Surface Smoothing: A Way Back in Early Brain

Abstract. In this article we propose to investigate the analogy between early cortical folding process and cortical smoothing by mean curvature flow. First, we introduce a one-parameter model that is able to fit a developmental trajectory as represented in a Volume-Area plot and we propose an efficient optimization strategy for parameter estimation. Second, we validate the model on forty cortical surfaces of preterm newborns by comparing global geometrical indices and trajectories of central sulcus along developmental and simulation time.

Recueil d'actes de Saint-Lazare de Paris 1124-1254

, . Recueil d'actes de Saint-Lazare de Paris 1124-1254. Aubervilliers : Institut de Recherche et d'Histoire des Textes (IRHT), 2005. 358 p. (Documents, études et répertoires de l'Institut de Recherche et d'Histoire des Textes, 75

Les peintures murales du IIe s. p.C. de deux chambres d’une auberge d’Augustonemetum/Clermont-Ferrand

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Peintures de Périgueux. Édifice de la rue des Bouquets ou la Domus de Vésone, IV

Tra gli ultimi sistemi di pitture identificati, uno con ghirlanda a effetto di perle è particolarmente precoce, di un terzo stile pompeiano che potrebbe collocarsi all’inizio del primo secolo d. C. Questo fatto presenta un problema di una installazione anteriore al primo insediamento riconosciuto della domus. Un secondo sistema decorativo, con dentelli, predella con figure, e pannelli con bordi diversi e candelabri, fanno parte del gruppo della metà del primo secolo d. C. gia pubblicati nella rivista Aquitania (vedere i n° 19, 20, 21), Altri brani di decorazioni presentano particolari originali. Un “atelier” regionale emerge da tutto questo gruppo di decorazioni diverse nascoste, di una richezza che non è encora esaurita.Parmi les derniers ensembles de peintures identifiés, l’un à guirlande à effet de perlage est particulièrement précoce, d’un IIIe style pompéien qui pourrait se rattacher au tout début du Ier siècle p. C. Il pose le problème d’une occupation antérieure au premier état de la domus reconnue. Un deuxième décor, à redans, prédelle à personnages, et panneaux à bordures diverses, accompagnés de candélabres, se rattache à la série du milieu du Ier siècle p. C. déjà publiée dans Aquitania (voir les n° 19, 20, 21), de même que d’autres bribes de décors aux détails parfois originaux. Un atelier régional émerge de cette variété de peintures enfouies dont la richesse n’est pas encore épuisée.Barbet Alix, Bujard Sophie, Dagand Patricia, Lefèvre Jean-François, Lemoigne Lucie, Maleyre Isabelle. Peintures de Périgueux. Édifice de la rue des Bouquets ou la Domus de Vésone, IV. In: Aquitania : une revue inter-régionale d'archéologie, tome 24, 2008. pp. 41-76

Huaca Amarilla, un espace funéraire andin unique dédié à l’inhumation de fœtus, de nouveau-nés, de nourrissons et de jeunes enfants du IXe au XVe siècle (Désert de Sechura, Pérou)

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Peintures de Périgueux. Édifice de la rue des Bouquets ou la Domus de Vésone III - Les peintures jadis en place et les peintures fragmentaires

When we removed the tissue and adhesive which covered the painting detached from the south wall of room 10 and which had never been restored onto a new support as the other walls, we discovered that the decoration was the same as those of the other inner walls of the room and integrated the fireplace. We can reconstruct the upper zones of peristyle 6. The black panels were surmounted by entablatures of scrolled coping, accompanied by foliage, candelabras, medallions and birds. The three types of mortar identified corresponded to the three porticos. The last décor came from a large rectangular room in the north-west corner of the domus, its estimated height was 3,6 m. We reconstructed a lower black zone which had geometrical compartments, a middle zone which had red panels and intermediary black panels decorated with candelabras or small columns which rose to enter an upper zone, an upper zone in which the small columns from the intermediate zone were crowned with sphinxes or griffons having a Medusa head. The upper zone included small yellow pictures decorated with vases and surmounted with swans, black acanthus-base indentations, vase and parasol, with garlands, cymbals and birds. The stylistic comparisons are obvious with other groups from the same domus and with paintings of the end of the 3rd Pompeian style, from Perigueux itself and neighbouring provinces.L’exploration des peintures fragmentaires se poursuit et amène à identifier encore d’autres ensembles. Le désencollage de peintures en place déposées jadis et jamais restaurées a permis de retrouver le décor du mur sud de la salle 10 qui était identique aux autres et peint en respectant la place de la cheminée. Nous pouvons restituer les zones supérieures du péristyle 6. Les panneaux noirs étaient sommés d’entablements à frontons à volutes, accompagnés de rinceaux, de candélabres, avec médaillons et oiseaux. Les trois types de mortier reconnus correspondraient aux trois portiques. Le dernier décor provient d’une grande salle rectangulaire de l’angle nord-ouest de la domus à quatre parois distinctes et d’une élévation de 3,60 m. On restitue une zone inférieure noire à compartiments géométriques, une zone moyenne à panneaux rouges et inter-panneaux noirs à candélabres ou à colonnettes qui montent jusqu’en zone supérieure où ils sont couronnés par des sphinges ou des griffons et une tête de Méduse. La zone supérieure comprend des tableautins jaunes décorés de vases et surmontés de cygnes, des découpes noires à culot d’acanthe, vase et parasol, avec guirlandes, cymbales et oiseaux. Les comparaisons stylistiques sont évidentes avec d’autres ensembles de la même domus et avec des peintures de la fin du IIIe style pompéien, à Périgueux même et dans les provinces voisines.Barbet Alix, Bujard Sophie, Dagand Patricia, Lefèvre Jean-François, Maleyre Isabelle, Amadei Béatrice, Lemoigne Lucie. Peintures de Périgueux. Édifice de la rue des Bouquets ou la Domus de Vésone III - Les peintures jadis en place et les peintures fragmentaires. In: Aquitania : une revue inter-régionale d'archéologie, tome 21, 2005. pp. 189-239

