The group lock and its applications

Parallel algorithms that use shared resources are notoriously difficult to write and verify, especially when properties such as fairness and efficiency are desired. This paper introduces a new synchronization method called the group lock. This method has some of the advantages of strict synchronization methods such as monitors; algorithms written using group lock are quite clear and easy to verify. At the same time, these algorithms generally make better use of parallelism than those written using stricter synchronization methods. In many cases we can obtain worst case time bounds that are constant or logarithmic in the number of processes, thus also insuring bounded fairness. The paper begins with a discussion of related synchronization methods and an introduction to the group lock. This is followed by some examples of applications in algorithms for a readers/writers problem, parallel stacks and queues, implementation of fetch- and-phi routines, and others. Finally, two implementations of group lock are described. A detailed implementation is given for the paracomputer, an idealized MIMD multiprocessor that supports the fetch-and-add synchronization instruction. An implementation is also outlined for general CREW multiprocessors using only reads and writes to shared memory.     

Interpretation of facial expressions of affect in children with learning disabilities with verbal or nonverbal deficits

The ability to identify facial expressions of happiness, sadness, anger, surprise,fear, and disgust was studied in 48 nondisabled children and 76 children with learning disabilities aged 9 through 12. On the basis of their performance on the Rey Auditory-Verbal Learning Test and the Benton Visual Retention Test, the LD group was divided into three subgroups: those with verbal deficits (VD), nonverbal deficits (NVD), and both verbal and nonverbal (BD) deficits. The measure of ability to interpret facial expressions of affect was a shortened version of Ekman and Friesen's Pictures of Facial Affect. Overall, the nondisabled group had better interpretive ability than the three learning disabled groups and the VD group had better ability than the NVD and BD groups. Although the identification level of the nondisabled group differed from that of the VD group only for surprise, it was superior to that of the NVD and BD groups for four of the six emotions. Happiness was the easiest to identify, and the remaining emotions in ascending order of difficulty were anger, surprise, sadness, fear, and disgust. Older subjects did better than younger ones only for fear and disgust, and boys and girls did not differ in interpretive ability. These findings are discussed in terms of the need to take note of the heterogeneity of the learning disabled population and the particular vulnerability to social imperception of children with nonverbal deficits.     

Cognitive appraisals, coping strategies, and support resources as correlates of parenting and infant development

By applying R. S. Lazarus's (1993) theoretical model, the authors explored the dynamics of stress and coping as central mechanisms underlying parenting adjustment and infant development. Longitudinal assessment of 140 primiparous mothers included measures of cognitive appraisals of parenting, coping strategies used, and supportive coping resources at pregnancy and 1 month, 6 months, and 12 months postpartum. Maternal outcome measures of adjustment included maternal well-being, parental efficacy, and observed behaviors of caregiving and affiliation. Infant developmental outcome was measured by the Bayley Scales of Infant Development (N. Bayley, 1993). All measures of the stress and coping model showed systematic developmental changes across the transition to parenthood as well as relative stability of individual differences. In addition, the stress and coping variables were found to have additive and interactive effects in predicting both maternal adjustment and infant development.     

Masculine and feminine traits: Their relation to suitedness for and success in training for traditionally masculine and feminine army functions.

Evidence in support of the androgyny, masculinity, and congruence models is compared in a study of 200 men and 299 women training for traditionally masculine and feminine army functions. Ss rated their chances for success in and suitedness for functions for which they were being trained, and responded to the Bem Sex-Role Inventory. At the end of training they were rated by peers and training officers. Men rated themselves more likely to succeed than did women and had higher officer and peer ratings. Suitedness self-ratings were higher for sex-typed and androgynous men and cross-sex-typed women. Androgynous men and women, sex-typed men, and cross-sex-typed women saw themselves as most likely to succeed. Officers' ratings favored the sex-typed. Men and women high in masculinity had better self- and peer ratings than did those low in masculinity. These results lend most support to the masculinity model. (PsycINFO Database Record (c) 2010 APA, all rights reserved)