As representações sociais de professores acerca das possibilidades e desafios do uso das tecnologias de informação e comunicação no ensino de física

As Tecnologias de Informação e Comunicação (TIC), podem ser vistas como a área que se vale das ferramentas tecnológicas para veicular a informação pelos meios de comunicação, propiciando interação e troca de informação entre os sujeitos. Assim, foi conduzida uma investigação sobre o pensamento do professor, objetivando, analisar as suas Representações Sociais, acerca das possibilidades e desafios do uso das TIC no ensino de física. Para tal foi realizado um estudo de caso qualitativo com a participação de seis professores-pesquisadores. Ao longo da pesquisa evidênciou-se que o uso das TICs e de suas ferramentas nas aulas, podem promover o diálogo e a comunicação dos atores sociais com o mundo

Photodynamic Therapy: A Novel Ally for Surgical Endodontic Treatment? Case Report

Introduction: Photodynamic therapy (PDT) has emerged as a powerful tool for conventionalendodontic treatment, capable of eradicating microorganisms present in endodontic infections.Despite this, the use of PDT in the surgical endodontic treatment is not well-known.Case Report: This paper describes the case of a patient with asymptomatic apical periodontitisin a mandibular incisor submitted to surgical endodontic treatment associated with PDT. Afterconventional procedures, photosensitizer methylene blue (0.01%) was applied to the retrogradecavity for 3 minutes, followed by irradiation with diode laser (100 mW and 660 nm) for 3minutes. Six months after the procedure, the patient was asymptomatic, and the radiographicexamination showed healthy periradicular tissues.Conclusion: The association of PDT with surgical endodontic treatment was effective, suggestingthat this therapy may provide additional benefits to patients when compared to the conventionalsurgical technique

Chlorophyll, nitrogen and antioxidant activities in Cumaru (Dipteryx odorata (Aubl.) Willd) (Fabaceae) in two water regimes

The Cumaru (Dipteryx odorata (Aubl.) Willd.) is a species used by traditional populations and industries using timber and non-timber forest products. This study aimed to analyze the levels of chlorophyll A, B, total ammonia levels, nitrate, proline, electrolyte leakage and activity of oxidative enzymes in evaluation to tolerance of cumaru plants subjected to drought for 21 days of stress. The experiment was conducted in a greenhouse at the Federal Rural University of Amazonia (UFRA), Belém, Pará, in the period from March to July 2015. The results showed a significant decrease in the relative water content of 50.8 and 55% for chlorophyll b, 45% to total chlorophyll and an increase in proline to the plants under drought. There was no significant difference to chlorophyll a, ammonium and nitrate. Increases in electrolyte leak with 22.74% for roots and 39.55% for leaves were observed. The enzyme catalase (CAT) showed a significant increase from the 14th day of the experiment, while changes in superoxide dismutase (SOD) and ascorbate peroxidase (APX) activities were observed from the 7th day of the experiment. Cumaru plants are not drought tolerant over 21 days; also, young plants of cumaru respond negatively to conditions of low water availability in the soil.Key words: Drought, oxidative stress, chlorophyll, tolerance, Dipteryx odorata

Como o estresse nutricional do solo limita a restauração na Amazônia? : Respostas fisiológicas, bioquímicas e anatômicas de espécies arbóreas

