Seeing a phrase “time and again” matters: The role of phrasal frequency in the processing of multiword sequences.

Are speakers sensitive to the frequency with which phrases occur in language? The authors report an eye-tracking study that investigates this by examining the processing of multiword sequences that differ in phrasal frequency by native and proficient nonnative English speakers. Participants read sentences containing 3-word binomial phrases (bride and groom) and their reversed forms (groom and bride), which are identical in syntax and meaning but that differ in phrasal frequency. Mixed-effects modeling revealed that native speakers and nonnative speakers, across a range of proficiencies, are sensitive to the frequency with which phrases occur in English. Results also indicate that native speakers and higher proficiency nonnatives are sensitive to whether a phrase occurs in a particular configuration (binomial vs. reversed) in English, highlighting the contribution of entrenchment of a particular phrase in memory. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Evaluation of a radioiodine plume increasing in concentration at the Savannah River Site

Field and laboratory studies were carried out to understand the cause for steady increases in (129)I concentrations emanating from radiological basins located on the Savannah River Site, South Carolina. The basins were closed in 1988 by adding limestone and slag and then capping with a low permeability engineered cover. Groundwater (129)I concentrations in a well near the basins in 1993 were 200 pCi L(-1) and are presently between 400 and 1000 pCi L(-1). Iodine speciation in the plume contained wide ranges of iodide, iodate, and organo-iodine concentrations. First-order calculations based on a basin sediment desorption study indicate that the modest increase of 0.7 pH units detected in the study site groundwater over the last 17 years since closure of the basins may be sufficient to produce the observed increased groundwater (129)I concentrations near the basins. Groundwater monitoring of the plume at the basins has shown that the migration of many of the high risk radionuclides originally present at this complex site has been attenuated. However, (129)I continues to leave the source at a rate that may have been exacerbated by the initial remediation efforts. This study underscores the importance of identifying the appropriate in situ stabilization technologies for all source contaminants, especially if their geochemical behaviors differ.     

Ecosystem,Location, and Climate Effects on Foliar Secondary Metabolites of Lodgepole Pine Populations from Central British Columbia

Lodgepole pines, Pinus contorta Douglas ex Louden var. latifolia Engelm. ex S. Watson, are encountering increased abiotic stress and pest activity due to recent increases in temperature and changes in precipitation throughout their range. This tree species counters these threats by producing secondary metabolites, including phenolics and terpenoids. We examined foliar levels of lignin, soluble phenolics, monoterpenoids, sesquiterpenoids, and diterpenoids in 12 stands in British Columbia, Canada. We used these data to assess associations among foliar secondary metabolite levels and ecosystem, geographic, and climatic variables. Regressions were also performed to observe which combinations of variables best explained secondary metabolite variance. Stands of P. c. latifolia in the Coastal Western Hemlock and Interior Cedar/Hemlock biogeoclimatic zones had consistently greater foliar levels of almost all measured secondary metabolites than did other stands. Lignin was present in greater amounts in Boreal White/Black Spruce ecosystem (i.e., northern) stands than in southern stands, suggesting a role for this metabolite in pine survival in the boreal forest. Attempts to develop regression models with geographic and climatic variables to explain foliar secondary metabolite levels resulted in multiple models with similar predictive capability. Since foliar secondary metabolite levels appeared to vary most between stand ecosystem types and not as much due to geographic and climatic variables, metabolic profiles appeared best matched to the stress levels within local environments. It is unknown if differences in secondary metabolite levels are the result of genetic adaptation or phenotypic plasticity, but results from this and other studies suggest that both are important. These results are interpreted in light of ongoing efforts to assist in the migration of certain populations of P. c. latifolia northward in an effort to counter predicted effects of climate change.     

Comparison of N-Heterocyclic Aromatics Dibenzo[c,g]Carbazole and Dibenz[a,j]Acridine : Metabolism,DNA Binding and Mutation

N-Heterocyclic aromatics, such as carbazole and acridine derivatives, are environmental carcinogenic pollutants. Examples of these compounds are 7H-dibenzo[c,g]carbazole (DBC) and dibenz[a,j]acridine (DBA). The ionization potential (IP) for DBC is lower than for DBA. DBC is metabolized in lung and liver by way of phenols or directly through radical cations. DBC-induced liver and lung tumors have mutations in the 61^st codon of ras. DBA is metabolized in skin by way of a diol-epoxide of DBA. DBA-induced skin tumors have mutations in 12^th, 13^th and 61^st codons of ras. In summary, the metabolic activation of DBC proceeds through different adduction pattern pathways than does DBA and leads to different ras mutational spectra.     

