Mapping New Zealand and Antarctic snowpack from LANDSAT

Ther are no author-identified significant results in this report

Item response theory and validity of the NEO-FFI in adolescents

The present study applied item response theory (IRT) to the NEO five factor inventory (NEO-FFI) completed by a community based sample of adolescents. The results revealed that many of these personality items may not be discriminating well, with some traits demonstrating greater reliability than others. Furthermore, the threshold values highlighted that the majority of the items had skewed responses, suggesting a limited utility of some response categories. Generally, removing poorly discriminating items does not harm external validity, suggesting IRT reduces measurement error and increases reliability without compromising validity

Help-seeking in emerging adults with and without a history of mental health referral: a qualitative study

Background: Young people are generally reluctant to seek professional help when experiencing problems. However, past experience of services is often cited as increasing the intention to seek help, therefore those with a history of mental health referral may adopt more adaptive help seeking strategies. The current study investigated whether the pattern of different help seeking strategies and barriers to help seeking differed as a function of previous referral history. Methods: Semi-structured interviews were conducted with 29 emerging adults (12 males, 17 females); 17 with a history of mental health referral and 12 without and analysed using thematic analysis. Results: Overall, those with a referral to services were more likely than those without to rely on avoidant coping, especially techniques that depended upon suppression. This could help account for the increased use of strategies involving self-harm and substances in those with past referral. An exploration of barriers to help seeking showed those with a history of mental health referral were much more likely to self-stigmatise and this became attached to their sense of identity. Conclusions: Emerging adults with a history of referral are more likely to adopt avoidant coping strategies when dealing with problems and self-stigmatise to a greater degree than those without a history of referral. This suggests that current approaches to mental health in emerging adults are not decreasing the sense of stigma with potentially far-reaching consequences for the developing sense of self and choice of help seeking strategie

The Experiences of Ethical Tensions When Using Harm Reduction with High-Risk Youth

Little is known about the ethical experiences of psychologists who work with high-risk youth using a harm reduction approach. We used interpretative phenomenological analysis (IPA) to explicitly explore this phenomenon. In this small exploratory study three participants were interviewed to glean their experiences of ethical tension. Data analysis revealed three superordinate themes (questioning, acting, and holding) within which eight subthemes are subsumed (questioning beneficence, questions from others, self-care, social change, negotiation, consultation and supervision, acceptance, and sitting with tension). The results of this research suggest that context-specific ethical tensions may arise for psychologists who work with high-risk youth using a harm reduction approach, which in turn lead to and necessitate a tailored ethical response. The results also suggest that harm reduction promoters may benefit from increased dialogue with licencing and professional bodies to foster awareness and develop guidelines on promoting ethical practice when using a harm reduction approach with high-risk youth. Future research can profitably be directed towards an increased experiential understanding of some of the central themes of this research, such as “sitting with tension” and “holding.

A Multi-signal Variant for the GPU-based Parallelization of Growing Self-Organizing Networks

Among the many possible approaches for the parallelization of self-organizing networks, and in particular of growing self-organizing networks, perhaps the most common one is producing an optimized, parallel implementation of the standard sequential algorithms reported in the literature. In this paper we explore an alternative approach, based on a new algorithm variant specifically designed to match the features of the large-scale, fine-grained parallelism of GPUs, in which multiple input signals are processed at once. Comparative tests have been performed, using both parallel and sequential implementations of the new algorithm variant, in particular for a growing self-organizing network that reconstructs surfaces from point clouds. The experimental results show that this approach allows harnessing in a more effective way the intrinsic parallelism that the self-organizing networks algorithms seem intuitively to suggest, obtaining better performances even with networks of smaller size.Comment: 17 page

The floor in the interplanetary magnetic field: Estimation on the basis of relative duration of ICME observations in solar wind during 1976-2000

To measure the floor in interplanetary magnetic field and estimate the time- invariant open magnetic flux of Sun, it is necessary to know a part of magnetic field of Sun carried away by CMEs. In contrast with previous papers, we did not use global solar parameters: we identified different large-scale types of solar wind for 1976-2000 interval, obtained a fraction of interplanetary CMEs (ICMEs) and calculated magnitude of interplanetary magnetic field B averaged over 2 Carrington rotations. The floor of magnetic field is estimated as B value at solar cycle minimum when the ICMEs were not observed and it was calculated to be 4,65 \pm 6,0 nT. Obtained value is in a good agreement with previous results.Comment: 10 pages, 2 figures, submitted in GR

Jets in GRBs

In several GRBs afterglows, rapid temporal decay is observed which is inconsistent with spherical (isotropic) blast-wave models. In particular, GRB 980519 had the most rapidly fading of the well-documented GRB afterglows, with t^{-2.05\pm 0.04} in optical as well as in X-rays. We show that such temporal decay is more consistent with the evolution of a jet after it slows down and spreads laterally, for which t^{-p} decay is expected (where p is the index of the electron energy distribution). Such a beaming model would relax the energy requirements on some of the more extreme GRBs by a factor of several hundreds. It is likely that a large fraction of the weak (or no) afterglow observations are also due to the common occurrence of beaming in GRBs, and that their jets have already transitioned to the spreading phase before the first afterglow observations were made. With this interpretation, a universal value of p~2.5 is consistent with all data.Comment: 4 page