Capital simbólico e investigación. Una nota sobre el capital corporal

Este trabajo tiene como propósito presentar algunos potenciales aportes de la Teoría del Campo de Pierre Bourdieu en tres niveles de lectura: El de los fenómenos a estudiar en el marco de un proyecto de investigación, el del estatuto de esta teoría dentro de la Teoría Social Contemporánea y, finalmente, el de la posición del que escribe dentro del campo de investigación. El énfasis va a ponerse en el nivel de los fenómenos que es posible reconstruir a partir del análisis de fragmentos de documentos producidos en el trabajo de campo. Finalmente se harán algunas conclusiones sobre el uso de la categoría capital corporal para designar una subespecie de capital simbólico en el dominio de las prácticas corporales parte de la intervención de la Educación Física en una cárcel de la Provincia de Buenos Aires.

Capital simbólico e investigación. Una nota sobre el capital corporal

Este trabajo tiene como propósito presentar algunos potenciales aportes de la Teoría del Campo de Pierre Bourdieu en tres niveles de lectura: El de los fenómenos a estudiar en el marco de un proyecto de investigación, el del estatuto de esta teoría dentro de la Teoría Social Contemporánea y, finalmente, el de la posición del que escribe dentro del campo de investigación. El énfasis va a ponerse en el nivel de los fenómenos que es posible reconstruir a partir del análisis de fragmentos de documentos producidos en el trabajo de campo. Finalmente se harán algunas conclusiones sobre el uso de la categoría capital corporal para designar una subespecie de capital simbólico en el dominio de las prácticas corporales parte de la intervención de la Educación Física en una cárcel de la Provincia de Buenos Aires.

Capital simbólico e investigación. Una nota sobre el capital corporal

Este trabajo tiene como propósito presentar algunos potenciales aportes de la Teoría del Campo de Pierre Bourdieu en tres niveles de lectura: El de los fenómenos a estudiar en el marco de un proyecto de investigación, el del estatuto de esta teoría dentro de la Teoría Social Contemporánea y, finalmente, el de la posición del que escribe dentro del campo de investigación. El énfasis va a ponerse en el nivel de los fenómenos que es posible reconstruir a partir del análisis de fragmentos de documentos producidos en el trabajo de campo. Finalmente se harán algunas conclusiones sobre el uso de la categoría capital corporal para designar una subespecie de capital simbólico en el dominio de las prácticas corporales parte de la intervención de la Educación Física en una cárcel de la Provincia de Buenos Aires.

A level set approach for the analysis of flow and compaction during resin infusion in composite materials

Fluid flow and fabric compaction during vacuum assisted resin infusion (VARI) of composite materials was simulated using a level set-based approach. Fluid infusion through the fiber preform was modeled using Darcy’s equations for the fluid flow through a porous media. The stress partition between the fluid and the fiber bed was included by means of Terzaghi’s effective stress theory. Tracking the fluid front during infusion was introduced by means of the level set method. The resulting partial differential equations for the fluid infusion and the evolution of flow front were discretized and solved approximately using the finite differences method with a uniform grid discretization of the spatial domain. The model results were validated against uniaxial VARI experiments through an [0]8 E-glass plain woven preform. The physical parameters of the model were also independently measured. The model results (in terms of the fabric thickness, pressure and fluid front evolution during filling) were in good agreement with the numerical simulations, showing the potential of the level set method to simulate resin infusion

Computational method to reduce the search space for directed protein evolution

We introduce a computational method to optimize the in vitro evolution of proteins. Simulating evolution with a simple model that statistically describes the fitness landscape, we find that beneficial mutations tend to occur at amino acid positions that are tolerant to substitutions, in the limit of small libraries and low mutation rates. We transform this observation into a design strategy by applying mean-field theory to a structure-based computational model to calculate each residue's structural tolerance. Thermostabilizing and activity-increasing mutations accumulated during the experimental directed evolution of subtilisin E and T4 lysozyme are strongly directed to sites identified by using this computational approach. This method can be used to predict positions where mutations are likely to lead to improvement of specific protein properties.

Quantisation of the bosonic string

In this work we review the basic principles of the theory of the relativistic bosonic string through the study of the action functionals of Nambu-Goto and Polyakov and the techniques required for their canonical, light-cone, and path-integral quantisation. For this purpose, we briefly review the main properties of the gauge symmetries and conformal field theory involved in the techniques studied.

Improved and customized secondary optics for photo-voltaic concentrators

In this contribution the line flow method is applied to an optimized secondary optics in a photovoltaic concentration system where the primary optics is already defined and characterized. This method is a particular application of photic field theory. This method uses the parameterization of a given primary optics, including actual tolerances of the manufacturing process. The design of the secondary optics is constrained by the selection of primary optics and maximizes the concentration at a previously specified collection area. The geometry of the secondary element is calculated by using a virtual source, which sends light in a first concentration step. This allows us to calculate the line flow for this specific case. This concept allows designing more compact and efficient secondary optics of photovoltaic systems.

