The earliest evidence for animal life comes from the fossil record of 24-isopropylcholestane, a sterane found in Cryogenian deposits, and whose precursors are found in modern demosponges, but not choanoflagellates, calcareans, hexactinellids, or eumetazoans. However, many modern demosponges are also characterized by the presence of siliceous spicules, and there are no convincing demosponge spic...

Lysyl-transfer ribonucleic acid (tRNA) species from a spore-forming strain of Bacillus subtilis (168 trp2(-)) and an early blocked asporogenous mutant (spoA 12) were compared on reversed-phase and methylated albumin-kieselguhr columns. Lysyl-tRNA species from spores and the asporogenous mutant in stationary phase both exhibited altered chromatographic profiles compared to that of log-phase cell...

HERE IS NEED FOR a simple and convenient procedure to conserve small volumes of blood for subsequent estimation of clinically significant enzymes and circulating metabolites. This requirement is especially necessary for such enzymes as cholinesterase, in view of the increasing use of cholinesterase inhibitors in agriculture and industry. It would be useful also in. the estimation. of alkaline p...

1. In batch adsorptions with prothrombin solutions, hyflo was the weakest adsorbent, standard super-cel intermediate, and filter-cel strongest. Of these three grades of diatomaceous earth, hyflo has the smallest surface area per gram and filter-cel the largest. In parallel breakthrough experiments, a column of standard super-cel had a capacity almost six times that of a hyflo column. 2. After p...

Inorganic micro®ltration membranes with a pore size down to 0.1 mm have been made using laser interference lithography and silicon micro machining technology. The membranes have an extremely small ̄ow resistance due to a thickness smaller than the pore size, a high porosity and a very narrow pore size distribution. They are relatively insensible to fouling, because they have a smooth surface, s...

Adults of Rhyzopertha dominica (F.), the lesser grain borer, were exposed on four varieties of rough rice with Dobie indices of susceptibility of 1.1 to 1.1 (low), and four varieties with Dobie indices of susceptibility of 3.4 to 3.8 (high). The varieties with low and high Dobie indices were classified as resistant and susceptible, respectively, to R. dominica. The purpose of the study was to e...