Lhomme au miroir de la science (Biologie, Ecologie, Agronomie) (French Edition)

For PNG this represents an improvement, but in what direction? Methylocella Species Are Facultatively Methanotrophic. All aerobic methanotrophic bacteria described to date are unable to grow on substrates containing carbon-carbon bonds. Here we demonstrate that members of the recently discovered genus Methylocella are an exception to this. These bacteria are able to use as their sole energy source the one-carbon compounds methane and methanol, as well as the multicarbon compounds acetate, pyruvate, succinate, malate, and ethanol.

To conclusively verify facultative growth, acetate and methane were used as mod Etude de pratiques d'enseignement relatives a la modelisation en sciences et technologies avec des enseignants du secondaire. Ministere de l'Education du Loisir et du Sport, a. Elle fait ainsi partie des sept demarches auxquelles eleves et enseignants sont censes recourir. Annales des Sciences Agronomiques - Vol 3, No 2 Revue des Sciences et de la Technologie - Vol 24 It aims at achieving a better understanding of the dynamic processes of teaching adjustment.

It relies on a qualitative methodology using focus groups. Data analysis shows the multiplicity of ways that teachers use to adjust their teaching. The adjustment of teaching approaches is also related to the quest for recognition, the teacher relationship with knowledge and the collective values in place. Changes in regional landscapes due to urban pressures raise questions regarding land use. They also give rise to economic, social and environmental issues related to urban sprawl, increases in daily commuting, and land consumption.

These changes and dysfunctions are ultimately underpinned by the question of sustainable regional development. Mountain regions such as the Alps, with their various outstanding biotopes in a restricted space, are particularly vulnerable. Methylocella species are facultatively methanotrophic. To conclusively verify facultative growth, acetate and methane were used as model substrates in growth experiments with the type strain Methylocella silvestris BL2.

Quantitative real-time PCR targeting the mmoX gene, which encodes a subunit of soluble methane monooxygenase, showed that copies of this gene increased in parallel with cell counts during growth on either acetate or methane as the sole substrate. This verified that cells possessing the genetic basis of methane oxidation grew on acetate as well as methane. Cloning of 16S rRNA genes and fluorescence in situ hybridization with strain-specific and genus-specific oligonucleotide probes detected no contaminants in cultures. The growth rate and carbon conversion efficiency were higher on acetate than on methane, and when both substrates were provided in excess, acetate was preferably used and methane oxidation was shut down.

Our data demonstrate that not all methanotrophic bacteria are limited to growing on one-carbon compounds. This could have major implications for understanding the factors controlling methane fluxes in the environment. We measure the weak lensing shear around galaxy troughs, i. These measurements probe the connection between the galaxy, matter density, and convergence fields.

Furthermore, the prediction for the lensing signal on large trough scales is virtually independent of the details of the underlying model for the connection of galaxies and matter.

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Our comparison of the shear around troughs with that around cylinders with large galaxy counts is consistent with a symmetry between galaxy and matter over- and underdensities. In addition, we measure the two-point angular correlation of troughs with galaxies which, in contrast to the lensing signal, is sensitive to galaxy bias on all scales. Finally, the lensing signal of troughs and their clustering with galaxies is therefore a promising probe of the statistical properties of matter underdensities and their connection to the galaxy field. Galaxy cross-correlations with high-fidelity redshift samples hold the potential to precisely calibrate systematic photometric redshift uncertainties arising from the unavailability of complete and representative training and validation samples of galaxies.

However, application of this technique in the Dark Energy Survey DES is hampered by the relatively low number density, small area, and modest redshift overlap between photometric and spectroscopic samples. We propose instead using photometric catalogues with reliable photometric redshifts for photo-z calibration via cross-correlations. We demonstrate how to combine photo-z with cross-correlation data to calibrate photometric redshift biases while marginalizing over possible clustering bias evolution in either the calibration or unknown photometric samples. We forecast that our proposal can, in principle, control photometric redshift uncertainties in DES weak lensing experiments at a level near the intrinsic statistical noise of the experiment over the range of redshifts where redMaPPer clusters are available.

