Le rouge est mis: analyse des rouges dans la faïence de « grand feu » du xviiie et du xixesiècle (avec le rouge de Thiviers)

En faïence, le rouge de grand feu pose de nombreux problèmes dus à l’instabilité des oxydes de fer. Cette expérimentation porte sur l’analyse de divers échantillons de faïences archéologiques des xviiie et xixe siècles (Rouen, Nevers, Thiviers) par les méthodes MEB-EDS et la spectrométrie Raman. Avant les années 1760, les faïenciers ont obtenu des résultats variés et plus ou moins satisfaisants. Ensuite, ils sont parvenus à une maîtrise plus grande en employant directement une ocre ferrugineuse. Dès le début du xixe siècle, les faïenciers de Thiviers, dans le Périgord, ont su tirer parti d’un pigment issu des dalles silico-ferrugineuses locales, pour obtenir une couleur stable justement nommé rouge de Thiviers. Les analyses ont confirmé les textes qui assurent que ce pigment a également été utilisé à Nevers où on le trouve couramment dès les années 1835-1840. Malgré le petit nombre d’échantillons analysés, ces résultats montrent comment certaines manufactures régionales ont réussi à obtenir une couleur stable grâce au rouge de Thiviers dès le début du xixe siècle, rencontrant un large succès populaire qui leur a permis de survivre quelques décennies jusqu’ au développement des grandes usines produisant de nouveaux types de céramique qui allaient définitivement causer leur perte peu après le milieu du xixe siècle.The instability of the iron oxides make it very difficult to obtain the colour red in single- fired faïence. In this experiment, various samples of archaeological faïence from the 18th and 19th centuries were analysed (BSE images by SEM and Raman spectrometry). Before the 1760’s, the results obtained by faience manufacturers were various and more or less satisfactory. Later on, they eventually managed to reach a greater command by using directly an iron rich ochre. At the beginning of the 19th century, the manufacturers from Thiviers, in the Perigord region, managed to make the best use of a pigment extracted from the local quartz-ferriferous rock to obtain a stable colour precisely called Thiviers red. The analyses confirm the written sources which say that this pigment was also used in Nevers where it can commonly be found from 1835-1840 on. In spite of the small number of samples analysed, these results show how some local manufactures managed to obtain a stable colour thanks to Thiviers red at the beginning of the 19th century, meeting a large popular success which enabled them to survive for a few decades until the development of the large factories producing new types of ceramics which were eventually to cause their ruin shortly after the middle of the 19th century

State of the art in texture analysis and synthesis

Livrable D2.1 du projet ANR PERSEECe rapport a été réalisé dans le cadre du projet ANR PERSEE (n° ANR-09-BLAN-0170). Exactement il correspond au livrable D2.1 du projet

La collation en maternelle : étude descriptive des interventions d’enseignantes à l’égard des garçons et des filles

Cette étude vise à décrire les interventions des enseignant.e.s auprès des garçons et des filles de leur classe lors d’une routine bien établie en maternelle, la collation. Des captations vidéo ont été réalisées dans 15 classes de maternelle 4 ans au Québec afin d’analyser la durée de la collation, la disponibilité psychologique de l’enseignante et quatre interventions spécifiques. Les résultats montrent que la collation dure en moyenne 8 minutes et que les enseignantes sont disponibles psychologiquement pour les enfants 73% du temps. La directive est l’intervention la plus fréquemment observée, alors que l’encouragement est la moins fréquente. De plus, les enseignantes tendent à agir de manière similaire envers les garçons et les filles. Considérant que la collation pourrait être un contexte propice aux échanges, elle pourrait être davantage exploitée par les enseignant.e.s de maternelle pour soutenir le développement et les apprentissages des filles et des garçons

Assessing the severity of diatom deformities using geometric morphometry

<p>Deformities in diatoms are increasingly used as an indicator of toxic stress in freshwaters. However, the percentage of deformities alone often fails at highlighting the magnitude of toxic exposure. An approach combining the assessment of deformities coupled with information on their severity could improve the sensitivity of this biomarker. With the aim of quantifying the deviation from the normal form, we tested the applicability of geometric morphometry to evaluate the degree of deformities in different diatom species. We used photomicrographs of normal and deformed specimens from laboratory cultures of <i>Gomphonema gracile, Nitzschia palea</i>, and of <i>Achnanthidium minutissimum</i> from field samples collected along a gradient of toxic contamination. The geometric morphometry approach is based on several landmarks positioned on the outline of the diatom valves. Statistical analyses were conducted based on the geometrical coordinates of the landmarks. This technique allowed to discriminate between normal and deformed individuals. The geometric morphometry approach revealed a gradient in the intensity of the deformities observed on <i>Gomphonema gracile</i> and <i>Achnanthidium minutissimum</i>, in-line with <i>a priori</i>, visually determined (subjective) classifications. A relationship between the degree of deformity in <i>Achnanthidium minutissimum</i> and a gradient of zinc contamination was found. In contrast, the approach failed to obtain good fit for <i>Nitzschia palea</i> individuals because deformities in this species were more variable in terms of their location on the valves. Geometric morphometry provided encouraging results to objectively quantify the intensity of diatom deformities affecting valve outline, and could easily be implemented in further automatic diatom identification developments.</p

C-C chemokine receptor-7 mediated endocytosis of antibody cargoes into intact cells

