bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analyse d'une image satellitaire
Authors: Cariou François , Le Gall Rudolf 
Published: June 2010

Analysis of a satellite image.
As part of a pluridisciplinary study (associating physics, biology and geography) conducted on the Natural Reserve of Grand-Lieu, in Loire-Atlantique, pupils of 16-17 years'old worked on a digital image of Nantes'region taken by the satellite Spot on june the 26th, 1986. With computer help, they were able to treat the numerical data and to obtain a map of the vegetation in summer. This document was used to study the ecosystem of this area and its evolution.
Le concept de réseau idiotypique : une nouvelle façon de penser le système immunitaire
Authors: Dewaele Jacques 
Published: June 2010

El concepto de red idiotipica : Una nueva manera de pensar el sistema inmunitario.
La inmunología enseñada actualmente es esencialmente pasteuriana. Su teoría explicativa,fechada en el año 1957, es la teoría de la selección clonal. Existe, sin embargo una teoría más reciente (1974), es la teoría de la red inmunitaría. Intentamos de mostrar, que esta teoría utiliza un concepto interdisciplinario, que es bien explicativa, tratando de cesar de ser un andamiaje conceptual reservado a los inmunologistas advertidos ; y en fin que entra en ruptura con un conocimiento anterior muy resistente que es la idea que nosotros nos hacemos del ser y del no ser. Esta ruptura sería la causa de las resistencias a su adopción en la enseñanza.
Les formulations successives du savoir : le concept de récepteur et le modèle clé-serrure
Authors: Perez Eric 
Published: June 2010

Admettre la possibilité de formulations successives d'un même savoir ayant une valeur explicative réelle mais partielle n'est pas une banalité. Cette conception se heurte à celle qui identifie vérité et savoir le plus récent, autrement dit qui nie la dimension historique du travail des savants.
Pour le modèle analogique "clé-serrure" qui fournit une explication du fonctionnement des récepteurs biologiques il est possible de définir quatre formulations qui intègrent les concepts impliqués et les représentations auxquelles il faut renoncer.
Présentation du concept de climax aux visiteurs du Marais Vernier
Authors: Lemare Emmanuel 
Published: June 2010

Presentación del concepto de "climax" a los visitantes del "Marais Vernier".
Este trabajo resulta de la observación de la evolución del "Marais Vernier" luego del abandono de las practicas agrícolas
de pastura y de siega llevadas a cabo por un equipo de biologos (CEDENA, Pare Natural Régional de Bretonne), T.Lecomte y C.Le Neveu. La degradación ecológica que siguió, conduzco la puesta a punto de la Reserva Natural de Mannevilles, de una gestión restauradora compatible con los apremios del medio, y a una reflexión teórica sobre el concepto de "climax". Contribuyendo a promover y a difundir ese modo de gestión, el autor ha intentado un primer análisis de las reacciones del público, de sus resistencias y sus adhesiones.
L'art comme jubilation critique
Authors: Caillet Elisabeth , Ba Catherine 
Published: June 2010

El arte como jubilo critico.
Nosotros consideramos aquí la actividad creadora del arte como homologa a la actividad del científico que imagina sus conceptos, del técnico que imagina sus dispositivos. El arte no es pues examinado como ilustrador de los "describrimientos de la ciencia o de la técnica (papel que juega a menudo en las exposiciones y museos científicos y o técnicos) es necesario considerarlo como un acto de un imaginario creador, al mismo título que la actividad de investigación científica.
Pero el trabajo del artista que se encuentra con los conceptos científicos o técnicos es del mismo orden que de l'investigador, del inventor ? Con el fin de avanzar en esta reflexión, lo abordaremos bajo el ángulo particular : aquel de la puesta en oliras y operaciones de dos tipos de actores, en ciertas ocasiones de exposiciones en las cuales, hemos buscado a establecer un diálogo entre las dos aproximaciones. Y luego analizaremos ciertos aspectos de las primeras acciones experimentales de clases inter-museos ciencias y artes.
La ville, lieu d'éducation à l'environnement
Authors: Lapoix Catherine , Lapoix François 
Published: June 2010

