High-Contrast OLEDs with High-Efficiency

Peer reviewed: YesNRC publication: Ye

Les outils pour acquérir et transformer la matière ligneuse dans les chaînes opératoires techniques des artisanats forestiers en Provence et Haut-Dauphiné au Moyen Âge

International audienceThe interweaving of historical (charters and notarial sources, literary sources, iconography), archaeological and ethnoarchaeological data focuses on three major questions : how are tools made partially from wood made to work this same material, how can they be identified and recognized in technical processes, and what are the technical gestures used . The results underline the great variability in the way of using the same Tools in different stages of different technical processes. Technical innovation and intensive change in craft production during the late Middle Ages is also discussed.Le croisement des données historiques (actes de la ratique, littérature savante, iconographie), archéologiques et thnoarchéologiques s'organise autour de trois questions principales : celle de la fabrication même des outils qui sont façonnés pro parte dans la matière qu'ils ont vocation à travailler, le bois ; celle de l'identification des outils et de leur mise en oeuvre dans les chaînes opératoires techniques liées à l'acquisition et à la transformation de la matière ligneuse et enfin celle des gestes techniques. Les résultats soulignent une grande polyvalence des outils qui interviennent à des stades précis d'opérations de chaînes différentes. La question de l'innovation technique et de l'" industrialisation " au Bas Moyen Âge est abordée

Une mine de plomb argentifère dans un environnement montagnard : la mine médiévale du Fournel à L'Argentière-la-Bessée (Hautes-Alpes)

National audienceLa mine d'argent du Fournel a été en activité entre le Xe et le XIVe siècle. Les textes conservés concernent la phase de maturité du XIIe siècle et la phase de ralentissement du milieu du XIIIe siècle. Plusieurs panneaux filoniens ont été exploités à partir d'affleurements, depuis des escarpements rocheux abrupts, jusqu'au fond d'une gorge. La grande dureté de la roche a obligé les mineurs à recourir à l'abattage par le feu. Le relief a grandement facilité la prospection des filons, le démarrage de chantiers à ciel ouvert et l'organisation des exploitations souterraines. Les chantiers s'étendent jusqu'à 150 m du jour et sont assistés par des niveaux de circulation par traînage, des conduits d'aérage perchés en hauteur et des galeries de drainage ouvertes à la base. Ces ouvrages d'assistance reflètent une organisation opportuniste de la mine, facilitée par la topographie et la géologie du gisement. L'analyse sédimentologique et anthracologique des remblais, associée à des expérimentations sérielles, permet de caractériser la chaîne opératoire technique de l'abattage par le feu et son impact sur les modalités de gestion de la forêt arborescente d'altitude, comprimée entre les activités agropastorales et minières

De l'usage minier du feu : sources et expérimentations

Éditeur scientifique : Aline DurandNational audienceL'abattage par le feu est auréolé de mystères en raison de son caractère séculaire et archaïque . Les découvertes récentes liées au développement des méthodes de l'archéologie minière lèvent le voile. Or, des questions restent toujours posées notamment concernant la technique et la pratique du travail par le feu sous terre, son évolution, et ses conséquences sur l'architecture des ouvrages, la morphologie et la composition des déblais, l'organisation du travail et la gestion de la forêt. Cet article qui n'a pas la prétention d'être exhaustif sur la diversité des sources et des outils utilisés pour nourrir cette problématique, a pour objectif de dégager les traits forts d'une approche pluridisciplinaire située au croisement des sciences humaines et de l'environnement, pour accéder à des notions de mode opératoire, de systèmes techniques et d'adaptation - réaction entre les mineurs et leur environnement

Grabbing Water

We introduce a novel technique for grabbing water with a flexible solid. This new passive pipetting mechanism was inspired by floating flowers and relies purely on the coupling of the elasticity of thin plates and the hydrodynamic forces at the liquid interface. Developing a theoretical model has enabled us to design petal-shaped objects with maximum grabbing capacity

Une mine de plomb argentifère dans un environnement montagnard

La mine d’argent du Fournel a été en activité entre le xe et le xive siècle. Les textes conservés concernent la phase de maturité du xiie siècle et la phase de ralentissement du milieu du xiiie siècle. Plusieurs panneaux filoniens ont été exploités à partir d’affleurements, depuis des escarpements rocheux abrupts, jusqu’au fond d’une gorge. La grande dureté de la roche a obligé les mineurs à recourir à l’abattage par le feu. Le relief a grandement facilité la prospection des filons, le démarrage de chantiers à ciel ouvert et l’organisation des exploitations souterraines. Les chantiers s’étendent jusqu’à 150 m du jour et sont assistés par des niveaux de circulation par traînage, des conduits d’aérage perchés en hauteur et des galeries de drainage ouvertes à la base. Ces ouvrages d’assistance reflètent une organisation opportuniste de la mine, facilitée par la topographie et la géologie du gisement. L’analyse sédimentologique et anthracologique des remblais, associée à des expérimentations sérielles, permet de caractériser la chaîne opératoire technique de l’abattage par le feu et son impact sur les modalités de gestion de la forêt arborescente d’altitude, comprimée entre les activités agropastorales et minières.The Fournel silver mine was in operation between the tenth and fourteenth century. The extant texts concern the twelfth century mature phase and the mid-thirteenth century slowdown. Several vein panels were exploited from outcroppings, in steep rocky cliffs, to the bottom of a gorge. Because of the extreme hardness of the rock, the miners used firesetting. The topography of the site greatly facilitated vein exploration, initiating opencast sites and mine organisation. The stopes stretch up to 150 m from daylight, and were assisted by access levels by sledge, high perched ventilation ducts and drainage adits open to base level. These works reflect an opportunist support organisation in the mine, facilitated by relief and deposit geology. Sedimentological analysis of backfill and the use of anthracology associated with serial experiments, enable characterisation of the operative chain techniques of firesetting and its impact on high altitude forest management up to tree level, between the higher pastures and the mines

