996 research outputs found
Analysis of Mathieu Equation Stable Solutions in the First Zone of Stability
No full textAbstractThe paper presents the results of a homogeneous Mathieu equation studies. Mathieu equation solutions are oscillations, modulated in amplitude and frequency. In the computational experiments we found dependences of the given oscillations on the ratio of the coefficients. These dependences are shown in graphs that can be used for an approximate estimation of the Mathieu equation solutions without integration
Pensar las escalas para pensar las luchas: Autor: Mathieu UHEL
No full textA través de un título sugerente, “pensar las escalas para pensar las luchas”, Mathieu Uhel entreteje la construcción teórico-crítica del concepto escala, generada por la geografía radical anglosajona de finales del siglo XX, con la necesidad/utilidad práctica de la escala para concienciar las luchas sociales. El artículo cumple un doble propósito: por un lado, delinear los elementos de lectura sobre el concepto escala; y, con ello, promover la atención de esta problemática en las luchas contemporáneas. En un primer apartado, Uhel ubica las discusiones académicas en torno a la escala, como herramienta metodológica útil para comprender la complejidad de las sociedades capitalistas; en el segundo apartado, el autor avanza la exposición en torno al contexto de la dimensión escalar del imperialismo capitalista; finalmente, el autor se centra en el rol de la actividad política a escala nacional en la tensa relación entre las imposiciones del capital y la lucha social.Por meio de um título sugestivo, “pensando escalas para pensar lutas”, Mathieu Uhel entrelaça a construção teórico-crítica do conceito de escala, gerado pela geografia radical anglo-saxônica do final do século XX, com a necessidade / utilidade prática escala para aumentar a consciência das lutas sociais. O artigo tem um duplo propósito: por um lado, delinear os elementos de leitura sobre o conceito de escala; e, com isso, promover atenção a esse problema nas lutas contemporâneas. Na primeira seção, Uhel localiza as discussões acadêmicas em torno da escala, como uma ferramenta metodológica útil para compreender a complexidade das sociedades capitalistas; na segunda seção, o autor avança a exposição em torno do contexto da dimensão escalar do imperialismo capitalista; por fim, o autor enfoca o papel da atividade política em escala nacional na tensa relação entre as imposições do capital e a luta social.Mathieu Uhel\u27s suggestive title, “Thinking about scales to think about struggles”, he interweaves the theoretical-critical construction of concept scale, generated by radical Anglo-Saxon geography in the late 20th century, with it´s practical utility to social struggles. The article serves two purposes: on the one hand, Uhel locates academic discussion around scale; and, with this, he promotes attention to this problem in contemporary struggles. In the first section, Uhel locates academic discussions around scale, as a useful methodological tool to understand the complexity of capitalist societies; in the second section, the author advances the argument around the context of the scalar dimension of capitalist imperialism; finally, the author focuses on the role of political activity on a national scale in the tense relationship between the impositions of capital and the social movement
Mathieu Ichou, Les Enfants d’immigrés à l’école
No full textIt is common to hear in the fields of educational and immigration sociology that on average, the children of immigrants do not perform as well in school as children of native-born parents. Mathieu Ichou offers an innovative sociological analysis on a topic that is heavily exploited by political and media discourse, and subject to much scientific controversy. The author takes distance from the homogenized vision of a “second generation” of students who have totally failed academically, and rep..