La ciudad, lugar de educación al medio ambiente.
Después de haber mostrado como la nueva pedagogía de descubrimiento del medio urbano puede ser una ayuda a la educación al medio ambiente, los autores presentan una experimentación realizada en Melun-Sénart a propósito del medio urbano.
Van presentando diferentes instrumentos orignales de tal educación urbana, así como las estructuras, y los actores de la investigación pedagógica. Aparece que lo que prevale en ese tipo de estudio, es el descubrimiento de las ciencias humanas y la educación de los sentidos.
Los autores dan ciertos resultados de la evaluación, y enumeran los principales propósitos de esa nueva deucación cuya finalidad es formar niños-ciudadanos, capaces de llegar a ser gerentes del futuro urbano.
Alors! Raconte-moi ton excursion de géologie !
Authors: Jacob Jean-Pierre 
Published: June 2010

Well - tell me about your geology excursion !
The writer describes an innovation in one of his classes, with 13-14-years olds : during the whole year, his pupils were acquiring the necessary skills for producing reports on geological excursions.
Various tools are presented, which aim at helping the pupils to write and to draw, at first with much guidance from the teacher, but progressively less and less. Students are often strongly motivated for this type of work, and are aware of its potential use in other disciplines.
In Natural Science, writing takes up time : the present syllabus is so heavy, that detailed, individual scientific texts produced in class will long remain exceptional in our secondary education.
Deux approches pour modifier les activités de résolution de problèmes en physique dans l'enseignement secondaire : une tentative de synthèse
Authors: Dumas-carré Andrée , Caillot Michel , Martinez-Torregrossa Joaquim , Gil-Pérez Daniel 
Published: June 2010

Dans cet article nous présentons un cadre théorique pour analyser les activités de résolution de problèmes "papier crayon" issu de la confrontation des recherches menées par deux équipes (Gil Perez D. et Martinez Torregrossa J. en Espagne et Caillot M. et Dumas-Carré A. en France) dans le domaine de la physique.
Le point de départ commun des deux équipes est de considérer que l'échec généralisé des élèves ne peut être imputé seulement (ni principalement) à des caractéristiques ou des lacunes des élèves, mais que la plus grande responsabilité doit être cherchée du côté de la didactique habituelle. Ce qui doit être remis en question de façon prioritaire est la conception même des activités de résolution de problèmes. Cette remise en question de la conception didactique commence par une interrogation sur le concept de problème lui-même. De même, le comportement habituellement retenu comme modèle (celui de l'expert) est remis en question ; le comportement proposé comme modèle est celui du chercheur scientifique.
Approche didactique de quelques aspects du concept d'écosystème. Introduction
Authors: Astolfi Jean-Pierre 
Published: June 2010

Aproximación didáctica de algunos aspectos del concepto de ecosistema.
Tres artículos de este numero de Aster, relacionados a las nociones de Medio, Población y de Relaciones alimenticias prolongan la publicación de un precedente informe de investigación.
Esta introducción desarrolla la problemática del conjunto que orientó la redacción de estos artículos, insistiendo particularmente sobre los dos conceptos didácticos de objetivo obstáculo y de nivel/registro de formulación.
Utilisation des représentations enfantines en biologie et formation des maîtres
Authors: De Vecchi Gérard 
Published: June 2010

Using children's representations in biology teaching and in teacher-training.
This article develops some of the ideas put forward in a thesis on the importance of taking representations into account. The use of these in the classroom provides tools for prediction and anticipation, but also for elaboration and diagnosis. For teacher-training, representations are valuable in throwing light on "what" and "how" to teach, and also in helping to understand how scientific knowledge is built up.
Un instrument d'analyse des modèles implicites de l'enseignement scientifique chez les enseignants
Authors: Vérin Anne , Peterfalvi Brigitte 
Published: June 2010

A technique for analysing implicit models teachers have of science teaching.
The "Q-sort" technique is used here as a means of exploring the different conceptions that science teachers have of their teaching, and to measure what can be imputed to personal choice of values in the research work they are associated with.
Quelques représentations à propos de la photosynthèse
Authors: Rumelhard Guy 
Published: June 2010

Dans le cadre des programmes antérieurs un séminaire a été consacré aux représentations à propos de la photosynthèse.
S'appuyant sur trois types d'analyses, celle de réponses d'élèves obtenues à partir de questionnement en classe, celle d'études historiques faites dans une optique épistémologique, celle de manuels scolaires, ce travail tente de dégager certaines difficultés qui peuvent se présenter dans l'appropriation des concepts de la photosynthèse. Quelques propositions sont discutées, dans une perspective Interdisciplinaire, pour surmonter ces obstacles et résistances.
Statut et rôle des modèles dans le travail scientifique et dans l'enseignement de la biologie
Authors: Rumelhard Guy 
Published: June 2010

