Aprendendo e ensinando o sistema de numeração decimal: uma contribuição à prática pedagógica do professor

The central question of the present study is to identify the epistemological knowledge that the teachers-trainees possess regarding the characteristics (properties) of the decimal numbering system; its purpose is to offer a contribution to the pedagogic practice of the teachers who work within the Basic Literacy Cycle, in terms of what concerns both the acquisition of contents and the development of the knowledge that helps them in the elaboration of adequate strategies to working with the Decimal Numbering System in the classroom. The study is based on the constructivist sociointeractionist approach to teaching Mathematics and it constitutes, in itself, a methodological intervention with the teachers-trainees engaged in the Professional Qualification Program in Basic Education of the Federal University of Rio Grande do Norte. The foundations of the study were found in investigations of researchers who had carried out studies on the construction of numerical writing, showing, for instance, that the construction process of ideas and procedures involved in groupings and changes to base 10 take a lot longer to be accomplished than one can imagine. A set of activities was then elaborated which could not only contribute to the acquisition of contents but that could also make the teachers-trainees reflect upon their teaching practices in the classroom so that in this way they will be able to elaborate more consistent didactic approaches, taking into consideration the previous knowledge of the students and also some obstacles that often appear along the way. Even when teachers have access to the most appropriate dicactic resources, the lack of knowledge of the content and of the real meaning of that content make the Decimal Numbering System, a subject of fundamental importance, be taught most times in a mechanical way. The analisys of the discussions and behaviours of the teachers-trainees during the activities reavealed that they made them reflect upon their current practices in the classroom and that, as a whole, the aims of each of the activities carried out with the teachers-trainers were reached

Ensino por investigação: contribuições de um curso de formação continuada para a prática de professores de ciências naturais e biologia

Normally initial teacher training has not been sufficient to provide all the tools for an updated and efficient teaching practice. It is presented here one of the ways of working the completion of the initial training through a course of continuing education. This course is based on inquiry teaching which is considered an important teaching strategy for science education. This kind of teaching enables improvement of students reasoning and cognitive skills, the cooperation among them, the understanding of the nature of scientific work, and the motivation to think about the relationship between science, technology, society and environment. For this dissertation a course of continuing education based on this approach was followed in order to evaluate which contributions it can bring to the teaching practice. The course was followed based on three stages: on the first there was a questionnaire and an informal interview; next it happened through participant observation with audio and visual aid; the third stage happened through semi structured interview. The collected information was analyzed based on Content Analysis. An inquiry teaching pedagogical material was produced for the course including some examples and applications of this approach. The aim of the material is that it can be a support for the teachers after de course. The results allowed seeing that the course was very useful, different from the traditional and the teachers that put the approach to use found it to be very positive. Thus it can be said that some of the teachers who participated will try again to apply it, try to contextualize more the teaching situations with the students day to day life, as well make them more active and critic. We can also gather from the study, that the inquiry teaching is a very different tool from what the teacher was taught and is accustomed to use and the theoretical comprehension, acceptance and practice change is a complicated process and demands time

Período de mínima atividade solar: melhora no desempenho do posicionamento relativo

In the relative positioning, even considering that part of the errors due to ionosphere is canceled with the double-difference observations, strong ionospheric effects can occur in maximum solar activity period. However, in minimum solar activity period, the ionospheric effects decrease significantly and therefore an improvement of the relative positioning performance takes place. In this paper we aim at showing that improvement for the scientific and GPS community users. So, have been experiments by using GPS data of two stations of the Brazilian Network for Continuous Monitoring of GPS, forming a baseline of 430 km. The processing were use accomplished with interval of two hours, and only L1 carrier data have been used. The analysis of the obtained results has been carried out from the discrepancies between the "true" coordinates and corresponding ones obtained in the processing. In maximum solar activity period the discrepancy value reached 25 m. on the other hand, in minimum solar activity period, the discrepancy value reached 5,5 m. It is important to emphasize that the majority of the discrepancy values didn't exceed 0,50 m, and in some cases only reached 0,10 m. This shows the increase of application possibilities of the relative positioning using single-frequency GPS receivers in minimum solar activity period.

