Nanocomposite-like structure in an epitaxial CaCu3Ti4O12 film on LaAlO3 (001)

We report the detailed microstructural study of a CaCu₃Ti₄O₁₂ (CCTO) thin film using transmission electron microscopy (TEM). The CCTO thin film studied in this work was deposited on a (001)-oriented LaAlO₃ (LAO) substrate by pulsed-laser ablation and has a high dielectric constant of about 10⁴ at 1?MHz at room temperature; however, the mechanism for such a dielectric property is not yet understood. Plan-view TEM studies show that the CCTO samples have orthogonal domain structures with the edge nearly parallel to either the [100] or the [010] direction of the CCTO. A minor anatase TiO₂ phase was found at the domain boundaries. The CCTO and the TiO₂ phases are separated by an amorphous-like layer that has a thickness of several nanometres. Cross-sectional TEM studies reveal that both CCTO and TiO₂ in the films are c axis oriented with a very sharp interface to the LAO-(001) substrate and possess a unique crystallographic orientation relationship of (001) _CCTO //(001)_{TiO 2} //(001) _LAO and [100] _CCTO //[100] _{TiO 2} //[100] _LAO. The Rutherford back-scattering ion chanelling studies suggest a composition of Ca_1.5Cu₃Ti_5.5O₁₆ for the film, in which the extra calcium, titanium and oxygen form the anatase TiO₂ phase and amorphous calcium oxide layer that separates the CCTO and TiO₂ phases. Such nanocomposite-like structures may provide an important clue to the mechanism of the dielectric property of these films.     

Stages of change in fruit intake: A longitudinal examination of stability,stage transitions and transition profiles

The present study examined stability and transitions in Transtheoretical stages of change for fruit intake in an adult cohort of 735 individuals not exposed to a planned intervention. Six assessments took place within a four-month period with varying time intervals using electronic questionnaires, measuring fruit intake, stage of change and demographic characteristics. Precontemplation and maintenance were the most stable stages of change, while preparation was the least stable. Longer time intervals showed lower stability, but frequent stage transitions also occurred in shorter time intervals. Seven transition profiles were distinguished. Sequences within transition profiles mostly showed stage transitions to adjacent stages, independent of the interval duration. Differences in fruit intake, age, level of education and ethnicity were found between different transition profiles. Stability rates and most transition sequences largely support the Transtheoretical Model. Results indicating potential deviations from the model, e.g. short-term stage instability and stage transition profiles not in accordance with the Transtheoretical Model are discussed.     

Stability and predictors of psychopathic traits from mid‐adolescence through early adulthood

High levels of psychopathic traits in youth are associated with multiple negative outcomes including substance misuse, aggressive behavior, and criminality. Evidence regarding stability of psychopathic traits is contradictory. No previous study has examined long‐term stability of psychopathic traits assessed with validated clinical measures. The present study examined the stability of psychopathic traits from mid‐adolescence to early adulthood and explored adolescent factors that predicted psychopathic traits five years later. The sample included 99 women and 81 men who had consulted a clinic for substance misuse in adolescence. At an average age of 16.8 years, the adolescents were assessed using the Psychopathy Checklist: Youth Version (PCL: YV) and five years later using the PCL‐Revised (PCL‐R). Additionally, extensive clinical assessments of the adolescents and their parents were completed in mid‐adolescence. Among both females and males, moderate to high rank‐order stability was observed for total PCL and facet scores. Among both females and males, there was a decrease in the mean total PCL score, interpersonal facet score, affective facet score, and lifestyle facet score. However, the great majority of females and males showed no change in psychopathy scores over the five‐year period as indicated by the Reliable Change Index. Despite the measures of multiple family and individual factors in adolescence, only aggressive behavior and male sex predicted PCL‐R total scores in early adulthood after taking account of PCL:YV scores. Taken together, these results from a sample who engaged in antisocial behavior in adolescence suggest that factors promoting high psychopathy scores act early in life.     

