such aabiotic stresses like water stress are some of the most important threats to the production of agricultural crops. it is almost very rare to find a place with no stress where plants can reach their potential yield. a water stress of 17 percent decrease yield, due to its effect upon fruit setting is notable. therefore, a study was conducted in bushehr agricultural research center (located ...

Hydrogen metabolism was studied in the anaerobic bacterium, Sporomusa sp. strain DMG 58, by measuring natural abundance levels of deuterium in H 2 , H 2 O, and individual fatty acids during acetogenic growth on H 2 / CO 2 . Four cultures were grown, each in medium with a distinct hydrogen-isotopic composition ( δ D-H 2 O). The δ D value of H 2 was quantified in the residual gas exiting the grow...

The persistent organic pollutant DDT (1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane) is still indispensable in the fight against malaria, although DDT and related compounds pose toxicological hazards. Technical DDT contains the dichloro congener DDD (1-chloro-4-[2,2-dichloro-1-(4-chlorophenyl)ethyl]benzene) as by-product, but DDD is also formed by reductive degradation of DDT in the environment...

Among all isotopes those which would be expected to show the greatest differences from the original element are the isotopes of hydrogen. The addition of one or two protons to a relatively large atom is an insignificant change in comparison with that undergone by the transformation of hydrogen to its nearest isotope, deuterium, for here the extra proton practically doubles the mass. In fact deu...

Increased calcium uptake in vascular tissue, leading to elevated cytosolic free calcium, has been implicated in the pathophysiology of hypertension. This study examined the dose-dependent effect of deuterium oxide (5%, 10%, or 20% in drinking water) on systolic blood pressure, aortic calcium uptake, and platelet cytosolic free calcium in spontaneously hypertensive rats. Starting at age 8 weeks,...

We have studied the surface coverage dependence of the co-adsorption of D and D(2)O on the Ni(111) surface under UHV conditions. We use detailed temperature-programmed desorption studies and high resolution electron energy loss spectroscopy to show how pre-covering the surface with various amounts of D affects adsorption and desorption of D(2)O. Our results show that the effects of co-adsorptio...

We report observations of several deuterated species in the dark clouds L134N and TMC1, and in particular of NH2D (deuterated ammonia). NH2D has been detected for the first time towards the dense core TMC1-N and very strong emission has been confirmed towards L134N. The deuterium fractionation is very different in these two clouds, with abundance ratio [NH2D]/[NH3]∼ 0.1 and ∼ 0.02, [N2D]/[N2H]∼...

I . The use of deuterium oxide dilution to obtain an indirect estimate of body water in pregnant ewes was examined and the value of such an estimate in predicting body fat was investigated. 2. Deuterium oxide was infused intravenously into fourteen twin-bearing Blackface ewes and blood samples were taken 6-7 h later. The animals were subsequently slaughtered. 3. Deuterium oxide concentration wa...

Deuterium desorption and reaction between deuterium and oxygen to water has been studied on ultrathin vanadium oxide structures prepared on Pd(111). The palladium sample was part of a permeation source, thus enabling the supply of atomic deuterium to the sample surface via the bulk. Different vanadium oxide films have been prepared by e-beam evaporation in UHV under oxygen atmosphere. The struc...