Diel changes in water chemistry in an arsenic-rich stream and treatment-pond system

Arsenic concentrations are elevated in surface waters of the Warm Springs Ponds Operable Unit (WSPOU), located at the head of the upper Clark Fork River Superfund site, Montana, USA. Arsenic is derived from historical deposition of smelter emissions (Mill and Willow Creeks) and historical mining and milling wastes (Silver Bow Creek). Although long-term monitoring has characterized the general seasonal and flow-related trends in As concentrations in these streams and the pond system used to treat Silver Bow Creek water, little is known about solubility controls and sorption processes that influence diel cycles in As concentrations. Diel (24-h) sampling was conducted in July 2004 and August 2005 at the outlet of the treatment ponds, at two locations along a nearby reconstructed stream channel that diverts tributary water around the ponds, and at Silver Bow Creek 2 km below the ponds. Dissolved As concentration increased up to 51% during the day at most of the stream sites, whereas little or no diel change was displayed at the treatment-pond outlet. The strong cycle in streams is explained by pH- and temperature-dependent sorption of As onto hydrous metal oxides or biofilms on the streambed. Concentrations of dissolved Ca(2+) and HCO(3)(-) at the stream sites showed a diel temporal pattern opposite to that of As, and geochemical modeling supports the hypothesis that the concentrations of Ca(2+) and HCO(3)(-) were controlled by precipitation of calcite during the warm afternoon hours when pH rose above 9.0. Nightly increases in dissolved Mn and Fe(II) concentrations were out of phase with concentrations of other divalent cations and are more likely explained by redox phenomena.     

Mechanistic principles of nanoparticle evolution to zeolite crystals

Precursor nanoparticles that form spontaneously on hydrolysis of tetraethylorthosilicate in aqueous solutions of tetrapropylammonium (TPA) hydroxide evolve to TPA-silicalite-1, a molecular-sieve crystal that serves as a model for the self-assembly of porous inorganic materials in the presence of organic structure-directing agents. The structure and role of these nanoparticles are of practical significance for the fabrication of hierarchically ordered porous materials and molecular-sieve films, but still remain elusive. Here we show experimental findings of nanoparticle and crystal evolution during room-temperature ageing of the aqueous suspensions that suggest growth by aggregation of nanoparticles. A kinetic mechanism suggests that the precursor nanoparticle population is distributed, and that the 5-nm building units contributing most to aggregation only exist as an intermediate small fraction. The proposed oriented-aggregation mechanism should lead to strategies for isolating or enhancing the concentration of crystal-like nanoparticles.     

DConfusion: a technique to allow cross study performance evaluation of fault prediction studies

There are many hundreds of fault prediction models published in the literature. The predictive performance of these models is often reported using a variety of different measures. Most performance measures are not directly comparable. This lack of comparability means that it is often difficult to evaluate the performance of one model against another. Our aim is to present an approach that allows other researchers and practitioners to transform many performance measures back into a confusion matrix. Once performance is expressed in a confusion matrix alternative preferred performance measures can then be derived. Our approach has enabled us to compare the performance of 600 models published in 42 studies. We demonstrate the application of our approach on 8 case studies, and discuss the advantages and implications of doing this.     

Effects of children's family structure status on the development of stereotypes by teachers.

The possibility that teacher ratings of children may indicate a stereotype on the part of teachers was investigated by showing 30 teachers a videotape that focused on the social interaction of an 8-yr-old boy. Half of the teachers were given a background information sheet indicating that he was from a divorced home, while the other half were told he was from an intact home. Ss rated the boy on a wide range of 11 personality traits and predicted what his behavior would be like in 5 different school situations (e.g., copes with stress and popularity). The Bonferroni multiple-comparisons procedure indicated that the teachers rated the divorced child more negatively on the following 3 variables reflecting affective state or relations: happiness, emotional adjustment, and copes with stress. (9 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perfectionistic self-presentation in children and adolescents: Development and validation of the Perfectionistic Self-Presentation Scale—Junior Form.

Research on adults indicates that perfectionistic self-presentation, the interpersonal expression of one's perfection, is associated with a variety of psychopathological outcomes independent of trait perfectionism and Big Five traits. The current article reports on the development and evidence for the validity of the subtest score interpretations of an 18-item self-report measure of perfectionistic self-presentation for children and adolescents. Analyses conducted on data from two clinical samples and one nonclinical sample of children and adolescents found that the Perfectionistic Self-Presentation Scale—Junior Form (PSPS–Jr) reflected a multidimensional model of perfectionistic self-presentation with three subscales: Perfectionistic Self Promotion, Nondisplay of Imperfection, and Nondisclosure of Imperfection. The subscale scores were found to demonstrate internal consistency, and there was good evidence supporting the validity of the interpretation of subscale scores based on this new measure. The subscales were associated with maladaptive outcomes, but were not influenced unduly by biases that included social desirability and differential item functioning by gender. Overall, the PSPS-Jr appears to be a useful measure of the expression of perfection among youths and an important tool in attempting to understand the nature and the consequences of perfectionistic self-presentation in children and adolescents. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Psychodynamic approach to the addictive personality structure specific for alcohol and hard drugs

The overconsumption of psychotropic substances is a major problem for contemporary societies. In the USA, 14.1% of the population between the age 15 and 54 have experienced addiction problems to alcohol during their lives while as 7.5% are addicted for life to other drugs (cannabis, cocaine, stimulants, etc). Many studies report that excessive consumption of alcohol, with or without illegal drug use, is associated to social conditions favoring the development of psychological distress and isolation. Although there are many studies on the differences between personality traits of alcoholics and drug users, few authors have examined the possibility to bring to the fore a specificity between the personality structures of the alcoholic and the drug user from a psychodynamic approach. This exploratory review of literature, first presents studies already conducted in order to identify common or distinct personality features for these types of addition. This article then reviews psychodynamic writings examining the possibility of a structural organization that is specific to addiction. Finally, the authors propose a few thoughts allowing to postulate on the existence of a structural organization specific to these two types of addiction.     

National Ignition Facility and managing location,component, and state

The National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory is a stadium-sized facility that contains a 192-beam, 1.8-MJ, 500-TW, ultraviolet laser system coupled with a 10-m diameter target chamber. There are over 6200 Line Replaceable Units (LRUs) comprised of more than 104,000 serialized parts that make up the NIF. Each LRU is a modular unit typically composed of a mechanical housing, laser optics (glass, lenses, or mirrors), and utilities. To date, there are more than 120,000 data sets created to characterize the attributes of these parts. Greater than 51,000 Work Permits have been issued to install, maintain, and troubleshoot the components. One integrated system is used to manage these data, and more. The Location Component and State (LoCoS) system is a web application built using Java Enterprise Edition technologies and is accessed by over 1200 users. It is either directly or indirectly involved with each aspect of NIF work activity, and interfaces with ten external systems including the Integrated Computer Control System (ICCS) and the Laser Performance Operations Model (LPOM). Besides providing business functionality, LoCoS also acts as the NIF enterprise service bus. In this role, numerous integration approaches had to be adopted including: file exchange, database sharing, queuing, and web services in order to accommodate various business, technical, and security requirements. Architecture and implementation decisions are discussed.