1,978 research outputs found
Revisiting scaling relations for giant radio halos in galaxy clusters
Many galaxy clusters host Megaparsec-scale radio halos, generated by
ultrarelativistic electrons in the magnetized intracluster medium. Correlations
between the power of radio halos and the thermal properties of the hosting
clusters were established in the last decade, including the connection between
the presence of a halo and cluster mergers. The X-ray luminosity and redshift
limited Extended GMRT Radio Halo Survey provides a rich and unique dataset for
statistical studies of the halos. We uniformly analyze the radio and X-ray data
for the GMRT cluster sample, and use the new Planck SZ catalog, to revisit the
correlations between the power of halos and the thermal properties of galaxy
clusters. We find that the radio power of halos at 1.4 GHz scales with the
cluster X-ray (0.1--2.4 keV) luminosity computed within R_500 as P_1.4
L_500^2.0. Our bigger and more homogenous sample confirms that the X-ray
luminous (L_500 > 5x10^44 erg/s) clusters branch into two populations --- radio
halos lie on the correlation, while clusters with upper limits to radio-halo
emission are well below that correlation. This bimodality remains if we excise
cool cores from the X-ray luminosities. Correlating with Planck data, we find
that P_1.4 scales with the cluster integrated SZ signal within R_500 as P_1.4
Y_500^2.1, in line with previous findings. However, contrary to previous
studies that were limited by incompleteness and small sample size, we find that
the "SZ-luminous" Y_500 > 6x10^-5 Mpc^2 clusters show a bimodal behavior
similar to that in the radio-X-ray diagram. Bimodality of both correlations can
be traced to clusters dynamics, with radio halos found exclusively in merging
clusters. These results confirm the key role of mergers for the origin of giant
radio halos, suggesting that they trigger the relativistic particle
acceleration.Comment: 16 pages, 7 figures, accepted for publication in ApJ on September 12,
201
Estradiol Modulates Membrane-Linked ATPases, Antioxidant Enzymes, Membrane Fluidity, Lipid Peroxidation, and Lipofuscin in Aged Rat Liver
Free radical production and oxidative stress are known to increase in liver during aging, and may contribute to the oxidative damage. These changes increase during menopausal condition in females when the level of estradiol is decreased. The objective of this study was to observe the changes in activities of membrane linked ATPases (Na+K+ ATPase, Ca2+ ATPase), antioxidant enzymes (superoxide dismutase, glutathione-S-transferase), lipid peroxidation levels, lipofuscin content and membrane fluidity occurring in livers of female rats of 3, 12 and 24 months age groups, and to see whether these changes are restored to 3 months control levels rats after exogenous administration of 17-β-estradiol (E2). The aged rats (12 and 24 months) were given subcutaneous injection of E2 (0.1 μg/g body weight) daily for one month. The results obtained in the present work revealed that normal aging was associated with significant decrease in the activities of membrane linked ATPases, antioxidant enzymes, membrane fluidity and an increase in lipid peroxidation and lipofuscin content in livers of aging female rats. The present study showed that E2 treatment reversed the changes to normal levels. E2 treatment may be beneficial in preventing some of the age related changes in the liver by increasing antioxidant defenses
High temperature magnetic ordering in La2RuO5
Magnetic susceptibility, heat capacity and electrical resistivity
measurements have been carried out on a new ruthenate, La2RuO5 (monoclinic,
space group P21/c) which reveal that this compound is a magnetic semiconductor
with a high magnetic ordering temperature of 170K. The entropy associated with
the magnetic transition is 8.3 J/mole-K -close to that expected for the low
spin (S=1) state of Ru4+ ions. The low temperatures specific heat coefficient g
is found to be nearly zero consistent with the semiconducting nature of the
compound. The magnetic ordering temperature of La2RuO5 is comparable to the
highest known Curie temperature of another ruthenate, namely, metallic SrRuO3,
and in both these compounds the nominal charge state of Ru is 4+.Comment: 16 pages, 6 figures, To be published in Solid State Communication
Naturally Occurring Hydroxy Napthoquinones and Their Iron Complexes as Modulators of Radiation Induced Lipid Peroxidation in Synaptosomes
The modulation of radiation induced lipid peroxidation in synaptosomes by iron (II) and iron (III) complexes of two naturally occurring and therapeutically relevant naphthoquinones viz.
