Nanoindentation measurements on deformation-induced α’-martensite in a metastable austenitic high-alloy CrMnNi steel

The hardness of deformation-induced α’- martensite and parent austenitic matrix in high-alloy CrMnNi steel was investigated by nanoindentation measurements inside scanning electron microscope using picoindenter. After the indentation, the microstructure was investigated by electron backscattered diffraction measurements. The hardness values for α’-martensite are only 24% higher than those of austenite. Thus, the increase in strength during the formation of deformation-induced α’-martensite is rather caused by the small grain size of α’-nuclei resulting in a dynamic Hall–Petch effect than by its “intrinsic” hardness.     

Psychometric properties of the German version of the Barratt Impulsiveness Scale, Version 11 (BIS-11) for adolescents

Impulsiveness is increasingly gaining attention as a potential risk factor for various mental disorders. Until now, there have been German instruments that allowed for assessing adolescents' self-reported impulsiveness multi-dimensionally. The present study examined the German version of the Barratt Impulsiveness Scale-11 (BIS-11) for adolescents. The instrument was completed by 659 adolescents ages 10 to 20 years; 98 were retested after 6 months. Items showed adequate psychometric properties. An exploratory factor analysis identified three factors that showed slightdifferences from the initial questionnaire proposed by Barratt. The factors showed low to moderate intercorrelations, satisfactory internal consistency (dependent on factor), and were stable over time. Convergent validity was ascertained, and the item pool showed sufficient power to discriminate adolescents with symptoms of attention deficit hyperactivity disorder and those with loss of eating control from healthy adolescents. Findings suggest that the German BIS-11 is appropriate for reliable investigation of impulsiveness in adolescents. Future research should examine sensitivity as a screening tool, as well as sensitivity to change.     

CHRM2, parental monitoring, and adolescent externalizing behavior: evidence for gene-environment interaction

Psychologists, with their long-standing tradition of studying mechanistic processes, can make important contributions to further characterizing the risk associated with genes identified as influencing risk for psychiatric disorders. We report one such effort with respect to CHRM2, which codes for the cholinergic muscarinic 2 receptor and was of interest originally for its association with alcohol dependence. We tested for association between CHRM2 and prospectively measured externalizing behavior in a longitudinal, community-based sample of adolescents, as well as for moderation of this association by parental monitoring. We found evidence for an interaction in which the association between the genotype and externalizing behavior was stronger in environments with lower parental monitoring. There was also suggestion of a crossover effect, in which the genotype associated with the highest levels of externalizing behavior under low parental monitoring had the lowest levels of externalizing behavior at the extreme high end of parental monitoring. The difficulties involved in distinguishing mechanisms of gene-environment interaction are discussed.     

Barriers and Supports for Continuing in Mathematics and Science: Gender and Educational Level Differences

This article presents three studies that provide an in-depth examination of STEM-related supports and barriers. These studies constructed an instrument to identify male and female perceptions of the barriers and supports for pursuing coursework and/or careers in mathematics and sciences domains; to pilot test and refine that instrument; and then to explore gender differences in perceptions of supports and barriers at three different educational levels: middle school, high school, and college. Study 1 involved using literature reviews and in-depth interviews at the three educational levels to broadly identify perceived supports and barriers, and to develop a taxonomy of barrier and supports at each level. Based upon the taxonomy, study 2 involved the construction and pilot testing of a barriers and support instrument. Study 3 involved administering the revised instrument to a large sample of participants at each educational level. Results indicate both gender and developmental differences in perceptions of the barriers and supports for pursuing a math or science curriculum.     

Outcome of aggression affects processing and can legitimise subsequent aggression: Influence of trait aggressiveness

The present study investigated differences in processing times between positive and negative outcomes to an aggressive reaction to provocation. The effects of outcome, sex, trait aggressiveness and current mood on subsequent subject‐generated material were also examined. Fifty subjects read stories line by line on a computer screen. Reading time for the key sentence describing a positive or negative outcome to an aggressive reaction to provocation was recorded and subjects wrote a continuing sentence to half the stories. Subjects took less time to process the negative outcome. The positive outcome resulted in more subject‐generated aggression than the negative outcome. There were few sex differences but men wrote more aggressive endings than women for the stories containing physical aggression. Trait aggressiveness was correlated with producing more aggressive content in the continuing sentence for both outcomes. Feeling peaceful was correlated with producing prosocial material to neutral stories. Subjects therefore expect a negative outcome to aggressive behaviour. Reading stories which present a positive outcome to aggression increases the accessibility of aggressive cognitions. Subjects high in trait aggressiveness are not inhibited by a negative outcome. Aggr. Behav. 30:284–297, 2004. © 2004 Wiley‐Liss, Inc.     

