Structure and evolution of the Demerara Plateau, offshore French Guiana : rifting, tectonic inversion and post-rift tilting at transform-divergent margins intersection

International audienceWe present the structure and evolution of the eastern part of the Demerara plateau, offshore French Guiana, from the analysis of geophysical data collected during GUYAPLAC cruise. This area is located at the intersection of a transform segment and a divergent segment of a continental margin related to the Early Cretaceous opening of the Equatorial Atlantic. The main structures are NNE-SSW to NNW-SSE trending normal faults on the eastern edge of the plateau, and WNW-ESE to NW-SE trending acoustic basement ridges on its northern edge. When replaced in their Albian position, these structures appear to be parallel to the coeval oceanic accretion axis and transform faults, respectively. The most striking structures are related to a post-rift but syn-transform tectonic inversion, producing E-W to WNW-ESE trending folds, sealed by a regional unconformity. This shortening can not be related to ridge push, but is probably related to a plate kinematic change 105 My ago, that modified the deformation in the vicinity of the transform fault. Late post-rift evolution also includes a significant Tertiary oceanward tilt of the edge of the Demerara plateau. The driving mechanism of this late tilt is unclear, but may be related to a lithospheric flexure resulting from the loading of the abyssal plain by the Orinoco and Amazon deep-sea fans

20-year longitudinal follow-up of measured and estimated glomerular filtration rate in kidney transplant patients

peer reviewe

Digging deeper into lymphatic vessel formation in vitro and in vivo

Background Abnormal lymphatic vessel formation (lymphangiogenesis) is associated with different pathologies such as cancer, lymphedema, psoriasis and graft rejection. Lymphatic vasculature displays distinctive features than blood vasculature, and mechanisms underlying the formation of new lymphatic vessels during physiological and pathological processes are still poorly documented. Most studies on lymphatic vessel formation are focused on organism development rather than lymphangiogenic events occurring in adults. We have here studied lymphatic vessel formation in two in vivo models of pathological lymphangiogenesis (corneal assay and lymphangioma). These data have been confronted to those generated in the recently set up in vitro model of lymphatic ring assay. Ultrastructural analyses through Transmission Electron Microscopy (TEM) were performed to investigate tube morphogenesis, an important differentiating process observed during endothelial cell organization into capillary structures

A song of volumes, surfaces and fluxes: The case study of the Central Mallorca Depression (Balearic Promontory) during the Messinian Salinity Crisis

The Central Mallorca Depression (CMD) located in the Balearic Promontory (Western Mediterranean) contains a well-preserved evaporitic sequence belonging to the Messinian Salinity Crisis (MSC) salt giant, densely covered by high- and low-resolution seismic reflection data. It has been proposed recently that the MSC evaporitic sequence in the CMD could be a non-deformed analogue of the key MSC area represented by the Caltanissetta Basin in Sicily. This presumed similarity makes the CMD an interesting system to better understand the MSC events. Physics-based box models of the water mixing between sub-basins, built on conservation of mass of water and salt, help constrain the hydrological conditions under which evaporites formed during the MSC. Those models have been widely used in the literature of the MSC in the past two decades. They have been mostly applied to the Mediterranean Sea as a whole focusing on the Mediterranean–Atlantic connection, or focusing on the influence of the Sicily Sill connecting the Western and Eastern Mediterranean Sea. In this study, we apply a downscaled version of such modelling technique to the CMD. First, we quantify the present-day volumes of the MSC units. We then use a reconstructed pre-MSC paleo-bathymetry to model salinity changes as a function of flux exchanges between the CMD and the Mediterranean. We show that a persistent connection between the CMD and the Mediterranean brine near gypsum saturation can explain volume of Primary Lower Gypsum under a sea level similar to the present. For the halite, on the contrary, we show that the observed halite volume cannot be deposited from a connected CMD-Mediterranean scenario, suggesting a drawdown of at least 850 m (sill depth) is necessary. Comparison between the deep basin halite volume and that of the CMD shows that it is possible to obtain the observed halite volume in both basins from a disconnected Mediterranean basin undergoing drawdown, although determining the average salinity of the Western Mediterranean basin at the onset of drawdown requires further investigation

Genetic diversity of Anaplasma Phagocytophilum, the causative agent of granulocytic anaplasmosis, implications for epidemiology and control in france

