Chirality of Alanine Molecules in Water Solvent:A Theoretical Perspective

Sequential quantum mechanics/molecular mechanics (QM/MM) calculations combining the average solvent electrostatic configuration (ASEC) and the free energy gradient method are employed to locate minimum structures of α- and β-alanine in a water environment. Herein, we study the solvation effects in the nuclear magnetic resonance (NMR) spectroscopy, vibrational circular dichroism (VCD) spectroscopy, and electronic circular dichroism (ECD) spectroscopy of dl-α-alanine and β-alanine molecules. Our results point out that the ASEC-FEG (average solvent electrostatic configuration with the free energy gradient) method is a suitable approach for finding equilibrium structures of the alanine molecules in aqueous solution. Its accuracy is checked by comparing the optimized structures with those reached by the polarizable continuum model (PCM) and via experimental data. NMR parameters and vibrational and electronic UV-vis spectra are computed with a remarkable agreement with their corresponding experimental values.</p

Editorial Note

In difficult times, it is with great pleasure that we offer the community the third issue of the Quarks – Brazilian Electronic Journal of Physics, Chemistry and Materials Science. Given the broad scope of the Quarks periodic, a range of experts in their fields of study provides their research from fundamental science to materials with biological and optical applications. In addition to studies developed by Brazilian groups, researchers from countries such as Spain, France, Germany, Russia, and Switzerland have contributed to this present issue

Dinâmica socioambiental na Vila dos Pescadores (Amazônia Oriental, Pará, Brasil)

This study describes the social, economic and environmental aspects of a fishing community “Vila dos Pescadores” situated in the Caeté River Estuary, northeastern Pará (Brazil). The methodology adopted in this study was based on interviews, questionnaires and direct observations to characterize some social, economic and environmental aspects and on monitored of beach profile to know the local coastal dynamic. Results show that the majority of the interviewed are between 18-35 years (50.97%), are fishermen (62.13%), married (68.93%), with elementary school not completed (77.67%), live with the family (2-4 persons, 39.85%) in their own houses (86.89%) and earn monthly less than one salary (95.63%). The majority of the people has been living in the village for 10 years or more (42.71%) and do not like their current social, economic and environmental situation. The village has someenvironmental problems such as coastal erosion and serious service and infrastructure problems (e.g. little or total absence of public transports, public telephones, garbage collectors, public illumination, drinking water, basic sanitary facilities, underdeveloped commercial area, sport area, health post, police post, car parking, lifeguard, school, among others). The absence of employment opportunities is another problem, being the fisheries the main source of income in the village. On the other hand, the exuberant nature, the equatorial weather, the tranquility and the large amount of fish are the main positive aspects according to the opinion of those interviewed

Educação de crianças: idéias numa revista católica brasileira (1935 a 1988)

Este estudo objetivou descrever elementos do ideário de educação de crianças ao longo do século XX no Brasil, através da análise de um veículo de comunicação escrita selecionado em função de sua temática, e da regularidade de sua publicação. O material selecionado foi a revista Família Cristã referente ao período de 1935 a 1988, cujos artigos foram analisados qualitativamente; os dados evidenciaram que a evolução na concepção de educação, ao longo das seis últimas décadas, traça um caminho que vai: a) de um enfoque moral (décadas de 30 a 50) a uma abordagem psicológica (décadas de 70 a 80), que diz que educar é levar ao amadurecimento e equilíbrio emocional; b) de uma ênfase no controle exercido sobre o comportamento (décadas de 30 a 50) para o exercido sobre a subjetividade (década de 80); c) da valorização da sabedoria popular (décadas de 30 e 40) à fala do especialista (década de 50 em diante)

Atividades da criança: educação x liberdade x restrições

Este estudo teve por objetivo descrever e analisar o grau de liberdade de ação e escolha permitido pela mãe nas atividades diárias e brincadeiras da criança. Os dados foram obtidos através da análise das respostas de 110 mães a 15 questões do Roteiro Reestruturado de Biasoli-Alves e Graminha (1979), que investigam as condições oferecidas à criança em termos de movimentação e espaço físico, determinação de atividades e horários, uso da casa, da TV, brincadeiras e brinquedo. Os resultados indicam que as mães procuram dar liberdade a seus filhos, mas também lhes colocam restrições, num padrão próximo ao sugerido pela literatura psicológica, o que não deixa de implicar numa tutela coastante sobre a criança