20,754 research outputs found

    State education as high-yield investment: human capital theory in European policy discourse

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    Human Capital Theory has been an increasingly important phenomenon in economic thought over the last 50 years. The central role it affords to education has become even more marked in recent years as the concept of the ‘knowledge economy’ has become a global concern. In this paper, the prevalence of Human Capital Theory within European educational policy discourse is explored. The paper examines a selection of policy documents from a number of disparate European national contexts and considers the extent to which the ideas of Human Capital Theory can be seen to be influential. In the second part of the paper, the implications of Human Capital Theory for education are considered, with a particular focus on the possible ramifications at a time of economic austerity. The paper argues that Human Capital Theory risks offering a diminished view of the person, a diminished view of education, but that with its sole focus on economic goals leaves room for educationists and others to argue for the educational, social, and moral values it ignores, and for the conception of the good life and good society it fails to mention

    Are Men Cheaper Than Women? Insights From Walking Economy

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    ARE MEN CHEAPER THAN WOMEN? INSIGHTS FROM WALKING ECONOMY Nicole S. Schultz and Peter G. Weyand Southern Methodist University, Locomotor Performance Laboratory, Department of Applied Physiology and Wellness, Dallas, TX 75205 Introduction: The metabolic energy cost of human walking has been extensively studied. However, whether men and women require the same amount of energy (per kg of body mass) to walk at the same speed or cover the same distance remains unresolved. While most predictive algorithms incorporate only body mass and walking speed, we have recently found that mass-specific walking metabolic rates are inversely related to stature. Objective: We tested the specific hypothesis that walking economy does not differ between males and females when stature is controlled. We evaluated our hypothesis by comparing stature-matched adult males vs. females in each of three categories: short, medium and tall, at their respective most economical walking speeds. We predicted that minimum transport costs (COTmin, ml O2·kg-1·m-1) would not vary between gender groups of each stature. Methods: 30 subjects (15 male, 15 female) walked on a level treadmill at speeds ranging from 0.4 m·s-1 to 1.9 m·s-1. Indirect calorimetry was used to measure rates of oxygen uptake under steady-state conditions (Parvo Medics TrueOne 2400, Sandy, UT). Analysis: Minimum net transport cost, or net transport cost at the most economical walking speed, was determined for each subject by: 1) subtracting resting rates of oxygen uptake from the gross rates measured (VO2net, ml O2·kg-1·min-1), and 2) dividing VO2net by walking speed to identify the minimum COT. Unpaired t-tests were used to compare males and females within each stature group. Results: Transport costs were essentially identical for male and female groups of all three statures: short, medium and tall, and were inversely related to stature as expected. Conclusion: We conclude that men and women are equally cheap and gender does not influence walking energy expenditure. The mass-specific energy cost of transport does not differ in males and females of the same stature

    The role of carbon for superconductivity in MgCx_{x}Ni3_{3} from specific heat

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    The influence of carbon deficiency on superconductivity of MgCNi3_{3} is investigated by specific heat measurements in the normal and superconducting state. In order to perform a detailed analysis of the normal state specific heat, a computer code is developed which allows for an instantaneous estimate of the main features of the lattice dynamics. By analyzing the evolution of the lattice vibrations within the series and simultaneously considering the visible mass enhancement, the loss in the electron-phonon coupling can be attributed to significant changes of the prominent Ni vibrations. The present data well supports the recently established picture of strong electron-phonon coupling and ferromagnetic spin fluctuations in this compound.Comment: 4 pages, latex, corrections to the text, one reference added, one figure correcte

    Dissipative Taylor-Couette flows under the influence of helical magnetic fields

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    The linear stability of MHD Taylor-Couette flows in axially unbounded cylinders is considered, for magnetic Prandtl number unity. Magnetic fields varying from purely axial to purely azimuthal are imposed, with a general helical field parameterized by \beta=B_\phi/B_z. We map out the transition from the standard MRI for \beta=0 to the nonaxisymmetric Azimuthal MagnetoRotational Instability (AMRI) for \beta\to \infty. For finite \beta, positive and negative wave numbers m, corresponding to right and left spirals, are no longer identical. The transition from \beta=0 to \beta\to\infty includes all the possible forms of MRI with axisymmetric and nonaxisymmetric modes. For the nonaxisymmetric modes, the most unstable mode spirals in the opposite direction to the background field. The standard (\beta=0) MRI is axisymmetric for weak fields (including the instability with the lowest Reynolds number) but is nonaxisymmetric for stronger fields. If the azimuthal field is due in part to an axial current flowing through the fluid itself (and not just along the central axis), then it is also unstable to the nonaxisymmetric Tayler instability, which is most effective without rotation. For large \beta this instability has wavenumber m=1, whereas for \beta\simeq 1 m=2 is most unstable. The most unstable mode spirals in the same direction as the background field.Comment: 9 pages, 11 figure