Forest restoration is an urgent demand in the national and global scenario, especially in the Amazon due to the advance of forest cover loss. On the other hand, the nutritional limitation of soils in this biome is a challenge for this practice, considering the entire impact of stress on plants. Considering it, this review sought to compile the findings on the impacts of nutritional stress on tree species, as well as the strategies used to reverse this impasse in the Amazon. As a result, it was possible to observe biochemical, physiological, and morphological responses in tree species. In general, we found that nutritional stress results in changes in the biochemical and physiological activities of the plant since most nutrients are related to the function, structure, and/or composition of cellular elements. For morphological characteristics, a decrease in height, biomass and leaf area are the most recurrent damages. Regarding restoration methods used to minimize nutritional stress, besides conventional techniques such as phosphate fertilization and liming, it was observed the scientific community has invested in strategies mainly based on the reuse of waste. Furthermore, the application of biostimulants, biochar, and biofortification is increasingly common and promising. In this context, the promotion of research in the Amazon biome is strongly recommended to reduce existing gaps.A restauração florestal é uma demanda urgente no cenário nacional e global, especialmente na Amazônia devido ao avanço da perda de cobertura florestal. Por outro lado, a limitação nutricional dos solos do bioma é um gargalo para esta prática, tendo em vista uma série de impactos causados pelo estresse às plantas. Diante disso, está revisão buscou compilar os achados sobre os impactos do estresse nutricional para espécies arbóreas, bem como as estratégias utilizadas para reverter este impasse na Amazônia. Por meio da revisão, foi possível observar respostas bioquímicas, fisiológicas e morfológicas em espécies arbóreas. De maneira geral, constatou-se que o estrese nutricional resulta nas alterações de atividades bioquímicas e fisiológicas do vegetal, já que a maioria dos nutrientes constituem funções relacionadas à função, estrutura e/ou composição de elementos celulares. Para as características morfológicas, decréscimo em altura, biomassa e área foliar são os prejuízos mais recorrentes. Em relação aos métodos de restauração utilizados para minimizar o estresse nutricional, além de técnicas convencionais como a adubação fosfatada e a calagem, observou-se que a comunidade científica tem investido em estratégias orgânicas, baseadas principalmente no reaproveitamento de resíduos. Ademais, o uso de bioestimulantes, do biochar e da biofortificação são cada vez mais usuais e promissores. Nesse contexto, recomenda-se incisivamente o fomento de pesquisas no bioma, visando diminuir as lacunas existentes

Effect of salicylic acid on cowpea seedlings under saline stress

The aim of this work was applying salicylic acid (SA) in cowpea seedlings under saline stress. The experiment took place in the seed laboratory of the Universidade Federal Rural da Amazônia with a completely randomized experimental design in a 2 x 2 x 3 factorial scheme, with two bean cultivars (Canapu and Pingo-de-ouro), two levels of salicylic acid (0, and 0.50 mM) and three salt stress levels (0, 25, 50 mM). The seeds were previously soaked in salicylic acid (0 and 0.50 mM) for a period of 12 hours and then placed in germitest paper rolls for treatments with NaCl (0, 25, 50 mM) for a period of 12 days at room temperature constant 27 °C. There was a significant effect of cultivars, AS dose and NaCl concentrations and their interactions on most of the analyzed variables. Root and leaf proline concentrations were higher in pingo-de-ouro cultivar, Canapu cultivar had better performance in biomass accumulation. Salicylic acid reduced proteins in the leaves by 13.33%, while in the root there was an increase of 12.61%, ammonium concentrations reduced in the roots by 11.9%. When applied to salinity (25 and 50 mM) there was an increase of proteins in the leaves 40.83% and 27.48% respectively, and a reduction of amino acids of 30.24 and 25.24% in NaCl dosages (25 and 50 mM) respectively. Salinity reduced biomass accumulation and interfered with cellular solute production. However, the application of salicylic acid promoted salt stress tolerance in Canapu cultivar

Characterization of biochemical behavior of sorghum (Sorghum bicolor [Moench.]) under saline stress conditions using multivariate analysis

The aim of this research was to characterize the biochemical behavior of sorghum plants under saline stress using multivariate statistical analysis methods for efficient management of Sorghum bicolor [Moench.]). The experimental design was completely randomized design composed of three saline concentrations (0, 1.5 and 2.0 M) in 10 replications. In the multivariate analysis (hierarchical method), there were distinct and sub-groups in the sorghum plant treatments. Group 1 consisted of the root parts and under this group there were two subgroups: 1.5 to 2.0 concentration (Group 1) and 2 concentration (Group 2). The increase of NaCl concentration in the roots and leaves has inverse correlation with decrease of nitrate reductase, amino acids, protein and starch. The amounts of amino acids, carbohydrates, sucrose and proline in the roots and carbohydrates, sucrose and proline in the leaves of sorghum plants are reliable biological indicators of saline stress conditions in the soil. The nitrate compound differed (p ≤ 0.05) in the sorghum plant roots; it had an average value of 0.04 μmol kg-1 of nitrate in the control treatment dry matter. The nitrate average was between 0.04 and 0.06 μmol kg-1, but without statistical difference for all concentrations.Key words: Multivariate statistics, salt concentration, proline, carbohydrate

