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Current interest in seed hydration treatments for the improvement of level, rate and uniformity of germination or field emergence has revealed how little is known of the physiology of germination control under water stress. This review surveys briefly the responses of seeds held at different hydration levels, from normal germination in a free water supply to seed activation without germination under slight moisture stress, seed deterioration at greater moisture stress and the damage that can be caused to seeds in very dry conditions, as well as the responses to subsequent dehydration. Inhibition of germination, though not of seed activation, at certain levels of water stress is likened to various forms of dormancy, and the mechanism governing the initiation of cell elongation is suggested as the possible key to control over germination. Several lines of evidence on cell membrane integrity and action, and their responses to external factors, point to the role that the membrane may play in cell elongation (and hence germination) control, and membrane integrity may also be associated with the transition between seed deterioration at one hydration level and seed activation and repair at slightly higher hydration levels. Seed activation without germination is also considered in an ecological context. [ABSTRACT FROM AUTHOR]

The pharmacokinetics of cefotetan following a 0.5 g intravenous dose were studied in 15 patients with varying degrees of renal failure. In patients with glomerular filtration rates (GFR) greater than 50 ml/min the serum half-life was between 3 and 5 h. The half-life increased to 15 h as the GFR fell to 10 ml/min. When the GFR was less than 10 ml/min the serum clearance of cefotetan was very variable, the half-life being between 15 and 50 h. Cefotetan was eliminated almost entirely by the kidneys. It is suggested that cefotetan 0.5 g 12-hourly is appropriate for patients with GFRs greater than 20 ml/min. For patients with GFRs between 10 and 20 ml/min 0.5 g every 24 h should avoid gross accumulation. [ABSTRACT FROM AUTHOR]

Emergence trials with carrot seed showed that response to dusting with captan varied between seed lots and on different sowing dates. The response was greatest when seeds were exposed to soil moisture stress. Correlation coefficients between germination and emergence of treated seed were significant. [ABSTRACT FROM AUTHOR]