Magnetiza����o remanescente: um par��metro crucial para a interpreta����o e modelamento de anomalias magn��ticas em territ��rio brasileiro

A quest��o da magnetiza����o remanescente na interpreta����o de anomalias magn��ticas �� frequentemente negligenciada, principalmente em fun����o da dificuldade em se lidar com a mesma. Na maioria dos casos, tanto nos trabalhos acad��micos quanto nos modelos que circulam nos meios profissionais da explora����o mineral e de petr��leo, assume-se que a magnetiza����o remanescente �� desprez��vel e utiliza-se apenas a induzida. O presente artigo mostra que o uso desse par��metro �� particularmente importante no tocante ��s anomalias magn��ticas brasileiras, e procura fornecer subs��dios para o uso desta informa����o. Discute-se o uso de duas t��cnicas consagradas, a Redu����o ao P��lo e o Sinal Anal��tico, em anomalias brasileiras com e sem magnetiza����o remanescente. Mostramos a aplica����o da t��cnica de determina����o da magnetiza����o total, permitindo que os modelos sejam constru��dos a partir da resultante da soma das magnetiza����es induzida e remanescente, e posteriormente apresentamos uma metodologia de uso da informa����o remanescente na data����o das rochas fonte.

Novos paradigmas e velhos discursos: analisando processos de adolescentes em conflito com a lei

Este artigo evidencia an��lises contidas na disserta����o cujo objetivo foi analisar os discursos dos operadores jur��dico-sociais em processos judiciais de Varas da Inf��ncia e Juventude de duas cidades brasileiras. Os direitos das crian��as e adolescentes, a quest��o social e a an��lise do discurso configuraram-se como referenciais te��ricos e de an��lise. Resultados evidenciaram discursos de prote����o e revelaram tamb��m a inten����o de puni����o. A quest��o social foi ignorada pelos operadores a despeito dos contextos em que ocorreram as infra����es.

��ndice h de docentes em Sa��de Coletiva no Brasil

OBJETIVO: Estimar valores de refer��ncia e fun����o de hierarquia de docentes em Sa��de Coletiva do Brasil por meio de an��lise da distribui����o do ��ndice h. M��TODOS: A partir do portal da Coordena����o de Aperfei��oamento de Pessoal de N��vel Superior, 934 docentes foram identificados em 2008, dos quais 819 foram analisados. O ��ndice h de cada docente foi obtido na Web of Science mediante algoritmos de busca com controle para homon��mias e alternativas de grafia de nome. Para cada regi��o e para o Brasil como um todo ajustou-se fun����o densidade de probabilidade exponencial aos par��metros m��dia e taxa de decr��scimo por regi��o. Foram identificadas medidas de posi����o e, com o complemento da fun����o probabilidade acumulada, fun����o de hierarquia entre autores conforme o ��ndice h por regi��o. RESULTADOS: Dos docentes, 29,8% n��o tinham qualquer registro de cita����o (h = 0). A m��dia de h para o Pa��s foi 3,1, com maior m��dia na regi��o Sul (4,7). A mediana de h para o Pa��s foi 2,1, tamb��m com maior mediana na Sul (3,2). Para uma padroniza����o de popula����o de autores em cem, os primeiros colocados para o Pa��s devem ter h = 16; na estratifica����o por regi��o, a primeira posi����o demanda valores mais altos no Nordeste, Sudeste e Sul, sendo nesta ��ltima h = 24. CONCLUS��ES: Avaliados pelos ��ndices h da Web of Science, a maioria dos autores em Sa��de Coletiva n��o supera h = 5. H�� diferen��as entres as regi��es, com melhor desempenho para a Sul e valores semelhantes entre Sudeste e Nordeste.

