We define sink marks for branched complexes and find conditions for them to determine a branched surface structure. These will be used to construct branched surfaces in knot and tangle complements. We will extend Delman’s theorem and prove that a non 2-bridge Montesinos knot K has a persistently laminar branched surface unless it is equivalent to K(1/2q1, 1/q2, 1/q3, −1) for some positive integ...

BACKGROUND Assessment centres are an accepted method of recruitment in industry and are gaining popularity within medicine. We describe the development and validation of a selection centre for recruitment to speciality training in anaesthesia based on an assessment centre model incorporating the rating of candidate's non-technical skills. METHODS Expert consensus identified non-technical skil...

Pakistan has one of the largest cohorts of young people in its history, yet research on their circumstances and needs is still relatively new. In this study, twenty four focus group discussions were conducted to explore young peoples' experiences of gaining knowledge of personal and sexual development. Young women typically gained information from a limited number of sources within the home, wh...

This study examined the effects of program pacing, defined as the rate of scene and character change per minute, on infants’ visual attention to video presentations. Seventy-two infants (twenty-four 6-month-olds, twenty-four 9-montholds, twenty-four 12-month-olds) were exposed to one of two sets of highand low-paced commercial infant DVDs. Each DVD was approximately 5-min long, and the order th...

We study the international standard XACML 3.0 for describing security access control policy in a compositional way. Our main contribution is to derive a logic that precisely captures the idea behind the standard and to formally define the semantics of the policy combining algorithms of XACML. To guard against modelling artefacts we provide an alternative way of characterizing the policy combini...

A critical view of the alleged significance of Belnap four-valued logic for reasoning under inconsistent and incomplete information is provided. The difficulty lies in the confusion between truth-values and information states, when reasoning about Boolean propositions. So our critique is along the lines of previous debates on the relevance of many-valued logics and especially of the extension o...

Erdős, Purdy, and Straus conjectured that the number of distinct (nonzero) areas of the triangles determined by n noncollinear points in the plane is at least b 2 c, which is attained for dn/2e and respectively bn/2c equally spaced points lying on two parallel lines. We show that this number is at least 17 38 n − O(1) ≈ 0.4473n. The best previous bound, ( √ 2 − 1)n − O(1) ≈ 0.4142n, which dates...

A projective bundle in PG(2, q) is a collection of q + q + 1 conics that mutually intersect in a single point and hence form another projective plane of order q. The purpose of this paper is to investigate the possibility of partitioning the q5 − q2 conics of PG(2, q) into q2(q − 1) disjoint projective bundles. As a by-product we obtain a multiplier theorem for perfect difference sets that gene...

Theory is critical to science. Group Support Systems (GSS), as a field of scientific inquiry is no exception. The important issue about theory in GSS is then not why theory, but where should theory come from (or how should theory be developed) and how to assess it (or evaluate its usefulness). This paper expounds on these issues by considering various approaches to theorizing about GSS, and del...

Workers' compensation insurance provides cash benefits and health care for workers who are injured on the job. This DataWatch considers the costs and benefits of combining the health insurance component of workers' compensation with universal health insurance, creating a twenty-four-hour coverage plan. The paper documents a large potential savings from twenty-four-hour coverage: Workers' compen...