Our results provide strong motivation to launch a programme to fully characterize the systematic errors from bias evolution and photo-z shapes in our calibration procedure. Facultative symbiont infections affect aphid reproduction. Some bacterial symbionts alter their hosts reproduction through various mechanisms that enhance their transmission in the host population. In addition to its obligatory symbiont Buchnera aphidicola, the pea aphid Acyrthosiphon pisum harbors several facultative symbionts influencing several aspects of host ecology.

Aphids reproduce by cyclical parthenogenesis whereby clonal and sexual reproduction alternate within the annual life cycle. Many species, including the pea aphid, also show variation in their reproductive mode at the population level, with some lineages reproducing by cyclical parthenogenesis and others by permanent parthenogenesis. While the role of facultative symbionts has been well studied during the parthenogenetic phase of their aphid hosts, very little is known on their possible influence during the sexual phase.

Here we investigated whether facultative symbionts modulate the capacity to produce sexual forms in various genetic backgrounds of the pea aphid with controlled symbiont composition and also in different aphid genotypes from natural populations with previously characterized infection status and reproductive mode.

We found that most facultative symbionts exhibited detrimental effects on their hosts fitness under sex-inducing conditions in comparison with the reference lines. We also showed that the loss of sexual phase in permanently parthenogenetic lineages of A. Finally, we demonstrated that Spiroplasma infection annihilated the production of males in the host progeny by inducing a male-killing phenotype, an unexpected result for organisms such as aphids that reproduce primarily through clonal reproduction.

Full Text Available Some bacterial symbionts alter their hosts reproduction through various mechanisms that enhance their transmission in the host population. The Science Verication data spans approximately sq. Les villes et la science: Pour une automythanalyse au risque de la Science Fiction et des Sciences Occultes. Et puis, il y a toujours eu des temps difficiles. Becker, La Bonne focale.

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Tensions et coordinations entre les acteurs des sciences de la performance sportive. Tensions and coordinations between the actors of sports performance sciences This article is based on a study which examines how knowledge is produced in the field of sports performance, looking at the modes of coordination between researchers and the coaches with whom they collaborate.

The analysis of empirical data made of interviews and texts leads us to show three scientific regimes, which are at the same time specific modes of coordination between scientists and coaches and particular forms of knowledge production. The paper sheds light on the tensions inherent in each regime and the solutions which the actors adopt in order to co-operate.

Finally, we study the constraints scientists face when they go from one regime to another. We describe updates to the redMaPPer algorithm, a photometric red-sequence cluster finder specifically designed for large photometric surveys. Facultative hyperaccumulation of heavy metals and metalloids. Approximately species of plants are known to hyperaccumulate heavy metals and metalloids.

The majority are obligate metallophytes, species that are restricted to metalliferous soils. However, a smaller but increasing list of plants are " facultative hyperaccumulators" that hyperaccumulate heavy metals when occurring on metalliferous soils, yet also occur commonly on normal, non-metalliferous soils.

This paper reviews the biology of facultative hyperaccumulators and the opportunities they provide for ecological and evolutionary research. The existence of facultative hyperaccumulator populations across a wide edaphic range allows intraspecific comparisons of tolerance and uptake physiology. This approach has been used to study zinc and cadmium hyperaccumulation by Noccaea Thlaspi caerulescens and Arabidopsis halleri, and it will be instructive to make similar comparisons on species that are distributed even more abundantly on normal soil.

Several hypotheses suggested to explain the evolution of hyperaccumulation seem unlikely when most populations of a species occur on normal soil, where plants cannot hyperaccumulate due to low metal availability. In such species, it may be that hyperaccumulation is an ancestral phylogenetic trait or an anomalous manifestation of physiological mechanisms evolved on normal soils, and may or may not have direct adaptive benefits. Le Phosphate naturel PNY. Orientations scientifiques des filles en France: There was a positive evolution at the secondary level but rather less obvious at higher education.

