The pasta phase and its consequences on neutrino opacities

In this paper, we calculate the diffusion coefficients that are related to the neutrino opacities considering the formation of nuclear pasta and homogeneous matter at low densities. Our results show that the mean free paths are significantly altered by the presence of nuclear pasta in stellar matter when compared with the results obtained with homogeneous matter. These differences in neutrino opacities certainly influence the Kelvin-Helmholtz phase of protoneutron stars and consequently the results of supernova explosion simulations

Electrically charged pulsars

n the present work we investigate one possible variation on the usual electrically neutral pulsars: the inclusion of electric charge. We study the effect of electric charge in pulsars assuming that the charge distribution is proportional to the energy density. All calculations were performed for zero temperature and fixed entropy equations of state

Mass radius relation of compact stars in the braneworld

The braneworld scenario, based on the fact that the four dimension space-time is a hyper-surface of a five dimensional manifold, was shown to deal in a satisfactory way with the hierarchy problem. In this work we study macroscopic stellar properties of compact stars from the braneworld point of view. Using neutron star equations of state, we test the possibility of extra dimensions by solving the brane Tolman-Oppenheimer-Volkoff equations obtained for three kinds of possible compact objects: hadronic, hybrid and quark stars. By comparing the macroscopic solutions with observational constraints, we establish a brane tension lower limit and the value for which the Tolman-Oppenheimer-Volkoff equations in the braneworld converge to the usual Tolman-Oppenheimer-Volkoff equations.Comment: 15 pages, 5 figures, 4 tables, to appear in JCA

Spontaneous thought and vulnerability to mood disorders : the dark side of the wandering mind

There is increasing interest in spontaneous thought, namely task-unrelated or rest-related mental activity. Spontaneous thought is an umbrella term for processes like mind-wandering, involuntary autobiographical memory, and daydreaming, with evidence elucidating adaptive and maladaptive consequences. In this theoretical framework, we propose that, apart from its positive functions, spontaneous thought is a precursor for cognitive vulnerability in individuals who are at risk for mood disorders. It is important that spontaneous thought mostly focuses on unattained goals and evaluates the discrepancy between current and desired status. In individuals who stably (i.e., trait negative affectivity) or transitorily (i.e., stress) experience negative emotions in reaction to goal-discrepancy, spontaneous thought fosters major cognitive vulnerabilities (e.g., rumination, hopelessness, low self-esteem, and cognitive reactivity), which, in turn, enhance depression. Furthermore, we also highlight preliminary links between spontaneous thought and bipolar disorder. The evidence for this framework is reviewed, and we discuss theoretical and clinical implications of our proposal

Generation of the magnetic field in jets

We consider dynamo action under the combined influence of turbulence and large-scale shear in sheared jets. Shear can stretch turbulent magnetic field lines in such a way that even turbulent motions showing mirror symmetry become suitable for generation of a large-scale magnetic field. We derive the integral induction equation governing the behaviour of the mean field in jets. The main result is that sheared jets may generate a large-scale magnetic field if shear is sufficiently strong. The generated mean field is mainly concentrated in a magnetic sheath surrounding the central region of a jet, and it exhibits sign reversals in the direction of the jet axis. Typically, the magnetic field in a sheath is dominated by the component along the jet that can reach equipartition with the kinetic energy of particles, The field in the central region of jets has a more disordered structure.Comment: 7 pages, accepted for publication in A&

Prospective cognitions in anxiety and depression: Replication and methodological extension

The present study presents a replication and methodological extension of MacLeod, Tata, Kentish, and Jacobsen (1997) with a nonclinical sample, using future-directed imagery to assess prospective cognitions. Results showed that only anxiety (but not depression) was related to enhanced imagery for future negative events. Both anxiety and depression showed significant zero-order correlations with reduced imagery for future positive events. However, when the overlap between anxiety and depression was controlled for, only depression (but not anxiety) showed a unique association with reduced imagery for positive events. Implications of these findings for cognitive models of anxiety and depression are discussed

Nosology, epidemiology and pathogenesis of bipolar disorder: Recent approaches

Bipolar disorder is a highly prevalent, chronic and deteriorating mental illness that requires medical, psychological and social care for life. Realizing that bipolar disorder is more common than initially thought, the associated disability and the heterogeneity in their clinical presentation, has strengthened the research on this topic. Recent advances in the field of nosology, epidemiology and pathogenesis have begun to unravel some of the complexity of this disorder and have had a marked influence on the changes in the way they are beginning to diagnose a broad spectrum of bipolar disorders according to the latest version of the Diagnostic and Statistical Manual of Mental Disorders (DSM 5)

Executive Function in Pediatric Bipolar Disorder and Attention-Deficit Hyperactivity Disorder: In Search of Distinct Phenotypic Profiles

Often, there is diagnostic confusion between bipolar disorder (BD) and attention-deficit hyperactivity disorder (ADHD) in youth due to similar behavioral presentations. Both disorders have been implicated as having abnormal functioning in the prefrontal cortex; however, there may be subtle differences in the manner in which the prefrontal cortex functions in each disorder that could assist in their differentiation. Executive function is a construct thought to be a behavioral analogy to prefrontal cortex functioning. We provide a qualitative review of the literature on performance on executive function tasks for BD and ADHD in order to determine differences in task performance and neurocognitive profile. Our review found primary differences in executive function in the areas of interference control, working memory, planning, cognitive flexibility, and fluency. These differences may begin to establish a pediatric BD profile that provides a more objective means of differential diagnosis between BD and ADHD when they are not reliably distinguished by clinical diagnostic methods