Amorphization of cubic zirconia by caesium-ion implantation

Stabilized cubic zirconia is a promising candidate material for use as an inert fuel matrix for 'burning' excess Pu in light-water nuclear reactors. Zirconia is also considered to be an excellent nuclear waste form for direct geological disposal. Both applications are based on zirconia's high solubility for actinides, high chemical durability and high stability under irradiation. We report the first evidence of solid-state amorphization of yttria-stabilized cubic zirconia (YSZ) by 400keV Cs-ion implantation to 1 x 10²¹ ions m^-2 at room temperature. Amorphization of YSZ is caused by the large size incompatibility and low mobility of Cs ions in the YSZ structure, reflecting a relatively low solubility of Cs in YSZ. Nevertheless, the Cs concentration at which amorphization of YSZ occurred (about 8at.%) is well above the value that will typically be reached in an inert fuel matrix.     

Cascade effects on the irradiation stability of amorphous SiOC

We studied the heavy ion radiation tolerance of amorphous silicon oxycarbide (SiOC) alloys by in situ Kr ion irradiation within a transmission electron microscopy. The amorphous SiOC thin films were grown via co-sputtering from SiO₂ and SiC targets on a surface-oxidized Si (100) substrate. These films were irradiated by 1 MeV Kr ions at both room temperature and 300 °C with damage levels up to 5 displacements per atom (dpa). TEM characterization shows no sign of crystallization, void formation or segregation in all irradiated samples. Our findings suggest that SiOC alloys are a class of promising radiation tolerant materials.     

The structure of self–other overlap and its relationship to perspective taking

Two studies tested whether “self–other overlap” is a multidimensional construct, with only some dimensions affected by perspective taking. In Study 1, participants (n = 132) completed several previously used measures of self–other overlap for their best friend and acquaintance. Factor analyses revealed 2 distinct dimensions of self–other overlap—perceived closeness and overlapping representations. Perceived closeness but not overlapping representations was generally associated with relationship quality. Study 2 (n = 118) manipulated perspective taking of a stranger. Results replicated a factor structure similar to Study 1, and found that perspective taking had different effects on the 2 dimensions of overlap. These results are discussed with regards to the debate over self–other overlap as a mediator of perspective taking's pro‐social effects.     

Different Types of Religious/Spiritual Well-Being in Relation to Personality and Subjective Well-Being

In this study the authors attempt to present different types of Religious/Spiritual Well-Being (RSWB) and discuss their relation to personality and psychological well-being. The Multidimensional Inventory for Religious/Spiritual Well-Being 48 is employed for this study, which consists of 6 subscales. To find different types of RSWB, an agglomerative cluster analysis on these subscales was performed based on the responses obtained in a nonclinical adult sample (n = 463). A 4-cluster solution was accepted. The clusters were labeled as Religious/Spiritual High, Religiously Oriented, Existentially Oriented, and Religious/Spiritual Low, and were found to be substantially related to Sense of Coherence (n = 263) and Six Factors of Personality (n = 200) in two different subsamples. By presenting a first empirical model for a 4-field typology of RSWB, we hope to further contribute to the ongoing discussion on how to deal with religious/spiritual issues in personality research.     

Search for multiple targets: Evidence for memory-based control of attention

There are two opposing models with regard to the function of memory in visual search: a memorydriven model and a memory-free model. Recently, Horowitz and Wolfe (2001) investigated a multipletarget search task. Participants were required to decide whether or not there were at leastn targets present. They demonstrated that the reaction time ×n function has a positive and accelerated curve. They argued that the memory-free model predicts this curve, whereas the memory-driven model predicts a linear function. In this study, I varied the total set sizes of a multiple-target search task and fitted the models separately for eachn condition. The model fit indicated that the memory-driven model is more appropriate than the memory-free model in eachn condition. These results suggest that an amnesic process does not cause the positive accelerated curve of the reaction time ×n function but that it is the result of the time needed to examine each additionaln item.     

Delivering your daily dose of well-being to the workplace: a randomized controlled trial of an online well-being programme for employees

The purpose of this study was to evaluate a newly developed brief, cost-effective, flexible, and broadly accessible online programme designed to enhance employee well-being. Considering the demands of the working world, the development of the positive intervention (PI) programme was based on empirical findings and latest theoretical advances from the field of positive psychology, namely the PERMA model of well-being. The new PERMA-based programme’s effectiveness to increase employee well-being was evaluated with a longitudinal field experiment, including a wait list control group and an already established PI programme (i.e., gratitude programme) for comparison (three-armed randomized controlled trial; n = 303, N_male = 99, N_female = 203, M_age = 41.16, SD = 12.26). Repeated measures analyses of variance (ANOVAs) supported that on average, participants of the gratitude programme and the PERMA-based programme reported significant increases in employee well-being after the intervention, as compared to no increases in the wait list control group. The significant increases yielded small effect sizes for general subjective well-being and medium effect sizes for work-related subjective well-being. Post-hoc analyses controlling for baseline well-being also supported the efficacy of the PIs. Contrary to the prediction of the PERMA-based programme’s superiority, participants of both online PI programmes reported similar gains in employee well-being components. Practical implications, limitations, and future research are discussed.     

