34 research outputs found
Constraints on R-parity violating supersymmetry from neutral meson mixing
Upper bounds at the weak scale are put on all
type products of R-parity violating supersymmetry that may affect K-Kbar and
B-Bbar mixing. We constrain all possible products, including some not
considered before, using next-to-leading order QCD corrections to the mixing
amplitudes. Constraints are obtained for both real and imaginary parts of the
couplings. We also discuss briefly some correlated decay channels which should
be investigated in future experiments.Comment: 13 pages, 2 figures, uses revtex. Constraints updated, and new
constraints adde
Constraining Scalar Leptoquarks from the K and B Sectors
Upper bounds at the weak scale are obtained for all
type product couplings of the scalar leptoquark
model which may affect K-K(bar), B_d-B_d(bar), and B_s-B_s(bar)$ mixing, as
well as leptonic and semileptonic K and B decays. Constraints are obtained for
both real and imaginary parts of the couplings. We also discuss the role of
leptoquarks in explaining the anomalously large CP-violating phase in
B_s-B_s(bar) mixing.Comment: 16 pages, 5 figures, more constraints analyzed, added a number of
reference
Morphometric analysis of menisci of adult human knee joint in North Indian population
Background: Of the synovial joints in the body knee joint is the largest. Each meniscus is a piece of fibrocartilage with a thickened outside edge and a thin inner edge so that it is wedge-shaped in cross section. The purpose of the present study was to establish database on standard dimensions in knee menisci of adults of north Indian population.Methods: The sample for this study was collected from April, 2012 to June, 2013. For this study, 200 menisci (100 right and left each) of 50 adult humans were taken for analysis. Measurements were done with the help of non-elastic thread and digital vernier calipers. All dissections were performed in a systematic fashion.Results: The width of the lateral meniscus was significantly different form medial meniscus with lateral and medial menisci widest in middle and posterior third respectively. The middle one third of both lateral and middle menisci was the thickest.Conclusions: It is always good to have a set of anatomical morphometric parameters of the menisci like the width and thickness. The measurements of suitable grafts may provide a more acceptable meniscal replacement in the future
New Physics in b --> s bar(s) s Decay
We perform a model-independent analysis of the data on branching ratios and
CP asymmetries of and modes. The present
data is encouraging to look for indirect evidences of physics beyond the
Standard Model. We investigate the parameter spaces for different possible
Lorentz structures of the new physics four-Fermi interaction. It is shown that
if one takes the data at confidence level, only one particular
Lorentz structure is allowed. Possible consequences for the system are
also discussed.Comment: 9 pages, 3 encapsulated figures, minor changes in the text,
conclusions unchanged, a few references added, version to appear in PL
Synthesis of Brushite Particles in Reverse Microemulsions of the Biosurfactant Surfactin
In this study the “green chemistry” use of the biosurfactant surfactin for the synthesis of calcium phosphate using the reverse microemulsion technique was demonstrated. Calcium phosphates are bioactive materials that are a major constituent of human teeth and bone tissue. A reverse microemulsion technique with surfactin was used to produce nanocrystalline brushite particles. Structural diversity (analyzed by SEM and TEM) resulted from different water to surfactin ratios (W/S; 250, 500, 1000 and 40,000). The particle sizes were found to be in the 16–200 nm range. Morphological variety was observed in the as-synthesized microemulsions, which consisted of nanospheres (~16 nm in diameter) and needle-like (8–14 nm in diameter and 80–100 nm in length) noncalcinated particles. However, the calcinated products included nanospheres (50–200 nm in diameter), oval (~300 nm in diameter) and nanorod (200–400 nm in length) particles. FTIR and XRD analysis confirmed the formation of brushite nanoparticles in the as-synthesized products, while calcium pyrophosphate was produced after calcination. These results indicate that the reverse microemulsion technique using surfactin is a green process suitable for the synthesis of nanoparticles
Constraints on R-parity violating supersymmetry from leptonic and semileptonic tau, B_d and B_s decays
We put constraints on several products of R-parity violating lambda lambda'
and lambda' lambda' type couplings from leptonic and semileptonic tau, B_d and
B_s decays. Most of them are one to two orders of magnitude better than the
existing bounds, and almost free from theoretical uncertainties. A significant
improvement of these bounds can be made in high luminosity tau-charm or B
factories.Comment: 14 pages, latex. A few references added, two typos corrected. Version
to be published in Physical Review
Low Concentration of a Dioxin (2, 3, 7, 8 TCDD) Affects the Glycosidases and Acid Phosphatase Activity in Mice Hepatocytes
Present communication reports the effects of environmentally available, low doses of tetra chloro di benzo-p-dioxin (2,3,7,8 TCDD) to lysosomal enzymes in mice liver. The study tests the hypothesis, in vivo exposure of low dose TCDD provokes dose and duration dependent toxic effects to key lysosomal enzymes and thereby causes cellular apoptotic changes. Three groups of female Swiss albino mice were subjected to two doses of TCDD (0.004 mg/kg bw/d, 0.04 mg/kg bw/d) for 2, 4 and 6 days of exposure durations. The results indicated significant exposure duration dependent effects of TCDD in mice liver cells. The results suggested that TCDD possibly induced an increase in intracellular ions or ROS which in turn altered different physiological activities by affecting different metabolic pathway of the liver cells. The altered functions of key lysosomal enzymes by TCDD may also evoke the process of cellular apoptosis