Lack of consensus among competency ratings of the same occupation: Noise or substance?

Although rating differences among incumbents of the same occupation have traditionally been viewed as error variance in the work analysis domain, such differences might often capture substantive discrepancies in how incumbents approach their work. This study draws from job crafting, creativity, and role theories to uncover situational factors (i.e., occupational activities, context, and complexity) related to differences among competency ratings of the same occupation. The sample consisted of 192 incumbents from 64 occupations. Results showed that 25% of the variance associated with differences in competency ratings of the same occupation was related to the complexity, the context, and primarily the nature of the occupation's work activities. Consensus was highest for occupations involving equipment-related activities and direct contact with the public. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The response of the BTI bubble detectors in mixed gamma-neutron workplace fields

Bubble detectors have become a mature technology and are used as neutron dosemeters in a wide range of applications. At the SCK-CEN and Belgonucléaire they are used as official personal neutron dosemeter for the personnel. In the European Commission (EC) project of Evaluation of Individual Dosimetry in Mixed Neutron and Photon Radiation Fields (EVIDOS), a whole range of neutron dosemeters were irradiated in workplace fields in nuclear installations in Europe, including two types of bubble detectors. The responses of the bubble detectors are compared with the reference values determined using a directional spectrometer and a reference instrument to measure Hp(10).     

Studies on the development of a quick inertness test procedure for multi-use PET containers—sorption behaviour of bottle wall strips

This study is part of a larger project aimed at establishing criteria to ensure the quality and safety-in-use of recycled and re-used plastics for food packaging. A major concern is that plastic materials can interact with chemicals to a greater or lesser extent. As a consequence, refillable containers may be contaminated by migration of harmful substances into the plastic material due to misuse by consumers before return. On the other hand, there is currently neither any specific national or EU regulation nor a standard test available which could be applied by industry or enforcement laboratories to meet this situation appropriately. In this study, a relative simple inertness test which focuses on the interaction of PET bottle wall strips with a selection of model contaminants was investigated. The model contaminants were selected to include four different sets of chemical functional classes (set A, alcohol-type compounds; B, ester/ketone type compounds; set C, hydrocarbon-type compounds; set D, chlorinated hydrocarbons). A simple gas chromatographic method using flame ionization detection was developed to allow quantification of the whole range of model contaminants. Linearity and reproducibility of the calibration curves for all contaminants were excellent, which indicates the validity and efficacy of the proposed methodology. The sorption experiments with PET bottle wall strips showed that significant amounts of chemicals can be absorbed into the plastic material if misused, thus establishing a remigration potential in the bottle material after refilling. © 1997 John Wiley & Sons, Ltd.     

Impact of wood species on microbial community composition,beer chemistry and sensory characteristics during barrel-ageing of beer

Barrel-ageing of conventionally fermented beers is becoming increasingly popular in recent years, but only very little is known about the underlying process. In this study, we show that wood species significantly affects the bacterial community composition, beer chemistry and sensory characteristics throughout 38 weeks of barrel-ageing. Whereas the microbial communities of oak- and acacia-aged beer became dominated by Pediococcus damnosus and Brettanomyces bruxellensis, beer aged in oak barrels also contained a large fraction of Acetobacter sp. (29.34%) and to a lesser extent Paenibacillus sp. (2.74%) that were almost undetected in acacia-aged beer. Oak barrels also imparted substantial concentrations of eugenol, lactones and vanillin, while acacia-aged beer contained high concentrations of total polyphenols and β-glucan, which also translated into different sensory perceptions. Altogether, our results provide novel insights into the barrel-ageing process of beer, and may pave the way for a new generation of beers with a noteworthy flavour complexity.     

Four new SYBR<Superscript>®</Superscript>Green qPCR screening methods for the detection of Roundup Ready<Superscript>®</Superscript>, LibertyLink<Superscript>®</Superscript>, and CryIAb traits in genetically modified products

SYBR^®Green qPCR methods for the detection of the Roundup Ready^® “CP4-EPSPS”, LibertyLink^® “PAT” and “BAR,” and the Bacillus thuringiensis “CryIAb” traits as present in genetically modified organisms (GMO) were developed. Their specificity, sensitivity, and PCR method efficiency were determined. All methods are specific and generate amplicons of 108, 73, 109, and 69 bp, respectively, for “CP4-EPSPS,” “CryIAb,” “PAT,” and “BAR” targets. They perform well at low target levels and can detect down to 5 copies of their respective targets extracted from a sample. The PCR efficiency of the methods ranges between 91 and 109%. Due to their trait-specific nature, these methods allow an efficient screening between the different GMO. In this way, the number of possible GMO candidates present in a sample can be reduced what results in lower global costs due to limiting of further the number of analytical identification steps. The application of these methods in CoSYPS GMO analysis is illustrated using two GEMMA proficiency test samples and a reference material from the GM rapeseed event RF3. This set of SYBR^®Green qPCR trait-specific methods represents a very interesting novel set of GMO analysis methods allowing cost-effective identification of GM materials in products.     

