Language documentation and archives in South America

This paper addresses a set of issues related to language documentation that are not often explicitly dealt with in academic publications, yet are highly important for the development and success of this new discipline. These issues include embedding language documentation in the socio-political context not only at the community level but also at the national level, the ethical and technical challenges of digital language archives, and the importance of regional and international cooperation among documentation activities. These issues play a major role in the initiative to set up a network of regional language archives in three South American countries, which this paper reports on. Local archives for data on endangered languages have recently been set up in Iquitos (Peru), Buenos Aires (Argentina), and in various locations in Brazil. An important feature of these is that they provide fast and secure access to linguistic and cultural data for local researchers and the language communities. They also make data safer by allowing for regular update procedures within the network

Language documentation and archives in South America

This paper addresses a set of issues related to language documentation that are not often explicitly dealt with in academic publications, yet are highly important for the development and success of this new discipline. These issues include embedding language documentation in the socio-political context not only at the community level but also at the national level, the ethical and technical challenges of digital language archives, and the importance of regional and international cooperation among documentation activities. These issues play a major role in the initiative to set up a network of regional language archives in three South American countries, which this paper reports on. Local archives for data on endangered languages have recently been set up in Iquitos (Peru), Buenos Aires (Argentina), and in various locations in Brazil. An important feature of these is that they provide fast and secure access to linguistic and cultural data for local researchers and the language communities. They also make data safer by allowing for regular update procedures within the network

Directional statistics and filtering using libDirectional

In this paper, we present libDirectional, a MATLAB library for directional statistics and directional estimation. It supports a variety of commonly used distributions on the unit circle, such as the von Mises, wrapped normal, and wrapped Cauchy distributions. Furthermore, various distributions on higher-dimensional manifolds such as the unit hypersphere and the hypertorus are available. Based on these distributions, several recursive filtering algorithms in libDirectional allow estimation on these manifolds. The functionality is implemented in a clear, well-documented, and object-oriented structure that is both easy to use and easy to extend

Recent Results on the Periodic Lorentz Gas

The Drude-Lorentz model for the motion of electrons in a solid is a classical model in statistical mechanics, where electrons are represented as point particles bouncing on a fixed system of obstacles (the atoms in the solid). Under some appropriate scaling assumption -- known as the Boltzmann-Grad scaling by analogy with the kinetic theory of rarefied gases -- this system can be described in some limit by a linear Boltzmann equation, assuming that the configuration of obstacles is random [G. Gallavotti, [Phys. Rev. (2) vol. 185 (1969), 308]). The case of a periodic configuration of obstacles (like atoms in a crystal) leads to a completely different limiting dynamics. These lecture notes review several results on this problem obtained in the past decade as joint work with J. Bourgain, E. Caglioti and B. Wennberg.Comment: 62 pages. Course at the conference "Topics in PDEs and applications 2008" held in Granada, April 7-11 2008; figure 13 and a misprint in Theorem 4.6 corrected in the new versio

Optical activity induced by curvature in a gravitational pp-wave background

We study optical activity induced by curvature. The optical activity model we present has two phenomenological gyration parameters, within which we analyze three model cases, namely, an exactly integrable model, the Landau-Lifshitz model and the Fedorov model, these latter two are solved in the short wavelength approximation. The model background is a gravitational pp-wave. The solutions show that the optical activity induced by curvature leads to Faraday rotation.Comment: 16 pages, late

Nonlinear Coherent Magneto-Optical Response of a Single Chiral Carbon Nanotube

Published versio

Effect of transition layers on the electromagnetic properties of composites containing conducting fibres

The approach to calculating the effective dielectric and magnetic response in bounded composite materials is developed. The method is essentially based on the renormalisation of the dielectric matrix parameters to account for the surface polarisation and the displacement currents at the interfaces. This makes it possible the use of the effective medium theory developed for unbounded materials, where the spatially-dependent local dielectric constant and magnetic permeability are introduced. A detailed mathematical analysis is given for a dielectric layer having conducting fibres with in-plane positions. The surface effects are most essential at microwave frequencies in correspondence to the resonance excitation of fibres. In thin layers (having a thickness of the transition layer), the effective dielectric constant has a dispersion region at much higher frequencies compared to those for unbounded materials, exhibiting a strong dependence on the layer thickness. For the geometry considered, the effective magnetic permeability differs slightly from unity and corresponds to the renormalised matrix parameter. The magnetic effect is due entirely to the existence of the surface displacement currents.Comment: PDF, 33 pages, 10 figure

Gastric xanthomatosis and cholestasis

We report two cases of gastric xanthomatosis which developed in patients with marked cholestasis. In both cases, one with acute and one with chronic cholestasis, the gastric xanthomas disappeared with resolution of the cholestasis. A review of the literature is also provided.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44402/1/10620_2005_Article_BF01303212.pd

Empoderamiento y feminismo comunitario en la conservación del maíz en México

Articulo científico para revista indizada.El objetivo es analizar, desde una perspectiva basada en el feminismo comunitario, el proceso de empoderamiento de las mujeres que conforman un grupo de ocho integrantes matlatzincas de la comunidad de San Francisco Oxtotilpan, México, a través de prácticas productivas, alimentarias y culturales en torno al maíz nativo. Los datos fueron recogidos durante 2014 y 2015 con técnicas etnográficas que incluyen: observación participante, historias de vida, grupos focales, entrevistas semiestructuradas y a profundidad. Son mujeres que muestran cinco dimensiones de poder (social, corporal, material, simbólico y cognitivo) que repercuten en la preservación del maíz nativo, al generar la masa crítica necesaria para incorporar a otras mujeres en acciones favorables para la soberanía alimentaria