Free operant avoidance in rats under increased nitrogen pressures.

6 male albino Sprague-Dawley rats performed on a free operant avoidance schedule with a response-shock interval of 20 sec and a shock-shock interval of 2 sec. Avoidance response rates increased, and shock frequency decreased when the Ss were exposed to elevated pressures of both air and a nitrogen-oxygen mixture in a hyperbaric chamber. Increases in response rates were related to raised partial pressures of nitrogen at 89.0 psi and 111.3 psi. Conditional probabilities of interresponse times indicate that increases in response rates were not due to disruption of temporal discrimination. Increased avoidance rates under pressure suggest direct excitatory effects of high pressures of nitrogen. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Social skills training: Behavior rehearsal in groups and dating skills.

Minimal dating, identified as a significant target problem, generally has been thought to result from either conditioned anxiety or negative self-evaluations. In the present study, minimal dating was formulated as the result of a social skills deficit. In accord with this formulation, 2 direct skill-training programs involving behavior rehearsal with and without extrasession tasks were evaluated against attention-placebo and waiting-list controls. 48 college males reporting anxiety and shyness about meeting females were carefully screened and assigned to 1 of 2 groups included in each of 4 treatment conditions. Results indicate that 3 of the 4 skill-training groups showed significant (p     

Shape from shading using the facet model

In this paper, the facet model is used in the recovery of surface orientation from single and multiple images. Two methods for determining surface orientation from image shading are presented. The first method works in the single image domain and is formulated as a non-linear optimization problem. Since three-dimensional scene information available in a single image is usually ambiguous, the optimization procedure can result in multiple solutions. The possibility of adding boundary constraints to the optimization process is also investigated. In the second method, additional images are obtained from the same viewing position, but with changing illumination direction. With these additional images, local surface orientation is determined uniquely by a linear optimization procedure. Experimental results of the shape-from-shading methods are also described.     

Application of biofeedback in the treatment of urinary incontinence.

There is sufficient empirical support to warrant the use of biofeedback for the treatment of common forms of urinary incontinence. However, biofeedback should be provided as a part of a behavioral "package" that includes a functional analysis of the disorder, patient education, a home exercise program, and bladder training strategies when indicated for urge incontinence. Our understanding of the physiologic events associated with clinical improvement will improve with further study. Because incontinence is a symptom of an underlying disorder, a medical evaluation should always be undertaken before a psychophysiological treatment begins. Ideally, biofeedback and other behavioral therapies for incontinence should be offered as an integral part of a multidisciplinary evaluation and treatment program. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Impact of genetic risk information and type of disease on perceived risk, anticipated affect, and expected consequences of genetic tests.

Objective: Genetic tests vary in their prediction of disease occurrence, with some mutations conferring relatively low risk and others indicating near certainty. The authors assessed how increments in absolute risk of disease influence risk perceptions, interest, and expected consequences of genetic tests for diseases of varying severity. Design: Adults (N = 752), recruited from New Zealand, Australia, and the United Kingdom for an online analogue study, were randomly assigned to receive information about a test of genetic risk for diabetes, heart disease, colon cancer, or lung cancer. The lifetime risk varied across conditions by 10% increments, from 20% to 100%. Main Outcome Measures: Participants completed measures of perceived likelihood of disease for individuals with mutations, risk-related affect, interest, and testing consequences. Results: Analyses revealed two increment clusters yielding differences in likelihood perceptions: A “moderate-risk” cluster (20%–70%), and a “high-risk” cluster (80%–100%). Risk increment influenced anticipated worry, feelings of risk, testing-induced distress, and family obligations, with nonlinear patterns including disproportionately high responses for the 50% increment. Risk increment did not alter testing interest or perceived benefits. These patterns of effects held across the four diseases. Conclusion: Magnitude of risk from genetic testing has a nonlinear influence on risk-related appraisals and affect but is unrelated to test interest. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A rotational calibration method using thermoluminescent dosemeters for dose determination in computed tomography beams

A procedure for calibration of thermoluminescent dosimeters, called rotational calibration, was developed to create a procedure more adequate for dose procedures used in computed tomography. Thermoluminescent dosimeters were rotated during irradiation to simulate the set-up used in dosimetric procedures in computed tomography equipment. Three commercial types of thermoluminescent dosimeters were calibrated using this methodology. The results showed that the measured values were lower when the dosimeters were irradiated with rotation than in a static geometry. Although the reading differences were not very large, they are not negligible, and they contribute to underestimating the dose.     

