Formação docente e as relações dialéticas da brincadeira e do jogo nas teorias de Elkonin, Vigotski, Luria, Leontiev e Wallon

The article aims to analyze the dialectical relationships of play and game in the field of education, as activities that promote human development in a historical-social-cultural and dialectical perspective, referenced in Elkonin theories (2009, 2017) , Vigotski (2017, 2008, 1996), Leontiev (2010, 1983), Luria (1992, 2010) and Wallon (1975, 2007). One has as a problem: what theoretical determinations do the authors Elkonin, Vigotski, Leontiev, Luria and Wallon present regarding the perception and development of play and play as: activity, human development and teaching resource? In this perspective, fundamental elements are highlighted in the theories of the mentioned authors determining their main contributions, based on the historical-dialectical method for analysis evidenced in the work of Marx (1968, 1982) and Vicente (2007). Next, some considerations are developed, signaling a theoretical approximation, through dialectical historical materialism, about the knowledge of play and game, developing categories of totality, contradiction, movement and transformation.El artículo se presenta con el objetivo de analizar las relaciones dialécticas del juego y el juego en el campo de la educación, como actividades que promueven el desarrollo humano en una perspectiva histórico-social-cultural y dialéctica, haciendo referencia a las teorías de Elkonin (2009, 2017), Vigotski. (2017, 2008, 1996), Leontiev (2010, 1983), Luria (1992, 2010) y Wallon (1975, 2007). El problema es: ¿qué determinaciones teóricas presentan los autores Elkonin, Vigotski, Leontiev, Luria y Wallon sobre la percepción y el desarrollo del juego y el juego como actividad, desarrollo humano y recurso didáctico? Desde esta perspectiva, se destacan elementos fundamentales en las teorías de los autores mencionados, determinando sus principales aportes, basados ​​en el método histórico-dialéctico de análisis, como se evidencia en el trabajo de Marx (1968, 1982) y Vicente (2007). Luego, se desarrollan algunas consideraciones, señalando un acercamiento teórico, a través del materialismo histórico-dialéctico, sobre el conocimiento de los juegos y los juegos, desarrollando categorías de totalidad, contradicción, movimiento y transformación.The article aims to analyze the dialectical relationships of play and game in the field of education, as activities that promote human development in a historical-social-cultural and dialectical perspective, referenced in Elkonin theories (2009, 2017) , Vigotski (2017, 2008, 1996), Leontiev (2010, 1983), Luria (1992, 2010) and Wallon (1975, 2007). One has as a problem: what theoretical determinations do the authors Elkonin, Vigotski, Leontiev, Luria and Wallon present regarding the perception and development of play and play as: activity, human development and teaching resource? In this perspective, fundamental elements are highlighted in the theories of the mentioned authors determining their main contributions, based on the historical-dialectical method for analysis evidenced in the work of Marx (1968, 1982) and Vicente (2007). Next, some considerations are developed, signaling a theoretical approximation, through dialectical historical materialism, about the knowledge of play and game, developing categories of totality, contradiction, movement and transformation.O artigo apresenta-se com o objetivo de analisar as relações dialéticas da brincadeira e do jogo no campo da educação, como atividades que promovem o desenvolvimento humano em uma perspectiva histórico-social-cultural e dialética, referenciando-se nas teorias de Elkonin (2009, 2017), Vigotski (1996, 2008, 2017), Leontiev (1983, 2010), Luria (1992, 2010) e Wallon (1975, 2007). Tem-se como problema: quais determinações teóricas os autores Elkonin, Vigotski, Leontiev, Luria e Wallon apresentam quanto à percepção e ao desenvolvimento da brincadeira e do jogo como atividade, desenvolvimento humano e recurso de ensino? Nessa perspectiva, destacam-se elementos fundamentais nas teorias dos autores mencionados determinando suas principais contribuições para sustentar as ações do trabalho docente. Apoia-se no método histórico-dialético para análise, evidenciado na obra de Marx (1968, 1982) e de Vicente (2007). Em seguida, desenvolvem-se algumas considerações, sinalizando uma aproximação teórica, por meio do materialismo histórico-dialético sobre os conhecimentos da brincadeira e do jogo, desenvolvendo categorias de totalidade, contradição, movimento e transformação

Mechanical properties of phenine nanotubes

Phenine Nanotubes (PhNT) are cylinder-shaped molecules synthetized from 1,3,5-trisubstituted benzene ring building blocks that can form tubular segments of different sizes. Small nanotube segments have been recently synthetized, and efforts are being made to increase the nanotubes’ length by adding more “phenine” units. To the authors’ best knowledge, a complete characterization of the mechanical properties of these nanotubes has not yet been accomplished. In this work, Reax and AIREBO forcefields were used to model armchair and zigzag PhNTs and Molecular Dynamics simulations were employed to determine their mechanical properties for tensile, compressive, bending and twisting loadings. It was found that PhNTs have a much lower Young’s modulus (about 30%) and tensile strengths (about 45%) than carbon nanotubes (CNTs), but can endure longer tensile strains without breaking apart. Although possessing a lower bending and twisting stiffness than CNTs, PhNT have highly flexible sidewalls due to their superior porosity, and therefore can withstand higher angles of twist and angles of bend without breaking bonds. This extra flexibility; extended porosity; possibility for heteroatom doping and reasonable strength, make PhNTs very promising candidates for a wide range of applications, such as sensing, ionic transistors or molecular sieving. Finally, a brief study on the application of elastic continuum shell formulas to predict the critical stress (compression), critical moment (bending) and critical torque (twisting) is also presented

