Nitrogenase activity (acetylene reduction) associated with leaves of different cultivars of paddy

An investigation was conducted to study the levels of nitrogen fixation on the leaf or sheath surfaces of four cultivars of paddy plants by using acetylene reduction technique. Varying levels of positive nitrogenase activity were observed on all the leaf surfaces. Sheath of IET 1991 cultivar showed a higher rate of fixation than the leaf surface. All the nitrogen-fixing organisms on the leaf or sheath surfaces belonged to the genus Beijerinckia. There was no correlation between the bacterial density and the level of fixation. Scanning electron microscopic data revealed that the upper surface of IET 1991 leaf was highly silicified and the microflora was either scanty or nil while the lower surface appeared quite different and harboured more micro-organisms. Similarly, the inner surface of sheath was devoid of silicification and showed the presence of micro-organisms.

Nitrogenase activity (acetylene reduction) associated with leaves of different cultivars of paddy (Oryza sativa L.)

An investigation was conducted to study the levels of nitrogen fixation on the leaf or sheath surfaces of four cultivars of paddy plants by using acetylene reduction technique. Varying levels of positive nitrogenase activity were observed on all the leaf surfaces. Sheath of IET 1991 cultivar showed a higher rate of fixation than the leaf surface. All the nitrogen-fixing organisms on the leaf or sheath surfaces belonged to the genus Beijerinckia. There was no correlation between the bacterial density and the level of fixation. Scanning electron microscopic data revealed that the upper surface of IET 1991 leaf was highly silicified and the microflora was either scanty or nil while the lower surface appeared quite different and harboured more micro-organisms. Similarly, the inner surface of sheath was devoid of silicification and showed the presence of micro-organisms.

Topochemically controlled hydrogen reduction of scheelite-related rare-earth metal molybdates

Scheelite-related -Ln2Mo3O12(Ln = La, Pr, Nd, Sm, Gd, Tb, or Dy) oxides are reduced by hydrogen at 780–870 K yielding molybdenum (IV) oxides of formula Ln2Mo3O9. The latter crystallize in a tetragonal scheelite (ABO4) type structure where one third of the A sites and a quarter of the anion sites are vacant: Ln2/3(cat)1/3MoO3(an). The reaction Ln2Mo3O12+ 3H2 Ln2Mo3O9(an)3+ 3H2O may be regarded as topochemically controlled, since both the parent and the product phases have scheelite-related structures. Infrared spectra and electrical and magnetic properties of these metastable defect scheelite phases are reported.

Energy-output linkages in Australia: Implications for emissions reduction policies

The study investigates the long-run and dynamic relationships between energy consumption and output in Australia using a multivariate cointegration and causality framework. Using both Engle-Granger and Johansen cointegration approaches, the study finds that energy consumption and real Gross Domestic Product are cointegrated. The Granger causality tests suggest bidirectional Granger causality between energy consumption and real GDP, and Granger endogeineity in the system. Since the energy sector largely contributes to carbon emissions in Australia, we suggest that direct measures to reduce carbon by putting constraints on the energy consumption would pose significant economic costs for the Australian economy.

Letters from Moise and Jacob Seixas to K. K. S. I. regarding reduction in seat costs because they are refugees

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Investigations on the preparation, oxidation and reduction reactions of thiophosphoryl fluoride

Pure thiophosphoryl fluoride has been prepared by the fluorination of thiophosphoryl chloride by sodium fluoride in acetonitrile medium. Oxidation of this phosphoryl fluoride by acidified chloramine-T ruptures the phosphorus-sulphur bond and oxidises the sulphur present to the hexavalent state. Anhydrous hydrogen iodide reduces the sulphur to hydrogen sulphide and phosphorus to the trivalent state.

Sodium-ammonia reduction of some cyclic vinyl bromides

Abstract is not available.

