Limiting nutrients for bean production on contrasting soil types of Lake Victoria Crescent of Uganda

Common bean (Phaseolus vulgaris L.) is one of the most important grain legumes in East Africa, but its yield has remained below the genetic potential. Declining soil fertility is among the primary constraints to bean production in most East African bean producing regions. Often existing recommendations are generic and inept to guide farm level decision making on nutrient replenishment. A greenhouse nutrient omission study was conducted to determine the limiting nutrients in three soils of Masaka District, commonly cropped to beans: “Liddugavu” a Phaeozem, “Limyufumyufu” a Cambisol and “Luyinjayinga” an Umbrisol soil. Nine treatments; (i) complete nutrient treatment, (ii) N omitted, (iii) P omitted, (iv) K omitted, (v) Mg omitted, (vi) S omitted, (vii) Ca omitted, (viii) Micronutrients omitted and (ix) control without nutrients. Each treatment was randomly assigned to the three soils and replicated three times using a completely randomised design. Nitrogen, phosphorus and potassium were limiting nutrients for bean production in Umbrisol (Luyinjayinja) while in Cambisol (‘Limyufumyufu), common bean production was most limited by soil acidity. The performance varied with soil types, with beans grown on the Phaeozem registering greater leaf number and growth, confirming both scientist’s and local farmer’s knowledge that this soil has greater potential than the other two soils

Dryland Malt Barley Yield and Quality Affected by Tillage, Cropping Sequence, and Nitrogen Fertilization

Malt barley (Hordeum vulgare L.) yield and quality have been evaluated using various cultivars and N rates but little is known about the effects of tillage and cropping sequence. We evaluated the effects of tillage, cropping sequence, and N fertilization on dryland malt barley yield, grain characteristics, N uptake, and N use-efficiency from 2006 to 2011 in eastern Montana. Treatments were no-till continuous malt barley (NTCB), no-till malt barley–pea (Pisum sativum L.) (NTB–P), no-till malt barley–fallow (NTB–F), and conventional till malt barley–fallow (CTB–F), with split application of N rates (0,40, 80, and 120 kg N ha–1) in randomized complete block with three replications. As N rates increased, malt barley grain yield, protein concentration, and N uptake increased in NTB–F, NTB–P, and NTCB, but test weight, plumpness, and N-use efficiency decreased in all tillage and cropping sequence treatments. Similarly, plant stand, biomass (stems and leaves) yield, and N uptake increased with increased N rates. Grain and biomass yields, N uptake, and N-use efficiency were greater in CTB–F than in NTB–P and NTCB but tillage had no effect on these parameters. Malt barley yield and N uptake varied with cropping sequences and N rates among years. Although grain yield increased with increased N rates, NTB–P with N rates between 40 and 80 kg N ha−1 may be used to sustain dryland malt barley yield and quality (protein concentration \u3c 135 g kg−1, plumpness \u3e 800 g kg−1), thereby helping to reduce the potentials for soil erosion and N leaching and increase soil organic matter in the northern Great Plains

Adiabatic Dynamics of Superconducting Quantum Point Contacts

Starting from the quasiclassical equations for non-equilibrium Green's functions we derive a simple kinetic equation that governs ac Josephson effect in a superconducting quantum point contact at small bias voltages. In contrast to existing approaches the kinetic equation is valid for voltages with arbitrary time dependence. We use this equation to calculate frequency-dependent linear conductance, and dc $I\!-\!V$ characteristics with and without microwave radiation for resistively shunted quantum point contacts. A novel feature of the $I\!-\!V$ characteristics is the excess current $2I_c/\pi$ appearing at small voltages. An important by-product of our derivation is the analytical proof that the microscopic expression for the current coincides at arbitrary voltages with the expression that follows from the Bogolyubov-de Gennes equations, if one uses appropriate amplitudes of Andreev reflection which contain information about microscopic structure of the superconductors.Comment: 12 Pages, REVTEX 3.0, 3 figures available upon reques

Limiting nutrients for bean production on contrasting soil types of Lake Victoria Crescent of Uganda