Boumahrat , La fuite des cerv Facultative reinsurance and the full reinsurance clause. In most disputes the outcome depends upon resolving the fundamental question of whether reinsurance is either a further insurance on the subject matter insured or is a reinsurance of the liability of the reinsured under the direct policy.

Facultative parthenogenesis discovered in wild vertebrates. Booth, Warren; Smith, Charles F. Facultative parthenogenesis FP —asexual reproduction by bisexual species—has been documented in a variety of multi-cellular organisms but only recently in snakes, varanid lizards, birds and sharks. Unlike the approximately 80 taxa of unisexual reptiles, amphibians and fishes that exist in nature, FP has yet to be documented in the wild. Based on captive documentation, it appears that FP is widespread in squamate reptiles snakes, lizards and amphisbaenians , and its occurrence in nature seem Mapping and simulating systematics due to spatially varying observing conditions in DES science verification data.

Spatially varying depth and the characteristics of observing conditions, such as seeing, airmass, or sky background, are major sources of systematic uncertainties in modern galaxy survey analyses, particularly in deep multi-epoch surveys. We present a framework to extract and project these sources of systematics onto the sky, and apply it to the Dark Energy Survey DES to map the observing conditions of the Science Verification SV data. The resulting distributions and maps of sources of systematics are used in several analyses of DES—SV to perform detailed null tests with the data, and also to incorporate systematics in survey simulations.

We show that the spatially varying survey depth imprinted in the observed galaxy densities and the redshift distributions of the SV data are successfully reproduced by the simulation and are well-captured by the maps of observing conditions. The combined use of the maps, the SV data, and the BCC-UFig simulation allows us to quantify the impact of spatial systematics on N z , the redshift distributions inferred using photometric redshifts. We conclude that spatial systematics in the SV data are mainly due to seeing fluctuations and are under control in current clustering and weak-lensing analyses.

However, they will need to be carefully characterized in upcoming phases of DES in order to avoid biasing the inferred cosmological results. Finally, the framework presented here is relevant to all multi-epoch surveys and will be essential for exploiting future surveys such as the Large Synoptic Survey Telescope, which will require detailed null tests and realistic end-to-end image simulations to correctly interpret the deep, high.

Dictionary of nuclear sciences and techniques; Dictionnaire des sciences et techniques nucleaires. This reference book has been totally reworked in its fourth edition, in order to answer the needs of the numerous sectors of activity concerned by nuclear sciences and technologies: This complete overview of the nuclear world integrates the regulatory aspects, necessary to shade light on it, and many other technological innovations.

Elaborated with harmonization, clarification and exhaustiveness concerns, this dictionary is the result of a large consensus among the French-speaking nuclear community. It includes some entries with more than color illustrations and an English-French glossary.

Its aim is to offer to everyone a precise vocabulary, fully shared by everybody and necessary for exchanges and debates clarity. Cultivate Africa's Future - Phase 2. The main objective of this competitive research fund is to support applied research in areas vital to achieving long-term food security.

The algorithm was developed to minimize photometric redshift uncertainties in photometric large-scale structure studies. Additionally, we demonstrate that redMaGiC photo-zs are very nearly as accurate as the best machine-learning based methods, yet they require minimal spectroscopic training, do not suffer from extrapolation biases, and are very nearly Gaussian. Dose-dependent effects of cadmium on the growth of snails in toxicity. Evaluation d'une approche pedagogique respectant les facons d'apprendre des filles en sciences et en TIC en 9e annee au Nouveau-Brunswick.

La reussite scolaire des filles les amene de plus en plus a poursuivre une formation postsecondaire et a exercer des professions qui demandent un haut niveau de connaissances et d'expertise scientifique. Toutefois, les filles demeurent toujours tres peu nombreuses a envisager une carriere en sciences chimie et physique , en ingenierie ou en TIC technologie d'information et de la communication , soit une carriere reliee a la nouvelle economie.