Status and role of models in scientific work and in the teaching of biology.
The word model is increasingly used in the vocabulary of science, and in teaching. Does this mean that we have a new scientific method in Biology, or a new philosophy of science ? The author, after analysing several historical and contemporary examples, elucidates certain common properties of analogical and formalised models, and defines the principal characteristics of the evolution of modélisation. He compares this scientific process with classical analytical experimentation, and describes three types of models used in Biology. Finally he underlines the principal obstacles, the false frontiers and the true limits to the use of models as a mean of reducing complexity. These limits are made apparent if attention is given to the specificity of the biological object and to the possibility of illness.
De l'interrupteur au relais électronique, du relais électromagnétique au transistor
Authors: Canal Jean-Loup 
Published: June 2010

From switch to electronic relay, from electro-magnetic relay to transistor.
We suggest that, in the field of science didactics, the introduction of modelisation can be an aid to the building up of knowledge. Without aiming at the rigour and efficacity of certain scientific models, we wish to show the effects of modelisation in the internalisation of knowledge. We base this hypothesis on the fact that one of the functions of models, the explanatory function, makes use of analogy. We give examples here in which, to explain the role of the electro magnetic relay, the mechanical switch serves as a model, then the relay itself becomes a model of the transistor. The idea of a model, in these situations, is used in the limited sense of a tool for thought, simplifying the complexity of reality. It will be seen how pupils aged 10-11 (highest primary class) were able, by means of this aid, to integrate the first principles of the transistor used as a switch.
Gestion d'activités de modélisation en classe
Authors: Lemeignan Gérard , Weil-Barais Annick 
Published: June 2010

Regulating modelisation activity in the classroom.
Two ways of regulating the formation of knowledge in a shool context are envisa ged : one using the building up of knowledge, the other the appropriation of knowledge. By studying the gap between the pupils’ first conceptions and the conceptualisation which they should have reached when they leave shool, we are led to recommend a double approach, involving the two different ways.
The description of a teaching sequence, introducing the "quantity of movement" in a "2nd class" (15-16 year-olds), gives practical indications on this approach, which seems to help pupils to acquire competence in the modélisation of situations in physics. Without changing the content of the syllabus, it seems possible to bring more pupils to a mastery of the methods and content of physics, provided a suitable regulation of class activities is organized to this end.
Les représentations du cerveau : modèles historiques
Authors: Mein Marie-Thérèse 
Published: June 2010

Une question essentielle posée dès le début des temps historiques est celle de la spécificité des phénomènes psychiques et de leur localisation, ainsi que celle du rapport entre ces phénomènes et notre corps matériel.
Au cours de l’Histoire des Sciences, la réponse à ces questions a pris des formes variées : thèse cardiocentrique ou céphalocentrique, cerveaux-machines, cerveau-mosaïque ou cerveau global se sont succédé ou plutôt ont coexisté sans se remplacer tout à fait. Le présent travail cherche à caractériser ces divers modèles explicatifs afin de mieux situer les modèles de notre temps.
Response of growing swine to dietary exposure to pure fumonisin B1 during an eight‐week period: Growth and clinical parameters
Authors: Rotter Barbara A. , Thompson Brian K. , Prelusky Dan B. , Trenholm H. Locksley , Stewart Brian , Miller J. David , Savard Marc E. 
Published: June 2010

