Mid-Infrared Images of Luminous Infrared Galaxies in a Merging Sequence

We report mid-infrared observations of several luminous infrared galaxies (LIGs) carried out with the Infrared Space Observatory. Our sample was chosen to represent different phases of a merger sequence of galaxy-galaxy interaction with special emphasis on early/intermediate stages of merging. The mid-infrared emission of these LIGs shows extended structures for the early and intermediate mergers, indicating that most of the mid-infrared luminosities are not from a central active galactic nucleus (AGN). Both the infrared hardness (indicated by the IRAS 12, 25, and 60 \micron flux density ratios) and the peak-to-total flux density ratios of these LIGs increase as projected separation of these interacting galaxies become smaller, consistent with increasing star formation activities that are concentrated to a smaller area as the merging process advances. These observations provide among the first observational constraint of largely theoretically based scenarios.Comment: 10 pages, 3 figures, please refer to ApJ Letters for the final versio

The neurobiological basis of binge-eating disorder

AbstractRelatively little is known about the neuropathophysiology of binge-eating disorder (BED). Here, the evidence from neuroimaging, neurocognitive, genetics, and animal studies are reviewed to synthesize our current understanding of the pathophysiology of BED. Binge-eating disorder may be conceptualized as an impulsive/compulsive disorder, with altered reward sensitivity and food-related attentional biases. Neuroimaging studies suggest there are corticostriatal circuitry alterations in BED similar to those observed in substance abuse, including altered function of prefrontal, insular, and orbitofrontal cortices and the striatum. Human genetics and animal studies suggest that there are changes in neurotransmitter networks, including dopaminergic and opioidergic systems, associated with binge-eating behaviors. Overall, the current evidence suggests that BED may be related to maladaptation of the corticostriatal circuitry regulating motivation and impulse control similar to that found in other impulsive/compulsive disorders. Further studies are needed to understand the genetics of BED and how neurotransmitter activity and neurocircuitry function are altered in BED and how pharmacotherapies may influence these systems to reduce BED symptoms

Dysregulated oscillatory connectivity in the visual system in autism spectrum disorder

Autism spectrum disorder is increasingly associated with atypical perceptual and sensory symptoms. Here we explore the hypothesis that aberrant sensory processing in autism spectrum disorder could be linked to atypical intra- (local) and interregional (global) brain connectivity. To elucidate oscillatory dynamics and connectivity in the visual domain we used magnetoencephalography and a simple visual grating paradigm with a group of 18 adolescent autistic participants and 18 typically developing control subjects. Both groups showed similar increases in gamma (40-80 Hz) and decreases in alpha (8-13 Hz) frequency power in occipital cortex. However, systematic group differences emerged when analysing intra- and interregional connectivity in detail. First, directed connectivity was estimated using non-parametric Granger causality between visual areas V1 and V4. Feedforward V1-to-V4 connectivity, mediated by gamma oscillations, was equivalent between autism spectrum disorder and control groups, but importantly, feedback V4-to-V1 connectivity, mediated by alpha (8-13 Hz) oscillations, was significantly reduced in the autism spectrum disorder group. This reduction was positively correlated with autistic quotient scores, consistent with an atypical visual hierarchy in autism, characterized by reduced top-down modulation of visual input via alpha-band oscillations. Second, at the local level in V1, coupling of alpha-phase to gamma amplitude (alpha-gamma phase amplitude coupling) was reduced in the autism spectrum disorder group. This implies dysregulated local visual processing, with gamma oscillations decoupled from patterns of wider alpha-band phase synchrony (i.e. reduced phase amplitude coupling), possibly due to an excitation-inhibition imbalance. More generally, these results are in agreement with predictive coding accounts of neurotypical perception and indicate that visual processes in autism are less modulated by contextual feedback information

Exposure to War as a Risk Factor for Mental Disorders

The authors discuss a new study on the prevalence of mental disorders in Lebanon

Use of recombinant activated factor VII for acute bleeding episodes in acquired hemophilia: final analysis from the Hemostasis and Thrombosis Research Society Registry acquired hemophilia study

The Hemostasis and Thrombosis Research Society Registry was used to monitor the postapproval use and safety of recombinant activated factor VII (rFVIIa). The objective of this article is to evaluate the data from the Hemostasis and Thrombosis Research Society Registry related to rFVIIa-treated bleeding episodes in patients with acquired hemophilia. For each rFVIIa-treated bleeding episode, the initial dose, total dose, average infused dose, number of doses, and treatment duration were calculated. Efficacy was assessed on a three-point scale. Out of the 166 registered patients with acquired hemophilia, 110 patients were treated for 237 bleeding episodes (139 rFVIIa treated); the majority (70%) were in patients older than 60 years. The most frequently reported bleeding locations were subcutaneous (40%) and mucosal (32%). Subcutaneous bleeding episodes were more commonly reported in women (55% vs. 40% men) and white patients (44 vs. 27% black). Of the 139 rFVIIa-treated bleeding episodes, rFVIIa was used as first-line treatment in 127 bleeding episodes. The median initial dose was 90 μg/kg; the median total dose per episode was 333.5 μg/kg. Physician-rated efficacy of rFVIIa for each bleeding episode was reported as ‘bleeding stopped’ in 85% of bleeding episodes, ‘bleeding slowed’ in 11% of bleeding episodes, ‘no improvement’ in 4% of bleeding episodes, and was not documented in 1 bleeding episode. One thromboembolic event was reported; transient neurologic symptoms were reported in a 31-year-old postpartum patient after 110 doses of rFVIIa. Adequate hemostasis was provided for most rFVIIa-treated bleeding episodes at doses largely conforming to the package insert. No major safety concerns were reported