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High Mortality Due to Pneumococcal Meningitis in Children With Sickle Cell Disease: A French Multicenter Observational Study From 2001 to 2021
No full textInternational audienceBackground: Sickle cell disease (SCD) predisposes children to bacterial infections, particularly invasive pneumococcal disease. Pneumococcal immunization associated with antibiotic prophylaxis reduced the incidence of invasive pneumococcal disease in these patients. However, the risk remains higher than in the general population. Our main objective was to describe the features of pneumococcal meningitis and estimate the case-fatality rate in children with SCD. The secondary objective was to assess serotype distribution and resistance patterns and the proportion of cases related to vaccine failure. Methods: This nationwide multicenter observational study was conducted in France between 2001 and 2021. All cases of pneumococcal meningitis in children with SCD < 18 years old from the French National Registry of Pediatric Pneumococcal Meningitis were included. Results: Of 2145 pneumococcal meningitis, 25 cases (1.2%, 95% CI: 0.8–1.7) occurred in children with SCD [mean age = 4.6 years (±4)], with a high case-fatality rate (28%, n = 7, 95% CI: 10.4–45.6). Nonvaccine serotypes were predominant (n = 15, 65%, 95% CI: 45.8–84.7) over vaccine serotypes (n = 8, 35%, 95% CI: 15.3–54.3). One case of vaccine failure (4%, n = 1/23) and 2 breakthrough cases (n = 2/23, 9%) were observed. Penicillin-non-susceptible Streptococcus pneumoniae strains were identified in 39% (n = 7). Conclusions: The occurrence of pneumococcal meningitis in children with SCD during the pneumococcal conjugate vaccines era was associated with a high case-fatality rate and a predominance of nonvaccine serotypes. The implementation of new serotype-expanded PCV may have a potentially positive impact on this vulnerable population
La dengue en Asie du Sud-Est. Enjeux pour un système de surveillance transnational : Thaïlande, Laos, Cambodge et Viêtnam
No full textInternational audienceDengue is a disease caused by an arbovirus transmitted by mosquito vectors of the Aedes genus, primarily Aedes aegypti and Aedes albopictus, which are widely distributed across Southeast Asia. The region’s climatic conditions favor their proliferation, while increasing urbanization provides abundant breeding sites and opportunities for human-mosquito contact. In the absence of an effective vaccine, monitoring and controlling mosquito populations remain essential strategies for combating the disease, alongside tracking the dynamics of local and regional epidemics. This requires regular monitoring of two key factors: meteorological parameters, which influence the growth and decline of vector populations, and human mobility at local, regional and transnational scales, which shape the spatio-temporal dynamics of dengue transmission. Dengue is therefore a complex pathogenic system, with a geography influenced by both local and transnational factors, requiring multi-scale intervention strategies. This chapter aims to present dengue epidemic surveillance systems in four countries (Thailand, Laos, Cambodia and Vietnam) and to outline the requirements for establishing a transnational surveillance system.La dengue est une maladie virale transmise par les moustiques vecteurs du genre Aedes largement présents dans tous les pays d’Asie du Sud-Est. On y trouve en effet des conditions climatiques favorables à leur prolifération et des taux d’urbanisation croissants qui leur procurent une infinité de lieux de ponte et d’opportunités de piqure. La lutte contre cette maladie passe par la surveillance et le contrôle des populations de moustique, ainsi que par le suivi des dynamiques des épidémies locales et régionales. Cela implique entre autres le suivi régulier de deux facteurs essentiels : les paramètres météorologiques qui impactent directement la croissance et décroissance des populations de vecteur ; les flux des populations humaine aux échelles locales, régionales et transnationales qui orientent les dynamiques spatio-temporelles des cas de dengue. La dengue est ainsi un système pathogène complexe dont la géographie dépend aussi bien de conditions locales que transnationales, nécessitant des interventions à plusieurs échelles. L’objectif de ce chapitre est de présenter les systèmes de surveillance des épidémies de dengue dans quatre pays (Thaïlande, Laos, Cambodge et Viêtnam) et de poser les conditions de la mise en place d’un système de surveillance transnational
Mixotrophy in orchids: facts, questions, and perspectives
No full textInternational audienceWhile orchids germinate thanks to carbon from their symbiotic fungi, variable carbon exchanges exist between adult orchids and their mycorrhizal fungi. Although some truly autotrophic orchids reward their fungi with carbon at adulthood, some species remain achlorophyllous and fully dependent on fungal carbon (mycoheterotrophy). Others are photosynthetic but also import fungal carbon: The so‐called mixotrophic (MX) orchids rely on fungi of diverse taxonomy and ecology. Here, we classify MX nutrition of orchids into three types. Type I mixotrophy associates with diverse Asco‐ and Basidiomycota that are either saprotrophic or ectomycorrhizal, entailing enrichment of the orchids in 2 H, 13 C, and 15 N. The two other types associate with rhizoctonias, a polyphyletic assemblage of Basidiomycotas that is ancestrally mycorrhizal in orchids. Type II mixotrophy associates with rhizoctonias that secondarily evolved into saprotrophic or ectomycorrhizal ecology, and thus enrich the orchid in 2 H, 13 C, and 15 N. Type III mixotrophy, which remains debated, associates with rhizoctonias that have retained their ancestral lifestyle, that is saprotrophic and/or endophytic in nonorchids, and only entail orchid enrichment in 2 H and 15 N. Based on a case study of achlorophyllous variants in Mediterranean Ophrys and on published data, we discuss the distinct nature and research perspectives of type III mixotrophy
