bluuebunny/crossref_metadata_2025_split huggingface dataset:
Esprit déductif versus esprit inductif
Authors: Gohau Gabriel 
Published: June 2010

Deductive versus inductive thinking , Gabriel Gohau
Deductive reasoning is rigorous, but no new truth emerges from it. Induction presents new truths, but with no certainty. The dilemma can be resolved when one understands that mathematical deduction and the induction of the empirical sciences cannot be reduced to the syllogisms and amplification belonging to philosophy. Their value stems also from the element of invention they contain. The author criticises Popperist “deductivism”, and aims to show how investigation necessarily includes an element of trial and error and personal intuition. aking issue with Kuhn, he puts more value on normal science than on revolutions, and concludes with the necessary limitation of pupils’initiatives, by close guidance.
Guider le raisonnement d'élèves de collège avec des modèles particulaires de la matière
Authors: Séré Marie-Geneviève 
Published: June 2010

Helping young secondary college students in their reasoning, with particulate models of matter , Marie-Geneviève Séré
In this pedagogical experiment, we engaged our pupils in the main steps of an experimental process. They observed experiments, and interpreted them with their own spontaneous models till they were faced with contradictions. The teacher examined the conflicts that arose, which we describe as socio-cognitive. Two particulate models were then put before the class, taking them beyond these conflicts. The pupils were thus enabled to read the same experiments at different levels, to assimilate models imposed on them (as often is the case) and to understand that new experiments may lead to the replacement of one model by another. In this guided appropriation of models, some of the intellectual processes brought into play were, at an elementaiy level, those of scientific reasoning.
Les conceptions comme levier d'apprentissage du concept de respiration
Authors: Paccaud Madeleine 
Published: June 2010

Conceptions as learning tools : the concepts of respiration , Madeleine Paccaud
Our conceptions are ingrained traces of our family, socio-cultural and school histories, they are “what remains... when all else is forgotten”. As they have already been systematically indexed, there is no need to give a description of them in this document.
Through the concept of respiration, I shall speak of using pupils' conceptions as a tool for helping them to master a subject. I shall therefore retrace my teaching experience, as regards both the questions I asked myself concerning this concept, and the strategy adopted to help the pupils assimilate It. I shall explain how my pupils were engaged in analysing their own mental processes when they let their conceptions come to the surface. Then I shall retrace from the “departure point” to the “arrival point” the path of the learners, In order to evaluate their progression.
I shall also indicate my chief preoccupation during this whose process : does working through conceptions improve the pupils' performance ? and what criteria are to be used in evaluating it ? The methodology I adopted will be explained, which, it is hoped, will help to answer these questions.
Les manuels, un mode de textualisation scolaire du savoir savant
Authors: Grosbois Michèle , Ricco Graciela , Sirota Régine 
Published: June 2010

Textbooks as a mode of textualisation of scientific knowledge for schools , Michèle Grosbois Graciela, Ricco Régine Sirota
How does the process of didactic transposition operate in the field of school to transform a scientific object into a teaching object ? The analysis of scholar textbooks is one of the best way to answer this question, insofar as textbooks express the formal curriculum and can be considered as the scholar form of knowledge.
Textbooks have been considered as actors in the didactic transposition process, for they select knowledge on one hand, and they put it into a text on the other hand.
Three aspects of the didactic transposition of the respiration concept have been selected :
1. Which knowledge about the concept of respiration is presented in the textbook ?
2. How is the evolution of knowledge and scientific actuality taken into account ?
3. Which model of scientific approach is selected in the textbooks ?
Conceptions des enseignants sur la démarche expérimentale. Analyse de quelques cas à propos de digestion en classe de troisième
Authors: Orlandi Éliane 
Published: June 2010

La partie du programme de la classe de troisième axé sur la nutrition est un moment privilégié pour l’apprentissage de la démarche expérimentale. Nous avons à ce propos tenté de cerner les conceptions de cinq enseignants de biologie en les interviewant au sujet de leurs pratiques de classe -plus précisément sur la séquence expérimentale "digestion artificielle d’un aliment par la salive”.
L’analyse des entretiens permet de faire apparaître le regroupement des enseignants autour de deux pôles, l’un qui privilégie, avec la rigueur, une logique de type linéaire , allant de pair avec une grande directivité pédagogique ; l’autre qui privilégie une logique moins linéaire incluant le tâtonnement, plus proche d’une démarche de recherche, et au plan pédagogique, moins canalisée et planifiée d’avance par l’enseignant.
Quelques logiques de construction d'une séquence d'apprentissage en sciences. L'exemple de la géologie à l'école élémentaire
Authors: Astolfi Jean-Pierre 
Published: June 2010

