Method and data evaluation at NASA endocrine laboratory

The biomedical data of the astronauts on Skylab 3 were analyzed to evaluate the univariate statistical methods for comparing endocrine series experiments in relation to other medical experiments. It was found that an information storage and retrieval system was needed to facilitate statistical analyses

A robust method for measurement of fluctuation parallel wavenumber in laboratory plasmas

Measuring the parallel wavenumber is fundamental for the experimental characterization of electrostatic instabilities. It becomes particularly important in toroidal geometry, where spatial inhomogeneities and curvature can excite both drift instabilities, whose wavenumber parallel to the magnetic field is finite, and interchange instabilities, which typically have vanishing parallel wavenumber. We demonstrate that multipoint measurements can provide a robust method for the discrimination between the two cases

Gas phase homolytic bond dissociation enthalpies of common laboratory solvents: A G4 theoretical study

Gas phase standard state (298.15 K, 1 atm) calculations were conducted at the Gaussian-4 (G4) composite method level of theory to estimate the bond dissociation enthalpies (BDEs) of various common laboratory solvents. Excellent agreement was obtained between experimental and G4 estimated BDEs. The current study demonstrates the BDE prediction accuracy of the G4 method, and is also intended to function as a potentially useful resource in any reevaluations of the preferred BDEs for these common laboratory solvents

Review of the AGARD S and M panel evaluation program of the NASA-Lewis SRP approach to high-temperature LCF life prediction

Twenty laboratories in six countries participated in testing their own materials of interest under their own laboratory conditions. In this way the results obtained provided validation of the Strainrange Partitioning (SRP) method for a wide range of materials and insured maximum usefulness to each of the participating laboratories. The various investigators shared their findings, thus providing the basis for an in-depth evaluation of the SRP method. While the results were variable from laboratory to laboratory, most investigators agreed that the SRP method was a significant step toward life prediction in the presence of high temperature and cyclic stresses

A laboratory method for precisely determining the micro-volume-magnitudes of liquid efflux

Micro-volumetric quantities of ejected liquid are made to produce equal volumetric displacements of a more dense material. Weight measurements are obtained on the displaced heavier liquid and used to calculate volumes based upon the known density of the heavy medium

Gene doctoring: a method for recombineering in laboratory and pathogenic Escherichia coli strains

Background: Homologous recombination mediated by the lambda-Red genes is a common method for making chromosomal modifications in Escherichia coli. Several protocols have been developed that differ in the mechanisms by which DNA, carrying regions homologous to the chromosome, are delivered into the cell. A common technique is to electroporate linear DNA fragments into cells. Alternatively, DNA fragments are generated in vivo by digestion of a donor plasmid with a nuclease that does not cleave the host genome. In both cases the lambda-Red gene products recombine homologous regions carried on the linear DNA fragments with the chromosome. We have successfully used both techniques to generate chromosomal mutations in E. coli K-12 strains. However, we have had limited success with these lambda-Red based recombination techniques in pathogenic E. coli strains, which has led us to develop an enhanced protocol for recombineering in such strains. \ud \ud Results: Our goal was to develop a high-throughput recombineering system, primarily for the coupling of genes to epitope tags, which could also be used for deletion of genes in both pathogenic and K-12 E. coli strains. To that end we have designed a series of donor plasmids for use with the lambda-Red recombination system, which when cleaved in vivo by the I-SceI meganuclease generate a discrete linear DNA fragment, allowing for C-terminal tagging of chromosomal genes with a 6xHis, 3xFLAG, 4xProteinA or GFP tag or for the deletion of chromosomal regions. We have enhanced existing protocols and technologies by inclusion of a cassette conferring kanamycin resistance and, crucially, by including the sacB gene on the donor plasmid, so that all but true recombinants are counter-selected on kanamycin and sucrose containing media, thus eliminating the need for extensive screening. This method has the added advantage of limiting the exposure of cells to the potential damaging effects of the lambda-Red system, which can lead to unwanted secondary alterations to the chromosome. \ud \ud Conclusion: We have developed a counter-selective recombineering technique for epitope tagging or for deleting genes in E. coli. We have demonstrated the versatility of the technique by modifying the chromosome of the enterohaemorrhagic O157:H7 (EHEC), uropathogenic CFT073 (UPEC), enteroaggregative O42 (EAEC) and enterotoxigenic H10407 (ETEC) E. coli strains as well as in K-12 laboratory strains

Effect of moisture on mechanical behavior of granular material in initial laboratory and mechanical tests

In this article authors present results of initial laboratory tests and further numerical analyses using finite element method (FEM) and back - calculation method. Laboratory tests are based on trial loadings of granular material in different moisture conditions. Numerical analyses were obtained in FEM software using Coulomb - Mohr model of tested material. Presented results are the part of wider research program in which the main aim is to evaluate the influence of variable moisture content of granular materials used in road pavement structures on their fatigue life and in Life Cycle Assessment (LCA)

The formation of catechists through a laboratory

This article seeks to show how the on-going formation of catechists can be more adapted to the contemporary needs of catechists. Today, we can no longer speak of a homogeneous society which encounters the same difficulties and problems. On the other hand, our society is characterised by fluidity and constant change. The laboratory as a method for the on-going formation of catechists seeks to actively meet this demand. The laboratory as a method for the formation of catechists is undergirded by characteristics and advantages over and above the other traditional methods of catechist formation which clearly make it the preferred method for the on-going formation of catechists today. These characteristics and advantages are explored in the text.peer-reviewe

Evaluation of Prepackaged Kits

Prepackaged laboratory kits for performing diagnostic procedures are frequently the most suitable alternative in the selection of laboratory methods, especially in the physicians\u27 offices and small laboratories. Because of the previous lack of governmental regulations covering the manufacture of kits, many kits now on the market do not perform adequately and may produce misleading results. Each laboratory must evaluate each type of kit before it is put into routine use. This evaluation should include a review of published experimental data, comparison of results using the kit to results using a reference method and an experimental evaluation of the kit in the laboratory in which it is to be used