On the Interpretation of Response Time vs Onset Asynchrony Functions: Application to Dual-Task and Precue-Utilization Paradigms

The central bottleneck model of dual-task performance (H. Pashler and J. C. Johnston, 1998, Quarterly Journal of Experimental Psychology, 46A, 51-82) and the serial processing model of precue utilization (R. Gottsdanker, 1992, Acta Psychologica, 79, 21-43) are based on a common formal structure: They both represent response time as RT(tau)=max(X-tau, Y)+Z, where X, Y, Z denote the duration of certain processing stages specified by the models and tau denotes the onset asynchrony (SOA) between two stimuli. We consider this model within a stochastic framework in which the stage durations are random variables following an arbitrary joint distribution and derive properties of the function relating E[RT(tau)] to SOA. We present a distribution-free result which relates the slope of this function to the distribution of the random durations of the assumed processing stages. Our results allow for a direct, model-based interpretation of data from related experiments; specifically, they show how the slope of the SOA-function depends on experimental factors which selectively influence individual processing stages. We explain the implications of our results for models of dual-task performance and precue utilization and illustrate their application to data obtained by M. C. Smith (1969, Acta Psychologica, 30, 220-231) and R. Gottsdanker (1992, loc. cit.) Copyright 2001 Academic Press.     

Analysis of Cognitive Dysfunction in Patients with Low-Grade Glioma

All living adults with histopatologically proven diagnosis of low-grade glioma in a Swedish county were identified with help of the Regional Cancer Register, half of them (n = 24) participated in a neuropsychological evaluation. A considerable variation was found in cognitive function within this group of patients, ranging from good ability to severe disturbance. Different patterns of cognitive dysfunction emerged resulting in three subgroups; patients with severe, mild, and minimal selective dysfunction. The patients with severe disturbance had a global dysfunction covering most assessed cognitive domains. Slow information-processing speed was obvious in the subgroups with both severe and mild dysfunction. Cognitive problems present in the best performing group seemed related to tumor localization. Cognitive function in the whole sample was related to histopathological diagnosis of the tumor, as well as to educational level of the patients. The nonworking patients had significantly poorer performance than the working patients.     

Distinct Neurophysiological Patterns Reflecting Aspects of Syntactic Complexity and Syntactic Repair

Aspects of syntactic complexity and syntactic repair were investigated by comparing the event-related (brain) potentials (ERPs) for sentences of different syntactic complexity to those containing a syntactic violation. Previous research had shown that both aspects of syntactic processing are reflected in a late positivity (P600). Results from the present reading experiment demonstrate, however, that although both processing aspects elicit a late positivity, they are different in distribution. The repair-related positivity preceded by a negativity displayed a centroparietal distribution, whereas the complexity-related positivity showed a frontocentral scalp distribution. These data indicate that the P600 is not a unitary phenomenon. Moreover, the distributional differences strongly suggest that different neural structures underlie the two aspects of processing, namely syntactic repair and syntactic integration difficulties, most evident when processing syntactically complex sentences.     

Differences between digit naming and number word reading in a flanker task

Numbers can be represented as number words or as digits, but are the two notations processed differently? Two experiments in which a flanker paradigm with a naming task was used were conducted, with digits and number words as targets and flankers. Reaction times were shortest when the flanker denoted the same numerical value as the target. The numerical distance between the target and a numerically different flanker modulated reaction times in all conditions, except for number word targets with digit flankers. The direction of this effect—targets were named faster when the flanker was numerically close than when it was far—indicates that the numerical magnitude representations of numbers are associatively connected. When the target and the flanker were presented in the same format, no difference was observed in the distance effects for the two formats. This indicates that number words activate the abstract representation of their numerical value in a way that is very similar to that for digits.