Desempenho do modelo global da ionosfera do IGS: avaliação no posicionamento por ponto na região sul do Brasil em período de alta atividade solar

One of the main drawbacks of the GPS accuracy for L1 users is the error due to ionosphere. This error depends on the total electron content presents in the ionosphere, as well as of the carrier frequency. Some models have been developed to correct GPS observables of the systematic error due to the ionosphere. The model more known and used is the Klobuchar model, which corrected 50-60% of the ionospheric error approximately. Alternatively, IGS (International GNSS Service) also has developed a model called Global Ionospheric Map (GIM). These maps, in format IONEX, are available in the site of the IGS, and one of the applications of them is to correct the GPS observables of the error due to ionosphere. This work aims at evaluating the quality of GPS point positioning using the IGS ionospheric model in the southerm region of Brazil. Tests carried out had shown an average improvement in the horizontal and vertical determination of 44% and 77%, respectively, when GIM is used in the point positioning.

Análise e comparação do comportamento da ionosfera e do posicionamento por ponto em períodos de alta e baixa atividade solar

The ionosphere is a major source of systematic error in the GPS observables. As this error is directly proportional to the TEC (Total Electron Content), the quality of GPS positioning (especially with single frequency receivers) can be significantly affected by regular changes of TEC. The ionosphere factor is even more relevant in the Brazilian region, where ionospheric phenomena, such as the Equatorial Anomaly, intensify these variations. Taking the above mentioned factors into account, experiments were conducted in this research to evaluate the daily and seasonal behavior of the TEC and the point positioning with GPS (single frequency) in periods of high and low solar activity in the Brazilian region. The results showed a direct correlation between the decrease in electrons density in the ionosphere (period of low solar activity) and improvement in positioning accuracy, as well as a large influence of Equatorial Anomaly on the results of point positioning.

Proposta de teste incremental baseado na percepção subjetiva de esforço para determinação de limiares metabólicos e parâmetros mecânicos do nado livre

A percepção subjetiva de esforço (PSE) é determinada de forma não invasiva e utilizada juntamente com a resposta lactacidêmica como indicadores de intensidade durante teste incremental. em campo, especialmente na natação, há dificuldades nas coletas sanguíneas; por isso, utilizam-se protocolos alternativos para estimar o limiar anaeróbio. Assim, os objetivos do estudo foram: prescrever um teste incremental baseado na PSE (Borg 6-20) visando estimar os limiares metabólicos determinados por métodos lactacidêmicos [ajuste bi-segmentado (V LL), concentração fixa-3,5mM (V3,5mM) e distância máxima (V Dmáx)]; relacionar a PSE atribuída em cada estágio com a freqüência cardíaca (FC) e com parâmetros mecânicos de nado [freqüência (FB) e amplitude de braçada (AB)], analisar a utilização da escala 6-20 na regularidade do incremento das velocidades no teste e correlacionar os limiares metabólicos com a velocidade crítica (VC). Para isso, 12 nadadores (16,4 ± 1,3 anos) realizaram dois esforços máximos (200 e 400m); os dados foram utilizados para determinar a VC, velocidade de 400m (V400m) e a freqüência crítica de braçada (FCb); e um teste incremental com intensidade inicial baseada na PSE, respectivamente, 9, 11, 13, 15 e 17; sendo monitorados em todos os estágios a FC, lactacidêmia e os tempos de quatro ciclos de braçadas e das distâncias de 20m (parte central da piscina) e 50m. Posteriormente, foram calculadas as velocidades dos estágios, FB, AB, V LL, V3,5mM e V Dmáx. Utilizaram-se ANOVA e correlação de Pearson para análise dos resultados. Não foram encontradas diferenças entre VC, V Dmáx e V LL, porém a V3,5mM foi inferior às demais velocidades (P < 0,05). Correlações significativas (P < 0,05) foram observadas entre VC versus V400m, V Dmáx e V3,5mM; V400m versus V3,5mM e V Dmáx; V Dmáx versus V LL; e no teste incremental entre PSE versus velocidade, [Lac], FC, FB e AB (P < 0,05). Concluímos que a PSE é uma ferramenta confiável no controle da velocidade dos estágios durante teste incremental na natação.