    The influence of African air pollution on regional and global tropospheric chemistry

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    International audienceWe investigate the relative importance of African biomass burning, biogenic volatile organic compounds (VOC), lightning and anthropogenic emissions to the tropospheric ozone budget over Africa and globally using a coupled global chemistry climate model. Our model studies indicate that the photochemical surface ozone concentration may rise by up to 50 ppbv in the burning region during the biomass burning seasons. Biogenic VOCs contribute between 5?20 ppbv to the near surface ozone concentration over the tropical African region. The impact of lightning on surface ozone is negligible, while anthropogenic emissions contribute a maximum of 10 ppbv to the surface ozone over Nigeria, South-Africa and Egypt. The annual average of the surface and column ozone over Africa shows that biomass burning is the single most important emission source affecting the African region, while biogenic emissions have the highest contribution during the rainy seasons. The contributions of African emissions to global tropospheric ozone burden (TOB) are about 9 Tg, 13 Tg, 8 Tg and 4 Tg for African biomass burning, biogenic VOC, lightning and anthropogenic emissions respectively. These correspond to 2.4%, 3.4%, 2.1% and 1% of the global tropospheric ozone budget respectively. Over Africa itself, the contribution of each of these emission types is only 2.4 Tg, 2.2 Tg, 1.4 Tg and 0.8 Tg respectively. Outside the continent, African biogenic VOC emissions yield the highest contribution to the TOB. Our model calculations suggest that about 70% of the tropospheric ozone produced from emissions in Africa is found outside the continent, thus exerting a noticeable influence on a large part of the tropical troposphere. Latin America experiences the highest impact of African emissions, followed by southeast and south-central Asia, Oceania, and the Middle East for all the emission categories; while Canada, the United States, Russia, Mongolia, China and Europe experience the least impact of African emissions

    Effects of maternal subnutrition during early pregnancy on cow hematological profiles and offspring physiology and vitality in two beef breeds

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    This experiment evaluated the effects of subnutrition during early gestation on hematology in cows (Bos Taurus) and on hematological, metabolic, endocrine, and vitality parameters in their calves. Parda de Montaña and Pirenaica dams were inseminated and assigned to either a control (CONTROL, 100% requirements) or a nutrient‐restricted group (SUBNUT, 65%) during the first third of gestation. Dam blood samples were collected on days 20 and 253 of gestation, and calf samples were obtained during the first days of life. Pirenaica dams presented higher red series parameters than Parda de Montaña dams, both in the first and the last months of gestation. During early pregnancy, granulocyte numbers and mean corpuscular hemoglobin were lower in Pirenaica‐SUBNUT than in Pirenaica‐CONTROL cows. Calves from the SUBNUT cows did not show a physiological reduction in red series values in early life, suggesting later maturation of the hematopoietic system. Poor maternal nutrition affected calf endocrine parameters. Newborns from dystocic parturitions showed lower NEFA concentrations and weaker vitality responses. In conclusion, maternal nutrition had short‐term effects on cow hematology, Pirenaica cows showing a higher susceptibility to undernutrition; and a long‐term effect on their offspring endocrinology, SUBNUT newborns showing lower levels of IGF‐1 and higher levels of cortisol.This work was supported by the Spanish Ministry of Economy and Business and the European Union Regional Development Funds (INIA RTA 2013‐00059‐C02 and INIA RZP 2015‐001) and the Government of Aragon under the Grant Research Group Funds (A14_17R). A. Noya received a PhD grant from INIA‐Government of Aragon

    Chemical NOx budget in the upper troposphere over the tropical South Pacific

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    The chemical NOx budget in the upper troposphere over the tropical South Pacific is analyzed using aircraft measurements made at 6-12 km altitude in September 1996 during the Global Tropospheric Experiment (GTE) Pacific Exploratory Mission (PEM) Tropics A campaign. Chemical loss and production rates of NOx along the aircraft flight tracks are calculated with a photochemical model constrained by observations. Calculations using a standard chemical mechanism show a large missing source for NOx; chemical loss exceeds chemical production by a factor of 2.4 on average. Similar or greater NOx budget imbalances have been reported in analyses of data from previous field studies. Ammonium aerosol concentrations in PEM-Tropics A generally exceeded sulfate on a charge equivalent basis, and relative humidities were low (median 25% relative to ice). This implies that the aerosol could be dry in which case N2O5 hydrolysis would be suppressed as a sink for NOx. Suppression of N2O5 hydrolysis and adoption of new measurements of the reaction rate constants for NO2 + OH + M and HNO3 + OH reduces the median chemical imbalance in the NOx budget for PEM-Tropics A from 2.4 to 1.9. The remaining imbalance cannot be easily explained from known chemistry or long-range transport of primary NOx and may imply a major gap in our understanding of the chemical cycling of NOx in the free troposphere. Copyright 2000 by the American Geophysical Union
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