Noncommutative geometry for three-dimensional topological insulators

We generalize the noncommutative relations obeyed by the guiding centers in the two-dimensional quantum Hall effect to those obeyed by the projected position operators in three-dimensional (3D) topological band insulators. The noncommutativity in 3D space is tied to the integral over the 3D Brillouin zone of a Chern-Simons invariant in momentum-space. We provide an example of a model on the cubic lattice for which the chiral symmetry guarantees a macroscopic number of zero-energy modes that form a perfectly flat band. This lattice model realizes a chiral 3D noncommutative geometry. Finally, we find conditions on the density-density structure factors that lead to a gapped 3D fractional chiral topological insulator within Feynman's single-mode approximation.Comment: 41 pages, 3 figure

Rethinking engineering education

The Professional of today needs to acquire a dynamic ability to absorb information, adjust to organizational goals, and navigate in a complex work environment. For this reason, a classic approach seems to be more useful for the demands of today's job market. It is at least interesting to notice, that the classic approach is being neglected, at a time when its product might be more interesting than ever. The Engineering Education Team of COPEC – Science and Education Research Council has designed a program that is knowledge centered and specially challenging, which integrates classical engineering approaches and real experience in order to achieve a high level of engineers ready to perform as professionals or researchers. It aims to form the Engineer – a professional that is capable to learn for life and be creative in many ways.This work is financed by FEDER funds through the Competitivity Factors Operational Programme – COMPETE: POCI-01-0145-FEDER-007043 and by national funds through FCT – Foundation for Science and Technology within the scope of the project POCI-01-0145-FEDER-007136 and project UID/CEC/00319/2013.info:eu-repo/semantics/publishedVersio

International experiences and the implications for the success of engineering programs

The working midst has become challenging due to the multicultural environment and the need of skills such as cultural understanding, are very important in the formation of an engineer. It has been like this for many years however, now more than ever. So, for engineering schools, internationalization has become, on top of others, another demand for the accomplishment of a good program. It became necessary to provide international academic experience for the students. For this reason, internationalization is now a strategy to raise the quality of courses and as another result of these efforts, to raise the engineering students’ retention rate along the program. The goal of this paper is to present and discuss the internationalization process of a University’s engineering school, with the objective of making the program more attractive and promoting the double diploma in order to higher the quality of the programs.(undefined)info:eu-repo/semantics/publishedVersio

Mercury adsorption on natural and organofunctionalized smectites - thermodynamics of cation removal

