Nondestructive Evaluation of Fatigue Damage on Steels using Magnetic Techniques

In many cases, where a high reliability is demanded, such as in nuclear power plants or civil engineering structures, steel components are subject to fatigue damage. The possibility of nondestructively assessing this damage would thus be of great interest, especially in order to evaluate the remaining lifetime and the point when the risk of failure becomes too important.</p

Nondestructive Evaluation of Fatigue Damage on Steels using Magnetic Techniques

In many cases, where a high reliability is demanded, such as in nuclear power plants or civil engineering structures, steel components are subject to fatigue damage. The possibility of nondestructively assessing this damage would thus be of great interest, especially in order to evaluate the remaining lifetime and the point when the risk of failure becomes too important.</p

Genetic isolation and characterization of a splicing mutant of zebrafish dystrophin

Sapje-like (sapcl100) was one of eight potential zebrafish muscle mutants isolated as part of an early-pressure screen of 500 families. This mutant shows a muscle tearing phenotype similar to sapje (dys−/−) and both mutants fail to genetically complement suggesting they have a mutation in the same gene. Protein analysis confirms a lack of dystrophin in developing sapje-like embryos. Sequence analysis of the sapje-like dystrophin mRNA shows that exon 62 is missing in the dystrophin transcript causing exon 63 to be translated out of frame terminating translation at a premature stop codon at the end of exon 63. Sequence analysis of sapje-like genomic DNA identified a mutation in the donor splice junction at the end of dystrophin exon 62. This mutation is similar to splicing mutations associated with human forms of Duchenne Muscular Dystrophy. Sapje-like is the first zebrafish dystrophin splicing mutant identified to date and represents a novel disease model which can be used in future studies to identify therapeutic compounds for treating diseases caused by splicing defects

CX3CR1 deficiency promotes muscle repair and regeneration by enhancing macrophage ApoE production

International audienceMuscle injury triggers inflammation in which infiltrating mononuclear phagocytes are crucial for tissue regeneration. The interaction of the CCL2/CCR2 and CX3CL1/CX3CR1 chemokine axis that guides phagocyte infiltration is incompletely understood. Here, we show that CX3CR1 deficiency promotes muscle repair and rescues Ccl2 (-/-) mice from impaired muscle regeneration as a result of altered macrophage function, not infiltration. Transcriptomic analysis of muscle mononuclear phagocytes reveals that Apolipoprotein E (ApoE) is upregulated in mice with efficient regeneration. ApoE treatment enhances phagocytosis by mononuclear phagocytes in vitro, and restores phagocytic activity and muscle regeneration in Ccl2 (-/-) mice. Because CX3CR1 deficiency may compensate for defective CCL2-dependant monocyte recruitment by modulating ApoE-dependent macrophage phagocytic activity, targeting CX3CR1 expressed by macrophages might be a powerful therapeutic approach to improve muscle regeneration

Le Mal et ses masques

Le « mal », impensé collectif, prend corps au gré de diverses représentations mythiques, poétiques, graphiques, musicales. Sorcières, guérisseuses, Machiavels, Antéchrists, voire bestiaire infernal, incarnent au théâtre ou dans la littérature pamphlétaire des xvie et xviie siècles ces « agents du diable » censés rendre visibles les dangers de l'invisible, mais que seuls leurs masques permettent de démasquer. La « diabolisation » de l'adversaire politique autorise une «chasse aux sorcières» qui n'a rien de métaphorique, mais au théâtre comme sur la scène politique, elle permet aussi la mise en évidence des jeux pervers du discours, le mal aux prises avec les mots, masque de l' « équivoque » qui ne parle pas seulement par la voix des sorcières comme dans Macbeth, mais inscrit l'ambivalence, menace de dévotement, comme mal au cœur de tout discours. L'ambivalence contient en elle la parodie, qui ne retient de l'invisible que le risible, mais elle permet aussi toutes les ruses de l'imaginaire pour surmonter les traumatismes du corps et de l'esprit, comme chez Graves ou Coleridge. Le théâtre lyrique, « chant des Enfers », témoigne aussi de cette « double voix ». Divertissement entre éthique et esthétique avec Purcell, ou affrontement idéologique entre choeurs des opprimés et chœurs des oppresseurs chez Haendel, il peut aussi prendre le relais du tragique : l'amalgame sensationnel, « théâtral », entre les monstres des enfers païens et l'enfer chrétien prive ce lieu par excellence du mal de toute référence métaphysique, pour mieux isoler comme nouveau « mal » le seul malheur de la passion trop humaine. L'enfer traditionnel se réduit à ses propres représentations parodiques, combien moins angoissantes que l'ontologie infernale proposée dans le Faust de Marlowe, égale à la contingence de l'être-là sans lieu ni durée définis

Fate and effects of metal-based nanoparticles in two marine invertebrates, the bivalve mollusc Scrobicularia plana and the annelid polychaete Hediste diversicolor

The objective of this paper is to synthesize results from seven published research papers employing different experimental approaches to evaluate the fate of metal-based nanoparticles (Ag NPs, Au NPs, CuO NPs, CdS NPs, ZnO NPs) in the marine environment and their effects on two marine endobenthic species, the bivalve Scrobicularia plana and the ragworm Hediste diversicolor. The experiments were carried out under laboratory (microcosms) conditions or under environmentally realistic conditions in outdoor mesocosms. Based on results from these seven papers, we addressed the following research questions: (1) How did the environment into which nanoparticles were released affect their physicochemical properties?, (2) How did the route of exposure (seawater, food, sediment) influence bioaccumulation and effects?, (3) Which biomarkers were the most responsive? and (4) Which tools were the most efficient to evaluate the fate and effects of NPs in the marine environment? The obtained results showed that metal-based NPs in general were highly agglomerated/aggregated in seawater. DGT tools could be used to estimate the bioavailability of metals released from NPs under soluble form in the aquatic environment. Both metal forms (nanoparticulate, soluble) were generally bioaccumulated in both species. Among biochemical tools, GST and CAT were the most sensitive revealing the enhancement of anti-oxidant defenses in both species exposed to sub-lethal concentrations of metal-based NPs. Apoptosis and genotoxicity were frequently observed.</p