Larger seems twistier : Spectral Analysis of Gyrification patterns (SpAnGy) applied to adult brain size polymorphism

The description of cortical folding pattern (CFP) is challenging because of geometric complexity and inter-subject variability. On a cortical surface mesh, curvature estimation provides a good scalar proxy of CFP. The oscillations of this function can be studied using a Fourier-like analysis to produce a power spectrum representative of the spatial frequency composition of CFP. First, we introduce an original method for the SPectral ANalysis of GYrication (Spangy), which performs a spectral decomposition of the mean curvature of the grey/white interface mesh based on the Laplace-Beltrami operator eigenfunctions. Spangy produces an ordered 7 bands power spectrum of curvature (B0-B6) and provides an anatomically relevant segmenta-tion of CFP based on local spectral composition. A spatial frequency being associated with each eigenfunction, the bandwidth design assumes frequency doubling between consecutive spectral bands. Next, we observed that the last 3 spectral bands (B4, 5 and 6) accounted for 93% of the analyzed spectral power and were associated with fold-related variations of curvature, whereas the lower frequency bands were related to global brain shape. The spectral segmentation of CFP revealed 1st, 2nd and 3rd order elements associated with B4, B5 and B6 respectively. These elements could be related to developmentally-defined primary, secondary and tertiary folds. Finally, we used allometric scaling of frequency bands power and segmentation to analyze the relationship between the spectral composition of CFP and brain size in a large adult dataset. Total folding power followed a positive allometric scaling which did not divide up proportionally between the bands: B4 contribution was constant, B5 increased like total folding power and B6 much faster. Besides, apparition of new elements of pattern with increasing size only concerned the 3rd order. Hence, we demonstrate that large brains are twistier than smaller ones because of an increased number of high spatial frequency folds, ramifications and kinks that accommodate the allometric increase of cortical surface

Is the Blood Oxygenation Level-Dependent fMRI Response to Motor Tasks Altered in Children After Neonatal Stroke?

International audienceFunctional MRI is increasingly being used in the assessment of brain activation and connectivity following stroke. Many of these studies rely on the Blood Oxygenation Level Dependent (BOLD) contrast. However, the stability, as well as the accuracy of the BOLD response to motor task in the ipsilesional hemisphere, remains ambiguous. In this work, the BOLD signal acquired from both healthy and affected hemispheres was analyzed in 7-year-old children who sustained a Neonatal Arterial Ischemic Stroke (NAIS). Accordingly, a repetitive motor task of the contralesional and the ipsilesional hands was performed by 33 patients with unilateral lesions. These patients were divided into two groups: those without cerebral palsy (NAIS), and those with cerebral palsy (CP). The BOLD signal time course was obtained from distinctly defined regions of interest (ROIs) extracted from the functional activation maps of 30 healthy controls with similar age and demographic characteristics as the patients. An ROI covering both the primary motor cortex (M1) and the primary somatosensory cortex (S1) was also tested. Compared with controls, NAIS patients without CP had similar BOLD amplitude variation for both the contralesional and the ipsilesional hand movements. However, in the case of NAIS patients with CP, a significant difference in the averaged BOLD amplitude was found between the healthy and affected hemisphere. In both cases, no progressive attenuation of the BOLD signal amplitude was observed throughout the task epochs. Besides, results also showed a correlation between the BOLD signal percentage variation of the lesioned hemisphere and the dexterity level. These findings suggest that for patients who sustained a NAIS with no extensive permanent motor impairment, BOLD signal-based data analysis can be a valuable tool for the evaluation of functional brain networks

Innate T-αβ lymphocytes as new immunological components of anti-tumoral "off-target" effects of the tyrosine kinase inhibitor dasatinib

International audienceKinase inhibitors hold great potential as targeted therapy against malignant cells. Among them, the tyrosine kinase inhibitor dasatinib is known for a number of clinically relevant off-target actions, attributed in part to effects on components of the immune system, especially conventional T-cells and natural killer (NK)-cells. Here, we have hypothesized that dasatinib also influences non-conventional T-αβ cell subsets known for their potential anti-tumoral properties, namely iNKT cells and the distinct new innate CD8 T-cell subset. In mice, where the two subsets were originally characterized, an activated state of iNKT cells associated with a shift toward an iNKT cell Th1-phenotype was observed after dasatinib treatment in vivo. Despite decreased frequency of the total memory CD8 T-cell compartment, the proportion of innate-memory CD8 T-cells and their IFNγ expression in response to an innate-like stimulation increased in response to dasatinib. Lastly, in patients administered with dasatinib for the treatment of BCR-ABL-positive leukemias, we provided the proof of concept that the kinase inhibitor also influences the two innate T-cell subsets in humans, as attested by their increased frequency in the peripheral blood. These data highlight the potential immunostimulatory capacity of dasatinib on innate T-αβ cells, thereby opening new opportunities for chemoimmunotherapy

Datation par radiocarbone, datation par archéomagnétisme et modélisation par ChronoModel : chronologie de la production céramique médiévale du site de Castelnau-le-Lez (Hérault, France)

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