1,007 research outputs found
Importance de la photorespiration dans le bilan photosynthétique au cours de la croissance foliaire
As novas tecnologias de informação no ensino da biologia: um estudo sobre fotossĂntese com alunos do 10Âş ano de escolaridade
Ao longo das duas Ăşltimas dĂ©cadas, investigações desenvolvidas no domĂnio do ensino da Biologia revelaram que muitos alunos possuĂam concepções alternativas. Este facto conduziu ao incremento de uma linha de investigação centrada em estratĂ©gias de ensino que pudessem facilitar o desenvolvimento/ reestruturação dessas concepções. Algumas dessas estratĂ©gias incluem o recurso Ă s Tecnologias de Informação, nomeadamente, ao Sistema de Aquisição e Tratamento de Dados (SATD), uma vez que este equipamento, ao permitir reduzir o tempo gasto no tratamento de dados, disponibiliza um maior perĂodo de tempo para os alunos preverem resultados, reflectirem e discutirem resultados obtidos, bem como compararem resultados discrepantes. Tendo como referĂŞncia estas investigações, realizou-se um estudo, no tema "FotossĂntese", que incluiu 41 alunos do 10.0 ano de escolaridade, distribuĂdos por duas turmas - uma experimental e outra de controlo. As duas desenvolveram actividades laboratoriais, com recurso, respectivamente, ao SATD (turma experimental) e a equipamento tradicional (turma de controlo). A análise de resultados mostrou que os alunos da primeira revelaram, relativamente aos alunos da segunda, uma evolução conceptual mais extensa no tĂłpico "FotossĂntese". Estes resultados parecem indicar que o SATD constitui um factor facilitador da aprendizagem dos alunos.During the last two decades, research studies carried out within the domain of biology educacion have shown that many students' hold alternative conceptions. This fact led to the development of another area of research that focuses on teaching strategies aiming at developing/restructuring those conceptions. Some of those strategies are based on information technology, namely on datalloging. Several researchers have argued that datalogging reduces the time usually spent with data handling and therefore releases a longer time interval (that can be used) for prevision of results, reflection upon both discussion of data collected and discrepant results. In order to evaluate the efficacy of datalogging to promote students' conceptual development a research study focusing on photosynthesis was canied out. The research was undertaken with 41 tenth graders that were allocated to a control class and to an experimental class. Both classes carried out the sarne laboratory activities but the former used traditional lab equipment whilst the latter utilised datalogging. The analysis of the results shows that students in the experimental class experienced a deeper conceptual change than their control class counterparts. These results seem to indicare that datalogging facilitares students’ learning on photosynthesis.Des recherches dans le domaine de l'enseignement de la Biologie ont rĂ©vĂ©lĂ© que bien des d'Ă©leves possedent des conceptions alternatives. Ce fait a conduit au dĂ©veloppement d'une autre ligne de recherche centrĂ©e sur des sLratĂ©gies d'enseignement qui facilitem le dĂ©veloppement/restructuration de ces conceptions. Certaines de ces stratĂ©gies incluent des Technologies de l'Information, notamment "l'expĂ©rimentation assistĂ©e par ordinateur" (ExAO), vu qu'il permet de rĂ©duire le temps gaspillĂ© avec le traitement des donnĂ©es, offre plus de temps pour que les Ă©leves prĂ©voient des rĂ©sultats, rĂ©flĂ©chissent sur les rĂ©sultats obtenus et en discutent, et qu'ils comparent les rĂ©sultats discordants. Ayant pour rĂ©fĂ©rence ces lignes de recherche, on a rĂ©alisĂ© une Ă©tude, sur la photosynthese, qui a indu 41 Ă©leves de la lĂĽe annĂ©e de scolaritĂ©, distribuĂ©s dans deux classes - une expĂ©rimentale et une autre de contrĂ´le. Les deux classes ont dĂ©veloppĂ© des activitĂ©s de laboratoire en recourant respectivement au ExAO et Ă un Ă©quipement traditionnel. L'analyse des rĂ©sultats a montrĂ© que les Ă©leves de la classe expĂ©rimentale ont rĂ©vĂ©lĂ©, relativement aux Ă©leves de la classe de contĂ´le, une Ă©volution conceptuelle plus large dans la photosynthese. Ces rĂ©sultats semblent indiquer que le ExAO constitue un facteur qui facilite l'apprentissage des Ă©leves
Emeralds from the Delbegetey deposit (Kazakhstan): mineralogical characteristics and fluid-inclusion study
The aim of this study is to provide the first detailed mineralogical and fluid-inc1usion description of emeralds from the Delbegetey deposit (Kazakhstan). The characteristic features of Delbegetey emeralds are established: they have dissolution figures on crystal faces, bluish colour and distinct colour zoning; the refractive indices are ro = 1.566-1.570, E = 1.558-1.562, and the specific gravity is 2.65±0.005, relatively low for natural emeralds; they have very small concentrations of the impurities (Fe, Mg, Na and others) typical of other emeralds, and contain Cr and V; there is a significant preponderance of vapour in fluid inc1usions of all types and there is liquid-to-vapour homogenization of primary fluid inc1usions (at 395-420°C). The lattice oxygen isotope composition data obtained (0180 SMOW value of 11.3%0) situate the deposit within the range characteristic of other granite-related emerald deposits. Emerald crystallization took place in low-density (0.40-0.55 g/cm3 ) aqueous fluid, with the following chemical composition (mol.%): 75.6-97.4 HzO, 0.0-18.4 caz, 0.0-0.9 C~, and 4.06-9.65 wt.% NaCI equiv. salinity. According to the calculated isochores, the pressure offormation ofthe Delbegetey emeralds can be estimated at 570-1240 bar
Les substituts au réseau : arbitrages des consommateurs et conséquences pour le gestionnaire : réflexions à partir de l'exemple des forages privés
L'augmentation régulière du prix de l'eau potable semble inciter les ménages français à recourir à des ressources de substitution pour certains usages n'exigeant pas une eau de qualité. Certains mettent en place des systèmes pour récupérer l'eau de pluie et d'autres installent des forages individuels dans leurs jardins. Les auteurs s'intéressent ici au raisonnement économique qui motive la décision d'investir dans ce type d'installation et aux impacts des tarifications incitatives qui favorisent le développement des forages individuels, non sans risque du point de vue économique, environnemental et social
Conseils d’un père à son fils Augustin-Mathurin Le Coz (1752-1780), pour devenir notaire
Augustin-Mathurin Le Coz quitte le domicile familial a 18 ans en 1770. Les correspondances échangées avec son père, receveur des devoirs à Landerneau, font connaître les règles d’éducation données à son fils. Le savoir-vivre le savoir écrire, les rapports à l’argent, le religieux sont autant de thèmes abordés. Les courriers reconstituent également le parcours professionnel et le contexte local. Les autres missives et documents officiels restituent d’autres pans de la vie de ce jeune notaire décédé au Guémené à 27 ans.Augustin-Mathurin Le Coz left his family home at 18 years old in 1770. His correspondence with his father, a tax collector in Landerneau, reveals the educational guidelines the latter gave to his son. Manners, writing skills, relationship to money, and view of religion were a few of the many topics broached. The letters also help piece together his professional life, as well as the local context. Other letters and official documents show the other aspects of the life of this young notary who died in Guémené at the age of 27
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