Anaplasma phagocytophilum is a tick-borne bacterium and the etiologic agent of granulocytic anaplasmosis, an emerging disease that affects a wide range of mammals. In this paper, we present the recent knowledge gained from studies on the genetic diversity of this pathogen in France. Multilocus sequence analysis (MLSA) was used to characterize the genetic diversity of A. phagocytophilum in populations of French cattle, horses, dogs, and roe deer. MLSA was based on nine loci (ankA, msp4, groESL, typA, pled, gyrA, recG, polA, and an intergenic region). Phylogenic analysis revealed three genetic clusters of bacterial variants in domesticated animals. The two principal clusters included 98% of the bacterial genotypes found in cattle, which were only distantly related to those in roe deer. One cluster comprised only cattle genotypes, while the second contained genotypes from cattle, horses, and dogs. The third contained all roe deer genotypes and three cattle genotypes. These results suggest that roe deer do not contribute to the spread of A. phagocytophilum in cattle in France. A Multiple-Locus Variable number tandem repeat (VNTR) Analysis typing technique was developed for A. phagocytophilum. Five VNTRs were selected based on the HZ human-derived strain genome, and were tested on the Webster human-derived strain and on 123 DNA samples. This study confirmed that A. phagocytophilum from roe deer or domestic ruminants belong to two different clusters, while A. phagocytophilum from red deer and domestic ruminants locate within the same cluster, questioning the respective roles of roe vs red deer as reservoir hosts for domestic ruminant strains in Europe. The molecular techniques recently developed have great potential to provide detailed information on A. phagocytophilum isolates,improving both epidemiological and phylogenic investigations, thereby helping in the development of relevant prevention and control measures.A. phagocytophilum, bactérie transmise par les tiques, est responsable de l’anaplasmose granulocytaire, une maladie émergente qui infecte une large gamme de mammifères dont l’homme. L’objectif de cet article est de présenter les nouvelles connaissances acquises sur la diversité génétique d’A. phagocytophilum chez différentes espèces d’hôtes en France, afin de déterminer quelles espèces participent au même cycle épidémiologique. Une analyse par séquençage multi-locus (MLSA) a été effectuée dans des populations de bovins, chevaux, chiens et chevreuils. Trois groupes de génotypes infectant les bovins ont été identifiés. Les deux groupes principaux incluent 98% des génotypes bactériens trouvés chez les bovins et sont éloignés de ceux des chevreuils. Un cluster ne comprenait que les génotypes de bovins, tandis que le second génotype contenant des bovins comprenait également des chevaux et des chiens. Le troisième cluster contenait tous les génotypes de chevreuils et trois génotypes de bovins. Ces résultats suggèrent que les chevreuils ne contribuent pas à la propagation d’A. phagocytophilum chez les bovins en France. Puis, une technique MLVA (Multiple Loci VNTR Analysis) a été développée pour A. phagocytophilum. Cinq VNTR ont été sélectionnés sur la base du génome de la souche d’origine humaine HZ, et ont été testés sur 123 échantillons d’ADN provenant d’animaux domestiques ou sauvages. Cette étude a confirmé que les souches d’A. phagocytophilum retrouvées chez les chevreuils et les ruminants domestiques appartiennent à deux groupes différents, alors que les souches identifiées chez les cerfs et les ruminants domestiques sont localisées dans le même cluster. Ces résultats remettent en question les rôles respectifs des chevreuils et des cerfs comme hôtes réservoirs pour les souches d’A. phagocytophilum de ruminants domestiques en Europe. Ces techniques moléculaires ont un grand potentiel pour améliorer nos connaissances sur les cycles épidémiologiques d’A. phagocytophilum, contribuant ainsi à l’élaboration de mesures de prévention et de contrôle pertinents

Does Plasminogen Activator Inhibitor-1 Drive Lymphangiogenesis?

The purpose of this study is to explore the function of plasminogen activator inhibitor-1 (PAI-1) during pathological lymphangiogenesis. PAI-1, the main physiological inhibitor of plasminogen activators is involved in pathological angiogenesis at least by controlling extracellular proteolysis and by regulating endothelial cell survival and migration. Protease system's role in lymphangiogenesis is unknown yet. Thus, based on its important pro-angiogenic effect, we hypothesized that PAI-1 may regulate lymphangiogenesis associated at least with metastatic dissemination of cancer cells. To address this issue, we studied the impact of PAI-1 deficiency in various murine models of tumoral lymphangiogenesis. Wild-type PAI-1 proficient mice were used as controls. We provide for the first time evidence that PAI-1 is dispensable for tumoral lymphangiogenesis associated with breast cancers either induced by mammary carcinoma cell injection or spontaneously appearing in transgenic mice expressing the polyomavirus middle T antigen (PymT) under the control of a mouse mammary tumor virus long-terminal repeat promoter (MMTV-LTR). We also investigated inflammation-related lymphatic vessel recruitment by using two inflammatory models. PAI-1 deficiency did neither affect the development of lymphangioma nor burn-induced corneal lymphangiogenesis. These novel data suggest that vascular remodelling associated with lymphangiogenesis and angiogenesis involve different molecular determinants. PAI-1 does not appear as a potential therapeutic target to counteract pathological lymphangiogenesis

