Non-invasive Evaluation of Aortic Stiffness Dependence with Aortic Blood Pressure and Internal Radius by Shear Wave Elastography and Ultrafast Imaging

Elastic properties of arteries have long been recognized as playing a major role in the cardiovascular system. However, non-invasive in vivo assessment of local arterial stiffness remains challenging and imprecise as current techniques rely on indirect estimates such as wall deformation or pulse wave velocity. Recently, Shear Wave Elastography (SWE) has been proposed to non-invasively assess the intrinsic arterial stiffness. In this study, we applied SWE in the abdominal aortas of rats while increasing blood pressure (BP) to investigate the dependence of shear wave speed with invasive arterial pressure and non-invasive arterial diameter measurements. A 15MHz linear array connected to an ultrafast ultrasonic scanner, set non-invasively, on the abdominal aorta of anesthetized rats (N=5) was used. The SWE acquisition followed by an ultrafast (UF) acquisition was repeated at different moment of the cardiac cycle to assess shear wave speed and arterial diameter variations respectively. Invasive arterial BP catheter placed in the carotid, allowed the accurate measurement of pressure responses to increasing does of phenylephrine infused via a venous catheter. The SWE acquisition coupled to the UF acquisition was repeated for different range of pressure. For normal range of BP, the shear wave speed was found to follow the aortic BP variation during a cardiac cycle. A minimum of (5.06$\pm$0.82) m/s during diastole and a maximum of (5.97$\pm$0.90) m/s during systole was measured. After injection of phenylephrine, a strong increase of shear wave speed (13.85$\pm$5.51) m/s was observed for a peak systolic arterial pressure of (190$\pm$10) mmHg. A non-linear relationship between shear wave speed and arterial BP was found. A complete non-invasive method was proposed to characterize the artery with shear wave speed combined with arterial diameter variations. Finally, the results were validated against two parameters the incremental elastic modulus and the pressure elastic modulus derived from BP and arterial diameter variations

Parallel graded attention in reading: A pupillometric study

There are roughly two lines of theory to account for recent evidence that word processing is influenced by adjacent orthographic information. One line assumes that multiple words can be processed simultaneously through a parallel graded distribution of visuo-spatial attention. The other line assumes that attention is strictly directed to single words, but that letter detectors are connected to both foveal and parafoveal feature detectors, as such driving parafoveal-foveal integrative effects. Putting these two accounts to the test, we build on recent research showing that the pupil responds to the brightness of covertly attended (i.e., without looking) locations in the visual field. Experiment 1 showed that foveal target word processing was facilitated by related parafoveal flanking words when these were positioned to the left and right of the target, but not when these were positioned above and below the target. Perfectly in line with this asymmetry, in Experiment 2 we found that the pupil size was contingent with the brightness of the locations of horizontally but not vertically aligned flankers, indicating that attentional resources were allocated to those words involved in the parafoveal-on-foveal effect. We conclude that orthographic parafoveal-on-foveal effects are driven by parallel graded attention

Chênes vert et blanc : aspects phytosanitaires

Décrit la situation sanitaire des chênaies qui reste globalement satisfaisante malgré le risque de l'introduction accidentelle d'un pathogène comme aux USA. Des déperissements d'ampleurs diverses sont observés et sont induits par des contraintes climatiques

Les contraintes phytosanitaires en forêt méditerranéenne

International audienc

Fonctions et logiques d’interface des récifs coralliens sur le littoral de la Réunion

Les récifs coralliens forment une interface entre la terre et la mer. À la Réunion, les récifs coralliens n’occupent que 12 % du linéaire côtier total, mais leur importance pour l’activité économique de l’île et pour le bien-être de ses habitants est sans commune mesure avec leur taille. Ce littoral récifal concentre en effet la quasi-totalité de l’activité balnéaire de l’île (la totalité des plages où la baignade est possible et autorisée, 70 % de la capacité d’accueil hôtelière). Comparée aux autres littoraux de l’île, la diversité des usages pratiqués par kilomètre de linéaire côtier est nettement supérieure. À l’évidence, les récifs sont une interface qui attire et polarise les activités humaines. Cette fonction de polarisation vaut également pour les espèces marines qui utilisent le récif comme une nourricerie et comme un garde-manger. Hormis cette fonction de polarisation, les récifs coralliens exercent également une fonction de filtre et une fonction d’enrichissement. La première est de nature purement physique. Les récifs brisent l’énergie des vagues et de la houle évitant ainsi une érosion trop importante du littoral sédimentaire et autorisant des activités économiques dans la plaine littorale adjacente à la ligne de rivage. Comme la polarisation, la fonction d’enrichissement présente une dimension écologique et anthropique. Les récifs enrichissent, en effet, le milieu océanique en flux larvaires et le milieu terrestre en produits de la pêche, et en flux d’images. Autrefois, ils approvisionnaient également l’agriculture en chaux. Ces trois fonctions de polarisation, de filtre et d’enrichissement relèvent d’une interface globale terre – mer, mais elles conduisent à diviser le récif en espaces plurifonctionnels.Functions and logics of interface within the Reunion island’s coral reefs Coral reefs are an interface between land and sea. They attract and polarize human activities. In Reunion island, coral reefs occupy only 12% of the total coastline, but their importance to the economy and the well-being of its population is much higher. They focus 70% of the island accommodation capacity and the variety of uses charged per kilometre of coastline is higher than in the other parts of the coast. Coral reefs also play a role of nursery and pantry within the coastal ecosystem. Besides this function of polarization, coral reefs also have a filter function and a function of enrichment. The first is purely physical. The reefs break the wave energy and avoid excessive erosion of the beach sediment, allowing economic activities in the coastal plain. Coral reefs enrich the ocean environment in larval flows and the human consumers in fishery products, and images. Previously, they also supplied agricultural lime. These three functions (polarization, filter and enrichment) lead to divide the reef into multifunctional spaces