LIGAND ASSISTED DESULFURIZATION OF LIGNITE USING THE PERCHLOROETHYLENE COAL REFINING PROCESS

ABSTRACT

The perchloroethylene coal refining process was used on North Dakota lignite coal. Effects of extraction time, perchloroethylenexoal ratio and artificial weathering were studied to determine their effects on the removal of organic sulfur. The artificial weathering conditions used were found to be too harsh and caused a decrease in the amount of organic sulfur removed, unlike normal weathering conditions. Additional studies were done involving various ligands, and showed that the addition of certain ligands during the process aided in the extraction of organic sulfur from the coal.     

Trajectories of autonomy development across the adolescent transition in children with spina bifida.

Objective: The current study investigated individual growth in autonomy development across the adolescent transition, comparing the trajectories of children with and without spina bifida. Method: Individual growth curve modeling procedures were utilized to describe the developmental course of autonomy across four waves of data collection, from ages 9 to 15, and to test whether illness status [spina bifida vs. matched comparison group (N = 68 for both groups at Time 1)] would significantly predict individual variability in autonomy development. Potential moderators [child gender, SES, and Peabody Picture Vocabulary Test (PPVT) score] of the association between illness status and autonomy development were also examined. Results: Children with spina bifida demonstrated distinct developmental trajectories, though the nature of the group differences varied by type of autonomy development (emotional vs. behavioral), context (i.e. school vs. family), and reporter. Significant interactions with PPVT score and child gender were found. Conclusion: Overall, children with spina bifida show considerable developmental resiliency, but may lag behind their peers in specific areas of autonomy. Boys with spina bifida, and children with spina bifida who have lower than average levels of verbal intelligence, appear to be at greater risk for exhibiting delays in autonomy development. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Nickel-containing magnetoceramics from water vapor-assisted pyrolysis of polysiloxane and nickel 2,4-pentanedionate

In this study, novel ferromagnetic Ni-containing silicon oxycarbide (SiOC–Ni) was successfully fabricated from a base polysiloxane (PSO) with the addition of nickel 2,4-pentanedionate. The resultant SiOC–Ni nanocomposite consists of in situ formed Ni nanocrystallites with a small amount of NiO uniformly dispersed in the amorphous SiOC matrix, and the corresponding nanocrystallite size increases with the increase of the pyrolysis temperature. The formation of nickel silicides (Ni_xSi_y) is completely suppressed by the effect of water vapor during the pyrolysis. The fundamental phase evolution process and mechanisms are explained. In an argon atmosphere, the SiOC–Ni materials pyrolyzed at 900°C are stable up to 1000°C with less than 6 wt% weight loss; they exhibit desirable electrical conductivity up to ~900°C with the highest electrical conductivity at ~247 S/m. This series of SiOC–Ni materials also demonstrates exciting ferromagnetic behaviors. Their new semiconducting behavior with soft ferromagnetism presents promising application potentials for magnetic sensors, transformers, actuators, etc.     

A developmental study of practical problem solving in adults.

Previous research indicates that young and middle-aged adults perform better than other age groups on problems similar to those they might encounter in their everyday lives. However, elderly adults have not performed better than other age groups on problems designed to give them the advantage. In order to ensure that the problems used in the present study were ones that elderly adults might encounter, elderly adults were recruited to help develop the problems. The resulting problems were administered to adults between the ages of 20 and 80. Performance was found to increase from the 20- to 40-year-old age group and decrease thereafter. Thus, when elderly adults devise practical problems that are intended to give elderly adults the advantage, the elderly adults still perform less well than do middle-aged adults. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Instrumentality as a life-stress moderator for early versus middle adolescents.

Used a longitudinal design to test the main and stress-buffering effects of instrumentality on measures of trait anxiety, depression, and self-esteem. Ss were early (junior high school) and middle (senior high school) adolescent boys and girls. The hypothesis that instrumentality would be negatively related to psychological distress was supported by the cross-sectional and longitudinal regression analyses of every subgroup of Ss. The hypothesized stress-buffering effect of instrumentality was found in the cross-sectional and longitudinal analyses of senior high girls, specifically in the context of interpersonal negative events (relationship stress). The analyses for junior high girls revealed that instrumentality was beneficial only at a low level of relationship stress. There were no significant interaction effects in the regression analyses of boys. The findings suggest that, when experiencing relationship stress, instrumentality is helpful for middle adolescent girls but not for early adolescent girls. Therefore, future research on adolescents' life-stress adjustment should consider the roles of gender, age, personality, and type of life stress. (PsycINFO Database Record (c) 2010 APA, all rights reserved)