Higher sensitivity of Adamts12-deficient mice to tumor growth and angiogenesis.

ADAMTS (a disintegrin and metalloproteinase domain with thrombospondin motifs) constitute a family of endopeptidases related to matrix metalloproteinases. These proteases have been largely implicated in tissue remodeling and angiogenesis associated with physiological and pathological processes. To elucidate the in vivo functions of ADAMTS-12, we have generated a knockout mouse strain (Adamts12−/−) in which Adamts12 gene was deleted. The mutant mice had normal gestations and no apparent defects in growth, life span and fertility. By applying three different in vivo models of angiogenesis (malignant keratinocyte transplantation, Matrigel plug and aortic ring assays) to Adamts12−/− mice, we provide evidence for a protective effect of this host enzyme toward angiogenesis and cancer progression. In the absence of Adamts-12, both the angiogenic response and tumor invasion into host tissue were increased. Complementing results were obtained by using medium conditioned by cells overexpressing human ADAMTS-12, which inhibited vessel outgrowth in the aortic ring assay. This angioinhibitory effect of ADAMTS-12 was independent of its enzymatic activity as a mutated inactive form of the enzyme was similarly efficient in inhibiting endothelial cell sprouting in the aortic ring assay than the wild-type form. Altogether, our results show that ADAMTS-12 displays antiangiogenic properties and protect the host toward tumor progression

Effects of eight neuropsychiatric copy number variants on human brain structure

Many copy number variants (CNVs) confer risk for the same range of neurodevelopmental symptoms and psychiatric conditions including autism and schizophrenia. Yet, to date neuroimaging studies have typically been carried out one mutation at a time, showing that CNVs have large effects on brain anatomy. Here, we aimed to characterize and quantify the distinct brain morphometry effects and latent dimensions across 8 neuropsychiatric CNVs. We analyzed T1-weighted MRI data from clinically and non-clinically ascertained CNV carriers (deletion/duplication) at the 1q21.1 (n = 39/28), 16p11.2 (n = 87/78), 22q11.2 (n = 75/30), and 15q11.2 (n = 72/76) loci as well as 1296 non-carriers (controls). Case-control contrasts of all examined genomic loci demonstrated effects on brain anatomy, with deletions and duplications showing mirror effects at the global and regional levels. Although CNVs mainly showed distinct brain patterns, principal component analysis (PCA) loaded subsets of CNVs on two latent brain dimensions, which explained 32 and 29% of the variance of the 8 Cohen’s d maps. The cingulate gyrus, insula, supplementary motor cortex, and cerebellum were identified by PCA and multi-view pattern learning as top regions contributing to latent dimension shared across subsets of CNVs. The large proportion of distinct CNV effects on brain morphology may explain the small neuroimaging effect sizes reported in polygenic psychiatric conditions. Nevertheless, latent gene brain morphology dimensions will help subgroup the rapidly expanding landscape of neuropsychiatric variants and dissect the heterogeneity of idiopathic conditions

La politique de reconstruction urbaine à Aire au XVIIIe siècle.

