Effect of Salinity on Stomatal Conductance,Leaf Hydraulic Conductance,HvPIP2 Aquaporin,and Abscisic Acid Abundance in Barley Leaf Cells

The stomatal closure of salt-stressed plants reduces transpiration bringing about the maintenance of plant tissue hydration. The aim of this work was to test for any involvement of aquaporins (AQPs) in stomatal closure under salinity. The changes in the level of aquaporins in the cells were detected with the help of an immunohistochemical technique using antibodies against HvPIP2;2. In parallel, leaf sections were stained for abscisic acid (ABA). The effects of salinity were compared to those of exogenously applied ABA on leaf HvPIP2;2 levels and the stomatal and leaf hydraulic conductance of barley plants. Salinity reduced the abundance of HvPIP2;2 in the cells of the mestome sheath due to it being the more likely hydraulic barrier due to the deposition of lignin, accompanied by a decline in the hydraulic conductivity, transpiration, and ABA accumulation. The effects of exogenous ABA differed from those of salinity. This hormone decreased transpiration but increased the shoot hydraulic conductivity and PIP2;2 abundance. The difference in the action of the exogenous hormone and salinity may be related to the difference in the ABA distribution between leaf cells, with the hormone accumulating mainly in the mesophyll of salt-stressed plants and in the cells of the bundle sheaths of ABA-treated plants. The obtained results suggest the following succession of events: salinity decreases water flow into the shoots due to the decreased abundance of PIP2;2 and hydraulic conductance, while the decline in leaf hydration leads to the production of ABA in the leaves and stomatal closure.     

Differentiation of Romashkino crude oils according to biomarker hydrocarbon parameters

The trends in composition of higher biomarker hydrocarbons (steranes and tri-, tetra-, and pentacyclic terpanes) in crude oils from diachronous producing complexes of deposits of the Romashkino oil field, which occurs in the central part of the South Tatarian arch, were studied. On the basis of variations in molecular biomarker parameters that reflect the type of source organic matter and the facies conditions of its accumulation and early diagenesis, the oils are classified with three groups.     

Phase and structural transformations and mechanism of propagation of self-propagating high-temperature synthesis in a V2O5-Al mixture

Physicochemical transformations upon heating and combustion of an Al−V₂O₅ mixture are investigated. It is established that the process proceeds in a one- or two-wave regime, depending on the method of initiation. Concentration profiles of the starting and intermediate products are obtained in various zones of the wave of self-propagating high-temperature synthesis. The presence of vanadium radicals in the preflame zone is detected. It is proposed that the main feature of transformation of the mixture in the processes of a low-temperature wave is chain autocatalysis. It is established that, at initial temperatures in vacuum or upon dilution of the mixture, a low-temperature wave stabilizes near a high-temperature wave, thus entering a “satellite” regime. Institute of Problems of Combustion, Almaty 480012. Translated from Fizika Goreniya i Vzryva, Vol. 33, No. 6, pp. 36–47, November–December, 1997.     

Calculating the temperature dependence of the specific heat for rare-earth arsenates

Equations have been derived for the temperature dependence of the specific heat for 14 rare-earth arsenates. The standard specific heats of some of them have also been calculated by Debye's and Ivanova's methods.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 59, No. 6, pp. 956–958, December, 1990.     

Transformation of residual oil in producing formations of the Romashkino oil field during hydrothermal treatment

Changes in the composition of organic matter of rocks and residual oil from multiage deposits of the Romashkino oil field in a reducing environment in a continuous-flow aqueous system were studied. It was shown that, as a result of the action of hydrothermal factors, the amount of hydrocarbon fractions increases and the amounts of alcohol-benzene-extractable resins, asphaltenes, and total sulfur decrease in organic extracts obtained from the rocks after hydrothermal experiments. The concentration of free radicals, as well as tetravalent vanadium (which is present in the form of vanadyl prophyrin complexes) and other heavy metals, in asphaltenes decreases. The hydrothermal treatment of petroliferous rock leads to the degradation of the structure of insoluble kerogen and unrecoverable components of residual oil, as well as to the washout of free hydrocarbons from the rock with the aqueous phase, n-Alkanes; ethyl, butyl, and octyl phthalates; furan; acids; and unsaturated oxygen-containing compounds with the isoprenoid structure were detected in the products of hydrothermal experiments isolated from aqueous extracts.     

The characterisation and origins of interphase substances (cruds) in the rhenium solvent extraction circuit of a copper smelter

It has been determined that the reason for the formation of interphase substances (IS) during rhenium extraction is the presence of a black-colored fine precipitate in the feed solution. The same precipitate is formed when extraction process solutions are mixed with the original feed solution, which is wash sulfuric acid from the scrubbing of copper smelter off-gases. The elemental composition of the interphase substances has been determined, including the content of trialkylamine. The precipitate in the original solution is the result of chemical reactions between Re and Os oxides, and SO2 and H2S. It is also the result of the formation of humic acid in the gas phase and in the scrubbing of metallurgical gases.     

Cold Sintering of Fe–Ag and Fe–Cu Nanocomposites by Consolidation in the High-Pressure Gradient

Russian Journal of Non-Ferrous Metals - The results of fabricating dense Fe–Ag and Fe–Cu nanocomposites from mixtures of powders consolidated by high-pressure cold sintering and from...     

Isolation and properties of extracellular alkaline phosphatase from Bacillus intermedius

Patients with chronic disease may be excluded from capitated managed care plans due to higher than average expected costs. In an attempt to remedy this inequity, one type of risk adjustment technique proposes to set separate capitation rates for certain chronic illnesses, including coronary artery disease (CAD). Cardiologists, who increasingly are requested to accept capitation, will benefit from understanding the impact of using clinical factors as opposed to using demographic factors to set capitation rates. Using a 5% national random sample of the 1992 Medicare population, we determined mean annual expenditures and variation in expenditures of individuals with CAD. We compared the use of 2 demographic factors currently used for capitation rate adjustment (age and gender) with 2 factors not currently used--3-digit International Classification of Disease (ICD-9) code (a measure for severity) and Charlson index (a measure for comorbidity). Mean annual expenditures for individuals with CAD were more than double mean annual expenditures for the general Medicare population ($6,944 vs $3,247). Among individuals with CAD, mean expenditures of subgroups defined by both age and gender ranged from $6,205 to $7,724. In comparison, stratifying by measures of severity and comorbidity identified subgroups with lower and higher mean expenditures, producing a range of $1,702 to $19,959. Substantial variation of expenditures for individuals within subgroups defined by severity and comorbidity remained, with few patients having substantially higher expenditures than the rest. When capitation rates are set with the use of demographic factors alone, patients may be subjected to risk selection and physicians to financial loss. Using clinical measures may decrease the incentive for patient risk selection, but substantial financial risk to physicians would remain, because of a relatively few patients with high expenditures (or costs).