A interface entre o movimento lógico-histórico e a organização do ensino do conceito matemático de ângulos

O artigo resulta de uma investigação desenvolvida com estudantes dos anos finais do ensino fundamental quanto ao movimento lógico-histórico do conceito de ângulo e está vinculado à disciplina de Estágio Supervisionado II, do curso de licenciatura em Matemática de uma universidade pública de Goiás. Destaca-se como objetivo principal: analisar as possíveis apropriações dos estudantes do sétimo ano quanto o conceito matemático de ângulos a partir do desenvolvimento de atividades de ensino organizadas segundo o movimento lógico-histórico. Atrelado ao desenvolvimento desse conceito tínhamos a ideia de movimento e na busca por respostas de como ocorreu essa apropriação, foi organizado um experimento didático como caminho metodológico da pesquisa. O materialismo histórico dialético, apresenta-se como método de pesquisa que sustentou e mediou todas as escolhas e ações da investigação. Ofertamos aos estudantes um texto com informações sobre o Sistema Solar, além de que foi confeccionado e utilizado com os alunos um transferidor artesanal. Tais ações - exploração do texto e uso do transferidor – serviram para que o conceito de ângulo fosse apreendido como resposta aos avanços históricos humanos. Concernente a tais escolhas a estrutura de análise é composta de unidade, episódios e flashes. Os resultados dão indícios de que a interface entre a organização do ensino do conceito de ângulo e o movimento lógico-histórico possibilitou a interconexão do conhecimento matemático com a produção de conhecimento humano, conferindo-lhe o caráter formativo do sujeito

Mechanical characterization of polymer-grafted graphene PEG nanocomposites using molecular dynamics

Available online 28 February 2024It is known that most polymers exhibit poor interfacial compatibility with graphene sheets. Modification of graphene's surface by functionalization with small polymer chains from the same building blocks as the matrix polymer improves the compatibility of graphene in polymeric materials. In this paper, the mechanical behaviour of polyethylene glycol (PEG) nanocomposites with graphene grafted with polymeric chains under tensile and compression is investigated using molecular dynamics. The influence of the functional groups (-NH2 and –OH) that bond the polymer chain to graphene is analysed. It is found that the system containing the –NH2 functional group showed lower mechanical properties than the system containing the –OH functional group. The mechanical properties of five PEG-nanocomposites are investigated: PEG/G, PEG/GNH-1PEG-S, PEG/GNH-2PEG-L, PEG/GNH-1PEG-S-NH2, PEG/GO-1PEG-S. The radius distribution function values and the variation of interfacial interaction energy are also examined. It is shown that functionalization of the graphene sheet increases the magnitude of the interaction energy, and it also reveals higher adhesion between graphene surface and PEG matrix. It is found that the mechanical properties of PEG are mostly improved in the longitudinal direction (reinforcement up to 43 %). Despite the high interaction between the nanofiller and PEG matrix, the low intrinsic properties of the nanofiller, namely Young's modulus, as well as the rupture of the graphene sheet during the deformation process deteriorated the mechanical properties of the nanocomposite. The presence of polymeric chains grafted to graphene improves the adhesion between the graphene surface and the polymeric matrix but decreases its mechanical properties.This work was supported by FCT, through IDMEC, under LAETA, project UIDB/50022/2020 [Grant No. 10.54499/UIDB/50022/2020], through Centro de Química Estrutural (CQE), project UIDB/00100/2020 and through Institute for Polymers and Composites, and through IDMEC, under LAETA, project UIDP/50022/2020 [Grant No. 10.54499/UIDP/50022/2020]. The first author gratefully acknowledges the financial support given by FCT in the context of the PhD scholarship SFRH/BD/129589/2017. The second author gratefully acknowledges the financial support given by FCT in the context of the Postdoctoral contract CEECINST/00156/2018

