3,387 research outputs found
(086–087) Proposals to amend Arts. 7.11 and 9.21
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146988/1/tax591043.pd
(097) Proposal to revise Art. 60 Ex. 21 and add a new Example
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147176/1/tax591049.pd
Diffraction-limited Subaru imaging of M82: sharp mid-infrared view of the starburst core
We present new imaging at 12.81 and 11.7 microns of the central ~40"x30"
(~0.7x0.5 kpc) of the starburst galaxy M82. The observations were carried out
with the COMICS mid-infrared (mid-IR) imager on the 8.2m Subaru telescope, and
are diffraction-limited at an angular resolution of <0".4. The images show
extensive diffuse structures, including a 7"-long linear chimney-like feature
and another resembling the edges of a ruptured bubble. This is the clearest
view to date of the base of the kpc-scale dusty wind known in this galaxy.
These structures do not extrapolate to a single central point, implying
multiple ejection sites for the dust. In general, the distribution of dust
probed in the mid-IR anticorrelates with the locations of massive star clusters
that appear in the near-infrared. The 10-21 micron mid-IR emission,
spatially-integrated over the field of view, may be represented by hot dust
with temperature of ~160 K. Most discrete sources are found to have extended
morphologies. Several radio HII regions are identified for the first time in
the mid-IR. The only potential radio supernova remnant to have a mid-IR
counterpart is a source which has previously also been suggested to be a weak
active galactic nucleus. This source has an X-ray counterpart in Chandra data
which appears prominently above 3 keV and is best described as a hot (~2.6 keV)
absorbed thermal plasma with a 6.7 keV Fe K emission line, in addition to a
weaker and cooler thermal component. The mid-IR detection is consistent with
the presence of strong [NeII]12.81um line emission. The broad-band source
properties are complex, but the X-ray spectra do not support the active
galactic nucleus hypothesis. We discuss possible interpretations regarding the
nature of this source.Comment: Accepted for publication in PASJ Subaru special issue. High
resolution version available temporarily at
http://www.astro.isas.jaxa.jp/~pgandhi/pgandhi_m82.pd
OPTIMIZATION OF GREEN SYNTHESIZED SILVER NANOPARTICLES FROM CARALLUMA UMBELLATA
Objective: The current study focuses on optimization and ecologically innocuous green synthesis of silver nanoparticles (AgNPs) using tribal plant Caralluma umbellata and to study its potential as an antibacterial and antifungal agent.
Methods: The synthesis of AgNPs were confirmed by the colour change of the stem extract from yellow to dark brown and by UV-Visible spectroscopy. The optimum conditions for synthesis of AgNPs were analysed using Response surface methodology (RSM) based Box-Behnken design (BBD) using Design Expert software (7.0.0 trial version). The AgNPs synthesized were characterized by Scanning electron microscope (SEM), Energy dispersive X-ray (EDX), Fourier transform infrared (FTIR) and X-ray diffraction (XRD) analysis. Further, antibacterial and antifungal activity were performed using well diffusion method for both plant extract and AgNPs.
Results: The UV-Visible spectrum of AgNPs revealed characteristic peak at 425.5 nm. The crystalline nature of synthesized AgNPs was confirmed by XRD with average size 26 nm. SEM confirms the spherical shape of AgNPs and by EDX the presence of elemental silver was observed. The ability of the plant to produce both reducing and capping agents were confirmed by FTIR. The optimum conditions for synthesis of AgNPs were found to be 0.55 mmol AgNO3 concentration, 45 °C temperature and 24h reaction time. Both plant sample and synthesized AgNPs exhibited good antimicrobial activity where AgNPs showed superior efficacy as an antimicrobial agent over the other.