Urban Construction Policy in Aire in the XVIIIth Century. The city of Aire, extensively destroyed during the two month long siege of 1720, then occupied by the Dutch during three years, was nearly totally rebuilt in the xvmth century along the guidelines set on November 17, 1722. These regulations imposed to all the streets an identical pattern made of woven façades, with a first floor, alternating stonework and brickwork piers, stone cornices and cordons perfectly adjusted, in continuous lines ; all the façades of the triangular "Grand-Place" were given a decoration consisting in stone pilasters, two floor high and crowned by Corinthian capitals similar to those of the City Hall situated along the base of the triangle. These regulations, enforced rigorously and even drastically for more than a century, yet backed by a municipal policy of subsidies and interest-free loans, still give the city a very consistent aspect, an illustration of French- style classicism. These regulations, with their nineteen articles, were adopted by several other cities, among which Arras and Saint-Omer, at that time, but their rigorous and persistant implementation turned Aire into a harmonious and exceptional whole ; it was the work of two families : the "Mayeurs" François and Charles-Louis de Lencquesaing, and the Beugin family, which provided 7 master-carpenters in 3 generations, and were the foremen and commisioners of these works. The petitions and the wash-paint plans deposited by the landlords and kept in the municipal records, are, for today's historians, a treasure trove of information and still permit to identify most of the houses. The "intra-muros" city has been classified as a "Zone de Protection du Patrimoine Architectural et Urbain (ZPPAU)" since 1988.La ville d'Aire, fortement démolie par un siège de deux mois en 1710, puis occupée par les Hollandais pendant 3 ans, fut presque entièrement reconstruite au XVIIIe siècle selon un règlement du 17 novembre 1722. Ce règlement imposa à toutes les rues un même modèle fait de façades tramées, d'un étage, avec pierres et trumeaux de briques alternés, corniches et cordons de pierre parfaitement raccordés, en lignes continues ; toutes les façades de la Grand Place triangulaire reçurent un décor de pilastres en pierre, élevés sur 2 étages et terminés par des chapitaux corinthiens semblables à ceux de l'hôtel de ville qui occupe la base du triangle. Ce règlement, imposé pendant plus d'un siècle avec rigueur et même sévérité, mais secondé par une politique municipale de subventions et de prêts sans intérêt, donne encore maintenant, à la ville un aspect très homogène, d'un classicisme à la française. Le règlement et ses dix-neuf articles furent adoptés par plusieurs autres villes, dont Arras, Saint-Omer, à la même époque, mais sa mise en application rigoureuse et persévérante ont fait à Aire un ensemble harmonieux et exceptionnel ; ce fut l'œuvre de 2 familles : les mayeurs François et Charles-Louis de Lencquesaing, et la famille Beugin, dont 7 maîtres- charpentiers, en 3 générations, furent les maîtres-d'oeuvre et commissaires aux travaux. Les requêtes et les plans déposés par les propriétaires, et conservés aux archives municipales, sont pour l'historien d'aujourd'hui, une mine de renseignements et permettent encore d'identifier la plupart des maisons. La ville intra muros est classée en Zone de Protection du Patrimoine Architectural et Urbain (ZPPAU) depuis 1988.Het stedebouwbeleid in Aire in de XVIIIade eeuw. De stad Aire werd in 1710 in grote mate verwoest tijdens een beleg dat twee maand duurde en daarna drie jaar bezet door de Hollanders. De stad werd in de loop van de XVIIIde eeuw haast volledig herbouwd met inachtname van een op 17 november 1722 uitgevaardigd règlement. Dat legde een uniforme gevelopbouw op, met op de verdiepingen een afwisseling van lagen natuuren baksteen, met een perfekt aansluiten van goten en versieringen. Aile huizen op de driehoekige Grote Markt kregen een dekor met pilasters over twee verdiepingen bekroond met korinthische kapitelen naar het voorbeeld van het stadhuis dat de basis van de driehoek vormt. De strenge toepassing van dit règlement gedurende een eeuw en het toekennen van renteloze leningen door de gemeente verklaren het zeer homogène uitzicht, ook nog vandaag, van de stad, een voorbeeld van Frans classicisme. Het negentien artikelen omvattende règlement werd door andere steden overgenomen, als Atrecht en Sint-Omaars. Voor de strenge toepassing in Aire gedurende heel die période — met als gevolg een uitzonderlijk en harmonieus ensemble — zijn twee families verantwoordelijk : de burgemeesters François en Charles-Louis de Lencquesaing en de familie Beugin, waarvan zeven leden als meester-timmerman, gedurende drie generaties, de noodzakelijke werken uitvoerden. De bouwaanvragen en plannen die de eigenaars neelegden worden bewaard in het stadsarchief en vormen een rijke bron voor de historious vandaag. Men kan de meeste huizen zo nog indentificeren. De binnenstad werd in 1988 beschermd en geklasseerd als ZPPAU (Zone de protection du Patrimoine Architectural et Urbain).Maillard-Delbende Agnès. La politique de reconstruction urbaine à Aire au XVIIIe siècle.. In: Revue du Nord, tome 78, n°314, Janvier-mars 1996. pp. 49-70