Differents logics of construction of a scientific teaching sequence , Jean-Pierre Astolfi
The constructivist model of teaching is often conceived as a single and overvalued type. Thus the model aims to break free from the transmissive tradition, and from the non-directive influence.
It would be useful for the teacher to have alternatives and multiple didactic variantes at his/her disposal, for different purposes, but of equal value. We propose to distinguish between four different logics for a scientific teaching sequence, which could in practice be combined according to need. This could help to avoid monotonous didactic situations. In the article, examples taken from recent research into geology teaching in the primary school are developed and discussed.
Construire des méthodes à l'école élémentaire : la séparation de variables et la modélisation
Authors: Genzling Jean-Claude 
Published: June 2010

Les méthodes de résolution de problèmes (nous entendons par là ce qui est commun dans la diversité des procédures de résolution), tout comme les concepts, ne peuvent être appréhendées efficacement par les élèves par un simple effort d’exposition de l’enseignant : elles doivent être construites par les élèves engagés dans des activités de recherches de solutions à des problèmes posés par des situations fort diverses.
Les problèmes que peuvent rencontrer les élèves de l’école élémentaire peuvent être classés en deux catégories :
-les recherches de relations causales (une grandeur effet peut dépendre de plusieurs grandeurs causes). Le problème porte généralement sur l’existence d’une relation entre deux grandeurs. De tels problèmes conduisent les élèves à maîtriser peu à peu la méthode qui consiste à séparer les variables causes et à faire varier l’une d’entre elles, en fixant la valeur des autres ;
-les recherches d’explications (autres que causales). Elles nécessitent la construction et l’utilisation de représentations (ou modèles) du réel.
Dans les deux cas, la simple répétition d’activités ne suffit probablement pas à faire prendre conscience aux élèves de la méthode. Il semble qu’il soit nécessaire de provoquer un retour sur les procédures de résolution (à l’aide de documents témoins) pour en dégager les spécificités, et de comparer entre elles des procédures de résolution portant sur des problèmes différents. Les élèves (guidés par le maître) peuvent dans ce cas mettre en évidence ce qui est commun dans des situations qui peuvent être, quant à elles, très éloignées.
L'émergence de la didactique de la biologie, un itinéraire
Authors: Astolfi Jean-Pierre 
Published: June 2010

The emergence of biology didactics, an itinerary.
Biology didactics has been developing for the last fifteen years or so, and is tending to become an independant academic discipline, creating its own specific concepts. The author, who is head of the research team of the Institut National de Recherche Pédagogique - one of the longest standing in this field, describes here the itinerary and the intellectual developments which have led to the emergence of a specialised didactics, starting from a "science pedagogy", which was then more concerned with general pedagogical questions (objectives oriented teaching, independant learning), applied to the field of science teaching.
This text attempts to define the new problems and theoretical break-ups which this developing discipline is confronted with. It originated in a "note de synthèse" introductory to a thesis at the University of Lyons II, in 1989.
Le film d'exposition scientifique, un choc entre deux cultures
Authors: Scrive Martine 
Published: June 2010

The scientific exhibition film -an intercultural shock.
The aim of scientific exhibitions is to attract and hold the interest of visitors in scientific subjects. They make a great use of images proceeding from research : films or conceptuad images designed to facilitate the dialogue between scientists. Some examples will show that unfortunately these images do not achieve the desired result. Often an explanatory photograph or shot has no impact on the public because it fails to reveal the beauty of what it illustrates. As to conceptual images, they are incomprehensible to the uninitiated.
Film editing reveals the deep contradictions between the rational language of the scientist and the emotional language of the film-maker.
It seems to us that cinema and science can find a common language if science is placed in its social and philosophical context. The film-maker will then be able to express himself in terms of a science that is rich in adventure and poetry, and fraught with incertitudes. Scientific films will then once more be attractive and instructive.
Sortir de la classe pour enrichir les savoirs sur l'environnement
Authors: Bailet André , Clavel Françoise , Maglione Anne 
Published: June 2010

