There has been much discussion about what, if any, legal and moral duties professionals have to disclose relevant genetic information to the family members of someone with an identified disease predisposing mutation. Here, we present a case report where dissemination of such a genetic test result did not take place within a family. In contrast to previous literature, there appeared to be no deliberate withholding of information, instead distant relatives were unable to communicate relevant information appropriately. When communication was facilitated (...) through the follow-up of a chance remark, the patient was able to avoid planned major surgery, with its attendant morbidity, and her high anxiety levels were much reduced. We believe this case highlights the need for an ongoing debate on how genetic services can best support patients and their families with disclosing relevant genetic information to other family members. (shrink)

The phenomenon of probability backflow, previously quantified for a free nonrelativistic particle, is considered for a free particle obeying Dirac's equation. It is shown that probability backflow can occur in the opposite direction to the momentum; that is to say, there exist positive-energy states in which the particle certainly has a positive momentum in a given direction, but for which the component of the probability flux vector in that direction is negative. It is shown that the maximum possible amount of (...) probability that can flow “backwards,” over a given time interval of duration T, depends on the dimensionless parameter ε = (4ℏ/mc2T)1/2, where m is the mass of the particle and c is the speed of light. At ε = 0, the nonrelativistic value of approximately 0.039 for this maximum is recovered. Numerical studies suggest that the maximum decreases monotonically as ε increases from 0, and show that it depends on the size of m, ℏ, and T, unlike the nonrelativistic case. (shrink)

This paper describes the topological aspect of a logic-based, artificial intelligence approach to formalising the qualitative description of spatial properties and relations, and reasoning about those properties and relations. This approach, known as RCC theory, has been under development for several years at the University of Leeds. The main rationale for this project is that qualitative descriptions of spatial properties and relationships, and qualitative spatial reasoning, are of fundamental importance in human thinking about the world: even where quantitative spatial data (...) are most important, they must be attached to the components of a perceived spatial structure if we are to make use of them. RCC theory covers other qualitative aspects of spatial description and reasoning, but the topological properties and relations of spatially extended entities are fundamental to our work. The topological formalisms used by mathematicians are, in general, not well suited to the task of formalising the kinds of ‘common-sense’ or ‘everyday’ qualitative spatial description and reasoning which are our primary interest. Nevertheless, we must come to grips with the concepts of topology as practised by mathematicians if we are not to risk constantly ‘reinventing wheels’. (shrink)

On Roger Bacon's life and works, by A. G. Little.--Der einfluss des Robert Grosseteste auf die wissenschaftliche richtung des Roger Bacon, von Ludwig Baur.--La place de Roger Bacon parmi les philosophes du XIIIe siècle, par François Picavet.--Roger Bacon and the Latin vulgate, by Francis Aidan, cardinal Gasquet.--Roger Bacon and philology, by S. A. Hirsch.--The place of Roger Bacon in the history of mathematics, by David Eugene Smith.--Roger Bacon und seine verdienste um die optik, von Eilhard Wiedemann.--Roger Bacons lehre von der (...) sinnlichen spezies und vom seḣvorgange, von Sebastian Vogl.--Roger Bacons art des wissenschaftlichen arbeitens dargestellt nach seiner schrift De speculis, von J. Würschmidt.--Roger Bacon et l'horreur du vide, par Pierre Duhem.--Roger Bacon, his relations to alchemy and chemistry, by M. M. Pattison Muir.--Roger Bacon and gunpowder, by H. W. L. Hime.--Roger Bacon and medicine, by E. Withington. (shrink)

I am now sitting in La Antigua, Guatemala. It's 6:00 a.m. Ancient church bells compete with their clanging. Some with a clear ringing, others of dead metal. For centuries this tiny town of some 20 square blocks was the very center of Christianity in the "new" world. Its philosophy was brought to this place, lock, stock, and barrel. And, from here it was funneled south to Peru and north to Mexico. Not a philosophy of "liberation." Just ask the Maya who (...) remain. (shrink)