129 research outputs found

    Kolmogorov turbulence, Anderson localization and KAM integrability

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    The conditions for emergence of Kolmogorov turbulence, and related weak wave turbulence, in finite size systems are analyzed by analytical methods and numerical simulations of simple models. The analogy between Kolmogorov energy flow from large to small spacial scales and conductivity in disordered solid state systems is proposed. It is argued that the Anderson localization can stop such an energy flow. The effects of nonlinear wave interactions on such a localization are analyzed. The results obtained for finite size system models show the existence of an effective chaos border between the Kolmogorov-Arnold-Moser (KAM) integrability at weak nonlinearity, when energy does not flow to small scales, and developed chaos regime emerging above this border with the Kolmogorov turbulent energy flow from large to small scales.Comment: 8 pages, 6 figs, EPJB style

    Atitude e percepção sobre epilepsia em diferentes segmentos sociais no Brasil

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    PURPOSE: To assess public awareness and attitudes toward epilepsy in Brazilians of different cultural and socioeconomic backgrounds. BACKGROUND: Several studies have examined public awareness and attitudes toward epilepsy in various countries but there are no equivalent data for Brazil or South America. MATERIAL AND METHODS: We have applied the survey proposed by Caveness and Gallup , with some modifications and adaptations to four groups (I-IV) of subjects: I- 105 individuals accompanying patients to the Ophthalmologic outpatient clinic of the Hospital das Clínicas of the State University of Campinas (UNICAMP); II- 93 students recently admitted to medical and nursing school; III- 101 senior non-medical students; and IV- 69 senior medical students. Groups II, III, and IV were students at UNICAMP. RESULTS: Individuals with a low socioeconomic standing had a poor profile of familiarity, knowledge and attitudes toward epilepsy. The pre-university and university students had a relatively good profile when compared to the published international polls. Senior medical students had an excellent level of familiarity and knowledge, but showed no change in their objection to having a son or a daughter marry an epileptic person. CONCLUSIONS: Our data suggest that there is a clear-cut relationship between the level of education and the individual's familiarity and attitudes toward epilepsy. Effective elimination of the prejudice toward epilepsy requires specific training and not just general, superficial information about the condition.Com o objetivo de avaliar a percepção e a atitude em relação à epilepsia aplicamos questionário de 9 perguntas, modificado de Caveness e Gallup,1980. Foram entrevistados 105 acompanhantes de pacientes da Clínica de Oftalmologia do Hospital das Clínicas da UNICAMP (grupo I); 93 estudantes admitidos em 1996 nos cursos de medicina e enfermagem (grupo II); 101 estudantes do último ano de outros cursos, que não medicina (grupo III); e 69 estudantes do sexto ano do curso de medicina (grupo IV). Todos os estudantes eram da UNICAMP. Responderam que já tinham ouvido falar em epilepsia 87,6% do grupo I e 100% dos demais grupos. Com relação à causa da epilepsia responderam não sei ou respostas erradas: grupo-I 51,1%, grupo-II 30,2%, grupo-III 32,7% e grupo-IV 0%. Os autores discutem os seus achados comparativamente à literatura internacional pertinente e concluem que: 1. Há clara relação entre o nível educacional e familiaridade e atitude em relação à epilepsia; 2. Eliminação efetiva do preconceito em relação à epilepsia exige treinamento específico e não informações superficiais, de cunho amplo sobre a condição. Estes dados suportam a noção de que campanhas nacionais devam ser realizadas para melhor esclarecimento leigo sobre as epilepsias, incluindo a população universitária.323

    The state of the Martian climate

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    60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes

    The WOCE–era 3–D Pacific Ocean circulation and heat budget

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    Author Posting. © The Author(s), 2009. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Progress In Oceanography 82 (2009): 281-325, doi:10.1016/j.pocean.2009.08.002.To address questions concerning the intensity and spatial structure of the 3–dimensional circulation within the Pacific Ocean and the associated advective and diffusive property flux divergences, data from approximately 3000 high–quality hydrographic stations collected on 40 zonal and meridional cruises have been merged into a physically consistent model. The majority of the stations were occupied as part of the World Ocean Circulation Experiment (WOCE), which took place in the 1990s. These data are supplemented by a few pre–WOCE surveys of similar quality, and time–averaged direct–velocity and historical hydrographic measurements about the equator. An inverse box model formalism is employed to estimate the absolute along–isopycnal velocity field, the magnitude and spatial distribution of the associated diapycnal flow and the corresponding diapycnal advective and diffusive property flux divergences. The resulting large–scale WOCE Pacific circulation can be described as two shallow overturning cells at mid– to low latitudes, one in each hemisphere, and a single deep cell which brings abyssal waters from the Southern Ocean into the Pacific where they upwell across isopycnals and are returned south as deep waters. Upwelling is seen to occur throughout most of the basin with generally larger dianeutral transport and greater mixing occurring at depth. The derived pattern of ocean heat transport divergence is compared to published results based on air–sea flux estimates. The synthesis suggests a strongly east/west oriented pattern of air–sea heat flux with heat loss to the atmosphere throughout most of the western basins, and a gain of heat throughout the tropics extending poleward through the eastern basins. The calculated meridional heat transport agrees well with previous hydrographic estimates. Consistent with many of the climatologies at a variety of latitudes as well, our meridional heat transport estimates tend toward lower values in both hemispheres.This work was funded by National Science Foundation grants OCE–9710102, OCE– 9712209 and OCE–0079383, and also benefited from work on closely related projects funded by NSF grants OCE–0223421 and OCE–0623261, and NOAA grant NA17RJ1223 funded through CICOR. For G.C.J. NASA funding came under Order W–19,314

    Modifiable risk factors associated with prediabetes in men and women: A cross-sectional analysis of the cohort study in primary health care on the evolution of patients with prediabetes

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    Background: Prediabetes is a high-risk state for diabetes development, but little is known about the factors associated with this state. The aim of the study was to identify modifiable risk factors associated with the presence of prediabetes in men and women. Methods: Cohort Study in Primary Health Care on the Evolution of Patients with Prediabetes (PREDAPS-Study) is a prospective study on a cohort of 1184 subjects with prediabetes and another cohort of 838 subjects without glucose metabolism disorders. It is being conducted by 125 general practitioners in Spain. Data for this analysis were collected during the baseline stage in 2012. The modifiable risk factors included were: smoking habit, alcohol consumption, low physical activity, inadequate diet, hypertension, dyslipidemia, and obesity. To assess independent association between each factor and prediabetes, odds ratios (ORs) were estimated using logistic regression models. Results: Abdominal obesity, low plasma levels of high-density lipoprotein cholesterol (HDL-cholesterol), and hypertension were independently associated with the presence of prediabetes in both men and women. After adjusting for all factors, the respective ORs (95% Confidence Intervals) were 1.98 (1.41-2.79), 1.88 (1.23-2.88) and 1.86 (1.39-2.51) for men, and 1.89 (1.36-2.62), 1.58 (1.12-2.23) and 1.44 (1.07-1.92) for women. Also, general obesity was a risk factor in both sexes but did not reach statistical significance among men, after adjusting for all factors. Risky alcohol consumption was a risk factor for prediabetes in men, OR 1.49 (1.00-2.24). Conclusions: Obesity, low HDL-cholesterol levels, and hypertension were modifiable risk factors independently related to the presence of prediabetes in both sexes. The magnitudes of the associations were stronger for men than women. Abdominal obesity in both men and women displayed the strongest association with prediabetes. The findings suggest that there are some differences between men and women, which should be taken into account when implementing specific recommendations to prevent or delay the onset of diabetes in adult population
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