Introduction: We have investigated cardiac SPECT with slant hole collimator in which the holes are slanted towards the target organ, to provide greater sensitivity over the parallel hole collimator. In addition, parallel hole collimator was used to obtain a comparison in FWHM, sensitivity, Compton and photoelectric area values in the simulations. Materials and Methods...

Abstract Observational evidence suggests that the majority of stars may have been born in stellar clusters or associations. Within these dense environments, dynamical interactions lead to high rates close encounters. A variety recent observational and theoretical indications suggest stellar-mass black holes be present play an active role all masses. In this study, we explore tidal disruption ma...

I discuss the recent progress in our understanding of nucleosynthesis via rapid neutron capture, the r-process, based on meteoritic data for the early solar system and observations of stars at low metallicities. At present, all data require that there be two distinct kinds of r-process events and suggest that supernovae are associated with these events. The diversity of supernova sources for th...

We model the 1990 giant X-ray flare of the quiescent galaxy NGC 5905 as the tidal disruption of a star by a supermassive black hole. From the observed rapid decline of the luminosity, over a timescale of a few years, we argue that the flare was powered by the fallback of debris rather than subsequent accretion via a thin disk. The fallback model allows constraints to be set on the black hole ma...

This paper looks at the history and development of an agent testbed called Tileworld. It defines the original testbed and documents its gradual development up to its current form. It also introduces some of the experiments performed using Tileworld and their results. It concludes with a comparison of Tileworld with other agent testbeds and a look at agent testbeds as a whole. Tileworld A Histor...

The tight correlation between the masses of central black holes and their host spheroids in nearby galaxies and active galactic nuclei (AGN) suggests that black hole growth is closely related to their spheroid formation. Based on our previous work regarding such a joint evolutionary scheme and the consequential black hole to bulge mass correlation, we use the X-ray luminosity function of AGN an...