378 research outputs found

    Prescriptive Travel and Adventure-Based Activities as Adjuncts to Counselling

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    One of the greatest challenges for counsellors is finding ways to promote constructive client actions outside sessions (Shelton & Levy, 1981). Often, clients perform well during therapeutic encounters but have difficulty applying what they have learned to real life situations (Stokes & Baer, 1977). In fact, inability to generalize learning is one of the most frequent problems encountered in our field (Rose, 1989). Some of our most difficult and resistant clients are those who appear compliant, cooperative, eager, and solicitous in sessions but don\u27t translate insights into action in their lives (Kottler, 1992), and don\u27t continue their progress after treatment ends (Davison, 1997). Yet they will have achieved little for their efforts if they cannot apply what they have learned in other settings and at other times

    Theories of Crying

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    It was dark outside, and cold, so cold the man’s eyes stung from the moisture on his lids. He was hunched over, trying to make himself as small a target as possible against the frigid wind. He shuffled along at an unsteady gait, trying to keep his balance on the slick sidewalk. Occasionally, he would stop, peek out from under his hood to reorient himself in the blowing snow, and then step cautiously but purposefully onward toward his destination

    Static Einstein-Maxwell Solutions in 2+1 dimensions

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    We obtain the Einstein-Maxwell equations for (2+1)-dimensional static space-time, which are invariant under the transformation q0=i q2,q2=i q0,Î±â‡ŒÎłq_0=i\,q_2,q_2=i\,q_0,\alpha \rightleftharpoons \gamma. It is shown that the magnetic solution obtained with the help of the procedure used in Ref.~\cite{Cataldo}, can be obtained from the static BTZ solution using an appropriate transformation. Superpositions of a perfect fluid and an electric or a magnetic field are separately studied and their corresponding solutions found.Comment: 8 pages, LaTeX, no figures, to appear in Physical Review

    Gravitational Collapse with a Cosmological Constant

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    We consider the effect of a positive cosmological constant on spherical gravitational collapse to a black hole for a few simple, analytic cases. We construct the complete Oppenheimer-Snyder-deSitter (OSdS) spacetime, the generalization of the Oppenheimer-Snyder solution for collapse from rest of a homogeneous dust ball in an exterior vacuum. In OSdS collapse, the cosmological constant may affect the onset of collapse and decelerate the implosion initially, but it plays a diminishing role as the collapse proceeds. We also construct spacetimes in which a collapsing dust ball can bounce, or hover in unstable equilibrium, due to the repulsive force of the cosmological constant. We explore the causal structure of the different spacetimes and identify any cosmological and black hole event horizons which may be present.Comment: 7 pages, 10 figures; To appear in Phys. Rev.

    Maximally extended, explicit and regular coverings of the Schwarzschild - de Sitter vacua in arbitrary dimension

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    Maximally extended, explicit and regular coverings of the Schwarzschild - de Sitter family of vacua are given, first in spacetime (generalizing a result due to Israel) and then for all dimensions DD (assuming a D−2D-2 sphere). It is shown that these coordinates offer important advantages over the well known Kruskal - Szekeres procedure.Comment: 12 pages revtex4 5 figures in color. Higher resolution version at http://www.astro.queensu.ca/~lake/regularcoordinates.pd

    Inflammatory bowel disease in Cape Town, 1975-1980 Part I. Ulcerative colitis

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    Previously documented and new patients with ulcerative colitis seen between 1975 and 1980 in the Gastro-intestinal Clinic of Groote Schuur Hospital were studied to establish the local incidence and clinical features of tHis disease. There were 220 patients and the mean follow-up was 7,7 ± 0,4 years. Sixty percent of patients were White, 37% Coloured and 3% Black. The incidence for the Coloured and White population was calculated' to be 1,3 and 2,4/100000 per year during 1970-1974 and 1,6 and 2,1/100000per year during 1975-1980. respectively. In Jews the rates were 8.5 and 10.4/100 000 per year for the two periods. Insufficient data are available to calculate an incidence for the Black population. The disease was limited to less than 15 cm above the anus in 14% of patients, to the rectoSigmoid colon in 45%. and to the rest of the colon in 40%. Although the severity of symptoms was related to the extent of disease, 22% of patients with extensive colitis had mild symptoms, while 15% with disease limited to the rectum had severe symptoms. The clinical features were similar in the White and Coloured population groups. A total colectomy was performed on 20% of patients with extensive colitis; in 2%the diseasewas complicated by colonic-carcinom

    An instability of the Reissner-Nordstrom solution and new hairy black holes in d=5 dimensions

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    The d=5 Reissner-Nordstrom black hole becomes unstable when considered as a solution of Einstein--Yang-Mills--Chern-Simons theory. The existence of a marginally stable mode gives rise to a new branch of black holes with non-Abelian magnetic fields outside the horizon. These solutions carry a nonzero electric charge and have finite mass. We argue that these features manifest themselves both for Minkowski and (Anti-)de Sitter asymptotics. The properties of solutions in a de Sitter background are new to the present work and are emphasised. All solutions constructed have finite mass by virtue of the presence of the Chern-Simons term, which in d=5 plays the role of a higher order term scaling appropriately for this purpose.Comment: 14 pages, 6 figure

    General Gauss-Bonnet brane cosmology

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    We consider 5-dimensional spacetimes of constant 3-dimensional spatial curvature in the presence of a bulk cosmological constant. We find the general solution of such a configuration in the presence of a Gauss-Bonnet term. Two classes of non-trivial bulk solutions are found. The first class is valid only under a fine tuning relation between the Gauss-Bonnet coupling constant and the cosmological constant of the bulk spacetime. The second class of solutions are static and are the extensions of the AdS-Schwarzchild black holes. Hence in the absence of a cosmological constant or if the fine tuning relation is not true, the generalised Birkhoff's staticity theorem holds even in the presence of Gauss-Bonnet curvature terms. We examine the consequences in brane world cosmology obtaining the generalised Friedmann equations for a perfect fluid 3-brane and discuss how this modifies the usual scenario.Comment: 20 pages, no figures, typos corrected, refs added, section IV changed yielding novel result

    The geodesic structure of the Schwarzschild Anti-de Sitter black hole

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    In the present work we found the geodesic structure of an AdS black hole. By means of a detailed analyze of the corresponding effective potentials for particles and photon, we found all the possible motions which are allowed by the energy levels. Radial and non radial trajectories were exactly evaluated for both geodesics. The founded orbits were plotted in order to have a direct visualization of the allowed motions. We show that the geodesic structure of this black hole presents new type of motions not allowed by the Schwarzschild spacetime.Comment: 17 pages, 11 figure
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