Structure of a phase induced with Xe-ion irradiation-implantation in γ-TiAl

A phase transformation in γ-TiAl intermetallic alloy was found to be induced with 50keV Xe-ion irradiation-implantation at doses larger than 2.2 x 10¹⁸ ions m^-2 at room temperature. The structure and the chemical composition of the induced phase were investigated with high-resolution transmission electron microscopy and energy-dispersive X-ray spectroscopy. The zones of the induced phase have sizes up to about several tens of nanometres. The phase has a hexagonal structure with a = 0.286 nm and c = 0.462nm. The crystallographic orientation relationship between the phase (P) and the gamma-TiAl matrix is (001)_P//(111)_γ and \[100]_P//[011]_γ. The \[Al]/[Ti] atomic composition ratio in the phase is analysed to be 56/44, slightly different from that of the matrix, 51/49. These results suggest that the induced phase is an Al solid solution of α-Ti alloy phase, which has different structural parameters and chemical composition from those of the reported phase. It is suggested that the size of the ions is important in the phase transformation.     

How Distinctive are ADHD and RD? Results of a Double Dissociation Study

The nature of the comorbidity between Attention-Deficit/Hyperactivity Disorder (ADHD) and Reading Disability (RD) was examined using a double dissociation design. Children were between 8 and 12 years of age and entered into four groups: ADHD only (n = 24), ADHD+RD (n = 29), RD only (n = 41) and normal controls (n = 26). In total, 120 children participated in the study; 38 girls and 82 boys. Both ADHD and RD were associated with impairments in inhibition and lexical decision, although inhibition and lexical decision were more severely impaired in RD than in ADHD. Visuospatial working memory deficits were specific to children with only ADHD. It is concluded that there was overlap on lexical decision and to a lesser extent on inhibition between ADHD and RD. In ADHD, impairments were dependent on IQ, which suggest that the overlap in lexical decision and inhibition is different in origin for ADHD and RD. The ADHD only group was specifically characterized by deficits in visuospatial working memory. Hence, no double dissociation between ADHD and RD was found on executive functioning and lexical decision.     

Tests of Homoscedasticity,Normality, and Missing Completely at Random for Incomplete Multivariate Data

Test of homogeneity of covariances (or homoscedasticity) among several groups has many applications in statistical analysis. In the context of incomplete data analysis, tests of homoscedasticity among groups of cases with identical missing data patterns have been proposed to test whether data are missing completely at random (MCAR). These tests of MCAR require large sample sizes n and/or large group sample sizes n _i , and they usually fail when applied to nonnormal data. Hawkins (Technometrics 23:105–110, 1981) proposed a test of multivariate normality and homoscedasticity that is an exact test for complete data when n _i are small. This paper proposes a modification of this test for complete data to improve its performance, and extends its application to test of homoscedasticity and MCAR when data are multivariate normal and incomplete. Moreover, it is shown that the statistic used in the Hawkins test in conjunction with a nonparametric k-sample test can be used to obtain a nonparametric test of homoscedasticity that works well for both normal and nonnormal data. It is explained how a combination of the proposed normal-theory Hawkins test and the nonparametric test can be employed to test for homoscedasticity, MCAR, and multivariate normality. Simulation studies show that the newly proposed tests generally outperform their existing competitors in terms of Type I error rejection rates. Also, a power study of the proposed tests indicates good power. The proposed methods use appropriate missing data imputations to impute missing data. Methods of multiple imputation are described and one of the methods is employed to confirm the result of our single imputation methods. Examples are provided where multiple imputation enables one to identify a group or groups whose covariance matrices differ from the majority of other groups.     

Pooling data versus averaging model fits for some prototypical multinomial processing tree models

For a study with multinomial data where there are n_g individuals and with each person having n_r test trials, the question arises as to how to fit the parameters of a multinomial processing tree (MPT) model. Should each parameter be estimated for each individual and then averaged to obtain a group estimate, or should the frequencies in the multinomial categories be pooled so that the model is fit once for the entire group? This basic question is explored with a series of Monte Carlo simulations for some prototypical MPT models. There is a general finding of a pooling advantage for the case where there is a single experimental condition. Also when there are different experimental conditions, there is reduced bias for detecting condition differences for a method based on the pooled data. Although the focus of the paper is on multinomial models, a general theorem is advanced that establishes a basic condition that determines whether there is or is not a difference between the averaging of individual estimates and the estimate based on the pooled data.     

