Variational solution of the one-dimensional t–J model

A new variational scheme based on a modified Bethe–Peierls method is used to study the ground state properties of the one-dimensional t–J model. Expectation values are evaluated by cutting out a four-site cluster from a correlated Fermi sea, the ground state of which is described by a variational trial wave function. We study a generalized Gutzwiller state where nearest-neighbour hole–hole correlations are controlled variationally. From the electron concentration dependence of the ground state energy, we determine the true thermodynamic boundary where segregation into an electron-rich, and purely hole phase sets in. We also determine the spinodal line and pair susceptibilities. The variational method is applied also to an extended t–J–V model, where V is the coupling constant of the charge interaction term.     

Cultural effects in emotion and gender recognition

There is evidence for cultural differences in how people respond to basic properties of faces. We examined task switching between two properties of faces, emotion and gender, for individuals drawn from Western (White UK citizens) and Asian (Pakistani) cultures. There were three main results of interest. First, there was a double dissociation between gender and emotion classification across the participant populations – Western participants were faster to make gender than emotion classifications while Asian participants were faster to make emotion than gender classifications. It is argued that the different patterns of results reflect the greater attentional weight given to contrasting face dimensions in the different cultures, and the dependence on using different attributes to make gender discriminations in individuals from varying cultures. Second, Asian participants showed smaller switch costs overall than did White British participants. This result may be attributed to effects of bilingualism in the Asian participants, which results in their having greater executive resources. Third, emotion decisions showed larger switch costs than gender decisions but essentially because emotion decisions benefited from priming on non‐switch trials. It is argued that emotion decisions benefit from the activation of a specific processing module across consecutive trials.     

Temperature dependence of the flow stress in Ir3Nb with the L12 structure

The effective s-d spin interaction is derived exactly for the one-impurity Anderson model via a unitary transformation. The unitary transformation has been calculated up to infinite order, thus an exact transformation was performed in the strict mathematical sense.     

Higher-order Traits and Happiness in the Workplace: The Importance of Occupational Project Scale for the Evaluation of Characteristic Adaptations

This study attempts to explain the relationship between job satisfaction and the Big Two, Stability and Plasticity, which are the higher-order traits of Big Five. Occupational Project, a narrative construct, was considered a mediator variable in this relationship. Occupational Project consists of affective and cognitive evaluations of an individual's work life as a project in terms of the completed (past), the ongoing (present) and the prospective (future) parts. The survey method was applied to a sample of 253 participants. The results supported the proposed model, in which Occupational Project mediated the relationship between the Big Two and both job satisfaction and affect in workplace. Discussion is focused on applying Occupational Project as a practical tool for management. Consideration of an employee's Occupational Project could provide management with a means to question, understand, intervene with and redefine the narrative quality of his/her occupational project that influences job satisfaction.     

Procrastination and predictor variables among a group of dental students in Turkey

The aim of this study was to assess the prevalence of procrastination among a group of Turkish dental students and to determine the predictors and consequences of procrastination. A total number of 273 females and 179 males (aged between 18 and 28) were included in the study. Tuckman procrastination scale, Academic Life Satisfaction Scale, Concern over Mistake Scale, Poor Time Management Scale, Self-Doubt Scale, Irrational Beliefs about Studying Scale, Positive and Negative Affect Schedule and Life Satisfaction Scale were used to gather data. Results indicated that 50% of participants were more likely to procrastinate their academic assignments or tasks. Procrastination score did not differ according to gender. The findings suggested that procrastinating students had a higher level of poor time management, self-doubt and irrational beliefs about studying, and poor academic performance and well-being than their non-procrastinating counterparts. Preventive strategies are necessary to overcome procrastination which affects the academic achievement, satisfaction, and well-being of dental students.     

The Shape Bias is Affected by Differing Similarity Among Objects

Previous research has demonstrated that visual properties of objects can affect shape-based categorization in a novel-name extension task; however, we still do not know how a relationship between visual properties of objects affects judgments in a novel-name extension task. We examined effects of increased visual similarity among the target and test objects in a shape bias task in young children and adults. Experiment 1 assessed college students with sets of objects whose similarity between target and test objects was either low or high similarity. Adults preferred shape when the similarity among objects was minimized. Experiment 2 tested 24-month olds in their use of the shape bias using the Intermodal Preferential Looking Paradigm. Children showed a shape bias only with items whose similarity to each other was low. These findings suggest that the visual properties of objects affect shape bias performance.     

Psychoeducation and expressed emotion by parents of children with learning disorders

The present study assessed use of a psychoeducation group program on expressed emotion, family functioning, and child behavior by parents of children with learning disorders. 81 parents of children with learning disorders were randomly assigned to a psychoeducation group program (n=46) or to a regular treatment group (n=35). A semistructured interview for parental expressed emotion, self-reports of family functioning, and child behavior were utilized at baseline and after an 8-session psychoeducation group program. Parents who attended the program differed significantly from parents in the regular treatment group on measures of criticism, warmth, and positive remarks, and overall expressed emotion, but not on measures of perceived family functioning and child behavior. Findings indicate a psychoeducation group program could be effective in helping parents to establish a more positive emotional climate in their relationships with their children who have learning disorders.     

Parental attitudes and ego identity status of Turkish adolescents

This study investigated the differences among 403 middle adolescents regarding Marcia's four identity statuses in terms of perceived parental attitudes and gender. The Extended Objective Measure of Ego Identity Status (EOMEIS-2) and Parental Education Scale (PAS) were used to collect data. Results showed that children of authoritative parents scored significantly higher on identity foreclosure than those of neglectful parents. Children of permissive parents scored significantly higher on identity foreclosure than those of neglectful parents. In addition, female students scored higher on achievement identity status while male students scored higher on identity foreclosure.