Influência da atividade e inatividade física na composição corporal e adiposidade central

To analyze influences of the physical activity and sedentary behaviors on indicators of both central and total body fat in male adolescents. Cross-sectional study with 60 male students of age range from 11 to 14 years old. It were evaluated the body mass, height, triceps skinfold, waist circumference, body fat percentage (bioelectrical impedance) and the physical activity level through questionnaire. The physical inactivity prevalence was of 35%, and the excessive total and central body fat were observed in 38.3% and 48.3% of the sample, respectively. There was association of the sedentary behaviors with the excessive total and central body fat (OR = 5.2 e OR = 6.4, respectively), however there was not for physical activity. The adoption of sedentary behaviors is associated at the development of the total and central obesity among male adolescents.

Relacionamento de diferentes domínios da atividade física habitual com indicadores de risco cardiovascular em adultos jovens do sexo masculino

Objectives: To analyze different physical activities domains in healthy adults and correlate with cardiovascular risk factors. Methods: The sample was composed by 32 Physical Education undergraduate students, with mean age of 22.6 years old. Adiposity was assessed by waist circumference (WC), body mass index (BMI) and bioelectrical impedance. Additionally, fast glucose (10-12 hours), systolic (SBP) and diastolic (DBP) blood pressure were assessed. Physical activity level was assessed by questionnaire (Baecke et al., 1982). Results: sports activities and leisure time were not related with cardiovascular risk factors. However, job activities were negatively related with %BF, SBP and DBP. Conclusion: Different physical activity domains should be considered when analyzing its associations with health indicators.

Um olhar dialógico sobre a atividade de revisão de textos escritos: entrelaçamento dizeres e fazeres

This research deals with the activity of text revision. It aims at understanding the work of the text reviewer, taking into consideration the professional experiences of the subjects who work in the area. It s theoretical basis comes from Bakhtin Circle, mainly the concept of verbal interaction formulated from reflections on language used in different spheres of human activities, which implies the notions of discourse genres, alterity, as well as exotopy. The methodology follows the tradition of the qualitative and interpretative research. The data is composed of the statements of text reviewers both in handbooks and interviews, as well as of the description of the researcher s own experience as text reviewer. The results indicate that the revision activity needs to be orientated by a dialogical conception of language, which takes into consideration the interaction between the reviewer and the author, aiming the text finalization

O papel da atividade lúdica como motivadora da aprendizagem da língua inglesa: análise de um livro didático

This work aims at analyzing the activities presented in the book On Stage for junior high school students, which was selected by IFRN, as well as checking out the students interest for play activities. We have come from the point that playing activities can contribute to the increasing of motivation for the teaching of English (BROUGERE, 1999; WRIGHT, BETTERIDGE, BUCKBY, 2006; LANGRAN e PURCELL, 1994). At first place, our research is a document analysis and in second place, it is an action research. We have proposed two questionnaires for the participants of this work, all of them are High school students at IFRN-Campus Zona Norte, in order to check out their interests and the degree of motivation for the English learning before and after the carrying out of play activities. The obtained data also showed that the students became more motivated and interested in the classes after working with play activities, and most of the students agreed with the inclusion of these activities in the selected course book. The result of our work proved the benefits of play activities according to researches available in the literature about this subject. From the results acquired in the present work, we suggest that play activities should be included in English course books, even when they are addressed to High School teaching in order to help increasing the motivation for the learning of a foreign language

