Limitations on the uses of multimedia exposure measurements for multipathway exposure assessment--Part II: Effects of missing data and imprecision.

Multimedia data from two probability-based exposure studies were investigated in terms of how missing data and measurement-error imprecision affected estimation of population parameters and associations. Missing data resulted mainly from individuals'refusing to participate in certain measurement activities, rather than from field or laboratory problems; it suggests that future studies should focus on methods for maximizing participation rates. Measurement error variances computed from duplicate-sample data were small relative to the inherent variation in the populations; consequently, adjustments in nonparametric percentile estimates to account for measurement imprecision were small. Methods of adjustment based on lognormality assumptions, however, appeared to perform poorly.     

Differential gastric ulceration in rats receiving shocks on either fixed-time or variable-time schedules.

Research suggests that predictable electric shocks produce less stress than unpredictable shocks. In this experiment, predictability was manipulated by using fixed-time (FT, predictable) and variable-time (VT, unpredictable) schedules of shock delivery. Rats receiving 3-mA, 1-s electric shocks on a FT 45-s schedule developed less gastric pathology than another group that was administered identical shocks on a VT 45-s schedule. It is argued that this finding represents a more subtle effect of predictability than has been obtained heretofore. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A goal-striving life event and the onset of hypomanic and depressive episodes and symptoms: Perspective from the Behavioral Approach System (BAS) dysregulation theory.

On the basis of the behavioral approach system (BAS) dysregulation theory of bipolar disorder, this study examined the relation between occurrence of a BAS activation-relevant life event--goal striving--and onset of hypomanic and depressive episodes and symptoms. In particular, the authors examined the relation between preparing for and completing final exams (a goal-striving event) and onset of bipolar spectrum episodes and symptoms in college students with bipolar II disorder or cyclothymia (i.e., "soft" bipolar spectrum conditions). One hundred fifty-nine individuals with either a bipolar spectrum disorder (n=68) or no major affective psychopathology (controls; n=91) were further classified on the basis of whether they were college students (i.e., completed final exams). Consistent with the BAS dysregulation theory, preparing for and completing final exams was associated with an increase in hypomanic but not depressive episodes and symptoms in individuals with a soft bipolar spectrum diagnosis. Furthermore, self-reported BAS sensitivity moderated the presence of certain hypomanic symptoms during final exams. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Integrating psychology and politics.

Comments on the article "A house divided? The psychology of red and blue America" by D. C. Seyle and M. L. Newman (see record 2006-11202-001). Seyle and Newman concluded that the red and blue metaphor is inaccurate and proposed a purple America strategy to better convey that the majority of people do not align themselves with political extremes. There is interdisciplinary agreement on this. Although not cited by Seyle and Newman, the findings by Professor Fiorina of Stanford University were reported by the APA Monitor on Psychology in its coverage of the 2005 APA State Leadership Conference (Murray Law, 2005). In contrast to their social psychological analysis, Seyle and Newman were incorrect in concluding that "[a]s psychologists, we are not in a position to change either the elements of the American political system that may spur this conflict or even the decisions made by pundits, politicians, and reporters about the terms they choose to use in political discussion" (p. 579). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of situational demand upon social enjoyment and preference in schizotypy.

The socioemotional functioning of schizophrenic and schizotypic individuals is marked by withdrawal, poor organization, and limited emotional displays. Such behavioral tendencies and lack of social enjoyment in schizotypy could be linked to the relative situational demands or role ambiguity inherent in specific social activities. To determine whether high-schizotypy individuals prefer more clearly role-defined social activities (e.g., visiting relatives) to more ambiguous, novel situations (e.g., going alone to a party), the authors gathered reports from 52 high-schizotypy and 60 low-schizotypy individuals on their enjoyment and frequency of engaging in social situations varying in relative situational demand. Parallel reports were obtained from knowledgeable others. Group × Situational Demand interactions revealed the hypothesized pattern of reduced frequency and enjoyment ratings for ambiguous or novel situations by the high-schizotypy participants in both self and others' reports. Groups were more comparable in their reported frequency and enjoyment of less ambiguous situations. Results suggest the importance of situational demands in the socioemotional experience and behavioral withdrawal in schizotypy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Bench-Scale Testing of Nanofiltration for Seawater Desalination

A dual-staged nanofiltration process is being evaluated as an alternative to reverse osmosis for seawater desalination. The primary goal of this system is to reduce energy consumption while producing potable water at an acceptable recovery rate. Investigation of this system at the bench-scale level focused on membrane surface characterization, ion rejection (including boron, bromide, and iodide rejection), and flux decline. Results from this study showed that two commercially available nanofiltration membranes can effectively desalinate seawater. Although fouling was apparent—and resulted in approximately 20% flux decline over 3 days—a critical flux was not identifiable. Operation of the system at different cross-flow velocities revealed the significance of hydrodynamic conditions on the polarization modulus, and hence on membrane performance.     

Modeling language acquisition in atypical phenotypes.

An increasing number of connectionist models have been proposed to explain behavioral deficits in developmental disorders. These simulations motivate serious consideration of the theoretical implications of the claim that a developmental disorder fits within the parameter space of a particular computational model of normal development. The authors examine these issues in depth with respect to a series of new simulations investigating past-tense formation in Williams syndrome. This syndrome and the past-tense domain are highly relevant because both have been used to make strong theoretical claims about the processes underlying normal language acquisition. The authors conclude that computational models have great potential to advance psychologists' understanding of developmental deficits because they focus on the developmental process itself as a pivotal causal factor in producing atypical phenotypic outcomes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Online Calculation and Prediction of the Strip Temperature in a Hot Strip Finishing Mill

The paper deals with a physical model for the calculation of the strip temperature in a hot rolling mill. Beside the heat transfer from the strip to the environment in the different mill sections a sub‐model for the material properties of steel including phase transitions is introduced. For the application in a process automation system an online adaptation of the model to the current state of the mill is indispensable. The adaptation is explained in detail.     

Minimum effort factor approach for sensor-based control of a four-joint 6-dof redundant manipulator

A sensor-driven control model and a minimum effort control algorithm in terms of time and energy expended during the execution of a movement strategy are described and validated for a multijointed cooperating robotic manipulator. Considering smooth, human-like (anthropomorphic) movements, using joint motion profiles achievable in real time as well as sensory information from all joints, and evaluating the total work expended by each manipulator joint during the execution of a movement strategy, a minimum effort motion trajectory is synthesized to precisely and efficiently position the robotic arm end-effector. This sensor-based approach significantly reduces the computational requirements for such cooperative motion. The minimum effort control algorithm generates several human-like arm movement strategies and selects the best strategy on the basis of expendable effort. The algorithm has an inherent basis to deal with obstacles in an efficient way. Detailed examples are described from the simulation studies. © 1994 John Wiley & Sons, Inc.