The Conserved Glu in the Cyclotide Cycloviolacin O2 Has a Key Structural Role

Cyclotides are a large family of plant peptides that are characterised by a head‐to‐tail circular backbone and three disulfide bonds that are arranged in a cystine knot. This unique structural feature, which is referred to as a cyclic cystine knot, gives the cyclotides remarkable stability against chemical and biological degradation. In addition to their natural function as insecticides for plant defence, the cyclotides have a range of bioactivities with pharmaceutical relevance, including cytotoxicity against cancer cell lines. A glutamic acid residue, aside from the invariable disulfide array, is the most conserved feature throughout the cyclotide family, and it has recently been shown to be crucial for biological activity. Here we have used solution‐state NMR spectroscopy to determine the three‐dimensional structures of the potent cytotoxic cyclotide cycloviolacin O2, and an inactive analogue in which this conserved glutamic acid has been methylated. The structures of the peptides show that the glutamic acid has a key structural role in coordinating a set of hydrogen bonds in native cycloviolacin O2; this interaction is disrupted in the methylated analogue. The proposed mechanism of action of cyclotides is membrane disruption and these results suggest that the glutamic acid is linked to cyclotide function by stabilising the structure to allow efficient aggregation in membranes, rather than in a direct interaction with a target receptor.     

Listener Responses as a Collaborative Process: The Role of Gaze

The authors examined precisely when and how listeners insert their responses into a speaker's narrative. A collaborative theory would predict a relationship between the speaker's acts and the listener's responses, and the authors proposed that speaker gaze coordinated this collaboration. The listener typically looks more at the speaker than the reverse, but at key points while speaking the speaker seeks a response by looking at the listener, creating a brief period of mutual gaze called here a gaze window . The listener was very likely to respond with "mhm," a nod, or other reaction during this period, after which the speaker quickly looked away and continued speaking. This model was tested with 9 dyads in which 1 person was telling a close-call story to the other. The results confirmed the model for each dyad, demonstrating both collaboration in dialogue at the microlevel and a high degree of integration and coordination of audible and visible acts, in this case, speech and gaze.     

THE LazyRMS: AVOIDING WORK IN THE ATMS

The basic algorithms involved in reason maintenance in the standard ATMS is known to have a computational complexity that is exponential in the worst case. Yet, also in average-case problem solving, the ATMS often lays claim to a major part of the computational effort spent by a problem solver/ATMS system. In this paper, we argue that within the limits of the worst-case computational complexity, it is possible to improve on the average-case complexity of reason maintenance and query processing by eliminating computation that is of no relevance to the problem solver's performance. To this purpose, we present a set of algorithms designed to control the effort spent by the ATMS on label updating. The basic idea underlying these algorithms is that of lazy evaluation: labels are not automatically maintained on all datums but are computed only when needed (either directly or indirectly) by the problem solver. The algorithms have been implemented in the LazyRMS with which we have experimented in the context of model-based diagnosis; our experiments show a substantial saving in the computational effort spent on reason maintenance.     

Sex bias in psychological research: Progress or complacency?

A total of 4,952 articles published in 1970, 1975, 1980, 1985, and 1990 in the areas of developmental, clinical, physiological, and social psychology were reviewed for the purpose of assessing various indicators of sexism in human psychological research. Significant changes in sex of 1st author, sex of participants, sexist language, and inappropriate generalization indicated that sexism has clearly diminished in the past 2 decades. Despite these improvements, however, the data revealed continued evidence of discriminatory practices, suggesting that efforts to eliminate sexism must be strengthened if psychology is to be a nonsexist discipline. (PsycINFO Database Record (c) 2010 APA, all rights reserved)