120 Superiority of CT scan over transthoracic echocardiography in predicting aortic regurgitation after TAVI

BackgroundParavalvular aortic regurgitation (AR) occurs in up to 86% of patients undergoing Transcatheter Aortic Valve Implantation (TAVI). Its prevalence remains unchanged after one year follow-up but its determinants are unclear. We sought to evaluate the impact of annulus measurement by transthoracic echocardiography (TTE) and by CT scan on the occurrence of AR.MethodsThe study included 43 symptomatic patients (83±8 years, 72% in NYHA≥III) with severe aortic stenosis [0.76±0.19cm2, mean gradient 42±14mmHg] who underwent TAVI using CoreValve® LLC Percutaneous Aortic Valve Implantation System, Medtronic, Minneapolis USA. Left ventricular outflow tract (LVOT) area was computed from LVOT diameter (21±2mm) by TTE using a spherical model and from CT using an ellipsoidal model according to the larger (25±3mm) and the smaller outflow tract diameters (22±3mm). These data were compared to the prosthesis area and the occurrence of AR after TAVI.ResultsIn patients with AR greater or equal to 2/4 (32%), LVOT area measured by CT was significantly greater as compared to patients with no or mild AR (478±65mm 2 vs. 411±85mm2, p=0.009). Furthermore, the difference between actual prosthesis area and LVOT area measured by CT scan was significantly smaller (113±55 vs. 171±67, p=0.009) in patients with significant AR (≥2/4) after TAVI. In contrast, LVOT area from TTE did not correlate with AR severity.ConclusionCT scan is more accurate than TTE for calculating LVOT area for prosthesis sizing before TAVI in order to avoid post-implantation AR

Spatial Vulnerability: Bacterial Arrangements, Microcolonies, and Biofilms as Responses to Low Rather than High Phage Densities

The ability of bacteria to survive and propagate can be dramatically reduced upon exposure to lytic bacteriophages. Study of this impact, from a bacterium’s perspective, tends to focus on phage-bacterial interactions that are governed by mass action, such as can be observed within continuous flow or similarly planktonic ecosystems. Alternatively, bacterial molecular properties can be examined, such as specific phage‑resistance adaptations. In this study I address instead how limitations on bacterial movement, resulting in the formation of cellular arrangements, microcolonies, or biofilms, could increase the vulnerability of bacteria to phages. Principally: (1) Physically associated clonal groupings of bacteria can represent larger targets for phage adsorption than individual bacteria; and (2), due to a combination of proximity and similar phage susceptibility, individual bacteria should be especially vulnerable to phages infecting within the same clonal, bacterial grouping. Consistent with particle transport theory—the physics of movement within fluids—these considerations are suggestive that formation into arrangements, microcolonies, or biofilms could be either less profitable to bacteria when phage predation pressure is high or require more effective phage-resistance mechanisms than seen among bacteria not living within clonal clusters. I consider these ideas of bacterial ‘spatial vulnerability’ in part within a phage therapy context

Determination of rapid Deccan eruptions across the Cretaceous-Tertiary boundary using paleomagnetic secular variation: 2. Constraints from analysis of eight new sections and synthesis for a 3500-m-thick composite section