Em cantos de reis: a tradição discursiva em Autos de Natal

This study incorporates many areas of knowledge to the Linguistics field, as it centers the social historicity of Brazilian and autos potiguares on two analytical proposes: the presence of linguistic formulas - in its macrostructure - into the paradigm of discursive traditions, following Kabatek (2006), Koch and Oesterreicher (2007), besides the theory of Speech Acts, in its microstructure, proposed by Austin (1990) and Searle (1995). Under Zumthor (1993; 1997; 2000; 2005; 2010), the idea of textual variability (mouvance) was alluded, highlighting that the text is always modifying, according to the performance and reception of the language uses. Considering this theoretical framework, we focus on the trinomial linguistic formulas, orality and performance, in order to describe the dynamics of stability, variation and change, emphasizing yet how extra-linguistic social-historic cultural relations influence its composition. Such discuss is inherent more precisely to Textual Analysis in enhancing the orality tradition as a linguistic support. The text, in its turn, becomes effective as an evocation, motivated by the transmission, reception and variability from its conservation and reiteration. Naturally, a methodological support based on quali-quantitative research was chosen, based on Flick (2009), who justifies the corpus composed by Brazilian Folias de Reis chants and Bois de Reis potiguares . Thereby Language dynamics, subjacent to tradition which takes effect by the use of a common social memory, are observed from two dimensions: on the first, it evocates the sacralization (religious) in which they stand their devotion to biblical History; secondly, a dissacralization with identified and ideological values, inherent to a people culture. The chant shows, in this ludic impulse, a contextualized activity which results in the following conclusion: the changing and stability processes in textual macro and microstructures occur, at the same time, by the adjustment to the use of the text accomplishing a social-political function and an ethical-pedagogic one; supposedly, social relationships arise the tradition and it, on its turn, evocates the variability and the nomadism in the text

O índice BODE reflete o nível de atividade física na vida diária de pacientes com DPOC?

Objectives: To study the relationship between the level of physical activity in daily life and disease severity assessed by the BODE index in patients with chronic obstructive pulmonary disease (COPD). Methods: Sixty-seven patients with COPD (36 men) with forced expiratory volume in the first second (FEV(1)) of 39 (27-47)% predicted and age of 66 (61-72) years old were evaluated by spirometry, dyspnea levels (measured by the Medical Research Council scale, MRC) and by the 6-minute walking test (6MWT). The BODE index was calculated based on the body mass index (weight/height(2)), FEV(1), MRC and 6MWT, and then the patients were divided in four quartiles according to their scores (Quartile I: 0 to 2 points, n=15; Quartile II: 3 to 4 points, n=20; Quartile III: 5 to 6 points, n=23; Quartile IV: 7 to 10 points, n=9). Two activity monitors (DynaPort (R) and SenseWear (R)) were used to evaluate the level of physical activity in daily life. The Kruskal-Wallis test (Dunns's post-hoc test), the Mann-Whitney test and the Spearman Correlation Coefficient were used for statistical analysis. Results: There were modest correlation between the BODE index and the time spent walking per day, the total daily energy expenditure and the time spent in moderate and vigorous activities per day (-0.32 <= r <=- 0.47; p <= 0.01 for all variables). When comparing the pooled quartiles I+II with III+IV, there were significant difference between the time spent walking per day, the total daily energy expenditure and the time spent in moderate activities per day (p <= 0.05). Conclusion: The level of physical activity in daily life has a modest correlation with the classification of COPD severity assessed by the BODE index, reflecting only differences between patients with classified as mild-moderate and severe-very severe COPD.

