3,280 research outputs found
Cytisus scoparius link - A natural antioxidant
BACKGROUND: Recent investigations have shown that the antioxidant properties of plants could be correlated with oxidative stress defense and different human diseases. In this respect flavonoids and other polyphenolic compounds have gained the greatest attention. The plant Cytisus scoparius contains the main constituent of flavone and flavonals. The present study was undertaken to evaluate the in vitro antioxidant activities of extract of aerial part of Cytisus scoparius. METHODS: The plant extract was tested for DPPH (1, 1-diphenyl, 2-picryl hydrazyl) radical scavenging, nitric oxide radical scavenging, superoxide anion radical scavenging, hydroxyl radical scavenging, antilipid peroxidation assay, reducing power and total phenol content. RESULTS: The extract exhibited scavenging potential with IC(50 )value of 1.5 μg/ml, 116.0 μg/ml and 4.7 μg/ml for DPPH, nitric oxide and superoxide anion radicals. The values were found to lesser than those of vitamin C, rutin, and curcumin, as standards. The extract showed 50% protection at the dose of 104.0 μg/ml in lipid peroxidation induced by Fe(2+)/ ascorbate system in rat liver microsomal preparation. There is decrease in hydroxyl radical generation with IC(50 )value of 27.0 μg/ml when compared with standard vitamin E. The reducing power of the extract depends on the amount of extract. A significant amount of polyphenols could be detected by the equivalent to 0.0589 μg of pyrocatechol from 1 mg of extract. CONCLUSION: The results obtained in the present study indicate that hydro alcoholic extract of aerial part of Cytisus scoparius is a potential source of natural antioxidants
Sensitivity to Gravitational Waves from Compact Binary Coalescences Achieved during LIGO's Fifth and Virgo's First Science Run
We summarize the sensitivity achieved by the LIGO and Virgo gravitational
wave detectors for compact binary coalescence (CBC) searches during LIGO's
fifth science run and Virgo's first science run. We present noise spectral
density curves for each of the four detectors that operated during these
science runs which are representative of the typical performance achieved by
the detectors for CBC searches. These spectra are intended for release to the
public as a summary of detector performance for CBC searches during these
science runs.Comment: 12 pages, 5 figure
Directional limits on persistent gravitational waves using LIGO S5 science data
The gravitational-wave (GW) sky may include nearby pointlike sources as well
as astrophysical and cosmological stochastic backgrounds. Since the relative
strength and angular distribution of the many possible sources of GWs are not
well constrained, searches for GW signals must be performed in a
model-independent way. To that end we perform two directional searches for
persistent GWs using data from the LIGO S5 science run: one optimized for
pointlike sources and one for arbitrary extended sources. The latter result is
the first of its kind. Finding no evidence to support the detection of GWs, we
present 90% confidence level (CL) upper-limit maps of GW strain power with
typical values between 2-20x10^-50 strain^2 Hz^-1 and 5-35x10^-49 strain^2
Hz^-1 sr^-1 for pointlike and extended sources respectively. The limits on
pointlike sources constitute a factor of 30 improvement over the previous best
limits. We also set 90% CL limits on the narrow-band root-mean-square GW strain
from interesting targets including Sco X-1, SN1987A and the Galactic Center as
low as ~7x10^-25 in the most sensitive frequency range near 160 Hz. These
limits are the most constraining to date and constitute a factor of 5
improvement over the previous best limits.Comment: 10 pages, 4 figure
Measurements of branching fraction ratios and CP-asymmetries in suppressed B^- -> D(-> K^+ pi^-)K^- and B^- -> D(-> K^+ pi^-)pi^- decays
We report the first reconstruction in hadron collisions of the suppressed
decays B^- -> D(-> K^+ pi^-)K^- and B^- -> D(-> K^+ pi^-)pi^-, sensitive to the
CKM phase gamma, using data from 7 fb^-1 of integrated luminosity collected by
the CDF II detector at the Tevatron collider. We reconstruct a signal for the
B^- -> D(-> K^+ pi^-)K^- suppressed mode with a significance of 3.2 standard
deviations, and measure the ratios of the suppressed to favored branching
fractions R(K) = [22.0 \pm 8.6(stat)\pm 2.6(syst)]\times 10^-3, R^+(K) =
[42.6\pm 13.7(stat)\pm 2.8(syst)]\times 10^-3, R^-(K)= [3.8\pm 10.3(stat)\pm
2.7(syst]\times 10^-3, as well as the direct CP-violating asymmetry A(K) =
-0.82\pm 0.44(stat)\pm 0.09(syst) of this mode. Corresponding quantities for
B^- -> D(-> K^+ pi^-)pi^- decay are also reported.Comment: 8 pages, 1 figure, accepted by Phys.Rev.D Rapid Communications for
Publicatio
Collagen induced arthritis increases secondary metastasis in MMTV-PyV MT mouse model of mammary cancer
First narrow-band search for continuous gravitational waves from known pulsars in advanced detector data
Spinning neutron stars asymmetric with respect to their rotation axis are potential sources of
continuous gravitational waves for ground-based interferometric detectors. In the case of known pulsars a
fully coherent search, based on matched filtering, which uses the position and rotational parameters
obtained from electromagnetic observations, can be carried out. Matched filtering maximizes the signalto-
noise (SNR) ratio, but a large sensitivity loss is expected in case of even a very small mismatch
between the assumed and the true signal parameters. For this reason, narrow-band analysis methods have
been developed, allowing a fully coherent search for gravitational waves from known pulsars over a
fraction of a hertz and several spin-down values. In this paper we describe a narrow-band search of
11 pulsars using data from Advanced LIGO’s first observing run. Although we have found several initial
outliers, further studies show no significant evidence for the presence of a gravitational wave signal.
Finally, we have placed upper limits on the signal strain amplitude lower than the spin-down limit for 5 of
the 11 targets over the bands searched; in the case of J1813-1749 the spin-down limit has been beaten for
the first time. For an additional 3 targets, the median upper limit across the search bands is below the
spin-down limit. This is the most sensitive narrow-band search for continuous gravitational waves carried
out so far
First Low-Latency LIGO+Virgo Search for Binary Inspirals and their Electromagnetic Counterparts
Aims. The detection and measurement of gravitational-waves from coalescing
neutron-star binary systems is an important science goal for ground-based
gravitational-wave detectors. In addition to emitting gravitational-waves at
frequencies that span the most sensitive bands of the LIGO and Virgo detectors,
these sources are also amongst the most likely to produce an electromagnetic
counterpart to the gravitational-wave emission. A joint detection of the
gravitational-wave and electromagnetic signals would provide a powerful new
probe for astronomy.
Methods. During the period between September 19 and October 20, 2010, the
first low-latency search for gravitational-waves from binary inspirals in LIGO
and Virgo data was conducted. The resulting triggers were sent to
electromagnetic observatories for followup. We describe the generation and
processing of the low-latency gravitational-wave triggers. The results of the
electromagnetic image analysis will be described elsewhere.
Results. Over the course of the science run, three gravitational-wave
triggers passed all of the low-latency selection cuts. Of these, one was
followed up by several of our observational partners. Analysis of the
gravitational-wave data leads to an estimated false alarm rate of once every
6.4 days, falling far short of the requirement for a detection based solely on
gravitational-wave data.Comment: 13 pages, 13 figures. For a repository of data used in the
publication, go to:
http://dcc.ligo.org/cgi-bin/DocDB/ShowDocument?docid=P1100065 Also see the
announcement for this paper on ligo.org at:
http://www.ligo.org/science/Publication-S6CBCLowLatency
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