Um hipermídia sobre fases da lua para o ensino de astronomia a distância

The interdisciplinary nature of Astronomy makes it a field of great potential to explore various scientific concepts. However, studies show a great lack of understanding of fundamental subjects, including models that explain phenomena that mark everyday life, like the phases of the moon. Particularly in the context of distance education, learning of such models can be favored by the use of technologies of information and communication. Among other possibilities, we highlight the importance of digital materials that motivate and expand the forms of representation available about phenomena and models. It is also important, however, that these materials promote the explicitation of student's conceptions, as well as interaction with the most central aspects of the astronomical model for the phenomenon. In this dissertation we present a hypermedia module aimed at learning about the phases of the moon, drawn from an investigation on the difficulties with the subject during an Astronomy course for teaching training at undergraduate level at UFRN. The tests of three semesters of course were analyzed, taking into account also the alternative conceptions reported in the literature in astronomy education. The product makes use of small texts, questions, images and interactive animations. Emphasizes questions about the illumination of the Moon and other bodies, and their relationship to the sun, the perception from different angles of objects illuminated by a single source, the cause of the alternation between day and night, the identification of Moon's orbit around the Earth and the occurrence of the phases as a result of the position of observing it, and the perception of time involved in the phenomenon. The module incorporated considerations obtained from interviews with students in two poles where its given presential support for students of the course, and subjects from different pedagogical contexts. The final form of the material was used in a real situation of learning, as supplementary material for the final test of the discipline. The material was analyzed by 7 students and 4 tutors, among 56 users, in the period in question. Most students considered that the so called "Lunar Module" made a difference in their learning, the animations were considered the most prominent aspect, the images were indicated as stimulating and enlightening, and the text informative and enjoyable. The analysis of learning of these students, observing their responses to issues raised at the last evaluation, suggested gains in key aspects relating to the understanding of the phases, but also indicates more persistent difficulties. The work leads us to conclude that it is important to seek contributions for the training of science teachers making use of new technologies, with attention to the treatment of computer as a complementary resource. The interviews that preceded the use of the module, and the way student has sought the module if with questions and/or previous conflicts - established great difference in the effective contribution of the material, indicating that it should be used with the mediation of teacher or tutor, or via strategies that cause interactions between students. It is desirable that these interactions are associated with the recovery of memories of the subjects about previous observations and models, as well as the stimulus to new observations of phenomena

O uso da abordagem CTSA para o ensino de energia tendo o desenvolvimento sustentável como eixo temático

In recent decades, humanity has become increasingly concerned with environmental problems. Proofs of this are increasing initiatives in civil society organizations, private institutions and government actions, either local, state or national actions to promote environmental protection. The goal of this research is to contribute to the formation of citizens more aware of their responsibilities to sustainable development issues, simultaneously to their learning of physics in the secondary school. Thus, we have designed a research project that aims to evaluate the effectiveness of the adoption of the concept of sustainable development as a central theme in physics classes in high school. From this goal, we designed, implemented and evaluate lesson plans that aim not only to construct and apply the concept of energy, but also to understand their transformations and conservation law, as well as their processes of production, distribution and consume in the context of physical laws in which it is involved. Then, it was deliberately provided to students, during classes, to read, interpret and produce texts, by this way being able to think and start to have a critical view of the world around him, as well as absorb the energy concept and understand his occurrence in phenomena of nature and in technologies. The approach used for this was that constraining science, technology, society and environment - STSE. This teaching methodology has been applied in the IFRN Ipanguaçu campus, for students of two classes of first year of high school integrated course in agroecology and in technical computing. The survey results show the effectiveness of both methods with respect to the viewpoints of students in relation to the guidelines of sustainable development and the learning of physics content proposed. It is hoped with this dissertation to contribute to the formation of future men and women as citizens environmentally friendly, but also as a source of inspiration for teachers who wish to foster in its students such a critical position about civic education, from their classes

Ensinando sobre a natureza da ciência: uma abordagem explícita e contextualizada a partir da história do vácuo

In last decades, the importance of including the contents of the Nature of Science (NOS) in Science Education has been emphasized. Several studies have focused on investigating the conceptions of NOS, supported by students and teachers, as well as design, implement and evaluate proposals that aim to provide a reflection on this theme in the educational context. Considering the complexity of such content, studies indicate the need for explicit and contextualized approaches and the History of Science (HS) is one of the possible paths to this inclusion. We started from the premise that, through a historical study, that aims to discuss the meaning and the basis of our "beliefs", we can know the process of building on what we "believe" and better understand its meaning. This thesis is part of this perspective, proposing to explore the History of the Vacuum, a themed high didactic potential still little used, in order to collaborate with the teaching content of NOS. We present actions on different fronts that originated three products in the context of this research. On the first front, we insert the research and production of instructional materials (three historical texts) to subsidize people interested in the implementation of HPS for educational context through this material. The relevance of this front is justified by the existence of gaps with regard to the production of such material for the context of teacher training. However, we consider that the preparation of instructional material of good quality and accessible does not guarantee that these resources will be used, if they will not be accompanied by discussions in teacher training, on how to use them, contexts and obstacles to be faced. The second part presented refers to the organization and implementation of a workshop for undergraduate students in physics and physics teachers, considering the instrumentalization of these individuals to the preparation and use of teaching strategies to approach aspects of NOS through episodes of History of the Vacuum, as well as the preparation of the text orientation for people interested in implementing the instructional material for secondary education. This guidance text contemplates the difficulties anticipated by the literature of the area and the main challenges faced by the participants about the didactic transposition of HPS for the educational context they were noted during the workshop. The relevance of this second front, in particular, is justified by the existence of gaps with regard to the inclusion of the theme of NOS and the HPS teacher training