Forms of friendship: A person-centered assessment of the quality,stability, and outcomes of different types of adolescent friends

Friendships differ in terms of their quality and participants may or may not agree as to their perceptions of relationship quality. Two studies (N = 230 and 242) were conducted to identify distinct and replicable categories of friendship among young adolescents (M = 11.6 years old) using self and partner reports of relationship quality. Same-sex friendships were identified from reciprocated friend nominations. Each friend described perceptions of negativity and social support in the relationship. Cluster analyses based on reports from both friends yielded 4 friendship types in each study: a high quality group, a low quality group, and two groups in which friends disagreed about the quality of the relationship. High quality friendships were most apt to be stable from the 6th to the 7th grade. Participants in high quality friendships reported the highest levels of global self-worth and perceived behavioral conduct and the lowest levels of problem behaviors. Dyads reporting discrepant perceptions of quality differed from dyads who agreed that the friendship was high quality in terms of stability and individual adjustment, underscoring the advantages of person-centered strategies that incorporate perceptions of both partners in categorizations of relationships.     

Stabilité à long terme des scores du WISC-IV : forces et faiblesses personnelles

Intelligence is considered as a stable trait over time; psychologists make predictions about the future performance of the child from the interpretation of the WISC-IV scores. However, stability at interindividual level does not necessarily imply stability at intra-individual level. By a test-retest procedure, the stability of categories that classify the performances, and the stability of the personal strengths and personal weaknesses are evaluated on a sample of 277 children aged from seven to 12 years. Categorical stability reveals that the classification into seven categories proposed by the designers of the WISC-IV does not allow reliable predictions. The stability of personal strengths and personal weaknesses is unsatisfactory for the different index scores.     

Neighbourhood preferences,active travel behaviour,and built environment: An exploratory study

In the current study we investigated the extent to which neighbourhood preferences could be used as a base to group people in order to explore their residential and travel choices. The basic idea of this study was that the preferences people would have for their residential and travel choices might be a robust predictor of their actual travel behaviour, and that the neighbourhood preferences might distinguish people in terms of the characteristics of their living environment. We used a moderation model to test whether the effect of built environment on travel behaviour varied in terms of resident’s type. A total of 3403 inhabitants of the city of Tampere in Finland participated in the study. A web-based public participation GIS survey combining the questionnaires with a map (SoftGIS technique) was used to collect the data. We identified two distinct groups of residents in terms of general neighbourhood preferences. The findings showed that clustering residents based on neighbourhood preferences moderated the association between some features of density measures and travel behaviour. We found significant differences between the two clusters in both the frequencies and the distance of pedestrian and bike travel. The findings revealed that inhabitants of neighbourhoods with a larger percentage of green surroundings had a greater perception of neighbourhood stability than did the residents of neighbourhoods with a smaller percentage of green surroundings.     

Structural stability of W2B5 under high pressure

High-pressure structural stability studies have been carried out on tungsten boride W₂B₅ up to maximum pressure of 36 GPa using a Mao-Bell diamond-anvil cell at beamline BR-12 of the ELETTRA synchrotron facility (λ = 0.68881 Å). The hexagonal phase (S.G:P6₃/mmc) of W₂B₅ is stable up to the maximum pressure studied. The bulk modulus is estimated to be ~347 GPa using the Birch–Murnaghan equation of state. The variation of lattice parameters and bond lengths B–B and W–B have been studied and the c-axis is seen to be marginally more compressible than the a-axis.     

Étude exploratoire de la stabilité à long terme des indices standard du WISC-IV

By a Test–Retest procedure, this study explores the long-term stability of the French WISC-IV index scores. The average Test–Retest interval was 2.33 years. The sample consisted of 96 non-clinical children aged between 8 and 12 years. Mean difference between the two testings was not statistically significant for VCI, PRI, WMI, GAI and FSIQ. Test–Retest reliability correlations between the two assessments are high for VCI, GAI and FSIQ (ranging from .81 to .82). An analysis of the performance differences between two assessments indicates intra-individual stability for WMI and GAI. In sum, only GAI demonstrates reliable long-term stability at an inter-and intra-individual level.