5,hydroxy-1,4 naphthoquinone; juglone and 2,hydroxy-1,4 naphthoquinone; lawsone, have been studied. At lower concentrations the complexes enhance lipid peroxidation predominantly through
redox cycling as observed for Fe(II)- juglonate while at higher concentrations the complexes tend to
limit lipid peroxidation through fast recombinations
UJI TOKSISITAS EKSTRAK AIR DAUN KELOR (Moringan oleifera, L) ASAL LAHAN KERING NUSA TENGGARA TIMUR
Moringa Oleifera (Moringa oleifera Lamk) found excessive growth in dry East Nusa Tenggara (NTT) province. The plant has not only been primarily consumed as food especially for its leaves but also is rich in nutrients in its fruits to roots, benefits as coagulants, vitamins, and medicines. This research studied the toxic effect of the water extract of Moringa leaves to Artemia Salina Leach shrimp larvae according to BST method using water (room temperature) as a solvent, a preliminary study of the antibacterial and the anticancer target of study of the Morinaga. Moringa leaves were macerated for 3 x 24 hours using water, the results of phytochemical tests identified secondary metabolic content, among others, alkaloids, flavonoids, triterpenes, and tannins. The results of the BSLT test showed that the water extract (room temperature) of Moringa leaves had a toxicity level against Artemia Salina Leach as indicated by an LC50 value of 888, 34 less than 1000 ppm. It can be concluded that Moringa leaves have potential as a plant which can later be used as anti-bacterial and anti-cancer
Seed protein content and its relationships with agronomic traits in pigeonpea is controlled by both main and epistatic effects QTLs
The genetic architecture of seed protein content (SPC) and its relationships to agronomic traits
in pigeonpea is poorly understood. Accordingly, five F2 populations segregating for SPC and four
agronomic traits (seed weight (SW), seed yield (SY), growth habit (GH) and days to first flowering
(DFF)) were phenotyped and genotyped using genotyping-by-sequencing approach. Five high-density
population-specific genetic maps were constructed with an average inter-marker distance of 1.6 to
3.5 cM, and subsequently, integrated into a consensus map with average marker spacing of 1.6 cM.
Based on analysis of phenotyping data and genotyping data, 192 main effect QTLs (M-QTLs) with
phenotypic variation explained (PVE) of 0.7 to 91.3% were detected for the five traits across the five
populations. Major effect (PVE ≥ 10%) M-QTLs included 14 M-QTLs for SPC, 16 M-QTLs for SW, 17
M-QTLs for SY, 19 M-QTLs for GH and 24 M-QTLs for DFF. Also, 573 epistatic QTLs (E-QTLs) were
detected with PVE ranging from 6.3 to 99.4% across traits and populations. Colocalization of M-QTLs
and E-QTLs explained the genetic basis of the significant (P < 0.05) correlations of SPC with SW,
SY, DFF and GH. The nature of genetic architecture of SPC and its relationship with agronomic traits
suggest that genomics-assisted breeding targeting genome-wide variations would be effective for the
simultaneous improvement of SPC and other important traits
Ocean atmospheric processes over Bay of Bengal during two contrasting northeast monsoon onsets
1611-1618Conditions leading at the beginning of North-East Monsoon season on the Bay of Bengal studied using various ocean/ atmosphere parameters such as wind speed, shortwave radiation, sea surface temperature, latent heat flux, net surface heat flux and outgoing longwave radiation for two contrasting North-East monsoon onset years such as 1984 (Delayed) and 1999 (Early). During 1984 sea surface temperature is high over the northern portion of the Bay of Bengal but in 1999 which is the early North-East Monsoon year it is high over the south-eastern portion. In the delayed year i.e. in 1984, sea surface temperature over northern portion of Bay of Bengal warms more than an earlier year i.e. 1999, but contrast behaviour is observed in the south-eastern portion, it warms more in 1999 than 1984. From the analysis, it also observed that in delayed year more heat evaporates than an early year
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