2,606 research outputs found
L\'evy processes with marked jumps I : Limit theorems
Consider a sequence (Z_n,Z_n^M) of bivariate L\'evy processes, such that Z_n
is a spectrally positive L\'evy process with finite variation, and Z_n^M is the
counting process of marks in {0,1} carried by the jumps of Z_n. The study of
these processes is justified by their interpretation as contour processes of a
sequence of splitting trees with mutations at birth. Indeed, this paper is the
first part of a work aiming to establish an invariance principle for the
genealogies of such populations enriched with their mutational histories. To
this aim, we define a bivariate subordinator that we call the marked ladder
height process of (Z_n,Z_n^M), as a generalization of the classical ladder
height process to our L\'evy processes with marked jumps. Assuming that the
sequence (Z_n) converges towards a L\'evy process Z with infinite variation, we
first prove the convergence in distribution, with two possible regimes for the
marks, of the marked ladder height process of (Z_n,Z_n^M). Then we prove the
joint convergence in law of Z_n with its local time at the supremum and its
marked ladder height process.Comment: 27 pages. Final version accepted for publication in Journal of
Theoretical Probabilit
L\'evy processes with marked jumps II : Application to a population model with mutations at birth
Consider a population where individuals give birth at constant rate during
their lifetimes to i.i.d. copies of themselves. Individuals bear clonally
inherited types, but (neutral) mutations may happen at the birth events. The
smallest subtree containing the genealogy of all the extant individuals at a
fixed time \tau, is called the coalescent point process. We enrich this process
with the history of the mutations that appeared over time, and call it the
marked coalescent point process. With the help of limit theorems for L\'evy
processes with marked jumps established in a previous work (arXiv:1305.6245),
we prove the convergence of the marked coalescent point process with large
population size and two possible regimes for the mutations - one of them being
a classical rare mutation regime, towards a multivariate Poisson point process.
This Poisson point process can be described as the coalescent point process of
the limiting population at \tau, with mutations arising as inhomogeneous
regenerative sets along the lineages. Its intensity measure is further
characterized thanks to the excursion theory for spectrally positive L\'evy
processes. In the rare mutations asymptotic, mutations arise as the image of a
Poisson process by the ladder height process of a L\'evy process with infinite
variation, and in the particular case of the critical branching process with
exponential lifetimes, the limiting object is the Poisson point process of the
depths of excursions of the Brownian motion, with Poissonian mutations on the
lineages.Comment: 45 pages, 6 figure
Des rituels funéraires à la fête patronale Les miroloyia, lamentations vocales et instrumentales de l’Épire, Grèce
En Épire, le terme miroloyia désigne deux types de lamentations appartenant à des contextes très différents. Les premières sont le fait des femmes qui se lamentent lors des rituels funéraires ou au quotidien en cachette des hommes, les secondes sont jouées par des musiciens tsiganes dans les fêtes patronales. L’article s’interroge sur l’articulation entre ces deux formes de miroloyia et met en évidence le rôle différencié des femmes et des hommes face à la mort. Si les femmes gèrent la mort alors qu’elle vient de surgir et s’adressent directement aux défunts, les hommes sont alors très en retrait. En revanche, c’est à l’occasion des fêtes patronales que les hommes pleurent leurs morts. Ils ne s’adressent pas directement à eux mais passent par un intermédiaire, le clarinettiste tsigane, à qui ils confient la gestion de leurs émotions.In Epirus, the word miroloyia refers to two types of laments, performed in very different circumstances. The former are women’s laments, occurring during funerary rituals or, unknown from men, in everyday life ; the latter are played by gypsy musicians during patronal feasts. This article questions the link between both types of miroloyia and shows up the differentiated roles of women and men as regards death. Women manage death when it has just happened and speak directly to the dead persons, while men stand aside. On the other hand, patronal feasts give men the opportunity to weep over their dead. They do not directly speak to them but do it through an intermediary, the gypsy clarinet player, whom they entrust with managing their emotions
Curse to Co-creation: Religious Models of Labour Pain
Until the nineteenth century when labour pain became a technical problem to be solved, such pain was given religious meaning. Christian understandings of labour pain have long been based in interpretations of key Biblical texts, beginning with Genesis 3:16 and continuing with New Testament texts, which are understood to be commentary to this primary text. This article examines the four major spiritual models of labour pain that stem from these interpretations— curse of Eve, salvific, growth and perfectionist—and charts their rise and fall. The models are not distinct but intertwine and affect each other over time. The curse model—labour pain as punishment for Eve’s disobedience—was not used on its own but was most often paired with the salvation model or growth model so that the punishment of Eve was healing or generative. Salvation and growth intertwine as well in some understandings, as a woman’s spiritual and emotional growth lead to her active role in salvation history. The perfectionist model turns the curse model on its head, as it strives for a prelapsarian state in which women will not suffer the curse of Eve. Perfectionism in this sense is a belief that one can return, in this world, to a perfect union with God, a form of divinization. In conclusion, the four models are seen to have adapted to the secular transformation of pregnancy and labour, offering a potential model comingling pain and pleasure, spirit and body
Blue frontiers: managing the environmental costs of aquaculture
