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A construção escolar do plano nacional de leitura: um estudo num agrupamento de escolas do ensino básico
Get PDFDoutoramento em DidácticaAs medidas políticas tornam-se palco dos processos de apropriação e
recepção que se desenvolvem a vários níveis, especificamente, na escola, na
sociedade civil e na comunidade científica.
A escola apresenta-se, neste processo, como um dos cenários em que alunos,
pais e, em especial, os professores surgem como actores que reinterpretam o
discurso oficial, reconhecendo nele potencialidades e limites, em face das suas
expectativas, concepções e práticas, e que procedem à sua transposição
pedagógica, através dos objectivos que seleccionam, dos objectos que lêem,
das actividades e dos recursos mobilizados.
A relevância social da leitura, a sua centralidade e transversalidade
curriculares, assim como o investimento político no domínio da promoção
leitora, na escola, através da criação do Plano Nacional de Leitura, fazem
desta medida política, um campo privilegiado para a análise dos modos de
recepção desenvolvidos pelos professores.
Enquadrado numa perspectiva descritiva e interpretativa da investigação em
Didáctica, assumindo a importância da construção pessoal e colectiva da
leitura e dos leitores num quadro escolar, este estudo baseia-se no
pressuposto de que a promoção da leitura, na escola, tendo como referência o
PNL, terá de se ancorar no conhecimento sobre os modos de recepção desta
medida política.
Partindo de um desenho metodológico assente num estudo de caso,
recolhemos dados, de natureza qualitativa e quantitativa, que nos permitem
conhecer e interpretar a relação de um agrupamento de escolas do ensino
básico com as práticas de leitura realizadas no âmbito do PNL.
O percurso de análise e reflexão que construímos durante este estudo
permitiu-nos sobretudo evidenciar a receptividade às propostas políticas, de
nível global, actualizadas numa lógica de especificidade local.
Constituem lugares de maior adesão, por parte dos professores, o
reconhecimento das potencialidades do PNL, especificamente, o alargamento
do fundo bibliográfico, o aumento das práticas de leitura, o maior conhecimento
de diferentes géneros textuais e a possibilidade de integrar o livro nas práticas
de leitura.
O processo de interpretação destas propostas aparece contudo atravessado
por tensões e ambiguidades. Entre os lugares de resistência, verifica-se uma
certa dificuldade em desenvolver competências de leitura, de diversificação de
textos e de modos de os ler.
O estudo pretende constituir um contributo para o alargamento do
conhecimento sobre os processos de construção escolar da leitura, de
recepção desenvolvidos pelos professores, no âmbito do PNL, apresentando
igualmente pistas para a avaliação das possibilidades de desenvolvimento e
consecução desta medida política, assim como para a definição de políticas de
formação contínua de professores.Political measures become the stage of appropriation and reception processes
which develop at various levels, specifically in the school, the civil and the
scientific community.
Within this process, the school is one of the sceneries where students, parents
and teachers appear as actors. This makes it necessary to recognize the ways
all of them, and teachers in particular, reinterpret the official discourse and
recognize its potentials and limitations, according to their expectations. Also, it
is important to investigate how they activate their pedagogical transposition,
through the objectives they select, the objects they read, the activities they
perform, and the resources they use.
The social crediting of reading, its centrality and curricular transversality, as
well as the political investment materialized in the National Reading Plan
(PNL), make it a privileged field to analyze the reception modes developed by
teachers.
Framed within a descriptive and interpretive perspective of research in
Didactics, and acknowledging the importance of the personal and collective
construction of reading and readers in a school context, this study is grounded
on the assumption that the promotion of reading, as referenced on the PNL, will
have to be anchored in the knowledge about modes of reception of this political
measure.
Starting from a methodological framework applied in a study case, we gathered
qualitative and quantitative data which allowed us to know and interpret the
relationship of a group of basic education schools with the reading practices
activated in the context of the PNL.
The path of analysis and reflection we have built up during this study allowed
us to highlight the receptivity to the political proposals, applied at a global level,
materialized and updated in specific local contexts.
The aspect which received more adherence was the recognition of the PNL´s
potential, regarded as an opportunity to enlarge the bibliographical repository,
increase reading practices, widen the knowledge of different textual genres,
and integrate the book in reading practices.
The process of interpretation of these proposals is, however, characterized by
tensions and ambiguities. The resisting areas include a relative impossibility to
develop reading competencies, as well as to diversify objects and modes of
reading the texts.
