Chronic toxicity of hydrogen peroxide to Daphnia magna in a continuous exposure, flow-through test system

A flow-through, continuous exposure test system was developed to expose Daphnia magna to an unstable compound. 35% Perox-Aid is a specially formulated hydrogen peroxide (a highly oxidative chemical) product approved for use in U.S. aquaculture and therefore has the potential to be released from aquaculture facilities and pose a risk to aquatic invertebrates. The study objective was to assess the effects of 35% Perox-Aid on an aquatic invertebrate by evaluating the survival, growth, production, and gender ratio of progeny from a representative aquatic invertebrate continuously exposed to 35% Perox-Aid. The study design consisted of 6 treatment groups (10 test chambers each) with target hydrogen peroxide concentrations of 0.0, 0.32, 0.63, 1.25, 2.5, and 5.0 mg L(-1). The study was initiated with <24-h-old Daphnia (1 daphnid per chamber) that were exposed to hydrogen peroxide for 21 days. Hydrogen peroxide concentrations < or =1.25 mg L(-1) had no significant effect on Daphnia time to death compared to controls and no significant effect on the time to first brood production and the number of broods produced. Concentrations < or =0.63 mg L(-1) had no significant effect on the total number of young produced. Concentrations > or =0.32 mg L(-1) had a negative effect on Daphnia growth. Hydrogen peroxide had no significant effect on the gender ratio of young produced. All second generation Daphnia were female. A continuous discharge of hydrogen peroxide into aquatic ecosystems is not likely to affect cladocerans if the concentration is maintained at < or =0.63 mg L(-1) for less than 21 days.     

Growth Kinetics of Mixed Cultures under Chlorate-Reducing Conditions

Although chlorate (ClO3?) is not a naturally occurring compound, chlorate can serve as an electron acceptor for a number of microorganisms. To investigate the rate that chlorate-reducing microbes can grow on different substrates, growth rate constants were determined in chemostat studies under chlorate-reducing conditions. Maximum growth rates using acetate, glucose-glutamic acid, and phenol were 0.56, 0.12, and 0.040 h?1, with cell yields of 0.12, 0.41, and 0.12 g-cell∕g-substrate, respectively.     

Influences on first-year recovery from traumatic brain injury in children.

This study examined recovery over the first year following traumatic brain injury (TBI) in children 6–12 years of age. Forty-two children with severe TBI and 52 with moderate TBI were compared to 58 children with orthopedic injuries. The children and their families were evaluated at a baseline assessment and at 6- and 12-month follow-ups. Findings documented cognitive, achievement, and behavioral sequelae of TBI, with only limited evidence for recovery over the first year postinjury. Outcomes were predicted by preinjury factors, TBI severity, and measures of the postinjury family environment. Some of the sequelae of severe TBI were more marked in the context of higher compared with lower levels of family burden or dysfunction. The findings confirm the need to consider environmental contributions to outcomes of TBI in children. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

3D集成中晶圆链中缺陷的成像检测

本文介绍了一种实用的声学成像技术,可以在键合晶圆对的同时,对界面缺陷以及不同材料的晶圆划痕进行成像检测。     

Instructing on death: Psychologists, juries, and judges.

The American legal system depends on judicial instructions to structure jury death penalty decisions and thus avoid unconstitutional arbitrariness. Some death penalty instructions, however, provide woefully inadequate guidance and ignore schemas that lead jurors to misconstrue instructions. Empirical research has just begun to document sources of misunderstanding and ways to improve communication. Psychological research can assist in reducing arbitrariness in death penalty decisions, but even optimal instructions may not produce constitutionally sufficient consistency. To be constitutional, capital punishment must be imposed according to a consistent set of standards. Simultaneously, juries must be free to consider in mitigation any relevant case or offender characteristic. It is far from clear that this constitutional conflict between standards and discretion can be resolved. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The family environment as a moderator of psychosocial outcomes following traumatic brain injury in young children.

Objective: This study sought to determine whether the family environment moderates psychosocial outcomes after traumatic brain injury (TBI) in young children. Method: Participants were recruited prospectively from consecutive hospital admissions of 3- to 6-year-old children, and included 19 with severe TBI, 56 with complicated mild/moderate TBI, and 99 with orthopedic injuries (OI). They completed 4 assessments across the first 18 months postinjury. The initial assessment included measures of parenting style, family functioning, and the quality of the home. Children's behavioral adjustment, adaptive functioning, and social competence were assessed at each occasion. Mixed model analyses examined the relationship of the family environment to psychosocial outcomes across time. Results: The OI and TBI groups differed significantly in social competence, but the family environment did not moderate the group difference, which was of medium magnitude. In contrast, group differences in behavioral adjustment became more pronounced across time at high levels of authoritarian and permissive parenting; among children with severe TBI, however, even those with low levels of permissive parenting showed increases in behavioral problems. For adaptive functioning, better home environments provided some protection following TBI, but not over time for the severe TBI group. These 3-way interactions of group, family environment, and time postinjury were all of medium magnitude. Conclusion: The findings indicate that the family environment moderates the psychosocial outcomes of TBI in young children, but the moderating influence may wane with time among children with severe TBI. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The efficacy of an online cognitive-behavioral family intervention in improving child behavior and social competence following pediatric brain injury.

Objective: To examine whether an online cognitive-behavioral intervention could improve child adjustment following traumatic brain injury (TBI). Participants: Thirty-nine families of children with moderate to severe TBI. Intervention: Families were randomly assigned to the online family problem-solving (FPS) group or to the Internet resources comparison (IRC) group. Main Outcome Measures: Outcomes included child behavior problems, social competence, and self-management/compliance. Results: The FPS group reported better child self-management/compliance at follow-up than did the IRC group. The child's age and socioeconomic status (SES) moderated treatment effects, with older children and those of lower SES who received FPS showing greater improvements in self-management and behavior problems, respectively. Conclusions: Findings suggest that an online cognitive- behavioral approach can improve child adjustment after TBI, particularly in older children and children of lower SES. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Synthesis of (±)-disparlure

A six-step, convergent synthesis has been developed for racemic (Z)-7,8-epoxy-2-methyloctadecane (disparlure), the sex pheromone of the gypsy moth. The key step is a Wittig reaction between 6-methylheptanal and triphenylundecylphosphonium bromide effected by potassium carbonate in the presence of a crown ether.     

Making the Best Use of Cybersecurity Economic Models

This article describes an analysis of several representative cybersecurity economic models, where the authors seek to determine whether each model's underlying assumptions are realistic and useful. They find that many of the assumptions are the same across disparate models, and most assumptions are far from realistic. They recommend several changes so that the predictions from economic models can be more relevant and useful.