Pedro Sarreira | Instituto Politécnico de Lisboa (original) (raw)
Papers in Conference Proceedings by Pedro Sarreira
EDULEARN18 Proceedings, 2018
Abstract: Using natural phenomena to scaffold children’s inner interest in doing questions and se... more Abstract: Using natural phenomena to scaffold children’s inner interest in doing questions and seeking for answers are current orientations to early childhood education. Recent research has shown that children at preschool bring unsuspected abilities in learning. Since some elementary astronomic phenomena are an everyday experience they should integrate the pool of resources from which the educators withdraw their material to promote an intentional teaching.
This brings to the fore the assessment of preservice teacher education in basic astronomic phenomena, their previous education in this subject and the robust misconceptions they hold.
This study report on misconceptions held by preservice elementary teachers and educators in a higher education institution in Lisbon. We had developed and validate a closed questionnaire constructed to probe the understanding of basic astronomic phenomena (day and night, moon phases and movements, earth movements, stars and constellations). Among the answers provided in the questionnaire were present as distractors misconceptions reported in the literature, so they could be assessed.
The questionnaire was applied in 2017 and 2018 before and after the teaching and learning module of astronomy. Here we will work on the answers obtained in those years before the teaching and learning module.
After a descriptive statistical analysis of the responses, we proceed to group the answers in main alternative conceptions and assess how prevalent they were among preservice teachers before they attend the module in elementary astronomy.
The results show, as expected, a similar distribution of alternative conceptions before the teaching and learning module in 2017 and in 2018. The Moon movements and its phases are poorly understood; the explanation for the seasons rest largely in the distance to the Sun framework; the apparent movement of the stars (and constellations) in the sky are detached from the apparent diurnal movement of the Sun. Scales are poorly understood and the Universe is seen as being much smaller than it is.
We conclude showing how the two main conceptual change frameworks, the Vosniadou’s ‘Framework theory” and diSessa’s “knowledge in pieces” explain our results and hint on what future work can improve our teaching and learning on elementary astronomy.
ICERI2017 Proceedings, 2017
Abstract: Scientific models are important thinking tools, which are used to generate explanations... more Abstract: Scientific models are important thinking tools, which are used to generate explanations and predications. Despite the relevance of scientific models and modelling in science education, several studies reveal that students and teachers do not possess adequate views regarding these topics. This study investigated preservice elementary teachers' views about scientific models and modelling. Research questions included: (1) what do preservice elementary teachers understand about models and modelling in science?; (2) is there a relationship between preservice teachers' views about scientific models and modelling and their scientific background in high school or year of course attendance? A questionnaire adopted form the literature was applied to a sample of preservice elementary teachers of one Portuguese institution of higher education at 1st, 2nd and 3th years of the course. This questionnaire comprised five aspects of students' understanding of models and modelling: nature of models, multiple models, purpose of models, testing models, and changing models. Descriptive analysis showed that a high percentage of preservice elementary teachers hold naive or uninformed understandings of models and modelling. From this we can infer that this lack of understanding would hamper their pedagogical practice related to scientific issues in a fundamental way as well their teaching and learning in their initial formation. Moreover, students' understanding of models and modelling didn't became more elaborated with increasing university years and no difference was found taking in account the area chosen in high school.
19th International Symposium on Computers in Education (SIIE) || 8th CIED Meeting/ 3rd CIED International Meeting, 2017
Abstract: In this article we assess the implementation of four learning objects directed to diffe... more Abstract: In this article we assess the implementation of four learning objects directed to different basic astronomy subjects. A questionnaire aiming at assessing preservice teachers' perception on the use of the learning objects in self-study was applied after an initial exploration of the learning objects in the classroom. This took place during a four-week teaching and learning of astronomy in a preservice teacher course. Most of respondents report positive impact both at emotional as well as at cognitive level. Some differences are reported in relations to the structure of the learning objects, which we discuss.
