Search results for "Lag"
showing 10 items of 3124 documents
Principes généraux d'évaluation/gestion du risque des matériaux au contact des denrées alimentaires
2017
International audience; Les matériaux au contact des denrées alimentaires (MCDA) jouent un rôle incontournable en matière de conservation et de protection des aliments. Cependant, des substances de l'emballage (monomères, additifs) peuvent migrer dans les aliments. Ainsi, pour être aptes au contact alimentaire, les MCDA ne doivent pas libérer des substances en une quantité qui pourrait mettre en danger la santé humaine ou modifier les caractères organoleptiques et la composition des aliments : c'est le principe d'inertie du Règlement no 1935/2004 du Parlement européen et du Conseil sur les MCDA. De plus, une réglementation harmonisée au niveau européen existe pour certains matériaux (cas de…
Sentinel-1 & Sentinel-2 Data for Soil Tillage Change Detection
2018
In this paper, an algorithm using Sentinel-1 (S-1) and Sentinel-2 (S-2) data to identify changes of tillage over agricultural fields at approximately similar to 100m resolution is presented. The methodology implements a multiscale temporal change detection on S-1 VH backscatter in order to single out VH changes due to agricultural practices only. The algorithm can be applied over bare or scarcely vegetated agricultural fields, which are identified from S-2 NDVI measurements. An initial assessment at farm scale using in situ and S-1 and SPOT5-Take5 data, acquired over the Apulian Tavoliere in southern Italy in 2015, is illustrated. A full validation of the approach is in progress over three …
Transition vers des systèmes agricole et agroalimentaire durables : quelle place et qualification pour les légumineuses à graines ?
2017
Cet article propose une analyse historique du processus de verrouillage du système agroalimentaire en défaveur des légumineuses à graines, à l’aune des théories évolutionnistes. Plusieurs mécanismes d’autorenforcement permettent de comprendre pourquoi ces espèces sont de moins en moins cultivées en France face à un système agro-industriel qui s’est spécialisé en faveur des céréales, favorisant à l’amont l’usage d’engrais azotés de synthèse et limitant à l’aval les investissements pour les légumineuses en alimentation humaine. Cet article s’interroge alors sur les perspectives de déverrouillage.
De la maison au " village" . Les origines de la morphologie de l'habitat dispersé dans les montagnes de la Savoie du nord
2002
Dans les hautes vallées savoyardes, le peuplement d'avant l'invasion touristique était caractérisé par une implantation en hameaux dispersés à travers le territoire communal. Dispersion relative en Savoie du sud (Maurienne, Tarentaise, Combe de Savoie) où les hameaux étaient fédérés par un « chef-lieu » qui était un véritable bourg ; dispersion fréquemment absolue en Savoie du nord (Faucigny, Chablais), où le chef-lieu n'avait souvent pas plus d'importance que les écarts. C'est aux massifs mo...
2012
Hunter-gatherers living in Europe during the transition from the late Pleistocene to the Holocene intensified food acquisition by broadening the range of resources exploited to include marine taxa. However, little is known on the nature of this dietary change in the Mediterranean Basin. A key area to investigate this issue is the archipelago of the Egadi Islands, most of which were connected to Sicily until the early Holocene. The site of Grotta d’Oriente, on the present-day island of Favignana, was occupied by hunter-gatherers when Postglacial environmental changes were taking place (14,000-7,500 cal BP). Here we present the results of AMS radiocarbon dating, palaeogenetic and isotopic ana…
Learning from the past in the COVID-19 era: rediscovery of quarantine, previous pandemics, origin of hospitals and national healthcare systems, and e…
2020
Abstract After the dramatic coronavirus outbreak at the end of 2019 in Wuhan, Hubei province, China, on 11 March 2020, a pandemic was declared by the WHO. Most countries worldwide imposed a quarantine or lockdown to their citizens, in an attempt to prevent uncontrolled infection from spreading. Historically, quarantine is the 40-day period of forced isolation to prevent the spread of an infectious disease. In this educational paper, a historical overview from the sacred temples of ancient Greece—the cradle of medicine—to modern hospitals, along with the conceive of healthcare systems, is provided. A few foods for thought as to the conflict between ethics in medicine and shortage of personne…
Lièvre et lapin à Regourdou (Montignac-sur-Vézère, Dordogne, France) : études paléontologique et taphonomique de deux accumulations osseuses d’origin…
2015
Since the end of the nineteenth century, a great deal of work studyingsubsistence patterns of prehistoric societies in Western Europe has been done. During the Middle Paleolithic, humanswere interested in small game, particularly the Leporidae, taxa that were abundant in their territories. However,distinguishing the exact nature of their origin in an archaeological site is not an easy task, given that numerous agentscould be responsible for their accumulation (i.e., natural mortality, acquisition by humans and/or other terrestrialcarnivores, or even nocturnal or diurnal raptors). In this contribution, we put forth a new taphonomic and paleontologicalstudy of the leporids of Regourdou, a Mou…
Microplastic incorporation into soil in agroecosystems
2017
Background: We live in a plastic age (Thompson et al., 2009), with microplastic (typically defined as plastic particles < 5 mm) becoming an increasingly appreciated aspect of environmental pollution. Research has been overwhelmingly focused on aquatic systems, especially the oceans, but there is a current shift to more strongly consider terrestrial ecosystems (Rillig, 2012; Horton et al., 2017). In particular agroecosystems are coming into focus as a major entry point for microplastics in continental systems (Nizzetto et al., 2016b), where contamination might occur via different sources as sludge amendment or plastic mulching (Steinmetz et al., 2016). Given the central role of agroecosystem…
The intensity contrast of solar photospheric faculae and network elements : II. Evolution over the rising phase of solar cycle 23
2006
We studied the radiative properties of small magnetic elements (active region faculae and the network) during the rising phase of solar cycle 23 from 1996 to 2001, determining their contrasts as a function of heliocentric angle, magnetogram signal, and the solar cycle phase. We combined near-simultaneous full disk images of the line-of-sight magnetic field and photospheric continuum intensity provided by the MDI instrument on board the SOHO spacecraft. Sorting the magnetogram signal into different ranges allowed us to distinguish between the contrast of different magnetic structures. We find that the contrast center-to-limb variation (CLV) of these small magnetic elements is independent of …
Análisis de la función de los espacios culturales en la redefinición de las políticas culturales de las ciudades. Un estudio de los casos de las área…
2021
Esta tesis aborda la relación entre los espacios culturales y las políticas culturales, específicamente en el ámbito urbano. Concretamente, en este proyecto de investigación argumentamos, en primer lugar, que las políticas culturales urbanas y las políticas de creación de espacios culturales están regidas por una misma lógica se articulan en un todo funcional al paradigma dominante de política cultural (en la que los espacios culturales son a la vez derivada y condición del modelo de democratización cultural). En segundo lugar, sostenemos que los espacios culturales son la clave de bóveda de las políticas de democratización cultural, en tanto que constituyen la herramienta principal de su m…