Representações sociais de docentes e alunos sobre educação à distância online

A comunicação apresenta um estudo sobre as representações sociais de como alunos e docentes avaliam a Educação a Distância online. Foram analisados as representações sociais de 20 sujeitos, 10 alunos e 10 docentes de cursos de graduação de duas universidades privadas na região do ABC paulista. Subdividos em Grupo A (alunos e docentes que tiveram experiência com a modalidade online) e Grupo B (alunos e docentes que não tiveram a experiência online). Buscou-se encontrar atitudes de resistência e/ou preconceito na modalidade de EAD online. Como pressupostos teóricos adotou-se a teoria das Representações Sociais de Moscovici, que define representações sociais (RS) como o conjunto de opiniões, crenças ou valores que são socialmente construídos em grupos delimitados em relação a um determinado objeto e a teoria da Abordagem Estrutural das Representações Sociais de Abric, que leva à identificação de quais são as palavras e as expressões que têm maior importância no significado de uma determinada RS. O resultado apresentou a co-ocorrência de quatro palavras integrantes do núcleo central da representação social da EAD online nos grupos A e B. As ocorrências comuns ao núcleo central da RS da EAD online para ambos os grupos foram “futuro” e “versatilidade”, que permitem ter mais comodidade com horário flexível para os estudos. Em contrapartida nesses mesmos grupos tem-se “superficial” e “economia” como integrantes desse mesmo núcleo central da RS da EAD online. Outras expressões palavras, como “qualidade duvidosa”, “ausência de professor” e “superficialidade” também são evocadas, o que demonstra atitudes de preconceito e/ou resistência dos sujeitos investigados. A resistência e/ou preconceito à EAD online parece ser um problema significativo e ainda é uma das barreiras para a implementação de cursos de graduação na modalidade online ou semipresencial.This communication presents a study on social representations of how students and teachers assess distance learning education online. We analyzed the social representations of 20 subjects, including 10 students and 10 teachers of undergraduate courses from two private universities in the region of Sao Paulo city. Subdivided into Group A (students and teachers who had experience with online distance education) and Group B (students and teachers who had experience with distance learning online), it was aimed to find some resistance and/or prejudice attitudes in the modality of online distance education. As theoretical background it was adopted Moscovici’s theory of social representation, which defines social representations (SR) as the set of opinions, beliefs or values that are socially constructed in groups defined in relation to a particular object: and Abric’s theory of the Structural Approach Social Representations, which leads to the identification of the words and expressions that have major significance to the meaning of a given SR. The result presented the co-occurrence of four words members of the central nucleus of social representation of online in groups A and B. The common occurrences to central nucleus of RS of online for both groups were "future” and “versatility” which allows more comfort with a flexible timetable for the studies. On the other hand in these same groups we have the words “superficial” and “economy” as part of that core of the RS online. Other expressions, such as “questionable quality”, “lack of teacher” and “superficiality” are also mentioned, which show attitudes of prejudice and / or resistance of the subjects investigated. The resistance and/or prejudice regarding online distance education seems to be a significant problem and is still one of the barriers to the implementation of undergraduate courses in online or blended mode

Resposta de plantas jovens de limeira-ácida 'Tahiti' a diferentes níveis de irrigação