Salir de la clase para enriquecer los conocimientos sobre el medio.
Podemos elegir el espacio exterior para instruir los alumnos ? Los docentes del colegio, habiendo llevado a menudo sus alumnos fuera de la clase, intentan una reflexión sobre ese sujeto : Fuera de la escuela, los problemas encontrados son complejos, las realidades diversas y las personas diferentes Podemos ver, escuchar, tocar una aproximación sensible del medio. Los aprendizajes se organizan de otra manera que en un cuadro escolar, ponen en juego en todos los participantes aptitudes diversificadas en un contexto donde las disciplinas son llevadas a funcionar de una manera coordenada. Sumergidos en ese "Vivir otra cosa" los alumnos van a encontrar un cierto numero de situaciones en el terreno y luego en la explotación en la clase, que les va a permitir entre otras cosas aprender en ciencias.
Population
Authors: Develay Michel , Ginsburger-Vogel Yvette 
Published: June 2010

Population.
The natural populations which make up the elementary structure studied by researchers in ecology are seldom taken into consideration in our teaching : when talking about population in didactical situations, we generally mean a group of individuals of the same species, and the functional implications of the concept are not apparent.
An analysis of the conceptual field shows the complexity of this concept which finds its place in an evolutionist perspective, even if the genetic dimension is not dwelt upon. It is clear moreover that the mastery of the concept's constituent elements entails a more effective understanding of classroom situations in which it is implicitely referred to. In particular all the problems of interactions and equilibrium are clarified and structured when considered in terms of populations dynamics.
Rich and complex, the concept of population constitutes an important level of integration in modern evolutive biology.
Milieu
Authors: Drouin Anne-Marie , Astolfi Jean-Pierre 
Published: June 2010

Le concept de Milieu présente la particularité d'être présent de façon implicite dans de nombreux textes scientifiques sans faire l'objet d'une définition précise. Lorsqu'il est employé, on constate une large variabilité de significations, que l'on peut souvent rattacher aux stades successifs de son élaboration historique.
De même, en situation didactique, l'emploi du mot milieu est beaucoup plus fréquent que les séances de classe où sa construction comme concept est travaillée précisément.
On essaiera, après une analyse de contenu de cette notion, de caractériser les obstacles auxquels sa construction se heurte et ¡es étapes possibles de son appropriation. On étudiera en fonction de cette grille de lecture quelques exemples de séances de classe, et l'on proposera de situer les étapes de construction mises en oeuvre.
Relations alimentaires
Authors: Peterfalvi Brigitte , Rumelhard Guy , Vérin Anne 
Published: June 2010

Relaciones alimenticias.
La noción de "relaciones alimenticias" es una entrucijada para multiples conceptos. A su nivel de formulación mas simple, se trata de una relación constatada o afirmada entre dos individuos vivantes.
A los niveles de formulación mas elevados, nosotros tenemos conceptos que buscan a modelizar, a representar conjuntos de relaciones de un punto de vista cada vez diferente.
Las palabras mismas, cadena, red, flujo, ciclo se proyectan en una figuración, una imagen que es necesario sobrepasar definiendo el contenido conceptual preciso al cual ellos se refieren.
La dificultad aquí es doble :
- las palabras "relaciones alimenticias" son vaciás. Son un objeto de estudio y lo que se estudia son : sea los factores que juegan sobre estas relaciones, sea las maneras por las cuáles estas relaciones se organizan y evolucionan.
- nada mas frecuente que un estudio de cadena alimenticia a la escuela primaria o al colegio cuando queremos abordar el ecosistema.
La situaciones de clase que llevan sobre este conjunto de conceptos son numerosas pero conducen a adquisiciones puntuales y diversas. Como precisar las organizaciones conceptuales que es posible de construir ?
La conservation, un grand principe
Authors: Trellu Jean-Louis , Toussaint Jacques 
Published: June 2010