Atas do XVII Encontro Nacional de Educação em Ciências, XVII ENEC, I Seminário Internacional de Educação em Ciências, I SIEC., 2017
Resumo: Esta comunicação tem como objetivo a apresentação dos primeiros resultados de um projeto ... more Resumo: Esta comunicação tem como objetivo a apresentação dos primeiros resultados de um projeto de investigação sobre o ensino e aprendizagem de astronomia na formação inicial de educadores e professores do 1º e 2º Ciclo do Ensino Básico de uma instituição de formação da região de Lisboa. Para que os educadores e professores do 1º e 2º CEB desenvolvam o seu trabalho de modo a inspirar os alunos para as áreas STEM, devem adquirir na sua formação inicial, um sólido conhecimento de conteúdo e pedagógico. No que respeita à astronomia e espaço, a literatura relevante diz-nos que o conhecimento dos movimentos elementares da Terra, Lua e planetas e suas consequências, bem como uma apreciação das escalas do Sistema Solar e das estrelas em conjunto com algum conhecimento da estrutura do universo e do espaço, fornecem as componentes de um adequado conhecimento de conteúdo. Com base na literatura, desenvolvemos um questionário fechado com o objetivo de avaliar o conhecimento de conteúdo. Depois de pilotado com uma amostra de estudantes da formação inicial de e validado por peritos, foi aplicado antes e depois do ensino e aprendizagem do tema aos estudantes no primeiro ano da sua formação inicial. Foram realizadas entrevistas de follow-up a uma amostra de respondentes para explicitar o raciocínio. Dado que a sequência de ensino e aprendizagem tem sido usada desde há vários anos, o questionário foi também aplicado a uma amostra de estudantes nos restantes anos da formação inicial. Pretendemos deste modo avaliar como o conhecimento de conteúdo de astronomia e espaço evolui com o tempo. Os dados recolhidos pelo questionário foram sujeitos a uma análise estatística descritiva, enquanto os dados resultantes da entrevista de follow-up contribuíram para a interpretação dos resultados. A análise dos resultados revela a prevalência de retenção de conhecimento de conteúdo de curto prazo que atribuímos à proximidade da aplicação do questionário da sequência de ensino e aprendizagem. Os estudantes nos anos subsequentes revelam um declínio do conhecimento de conteúdo, o qual, ainda que esperado, é demasiado para ser atribuído apenas à passagem do tempo. Serão avançadas algumas hipóteses explicativas. Palavras-Chave: formação inicial de professores; astronomia; conhecimento de conteúdo; mudança conceptual. Abstract This communication aims at presenting the first results of a research project on teaching and learning astronomy and space in a preservice programme of a higher education institution in Lisbon. It is our understanding that for educators and elementary teachers develop their work in a way to inspire children to STEM, they should acquire, in their initial training, a solid content and pedagogical knowledge. Regarding astronomy and space, the relevant literature evinces that knowledge of the basic movements of Earth, Moon, and planets and its consequences as well as awareness of the scales of the Solar System and distant stars coupled with some knowledge
Talks by Pedro Sarreira
XV Encontro Nacional de Educação em Ciências – Livro de Resumos, 2014
Resumo: O acesso à cultura científica e tecnológica tem vindo a ser considerado um direito de cid... more Resumo: O acesso à cultura científica e tecnológica tem vindo a ser considerado um direito de cidadania de todos, devendo ocorrer desde os primeiros anos de escolaridade. Mas, iniciar as crianças à ciência e tecnologia, desde os primeiros anos, exige uma adequada formação em ensino das ciências de professores e educadores. Para Lederman (1998) dotar os professores de uma compreensão funcional sobre a natureza da ciência e sobre a pesquisa científica é um " pré-requisito para a esperança de alcançar a visão de ensino e aprendizagem de Ciência especificadas nos diferentes esforços de reforma " (p. 2) tais como a proposta no Project 2061. Contudo, a investigação tem evidenciado a deficiente formação científica dos professores. Capacitar os professores dos primeiros níveis de escolaridade para iniciarem as crianças à ciência, contemplando as dimensões referidas anteriormente, é uma tarefa complexa. Por outro lado, a redução do tempo atribuído à formação científica nos cursos de Educação Básica constitui uma dificuldade acrescida. Face à complexidade e dificuldade de que se reveste a formação científica dos futuros professores e educadores, os autores do presente trabalho (professores das Escolas Superiores de Educação de Lisboa, Santarém e Setúbal) iniciaram uma investigação no sentido de identificar metodologias de ensino, materiais e currículos que mais se adequam à formação científica pretendida. Esta comunicação apresenta os resultados do estudo comparativo das conceções de ciência identificadas através de um questionário aplicado no início e no final da formação inicial em cada uma das Escolas e uma primeira análise com vista à identificação da influência do currículo na formação científica dos alunos. Estes resultados são parte de um trabalho mais amplo que pretende seguir o percurso dos alunos, identificando quais as unidades curriculares (considerando conteúdos, estratégias, materiais, situações de aprendizagem) que contribuem de forma mais eficaz para a formação científica dos futuros professores e educadores.
Papers by Pedro Sarreira
Participatory design of a high-fidelity prototype of an essential learning curricular tool
Preservice Elementary Teachers’ Understandings About Scientific Models and Modelling
ICERI proceedings, Nov 1, 2017
Journal of Cardiovascular Electrophysiology, Oct 1, 1999
Heart Rate in Normal and Cardiac Transplant Snbjects. Introduction: The variability observed in t... more Heart Rate in Normal and Cardiac Transplant Snbjects. Introduction: The variability observed in tbe beart rate may reflect fundamental aspects of cardiac activity. It ba.s been under discussion wbetber beart rate variability (HRV) is due to noise or cbaos, whicb is irregular bebavior occurring in deterministic nonlinear systems. Methods and Results: Using chaos analysis techniques, we analyzed HRV of five normal and flve human cardiac transplant subjects at rest. HRV is studied using tbe beat-to-beat RR interval time .series extracted from tbe ECG. Tbe cardiac transplant subjects exhibited a mucb smaller HRV tban tbe normal subjects because of beart denervation. We present tbe map and correlation dimension estimation for tbe RR time series. To test for nonlinear correlations in tbe dynamics, we built surrogate time series that have the same power spectra as the experimental time series, but also bave randomized pbases. Tbe experimental and tbe surrogate data were compared using tbe correlation integral. No correlation dimension was found for tbe RR time series of eitber the normal or the cardiac transplant subjects. Nevertheless, nonlinear correlations were detected in tbe HRV of tbe normal subjects but not in HRV of tbe cardiac transplant subjects. For the latter, no significant changes were observed in the correlation integral as a function of time after transplantation. Conclusion: We found no evidence of low-dimensional cbaos in tbe HRV of normal and cardiac transplant subjects. However, some nonlinear correlations were detected in the HRV of tbe normal subjects, whicb may be associated with autonomic nervous system influence.