International audienceThe present paper completes a restudy of the main lava pile in the Deccan flood basalt province (trap) of India. Chenet et al. (2008) reported results from the upper third, and this paper reports the lower two thirds of the 3500-m-thick composite section. The methods employed are the same, i.e., combined use of petrology, volcanology, chemostratigraphy, morphology, K-Ar absolute dating, study of sedimentary alteration horizons, and as the main correlation tool, analysis of detailed paleomagnetic remanence directions. The thickness and volume of the flood basalt province studied in this way are therefore tripled. A total of 169 sites from eight new sections are reported in this paper. Together with the results of Chenet et al. (2008), these data represent in total 70% of the 3500-m combined section of the main Deccan traps province. This lava pile was erupted in some 30 major eruptive periods or single eruptive events (SEE), each with volumes ranging from 1000 to 20,000 km 3 and 41 individual lava units with a typical volume of 1300 km 3. Paleomagnetic analysis shows that some SEEs with thicknesses attaining 200 m were emplaced over distances in excess of 100 km (both likely underestimates, due to outcrop conditions) and up to 800 km. The total time of emission of all combined SEEs could have been (much) less than 10 ka, with most of the time recorded in a very small number of intervening alteration levels marking periods of volcanic quiescence (so-called ''big red boles''). The number of boles, thickness of the pulses, and morphology of the traps suggest that eruptive fluxes and volumes were larger in the older formations and slowed down with more and longer quiescence periods in the end. On the basis of geochronologic results published by Chenet et al. (2007) and paleontological results from Keller et al. (2008), we propose that volcanism occurred in three rather short, discrete phases or megapulses, an early one at $67.5 ± 1 Ma near the C30r/C30n transition and the two largest around 65 ± 1 Ma, one entirely within C29r just before the K-T boundary, the other shortly afterward spanning the C29r/C29n reversal. We next estimate sulfur dioxide (likely a major agent of environmental stress) amounts and fluxes released by SEEs: they would have ranged from 5 to 100 Gt and 0.1 to 1 Gt/a, respectively, over durations possibly as short as 100 years for each SEE. The chemical input of the Chicxulub impact would have been on the same order as that of a very large single pulse. The impact, therefore, appears as important but incremental, neither the sole nor main cause of the Cretaceous-Tertiary mass extinctions

Dynamique de la sédimentation dans les grottes du karst de Punung (Pacitan, Java) (relations avec les occupations paléolithiques)

Le karst de Punung (Pacitan, Java Est, Indonésie) est célèbre pour ses nombreuses cavités dont plusieurs d'entre elles ont livré un patrimoine archéologique important. La grotte de Song Terus est le siège de fouilles archéologiques qui ont livré, outre un assemblage archéologique, une importante séquence stratigraphique. L'existence de ce remplissage offrait pour la première fois un cadre sédimentaire bien conservé dans lequel les niveaux d'occupations humaines étaient bien identifiés. Ce site apparaissait donc comme une référence majeure et inédite pour l'établissement d'un cadre stratigraphique et géologique des occupations humaines de la région. Une étude géologique du site de Song Terus a permis de mettre en évidence les cinq grandes influences sédimentaires qui ont conduit à la mise en place des dépôts : la dynamique fluviatile, le transport éolien, l'impact volcanique, l'influence karstique et l'action anthropique. Ces grands phénomènes montrent la grande variabilité du processus sédimentaire dans le karst de Punung. Ces résultats nous ont également permis d'envisager des hypothèses climatiques liées à la sédimentation, d'établir des corrélations chronostratigraphiques entre le site de Song Terus et la grotte voisine de Goa Tabuhan et de reconstituer l'histoire géologique de la région. Ce travail apporte donc de nouvelles données sur la dynamique de la sédimentation en relations avec les occupations humaines dans le karst de PunungThe Punung karstic area (Pacitan, East Java, Indonesia) is well known for its numerous caves, some of them containing archaeological remains. Excavations in the Song Terus cave offers an important sedimentary filling beside archaeological remains. This section exploits first time a well preserved sedimentary background with human occupations in stratigraphical positions. The cave shows a new and major reference for proposing a stratigraphical and geological background to the humain occupations in this area. The geological study of the Song Terus cave pinpointed five major sedimentary processes : alluvials deposits, aeolian transport, volcanic impact, karstic activity and anthropic actions. These influences show the variability of sedimentary processes in the Punung karstic area. These results also arise climatic hypothesis, chronostratigraphic correlations between Song Terus and the nearby cave of Goa Tabuhan and a geological history of this area. This work gives new datas about the dynamic of sedimentation relating to human occupations in the Punung karstic areaPARIS-Museum Hist.Naturelle (751052304) / SudocSudocFranceF

A fast method to predict protein-protein interaction sites from sequence analysis

peer reviewe

Apports isotopiques à la compréhension du commerce de l’ichtyofaune dulçaquicole à Délos (IIe-Ier siècles a.C.)

