Les Français et la lecture - 2017

Selon le baromètre bisannuel Ipsos/CNL, 91% des personnes interrogées déclarent avoir lu au moins un livre au cours des 12 derniers mois. Si le papier demeure le format le plus courant pour 89% des lecteurs, le numérique progresse (+5% par rapport à 2015). À retenir, le développement du livre d\u27occasion et la progression de la vente en ligne au détriment de la librairie, en raison d\u27une méconnaissance du prix unique du livr

Changes in tolerance to herbicide toxicity throughout development stages of phototrophic biofilms

Ecotoxicological experiments have been performed in laboratory-scale microcosms to investigate thesensitivity of phototrophic biofilm communities to the alachlor herbicide, in relation to the stages ofphototrophic biofilm maturation (age of the phototrophic biofilms) and physical structure (intact biofilmversus recolonization). The phototrophic biofilms were initially cultivated on artificial supports in aprototype rotating annular bioreactor (RAB) with Taylor–Couette type flow under constant operatingconditions. Biofilms were collected after 1.6 and 4.4 weeks of culture providing biofilms with differentmaturation levels, and then exposed to nominal initial alachlor concentration of 10 ug L−1in either intactor recolonized biofilms for 15 days in microcosms (mean time-weighted average concentration – TWACof 5.52 ± 0.74 ug L−1).At the end of the exposure period, alachlor effects were monitored by a combination of biomass descrip-tors (ash-free dry mass – AFDM, chlorophyll a), structural molecular fingerprinting (T-RFLP), carbonutilization spectra (Biolog) and diatom species composition. We found significant effects that in terms ofAFDM, alachlor inhibited growth of the intact phototrophic biofilms. No effect of alachlor was observedon diatom composition or functional and structural properties of the bacterial community regardless ofwhether they were intact or recolonized. The intact three-dimensional structure of the biofilm did notappear to confer protection from the effects of alachlor. Bacterial community structure and biomass levelof 4.4 weeks – intact phototrophic biofilms were significantly influenced by the biofilm maturation pro-cesses rather than alachlor exposure. The diatom communities which were largely composed of mobileand colonizer life-form populations were not affected by alachlor.This study showed that the effect of alachlor (at initial concentration of 10 ug L−1or mean TWAC of5.52 ± 0.74 ug L−1) is mainly limited to biomass reduction without apparent changes in the ecologicalsuccession trajectories of bacterial and diatom communities and suggested that carbon utilization spec-tra of the biofilm are not damaged resulting. These results confirmed the importance of consideringthe influence of maturation processes or community age when investigating herbicide effects. This isparticularly important with regard to the use of phototrophic biofilms as bio-indicators

Les français et les livres audio

Cette étude à pour objectif d\u27évaluer les pratiques actuelles des Français en matière d’écoute de livres audio, de dresser le profil des lecteurs actuels, potentiels et réfractaires (pour eux-mêmes ou pour leurs enfants). Mais également de comprendre les perceptions, les motivations et les freins à écouter personnellement des livres audio… ou à en faire écouter aux enfant

Jeunes et la lecture : synthèse des résultats (Les)

La lecture, une activité qui serait délaissée par les jeunes ? Rien n’est moins sûr, si l’on en juge par une étude réalisée par l’institut Ipsos pour le Centre national du livre (CNL) auprès d’un échantillon de 1500 jeunes âgés de 7 à 19 ans. Les résultats de cette enquête, qui ont été dévoilés le 28 juin 2016, permettent de dresser, à rebours des idées reçues déclinistes, un état des lieux précis et documenté de la lecture chez les jeunes

When Higher Activations Reflect Lower Deactivations: A PET Study in Alzheimer’s Disease during Encoding and Retrieval in Episodic Memory

The aim of the present study was to explore the cerebral substrates of episodic memory disorders in Alzheimer’s disease (AD) and investigate patients’ hyperactivations frequently reported in the functional imaging literature. It remains unclear whether some of these hyperactivations reflect real increased activity or deactivation disturbances in the default mode network (DMN). Using positron emission tomography (15O-H2O), cerebral blood flow was measured in 11 AD patients and 12 healthy elderly controls at rest and during encoding and stem-cued recall of verbal items. Subtractions analyses between the target and control conditions were performed and compared between groups. The average signal was extracted in regions showing hyperactivation in AD patients versus controls in both contrasts. To determine whether hyperactivations occurred in regions that were activated or deactivated during the memory tasks, we compared signal intensities between the target conditions versus rest. Our results showed reduced activation in AD patients compared to controls in several core episodic memory regions, including the medial temporal structures, during both encoding and retrieval. Patients also showed hyperactivations compared to controls in a set of brain areas. Further analyses conducted on the signal extracted in these areas indicated that most of these hyperactivations actually reflected a failure of deactivation. Indeed, whereas almost all of these regions were significantly more activated at rest than during the target conditions in controls, only one region presented a similar pattern of deactivation in patients. Altogether, our findings suggest that hyperactivations in AD must be interpreted with caution and may not systematically reflect increased activity. Although there has been evidence supporting the existence of genuine compensatory mechanisms, dysfunction within the DMN may be responsible for part of the apparent hyperactivations reported in the literature on AD

From Relevant High-level Properties to WCET Computation Improvement

The scheduling of real-time systems requires knowing the Worst Case Execution Time (WCET) of their tasks. WCET analysers compute timings by analysis of the low level behaviour of the target task. This document presents improvements in the WCET computation allowed by taking into account high level behaviours of the tasks. We first classify high level knowledge according to the relevance with respect to WCET estimation. We then propose a systematic method to bring this information back to the low level on which operate most WCET analysers. This approach separates the concerns of stating properties, integrating properties and computing a WCET aware of these properties

Lead2Gold: Towards exploiting the full potential of noisy transcriptions for speech recognition

International audienceThe transcriptions used to train an Automatic Speech Recognition (ASR) system may contain errors. Usually, either a quality control stage discards transcriptions with too many errors, or the noisy transcriptions are used as is. We introduce Lead2Gold, a method to train an ASR system that exploits the full potential of noisy transcriptions. Based on a noise model of transcription errors, Lead2Gold searches for better transcriptions of the training data with a beam search that takes this noise model into account. The beam search is differentiable and does not require a forced alignment step, thus the whole system is trained end-to-end. Lead2Gold can be viewed as a new loss function that can be used on top of any sequence-to-sequence deep neural network. We conduct proof-of-concept experiments on noisy transcriptions generated from letter corruptions with different noise levels. We show that Lead2Gold obtains a better ASR accuracy than a competitive baseline which does not account for the (artificially-introduced) transcription noise

Les 15-25 ans & les YouTubers de sciences : les chiffres clés

Qui sont les 15-25 ans qui s’intéressent aux YouTubers scientifiques ? Quelles sont leurs motivations ? Pourquoi regardent-ils ces vidéos et à quoi leur servent-elles ? Pallient-elles un manque de ressources culturelles sur certains territoires ou viennent-elles se cumuler à d’autres pratiques déjà existantes ? Comment réutilisent-ils éventuellement les contenus qu’ils ont regardés ? Et qui sont les vidéastes qui les animent