The gamma-ray imaging spectrometer (GRIS) we have assembled comprises four coaligned, independent imagers, each with its own detector and coded-aperture mask (Figure 1). Each detector “sees” incoming gamma rays only through its mask, which serves as the imaging optic for the gamma rays (see box, pp. 1819). This mask is mounted on a movable mask plate in front of the detector plane; moving the p...

This article reviews the present status of high energy γ-ray astronomy at energies above 30 MeV. Observations in the past decade using both spaceand ground-based experiments have been primarily responsible for giving a tremendous boost to our knowledge of the high energy Universe. High energy γ-rays have been detected from a wide range of Galactic and extragalactic astrophysical sources, such a...

The class II transactivator (CIITA) is induced by gamma interferon (IFN-gamma) and activates major histocompatibility complex class II; however, this report shows it suppresses other genes. An N-terminal 36 amino acids of CIITA mediates suppression of the collagen alpha(2)(I) promoter via binding to CREB-binding protein (CBP). Reconstitution of cells with CBP reverts this suppression. IFN-gamma...

Direct regenerations by using mature cotyledonary node as a explants has been shown to be time-saving and convenient strategy for micropropagation of soybean. So we have evaluated regeneration protocol through single shoot using cotyledonary node as a rapid and efficient protocol for two soybean cultivars and one mutant line. Cotyledonary nodes explants obtained from 7-days-old in vitro</em...

We briefly review the fundamentals of nuclear gamma-ray line astronomy (radioactive astronomy), focusing on its role to decipher the intimate physics of supernovae, either immediatly (via 56 Co) or after a time delay (via 44 T i). All kinds of super-novae can be in principle tested through their radioactivities and their associated gamma-ray lines. Dedicated to the spectroscopy and imaging of c...

nowadays, the separation of pistachios which seem to have aflatoxin is done according to their organoleptic physical qualities like color and etc. as these methods are not  fully practical, and there is always a possibility of error and also the conditions like the wrong time harvest, the transportation of picked pistachios, the delay on the processing cause some contaminations in pistachios wh...

A position sensitive detector for 9 MeV gamma rays has been developed as part of a contraband detection system for airports. The system images contraband, such as explosives or drugs, in a geometry similar to medical x-ray computed tomography. A point source of gamma rays shines through an unknown object. Transmission projections of the areal density of detected gamma rays are reconstructed int...

Cowpea (Vigna unguiculata [L.] Walp.) yields are considerably low in Namibia due to lack of improved varieties and biotic and abiotic stresses, notably, recurrent drought. Thus, genetic improvement in cowpea aims to develop cultivars with improved grain yield and tolerance to abiotic and biotic stress factors. The objective of this study was to identify agronomically desirable cowpea genotypes ...

When Nereis eggs are exposed to radiations from a tube of radium emanation, the walls of which absorb all the alpha-rays, the resulting physiological change is produced by rays having a coefficient of absorption of the order of 23.9 cm.(-1) This fact indicates that the physiological effect is due almost exclusively to beta-rays. The gamma-rays alone can produce the reaction. To produce equivale...