Contingency management for smoking cessation in adolescent smokers.

This pilot study evaluated the use of contingency management (CM) procedures in combination with cognitive-behavioral therapy (CBT) for smoking cessation in adolescents. Twenty-eight treatment-seeking adolescent smokers participated in a 1-month, school-based smoking cessation program and were randomly assigned to receive either CM with weekly CBT or CBT alone. In the CM+CBT group, biochemical verification of abstinence was obtained twice daily during the first 2 weeks, followed by daily appointments during the 3rd week and once every other day during the 4th week. Participants were monetarily reinforced for abstinence on an escalating magnitude schedule with a reset contingency. At the end of 1 week and 1 month of treatment, abstinence verified using quantitative urine cotinine levels was higher in participants in the CM+CBT group (1 week: 76.7%; 1 month: 53.0%) when compared with the CBT-alone group (1 week: 7.2%; 4 weeks: 0%). These preliminary results provide a strong initial signal supporting the utility of CM techniques for smoking cessation in adolescents and demonstrate the feasibility of implementing such a program in a school setting. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

LEARNING PRECONDITIONS FOR PLANNING FROM PLAN TRACES AND HTN STRUCTURE

A great challenge in developing planning systems for practical applications is the difficulty of acquiring the domain information needed to guide such systems. This paper describes a way to learn some of that knowledge. More specifically, the following points are discussed. (1) We introduce a theoretical basis for formally defining algorithms that learn preconditions for Hierarchical Task Network (HTN) methods. (2) We describe Candidate Elimination Method Learner ( CaMeL ), a supervised, eager, and incremental learning process for preconditions of HTN methods. We state and prove theorems about CaMeL's soundness, completeness, and convergence properties. (3) We present empirical results about CaMeL's convergence under various conditions. Among other things, CaMeL converges the fastest on the preconditions of the HTN methods that are needed the most often. Thus CaMeL's output can be useful even before it has fully converged.     

Preface: Volume 23, Issue 1

This volume contains the Proceedings of A Tutorial Workshop on Realizability Semantics and Applications. The workshop was associated to the 1999 Federated Logic Conference, held in Trento, Italy, from June 30 to July 1, 1999.There has been recently a reawaking of interest in many aspects of realizability interpretations---especially as regards semantics of type theories for constructive reasoning and semantics of programming languages. As the details of realizability can be quite technical, it seemed appropriate to have a tutorial workshop, connected to the Federated Logic Conference, aimed at offering presentations of the various aspects of realizability and directed to a wide audience, not necessarily only for the experts in the field.The Tutorial Workshop on Realizability Semantics and Applications was proposed to the 1999 Federated Logic Conference, Trento, June 29-July 12, 1999, was accepted, and is organized around several tutorial lectures on history, basic definitions and results, recent applications, connections to category theory and then offers a few contributed research talks of 30 minutes each.The Tutorial Presenters are:

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Costs of predoctoral clinical psychology internship training in a Canadian health care setting.

Financial pressures on institutional health care in Canada in recent years have led to substantial pressures on institutional psychological services. These pressures have resulted in the elimination or substantial diminution of psychological services in some of these institutions, including the discontinuation of many longstanding psychology internship programs. It is therefore important for psychologists to demonstrate their cost-efficiency in delivering services. However, evidence for this efficiency in the current Canadian context is lacking. This investigation examines the costs and clinical activities of the interns and staff at a major Canadian teaching hospital in order to determine the degree to which the internship is a cost-efficient method of delivering services. The results indicate that there is a small increased cost to having the services delivered through an internship program. The results are viewed as part of a balanced scorecard approach to the evaluation of an internship program. From such a perspective, other factors can be seen as balancing out the slightly increased cost. Also, a number of strategies are outlined for increasing internship cost-efficiency. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

More Harvard humbug.

Replies to J. Sonnenfeld's (1982) critique of D. Bramel and R. Friend's (see record 1982-08638-001) article on the studies performed at the Hawthorne plant of Western Electric. Sonnenfeld fails to recognize the unique aspects of Bramel and Friend's reinterpretation of what happened at Hawthorne. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Three-dimensional finite-element analysis of laminated composites

A three-dimensional finite-element analysis treating the mechanical response of thick laminated composite plates in bending is presented. An isoparametric solid element with a cubic displacement expansion in planform and a linear variation through the thickness is used to model each layer of the laminate. The degrees-of-freedom of the element are retained at its boundaries so that interconnections between lamina with different fiber orientations can be made at their interfaces. An incore version of the conjugate gradient technique, which does not have bandwidth restrictions, is used to minimize the total potential energy of the system with the number of iterations to convergence being about one-fifth the total global degrees-of-freedom. Because a three-dimensional analysis is used, the effects of thickness-stretching, transverse shear, extension, and bending deformations are obtained. Comparisons with three-dimensional elasticity solutions are in excellent agreement and show the necessity of having individual elements for each layer when they have different fiber orientations and when the plates are thick.     