Mathematics in Environmental Issues
Advances in educational technologies and instructional design book series, Jan 27, 2023
The Noise about Chaos in Heart Rate
Journal of Cardiovascular Electrophysiology, Feb 1, 2000
In their recent article, Costa et al.' reported a failure to determine a finite correlation d... more In their recent article, Costa et al.' reported a failure to determine a finite correlation dimension for the heartbeat time series of normal and cardiac transplant subjects, and they asserted that there is no evidence of chaos in heart rate variability in these subjects. The negative account is amplified in an accompanying commentary.^ Cautions about the limitations of some previous tests of heart rate chaos are not new, but here the authors go even further by applying their inconclusive data to "rule out evidence of chaos." Both publications''^ repudiate previous reports of heart rate chaos, citing the unreliability of dimension and Liapunov measures as chaos indicators. If so, then the present claim for absence of heart rate chaos, based on a similar unreliable indicator, likewise should be viewed with caution. In hypothesis testing, a false-negative (type II error) is as undesirable as, and indeed more prevalent than, a false-positive (type I error).^ Failure to reject the null hypothesis (absence of chaos) could stem from a variety of reasons, including poor testing method, poor statistical design, poor quality and quantity of data, or all of the above. A graphical approach, such as correlation dimension with 30 minutes of ECG recordings, may not allow a sufficiently sensitive and specific test of heart rate chaos, whether or not surrogate data are used. It is well known that short datasets and observational noise could foil the determination of correlation dimension."* Surrogate data, such as those used by the authors, have known artifacts that can be avoided only with more elaborate construction schemes.^ At any rate, failure to demonstrate chaos by itself does not prove anything, much less a "compelling case to the contrary." Is heart rate variability chaotic? We believe this question can be resolved only with the use of a rigorous analytic procedure in combination with careful statistical and experimental design. One of the cited references^ was meant to expressly deal with this issue, but perhaps was misunderstood by the authors. Rather than relying on dimension or Liapunov measures of short data series, the referenced study used a sensitive analytic technique with demonstrated power for short, noisy data^ and applied it to multiple heartbeat data segments to establish statistical significance of outcomes. Results demonstrated that a nonlinear dynamic model accounted for much of the irregularity in heart rate variability in normal subjects and that a decline of such nonlinear determinism underlies the decreased heart rate variability in congestive heart failure. These critical findings should not be ignored. Nevertheless, it is noteworthy that decreased nonlinear determinism in heart rate variability of congestive heart failure patients^ also is manifested in cardiac transplant patients.'-^ Although decreases of nonlinear deterministic component in heart rate variability could result from decreases of nonlinear stochasticity or chaos, both cases involve a nonlinear deterministic process.' Changes in such a deterministic process could represent a common denominator, such as deranged autonomic regulation, for the decreased heart rate variability in both patient groups. Reliable measurement of the deterministic component of heart rate variability may shed light on the underlying pathogenesis and may offer a useful tool for improved diagnosis, prognosis, and intervention of such cardiac abnormalities.
Chaotic Discrete Learning Systems
ABSTRACT Better understanding of brain functions can have implications for the study of the dynam... more ABSTRACT Better understanding of brain functions can have implications for the study of the dynamics of learning. We apply concepts and tools of nonlinear dynamics and chaos to the modelling and study of learning. We use the sinusoidal activation function to adjust the sinaptic weights of a neuron and we investigate the behaviour of the network when the learning rate changes. Our results show that these systems can exhibit a very rich dynamics, from regular to chaotic, and we calculate the topological entropy.
Mathematics in Environmental Issues
Advances in educational technologies and instructional design book series, Jan 27, 2023
Aprendizagem e Complexidade Em Ciências: Uma Investigação Sobre a Aprendizagem De Ciências e a Teoria Dos Sistemas Dinâmicos Não Lineares
2017 International Symposium on Computers in Education (SIIE), 2017
In this article we assess the implementation of four learning objects directed to different basic... more In this article we assess the implementation of four learning objects directed to different basic astronomy subjects. A questionnaire aiming at assessing preservice teachers' perception on the use of the learning objects in self-study was applied after an initial exploration of the learning objects in the classroom. This took place during a four-week teaching and learning of astronomy in a preservice teacher course. Most of respondents report positive impact both at emotional as well as at cognitive level. Some differences are reported in relations to the structure of the learning objects, which we discuss.
