The yeast growth control gene GRC5 is highly homologous to the mammalian putative tumor suppressor gene QM

We isolated the Saccharomyces cerevisiae GRC5 (gr owth control) gene by functional complementation in vivo of a ts (t emperature s ensitive) mutation. Phenotypic analysis suggested involvement of GRC5 in cell growth and proliferation. Mutant cells arrest their cell cycles after one to three cell divisions predominantly as mother cells with a large bud. In the region of the septum, a massive accumulation of cell wall material is observed. The mother and daughter nuclei are well separated and spindles are no longer present, while the cytoskeleton is of aberrant appearance. Arrested cells do not perform protein synthesis and are unable to mate. Furthermore, grc5-1^ts cells rapidly lose viability at the restrictive temperature (37°C) only on full media, but not under nitrogen-starvation conditions, indicating that proper response to this nutrient limitation is still intact in mutant cells after cell cycle arrest. The sequence of GRC5 translates into a basic protein of 221 amino acids with a corresponding M_r of 25·4 kDa. GRC5 is a member of the highly conserved QM gene family, members of which have been reported from plants, invertebrates and vertebrates. The amino acid sequence of GRC5 over its entire length is more than 60% identical to the human QM protein, expression of which is associated with loss of the tumorigenic phenotype in a cell line derived from Wilms' tumor, a malignancy of the embyronic kidney. Here, we show that GRC5 is an essential yeast gene, the function of which as inferred from analysis of the grc5-1^ts mutant is crucial for establishment of proper cytoskeletal structure and regulation of growth in yeast cells.     

Distribution patterns of chalcogens (S, Se, Te, and 210Po) in various tissues of a squid, Todarodes pacificus

In order to elucidate the relationship between the chemically similar chalcogen elements S, Se, Te, and 210Po in marine invertebrates, we conducted a comparative study of the distribution patterns of these elements in a squid, Todarodes pacificus. Elemental concentrations of the four chalcogens were determined in (mantle) muscle, gill, stomach, and hepatopancreas tissues. No relationship between chalcogen concentrations and morphological parameters (mantle length, body weight, and sex) was evident. Gills showed slightly elevated levels of Se and 210Po, which may indicate absorption and uptake of these elements over the gill surface. All four chalcogens have their highest concentrations in the hepatopancreas and the lowest concentrations in the muscle tissue. However, concentration differences between tissues, revealed by (1) bioaccumulation values based on reference seawater values and (2) internal relative enrichment factors (IREF) based on enrichment of hepatopancreas compared to muscle tissue, were least pronounced for S, most distinct for 210Po, and moderate for Se and Te. Furthermore, no significant correlation for Se, Te, and 210Po with S within tissue concentrations, and only a slightly negative correlation between S and 210Po in the squid muscle and hepatopancreas tissues were found, which indicates either an antagonistic effect between, or a disconnection of the two elements through metabolic processing. Overall, the distribution patterns of Se and Te resemble those of essential trace elements, such as Zn and Cu, whereas 210Po is partitioned in a manner similar to toxic heavy metals, such as Cd and Ag.     

Evaluation of oxygen content on silicon nitride powder surface from the measurement of the isoelectric point

The oxygen content associated to the surface of silicon nitride powder particles was characterized using a method which is based on the measurement of the specific surface area and the isoelectric point in aqueous solution. From the dissociation model of hydrolyzed surface groups a linear dependence between the fraction of silanol groups (SiOH) and the pH of the isoelectric point is predicted, which was confirmed by electrophoretic measurements of various commercial silicon nitride powders. The proposed method provides rapid information on the particle surface composition, which is of particular relevance for colloidal processing of silicon nitride powders.     

On-line recording of solar cooker use rate by a novel metering device: Prototype description and experimental verification of output data

A metering device for the determination of solar cooker use rate is presented. The device records food temperature, ambient temperature and irradiance. Automatic data evaluation yields the number of cooking cycles, cooking time, food “thermal mass”, as well as the impact on fuel consumption and GHG emission compared to other cooking techniques. Metering results are compared with actual conditions for box-type and concentrating solar cookers and found to be in agreement.     

Eine einfache Synthese des Cyclohexanon-2-carbonsäure-amids sowie dessen Reaktionen

A Simple Synthesis of Cyclohexanone-2-carboxamide and its Reactions By reaction of urea with cyclohexanone and subsequent acid hydrolysis cyclohexanone-2-carboxamide 2 is formed. 2 is C-alkylated by alkyl halides yielding compounds 6a—g . With amines, the enamines 10a and 10b , and with hydrazines the tetrahydroindazolones 8a and 8b are formed. 2 reacts with aqueous alkali to give pimelic acid. Cyclopentanone-2-carboxamide 3 and cycloheptanone-2-carboxamide 4 are formed in an analogous way.