Aplicações da matemática e da física para a construção de uma ponte treliçada no ensino médio

Através dos conhecimentos adquiridos pelos alunos nas aulas de matemática e física no que diz respeito aos conteúdos de geometria plana, geometria espacial, força e momento, foi dada a proposta de construir uma ponte treliçada com palitos de churrasco na qual o sistema deveria suportar uma carga inúmeras vezes maior que o seu próprio peso. Os alunos, mesmo sendo do ensino médio, deveriam pesquisar a respeito do equilíbrio, dos esforços e das condições de construção para um sistema treliçado baseados em literaturas das disciplinas básicas dos cursos de arquitetura e engenharia. Os alunos que desenvolveram o projeto e fizeram a sua apresentação numa feira de matemática em uma universidade local fazem parte de um grupo de pesquisa em física aplicada. Este grupo é formado por alunos dos três anos do ensino médio

Systemic Toxoplasmosis in Kittens

Background: Toxoplasmosis is a worldwide disease that affects virtually all species of warm-blooded animals. The felids, domestic and wild, are considered the definitive hosts of the protozoan. In Brazil, Toxoplasma gondii infection has been diagnosed in horses, goats, primates, dogs and cats. In the backlands of Paraíba, the disease has been sporadically reported affecting dogs with canine distemper and swine, but cases of systemic toxoplasmosis in cats have not yet been described. The aim of the present study was to describe the main epidemiological, clinical and anatomopathological aspects of two cases of systemic toxoplasmosis in kittens.Cases: Two kittens were affected with three (cat 1) and six (cat 2) months old, females, and crossbreed. The kittens had not been vaccinated or dewormed, and were raised with other cats in a peridomiciliary regime in a rural area in the backlands of Paraíba. Cat 1 was thin, apathetic, dehydrated, tachypneic and with pale mucous membranes. Cat 2, showed inappetence, apathy, jaundice, fever, dehydration, dyspnea and abdominal breathing pattern. At necropsy, non-collapsed, shiny, reddish lungs with multifocal whitish areas, punctuated or nodular, measuring from 0.1 to 0.3 cm in diameter, were found on the pleural surface and parenchyma. The livers were pale, with lobular pattern accentuation, and reddish depressed multifocal areas randomly distributed on the capsular surface. Histologically, multifocal to coalescent areas of necrosis, moderate (cat 1) or marked (cat 2), associated with intralesional bradyzoites and tachyzoites and variable lymphoplasmacytic infiltrate were observed. In cat 2, numerous bradyzoites were visualized in the gray matter of the left cerebral hemisphere (temporal and parietal lobes), sometimes associated with a moderate lymphoplasmacytic inflammatory infiltrate. In the perivascular spaces of the cerebral cortex, discrete inflammatory lymphoplasmacytic infiltrate (perivascular cuffs) were observed. Immunohistochemistry for T. gondii revealed strong immunolabelling of the parasitic organisms.Discussion: The diagnosis of systemic toxoplasmosis was established based on anatomopathological findings and histomorphological characteristics of the agent, being confirmed by immunohistochemistry. The systemic disease occurs most often in young animals, especially immunocompromised or immunologically immature neonates. In these kittens, it was not possible to determine the presence of an intercurrent immunosuppressive condition; however, both animals were kept in the peridomiciliary regime and were in contact with other cats, which may have acted as a source of infection. Besides, both kittens were raised in rural environments, condition that associated with the usual predatory behavior of this species may have favored the ingestion of infected intermediate hosts. The clinical signs of the disease vary considerably depending on the location and severity of the lesions. Infection in cats usually is asymptomatic or promotes self-limiting diarrhea as a result of protozoal enteroepithelial replication; but in some cases the protozoan can spread to other tissues, determining the occurrence of necrotic processes, dysfunction and clinical manifestations. Systemic toxoplasmosis occurs sporadically in kittens in the backlands of Paraíba, with pulmonary and hepatic clinical manifestations. The histopathological findings are characterized by tissue necrosis and lymphoplasmacytic inflammation associated with intralesional protozoa. The diagnosis can be established based on the histomorphologic characteristics of the agent and confirmed by immunohistochemistry