Pour plusieurs filles, les sciences et les TIC ne sont pas des matieres scolaires qu'elles trouvent interessantes meme si elles y reussissent tres bien. Ces filles admettent que leurs experiences d'apprentissage en sciences et en TIC ne leur ont pas permis de developper un interet ni de se sentir confiante en leurs habiletes a reussir dans ces matieres.

Par consequent, peu de filles choisissent de poursuivre leurs etudes postsecondaires dans ces disciplines. La theorie sociocognitive du choix carriere a ete choisie comme modele theorique pour mieux comprendre quelles variables entrent en jeu lorsque les filles choisissent leur carriere. Notre etude a pour objet la conception et l'evaluation de l'efficacite d'un materiel pedagogique concu specifiquement pour ameliorer les experiences d'apprentissage en sciences et en TIC des filles de 9e annee au Nouveau-Brunswick. L'approche pedagogique privilegiee dans notre materiel a mis en oeuvre des strategies pedagogiques issues des meilleures pratiques que nous avons identifiees et qui visaient particulierement l'augmentation du sentiment d'auto-efficacite et de l'interet des filles pour ces disciplines.

Ce materiel disponible par Internet a l'adresse http: L'evaluation de l'efficacite de notre materiel pedagogique a ete faite selon deux grandes etapes methodologiques: The proximity of steel pollution industry is a factor limiting the growth of Helix aspersa in the area of Sidi Amar. Helix aspersa - Bio indicator — Biometry — Growth — Glutathione The presence and expression of genes controlling the synthesis and secretion of cytokinins by the pink-pigmented facultative methylotroph Methylobacterium mesophilicum VKM B with the serine pathway and nonpigmented obligate methylotroph Methylovorus mays VKM B with the ribulose monophosphate pathway of C1 metabolism were shown using the polymerase chain reaction PCR and reverse transcription-PCR methods.

The presence of the corresponding mRNA in M. The cytokinin activity of culture liquid and its fractions was determined by a biotest with Amarantus caudatus L. Using enzyme-linked immunosorbent analysis, we detected zeatin riboside in the culture liquid of both bacteria studied. The data obtained show that the aerobic methylobacteria are phytosymbionts that are able to utilize the single- and polycarbon compounds secreted by symbiotic plants and to synthesize cytokinins. We measure the cross-correlation between weak lensing of galaxy images and of the cosmic microwave background CMB.

The effects of gravitational lensing on different sources will be correlated if the lensing is caused by the same mass fluctuations. We demonstrate that our results are robust to a number of important systematic effects including the shear measurement method, estimator choice, photometric redshift uncertainty and CMB lensing systematics.

With three measurements of this cross-correlation now existing in the literature, there is not yet reliable evidence for any deviation from the expected LCDM level of cross-correlation, given the size of the statistical uncertainties and the significant impact of systematic errors, particularly IAs. In addition to the more usual methods, the following methods are used at the Boris Kidric Institute of Nuclear Sciences in the medical supervision of occupationally exposed staff: These methods are described briefly and their practical application discussed.

Ces methodes sont brievement decrites et leurs applications pratiques discutees. We split these lenses into three photometric-redshift bins from 0. We compare our galaxy bias results from galaxy-galaxy lensing with those obtained from galaxy clustering Crocce et al.

Our results are found to be rather insensitive to a large range of systematic effects. Centre d' Etudes Nucleaires.

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The measurements were begun in September and were continued in an increasing number of stations both in France and in the rest of the world. The present report deals with the period up to the end of august , that is up to the end of the nuclear moratorium. After recalling the constitution and the properties of radioactive aerosols present in the atmosphere, the authors describe the measurement methods, estimate their accuracy and discuss various aspects of the results. Les mesures ont commence en septembre et ont ete poursuivies dans un nombre croissant de stations, tant en France que dans le reste du monde.

