847 research outputs found
Homeownership of Immigrants in France: Selection Effects Related to International Migration Flows
We investigate the difference in homeownership rates between natives and first-generation immigrants in France, and how this difference evolves over the 1975-1999 period, by using a large longitudinal dataset. We find that the homeownership gap is large and has increased. Entries into the territory have a large negative effect on the evolution of homeownership rates for immigrants. Although entrants have on average better education than people staying in the territory for the entire period (i.e. stayers), they are younger and thus at an earlier stage in the wealth accumulation process. They are also located in large cities, where the homeownership rate is lower, and the returns to their characteristics are lower than those for stayers. Leavers have a positive effect on the evolution of homeownership rates for immigrants because they have a low access to homeownership and they exit the country. But this effect is only one-third that of entrants. For stayers, we show that returns to characteristics change in favor of immigrants, which is consistent with assimilation theories. However, among stayers who access homeownership, immigrants end up in owned dwellings that are of lesser quality than natives
A new Coniopterygidae from Lebanese amber
We describe the oldest fossil Coniopterygidae, possibly attributable to the Coniopteryginae, in the new genus and species Libanosemidalis hammanaensis, from the outcrop Hammana / Mdeyrij in the Lower Cretaceous amber of Lebanon. This fossil shares with the extant and Cenozoic lineages of Coniopterygidae the presence of only two M branches, unlike other Cretaceous representatives of the family
A new Coniopterygidae from Lebanese amber
We describe the oldest fossil Coniopterygidae, possibly attributable to the Coniopteryginae, in the new genus and species Libanosemidalis hammanaensis, from the outcrop Hammana / Mdeyrij in the Lower Cretaceous amber of Lebanon. This fossil shares with the extant and Cenozoic lineages of Coniopterygidae the presence of only two M branches, unlike other Cretaceous representatives of the family.We describe the oldest fossil Coniopterygidae, possibly attributable to the Coniopteryginae, in the new genus and species Libanosemidalis hammanaensis, from the outcrop Hammana / Mdeyrij in the Lower Cretaceous amber of Lebanon. This fossil shares with the extant and Cenozoic lineages of Coniopterygidae the presence of only two M branches, unlike other Cretaceous representatives of the family
Ocean and climate changes in polar and sub-polar environments: proceedings from the 2010 IODP-Canada/ECORD summer school
The European Consortium for Ocean Drilling Program (ECORD), the Canadian Consortium for Ocean Drilling (CCOD), the Network of the Universités du Québec (UQ), the Université du Québec à Montréal (UQAM) and GEOTOP sponsored, in 2010, a summer school entitled Ocean and climate changes in polar and sub-polar environments. This summer school took place from 27 June to 12 July in Rimouski, Québec city and Montréal (Quebec, Canada) and was attended by nineteen students and postdoctoral fellows from seven countries: Canada, France, Germany, UK, Serbia, Portugal and the USA. Lectures, hands-on laboratory exercises and laboratory visits were conducted at the Institut des Sciences de la Mer de Rimouski (ISMER), Institut National de la Recherche Scientifique Centre Eau Terre Environnement (INRS-ETE) and UQAM, in addition to two field trips and a short geological and geophysical cruise on board the R/V Coriolis II in the St Lawrence Estuary and Saguenay Fjord. During the summer school, more than twenty researchers gave lectures on the use of several paleoceanographic and geophysical techniques to reconstruct ocean and climate changes in polar and sub-polar environments. Some of these lectures are presented as short review papers in this volume. They are intended to portray a brief, but state-of-the-art overview of an array of techniques applied to Arctic and sub-Arctic environments, as well as the geological background information needed by the summer school participants to put the scientific expedition and fieldwork into context. The volume begins with a view on the great challenges and key issues to be addressed in the Arctic Ocean (Stein) in the forthcoming years and is followed by a review (O'Regan) on Late Cenozoic paleoceanography of the Central Arctic. The two subsequent papers (St-Onge et al and de Vernal et al) deal with the oceanographic, paleoceanographic and geological context of the Saguenay Fjord, and St Lawrence Estuary and Gulf. The subsequent set of papers review the use of planktonic foraminifers (Eynaud), diatoms (Crosta) and dinocysts (de Vernal and Rochon) in polar or sub-polar environments. These articles are followed by a paper on transfer functions (Guiot) summarizing the different approaches used to reconstruct past environmental conditions from micropaleontological proxy data. Two papers on geochemical and isotopic proxies are then presented and related to either foraminifera isotopic records (Hillaire-Marcel) in high northern latitudes or changes in ocean circulation and weathering inputs derived from radiogenic isotopes (Frank). The volume concludes with a paper on the application of visible/near infrared derivative spectroscopy to Arctic sediments (Ortiz). All the papers published in this volume benefited from the reviews of at least two reviewers, whom we thank for their valuable time and comments. We also thank the crew of the Coriolis II, and the many scientists, participants and volunteers who contributed to the summer ..