Physics teacher education on the Activity Theory perspective: the analysis of Teaching Practice course and implications to coteaching

Os trabalhos sobre formação de professores sempre estiverem presentes na área de pesquisa em Ensino de Ciências, especialmente, as investigações sobre os cursos de licenciatura. Estudos sobre a formação dos professores de ciências no Brasil apontam três elementos centrais que estiveram constantemente presente: os gestores públicos, a universidade e a escola, cujas ações são movidas por necessidades distintas, provocando uma tensão na formação docente. Contudo, investigações que abordem o problema da articulação desses elementos são menos frequentes. O presente trabalho, então, trata de algumas questões relativas a articulação entre a universidade e escola, no contexto de uma disciplina do curso de Licenciatura em Física do Instituto de Física da USP- Práticas em Ensino de Física- em que os licenciandos tinham que cumprir parte do estágio supervisionado na Escola de Educação Básica. O objetivo da pesquisa é caracterizar o processo de tornar-se professor, circunscrito ao contexto dessa disciplina, que ao focalizar as mudanças dos licenciandos aborda alguns aspectos da relação Universidade - Escola. A nossa hipótese básica está na ideia de que a formação inicial do professor ocorre na universidade e na escola e que ser professor se constitui historicamente na trama de relações sociais, especialmente, entre essas duas instituições, por meio da apropriação e objetivação da prática docente vivenciado pelo sujeito no processo da atividade do tornar-se professor. A nossa metodologia é baseada nos procedimentos da pesquisa qualitativa. Os dados foram coletados por meio de vídeo-gravação das aulas e das oficinas de preparação do estágio, ambas na universidade; e por meio de entrevistas semi-estruturadas realizadas com alguns licenciandos ao final daquele ano. A Teoria da Atividade constitui o nosso referencial teórico, a partir do qual conduzimos a análise dos dados seguindo uma heurística de multi níveis: (i) macro, evidenciando os aspectos mais gerais da disciplina e as relações com a instituição; (ii) meso, focalizando as aulas da disciplina ao longo do ano e as mudanças dos objetos da atividade dos licenciandos como indicativo de mudança de estudante para professor; (iii) micro, indicando as relações entre a professora da disciplina e os licenciandos, considerando o papel das contradições no processo de tornar-se professor. Em especial, no nível micro, a nossa atenção se volta para contradição entre a iniciativa e limitação vivenciada pelos licenciandos no desenvolvimento da atividade de confeccionar o roteiro. Ao final, vamos mostrar como a rotina da disciplina de ir e vir entre a universidade e a escola teria provocado uma mudança nos licenciandos de estudante para professor. Concluímos este trabalho destacando que é preciso haver um momento durante o estágio que tenha um caráter intermediário e organizador do processo, no qual a escola deixa ser o local de mera aplicação do estágio e passa a ser o local de ensinoaprendizagem; e que a codocência, enquanto uma prática de ensino de Física, pode se constituir em um aspecto importante para construir pontes entre a universidade e a escola.Situated among investigations on Teacher Education in Brazil, which has been taking part in research agenda on Science Education for many years, the purpose of this study is to present our findings about a research focused on the pre-service physics teacher program, in which undergrad students had to take their practicum in the High School. The methodology is based on the qualitative research methods and data were gathered by videotaping classes at university involving about 75 people and 70 hours of video. In addition, in the very beginning the students were invited to respond to a questionnaire about their perspectives about the High School reality and the work that would be held throughout the internship. The research takes place in course termed Practices on Physics Teaching, addressed to third-year undergraduate physics students (pre-service physics teachers) at a Brazilian public university. Classes were taken as our object of research, in which students and professor gathered every fifteen days to discuss different sort of topics. Using Cultural Historical Activity Theory and Multi-level analysis we will reveal a process of becoming teacher and will highlight changes that happened within the activity system, especially, modifications of objects and instruments. To extend the possible we will present two situations in which (I) in the very beginning undergrad students were asked to sketch one lesson based on a set of low-cost hands-on experiment and (II) in the opposite way, in the second semester they were asked to discuss how these experiments worked regarded to concepts of physics. As a result students failed in both tasks. We will argue in terms of the changes of objects of activity, that is, whereas in the first moment it was contents of physics, in the third, the object was how physics could be taught at High School. It seems High School was an important element in this process because schoolchildren became part of pre-service activity. Indeed different objects indicate that changes have happened between human subjects relations embedded in certain activity. In this particular case, new instruments were required when undergraduate students went to the High School. Therefore, by the third moment a new type of relationship arises, that is, the prospective-teacher and High School student, absent at the first part of the classes. Thus, that new relationship, that requires new instruments, works as a guide to the future teachers, making them shift from student\'s perspective to teacher\'s. In conclusion, we argue both University and High School are the appropriate places where physics teacher education should be held, and coteaching seems to be an important action to bridge both University and High School