Saberes ambientais e estações do ano

La enseñanza de las estaciones es fundamental para la comprensión de muchos ciclos naturales de la Tierra y, por consiguiente, debe integrar una educación en astronomía comprometidos con una educación ambiental más amplio. Sin embargo, la literatura en la educación científica ha puesto de manifiesto durante mucho tiempo la existencia de asociaciones erróneas de las estaciones astronómicas con características contradictorias de los ambientes que experimentamos en nuestro país. Los estudios de los autores de la historia de la astronomía y la astronomía cultural sugieren que la corrección de este error requiere la sistematización de los conocimientos sobre el comportamiento anual del medio ambiente local y, al mismo tiempo, la comprensión de los diferentes puntos de vista en el que las estaciones estaban y se cree por diferentes culturas, en particular, pero sin limitarse, a la perspectiva que utiliza como referencia el movimiento anual del Sol como base para la división del año en cuatro estaciones. Agregado a la reflexión sobre el enfoque humanista a la enseñanza de la astronomía, estos estudios sirvieron de base para la realización de investigaciones con los pescadores de la playa de Ponta Negra, durante los meses de mayo, junio y julio de 2012 y mayo-agosto en 2013; con el fin de conocer sus percepciones sobre el ambiente de la playa e investigar las posibles referencias que tienen del cielo durante el año. Más allá de la contextualización y reflexiones desarrolladas en la tesis, se presentan como un producto de la investigación el material educativo que consiste en el video "Las estaciones del mar de Ponta Negra" para ser utilizado como apoyo en talleres o cursos para estudiantes universitarios y profesores, que implica el tema de las estaciones . El material se utiliza la percepción de los pescadores en la playa dirigidas a contribuir así al diálogo entre la ciencia y el conocimiento cotidiano, y para reducir la brecha del conocimiento sistematizado sobre las características y los cambios anuales en el entorno de Natal / RN, en particular en el contexto de la enseñanza de las Ciencias. Al mismo tiempo, se espera favorecer la mirada del los profesores y futuros profesores para el medio ambiente local y la variedad que las diferentes culturas perciben los ciclos anuales y sus entornos

Propostas e discussões para o ensino de astronomia nos 1º e 2º ciclos do nível fundamental e na educação de jovens e adultos

This work aims to propose and to discuss methodologies and practical activities for Astronomy teaching in the 1st and 2nd cycles of the primary education and in the adult education. The proposals presented here were applied to students from the metropolitan region of Natal (RN), including students of the called normal education (formerly magisterial education) and of the undergraduate formation in pedagogy at the Instituto de Formação Superior Presidente Kennedy , and also, in particular, to teachers and students of public municipal school Escola Municipal Djalma Maranhão at the district of Felipe Maranhão II, also analyzing some didactic books used by these institutions. Several elements which we confronted with during this didactic-pedagogical experience were systematized, indicating principles, contents, reflections and procedures related to Astronomy teaching to students of those levels of education. Doing this we aim to make such an experience accessible to those interested in developing a similar approach involving the themes treated here as well as other ones related to Astronomy for those levels of education. The resources and practices implemented here aim to contribute to the effective realization of an interdisciplinary and contextualized education according to orientations proposed by the Parâmetros Curriculares Nacionais (Brazilian National Curricular Guidelines). In order to guarantee a broad accessibility to what we propose in this work, we intend to make available in printed form and also in an Internet page the procedures, instruction materials and texts we developed

Antioxidant Activity of Commercial Ready-to-Drink Orange Juice and Nectar

Total antioxidant activity (TAA), total phenolic compounds (TPC), and physicochemical characteristics of ready-to-drink orange juice and nectar from the most consumed brands available in Brazil were evaluated. TPC ranged from 18.7 to 54.2 mg of gallic acid/100 mL, and TAA varied from 57.88 to 349.32 mu mol TEAC/100 mL ready-to-drink orange juice and nectar. The ascorbic acid content was the only physicochemical parameter that showed strong variation among packages and brands. Correlation of TPC with TAA showed that the higher the level of TPC the higher the TAA. Correlation of ascorbic acid content with TAA is higher for ready-to-drink orange juice than nectar. The same was found for the correlation of ascorbic acid content with TPC. The results confirm the contribution of the TPC to TAA.

