Craving and physiological reactivity to trauma and alcohol cues in posttraumatic stress disorder and alcohol dependence.

The high comorbidity of posttraumatic stress disorder (PTSD) and alcohol dependence (AD) has been firmly established. Although laboratory studies have examined self-reported craving in response to trauma and alcohol cues, no studies have reported on alcohol-related physiological responding in response to trauma cues in PTSD-AD individuals. Using a cue reactivity paradigm, this study examined the impact of personalized trauma-image cues and in vivo alcohol cues on alcohol-related responding (e.g., salivation, craving) in individuals with PTSD and AD (n = 40). Participants displayed reactivity to both trauma and alcohol cues when compared to neutral cues, including increased self-reported craving and distress, as well as greater salivation. These findings suggest that through repeated pairings of trauma memories and alcohol consumption, salivation may become classically conditioned to trauma cues. Moreover, the fact that the trauma-alcohol cue combination elicited greater alcohol craving, salivary responding, distress, and arousal than either the trauma-neutral or neutral-alcohol cue combinations suggests that effects of the trauma and alcohol cues were additive in nature. Evidence that AD individuals with PTSD report increased alcohol craving and display greater salivation in response to trauma memories, supplements prior research indicating that PTSD-related negative emotion and trauma-related alcohol craving may play an important role in the maintenance of AD. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A Dual-Synchrony Chaotic Communication Scheme

We demonstrate here a new dual receiver synchronization scheme that works because we are able to store samples over an entire bit period and then perform an intelligent comparison by methods we introduce. We discuss advantages for message camouflage of transmissions near the noise floor. Our results show better bit error probability performance in comparison to previously published methods. This represents a significantly different and promising new way to use chaotic transmitters to advantageously transmit designed signals.     

Combined physical/microbial beneficiation of coal using the flood/drain bioreactor

The flood/drain reactor consists of a bed of intermediate-sized coal (roughly 0.5 to 5 mm) periodically fluidized by pumping in a mixed bacterial culture. Metabolic products and coal fines are washed out of the bed, and large pyritic inclusions and other dense mineral matter tends to settle to the base of the bed. Draining the bed then draws in fresh air for subsequent pyrite removal by microorganisms. Experiments on a laboratory-scale bed, 10.2 cm diameter with two 12 × 30 mesh Illinois # 6 coals and a Pittsburgh # 8 coal showed that up to 80% pyrite removal could be achieved in four weeks by this combination of physical separation and microbial activity. Operational problems included removal of fines from the bed during start-up and the appearance of acidophilic protozoa grazing on the pyrite-oxidizing bacteria. Significant improvement in performance is anticipated by eliminating the lag-phase of the sulfur-oxidizing bacteria and optimizing the timing of the flood/drain cycles.     

Determinants of academic use of the Internet: a structural equation model

The last decade of the 20th century brought radical changes in information and communication technology. Internet usage is being widely researched in the business world. However, the use of the Internet in academic settings in general and in vocational and technical establishment in particular is a neglected area. Successful use of the Internet is largely dependent upon the user's behaviour that, in turn, affects their attitudes. Even when remarkable opportunities exist for the deployment of technology, adverse attitude can inhibit use. Keeping this in mind, a survey of 166 academics of four technical and vocational colleges was conducted to study the attitudes of academics toward the use of the Internet. This study develops a model and validates two specific attitudinal variables--perceived usefulness and perceived ease of use--which are hypothesized to be fundamental determinants of use of the Internet. Adding two more variables--such as task characteristics and computer exposure--test the parsimony of the model further. A structural equation modelling technique is used to validate the model. The study confirmed that 79% of academics are using the Internet. Computer experience, perceived usefulness and perceived ease of use remain to be fundamental determinants of attitude formation. No other variables have been found to be significant.     

Nb-Based Nb-Al-Fe Alloys: Solidification Behavior and High-Temperature Phase Equilibria

High-melting Nb-based alloys hold significant promise for the development of novel high-temperature materials for structural applications. In order to understand the effect of alloying elements Al and Fe, the Nb-rich part of the ternary Nb-Al-Fe system was investigated. A series of Nb-rich ternary alloys were synthesized from high-purity Nb, Al, and Fe metals by arc melting. Solidification paths were identified and the liquidus surface of the Nb corner of the ternary system was established by analysis of the as-melted microstructures and thermal analysis. Complementary analysis of heat-treated samples yielded isothermal sections at 1723 K and 1873 K (1450 °C and 1600 °C).