Palynologie et lithostratigraphie du Pléistocène du site de Donnacona, vallée du Saint-Laurent, Québec

À Donnacona, une séquence de sédiments non glaciaires est intercalée entre un complexe glaciaire inférieur et le Till de Gentilly. Le complexe inférieur comprend un till basal, des dépôts de marge glaciaire, un diamicton, quelques varves, un till et une rudite sommitale. La séquence intermédiaire est composée de trois unités: des silts et sables riches en débris végétaux, datés à >35 000 BP (UQ-678), des sables stratifiés et des silts massifs. L'interprétation paléoenvironnementale de la séquence tient compte du spectre et de la concentration polliniques, de la diversité taxonomique et de la nature des sédiments. Un traitement statistique met en évidence quatre palynozones. La palynologie démontre que les dépôts stratifiés intermédiaires de Donnacona sont en fait postérieurs aux Sédiments de Saint-Pierre, à l'exception d'une mince zone inférieure (palynozone Donnacona 1 à Picea et Abies dominants) corrélée au sommet des Sédiments de Saint-Pierre. Le reste de l'unité à débris organiques est attribué aux Rythmites du Saint-Maurice. Des rythmites saisonnières sont révélées par la palynologie. Le contenu pollinique (palynozone Donnacona 2) évoque une sapinière méridionale incluant des espèces thermophiles dont Tsuga et Tilia, progressivement remplacée par une pes-sière. L'unité de sables contenant les palynozones Donnacona 3 et la base de Donnacona 4 est corrélée aux Sables des Vieilles-Forges. Elle représente une détérioration climatique. L'unité sous le Till de Gentilly indique un environnement glaciolacustre contemporain d'une toundra forestière puis d'une toundra (partie supérieure de la palynozone Donnacona 4).At Donnacona, a sequence of non-glacial sediments is intercalated between a lower glacial complex and the Gentilly Till. The lower complex consists of a basal till, ice margin deposits, a diamicton, some varves, a till and an upper rudite. The intermediate stratified sequence includes three units: silt and sand with plant debris, dated at >35,000 BP (UQ-678), stratified coarse sands and a massive sift. The paleoenvironments are assessed from the pollen spectra and concentrations, the taxonomic diversity and the sedimentology. The pollen diagram is divided into four palynozones by statistical treatment. Pollen study demonstrates that the intermediate stratified deposits at Donnacona are younger than the St. Pierre Sediments, except a thin lower zone (palynozone Donnacona 1 with dominant Picea and Abies) which is correlated with the upper part of the St. Pierre Sediments. The remainder of the unit with plant debris is correlated with the Saint-Maurice Rhyth-mites. Pollen analysis revealed that this unit contains seasonal rhythmites. The pollen content (palynozone Donnacona 2) indicates that a southern Abies forest, which included thermophilous species such as Tsuga and Tilia, was gradually replaced by a Picea forest. The coarse sand unit contains the Donnacona 3 and the lower part of Donnacona 4 palynozones. It is related to the Vieilles-Forges Sands and to a climatic deterioration. The unit below Gentilly Till was deposited in a glacial lake coeval with a forest tundra and later with a tundra (upper part of palynozone Donnacona 4).Bei Donnacona ist eine Sequenz nicht glazialer Sedimente zwischen einen tieferen glazialen Komplex und die Grundmorane von Gentilly eingefugt. Der untere glaziale Komplex urnfaRt ein Basaltill, Ablagerungen von dem glazialen Saum, ein Diamikton, einige War-wen, eine Grundmorane und eine daruberliegende Rudite. Die mittlere Sequenz besteht aus drei Einheiten: Schlamm und Sand, die sehr viel pflanzliche Uberreste en-thalten und die auf > 35 000 v.u.Z. (UQ-678) datiert werden, geschichteter Sand und massiver Schlamm. Die Interpretation der Palaoumwelt der Sequenz berucksichtigt Pollen-Spektrum und -Konzentration, die Vielfalt der Systematik und der Natur der Sedimente. Eine statistische Verarbeitung hebt vier Palynozonen hervor. Die Pollen-Analyze zeigt, dafî die geschichteten mittleren Ablagerungen von Donnacona in der Tatjungerals die Sedimente von Saint-Pierre sind mit Ausnahme einer feinen unteren Zone (Palynozone Donnacona 1 mit Dominanz von Picea und Abies), die mit der Spitze der Sedimente von Saint-Pierre korreliert wird. Der Rest der Einheit mit organischen Frag-menten wird den Rythmiten von Saint-Maurice zugeordnet. Die Pollen-Analyse deckt saisonbedingte Rythmite auf. Der Pollen-Gehalt (Palynozone Donnacona 2) weist auf einen sudlichen Tannenwald, der thermophile Arten wie Tsuga und Tilia enthielt und allmâhlich durch einen Picea-Wald ersetzt wurde. Die Sandeinheit, welche die Palynozonen Donnacona 3 und die Basis von Donnacona 4 enthalt, wird mit dem Sand von Vieilles-Forges korreliert. Sie stellt eine KIi-maverschlechterung dar. Die Einheit unter der Grundmorane von Gentilly weist auf eine glaziallimnische Unwelt, die mit einer WaId-Tundra und dann einer Tundra zeitlich zusammenfiel (obérer Teil der Palynozone Donnacona 4)

Toward an Understanding of the Microstructure and Interfacial Properties of PIMs/ZIF-8 Mixed Matrix Membranes

