aeruginosa strain JBT18N was therapeutically potential
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