Imitation and pantomime in high-functioning adolescents with autism spectrum disorders

A study was designed to test 2 alternative hypotheses--a symbolic hypothesis and an executive function hypotheses--for the imitation and pantomime deficits found in previous studies of autism. The subjects were 17 adolescent high-functioning subjects with autism spectrum disorders and 15 clinical comparison subjects who were matched on chronological age and verbal IQ. Meaning and sequence were manipulated in facial and manual imitation tasks. Sequence was manipulated in the pantomime and control tasks. Recognition memory and motor control tasks were matched to the experimental tasks. The results provided no support for the symbolic deficit hypothesis; meaning aided rather than hindered the performance of the group with autism. Partial support for the executive deficit hypothesis was found. There were no group differences on motor control tasks, and few on the memory control tasks, arguing against deficits in motor initiation, basic motor coordination, or visual recognition memory.     

Implicit processing in the cued recall of young and old adults.

Reports 2 cued recall experiments in which younger and older Ss studied target words varying in number of preexperimental associates. In Exp 1, targets were studied in either the absence or presence of meaning-related context cues, with recall always prompted by the cues. In the absence of context, words with smaller sets of associates were easier to recall than those with larger sets, but this effect was reduced for older Ss. The presence of a study context cue facilitated recall and eliminated the effect of associative set size for both ages. In Exp 2, targets were studied and tested in the presence of unrelated words. In this situation, words with smaller sets of associates were less likely to be recalled than words with larger sets; again the effect was reduced for older Ss. The results are interpreted as an age decrement in processing implicitly activated information. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Large deformation and ultimate properties of biopolymer gels: 2. Mixed gel systems

Biphasic, mixed gels of agarose and gelatin were prepared, and their mechanical behaviour in tensile tests was determined, up to failure, utilising four decades of (constant) strain rate. The behaviour of pure agarose and pure gelatin in such tests has been determined previously. Suitable ‘blending-laws’ relating the small deformation shear modulus of the composite to the moduli of the component phases have also been discussed elsewhere. This report extends the latter treatment to the more aggressive large deformation regime, deriving bounds for modulus and break stress which closely model observed behaviour.     

Deviant auditory stimuli activate human left and right auditory cortex differently

Infrequent "deviant' auditory stimuli embedded in a homogeneous sequence of "standard' sounds evoke a neuromagnetic mismatch field (MMF), which is assumed to reflect automatic change detection in the brain. We investigated whether MMFs would reveal hemispheric differences in cortical auditory processing. Seven healthy adults were studied with a whole-scalp neuromagnetometer. The sound sequence, delivered to one ear at time, contained three infrequent deviants (differing from standards in duration, frequency, or interstimulus interval) intermixed with standard tones. MMFs peaked 9-34 msec earlier in the right than in the left hemisphere, irrespective of the stimulated ear. Whereas deviants activated only one MMF source in the left hemisphere, two temporally overlapping but spatially separate sources, one in the temporal lobe and another in the inferior parietal cortex, were necessary to explain the right-hemisphere MMFs. We suggest that the bilateral MMF components originating in the supratemporal cortex are feature specific whereas the right-hemisphere parietal component reflects more global auditory change detection. The results imply hemispheric differences in sound processing and suggest stronger involvement of the right than the left hemisphere in change detection.     

Work-arounds and Boundary Crossing in a High Tech Optronics Company: The Role of Co-operative Workflow Technologies

This study examines how some employeescoped with the exceptions that they encountered withtheir on-going use of a co-operative workflowtechnology in an optronics company. By drawing on thecase material, this paper will indicate thatapproaches which view work as being capable of beingplanned and managed through the formal authority ofthe hierarchy are insufficient. Instead, this paperwill suggest that exception handling, work-arounds andimprovisation are more characteristic of humanactivity. Computer supported co-operative work will beconceptualised as being embedded in a dynamicrelationship between the context it is situatedwithin, and the actors that engage in it. Theprinciples underlying ethnography have informed theresearch approach.     

Using Diary Methods to Study Marital and Family Processes.

Diary methods allow researchers to study marital and family processes within the context of daily life in a way that is not possible with more traditional methods. The authors review applications of diary designs in marital and family research and detail the types of research questions that can uniquely be asked of dyadic/family diary data. Technological developments for the use of electronic palm-top devices for implementing diary methods are also reviewed. Additionally, the authors discuss specific issues relevant to the analysis of diary data that come from dyads or families. Last, the authors raise unresolved issues and directions for future research in the use of diary methods for studying marital and family processes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Activation of microcomponents with light for micro-electro-mechanical systems and micro-optical-electro-mechanical systems applications

We examine the light-activation properties of micrometer-sized gear structures fabricated with polysilicon surface micromachining techniques. The gears are held in place on a substrate through a capped anchor post and are free to rotate about the post. The light-activation technique is modeled on photon radiation pressure, and the equation of motion of the gear is solved for this activation technique. Experimental measurements of torque and damping are found to be consistent with expected results for micrometer-scale devices. Design optimization for optically actuated microstructures is discussed.     

Development,amino acid utilization and cell allocation in bovine embryos after in vitro production in contrasting culture systems

The effects of protein-supplemented and protein-free media on amino acid uptake, protein synthesis and cell differentiation in bovine blastocysts were investigated. Four formulations of synthetic oviduct fluid were used. Each formulation was identified by the principal supplement: bovine serum albumin (0.4%, w/v); polyvinyl alcohol (0.3%, w/v); or either of two steer sera (10%, v/v). After zygote culture, blastocyst yields (day 7.5) were lowest in protein-free medium and highest in albumin-supplemented medium. Subsequent 12 h incubation in the presence of both essential and non-essential amino acids was used for the measurement of amino acid flux. All blastocysts released alanine but consumed aspartate (P < 0.001) and the extent was influenced by prior culture conditions. Aspartate uptake was lower in blastocysts produced in protein-free conditions (P < 0.05) than in blastocysts produced in albumin-supplemented conditions. Consumption indices for 16 other amino acids were not influenced by blastocyst source. Cell counts and hatching incidences were highest for albumin-supplemented blastocysts, but were similar among blastocysts from the protein-free and serum-dependent treatments. Crucially, the use of protein-free medium for zygote culture did not compromise resultant blastocysts in terms of either de novo protein synthesis ([3H]phenylalanine incorporation) or trophectoderm function (phenotype based on interferon-tau detection). Thus, although blastocyst yields were compromised after zygote culture in a protein-free (vis-à-vis albumin-supplemented) medium, amino acid flux was qualitatively conserved, and only quantitatively modified in the case of alanine and aspartate. Moreover, vital properties of blastocysts that were produced, including de novo protein synthesis and trophectodermal cell function, apparently were not adversely affected by protein deprivation.     

Laser projection versus a CRT display in the visual perception of aircraft aspect

High-resolution visual displays have been designed for flight simulation so that observers may judge the aspect angle of aircraft at far distances. The present experiment compares two display devices as untrained observers judge the spatial orientation of two target aircraft: F-15 and F-16 jets. The display devices are a prototype direct-write microlaser projector and an SXGA-format CRT display. Observers' accuracy of aircraft identification is better with the laser projector, and recognition response times are faster. A simple rule was found to fit the observers' response times; it is expressed in terms of a statistic on the autocorrelation of black-and-white silhouette images of aircraft. Observers' estimates of aspect are biased by the laser projector, whereas observers' estimates of aspect are accurate on average with the SXGA display. This bias in estimation of aspect may be attributable to variations in line brightness introduced by the laser projector. Actual or potential applications of this research include the evaluation of high-resolution visual displays for the training of basic fighter maneuvers with military jet pilots.