Internet matarà o salvarà la premsa científica? L'experiència de la revista francesa 'La Recherche'

Des que es va començar a desenvolupar, no fa ni vint anys, Internet ha trasbalsat el paisatge mediàtic, començant per l’escrit. Els diaris de paper han hagut de prendre-ho ben en compte. En aquest article presentem una panoràmica de la situació de la divulgació científica a França a partir de l’experiència de La Recherche, una revista mensual de divulgació científica, i de la d’altres mitjans francesos

Impact of residential wood burning on indoor air quality

International audienceThis study aims at characterizing indoor air quality in single family dwellings burning wood regularly, studying the air change rate during wood burning and analyzing impact on outdoor air. Field investigations were performed, in February and November 2007, in six occupied houses located in rural areas (two equipped with an opened fireplace, two with respectively an old closed fireplace and a recent one, and two with respectively an old woodstove and a recent one). Continuous measurements of air temperature, relative humidity, carbon monoxide, nitrogen oxides, polycyclic aromatic hydrocarbons (PAHs) were performed in the room equipped with the wood burning appliance. Moreover in this room and in the main bedroom, PM10 and PM2.5, PAHs (on PM10 fraction), volatile organic compounds (VOCs), aldehydes, ketones, and tracers of wood combustion such as levoglucosan and methoxyphenols on PM10 fraction, were also measured. Air exchange rates and building permeability were characterized through different means

Variability of venom components in immune suppressive parasitoid wasps: From a phylogenetic to a population approach

International audienceEndoparasitoid wasps develop at the expense of other insects, leading to their death. Eggs deposited inside the host body induce an immune response, which results in the formation of a melanized cellular capsule around the egg. To evade or counteract this response, endoparasitoids have evolved different strategies, the most often reported being injection into the host of immunosuppressive factors, notably venom proteins, along with the egg. The analysis of venom components has been performed independently in species of different taxa, but the present picture is far from complete. Intriguingly, the question of the level of venom variability inside species has been neglected, although it may partly determine the potential for parasitoid adaptation. Here, we present a short review of our present knowledge of venom components in endoparasitoids, as well as of the only well-known example of intraspecific variability in a venom immune suppressive protein being responsible for variation in parasitoid virulence. We then present data evidencing inter-individual variation of venom protein profiles, using a gel electrophoresis approach, both in laboratory strains and field populations of a figitid and a braconid species. Whether occurrence of such variability may permit a selection of parasitoid venom components driven by the host remains to be tested, notably in the context of the production and use of biological control auxiliaries

Electrocristallisation de metaux sur n-GaAs et n-InP

SIGLEAvailable from INIST (FR), Document Supply Service, under shelf-number : T 77911 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Vulgariser pour valoriser les sciences humaines et sociales

Le 18 mai 2015, le quotidien Libération lançait une pétition réclamant que le mot « bolos », tout juste entré dans le Petit Larousse, soit plutôt orthographié « boloss ». Qui doute, pourtant, que le choix fait par l’éditeur du dictionnaire repose sur le travail de linguistes compétents, formés à l’université et au fait des derniers développements du domaine ? Imaginerait-on une pétition analogue pour réclamer une augmentation du diamètre des câbles soutenant le viaduc de Millau ou la longueur..

Electrocristallisation de métaux sur n-GaAs et n-InP.

We study the mechanisms of formation by electrocrystallization of metallic deposits on semiconductor (s. C. ). The use of different materials (n-gaas, n-inp) has made it possible to evaluate the influence of the chemical and electronic properties of the substrate on the nucleation and growth of metallic films. The measurement of the interfacial capacity shows that the deposit only starts if the strips of the semiconductor are sufficiently decourbed to allow the arrival of electrons on the surface and that there is simultaneously at the deposit a deplacement of the strips on n-gaas and not on n-inp. This suggests that the electronic transfer is carried out via existing surface states on n-gaas as on n-inp, but located has different energetic positions in the band gap. The morphology of the deposits from the analysis of the transient current and the observation by electron microscopy depends on the electrochemical reaction and the substrate: a diffusional kinetic control (ag, cu) causes the formation of large crystallites with little influence from the substrate; in the case of a slow electrochemical reaction (ni), the structure of the deposit depends on surface phenomena. Energy level diagrams are proposed at the metal/s interface. C. At the beginning and during the deposit. The obtaining of various morphologies of the deposits by simple adjustment of the electrolysis conditions opens perspectives of applications: the optimization of the metal/s junctions. C. modification of photoelectrodes whose electrical and electrochemical properties depend on the interfaceOn etudie les mecanismes de formation par electrocristallisation de depots metalliques sur semi-conducteur (s. C. ). L'utilisation de differents materiaux (n-gaas, n-inp) a permis d'evaluer l'influence des proprietes chimiques et electroniques du substrat sur la nucleation et la croissance des films metalliques. La mesure de la capacite interfaciale montre que le depot ne demarre que si les bandes du semi-conducteur sont suffisamment decourbees pour permettre l'arrivee des electrons en surface et qu'il existe simultanement au depot un deplacement des bandes sur n-gaas et pas sur n-inp. Ceci suggere que le transfert electronique s'effectue via des etats de surface existants sur n-gaas comme sur n-inp, mais situes a des positions energetiques differentes dans la bande interdite. La morphologie des depots deduite de l'analyse du courant transitoire et de l'observation par microscopie electronique depend de la reaction electrochimique et du substrat: un controle cinetique diffusionnel (ag, cu) provoque la formation de gros cristallites peu influences par le substrat; dans le cas d'une reaction electrochimique lente (ni), la structure du depot depend des phenomenes de surface. On propose les diagrammes des niveaux d'energie a l'interface metal/s. C. Au debut et en cours de depot. L'obtention de morphologies variees des depots par simple ajustement des conditions d'electrolyse ouvre des perspectives d'applications: l'optimisation des jonctions metal/s. C. , la modification des photoelectrodes dont les proprietes electriques et electrochimiques dependent de l'interfac