Improved set‐size labeling mediates the effect of a counting intervention on children's understanding of cardinality

How does improving children's ability to label set sizes without counting affect the development of understanding of the cardinality principle? It may accelerate development by facilitating subsequent alignment and comparison of the cardinal label for a given set and the last word counted when counting that set (Mix et al., 2012). Alternatively, it may delay development by decreasing the need for a comprehensive abstract principle to understand and label exact numerosities (Piantadosi et al., 2012). In this study, preschoolers (N = 106, M_age = 4;8) were randomly assigned to one of three conditions: (a) count‐and‐label, wherein children spent 6 weeks both counting and labeling sets arranged in canonical patterns like pips on a die; (b) label‐first,wherein children spent the first 3 weeks learning to label the set sizes without counting before spending 3 weeks identical to the count‐and‐label condition; (c) print referencing control. Both counting conditions improved understanding of cardinality through increases in children's ability to label set sizes without counting. In addition to this indirect effect, there was a direct effect of the count‐and‐label condition on progress toward understanding of cardinality. Results highlight the roles of set labeling and equifinality in the development of children's understanding of number concepts.     

An inverse Ruddlesden-Popper nitride Ca7(Li1−xFex)Te2N2 grown from Ca flux

Nitridoferrates containing monovalent iron ions are a class of materials of recent interest as potentially novel magnetic materials. Aiming at the exploration of nitridoferrates of calcium, we report the single crystal growth from Ca ?ux and crystal structure of the first member (n?=?2) of a series of inverse Ruddlesden-Popper nitrides with a general formula of A_n?1A'₂B_nX_3n+1, where A?=?Li/Fe, A'?=?Te, B?=?N, and X?=?Ca. Single crystal X-ray diffraction analyses indicate the crystal with a composition of Ca₇(Li_0.32(1)Fe_0.68(1))Te₂N₂ and the tetragonal space group I4/mmm (a?=?4.7884(1) Å, c?=?25.3723(4) Å, Z?=?2). The structure features alternately stacking NaCl-type A'X slabs and the perovskite-type ABX₃ slabs along the c axis. The Li/Fe atoms are located in cuboctahedral cavities surrounded by eight Ca₆N octahedra in the ABX₃ slab. This work demonstrates the viability of the Ca-rich ?ux as a suitable solvent for the exploration of new complex nitrides with interesting crystal structure and properties.     

Mislocated fixations can account for parafoveal-on-foveal effects in eye movements during reading

Contrasting predictions of serial and parallel views on the processing of foveal and parafoveal information during reading were tested. A high-frequency adjective (young) was followed by either a high-frequency word_n (child) or a low-frequency word_n (tenor), which in turn was followed by either a correct (performing) or an orthographic illegal word_{n + 1} (pxvforming) as a parafoveal preview. A limited parafoveal-on-foveal effect was observed: There were inflated fixation times on word_n when the preview of word_{n + 1} was orthographically illegal. However, this parafoveal-on-foveal effect was (a) independent of the frequency of word_n, (b) restricted to those instances when the eyes were very close to word_{n + 1}, and (c) associated with relatively long prior saccades. These observations are all compatible with a mislocated fixation account in which parafoveal-on-foveal effects result from saccadic undershoots of word_{n + 1} and with a serial model of eye movement control during reading.     

Movement Control Strategies in a Dynamic Balance Task in Children With and Without Developmental Coordination Disorder

Abstract

Our study aimed to analyze movement control strategies using predefined criteria for amplitude and differences in these strategies between children with and without DCD. Children with (n?=?28) and without DCD (n?=?15) were included. A video-observation-tool was used to score the moving body parts during a Wii Fit slalom task over multiple time points. Two-step cluster analysis was used to extract distinct movement strategies. Two different movement strategies were identified that were independently validated by a measure of task performance and a subjective mark of quality of the movement. Initial differences between groups and changes over time toward the more successful strategy were found in both groups, albeit in a different percentage. This study shows that the more efficient movement strategy is seen in the majority of the TD children and only in a small number of children with DCD, even after practice.     

Mechanical-milling-induced amorphization of Se: A crystallite destabilization model

Complete solid-state amorphization has been realized in elemental Se by means of mechanical milling of crystalline Se powder. Quantitative X-ray diffraction and thermal analyses were employed to characterize the amorphization process and indicated that the amorphization onset corresponds to a critical crystallite size and a drop in microstrain. During the major amorphization process, the remaining crystallite size remains unchanged with a constant lattice expansion. A new kinetics model of crystallite destabilization is proposed for the solid-state amorphization which satisfactorily explains the experimental observations.     

