When caring hurts: “Foreign” teachers in Texas bilingual classrooms

As the U.S. teacher shortage continues to worsen, large, urban districts have turned to hiring teachers from abroad, including countries like Spain, Mexico, and the incorporated U.S. territory of Puerto Rico. However, several researchers in the field of have pointed out to the unexamined complexities of hiring Latin American and Spanish teachers to fill in vacancies in U.S. bilingual classrooms. Although these teachers are often what some deem a linguistic match, differences in class, culture, and migratory experiences should send, in the least, a cautionary message to school districts, oversea recruiters, and school administrators. In this essay I discuss and problematize these complexities and offer recommendations for researchers, district personnel, and teachers.Educatio

Hidden unity in the quantum description of matter

We introduce an algebraic framework for interacting quantum systems that enables studying complex phenomena, characterized by the coexistence and competition of various broken symmetry states of matter. The approach unveils the hidden unity behind seemingly unrelated physical phenomena, thus establishing exact connections between them. This leads to the fundamental concept of {\it universality} of physical phenomena, a general concept not restricted to the domain of critical behavior. Key to our framework is the concept of {\it languages} and the construction of {\it dictionaries} relating them.Comment: 10 pages 2 psfigures. Appeared in Recent Progress in Many-Body Theorie

Short-term tuna fishing community: the dwellings in the 30s and 60s

This article describes the dwellings of a short-term tuna fishing community settled in Faro beach, Algarve, Portugal, between the 30s and 60s, that already disappeared. It is related how the change from the reed houses to the wooden sheds took place and how was the day-by-day of fishermen and their families during the tuna fishing season, from March to June. In the course of this research it was discovered that such fishing community took place in Faro beach for long decades, involved a large group of fishermen and their families that lived there, in a structured way. The main results we hope to achieve are the general awareness of this heritage and its dissemination. This research was based on documentary analysis, photographic and bibliographic research but, more importantly, interviews with people involved in this art, that still remains. During the development of this research, limitations were found due to the scarcity of available information and to the advanced age of the people involved, now with around 90 years old. That's why there's an urgency to make an adequate registration and disclosure of this heritage. This paper is original because there aren't many works about this theme under this point of view, taking Faro beach as object of study. As a vernacular heritage, it must be valued, so, publishing such work would influence the society in general, but primarily, the region's society, to alert them to a value that has been forgotten and, at the same time, clarify the future generations, helping to preserve the collective memory of a professional art that disappeared from the Algarve.info:eu-repo/semantics/publishedVersio

Electronic Orbital Currents and Polarization in Mott Insulators

The standard view is that at low energies Mott insulators exhibit only magnetic properties while charge degrees of freedom are frozen out as the electrons become localized by a strong Coulomb repulsion. We demonstrate that this is in general not true: for certain spin textures {\it spontaneous circular electric currents} or {\it nonuniform charge distribution} exist in the ground state of Mott insulators. In addition, low-energy ``magnetic'' states contribute comparably to the dielectric and magnetic functions $\epsilon_{ik}(\omega)$ and $\mu_{ik}(\omega)$ leading to interesting phenomena such as rotation the electric field polarization and resonances which may be common for both functions producing a negative refraction index in a window of frequencies

Vortex Dynamics in Ferromagnetic Superconductors: Vortex Clusters, Domain Walls and Enhanced Viscosity

We demonstrate that there is a long-range vortex-vortex attraction in ferromagnetic superconductors due to polarization of the magnetic moments. Vortex clusters are then stabilized in the ground state for low vortex densities. The motion of vortex clusters driven by the Lorentz force excites magnons. This regime becomes unstable at a threshold velocity above which domain walls are generated for slow relaxation of the magnetic moments and the vortex configuration becomes modulated. This dynamics of vortices and magnetic moments can be probed by transport measurements.Comment: 6 pages and 3 figure

Sampling system for wheat (Triticum aestivum L) area estimation using digital LANDSAT MSS data and aerial photographs

A procedure to estimate wheat (Triticum aestivum L) area using sampling technique based on aerial photographs and digital LANDSAT MSS data is developed. Aerial photographs covering 720 square km are visually analyzed. To estimate wheat area, a regression approach is applied using different sample sizes and various sampling units. As the size of sampling unit decreased, the percentage of sampled area required to obtain similar estimation performance also decreased. The lowest percentage of the area sampled for wheat estimation with relatively high precision and accuracy through regression estimation is 13.90% using 10 square km as the sampling unit. Wheat area estimation using only aerial photographs is less precise and accurate than those obtained by regression estimation

Quantum critical 5f-electrons avoid singularities in U(Ru,Rh)2Si2

We present specific heat measurements of 4% Rh-doped U(Ru,Rh)2Si2 at magnetic fields above the proposed metamagnetic transition field Hm~34 T, revealing striking similarities to the isotructural Ce analog CeRu2Si2, suggesting that strongly renormalized hybridized band models apply equally well to both systems. The vanishing bandwidths as H --> Hm are consistent with a putative quantum critical point close to Hm. The existence of a phase transition into an ordered phase in the vicinity of Hm for 4% Rh-doped U(Ru,Rh)2Si2, but not for CeRu2Si2, is consistent with a stronger super-exchange in the case of the U 5-f system, with irreversible processes at the transition revealing a strong coupling of the 5f orbitals to the lattice, most suggestive of orbital or electric quadrupolar order.Comment: 4 pages, 4 figure

Vortex Viscosity in Magnetic Superconductors Due to Radiation of Spin Waves

In type-II superconductors that contain a lattice of magnetic moments, vortices polarize the magnetic system inducing additional contributions to the vortex mass, vortex viscosity, and vortex-vortex interaction. Extra magnetic viscosity is caused by radiation of spin waves by a moving vortex. Like in the case of Cherenkov radiation, this effect has a characteristic threshold behavior and the resulting vortex viscosity may be comparable to the well-known Bardeen-Stephen contribution. The threshold behavior leads to an anomaly in the current-voltage characteristics, and a drop in dissipation for a current interval that is determined by the magnetic excitation spectrum.Comment: 4 pages, 1 figur