Does the medium matter? The interaction of task type and technology on group performance and member reactions.

Investigated the hypothesis that as group tasks pose greater requirements for member interdependence, communication media that transmit more social context cues will foster group performance and satisfaction. 72 3-person groups of undergraduates worked in either computer-mediated or face-to-face meetings on 3 tasks with increasing levels of interdependence: an idea-generation task, an intellective task, and a judgment task. Results showed few differences between computer-mediated and face-to-face groups in the quality of the work completed but large differences in productivity favoring face-to-face groups. Analysis of productivity and of members' reactions supported the predicted interaction of tasks and media, with greater discrepancies between media conditions for tasks requiring higher levels of coordination. Results are discussed in terms of the implications of using computer-mediated communication systems for group work. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Water deprivation enhances fear conditioning to contextual, but not discrete, conditional stimuli in rats.

Water-deprived and nondeprived rats were fear conditioned with a discrete tone CS and an aversive footshock unconditioned stimulus/stimuli (UCS). 24 and 48 hrs following conditioning, conditional fear to the tone CS and the context cues of the conditioning chamber, respectively, were assessed by measuring freezing behavior. Water deprivation had no effect on baseline responding to either tone or contextual stimuli. Following either 1 or 3 tone-shock pairings, however, water deprivation selectively enhanced conditional freezing to the contextual cues of the training chamber; conditional freezing to the tone was unaffected by water deprivation. These results are consistent with the view that water deprivation affects fear conditioning via an influence on the hippocampus. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Role of attention in face encoding.

Ss studied faces in a full- or a divided-attention condition and then received a recognition test that included old faces, new faces constructed by combining facial features from previously studied faces ("conjunction faces"), and partly or completely new faces. Full- but not divided attention Ss responded "old" more often to old than to conjunction faces; all Ss responded "old" to these faces more often than to partially or completely new faces. Thus it is less attentionally demanding to encode facial features than it is to encode their interrelations. Dividing attention had identical effects on an incidental and an intentional learning group. Exp 3 demonstrated that dividing attention primarily affected explicit recollection rather than stimulus familiarity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Pulp Pulpits: Self-Disclosure on "Donahue"

This study examines why people choose to self-disclose on "Donahue" and what role television plays in their lives prior to disclosure. Focused interviews were conducted with 29 informants between the ages of 12 and 68 who had appeared on the program. Analysis revealed that an evangelical fervor underpinned their decision, overshadowing other concerns about disclosure in a public forum. Informants generally reported low levels of television viewing. They held a pragmatic view of talk shows as avenues to reach a dual audience that included the mainstream public and members of their out-groups. Television disclosure is a tactic in a counterhegemonic struggle. Respondents utilized numerous impression management techniques in their efforts to manage their stigmatized status. Participants on "Donahue" risk co-optation, but running the gauntlet of criticism and ridicule allows an opportunity for delabeling rarely afforded to out-groups.     

Environmental effects on ductile-phase toughening in Nb5Si3-Nb composites

A variety of materials have been toughened via the addition of a ductile phase. Brittle silicide intermetallics such as Nb₅Si₃ have been significantly toughened by niobium particles incorporated during in-situ processing techniques. In the work described here, toughness tests conducted on Nb₅Si₃ were monitored in a scanning electron microscope to view the process of toughening provided by the niobium particles. In particular, the behavior of the ductile phase was monitored and related to the toughness obtained. In an attempt to vary the behavior of the ductile phase, the composite materials were exposed to a variety of gaseous environments and subsequently tested in air. The resulting toughness, resistance-curve behavior, and in-situ results highlight the importance of the behavior of the ductile phase on subsequent properties.     

Visual masking and visual integration across saccadic eye movements.

Studied visual masking and visual integration across saccadic eye movements in 4 experiments. In a 5th experiment, 4 randomly chosen dots from a 3?×?5 dot matrix were presented in 1 fixation, and 4 different dots from the matrix were presented in a 2nd fixation. Ss reported the location of the missing dot. When the 1st display was presented just before the saccade (as in Exps I–III), Ss accurately specified the missing dot location when the dots were presented to the same region of the retina but not when they were presented in the same place in space. When the 1st display was presented well before the saccade (as in Exp IV), Ss performed poorly regardless of retinal or spatial overlap. Results indicate the existence of a short-lived retinotopic visual persistence but provide no support for a spatiotopic visual persistence capable of fusing the contents of successive fixations. It is concluded that transsaccadic integration depends instead on an abstract memory that accumulates position and identity information about the contents of successive fixations. Results are discussed in relation to the work by M. L. Davidson et al (see record 1974-10245-001). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Oxygen Tracer Diffusion in Vitreous Silica

Oxygen diffusion in vitreous silica glass is studied using the gas exchange technique. The tracer concentration profiles are consistent with a model based on two mechanisms, one network and the other interstitial. These processes are coupled through limited network–interstitial exchange. Nuclear reaction analysis and secondary ion mass spectrometry techniques are performed and compared. These results are compared to experiments on transport in thin silica films grown on single-crystal silicon.     

Loss of control, self-blame, and depression: An investigation of spouse caregivers of Alzheimer's disease patients.

Tested several predictions derived from the reformulated learned helplessness (RLH) depression model developed by L. Y. Abramson et al (see record 1979-00305-001) and from recent critiques of that model, in a longitudinal study of spouses caring for a husband or wife with Alzheimer's disease. During initial interviews, 68 caregivers (aged 37–85 yrs) rated the uncontrollability of important upsetting events related to their spouse's disease and were scored on an index of internal–external causal attribution (CATN) for those events. In addition, at both the initial and follow-up interviews (n?=?38) about 10 mo later, caregivers were rated for depression, anxiety, and hostility. Results indicate that the indices of loss of control and CATN were more consistently related to depression than to anxiety or hostility, although hostility was related to CATNs. Correlations of the loss of control and CATN variables with depression remained significant after controlling for a measure of the spouse's objective disability. In hierarchical regression analyses, perceived loss of control and its interaction with CATN significantly predicted follow-up depression after controlling for initial depression. The interaction showed that loss of control combined with an internal attribution predicted higher depression than did either one alone. The importance of including specific uncontrollable events when studying the RLH model is emphasized. (36 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Crystal plasticity modeling of deformation and creep in polycrystalline Ti-6242

This paper develops an experimentally validated computational model based on crystal plasticity for the analysis of two-phase α/β Ti-6242 polycrystalline alloys. A rate-dependent elastic-crystal plasticity model is incorporated in this model to accommodate anisotropy in material behavior and tension-compression asymmetry inherent to this alloy. A combination of microtesting, orientation imaging microscopy, computational simulations, and minimization process, involving genetic algorithms, is implemented in this study for careful characterization and calibration of the material parameters. Size effects are considered in this analysis through a simple scaling process. A homogenized equivalent model of the primary α with transformed β colonies is developed for incorporation in the Ti-6242 FE model. The polycrystalline Ti-6242 computational model incorporates accurate phase volume fractions, as well as statistically equivalent orientation distributions to those observed in the orientation imaging microscopy scans. The effects of orientation, misorientations, and microtexture distributions are investigated through simulations by this computational model. The model is used to simulate constant strain rate and creep tests in compression and tension, and the results are compared with experiments. The effects of microstructure and creep-induced load-shedding on the localization of microstructural stresses and strains are studied for potential crack initiation criteria.