Micromagnetic simulations of persistent oscillatory modes excited by spin-polarized current in nanoscale exchange-biased spin valves

We perform 3D micromagnetic simulations of current-driven magnetization dynamics in nanoscale exchange biased spin-valves that take account of (i) back action of spin-transfer torque on the pinned layer, (ii) non-linear damping and (iii) random thermal torques. Our simulations demonstrate that all these factors significantly impact the current-driven dynamics and lead to a better agreement between theoretical predictions and experimental results. In particular, we observe that, at a non-zero temperature and a sub-critical current, the magnetization dynamics exhibits nonstationary behaviour in which two independent persistent oscillatory modes are excited which compete for the angular momentum supplied by spin-polarized current. Our results show that this multi-mode behaviour can be induced by combined action of thermal and spin transfer torques.Comment: 7pages, 2 figures, submitted JAP via MMM 200

Variation in the μ-opioid receptor gene (OPRM1) moderates the influence of early maternal care on fearful attachment

There is evidence that both early experience and genetic variation play a role in influencing sensitivity to social rejection. In this study, we aimed at ascertaining if the A118G polymorphism of the k-opioid receptor gene (OPRM1) moderates the impact of early maternal care on fearful attachment, a personality trait strongly related to rejection sensitivity. In 112 psychiatric patients, early maternal care and fearful attachment were measured using the Parental Bonding Inventory and the Relationship Questionnaire (RQ), respectively. The pattern emerging from the RQ data was a crossover interaction between genotype and maternal caregiving. Participants expressing the minor 118 G allele had similar and relatively high scores on fearful attachment regardless of the quality of maternal care. By contrast, early experience made a major difference for participants carrying the A/A genotype. Those who recalled higher levels of maternal care reported the lowest levels of fearful attachment whereas those who recalled lower levels of maternal care scored highest on fearful attachment. Our data fit well with the differential susceptibility model which stipulates that plasticity genes would make some individuals more responsive than others to the negative consequences of adversity and to the benefits of environmental support and enrichment

Time domain study of frequency-power correlation in spin-torque oscillators

This paper describes a numerical experiment, based on full micromagnetic simulations of current-driven magnetization dynamics in nanoscale spin valves, to identify the origins of spectral linewidth broadening in spin torque oscillators. Our numerical results show two qualitatively different regimes of magnetization dynamics at zero temperature: regular (single-mode precessional dynamics) and chaotic. In the regular regime, the dependence of the oscillator integrated power on frequency is linear, and consequently the dynamics is well described by the analytical theory of current-driven magnetization dynamics for moderate amplitudes of oscillations. We observe that for higher oscillator amplitudes, the functional dependence of the oscillator integrated power as a function of frequency is not a single-valued function and can be described numerically via introduction of nonlinear oscillator power. For a range of currents in the regular regime, the oscillator spectral linewidth is a linear function of temperature. In the chaotic regime found at large current values, the linewidth is not described by the analytical theory. In this regime we observe the oscillator linewidth broadening, which originates from sudden jumps of frequency of the oscillator arising from random domain wall nucleation and propagation through the sample. This intermittent behavior is revealed through a wavelet analysis that gives superior description of the frequency jumps compared to several other techniques.Comment: 11 pages, 4 figures to appear in PR

Catheters and Infections

Catheters are used for effective drainage of the bladder, either temporally or permanently, in the presence of physiological and anatomical defects or obstruction of the lower urinary tract. Catheters are used for a variety of reasons, as follows, to maintain bladder drainage during and following surgery or epidurals anesthesia for minimizing and prevention of the risk of distension injuries; investigations, for accurate urine output measurement, and measurement of post-micturition residuals; treatments, to relieve urinary retention or for chemotherapy instillation; intractable incontinence, as the final option for containment

Positive and psycho-pathological aspects between shame and shamelessness

Interpersonal relationships represent an essential aspect of mental wellbeing and social functioning. If all the symptoms contain a relational meaning, shame represents the relational affect par excellence both in terms of its origin and its purpose. This paper aims to highlight the role of shame as an affect inherent in the rhythmic nature of the encounter with the other, as well as the pathological elements of this aspect in both its conscious and unconscious dimensions. There is a heterogeneous quantitative and qualitative declination of shame, or of the defenses against this affect, among the various pathologies. We consider the fundamental needs of belonging and acceptance and the parallel abandonment anguish from various psychoanalytic and philosophical theoretical perspectives and then analyze the link between their dissatisfaction and the origin of shame. We also touch on the different interpretaions of shame based on eastern and western cultural norms. These hypotheses are closely intertwined with the beliefs of classical psychopathology. The role of the body in the encounter with the other and in the experience of shame is also examined. In particular, we study the role of this affect in schizophrenia, depression, eating disorders, and personality disorders

Correlatos de la terapia EMDR en la neuroimagen funcional y estructural: Un resumen cr?tico de los hallazgos recientes

Neuroimaging investigations of the effects of psychotherapies treating posttraumatic stress disorder (PTSD), including eye movement desensitization and reprocessing (EMDR), have reported findings consistent with modifications in cerebral blood flow (CBF; single photon emission computed tomography [SPECT]), in neuronal volume and density (magnetic resonance imaging [MRI]), and more recently in brain electric signal (electroencephalography [EEG]). Additionally in the recent past, EMDR- related neurobiological changes were monitored by EEG during therapy itself and showed a shift of the maximal activation from emotional limbic to cortical cognitive brain regions. This was the first time in which neurobiological changes occurring during any psychotherapy session have been reported, making EMDR the first psychotherapy with a proven neurobiological effect. The purpose of this article was to review the results of functional and structural changes taking place at PTSD treatment and presented during the period of 1999-2012 by various research groups. The reported pathophysiological changes are presented by neuropsychological technique and implemented methodology and critically analyzed.Las investigaciones con neuroimagen sobre los efectos de las psicoterapias que tratan el trastorno de estr?s postraum?tico (TEPT), incluyendo la terapia de desensibilizaci?n y reprocesamiento por movimientos oculares (EMDR), han mostrado hallazgos conformes con modificaciones en el flujo sangu?neo cerebral (FSC; tomograf?a computerizada de emisi?n monofot?nica [SPECT]), en el volumen y la densidad neuronal (im?genes por resonancia magn?tica [MRI]) y, m?s recientemente, en las se?ales el?ctricas del cerebro (electroencefalograf?a [EEG]). Adem?s, en el pasado reciente, se han monitorizado, por medio de EEG, cambios neurobiol?gicos relacionados con EMDR durante la misma terapia y han mostrado un cambio en la activaci?n m?xima desde las regiones l?mbicas emocionales a las regiones cognitivas corticales del cerebro. Esta ha sido la primera vez que se han se?alado los cambios neurobiol?gicos que tienen lugar durante una sesi?n de psicoterapia, lo que ha hecho que EMDR sea la primera psicoterapia con un efecto neurobiol?gico probado. El prop?sito de este art?culo ha sido analizar los resultados de los cambios funcionales y estructurales que han tenido lugar durante el tratamiento del TEPT y que han sido presentados por diversos grupos de investigaci?n durante el per?odo entre 1999 y 2012. Los cambios fisiopatol?gicos referidos se presentan en funci?n de las t?cnicas neuropsicol?gicas y la metodolog?a implementadas y son analizados de manera cr?tica