Synthèse de nanoparticules mésoporeuses de silice et encapsulation du cisplatine en vue du ciblage des traitements de chimiothérapie anticancéreuse
Get PDFThe aim of this PhD thesis is to elaborate mesoporous silica nanoparticles (MSNs) able to sustain the release of cisplatin into the intracellular compartments of solid tumors. The parametric study shows that morphological, structural and textural properties of MSNs-MCM-41, synthesized by sol-gel reaction by using TEOS as a silica source and CTAB as a structure-directing agent, depend on pH, stirring speed, temperature and extraction process of CTAB. The synthesis atmosphere has to be controlled in order to avoid the presence of ethanol and carbonate species which are responsible of necks between particles generating unstable suspensions of MSNs.MSNs were functionalized in order to control the interactions between cisplatin and MSNs or to improve their colloidal stability in physiological media.Various silanated organic molecules (APTES, TESP, MPTES, CEST) and neutral or ionised polymers were grafted into the MSNs using a co-condensation approach or a postsynthetic functionalization method while keeping structural and textural properties of MSNs unchanged.The amount of cisplatin encapsulated by using impregnation are higher than those obtained by using adsorption and depend on MSNs fonctionalization. MSNs grafted by PEI allow a sustained drug release and cytotoxic effects similar to cisplatin. In vitro assays show that MSNs devoid of cisplatin are not cytotoxic up to 200 µg/mL. Confocal microscopy study reveals that MSNs internalization is efficient after about 2h of contact with cells.L’objectif de cette thèse est de développer des nanoparticules mésoporeuses de silice (MSNs) capables de libérer un anticancéreux, le cisplatine, dans le milieu intracellulaire de tumeurs solides. Une étude paramétrique montre que les propriétés morphologiques, structurales et texturales des MSNs de type MCM-41, synthétisées par voie sol-gel à partir d’un mélange d’un précurseur de silice (TEOS) et de tensioactif (CTAB), dépendent du pH, de la vitesse d’agitation, de la température et du mode d’extraction du CTAB. La synthèse doit avoir lieu sous atmosphère contrôlée pour éviter la présence en solution d’ions carbonates et d’éthanol à l’origine de ponts entre les particules qui altèrent la stabilité colloïdale des MSNs.Les MSNs ont été fontionnalisées pour contrôler l’affinité chimique du cisplatine pour la surface des MSNs et pour améliorer la stabilité colloïdale des MSNs en milieu physiologique. Des organosilanes (APTES, TESP, MPTES, CEST) et des polymères neutres ou ionisés (PEG, PEI) ont été ajoutés par co-condensation ou par greffage post synthèse tout en préservant les propriétés structurales et texturales des MSNs. Les quantités de cisplatine encapsulées par imprégnation sont plus élevées que par adsorption et dépendent de la fonctionnalisation des MSNs. Les MSNs greffées en surface par la PEI permettent une libération progressive de l’anticancéreux ainsi qu’une cytotoxicité comparable à celle du cisplatine administré seul.Des tests in vitro montrent que les MSNs en l’absence de cisplatine ne présentent pas d’effet cytotoxique jusqu’à une concentration de 200 µg/mL. Une étude par microscopie confocale montre une internalisation des MSNs à partir de 2h de mise en contact avec les cellules
Synthesis of mesoporous silica nanoparticles (MSNs) and encapsulation of cisplatin for targeted cancer therapies
No full textL’objectif de cette thèse est de développer des nanoparticules mésoporeuses de silice (MSNs) capables de libérer un anticancéreux, le cisplatine, dans le milieu intracellulaire de tumeurs solides. Une étude paramétrique montre que les propriétés morphologiques, structurales et texturales des MSNs de type MCM-41, synthétisées par voie sol-gel à partir d’un mélange d’un précurseur de silice (TEOS) et de tensioactif (CTAB), dépendent du pH, de la vitesse d’agitation, de la température et du mode d’extraction du CTAB. La synthèse doit avoir lieu sous atmosphère contrôlée pour éviter la présence en solution d’ions carbonates et d’éthanol à l’origine de ponts entre les particules qui altèrent la stabilité colloïdale des MSNs.Les MSNs ont été fontionnalisées pour contrôler l’affinité chimique du cisplatine pour la surface des MSNs et pour améliorer la stabilité colloïdale des MSNs en milieu physiologique. Des organosilanes (APTES, TESP, MPTES, CEST) et des polymères neutres ou ionisés (PEG, PEI) ont été ajoutés par co-condensation ou par greffage post synthèse tout en préservant les propriétés structurales et texturales des MSNs. Les quantités de cisplatine encapsulées par imprégnation sont plus élevées que par adsorption et dépendent de la fonctionnalisation des MSNs. Les MSNs greffées en surface par la PEI permettent une libération progressive de l’anticancéreux ainsi qu’une cytotoxicité comparable à celle du cisplatine