The aim of this study was to evaluate the effect of different irrigation levels on canopy and root growth, productivity, and fruit quality of young ‘Tahiti’ acid lime trees. The experiment was installed in Piracicaba, Brazil in a 1.0-ha orchard plot with ‘Tahiti’ acid lime trees, grafted on ‘Swingle’ citrumelo rootstock and carried out from August of 2002 to May 2005. Each treatment was assigned to a drip irrigation level, based on ETc as follows: T1) non-irrigated, T2) 25%, T3) 50%, T4) 75% and T5) 100% of ETc determined by weighing lysimeter presented in the orchard plot. Trunk diameter and tree height were evaluated monthly. The roots were evaluated when the trees were 30 and 48 months old. The yield and fruit quality was evaluated in 2004 and 2005. The results showed that irrigation did not influence root distribution in depth, and trees irrigated with 75% and 100% ETc showed horizontal root distribution concentrated until 0.6 m from the trunk. Irrigation did not improve the quality of fruit. Yield increased in all irrigated treatment, but the most efficient yield mean per unit of water applied was the 25% ETc treatment.O objetivo deste trabalho foi avaliar o efeito de diferentes níveis de irrigação sobre o crescimento da copa e raízes, produtividade e qualidade de frutos de plantas jovens de limeira-ácida ‘Tahiti’. O experimento foi instalado em Piracicaba, em um hectare plantado com limeira-ácida ‘Tahiti’ enxertadas sobre porta-enxerto citromelo ‘Swingle’e irrigadas por gotejamento. O experimento foi conduzido durante o período de agosto de 2002 a maio de 2005. Cada tratamento correspondeu a um nível de irrigação baseado nos valores de evapotranspiração da cultura (ETc): T1) não irrigado; T2) 25%; T3) 50%; T4) 75% e T5) 100% da ETc determinada por meio de um lisímetro de pesagem, presente na área. O diâmetro e a altura das plantas foram avaliados mensalmente. As raízes foram avaliadas quando as plantas estavam com 30 e 48 meses de idade. A produtividade e a qualidade dos frutos foram avaliadas em 2004 e 2005. Os resultados mostraram que a irrigação não influenciou na distribuição do sistema radicular em profundidade, e que plantas irrigadas com lâminas de água equivalentes a 75 e 100% da ETc mostraram uma distribuição horizontal de raízes concentradas a 0,60 m de distância do tronco. Aos 48 meses, a irrigação não influenciou na distribuição do sistema radicular no perfil do solo. A irrigação não melhorou a qualidade dos frutos. A produtividade aumentou em todos os tratamentos irrigados, mas o tratamento correspondente à lâmina de 25% da ETc foi o mais eficiente por unidade de água aplicada

Identification of hazardous nanoparticles present in the Caribbean Sea for the allocation of future preservation projects

The deposition of remaining nanoparticles in the Caribbean Sea generates the formation of potentially dangerous elements, which influence at the imbalance of ecosystems. The detection of nanoparticles is not simple and the use of conventional methods is difficult application, which is why we highlight the immediacy and importance of this research for the areas of marine biology, urbanism, engineering and geosciences, applied in the Caribbean Sea. The general objective of this study is to evaluate the use of advanced methods for the determination of toxic nanoparticles, which can directly affect the development of marine organisms in the aquatic ecosystem in waters of the Caribbean Sea, favoring the construction of future international public policies with the elaboration of projects capable of mitigating these levels of contamination. The morphology and structure of nanoparticles were analyzed by emission scanning electron microscope with a high-resolution electron microscope. The nanoparticles smaller than 97 nm were identified in different proportions. The morphological analyses indicated nanoparticles' presence in the form of nanotubes, nanospheres, and nanofibers, which were shown in an agglomerated form. The presence of potentially hazardous elements, such as As, Cd, Pb, Mg, Ni and V were verified. In addition, the presence of asbestos in the form of minerals was confirmed, and that of titanium dioxide was found in large quantities. The results provide new data and emphasize the possible consequences to the in the Caribbean Sea, with the identification of dangerous elements (As, Cb, Pb, Hg, Ni and V), harmful to the marine ecosystem. Therefore, there is a need for strict control to reduce contamination of the Caribbean Sea and avoid risks to the ecosystem and public health, through suggestions of international public policies, through constant monitoring and the application of environmental recovery projects in this marine estuary

Obtaining high purity silica from rice hulls

Many routes for extracting silica from rice hulls are based on direct calcining. These methods, though, often produce silica contaminated with inorganic impurities. This work presents the study of a strategy for obtaining silica from rice hulls with a purity level adequate for applications in electronics. The technique is based on two leaching steps, using respectively aqua regia and Piranha solutions, which extract the organic matrix and inorganic impurities. The material was characterized by Fourier-transform infrared spectroscopy (FTIR), powder x-ray diffraction (XRD), x-ray fluorescence (XRF), scanning electron microscopy (SEM), particle size analysis by laser diffraction (LPSA) and thermal analysis

Identification of hazardous nanoparticles present in the Caribbean Sea for the allocation of future preservation projects

