A congressional view of youth suicide.

Concern about adolescent suicide is pervasive among American teenagers. This article reviews the results of a national survey of adolescents about their knowledge of, and attitudes toward, youth suicide. More than 60% of teens surveyed reported knowing another teen who had attempted suicide and 6% reported having made an attempt themselves. The survey also provides information about adolescents' explanations for self-destructive behavior. Given this information, recommendations for effective preventive interventions and policy decisions are offered. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Characterizing residual reflections within semiconductor lasers,integrated sources, and coupling optics

We describe a method for analyzing reflections within or near semiconductor lasers and more complicated integrated sources. Through Fourier transformation of an optical spectrum from the wavevector to the length domain, reflections are analyzed for strength, round-trip path length, and current or voltage dependence. Identification of reflections from within semiconductor lasers, integrated electro-absorption modulated lasers, and from coupling optics is presented. Spatial resolution in InP of ~5 μm with over two orders of magnitude in dynamic range is demonstrated. Inverse transformation of a spatially resolved feature in a transformed reflection spectrum provides an optical spectrum due to that individual feature of sufficient resolution to study wavelength dependence, for example, of coatings and gratings     

Determinants of individual differences during skill acquisition: Cognitive abilities and information processing.

An integrative theory that links general models of skill acquisition with ability determinants of individual differences in performance is presented. Three major patterns of individual differences during skill acquisition are considered: changes in between-subjects variability, the simplex pattern of trial intercorrelations, and changing ability–performance correlations with practice. In addition to a review of previous theory and data, eight experimental manipulations are used to evaluate the cognitive ability demands associated with different levels of information-processing complexity and consistency. Subjects practiced category word search, spatial figure, and choice reaction time tasks over several hundred trials of task practice. An air traffic controller simulation was used to show generalization to a complex task. Examinations of practice-related between-subjects variance changes and ability–performance correlations are used to demonstrate that an equivalence exists between three broad phases of skill acquisition and three cognitive–intellectual determinants of individual differences. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Coherent transmission using an external waveguide Bragg reflector laser with direct frequency modulation

Single-frequency l.5?m semiconductor lasers, formed by butt-coupling of a regular Fabry?Perot laser to an external waveguide Bragg reflector, are shown to have very uniform frequency modulation characteristics under direct current modulation. The laser's frequency modulation characteristics, together with its narrow linewidth (? 1 MHz), make coherent transmission possible without external modulators. The laser performance was evaluated in a 417Mbit/s, 102 km, frequency-shift-keying coherent transmission experiment.     

Positive-engagement behaviors in observed family interactions: A social relations perspective.

The present study investigates the nature of positive engagement (an interpersonal style characterized by attentiveness, warmth, cooperation, and clear communication) in family interactions involving at least one adolescent. Approximately 400 families (mothers, fathers, and two siblings) were videotaped during brief conflict-resolution discussions that occurred on a yearly basis for 3 years. Coders rated the degree to which each family member was positively engaged with every other family member during the interactions. The social relations model was used to partition variation in positive-engagement behavior into family-level, individual-level, and dyad-level effects. Results demonstrated the importance of family norms and individual factors in determining the expression of positive-engagement behaviors in dyadic family relationships. Moreover, longitudinal analyses indicated that these effects are stable over a 3-year period. Finally, results highlighted the relative distinctiveness of the marital and sibling relationships, as well as the existence of reciprocity within these dyads. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Comparison of two U.S. power-plant carbon dioxide emissions data sets

Estimates of fossil-fuel CO2 emissions are needed to address a variety of climate-change mitigation concerns over a broad range of spatial and temporal scales. We compared two data sets that report power-plant CO2 emissions in the conterminous U.S. for 2004, the most recent year reported in both data sets. The data sets were obtained from the Department of Energy's Energy Information Administration (EIA) and the Environmental Protection Agency's eGRID database. Conterminous U.S. total emissions computed from the data sets differed by 3.5% for total plant emissions (electricity plus useful thermal output) and 2.3% for electricity generation only. These differences are well within previous estimates of uncertainty in annual U.S. fossil-fuel emissions. However, the corresponding average absolute differences between estimates of emissions from individual power plants were much larger, 16.9% and 25.3%, respectively. By statistical analysis, we identified several potential sources of differences between EIA and eGRID estimates for individual plants. Estimates that are based partly or entirely on monitoring of stack gases (reported by eGRID only) differed significantly from estimates based on fuel consumption (as reported by EIA). Differences in accounting methods appear to explain differences in estimates for emissions from electricity generation from combined heat and power plants, and for total and electricity generation emissions from plants that burn nonconventional fuels (e.g., biomass). Our analysis suggests the need for care in utilizing emissions data from individual power plants, and the need for transparency in documenting the accounting and monitoring methods used to estimate emissions.     

Shape-dependent oriented trapping and scaffolding of plasmonic nanoparticles by topological defects for self-assembly of colloidal dimers in liquid crystals

We demonstrate scaffolding of plasmonic nanoparticles by topological defects induced by colloidal microspheres to match their surface boundary conditions with a uniform far-field alignment in a liquid crystal host. Displacing energetically costly liquid crystal regions of reduced order, anisotropic nanoparticles with concave or convex shapes not only stably localize in defects but also self-orient with respect to the microsphere surface. Using laser tweezers, we manipulate the ensuing nanoparticle-microsphere colloidal dimers, probing the strength of elastic binding and demonstrating self-assembly of hierarchical colloidal superstructures such as chains and arrays.     

South Carolina's village system

The authors describe the architectural, design, and mental health treatment concepts underlying the village system, a group of regional inpatient mental health facilities planned in South Carolina. One of the villages is currently under construction and is expected to open early in 1977. In design it resembles a residential community with all the elements of a normal small town or neighborhood.