Associa����o entre excesso de peso e h��bito de fumar, Santar��m, PA, 2007

OBJETIVO: Estudar associa����o entre excesso de peso e h��bito de fumar. METODOLOGIA: Estudo transversal desenvolvido por telefone numa amostra probabil��stica de adultos (Santar��m /PA), em 2007. Vari��vel desfecho foi excesso de peso, explanat��ria h��bito de fumar e de confus��o idade, escolaridade, uni��o conjugal, estado nutricional pr��vio, abuso de bebidas alco��licas, atividade f��sica no lazer e padr��o alimentar. Associa����o entre excesso de peso e demais vari��veis foi investigada pelo teste do qui-quadrado e regress��o de Poisson para o c��lculo das raz��es de preval��ncia de excesso de peso conforme h��bito de fumar, considerando-se tr��s n��veis de hierarquia: caracter��sticas sociodemogr��ficas, estado nutricional pr��vio e padr��o comportamental. RESULTADOS: Verificou-se 40,6% de excesso de peso e 16,4% de fumantes. As vari��veis associadas ao excesso de peso foram: maior idade, menor escolaridade, uni��o conjugal est��vel, excesso de peso aos 20 anos e h��bito de n��o consumo de refrigerante para ambos os sexos; n��o ativo no lazer para homens e h��bito de fumar (atual e passado) para mulheres. As raz��es de preval��ncia de excesso de peso n��o apresentaram associa����o com h��bito de fumar para homens, por��m para mulheres houve tend��ncia de maior preval��ncia de excesso de peso para fumantes atuais, chegando a 2,56 vezes mais do que para nunca fumantes e ex-fumantes. CONCLUS��O: Este estudo constatou que a preval��ncia de excesso de peso foi maior para mulheres fumantes, comparativamente ��s ex-fumantes e nunca fumantes. Para os homens n��o se observou nenhuma associa����o entre excesso de peso e tabagismo.

Self-medication: initial treatments used by patients seen in an ophthalmologic emergency room

OBJECTIVE: This study seeks to identify practices of self-medication in the treatment of ocular emergencies. We examine patients' use of both homemade preparations and manufactured products before seeking specialized care. MATERIALS AND METHODS: We conducted a cross-sectional analytic survey of consecutive patients seen in the ophthalmology emergency room of a teaching hospital. RESULTS: The sample included 561 subjects, 51.3% males and 48.7% females, with a mean age of 39.8 years. Prior to seeking emergency care, 40.5% reported self-medicating; 29.4% used a homemade preparation (13.9% referred to an industrialized product like boric acid as a homemade preparation), and 11.1% used a manufactured product. The most frequently used products included a boric acid solution (53.3%), a normal saline solution (35.7%), herbal infusions (6.1%) and breast milk (4.8%). Viral conjunctivitis was the most frequent diagnosis (24.4%), followed by the presence of a corneal foreign body (7.4%). No significant differences were found in the self-treatment of ocular injuries according to gender (p = 0.95), level of education (p = 0.21) or age (p = 0.14). In addition, self-medication practices were not related to the medically judged severity of the condition. CONCLUSION: Patients often attempt to treat conditions that require ophthalmologic emergency care by self-medicating with homemade or manufactured products. The most widely used products include boric acid, normal saline, leaf infusions and breast milk. This behavior occurs independently of educational level, gender, age or the nature of the ocular condition. Self-medication is a culturally driven practice that is used even in cases of acute ocular injuries.

A primeira planta cartogr��fica da cidade de S��o Paulo

The first known plan of the city of Sao Paulo, made in 1810 by Rufino Felizardo e Costa, is analyzed with emphasis on the cartographic and astronomical details: the precision, scale, magnetic declination, and orientation in relation to the north, the prime meridian, the precision of the coordinates (latitude and longitude) and others. An analytic methodology is followed, observing the plan and formulating questions. To answer then, resources of modern technologies are employed (digital cartography, GPS) as well as knowledge of the history of cartography. The work is justified by the fact that there are no cartographic studies about this important document.