microRNA-22 (miR-22) is a brain-enriched regulatory gene which has been reported to be involved i... more microRNA-22 (miR-22) is a brain-enriched regulatory gene which has been reported to be involved in the development of cancers. The Notch signaling pathway exerts important functions in cell growth. This study is designed to investigate the mechanisms of miR-22-Notch signaling pathway in apoptosis and autophagy of human ovarian cancer cells. After over-expressing miR-22 in human ovarian cancer cell lines OVCAR-3 and SKOV3, cell viability is determined by 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) method, cell apoptosis is observed by Flow cytometry (FCM), mRNA expression of miR-22 is measured by RNA preparation and RT-PCR, protein expression of Notch1, Hes1, Beclin1 and LC3B-II is analyzed by Western blot. It is suggested that miR-22 expression is heavily decreased in human ovarian cancer cell lines OVCAR-3 and SKOV3. Over-expression of miR-22 potently suppresses cell viability and authophagy while promotes the percentage of apoptotic cancer cells. In addition, the decreased expression level of Notch1 and its targeted gene is detected in miR-22-over-expressed cells. Moreover, followed by the block of the Notch signaling pathway using Notch1 small interference RNA (siRNA), the effects of miR-22 on the apoptosis and autophagy of human ovarian cancer cell lines OVCAR-3 and SKOV3 are obviously blocked. Together, miR-22 inhibits apoptosis and promotes autophagy of human ovarian cancer cells through the suppression of the Notch signaling pathway, indicating a potential use of miR-22 in the ovarian cancer treatment.
Competences and Use of Ict by Future Teachers and Kindergarten Educators: Using an Online Survey to Portray the Case of a Portuguese School of Education
EDULEARN18 Proceedings, 2018
O Que É a Ciência? Ideias Expressas Por Alunos Da Formação Inicial e Por Professores Em Exercício
Resumo: A investigação das últimas décadas tem mostrado que as conceções de ciência influenciam o... more Resumo: A investigação das últimas décadas tem mostrado que as conceções de ciência influenciam o modo como os estudantes de formação inicial aprendem ciência e didáctica das ciências, bem como, o modo como os professores planificam e implementam as actividades com as crianças. A presente comunicação visa inventariar conceções de ciência de alunos no início da formação inicial (2005/2006-2010/2011) e de professores em exercício no começo da frequência do Programa de Formação em Ensino Experimental das Ciências (2007/2008), numa ESE pública. Aos dois grupos aplicou-se um questionário contendo a questão de resposta aberta "O que é a Ciência?". Compara-se o padrão de resposta dos dois grupos entre si e com o obtido num estudo anterior (Grais et al., 2005). Discute-se a influência que as conceções identificadas poderão ter: na aprendizagem de ciência; no desenvolvimento de atitudes positivas face ao ensino da ciência; e nas metodologias de ensino a adoptar na formação inicial ...
O acesso à cultura científica e tecnológica tem vindo a ser considerado um direito de cidadania d... more O acesso à cultura científica e tecnológica tem vindo a ser considerado um direito de cidadania de todos, devendo ocorrer desde os primeiros anos de escolaridade. Mas, iniciar as crianças à ciência e tecnologia, desde os primeiros anos, exige uma adequada formação em ensino das ciências de professores e educadores. Para Lederman (1998) dotar os professores de uma compreensão funcional sobre a natureza da ciência e sobre a pesquisa científica é um "pré-requisito para a esperança de alcançar a visão de ensino e aprendizagem de Ciência especificadas nos diferentes esforços de reforma" (p. 2) tais como a proposta no Project 2061. Contudo, a investigação tem evidenciado a deficiente formação científica dos professores. Capacitar os professores dos primeiros níveis de escolaridade para iniciarem as crianças à ciência, contemplando as dimensões referidas anteriormente, é uma tarefa complexa. Por outro lado, a redução do tempo atribuído à formação científica nos cursos de Educação...
Journal of Cardiovascular Electrophysiology, 2000
Journal of Cardiovascular Electrophysiology, 1999
Heart Rate in Normal and Cardiac Transplant Snbjects. Introduction: The variability observed in t... more Heart Rate in Normal and Cardiac Transplant Snbjects. Introduction: The variability observed in tbe beart rate may reflect fundamental aspects of cardiac activity. It ba.s been under discussion wbetber beart rate variability (HRV) is due to noise or cbaos, whicb is irregular bebavior occurring in deterministic nonlinear systems. Methods and Results: Using chaos analysis techniques, we analyzed HRV of five normal and flve human cardiac transplant subjects at rest. HRV is studied using tbe beat-to-beat RR interval time .series extracted from tbe ECG. Tbe cardiac transplant subjects exhibited a mucb smaller HRV tban tbe normal subjects because of beart denervation. We present tbe map and correlation dimension estimation for tbe RR time series. To test for nonlinear correlations in tbe dynamics, we built surrogate time series that have the same power spectra as the experimental time series, but also bave randomized pbases. Tbe experimental and tbe surrogate data were compared using tbe correlation integral. No correlation dimension was found for tbe RR time series of eitber the normal or the cardiac transplant subjects. Nevertheless, nonlinear correlations were detected in tbe HRV of tbe normal subjects but not in HRV of tbe cardiac transplant subjects. For the latter, no significant changes were observed in the correlation integral as a function of time after transplantation. Conclusion: We found no evidence of low-dimensional cbaos in tbe HRV of normal and cardiac transplant subjects. However, some nonlinear correlations were detected in the HRV of tbe normal subjects, whicb may be associated with autonomic nervous system influence.
