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.

Uptake and transport of zinc in the hyperaccumulator Thlaspi caerulescens and the non‐hyperaccumulator Thlaspi ochroleucum

Abstract: Growth and zinc uptake of the hyperaccumulator species Thlaspi caerulescens J. & C. Presl and the non-hyperaccumulator species Thlaspi ochroleucum Boiss. & Heldr. were compared in solution culture experiments. T. caerulescens was able to tolerate 500 mmol m−3 (32.5 g m−3) Zn in solution without growth reduction, and up to 1000 mmol m−3 (65 g m−3) Zn without showing visible toxic symptoms but with a 25% decrease in dry matter (DM) yield. Up to 28 g kg−1 of Zn in shoot DM was obtained in healthy plants of T. caerulescens. In contrast, T. ochroleucum suffered severe phytotoxicity at 500 mmol m−3 Zn. Marked differences were shown in Zn uptake, distribution and redistribution between the two species. T. caerulescens had much higher concentrations of Zn in the shoots, whereas T. ochroleucum accumulated higher concentrations of Zn in the roots. When an external supply of 500 mmol m−3 Zn was withheld, 89% of the Zn accumulated previously in the roots of T. caerulescens was transported to the shoots over a 33 d period, whereas in T. ochroleucum only 32% was transported. T. caerulescens was shown to have a greater internal requirement for Zn than other plants. Increasing the supply of Zn from 1 to 10 mmol m−3 gave a 19% increase in the total DM of this species. liven the shoots from the 1 mmol m−3 Zn treatment which showed Zn deficiency contained 10 times greater Zn concentrations than the widely reported critical value for Zn deficiency to occur in many other plant species. The results obtained suggest that strongly expressed constitutive sequestration mechanisms exist in the hyperaccumulator T. caerulescens, which detoxify the large amount of Zn present in shoot tissues and decrease its physiological availability in the cytosol. Both T. caerulescens and T. ochroleucum had constitutively high concentrations of malate in shoots, which were little affected by different Zn treatments. Although malate may play a role in Zn chelation because of the high concentrations present, it cannot explain the species specificity of Zn tolerance and hyperaccumulation.

Thermal Properties of the Starch/Water System Part I. Measurement of Heat of Gelatinisation by Differential Scanning Calorimetry

Abstract: The application of Differential Scanning Calorimetry to the gelatinisation of concentrated starch/water suspensions produced a well-defined endotherm under suitable conditions. Measurement of the peak area enabled the heat of gelatinisation to be calculated. The method has been applied to the following aspects of gelatinisation: — 1 Intercomparison of different starches, 2) Effect of granule size, 3 Application to wheat flour, 4 Effect of starch damage, 5 Staling of starch gels, 6 Amylose and amylopectin.

Endothelin ETA and ETB receptors mediate vascular smooth muscle contraction.

Abstract: 1. We have investigated the receptors mediating endothelin-induced contraction of rabbit isolated jugular vein (RJV) and rat isolated thoracic aorta (RTA). 2. Endothelin-1 (ET-1) and endothelin-3 (ET-3) contracted RJV preparations with similar potency (EC50 values approximately 1 nM), whereas, ET-1 (EC50:4.5 nM) was approximately 80 fold more potent than ET-3 in contracting RTA. In addition, the ETB receptor-selective agonist [Ala1,3,11,15]ET-1 contracted RJV (EC50:2.1 nM) but not RTA. 3. The ETA receptor antagonist, BQ123, competitively antagonized (pA2 6.93) the contraction of RTA produced by ET-1, but had no effect (at 10 microM) on the contractile effects of either ET-1, ET-3 or [Ala1,3,11,15]ET-1 in RJV. 4. These data suggest that both ETA and ETB receptors can mediate vascular smooth muscle contraction.