Cette réflexion met en évidence les difficultés rencontrées lors de la genèse d'un concept comme celui d'énergie, tant au plan épistémologigue que pédagogigue : quels sont les cheminements possibles, les obstacles à franchir ou contourner par les élèves dans un tel réseau multi-sémantigue et peut-on en préciser les noeuds ?
Par des essais de clarification et d'analyse de situations de classe à mettre en oeuvre, dont le mot énergie serait le pôle central, on tente de montrer des méthodes d'approche en terme de transferts et de conservation, d'un concept intégrateur d'un champ disciplinaire.
La vitesse au cours moyen
Authors: Canal Jean-Loup 
Published: June 2010

Tout enfant, dès son jeune âge, est confronté à la "vitesse" et se donne une représentation de cette grandeur. Mais cette grandeur est complexe et ne peut se construire seule car elle dépend de deux autres, la distance et le temps. Elle se trouve au carrefour d'une foule de difficultés complexes de toutes sortes.
C'est au cours moyen deuxième année (10-11 ans) que nous nous intéresserons Ici, classe où traditionnellement est abordée l'étude mathématique de la vitesse. La vitesse est posée a priori comme une évidence : c'est le résultat du quotient de la distance par la durée mise pour la parcourir. Le raccourci est effrayant et le résultat évident : seule une minorité d'élèves intègre cette définition. Le mécanisme étant monté, d'autres élèves l'utilisent sans comprendre, d'autres se bloquent.
Le modèle en questions
Authors: Drouin Anne-Marie 
Published: June 2010

The model in question.
Is a single concept hidden behind the many different uses of the term "model" or must we be content to accept its heterogeneity ? The following text gives an account of the discussion of this question at a seminar. A single closed definition is not the end envisaged in this study, but an attempt is made to find coherence among contradictions. Some characteristics pointed out in the study are illustrated by the analysis of a biology model.
Modélisation et astronomie
Authors: Pierrard Marie-Anne 
Published: June 2010

Modélisation and astronomy.
Astronomy is a particularly suitable field for modelisation. What sort of models can primary school children achieve ? A series of activities in "Cours Moyen" (9-11 or 12) are here analysed, providing an opportunity to assess the areas in which children have been able to modelize, and how far they have advanced in it.
Brazilian baccharis toxins: Livestock poisoning and the isolation of macrocyclic trichothecene glucosides
Authors: Jarvis Bruce B. , Wang Shengjun , Cox Christopher , Rao M. Madhusudana , Philip Valsa , Varaschin Mary S. , Barros Claudio S. 
Published: June 2010

AbstractSamples of the toxic Brazilian plant, Baccharis coridifolia, which is reponsible for numerous cases of livestock poisoning in southern Brazil and Argentina, were collected during the growing season, and the toxicities in calves of the plant materials were correlated with the levels of macrocyclic trichothecenes present. Female plants in flower were considerably more toxic than male plants or plants not in flower. Plants not in flower were of intermediate toxicity The female plants in flower typically contained 5–10 times the levels of toxins as were found in the male plants. In addition, six new glucosides of the macrocyclic trichothecenes were isolated and characterized. The most prominent glucosides, those of roridins A and E, were found in high levels in the female plants.
Effect of an unknown toxin isolated from dinophysis sp.‐contaminated French mussels, on the electrical and mechanical activity of frog heart
Authors: Sauviat Martin‐Pierre , Vernoux Jean‐Paul , Le Baut Claire Marcaillou , Bansard Stéphane , Hamelin Magali 
Published: June 2010

AbstractThe effects of an unknown toxin, isolated along with okadaic acid from the hepatopancreas of French mussels contaminated by Dinophysis sp., producing ataxia, neurologic symptoms, bradycardia, arythmias, electrocardiographic changes, and cardiac arrest, have been studied in terms of the electrical and mechanical activity of frog atrial heart muscle. The toxin, in a dose‐dependent manner, decreased the amplitude of the stimulated peak tension of isolated fibers. The toxin (1–36 μg/ml) did not modify the membrane resting potential but decreased the amplitude of the plateau and shortened the duration of the action potential. The toxin inhibited the Cd‐sensitive L‐type Ca current and increased a 4‐aminopyridine‐sensitive outward current in voltage‐clamped cardiac myocytes. The data show that the cardiac effect of the toxin is markedly different from that of okadaic acid.
Comparison of detection methods for trichothecenes produced by fusarium sporotrichioides on fodder and grains at different air humidities
Authors: Nikulin Marjo , Lappalainen Sanna , Pasanen Anna‐Liisa , Laamanen Ilona , Veijalainen Pirjo , Berg Seija , Hintikka Eeva‐Liisa 
Published: June 2010