EDULEARN18 Proceedings, 2018
Abstract: Using natural phenomena to scaffold children’s inner interest in doing questions and se... more Abstract: Using natural phenomena to scaffold children’s inner interest in doing questions and seeking for answers are current orientations to early childhood education. Recent research has shown that children at preschool bring unsuspected abilities in learning. Since some elementary astronomic phenomena are an everyday experience they should integrate the pool of resources from which the educators withdraw their material to promote an intentional teaching.
This brings to the fore the assessment of preservice teacher education in basic astronomic phenomena, their previous education in this subject and the robust misconceptions they hold.
This study report on misconceptions held by preservice elementary teachers and educators in a higher education institution in Lisbon. We had developed and validate a closed questionnaire constructed to probe the understanding of basic astronomic phenomena (day and night, moon phases and movements, earth movements, stars and constellations). Among the answers provided in the questionnaire were present as distractors misconceptions reported in the literature, so they could be assessed.
The questionnaire was applied in 2017 and 2018 before and after the teaching and learning module of astronomy. Here we will work on the answers obtained in those years before the teaching and learning module.
After a descriptive statistical analysis of the responses, we proceed to group the answers in main alternative conceptions and assess how prevalent they were among preservice teachers before they attend the module in elementary astronomy.
The results show, as expected, a similar distribution of alternative conceptions before the teaching and learning module in 2017 and in 2018. The Moon movements and its phases are poorly understood; the explanation for the seasons rest largely in the distance to the Sun framework; the apparent movement of the stars (and constellations) in the sky are detached from the apparent diurnal movement of the Sun. Scales are poorly understood and the Universe is seen as being much smaller than it is.
We conclude showing how the two main conceptual change frameworks, the Vosniadou’s ‘Framework theory” and diSessa’s “knowledge in pieces” explain our results and hint on what future work can improve our teaching and learning on elementary astronomy.
ICERI2017 Proceedings, 2017
Abstract: Scientific models are important thinking tools, which are used to generate explanations... more Abstract: Scientific models are important thinking tools, which are used to generate explanations and predications. Despite the relevance of scientific models and modelling in science education, several studies reveal that students and teachers do not possess adequate views regarding these topics. This study investigated preservice elementary teachers' views about scientific models and modelling. Research questions included: (1) what do preservice elementary teachers understand about models and modelling in science?; (2) is there a relationship between preservice teachers' views about scientific models and modelling and their scientific background in high school or year of course attendance? A questionnaire adopted form the literature was applied to a sample of preservice elementary teachers of one Portuguese institution of higher education at 1st, 2nd and 3th years of the course. This questionnaire comprised five aspects of students' understanding of models and modelling: nature of models, multiple models, purpose of models, testing models, and changing models. Descriptive analysis showed that a high percentage of preservice elementary teachers hold naive or uninformed understandings of models and modelling. From this we can infer that this lack of understanding would hamper their pedagogical practice related to scientific issues in a fundamental way as well their teaching and learning in their initial formation. Moreover, students' understanding of models and modelling didn't became more elaborated with increasing university years and no difference was found taking in account the area chosen in high school.
19th International Symposium on Computers in Education (SIIE) || 8th CIED Meeting/ 3rd CIED International Meeting, 2017
Abstract: In this article we assess the implementation of four learning objects directed to diffe... more Abstract: In this article we assess the implementation of four learning objects directed to different basic astronomy subjects. A questionnaire aiming at assessing preservice teachers' perception on the use of the learning objects in self-study was applied after an initial exploration of the learning objects in the classroom. This took place during a four-week teaching and learning of astronomy in a preservice teacher course. Most of respondents report positive impact both at emotional as well as at cognitive level. Some differences are reported in relations to the structure of the learning objects, which we discuss.
Atas do XVII Encontro Nacional de Educação em Ciências, XVII ENEC, I Seminário Internacional de Educação em Ciências, I SIEC., 2017
Resumo: Esta comunicação tem como objetivo a apresentação dos primeiros resultados de um projeto ... more Resumo: Esta comunicação tem como objetivo a apresentação dos primeiros resultados de um projeto de investigação sobre o ensino e aprendizagem de astronomia na formação inicial de educadores e professores do 1º e 2º Ciclo do Ensino Básico de uma instituição de formação da região de Lisboa. Para que os educadores e professores do 1º e 2º CEB desenvolvam o seu trabalho de modo a inspirar os alunos para as áreas STEM, devem adquirir na sua formação inicial, um sólido conhecimento de conteúdo e pedagógico. No que respeita à astronomia e espaço, a literatura relevante diz-nos que o conhecimento dos movimentos elementares da Terra, Lua e planetas e suas consequências, bem como uma apreciação das escalas do Sistema Solar e das estrelas em conjunto com algum conhecimento da estrutura do universo e do espaço, fornecem as componentes de um adequado conhecimento de conteúdo. Com base na literatura, desenvolvemos um questionário fechado com o objetivo de