Le present rapport s'arrete a la fin aout , c'est-a-dire au moment de la reprise des essais nucleaires. Apres avoir rappele la constitution et les proprietes des aerosols radioactifs presents dans l'atmosphere, les auteurs indiquent les methodes de mesure utilisees, evaluent leur precision et discutent les differents aspects des resultats de leurs mesures. Revue des Sciences et de la Technologie - Vol 16 Damage process in a discrete disordered model and consequences on Revue des Sciences et de la Technologie - Vol 18 Etude de l'action du phosphate dipotassique sur la Dolomite: Detoxification of hexavalent chromium by an indigenous facultative Full Length Research Paper Biological degradation and bioremediation of toxic chemicals,.

Facultative parthenogenesis FP -asexual reproduction by bisexual species-has been documented in a variety of multi-cellular organisms but only recently in snakes, varanid lizards, birds and sharks. Based on captive documentation, it appears that FP is widespread in squamate reptiles snakes, lizards and amphisbaenians , and its occurrence in nature seems inevitable, yet the task of detecting FP in wild individuals has been deemed formidable.

Here we show, using microsatellite DNA genotyping and litter characteristics, the first cases of FP in wild-collected pregnant females and their offspring of two closely related species of North American pitviper snakes-the copperhead Agkistrodon contortrix and cottonmouth Agkistrodon piscivorus. Our findings support the view that non-hybrid origins of parthenogenesis, such as FP, are more common in squamates than previously thought. With this confirmation, FP can no longer be viewed as a rare curiosity outside the mainstream of vertebrate evolution.

Future research on FP in squamate reptiles related to proximate control of induction, reproductive competence of parthenogens and population genetics modelling is warranted. Facultative parthenogenesis in vertebrates: Parthenogenesis, the development of an embryo from a female gamete without any contribution of a male gamete, is very rare in vertebrates. Parthenogenetically reproducing species have, so far, only been found in the Squamate reptiles lizards and snakes.

Facultative parthenogenesis, switching between sexual and clonal reproduction, although quite common in invertebrates, e. Daphnia and aphids, seems to be even rarer in vertebrates. However, isolated cases of parthenogenetic development have been reported in all vertebrate groups. Facultative parthenogenesis in vertebrates has only been found in captive animals but might simply have been overlooked in natural populations. Even though its evolutionary impact is hard to determine and very likely varies depending on the ploidy restoration mechanisms and sex-determining mechanisms involved, facultative parthenogenesis is already discussed in conservation biology and medical research.

To raise interest for facultative parthenogenesis especially in evolutionary biology, I summarize the current knowledge about facultative parthenogenesis in the different vertebrate groups, introduce mechanisms of diploid oocyte formation and discuss the genetic consequences and potential evolutionary impact of facultative parthenogenesis in vertebrates. Bordry et le chef de groupe L. Joint sciences academies statement: Taking into account that there is now strong evidence that significant global warming is occurring, the Joint Science Academies, urge, by this statement, all nations in the line with the UNFCCC principles, to take prompt action to reduce the causes of climate change, adapt to its impacts and ensure that the issue is included in all relevant national and international strategies.

Some recommendations are also given. Department of Agriculture, 40p. Department of Agriculture, 19p. Denis de Casabianca, Montesquieu. Facultative and obligate methanotrophs how to identify and differentiate them. Aerobic methanotrophs are metabolically unique bacteria that are able to utilize methane and some other C1-compounds as sole sources of carbon and energy. A defining characteristic of these organisms is the use of methane monooxygenase MMO enzymes to catalyze the oxidation of methane to methanol.

For a long time, all methanotrophs were considered to be obligately methylotrophic, that is, unable to grow on compounds containing C-C bonds. This notion has recently been revised. Some members of the genera Methylocella, Methylocystis, and Methylocapsa are now known to be facultative methanotrophs, that is, capable of growing on methane as well as on some multicarbon substrates. The diagnosis of facultative methanotrophy in new isolates requires a great degree of caution since methanotrophic cultures are frequently contaminated by heterotrophic bacteria that survive on metabolic by-products of methanotrophs.