A natural smectite clay sample from Piauí State, Brazil, was organofunctionalized with 3-mercaptopropyltrimethoxysilane and 3-aminopropyltriethoxysilane silyating agents. The basal spacing of 0.99 nm and surface area of 48 m² g-1 for natural clay increased to 1.84 and 2.01 nm, and 781 and 795 m² g-1 for modified clays, respectively. The natural and chemically immobilized clay samples adsorb mercury cations from aqueous solutions at pH 3.0 at 298 ± 1 K. The Langmuir, Redlich-Peterson and Toth adsorption isotherm models were applied to fit the experimental data with a nonlinear approach. From the cation/basic center interactions for each smectite at the solid-liquid interface, by using calorimetry methodology, the equilibrium constant and exothermic thermal effects were obtained. By considering the net interactive number of moles for each cation and the equilibrium constant, the enthalpy, intHº (-11.98 to -13.93 kJ mol-1) and negative free Gibbs energy, intGº (-22.4 ± 0.1 to -23.9 ± 0.1 kJ mol-1) were calculated. These values enabled the determination of positive entropy, intSº (51 ± 01 to 55 ± 2 J K-1 mol-1). The cation-basic center interactions are spontaneous in nature as demonstrated from favorable enthalpic and entropic results. Natural and anchored smectites have the ability to complex mercury, acting as useful materials for removal of this hazardous metal from an ecosystem.Uma amostra natural de esmectita oriunda do estado do Piauí, Brasil, foi organofuncionalizada com 3-mercaptopropiltrimethoxissilano e 3-aminopropiltriethoxissilano. O espaçamento basal da argila natural é de 0,99 nm e área superficial 48 m² g-1. Houve um aumento no espaçamento basal para 1,84 e 2,01 nm e o aumento da área específica para 781 e 795 m² g-1 para as argilas quimicamente modificadas, respectivamente. A argila natural e a argila quimicamente modificada adsorveram cátions mercúrio em solução aquosa em pH 3,0 e 298 ± 1 K. Os modelos de isotermas de adsorção de Langmuir, Redlich-Peterson e Toth foram aplicados para ajuste dos dados experimentais com aproximação não linear. Para as interações cátion/centros básicos para cada esmectita na interface sólido/líquido foi utilizada metodologia calorimétrica e foram obtidas as constantes de equilíbrio e os efeitos térmicos exotérmicos. Considerando o número interativo de moles para cada cátion e as constantes de equilíbrio, a entalpia, intHº (-11,98 a -13,93 kJ mol-1) e a energia livre de Gibbs negativa, intGº (-22,4 ± 0,1 a -23,9 ± 0,1 kJ mol-1) foram calculadas, o que permitiram a determinação da entropia positiva intSº (51 ± 01 a 55 ± 2 J K-1 mol-1). As interações cátion/centros básicos são de natureza espontânea como demonstram os valores de energia livre de Gibbs, dando o conjunto de dados favoráveis como expressam a entalpia exotérmica e a entropia positiva, mostrando que a esmectita natural e as quimicamente modificadas têm habilidade em complexar mercúrio. Logo, esses materiais são úteis na remoção de mercúrio em um ecossistema.594603Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Association between lowering restriction levels during the coronavirus outbreak and physical activity among adults: a longitudinal observational study in Brazil

OBJECTIVE The COVID-19 pandemic has had significant consequences on public health and lifestyle and has negatively affected mental health and the level of physical activity worldwide. This study examined the impact of reopening fitness centers and nonessential services and introducing flexible measures to ensure social distancing on physical activity and mental health. MATERIALS AND METHODS This was a longitudinal study. A self-administered questionnaire, including personal, behavioral, physical activity, perception of health, and mood state disorder information, was answered by 128 Brazilians in June 2020 (during severe restrictive measures) and again in April 2021 (after fitness centers and nonessential services were reopened). RESULTS The restriction level adopted in April 2021 was significantly lower than that in June 2020 (p<0.001). The level of physical activity (p<0.001) and health status perception (p<0.001) decreased from June 2020 to April 2021. The median values for depression and anxiety did not differ across the study period. CONCLUSIONS The level of physical activity was reduced during the COVID-19 pandemic, and anxiety and depression were not improved following less restrictive social distancing measures and the reopening of fitness centers. Thus, the return to a prepandemic level of physical activity and mental health status may not be automatic. The results presented herein suggest that the decrease in physical activity observed in the population may be challenging in the postpandemic period

Mercury adsorption on natural and organofunctionalized smectites - thermodynamics of cation removal

A natural smectite clay sample from Piauí State, Brazil, was organofunctionalized with 3-mercaptopropyltrimethoxysilane and 3-aminopropyltriethoxysilane silyating agents. The basal spacing of 0.99 nm and surface area of 48 m² g-1 for natural clay increased to 1.84 and 2.01 nm, and 781 and 795 m² g-1 for modified clays, respectively. The natural and chemically immobilized clay samples adsorb mercury cations from aqueous solutions at pH 3.0 at 298 ± 1 K. The Langmuir, Redlich-Peterson and Toth adsorption isotherm models were applied to fit the experimental data with a nonlinear approach. From the cation/basic center interactions for each smectite at the solid-liquid interface, by using calorimetry methodology, the equilibrium constant and exothermic thermal effects were obtained. By considering the net interactive number of moles for each cation and the equilibrium constant, the enthalpy, "intHº (-11.98 to -13.93 kJ mol-1) and negative free Gibbs energy, "intGº (-22.4 ± 0.1 to -23.9 ± 0.1 kJ mol-1) were calculated. These values enabled the determination of positive entropy, "intSº (51 ± 01 to 55 ± 2 J K-1 mol-1). The cation-basic center interactions are spontaneous in nature as demonstrated from favorable enthalpic and entropic results. Natural and anchored smectites have the ability to complex mercury, acting as useful materials for removal of this hazardous metal from an ecosystem