AbstractConsumption of corn or corn‐based products contaminated with Fusarium moniliforme/fumonisins has been associated with a variety of animal and human diseases and is a major food/feed safety issue. This study focused on the clinical toxicity and performance parameters in growing swing exposed to low to moderate levels of pure fumonisin B1 (FB1) for 8 weeks. Male (castrated) and female pigs were fed diets containing 0, 0.1, 1.0, and 10 mg FB1/kg diet (ppm). Weight gains and feed consumption were measured weekly. Blood samples were collected throughout the study, and various clinical and hematological parameters were measured. Because fumonisins are potent inhibitors of sphingolipid biosynthesis, sphinganine and sphingosine concentrations were determined in the liver, lung, and kidney. Organ weights and carcass quality were measured at the end of the trial.In general, male pigs were more adversely affected by FB1 in the diet than females. The average daily gain for males decreased by 8% for pigs fed 1.0 ppm and by 11% at 10.0 ppm, when compared to the control (0 ppm). Males fed 0.1 ppm showed an erratic growth pattern during the first 5 weeks of the experiment. Feed consumption for the same animals was somewhat higher than that of the controls during each of the first 4 weeks but thereafter was 6–7% lower each week as compared to controls. Female pigs fed FB1‐diets showed a general enhancement of feed consumption until week 4. Among clinical chemistry parameters, cholesterol increased in males for the 1.0 and 10.0 ppm diets as compared to controls after 2 weeks, while the levels in both sexes were elevated for the 1.0 ppm diet only by the end of the experiment. Serum liver enzyme concentrations were altered during week 2 only. Changes were observed in the weight of the pancreas and adrenals for male pigs fed FB1 diets as compared to controls. The free sphinganine to free sphingosine ratio (biomarker of exposure in FB1‐consuming animals) increased in all three organs for the 10 ppm diet, regardless of sex. The study indicated that FB1 can cause different effects at each dose level, at concentrations as low as 0.1 ppm (showing erratic growth) followed by a reduced growth and biochemical abnormalities in blood (1.0 ppm) and sphingolipid alterations in tissues (10.0 ppm). Some of these effects occurred below the exposure level that caused alteration in sphingolipid metabolism. c̊ 1996 Wiley‐Liss, Inc
Enzymatic oxidation products of allelochemicals as a basis for resistance against insects: Effects on the corn leafhopper dalbulus maidis
Authors: Dowd Patrick F. , Vega Fernando E. 
Published: June 2010

AbstractOxidation products of com allelochemicals generated by peroxidases or tyrosinases were tested in 10% sucrose solutions for effects on the com leafhopper Dalbulus maidis. Some reduction in feeding was noted with hydrogen peroxide (a cofactor for peroxidase). Significant reduction in feeding was noted with chlorogenic acid, ferulic acid, p‐coumaric acid, and 6‐methoxybenzoxazolinone (MBOA), but not rutin at 400 ppm in solution. Oxidation products of these compounds all caused significantly less feeding by the leafhoppers compared to the original compound. Oxidation products generated by peroxidase from ferulic acid and 6‐methoxybenzoxazolinone caused significant mortality to the leafhoppers within 5 days. Thus, provided conditions are such that oxidizing enzymes and allelochemicals can interact due to damage by insects, resistance may be significantly enhanced by the oxidized products as opposed to the effects of the allelochemicals alone.
(2,4‐cis)‐asimicinone and (2,4‐trans)‐asimicinone: Two novel bioactive ketolactone acetogenins from asimina triloba (annonaceae)
Authors: Zhao Geng‐Xian , Chao Jin‐Feng , Zeng Lu , McLaughlin Jerry L. 
Published: June 2010

AbstractTwo novel bioactive ketolactone Annonaceous acetogenins, (2,4‐cis)‐asimicinone (1) and (2,4‐trans)‐asimicinone (2), have been isolated from Asimina triloba (Annonaceae) by bioactivity directed fractionation The separation of these two epimeric compounds was achieved by HPLC methods using a Si gel normal phase column eluted with acetone in hexane gradients. The assignments of cis or trans stereochemistry of the ketolactone moieties were made on the bases of 1H‐1H COSY and NOESY experiments. 1 and 2 showed selective cytotoxicities against A‐549 (human lung cancer) and MCF‐7 (human breast cancer) cell lines with ED50 values as low as <10−7 μg/ml with 2 being the more active isomer.
Fumonisin B1 production by fusarium proliferatum strain M5991 in a modified myro liquid medium
Authors: Dantzer W. R. , Pometto A. L. , Murphy P. A. 
Published: June 2010

AbstractFusarium proliferatum strain M5991 cultures were grown in shake flasks containing modified Myro (MM) medium (MgSO4 reduced to 0.5 g/L) plus 0, 0.25, 0.50, 0.75, 1.00, or 1.25% (v/v) hot‐water corn‐hull‐extract (CHE) for 69 days. After 4 days of incubation, shake flask liquid cultures with 0.75, 1.00, and 1.25% (v/v) CHE showed a reduction in pH from 6.0 to 2.6 and consumed sucrose at > 6.3 g/L/d. After 69 days of incubation, the same shake flask cultures produced over 7.8 g/L cell mass and over 990 mg/L fumonisin B1 (FB1). A minimum CHE level of 0.75% was recommended for enhanced FB1 production by F. proliferatum strain M5991 During three serial (10, 12, and 12 L) batch fermentations in MM medium + 1.00% (v/v) CHE (first batch only), F. proliferatum strain M5991 produced FB1 concentrations of 619, 659, and 375 mg/L after 35, 47, and 52 days of incubation, respectively. By analysis, a total yield of 20 g FB1 was obtained from three serial batch fermentations
SARs of annonaceous acetogenins in rat liver mitochondria
Authors: Alfonso Dorothée , Johnson Holly A. , Colman‐Saizarbitoria Trina , Presley Christopher P. , McCabe George P. , McLaughlin Jerry L. 
Published: June 2010

