Ecological predictors of substance use in middle school students.

The current study examined important predictors of substance use during early adolescence. The authors hypothesized that adolescents' relationships with key adults (i.e., teachers and parents) influence their choices to use substances indirectly through links with their decisions regarding peer groups. A total of 461 middle school students from an affluent suburban community completed self-report measures of authoritative parenting, perceived social support from teachers, affiliation with rule-breaking and substance-using peers, and frequency of alcohol, cigarette, and drug use. Results of structural equation modeling supported the hypothesized model. Authoritative parenting and teacher support accounted for 31% of the variance in affiliation with deviant peers which, in turn, accounted for 27% of the variance in adolescent substance use; direct paths from parenting and teacher support to substance use were not indicated. Implications for school psychologists' involvement in substance use prevention and intervention are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Remote sensing of phytoplankton functional types

The principal goal in early missions of satellite-borne visible spectral radiometry (ocean colour) was to create synoptic fields of phytoplankton biomass indexed as concentration of chlorophyll-a. In the context of climate change, a major application of the results has been in the modelling of primary production and the ocean carbon cycle. It is now recognised that a partition of the marine autotrophic pool into a suite of phytoplankton functional types, each type having a characteristic role in the biogeochemical cycle of the ocean, would increase our understanding of the role of phytoplankton in the global carbon cycle. At the same time, new methods have been emerging that use visible spectral radiometry to map some of the phytoplankton functional types. Here, we assess the state of the art, and suggest paths for future work.     

Consistency-based compliance: When and why do children become vulnerable?

This study examines the nature and development of behavioral consistency pressures in children. Specifically, we examined the effectiveness of the foot-in-the-door procedure in producing consistent prosocial behavior and self-attributions in kindergartners and second and fifth graders. Children were either induced to comply with a request to share prize coupons or were not given this initial prosocial experience. Those who complied either were labeled as helpful by an adult or were not. Later, children were given the opportunity to help under public or private circumstances. Moreover, children's understanding of trait stability, their internal preference for consistent behavior, and their belief that adults prefer behavioral consistency were assessed. Consistent responding began to occur within the foot-in-the-door procedure in the second grade, and this developmental shift was paralleled by a shift in children's understanding of trait stability. Furthermore, once the foot-in-the-door effect appeared among the second and fifth graders, its strength was significantly affected by the children's internal preference for consistency. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Person€nvironment intersections: Everyday settings and common trait dimensions.

Intersection of personality dimensions (adjustment, likeability, self-control, social inclination, intellectance, and dominance) and taxonomy of everyday settings were examined. In Studies 1 and 2, Ss recalled situations relevant to each personality dimension. Judges categorized into six nondomicile (academic, athletic, business, play, religious, and streets) and six domicile (bedroom, eating room, living room, dormitory room, fraternity or sorority house, and outside house) categories. Trait/setting profiles converged across two methods and two regions. In Study 3, Ss rated visibility of each trait dimension in each setting. Interactions show some settings seen to allow more expression of some traits. Main effects show some settings seen as more generally illuminative, and some traits as more generally visible. Similarities in trait/setting profiles across three studies are discussed; joint importance of situational constraint and public observability in a setting's relevance to display of traits is considered. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Screening effectiveness of the Minnesota Child Development Inventory expressive and receptive language scales: Sensitivity, specificity, and predictive value.

This study examines the sensitivity, specificity, and predictive value of the Expressive Language (EL) and Comprehension-Conceptual (CC) subscales of the Minnesota Child Development Inventory (MCDI) in 152 consecutive referrals to a communication disorders clinic. Correlational analyses revealed moderate agreement between parent report (MCDI) and formal measures of expressive and receptive language ability from the Reynell Development Language Scales. Classification analyses comparing parent-report (MCDI) measures with direct assessment results (Reynell) revealed high sensitivity (88% and 77%) and good positive predictive value (80% and 75%) for the MCDI EL and CC subscales, respectively. Low to moderate specificity rates, however, suggest that the MCDI classifies normal expressive and receptive language status less accurately (45% and 64%, respectively). These findings suggest that the MCDI is an efficient screening tool under high-prevalence conditions such as a clinic population of language-disordered children. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Deformation-morphology correlations in electrically conductive carbon nanotube—thermoplastic polyurethane nanocomposites

