The effects of a sequential behavior analysis protocol on the teaching practices of undergraduate trainees.

Studied the effects of a sequential behavior feedback procedure on the practice teaching experiences of undergraduate teacher trainees. Teaching performances of 4 Ss were analyzed using Alternative Appropriate Instructional and Organizational Action measures within the ecological context of Instructional and Organizational challenges in the practice teaching setting. Data support the added utility of sequential information when using behavior analysis approaches to teacher training. One field-based undergraduate teaching practicum was monitored. The key elements summarized are (1) classroom instruction tied to the practicum experience, (2) practice teaching experience, and (3) sequential observation system used for evaluation and feedback, including multiple-baseline data to support this approach to teacher training. Results point to the strong relationship between sequential behavior feedback and (1) teacher-trainee improvement in meeting instructional and organizational challenges in the classroom, (2) teacher-trainee movement from an organizational to an instructional focus over the course of the experiment, and (3) positive changes in pupil practices as a function of changes in teacher-trainee instruction. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Counselor and client personality as determinants of counselor expectancy effects.

78 students enrolled in summer-session college courses were randomly assigned to serve either as counselors or as clients for a 20-min, role-played peer counseling session. Ss completed a battery of standardized personality measures, including the Personality Research Form. Each counselor interacted with 2 clients. Prior to the sessions, the counselor was led to believe that one of the clients was especially introverted and that the other client was especially extraverted. Dependent measures were based on clients' change scores on a mood adjective rating scale administered before and after the peer counseling sessions. Analyses showed that counselors who were more successful at biasing their clients in the direction of their expectancies (a) scored higher on measures of dogmatism, nurturance, and social recognition; (b) scored lower on impulsivity; and (c) were more likely to be female. Clients who were more susceptible to counselor bias scored higher on the Self-Monitoring Scale, its Other-Directedness subscale, and social recognition. (32 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Tannic acid and oxidized tannic acid on the functional state of rat intestinal epithelium

Diets containing tannic acid at the level of 3% of dry matter were fed to rats in order to ascertain the origin of fecal nitrogen and the effect of tannic acid on the intestinal mucosa. At the same time in order to explain the effect of oxidation of tannins, we administered diets containing oxidized tannic acid or tannic acid associated with an antioxidizer (sodium sulfite) at the level of 1% of dry matter. The increased excretion of sialic acid and glucosamine during ingestion of tannic acid indicated that the excess of fecal nitrogen mainly corresponds to the mucus hypersecretion observed by histology. Fecal analysis revealed perturbations in movements of water and ions. The study of the metabolic activity of isolated enterocytes and the activity of some enzymes in a homogenate of these cells showed an inhibition of oxygen consumption and succinic dehydrogenase activity. Addition of reducing agent (sodium sulfite) to the diet had little effect on the action of tannic acid; but previous oxidation of the tannin reduced the effects observed, particularly in the case of fecal nitrogen loss.     

A new method for selecting calf pericardium for use in cardiac bioprostheses on the basis of morphological and mechanical criteria

The durability of existing calf pericardium bioprostheses is limited by phenomena such as mechanical stress and calcification, the factors most frequently implicated in valve failure. Varying the preferred direction of the collagen fibers influences the mechanical behavior of the pericardial membrane. Given this possible variation, a strict control of the selection of the biomaterial employed in the construction of valve leaflets is essential, but a reliable method of selection has yet to be established.This study describes the development of a new system of in vitro selection involving a hydraulic simulator that reproduces the mechanical behavior of pericardial membranes subjected to the stress of continuous flow.By combining morphological criteria such as thickness and homogeneity with those of mechanical behavior, and by selecting paired samples from different parts of the pericardium, we obtained excellent mathematical fits. Linear regression analysis provided the mode of predicting the tensile strength in a given sample when this value had been determined in its twin. The upper zones of calf pericardium, corresponding to either right or left ventricle but at a distance from ligamentous structures, showed the best mean results at rupture (60 MPa) and permitted the most reliable prediction. The expected stress for an elongation of 30% was 1.12 MPa, as was previously observed, with a 95% confidence interval of between 1.11 and 1.14 MPa.These trials, together with the careful selection of the pairs, should help to establish definitive selection criteria. © 2001 Kluwer Academic Publishers     

Erythropoietic changes effected by foreign serum in the mouse

Injection of foreign serum into mice increases erythrocyte formation as evaluated by ferrokinetics studies. When erythropoiesis is depressed either by fasting or plethora, the wave of erythropoiesis that follows a transient increase of endogenous erythropoietin is clearly enhanced by pretreatment of the recipients with foreign serum. The response includes a restoration of the responsiveness of the spleen of fasted mice to endogenous erythropoietin stimulation. These changes seem related to an effect of foreign serum on the transition of primitive hematopoietic progenitors into erythroid-committed progenitors.     

