L’obra de Guillaume de Machaut en el Manuscrit Mòdena, Biblioteca Estense, a.M.5.24

Entre finals del segle XIV i principis del XV es data la redacció del Manuscrit Mòdena, Biblioteca Estense, .M.5.24, un dels principals manuscrits del moment que han arribat als nostres dies, essent un element culminant pel que fa a penetració de l’art polifònic francès a la Itàlia d’inicis del ‘400. En ell es copien quatre peces de Guillaume de Machaut i l’únic poema de l’autor francès musicat per un altre compositor. En els treballs sobre el manuscrit molt sovint s’obvien aquestes quatre peces, i l’estudi sobre Machaut es fa quasi exclusivament des de les fonts franceses. Aquest treball pretén respondre, sobretot, a dues preguntes: Què ens poden explicar aquestes peces sobre el procés d’afrancesament de la música italiana? Què ens poden explicar sobre la difusió de l’obra de Machaut pel vell continent?

A Characterization of single-peaked preferences

We identify in this paper two conditions that characterize the domain of single-peaked preferences on the line in the following sense: a preference profile satisfies these two properties if and only if there exists a linear order $L$ over the set of alternatives such that these preferences are single-peaked with respect L. The first property states that for any subset of alternatives the set of alternatives considered as the worst by all agents cannot contains more than 2 elements. The second property states that two agents cannot disagree on the relative ranking of two alternatives with respect to a third alternative but agree on the (relative) ranking of a fourth one. Classification-JEL: D71, C78

The making of international environmental agreements

We examine in this paper the formation and the stability of international environmental agreements when cooperation means to commit to a minimum abatement level. Each country decides whether to ratify the agreement and this latter enters into force only if it is ratified by a number of countries at least equal to some ratification threshold. We analyze the role played by ratification threshold rules and provide conditions for international environmental agreements to enter into force. We show that a large typology of agreements can enter into force among the one constituted by the grand coalition.

On the stability of cooperation structures

Qin [J. Eco. Th., 1996] recently showed that in a game of endogenous formation of cooperation structure, if the underlying TU-game is superadditive, then the full cooperation structure is stable. In this note, we characterize the class of games that ensure the stability of the full cooperation structure, and show that this class is much larger than that of superadditive TU-games.

Stable coalition structures with fixed decision scheme

This paper studies the stability of a finite local public goods economy in horizontal differentiation, where a jurisdiction's choice of the public good is given by an exogenous decision scheme. In this paper, we characterize the class of decision schemes that ensure the existence of an equilibrium with free mobility (that we call Tiebout equilibrium) for monotone distribution of players. This class contains all the decision schemes whose choice lies between the Rawlsian decision scheme and the median voter with mid-distance of the two median voters when there are ties. We show that for non-monotone distribution, there is no decision scheme that can ensure the stability of coalitions. In the last part of the paper, we prove the non-emptiness of the core of this coalition formation game

Constrained school choice

Recently, several school districts in the US have adopted or consider adopting the Student-Optimal Stable Mechanism or the Top Trading Cycles Mechanism to assign children to public schools. There is clear evidence that for school districts that employ (variants of) the so-called Boston Mechanism the transition would lead to efficiency gains. The first two mechanisms are strategy-proof, but in practice student assignment procedures impede students to submit a preference list that contains all their acceptable schools. Therefore, any desirable property of the mechanisms is likely toget distorted. We study the non trivial preference revelation game where students can only declare up to a fixed number (quota) of schools to be acceptable. We focus on the stability of the Nash equilibrium outcomes. Our main results identify rather stringent necessary and sufficient conditions on the priorities to guaranteestability. This stands in sharp contrast with the Boston Mechanism which yields stable Nash equilibrium outcomes, independently of the quota. Hence, the transition to any of the two mechanisms is likely to come with a higher risk that students seek legal actionas lower priority students may occupy more preferred schools.