Efeitos da previdência rural na agricultura familiar da microrregião Serra de São Miguel - RN

The objective of the present work is to verify the effects of Rural Social welfare in the family agriculture of the microrregião Serra de São Miguel-RN. The study based on available bibliography on the theme, in secondary data and in a rising amostral accomplished in three municipal districts (Encanto, São Miguel and Riacho de Santana) of the microrregião. The universe of the study was the establishments of the family agriculture appeared in the Agricultural Census of 2006, in those municipal districts. The unit of considered analysis was the rural family, with the interviews being applied close to the farmers' families with and without retired rural. The sample was of 94 present families in the family establishments. The results demonstrate that the Rural Precaution reaches a significant covering degree in the rural area of the researched municipal districts, with an average of 1,57 beneficiaries for home in the families with retired. The data of the research attest that the family agriculture in the microrregião Serra de São Miguel-RN it has few favorable conditions for his/her development, once, besides the shortage of lands and of the climatic factor of the area, the returned public politics the family farmers' totality - like PRONAF and PAA -, it has been unable to give effective answers for the improvement of the life conditions in the rural way, have seen the minimum amount of families reached by those politics, be in function of the drawing or of the atmosphere where they are done. In this context, he/she stands out the importance of the Rural Precaution that, in function of the application of the constitutional devices that you/they guaranteed his/her universalization, it has been the only relevant public politics that, in fact, it has been reaching her/it all their beneficiary potentials. Given the general situation of the family agriculture of the microrregião and of the specific characteristics of the researched family establishments, the hypothesis was corroborated that the rural retirement doesn't contribute directly to the increase / making possible of the family agriculture. In spite of 57,4% of the families with retired have declared to use resources of the retirement in the costing of the rural activity carried out by the family, the annual medium value of the expense just located around 7,02% of the annual value of the retirements gained by the families in the year of 2010. Data the low levels in that the social reproduction of the great majority of the family establishments of the microrregião, the maintenance of the families is operated represents the main destiny of the resources precautions. It was also confirmed the hypothesis that the Rural Precaution constitutes the main monetary contribution of the families with retired. For more than 93% of the families with retired, the retirements doing 50% or more of the total of the family monetary income, and in the composition of the rural income of the families with retired and pensioners, the originating from income the rural retirements are equal to 65,24% of the total of the annual income obtained by the families. It is ended, because, that the rural precaution, given to the adversities for the development of the family agriculture, of the operational inefficacy of the public politics and of the few opportunities of generation of existent income in the local savings, it is the main responsible for the reduction of the poverty and, consequently, for the improvements of the conditions of life of the families of and with seniors in the rural way of the microrregião Serra de São Miguel-RN

Análise farmacognóstica e atividade antibacteriana de extratos vegetais empregados em formulação para a higiene bucal

A utilização de extratos vegetais vem se tornando uma alternativa importante para a prevenção de doenças periodontais. Este trabalho objetivou desenvolver uma formulação de enxagüatório bucal, contendo, em associação, extratos hidroalcoólicos de Rosmarinus officinalis, Plantago major, Tabebuia impetiginosa, Achillea millefollium e Nasturtium officinale; avaliar sua composição farmacognóstica e sua atividade antibacteriana, como também da fórmula proposta. Foram realizados estudos de pré-formulação e análises farmacognósticas para as espécies vegetais. A atividade antibacteriana in vitro foi observada por meio dos métodos de difusão em disco de papel, por hole- plate e por template, frente a Staphylococcus aureus, Bacillus subtilis, Escherichia colik, Enterococcus faecalis e Pseudomonas aeruginosa. A concentração inibitória mínima (CIM) foi determinada por meio do método de macrodiluições sucessivas em caldo. Os resultados obtidos apresentaram-se de acordo com o histórico farmacognóstico das drogas estudadas. Todas as bactérias foram inibidas pelos extratos, observando-se que as espécies S. aureus e B. subtilis mostraram, aparentemente, maior sensibilidade. A CIM variou, em relação a sensibilidade de cada espécie bacteriana estudada, de 312,5 µL/mL a 1250 µL/mL para os extratos vegetais e de 625 µL/mL a 2500 µL/mL para o enxaguatório bucal. São necessários estudos complementares para a confirmação da eficácia deste produto e sua utilização na prevenção de doenças periodontais.

Exposição repetida à cafeína aumenta a atividade locomotora induzida pelo femproporex em ratos adolescentes e adultos

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