Totum et totalitas dans la première école franciscaine
La totalité n’est-elle que réduction à l’Un et sclérose de la pensée ? Pour Alexandre de Halès et saint Bonaventure, la totalité bien comprise n’est pas incompatible avec une multiplicité réelle et favorise à la fois la consistance ontologique et l’intelligibilité de celle-ci. À partir d’une réflexion sur le « tout parfait » (Aristote) et le « tout de puissances » (Boèce), Alexandre forge un concept de totalité compatible avec la présence d’immensité divine et même, dans le cas de Bonaventure, avec l’infinité et la simplicité de Dieu. Apparaît ainsi une conception hospitalière de la totalité, qui rejaillit sur la cosmologie et l’anthropologie.Is totality nothing but reduction to the One and (therefore) intellectual sclerosis? For Alexander of Hales and St Bonaventure, not only is there no logical incompatibility between “totality” (totalitas) properly understood and multiplicity but the former gives ontological consistency and intelligibility to the latter. Starting from a reflection on Aristotle’s totum perfectum and Boethius’ totum potentiarum, Alexander develops a concept of totality that is compatible with the immensity of God’s presence and, following Bonaventure, even with divine infinity and simplicity. The result is a broad and hospitable conception of totality with ramifications in cosmology and anthropology
Conception, réalisation et mise en oeuvre d'un scintillomètre : influence de la vapeur d'eau dans la bande 940nm
L'atmosphère et la surface terrestre interagissent en permanence par le biais des échanges d'énergie et de matière. Ces flux jouent un rôle important dans l'étude de l'hydrologie des surfaces ou de l'écologie terrestre, ou bien encore l'étude des phénomènes météorologiques et climatiques. En effet, ils représentent les conditions aux limites des différents compartiments du système Terre et la quantification de ces échanges à différentes échelles spatiales est indispensable pour les modèles de prévision. Les mesures de flux d'énergie sont très répandues pour des mesures très localisées, in situ et au sol. Cependant, peu d'instruments de mesures permettent d'obtenir des flux intégrés sur des distances de l'ordre de la centaine de mètres à quelques kilomètres, c'est-à-dire des distances correspondant à la représentativité des pixels des images satellitaires. On compte parmi eux les scintillomètres, instrument de mesure optique, permettant de calculer les flux intégrés de chaleur sensible à partir des mesures de paramètres caractérisant l'intensité turbulente de l'atmosphère tels que le paramètre de structure de l'indice de réfraction de l'air Cn². La présence de vapeur d'eau dans l'atmosphère peut cependant perturber le signal de ces instruments. L'objectif de ce travail est le développement et la mise en oeuvre d'un scintillomètre optique permettant de mettre en évidence la contribution de l'absorption par la vapeur d'eau sur les scintillations. Les études menées à partir du développement instrumental ne s'orienteront qu'autour de la bande d'absorption à 940nm, longueur d'onde d'émission de certains scintillomètres LAS (Large Aperture Scintillometer). Au début de ma thèse, un prototype de scintillomètre, type LAS, a été conçu de façon à maitriser complètement la technologie : partie optique électronique et le traitement du signal reçu. Celui-ci a ensuite été installé au-dessus d'un site de cultures dans les environs de Toulouse, au cours des années 2007 et 2008. Les résultats obtenus avec ce prototype ont permis d'optimiser le choix de la méthode de calcul H à partir du Cn², en fonction du rapport de Bowen (rapport du flux de chaleur sensible sur le flux de chaleur latente). Les variations de l'intensité lumineuse de l'onde, menant au Cn², sont principalement dues à des effets de réfraction et de dispersion, maissont aussi sensibles à l'absorption de la vapeur d'eau. Afin de quantifier l'influence de 'absorption sur le signal Cn², j'ai utilisé 2 approches : une première approche par filtrage numérique (‘Gabor Transform'), et une seconde, par méthode chromatique. Cette dernière a nécessité de modifier