Retention of a standard operating procedure under the influence of social stress and refresher training in a simulated process control task

In a simulated process control task, we investigated the effects of refresher training and acute social stress on performing a standard operating procedure (SOP) containing a production and monitoring task and knowledge recall after a retention interval of two weeks. In a 2?×?2 between-group design (Factor 1: induced social stress, Factor 2: refresher training), 76 engineering students performed an SOP at t1 in week 1 and at t2 in week 3. A MANOVA in week three (t2) indicated a main effect of the refresher training for the SOP execution containing a production and a monitoring task and an impairing effect of stress on the monitoring task. That means that after a retention interval, stress mainly affects the SOP’s monitoring task. An additional correlational analysis showed that knowledge test performance is negatively associated with cortisol level and that retentivity is a strong predictor for knowledge test performance and production task performance, too.

Practitioner Summary: We investigated effects of social stress and refresher training on performing a standard operating procedure (SOP) after a retention interval of two weeks. The impact of social stress reduced the monitoring task performance as part of the SOP, but not the production outcome. Without refresher training, performance is significantly worse.

Abbreviation: SOP: Standard Operating Procedure; MANOVA: Multivariate Analysis of Variance; CSB: Chemical Safety and Hazard Investigation Board; TSST: Trierer Social Stress Test; P-TSST: Placebo Trierer Social Stress Test; WaTrSim: Water Treatment Simulation; HPA axis: hypothalamic pituitary adrenal axis; WIT-2: Wilde Intelligenztest – 2; SPSS: Statistical Package for the Social Sciences; ANOVA: Analysis of Variance.     

Artificial neural network study of whole-cell bacterial bioreporter response determined using fluorescence flow cytometry

Genetically engineered bioreporters are an excellent complement to traditional methods of chemical analysis. The application of fluorescence flow cytometry to detection of bioreporter response enables rapid and efficient characterization of bacterial bioreporter population response on a single-cell basis. In the present study, intrapopulation response variability was used to obtain higher analytical sensitivity and precision. We have analyzed flow cytometric data for an arsenic-sensitive bacterial bioreporter using an artificial neural network-based adaptive clustering approach (a single-layer perceptron model). Results for this approach are far superior to other methods that we have applied to this fluorescent bioreporter (e.g., the arsenic detection limit is 0.01 microM, substantially lower than for other detection methods/algorithms). The approach is highly efficient computationally and can be implemented on a real-time basis, thus having potential for future development of high-throughput screening applications.     

Grazing effects on the greenhouse gas balance of a temperate steppe ecosystem

Although a significant fraction of the global soil?Catmosphere exchange of greenhouse gases (GHGs) occurs in semi-arid zones little is known about the magnitude of fluxes in grazed steppe ecosystems and the interference with grazing intensity. In order to assess GHG burdens and to identify options of climate-optimized livestock farming, GHG emissions of sheep grazing in Inner Mongolia steppe were analyzed. Carbon sequestration and field-fluxes of methane (CH₄) and nitrous oxide (N₂O) were measured at a range of steppe sites differing in grazing intensity and management, i.e. ungrazed (UG), ungrazed with hay cutting (HC), lightly grazed (LG), moderately grazed (MG), and heavily grazed (HG). In addition, GHG emissions from enteric fermentation, manure management, and farming inputs (i.e. fossil fuels) were quantified for LG, MG, and HG. Monte Carlo simulation was used to estimate uncertainty. Sheep grazing changed the net GHG balance of the steppe from a significant sink at UG (?1476?±?2481?kg CO_2eq ha^?1?year^?1) to a significant source at MG (2350?±?1723?kg CO_2eq ha^?1?year^?1) and HG (3115?±?2327?kg CO_2eq ha^?1?year^?1). In a similar way, the GHG intensity increased from 8.6?±?79.2?kg CO_2eq?kg^?1 liveweight gain at LG up to 62.2?±?45.8 and 62.6?±?46.7?kg CO_2eq?kg^?1 liveweight gain at MG and HG, respectively. GHG balances were predominantly determined by CO₂ from changes in topsoil organic carbon. In grazing systems, CH₄ from enteric fermentation was the second most important component. The results suggest that sheep grazing under the current management changes this steppe ecosystem from a sink to a source of GHGs and that grazing exclusion holds large potential to restore soil organic carbon stocks and thus to sequester atmospheric CO₂. The balance between grazing intensity and grazing exclusion predominantly determines GHG balances of grass-based sheep farming in this region. Therefore, a high proportion of ungrazed land is most important for reducing GHG balances of sheep farms. This can be either achieved by high grazing intensity on the remaining grazed land or by confined hay feeding of sheep.     

Norovirus outbreak in a restaurant: investigation of the path of infection by sequence analysis of food and human samples

In September 2014, a small gastroenteritis outbreak occurred in a Greek restaurant. Primary investigations by official food surveillance revealed significant hygienic problems in the premises. Food samples and environmental samples were analyzed for the presence of bacterial and viral food pathogens. Norovirus genogroup I (GI) was detected in 2 environmental samples and in mixed salad. At the same time, stool samples from patients were analyzed and norovirus GI was detected. Further investigations revealed the presence of norovirus GI on some of the restaurant employees. Comparison of nucleic acid sequences revealed full sequence homology between norovirus RNA genotype 1.2 in food, environmental and stool samples, suggesting a common source of contamination and infection. Sequence analysis of food and environmental samples was facilitated by application of a system for total RNA amplification. Despite the fact that original source of contamination could be determined doubtlessly, observed weaknesses in the food production that caused this outbreak were discussed. The mixed salad could have been contaminated either by the lettuce contaminated at primary production or by one of the food-handlers. The investigation of the path of infection is necessary for the kind of legal consequences to be directed by authorities and may contribute to measures to eliminate possible sources of food contamination.     