Thermal Analysis of Ammonium Perchlorate and of its Mixtures with Inorganic Substances

Solid mixtures containing ammonium perchlorate diluted with reputedly inert substances SiC, SiO₂, TiO₂, Al₂O₃ and the salts: KCl, NaCl, BaCO₃, CaCO₃ respectively were studied by TGA and DTA. Undiluted NH₄ClO₄ and the perchlorates of K, Na, Ba, Ca were also examined. The two known temperature regions of NH₄ ClO₄ thermolysis were confirmed. The first DTA exotherm of NH₄ClO₄ seems to be related to its limited decomposition; it can be suppressed by an ammonia atmosphere, by thermal cycles, or by heat-dissipating conditions. The second exotherm is related to the change of the decomposition mechanism of HClO₄ above 330°. TGA rate curves of stoichiometric mixtures of NHClO₄ with salts show two peaks due to decomposition of NH₄ClO₄ and one peak due to the MeClO₄ formed on heating. The formation of MeClO₄ is confirmed by visual observations and by DTA. Thermal cycles followed by DTA of stoichiometric mixtures of (NH₄ClO₄ + KCl), (NH₄ClO₄ + BaCO₃) reveal the systematic formation of MeClO₄ at the expense of NH₄ClO₄. For (NH₄ClO₄ + NaCl), (NH₄ClO₄ + CaCO₃) there appear in the vicinity of the transition endotherm of NH₄ClO₄ new reversible endotherms difcontaining NH₄ClO₄. Only after their thermal decomposition do the transition endotherms of MeClO₄ appear.     

Comparative psychometric analysis of vector and isochrone cardiac activation maps

Isochronal cardiac activation maps can be constructed from local activation times associated with spatial locations, and are frequently used to study cardiac arrhythmias. Cardiac velocity vector mapping has been proposed as an alternative method to study cardiac activation in both clinical and research environments. Velocity vectors inherently contain more information than scalar measures of latency, but it is unknown how vector maps and isochronal maps compare when they are used to identify patterns and features associated with arrhythmias. In order to quantitatively compare these two visualization methods, eight cardiologists were asked to complete forced-choice tasks in which they selected ablation sites based on synthetic vector or isochronal maps. Maps varied in arrhythmia complexity, number of vectors or activation times included, and errors in magnitude or angle for maps of velocity vectors. Quantitative comparison was achieved by using psychometric functions to characterize the learning curve and the total number of measurements needed in order to choose a correct ablation site. For simple arrhythmias, performance with vector maps was superior to isochronal maps. Subjects required fewer measurements, and learned more rapidly by studying vector maps. For more complex arrhythmias, there was no significant difference in performance between vector and isochronal maps. However, arrhythmia features were clearer with vector maps, even though this clarity did not necessarily change the ablation site choice. When errors were added to vector maps, performance was satisfactory for angle errors < 55 degrees, and speed errors did not affect performance.     

Deformation-induced release of ATP from erythrocytes in a poly(dimethylsiloxane)-based microchip with channels that mimic resistance vessels

The ability of nitric oxide to relax smooth muscle cells surrounding resistance vessels in vivo is well documented. Here, we describe a series of studies designed to quantify amounts of adenosine triphosphate (ATP), a known stimulus of NO production in endothelial cells, released from erythrocytes that are mechanically deformed as these cells traverse microbore channels in lithographically patterned microchips. Results indicate that micromolar amounts of ATP are released from erythrocytes flowing through channels having cross sectional dimensions of 60 x 38 micron (2.22 +/- 0.50 microM ATP). Microscopic images indicate that erythrocytes, when being pumped through the microchip channels, migrate toward the center of the channels, leaving a cell-free or skimming layer at the walls of the channel, a profile known to exist in circulatory vessels in vivo. A comparison of the amounts of ATP released from RBCs mechanically deformed in microbore tubing (2.54 +/- 0.15 microM) vs a microchip (2.59 +/- 0.32 microM) suggests that channels in microchips may serve as functional biomimics of the microvasculature. Control studies involving diamide, a membrane-stiffening agent, suggest that the RBC-derived ATP is not due to cell lysis but rather physical deformation.