Literacy teacher research in high poverty schools: Why it matters

Teachers who work in contexts in which their students’ lives are affected by poverty take up the challenge of learning to teach diverse students in ways that teachers in other contexts may not be required to do. And they do this work in contexts of immense change. Students’ communities change, neighborhoods change, educational policies change, literate practices and the specific effects of what it means to be poor in particular places also change. What cannot change is a commitment to high-equity, high-quality education for the students in these schools. Teachers need to analyze situations and make ongoing ethical decisions about pedagogy and curriculum. To do this, they must be able to continuously gauge the effects of their practices on different students. Hence, we argue that building teacher-researcher dispositions and repertoires is a key goal for teacher education across the teaching life-span. Drawing on a range of recent and ongoing collaborative research projects in schools situated in areas of high poverty, we draw out some principles for literacy teachers’ education.

Alloying gold with copper makes for a highly selective visible-light photocatalyst for the reduction of nitroaromatics to anilines

Finely control of product selectivity is an essential issue in organic chemical production. In the synthesis of functionalized anilines via reduction of the corresponding nitroarenes, the challenge is to selectively reduce only the nitro group in the presence of other reducible functional groups in nitroarene molecules at a high reaction rate. Normally, the nitroarene is reduced stepwise through a series of intermediates that remain as byproducts, increasing the aniline synthesis cost. Here we report that alloying small amounts of copper into gold nanoparticles can alter the reaction pathway of the catalytic reduction under visible-light irradiation at ambient temperature, allowing nitroaromatics to be transformed directly to anilines in a highly selective manner. The reasons for the high efficiency of the photocatalytic reduction under these comparatively benign conditions as well as the light-excited reaction mechanisms are discussed. This photocatalytic process avoids byproducts, exhibits a high reaction rate and excellent substituent tolerance, and can be used for the synthesis of many useful functionalized anilines under environmentally benign conditions. Switching of the reaction pathway simply by tailoring the bimetallic alloy NPs of the photocatalysts is effective for engineering of product chemoselectivity.

Carbon-Supported Pt-TiO2 as a Methanol-Tolerant Oxygen-Reduction Catalyst for DMFCs

Carbon-supported Pt-TiO2 (Pt-TiO2/C) catalysts with varying at. wt ratios of Pt to Ti, namely, 1:1, 2:1, and 3:1, are prepared by the sol-gel method. The electrocatalytic activity of the catalysts toward oxygen reduction reaction (ORR), both in the presence and absence of methanol, is evaluated for application in direct methanol fuel cells (DMFCs). The optimum at. wt ratio of Pt to Ti in Pt-TiO2/C is established by fuel cell polarization, linear sweep voltammetry, and cyclic voltammetry studies. Pt-TiO2/C heattreated at 750 degrees C with Pt and Ti in an at. wt ratio of 2:1 shows enhanced methanol tolerance, while maintaining high catalytic activity toward ORR. The DMFC with a Pt-TiO2/C cathode catalyst exhibits an enhanced peak power density of 180 mW/cm(2) in contrast to the 80 mW/cm(2) achieved from the DMFC with carbon-supported Pt catalyst while operating under identical conditions. Complementary data on the influence of TiO2 on the crystallinity of Pt, surface morphology, and particle size, surface oxidation states of individual constituents, and bulk and surface compositions are also obtained by powder X-ray diffraction, scanning and transmission electron microscopy, X-ray photoelectron spectroscopy, energy dispersive analysis by X-ray, and inductively coupled plasm optical emission spectrometry.

Probing the mechanism of benzaldehyde reduction to chiral hydrobenzoin on the CNT surface under near-UV light irradiation

Metal-free CNTs exhibit high activity (conversion rate 99.6%, 6 h) towards the synthesis of chiral hydrobenzoin from benzaldehyde under near-UV light irradiation (320–400 nm). The CNT structure before and after the reaction, the interaction between the molecule and the CNT surface, the intermediate products, the substitution effect and the influence of light on the reaction were examined using various techniques. A photo-excited conduction electron transfer (PECET) mechanism for the photocatalytic reduction using CNTs has been proposed. This finding provides a green photocatalytic route for the production of hydrobenzoin and highlights a potential photocatalytic application of CNTs.

