197 research outputs found

    Evidence and Ideology in Macroeconomics: The Case of Investment Cycles

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    The paper reports the principal findings of a long term research project on the description and explanation of business cycles. The research strongly confirmed the older view that business cycles have large systematic components that take the form of investment cycles. These quasi-periodic movements can be represented as low order, stochastic, dynamic processes with complex eigenvalues. Specifically, there is a fixed investment cycle of about 8 years and an inventory cycle of about 4 years. Maximum entropy spectral analysis was employed for the description of the cycles and continuous time econometrics for the explanatory models. The central explanatory mechanism is the second order accelerator, which incorporates adjustment costs both in relation to the capital stock and the rate of investment. By means of parametric resonance it was possible to show, both theoretically and empirically how cycles aggregate from the micro to the macro level. The same mathematical tool was also used to explain the international convergence of cycles. I argue that the theory of investment cycles was abandoned for ideological, not for evidential reasons. Methodological issues are also discussed

    The OpenMolcas Web: A Community-Driven Approach to Advancing Computational Chemistry

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    The developments of the open-source OpenMolcas chemistry software environment since spring 2020 are described, with a focus on novel functionalities accessible in the stable branch of the package or via interfaces with other packages. These developments span a wide range of topics in computational chemistry and are presented in thematic sections: electronic structure theory, electronic spectroscopy simulations, analytic gradients and molecular structure optimizations, ab initio molecular dynamics, and other new features. This report offers an overview of the chemical phenomena and processes OpenMolcas can address, while showing that OpenMolcas is an attractive platform for state-of-the-art atomistic computer simulations

    Влияние фосфатных связующих на физико-механические свойства периклазохромитовых огнеупоров

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    У данній статті наведено та порівняно фізико-механічні властивості периклазо-хромітових матеріалів в залежності від різних типів фосфатних зв’язуючих та введення різних домішок. Визначено, що найбільш раціональним є введення триполіфосфату натрію.In given clause are resulted and the physycal-mechanical properties periclase-cgromite of materials are compared depending on different of types phosphate binding and introduction of the various additives. Is determined, that most rational is the introduction treepolyphosphate sodume

    Relatedness with plant species in native community influences ecological consequences of range expansions

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    Global warming is enabling many plant species to expand their range to higher latitudes and altitudes, where they may suffer less from natural aboveground and belowground enemies. Reduced control by natural enemies can enable climate warming-induced range expanders to get an advantage in competition with natives and become disproportionally abundant in their new range. However, so far studies have examined individual growth of range expanders, which have common congeneric plant species in their new range. Thus it is not known how general is this reduced effect of above- and belowground enemies and how it operates in communities, where multiple plant species also interact with each other. Here we show that range-expanding plant species with and without congenerics in the invaded habitats differ in their ecological interactions in the new range. In a community-level experiment, range-expanding plant species, both with and without congenerics, suppressed the growth of a herbivore. However, only range expanders without congenerics reduced biomass production of the native plant species. In the present study, range expanders without congenerics allocated more biomass aboveground compared to native plant species, which can explain their competitive advantage. Competitive interaction and also biomass allocation of native plants and their congeneric range expanders were similar. Our results highlight that information about species phylogenetic relatedness with native flora can be crucial for improving predictions about the consequences of climate warming-induced range expansions

    Increase of Cu,Zn-superoxide dismutase activity during differentiation of human K562 cells involves activation by copper of a constantly expressed copper-deficient protein

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    Cu,Zn-superoxide dismutase activity, expressed on the basis of cell number, increased by 50% during sodium butyrate-induced differentiation of human K562 erythroleukemia cells. The increased enzyme activity was found to be concomitant with constant Cu,Zn-superoxide dismutase mRNA and immunoreactive protein levels and was accompanied by a rise in intracellular copper and glutathione. Incubation of K562 cell homogenates with copper caused an increase of Cu,Zn-superoxide dismutase activity which reached the levels observed after differentiation in the presence of sodium butyrate. The same treatment led to no significant activity increase in homogenates derived from differentiated cells. Externally added ceruloplasmin increased both intracellular copper levels and Cu,Zn-superoxide dismutase activity in undifferentiated cells to a level comparable with that observed after induction of differentiation. Both increments were abolished by depletion of cell glutathione. Cu,Zn-superoxide dismutase purified from control cells had both a lower kcat and a lower copper content than the enzyme purified from differentiated cells. From these data we conclude that: 1) Cu,Zn-superoxide dismutase is present in K562 cells also under the form of a less active copper-deficient enzyme, 2) the extent of enzyme activation is regulated post-translationally by differential delivery of copper as a function of differentiation stage, and 3) glutathione is likely to play a role in delivering copper to the copper-deficient protein in intact K562 cells

    Increase of Cu,Zn-superoxide dismutase activity during differentiation of human K562 cells involves activation by copper of a constantly expressed copper-deficient protein

    No full text
    Cu,Zn-superoxide dismutase activity, expressed on the basis of cell number, increased by 50% during sodium butyrate-induced differentiation of human K562 erythroleukemia cells. The increased enzyme activity was found to be concomitant with constant Cu,Zn-superoxide dismutase mRNA and immunoreactive protein levels and was accompanied by a rise in intracellular copper and glutathione. Incubation of K562 cell homogenates with copper caused an increase of Cu,Zn-superoxide dismutase activity which reached the levels observed after differentiation in the presence of sodium butyrate. The same treatment led to no significant activity increase in homogenates derived from differentiated cells. Externally added ceruloplasmin increased both intracellular copper levels and Cu,Zn-superoxide dismutase activity in undifferentiated cells to a level comparable with that observed after induction of differentiation. Both increments were abolished by depletion of cell glutathione. Cu,Zn-superoxide dismutase purified from control cells had both a lower kcat and a lower copper content than the enzyme purified from differentiated cells. From these data we conclude that: 1) Cu,Zn-superoxide dismutase is present in K562 cells also under the form of a less active copper-deficient enzyme, 2) the extent of enzyme activation is regulated post-translationally by differential delivery of copper as a function of differentiation stage, and 3) glutathione is likely to play a role in delivering copper to the copper-deficient protein in intact K562 cells
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