The deposition of remaining nanoparticles in the Caribbean Sea generates the formation of potentially dangerous elements, which influence at the imbalance of ecosystems. The detection of nanoparticles is not simple and the use of conventional methods is difficult application, which is why we highlight the immediacy and importance of this research for the areas of marine biology, urbanism, engineering and geosciences, applied in the Caribbean Sea. The general objective of this study is to evaluate the use of advanced methods for the determination of toxic nanoparticles, which can directly affect the development of marine organisms in the aquatic ecosystem in waters of the Caribbean Sea, favoring the construction of future international public policies with the elaboration of projects capable of mitigating these levels of contamination. The morphology and structure of nanoparticles were analyzed by emission scanning electron microscope with a high-resolution electron microscope. The nanoparticles smaller than 97 nm were identified in different proportions. The morphological analyses indicated nanoparticles' presence in the form of nanotubes, nanospheres, and nanofibers, which were shown in an agglomerated form. The presence of potentially hazardous elements, such as As, Cd, Pb, Mg, Ni and V were verified. In addition, the presence of asbestos in the form of minerals was confirmed, and that of titanium dioxide was found in large quantities. The results provide new data and emphasize the possible consequences to the in the Caribbean Sea, with the identification of dangerous elements (As, Cb, Pb, Hg, Ni and V), harmful to the marine ecosystem. Therefore, there is a need for strict control to reduce contamination of the Caribbean Sea and avoid risks to the ecosystem and public health, through suggestions of international public policies, through constant monitoring and the application of environmental recovery projects in this marine estuary

Drug release mechanisms of chemically cross-linked albumin microparticles: effect of the matrix erosion

Albumin (BSA) microparticles were developed as a biotechnological alternative for drug delivery. Vitamin B12 (Vit-B12) was used as a model drug. The microparticles were obtained from maleic anhydride-functionalized BSA and N′,N′-dimethylacrylamide (DMAAm) in a W/O emulsion without and with PVA. The microparticles produced at 15 min of stirring without PVA showed the best results in terms of size, homogeneity, and sphericity. In such a case, BSA played a role as a surface active agent, replacing PVA. For longer stirring times, BSA was unable to act as an emulsifier. These microparticles showed an uncommon release profile, consisting of a two-step release mechanism, at the pH range studied. Considering that a two-step release mechanism is occurring, the experimental data were adjusted by applying modified power law and Weibull equations in order to describe release mechanism n and release rate constant k, respectively. Each one of the release stages was related to a specific value of n and k. The second stage was driven by a super case II transport mechanism, as a result of diffusion, macromolecular relaxation, and erosion. A third model, described by Hixson–Crowell, confirmed the erosion mechanism. Vit-B12 diffusion kinetics in aqueous solutions (i.e., without the microparticles) follows a one-step process, being k dependent on the pH, confirming that the two-step release mechanism is a characteristic profile of the developed microparticles. The microparticles released only 2.70% of their initial drug load at pH 2, and 58.53% at pH 10

O Estresse Ocupacional e a Síndrome de Burnout no Ambiente de Trabalho: Suas Influências no Comportamento dos Professores da Rede Privada do Ensino Médio de João Pessoa

O propósito da presente pesquisa foi investigar a ocorrência de estresse ocupacional e síndrome de burnout em professores da rede de ensino privado da cidade de João Pessoa. Participaram da pesquisa nove professores, de ambos os sexos, que lecionam em diversas escolas e estas foram escolhidos aleatoriamente. Na coleta dos dados foi empregado um quadro baseado no Maslach Burnout Inventory (MBI), composto por 29 questões que buscavam identificar a presença do burnout a partir de três dimensões: comportamental, cognitiva e física, e 17 perguntas que analisaram o perfil dos pesquisados. Os resultados obtidos demonstram que: 30,76% comportamentais, 38,45% físicos e 30,76% cognitivos, sendo assim podemos afirmar que a maioria dos professores apresentou diversos sintomas do estresse ocupacional e em apenas 11,11% foram apresentadas características da síndrome de burnou

2-(4,5-Dihydro-1,3-oxazol-2-yl)quinoline

The title compound, C12H10N2O, is approximately planar. The angle between the quinoline and 4,5-dihydro­oxazole ring systems is 11.91 (12)°. The mol­ecules pack into a herringbone array with no significant π–π inter­actions. The dihydro­oxazole N and O atoms are disordered over two positions, with almost equal site occupancy factors