This paper presents an algorithm to deploy a team of free guards equipped with omni-directional cameras for tracking a bounded speed intruder inside a simply-connected polygonal environment. The proposed algorithm partitions the environment into smaller polygons, and assigns a guard to each partition so that the intruder is visible to at least one guard at all times. Based on the concept of dyn...

Studies on violence in the work of security guards are largely lacking. This study is unique in that it focuses on security guards (n=1,010) in Finland, and assesses the different forms, prevalence, and risk factors of the work-related violence they often face. Information to a survey instrument was obtained by first interviewing 30 volunteers. Then we made a cross-sectional mailed survey that ...

Entropy guards pore T he rapid fl uctuations of fl exible FG repeat–containing nucleoporins (FG Nups) form an entropic barrier to would-be entrants into the nuclear pore complex (NPC), according to Roderick Lim (University of Basel, Switzerland) and colleagues. FG Nups, which consist of large natively unfolded domains, are the pore’s gatekeepers—they keep out proteins that are not bound to tran...

Alzheimer’s disease is characterized by protein deposits of amyloid-β as plaques in the brain (1). The suite of enzymes that produce amyloid-β by cutting it out of the amyloid-β precursor protein (APP) have long been considered to be prime targets for therapeutic intervention. Converting this promise into reality, however, continues to be stalled by a series of obstacles, including an inaccurat...

A Herbrand equality between expressions in a program is an equality which holds relative to the Herbrand interpretation of operators. We show that the problem of checking validity of positive Boolean combinations of Herbrand equalities at a given program point is decidable — even in presence of disequality guards. This result vastly extends the reach of classical methods for global value number...