168 research outputs found

    Le bipÎle objet/conduites : réflexions sur l'objectif de la sémiologie musicale

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    Les limites d'une sémiologie de la signification de l'objet musical. Le fait musical comme faisceau de conduites. Objet et conduites, une réalité à deux faces. Le bipÎle objet/conduites comme objet de la sémiologie musicale. Pertinence théorique et conduites- types. La métaphorisation. Sémiologie et psychologie.The limitations of a semiology of signification applied to music as an object. Music as a network of behaviors. Object and behavior, a two-sided reality. The bipolar phenomenon, object/behavior, as object of study within the semiology of music. Theoretical pertinence and typical behaviors Metaphorization. Semiology and psychology

    Towards an Analysis of Compositional Strategies1

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    The author is interested in the process of composing, i.e. the invention of a piece of music from the initial spark of intuition to the final product. His study is based on the “Germinal” project, an experiment in composition involving fourteen composers working with identical technical resources in computer studio 123 of the grm (Groupes de recherches musicales) in Paris in 1985. Their creations all followed a common work schedule in four stages, with each composer adopting a very personal strategy at each of these stages. Describing their strategies amounts to giving an account not only of their actions, but also of the attitudes and decisions that led from an initial project to a final product. Four levels of criteria governing the decision-making process are then proposed: technical quality, grammaticality, the musical idea and the topic. The first two conform to a search for regularity while the latter two suggest a desire for singularity. These levels determine work attitudes in relation to sound and machines, i.e., poietic attitudes. From this comparative study several strategies have emerged, three of which are explained. Finally, the author develops the concept of singularity, which is a central concern of composers, and which may also be viewed as a challenge to computers and music analysis.L’auteur s’intĂ©resse Ă  une analyse de l’acte mĂȘme de composer, ou plus gĂ©nĂ©ralement d’inventer une musique, depuis l’étincelle initiale jusqu’à l’objet fini. L’étude est basĂ©e sur le projet « Germinal », une expĂ©rience de rĂ©alisation mettant en jeu les mĂȘmes ressources du studio informatique 123 du grm (Groupe de recherches musicales) Ă  Paris avec quatorze compositeurs en 1985. Les rĂ©alisations ont toutes suivi un plan de travail commun en quatre Ă©tapes tout en empruntant, pour chaque Ă©tape, des stratĂ©gies trĂšs personnelles de composition. DĂ©crire ces stratĂ©gies revient Ă  rendre compte de l’histoire rĂ©elle non seulement des actes, mais aussi des attitudes et des dĂ©cisions qui mĂšnent d’un projet initial Ă  un objet final. L’auteur Ă©tudie ensuite les quatre niveaux de critĂšres qui prĂ©sident Ă  la prise de dĂ©cision : la qualitĂ© technique, la grammaticalitĂ©, l’idĂ©e musicale, le propos. Les deux premiers expriment la recherche de rĂ©gularitĂ© alors que les deux derniers manifestent un souci de singularitĂ©. Ces niveaux dĂ©terminent des attitudes de travail face au son et aux machines — les attitudes poĂŻĂ©tiques. De cette Ă©tude comparative se dĂ©gagent plusieurs stratĂ©gies, dont trois sont exposĂ©es. L’auteur dĂ©veloppe enfin le concept de singularitĂ©, central dans les prĂ©occupations des compositeurs, et qui constitue une sorte de dĂ©fi Ă  l’informatique et Ă  l’analyse

    Where have the rebels gone? Interview with Eric Hobsbawm

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    Fifty years after his pioneering books on rebellion and social banditry, Eric Hobsbawm explains why he always paid close attention to “uncommon people” and popular forms of revolt, and analyses how globalization has triggered off new political mobilizations

    The spectrin family of proteins: a unique coiled-coil fold for various molecular surface properties

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    International audienceThe spectrin superfamily is composed of proteins involved in cytolinker functions. Their main structural feature is a large central subdomain with numerous repeats folded in triple helical coiled-coils. Their similarity of sequence was considered to be low without detailed quantification of the intra- and intermolecular levels. Among the superfamily, we considered as essential to propose an overview of the surface properties of all the repeats of the five proteins of the spectrin family, namely α- and ÎČ-spectrins, α-actinin, dystrophin and utrophin. Therefore, the aim of this work was to obtain a quantitative comparison of all the repeats at both the primary sequence and the three-dimensional levels. For that purpose, we applied homology modelling methods to obtain structural models for successive and overlapping tandem repeats of the human erythrocyte α- and ÎČ-spectrins and utrophin, as previously undertaken for dystrophin, and we used the known structure of α-actinin. The matrix calculation of the pairwise similarities of all the repeat sequences and the electrostatic and hydrophobic surface properties throughout the protein family support the view that spectrins and α-actinin on one hand and utrophin and dystrophin on the other hand share some structural similarities, but a detailed molecular characterisation highlights substantial differences. The repeats within the family are far from identical, which is consistent with their multiple interactions with different cellular partners, including proteins and membrane lipids

