Education in Contemporary Capitalism Britain: Actual and Potential

Este trabajo comienza con unos breves comentarios sobre las sociedades capitalistas contemporáneas, centrándose en la mercantilización del conocimiento y la agenda capitalista para y en educación. Al adentrarse en el terreno crucial de la formación de maestros, el autor analiza la vigilancia estatal para luego hacer unas sugerencias sobre las posibilidades que brinda la educación para crear una arena eficaz en la cual se puedan tratar los asuntos globales y locales, donde los estudiantes se puedan conectar con las comunidades oprimidas, y donde puedan desarrollar su conciencia crítica sobre el mundo neoliberal e imperialista de la actualidad

Ligand Discrimination in Myoglobin from Linear-Scaling DFT+U

Myoglobin modulates the binding of diatomic molecules to its heme group via hydrogen-bonding and steric interactions with neighboring residues, and is an important benchmark for computational studies of biomolecules. We have performed calculations on the heme binding site and a significant proportion of the protein environment (more than 1000 atoms) using linear-scaling density functional theory and the DFT+U method to correct for self-interaction errors associated with localized 3d states. We confirm both the hydrogen-bonding nature of the discrimination effect (3.6 kcal/mol) and assumptions that the relative strain energy stored in the protein is low (less than 1 kcal/mol). Our calculations significantly widen the scope for tackling problems in drug design and enzymology, especially in cases where electron localization, allostery or long-ranged polarization influence ligand binding and reaction.Comment: 15 pages, 3 figures. Supplementary material 8 pages, 3 figures. This version matches that accepted for J. Phys. Chem. Lett. on 10th May 201

Makani, a three-movement work for wind ensemble

Ph.D.Ph.D. Thesis. University of Hawaiʻi at Mānoa 201

Ca II triplet spectroscopy of RGB stars in NGC 6822: kinematics and metallicities

We present a detailed analysis of the chemistry and kinematics of red giants in the dwarf irregular galaxy NGC 6822. Spectroscopy at 8500 Angstroms was acquired for 72 red giant stars across two fields using FORS2 at the VLT. Line of sight extinction was individually estimated for each target star to accommodate the variable reddening across NGC 6822. The mean radial velocity was found to be v_helio = (52.8 +/- 2.2) km/s with dispersion rms = 24.1 km/s, in agreement with other studies. Ca II triplet equivalent widths were converted into [Fe/H] metallicities using a V magnitude proxy for surface gravity. The average metallicity was [Fe/H] = (-0.84 +/- 0.04) with dispersion rms = 0.31 dex and interquartile range 0.48. Our assignment of individual reddening values makes our analysis more sensitive to spatial variations in metallicity than previous studies. We divide our sample into metal-rich and metal-poor stars; the former are found to cluster towards small radii with the metal-poor stars more evenly distributed across the galaxy. The velocity dispersion of the metal-poor stars is higher than that of the metal-rich stars; combined with the age-metallicity relation this indicates that older populations have either been dynamically heated or were born in a less disclike distribution. The low ratio (v_rot/v_rms) suggests that within the inner 10', NGC 6822's stars are dynamically decoupled from the HI gas, possibly in a thick disc or spheroid.Comment: 15 pages, 12 figures, includes tabular dat

Renormalization of myoglobin-ligand binding energetics by quantum many-body effects

We carry out a first-principles atomistic study of the electronic mechanisms of ligand binding and discrimination in the myoglobin protein. Electronic correlation effects are taken into account using one of the most advanced methods currently available, namely a linear-scaling density functional theory (DFT) approach wherein the treatment of localized iron 3d electrons is further refined using dynamical mean-field theory (DMFT). This combination of methods explicitly accounts for dynamical and multi-reference quantum physics, such as valence and spin fluctuations, of the 3d electrons, whilst treating a significant proportion of the protein (more than 1000 atoms) with density functional theory. The computed electronic structure of the myoglobin complexes and the nature of the Fe-O2 bonding are validated against experimental spectroscopic observables. We elucidate and solve a long standing problem related to the quantum-mechanical description of the respiration process, namely that DFT calculations predict a strong imbalance between O2 and CO binding, favoring the latter to an unphysically large extent. We show that the explicit inclusion of many body-effects induced by the Hund's coupling mechanism results in the correct prediction of similar binding energies for oxy- and carbonmonoxymyoglobin.Comment: 7 pages, 5 figures. Accepted for publication in the Proceedings of the National Academy of Sciences of the United States of America (2014). For the published article see http://www.pnas.org/content/early/2014/04/09/1322966111.abstrac