Teacher\'s interventions and group\'s process in the Physics classes: an analysis by operative group theory

Quando alunos, convocados pelo professor, se reúnem em grupos numa sala de aula, inicia-se uma construção de relações interpessoais, envolvendo alunos e professor, que influenciam fortemente o processo grupal. O foco do nosso trabalho está neste processo, ou seja, em como um grupo de ensino-aprendizagem produz ou não seus resultados em sala de aula. Procuramos investigar questões do tipo: como e quando os grupos analisados funcionaram? Quais intervenções do professor favoreceram a aprendizagem? A pesquisa foi desenvolvida numa escola particular no interior de São Paulo, com alunos da 1ª série do Ensino Médio cujas aulas de Física foram marcadas pela constância de atividades em grupo em que o professor fazia uma série de intervenções (presencial, institucional e virtual) a fim de tornar o grupo mais operativo. Entre estas, consideramos significativa uma intervenção que consistiu em atribuições de funções (Líder, Anotador e Questionador) para cada um dos membros do grupo e que deveriam ser rotativas a cada atividade. O nosso trabalho consistiu na descrição dos episódios e na análise dos três grupos que compunham a classe investigada e encontramos resultados bem diferentes para cada um deles que foram caracterizados da seguinte maneira: o grupo 1, da dependência; o grupo 2 da resistência; grupo 3 da mudança. Utilizamos as concepções de grupos operativos de Pichon-Rivière, que focaliza a tarefa do grupo e o vinculo entre os membros como elementos essenciais do desenvolvimento grupal. Todo o processo tem na comunicação entre os membros do grupo o aspecto principal para atribuição de papéis (porta-voz, líder, bode expiatório e sabotador), os quais vão surgindo ao longo da tarefa e devem ser circular entre os atores. Quando estes estão estereotipados torna-se necessária a intervenção do professor que deve fazê-los circular, proporcionando mudanças que vão caracterizar a aprendizagem. O processo grupal é dividido em três etapas: a pré-tarefa, quando os alunos resistem à mudança; a tarefa, quando, por uma elaboração das ansiedades o grupo resolve atividade; e o projeto, que é o momento da criatividade e de uma projeção das suas atividades para além do \"aqui-agora\".When the teacher invites students to form groups inside the classroom, interpersonal relationship is built among students and teacher which influences the group process. Our work is focused in this process, in how a learning group is able, or not, to achieve good results. Some of our questions were: how and when the analyzed groups worked well? Which of the teacher\'s interventions were significant to learning? The research was developed with High School students from a private school in the state of São Paulo. The Physics teacher used to ask them to work in groups and he intervened in order to make the group operative. A significant intervention was the one in which the teacher asked each member of the group to act as an specific role (leader, writer and questioner). For each new activity they should chance roles. In this work, we described the events, analyzed the three groups formed in the chosen classroom and we found out different results for each of them. We could named the groups this way: group 1, of dependency; group 2, of resistance; group 3, of change. We used some concepts of operative groups from Pichon-Rivière, which focus the task and the bond among the members as essential to the group development. For him, the communication is the main aspect of the process. The roles appear during the development of the task and the members should change them. When they do not change, it is necessary that the teacher intervenes to promote learning. The group process is divided into three stages: the pre-task, when students resist changes; the task, when the group solves their anxieties and develops the activity; the project, which is the moment of creativity