A three-thousand-year history of vegetation and human impact in Burgundy (France) reconstructed from pollen and non-pollen palynomophs analysis

International audienceThis article presents a 241 cm long sediment record documenting the vegetation history using previous termpollen and non-pollennext term palynomorphs recovered from the Fénay marsh in Burgundy (Dijon area – previous termFrance). The pollen and non-pollennext term palynomorphs (NPP) record largely reflects intensive human influence (clearing, cultivation and grazing) on the surrounding area from the Late Bronze Age and Hallstatt period. La Tène period is marked by drier conditions and a substantial increase in Alnus. During the Gallo-Roman period, high values of Alnus decrease to the benefit of Quercus. In the Early Middle Ages (5th–10th C), the swamp becomes a temporary pond and Cerealia type and Secale are cultivated in this very open landscape. During the Late Middle Ages (13th–15th C), the temporary pond is transformed into a larger and deeper pond, used by the Cistercians for hydraulic power and perhaps as a hemp-retting pit. By the end of the 16th C, the pond had dried out and was used for the cultivation of cereal

The two-phase formation history of spiral galaxies traced by the cosmic evolution of the bar fraction

We study the evolution of galactic bars and the link with disk and spheroid formation in a sample of zoom-in cosmological simulations. Our simulation sample focuses on galaxies with present-day stellar masses in the 10^10-10^11 Msun range, in field and loose group environments, with a broad variety of mass growth histories. In our models, bars are almost absent from the progenitors of present-day spirals at z>1.5, and they remain rare and generally too weak to be observable down to z~1. After this characteristic epoch, the fractions of observable and strong bars raise rapidly, bars being present in 80% of spiral galaxies and easily observable in two thirds of these at z<0.5. This is quantitatively consistent with the redshift evolution of the observed bar fraction. Our models predict that the decrease in the bar fraction with increasing redshift should continue with a fraction of observable bars <10-15% in disk galaxies at z>1. Our models also predict later bar formation in lower-mass galaxies, in agreement with existing data. We find that the characteristic epoch of bar formation, namely redshift z~0.8-1, corresponds to the epoch at which today's spirals acquire their disk-dominated morphology. At higher redshift, disks tend to be rapidly destroyed by mergers and gravitational instabilities and rarely develop significant bars. The bar formation epoch corresponds to the transition between an early "violent" phase of spiral galaxy formation at z>1 and a late "secular" phase at z<0.8. In the secular phase, the presence of bars substantially contributes to the growth of the bulge, but the bulge mass budget remains statistically dominated by the contribution of mergers, interactions and disk instabilities at high redshift. Early bars at z>1 are often short-lived, while most of the bars formed at z<1 persist down to z=0, late cosmological gas infall being necessary to maintain some of them.Comment: 15 pages, 15 figures, ApJ accepte

Numerical study of a sinusoidal transverse propeller

In order to obtain higher propulsion efficiency for marine transportation, the authors have numerically tested a novel trochoidal propeller using a sinusoidal blade pitch function. The main results presented here are the evaluation of thrust and torque, as well as the calculated hydrodynamic efficiency, for various absolute advance coefficients. The performance of the present sinusoidal-pitch trochoidal propeller is compared with previous analytical calculations of transverse propeller performances. Calculations for the trochoidal propeller are performed using a two-dimensional model. The numerical calculation is used to optimize the foil pitch function in order to achieve the highest efficiency for a given geometry and operational parameters. Foil-to-foil interactions are also studied for multiple-foil propellers to determine the effects of the blade number on the hydrodynamic efficienc

The James Webb Space Telescope Mission

Twenty-six years ago a small committee report, building on earlier studies, expounded a compelling and poetic vision for the future of astronomy, calling for an infrared-optimized space telescope with an aperture of at least $4m$. With the support of their governments in the US, Europe, and Canada, 20,000 people realized that vision as the $6.5m$ James Webb Space Telescope. A generation of astronomers will celebrate their accomplishments for the life of the mission, potentially as long as 20 years, and beyond. This report and the scientific discoveries that follow are extended thank-you notes to the 20,000 team members. The telescope is working perfectly, with much better image quality than expected. In this and accompanying papers, we give a brief history, describe the observatory, outline its objectives and current observing program, and discuss the inventions and people who made it possible. We cite detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space Telescope Overview, 29 pages, 4 figure

A História da Alimentação: balizas historiográficas

Os M. pretenderam traçar um quadro da História da Alimentação, não como um novo ramo epistemológico da disciplina, mas como um campo em desenvolvimento de práticas e atividades especializadas, incluindo pesquisa, formação, publicações, associações, encontros acadêmicos, etc. Um breve relato das condições em que tal campo se assentou faz-se preceder de um panorama dos estudos de alimentação e temas correia tos, em geral, segundo cinco abardagens Ia biológica, a econômica, a social, a cultural e a filosófica!, assim como da identificação das contribuições mais relevantes da Antropologia, Arqueologia, Sociologia e Geografia. A fim de comentar a multiforme e volumosa bibliografia histórica, foi ela organizada segundo critérios morfológicos. A seguir, alguns tópicos importantes mereceram tratamento à parte: a fome, o alimento e o domínio religioso, as descobertas européias e a difusão mundial de alimentos, gosto e gastronomia. O artigo se encerra com um rápido balanço crítico da historiografia brasileira sobre o tema

Maladie de Crohn (traitements et prise en charge thérapeutique)

