74 research outputs found
Lensfree diffractive tomography for the imaging of 3D cell cultures
International audienceNew microscopes are needed to help realize the full potential of 3D organoid culture studies. In order to image large volume of 3D organoid cultures while preserving the ability to catch every single cell, we propose a new imaging platform based on lensfree microscopy. We have built a lensfree diffractive tomography setup performing multi-angle acquisitions of 3D organoid culture embedded in Matrigel ® and developed a dedicated 3D holographic reconstruction algorithm based on the Fourier diffraction theorem. With this new imaging platform, we have been able to reconstruct a 3D volume as large as 21.5 mm 3 of a 3D organoid culture of prostatic RWPE1 cells showing the ability of these cells to assemble in 3D intricate cellular network at the mesoscopic scale. Importantly, comparisons with 2D images show that it is possible to resolve single cells isolated from the main cellular structure with our lensfree diffractive tomography setup
Synergies between the constitutive relation error concept and PGD model reduction for simplified V&V procedures
Manejo sustentable del ecosistema Salinas Grandes, Chaco Árido
Este libro es el resultado de tres años de investigación adaptativa conjuntamente con los pobladores de la región de Salinas Grandes , Provincia de Catamarca, en el marco del Proyecto GEF “Manejo Sustentable del Ecosistema Salinas Grandes, Chaco Árido”. El trabajo fue realizado por la Facultad de Ciencias Agropecuarias de la Universidad Nacional de Córdoba, en forma conjunta con el Programa Social Agropecuario, Delegación Catamarca; Administración de Parques Nacionales, Delegación Centro; Centro de Zoología Aplicada de la Universidad Nacional de Córdoba y la Red Agroforestal Chaco Argentina
the forest vegetation of the tolfa ceriti mountains northern latium central italy
The Forest Vegetation of the Tolfa-Ceriti Mountains (Northern Latium - Central Italy)The forests of the Tolfa-Ceriti mountains (Latium, central Italy) were investigated through a phytosociological approach. 249 relevés were performed and treated with multivariate analysis. 13 woodland communities were identified, of which 7 belong toQuercetalia pubescenti-petraeae, 1 toFagetalia sylvaticae, 1 toPopuletaliaand 4 toQuercetalia ilicis. The thermophilous Turkey oak-forests occurring on the trachytic hills of the Ceriti Mountains and on the flysch substrates of the Tolfa Mountains were included inRubio peregrinae-Quercetum cerridisass. nova.Quercus cerrisandFraxinus angustifoliasubsp.oxycarpawoodland communities of the footslopes have been ascribed toFraxino oxycarpae-Quercetum cerridis, while the widespread mesophilus Turkey oak forests have been ascribed toMelico-Quercetum cerridis. Cephalantero longifoliae-Quercetum cerridishas been restricted to acid and oligotrophic soils.Quercus petraeawoodlands, occurring on trachytic substrates have been described as a new association namedCarici olbiensis-Quercetum petraeaeass. nova. All these mixed oak woods have been included in the allianceCrataego laevigatae-Quercion cerridisArrigoni 1997. The nomenclatural problems concerning the prior nameTeucrio siculi-Quercion cerridisUbaldi 1988 are also discussed. The beech forests of the higher altitudes have been included inFraxino orni-Fagetum sylvaticae, while theAlnus glutinosaravine woodlands have been described as belonging to the new associationPolysticho setiferi-Alnetum glutinosae. Secondary communities ofAcer monspessulanumandAcer campestredeveloped on flysch substrates, and ofErica arboreaandArbutus unedo(Erico-Arbutetum unedonis) developed on trachytic substrates, have also been identified. Finally two types ofQuercus ilexwood have been identified:Cyclamino repandi-Quercetum ilicis, on sandstones, and the new associationArbuto unedonis-Quercetum ilicisass. nova on volcanic soils. This latter community can be considered as a coenological and geographical vicariant in central Italy of the sicilianErico-Quercetum ilicis
Maquis et groupements végétaux de la série du chêne vert dans le bassin du Fango (Corse)
