Environmentally induced changes in peripheral benzodiazepine receptors are stressor and tissue specific

The stress-induced changes in peripheral benzodiazepine receptors (PBR) can be observed in a number of different tissues, depending upon the nature and chronicity of the aversive experience. In addition, virtually all stress procedures that cause rapid changes in PBR simultaneously increase the physical activity or metabolic rate of the subjects. The present study analyzed the contributions of rapid alterations in activity or metabolic rate with and without aversive stimulation and their subsequent impact on PBR. Mechanically induced increases in activity by forced running stress results in a significant reduction in [3H]Ro 5-4864 binding to PBR in olfactory bulb, opposite to the PBR changes in this tissue following forced cold-water swim stress. Pharmacological induction of increased locomotor activity as well as metabolic rate by d-amphetamine causes a significant increase in cardiac PBR binding, again, opposite to the response typically observed following inescapable shock stress. Finally, administration of the anxiogenic beta-carboline, FG-7142, causes increases in both hippocampus and adrenal gland PBR binding reminiscent of acute noise stress exposure. These experiments demonstrate that increased locomotor activity or metabolic rate alone is not a necessary and sufficient condition for previous stress-induced changes in PBR. Conversely, increased metabolic rate coupled with an aversive stimulus appears to be an important factor for inducing stress-like changes in PBR. This data, coupled with previous reports, suggests that rapid alterations in these sites are stressor and tissue dependent. Finally, we propose that the PBR may be involved in many aspects of the stress response including: a) a blowarning system in adrenal gland, b) participation in stress-induced hypertension via renal PBR, and c) a modulator of stress-induced immunosuppression and subsequent recovery of function or recuperation by actions on immune cells.     

Crank-angle-resolved laser-induced fluorescence imaging of NO in a spark-ignition engine at 248 nm and correlations to flame front propagation and pressure release

Inside the combustion chamber of a spark-ignition engine, NO fluorescence is excited with a narrow-band tunable KrF excimer laser. The fluorescence light is detected by an intensified CCD camera that yields images of the NO distributions. Rotational-vibrational transitions of NO are excited by the A(2)Σ+ ? X(2)Π (0, 2) band system around 248 nm. Single laser shot planar NO distributions are obtained with good signal-to-noise ratio at all crank angles and allow us to locate areas of NO formation during combustion. The pressure within the combustion chamber is measured simultaneously with the NO distributions, which allows the evaluation of correlations between indicated work and NO formation. The crank-angle-resolved sequences of two-dimensional NO distributions and averaged pressure traces are presented for different engine-operating conditions. In addition, laser-induced predissociation fluorescence of OH excited by the same laser source is measured in order to visualize the corresponding flame front propagation and to compare the time of formation of NO relative to that of OH.     

Meta-analyses of ALDH2 and ADH1B with alcohol dependence in Asians.

Meta-analyses were conducted to determine the magnitude of relationships between polymorphisms in 2 genes, ALDH2 and ADH1B, with alcohol dependence in Asians. For each gene, possession of 1 variant *2 allele was protective against alcohol dependence, and possession of a 2nd *2 allele did not offer significant additional protection. The protective effects of these 2 gene polymorphisms were independent. Diagnostic criteria, recruitment strategy, and Japanese ethnicity moderated the effect of ALDH2*2. Recruitment strategy and gender moderated the effect of ADH1B*2. These findings highlight the importance of methodological issues and potential gene-gene and gene-environment interactions that must be considered when examining relationships between genetic polymorphisms and phenotypes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A comparative simulation study of work processes in autonomous production cells

An approach to human‐centered design and assessment of work processes in flexible manufacturing systems with the help of dynamic task networks is presented. To model and simulate the task networks, the method of timed colored Petri Nets is used. Two task networks are developed. The first task network is a model of work processes in Autonomous Production Cells (APCs). The second task network represents work processes in conventional Computer Numerically Controlled (CNC)‐based manufacturing systems. The material processing technology is associated with 5‐axis milling. The values of attributes of task elements were acquired empirically on a fine‐grained level with reference to a sample milling order. Comparative hypotheses regarding time‐on‐task, supervisory control functions, levels of cognitive control, human error (HE), and labor division were then formulated. To test these hypotheses, several simulation experiments were conducted. The results from inferential statistics show that single‐operator APCs have a 30% higher efficiency in relation to total time‐on‐task. Moreover, the level of cognitive control is significantly shifted toward rule‐ and knowledge‐based behavior. Surprisingly, the simulation of minor HE does not demonstrate a significantly worse performance from APCs. A simulated labor division among central process planner and production operator allows an additional efficiency improvement of approximately 15%. However, the labor division has two important drawbacks: first, a sequential incompleteness of operators' task spectrum occurs; second, the operator has to cope with hierarchical task incompleteness. Finally, a sensitivity analysis was carried out to investigate the effects of varying lot sizes and number of processed orders. © 2002 John Wiley & Sons, Inc.     

Teams without trust? Investigations in the influence of video-mediated communication on the origin of trust among cooperating persons

Based on a model about the origin of trust among persons, who are meeting for the first time, the influence of video-mediated communication on confidence building was tested. Using a 'between-subjects'-design, two groups were compared, one carrying out a cooperative task face-to-face, the other using a video-conferencing system. Three measurements were taken. Measurement 1 registered the effects of anticipation. One group was instructed to get somebody to know faceto-face, the other group should meet their partner by videoconference. Measurement 2 registered the amount of trust the subjects had developed in their partner during the session. Measurement 3 was the analysis of the interpersonal interaction processes during the conversation. The results are that subjects who anticipated a video-conference showed no difference in mean, but a highly reduced variability in their assessment of their counterpart compared to those subjects who anticipated a meeting face-to-face. A similar pattern was observed for measurement 2. However, no systematically meaningful difference in the behavioural categories of measurement 3 could be found. The results are similar to experiments mostly carried out in the 1970s and 1980s, which had focused on comparisons between face-to-face and mediated communication.     

Argumentation-Based Ontology Engineering

The Diligent argumentation framework helps capture design deliberations in ontology-engineering discussions. It makes consensus-building tasks more efficient and provides detailed guidance for nonexperts. The semantic Web envisions an infrastructure in which humans and machines seamlessly exchange information on the Web. During the discussions participants raise new issues or elaborate on existing ones. Once a discussion evolves, participants can group issues and act on them accordingly.     

Field and laboratory studies of the stability of amorphous silicon solar cells and modules

If photovoltaic solar cells and modules are to be used as a major source of power generation it is important to have a good knowledge and understanding of their long-term performance under different climatic and operating conditions. A number of studies of the long-term performance of commercially available photovoltaic modules manufactured using different technologies have now been reported in the literature. These have shown clear differences in the seasonal and long term performance and stability of different solar cell techniques. In addition to general module engineering factors that result in a loss of performance in all modules some types of solar cells, such as those made from thin film amorphous silicon (a-Si:H), also suffer specific losses in performance due to fundamental material changes, such as photodegradation or the Staebler–Wronski effect (SWE). A field evaluation of the long term performance of state-of-the-art crystalline and amorphous silicon photovoltaic modules in Australian conditions is currently being undertaken at Murdoch University. The initial results from this monitoring program are reported. This paper also reports on laboratory and field studies being undertaken on the nature of the Staebler–Wronski effect in amorphous silicon solar cells and how the stability of these cells is affected by different operating conditions. Based on a mechanism for the SWE in a-Si:H solar cells developed as a result of our research we propose a number of possible ways to reduce the Staebler–Wronski effect in a-Si:H solar cells.