Evolution des méthodes de protection des procédés industriels contre les effets des explosions : le projet DELFINE)

National audienceClassical methods for vent sizing are based on experimental correlations coming from academic test situations, sometime quite different from real industrial conditions. Thus, they do not take into account the variation of turbulence in industrial enclosures, which may alter drastically the explosion violence. The DELFINE installation presently in construction will allow studying dust explosions in real working conditions of a dust collector. Preliminary experiments in an instrumented small size filter are presented, which allow characterizing the turbulence level in every work phase of the system. It appears that the turbulence level is generally lower than in the standard conditions for vent testing, even during reverse jet cleaning. It should offer perspective for optimization of the venting areas for dust collectors. Explosion tests in real conditions on the DELFINE installation will be performed to try to confirm these first observations.Les industries de la chimie, du bois et de l'agroalimentaire concentrent plus de 80% des explosions de poussières recensées en France au cours des 100 dernières années [1]. Pour cette raison il existe aujourd'hui un secteur industriel qui propose des solutions de maîtrise des risques d'explosion de poussière et met sur le marché, qui des technologies de protection, qui des appareils équipés de ces technologies dès la conception. Si des normes relatives à ces stratégies industrielles ont été proposées comme pendant à la Directive ATEX [2], il a été observé qu'elles étaient loin de couvrir la réalité des procédés industriels. Cela est perçu comme un obstacle majeur à l'ingénierie de la sécurité des procédés puisqu'on ne possède pas de " méthodes d'ingénieur " suffisantes. L'objectif du projet DELFINE qui réunit les moyens de FIKE Corp. (producteur de systèmes de protection), de DELTA NEU (producteur de process industriels de filtration) et de l'INERIS (Expert de la phénoménologie de l'explosion) est de promouvoir des méthodes de dimensionnement des systèmes de protection en commençant par la technologie des évents. On présente dans cette communication les résultats obtenus au plan de la modélisation phénoménologique du développement des explosions dans les systèmes industriels (réseaux d'enceintes et de canalisations) et les premiers résultats expérimentaux obtenus à l'échelle réelle au moyen d'une boucle d'essai de dépoussiérage spécialement conçue pour le projet

Transcriptome response to pollutants and insecticides in the dengue vector Aedes aegypti using next-generation sequencing technology

<p>Abstract</p> <p>Background</p> <p>The control of mosquitoes transmitting infectious diseases relies mainly on the use of chemical insecticides. However, mosquito control programs are now threatened by the emergence of insecticide resistance. Hitherto, most research efforts have been focused on elucidating the molecular basis of inherited resistance. Less attention has been paid to the short-term response of mosquitoes to insecticides and pollutants which could have a significant impact on insecticide efficacy. Here, a combination of LongSAGE and Solexa sequencing was used to perform a deep transcriptome analysis of larvae of the dengue vector <it>Aedes aegypti </it>exposed for 48 h to sub-lethal doses of three chemical insecticides and three anthropogenic pollutants.</p> <p>Results</p> <p>Thirty millions 20 bp cDNA tags were sequenced, mapped to the mosquito genome and clustered, representing 6850 known genes and 4868 additional clusters not located within predicted genes. Mosquitoes exposed to insecticides or anthropogenic pollutants showed considerable modifications of their transcriptome. Genes encoding cuticular proteins, transporters, and enzymes involved in the mitochondrial respiratory chain and detoxification processes were particularly affected. Genes and molecular mechanisms potentially involved in xenobiotic response and insecticide tolerance were identified.</p> <p>Conclusions</p> <p>The method used in the present study appears as a powerful approach for investigating fine transcriptome variations in genome-sequenced organisms and can provide useful informations for the detection of novel transcripts. At the biological level, despite low concentrations and no apparent phenotypic effects, the significant impact of these xenobiotics on mosquito transcriptomes raise important questions about the 'hidden impact' of anthropogenic pollutants on ecosystems and consequences on vector control.</p

Coherent c-axis transport in the underdoped cuprate superconductor YBCO

The electrical resistivity rho_c of the underdoped cuprate superconductor YBCO was measured perpendicular to the CuO_2 planes on ultra-high quality single crystals in magnetic fields large enough to suppress superconductivity. The incoherent insulating-like behavior of rho_c at high temperature, characteristic of all underdoped cuprates, is found to cross over to a coherent regime of metallic behavior at low temperature. This crossover coincides with the emergence of the small electron pocket detected in the Fermi surface of YBCO via quantum oscillations, the Hall and Seebeck coefficients and with the detection of a unidirectional modulation of the charge density as seen by high-field NMR measurements. The low coherence temperature is quantitatively consistent with the small hopping integral t_perp inferred from the splitting of the quantum oscillation frequencies. We conclude that the Fermi-surface reconstruction in YBCO at dopings from p = 0.08 to at least p = 0.15, attributed to stripe order, produces a metallic state with 3D coherence deep in the underdoped regime.Comment: 7 pages, 7 figure

NME6 is a phosphotransfer-inactive, monomeric NME/NDPK family member and functions in complexes at the interface of mitochondrial inner membrane and matrix

