47 research outputs found

    Removal of an obstruction from a tube by a collapsing bubble

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    The use of a collapsing bubble to clear an obstruction (in the form of a steel ball) near a tube, submerged in water, is studied with high speed photography. Tubes in horizontal and vertical configurations are studied. The bubble is generated via an electric spark discharge. The flow in the tubes resulting from the expansion of the bubble, or the high speed jet from the collapsing bubble pushes the ball away from the tubes and therefore clears the obstructions. In a case where airbacked tube is used, the bubble jets away from the tube. The resulting water plum at the hole (water-air interface) removes the blockage. The speed of the ball can be as high as 1 m/s shortly after the collapse of the bubble. Further studies are required to translate the phenomena observed to clinical applications such as the removal of blood clots in vessels or the clearing of blocked transplanted tubes..http://deepblue.lib.umich.edu/bitstream/2027.42/84282/1/CAV2009-final98.pd

    Femmes outsiders en politique

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    Les femmes sont-elles condamnĂ©es Ă  ĂȘtre des outsiders en politique, Ă©trangĂšres au groupe dominant ? Ce dossier donne une historicitĂ© au « stigmate » du genre en politique Ă  travers l’étude de trajectoires individuelles et collectives durant le XXe siĂšcle, en France mais aussi en Allemagne, en Italie ou encore en Belgique. Il en ressort que les outsiders d’hier ne sont plus les outsiders d’aujourd’hui, et que le terme, dans sa polysĂ©mie, recouvre une multiplicitĂ© de situations.  À cet Ă©gard, l’accĂšs des femmes aux droits politiques constitue une ligne de partage des eaux. Avant, ne pouvant pas voter ou ĂȘtre Ă©lues, elles sont nĂ©cessairement des outsiders dans la compĂ©tition Ă©lectorale mĂȘme si elles font de la politique autrement. AprĂšs, les femmes politiques doivent faire l’apprentissage de nouveaux rĂŽles pour passer de la marge au sommet du pouvoir. Elles dĂ©couvrent la persistance des mĂ©canismes discriminatoires dans les partis. Le fĂ©minisme dans et hors des partis contribue Ă  crĂ©er, Ă  la fin du siĂšcle, un climat plus favorable. Dans ce nouveau contexte – quotas, paritĂ© –, les femmes politiques dĂ©veloppent des stratĂ©gies de lĂ©gitimation particuliĂšres et leurs identitĂ©s de genre, de classe, de race ou de sexualitĂ© peuvent s’articuler pour freiner leurs carriĂšres ou au contraire les accĂ©lĂ©rer

    Introduction

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    Les femmes sont-elles condamnĂ©es Ă  ĂȘtre des outsiders en politique, Ă©trangĂšres au groupe dominant ? Ce dossier donne une historicitĂ© au « stigmate » du genre en politique Ă  travers l’étude de trajectoires individuelles et collectives durant le XXe siĂšcle, en France mais aussi en Allemagne, en Italie ou encore en Belgique. Il en ressort que les outsiders d’hier ne sont plus les outsiders d’aujourd’hui, et que le terme, dans sa polysĂ©mie, recouvre une multiplicitĂ© de situations. À cet Ă©gard, l’accĂšs des femmes aux droits politiques constitue une ligne de partage des eaux. Avant, ne pouvant pas voter ou ĂȘtre Ă©lues, elles sont nĂ©cessairement des outsiders dans la compĂ©tition Ă©lectorale mĂȘme si elles font de la politique autrement. AprĂšs, les femmes politiques doivent faire l’apprentissage de nouveaux rĂŽles pour passer de la marge au sommet du pouvoir. Elles dĂ©couvrent la persistance des mĂ©canismes discriminatoires dans les partis. Le fĂ©minisme dans et hors des partis contribue Ă  crĂ©er, Ă  la fin du siĂšcle, un climat plus favorable.Dans ce nouveau contexte – quotas, paritĂ© –, les femmes politiques dĂ©veloppent des stratĂ©gies de lĂ©gitimation particuliĂšres et leurs identitĂ©s de genre, de classe, de race ou de sexualitĂ© peuvent s’articuler pour freiner leurs carriĂšres ou au contraire les accĂ©lĂ©rer