The study aims at contributing towards the widening of knowledge about
reception processes of school construction. Furthermore, it presents clues
concerning the evaluation of the development and consecution of that political
measure, as well as the definition of continuing teacher training policies.POCTI; FCT; FS
Leitmann's direct method of optimization for absolute extrema of certain problems of the calculus of variations on time scales
No full textThe fundamental problem of the calculus of variations on time scales concerns the minimization of a delta-integral over all trajectories satisfying given boundary conditions. This includes the discrete-time, the quantum, and the continuous/classical calculus of variations as particular cases. In this note we follow Leitmann's direct method to give explicit solutions for some concrete optimal control problems on an arbitrary time scale. © 2010 Elsevier Inc. All rights reserved
Leitmann's direct method for fractional optimization problems
No full textBased on a method introduced by Leitmann [G. Leitmann, A note on absolute extrema of certain integrals, Int. J. Non-Linear Mech. 2 (1967) 55-59], we exhibit exact solutions for some fractional optimization problems of the calculus of variations and optimal control. © 2010 Elsevier Inc. All rights reserved.control theory group (cotg)CEOCFCTFEDER/POCI 201
Avoidance control on time scales
No full textWe consider dynamic systems on time scales under the control of two agents. One of the agents desires to keep the state of the system out of a given set regardless of the other agent's actions. Leitmann's avoidance conditions are proved to be valid for dynamic systems evolving on an arbitrary time scale. © Springer Science+Business Media, LLC 2010
Analysis of vibrations in large flexible hybrid systems
No full textThe mathematical model of a real flexible elastic system with distributed and discrete parameters is considered. It is a partial differential equation with non-classical boundary conditions. Complexity of the boundary conditions makes it impossible to find exact analytical solutions. To address the problem, we use the asymptotical method of small parameters together with the numerical method of normal fundamental systems of solutions. These methods allow us to investigate vibrations, and a technique for determination of complex eigenvalues of the considered boundary value problem is developed. The conditions, at which vibration processes of different characteristics take place, are defined. The dependence of the vibration frequencies on the physical parameters of the hybrid system is studied. We show that introduction of different feedbacks into the system allows one to control the frequency spectrum, in which excitation of vibrations is possible. © 2005 Elsevier Ltd. All rights reserved.FCTSFRH/BPD/14946/2004CEO
Proper extensions of Noether's symmetry theorem for nonsmooth extremals of the calculus of variations
No full textFor nonsmooth Euler-Lagrange extremals, Noether's conservation laws cease to be valid. We show that Emmy Noether's theorem of the calculus of variations is still valid in the wider class of Lipschitz functions, as long as one restrict the Euler-Lagrange extremals to those which satisfy the DuBoisReymond necessary condition. In the smooth case all Euler-Lagrange extremals are DuBois-Reymond extremals, and the result gives a proper extension of the classical Noether's theorem. This is in contrast with the recent developments of Noether's symmetry theorems to the optimal control setting, which give rise to non-proper extensions when specified for the problems of the calculus of variations. Results are also obtained for variational problems with higher-order derivatives
Direct photodegradation of carbamazepine followed by micellar electrokinetic chromatography and mass spectrometry
No full textCarbamazepine, a widely consumed psychotropic pharmaceutical, is one of the most commonly detected drugs in the environment. To better assess the environmental persistence of carbamazepine in aqueous matrices, the effect of pH and dissolved oxygen on the direct photodegradation rate of this pharmaceutical was evaluated in this study, using simulated solar irradiation. In order to follow the degradation and the emergence of photoproducts, a micellar electrokinetic chromatography based method was developed, consisting on the use of a dynamically coated capillary column. The developed methodology showed good repeatability and efficiency in the separation of carbamazepine and photoirradiation products. Also, seven photodegradation products were identified by electrospray mass spectrometry (ESI-MS), including the known carcinogenic acridine that was produced under all the pH and oxygenation levels studied and one newly identified photoproduct. This paper gives new insights into the role of dissolved oxygen on the photodegradation rate of carbamazepine. The results indicate that acidic pH, combined with the absence of dissolved oxygen in the aqueous matrix, results in very high direct photodegradation rates. At basic pH, dissolved oxygen does not interfere with the process and very low rates were observed. At environmentally relevant conditions, carbamazepine was shown to persist in the environment from 4.5 to 25 days. (C) 2010 Elsevier Ltd. All rights reserved
Heavy elements in the phosphorite from Kalaat Khasba mine (North-western Tunisia): Potential implications on the environment and human health
No full textTunisia is one of the largest phosphate producers in the world (more than 10 million tons per year since the early nineties). The Kalaat Khasba mine (NW of Tunisia) has operated from 1893 until 1993 and data demonstrate that, in the phosphorites of Kalaat Khasba, Cd is enriched 105-208 times, when compared with shales, and U is enriched by a factor varying between 18 and 44. The general trend shows an increase in heavy elements content with decreasing particle size. On the other hand, concentrations of Sr, Cr and U exhibit the same distribution for the different size fractions. It was found that Cd concentrations exceed the allowed EC soil limits for growing crops. Hence, owing to the tailings exposure and to the mobilisation of the finest particles by rainfall and wind. Cd could have detrimental effects on human health and on the environment because a significant portion of Cd was found in the exchangeable form. (C) 2010 Elsevier B.V. All rights reserved.GRICES (Portugal)INRST (Tunisia)Research Center GeoBioTecFC
On the spectra of some graphs like weighted rooted trees
No full textLet G be a weighted rooted graph of k levels such that, for j ∈ {2, ..., k}(1)each vertex at level j is adjacent to one vertex at level j - 1 and all edges joining a vertex at level j with a vertex at level j - 1 have the same weight, where the weight is a positive real number;(2)if two vertices at level j are adjacent then they are adjacent to the same vertex at level j - 1 and all edges joining two vertices at level j have the same weight;(3)two vertices at level j have the same degree;(4)there is not a vertex at level j adjacent to others two vertices at the same level;We give a complete characterization of the eigenvalues of the Laplacian matrix and adjacency matrix of G. They are the eigenvalues of leading principal submatrices of two nonnegative symmetric tridiagonal matrices of order k × k and the roots of some polynomials related with the characteristic polynomial of the referred submatrices. By application of the above mentioned results, we derive an upper bound on the largest eigenvalue of a graph defined by a weighted tree and a weighted triangle attached, by one of its vertices, to a pendant vertex of the tree. © 2008 Elsevier Inc. All rights reserved.Centro de Estruturas Lineares e CombinatóriasCEOCFCTFEDER/POCI 201
The diameter of the acyclic Birkhoff polytope
No full textIn this work we give an interpretation of vertices and edges of the acyclic Birkhoff polytope, Tn = Ωn (T), where T is a tree with n vertices, in terms of graph theory. We generalize a recent result relatively to the diameter of the graph G (Tn). © 2007 Elsevier Inc. All rights reserved.CEOCFCTFEDER/POCI 2010CMU