Homogeneity of wheat flour in 5ml containers for certified reference materials.

We aimed to develop certified reference materials that could be used for well-type HPGe detector. We chose wheat flour as a sample and evaluated the homogeneity of the sample in well-type container (5ml). Results showed that inhomogeneity was sufficiently small for validation checks of well-type HPGe detector (uhom = 0.44%).

Proficiency testing with uncertainty evaluation for measuring activities per unit mass of 134Cs and 137Cs in brown rice in Japan.

In Japan, we conducted proficiency testing of activity measurement by using high-purity germanium detectors for 134Cs and 137Cs in brown rice grains. Among 176 reported results, 86 % (for 134Cs) and 93 % (for 137Cs) of the results satisfied |En| â‰¦ 1. However, 58 reports for 134Cs and 51 reports for 137Cs had some failures in their evaluations of uncertainties. The proficiency testing was effective to improve the ability of uncertainty evaluation.

Loss of phosphatidylserine synthesis results in aberrant solute sequestration and vacuolar morphology in Saccharomyces cerevisiae.

Null cho1 mutants of Saccharomyces cerevisiae are incapable of phosphatidyl-serine synthesis. They were more susceptible than wild-type strains to 100 mM CaCl2, 3 mM ZnCl2 or 1 mM MnCl2, but not to MgCl2 nor KCl. They were also susceptible to high concentrations of basic amino acids, L-lysine and L-arginine, and to an L-lysine analog, S-2-aminoethyl-L-cysteine. Their vacuolar pools of amino acids, especially those of basic ones, were decreased. Pigmentation of cho1 ade2 double mutants was obscured and vacuoles of cho1 mutants were considerably fragmented. These indicate that phosphatidylserine plays vital roles in normal vacuolar function and morphogenesis.