The C-C chemokine receptor-7 (CCR7) is a G protein coupled receptor that has a role in leukocyte homing, but that is also expressed in aggressive tumor cells. Preclinical research supports that CCR7 is a valid target in oncology. In view of the increasing availability of therapeutic monoclonal antibodies that carry cytotoxic cargoes, we studied the feasibility of forcing intact cells to internalize known monoclonal antibodies by exploiting the cycle of endocytosis and recycling triggered by the CCR7 agonist CCL19. Firstly, an anti-CCR7 antibody (CD197; clone 150503) labeled surface recombinant CCR7 expressed in intact HEK 293a cells and the fluorescent antibody was internalized following CCL19 treatment. Secondly, a recombinant myc-tagged CCL19 construction was exploited along the anti-myc monoclonal antibody 4A6. The myc-tagged ligand was produced as a conditioned medium of transfected HEK 293a cells that contained the equivalent of 430 ng/ml of immunoreactive CCL19 (average value, ELISA determination). CCL19-myc, but not authentic CCL19, carried the fluorophore-labeled antibody 4A6 into other recipient cells that expressed recombinant CCR7 (microscopy, cytofluorometry). The immune complexes were apparent in endosomal structures, colocalized well with the small GTPase Rab5 and progressed toward Rab7-positive endosomes. A dominant negative form of Rab5 (GDP-locked) inhibited this endocytosis. Further, endosomes in CCL19-myc- or CCL19-stimulated cells were positive for β-arrestin2, but rarely for β-arrestin1. Following treatment with CCL19-myc and the 4A6 antibody, the melanoma cell line A375 that expresses endogenous CCR7 was specifically stained using a secondary peroxidase-conjugated antibody. Agonist-stimulated CCR7 can transport antibody-based cargoes, with possible therapeutic applications in oncology

Le rouge est mis : analyse des rouges dans la faïence de « grand feu » du XVIIIe et du XIXe siècle (avec le rouge de Thiviers)

International audienceThe instability of the iron oxides make it very difficult to obtain the colour red in single- fired faïence. In this experiment, various samples of archaeological faïence from the 18th and 19th centuries were analysed (BSE images by SEM and Raman spectrometry). Before the 1760’s, the results obtained by faience manufacturers were various and more or less satisfactory. Later on, they eventually managed to reach a greater command by using directly an iron rich ochre. At the beginning of the 19th century, the manufacturers from Thiviers, in the Perigord region, managed to make the best use of a pigment extracted from the local quartz-ferriferous rock to obtain a stable colour precisely called Thiviers red. The analyses confirm the written sources which say that this pigment was also used in Nevers where it can commonly be found from 1835-1840 on. In spite of the small number of samples analysed, these results show how some local manufactures managed to obtain a stable colour thanks to Thiviers red at the beginning of the 19th century, meeting a large popular success which enabled them to survive for a few decades until the development of the large factories producing new types of ceramics which were eventually to cause their ruin shortly after the middle of the 19th century.En faïence, le rouge de grand feu pose de nombreux problèmes dus à l’instabilité des oxydes de fer. Cette expérimentation porte sur l’analyse de divers échantillons de faïences archéologiques des XVIIIe et XIXe siècles (Rouen, Nevers, Thiviers) par les méthodes MEB-EDS et la spectrométrie Raman. Avant les années 1760, les faïenciers ont obtenu des résultats variés et plus ou moins satisfaisants. Ensuite, ils sont parvenus à une maîtrise plus grande en employant directement une ocre ferrugineuse. Dès le début du XIXe siècle, les faïenciers de Thiviers, dans le Périgord, ont su tirer parti d’un pigment issu des dalles silico-ferrugineuses locales, pour obtenir une couleur stable justement nommé rouge de Thiviers. Les analyses ont confirmé les textes qui assurent que ce pigment a également été utilisé à Nevers où on le trouve couramment dès les années 1835-1840. Malgré le petit nombre d’échantillons analysés, ces résultats montrent comment certaines manufactures régionales ont réussi à obtenir une couleur stable grâce au rouge de Thiviers dès le début du XIXe siècle, rencontrant un large succès populaire qui leur a permis de survivre quelques décennies jusqu’ au développement des grandes usines produisant de nouveaux types de céramique qui allaient définitivement causer leur perte peu après le milieu du XIXe siècle

Comparaison de la transmission horizontale d’une souche française InDel et d’une souche US non-InDel de virus de la diarrhée épidémique porcine (PEDV)

National audienc

Comparison of the horizontal transmission of a French InDel strain and a US non InDel strain of porcine epidemic diarrhea virus

National audienc

Better horizontal transmission of a US non-InDel strain compared with a French InDel strain of porcine epidemic diarrhoea virus

International audienceFrom the severe porcine epidemic diarrhoea (PED) epidemics that struck in 2013 in the United States of America and other countries of North and South America, two types of porcine epidemic diarrhoea virus (PEDV) were isolated, namely the InDel and the non-InDel strains. They are differentiated by insertions/deletions in the S1 nucleotide sequence of the S gene, and differences in virulence were observed from the clinical cases. In 2014, a PED outbreak occurred in a pig farm in France, from which an InDel strain was isolated. This study aimed at comparing, under experimental conditions, the pathogenicity and the direct and indirect transmissions between a non-InDel strain isolated from a PED-affected piglet in 2014 in the USA and the French InDel strain. All infected pigs showed clinical signs with the non-InDel strain although only the inoculated and direct contact pigs showed clinical signs in the InDel strain group. Although viral RNA was detected in air samples with both strains, the indirect contact pigs remained free from infection with the InDel strain in contrast to the non-InDel group in which airborne transmission occurred in the indirect contact pigs. All infected pigs shed virus in faeces regardless of PEDV strain with 9 of 30 pigs showing intermittent faecal shedding. The transmission rate by direct contact was found to be 2.17-fold higher than the non-InDel strain compared with the InDel. In conclusion, the InDel strain was less pathogenic than the non-InDel strain in our experimental conditions. The transmission route differed between the two strains. Direct contact was the main transmission route for the InDel strain, although the non-InDel strain was transmitted through direct contact and indirectly through the air