    Shavenbaby Couples Patterning to Epidermal Cell Shape Control

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    It is well established that developmental programs act during embryogenesis to determine animal morphogenesis. How these developmental cues produce specific cell shape during morphogenesis, however, has remained elusive. We addressed this question by studying the morphological differentiation of the Drosophila epidermis, governed by a well-known circuit of regulators leading to a stereotyped pattern of smooth cells and cells forming actin-rich extensions (trichomes). It was shown that the transcription factor Shavenbaby plays a pivotal role in the formation of trichomes and underlies all examined cases of the evolutionary diversification of their pattern. To gain insight into the mechanisms of morphological differentiation, we sought to identify shavenbaby's downstream targets. We show here that Shavenbaby controls epidermal cell shape, through the transcriptional activation of different classes of cellular effectors, directly contributing to the organization of actin filaments, regulation of the extracellular matrix, and modification of the cuticle. Individual inactivation of shavenbaby's targets produces distinct trichome defects and only their simultaneous inactivation prevent trichome formation. Our data show that shavenbaby governs an evolutionarily conserved developmental module consisting of a set of genes collectively responsible for trichome formation, shedding new light on molecular mechanisms acting during morphogenesis and the way they can influence evolution of animal forms

    Pedagogia da criação musical hoje: partir da infĂąncia, passar pela adolescĂȘncia e ir alĂ©m

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    A criação musical, que hĂĄ setenta anos estava restrita a mĂșsicos profissionais, Ă© hoje acessĂ­vel a amadores e crianças. Esta prĂĄtica pode ser sua primeira experiĂȘncia musical e a base de um processo educacional. O estudo de estratĂ©gias composicionais mostra que no centro do processo criativo encontra-se uma “ideia musical”. O que Ă© uma “ideia musical”? Trata-se de uma singularidade sonora que atrai a atenção do mĂșsico e o incita a estendĂȘ- -la. Para estender sua descoberta, ele a repete com variaçÔes. A ideia musical – que hĂĄ um sĂ©culo era geralmente um tema ou um motivo – Ă©, nos dias de hoje, geralmente uma sonoridade particular. No entanto, repetir e variar um som distinto Ă© tĂ­pico do comportamento de exploração sonora da primeira infĂąncia, algo conhecido como “reação circular”. Assim, desde a infĂąncia, Ă© possĂ­vel encorajar um comportamento de exploração que se torna invenção, uma vez que seja intencional. Tal comportamento pode ser enriquecido pela dimensĂŁo simbĂłlica e, posteriormente, pelo gosto pela construção. A criança percorre diferentes formas de jogo, como analisado por Piaget: o jogo sensĂłrio-motor, o jogo simbĂłlico e o jogo baseado em regras. O papel do educador Ă©, entĂŁo, estimular e guiar este desenvolvimento espontĂąneo, e alguns equipamentos podem ajuda-lo. Por volta de nove ou dez anos de idade, o computador Ă© uma ferramenta conveniente para a composição

    The Hrs/Stam Complex Acts as a Positive and Negative Regulator of RTK Signaling during Drosophila Development

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    BACKGROUND: Endocytosis is a key regulatory step of diverse signalling pathways, including receptor tyrosine kinase (RTK) signalling. Hrs and Stam constitute the ESCRT-0 complex that controls the initial selection of ubiquitinated proteins, which will subsequently be degraded in lysosomes. It has been well established ex vivo and during Drosophila embryogenesis that Hrs promotes EGFR down regulation. We have recently isolated the first mutations of stam in flies and shown that Stam is required for air sac morphogenesis, a larval respiratory structure whose formation critically depends on finely tuned levels of FGFR activity. This suggest that Stam, putatively within the ESCRT-0 complex, modulates FGF signalling, a possibility that has not been examined in Drosophila yet. PRINCIPAL FINDINGS: Here, we assessed the role of the Hrs/Stam complex in the regulation of signalling activity during Drosophila development. We show that stam and hrs are required for efficient FGFR signalling in the tracheal system, both during cell migration in the air sac primordium and during the formation of fine cytoplasmic extensions in terminal cells. We find that stam and hrs mutant cells display altered FGFR/Btl localisation, likely contributing to impaired signalling levels. Electron microscopy analyses indicate that endosome maturation is impaired at distinct steps by hrs and stam mutations. These somewhat unexpected results prompted us to further explore the function of stam and hrs in EGFR signalling. We show that while stam and hrs together downregulate EGFR signalling in the embryo, they are required for full activation of EGFR signalling during wing development. CONCLUSIONS/SIGNIFICANCE: Our study shows that the ESCRT-0 complex differentially regulates RTK signalling, either positively or negatively depending on tissues and developmental stages, further highlighting the importance of endocytosis in modulating signalling pathways during development

