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.     

Quasi‐in‐situ observations of the sintering behaviour of molybdenum‐alloyed sintered steels

The sintering behaviour of molybdenum pre‐alloyed sintered steels was investigated. A scanning electron microscope with a hot stage attachment was used, enabling quasi‐in‐situ observations of the sintering process. The material MSP 1.5Mo (Fe‐1.5% Mo) sinters in the austenitic phase, while MSP 3.5Mo (Fe‐3.5% Mo) sinters completely in the ferritic phase, due to the increased molybdenum mass content. The significantly higher self‐diffusion coefficient of iron in the ferritic phase leads to the accelerated sintering of MSP 3.5Mo, compared to MSP 1.5Mo. The effect on the sintering behaviour by adding the alloying elements chromium and phosphorus was also studied. While phosphorus accelerates sintering processes, chromium decreases the sintering rate. A pronounced shrinkage during non‐isothermal heating, due to cooperative particle movement, was detected for both sintered steels.     

Sputtered cathodes for polymer electrolyte fuel cells: insights into potentials, challenges and limitations

The level of Pt loadings in polymer electrolyte fuel cells (PEFC) is still one of the main hindrances for implementation of PEFCs into the market. Therefore, new catalyst and electrode preparation methods such as sputtering are of current interest, because they allow thin film production and have many cost saving advantages for electrode preparation. This paper summarises some of the most important studies done for sputtered PEFCs, including non carbon supported electrodes. Furthermore, it will be shown that an understanding of the main morphological differences between sputtered and ink-based electrodes is crucial for a better understanding of the resulting fuel cell performance. Especially, the electrochemical surface area (ECSA) plays a key role for a further increase in PEFC performance of sputtered electrodes. The higher surface specific activities i(k,spec) of sputtered compared to ink-based electrodes will be discussed as advantage of the thin film formation. The so- called particle size effect, known in literature for several years, will be discussed as reason for the higher i(k,spec) of sputtered electrodes. Therefore, a model system on a rotating disc electrode (RDE) was studied. For sputtered PEFC cathodes Pt loadings were lowered to 100 μg(Pt)/cm(2), yet with severe performance losses compared to ink-based electrodes. Still, for Pt sputtered electrodes on a carbon support structure remarkably high current densities of 0.46 A/cm(2) at 0.6 V could be achieved.     

Synthesis of water-soluble cellulose esters applying carboxylic acid imidazolides

Water-soluble, non-ionic cellulose esters with a degree of substitution in the range from 0.11 to 3.0 were synthesized homogeneously using ionic liquids (1-butyl-3-methylimidazolium chloride, 1-ethyl-3-methylimidazolium chloride, and 1-allyl-3-methylimidazolium chloride) as reaction medium. Highly substituted 3,6,9-trioxadecanoic acid esters and 3,6-dioxaheptanoic acid esters of cellulose were obtained via the activation of the carboxylic acids with N,N’-carbonyldiimidazole. The products were characterized by the means of FTIR-, ¹H- and ¹³C NMR spectroscopy.     

Influence of the type of gelatinized starch on the soiling of stainless steel

Quality assurance of cleaning procedures is important as regards production efficiency, food safety and food quality. Model routines for the assessment of cleaning methods require that materials can be fouled in a reliable manner. The present study was performed to demonstrate that a reproducible soiling of stainless steel can be achieved as long as the flow characteristics of the soiling fluid (i.e., different types of gelatinized starch) and specific aspects of the corresponding procedure for the quantification of soil residues are considered.     

A note on the validity and reliability of ergonomics methods

The view that, by analogy, ergonomics methods should be subject to the same requirements of validity and reliability as are demanded of psychometric tests is shown to be an oversimplification. Two broad classes of method are distinguished. Analytic methods aim to produce a better understanding of the processes affecting complex human-machine systems, whilst evaluative methods are limited to the measurement of specific variables. The analogy with psychometrics applies to the latter type but is less appropriate to the former. Analytic methods depend heavily on the application of currently accepted theories of performance. Empirical data may be variable, but the expertise of the analyst may be more to blame than the method as such.     

Drawing as a generative activity and drawing as a prognostic activity.

In this study, 9th-grade students (N = 196) with a mean age of 14.7 years read a scientific text explaining the chemical process of doing laundry with soap and water and then took 3 tests. Students who were instructed to generate drawings during learning scored higher than students who only read on subsequent tests of transfer (d = 0.91), retention (d = 0.87), and drawing (d = 2.00). For students who were instructed to generate drawings during learning, those who generated high-accuracy drawings (according to a median split) scored higher than students who generated low-accuracy drawings on subsequent tests of transfer (d = 0.99), retention (d = 0.79), and drawing (d = 1.87); furthermore, drawing-accuracy scores during learning correlated with learning-outcome scores on transfer (r = .57), retention (r = .50), and drawing (r = .82). Results suggest that drawing can serve as a generative activity and as a prognostic activity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Backings and targets for chemical and nuclear studies of transactinides with TASCA

At GSI the gas-filled separator TASCA (TransActinide Separator and Chemistry Apparatus) was set up to investigate the chemical and physical properties of the heaviest elements making use of the highest beam intensities available [www.gsi.de/tasca; M. Schädel, D. Ackermann, A. Semchenkov, A. Türler, GSI Scientific Report 2005, GSI Report 2006-1, p. 262]. Appropriate backings and targets have to be developed.Conceivable backing materials are aluminium, titanium, and carbon. Aluminium backings and titanium backings in different thickness and from different companies are produced by cold rolling. Deposition by resistance heating is applied for carbon backings. For experiments in a chemically active atmosphere, beryllium has to be employed as backing, which is commercially available and produced by cold rolling.The task is to find the best material and thickness for backings to withstand two different processes: the electrodeposition, applied for the production of lanthanide and actinide targets at the Institut für Kernchemie, at the Universität Mainz [K. Eberhardt, et al., Contribution to this conference; D. Liebe, et al., Contribution to this conference], on the one hand, and deposition by thermal evaporation and sputtering on the other.We report on first tests with targets of uranium tetrafluoride (UF₄) and metallic uranium on various backings. In addition, the behaviour and durability will be described for the different backing–target combinations in a C-beam and in an Mg beam. For the upcoming beam time U, ²⁰⁸PbS, ¹⁴⁴Sm, ¹⁵⁴Sm, and Gd are required.