avaliar o conhecimento de conteúdo. Depois de pilotado com uma amostra de estudantes da formação inicial de e validado por peritos, foi aplicado antes e depois do ensino e aprendizagem do tema aos estudantes no primeiro ano da sua formação inicial. Foram realizadas entrevistas de follow-up a uma amostra de respondentes para explicitar o raciocínio. Dado que a sequência de ensino e aprendizagem tem sido usada desde há vários anos, o questionário foi também aplicado a uma amostra de estudantes nos restantes anos da formação inicial. Pretendemos deste modo avaliar como o conhecimento de conteúdo de astronomia e espaço evolui com o tempo. Os dados recolhidos pelo questionário foram sujeitos a uma análise estatística descritiva, enquanto os dados resultantes da entrevista de follow-up contribuíram para a interpretação dos resultados. A análise dos resultados revela a prevalência de retenção de conhecimento de conteúdo de curto prazo que atribuímos à proximidade da aplicação do questionário da sequência de ensino e aprendizagem. Os estudantes nos anos subsequentes revelam um declínio do conhecimento de conteúdo, o qual, ainda que esperado, é demasiado para ser atribuído apenas à passagem do tempo. Serão avançadas algumas hipóteses explicativas. Palavras-Chave: formação inicial de professores; astronomia; conhecimento de conteúdo; mudança conceptual. Abstract This communication aims at presenting the first results of a research project on teaching and learning astronomy and space in a preservice programme of a higher education institution in Lisbon. It is our understanding that for educators and elementary teachers develop their work in a way to inspire children to STEM, they should acquire, in their initial training, a solid content and pedagogical knowledge. Regarding astronomy and space, the relevant literature evinces that knowledge of the basic movements of Earth, Moon, and planets and its consequences as well as awareness of the scales of the Solar System and distant stars coupled with some knowledge
XV Encontro Nacional de Educação em Ciências – Livro de Resumos, 2014
Resumo: O acesso à cultura científica e tecnológica tem vindo a ser considerado um direito de cid... more Resumo: O acesso à cultura científica e tecnológica tem vindo a ser considerado um direito de cidadania de todos, devendo ocorrer desde os primeiros anos de escolaridade. Mas, iniciar as crianças à ciência e tecnologia, desde os primeiros anos, exige uma adequada formação em ensino das ciências de professores e educadores. Para Lederman (1998) dotar os professores de uma compreensão funcional sobre a natureza da ciência e sobre a pesquisa científica é um " pré-requisito para a esperança de alcançar a visão de ensino e aprendizagem de Ciência especificadas nos diferentes esforços de reforma " (p. 2) tais como a proposta no Project 2061. Contudo, a investigação tem evidenciado a deficiente formação científica dos professores. Capacitar os professores dos primeiros níveis de escolaridade para iniciarem as crianças à ciência, contemplando as dimensões referidas anteriormente, é uma tarefa complexa. Por outro lado, a redução do tempo atribuído à formação científica nos cursos de Educação Básica constitui uma dificuldade acrescida. Face à complexidade e dificuldade de que se reveste a formação científica dos futuros professores e educadores, os autores do presente trabalho (professores das Escolas Superiores de Educação de Lisboa, Santarém e Setúbal) iniciaram uma investigação no sentido de identificar metodologias de ensino, materiais e currículos que mais se adequam à formação científica pretendida. Esta comunicação apresenta os resultados do estudo comparativo das conceções de ciência identificadas através de um questionário aplicado no início e no final da formação inicial em cada uma das Escolas e uma primeira análise com vista à identificação da influência do currículo na formação científica dos alunos. Estes resultados são parte de um trabalho mais amplo que pretende seguir o percurso dos alunos, identificando quais as unidades curriculares (considerando conteúdos, estratégias, materiais, situações de aprendizagem) que contribuem de forma mais eficaz para a formação científica dos futuros professores e educadores.
Participatory design of a high-fidelity prototype of an essential learning curricular tool
Preservice Elementary Teachers’ Understandings About Scientific Models and Modelling
ICERI proceedings, Nov 1, 2017
Journal of Cardiovascular Electrophysiology, Oct 1, 1999
Heart Rate in Normal and Cardiac Transplant Snbjects. Introduction: The variability observed in t... more Heart Rate in Normal and Cardiac Transplant Snbjects. Introduction: The variability observed in tbe beart rate may reflect fundamental aspects of cardiac activity. It ba.s been under discussion wbetber beart rate variability (HRV) is due to noise or cbaos, whicb is irregular bebavior occurring in deterministic nonlinear systems. Methods and Results: Using chaos analysis techniques, we analyzed HRV of five normal and flve human cardiac transplant subjects at rest. HRV is studied using tbe beat-to-beat RR interval time .series extracted from tbe ECG. Tbe cardiac transplant subjects exhibited a mucb smaller HRV tban tbe normal subjects because of beart denervation. We present tbe map and correlation dimension estimation for tbe RR time series. To test for nonlinear correlations in tbe dynamics, we built surrogate time series that have the same power spectra as the experimental time series, but also bave randomized pbases. Tbe experimental and tbe surrogate data were compared using tbe correlation integral. No correlation dimension was found for tbe RR time series of eitber the normal or the cardiac transplant subjects. Nevertheless, nonlinear correlations were detected in tbe HRV of tbe normal subjects but not in HRV of tbe cardiac transplant subjects. For the latter, no significant changes were observed in the correlation integral as a function of time after transplantation. Conclusion: We found no evidence of low-dimensional cbaos in tbe HRV of normal and cardiac transplant subjects. However, some nonlinear correlations were detected in the HRV of tbe normal subjects, whicb may be associated with autonomic nervous system influence.
