Édito : Méthode de Francais

214 p. : col. ill; 29 cm

Autopsie d’un scénario pédagogique

International audienc

Interaction between the Accumulation of Cadmium and Deoxynivalenol Mycotoxin Produced by Fusarium graminearum in Durum Wheat Grains

International audienceDurum wheat is one of the cereal crops that accumulates the highest concentrations of cadmium (Cd) and deoxynivalenol (DON) mycotoxin in its grains, thereby affecting the safety of products made of durum wheat grains (pasta and semolina). This study investigates in planta the interaction between Cd and Fusarium graminearum, the main causal agent of DON accumulation in grains. A pot experiment was designed to characterize the response of durum wheat to F. graminearum infection at three levels of Cd exposure: 0.1, 2, and 10 mg Cd kg(-1) soil, which showed that the accumulation of Cd and DON resulted from interacting processes. On the one hand, plant exposure to Cd reduced the concentration of DON in grains. The mitigating effect of Cd on DON accumulation was attributed to the restricted growth of F. graminearum, which could result from enhanced plant resistance to the fungal pathogen induced by Cd exposure. On the other hand, F. graminearum infection of durum wheat increased the Cd concentration in the grains. The promoting effect of Fusarium infection on Cd accumulation was attributed to decoupling of the allocation of Cd and photoassimilates to the grains and to the reduced strength of the grain sink for photoassimilates caused by the fungus. Provided that this result is confirmed in field conditions, it suggests that in Cd-contaminated soils, particular attention should be paid to agronomic practices that affect Fusarium head blight disease to avoid further increase in the risk of exceeding the regulatory limit set by the European Union for Cd in durum wheat

Les Scènes metal

Ce numéro de Volume ! se penche sur le metal, proposant un panorama de contributions inédites sur cette musique à partir de lectures multidisciplinaires et internationales (France mais aussi Espagne, États-Unis, Finlande, Maroc ou Taïwan). Existant depuis plus de trente ans, les genres musicaux que l’on regroupe aujourd’hui sous l’appelation « metal » ont longtemps été décriés par la critique journalistique, tout comme par la recherche. Quelles en sont les raisons ? La radicalité des sons, des looks ou des thèmes abordés par cette musique sont-ils des éléments d’explication ? En tenant compte de l’avancée des travaux universitaires sur le metal, les propos riches et étayés par des enquêtes proposés ici permettent enfin au lecteur français de faire le point sur cette pratique culturelle. Le numéro est accompagné de la première bibliographie exhaustive spécialement dédiée aux études metal ainsi que d'une tribune avec le métaleux Amine Hamma et la répression culturelle au Maroc ainsi qu'un ensemble de notes de lecture dédiées aux metal studies. Metal has existed for over thirty years now, and has always been stigmatized by the critics and moral authorities. Could it be the radicality of its sounds, styles or themes? This special issue of Volume! offers a first glance at the diversity of metal studies, thanks to an overview of new contributions on this music, from a pluridisciplinary (musicology, ethnomusicology and sociology) and international (France, Spain, U.S.A., Finland, Morocco, Taiwan) perspective. The issue comes with the first exhaustive metal studies bibliography, an interview of Amine Hamma, a metal musician in the repressive context of Morocco, and a set of book reviews dedicated to metal

Regulation of Endothelial Cell Cytoskeletal Reorganization by a Secreted Frizzled-Related Protein-1 and Frizzled 4- and Frizzled 7-Dependent Pathway : Role in Neovessel Formation

Consistent with findings of Wnt pathway members involved in vascular cells, a role for Wnt/Frizzled signaling has recently emerged in vascular cell development. Among the few Wnt family members implicated in vessel formation in adult, Wnt7b and Frizzled 4 have been shown as involved in vessel formation in the lung and in the retina, respectively. Our previous work has shown a role for secreted Frizzled-related protein-1 (sFRP-1), a proposed Wnt signaling inhibitor, in neovascularization after an ischemic event and demonstrated its role as a potent angiogenic factor. However the mechanisms involved have not been investigated. Here, we show that sFRP-1 treatment increases endothelial cell spreading on extracellular matrix as revealed by actin stress fiber reorganization in an integrin-dependent manner. We demonstrate that sFRP-1 can interact with Wnt receptors Frizzled 4 and 7 on endothelial cells to transduce downstream to cellular machineries requiring Rac-1 activity in cooperation with GSK-3β. sFRP-1 overexpression in endothelium specifically reversed the inactivation of GSK-3β and increased neovascularization in ischemia-induced angiogenesis in mouse hindlimb. This study illustrates a regulated pathway by sFRP-1 involving GSK-3β and Rac-1 in endothelial cell cytoskeletal reorganization and in neovessel formation

Low risk of embryonic and other cancers in PIK3CA ‐related overgrowth spectrum: Impact on screening recommendations

International audienceThe PIK3CA ‐related overgrowth spectrum (PROS) encompasses various conditions caused by mosaic activating PIK3CA variants. PIK3CA somatic variants are also involved in various cancer types. Some generalized overgrowth syndromes are associated with an increased risk of Wilms tumor (WT). In PROS, abdominal ultrasound surveillance has been advocated to detect WT. We aimed to determine the risk of embryonic and other types of tumors in patients with PROS in order to evaluate surveillance relevance. We searched the clinical charts from 267 PROS patients for the diagnosis of cancer, and reviewed the medical literature for the risk of cancer. In our cohort, six patients developed a cancer (2.2%), and Kaplan Meier analyses estimated cumulative probabilities of cancer occurrence at 45 years of age was 5.6% (95% CI = 1.35%–21.8%). The presence of the PIK3CA variant was only confirmed in two out of four tumor samples. In the literature and our cohort, six cases of Wilms tumor/nephrogenic rests (0.12%) and four cases of other cancers have been reported out of 483 proven PIK3CA patients, in particular the p.(His1047Leu/Arg) variant. The risk of WT in PROS being lower than 5%, this is insufficient evidence to recommend routine abdominal imaging. Long‐term follow‐up studies are needed to evaluate the risk of other cancer types, as well as the relationship with the extent of tissue mosaicism and the presence or not of the variant in the tumor samples