The presence of only a few satellite cells in a culture may lead to false conclusions regarding substrate utilization, and several early reports of facultative methanotrophy are likely attributable to impure cultures. Another recurring mistake is the misidentification of nonmethanotrophic facultative methylotrophs as facultative methanotrophs.

This chapter was prepared as an aid to avoid both kinds of confusion when examining methanotrophic isolates. Divergent biology of facultative heavy metal plants. Among heavy metal plants the metallophytes , facultative species can live both in soils contaminated by an excess of heavy metals and in non-affected sites. In contrast, obligate metallophytes are restricted to polluted areas. Metallophytes offer a fascinating biology, due to the fact that species have developed different strategies to cope with the adverse conditions of heavy metal soils.

The literature distinguishes between hyperaccumulating, accumulating, tolerant and excluding metallophytes, but the borderline between these categories is blurred. Due to the fact that heavy metal soils are dry, nutrient limited and are not uniform but have a patchy distribution in many instances, drought-tolerant or low nutrient demanding species are often regarded as metallophytes in the literature. In only a few cases, the concentrations of heavy metals in soils are so toxic that only a few specifically adapted plants, the genuine metallophytes, can cope with these adverse soil conditions.

Current molecular biological studies focus on the genetically amenable and hyperaccumulating Arabidopsis halleri and Noccaea Thlaspi caerulescens of the Brassicaceae. The two endemic zinc violets of Western Europe, Viola lutea ssp. The Caryophyllaceae, Silene vulgaris f. All Central European metallophytes have close relatives that grow in areas outside of heavy metal soils, mainly in the Alps, and have, therefore, been considered as relicts of the glacial epoch in the past.

Unrelated facultative endosymbionts protect aphids against a fungal pathogen. The importance of microbial facultative endosymbionts to insects is increasingly being recognized, but our understanding of how the fitness effects of infection are distributed across symbiont taxa is limited. In the pea aphid, some of the seven known species of facultative symbionts influence their host's resistance to natural enemies, including parasitoid wasps and a pathogenic fungus. Here we show that protection against this entomopathogen, Pandora neoaphidis, can be conferred by strains of four distantly related symbionts in the genera Regiella, Rickettsia, Rickettsiella and Spiroplasma.

They reduce mortality and also decrease fungal sporulation on dead aphids which may help protect nearby genetically identical insects. Pea aphids thus obtain protection from natural enemies through association with a wider range of microbial associates than has previously been thought. Providing resistance against natural enemies appears to be a particularly common way for facultative endosymbionts to increase in frequency within host populations.

Effects of vulture exclusion on carrion consumption by facultative scavengers. Vultures provide an essential ecosystem service through removal of carrion, but globally, many populations are collapsing and several species are threatened with extinction. Widespread declines in vulture populations could increase the availability of carrion to other organisms, but the ways facultative scavengers might respond to this increase have not been thoroughly explored. We aimed to determine whether facultative scavengers increase carrion consumption in the absence of vulture competition and whether they are capable of functionally replacing vultures in the removal of carrion biomass from the landscape.

We experimentally excluded 65 rabbit carcasses from vultures during daylight hours and placed an additional 65 carcasses that were accessible to vultures in forested habitat in South Carolina, USA during summer June-August. We used motion-activated cameras to compare carrion use by facultative scavenging species between the experimental and control carcasses.

Scavenging by facultative scavengers did not increase in the absence of competition with vultures. We found no difference in scavenger presence between control carcasses and those from which vultures were excluded. At the end of the 7-day trials, there was a Facultative scavengers did not functionally replace vultures during summer in our study. This finding may have been influenced by the time of the year in which the study took place, the duration of the trials, and the spacing of carcass sites. Our results suggest that under the warm and humid conditions of our study, facultative scavengers would not compensate for loss of vultures.

