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IMF forecasts and the EU's Fiscal Compact foresee Europe's heavily indebted countries running primary budget surpluses of as much as 5 percent of GDP for as long as 10 years in order to maintain debt sustainability and bring their debt/GDP ratios down to the Compact's 60 percent target. We show that primary surpluses this large and persistent are rare. In an extensive sample of high- and middle-income countries there are just 3 (nonoverlapping) episodes where countries ran primary surpluses of at least 5 per cent of GDP for 10 years. Analyzing a less restrictive definition of persistent surplus episodes (primary surpluses averaging at least 3 percent of GDP for 5 years), we find that surplus episodes are more likely when growth is strong, when the current account of the balance of payments is in surplus (savings rates are high), when the debt-to-GDP ratio is high (heightening the urgency of fiscal adjustment), and when the governing party controls all houses of parliament or congress (its bargaining position is strong). Left wing governments, strikingly, are more likely to run large, persistent primary surpluses. In advanced countries, proportional representation electoral systems that give rise to encompassing coalitions are associated with surplus episodes. The point estimates do not provide much encouragement for the view that a country like Italy will be able to run a primary budget surplus as large and persistent as officially projected.
The Middle Stone Age (MSA) of Africa, like the Middle Paleolithic of Europe, is thought to represent a time period wherein toolmakers acquired significant increases in cognitive abilities and physical dexterity. Existing data fail to resolve whether the MSA emerged gradually, abruptly, or discontinuously, and whether this industry reflects the activity of Homo sapiens. Here we present new 40Ar/39Ar geochronological data revealing that advanced MSA archaeology at two sites in the main Ethiopian Rift is older than 276 ka, much older than technologically comparable MSA archaeology from elsewhere. An age of 183 ka for a unit farther upsection, along with the technological stasis observed throughout the section, indicates that similar technology was used here for ~93 ka. These results suggest that MSA technology evolved asynchronously in different places, and challenge the notion of a distinct time line for either the appearance of the MSA or the disappearance of the earlier Acheulean. These and other recent results indicate that the oldest known MSA consistently predates fossil evidence for the earliest Homo sapiens.
Lattice models are powerful tools for studying configurational thermodynamics. For many years these models have been successfully applied in many binary and ternary metallic systems to study phase equilibria with little or no experimental input. Recently, the same models have been shown to work very well in ceramic systems including high temperature superconductors, and the MgO-CaO system. Two developments have made the extension of these models to systems with aliovalent doping practical. First, aliovalent systems can be treated as coupled binary systems with the same techniques as simple binary systems. Second, it has been shown that the conditionally convergent coulomb interactions can be well mated with short-ranged effective interactions. In this paper, we use a lattice model with which the pyrochlore to defect fluorite transition and defect interactions at any concentration or temperature can be studied with a no priori assumptions.
Most catalysts consist of nanometer-sized particles dispersed on a high-surface-area support. Advances in characterization methods have led to a molecular-level understanding of the relationships between nanoparticle properties and catalytic performance. Together with novel approaches to nanoparticle synthesis, this knowledge is contributing to the design and development of new catalysts.
We present an atlas of UV ($\sim 2300$ \AA) images, obtained with the Hubble Space Telescope (HST) Faint Object Camera, of the central $22''\times 22''$ of 110 galaxies. The observed galaxies are an unbiased selection constituting about one half of a complete sample of all large ($D>6'$) and nearby ($V< 2000$ km s$^{-1}$) galaxies. This is the first extensive UV imaging survey of normal galaxies. The data are useful for studying star formation, low-level nuclear activity, and UV emission by evolved stellar populations in galaxies. At the HST resolution ($\sim 0.05''$), the images display an assortment of morphologies and UV brightnesses. These include bright nuclear point sources, compact young star clusters scattered in the field or arranged in circumnuclear rings, centrally-peaked diffuse light distributions, and galaxies with weak or undetected UV emission. We measure the integrated $\sim 2300$ \AA\ flux in each image, classify the UV morphology, and examine trends between these parameters and the optical properties of the galaxies.
As fragments of the V2O5 layer structure (shown right; spheres for bridging O atoms are large and shaded, for terminal O atoms large and open, and for V atoms small and open) the recently prepared, novel polyvanadate structures mentioned in the title are reported and systematized. In contrast to the classical polyoxoanions of the Keggin and Schlemper type, these "more open" structures contain easily accessible vanadium centers with free coordination sites. Examples of the anticipated host–guest chemistry have already been reported.
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSupramolecular Liquid-Crystalline Complexes Exhibiting Room-Temperature Mesophases and Electrooptic Effects. Hydrogen-Bonded Mesogens Derived from Alkylpyridines and Benzoic AcidsTakashi Kato, Mitsuo Fukumasa, and Jean M. J. FrechetCite this: Chem. Mater. 1995, 7, 2, 368–372Publication Date (Print):February 1, 1995Publication History Published online1 May 2002Published inissue 1 February 1995https://pubs.acs.org/doi/10.1021/cm00050a021https://doi.org/10.1021/cm00050a021research-articleACS PublicationsRequest reuse permissionsArticle Views475Altmetric-Citations115LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts
High temperature aqueous electrolyte concentration cells with and without liquid junction are described. These cells were used to measure the ionization constant of water in 0.1, 0.25,0.5, and]1.0 mol/kg KCl solutions at temperatures to 200 °C. Extrapolation to infinite dilution yielded the following functions for the temperature dependence of log K w 0 and the thermodynamic parameters for ionization: log K w 0 = −4046.16/T + 3.537 − 0.01323T; ΔG 0 = 77458.0 − 67.71T + 0.253187T 2 J/mol; ΔH 0 = 77458.0 − 0.253187T 2 J/mol; ΔS 0 = 67.71 − 0.5063T J/K mol; ΔC p 0 = −0.5063T J/K mol.