Addition of small amounts (0.5-10 vol%) of multiwall carbon nanotubes (CNT) to thermoplastic elastomer Morthane produced polymer nanocomposites with high electrical conductivity (σ∼1-10 S/cm), low electrical percolation (?∼0.005) and enhancement of mechanical properties including increased modulus and yield stress without loss of the ability to stretch the elastomer above 1000% before rupture. In situ X-ray scattering during deformation indicated that these mechanical enhancements arise not only from the CNTs, but also from their impact on soft-segment crystallization. The deformation behavior after yielding of the nanocomposites, irrespective of CNT concentration, is similar to the unfilled elastomer, implying that the mechanistics of large deformation is mainly governed by the matrix. The relative enhancement of the Young's modulus of the nanocomposites is comparable to other elastomeric nanocomposites, implying that to the first order specific chemical details of the elastomeric system is unimportant.     

Contributions of automatic and controlled processes to the analysis of hierarchical structure.

Three experiments provide evidence that 2 mechanisms, 1 automatic and 1 controlled, produce variations in the efficiency with which local and global forms are processed. Targets are identified faster if they appear at the same level (global or local) as the target on the previous trial. M. R. Lamb, B. London, H. M. Pond, and K. A. Whitt (see record 1997-39043-003) provided evidence that the beneficial effect of level repetition is due to an automatic process that is outside voluntary control. In the present experiments, pretrial cues informed participants as to the level of the upcoming target. Valid cues benefited performance, whereas invalid cues harmed performance relative to noninformative neutral cues. This was so even when the relation between the cue and the level it signaled was arbitrary, indicating that the cues initiated voluntary shifts of attention. The benefit associated with level repetition, however, was unaffected by the cues. These data suggest that the benefit of level repetition results from a process that is not subject to voluntary control. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Work groups: From the Hawthorne studies to work teams of the 1990s and beyond.

This article summarizes the Hawthorne studies related to work groups and their legacy and traces applications of work groups and related empirical research through the 1990s. A selective review of empirical studies of work group effectiveness conducted in work settings and published in the last 20 years addresses 4 questions: (a) What identifying features have field researchers used in operationally defining work groups? (b) What research strategies have been used, and to address what kinds of questions? (c) What criteria of work group effectiveness has the field research measured, using what sources of data? (d) What variables have researchers sought to link with measures of work group effectiveness? On the basis of answers to these questions, an agenda for future research about work groups and work teams is suggested. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The impact of river regulation and climate change on the barred estuary of the Oued Massa,southern Morocco

The estuary of the Oued Massa, southern Morocco, has experienced alternating phases of tidal and lagoon conditions. Using field surveys, aerial photographs and rainfall–runoff records the dominant processes and recent evolution of the estuary are described. These data suggest that the character of the estuary has changed since the upstream impoundment of the river by the Youssef Ben Tachfine reservoir. The frequency of low‐flows has been significantly increased by river regulation, as has the mean interval between flood events. Using reconstructed flow series it is speculated that lagoon conditions have become more common in the post‐impoundment era than at any time since the 1920s. Although increases in winter precipitation projected by the global climate model HadCM2 for 2030–2049 imply a higher frequency of flood flows entering the reservoir in the future, the magnitude and frequency of such inflows are still within historic variability. Nonetheless, higher inflows may produce more frequent spills with concomitant bar breaching and termination of lagoon phases. Despite this, it is argued that the presence of the dam is ultimately of greater consequence to the functioning of the estuary–lagoon system than future precipitation changes over the region. Copyright © 2001 John Wiley & Sons, Ltd.