Trade-offs between foraging efficiency and pup feeding rate of lactating northern fur seals in a declining population

Foraging strategies and their resulting efficiency (energy gain to cost ratio) affect animals’ survival and reproductive success and can be linked to population dynamics. However, they have rarely been studied quantitatively in free-ranging animals. We investigated foraging strategies and efficiencies of wild northern fur seals Callorhinus ursinus during their breeding season to understand potential links to the observed population decline in the Bering Sea. We equipped 20 lactating females with biologgers to determine at-sea foraging behaviours. We measured energy expenditure while foraging using the doubly-labelled water method, and energy gained using (1) the types and energy densities of prey consumed, and (2) the number of prey capture attempts (from acceleration data). Our results show that seals employed 2 foraging strategies: one group (40%) fed mostly in oceanic waters on small, high energy-density prey, while the other (60%) stayed over the shallow continental shelf feeding mostly on larger, lower quality fish. Females foraging in oceanic waters captured 3 times more prey, and had double the foraging efficiencies of females that foraged on-shelf in neritic waters. However, neritic seals made comparatively shorter trips, and likely fed their pups ~20 to 25% more frequently. The presence of these strategies which either favor foraging efficiency (energy) or frequency of nursing (time) might be maintained in the population because they have similar net fitness outcomes. However, neither strategy appears to simultaneously maximize time and energy allocated to nursing, with potential impacts on the survival of pups during their first year at sea

From Understanding Cellular Function to Novel Drug Discovery: The Role of Planar Patch-Clamp Array Chip Technology

All excitable cell functions rely upon ion channels that are embedded in their plasma membrane. Perturbations of ion channel structure or function result in pathologies ranging from cardiac dysfunction to neurodegenerative disorders. Consequently, to understand the functions of excitable cells and to remedy their pathophysiology, it is important to understand the ion channel functions under various experimental conditions – including exposure to novel drug targets. Glass pipette patch-clamp is the state of the art technique to monitor the intrinsic and synaptic properties of neurons. However, this technique is labor intensive and has low data throughput. Planar patch-clamp chips, integrated into automated systems, offer high throughputs but are limited to isolated cells from suspensions, thus limiting their use in modeling physiological function. These chips are therefore not most suitable for studies involving neuronal communication. Multielectrode arrays (MEAs), in contrast, have the ability to monitor network activity by measuring local field potentials from multiple extracellular sites, but specific ion channel activity is challenging to extract from these multiplexed signals. Here we describe a novel planar patch-clamp chip technology that enables the simultaneous high-resolution electrophysiological interrogation of individual neurons at multiple sites in synaptically connected neuronal networks, thereby combining the advantages of MEA and patch-clamp techniques. Each neuron can be probed through an aperture that connects to a dedicated subterranean microfluidic channel. Neurons growing in networks are aligned to the apertures by physisorbed or chemisorbed chemical cues. In this review, we describe the design and fabrication process of these chips, approaches to chemical patterning for cell placement, and present physiological data from cultured neuronal cells

Neuroprotective Effect of Inhaled Nitric Oxide on Excitotoxic-Induced Brain Damage in Neonatal Rat

BACKGROUND: Inhaled nitric oxide (iNO) is one of the most promising therapies used in neonates. However, little information is known about its impact on the developing brain submitted to excitotoxic challenge. METHODOLOGY/PRINCIPAL FINDINGS: We investigated here the effect of iNO in a neonatal model of excitotoxic brain lesions. Rat pups and their dams were placed in a chamber containing 20 ppm NO during the first week of life. At postnatal day (P)5, rat pups were submitted to intracranial injection of glutamate agonists. At P10, rat pups exposed to iNO exhibited a significant decrease of lesion size in both the white matter and cortical plate compared to controls. Microglia activation and astrogliosis were found significantly decreased in NO-exposed animals. This neuroprotective effect was associated with a significant decrease of several glutamate receptor subunits expression at P5. iNO was associated with an early (P1) downregulation of pCREB/pAkt expression and induced an increase in pAkt protein concentration in response to excitotoxic challenge (P7). CONCLUSION: This study is the first describe and investigate the neuroprotective effect of iNO in neonatal excitotoxic-induced brain damage. This effect may be mediated through CREB pathway and subsequent modulation of glutamate receptor subunits expression