Dissolution of bismuth metal by tri-iodide ion in acidified potassium iodide medium has been studied using a rotating disc technique. The rate constant for the dissolution process, k T , in solutions 0.5 M in potassium iodide at 25.0 °C has been shown to be related to the square root of the disc angular velocity, ω, by the following expression[Formula: see text]The activation energy for this reaction was found to be 4.7 kcal mole −1 . These data clearly establish that the rate of dissolution is determined by the rate at which tri-iodide ion is transported to the metal surface. In solutions of [KI] = 0.10 M, however, the rate determining step appears to involve diffusion of tri-iodide ion through a layer of BiI 3 which forms on the bismuth metal surface as the reaction proceeds.
We quantified the spatial-temporal roles of photosynthesis, temperature and soil moisture on soil respiration of an oak savanna with a combination of field and laboratory measurements. Canopy photosynthesis was quantified from eddy covariance measurements over and under the woodland. Spatial gradients in soil respiration were surveyed with a portable soil respiration chamber. Contributions to soil respiration by autotrophs and heterotrophs were assessed using profiles of CO 2 sensors inserted in the soil under a tree and in the open grassland. At a given spot, soil respiration was a function of soil moisture and temperature and labile carbon pools associated with decomposing organic matter and recent photosynthetic production. Spatial/temporal variations in soil respiration reflect changes in these controlling factors. Spatial transect studies, for example, showed that soil respiration decreased by 60% as one radiates from a tree to the open grassland. Soil respiration measured under a tree crown reflected the sum of rhizosphere respiration and heterotrophic respiration while soil respiration measured in an open area represented heterotrophic respiration when the grass was dead during the summer. Basal rates of soil respiration diminished over the summer as the soil dried and it stressed photosynthetic and microbial activity. Summer rains, on the other hand, were found to stimulate the activity of latent microbes immediately, thereby pulsing soil respiration by more than a factor of 10 until the upper soil layer dries. Continuous measurements of soil respiration revealed that soil respiration under the tree was decoupled with soil temperature. Soil respiration was strongly correlated with tree photosynthesis, but with a time lag of 7 to 12 hours. These results indicate that photosynthesis drives soil respiration in addition to soil temperature and moisture. Measurements of soil respiration were combined with remote sensing information to upscale soil CO 2 efflux measurements. Cumulative soil respiration was 394 gC m -2 y -1 in the open area and 616 gC m -2 y -1 under trees producing a site-average of 488 gC m -2 y -1 .
Abstract Although curcumin has preventive actions in animal models of colon cancer, whether the mechanism of action is through anti‐proliferation in normal environment is not clearly understood. Here, we studied the effects of chemopreventive doses of curcumin on the proliferation rate of colon epithelial cells (CEC), using a recently developed stable isotope – mass spectrometric method for measuring DNA synthesis rate. Adult male F344 rats were given diets containing 0, 2 and 4% curcumin for 5 weeks. 4% 2 H 2 O was given in drinking water to label DNA, after a priming bolus, for 4 days prior to sacrifice. The isotopic enrichment of the deoxyribose moiety of deoxyadenosine from DNA was measured by gas chromatography – mass spectrometry. Cell cycle analysis was performed after propidium iodide staining of CECs. Curcumin administration did not reduce but instead resulted in dose‐dependent increases in CEC proliferation rate ( p < 0.05) for 2% and 4% curcumin vs 0%). The length of the colon crypts and the fraction of cells in S‐phase were also increased in the 2% and 4% curcumin groups ( p < 0.05). Thus, pharmacological doses of curcumin increase CEC proliferation rate and pool size in normal rats. Reduction of CEC proliferation therefore cannot explain the proposed chemopreventive actions of curcumin in colon cancer. Copyright © 2007 John Wiley & Sons, Ltd.
A rare event: The benzylpalladium amido complex 1 (Ar=napthyl) was used to study the mechanism of an unusual reductive elimination of amines (see scheme). The observed inversion of configuration is proposed to result from dissociation of the amido ligand, followed by nucleophilic attack on the benzylic carbon atom. binap=2,2′-bis(diphenylphosphanyl)-1,1′-binaphthyl, dppf=1,1′-bis(diphenylphosphanyl)ferrocene. Detailed facts of importance to specialist readers are published as "Supporting Information". Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.
Accountability structures and processes will need to be tailored to local membership composition, historical evolution, and current stage of development. There are also some common lessons to be drawn. Shared goals and incentives should be reflected through performance criteria. It is important to align measures and thresholds across payers to ensure ACOs are not unnecessarily burdened or compromised by reporting on different and potentially disjointed measures. Finally, emphasis needs to be placed on the importance of credible, transparent data. This exploratory study provides early evidence regarding how ACOs are establishing their governance and accountability arrangements and provides a foundation for future research and theory-building in this area.