Structural investigation of the HIV-1 envelope glycoprotein gp160 cleavage site, 2: relevance of an N-terminal helix

Proteolytic activation of the HIV-1 envelope glycoprotein gp160 is selectively performed by the proprotein convertase furin at the C-terminus of the sequence R508-E-K-R511 (site 1), in spite of the presence of another consensus sequence, Lys500-Ala-Lys-Arg503 (site 2). On the basis of the solution structural analysis of the synthetic peptide p498, spanning the gp160 sequence Pro498-Gly516, we previously suggested a possible role of an N-terminal helix in regulating the exposure and accessibility of the gp160 physiological cleavage site, enclosed in a loop. Here we report on the activity and conformation of the 23-residue peptide h-REKR, designed to exhibit a large N-terminal helix, followed by the gp160 native sequence, Arg508-Gly516. h-REKR is digested by furin with high efficiency, comparable to the full native p498. Circular dichroism analyses, in mixtures from pure water to 98 % trifluoroethanol, outline a significant content of helical structure in the peptide conformation. The molecular model obtained from NMR data collected in trifluoroethanol/water, by means of DYANA and AMBER simulations, indeed has helical structure on a large N-terminal segment. Such a long helix does not seem to affect the loop conformation of the C-terminal site 1-containing sequence, which exhibits the same proton chemical shifts already observed for the full native p498.     

Telerobotic systems design based on real‐time CORBA

A new class of telerobotic applications is making its way into research laboratories, fine arts or science museums, and industrial installations. Virtual laboratories and remote equipment maintenance are examples of these applications, which are built exploiting distributed computing systems and Internet technologies. Distributed computing technologies provide several advantages to telerobotic applications, such as dynamic and multiuser access to remote resources and arbitrary user locations. Nonetheless, building these applications remains a substantial endeavor, especially when performance requirements must be met. The aim of this paper is to investigate how mainstream and advanced features of the CORBA object‐oriented middleware can be put to work to meet the requirements of novel telerobotic applications. We show that Real‐Time CORBA extensions and asynchronous method invocation of CORBA services can be relied upon to meet performance and functional requirements, thereby enabling teleoperation on local area networks. Furthermore, CORBA services for concurrency control and large‐scale data distribution enable geographic‐scale access for robot teleprogramming. Limitations in the currently available implementations of the CORBA standard are also discussed, along with their implications. The effectiveness and suitability for telerobotic applications of several CORBA mechanisms are tested first individually and then by means of a software framework exploiting CORBA services and ensuring component‐based development, software reuse, low development cost, fully portable real‐time and communication support. A comprehensive telerobotic application built based on the framework is described in the paper and evaluated on both local and wide area networks. The application includes a robot manipulator and several sensory subsystems under concurrent access by multiple competing or collaborating operators, one of which is equipped with a multimodal user interface acting as the master device. © 2005 Wiley Periodicals, Inc.     

A TRAINING SIMULATION SYSTEM WITH REALISTIC AUTONOMOUS SHIP CONTROL

In this article we present a computational approach to developing effective training systems for virtual simulation environments. In particular, we focus on a Naval simulation system, used for training of conning officers. The currently existing training solutions require multiple expert personnel to control each vessel in a training scenario, or are cumbersome to use by a single instructor. The inability of current technology to provide an automated mechanism for competitive realistic boat behaviors thus compromises the goal of flexible, anytime, anywhere training. In this article we propose an approach that reduces the time and effort required for training of conning officers, by integrating novel approaches to autonomous control within a simulation environment. Our solution is to develop intelligent, autonomous controllers that drive the behavior of each boat. To increase the system's efficiency we provide a mechanism for creating such controllers, from the demonstration of a navigation expert, using a simple programming interface. In addition, our approach deals with two significant and related challenges: the realism of behavior exhibited by the automated boats and their real-time response to changes in the environment. In this article, we describe the control architecture we developed that enables the real-time response of boats and the repertoire of realistic behaviors we designed for this application. We also present our approach for facilitating the automatic authoring of training scenarios and we demonstrate the capabilities of our system with experimental results.     

Expectancy priming of smoking cessation messages enhances the placebo effect of tailored interventions.

Objective: Previous research (Webb, Simmons, & Brandon, 2005) suggested that smokers' reactions to self-help materials were more positive if they believed that the materials had been personally tailored to their individual characteristics and if they held expectancies that tailored interventions are superior to standard, or generic, interventions. The authors' objective in the current study was to replicate and extend this research by testing the efficacy expectancy priming before intervention delivery. Design: In a 2 × 2 factorial experiment, 210 smokers (M = 23 cigarettes/day) recruited from the community (62% female; 92% Caucasian; mean age = 49) were randomly assigned to 1 of 4 conditions: placebo-tailored intervention/no priming, placebo-tailored intervention/priming, standard intervention/no priming, or standard intervention/priming. The tailoring-related expectancies of participants' in the priming conditions were primed before they were presented with the respective intervention booklets. Main Outcome Measures: Content evaluations, readiness to quit smoking, cessation self-efficacy, smoking-related knowledge, and progress toward quitting (behavior changes). Assessments occurred by mail at baseline and at 1-month postintervention. Results: Similar to the earlier study, the placebo-tailored booklets produced superior evaluations and smoking-related cognitive and behavioral changes. Moreover, the pretreatment expectancy priming successfully altered participants' tailoring-related expectancies and also produced superior evaluations and outcomes. Conclusion: Findings support a causal role of tailoring-related expectancies on the efficacy of tailored interventions and suggest that interventions can be enhanced via expectancy priming. (PsycINFO Database Record (c) 2010 APA, all rights reserved)