The phytosociological study lead in western-north Corsica (Fango basin) in the Quercus ilex série (mesomediterranean belt) allows to define various insular syntaxons which correspond respectively to therophyte lawns (Helianthemo-Plantaginetum, Aira caryophyllea sub association) , rock-rose communities (Helicryso-Cistetum villosi) and final forest stade (Quercetum gallo provinciale ornetosum) . In regard to it, the maquis constitue a well individualized association, that distinguishes itself by an evolutive process in several separate sub-units (sub. ass. cistetosum, phillyrceetosum and quercetosum). This association lead to conceive a new alliance (Myrtion communi) that collects various heliophilous plant communities of Pistacio-Rhamnetalia in the french mediterranean eastern-south.L'étude phytosociologique menée en Corse nord-occidentale (bassin du Fango) au sein de la série du Quercus ilex (étage méso méditerranéen) permet la définition de divers syntaxons insulaires correspondant respectivement aux pelouses à thérophytes (Hélianthemo-Plantaginetum sous-association à Aira caryophyllea), aux cistaies (Helichryso-Cistetum villosi) ainsi qu'au stade forestier terminal (Quercetum galloprovinciale ornetosum). Par rapport à ce dernier, le maquis s'avère constituer une association bien individualisée (Erico-Arbutelum), se différenciant par processus évolutif en plusieurs sous-unités distinctes (sous-ass. cistetosum, phillyreetosum et quercetosum) . Elle conduit à la conception d'une alliance nouvelle (Myrtion communi) réunissant divers groupements héliophiles des Pistacio-Rhamnetalia dans le sud-est méditerranéen français.Allier C., Lacoste Alain. Maquis et groupements végétaux de la série du chêne vert dans le bassin du Fango (Corse). In: Ecologia mediterranea, tome 5,1979. pp. 59-82
Les hêtraies des Baronnies, des Préalpes de Digne et pays de Seyne. Leur place dans les Alpes du Sud
The study concerns the beech-groves of Peri-alpin country. By automatic analysis, these groupings have been comparated to those described from Alpes maritimes and ligures to Mont Ventoux and Valentinois-Vercors by severals authors. This analisis shows that Baronnies-Préalpes de Seyne are in the domain of 2 alliances (Cephalanthero-Fagion s. str. and Eu-Tagion) and three associations (Buxo-Fagetum, Fagetum gallicum and trochisceto-Abietetum more eastern). More over the others groupings analysed are placed in the syntaxinomic context determined. At last the dry southern beech-groves belonging to Quercetea pubescentis do not enter in this territory.L'étude porte sur des hêtraies de l'arc périalpin. Par analyse automatique, une comparaison entre ces groupements et ceux décrits par divers auteurs, des Alpes Maritimes et Ligures au Mont Ventoux et au Valentinois-Vercors. Le dépouillement permet de montrer que Baronnies-Préalpes de Seyne sont dans le domaine de deux alliances (Cephalanthero-Fagion s. str. et Eu-Fagion) et de trois associations (Buxo-Fagetum, Fagetum gallicum et le Throchisceto-Abietetum plus oriental). De plus les autres groupements pris en considération sont replacés dans le cadre syntaxinomique défini. Enfin les Hêtraies sèches méridionales appartenant aux Quercetea pubescentis ne pénètrent pas dans ce territoire.Allier C., Bresset Vivette. Les hêtraies des Baronnies, des Préalpes de Digne et pays de Seyne. Leur place dans les Alpes du Sud. In: Ecologia mediterranea, tome 5,1979. pp. 113-146
Quantitative phase imaging of adherent mammalian cells: a comparative study
International audienceThe quantitative phase imaging methods have several advantages when it comes to monitoring cultures of adherent mammalian cells. Because of low photo-toxicity and no need for staining, we can follow cells in a minimally invasive way over a long period of time. The ability to measure the optical path difference in a quantitative manner allows the measurement of the cell dry mass, an important metric for studying the growth kinetics of mammalian cells. Here we present and compare cell measurements obtained with three different techniques: digital holographic microscopy, lens-free microscopy and quadriwave lateral sheering interferometry. We report a linear relationship between optical volume density values measured with these different techniques and estimate the precisions of this measurement for the different individual instruments
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