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Investigating I/Ca ratio in planktic foraminifera: an integrated approach in the Mediterranean Sea and beyond
No full textInternational audienceGlobal ocean oxygen depletion is a growing concern, with direct observations showing widespread decline that is not fully captured by existing models. The dynamics of oxygenation are critical to marine ecosystem health and are influenced by physical and biogeochemical factors. To reconstruct past variation of dissolved oxygen content, foraminiferal iodine to calcium (I/Ca) ratio has been developed. This proxy is based on the fact that iodine speciation is dependent on oxygen content and that only iodate ions (IO3-) can be incorporated into the calcite lattice by substitution for carbonate ions. However, our knowledge of foraminiferal I/Ca behavior needs improvement because the relationship between planktonic foraminiferal I/Ca and oxygen content in the upper 500m water column appears to be empirical and the influence of physical and biogeochemical parameters has not been fully addressed yet, and thus prohibits the development of a fully quantitative proxy.In this study, we present the first planktic foraminiferal I/Ca data from core-top material (late Holocene) in the Mediterranean Sea and a compilation of previously published core-top and plankton tow I/Ca data from the global ocean. We use this database to examine the influence of the maximum and minimum oxygen concentration, temperature, salinity, nutrients, pH, alkalinity, chlorophyll, water velocities and mixed layer depth on the I/Ca proxy. Additionally, we assess the effects of water depth and sample age to monitor possible iodine accumulation during the foraminiferal test settling and early diagenetic effects. We also investigate the potential for differential behaviour between foraminiferal species by categorising by the presence/absence of symbionts.We find unexpectedly low I/Ca as low as 1 µmol/mol in samples from the western basin of the Mediterranean Sea, providing the first low I/Ca from fossil foraminiferal which lived in waters thought to be highly oxygenated. Principal Component Analysis (PCA) confirms the dominance of oxygen content on foraminiferal I/Ca, however, analysis of the foraminiferal I/Ca residuals after subtraction of oxygen dependence suggest a potential role of temperature. No clear trend is not observed between the residuals and sample age, suggesting a negligible influence of burial diagenesis. Iodine accumulation during the settling of foraminiferal tests has been proposed to explain the high I/Ca of fossil samples when compared to plankton tows, but no trends are visible between our residuals and water depth, implying that there is no systematic effect from post-mortem settling. The cause of low foraminiferal I/Ca in oxygenated waters remains unclear and may involve poorly constrained local oxygen variability, the chemical dynamics of iodine, iodine incorporation mechanisms, or other unknown parameters
Les mondes de Clio
No full textInternational audienceCet article propose une exploration critique de la place des sociétés extra-européennes et extra-occidentales dans les soixante numéros déjà parus de Clio. Après un panorama global des différentes manières dont la revue a intégré l’Ailleurs, il analyse les croisements entre histoire des femmes, du genre et études aréales. Il examine ensuite la manière dont Clio s’est appropriée le « tournant global » qui a marqué l’ensemble des sciences sociales. Si des évolutions se dessinent au fil des trente années de publication, elles ne suivent pas une trajectoire linéaire, l’ouverture aux sociétés autres que française, étasunienne ou d’Europe occidentale s’exprimant sous des formes variées dès les débuts de la revue
Harald Hauptmann ; Luca Maria Olivieri (ed.). 2024. Lords of the mountains: pre-Islamic heritage along the Upper Indus in Pakistan. Heidelberg: Heidelberg University Publishing; 978-3-96822-270-7 hardback €70 Open Access https://doi.org/10.17885/heiup.1358
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High-risk human papillomavirus cervical infection prevalence: a nationwide retrospective study comparing opportunistic and organised screening, France, 2020 to 2023
No full textInternational audienceBACKGROUND In France, cervical cancer screening for females aged 30–65 years primarily tests for high-risk (HR) human papillomavirus (HPV) infections. AIM We aimed to map the prevalence of cervical infections caused by HPV16 and/or 18, or by any of 12 other carcinogenic HPV genotypes and compare prevalence estimates from tests from spontaneous medical visits (opportunistic screening) or the national screening programme (organised screening). METHODS We extracted data from a large network of biology laboratories, containing all available results from HR HPV tests performed between 1 January 2020 and 30 November 2023 in metropolitan France. A full hierarchical Bayesian model was used to compute spatially resolved expected prevalence maps at the postcode level. RESULTS The analytic sample contained results of 362,963 HR HPV tests. Among samples positive for HPV16 and/or 18, 2.9% and 3.8% were from organised and opportunistic screening, respectively. Samples positive for other genotypes were 6.9% and 9.4%, respectively. During the last week of the study (week 48 2023), among females aged 30 years, opportunistic screening was associated with a greater expected prevalence of HPV16 and/or 18 and other genotypes in 97.2% and 99.9% of postcodes, respectively. The probability this percentage was lower among females aged 66 years was below 95% for both genotype groups. For organised screening, a pronounced north-west/south-east gradient in infection prevalence was found across France for both genotype groups, with hotspots located at the border with Italy, Spain and Switzerland.CONCLUSION Opportunistic screening is associated with systematic inflation of HR HPV infection prevalence
L'universalisme de Condorcet au prisme de la critique postcoloniale