    Categories of Resistance, Antibiosis and Tolerance, to Biotype I Greenbug (\u3ci\u3eSchizaphis graminum\u3c/i\u3e (Rondani) Homoptera: Aphididae) in Four Sorghum (\u3ci\u3eSorghum bicolor\u3c/i\u3e (L.) Moench. Poales:Gramineae) Hybrids

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    Resistance categories (antibiosis and tolerance) of four sorghum (Sorghum bicolor (L.) Moench) hybrids to biotype I greenbug, Schizaphis graminum (Rondani), were determined in environmental growth chamber and field studies. Greenbug weight and fecundity were lower on ‘Cargill 607E’ compared with ‘Cargill 797’. Percentage of leaf damage area was significantly less on two resistant hybrids (Cargill 607E and Cargill 797) after a 14-d greenbug feeding period compared to two susceptible hybrids (‘Golden Harvest 510B’ and Garst 5715). In growth chamber studies on sorghum seedlings, ‘Cargill 607E’ and ‘Cargill 797’ reduced greenbug weight significantly compared with ‘Golden Harvest 510B’ and ‘Garst 5715’. Greenbug weight was 2.9 mg/25 greenbugs on ‘Cargill 607E’, 3.1 mg/25 greenbugs on ‘Cargill 797’, 3.9 mg/25 greenbugs on ‘Golden Harvest 510B’, and 4.8 mg/25 greenbugs on ‘Garst 5715’. On field grown sorghum plants, ‘Cargill 797’ did not reduce greenbug growth compared with ‘Golden Harvest 510B’. ‘Cargill 607E’ had a negative impact on weight of greenbugs. Greenbug weight was 7.9 mg/25 greenbugs on ‘Cargill 607E’, 9.2 mg/25 greenbugs on ‘Cargill 797’, and 10.0 mg/25 greenbugs on ‘Golden Harvest 510B’. ‘Cargill 607E’ and ‘Cargill 797’ were resistant to biotype I greenbugs compared with susceptible ‘Golden Harvest 510B’ and ‘Garst 5715’. Antibiosis was confirmed as the primary category of resistance in ‘Cargill 607E.’ ‘Cargill 797’ was primarily tolerant but may have some level of antibiosis, because smaller greenbugs developed in some of the studies

    Abnormal nociception and opiate sensitivity of STOP null mice exhibiting elevated levels of the endogenous alkaloid morphine

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    <p>Abstract</p> <p>Background-</p> <p>Mice deficient for the stable tubule only peptide (STOP) display altered dopaminergic neurotransmission associated with severe behavioural defects including disorganized locomotor activity. Endogenous morphine, which is present in nervous tissues and synthesized from dopamine, may contribute to these behavioral alterations since it is thought to play a role in normal and pathological neurotransmission.</p> <p>Results-</p> <p>In this study, we showed that STOP null brain structures, including cortex, hippocampus, cerebellum and spinal cord, contain high endogenous morphine amounts. The presence of elevated levels of morphine was associated with the presence of a higher density of mu opioid receptor with a higher affinity for morphine in STOP null brains. Interestingly, STOP null mice exhibited significantly lower nociceptive thresholds to thermal and mechanical stimulations. They also had abnormal behavioural responses to the administration of exogenous morphine and naloxone. Low dose of morphine (1 mg/kg, i.p.) produced a significant mechanical antinociception in STOP null mice whereas it has no effect on wild-type mice. High concentration of naloxone (1 mg/kg) was pronociceptive for both mice strain, a lower concentration (0.1 mg/kg) was found to increase the mean mechanical nociceptive threshold only in the case of STOP null mice.</p> <p>Conclusions-</p> <p>Together, our data show that STOP null mice displayed elevated levels of endogenous morphine, as well as an increase of morphine receptor affinity and density in brain. This was correlated with hypernociception and impaired pharmacological sensitivity to mu opioid receptor ligands.</p
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