Managing patients with dengue fever during an epidemic: the importance of a hydration tent and of a multidisciplinary approach

<p>Abstract</p> <p>Background</p> <p>Dengue fever is one of the most common tropical diseases worldwide. Early detection of the disease, followed by intravenous fluid therapy in patients with dengue hemorrhagic fever (DHF) or with warning signs of dengue has a major impact on the prognosis. The purpose of this study is to describe the care provided in a hydration tent, including early detection, treatment, and serial follow-up of patients with dengue fever.</p> <p>Findings</p> <p>The analysis included all patients treated in the hydration tent from April 8 to May 9, 2008. The tent was set up inside the premises of the 2^ndMilitary Firemen Group, located in Meier, a neighborhood in Rio de Janeiro, Brazil. The case form data were stored in a computerized database for subsequent assessment. Patients were referred to the tent from primary care units and from secondary city and state hospitals. The routine procedure consisted of an initial screening including vital signs (temperature, blood pressure, heart rate, and respiratory rate), tourniquet test and blood sampling for complete blood count. Over a 31-day period, 3,393 case recordings were seen at the hydration tent. The mean was 109 patients per day. A total of 2,102 initial visits and 1,291 return visits were conducted. Of the patients who returned to the hydration tent for reevaluation, 850 returned once, 230 returned twice, 114 returned three times, and 97 returned four times or more. Overall, 93 (5.3%) patients with DHF seen at the tent were transferred to a tertiary hospital. There were no deaths among these patients.</p> <p>Discussion</p> <p>As the epidemics were already widespread and there were no technical conditions for routine serology, all cases of suspected dengue fever were treated as such. Implementing hydration tents decrease the number of dengue fever hospitalizations.</p

Non-canonical Wnt signaling regulates junctional mechanocoupling during angiogenic collective cell migration

© 2019, Carvalho et al. This article is distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use and redistribution provided that the original author and source are credited.Morphogenesis of hierarchical vascular networks depends on the integration of multiple biomechanical signals by endothelial cells, the cells lining the interior of blood vessels. Expansion of vascular networks arises through sprouting angiogenesis, a process involving extensive cell rearrangements and collective cell migration. Yet, the mechanisms controlling angiogenic collective behavior remain poorly understood. Here, we show this collective cell behavior is regulated by non-canonical Wnt signaling. We identify that Wnt5a specifically activates Cdc42 at cell junctions downstream of ROR2 to reinforce coupling between adherens junctions and the actin cytoskeleton. We show that Wnt5a signaling stabilizes vinculin binding to alpha-catenin, and abrogation of vinculin in vivo and in vitro leads to uncoordinated polarity and deficient sprouting angiogenesis in Mus musculus. Our findings highlight how non-canonical Wnt signaling coordinates collective cell behavior during vascular morphogenesis by fine-tuning junctional mechanocoupling between endothelial cells.Research was supported by European Research Council starting grant (679368), the H2020-Twinning grant (692322), the Fundação para a Ciência e a Tecnologia funding (grants: IF/00412/2012; EXPL-BEX-BCM-2258–2013; PRECISE-LISBOA-01–0145-FEDER-016394; UID/BIM/50005/2019, a project funded by Fundação para a Ciência e a Tecnologia (FCT)/ Ministério da Ciência,Tecnologia e Ensino Superior (MCTES) through Fundos do Orçamento de Estado; and a grant from the Fondation Leducq (17CVD03); and personal fellowships: BD/52224/2013​​ to JRC, BD/105856/2014 to PB, and BD/128375/2017 to CF) and LISBOA-01–0145-FEDER-007391, project cofunded by FEDER, through POR Lisboa 2020 - Programa Operacional Regional de Lisboa, PORTUGAL 2020, and Fundação para a Ciência e a Tecnologia.info:eu-repo/semantics/publishedVersio