980 resultados para Bonnet-type fundamental theorems


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Cette étude appartient à l un des principaux défis de l éducation dans l actualité qui est la production de connaissances concernant la mort comme objet d investigation théorique et empirique dans le domaine éducationnel. Des recherches récentes signalent le besoin d une éducation contemplant des études sur la mort et montrent l école tel qu un lieu de débats et reflexions à propos de ce thème. Cette reflexion est relevante et fondamentale, étant donné que la mort fait partie du cycle de la vie et se trouve présente dans les contenus scolaires des différents domaines de la connaissance. Ce travail a, donc, l objectif d analyser les signification attribués à ce concept mort et la relation qui s établit entre eux et la pratique des professeurs de l enseignement fondamental. Il adopte en tant que référentiel les principes de la recherche qualitative du type étnographique (André, Chizzotti et Meksenas), dans une approche socio-historique et en ce qui concerne la formation et le développement des concepts (Vygotsky, Kopnin, Guetamanova et Ferreira). La participation des professeurs a été faite par l observation participante, registres en cahier de bord et application d un instrument de construction de données pour l appréhension des significations attribués aux concepts qui sont à la base de la pratique de cinq enseignantes des premières séries de l Enseignement Fondamental d une école publique du réseau d enseignement de l État du Rio Grande do Norte située dans la Zone Sud de Natal. De ce fait, les analyses et les interprétations des observations de la pratique dans la salle de classe et des réponses aux quinze questions liées au thème ont permis de construire les significations des concepts qui appuient les pratiques enseignantes de ces professeurs, tout en mettant en relief la fragmentation et la désarticulation entre les expressions décrites dans les questionnaires et les pratiques développées en salle de clase. Ces reflexions mettent en évidence la nécessité de re-penser l articulation entre l énnoncé et la pratique des professeurs à propos de cette thématique au cours d une formation initiale et continue

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The discussion we have established in this study is about how the practice is developing educational projects based on work with because the methodological choice of the teacher. The study of an ethnographic qualitative approach was conducted with a group of six teachers in two public schools in School Administrative Zone north of the city of Natal / RN. Data were constructed from semi-structured, reinforced by the direct observation of the practice of teaching of teachers. The goals outlined were to identify the reasons why the option for the project, listing the benchmarks that subsidized their construction, the observation of everyday experience in educational planning and development of projects developed. In the light of information we can notice a complex and even contradictory, which is confusing the concepts and practices are weakened. The analysis revealed inconsistencies between theory and practice in working with projects, the fruit of little theoretical development of teachers. The adoption of the project as a methodological option has meant a change in direction of the effective action didactic. Reflects on this situation, it was concluded that there is a need to broaden the understanding of the significance of this type of work, covering the different dimensions that involve the practice of research, research and training of teachers. Even preventing the intentions and initiatives of the teachers, it must be emphasized is the process of learning within an approach that focuses the process of learning in multiple dimensions, inter-relational, both the capabilities of students in the areas of knowledge.

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Agaricus blazei Murill is a medicinal mushroom native to Brazil. The present work assessed the clastogenic and anticlastogenic potential of organic extracts (ethanol and chloroform/methanol) from the lineage AB97/11 in chinese hamster CHO-K-1 (wild type) and CHO-xrs5 (repair deficient) cells using the chromosome aberration (CA) and sister chromatid exchange (SCE) assays. In these experimental conditions were observed: (a) anticlastogenic effect at concentrations of 0.06 and 0.09% of the EtOH extract and at the 0.03 and 0.06% concentrations of the C/MetOH extract in CHO-K-1; (b) absence of protector effect on CHO-xrs5 cells; and (c) absence of protector effect in the SCE assay. These results indicate that organic extracts of A. blazei lineage AB97/11 present bio-antimutagenic type protective activity. (C) 2003 Elsevier B.V. B.V. All rights reserved.

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The intention of the present study was to analyze the adequacy of the playground of elementary schools, according to the point of view of the child student, direct user of this type of environment, what estimated its critical in respect to these spaces and aimed at to contribute for its improvement. Many studies have analyzed the quality of the physical environment available for activities of leisure in specific places for children, focusing in the influence of the physical space in the interpersonal relationships and the comfort and satisfaction generated by the physical characteristics of these spaces. Concern with scholar environment, specially the interest on playgrounds, has been subject of recent studies; however, little attention has been given to the opinion of the user-child in relation to this school environment. In this inquiry of the playground of two state schools of 1ª to 4ª series of elementary school in the city of Piracicaba, SP, was used: assystematics observations, photographic register of the studied environments, interviews with child-users and behavioral mapping. The main subjects resulting from the analysis of the interviews content were: adaptation, density and interpersonal relationships, and infantile confinement. The results revealed the unsatisfactory conditions of the courtyards, in respect to person-environment relationship. The children demonstrated to be critical, creative and responsible when answering questions related to the quality of the school courtyard. This finding confirms previous studies and leads to the conclusion that the child, as the direct user, should be included as an excellent source of consultation in the planning of the constructed environment