    Histoire des femmes dans la France des XIXe et XXe siĂšcles

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    Les recherches rĂ©centes mettent en Ă©vidence les femmes comme objets du regard ou de la politique, et montrent les femmes comme sujets, actrices de l\u27histoire, actives dans tous les domaines de la vie publique. ConfinĂ©es dans la vie privĂ©e par l\u27idĂ©ologie dominante qui les veut Ă©pouses, mĂšres et mĂ©nagĂšres, les femmes sont en effet, qu\u27elles le veuillent ou non, mĂȘlĂ©es Ă  toutes les Ă©volutions de la sociĂ©tĂ© française au fil des XIXe et XXe siĂšcles. Cette pĂ©riode les voit conquĂ©rir de nouveaux droits, revendiquer l\u27Ă©galitĂ© et l\u27indĂ©pendance, se libĂ©rer de nombreux tabous
 Une rĂ©volution fĂ©ministe s\u27accomplit, Ă  travers l\u27accĂšs Ă  l\u27Ă©ducation, au droit de vote, sans oublier la maĂźtrise de la fĂ©conditĂ©. Si l\u27ouvrage dessine une « condition fĂ©minine » en Ă©volution, il montre aussi l\u27hĂ©tĂ©rogĂ©nĂ©itĂ©, la diversitĂ© des statuts, des appartenances sociales, culturelles
 CentrĂ© sur les femmes, dans leur diversitĂ©, il est aussi une histoire du genre attentive aux rapports de pouvoir entre les sexes, Ă  la domination masculine et Ă  la fabrique du fĂ©minin et du masculin

    Vascular Endothelial Growth Factor-Related Pathways in Hemato-Lymphoid Malignancies

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    Angiogenesis is essential for malignant tumor growth. This has been documented for solid tumors, and there is an emerging evidence suggesting that tumor progression of hematolymphoid malignancies also depends on the induction of new blood vessel formation. The most important proangiogenic agent is vascular endothelial growth factor (VEGF), activating VEGF receptors 1 and 2. The available data on angiogenesis in hemato-lymphoid malignancies, such as acute leukemias, myelodysplastic syndromes, myeloproliferative neoplasms, multiple myeloma, and lymphomas, point towards the significance of autocrine and paracrine VEGF-mediated effects for proliferation and survival of leukemia/lymphoma cells in addition to tumor vascularization. Antiangiogenic strategies have become an important therapeutic modality for solid tumors. Several antiangiogenic agents targeting VEGF-related pathways are also being utilized in clinical trials for the treatment of hemato-lymphoid malignancies, and in some instances these pathways have emerged as promising therapeutic targets. This review summarizes recent advances in the basic understanding of the role of angiogenesis in hemato-lymphoid malignancies and the translation of such basic findings into clinical studies

    Neural noise distorts perceived motion: the special case of the freezing illusion and the Pavard and Berthoz effect

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    When a slowly moving pattern is presented on a monitor which itself is moved, the pattern appears to freeze on the screen (Mesland and Wertheim in Vis Res 36(20):3325–3328, 1996) even if we move our head with the monitor, as with a head mounted display (Pavard and Berthoz in Perception 6:529–540, 1977). We present a simple model of these phenomena, which states that the perceived relative velocity between two stimuli (the pattern and the moving monitor) is proportional to the difference between the perceived velocities of these stimuli in space, minus a noise factor. The latter reflects the intrinsic noise in the neural signals that encode retinal image velocities. With noise levels derived from the literature the model fits empirical data well and also predicts strong distortions of visually perceived motion during vestibular stimulation, thus explaining both illusions as resulting from the same mechanism

    Middleborns disadvantaged? testing birth-order effects on fitness in pre-industrial finns

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    Parental investment is a limited resource for which offspring compete in order to increase their own survival and reproductive success. However, parents might be selected to influence the outcome of sibling competition through differential investment. While evidence for this is widespread in egg-laying species, whether or not this may also be the case in viviparous species is more difficult to determine. We use pre-industrial Finns as our model system and an equal investment model as our null hypothesis, which predicts that (all else being equal) middleborns should be disadvantaged through competition. We found no overall evidence to suggest that middleborns in a family are disadvantaged in terms of their survival, age at first reproduction or lifetime reproductive success. However, when considering birth-order only among same-sexed siblings, first-, middle-and lastborn sons significantly differed in the number of offspring they were able to rear to adulthood, although there was no similar effect among females. Middleborn sons appeared to produce significantly less offspring than first-or lastborn sons, but they did not significantly differ from lastborn sons in the number of offspring reared to adulthood. Our results thus show that taking sex differences into account is important when modelling birth-order effects. We found clear evidence of firstborn sons being advantaged over other sons in the family, and over firstborn daughters. Therefore, our results suggest that parents invest differentially in their offspring in order to both preferentially favour particular offspring or reduce offspring inequalities arising from sibling competition
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