258,658 research outputs found
Band taut sutured manifolds
Attaching a 2-handle to a genus two or greater boundary component of a
3-manifold is a natural generalization of Dehn filling a torus boundary
component. We prove that there is an interesting relationship between an
essential surface in a sutured 3-manifold, the number of intersections between
the boundary of the surface and one of the sutures, and the cocore of the
2-handle in the manifold after attaching a 2-handle along the suture. We use
this result to show that tunnels for tunnel number one knots or links in any
3-manifold can be isotoped to lie on a branched surface corresponding to a
certain taut sutured manifold hierarchy of the knot or link exterior. In a
subsequent paper, we use the theorem to prove that band sums satisfy the
cabling conjecture, and to give new proofs that unknotting number one knots are
prime and that genus is superadditive under band sum. To prove the theorem, we
introduce band taut sutured manifolds and prove the existence of band taut
sutured manifold hierarchies.Comment: Final version. Accepted for publication in Algebraic & Geometric
Topolog
Nurses’ Perceptions of Horizontal Violence
In this article, I describe a study exploring horizontal violence and nurses’ perceptions of the phenomenon within the context of two 28-bed inpatient hospital units. The purpose of the study was to develop a clearer understanding of horizontal violence, incorporating observation and inquiry to identify the language nurses use to describe their experiences and factors in the nursing work environment that may perpetuate the phenomenon. Observation, review and analysis of policies, and interviews with staff were completed between June and November 2012. Thematic analysis resulted in five themes: (a) behaviors are minimized and not recognized, (b) fear inhibits all reporting, (c) avoidance and isolation are coping strategies, (d) lack of respect and support, and (e) organizational chaos. The findings suggest future interventions must address a range of factors that perpetuate horizontal violence within the nursing work environment with consideration for the embeddedness and complexity of the phenomenon
Fuel cell life improved by metallic sinter activation after electrode assembly welding
Technique improves the service life of fuel cell electrodes. The welding is done before the metallic sinter is activated by depositing finely divided metal within the sinter structure from a solution with corrosion inhibiting ions. The activator solution flows through the porous sinter while attached to the backup plate
Hugh Miller: stonemason, geologist, writer
Hugh Miller was born in 1802 in Cromarty, Ross-shire. He started his working life as a stonemason’s apprentice; he later became a social commentator and crusader. His was a household name in his lifetime, not only in Scotland but across the English-speaking world. A recent revival in Scottish history and culture, and a reassessment of the 19th century debates in science, geology and religion, have all led to a fuller appreciation of the rich and complex stories in which Hugh Miller played a part, and of the man himself. With the benefit of recent research for the 2002 conferences, this biography does full justice to the self-educated man, a figure of renown in the 19th century whose literary genius and scientific acumen still resonate in the 21s
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