Background NME6 is a member of the nucleoside diphosphate kinase (NDPK/NME/Nm23) family which has key roles in nucleotide homeostasis, signal transduction, membrane remodeling and metastasis suppression. The well-studied NME1-NME4 proteins are hexameric and catalyze, via a phospho- histidine intermediate, the transfer of the terminal phosphate from (d)NTPs to (d)NDPs (NDP kinase) or proteins (protein histidine kinase). For the NME6, a gene/protein that emerged early in eukaryotic evolution, only scarce and partially inconsistent data are available. Here we aim to clarify and extend our knowledge on the human NME6. Results We show that NME6 is mostly expressed as a 186 amino acid protein, but that a second albeit much less abundant isoform exists. The recombinant NME6 remains monomeric, and does not assemble into homo-oligomers or hetero- oligomers with NME1-NME4. Consequently, NME6 is unable to catalyze phosphotransfer: it does not generate the phospho-histidine intermediate, and no NDPK activity can be detected. In cells, we could resolve and extend existing contradictory reports by localizing NME6 within mitochondria, largely associated with the mitochondrial inner membrane and matrix space. Overexpressing NME6 reduces ADP-stimulated mitochondrial respiration and complex III abundance, thus linking NME6 to dysfunctional oxidative phosphorylation. However, it did not alter mitochondrial membrane potential, mass, or network characteristics. Our screen for NME6 protein partners revealed its association with NME4 and OPA1, but a direct interaction was observed only with RCC1L, a protein involved in mitochondrial ribosome assembly and mitochondrial translation, and identified as essential for oxidative phosphorylation. Conclusions NME6, RCC1L and mitoribosomes localize together at the inner membrane/matrix space where NME6, in concert with RCC1L, may be involved in regulation of the mitochondrial translation of essential oxidative phosphorylation subunits. Our findings suggest new functions for NME6, independent of the classical phosphotransfer activity associated with NME proteins

Biennale du livre de sciences humaines et sociales : La fabrique du travail

La deuxième édition de la Biennale du livre de sciences humaines et sociales s’attèle à une thématique complexe : la fabrique du travail. Ces rencontres permettent d’apporter un regard, une perspective, économique, philosophique, historique, sociologique et éthique : travailler, mais jusqu’où ? Le régime de l’intermittence est-il vraiment un modèle ? Et si, de plus en plus, on entendait : « le travail ? Non merci… ». Pour donner à réfléchir, nous avons fait appel à des chercheurs confirmés, des jeunes chercheurs - car il nous a semblé que c’était la place d’une institution que de leur donner aussi la parole - et à un écrivain

Regulating Factors of PrPres Glycosylation in Creutzfeldt-Jakob Disease - Implications for the Dissemination and the Diagnosis of Human Prion Strains

OBJECTIVE: The glycoprofile of pathological prion protein (PrP(res)) is widely used as a diagnosis marker in Creutzfeldt-Jakob disease (CJD) and is thought to vary in a strain-specific manner. However, that the same glycoprofile of PrP(res) always accumulates in the whole brain of one individual has been questioned. We aimed to determine whether and how PrP(res) glycosylation is regulated in the brain of patients with sporadic and variant Creutzfeldt-Jakob disease. METHODS: PrP(res) glycoprofiles in four brain regions from 134 patients with sporadic or variant CJD were analyzed as a function of the genotype at codon 129 of PRNP and the Western blot type of PrP(res). RESULTS: The regional distribution of PrP(res) glycoforms within one individual was heterogeneous in sporadic but not in variant CJD. PrP(res) glycoforms ratio significantly correlated with the genotype at codon 129 of the prion protein gene and the Western blot type of PrP(res) in a region-specific manner. In some cases of sCJD, the glycoprofile of thalamic PrP(res) was undistinguishable from that observed in variant CJD. INTERPRETATION: Regulations leading to variations of PrP(res) pattern between brain regions in sCJD patients, involving host genotype and Western blot type of PrP(res) may contribute to the specific brain targeting of prion strains and have direct implications for the diagnosis of the different forms of CJD

Les plus belles enveloppes illustrées de 1750 à nos jours

See French abstract

The medium helps the message: Early sensitivity to auditory fluency in children's endorsement of statements

Recently, a growing number of studies have investigated the cues used by children to selectively accept testimony. In parallel, several studies with adults have shown that the fluency with which information is provided influences message evaluation: adults evaluate fluent information as more credible than dysfluent information. It is therefore plausible that the fluency of a message could also influence children's endorsement of statements. Three experiments were designed to test this hypothesis with 3- to 5-year-olds where the auditory fluency of a message was manipulated by adding different levels of noise to recorded statements. The results show that 4 and 5-year-old children, but not 3-year-olds, are more likely to endorse a fluent statement than a dysfluent one. The present study constitutes a first attempt to show that fluency, i.e., ease of processing, is recruited as a cue to guide epistemic decision in children. An interpretation of the age difference based on the way cues are processed by younger children is suggested

Four- to Six-Year-Old Children's Sensitivity to Reliability Versus Consensus in the Endorsement of Object Labels

Recent studies have demonstrated that young children use past reliability and consensus to endorse object labels. Until now, no study has investigated how children weigh these two cues when they are in conflict. The two experiments reported here were designed to explore whether any initial preference for information provided by a consensual group would be influenced by the group's subsequent unreliability. The results show that 4- and 5-year-old children were more likely to endorse labels provided by an unreliable but consensual group than the labels provided by a reliable dissenter. Six-year-olds displayed the reverse pattern. The article concludes by discussing the methodological implications of the two experiments and the developmental trajectory regarding the way children weigh consensuality versus reliability

Étude de la reconstruction de la surface de Fermi des cuprates supraconducteurs dopés en trous

TOULOUSE3-BU Sciences (315552104) / SudocSudocFranceF