AbstractThe Annonaceous acetogenins represent a class of compounds with diverse bioactivities, including promising cytotoxicites. These are due, at least in part, to inhibition of complex I in the oxidative phosphorylation pathway in mitochondria. Fourteen Annonaceous acetogenins were tested in a rat liver mitochondrial oxygen uptake assay to probe additional structure‐activity relationships. In this subcellular assay, the activity of non‐adjacent bis‐THF ring acetogenins depends on the distance between the two THF rings; the activity decreases to that of a mono‐THF ring acetogenin if the distance is too long. When one THF ring is replaced with a tetrahydropyran ring, the activity remains comparable. The configuration of the THF ring, in mono ring compounds, seems to be more important than stereochemical differences in the rings of adjacent bis‐THF ring compounds. Bullatacin, an adjacent bis‐THF ring acetogenin, was used as a standard compound in every run to normalize the data. c̊ 1996 Wiley‐Liss, Inc.
A new interval‐based method to characterize estimability
Authors: Reynet O. , Jaulin L. 
Published: June 2010

AbstractEstimability is a property that states the accuracy of the parameter estimation in the case of experimental data. This paper defines a new method based on interval analysis and set inversion to characterize estimability in the case of a bounded additive noise. To illustrate this new method, the time difference of arrival (TDOA) passive location estimability is evaluated. Copyright © 2010 John Wiley & Sons, Ltd.
Dynamic Collapse Mechanisms in Metal Foam Expansion
Authors: Lehmhus Dirk 
Published: June 2010

AbstractThe study provides insight into decomposition of titanium hydride as foaming agent for powder metallurgically produced aluminum foams. Decomposition is characterized using thermal and kinetic analysis, allowing prediction of decomposition reactions. Such predictions are made for various time–temperature cycles, which are experimentally evaluated in parallel foaming experiments. A new explanation of foam collapse is derived from the results, which interprets hints at a maximum gas release rate, limiting maximum expansion, in terms of the existence of a maximum cell wall stretching rate and expanding foam can sustain. Thus a dynamic collapse criterion is added to existing static ones.
Fabrication of Sub‐10 nm Metallic Lines of Low Line‐Width Roughness by Hydrogen Reduction of Patterned Metal–Organic Materials
Authors: Nedelcu Mihaela , Saifullah Mohammad S. M. , Hasko David G. , Jang Arang , Anderson David , Huck Wilhelm T. S. , Jones Geraint A. C. , Welland Mark E. , Kang Dae Joon , Steiner Ullrich 
Published: June 2010

AbstractThe fabrication of very narrow metal lines by the lift‐off technique, especially below sub‐10 nm, is challenging due to thinner resist requirements in order to achieve the lithographic resolution. At such small length scales, when the grain size becomes comparable with the line‐width, the built‐in stress in the metal film can cause a break to occur at a grain boundary. Moreover, the line‐width roughness (LWR) from the patterned resist can result in deposited metal lines with a very high LWR, leading to an adverse change in device characteristics. Here a new approach that is not based on the lift‐off technique but rather on low temperature hydrogen reduction of electron‐beam patterned metal naphthenates is demonstrated. This not only enables the fabrication of sub‐10 nm metal lines of good integrity, but also of low LWR, below the limit of 3.2 nm discussed in the International Technology Roadmap for Semiconductors. Using this method, sub‐10 nm nickel wires are obtained by reducing patterned nickel naphthenate lines in a hydrogen‐rich atmosphere at 500 °C for 1 h. The LWR (i.e., 3 σLWR) of these nickel nanolines was found to be 2.9 nm. The technique is general and is likely to be suitable for fabrication of nanostructures of most commonly used metals (and their alloys), such as iron, cobalt, nickel, copper, tungsten, molybdenum, and so on, from their respective metal–organic compounds.