AbstractGrowth and toxin production of a highly toxic strain of Fusarium sporotrichioides Sherb. were studied on oat and wheat grains and on straw under experimental conditions, in which relative humidity (RH) of air was regulated. The materials were incubated at three different RH levels at a range of 84–100%. F. sporotrichioides grew well on oat and wheat grains at RH 97–100% but grew less well at RH 84–88% and on straw. Toxin production was measured with three biological toxicity tests (cytotoxicity test, dermotoxicity test, and yeast cell toxicity test), with chemical analysis, and T‐2 ELISA assay. Cytotoxicity and production of trichothecene mycotoxins were detected in all the samples incubated at all three RH levels. On oat and wheat grains, T‐2 toxin, neosolaniol, and diacetoxyscirpenol were found, and on straw T‐2 toxin, HT‐2 toxin, neosolaniol, and T‐2 tetraol were determined. In the T‐2 ELISA assay, all material samples were found to contain T‐2 toxin. The cytotoxicity test was the most sensitive method for detecting biological toxicity of samples inoculated with fungus. The T‐2 ELISA assay and chemical analysis were about equally sensitive to detect T‐2 toxin in samples.
Effects of the naturally occurring arginine analogues indospicine and canavanine on nitric oxide mediated functions in aortic endothelium and peritoneal macrophages
Authors: Pass Michael A. , Arab Hossein , Pollitt Sandra , Hegarty Mervan P. 
Published: June 2010

AbstractThe ability of the naturally occurring non‐protein toxic amino acids indospicine and canavanine to inhibit nitric oxide synthesis was tested in isolated rat aorta and cultured rat peritoneal macrophages. Both compounds inhibited acetylcholine induced relaxation of rat aorta contracted with noradrenaline, a process mediated by nitric oxide generated in vascular endothelium. Nitric oxide is generated in vascular endothelium from arginine by a constitutive nitric oxide synthase. Indospicine and canavanine also increased superoxide mediated reduction of cytochrome c by phorbol mynstate acetate stimulated rat peritoneal macrophages. The increase in superoxide under these conditions was due to decreased nitric oxide synthesis. Macrophage synthesis of nitric oxide is mediated by an inducible form of nitric oxide synthase. It is concluded that indospicine and canavanine are inhibitors of constitutive and inducible nitric oxide synthases and it is suggested that the toxicity associated with these compounds could be related to this activity.
Microcystin levels during 1992–95 for lakes sagami and tsukui‐japan
Authors: Tsuji Kiyomi , Setsuda Setsuko , Watanuki Tomohiko , Kondo Fumio , Nakazawa Hiroyuki , Suzuki Makoto , Harada Ken‐Ichi 
Published: June 2010

AbstractToxic cyanobacterial blooms have been frequently observed in Lakes Sagami and Tsukui, Kanagawa Prefecture, Japan, which are used as drinking and recreational water sources. As the first step toward the control and removal of cyanobacterial toxins, the present study evaluated the microcystin level in these lakes. Our established method using HPLC and LC/MS to pursue trace amounts of microcystins was applied to the determination of microcystins within cyanobacteria cells and in water. We could determine precisely the intracellular and extracellular microcystin level in the water environment during 1992–95. Microcystins RR, LR, and YR were detected at 0.02–2.64 μg/L in cell‐free water and at 0.02–378 μg/L in the cells. Although there were many cases in which microcystin concentrations in the cells exceeded the proposed guideline level (1 μg/L), there was only one example of this happening in cell‐free water samples. Because the present monitoring indicted that the amount of microcystins detected in water was much less than that estimated in cells, the release of microcystins from the cells and their stability in lake water were examined in the dark. The resulting toxins persisted at the same concentration level for 14 days and the microcystin concentrations steadily declined, showing that biodegradation using aquatic natural bacterial flora is an effective detoxification process under natural conditions.