In this paper we introduce a new class of partially ordered sets, called tree-visibility orders, extending the class of interval orders in a fashion similar to the extension of interval graphs to chordal graphs. This class contains interval orders, duals of generalized interval orders and height one orders. We give a characterization of tree-visibility orders by an innnite family of minimal for...

AIMS To investigate the incidence of ordering tests for tumor markers which are used in cancer diagnosis, follow-up treatment and detection of recurrence, the rate of elevation in benign diseases and which clinics order them frequently. MATERIALS AND METHOD Data for the tumor markers carbohydrate antigen 19-9 (CA 19-9), carcinoembryonic antigen (CEA), cancer antigen 125 (CA 125), cancer antig...

Many models of meta-stable supersymmetry (SUSY) breaking lead to a very light scalar pseudo-Nambu Goldstone boson (PNGB), P, associated with spontaneous breakdown of a baryon number like symmetry in the hidden sector. Current particle physics data provide no useful constraints on the existence of P. For example, the predicted decay rates for both K → π + P and Υ → γ + P are many orders of magni...

BACKGROUND AND PURPOSE Develop achievable benchmarks for 9 stroke performance measures (PM) and to identify organizational factors associated with adherence. METHODS Adherence rates and achievable benchmarks were determined for 9 PM within a study of patients (n=2294) admitted with acute ischemic stroke at 17 hospitals. Baseline information regarding hospital characteristics and stroke-specif...