Constrained school choice: an experimental study

The literature on school choice assumes that families can submit a preference list over all the schools they want to be assigned to. However, in many real-life instances families are only allowed to submit a list containing a limited number of schools. Subjects' incentives are drastically affected, as more individuals manipulate their preferences. Including a safety school in the constrained list explains most manipulations. Competitiveness across schools play an important role. Constraining choices increases segregation and affects the stability and efficiency of the final allocation. Remarkably, the constraint reduces significantly the proportion of subjects playing a dominated strategy.

Anàlisi de la controvèrsia L'Hôpital - Bernoulli

El 1696 el Marquès de L'Hôpital publicà el primer tractat sistemàtic sobre càlcul diferencial, l'"Analyse des infiniments petits", que es basava en les "Lectiones de calculo differentialium" de Johann Bernoulli. Però podem parlar d'aportacions originals per part de L'Hôpital? L'objectiu d'aquest treball de recerca és comparar el contingut i la forma de l'Analyse i de les Lectiones i detectar possibles influències d'altres autors per intentar, finalment, donar una resposta a aquesta qüestió.

Managing FOSS during development: preventive and curative approaches

Today, most software development teams use free and open source software (FOSS) components, because it increases the speed and the quality of the development. Many open source components are the de facto standard of their category. However, FOSS has licensing restrictions, and corporate organizations usually maintain a list of allowed and forbidden licenses. But how do you enforce this policy? How can you make sure that ALL files in your source depot, either belong to you, or fit your licensing policy? A first, preventive approach is to train and increase the awareness of the development team to these licensing issues. Depending on the size of the team, it may be costly but necessary. However, this does not ensure that a single individual will not commit a forbidden icon or library, and jeopardize the legal status of the whole release... if not the company, since software is becoming more and more a critical asset. Another approach is to verify what is included in the source repository, and check whether it belongs to the open-source world. This can be done on-the-fly, whenever a new file is added into the source depot. It can also be part of the release process, as a verification step before publishing the release. In both cases, there are some tools and databases to automate the detection process. We will present the various options regarding FOSS detection, how this process can be integrated in the "software factory", and how the results can be displayed in a usable and efficient way.

Reflexiones acerca de Les cinquante francs de Jeannette, de Ducrai-Duminil

L'article se propose d'analyser le role de quelques éléments-clé du conte, et leur valeur symbolique, dont le voyage, élément qui implique dans tous les cas la cloture d'une période et l'inauguration d'une autre. L'argent, image obsessionelle dans presque tous les contes de Ducrai-Duminil. Le culte du travail, pris en excuse pour le développement d'une activité frénétique, dans le but de permettre un déploiement énergétique seul capable. semble-t-il, d'ouvrir une voie de fuite contre la dégradation du temps chronologique, contre le statisme, tentation méphistophéleenne, toujours annonciatrice de la mort.

Reinforcement versus Fluidization in Cytoskeletal Mechanoresponsiveness

Every adherent eukaryotic cell exerts appreciable traction forces upon its substrate. Moreover, every resident cell within the heart, great vessels, bladder, gut or lung routinely experiences large periodic stretches. As an acute response to such stretches the cytoskeleton can stiffen, increase traction forces and reinforce, as reported by some, or can soften and fluidize, as reported more recently by our laboratory, but in any given circumstance it remains unknown which response might prevail or why. Using a novel nanotechnology, we show here that in loading conditions expected in most physiological circumstances the localized reinforcement response fails to scale up to the level of homogeneous cell stretch; fluidization trumps reinforcement. Whereas the reinforcement response is known to be mediated by upstream mechanosensing and downstream signaling, results presented here show the fluidization response to be altogether novel: it is a direct physical effect of mechanical force acting upon a structural lattice that is soft and fragile. Cytoskeletal softness and fragility, we argue, is consistent with early evolutionary adaptations of the eukaryotic cell to material properties of a soft inert microenvironment.