Conclusion: From the results obtained, it can be deduced that both C. umbellata stem extract and synthesized AgNPs can act as potent antimicrobial agent. But the synthesized AgNPs is more potent against bacteria and fungus
Serendipitous discovery of an extended X-ray jet without a radio counterpart in a high-redshift quasar
A recent Chandra observation of the nearby galaxy cluster Abell 585 has led
to the discovery of an extended X-ray jet associated with the high-redshift
background quasar B3 0727+409, a luminous radio source at redshift z=2.5. This
is one of only few examples of high-redshift X-ray jets known to date. It has a
clear extension of about 12", corresponding to a projected length of ~100 kpc,
with a possible hot spot located 35" from the quasar. The archival high
resolution VLA maps surprisingly reveal no extended jet emission, except for
one knot about 1.4" from the quasar. The high X-ray to radio luminosity ratio
for this source appears consistent with the amplification
expected from the inverse Compton radiative model. This serendipitous discovery
may signal the existence of an entire population of similar systems with bright
X-ray and faint radio jets at high redshift, a selection bias which must be
accounted for when drawing any conclusions about the redshift evolution of jet
properties and indeed about the cosmological evolution of supermassive black
holes and active galactic nuclei in general
Significance of anti-pre-S antibodies in patients with fulminant hepatic failure
Anti-pre-S antibody was tested in 38 sera from patients with fulminant hepatitis (positive for HBsAg and/or IgM anti-HBc) using a specific solid phase enzyme linked immunosorbent assay (ELISA). Anti-pre-S activity was detected in 50 percent sera samples positive for HBsAg but negative for IgM antiHBc. There were 12.5% sera positive for both HBsAg as well as IgM anti-HBc and 75% sera negative for HBsAg but positive for IgM anti-HBc. The prevalence of HBV-specific DNA-polymerase activity was high in all the three groups whereas anti-HBs positivity was low. Anti-pre-S activity was observed both in the presence as well as in the absence of DNA-polymerase activity. High-anti-pre-S level in fulminant hepatitis B patients was assumed to be implicated in the fast clearance of HBsAg from circulation
Hepatitis B virus replication in patients with chronic liver diseases
One hundred and seventy five subjects with chronic liver diseases which included patients with chronic active hepatitis (90), liver cirrhosis (31) and asymptomatic hepatitis B carriers (54), were included in the study. Hepatitis B virus (HBV) specific DNA-polymerase activity and HBe-markers were tested as markers of HBV-multiplicaiton. In HBsAg positive samples, DNA-P activity was positive in 44.4% of the HBV carriers, 52.9% of the patients with chronic active hepatitis and 81.8% of the patients with liver cirrhosis. The corresponding figures for the presence of HBeAg in these groups were 18.5, 26.5 and 45.5% respectively. Virus multiplication was also observed in 41.1 and 44.4% patients with chronic active hepatitis and liver cirrhosis respectively, in the absence of HBsAg. The results of the present study show that hepatitis B virus is the most important etiological factor of chronic liver diseases in India. Most of our patients of chronic liver diseases seems to have contacted HBV infection as young adults and the mode of transmission is likely to be horizontal rather than vertical. The virus replicating markers correlate well with the severity of the liver injury and decreased with the age. DNA-P activity is a more sensitive marker of viral multiplication than HBeAg. Viral multiplication was also found to occur in the absence of the usual HBV markers. Continued viral multiplication in patients with chronic active hepatitis and liver cirrhosis is implicated in continued liver injury and progressive liver disease
A high-density relativistic reflection origin for the soft and hard X-ray excess emission from Mrk 1044
We present the first results from a detailed spectral-timing analysis of a
long (130 ks) XMM-Newton observation and quasi-simultaneous NuSTAR and
Swift observations of the highly-accreting narrow-line Seyfert 1 galaxy Mrk
1044. The broadband (0.350 keV) spectrum reveals the presence of a strong
soft X-ray excess emission below 1.5 keV, iron K emission
complex at 67 keV and a `Compton hump' at 1530 keV. We find
that the relativistic reflection from a high-density accretion disc with a
broken power-law emissivity profile can simultaneously explain the soft X-ray
excess, highly ionized broad iron line and the Compton hump. At low frequencies
( Hz), the power-law continuum dominated 1.55 keV band
lags behind the reflection dominated 0.31 keV band, which is explained with
a combination of propagation fluctuation and Comptonization processes, while at
higher frequencies ( Hz), we detect a soft lag which is
interpreted as a signature of X-ray reverberation from the accretion disc. The
fractional root-mean-squared (rms) variability of the source decreases with
energy and is well described by two variable components: a less variable
relativistic disc reflection and a more variable direct coronal emission. Our
combined spectral-timing analyses suggest that the observed broadband X-ray
variability of Mrk~1044 is mainly driven by variations in the location or
geometry of the optically thin, hot corona.Comment: 23 pages, 19 figures, 4 tables, Published in MNRA
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