Conformal Scalar Propagation on the Schwarzschild Black-Hole Geometry

The vacuum activity generated by the curvature of the Schwarzschild black-hole geometry close to the event horizon is studied for the case of a massless, conformal scalar field. The associated approximation to the unknown, exact propagator in the Hartle-Hawking vacuum state for small values of the radial coordinate above $r = 2M$ results in an analytic expression which manifestly features its dependence on the background space-time geometry. This approximation to the Hartle-Hawking scalar propagator on the Schwarzschild black-hole geometry is, for that matter, distinct from all other. It is shown that the stated approximation is valid for physical distances which range from the event horizon to values which are orders of magnitude above the scale within which quantum and backreaction effects are comparatively pronounced. An expression is obtained for the renormalised $$ in the Hartle-Hawking vacuum state which reproduces the established results on the event horizon and in that segment of the exterior geometry within which the approximation is valid. In contrast to previous results the stated expression has the superior feature of being entirely analytic. The effect of the manifold's causal structure to scalar propagation is also studied.Comment: 34 pages, 2 figures. Published on line on October 16, 2009 and due to appear in print in Gen.Rel.Gra

Le Pongo, l’idiot et le cagot. Quelques remarques sur la définition de l’Autre

La question ici traitée concerne finalement la définition de la limite de l'humain ; c'est-à-dire la question de l'Autre. C'est le même problème, qu'il s'agisse de l'homme sylvestre (le Pongo), de l'idiot ou du cagot. Ces questions qui restent ouvertes encore au XVIIe siècle vont peu à peu se retrouver dans l'univers des débuts de la psychiatrie. La question de l'enfant sauvage de l'Aveyron, celle de l'idiot du Valais, celle du cagot se trouvent comme problèmes chez Pinel ou Esquirol. Nous avons pensé qu'il s'agissait bien là de questions qui pouvaient s'intégrer à la problématique de la tolérance.In the final analysis, this article takes up the question of defining the limit of the human — that is,the question of the Other. lt is the same problem, regardless of whether it involves the "man of the woods"(the orangutan),the idiot or the "cagot" (a member of a group of outcasts in the south-western France, considered to be cretins).These questions, still unsettled during the 17 th century, gradually became the purview of the nascent field of psychiatry. The question of the wild boy of Aveyron, like that of the idiot of the canton of Valais or that of the cagot were taken up as problems by Pinel or Esquirol. It is my opinion that such questions could indeed be integrated into a problematic surrounding tolerance

1940: Abilene Christian College Bible Lectures - Full Text

Delivered in the Auditorium of Abilene Christian College, February, 1940, Abilene, Texas. Published April, 1940 PRICE, $1.00 FIRM FOUNDATION PUBLISHING HOUSE Austin, Texas

Physical and mental effort disrupts the implicit sense of agency

We investigated the effect of effort on implicit agency ascription for actions performed under varying levels of physical effort or cognitive load. People are able to estimate the interval between two events accurately, but they underestimate the interval between their own actions and their outcomes. This effect is known as ‘intentional binding’, and may provide feedback regarding the consequences of our actions. Concurrently with the interval reproduction task, our participants pulled sports resistance bands at high and low resistance levels (Experiments 1 and 2), or performed a working memory task with high and low set-sizes (Experiment 3). Intentional binding was greater under low than high effort. When the effort was task-related (Experiment 1), this effect depended on the individual’s explicit appraisal of exertion, while the effect of effort was evident at the group level when the effort was task-unrelated (physical, Experiment 2; mental, Experiment 3). These findings imply that the process of intentional binding is compromised when cognitive resources are depleted, either through physical or mental strain. We discuss this notion in relation to the integration of direct sensorimotor feedback with signals of agency and other instances of cognitive resource depletion and action control during strain

Acupuncture for pain and osteoarthritis of the knee: a pilot study for an open parallel-arm randomised controlled trial

<p>Abstract</p> <p>Background</p> <p>There is some evidence that acupuncture for pain and osteoarthritis (OA) of the knee is more than a placebo, and short term clinical benefits have been observed when acupuncture is compared to usual care. However there is insufficient evidence on whether clinical benefits of acupuncture are sustained over the longer term. In this study our key objectives are to inform the design parameters for a fully powered pragmatic randomised controlled trial. These objectives include establishing potential recruitment rates, appropriate validated outcome measures, attendance levels for acupuncture treatment, loss to follow up and the sample size for a full scale trial.</p> <p>Methods</p> <p>Potential participants aged over 50 with pain and osteoarthritis of the knee were identified from a GP database. Eligible patients were randomised to either 'acupuncture plus usual care' and 'usual care' alone, with allocation appropriately concealed. Acupuncture consisted of up to 10 sessions usually weekly. Outcome measures included Western Ontario and McMaster Universities (WOMAC) index with the sample size for a full scale trial determined from the variance.</p> <p>Results</p> <p>From the GP database of 15,927 patients, 335 potential trial participants were identified and invited to participate. After screening responses, 78 (23%) were identified as eligible and 30 patients who responded most promptly were randomised to 'acupuncture plus usual care' (15 patients) and 'usual care' alone (15 patients). Attendance for acupuncture appointments was high at 90% of the maximum. Although the trial was not powered to detect significant changes in outcome, the WOMAC pain index showed a statistically significant reduction at 3 months in the acupuncture group compared to usual care. This was not sustained at 12 months. The sample size for a fully powered two-arm trial was estimated to be 350.</p> <p>Conclusion</p> <p>This pilot study provided the evidence that a fully powered study to explore the longer term impact of acupuncture would be worthwhile, and relevant design features for such a trial were determined.</p> <p>Trial registration number</p> <p>ISRCTN25134802.</p

Albatrosses Following Fishing Vessels: How Badly Hooked Are They on an Easy Meal?

Fisheries have major impacts on seabirds, both by changing food availability and by causing direct mortality of birds during trawling and longline setting. However, little is known about the nature and the spatial-temporal extent of the interactions between individual birds and vessels. By studying a system in which we had fine-scale data on bird movements and activity, and near real-time information on vessel distribution, we provide new insights on the association of a threatened albatross with fisheries. During early chick-rearing, black-browed albatrosses Thalassarche melanophris from two different colonies (separated by only 75 km) showed significant differences in the degree of association with fisheries, despite being nearly equidistant to the Falklands fishing fleet. Most foraging trips from either colony did not bring tracked individuals close to vessels, and proportionally little time and foraging effort was spent near ships. Nevertheless, a few individuals repeatedly visited fishing vessels, which may indicate they specialise on fisheries-linked food sources and so are potentially more vulnerable to bycatch. The evidence suggests that this population has little reliance on fisheries discards at a critical stage of its nesting cycle, and hence measures to limit fisheries waste on the Patagonian shelf that also reduce vessel attractiveness and the risk of incidental mortality, would be of high overall conservation benefit