During the absorption of phosphate by yeast, the cells acquire the capacity to absorb Mn ++ and Mg ++, a capacity which is retained even after phosphate is no longer present in the medium. Cells pretrcated with phosphate and then washed, slowly lose their ability to absorb Mn ++, the rate of loss depending on the temperature and on the metabolic state. The fermentation of sugars induces a very ...

We consider the deduction problem in the fragment of first-order logic (FOL) composed of existentially closed conjunctions of literals (without functions), denoted FOL{∃,∧,¬a}. This problem can be recast as several fundamental problems in artificial intelligence and databases, namely query containment for conjunctive queries with negation, clause entailment for clauses without functions and que...

The concept of signature was introduced by Samaniego for systems whose components have i.i.d. lifetimes. This concept proved to be useful in the analysis of theoretical behaviors of systems. In particular, it provides an interesting signature-based representation of the system reliability in terms of reliabilities of k-out-of-n systems. In the non-i.i.d. case, we show that, at any time, this re...

As a means of distinguishing between the broad groups of flay minerals, chemical analysis may be a valuable supijlement to other methods, but rarely will it remove the necessity for other methods, X-ray analysis in particular. The twoand three-layer clay minerals may be distinguished by the SiOj • AlzOs ratio or SiOz • sesquioxide ratio, but these ratios do not provide criteria for dividing eit...

Sustainability of maize-based cropping systems is a major challenge for southern Africa, yet the demand for maize as staple food and animal feed in the region continues to increase. A study was conducted on a sandy clay loam (220 g clay kg-1 soil) at Domboshawa in Zimbabwe to investigate the long-term effects of organic resource quality and application rate, and nitrogen (N) fertilization on so...

Nguyen, Minhtri K., and Ira Kurtz. Determinants of plasma water sodium concentration as reflected in the Edelman equation: role of osmotic and Gibbs-Donnan equilibrium. Am J Physiol Renal Physiol 286: F828–F837, 2004. First published January 20, 2004; 10.1152/ajprenal.00393.2003.—Edelman et al. have empirically shown that plasma water sodium concentration ([Na ]pw) is equal to 1.11(Nae Ke)/TBW ...

Edelman et al. have empirically shown that plasma water sodium concentration ([Na(+)](pw)) is equal to 1.11(Na(e) + K(e))/TBW - 25.6 (Edelman IS, Leibman J, O'Meara MP, Birkenfeld LW. J Clin Invest 37: 1236-1256, 1958). However, the physiological significance of the slope and y-intercept in this equation has not been previously considered. Our analysis demonstrates that there are several clinic...

Four large lysimeters on the San Dimas Experimental Forest, each filled with similar parent material and planted with monocultures of native species in 1946, provide a unique opportunity to quantify short-term effects of plant species on soil properties. The four species under which soils were investigated are scrub oak (Quercus dumosa Nutt.) , chamise (Adenostoma fasciculatum Hook. and Am.), c...