Carcasses would persist longer in the environment and consumption of carrion would likely shift from. Pollination and facultative ant-association in the African leopard The role of extra-floral nectar appears to be recruitment of foraging ants to tend the flowers resulting in a facultative ant-association between the orchid and gregarious ants. Four different ant species were found to forage on A. Ant-tended inflorescences suffered significantly less damage by insects.

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A chromate resistant facultative anaerobic bacterial strain FA-3 was isolated from the treated tannery effluent of Jajmau, Kanpur India and was identified as Bacillus cereus. The rate of growth of B. Traitements didactiques preventifs d'un type de conceptions erronees en sciences physiques chez des eleves du secondaire. Dans un contexte constructiviste, les connaissances anterieures d'un individu sont essentielles a la construction de nouvelles connaissances.

Quelle qu'en soit la source certaines de ces connaissances ont ete elaborees en classe, d'autres ont ete elaborees par interaction personnelle de l'individu avec son environnement physique et social , ces connaissances, une fois acquises, constituent les matieres premieres de l'elaboration des nouvelles conceptions de cet individu. Generalement, cette influence est consideree comme positive. Cependant, dans un milieu scolaire ou l'apprentissage de certaines conceptions enchassees dans un programme d'etudes et enterinees par l'ensemble d'une communaute est obligatoire, certaines connaissances anterieures peuvent entraver la construction des conceptions exigees par la communaute.

La litterature abonde de tels exemples. Cependant, certaines connaissances anterieures, en soi tout a fait conformes a l'Heritage, peuvent aussi, parce qu'utilisees de facon non pertinente, entraver la construction d'une conception exigee par la communaute. Ici, la litterature nous donne peu d'exemples de ce type, mais nous en fournirons quelques-uns dans le cadre theorique, et ce sera un d'entre eux qui servira de base a nos propos.

En effet, une grande proportion d'eleves inscrits a un cours de sciences physiques de la quatrieme secondaire, en reponse a un probleme deja solutionne durant l'annee et redonne lors d'un examen sommatif, "Pourquoi la Lune nous montre-t-elle toujours la meme face? En tant que responsable de l'enseignement de ce programme d'etudes, plusieurs questions nous sont venues a l'esprit, entre autres, comment, dans un contexte constructiviste, est-il possible de reduire chez un eleve, l'impact de cette connaissance anterieure dans l'elaboration de la solution et ainsi prevenir la construction d'une conception erronee?

Nous avons teste nos. Policy in Focus publie un L'Initiative des conseils subventionnaires de la recherche scientifique en Afrique subsaharienne remporte le prix de la diplomatie scientifique. Du changement conceptuel a la complexification conceptuelle dans l'apprentissage des sciences.

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Science learning has often been thought as a replacement process; learners' spontaneous ideas must be replaced by scientific ones. Many learning models in science education were formulated in this way at least implicitly. But theses spontaneous ideas proved to be more resistant than initially thought.

Several researchers concluded that students often possess an odd combination of intuitive and scientific ideas. Generally, the phenomenon of "multiple conceptions" refers to students having a repertoire of different conceptions, each associated with a context of relevance. A number of researchers in science education constructed models of this phenomenon, but none included a systematic treatment of what we consider one of its most important aspects: This whole constitute a complex of conceptions, whence our utilisation of the expression "conceptual complexification" to designate this form of learning.

Using ideas in the conceptual change literature and in philosophy of science , we propose five kinds of cognitive structures that could play an intermediary role between alternative conceptions, allowing the management of their multiplicity: In the empirical section of the research, we explore specifically decisional structures, which are responsible for the selection of one conception of the repertoire. In order to do so, we submitted two series of tasks to eight collegial and undergraduate students in two situations.

In the first tasks, subjects are asked to explain three phenomena one biological and two physical to fictive audiences of various ages 6 to 15 years old. In the second tasks, students' understanding of the quantum version of the Young's interference experiment is probed in order study their understanding of the demarcation between quantum and classical. La revolution des savants. Elle dirigee par le hollandais Huyggens jusqu'a sa fuite de France au moment de la revocation de l'Edit de Nantes.

