Modeling language acquisition in atypical phenotypes.

An increasing number of connectionist models have been proposed to explain behavioral deficits in developmental disorders. These simulations motivate serious consideration of the theoretical implications of the claim that a developmental disorder fits within the parameter space of a particular computational model of normal development. The authors examine these issues in depth with respect to a series of new simulations investigating past-tense formation in Williams syndrome. This syndrome and the past-tense domain are highly relevant because both have been used to make strong theoretical claims about the processes underlying normal language acquisition. The authors conclude that computational models have great potential to advance psychologists' understanding of developmental deficits because they focus on the developmental process itself as a pivotal causal factor in producing atypical phenotypic outcomes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

One-step synthesis of functional Co nanoparticles for surface-initiated polymerization

Much effort is conducted to construct artificial objects that are capable of converting chemical or electromagnetic energy into a specific, predetermined motion on the nanoscale. We present results on the synthesis of core–shell nanoparticles capable to be set in rotation by the application of electromagnetic fields. The nanorotors implied in the study are based on the cobalt nanospheres decorated with a stabilizing brush shell composed of poly(?-caprolactone) that is attached by surface-initiated polymerization. The functional cores used as macroinitiators can be fabricated alternatively by a two-step or a one-step process.     

Comparative study of three training methods for enhancing process control performance: Emphasis shift training,situation awareness training,and drill and practice

Three training methods to improve attention management skills in process control were compared. Forty students from technical disciplines participated in a five-hour module of emphasis shift training (EST), EST combined with situation awareness training (EST/SA), and drill and practice (D&P) on a simulated process control task. Participants were then tested three times for 45 min each (immediately after training, two weeks after training, and six weeks after training) for system control performance and diagnostic performance on familiar and nonfamiliar fault states. D&P led to superior diagnostic performance on familiar system faults. EST/SA training supported the diagnosis of novel system faults. EST was less effective than expected for system control performance. Implications for training design in process control are discussed.     

Childhood Peer Rejection and Aggression as Predictors of Adolescent Girls' Externalizing and Health Risk Behaviors: A 6-Year Longitudinal Study.

This 6-year longitudinal study examined girls' peer-nominated social preference and aggression in childhood as predictors of self- and parent-reported externalizing symptoms, substance use (i.e.. cigarette, alcohol, and marijuana use), and sexual risk behavior in adolescence. Participants were 148 girls from diverse ethnic backgrounds, who were initially assessed in Grades 4-6 and again in Grades 10-12. Results supported a moderator model, indicating that social preference changed the nature of the association between childhood aggression and adolescent outcomes. When accompanied by peer rejection, aggressive behavior was moderately stable over time and significantly associated with adolescent girls' substance use and sexual risk behavior. However, under conditions of peer acceptance, no significant association between childhood aggression and adolescent outcomes emerged. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Quantitation of estragole by stable isotope dilution assays

Various calibration strategies for the quantitation of the phenylpropane estragole by gas chromatography-mass spectrometry were developed and compared. For application in stable isotope dilution assays, two deuterium labelled estragole isotopologues were synthesized. Of these, [3′,3′-²H₂]estragole was prepared by Wittig reaction of 4-methoxy-phenylacetaldehyde with [²H₃]methyl-triphenyl-phosphonium bromide, whereas [1″,1″,1″-²H₃]estragole was obtained by demethylation of estragole and deuteromethylation of the resulting 4-allylphenole.Besides estragole isotopologues, 1,2,4-trimethoxybenzene and 4-propylanisole were also tested as internal standards (I.S.) for the determination of estragole in fennel tea.[1″,1″,1″-²H₃]Estragole, 1,2,4-trimethoxybenzene, and 4-propylanisole revealed linear calibration functions and, therefore, were suitable for estragole quantitation. In contrast to this, [3′,3′-²H₂]estragole could only be applied as I.S. if it was added to the extracts in stoichiometric deficiency compared to unlabelled estragole. Moreover, due to its different chemical and physical properties, 1,2,4-trimethoxybenzene showed a recovery as low as 77%, whereas the other I.S. revealed recovery rates close to 100%. Considering the “real” values of estragole in fennel tea, the choice of the I.S. obviously is less important than the way of preparing the tea. In contrast to the common method for tea preparation, squeezing of the teabags increased the estragole content significantly by 50%.     

Computer aided material selection for circular tubes designed to resist axial crushing

We consider optimal design of cylindrical shells under axial compression. The main motivation is the comprehensive study of Weaver and Ashby [Material limits for shape efficiency. Progress in Materials Science 1997;41:61–128] concerning tubes designed to resist local buckling, global buckling and yield. In this paper we add another mode to this set of possible failure mechanisms, namely axial crushing. This failure-mode turns out to be dominate for many materials in several relevant load-cases. In many cases, taking this mode into account changes the optimal design substantially. By analyzing the formulae for the failure-modes we obtain piecewise defined functions describing the optimal cross-section and the minimum mass of the tube. Combined with advanced computer aided material selection tools like the Cambridge Engineering Selector (CES), these functions enable us to identify the best possible materials which give the lightest possible tubes.     

Seasonal and diurnal variation of PM2.5 apparent particle density in urban air in Augsburg, Germany

The apparent particle density of particulate matter with aerodynamic diameter < 2.5 microm (rho2.5) was determined at an urban site in Augsburg, Germany and its correlation with chemical composition and meteorological conditions was investigated. rho2.5 showed strong day-to-day variation from 1.05 to 2.36 g cm(-3) (5 to 95% percentile), and nearly 64% of the daily variability could be explained by a multiple variable regression model. A minimum in the morning and afternoon (about 1.5 g cm(-3)), and a maximum (near 1.8 g cm(-3)) during midday was observed. The minima represent fresh primary aerosol emissions, which were related to traffic soot particles with low density due to their agglomerate structure, especially observed in the early morning hours of weekdays. The maximum is likely due to increased secondary particle production and the presence of more aged particles with the built-up of the convectively mixed boundary layer. rho2.5 has the potential to serve as a crude tracer for chemical composition and atmospheric processing and might play an important role when considering the associations between health effects and ambient particles.