considérablement le système optique du prototype LAS. Les résultats obtenus expérimentalement montrent que la contribution de l'absorption à la mesure du Cn² est en moyenne assez faible, mais qu'elle peut prendre de forte valeur, principalement lors de faibles flux H. La quantification de l'absorption par méthode hromatique est pour l'instant limité au développement technique de l'instrument. ABSTRACT : Atmosphere, soil and vegetation are in interactions by the bias of energetic or matter exchanges. This latters have an important impact on hydrology, ecology, meteorology. Actually, they represent the boundary conditions of the Earth-Atmosphere system. Then, the quantification of these exchanges or fluxes is necessary to understand large scales phenomena and to improve forecasting models. Numerous devices are able to quantify these fluxes at local scales, but few are available to measure them over kilometres, which mean at the resolution of remote sensing datas. Amongst them, we can notice the scintillometers that are able to calculate sensible heat fluxes over distances from hundred meters to few kilometres. Actually, these devices are sensitive to variations of the refractive index of air, mainly due to turbulent eddies, defined by the structure parameter of refractive index : Cn². However, this measurement can be altered by the presence of water vapour in the air. Thus, the aim of this work is to design and make a scintillometer which is able to quantify the water vapour contribution on the Cn² measurement. In this thesis, we will focus on this contribution in the 940nm band which is the wavelength of various scintillometers LAS (Large Aperture Scintillometers). At the beginning of my PhD thesis, un scintillometer prototype has been realised in order to master the technology : optics, electronics, signal processing…This latter has been set up over crops at a few kilometres from Toulouse, between 2007 and 2008. Thanks to the results of this scintillometer, we optimize the choice on the Cn² to H algorithm, according to the Bowen ratio β (ratio of sensible to latent heat flux). Variations of the light beam, leading to the Cn², are mainly due to refraction and dispersion effect. However, absorption can be important. In order to quantify the contribution of absorption on the Cn², 2 methods are suggested : one based on signal processing aspect (Gabor filtering), and the second one on two wavelengths propagation. To realize this latter the optics and electronics of the device have been really modified. Results show that absorption contribution is small, but can be important for low H values. Finally, the quantification of absorption by two wavelengths approach is nowadays bounded to instrumental development
Juegos didácticos para mejorar la expresión oral del idioma inglés en estudiantes de una institución educativa privada, 2021
La presente investigación titulada juegos didácticos para mejorar la expresión oral
del idioma inglés en estudiantes de una institución educativa privada 2021, tuvo
como objetivo general establecer la influencia de la aplicación de juegos didácticos
en la mejora de la expresión oral del idioma inglés en estudiantes de una institución
educativa, 2021. El enfoque fue cuantitativo de tipo básica de nivel explicativo y
diseño cuasi experimental. La muestra estuvo conformada por 63 estudiantes de
segundo de secundaria, con dos grupos uno de control (33 estudiantes) y otro
experimental (30 estudiantes) seleccionados mediante un muestreo no
probabilístico intencional.
Los resultados mostraron que, en el pretest del grupo experimental, el
90.91% de estudiantes obtuvo calificaciones en inicio, el 9.09%, en proceso,
ninguno en logro esperado ni logro destacado y en el post test del grupo
experimental 3.33% presentan calificaciones de nivel en inicio, 60% en proceso,
30.33% en logro esperado y el 3.33% en calificaciones de logro destacado en la
expresión oral. La investigación concluyó, que el juego influye significativamente en
la expresión oral del idioma inglés en estudiantes de una institución educativa
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