administré seul.Des tests in vitro montrent que les MSNs en l’absence de cisplatine ne présentent pas d’effet cytotoxique jusqu’à une concentration de 200 µg/mL. Une étude par microscopie confocale montre une internalisation des MSNs à partir de 2h de mise en contact avec les cellules.The aim of this PhD thesis is to elaborate mesoporous silica nanoparticles (MSNs) able to sustain the release of cisplatin into the intracellular compartments of solid tumors. The parametric study shows that morphological, structural and textural properties of MSNs-MCM-41, synthesized by sol-gel reaction by using TEOS as a silica source and CTAB as a structure-directing agent, depend on pH, stirring speed, temperature and extraction process of CTAB. The synthesis atmosphere has to be controlled in order to avoid the presence of ethanol and carbonate species which are responsible of necks between particles generating unstable suspensions of MSNs.MSNs were functionalized in order to control the interactions between cisplatin and MSNs or to improve their colloidal stability in physiological media.Various silanated organic molecules (APTES, TESP, MPTES, CEST) and neutral or ionised polymers were grafted into the MSNs using a co-condensation approach or a postsynthetic functionalization method while keeping structural and textural properties of MSNs unchanged.The amount of cisplatin encapsulated by using impregnation are higher than those obtained by using adsorption and depend on MSNs fonctionalization. MSNs grafted by PEI allow a sustained drug release and cytotoxic effects similar to cisplatin. In vitro assays show that MSNs devoid of cisplatin are not cytotoxic up to 200 µg/mL. Confocal microscopy study reveals that MSNs internalization is efficient after about 2h of contact with cells
L'impatto dell'attività tintoria sull'ambiente. Firenze alla fine del Medioevo
No full textThe author aims to examine and categorize the range of dyeings materials used in the Florentine wool and silk textile industries in the late Middle Ages, focusing mainly on those produced within the regional space in order to evaluate the impact of the Florentine dyeing activity on the natural environment and the productive landscape of the Tuscan countryside. In particular, the author establishes a line of demarcation between cultivated and uncultivated resources in order to verify which constitutes an indication of the level of industrial development of medieval textile production. This further focuses on how the transition from the exploitation of wild resources to the exploitation of cultivated resources could reflect a greater degree of economic integration between the countryside and the city and contribute to the formation of a regional economic space
Mathieu de Fossey: su visión del mundo indígena mexicano
No full textThroughout these pages the author shows how Mathieu de Fossey perceived that it was not easy to make indigenous communities fit within the mould of the nation-state which, being based on the liberal and egualitarian ideology, was against the recognition of special regimes, such as those that created a peculiar status for the native population of the American territory during the period of Spanish colonial domination
Mathieu de Fossey: su visión del mundo indígena mexicano
No full textÀ travers ces pages, l’auteur montre comment Mathieu de Fossey avait perçu la difficulté d’insérer le monde des communautés indigènes dans le moule d’un État national qui, accroché à une idéologie libérale égalitaire, refusait d’établir des régimes spéciaux comparables à ceux qui, durant la domination espagnole, avaient reconnu un statut particulier aux populations natives du continent américain.A través de estas páginas se muestra cómo Mathieu de Fossey percibió el difícil acoplamiento del mundo de las comunidades indígenas en el molde de un Estado nacional que, por estar sustentado en la ideología liberal igualitaria, era contrario al reconocimiento de regímenes especiales como los que, durante la dominación española, habían establecido un status peculiar para los aborígenes del territorio americano.Throughout these pages the author shows how Mathieu de Fossey perceived that it was not easy to make indigenous communities fit within the mould of the nation-state which, being based on the liberal and egualitarian ideology, was against the recognition of special regimes, such as those that created a peculiar status for the native population of the American territory during the period of Spanish colonial domination
Investigation of documents persistency on the Web
No full text@inproceedings{CI-Lancieri-2004-2, author = {Lancieri, Luigi and Lecouvey, Mathieu and Glasse, Veronique}, title = {Investigation of documents persistency on the Web}, booktitle = {International conference E-Society 2004 (ES2004), IADIS}, year = {2004}, address = {Spain} }International audienc
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