LILLE2-BU Santé-Recherche (593502101) / SudocSudocFranceF

Structures industrielles locales et formes d'organisation économique

[eng] Local industrial structures and forms of economic organisation categories: regions with low industrial density, regions with high industrial density dominated by supra-regional groups, and regions with substantial industrial density with : implications of regionally based units. The industrial organisation of the French regions depends on industrial density and the way in which businesses are structured: their size, whether they are part of a group, and, if so, the nationality and regional base of the group to which they belong. A summary typology of the industrial organisation of French employment areas can be drawn up based on industrial density, the weight and type of groups established locally (foreign groups, French groups with, national coverage and French groups with regional coverage) and the proportion of independent SMEs and very small independent enterprises. This typologys contains twelve classes grouped into three main From 1989 to 1996, industrial employment generally fell sharply in the regions dominated by both foreign groups and national groups and the dense, multiform regions. The dense industrial structures dominated by regional groups,however, were less vulnerable to this downturn. The employment areas with a high density of independent SMEs suffered from adverse sector positioning although they were the least vulnerable to the fall in industrial employment. [fre] Structures industrielles locales et formes L'organisation industrielle des territoires dépend de la densité industrielle mais aussi de la façon dont sont turées les entreprises : leur taille, leur dépendance ou non à un groupe, la nationalité et la territorialité de l'éventuel , groupe auquel l'entreprise appartient. . d'organisation économique On peut dresser une typologie synthétique de l'organisation industrielle des zones d'emploi françaises en fonction de la densité industrielle, du poids et du type de groupes présents localement (groupes étrangers, groupes français à déploiement national ou groupes français à déploiement régional) et la part représentée par les PME indépendantes - ou les très petites entreprises indépendantes. Cette typologie s'articule en douze classes qui se regroupent en trois grandes catégories : les territoires à faible densité industrielle, les territoires à forte densité industrielle dominés par des groupes supra-régionaux et les territoires à densité industrielle importante avec implications d'unités à ancrage régional. Les territoires dominés à la fois par des groupes étrangers et des groupes nationaux, ainsi que les territoires denses et multiformes ont connu en moyenne une baisse importante de l'emploi industriel sur la période 1989-1996. Par contre les structures industrielles denses dominées par des groupes régionaux ont mieux résisté. Quant aux zones d'emploi à densité forte de PME indépendantes, elles souffrent d'un positionnement sectoriel défavorable tout en résistant mieux à la baisse de l'emploi industriel. [spa] Estructuras industriales locales y formas de organizaciôn econômica. La organizaciôn industrial de los territorios dépende de la densidad industrial y también de cômo estân estructuradas las empresas :su tamarïo, el depender o no de un grupo, la nacionalidad y la territorialidad del eventual grupo al que la empresa pertenezca. Se puede establecer una tipologîa sintética de la organizaciôn industrial de las zonas de empleo francesas segûn la densidad industrial, el peso y el tipo de grupos localmente présentes (grupos extranjeros, grupos franceses de despliegue nacional o grupos de despliegue regional) y la proporciôn de pymes y de muy pequerïas empresas independientes. Esta tipologia se reparte en doce tipos que forman très grandes categorfas : los territorios de poca densidad industrial, los territorios dedominados por unos grupos supraregionales y los territorios de densidad industrial importante con implicaciones de unidades de anclaje regional, Los territorios dominados a la vez por unos grupos extranjeros y grupos nacionales, y los territorios densos y multiformes han sufrido en un promedio una baja importante del empleo industrial en el periodo 1989-1996. En cambio, las estructuras industriales densasdominadas por unos grupos régionales se han mantenido. En cuanto a las zonas de empleo de fuerte densidad en pymes independientes, estas tienen un posicionamiento sectorial desfavorable pero se resisten mejor a una baja del empleo industrial. [ger] Lokale Industriestrukturen und wirtschaftliche Organisationsformen Fur das industrielle Gefuge der Gebiete ist die Industriedichte, aber auch die Art der Strukturierung der Unternehmen ausschlaggebend, d. h. ihre Grôfîe, ihre etwaige Abhàngigkeit von einer Gruppe, ihre Nationalitàt und der Standort der Gruppe, der das Unternehmen môglicherweise angehôrt. Erstellen lâ(3t sich eine synthetische Typologie des industriel len Gefûges in den franzôsischen Beschàftigungszonen entsprechend der Industriedichte, der Bedeutung und der Art der vor Ort angesiedelten Gruppen (auslàndische Gruppen, franzôsische Gruppen mit landesweiter Ausrichtung oder franzôsische Gruppen mit lokaler Ausrichtung) und der Anzahl der unabhângigen KMU und der sehr kleinen unabhângigen Unternehmen. Eine solche Typologie umfaBt zwôlf Klassen, die drei gro(3e Kategorien bilden: die Gebiete mit geringer Industriedichte, die Gebiete mit starker Industriedichte, die von ûberregionalen Gruppen beherrscht werden, sowie die Gebiete mit bedeutender Industriedichte, die auf die regional ansàssigen Einheiten Auswirkungen hat. Die Gebiete, die sowohl von auslândischen als auch von nationalen Gruppen beherrscht werden, sowie die dicht besiedelten und vielgestaltigen Gebiete verzeichneten im Durchschnitt einen bedeutenden Abbau der Industriearbeitsplâtze im Zeitraum von 1989-1996. Dagegen widerstanden die dichten Industriestrukturen, die von regionalen Gruppen beherrscht werden, dieser Entwicklung besser. Was die Beschàftigungszonen mit zahlreichen unabhângigen KMU anbelangt, so leiden sie unter einer ungùnstigen sektoralen Positionierung, wobei sie gleichzeitig dem Abbau von Industriearbeitsplàtzen besser widerstehen.