Common bean (Phaseolus vulgaris L.) is one of the most important grain legumes in East Africa, but its yield has remained below the genetic potential. Declining soil fertility is among the primary constraints to bean production in most East African bean producing regions. Often existing recommendations are generic and inept to guide farm level decision making on nutrient replenishment. A greenhouse nutrient omission study was conducted to determine the limiting nutrients in three soils of Masaka District, commonly cropped to beans: \u201cLiddugavu\u201d a Phaeozem, \u201cLimyufumyufu\u201d a Cambisol and \u201cLuyinjayinga\u201d an Umbrisol soil. Nine treatments; (i) complete nutrient treatment, (ii) N omitted, (iii) P omitted, (iv) K omitted, (v) Mg omitted, (vi) S omitted, (vii) Ca omitted, (viii) Micronutrients omitted and (ix) control without nutrients. Each treatment was randomly assigned to the three soils and replicated three times using a completely randomised design. Nitrogen, phosphorus and potassium were limiting nutrients for bean production in Umbrisol (Luyinjayinja) while in Cambisol (\u2018Limyufumyufu), common bean production was most limited by soil acidity. The performance varied with soil types, with beans grown on the Phaeozem registering greater leaf number and growth, confirming both scientist\u2019s and local farmer\u2019s knowledge that this soil has greater potential than the other two soils.Le haricot commun (Phaseolus vulgaris L.) est un des l\ue9gumes \ue0 grains les plus importants en Afrique de l\u2019Est, mais son rendement reste toujours en dessous de son potentiel g\ue9n\ue9tique. La baisse de la fertilit\ue9 du sol est parmi les contraintes primaires \ue0 la production du haricot dans la plupart des r\ue9gions productrices de l\u2019Afrique de l\u2019Est. Le plus souvent, les recommandations sont g\ue9n\ue9riques et inad\ue9quates pour guider la prise de d\ue9cision au niveau champ sur le r\ue9approvisionnement en nutriment. Une \ue9tude sous serre sur l\u2019omission de nutriment a \ue9t\ue9 conduite pour d\ue9terminer les nutriments limitants dans les trois sols du district de Masaka, commun\ue9ment utilis\ue9s pour produire du haricot\ua0: \u201cLiddugavu\u201d un sol du Phaeozem, \u201cLimyufumyufu\u201d un sol du Cambisol et \u201cLuyinjayinga\u201d un sol du Umbrisol. Neuf traitements, (i) traitement complet de nutriments, (ii) N omis, (iii) P omis, (iv) K omis, (v) Mg omis, (iv) S omis, (vii) Ca omis, (viii) micronutriments omis et (ix) control sans nutriments. Chacun des traitements a \ue9t\ue9 al\ue9atoirement distribu\ue9 aux trois types de sols et r\ue9pliqu\ue9 trois fois dans un dispositif compl\ue8tement al\ue9atoire. Azote, phosphore, et potassium ont \ue9t\ue9 les nutriments limitants pour la production du haricot dans Umbrisol (Luyinjayinja) tandis que dans Cambisol (\u2018Limyufumyufu), la production du haricoct commun a \ue9t\ue9 limit\ue9e par l\u2019acidit\ue9 du sol. Les performances varient en fonction des types de sols, avec le haricot produit sur le Phaeozem comptant plus de feuilles et de croissance, confirmant \ue0 la fois les connaissances des scientifiques et des populations locales qui stipulent que le sol a un potentiel plus \ue9lev\ue9 que les deux autres sols

