Sequences with ultrashort echo times enable new applications of MRI, including bone, tendon, ligament, and dental imaging. In this article, a sequence is presented that achieves the shortest possible encoding time for each k-space point, limited by pulse length, hardware switching times, and gradient performance of the scanner. In pointwise encoding time reduction with radial acquisition (PETRA...

We consider the possibility that the dark matter in the halos of galaxies may be in the form of clusters of Machos within which are embedded cold, dense gas clouds. Mi-crolensing experiments have found evidence that the Galactic halo contains up to half of its mass in the form of low-mass Machos. A number of observational and dynamical arguments point to the existence of hitherto unobserved col...

Just a small contingent of Pharmamar’s staff, which is, with a total of 262 employees, one of the main biotechnological companies in Spain. Ph ot os (5 ): P ha rm am ar Like Captain Nemo, the mysterious character created by Jules Verne, Jose María Fernández Sousa-Faro decided to seek his fortune in the depths of the oceans. His reasons were not, however, as obscure as Nemo’s. He had inherited t...

Information about the X-ray luminosity of the supermassive black hole located at the Galactic center (GC), Sgr A, and its temporal variations in the past is imprinted in the scattered emission observed today in the direction towards giant molecular clouds (GMCs) located in our Galaxy. Due to light travel time effects these clouds probe the activity of Sgr A at different times in the past depend...

This paper deals with a tricriteria path problem involving two bottleneck objective functions and a cost. It presents two methods for computing shortest paths in subnetworks, obtained by restricting the set of arcs according to the bottleneck values in order to find the minimal complete set of Pareto-optimal solutions. These procedures are enhanced by using the objective values of the determine...