SOME IMPLICATIONS OF RESEARCH ON MOTION TIME PATTERNS

The ratio of motion times in a repetitive manual operation has been shown to vary with degree of skill and working pace, and to be less stable when the pace is controlled than when the worker is free to give his own ‘natural’ unpaced performance

It is suggested that these findings draw into question the validity of techniques used to establish systems of motion time standards and the inclusion of paced sequences in performance rating films.     

Commercially Available Rapid Methods for Detection of Selected Food-borne Pathogens

Generally, the enumeration and isolation of food-borne pathogens is performed using culture-dependent methods. These methods are sensitive, inexpensive, and provide both qualitative and quantitative assessment of the microorganisms present in a sample, but these are time-consuming. For this reason, researchers are developing new techniques that allow detection of food pathogens in shorter period of time. This review identifies commercially available methods for rapid detection and quantification of Listeria monocytogenes, Salmonella spp., Staphylococcus aureus, and Shiga toxin-producing Escherichia coli in food samples. Three categories are discussed: immunologically based methods, nucleic acid-based assays, and biosensors. This review describes the basic mechanism and capabilities of each method, discusses the difficulties of choosing the most convenient method, and provides an overview of the future challenges for the technology for rapid detection of microorganisms.     

Future emissions and atmospheric fate of HFC-1234yf from mobile air conditioners in Europe

HFC-1234yf (2,3,3,3-tetrafluoropropene) is under discussion for replacing HFC-134a (1,1,1,2-tetrafluoroethane) as a cooling agent in mobile air conditioners (MACs) in the European vehicle fleet. Some HFC-1234yf will be released into the atmosphere, where it is almost completely transformed to the persistent trifluoroacetic acid (TFA). Future emissions of HFC-1234yf after a complete conversion of the European vehicle fleet were assessed. Taking current day leakage rates and predicted vehicle numbers for the year 2020 into account, European total HFC-1234yf emissions from MACs were predicted to range between 11.0 and 19.2 Gg yr(-1). Resulting TFA deposition rates and rainwater concentrations over Europe were assessed with two Lagrangian chemistry transport models. Mean European summer-time TFA mixing ratios of about 0.15 ppt (high emission scenario) will surpass previously measured levels in background air in Germany and Switzerland by more than a factor of 10. Mean deposition rates (wet + dry) of TFA were estimated to be 0.65-0.76 kg km(-2) yr(-1), with a maxium of ～2.0 kg km(-2) yr(-1) occurring in Northern Italy. About 30-40% of the European HFC-1234yf emissions were deposited as TFA within Europe, while the remaining fraction was exported toward the Atlantic Ocean, Central Asia, Northern, and Tropical Africa. Largest annual mean TFA concentrations in rainwater were simulated over the Mediterranean and Northern Africa, reaching up to 2500 ng L(-1), while maxima over the continent of about 2000 ng L(-1) occurred in the Czech Republic and Southern Germany. These highest annual mean concentrations are at least 60 times lower than previously determined to be a safe level for the most sensitive aquatic life-forms. Rainwater concentrations during individual rain events would still be 1 order of magnitude lower than the no effect level. To verify these results future occasional sampling of TFA in the atmospheric environment should be considered. If future HFC-1234yf emissions surpass amounts used here studies of TFA accumulation in endorheic basins and other sensitive areas should be aspired.     

Short communication: the complete genome sequence of Bifidobacterium animalis subspecies animalis ATCC 25527(T) and comparative analysis of growth in milk with B. animalis subspecies lactis DSM 10140(T)

The objective of this work was to sequence the genome of Bifidobacterium animalis ssp. animalis ATCC 25527^T, the subspecies most closely related to B. animalis ssp. lactis, some strains of which are widely added to dairy foods as probiotics. The complete 1,932,963-bp genome was determined by a combination of 454-shotgun sequencing and PCR gap closing, and the completed assembly was verified by comparison with a KpnI optical map. Comparative analysis of the B. animalis ssp. animalis ATCC 25527^T and B. animalis ssp. lactis DSM 10140^T genomes revealed high degrees of synteny and sequence homology. Comparative genomic analysis revealed 156 and 182 genes that were unique to and absent in the B. animalis ssp. animalis genome, respectively. Among these was a set of unique clustered regularly interspaced short palindromic repeats (CRISPR)-associated genes and a novel CRISPR locus containing 30 spacers in the genome of B. animalis ssp. animalis. Although previous researchers have suggested that one of the defining phenotypic differences between B. animalis ssp. animalis and B. animalis ssp. lactis is the ability of the latter to grow in milk and milk-based media, the differential gene content did not provide insights to explain these differences. Furthermore, growth and acid production in milk and milk-based media did not differ significantly between B. animalis ssp. lactis (DSM 10140^T and Bl04) and B. animalis ssp. animalis (ATCC 25527^T). Growth of these strains in supplemented milk suggested that growth was limited by a lack of available low-molecular-weight nitrogen in the 3 strains examined.     

Experimental neutron spectroscopy data visualization: adaptive tessellation algorithm

We report on an adaptive binning approach designed for data visualization within scientific disciplines where counting statistics are expected to follow Poisson distributions. We envisage a wide range of applications stemming from astrophysics to the condensed matter sciences. Our main focus of interest concerns, however, neutron spectroscopy data from single-crystal samples where signals span a four-dimensional space defined by three spatial coordinates plus time. This makes widely used equal-width binning schemes inadequate since physically relevant information is often concentrated within rather small regions of such a space. Our aim is thus to generate optimally binned data sets from one-dimensional to three-dimensional volumes to provide the experimentalist with enhanced ability to carry out searches within a four-dimensional space. Several binning algorithms are then scrutinized against experimental as well as simulated data.     

Lenticel blotch pit,watercore, splitting and cracking in relation to calcium concentration in the apple fruit

Analyses of apples, of various varieties and from many sources, affected by lenticel blotch pit and/or watercore showed that calcium concentrations in the fruit were usually extremely low. The severity of lenticel blotch pit, either on the tree or during storage, increased with decreasing concentrations of calcium and/or increasing concentrations of potassium. Split and cracked apples had lower concentrations of calcium or higher concentrations of potassium than sound fruit from the same sources. The disorders usually occurred when mean concentrations of calcium in bulked random samples of fruit fell below 4 mg 100 g^?1 fresh wt and lenticel spotting was noted on apples with concentrations at this level. Incidences of these disorders in the orchard therefore indicate that the fruit is likely to develop bitter pit and breakdown during storage.