Structural, electronic and magnetic properties of SrRuO3_3 under epitaxial strain

Using density functional theory within the local spin density approximation, structural, electronic and magnetic properties of SRO are investigated. We examine the magnitude of the orthorhombic distortion in the ground state and also the effects of applying epitaxial constraints, whereby the influence of large (in the range of $\pm 4$) in-plane strain resulting from coherent epitaxy, for both [001] and [110] oriented films, have been isolated and investigated. The overall pattern of the structural relaxations reveal coherent distortions of the oxygen octahedra network, which determine stability of the magnetic moment on the Ru ion. The structural and magnetic parameters exhibit substantial changes allowing us to discuss the role of symmetry and possibilities of magneto-structural tuning of \SRO-based thin film structures.Comment: 11 page

Path Integral Treatment of Proton Transport Processes in BaZrO3

Nuclear quantum effects on proton transfer and reorientation in BaZrO3 is investigated theoretically using the ab initio path-integral molecular-dynamics simulation technique. The result demonstrates that adding quantum fluctuations has a large effect on, in particular, the transfer barrier. The corresponding rates and diffusion coefficient are evaluated using the path-centroid transition state theory. In contrast with what is found assuming classical mechanics for the nuclear motion, the reorientation step becomes rate limiting below 600 K

Si-compatible candidates for high-K dielectrics with the Pbnm perovskite structure

We analyze both experimentally (where possible) and theoretically from first-principles the dielectric tensor components and crystal structure of five classes of Pbnm perovskites. All of these materials are believed to be stable on silicon and are therefore promising candidates for high-K dielectrics. We also analyze the structure of these materials with various simple models, decompose the lattice contribution to the dielectric tensor into force constant matrix eigenmode contributions, explore a peculiar correlation between structural and dielectric anisotropies in these compounds and give phonon frequencies and infrared activities of those modes that are infrared-active. We find that CaZrO_3, SrZrO_3, LaHoO_3, and LaYO_3 are among the most promising candidates for high-K dielectrics among the compounds we considered.Comment: 17 pages, 9 figures, 4 tables. Supplementary information: http://link.aps.org/supplemental/10.1103/PhysRevB.82.064101 or http://www.physics.rutgers.edu/~sinisa/highk/supp.pd

In one’s own time: Contesting the temporality and linearity of bereavement

This article explores the experience and meaning of time from the perspective of caregivers who have recently been bereaved following the death of a family member. The study is situated within the broader cultural tendency to understand bereavement within the logic of stages, including the perception of bereavement as a somewhat predictable and certainly time-delimited ascent from a nadir in death to a ‘new normal’ once loss is accepted. Drawing on qualitative data from interviews with 15 bereaved family caregivers we challenge bereavement as a linear, temporally bound process, examining the multiple ways bereavement is experienced and how it variously resists ideas about the timeliness, desirability and even possibility of ‘recovery’. We posit, on the basis of these accounts, that the lived experience of bereavement offers considerable challenges to normative understandings of the social ties between the living and the dead and requires a broader reconceptualization of bereavement as an enduring affective state

Assessing Internet addiction using the parsimonious Internet addiction components model - a preliminary study [forthcoming]

Internet usage has grown exponentially over the last decade. Research indicates that excessive Internet use can lead to symptoms associated with addiction. To date, assessment of potential Internet addiction has varied regarding populations studied and instruments used, making reliable prevalence estimations difficult. To overcome the present problems a preliminary study was conducted testing a parsimonious Internet addiction components model based on Griffiths’ addiction components (2005), including salience, mood modification, tolerance, withdrawal, conflict, and relapse. Two validated measures of Internet addiction were used (Compulsive Internet Use Scale [CIUS], Meerkerk et al., 2009, and Assessment for Internet and Computer Game Addiction Scale [AICA-S], Beutel et al., 2010) in two independent samples (ns = 3,105 and 2,257). The fit of the model was analysed using Confirmatory Factor Analysis. Results indicate that the Internet addiction components model fits the data in both samples well. The two sample/two instrument approach provides converging evidence concerning the degree to which the components model can organize the self-reported behavioural components of Internet addiction. Recommendations for future research include a more detailed assessment of tolerance as addiction component

Psychometric validation of the Generalized Problematic Internet Use Scale 2 in a Portuguese sample

The Generalized Problematic Internet Use Scale 2 (GPIUS2) assesses individuals’ generalized problematic Internet use (PIU) cognitions, behaviors, and negative outcomes. To date, the GPIUS2 has only been validated in English, Spanish, German, and Italian language. Therefore, the aim of this study was to validate a Portuguese version of the GPIUS2 and provide a taxonomy of the potential risk of PIU among participants. A sample of 641 Portuguese-speaking Internet users was recruited online after a process of translation and back-translation of the original GPIUS2. In-depth validity and reliability analyses were conducted alongside latent profile analysis (LPA) to identify the potential risk of PIU of participants. The validity and reliability analyses revealed adequate results concerning the psychometric properties of the Portuguese GPIUS2. According to the LPA results, participants were classed as “low risk” (n = 289, 46.7%), “medium risk” (n = 256, 40.7%), and “high risk” (n = 77, 12.6%) of PIU with key differences emerging among the three classes. The present findings support the overall validity and usefulness of the Portuguese GPIUS2 and the results from the LPA may be potentially useful in informing practitioners currently working with clients struggling with PIU

Agreement on Web-based Diagnoses and Severity of Mental Health Problems in Norwegian Child and Adolescent Mental Health Services

Objective: This study examined the agreement between diagnoses and severity ratings assigned by clinicians using a structured web-based interview within a child and adolescent mental health outpatient setting. Method: Information on 100 youths was obtained from multiple informants through a web-based Development and Well-Being Assessment (DAWBA). Based on this information, four experienced clinicians independently diagnosed (according to the International Classification of Diseases Revision 10) and rated the severity of mental health problems according to the Health of the Nation Outcome Scales for Children and Adolescents (HoNOSCA) and the Children’s Global Assessment Scale (C-GAS). Results: Agreement for diagnosis was κ=0.69-0.82. Intra-class correlation for single measures was 0.78 for HoNOSCA and 0.74 for C-GAS, and 0.93 and 0.92, respectively for average measures. Conclusions: Agreement was good to excellent for all diagnostic categories. Agreement for severity was moderate, but improved to substantial when the average of the ratings given by all clinicians was considered. Therefore, we conclude that experienced clinicians can assign reliable diagnoses and assess severity based on DAWBA data collected online