Dissipative Electron Transport through Andreev Interferometers

We consider the conductance of an Andreev interferometer, i.e., a hybrid structure where a dissipative current flows through a mesoscopic normal (N) sample in contact with two superconducting (S) "mirrors". Giant conductance oscillations are predicted if the superconducting phase difference $\phi$ is varied. Conductance maxima appear when $\phi$ is on odd multiple of $\pi$ due to a bunching at the Fermi energy of quasiparticle energy levels formed by Andreev reflections at the N-S boundaries. For a ballistic normal sample the oscillation amplitude is giant and proportional to the number of open transverse modes. We estimate using both analytical and numerical methods how scattering and mode mixing --- which tend to lift the level degeneracy at the Fermi energy --- effect the giant oscillations. These are shown to survive in a diffusive sample at temperatures much smaller than the Thouless temperature provided there are potential barriers between the sample and the normal electron reservoirs. Our results are in good agreement with previous work on conductance oscillations of diffusive samples, which we propose can be understood in terms of a Feynman path integral description of quasiparticle trajectories.Comment: 24 pages, revtex, 12 figures in eps forma

The CCR4-NOT Complex Physically and Functionally Interacts with TRAMP and the Nuclear Exosome

BACKGROUND: Ccr4-Not is a highly conserved multi-protein complex consisting in yeast of 9 subunits, including Not5 and the major yeast deadenylase Ccr4. It has been connected functionally in the nucleus to transcription by RNA polymerase II and in the cytoplasm to mRNA degradation. However, there has been no evidence so far that this complex is important for RNA degradation in the nucleus. METHODOLOGY/PRINCIPAL FINDINGS: In this work we point to a new role for the Ccr4-Not complex in nuclear RNA metabolism. We determine the importance of the Ccr4-Not complex for the levels of non-coding nuclear RNAs, such as mis-processed and polyadenylated snoRNAs, whose turnover depends upon the nuclear exosome and TRAMP. Consistently, mutation of both the Ccr4-Not complex and the nuclear exosome results in synthetic slow growth phenotypes. We demonstrate physical interactions between the Ccr4-Not complex and the exosome. First, Not5 co-purifies with the exosome. Second, several exosome subunits co-purify with the Ccr4-Not complex. Third, the Ccr4-Not complex is important for the integrity of large exosome-containing complexes. Finally, we reveal a connection between the Ccr4-Not complex and TRAMP through the association of the Mtr4 helicase with the Ccr4-Not complex and the importance of specific subunits of Ccr4-Not for the association of Mtr4 with the nuclear exosome subunit Rrp6. CONCLUSIONS/SIGNIFICANCE: We propose a model in which the Ccr4-Not complex may provide a platform contributing to dynamic interactions between the nuclear exosome and its co-factor TRAMP. Our findings connect for the first time the different players involved in nuclear and cytoplasmic RNA degradation

DETERMINATION OF TYPES OF INDIVIDUALS IN APHIDS, ROTIFERS AND CLADOCERA 1

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72827/1/j.1469-185X.1929.tb00888.x.pd

The Ccr4-Not Complex Interacts with the mRNA Export Machinery

The Ccr4-Not complex is a key eukaryotic regulator of gene transcription and cytoplasmic mRNA degradation. Whether this complex also affects aspects of post-transcriptional gene regulation, such as mRNA export, remains largely unexplored. Human Caf1 (hCaf1), a Ccr4-Not complex member, interacts with and regulates the arginine methyltransferase PRMT1, whose targets include RNA binding proteins involved in mRNA export. However, the functional significance of this regulation is poorly understood.Here we demonstrate using co-immunoprecipitation approaches that Ccr4-Not subunits interact with Hmt1, the budding yeast ortholog of PRMT1. Furthermore, using genetic and biochemical approaches, we demonstrate that Ccr4-Not physically and functionally interacts with the heterogenous nuclear ribonucleoproteins (hnRNPs) Nab2 and Hrp1, and that the physical association depends on Hmt1 methyltransferase activity. Using mass spectrometry, co-immunoprecipitation and genetic approaches, we also uncover physical and functional interactions between Ccr4-Not subunits and components of the nuclear pore complex (NPC) and we provide evidence that these interactions impact mRNA export.Taken together, our findings suggest that Ccr4-Not has previously unrealized functional connections to the mRNA processing/export pathway that are likely important for its role in gene expression. These results shed further insight into the biological functions of Ccr4-Not and suggest that this complex is involved in all aspects of mRNA biogenesis, from the regulation of transcription to mRNA export and turnover