Mathematics in Environmental Issues
Advances in educational technologies and instructional design book series, Jan 27, 2023
The Noise about Chaos in Heart Rate
Journal of Cardiovascular Electrophysiology, Feb 1, 2000
In their recent article, Costa et al.' reported a failure to determine a finite correlation d... more In their recent article, Costa et al.' reported a failure to determine a finite correlation dimension for the heartbeat time series of normal and cardiac transplant subjects, and they asserted that there is no evidence of chaos in heart rate variability in these subjects. The negative account is amplified in an accompanying commentary.^ Cautions about the limitations of some previous tests of heart rate chaos are not new, but here the authors go even further by applying their inconclusive data to "rule out evidence of chaos." Both publications''^ repudiate previous reports of heart rate chaos, citing the unreliability of dimension and Liapunov measures as chaos indicators. If so, then the present claim for absence of heart rate chaos, based on a similar unreliable indicator, likewise should be viewed with caution. In hypothesis testing, a false-negative (type II error) is as undesirable as, and indeed more prevalent than, a false-positive (type I error).^ Failure to reject the null hypothesis (absence of chaos) could stem from a variety of reasons, including poor testing method, poor statistical design, poor quality and quantity of data, or all of the above. A graphical approach, such as correlation dimension with 30 minutes of ECG recordings, may not allow a sufficiently sensitive and specific test of heart rate chaos, whether or not surrogate data are used. It is well known that short datasets and observational noise could foil the determination of correlation dimension."* Surrogate data, such as those used by the authors, have known artifacts that can be avoided only with more elaborate construction schemes.^ At any rate, failure to demonstrate chaos by itself does not prove anything, much less a "compelling case to the contrary." Is heart rate variability chaotic? We believe this question can be resolved only with the use of a rigorous analytic procedure in combination with careful statistical and experimental design. One of the cited references^ was meant to expressly deal with this issue, but perhaps was misunderstood by the authors. Rather than relying on dimension or Liapunov measures of short data series, the referenced study used a sensitive analytic technique with demonstrated power for short, noisy data^ and applied it to multiple heartbeat data segments to establish statistical significance of outcomes. Results demonstrated that a nonlinear dynamic model accounted for much of the irregularity in heart rate variability in normal subjects and that a decline of such nonlinear determinism underlies the decreased heart rate variability in congestive heart failure. These critical findings should not be ignored. Nevertheless, it is noteworthy that decreased nonlinear determinism in heart rate variability of congestive heart failure patients^ also is manifested in cardiac transplant patients.'-^ Although decreases of nonlinear deterministic component in heart rate variability could result from decreases of nonlinear stochasticity or chaos, both cases involve a nonlinear deterministic process.' Changes in such a deterministic process could represent a common denominator, such as deranged autonomic regulation, for the decreased heart rate variability in both patient groups. Reliable measurement of the deterministic component of heart rate variability may shed light on the underlying pathogenesis and may offer a useful tool for improved diagnosis, prognosis, and intervention of such cardiac abnormalities.
Chaotic Discrete Learning Systems
ABSTRACT Better understanding of brain functions can have implications for the study of the dynam... more ABSTRACT Better understanding of brain functions can have implications for the study of the dynamics of learning. We apply concepts and tools of nonlinear dynamics and chaos to the modelling and study of learning. We use the sinusoidal activation function to adjust the sinaptic weights of a neuron and we investigate the behaviour of the network when the learning rate changes. Our results show that these systems can exhibit a very rich dynamics, from regular to chaotic, and we calculate the topological entropy.
Mathematics in Environmental Issues
Advances in educational technologies and instructional design book series, Jan 27, 2023
Aprendizagem e Complexidade Em Ciências: Uma Investigação Sobre a Aprendizagem De Ciências e a Teoria Dos Sistemas Dinâmicos Não Lineares
2017 International Symposium on Computers in Education (SIIE), 2017
In this article we assess the implementation of four learning objects directed to different basic... more In this article we assess the implementation of four learning objects directed to different basic astronomy subjects. A questionnaire aiming at assessing preservice teachers' perception on the use of the learning objects in self-study was applied after an initial exploration of the learning objects in the classroom. This took place during a four-week teaching and learning of astronomy in a preservice teacher course. Most of respondents report positive impact both at emotional as well as at cognitive level. Some differences are reported in relations to the structure of the learning objects, which we discuss.
microRNA-22 (miR-22) is a brain-enriched regulatory gene which has been reported to be involved i... more microRNA-22 (miR-22) is a brain-enriched regulatory gene which has been reported to be involved in the development of cancers. The Notch signaling pathway exerts important functions in cell growth. This study is designed to investigate the mechanisms of miR-22-Notch signaling pathway in apoptosis and autophagy of human ovarian cancer cells. After over-expressing miR-22 in human ovarian cancer cell lines OVCAR-3 and SKOV3, cell viability is determined by 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) method, cell apoptosis is observed by Flow cytometry (FCM), mRNA expression of miR-22 is measured by RNA preparation and RT-PCR, protein expression of Notch1, Hes1, Beclin1 and LC3B-II is analyzed by Western blot. It is suggested that miR-22 expression is heavily decreased in human ovarian cancer cell lines OVCAR-3 and SKOV3. Over-expression of miR-22 potently suppresses cell viability and authophagy while promotes the percentage of apoptotic cancer cells. In addition, the decreased expression level of Notch1 and its targeted gene is detected in miR-22-over-expressed cells. Moreover, followed by the block of the Notch signaling pathway using Notch1 small interference RNA (siRNA), the effects of miR-22 on the apoptosis and autophagy of human ovarian cancer cell lines OVCAR-3 and SKOV3 are obviously blocked. Together, miR-22 inhibits apoptosis and promotes autophagy of human ovarian cancer cells through the suppression of the Notch signaling pathway, indicating a potential use of miR-22 in the ovarian cancer treatment.