A study integrating advanced experimental and modeling tools was undertaken to characterize the microstructural and interfacial properties of mixed matrix membranes (MMMs) composed of the zeolitic imidazolate framework ZIF-8 nanoparticles (NPs) and two polymers of intrinsic microporosity (PIM-1 and PIM-EA-TB). Analysis probed both the initial ZIF-8/PIM-1 colloidal suspensions and the final hybrid membranes. By combination of dynamic light scattering (DLS) and transmission electron microscopy (TEM) analytical and imaging techniques with small-angle X-ray scattering (SAXS), the colloidal suspensions were shown to consist mainly of two distinct kinds of particles, namely, polymer aggregates of about 200 nm in diameter and densely packed ZIF-8-NP aggregates of a few 100 nm in diameter with a 3 nm thick polymer top-layer. Such aggregates are likely to impart the granular texture of ZIF-8/PIMs MMMs as shown by SEM-XEDS analysis. At the molecular scale, modeling studies showed that the surface coverage of ZIF-8 NPs by both polymers appears not to be optimal with the presence of microvoids at the interfaces that indicates only a moderate compatibility between the polymer and ZIF-8. This study shows that the microstructure of MMMs results from a complex interplay between the ZIF-8/PIM compatibility, solvent, surface chemistry of the ZIF-8 NPs, and the physicochemical properties of the polymers such as molecular structure and rigidity

Using the community-based breeding program (CBBP) model as a collaborative platform to develop the African Goat Improvement Network—Image collection protocol (AGIN-ICP) with mobile technology for data collection and management of livestock phenotypes

Introduction: The African Goat Improvement Network Image Collection Protocol (AGIN-ICP) is an accessible, easy to use, low-cost procedure to collect phenotypic data via digital images. The AGIN-ICP collects images to extract several phenotype measures including health status indicators (anemia status, age, and weight), body measurements, shapes, and coat color and pattern, from digital images taken with standard digital cameras or mobile devices. This strategy is to quickly survey, record, assess, analyze, and store these data for use in a wide variety of production and sampling conditions.Methods: The work was accomplished as part of the multinational African Goat Improvement Network (AGIN) collaborative and is presented here as a case study in the AGIN collaboration model and working directly with community-based breeding programs (CBBP). It was iteratively developed and tested over 3 years, in 12 countries with over 12,000 images taken.Results and discussion: The AGIN-ICP development is described, and field implementation and the quality of the resulting images for use in image analysis and phenotypic data extraction are iteratively assessed. Digital body measures were validated using the PreciseEdge Image Segmentation Algorithm (PE-ISA) and software showing strong manual to digital body measure Pearson correlation coefficients of height, length, and girth measures (0.931, 0.943, 0.893) respectively. It is critical to note that while none of the very detailed tasks in the AGIN-ICP described here is difficult, every single one of them is even easier to accidentally omit, and the impact of such a mistake could render a sample image, a sampling day’s images, or even an entire sampling trip’s images difficult or unusable for extracting digital phenotypes. Coupled with tissue sampling and genomic testing, it may be useful in the effort to identify and conserve important animal genetic resources and in CBBP genetic improvement programs by providing reliably measured phenotypes with modest cost. Potential users include farmers, animal husbandry officials, veterinarians, regional government or other public health officials, researchers, and others. Based on these results, a final AGIN-ICP is presented, optimizing the costs, ease, and speed of field implementation of the collection method without compromising the quality of the image data collection

Évolution de la côte du Calvados depuis l'Éémien et découvertes d'un squelette de Cheval dans les tourbières holocènes.

International audienceWithin the fauna harvested by J. Couvelard during prospectings made during several years to Graye-sur-Mer and Asnelles (Calvados), represents a skeleton about suit of a Horse (Equus caballus), obviously Holocene. It is situated in the top of peats and clays deposited since the Preboreal so far, behind dune cords gradually pushed away towards the current line of coast during the flandrian transgression. In these swamps the marine influence is sharply marked only in the transition Subboreal-Subatlantique. Peats recover heads and weichseliens loess. On the base, a marine formation of final Eemian and peaty clays of the beginning weichselien fossilize an ancient marine platform. The skeleton of horse is contemporary of shards of pompean ceramic of the third in the fourth century AD.Au sein de la faune récoltée par J. Couvelard au cours de prospections effectuées pendant plusieurs années à Graye-sur-Mer et Asnelles (Calvados), figure un squelette à peu près complet d'un Cheval (Equus caballus), à l'évidence holocène. Il se situe dans la partie supérieure de tourbes et d'argiles déposées depuis le Préboréal jusqu'à maintenant derrière des cordons dunaires progressivement repoussés vers le trait de côte actuel pendant la transgression flandrienne. Dans ces marais l'influence marine n'est nettement marquée qu'à la transition Subboréal-Subatlantique. Les tourbes recouvrent des heads et des lœss weichseliens. Tout à la base une formation marine de l'Éémien final et des argiles tourbeuses du début weichselien fossilisent une ancienne plate-forme marine. Le squelette de cheval est contemporain de tessons de céramique pompéenne du troisième au quatrième siècle après Jésus-Christ

Evolution de la côte du calvados depuis l'Eémien et découverte d'un squelette de cheval dans les tourbes holocènes.

International audienc

Sulla cornice della cupola di S. Sofia di Costantinopoli.

L'esame dalle impalcature all'interno di S. Sofia di Costantinopoli - avvenuto nell'agosto 2013 - ha permesso di studiare da vicino circa un quinto dei blocchi della cornice della cupola della chiesa. Ho potuto cosi' appurare che i blocchi non appartenevano all'edificio originario del 532-37, ma sono conseguenza della ricostruzione della cupola da parte di Isidoro il Giovane nel 558-62, quando l'architetto per motivi statici fu costretto a rialzare il sesto della cupola. Ho potuto anche verificare che i blocchi della cornice del 558-62 sono stati riutilizzati nel X e nel XIV secolo, in occasione delle parziali ricostruzioni della cupola nei settori ovest ed est a seguito di crolli o danneggiamenti provocati da terremoti