Analytical solutions for Tokamak equilibria with reversed toroidal current

In tokamaks, an advanced plasma confinement regime has been investigated with a central hollow electric current with negative density which gives rise to non-nested magnetic surfaces. We present analytical solutions for the magnetohydrodynamic equilibria of this regime in terms of non-orthogonal toroidal polar coordinates. These solutions are obtained for large aspect ratio tokamaks and they are valid for any kind of reversed hollow current density profiles. The zero order solution of the poloidal magnetic flux function describes nested toroidal magnetic surfaces with a magnetic axis displaced due to the toroidal geometry. The first order correction introduces a poloidal field asymmetry and, consequently, magnetic islands arise around the zero order surface with null poloidal magnetic flux gradient. An analytic expression for the magnetic island width is deduced in terms of the equilibrium parameters. We give examples of the equilibrium plasma profiles and islands obtained for a class of current density profile. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3624551]

New constraints on muon-neutrino to electron-neutrino transitions in MINOS

This paper reports results from a search for nu(mu) -> nu(e) transitions by the MINOS experiment based on a 7 x 10(20) protons-on-target exposure. Our observation of 54 candidate nu(e) events in the far detector with a background of 49.1 +/- 7.0(stat) +/- 2.7(syst) events predicted by the measurements in the near detector requires 2sin(2)(2 theta(13))sin(2)theta(23) < 0.12(0.20) at the 90% C.L. for the normal (inverted) mass hierarchy at delta(CP) = 0. The experiment sets the tightest limits to date on the value of theta(13) for nearly all values of delta(CP) for the normal neutrino mass hierarchy and maximal sin(2)(2 theta(23)).

Two-dimensional supersonic nonlinear Schrodinger flow past an extended obstacle

Supersonic flow of a superfluid past a slender impenetrable macroscopic obstacle is studied in the framework of the two-dimensional (2D) defocusing nonlinear Schroumldinger (NLS) equation. This problem is of fundamental importance as a dispersive analog of the corresponding classical gas-dynamics problem. Assuming the oncoming flow speed is sufficiently high, we asymptotically reduce the original boundary-value problem for a steady flow past a slender body to the one-dimensional dispersive piston problem described by the nonstationary NLS equation, in which the role of time is played by the stretched x coordinate and the piston motion curve is defined by the spatial body profile. Two steady oblique spatial dispersive shock waves (DSWs) spreading from the pointed ends of the body are generated in both half planes. These are described analytically by constructing appropriate exact solutions of the Whitham modulation equations for the front DSW and by using a generalized Bohr-Sommerfeld quantization rule for the oblique dark soliton fan in the rear DSW. We propose an extension of the traditional modulation description of DSWs to include the linear ""ship-wave"" pattern forming outside the nonlinear modulation region of the front DSW. Our analytic results are supported by direct 2D unsteady numerical simulations and are relevant to recent experiments on Bose-Einstein condensates freely expanding past obstacles.

Elastic Maier-Saupe-Zwanzig model and some properties of nematic elastomers

We introduce a simple mean-field lattice model to describe the behavior of nematic elastomers. This model combines the Maier-Saupe-Zwanzig approach to liquid crystals and an extension to lattice systems of the Warner-Terentjev theory of elasticity, with the addition of quenched random fields. We use standard techniques of statistical mechanics to obtain analytic solutions for the full range of parameters. Among other results, we show the existence of a stress-strain coexistence curve below a freezing temperature, analogous to the P-V diagram of a simple fluid, with the disorder strength playing the role of temperature. Below a critical value of disorder, the tie lines in this diagram resemble the experimental stress-strain plateau and may be interpreted as signatures of the characteristic polydomain-monodomain transition. Also, in the monodomain case, we show that random fields may soften the first-order transition between nematic and isotropic phases, provided the samples are formed in the nematic state.

