The Hertz Corporation

About: The Hertz Corporation is a based out in . It is known for research contribution in the topics: Population & Soil water. The organization has 9562 authors who have published 11044 publications receiving 447929 citations. The organization is also known as: Hertz Rental Car & Hertz Rent-a-Car.

New components of the vitamin B complex.

Abstract: AN attempt to prepare a concentrate of folic acid from liver by the method of Hutchings et al.1 resulted, as already noted in a recent review2, in the preparation of a fraction probably containing folic acid, together with another fraction soluble in chloroform, which likewise stimulated the growth of certain micro-organisms. A second chloroform-soluble fraction with similar properties has now been obtained. All three of these fractions stimulate the growth of Lactobacillus helveticus and Streptococcus lactis R 8082, but not that of Lactobacillus arabinosus 17/5. Although the growth-promoting properties of the chloroform-insoluble fraction are probably due to folic acid, the chloroform-soluble fractions are believed to contain new factors not previously described.

Determination of degree of crosslinking in natural rubber vulcanizates. Part III

Abstract: The two previous parts of this series described an attempt to relate the physical properties of natural rubber vulcanizates to their network structure. The first established an empirical relationship between the stress-strain behavior of highly swollen natural rubbers in simple extension, and their equilibrium volume swelling in n-decane. It also examined the effect of changes in initial molecular weight of the unvulcanized masticated rubber on these properties, and an empirical correction making allowance for network flaws due to chain-segments terminated by a crosslink at only one end was obtained. The second part gave measurements of the equilibrium volume swelling and the intrinsic viscosity before vulcanization for each of a range of natural rubber vulcanizates which had been prepared by a method which enabled the number of crosslinks to be determined by chemical analysis. These measurements permitted a comparison to be made between (i) the chemical estimate of the actual number of crosslink...

Glutamine and asparagine as nitrogen donors for reductant-dependent glutamate synthesis in pea roots.

Abstract: Glutamine, in the presence of alpha-oxoglutarate, stimulates nicotinamide nucleotide oxidation by crude extracts of pea roots and leads to a reductant-dependent formation of glutamate. Commercially available asparagine also stimulates nicotinamide nucleotide oxidation in the presence of alpha-oxoglutarate, but the reaction causing the stimulation can occur in the absence of a reductant, is inhibited by transaminase inhibitors, and is additive to the glutamine reaction. The asparagine used was found to be contaminated with aspartate. Repurified asparagine, chromatographically free of aspartate, did not stimulate the rate of nicotinamide nucleotide oxidation, and it is probable that the original stimulation was due to aspartate contamination. It is concluded that pea-root glutamine (amide)-alpha-oxoglutarate aminotransferase (glutamate synthase), in common with the enzyme in leaves, is specific for glutamine as the N donor and alpha-oxoglutarate as the N acceptor. The significance of the enzyme in conjunction with glutamine synthetase in the assimilation of nitrate by roots is discussed.

Heavy metals from past applications of sewage sludge decrease the genetic diversity of rhizobium leguminosarum biovar trifolii populations

Abstract: White clover plants grown at a site contaminated with heavy metals following applications of sewage sludge were found to have small white root nodules containing ineffective rhizobia (S isolates) which had identical plasmid profiles, unlike the diverse profiles of effective rhizobia from root nodules on adjacent control plots. Our paper supports an earlier suggestion that the ineffective S isolates of Rhizobium from nodules of white clover grown on heavy-metal contaminated soil represent a single strain. These new data include restriction fragment length polymorphism (RFLP) studies using probes specific for a chromosomally-located gene (lac), a plasmid-located symbiotic gene (nifH,D) and a repeated sequence specific for Rhizobium leguminosarum bv. trifolii (RtRS). RFLP patterns of isolates from control plots indicated that although these strains showed variation, they were related to one another but not to the S isolates. We also demonstrated that although the S isolates were ineffective on white clover, they formed normal nodules on subterranean clover, which were effective in nitrogen fixation. However, they ineffectively nodulated red clover and were unable to nodulate Vicia hirsuta. Thus the population of R. leguminosarum bv. trifolii had been radically altered by long-term exposure to heavy metal contamination, apparently losing those agronomically-important strains capable of forming effective symbiotic associations with white and red clover.