Magnetoresistance and spin-transfer torque in magnetic tunnel junctions

We comment on both recent progress and lingering puzzles related to research on magnetic tunnel junctions (MTJs). MTJs are already being used in applications such as magnetic-field sensors in the read heads of disk drives, and they may also be the first device geometry in which spin-torque effects are applied to manipulate magnetic dynamics, in order to make nonvolatile magnetic random access memory. However, there remain many unanswered questions about such basic properties as the magnetoresistance of MTJs, how their properties change as a function of tunnel-barrier thickness and applied bias, and what are the magnitude and direction of the spin-transfer-torque vector induced by a tunnel current.Comment: 37 pages, 2 figures. Contribution to a collection of "Current Perspectives" articles on spin transfer torque now available in the Journal of Magnetism and Magnetic Material

Multidimensional screening for predicting pain problems in adults : a systematic review of screening tools and validation studies

Screening tools allowing to predict poor pain outcomes are widely used. Often these screening tools contain psychosocial risk factors. This review (1) identifies multidimensional screening tools that include psychosocial risk factors for the development or maintenance of pain, pain-related distress, and pain-related disability across pain problems in adults, (2) evaluates the quality of the validation studies using Prediction model Risk Of Bias ASsessment Tool (PROBAST), and (3) synthesizes methodological concerns. We identified 32 articles, across 42 study samples, validating 7 screening tools. All tools were developed in the context of musculoskeletal pain, most often back pain, and aimed to predict the maintenance of pain or pain-related disability, not pain-related distress. Although more recent studies design, conduct, analyze, and report according to best practices in prognosis research, risk of bias was most often moderate. Common methodological concerns were identified, related to participant selection (eg, mixed populations), predictors (eg, predictors were administered differently to predictors in the development study), outcomes (eg, overlap between predictors and outcomes), sample size and participant flow (eg, unknown or inappropriate handling of missing data), and analysis (eg, wide variety of performance measures). Recommendations for future research are provided

The neurocognition of alexithymia: evidence from neuropsychological and neuroimaging studies

Objective: Alexithymia refers to an ineffective regulation and expression of emotions. It constitutes a major risk factor for a range of medical and psychiatric problems, including chronic pain, somatisation, anxiety and depression. Alexithymia is a multi-faceted concept, described in terms of cognitive and affective aspects. From a neuropsychological perspective, alexithymia can be defined as a disturbance in affective information processing and social cognition. As the growing literature on brain structures involved in alexithymia is fragmented and sometimes even contradictory, the aim of this article was to review findings on neural substrates with regard to their convergence. Methods: A narrative review was performed, including both early neuropsychological and more recent imaging studies, in order to achieve a better understanding of the aetiology of alexithymia. Results: Corpus callosum, cingulate cortex and insula are clearly involved in alexithymia. The amygdala and the orbitofrontal part of the cortex appear to be implicated as mediators, because of their broader involvement in emotional processing and executive control. Conclusion: Notwithstanding the diffuse neural representation, the alexithymia construct can be usefully applied in the clinical and empirical studies of social cognition, particularly when adopting a dimensional neuropsychological approach

Neuropsychological and Behavioral Aspects of Noonan Syndrome

The current paper introduces concise neuropsychological assessment as an essential tool for studying the contribution of cognition and behavior in the expression of genetic syndromes, like Noonan syndrome (NS). Cognitive and behavioral findings in NS show intelligence scores across a wide range, with a mildly lowered average level. Language and motor development are often delayed, but no longer dysfunctional in adulthood. Continuing mild problems in selective and sustained attention are noted, as well as suboptimal organization skills and compromised abilities to structure complex information. These problems seem to culminate in learning difficulties, requiring attention for special needs in education. It seems that a complex of psychosocial immaturity, alexithymia and amenable traits is typical of NS patients. Consequently, psychopathology or psychological problems in leading a self-serving life may often remain underreported. This is why the authors advocate the integration of the domain of social cognition and personality in NS assessment. Copyright (C) 2009 S. Karger AG, Base

Affective functioning and social cognition in Noonan syndrome

Background. Noonan syndrome (NS) is a common genetic disorder, characterized by short stature, facial dysmorphia, congenital heart defects and a mildly lowered IQ. Impairments in psychosocial functioning have often been suggested, without, however, systematic investigation in a clinical group. In this study, different aspects of affective processing, social cognition and behaviour, in addition to personal well-being, were assessed in a large group of patients with NS. Method. Forty adult patients with NS were compared with 40 healthy controls, matched with respect to age, sex, intelligence and education level. Facial emotion recognition was measured with the Emotion Recognition Task (ERT), alexithymia with both the 20-item Toronto Alexithymia Scale (TAS-20) and the Bermond-Vorst Alexithymia Questionnaire (BVAQ), and mentalizing with the Theory of Mind (ToM) test. The Symptom Checklist-90 Revised (SCL-90-R) and the Scale for Interpersonal Behaviour (SIB) were Results. Patients showed higher levels of cognitive alexithymia than controls. They also experienced more social distress, but the frequency of engaging in social situations did not differ. Facial emotion recognition was only slightly impaired. Conclusions. Higher levels of alexithymia and social discomfort are part of the behavioural phenotype of NS. However, patients with NS have relatively intact perception of emotions in others and unimpaired mentalizing. These results provide insight into the underlying mechanisms of social daily life functioning in this patient group. Received 5 April 2011; Revised 2 June 2011; Accepted 3 June 2011; First published online 11 July 201

Challenges and solutions in prognostic prediction models in spinal disorders

Methodological shortcomings in prognostic modeling for patients with spinal disorders are highly common. This general commentary discusses methodological challenges related to the specific nature of this field. Five specific methodological challenges in prognostic modeling for patients with spinal disorders are presented with their potential solutions, as related to the choice of study participants, purpose of studies, limitations in measurements of outcomes and predictors, complexity of recovery predictions, and confusion of prognosis and treatment response. Large studies specifically designed for prognostic model research are needed, using standard baseline measurement sets, clearly describing participants’ recruitment and accounting and correcting for measurement limitations