Lepton sector of a fourth generation

In extensions of the standard model with a heavy fourth generation, one important question is what makes the fourth-generation lepton sector, particularly the neutrinos, so different from the lighter three generations. We study this question in the context of models of electroweak symmetry breaking in warped extra dimensions, where the flavor hierarchy is generated by choosing the localization of the zero-mode fermions in the extra dimension. In this setup the Higgs sector is localized near the infrared brane, whereas the Majorana mass term is localized at the ultraviolet brane. As a result, light neutrinos are almost entirely Majorana particles, whereas the fourth-generation neutrino is mostly a Dirac fermion. We show that it is possible to obtain heavy fourth-generation leptons in regions of parameter space where the light neutrino masses and mixings are compatible with observation. We study the impact of these bounds, as well as the ones from lepton flavor violation, on the phenomenology of these models.

Testing for large extra dimensions with neutrino oscillations

We consider a model where sterile neutrinos can propagate in a large compactified extra dimension giving rise to Kaluza-Klein (KK) modes and the standard model left-handed neutrinos are confined to a 4-dimensional spacetime brane. The KK modes mix with the standard neutrinos modifying their oscillation pattern. We examine former and current experiments such as CHOOZ, KamLAND, and MINOS to estimate the impact of the possible presence of such KK modes on the determination of the neutrino oscillation parameters and simultaneously obtain limits on the size of the largest extra dimension. We found that the presence of the KK modes does not essentially improve the quality of the fit compared to the case of the standard oscillation. By combining the results from CHOOZ, KamLAND, and MINOS, in the limit of a vanishing lightest neutrino mass, we obtain the stronger bound on the size of the extra dimension as similar to 1.0(0.6) mu m at 99% C.L. for normal (inverted) mass hierarchy. If the lightest neutrino mass turns out to be larger, 0.2 eV, for example, we obtain the bound similar to 0.1 mu m. We also discuss the expected sensitivities on the size of the extra dimension for future experiments such as Double CHOOZ, T2K, and NO nu A.

Long life of Gauss-Bonnet corrected black holes

Dictated by the string theory and various higher dimensional scenarios, black holes in D > 4-dimensional space-times must have higher curvature corrections. The first and dominant term is quadratic in curvature, and called the Gauss-Bonnet (GB) term. We shall show that although the Gauss-Bonnet correction changes black hole's geometry only softly, the emission of gravitons is suppressed by many orders even at quite small values of the GB coupling. The huge suppression of the graviton emission is due to the multiplication of the two effects: the quick cooling of the black hole when one turns on the GB coupling and the exponential decreasing of the gray-body factor of the tensor type of gravitons at small and moderate energies. At higher D the tensor gravitons emission is dominant, so that the overall lifetime of black holes with Gauss-Bonnet corrections is many orders larger than was expected. This effect should be relevant for the future experiments at the Large Hadron Collider (LHC).

Instability of Higher-Dimensional Charged Black Holes in the de Sitter World

We have shown that higher-dimensional Reissner-Nordstrom-de Sitter black holes are gravitationally unstable for large values of the electric charge and cosmological constant in D >= 7 space-time dimensions. We have found the shape of the slightly perturbed black hole at the threshold point of instability.

Graviton emission in the bulk by a simply rotating black hole

In this work, we study the emission of tensor-type gravitational degrees of freedom from a higher-dimensional, simply rotating black hole in the bulk. The decoupled radial part of the corresponding field equation is first solved analytically in the limit of low-energy emitted particles and low-angular momentum of the black hole in order to derive the absorption probability. Both the angular and radial equations are then solved numerically, and the comparison of the analytical and numerical results shows a very good agreement in the low and intermediate energy regimes. By using our exact, numerical results we compute the energy and angular-momentum emission rates and their dependence on the spacetime parameters such as the number of additional spacelike dimensions and the angular momentum of the black hole. Particular care is given to the convergence of our results in terms of the number of modes taken into account in the calculation and the multiplicity of graviton tensor modes that correspond to the same angular-momentum numbers.