Perturbative approach to diatomic lattices

By using a small rotation approach, we show that it is possible to obtain well behaved perturbed solutions for the amplitude of the electromagnetic field propagating in a photonic waveguide array. This array mimics the propagation of a quasiparticle among the sites of an infinite one-dimensional chain.Comment: 7 pages, 4 figure

Predictors of English Health Literacy among U.S. Hispanic Immigrants: The importance of language, bilingualism and sociolinguistic environment

In the United States, data confirm that Spanish-speaking immigrants are particularly affected by the negative health outcomes associated with low health literacy. Although the literature points to variables such as age, educational background and language, only a few studies have investigated the factors that may influence health literacy in this group. Similarly, the role that bilingualism and/or multilingualism play in health literacy assessment continues to be an issue in need of further research. The purpose of this study was to examine the predictors of English health literacy among adult Hispanic immigrants whose self-reported primary language is Spanish, but who live and function in a bilingual community. It also explored issues related to the language of the instrument. An analysis of data collected through a randomized controlled study was conducted. Results identified English proficiency as the strongest predictor of health literacy (p < 0.001). The results further point to the importance of primary and secondary language in the assessment of heath literacy level. This study raises many questions in need of further investigation to clarify how language proficiency and sociolinguistic environment affect health literacy in language minority adults; proposes language approaches that may be more appropriate for measuring health literacy in these populations; and recommends further place-based research to determine whether the connection between language proficiency and health is generalizable to border communities

Invisible Cavity Resonators

This thesis studies one-dimensional structures based on a volume bounded by two metasurfaces. The main objective is to determine the properties of the metasurfaces such that under illumination by a normally incident plane wave the whole structure does not scatter; while the electromagnetic fields inside the bounded volume are not zero and can be tailored. Such invisible resonators are analysed from different perspectives: standing wave ratio, convergence, bandwidth, impact of dissipation losses, reciprocity, and effect of different objects inside the resonator. This thesis also introduces some concepts related to volumes bounded by multiple metasurfaces and some examples. Some applications for these resonators include cloaking and enhancing of low-power sensors

El proceso de asentamiento de la migración México-Estados Unidos

Existe un proceso de reconfiguración en la migración mexicana a Estados Unidos. En la actualidad la población migrante es de 11 millones de personas y equivale a 11 por ciento del total de la población mexicana. Los centros de expulsión siguen siendo los de origen rural del bajío mexicano, pero se han sumado los de tipo urbano y particularmente del sur sureste del país, con población indígena. En cuanto al género, éste es balanceado, 56 por ciento masculino y 44 por ciento femenino. Respecto a los destinos en Estados Unidos, Texas, California, Arizona, Nuevo México e Indiana siguen siendo importantes, pero ahora los migrantes mexicanos son mayoría en 43 Estados. Los cruces tradicionales han perdido importancia y han surgido otros como Altar Sonora (Sásabe-Sasabe, Sonoyta, Agua Prieta y Cd. Juárez) cuya principal característica es la peligrosidad para la vida del migrante y la utilización de coyotes para atravesar la frontera