Declines of large sharks and subsequent release of elasmobranch mesopredators (smaller sharks and rays) may pose problems for marine fisheries management as some mesopredators consume exploitable shellfish species. The spotted eagle ray (Aetobatus narinari) is the most abundant inshore elasmobranch in subtropical Bermuda, but its predatory role remains unexamined despite suspected abundance inc...

In this brief review we describe the theory of the origin of Galactic cosmic rays. The concept that interaction near the source is the dominant source of γ-rays, and spallation secondaries seems best suited to explain the EGRET γ-spectrum of the inner Galaxy, the abundances of light elements, the anti-protons and the positrons. Also the chemical abundances seem best described as resulting from ...

Microimaging refers to a group of imaging modalities that go beyond the limits of spatial resolution of the human eye into the microscopic world. The different image modalities within can be divided according to the nature of the signal measured, the dimensions imaged and the nature of the magnification. This review will deepen mostly in the two major modalities of magnification and try to make...

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...

On the evening of 8 November 1895, ous potential applicability to medical diWilhelm Conrad Rontgen immediately agnosis (2). recognized a remarkable new phenomOn_.zJJ~nu~ry, at his first and only enon. Fluorescent material lying on a public lecture on the discovery, Rontgen bench some distance from the cathode made an x-ray picture of the hand of Dr. ray tube with which he was experimentAlbert v...

A multilayered parabolic mirror with six W/Al bilayers was designed and fabricated to generate monochromatic parallel x-rays using a lab-based x-ray source. Using this mirror, curved bright bands were obtained in x-ray images as reflected x-rays. The parallelism of the reflected x-rays was investigated using the shape of the bands. The intensity and monochromatic characteristics of the reflecte...

This Fisheries Science Partnership project was developed to estimate the survival of rays, which are caught commercially in a target trawl fishery in the Bristol Channel, and subsequently discarded. The study was proposed by the NFFO and categorized by Defra and Cefas as priority for support. All ray and skate species are commonly marketed as skate. The status of several skate and ray stocks in...

We propose a novel method for construction of rectilinear BSP trees for ray shooting acceleration. The trees are contracted according to certain “preferred” set of rays. Particularly, we study ray sets formed by fixing either the direction or the origin of rays. The constructed trees can be used to answer ray shooting query for arbitrary rays, although with higher expected time complexity for r...