Plant Sterol-Poor Diet Is Associated with Pro-Inflammatory Lipid Mediators in the Murine Brain

Plant sterols (PSs) cannot be synthesized in mammals and are exclusively diet-derived. PSs cross the blood-brain barrier and may have anti-neuroinflammatory effects. Obesity is linked to lower intestinal uptake and blood levels of PSs, but its effects in terms of neuroinflammation—if any—remain unknown. We investigated the effect of high-fat diet-induced obesity on PSs in the brain and the effects of the PSs campesterol and β-sitosterol on in vitro microglia activation. Sterols (cholesterol, precursors, PSs) and polyunsaturated fatty acid-derived lipid mediators were measured in the food, blood, liver and brain of C57BL/6J mice. Under a PSs-poor high-fat diet, PSs levels decreased in the blood, liver and brain (>50%). This effect was reversible after 2 weeks upon changing back to a chow diet. Inflammatory thromboxane B2 and prostaglandin D2 were inversely correlated to campesterol and β-sitosterol levels in all brain regions. PSs content was determined post mortem in human cortex samples as well. In vitro, PSs accumulate in lipid rafts isolated from SIM-A9 microglia cell membranes. In summary, PSs levels in the blood, liver and brain were associated directly with PSs food content and inversely with BMI. PSs dampen pro-inflammatory lipid mediators in the brain. The identification of PSs in the human cortex in comparable concentration ranges implies the relevance of our findings for humans.     

Quantification of pathogenic microorganisms and microbial indicators in three wastewater reclamation and managed aquifer recharge facilities in Europe

Managed Aquifer Recharge (MAR) is becoming an attractive option for water storage in water reuse processes as it provides an additional treatment barrier to improve recharged water quality and buffers seasonal variations of water supply and demand. To achieve a better understanding about the level of pathogenic microorganisms and their relation with microbial indicators in these systems, five waterborne pathogens and four microbial indicators were monitored over one year in three European MAR sites operated with reclaimed wastewater. Giardia and Cryptosporidium (oo)cysts were found in 63.2 and 36.7% of the samples respectively. Salmonella spp. and helminth eggs were more rarely detected (16.3% and 12.5% of the samples respectively) and Campylobacter cells were only found in 2% of samples. At the Belgian site advanced tertiary treatment technology prior to soil aquifer treatment (SAT) produced effluent of drinking water quality, with no presence of the analysed pathogens. At the Spanish and Italian sites amelioration of microbiological water quality was observed between the MAR injectant and the recovered water. In particular Giardia levels decreased from 0.24-6.14 cysts/L to 0-0.01 cysts/L and from 0.4-6.2 cysts/L to 0-0.07 cysts/L in the Spanish and Italian sites respectively. Salmonella gene copies and Giardia cysts were however found in the water for final use and/or the recovered groundwater water at the two sites. Significant positive Spearman correlations (p < 0.05, r_s range: 0.45-0.95) were obtained, in all the three sites, between Giardia cysts and the most resistant microbial markers, Clostridium spores and bacteriophages.     

Complexity of ultrafiltration membrane fouling caused by macromolecular dissolved organic compounds in secondary effluents

Recent investigations indicate the relevance of extracellular polymeric substances (EPS) in terms of fouling of low-pressure membranes in advanced wastewater treatment. In this study, the high impact of the macromolecular fraction of effluent organic matter on fouling was confirmed in cross-flow ultrafiltration experiments using secondary effluent with and without autochthonous biopolymers. A method for the extraction of a natural mixture of EPS derived from the bacterium Sinorhizobium sp. is presented. Ultrafiltration of solutions of this bacterial EPS extract revealed a correlation between the concentration of EPS and the loss of permeate flux. However, in ultrafiltration tests using extracted bacterial EPS in a model solution as well as in secondary effluent without autochthonous biopolymers, the extent of membrane fouling was not identical with the fouling provoked by secondary effluent organic matter, although the biopolymer concentrations were comparable. The differences in the fouling behaviour of the extracted bacterial EPS and effluent organic matter are considered to be due to different compositions of the biopolymer fraction in terms of proteins, polysaccharides, and other organic colloids, indicating a particular impact of proteins on ultrafiltration membrane fouling.     

Audiovisual asynchrony detection in human speech.

Combining information from the visual and auditory senses can greatly enhance intelligibility of natural speech. Integration of audiovisual speech signals is robust even when temporal offsets are present between the component signals. In the present study, we characterized the temporal integration window for speech and nonspeech stimuli with similar spectrotemporal structure to investigate to what extent humans have adapted to the specific characteristics of natural audiovisual speech. We manipulated spectrotemporal structure of the auditory signal, stimulus length, and task context. Results indicate that the temporal integration window is narrower and more asymmetric for speech than for nonspeech signals. When perceiving audiovisual speech, subjects tolerate visual leading asynchronies, but are nevertheless very sensitive to auditory leading asynchronies that are less likely to occur in natural speech. Thus, speech perception may be fine-tuned to the natural statistics of audiovisual speech, where facial movements always occur before acoustic speech articulation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)