International audienceLa découverte récente d’ossements de poissons d’eau douce, dans des contextes d’époque hellénistique (IIe-Ier siècles a.C.) à Délos (Grèce), pose la question de leur provenance. En effet, aucun bassin naturel d’eau douce n’existe sur l’île. Cependant, des indices archéologiques, archéozoologiques et épigraphiques indiquent que ces poissons ont été transportés vivants et stockés à Délos dans un lac artificiel administré par le sanctuaire apollinien. Nous avons effectué des analyses d’isotopes stables du carbone, de l’azote et de l’oxygène sur le collagène et les carbonates de l’os et de l’émail dans l’objectif de déterminer des informations sur la provenance de ces poissons. L’interprétation des résultats est complexifiée par la grande variabilité intraspécifique des rapports isotopiques des poissons dulçaquicoles. Néanmoins, ces premières données, comparées à celles disponibles dans la littérature scientifique, semblent indiquer une provenance d’un milieu lacustre et sont en concordance avec des résultats publiés pour la Grèce du nord datés d’époque préhistorique

Teashirt 3 expression in the chick embryo reveals a remarkable association with tendon development

Drosophila teashirt (tsh) is involved in the patterning of the trunk identity together with the Hox genes. In addition, it is also a player in the Wingless and the Hedgehog pathways. In birds and mammals, three Tshz genes are identified and the expression patterns for mouse Tshz1 and Tshz2 have been reported during embryogenesis. Recently, we showed that all three mouse Tshz genes can rescue the Drosophila tsh loss-of-function phenotype, indicating that the function of the teashirt genes has been conserved during evolution. Here we describe the expression pattern of chick TSHZ3 during embryogenesis. Chick TSHZ3 is expressed in several tissues including mesodermal derivatives, the central and peripheral nervous systems. Emphasis is laid on the dynamic expression occurring in regions of the somites and limbs where tendons develop. We show that TSHZ3 is activated in the somites by FGF8, a known inducer of the tendon marker SCX. (c) 2006 Elsevier B.V. All rights reserved

Rapid quantification of bone collagen content by ATR-FTIR spectroscopy

International audienceExpensive and time-consuming preparation procedures for radiocarbon and stable isotope analyses can be conducted on archaeological bone samples even if no collagen is preserved. Such unsuccessful preparation can lead to the partial destruction of valuable archaeological material. Establishing a rapid prescreening method for evaluating the amount of bone collagen while minimizing the impact of sampling constitutes a challenge for the preservation of archaeological collections. This study proposes and discusses a new methodology to detect and quantify collagen content in archaeological bone samples by attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy. A total of 42 Pleistocene to modern bone samples were selected according to their nitrogen content measured using an elemental analyzer. Comparison of collagen content estimation using ATR-FTIR and mass spectrometry reveals that some of the studied samples are contaminated by a nitrogen source coming from the burial environment. Two different FTIR calibration approaches were tested on the uncontaminated samples: peak-to-peak ratio and multivariate regression (PLS). The two approaches yield similar results with a good correlation of ATR-FTIR analyses and N wt% from 0.7 to 4wt% (R²=0.97–0.99; standard error of estimation ±0.22 to 0.25wt%). While collagen content remains difficult to detect in poorly preserved bones (less than ~3wt%), ATR-FTIR analysis can be a fast alternative for sample screening to optimize the sampling strategy and avoid partial destruction of valuable samples that do not contain enough collagen for further analysis

Quelle place pour l’écologie des communautés végétales dans les programmes pluridisciplinaires ?

International audienc

Quelle place pour l’écologie des communautés végétales dans les programmes pluridisciplinaires ?

International audienc