A model-based cluster analysis of social experiences in clinically anxious youth: links to emotional functioning

Social difficulties are commonly associated with anxiety disorders in youth, yet are not well specified in the literature. The aim of this study was to identify patterns of social experiences in clinically anxious children and examine the associations with indices of emotional functioning. A model-based cluster analysis was conducted on parent-, teacher-, and child-reports of social experiences with 64 children, ages 7–12 years (M = 8.86 years, SD = 1.59 years; 60.3% boys; 85.7% Caucasian) with a primary diagnosis of separation anxiety disorder, social phobia, and/or generalized anxiety disorder. Follow-up analyses examined cluster differences on indices of emotional functioning. Findings yielded three clusters of social experiences that were unrelated to diagnosis: (1) Unaware Children (elevated scores on parent- and teacher-reports of social difficulties but relatively low scores on child-reports, n = 12), (2) Average Functioning (relatively average scores across all informants, n = 44), and (3) Victimized and Lonely (elevated child-reports of overt and relational victimization and loneliness and relatively low scores on parent- and teacher-reports of social difficulties, n = 8). Youth in the Unaware Children cluster were rated as more emotionally dysregulated by teachers and had a greater number of diagnoses than youth in the Average Functioning group. In contrast, the Victimized and Lonely group self-reported greater frequency of negative affect and reluctance to share emotional experiences than the Average Functioning cluster. Overall, this study demonstrates that social maladjustment in clinically anxious children can manifest in a variety of ways and assessment should include multiple informants and methods.     

A Model‐Based Cluster Analysis of Maternal Emotion Regulation and Relations to Parenting Behavior

In a diverse community sample of mothers (N = 108) and their preschool‐aged children (M_age = 3.50 years), this study conducted person‐oriented analyses of maternal emotion regulation (ER) based on a multimethod assessment incorporating physiological, observational, and self‐report indicators. A model‐based cluster analysis was applied to five indicators of maternal ER: maternal self‐report, observed negative affect in a parent–child interaction, baseline respiratory sinus arrhythmia (RSA), and RSA suppression across two laboratory tasks. Model‐based cluster analyses revealed four maternal ER profiles, including a group of mothers with average ER functioning, characterized by socioeconomic advantage and more positive parenting behavior. A dysregulated cluster demonstrated the greatest challenges with parenting and dyadic interactions. Two clusters of intermediate dysregulation were also identified. Implications for assessment and applications to parenting interventions are discussed.     

Role of Stressful Life Events in Homelessness: An Intragroup Analysis

The present paper describes the results of an analysis of individual differences—using multidimensional strategies—in stressful life event data collected from a representative sample of homeless people (N = 289) in Madrid, Spain, which revealed the existence of three subgroups within the sample. Each subgroup can be defined by the following differentiating characteristics: The first cluster (n = 124) was characterized by economic problems; the second (n = 80) by health problems, alcohol abuse, and death of one or both parents; and the third cluster (n = 50) by an accumulation of stressful life in childhood events and alcohol abuse. In order to define the subgroups, the article also examines the differences found in other variables such as total duration of homelessness, mental and physical health status, and social support availability, among others. The existence of such subgroups within the homeless population emphasizes the importance of designing different interventions for each of these groups, adapted to their diverse needs.     

Physical self-perceptions and self-esteem in adolescents participating in organized sports and religious groups

Drawing on the exercise and self-esteem model (EXSEM), the current study examined associations between sport activities and aspects of the self-system among adolescent members of sport groups. Youths attending religious groups were included in the study to allow for a test of generalization. Participants were 595 adolescents (sport groups: n = 355, M_age = 15.09 years, SD = 1.49, 54.6% female; religious groups: n = 240, M_age = 15.67 years, SD = 1.44, 53.8% female) who completed a series of paper and pencil measures detailing their involvement in sport activities (sport group only), their self-efficacy beliefs in the physical domain, perceived sport competence and attractiveness, as well as global self-esteem. A structural model was tested for sport youth, specifying an effect of sport activities on self-efficacy that, in turn, was expected to predict subjective sport competence and attractiveness. Finally, the model postulated effects of competence and attractiveness on self-esteem. The model test revealed a good fit. Multi-group models considering type of leisure group and sex pointed to parallel patterns in the associations of self-efficacy, competence, attractiveness, and self-esteem in the subgroups.     

On the relation between similarity and ratio estimates

Summary Data obtained in four sets of experiments involving pitch, heaviness, greyness, and circular area were re-analyzed. It was found (1) that similarity estimates S _ijare a power function of stimulus ratios S _ijwith the exponent n _s,(2) that ratio estimates q _ijare also a power function of stimulus ratios S _ijwith the exponent n _q(i.e., Stevens' power law), (3) that the exponent n of similarity estimates as power function of ratio estimates is equal to the ratio n _s/n _q,and (4) that, inversely, the exponent m of ratio estimates as power function of similarities is equal to the ratio n _q/n _s.The investigation was supported by a grant from the Swedish Council for Social Science Research.