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Among several theorems which are taught in basic education some of them can be proved in the classroom and others do not, because the degree of difficulty of its formal proof. A classic example is the Fundamental Theorem of Algebra which is not proved, it is necessary higher-level knowledge in mathematics. In this paper, we justify the validity of this theorem intuitively using the software Geogebra. And, based on [2] we will present a clear formal proof of this theorem that is addressed to school teachers and undergraduate students in mathematics

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General Fierz-type identities are examined and their well-known connection with completeness relations in matrix vector spaces is shown. In particular, I derive the chiral Fierz identities in a simple and systematic way by using a chiral basis for the complex 4 X 4 matrices. Other completeness relations for the fundamental representations of SU(N) algebras can be extracted using the same reasoning. (c) 2005 American Association of Physics Teachers.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Dynamical systems of the billiard type are of fundamental importance for the description of numerous phenomena observed in many different fields of research, including statistical mechanics, Hamiltonian dynamics, nonlinear physics, and many others. This Focus Issue presents the recent progress in this area with contributions from the mathematical as well as physical stand point. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4730155]

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The nonminimal pure spinor formalism for the superstring is used to prove two new multiloop theorems which are related to recent higher-derivative R-4 conjectures of Green, Russo, and Vanhove. The first theorem states that when 0 < n < 12, partial derivative R-n(4) terms in the Type II effective action do not receive perturbative contributions above n/2 loops. The second theorem states that when n <= 8, perturbative contributions to partial derivative R-n(4) terms in the IIA and IIB effective actions coincide. As shown by Green, Russo, and Vanhove, these results suggest that d=4 N=8 supergravity is ultraviolet finite up to eight loops.

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Complex mass poles, or ghost poles, are present in the Hartree-Fock solution of the Schwinger-Dyson equation for the nucleon propagator in renormalizable models with Yukawa-type meson-nucleon couplings, as shown many years ago by Brown, Puff and Wilets (BPW), These ghosts violate basic theorems of quantum field theory and their origin is related to the ultraviolet behavior of the model interactions, Recently, Krein et.al, proved that the ghosts disappear when vertex corrections are included in a self-consistent way, softening the interaction sufficiently in the ultraviolet region. In previous studies of pi N scattering using ''dressed'' nucleon propagator and bare vertices, did by Nutt and Wilets in the 70's (NW), it was found that if these poles are explicitly included, the value of the isospin-even amplitude A((+)) is satisfied within 20% at threshold. The absence of a theoretical explanation for the ghosts and the lack of chiral symmetry in these previous studies led us to re-investigate the subject using the approach of the linear sigma-model and study the interplay of low-energy theorems for pi N scattering and ghost poles. For bare interaction vertices we find that ghosts are present in this model as well and that the A((+)) value is badly described, As a first approach to remove these complex poles, we dress the vertices with phenomenological form factors and a reasonable agreement with experiment is achieved, In order to fix the two cutoff parameters, we use the A((+)) value for the chiral limit (m(pi) --> 0) and the experimental value of the isoscalar scattering length, Finally, we test our model by calculating the phase shifts for the S waves and we find a good agreement at threshold. (C) 1997 Elsevier B.V. B.V.

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The older Precambrian geological setting of north Goias/south Tocantins includes three areas of granite-greenstone terrains formed of medium-grade gneisses with associated greenstone belts and nepheline syenitic gneisses, separated by two orogenic belts composing a crustal-scale pop-up structure. The movements were firstly oblique towards NW along the northwestern NNE-SSW-trending Porto Nacional suture, and afterwards of essentially frontal type towards ESE along the southeastern Ceres suture of curved geometry with N-S direction at north and WNW-ESE at the south. The Porangatu block, limited by these sutures, was upthrusted over the neighbouring underthrusted blocks. Three principal kinematic phases are recognized along the orogenic belts. -from English summary

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A ten-dimensional super-Poincaré covariant formalism for the superstring was recently developed which involves a BRST operator constructed from superspace matter variables and a pure spinor ghost variable. A super-Poincaré covariant prescription was defined for computing tree amplitudes and was shown to coincide with the standard RNS prescription. In this paper, picture-changing operators are used to define functional integration over the pure spinor ghosts and and to construct a suitable b ghost. A super-Poincaré covariant prescription is then given for the computation of N-point multiloop amplitudes. One can easily prove that massless N-point multiloop amplitudes vanish for N < 4, confirming the perturbative finiteness of superstring theory. One can also prove the Type IIB S-duality conjecture that R4 terms in the effective action receive no perturbative contributions above one loop. © SISSA/ISAS 2004.

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

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Pós-graduação em Educação - FFC

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Pós-graduação em Educação - FFC