A presença do homo academicus na contabilidade: um olhar bourdieusiano sobre o contexto social do desenvolvimento da produção científica contábil brasileira

Esta pesquisa investiga o contexto social do desenvolvimento da produção científica contábil brasileira, defendendo a tese de que os agentes, no decorrer do processo de divulgação de suas investigações, estão priorizando aspectos produtivistas e quantitativos e, consequentemente, deixando em segundo plano a preocupação qualitativa e epistemológica [vigilância crítica] de tal produção. Fundamentado na Teoria de Campos de Pierre Bourdieu, este estudo busca relacionar a socialização acadêmica, o habitus dos agentes imbricados no campo, a distribuição do capital científico na área contábil e as características epistemológicas das publicações científicas da área, para obtenção das evidências sobre a problemática levantada. Trata-se de um levantamento operacionalizado por meio de entrevista semiestruturada, com uma amostra de 9 respondentes e estudo documental, com uma amostra de 43 artigos. Os dados foram analisados com emprego da técnica de análise de conteúdo. Apoiando-se em Bourdieu (2004, 2008, 2009, 2011, 2013) foram encontradas evidências de que as teorias, conceitos, metodologias, técnicas e demais escolhas realizadas pelos pesquisadores da área contábil, na maioria das vezes, não passam de manobras estratégicas que visam conquistar, reforçar, assegurar ou derrubar o monopólio da autoridade científica, visando a obtenção de maior poder simbólico no campo. Com relação ao habitus dos agentes pertencentes ao campo científico contábil, constatou-se uma tendência ao produtivismo em consequência das determinações dos órgãos reguladores da pesquisa em contabilidade (CAPES) e das lutas simbólicas travadas no campo para obtenção da autoridade científica. No tocante à socialização acadêmica, reforçou-se a presença de condutas produtivistas, por meio dos programas de pós-graduação stricto sensu, que repassam aos agentes as regras do jogo científico, doutrinando-os na maneira de publicar grande quantidade de comunicações em pouco tempo e com menos custos. As análises epistemológicas puderam triangular os dois últimos constructos, a fim de lhes dar validade, e evidenciaram uma preferência por temáticas que envolvem a contabilidade destinada aos usuários externos e procedimentos contábeis destinados ao mercado financeiro, privilegiando a utilização de dados secundários, por meio de pesquisas documentais. Em termos metodológicos, constatou-se a presença unânime de estudos positivistas, com alguns aspectos empiristas, mostrando uma ausência de inovação em termos de pesquisas norteadas por abordagens metodológicas alternativas e utilização de modelos econométricos para explicar a realidade observada sem teoria para embasar e explicar esses modelos. Por fim, a distribuição do capital simbólico no campo, mostrou que individualmente nenhum agente desponta com maior capital científico, mas, institucionalmente, a FEA/USP ocupa essa posição de destaque. Por conseguinte, pôde-se concluir que o campo científico contábil permanece estagnado e sem grandes modificações teóricas, pelo fato do produtivismo e das lutas simbólicas no interior do campo; fatos esses que, de certa maneira, motivaram a criação de uma espécie de \"receita mágica para publicar\" ou \"formato ideal\" legitimado, institucionalizado e difícil de ser modificado, a não ser que ocorra uma revolução científica que mude o paradigma existente

Critical behavior of su(1|1) supersymmetric spin chains with long-range interactions

We introduce a general class of su(1|1) supersymmetric spin chains with long-range interactions which includes as particular cases the su(1|1) Inozemtsev (elliptic) and Haldane-Shastry chains, as well as the XX model. We show that this class of models can be fermionized with the help of the algebraic properties of the su(1|1) permutation operator and take advantage of this fact to analyze their quantum criticality when a chemical potential term is present in the Hamiltonian. We first study the low-energy excitations and the low-temperature behavior of the free energy, which coincides with that of a (1+1)-dimensional conformal field theory (CFT) with central charge c=1 when the chemical potential lies in the critical interval (0,E(π)), E(p) being the dispersion relation. We also analyze the von Neumann and Rényi ground state entanglement entropies, showing that they exhibit the logarithmic scaling with the size of the block of spins characteristic of a one-boson (1+1)-dimensional CFT. Our results thus show that the models under study are quantum critical when the chemical potential belongs to the critical interval, with central charge c=1. From the analysis of the fermion density at zero temperature, we also conclude that there is a quantum phase transition at both ends of the critical interval. This is further confirmed by the behavior of the fermion density at finite temperature, which is studied analytically (at low temperature), as well as numerically for the su(1|1) elliptic chain.

