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L’art de faire vibrer les surfaces hyperboliques
No full textInternational audienceÀ quoi ressemble une surface « typique », en géométrie ? Comment vibre-t-elle, quand des ondes s’y propagent ? Est-il facile de s’y déplacer d’un point à un autre ? Une approche probabiliste donne des outils pour calculer le « trou spectral » des surfaces hyperboliques, un précieux paramètre qui renseigne sur leurs propriétés
Auto-fluorescent phytoliths: can we detect past fires in tropical and subtropical contexts?
No full textInternational audienceTo understand human practices and landscape evolution it is crucial to be able to trace evidence of past fires, notably in tropical environments. In such anthromes, phytoliths are generally well preserved and provide local signals on the environment. However, the different approaches to identifying burnt or heated phytoliths have proved inadequate. The recent investigation of auto-fluorescent phytoliths as proxy indicators of fire opens up new possibilities, however such studies have so far been limited to European temperate regions. The present contribution further explores the potential of this technique, attempting to reconstruct fire histories in tropical and subtropical latitudes. Therefore, we investigated various modern and ancient contexts in Guatemala, Senegal and the Canary Islands using descriptive and quantitative approaches to fluorescence. This comparative process revealed a diversity of fluorescence responses depending on the ecosystems studied, with anthropized areas often producing more fluorescent phytoliths. These results were obtained despite the use of different extraction and mounting methods. In contrast, coloured phytoliths, often considered an indicator of environmental burning, proved not very informative in some of the samples. This study reinforces our conviction that the auto-fluorescence of phytoliths is a universal phenomenon and is useful as a new proxy for detecting ancient fire in tropical and subtropical archaeological and palaeoenvironmental deposits
編集方針としてのメディア批判:日本型の「メディアクティビズム」についての考察
No full textInternational audienceIn both France and Japan, criticism of the media and of journalism has progressively intensified over the past thirty years. Within this broader trend, so-called “alternative” media, linked to various social movements, have traditionally played an active role in producing and disseminating critical discourses targeting institutional media (television and the press). Conceptualized under the term mediactivism, this mode of contesting the legitimacy of the media in the public sphere takes on a distinctive form in Japan. The context of declining audiences has led certain press organizations (daily newspapers and magazines) to adopt increasingly aggressive editorial lines directed against rival media, in an effort to secure and retain more narrowly defined readerships. In this way, institutional media—originally the targets of mediactivism—have themselves become among its principal drivers. Drawing on several case studies, the aim of this article is to explore the structures of this movement and to reflect on its consequences for the position of media institutions in contemporary Japanese society.En France comme au Japon, la critique des médias et du journalisme s’est progressivement renforcée au cours des trente dernières années. Au sein de cette tendance, les médias dits « alternatifs » rattachés à différents mouvements sociaux jouent traditionnellement un rôle actif dans la production et la diffusion de discours critiques à l’encontre des médias institutionnels (télévision et presse écrite).Conceptualisé sous le nom de « médiactivisme », ce mode de contestation de la légitimité des médias dans l’espace public prend au Japon un visage particulier. En effet, le contexte de raréfaction de l’audience pousse une partie des entreprises de presse (quotidienne et magazine) à développer des lignes éditoriales de plus en plus agressives à l’encontre des médias rivaux, afin de fidéliser un public plus ciblé. Les médias institutionnels, originellement cibles du médiactivisme, en deviennent ainsi l’un des principaux moteurs.En partant de plusieurs études de cas, l’objectif de cet article est de proposer des pistes de réflexion sur les structures de ce mouvement ainsi que ses conséquences sur la place de l’institution médiatique dans la société japonaise contemporaine.