Competences and Use of Ict by Future Teachers and Kindergarten Educators: Using an Online Survey to Portray the Case of a Portuguese School of Education
EDULEARN18 Proceedings, 2018
O Que É a Ciência? Ideias Expressas Por Alunos Da Formação Inicial e Por Professores Em Exercício
Resumo: A investigação das últimas décadas tem mostrado que as conceções de ciência influenciam o... more Resumo: A investigação das últimas décadas tem mostrado que as conceções de ciência influenciam o modo como os estudantes de formação inicial aprendem ciência e didáctica das ciências, bem como, o modo como os professores planificam e implementam as actividades com as crianças. A presente comunicação visa inventariar conceções de ciência de alunos no início da formação inicial (2005/2006-2010/2011) e de professores em exercício no começo da frequência do Programa de Formação em Ensino Experimental das Ciências (2007/2008), numa ESE pública. Aos dois grupos aplicou-se um questionário contendo a questão de resposta aberta "O que é a Ciência?". Compara-se o padrão de resposta dos dois grupos entre si e com o obtido num estudo anterior (Grais et al., 2005). Discute-se a influência que as conceções identificadas poderão ter: na aprendizagem de ciência; no desenvolvimento de atitudes positivas face ao ensino da ciência; e nas metodologias de ensino a adoptar na formação inicial ...
O acesso à cultura científica e tecnológica tem vindo a ser considerado um direito de cidadania d... more O acesso à cultura científica e tecnológica tem vindo a ser considerado um direito de cidadania de todos, devendo ocorrer desde os primeiros anos de escolaridade. Mas, iniciar as crianças à ciência e tecnologia, desde os primeiros anos, exige uma adequada formação em ensino das ciências de professores e educadores. Para Lederman (1998) dotar os professores de uma compreensão funcional sobre a natureza da ciência e sobre a pesquisa científica é um "pré-requisito para a esperança de alcançar a visão de ensino e aprendizagem de Ciência especificadas nos diferentes esforços de reforma" (p. 2) tais como a proposta no Project 2061. Contudo, a investigação tem evidenciado a deficiente formação científica dos professores. Capacitar os professores dos primeiros níveis de escolaridade para iniciarem as crianças à ciência, contemplando as dimensões referidas anteriormente, é uma tarefa complexa. Por outro lado, a redução do tempo atribuído à formação científica nos cursos de Educação...
Journal of Cardiovascular Electrophysiology, 2000
Journal of Cardiovascular Electrophysiology, 1999
Heart Rate in Normal and Cardiac Transplant Snbjects. Introduction: The variability observed in t... more Heart Rate in Normal and Cardiac Transplant Snbjects. Introduction: The variability observed in tbe beart rate may reflect fundamental aspects of cardiac activity. It ba.s been under discussion wbetber beart rate variability (HRV) is due to noise or cbaos, whicb is irregular bebavior occurring in deterministic nonlinear systems. Methods and Results: Using chaos analysis techniques, we analyzed HRV of five normal and flve human cardiac transplant subjects at rest. HRV is studied using tbe beat-to-beat RR interval time .series extracted from tbe ECG. Tbe cardiac transplant subjects exhibited a mucb smaller HRV tban tbe normal subjects because of beart denervation. We present tbe map and correlation dimension estimation for tbe RR time series. To test for nonlinear correlations in tbe dynamics, we built surrogate time series that have the same power spectra as the experimental time series, but also bave randomized pbases. Tbe experimental and tbe surrogate data were compared using tbe correlation integral. No correlation dimension was found for tbe RR time series of eitber the normal or the cardiac transplant subjects. Nevertheless, nonlinear correlations were detected in tbe HRV of tbe normal subjects but not in HRV of tbe cardiac transplant subjects. For the latter, no significant changes were observed in the correlation integral as a function of time after transplantation. Conclusion: We found no evidence of low-dimensional cbaos in tbe HRV of normal and cardiac transplant subjects. However, some nonlinear correlations were detected in the HRV of tbe normal subjects, whicb may be associated with autonomic nervous system influence.
Chaotic Discrete Learning Systems
Difference Equations, Special Functions and Orthogonal Polynomials - Proceedings of the International Conference, 2007
ABSTRACT Better understanding of brain functions can have implications for the study of the dynam... more ABSTRACT Better understanding of brain functions can have implications for the study of the dynamics of learning. We apply concepts and tools of nonlinear dynamics and chaos to the modelling and study of learning. We use the sinusoidal activation function to adjust the sinaptic weights of a neuron and we investigate the behaviour of the network when the learning rate changes. Our results show that these systems can exhibit a very rich dynamics, from regular to chaotic, and we calculate the topological entropy.