Comparison of Cholesterol Lowering Diets: Apple, Casein Cytochrom P450 protein and Cholesterol 7α Hydroxylase Activities in Hamsters

Lithogenic diet, casein and apple fiber diets were fed to hamsters for 3-5 weeks. For control group, animals were fed on normal Purina chow without any supplement. The cholesterol lowering effect of lithogenic diet, casein and apple diets were compared. After dietary regimen, animals were screened for any gall stone formation. The isolated liver microsomes were separated from animals and tested for the cholesterol-7α Hydroxylase (CH) enzyme activity measurement in all three groups. The control animals did not show any gall stone formation and their CH enzyme activities were normal. The lithogenic diet showed significantly enhanced CH enzyme activities while animals fed on casein and apple diet regimen showed moderate increase in microsomal CH enzyme activity indicated cholesterol lowering in liver. In conclusion, cholesterol 7α hydroxylase may be a biomarker of cholesterol status in the body and microsomal CH enzyme may be lowered down after treatment of casein and apple diets

Use of 'n' Value of the Length-weight Relationship in the Determination of Spawning 'Seasons in Selaroides leptolepis Cuv. & Val.

To find out the ‘n’ value of the length -weight relationship of different months can be made use of to find out the spawning seasons in Selaroides leptolepis, a common carangid in the Palk Bay and Gulf of Manner in the vicinity of Mandapam, a systematic study was carried out at the Central Marine Fisheries Research Station, Mandapam Camp during a detailed investigation on the biology of the fish

Studying the Imaging Characteristics of Ultra Violet Imaging Telescope (UVIT) through Numerical Simulations

Ultra-Violet Imaging Telescope (UVIT) is one of the five payloads aboard the Indian Space Research Organization (ISRO)'s ASTROSAT space mission. The science objectives of UVIT are broad, extending from individual hot stars, star-forming regions to active galactic nuclei. Imaging performance of UVIT would depend on several factors in addition to the optics, e.g. resolution of the detectors, Satellite Drift and Jitter, image frame acquisition rate, sky background, source intensity etc. The use of intensified CMOS-imager based photon counting detectors in UVIT put their own complexity over reconstruction of the images. All these factors could lead to several systematic effects in the reconstructed images. A study has been done through numerical simulations with artificial point sources and archival image of a galaxy from GALEX data archive, to explore the effects of all the above mentioned parameters on the reconstructed images. In particular the issues of angular resolution, photometric accuracy and photometric-nonlinearity associated with the intensified CMOS-imager based photon counting detectors have been investigated. The photon events in image frames are detected by three different centroid algorithms with some energy thresholds. Our results show that in presence of bright sources, reconstructed images from UVIT would suffer from photometric distortion in a complex way and the presence of overlapping photon events could lead to complex patterns near the bright sources. Further the angular resolution, photometric accuracy and distortion would depend on the values of various thresholds chosen to detect photon events.Comment: Submitted to PASP, 16 Pages, 9 figure

An Imaging Polarimeter(IMPOL) for multi-wavelength observations

Taking advantage of the advances in array detector technology, an imaging polarimeter (IMPOL) has been constructed for measuring linear polarization in the wavelength band from 400-800 nm. It makes use of a Wollaston prism as the analyser to measure simultaneously the two orthogonal polarization components that define a Stoke's parameter. An achromatic half-wave plate is used to rotate the plane of polarization with respect to the axis of the analyser so that the second Stoke's parameter also can be determined. With a field of view correponding to about 30x30 sq. mm for a 1.2 m, f/13 telescope, a sensitive, liquid-nitrogen cooled CCD camera as the detector and a built-in acquisition and guidance unit, the instrument can be used for studying stellar fields or extended objects with an angular resolution close to 2 arcsec. The instrumental polarization is less than 0.05% and the accuracies of measurement are primarily limited by photon noise for typical observations.Comment: 10 pages including 5 embedded figures; submitted to Astronomy and Astrophysics Supplement Series; available on request to A. N. Ramaprakash ([email protected] or [email protected]); quote report n