Le point sur la situation phytosanitaire du pin d'Alep

La situation phytosanitaire du pin d'Alep est globalement satisfaisante, malgré la sécheresse persistante des deux dernières années, peu de cas de mortalité directe ou indirecte sont pour l'instant observés. Toutefois le feu de 1985 puis l'épisode de sécheresse de 1989-1990 ont entraîné un affaiblissement de cette essence qui paraît dépérissante dans les stations les moins favorables

0195: Identification of patients (pts) with chronic myeloid leukemia (CML) at high risk of artery occlusive events (AOE) during treatment with the 2nd generation tyrosine kinase inhibitor (TKI) nilotinib

BackgroundNilotinib is approved for use in pts with CML after failure of imatinib and in newly diagnosed CP-CML. However, several studies report a nilotinib-associated risk of AOE (arterial occlusive event), especially in pts with preexisting risk factors for CVD. In this study, we aimed at determining whether CVD risk estimation using the 2012 ESC classification could be useful to identify patients at high risk of AOE during nilotinib therapy.MethodsPts (n=75) treated with nilotinib upfront or after failure of prior TKI at our institution were included provided that baseline CVD status could be retrospectively collected. Patients were categorized into 2 groups according to ESC 2012 classification: low/moderate (L/M) and high/very high (H/VH) CVD risk.ResultsAt nilotinib initiation, median age was 51 years (19-76), 41 pts (54.7%) were males. At baseline, medical history revealed H/VH risk category in 15 pts (20%) including established CVD in 6 pts (8%) (all diagnosed before CML), DM (diabete melitus) in 10 pts (13.3%), severe AH (arterial hypertension) in 1 pt (1.3%), familial dyslipidemia in 1 pt (1.3%) and a SCORE ≥5% in 2 pts (2.6%).AOE occurred in 12 pts with myocardial infarction (MI) or coronary heart disease (CHD) (n=3), cerebrovascular events (CeVD) (n=3) and peripheral artery disease (PAD) (n=6). Cumulative incidence of AOE by 48 months was 72.22% (95% CI: 47.46-100) in the H/VH group and only 12.13% (95% CI: 4.32-34.08) in the L/M group. Log Rank comparison of Kaplan Meier analysis of 48-month survival without AOE showed a significant difference between the 2 groups (27.78% (95% CI: 0-58.9) versus 84.38% (95% CI: 67.04-100) p=0.0001). Sensitivity of the ESC classification in nilotinib-treated patients was 67% and specificity 89%.ConclusionsIn our retrospective study, CVD risk estimation according to the 2012 ESC classification reveals that pts who belong to the H/VH risk group at baseline are at very high risk of AOE during nilotinib therapy. In this context, CVD risk should be reassessed throughout therapy and risk factors should be tightly controlled according to current guidelines

Aortic Wall Elastic Properties in Case of Bicuspid Aortic Valve

Purpose of the ReviewBicuspid aortic valve (BAV) is associated with a significant risk of development of aneurysm and dissection of the ascending thoracic aorta. Development of what is called BAV associated aortopathy is particularly heterogeneous with an uncertain prognosis and with no prognostic biomarkers except for the aortic diameter. This situation leads to an important variability of the therapeutic strategy of this aortopathy. By reviewing the literature on aortic stiffness in the case of BAV, we aimed at evaluating its potential prognostic role in the development of aortic dilatation.Recent FindingsStudies evaluating aortic stiffness, with ultrasound or magnetic resonance imaging, converge toward the description of an increased segmental aortic stiffness in BAV patients regardless of age, diameter or aortic level, from the root to the arch. Even though there is a lack of longitudinal studies evaluating the progression of aortic dilatation, new data have recently shown the potential prognostic role of the maximal rate of systolic distension of the aortic wall with magnetic resonance imaging.SummaryAlthough the use of aortic distensibility calculation is a simple evaluation of stiffness that could be easily transposed in daily practice, its interpretation remains uncertain. New arterial stiffening indicators seem more promising but need a stronger validation