ANÁLISE DE ÍNDICES DE VEGETAÇÃO PARA CLASSIFICAÇÃO DE ÁREAS POTENCIAIS DE OCORRÊNCIA DE ATTALEA SPECIOSA MART. EX SPRENG

O Babaçu possui importância industrial na extração de seu óleo, essa palmeira está presente na América do Sul, principalmente na Bolívia, nas Guianas, no Suriname, e no Brasil. Verifica-se a necessidade de identificação e mapeamento desta fitofisionomia. Técnicas de sensoriamento remoto, principalmente as razões entre as bandas espectrais para definição de índices de vegetação tem proporcionado grande auxílio nessa investigação, mas são muitos esses índices e cada qual é mais apropriado a uma determinada vegetação estudada, sendo sensíveis à estruturas que envolvem maior ou menor reflectância dependendo da composição estrutural da planta.  Portanto, foi objeto do presente estudo a análise de diferentes índices de vegetação que contribuam para a identificação do Babaçu por meio dos seus respectivos valores de biomassa. Essa busca pautou-se na investigação de outros alvos como áreas de ocorrência de Cerrado e Pastagem que estão associadas a fitofisionomia do babaçu. Foram analisadas amostras de pixels das imagens processadas do sensor TM /Landsat 7, no município de Babaçulândia, ao norte do estado de Tocantins, região com grande presença de babaçuais. O trabalho pode inferir sobre aspectos de correlação entre as bandas espectrais e a escolha do tipo de índice de vegetação que mais se adéqua a análise verificando que há forte tendência para a utilização do NDMI (Normalized  Difference  Moisture  Index) em relaçõao aos outros índices aplicados. Essa constatação serve de subsídeo para estudos de mapeamento do babaçu com dados Landsat.

A multibiomarker approach in the caged neotropical fish to assess the environment health in a river of central Brazilian Cerrado

Embargo until 19 August 2022.Water safety is a world-wide concern and several efforts have been made in order to ensure the conservation of aquatic ecosystems. Water quality monitoring must be performed with an integrated approach using biomonitor organisms allied to water parameters. Nonetheless, very few studies have focused on biomarker responses in neotropical fish, especially in the freshwater ecosystem of Brazilian Cerrado savanna. In present study, the active biomonitoring of the João Leite river (central Brazilian Cerrado river) was performed through the evaluation of biomarker responses in caged Astyanax lacustris in combination with land use classification and analysis of water parameters. Caged fish were exposed for seven days at four sites along the river and two control groups were kept in a tank under controlled conditions. Results showed that pasture was the predominant land use in the João Leite river basin (54.07%), followed by natural vegetation (34.92%) and other kind of land use (11.01%). Water analyses showed metal concentrations (Mn and Fe) above the maximum allowed by Brazilian regulation, with particularly higher concentrations at Site 2 (near to pasture area). Biomarker responses did not show significant differences for somatic and mutagenic biomarkers between sites. However, the comet assay showed high DNA damage at Sites 2 and 3, indicating genotoxic effects in caged fish at pasture areas. Histopathological analysis showed highest frequency of leukocyte infiltration in liver of fish from Site 2, confirming the ecotoxic effects on A. lacustris in streams impacted by grazing activities. DNA damage and leukocyte infiltration in fish hepatic tissues were sensitive biomarkers in the neotropical fish A. lacustris to assess the environment health of the Cerrado river. These results showed the importance of using a multibiomarker approach in environmental risk assessment, especially in areas more at risk from anthropogenic pollution.acceptedVersio

The anti-caspase inhibitor Q-VD-OPH prevents AIDS disease progression in SIV-infected rhesus macaques

Apoptosis has been proposed as a key mechanism responsible for CD4+ T cell depletion and immune dysfunction during HIV infection. We demonstrated that Q-VD-OPH, a caspase inhibitor, inhibits spontaneous and activation-induced death of T cells from SIV-infected rhesus macaques (RMs). When administered during the acute phase of infection, Q-VD-OPH was associated with (a) reduced levels of T cell death, (b) preservation of CD4+/CD8+ T cell ratio in lymphoid organs and in the gut, (c) maintenance of memory CD4+ T cells, and (d) increased specific CD4+ T cell response associated with the expression of cytotoxic molecules. Although therapy was limited to the acute phase of infection, Q-VD-OPH-treated RMs showed lower levels of both viral load and cell-associated SIV DNA as compared with control SIV-infected RMs throughout the chronic phase of infection, and prevented the development of AIDS. Overall, our data demonstrate that Q-VD-OPH injection in SIV-infected RMs may represent an adjunctive therapeutic agent to control HIV infection and delaying disease progression to AIDS.This article is dedicated to the memory of Bruno Hurtrel. We also thank Jean-Claude Ameisen for his initial support. We acknowledge Celine Gommet (Institut Pasteur) for her expertise in the follow-up of our primate cohort. We also acknowledge Francois Villinger, who performed TRIM5a polymorphism. ML and JG were supported by fellowships from ANRS. RS thanks Fundacao para a Ciencia e a Tecnologia (FCT) for Investigator FCT Grant IF/00021/2014. This study was supported by research funding from ANRS and CIHR (MOP-133476) to JE. VR is supported by a fellowship from FCT (code SFRH/BD/64064/2009). JE thanks the Canada Research Chair program for financial assistance