Development of a Classical Force Field for the Oxidised Si Surface: Application to Hydrophilic Wafer Bonding

We have developed a classical two- and three-body interaction potential to simulate the hydroxylated, natively oxidised Si surface in contact with water solutions, based on the combination and extension of the Stillinger-Weber potential and of a potential originally developed to simulate SiO2 polymorphs. The potential parameters are chosen to reproduce the structure, charge distribution, tensile surface stress and interactions with single water molecules of a natively oxidised Si surface model previously obtained by means of accurate density functional theory simulations. We have applied the potential to the case of hydrophilic silicon wafer bonding at room temperature, revealing maximum room temperature work of adhesion values for natively oxidised and amorphous silica surfaces of 97 mJ/m2 and 90mJ/m2, respectively, at a water adsorption coverage of approximately 1 monolayer. The difference arises from the stronger interaction of the natively oxidised surface with liquid water, resulting in a higher heat of immersion (203 mJ/m2 vs. 166 mJ/m2), and may be explained in terms of the more pronounced water structuring close to the surface in alternating layers of larger and smaller density with respect to the liquid bulk. The computed force-displacement bonding curves may be a useful input for cohesive zone models where both the topographic details of the surfaces and the dependence of the attractive force on the initial surface separation and wetting can be taken into account

Stress Development and Impurity Segregation during Oxidation of the Si(100) Surface

We have studied the segregation of P and B impurities during oxidation of the Si(100) surface by means of combined static and dynamical first-principles simulations based on density functional theory. In the bare surface, dopants segregate to chemically stable surface sites or to locally compressed subsurface sites. Surface oxidation is accompanied by development of tensile surface stress up to 2.9 N/m at a coverage of 1.5 monolayers of oxygen and by formation of oxidised Si species with charges increasing approximately linearly with the number of neighbouring oxygen atoms. Substitutional P and B defects are energetically unstable within the native oxide layer, and are preferentially located at or beneath the Si/SiOx interface. Consistently, first-principles molecular dynamics simulations of native oxide formation on doped surfaces reveal that dopants avoid the formation of P-O and B-O bonds, suggesting a surface oxidation mechanism whereby impurities remain trapped at the Si/SiOx interface. This seems to preclude a direct influence of impurities on the surface electrostatics and, hence, on the interactions with an external environment

System-dependent image distortion related to gantry positions of a 0.35 T MRgRT: Characterization and the corresponding correction

PURPOSE: MR-guided radiotherapy with high accuracy treatment planning requires addressing MR imaging artifacts that originate from system imperfections. This work presents the characterization and corresponding correction of gantry-related imaging distortions including geometric distortion and isocenter shift in a 0.35 T magnetic resonance imaging (MRI)-guided radiotherapy (MRgRT) system using distortion vector fields (DVFs). METHODS: Two phantoms, the magnetic resonance imaging distortion in 3D (MRID RESULTS: Geometric distortion with mean (± SD) distortion of 3.2 ± 0.02, 2.9 ± 0.02, and 1.8 ± 0.01 mm and isocenter shift (±SD) of 0.49 ± 0.3, 0.05 ± 0.2, and 0.01 ± 0.03 mm were present in the DstOff MRID CONCLUSION: The gantry-related MR imaging distortion including geometric distortion and isocenter shift was characterized and a corresponding correction was demonstrated using extended DVFs on 0.35 T MRgRT system. The characterized gantry-related isocenter shift can be combined with geometric distortion correction to provide a technique for the correction of the full system-dependent distortion in an MRgRT system

Capitalismo de austeridad / empobrecimiento: ¿Qué podemos aprender del socialismo venezolano?

In this article, we begin by discussing austerity/immiseration capitalism in Europe and the U.S. We go on to contrast this with twenty-first century socialism in the making, as an alternative to neoliberal capitalism in the Bolivarian Republic of Venezuela. Next we analyse opposition to the Bolivarian Revolution, with respect to internal and external forces, both of which are interlinked. We conclude with some thoughts about possible future developments in Europe and the U.S. respectively.En este artículo, comenzaremos hablando sobre el capitalismo de austeridad / empobrecimiento en Europa y EE. UU. Continuaremos comparándolo con el socialismo del siglo XXI en sus inicios, como alternativa al capitalismo neoliberal en la República Bolivariana de Venezuela. Después, analizaremos la oposición a la Revolución Bolivariana, con respecto a las fuerzas internas y externas, ambas relacionadas. Por último, concluiremos con algunas ideas sobre posibles desarrollos futuros en Europa y EE. UU., respectivamente