Blondlot's n-Rays

CONTRACTIBLE EXTREMAL RAYS ON M0,n

One of the richest objects of study in higher dimensional algebraic geometry is the Mori-Kleiman (closed) cone of curves, N E 1 (M), defined as the closed convex cone in H 2 (M, R) generated by classes of irreducible curves on M. A lot of geometric information about M is encoded in the cone of curves. For example the possibilities for maps with connected fibres are determined by the cone's face...

Galactic cosmic rays & gamma rays : a synthesis

We have developed a model which aims to reproduce observational data of many kinds related to cosmic-ray origin and propagation: direct measurements of nuclei, antiprotons, electrons and positrons, γ-rays, and synchrotron radiation. Our main results include evaluation of diffusion/convection and reacceleration models, estimates of the halo size, calculations of the interstellar positron and ant...

24 . Cosmic rays 1 24 . COSMIC RAYS

The cosmic radiation incident at the top of the terrestrial atmosphere includes all stable charged particles and nuclei with lifetimes of order 106 years or longer. Technically, “primary” cosmic rays are those particles accelerated at astrophysical sources and “secondaries” are those particles produced in interaction of the primaries with interstellar gas. Thus electrons, protons and helium, as...

Cosmic rays.

Genetic basis of susceptibility for neuroblastoma following treatment with N-methyl-N-nitrosourea and X-rays in Xiphophorus.

INTRODUCTION In 65 genotypes of Xiphophorus (nonhybnids and inter populational and interspecific F and backcnoss hybrids), the susceptibility to neuroblastoma following treatment with carcinogenic-mutagenic agents was tested. The fish were exposed to an aqueous solution of N-methyl-N-n itro sounea (MNU) or exposed to X-rays. Neunoblastoma was induced by MNU in 64 of about 3500 treated fish and ...