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Celle-ci continue cependant ses travaux pour les poids et mesures jusqu'en Lavoisier, Bailly et Condorcet. Au printemps 93, le Comite de Salut Publique s'inquiete du demi-million de soldats etrangers de toutes les pays frontaliers qui essai Soleil a new powerful tool for materials science ; Soleil, un nouvel outil puissant pour les sciences des materiaux.

The first photons delivered by the third generation synchrotron source SOLEIL will be soon available for the scientific community. In this context, this paper presents an overview of the potentialities offered by this new machine for the study of materials. The spatial resolution, from a few micrometers to sub micrometer scale, accessible by micro-diffraction and micro-spectroscopy in the wavelength range from the far IR to the hard X-rays, will provide spatial distributions of different elements atomic and chemical state selectivity in a material, from the working heterogeneous catalyst to the reservoir rocks.

The reactivity of surfaces and nano-particles exposed to controlled gas fluxes will be studied by several in situ techniques.

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Finally the combination of different synchrotron techniques diffraction, absorption and fluorescence X and the access to complementary information obtained through the simultaneous combination of these techniques with those routinely applied in Materials Science , such as UV-Vis or Raman spectroscopy, will offer enlarged capabilities for the operando characterization of materials. Environmental distribution and abundance of the facultative methanotroph Methylocella.

There is little information on the abundance and distribution of Methylocella spp. New primers were designed, and a real-time quantitative PCR method was developed Transcriptomes provide excellent foundational resources for mechanistic and evolutionary analyses of complex traits. We present a developmental transcriptome for the facultatively eusocial bee Megalopta genalis, which represents a potential transition point in the evolution of eusociality.

A de novo transcriptome assembly of Megalopta genalis was generated using paired-end Illumina sequencing and the Trinity assembler. Males and females of all life stages were aligned to this transcriptome fo International audience; Over the period a total 20 female scientific researchers eleven from the Spanish Institute of Oceanography IEO and nine from the Higher Council for Scientific Research CSIC had 65 articles published in the articles of these two government organisations.

The articles, relating to marine and freshwater sciences , which were written solely by them or in collaboration, deal with oceanography, plankton, algology, food-fish biology, food science , etc. You can suggest to your library or institution to subscribe to the program OpenEdition Freemium for books. Feel free to give our address: We will be glad to provide it with information about OpenEdition and its subscription offers.

We will forward your request to your library as soon as possible. OpenEdition is a web platform for electronic publishing and academic communication in the humanities and social sciences. Desktop version Mobile version. Results per book Results per chapter. Search inside the book.

Text Bibliography Notes Author s. Noctuidae on golf course fairways. Salamander dispersal across a forested landscape fragmented by a golf course. Journal of Wildlife Management, 71 4 June Montieth and Peter W. Golf and the environment: Hammond et Malcolm D. Quality of life capital. Island Press, New York, p. A typology for description, classification and valuation of ecosystem functions, goods and services.

Sustainable development and sustainable landscapes: Fennia 1 , 7— What matters and why. Haines-Young, Improving the quality of environmental assessments using the concept of natural capital: Markwick, Golf tourism development, stakeholders, differing discourses and alternative agendas: Do golf courses provide a refuge for flora and fauna in Japanese urban landscapes? Landscape and Urban Planning, Elsevier, 75 February 28 This document highlights the benefits of turf, trees, and natural areas commonly found on golf courses.

Nitrogen leaching in bermudagrass turf. Effect of nitrogen sources and rates. Maintaining quality turfgrass with minimal nitrogen leaching. Moisture sensor-controlled irrigation for reducing N leaching in bermudagrass turf. Fertigation for stabilizing turfgrass nitrogen nutrition. Schrlau, Raymond Snyder, George H. Snyder, Ming Chen, John L.