Glassy phases in organic semiconductors

Organic semiconductors may be processed from fluids using graphical arts printing and patterning techniques to create complex circuitry. Because organic semiconductors are weak van der Waals solids, the creation of glassy phases during processing is quite common. Because structural disorder leads to electronic disorder, it is necessary to understand these phases to optimize and control the electronic properties of these materials. Here we review the significance of glassy phases in organic semiconductors. We examine challenges in the measurement of the glass transition temperature and the accurate classification of phases in these relatively rigid materials. Device implications of glassy phases are discussed. Processing schemes that are grounded in the principles of glass physics and sound glass transition temperature measurement will more quickly achieve desired structure and electronic characteristics, accelerating the exciting progress of organic semiconductor technology development.     

Visuospatial neglect: the ultimate deconstruction?

Unilateral visuospatial neglect is now widely acknowledged to be a highly heterogeneous condition: The overt manifestations of visual neglect can vary as a function of task, spatial domain, and mode of response (at least). Double dissociations (sometimes of the strong form) have already been reported between most of the components of what was originally thought to be a relatively stable construct within the visual modality. Nonetheless, throughout successive fractionations of neglect, reported cases of bidirectional task-specific neglect after unilateral brain damage are rare. We now report two such cases. After right hemisphere stroke, the first patient reliably showed severe left neglect on cancellation but right neglect on line bisection. After left hemisphere stroke, the second case showed right neglect on cancellation but left neglect on line bisection. Extensive investigation of case 1 confirmed our previous conjecture that the crucial distinction between these tasks lies in the presence or the absence of an overt target. In contrast to cancellation, line bisection demands the internal computation of the location of the "target" (the midpoint), followed by executing a motor response toward the precise location of that "imaginary" midpoint. The relative attentional and premotor contributions of the intact and damaged hemispheres to these forms of bidirectional neglect are also assessed.     

Application of single-level,pointwise algebraic,and smoothed aggregation multigrid methods to direct numerical simulations of incompressible turbulent flows

Single- and multi-level iterative methods for sparse linear systems are applied to unsteady flow simulations via implementation into a direct numerical simulation solver for incompressible turbulent flows on unstructured meshes. The performance of these solution methods, implemented in the well-established SAMG and ML packages, are quantified in terms of computational speed and memory consumption, with a direct sparse LU solver (SuperLU) used as a reference. The classical test case of unsteady flow over a circular cylinder at low Reynolds numbers is considered, employing a series of increasingly fine anisotropic meshes. As expected, the memory consumption increases dramatically with the considered problem size for the direct solver. Surprisingly, however, the computation times remain reasonable. The speed and memory usage of pointwise algebraic and smoothed aggregation multigrid solvers are found to exhibit near-linear scaling. As an alternative to multi-level solvers, a single-level ILUT-preconditioned GMRES solver with low drop tolerance is also considered. This solver is found to perform sufficiently well only on small meshes. Even then, it is outperformed by pointwise algebraic multigrid on all counts. Finally, the effectiveness of pointwise algebraic multigrid is illustrated by considering a large three-dimensional direct numerical simulation case using a novel parallelization approach on a large distributed memory computing cluster.     

Bovine muscle shortening and protein degradation after electrical stimulation, excision and chilling

Electrical stimulation-dependent improvement in beef tenderness resulted from mechanisms other than avoidance of cold shortening in excised muscle chilled at a normal rate (10°C at 10h post-stimulation). At normal chilling rate, electrical stimulation enhanced degradation of the myofibrillar proteins, alpha actinin and troponin-T, and increased the amount of a 30 000 dalton protein, as assessed by gel electrophoresis, whereas sarcomere lengths were not different from unstimulated muscle. Under slightly accelerated chilling conditions (10°C at 5 h post stimulation), electrical stimulation prevented cold shortening but the meat was more tender than, and had the same sarcomere length as, unstimulated muscle chilled to 10°C in 10 h. Electrical stimulation did not improve the tenderness of beef chilled at a rapid rate (10°C at 2 h post stimulation), nor did it prevent cold shortening when muscles were chilled rapidly.     