Prediction of hidden multiferroic order in graphene zigzag ribbons

An electronic phase with coexisting magnetic and ferroelectric order is predicted for graphene ribbons with zigzag edges. The electronic structure of the system is described with a mean-field Hubbard model that yields results very similar to those of density functional calculations. Without further approximations, the mean-field theory is recasted in terms of a BCS wave function for electron-hole pairs in the edge bands. The BCS coherence present in each spin channel is related to spin-resolved electric polarization. Although the total electric polarization vanishes, due to an internal phase locking of the BCS state, strong magnetoelectric effects are expected in this system. The formulation naturally accounts for the two gaps in the quasiparticle spectrun, Δ0 and Δ1, and relates them to the intraband and interband self-energies.

Engineered surface waves in hyperbolic metamaterials

We analyzed surface-wave propagation that takes place at the boundary between a semi-infinite dielectric and a multilayered metamaterial, the latter with indefinite permittivity and cut normally to the layers. Known hyperbolization of the dispersion curve is discussed within distinct spectral regimes, including the role of the surrounding material. Hybridization of surface waves enable tighter confinement near the interface in comparison with pure-TM surface-plasmon polaritons. We demonstrate that the effective-medium approach deviates severely in practical implementations. By using the finite-element method, we predict the existence of long-range oblique surface waves.

Importancia de la caracterización de la masa de raíces en la simulación de ecosistemas forestales

Los análisis de sensibilidad son una herramienta importante para comprender el funcionamiento de los modelos ecológicos, así como para identificar los parámetros más importantes en su funcionamiento. Además, los análisis de sensibilidad pueden utilizarse para diseñar de forma más efectiva planes de muestreo de campo dirigidos a calibrar los modelos ecológicos. En los estudios de ecosistemas forestales, el análisis cuantitativo de la parte subterránea es mucho más costoso y complicado que el estudio de la parte aérea, en especial el estudio de la dinámica de producción y descomposición de raíces gruesas y finas de los árboles. En este trabajo se muestra un ejemplo de análisis de sensibilidad del modelo forestal FORECAST a parámetros que definen la biomasa, longevidad y concentración de nitrógeno en las raíces de los árboles. El modelo se calibró para simular dos rodales de pino silvestre (Pinus sylvestris) en los Pirineos de Navarra. Los resultados indican que la tasa de renovación de raíces finas es el parámetro más influyente en las estimaciones del modelo de crecimiento de los árboles, seguida de la concentración de N en las mismas, siendo la relación biomasa subterránea/total el parámetro al cual el modelo es menos sensible. Además, el modelo es más sensible a los parámetros que definen el componente subterráneo de la biomasa arbórea cuando simula un sitio de menor capacidad productiva y mayor limitación por nutrientes.

Dyakonov surface waves in lossy metamaterials

We analyze the existence of localized waves in the vicinities of the interface between two dielectrics, provided one of them is uniaxial and lossy. We found two families of surface waves, one of them approaching the well-known Dyakonov surface waves (DSWs). In addition, a new family of wave fields exists which are tightly bound to the interface. Although its appearance is clearly associated with the dissipative character of the anisotropic material, the characteristic propagation length of such surface waves might surpass the working wavelength by nearly two orders of magnitude.

Transport across two interacting quantum dots: Bulk Kondo, Kondo box, and molecular regimes

We analyze the transport properties of a double quantum dot device with both dots coupled to perfect conducting leads and to a finite chain of N noninteracting sites connecting both of them. The interdot chain strongly influences the transport across the system and the local density of states of the dots. We study the case of a small number of sites, so that Kondo box effects are present, varying the coupling between the dots and the chain. For odd N and small coupling between the interdot chain and the dots, a state with two coexisting Kondo regimes develops: the bulk Kondo due to the quantum dots connected to leads and the one produced by the screening of the quantum dot spins by the spin in the finite chain at the Fermi level. As the coupling to the interdot chain increases, there is a crossover to a molecular Kondo effect, due to the screening of the molecule (formed by the finite chain and the quantum dots) spin by the leads. For even N the two Kondo temperatures regime does not develop and the physics is dominated by the usual competition between Kondo and antiferromagnetism between the quantum dots. We finally study how the transport properties are affected as N is increased. For the study we used exact multiconfigurational Lanczos calculations and finite-U slave-boson mean-field theory at T=0. The results obtained with both methods describe qualitatively and also quantitatively the same physics.

Subwavelength Bessel beams in wire media

Recent progress is emerging on nondiffracting subwavelength fields propagating in complex plasmonic nanostructures. In this paper, we present a thorough discussion on diffraction-free localized solutions of Maxwell’s equations in a periodic structure composed of nanowires. This self-focusing mechanism differs from others previously reported, which lie on regimes with ultraflat spatial dispersion. By means of the Maxwell–Garnett model, we provide a general analytical expression of the electromagnetic fields that can propagate along the direction of the cylinder’s axis, keeping its transverse waveform unaltered. Numerical simulations based on the finite element method support our analytical approach. In particular, moderate filling fractions of the metallic composite lead to nonresonant-plasmonic spots of light propagating with a size that remains far below the limit of diffraction.