The report begins with an overview of the current status of world aquaculture. It then goes on to describe an approach for estimating the current combined biophysical resource demands of aquaculture for producer countries and regions. Following a comparison of these results with those available for other animal food production sectors the report then examines the consequences of likely future trends in production on the environmental impacts of aquaculture. Finally, the policy implications of the report’s findings are discussed along with the research agenda that should be pursued to meet the challenge of sustainable food production
PARTICIPATION ET CAUSALITE SELON SAINT THOMAS D’AQUIN de Cornelio Fabro
La quête de la “Métaphysique de l’acte d’être” passe inévitablement par Cornelio Fabro. La “Bibliothèque de la Revue Thomiste”, avec le concours des éditions “Parole et Silence”, a eu la bonne idée de rééditer son maître ouvrage : Participation et causalité selon Saint Thomas d’Aquin. Je m’attendais, comme dans mes explorations précédentes chez Gilson, Mercier et autres, à découvrir un auteur didactique, plus dialecticien et historien que philosophe, pour qui les pétitions de principe pèsent peu devant la faconde des dissertations. Mais au contraire, je dois reconnaître que nous avons devant les yeux un exercice de philosophie de très grande classe, sans comparaison avec les précités. Tout le mal que j’en pourrai dire par la suite, à cause de mon tempérament atrabilaire, doit être mesuré à l’aune de ce jugement premier
Essays on the Economic and Cultural Integration of Migrants
This thesis consists of three self-contained essays. The first, entitled "Integration of Humanitarian Migrants into the Host Country Labour Market: Evidence from Australia", aims at identifying the factors that influence the labour market integration of humanitarian migrants into the host country. A number of refugees' employment outcomes are examined including access to employment, access to stable employment, the wage/earnings level and the education-occupation mismatch. Using a recently collected panel survey data in Australia, the results show that pre-migration education, work experience, previous migration episodes, as well as English proficiency, English training, study/job training undertaken in Australia and social capital form important determinants of the labour market integration of refugees. Moreover, the essay highlights the differentiated impacts of these resources on the refugees' outcomes at six months, one year and two years after arrival in Australia. This essay provides a unique basis of knowledge for informed policy-making and helps identify the ways to facilitate the economic integration of refugees. The second essay, entitled "Ethnic Identity and the Employment Outcomes of Immigrants: Evidence from France", examines the relationship between economic and social integration. More specifically, it explores the influence that ethnic identity exerts on immigrants' labour market performance in the host country. The objective of this essay is twofold: first, to determine the immigrants' ethnic identity and second, to investigate the impact of ethnic identity on the immigrants' employment outcomes. Using a rich survey data from France and relying on a polychoric principal component analysis, this essay proposes two alternative measures of ethnic identity than the ones used in the literature, namely: i) the degree of commitment to the origin country culture and ii) the extent to which the individual holds multiple identities. The essay investigates the impact of the ethnic identity measures on the employment outcomes of immigrants in France. The results show that having multiple identities is associated with an improvement in the employment outcomes of the migrants. However, when addressing the endogenous nature of ethnic identity, there is no significant impact of ethnic identity on the employment outcomes of immigrants. The last essay, entitled "The Effect of 9/11 on Immigrants' Ethnic Identity and Employment: Evidence from Germany", aims at exploring the impact of terrorism on the economic and social integration of immigrants in the host country. Indeed, over the lifecourse of the migrants in the host country, there might be a number of identity shocks that would affect their social integration. This might as well have an effect on their labour market outcomes. This chapter investigates the effect of the 9/11 terrorist attacks on the identity choice and the employment outcomes of Muslim immigrants in Germany. Using longitudinal data from the German Socio-Economic Panel, this essay relies on a difference-in-differences strategy to compare the outcomes of Muslims with non-Muslim immigrants before and after the attacks. One concern is the lack of an appropriate comparison group. In order to address this issue, the essay relies on a regression-adjusted difference-in-differences matching strategy. The results show that Muslim immigrants have decreased their degree of identification with Germany after 9/11 compared to non-Muslims. There is no significant impact of the 9/11 terrorist attacks on Muslims' employment outcomes relative to non-Muslims. The results contribute to provide a better understanding of the process of social integration of immigrants
Procédés laser-particules : décontamination et nanofabrication
Les propriétés particulières des interactions entre une impulsion laser et des particules submicrométriques apportent de nouvelles solutions dans la course à la miniaturisation. Les travaux réalisés au laboratoire LP3 intéressent plus particulièrement les applications de nettoyage extrême pour l'industrie des semi-conducteurs et participent au développement de nouvelles techniques de nanofabrication
Question disputée sur la connaissance en Dieu
Une lecture d'Aristote se rattachant à un courant de pensée averroïste conclut à l'ignorance de Dieu sur tout autre objet que Lui-même. Thomas d'Aquin affirme au contraire que Dieu, se connaissant, connaît toutes choses. Un courant actuel du néo-thomisme veut expliquer cette réponse de Thomas par le fait que Dieu connaît ce qu'il cause, or, ce qu'il cause des choses, c'est leur acte d'être. Donc Dieu connaît l'acte d'être de toutes choses.
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