Prosocial Emotions and Helping: The Moderating Role of Group Membership.

In this article, the authors introduce and test a group-level perspective on the role of empathy and interpersonal attraction in helping. In line with our predictions, Study 1, a longitudinal field study of 166 AIDS volunteers, confirmed that empathy was a stronger predictor of helping when the recipient of assistance was an in-group member than when that person was an out-group member. Also as hypothesized, attraction was a stronger predictor of helping when the recipient was an out-group member than when that person was an in-group member. Study 2 replicated and further extended these results in a laboratory experiment on spontaneous helping of a person with hepatitis. Strengthening the validity of the findings, in both studies the effects of empathy and attraction held up even when the authors statistically controlled for potential alternative predictors of helping. The theoretical and practical implications of these findings for helping in intergroup contexts are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Ethnicity, Expressed Emotion, Attributions, and Course of Schizophrenia: Family Warmth Matters.

The authors examined the role of family factors and the course of schizophrenia by carrying out additional assessments and analyses in 2 previously published studies of Mexican American and Anglo American patients and families. The authors found partial support for an attributional model of relapse for families who are low in emotional overinvolvement. Attributions of control, criticism, and warmth together marginally predicted relapse. The data also indicated that for Mexican Americans, family warmth is a significant protective factor, whereas for Anglo Americans, family criticism is a significant risk factor. These findings suggest that the sociocultural context shapes the pathways by which family processes are related to the course of illness. Moreover, the warmth findings suggest that families may contribute to preventing relapse. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Role of Melodic and Temporal Cues in Perceiving Musical Meter.

A number of different cues allow listeners to perceive musical meter. Three experiments examined effects of melodic and temporal accents on perceived meter in excerpts from folk songs scored in 6/8 or 3/4 meter. Participants matched excerpts with 1 of 2 metrical drum accompaniments. Melodic accents included contour change, melodic leaps, registral extreme, melodic repetition, and harmonic rhythm. Two experiments with isochronous melodies showed that contour change and melodic repetition predicted judgments. For longer melodies in the 2nd experiment, variables predicted judgments best at the beginning of excerpts. The final experiment, with rhythmically varied melodies, showed that temporal accents, tempo, and contour change were the strongest predictors of meter. The authors' findings suggest that listeners combine multiple melodic and temporal features to perceive musical meter. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Interactions of EGF, Wnt and HOM-C genes specify the P12 neuroectoblast fate in C. elegans

We investigate how temporal and spatial interactions between multiple intercellular and intracellular factors specify the fate of a single cell in Caenorhabditis elegans. P12, which is a ventral cord neuroectoblast, divides postembryonically to generate neurons and a unique epidermal cell. Three classes of proteins are involved in the specification of P12 fate: the LIN-3/LET-23 epidermal growth factor signaling pathway, a Wnt protein LIN-44 and its candidate receptor LIN-17, and a homeotic gene product EGL-5. We show that LIN-3 is an inductive signal sufficient to promote the P12 fate, and the conserved EGF signaling pathway is utilized for P12 fate specification; egl-5 is a downstream target of the lin-3/let-23 pathway in specifying P12 fate; and LIN-44 and LIN-17 act synergistically with lin-3 in the specification of the P12 fate. The Wnt pathway may function early in development to regulate the competence of the cells to respond to the LIN-3 inductive signal.     

Analyzing Nonindependent Outcomes in Couple Therapy Using the Actor-Partner Interdependence Model.

The nonindependent components of couple data require data-analytic strategies tailored to the interpersonal processes occurring between relationship partners. This article examines the benefits of a specifically dyadic analytic method, the actor-partner interdependence model (APIM), for evaluating interpartner influence across time. Both conceptual and methodological features of the APIM are exemplified by applying this model to observations of negative and positive affect and global distress in spouses participating in a randomized trial of couple therapy. In addition to elucidating specific advantages of the APIM relative to alternative data-analytic strategies, the current results shed new light on previous findings from a comparative treatment outcome study evaluating behavioral and insight-oriented approaches to couple therapy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)