27 research outputs found
Effects of oxytocin on attention to emotional faces in healthy volunteers and highly socially anxious males
Background: Evidence suggests that individuals with social anxiety demonstrate vigilance to social threat, whilst the peptide hormone oxytocin is widely accepted as supporting affiliative behaviour in humans. Methods: This study investigated whether oxytocin can affect attentional bias in social anxiety. In a double-blind, randomized, placebo-controlled, within-group study design, 26 healthy and 16 highly socially anxious (HSA) male volunteers (within the HSA group, 10 were diagnosed with generalized social anxiety disorder) were administered 24 IU of oxytocin or placebo to investigate attentional processing in social anxiety. Attentional bias was assessed using the dot-probe paradigm with angry, fearful, happy and neutral face stimuli. Results: In the baseline placebo condition, the HSA group showed greater attentional bias for emotional faces than healthy individuals. Oxytocin reduced the difference between HSA and non-socially anxious individuals in attentional bias for emotional faces. Moreover, it appeared to normalize attentional bias in HSA individuals to levels seen in the healthy population in the baseline condition. The biological mechanisms by which oxytocin may be exerting these effects are discussed. Conclusions: These results, coupled with previous research, could indicate a potential therapeutic use of this hormone in treatment for social anxiety
Comparative antimicrobial activities of aerosolized sodium hypochlorite, chlorine dioxide, and electrochemically activated solutions evaluated using a novel standardized assay
The main aim of this study was to develop a standardized experimental assay to enable differential antimicrobial comparisons of test biocidal aerosols. This study represents the first chlorine-matched comparative assessment of the antimicrobial activities of aerosolized sodium hypochlorite, chlorine dioxide, and electrochemically activated solution (ECAS) to determine their relative abilities to decontaminate various surface-associated health care-relevant microbial challenges. Standard microbiological challenges were developed by surface-associating typed Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus subtilis spores, or a clinical methicillin-resistant S. aureus (MRSA) strain on stainless steel, polypropylene, or fabric. All test coupons were subjected to 20-min biocidal aerosols of chlorine-matched (100 ppm) sodium hypochlorite, chlorine dioxide, or ECAS within a standard aerosolization chamber using a commercial humidifier under defined conditions. Biocidal treatment type and material surface had a significant effect on the number of microorganisms recovered from various material surfaces following treatment exposure. Under the conditions of the assay, the order of antimicrobial efficacy of biocidal aerosol treatment was as follows: ECAS>chlorine dioxide>sodium hypochlorite. For all biocides, greater antimicrobial reductions were seen when treating stainless steel and fabric than when treating plastic-associated microorganisms. The experimental fogging system and assay protocol designed within this study were shown capable of differentiating the comparative efficacies of multiple chlorine-matched biocidal aerosols against a spectrum of target organisms on a range of test surface materials and would be appropriate for testing other biocidal aerosol treatments or material surfaces. Copyright © 2013, American Society for Microbiology. All Rights Reserved
New narrow-beam meteor radar results at Christmas Island: Implications for diurnal wind estimation
Solar heating of the atmosphere is responsible for most of the diurnal oscillations in the neutral wind velocities and temperatures of the mesosphere and lower thermosphere. When these oscillations are global-scale waves, they are called atmospheric tides. Excited in the lower atmosphere, tides can propagate up into the upper atmosphere where they can break and deposit considerable energy and momentum into the mean flow. Ground-based estimates of the diurnal winds over Christmas Island have been made using a narrow-beam meteor radar system. Previously, data collected using the three-beam antenna configuration of the meteor radar were processed under the assumption that the vertical wind component was at least 2 orders of magnitude smaller than the horizontal component for all temporal scales of motion. The addition of two oblique beams to the radar configuration in late 1993 made it possible to estimate the horizontal wind field without applying the negligible vertical wind assumption, by using a coplanar analysis technique. Not only did the diurnal fits of the horizontal coplanar winds agree better with the results of the collocated medium-frequency radar and model predictions, but also the Christmas Island meteor radar appears to be measuring a significant vertical velocity. This velocity has a diurnal amplitude of 10–15 m s⁻¹ and maximizes at midnight across all heights. Under the assumption that this strong vertical motion is produced by geophysical phenomena, two hypotheses to explain this velocity are presented: the vertical motion associated with gravity wave breaking and the influence of strong electric fields on the ionized meteor trails.J. L. Chang and S. K. Avery, R. A. Vincen