Caracterização molecular de estafilococos isolados de vacas com mastite subclínica e ordenhadores

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Anti-Helicobacter pylori activity and immunostimulatory effect of extracts from Byrsonima crassa Nied. (Malpighiaceae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effect of Byrsonima crassa and Phenolic Constituents on Helicobacter pylori-Induced Neutrophils Oxidative Burst

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effect of subinhibitory concentration of chlorhexidine on Streptococcus agalactiae virulence factor expression

The aim of the present study was to investigate the effect of chlorhexidine at subinhibitory concentration (50% minimal inhibitory concentration (MIC)) on the growth, cytolysin expression and phagocytosis of Streptococcus agalactiae ATCC 13813. Bacterial growth with and without chlorhexidine treatment was monitored by turbidity measurements, and exocytolysins were estimated by neutral red uptake assay by the McCoy cell line. The phagocytic process was evaluated using luminol-enhanced chemiluminescence to follow the respiratory burst of polymorphonuclear neutrophils exposed to bacteria. Chlorhexidine-treated culture did not exhibit a detectable decrease in cell growth, and no statistically significant reduction in the respiratory burst of polymorphonuclear neutrophils was observed. However, growth in the presence of chlorhexidine resulted in a significant reduction of S. agalactiae exocytolysins. Although 50% MIC of chlorhexidine did not interfere with S. agalactiae growth and phagocytosis, the knowledge that this concentration was still able to alter some bacterial virulence parameters may be useful in its therapeutic applications. (c) 2006 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

Antioxidant activity of isocoumarins isolated from Paepalanthus bromelioides on mitochondria

The isocoumarins (1-50 mu M) paepalantine (9,10-dihydroxy-5,7-dimethoxy-1H-naptho(2,3c)pyran-1-one), 8,8 '-paepalantine dimer, and vioxanthin isolated from Paepalanthus bromelioides, were assessed for antioxidant activity using isolated rat liver mitochondria and non-mitochondrial systems, and compared with the flavonoid quercetin. The paepalantine and paepalantine dimers, but not vioxanthin, were effective at scavenging both 1,1-diphenyl-2-picrylhydrazyl (DPPH*) and superoxide (O-2(-)) radicals in non-mitochondrial systems, and protected mitochondria from tert-butylhydroperoxide-induced H2O2 accumulation and Fe2+ -citrate-mediated mitochondrial membrane lipid peroxidation, with almost the same potency as quercetin. These results point towards paepalantine, followed by paepalantine dimer, as being a powerful agent affording protection, apparently via O-2(-) scavenging, from oxidative stress conditions imposed on mitochondria, the main intracellular source and target of those reactive oxygen species. This strong antioxidant action of paepalantine was reproduced in HepG2 cells exposed to oxidative stress condition induced by H2O2. (C) 2007 Elsevier Ltd. All rights reserved.

Indoor Air quality related to occupancy at an air-conditioned public building

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Screening for antimicrobial activity of natural products using a microplate photometer

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Antitumor and immunomodulatory effects of the naphthoquinone 5-methoxy-3,4-dehydroxanthomegnin

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Desenvolvimento de sistemas farmacêuticos emulsionados para veiculação gênica

Broadly speaking, the concept of gene therapy involves the transfer of a genetic material into a cell, tissue, or organ in order to cure a disease or at least improve the clinical status of a patient. Making it simple, gene therapy consists in the insertion of functional genes into cells containing defective genes by substituting, complementing or inhibiting them. The achievement of a foreigner DNA expression into a population of cells requires its transfer to the target. Therefore, it is a key issue to create systems able to transfer and protect the DNA until it reaches the target, the vectors. The disadvantages related to the use of viral vectors have encouraged efforts to develop emulsions as non-viral vectors. In fact, they are easily produced, present controllable stability and enable transfection. The aim of this work was to develop an emulsion for gene therapy and evaluate its ability to compact nucleic acids by the development of a complex with the plasmid pIRES2-EGFP. The first step was to determine the Hydrophilic Lipophilic Balance (HLB) of the Captex® 355 (oily internal phase of the emulsion) through long and short term stability assays. Based on the results, emulsions composed of Captex® 355, Tween 20® and Span 60® with 10.7 HLB were produced by three different methods: phase inversion, spontaneous emulsification and sonication. The results showed that the lowest diameter and best stability of the emulsions were achieved by the sonication method. The cationic emulsions were made by adding DOTAP to the basic emulsion. Its association with pIRES2-EGFP was evaluated by electrophoresis. Several rates of emulsion and DNA were evaluated and the results showed that 100% of the complex was formed when the rate DOTAP/DNA(nmol/µg) was 130. In conclusion, the overall results show the ability of the proposed emulsion to compact pIRES2-EGFP, which is a requirement to a successful transfection. Therefore, such formulation may be considered a promising candidate for gene therapy