フランスでも日本でも、メディアやジャーナリズムに対する批判はこの30年で着実に強まってきた。この流れの中で、さまざまな社会運動と結びついたいわゆる「オルタナティブ」メディアは、伝統的メディア（テレビや新聞）に対する批判的言説を生み出し、広める上で重要な役割を果たしてきた。以上の現象は「メディアクティビズム」(Médiactivisme)と呼ばれているが、公共圏におけるメディアの正当性に疑問を投げかける「メディアクティビズム」は、日本では特別な形をとっている。読者や視聴者数の減少を背景に、一部の報道機関（日刊紙や雑誌）は、よりオーディエンスの関心を獲得するために、ターゲットを絞り、ライバルメディアに対してますます攻撃的な編集方針を打ち出すようになった。つまり、もともと「メディアクティビズム」の標的であった大手メディアも、ここ数年、その原動力のひとつにもなりつつある。本論文の目的は、複数のケーススタディに基づき、この現象の構造とその背景を分析し、現代日本社会におけるメディア制度の位置づけへの帰結について考えることである
Zooarchaeology using mass spectrometry: an integrative approach to understanding subsistence behavior across the Middle-to-Upper Paleolithic transition in Europe
No full textInternational audienc
miRNA-503 inhibition exerts anticancer effects and reduces tumor growth in mesothelioma
No full textInternational audienceMalignant mesothelioma (MM) is a rare and aggressive form of cancer that affects the mesothelial surfaces, associated with exposure to asbestos fibres. To date, no cure is available for MM and therapeutically approved treatments are based on the use of platinum compounds often used in combination with other drugs. We have previously analysed the efficacy of a cisplatin/piroxicam (CDDP/P) combined treatment showing that this treatment was able to reduce in vivo tumor growth. Several studies reported that platinum-drug sensitivity in cancer is connected to modulation of the expression of non-coding RNAs. In this study we analysed if the CDDP/P treatment was able to modulate miRNAs expression in MM. Methods miRNA sequencing performed on MSTO-211 H cells treated with CDDP with CDDP/P led us to identify miRNA-503 - downregulated by CDDP/P - as a novel miRNA that acts as an oncomiR in MM. The effect of miRNA-503 inhibition was evaluated in vitro in mesothelioma cells analysing apoptosis induction and reduction of cancer properties. Inhibition of miR-503 expression in vivo, was analysed in ectopic mouse model of MM by using LNP encapsulating anti-mir-503 and miR-503 expression was evaluated in human MM samples. Results In vitro and in vivo analysis confirmed miR-503 acts as oncogene in MM since its inhibition was able to reduce cell cancer properties and tumor growth in ectopic mouse model of MM. Its expression was found upregulated in human MM patients compared to normal pleura. Bioinformatic analysis indicated BTG1, CCNG1, EDG1, and TIMP2 as putative target genes of miRNA-503. These genes showed an opposite expression compared to miR-503 levels both in cells and in MM samples. Finally, microarray analysis indicated that miR-503 inhibition affected the expression of the well-known MM biomarkers: CXCL8, SERPINE1 and Osteopontin. Conclusions Our study is the first reporting an oncomiR role for miR-503 in MM and suggests that its inactivation could have a clinical value in MM patients. This study reveals that miRNA-503 acts as an oncomiR in MM suggesting that its inhibition, through LNP delivery, has the potential to be considered as a novel therapeutic strategy in MM
Orient et Occident : transferts culturels à Byzance et au-delà
No full textLes trois textes ici réunis sont issus de la journée d’études « Orient et Occident : transferts culturels à Byzance et au-delà » qui s’est tenue le 13 mai 2024 à l’Institut de recherches historiques de l’EIE (Athènes), en partenariat avec l’École française d’Athènes et le CNRS (UMR 5189 Histoire et Sources des Mondes Antiques HiSoMA) . En partant du principe que les cultures se chevauchent, empruntent les unes aux autres et cohabitent de manière profonde , cette journée d’études s’est proposée de repenser l’articulation entre Orient grec et Occident latin dans une perspective chronologique large, allant de l’Antiquité tardive jusqu’à la période post-byzantine . L’originalité de cette approche consiste à ne pas se borner à l’optique habituellement adoptée qui veut que l’Orient donne et l’Occident reçoive, mais à s’interroger également sur le flux inverse, depuis l’Occident vers l’Orient, en termes d’échanges culturels, linguistiques et artistiques