Development of a DNA Array for the Simultaneous Detection and Identification of Sugar Thick Juice Bacterial Contaminants

Despite the use of generally accepted good storage practices, sugar thick juice degradation caused by microbiological contamination occasionally occurs, causing considerable financial loss. In this study, a DNA array was developed for simultaneous detection and identification of the most prominent microflora present during thick juice storage, which may cause degradation of the thick juice. Specific oligonucleotides were developed for several bacterial taxa, including the genera Bacillus, Kocuria, Staphylococcus and Tetragenococcus and the species Aerococcus viridans, Leuconostoc mesenteroides and Tetragenococcus halophilus. The DNA array was validated using both pure cultures and industrial samples. In addition, comparisons were made between the developed array, PCR assays specifically targeting the thick juice contaminants and classical microbial platings. The array was found to be reliable and sensitive enough to detect and identify the target bacteria. In addition, the array was used to monitor the target microbial populations in thick juice during long-term storage and degradation. Results are discussed in relation to DNA stability in thick juice.     

Toward an on-line characterization of kaolin calcination process using short-wave infrared spectroscopy

ABSTRACT

In the production of calcined kaolin, the on-line monitoring of the calcination reaction is becoming more relevant for the generation of optimal products. In this context, this study aimed to assess the suitability of using infrared (IR) spectroscopy as a potential technique for the on-line characterization of the calcination of kaolin. The transformation of kaolin samples calcined at different temperatures were characterized in the short-wave (SWIR) spectra using the kaolinite crystallinity (Kx) index and the depth of the water spectral feature (1900D). A high correlation between the standard operational procedure for the quality control of calcined kaolin and the Kx index was observed (r = -0.89), as well as with the 1900D parameter (r = -0.96). This study offers a new conceptual approach to the use of SWIR spectroscopy for the characterization the calcination of kaolin, withdrawing the need of using extensive laboratory techniques.     

Assessing the xylanolytic bacterial diversity during the malting process

The presence of microorganisms producing cell wall hydrolyzing enzymes such as xylanases during malting can improve mash filtration behavior and consequently have potential for more efficient wort production. In this study, the xylanolytic bacterial community during malting was assessed by isolation and cultivation on growth media containing arabinoxylan, and identification by 16S rRNA gene sequencing. A total of 33 species-level operational taxonomic units (OTUs) were found, taking into account a 3% sequence dissimilarity cut-off, belonging to four phyla (Actinobacteria, Bacteroidetes, Firmicutes and Proteobacteria) and 25 genera. Predominant OTUs represented xylanolytic bacteria identified as Sphingobacterium multivorum, Stenotrophomonas maltophilia, Aeromonas hydrophila and Pseudomonas fulva. DNA fingerprinting of all xylanolytic isolates belonging to S. multivorum obtained in this study revealed shifts in S. multivorum populations during the process. Xylanase activity was determined for a selection of isolates, with Cellulomonas flavigena showing the highest activity. The xylanase of this species was isolated and purified 23.2-fold by ultrafiltration, 40% ammonium sulfate precipitation and DEAE-FF ion-exchange chromatography and appeared relatively thermostable. This study will enhance our understanding of the role of microorganisms in the barley germination process. In addition, this study may provide a basis for microflora management during malting.     

Dose reconstruction using mobile phones

Electronic components inside mobile phones are regarded as useful tools for accident and retrospective dosimetry using optically stimulated luminescence (OSL) and thermoluminescence. Components inside the devices with suitable properties for luminescence dosimetry include, amongst others, ceramic substrates in resistors, capacitors, transistors and antenna switches. Checking the performance of such devices in dosimetric experiments is a crucial step towards developing a reliable dosimetry system for emergency situations using personal belongings. Here, the results of dose assessment experiments using irradiated mobile phones are reported. It will be shown that simple regenerative dose estimates, derived from various types of components removed from different mobile phone models, are consistent with the given dose, after applying an average fading correction factor.     

Simultaneous catalytic esterification of carboxylic acids and acetalisation of aldehydes in a fast pyrolysis bio-oil from mallee biomass

This paper reports the simultaneous catalytic esterification and acetalisation of a bio-oil with methanol using a commercial Amberlyst-70 catalyst at temperatures between 70 and 170 °C. The bio-oil was prepared from the pyrolysis of mallee woody biomass in a fluidised-bed pyrolysis reactor under the fast heating rate conditions. Our results show that the conversion of light organic acids and aldehydes to esters and acetals rises significantly with increasing temperature, reaction time and catalysts loading. However, some acetals (e.g. dimethoxymethane) could decompose at higher operating temperatures (>110 °C) and catalyst loadings (>6 wt.%). The medium and heavy fractions of bio-oil also reacted with methanol to result in increases in their volatility (or decreases in boiling points) when their reactive O-containing functional groups were stabilised. The acid-catalysed reactions between bio-oil and methanol also decreased the coking propensity of the bio-oil reaction products.