No full textInternational audienceCette contribution vise à évaluer la pertinence de la critique post-coloniale de l’universalisme des Lumières lorsqu’elle est appliquée à la philosophie politique de Condorcet. Dans quelle mesure l’approche de la colonisation par cet auteur remet-elle en question son idéal universaliste ? Pour répondre à cette question, nous identifions deux critiques formulées par les penseurs post-coloniaux à l’encontre des Lumières. La première critique soutient que le concept de civilisation a permis aux Lumières de justifier la colonisation, tout en différant l’octroi des droits de l’homme aux non-Européens. La seconde concerne la question de l’autonomie politique des peuples colonisés. En estimant que les nations insuffisamment civilisées ne pouvaient exercer le droit de souveraineté, l’universalisme des Lumières aurait permis de justifier les politiques coloniales au nom de la mission civilisatrice des nations européennes
Hubé Nicolas, La politique des chemins courts : un siècle de relations entre journalistes et communicants gouvernementaux en Allemagne 1918-2018 , Éditions du Croquant, 2022, 404 p
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L’évolution et la structure de la philosophie pratique kantienne
No full textInternational audienceMartial Gueroult avait le projet de publier un grand livre sur Kant issu de son enseignement. Cet ouvrage, qui aurait eu pour titre L’Évolution et la structure de la philosophie kantienne, n’a jamais vu le jour : retravaillés pendant près de quarante ans, les cours sont demeurés inédits. Après la publication, dans la même collection, des manuscrits traitant de la Critique de la raison pure (1957-1958), Arnaud Pelletier propose dans cette édition critique la version finale du cours consacré à la philosophie pratique de Kant, qui fut dispensé au Collège de France pendant deux ans (1958-1959 et 1959-1960).Sans se substituer au livre que Martial Gueroult n’a pas écrit, ce second volume permet de comprendre l’articulation des différentes leçons, tout comme la perspective qui les porte : restituer les difficultés internes des textes de Kant et la manière dont elles suscitent leur propre dépassement. Il donne ainsi à lire comment les problèmes relatifs à la philosophie morale dans la Critique de la raison pure (1781) trouvent leur solution, provisoire, dans le Fondement de la métaphysique des mœurs (1785)
Les témoins et leurs poids d'injustice. Désigner les responsables des dysfonctionnements judiciaires au parlement de Paris (fin XVIe-début XVIIe siècle)
No full textInternational audienceAu tournant des XVIe et XVIIe siècles, les faux témoins focalisent l’attention au sein du royaume de France et tout particulièrement en la chambre criminelle du parlement de Paris. Plusieurs accusés qui y sont jugés, notamment des membres des élites ou ceux qui risquent une lourde peine, redoutent que leur procès soit infesté par ces criminels de la parole. Les transcriptions des interrogatoires contiennent de nombreuses attaques contre les témoins, qui seraient faux, corrompus ou des ennemis. Ces individus dénatureraient le cours des procédures et, faisant peser dessus des intérêts particuliers, ils détruiraient l’équité de traitement que doit garantir le système judiciaire. Les accusés signalent ainsi un dysfonctionnement de la justice, mais sans s’en prendre aux officiers des tribunaux, dont les conseillers du Parlement font partie. Les principaux commis au greffe, qui notent les interrogatoires, ont soin de conserver ces exclamations d’injustice, en les synthétisant parfois. Les conseillers du Parlement, quant à eux, sont pris entre leur volonté de punir le faux témoignage et la difficile vérification de la véracité de ces dénonciations
Using MALDI‐FTICR Mass Spectrometry to Enhance ZooMS Identifications of Pleistocene Bone Fragments Showing Variable Collagen Preservation
No full textInternational audienceABSTRACT Rationale Recent advances in high‐throughput molecular analyses of collagen peptides, especially ZooMS (Zooarchaeology by Mass Spectrometry), have permitted breakthroughs in the analysis of archaeological material that is highly fragmented, a factor that hinders morphological identification. Despite these advances, the challenge of successfully analysing archaeological samples with poorer collagen preservation persists. This paper examines the potential of two mass analysers, TOF ( Time of Flight ) and FTICR ( Fourier‐transform ion cyclotron resonance ), and addresses how they can be used to optimise the ZooMS workflow. Methods Type 1 collagen (COL1) was extracted from 89 archaeological bones from the French Palaeolithic site of Le Piage (37–34 ka cal BP). Three ZooMS extraction protocols were applied, an acid‐free buffer method (AmBic), offering rapid and less destructive analysis, and two methods of acid demineralisation (HCl and TFA) that provide higher peptide resolution. After analysing the specimens with MALDI‐TOF and MALDI‐FTICR, we used bottom‐up and PRM ( Parallel Reaction Monitoring ) LC–MS/MS, and MALDI‐CASI‐FTICR ( Continuous Accumulation of Selected Ions ) to verify 26 ambiguous identifications. Results Overall, 99% of the samples could be identified to at least family level, with the rate of identification and precision varying by method. Despite challenges in detecting specific biomarkers with MALDI‐FTICR—especially peptide A (COL1ɑ2 978–990), which tends to be unstable and poorly ionised—the high resolution of this method allowed the successful identification of more degraded specimens, including burnt bones. Conclusions Our work highlights the robustness of traditional MALDI‐TOF ZooMS for retrieving collagen and for providing taxonomic identifications with low failure rates, features that are critical when processing large numbers of samples. MALDI‐FTICR shows better potential when working with precious samples or degraded collagen. This study advances the analytical detection of peptides by optimising the ZooMS workflow and by tailoring it to specific archaeological contexts showing variation in degree of preservation