The nexus between poverty and deprivation in Vietnam

Unlike previous studies’ finding on western and developed economies, income is a significant determinant of multidimensional deprivation in Vietnam. This first study on a developing country also incorporates food security in a latent class framework to compute a new multidimensional deprivation index. It was found that chronic poverty and not transient poverty has a detrimental effect on multidimensional deprivation and thus current poverty alleviation programs should potentially be tailored according to these poverty types to effectively combat multidimensional deprivation. The finding that 20% of non-poor are most deprived with85% of this group living in urban Vietnam also points to the need for a new form of targeted policy.

Studies on the reduction of hematite by carbon

Single pellet experiments have been carried out in a nitrogen atmosphere to study the reduction of hematite by graphite in the temperature range 925 to 1060°C. The effect of variables such as c/Fe2O3 molar ratio, pellet size, and so forth, has been investigated. Gas analysis data show a continuous decrease in CO2/CO ratio during reduction, the values being far away from Fe/FeO equilibrium for wustite reduction by CO. The activation energies associated with different degrees of reduction appear to be widely different suggesting a possible changeover in reaction mechanism during the progress of reduction. X-ray diffraction studies confirm the stepwise nature of hematite reduction.

Oxygen reduction and proton translocation by cytochrome c oxidase

Energy conversion by living organisms is central dogma of bioenergetics. The effectiveness of the energy extraction by aerobic organisms is much greater than by anaerobic ones. In aerobic organisms the final stage of energy conversion occurs in respiratory chain that is located in the inner membrane of mitochondria or cell membrane of some aerobic bacteria. The terminal complex of the respiratory chain is cytochrome c oxidase (CcO) - the subject of this study. The primary function of CcO is to reduce oxygen to water. For this, CcO accepts electrons from a small soluble enzyme cytochrome c from one side of the membrane and protons from another side. Moreover, CcO translocates protons across the membrane. Both oxygen reduction and proton translocation contributes to generation of transmembrane electrochemical gradient that is used for ATP synthesis and different types of work in the cell. Although the structure of CcO is defined with a relatively high atomic resolution (1.8 Å), its function can hardly be elucidated from the structure. The electron transfer route within CcO and its steps are very well defined. Meanwhile, the proton transfer roots were predicted from the site-specific mutagenesis and later proved by X-ray crystallography, however, the more strong proof of the players of the proton translocation machine is still required. In this work we developed new methods to study CcO function based on FTIR (Fourier Transform Infrared) spectroscopy. Mainly with use of these methods we answered several questions that were controversial for many years: [i] the donor of H+ for dioxygen bond splitting was identified and [ii] the protolytic transitions of Glu-278 one of the key amino acid in proton translocation mechanism was shown for the first time.

Rice husk filtrate as a nutrient medium for the growth of Desulfotomaculum nigrificans: characterisation and sulfate reduction studies

The filtrate obtained by interacting a known amount of rice husk with deionised, Milli-Q water was assessed as a carbon source and nutrient medium for the growth of Desulfotomaculum nigrificans, a typical sulfate-reducing bacterium. The filtrate contained essential growth constituents such as magnesium, potassium, phosphorous apart from calcium, sodium, chloride and sulfate ions. Based on the 1H and 13C NMR characterization studies, the organic composition of the components dissolved from the rice husk, was found to be: (i) 66% lignocellulosic material, (ii) 24% xylose + arabinose and (iii) 10% galactose. The growth studies indicated a 15-fold increase in the bacterial cell number in about 20 days. Nearly 81% and 66% reduction in sulfate concentration could be achieved in about 28 days, from the solutions containing initial sulfate concentrations of 550 mg/l and 1200 mg/l respectively. In both the cases studied, the iron concentration could be reduced by over 85%.