We propose a definition of physical objects that aims to clarify some interpretational problems in quantum mechanics. We claim that the transformations induced by an objective property of a physical system must leave invariant all the other objective properties of the same system. The uncertainty principle is understood as a natural consequence of the imbrication between objective properties an...

Context Hysterectomy is the most common nonobstetrical surgical procedure performed on women in the United States.2 In 2001, an estimated 649 000 hysterectomies were performed in the United States. Because most of the patients undergoing this procedure are between 25 and 54 years old, they live with the potential consequences of the procedure for many years.3 Thus, if hysterectomy is an indepen...

The outcomes of 60 sets of monochorionic diamniotic (MCDA) twins were compared with 218 sets of dichorionic diamniotic (DCDA) twins. The caesarean section rates for MCDA were similar to those for DCDA twins (56.6 versus 53.6%, P > 0.1). Although the number of babies with 5-minute Apgar score of <7 was significantly higher for vaginally delivered MCDA twins compared with that of DCDA twins (12 v...