The Pioneers of TransAmerican Art: In the Footsteps of a Caribbean Diaspora Aesthetic
No full textThe cosmopolitan aesthetics of the great TransAmerican Diaspora is, at its core, the diasporic repository of a millennial heritage, the bearer of a rich and complex civilization encoded in the mangrovian culture of the Greater Caribbean. Being part of a diasporic continuum, it is based on an oral, iconic, textual and performative literature which is itself a carrier of traditions. The fact that these symbolic, semiotic, mythological, teleological (inherent to Mesoamerican art), and experiential dimensions may have seemed abstruse to the eyes of the first Western chroniclers in no way obviates their intrinsic and primary quality, as the growing interest in native art studies attests today. The TransAmerican aesthetic that the peoples of the Americas have created, recreated, and transmitted for centuries aspires to discursive autonomy and generic authenticity. It supports the march of a civilization that has been progressing for millennia, despite all the obstacles that one would like to oppose it, as testified by recent connections between arts and reparation movements in the Americas. It founds the raison d'être and the daily heritage of the peoples of the Greater Anglophone Caribbean.Contributors to this thematic issue of Angles were invited to underline the connection to these ancestral memories and explore their current resurgence in the visual and living arts. Contributions can bear on scientific, fictional, and secular literature, the genius of dance and music, and the visual, scenic, culinary, performing, visual and ritual arts. Themes of interest could include but are not limited to, decoloniality, body politics, representation, restorative justice, Caribbean indigenous thought and practices, and diasporic art spaces. In the spirit of collegiality that animates this publication project, we intend to create the same dynamic between the communities of researchers and artists of the Greater Anglophone Caribbean. This dynamic is therefore open to all those who want to maintain a constructive dialogue to advance the knowledge and sharing of Caribbean aesthetics in the footsteps of the pioneers of TransAmerican art
Assessing the role of deformation and metamorphic recrystallization in the remobilization of critical metals in orogens
No full textInternational audienceCritical metals (CM) such as rare-earth elements (REE), platinum group elements (PGE), cobalt (Co), germanium (Ge), gallium (Ga), and indium (In) are commonly mined as by-products of base metals (i.e., Zn, Fe, Cu) with similar chemical affinities. Metamorphism can significantly influence the distribution of critical metals in base metal deposits, either upgrading or decreasing their economic importance. Critical metals deposits are frequently hosted in orogenic setting, but may be pre-, syn-or post-orogenesis. In this contribution, we will focus on the primary deposits that might have suffered metamorphism and fluid-assisted deformation during orogenesis, evaluating the role of deformation and metamorphic recrystallization on critical metals. This contribution sheds a novel light on the role of metamorphism, deformation, static or dynamic recrystallization and associated fluid flow in modifying the distribution of CM concentrations from primary into secondary-metamorphosed deposits, in a systematic manner from the large plate tectonic scale to the small mineral scale. Orogenic critical metals (OCM) can be broadly defined as the large-scale remobilization or sample-scale redistribution product of pre-existing CM concentrations, present in the primary ore, that have been triggered by metamorphism and/or tectonic processes (e.g., deformation, static or dynamic recrystallization, fluid and thermodynamic conditions). These processes may have positive or negative impacts on the endowment of the deposit. In either case, metamorphic processes may potentially create favorable conditions for redistributing CM in ore minerals (containing several wt% of CM) that may make them more accessible for industry if exploration/recovery strategies are adapted. In this contribution, the mineralogy and ore textures of ca. 200 deposits reported in the literature have been extracted in a systematic manner and in three regions of the world (Australia, China, and Europe). Based on quantitative estimations from the literature in these three districts, base metal resources, potentially hosting CM, are often found in orogens, and many show features of superimposed deformation and metamorphism. A general model is proposed, representing metamorphic and structural conditions enhancing the formation of orogenic critical metals (OCM).</div
An updated synthesis of ocean total alkalinity and dissolved inorganic carbon measurements from 1993 to 2023: the SNAPO-CO<sub>2</sub>-v2 dataset
No full textInternational audienceAbstract. Total alkalinity (AT) and dissolved inorganic carbon (CT) in the oceans are important properties to understand the ocean carbon cycle and its link with global change (ocean carbon sinks and sources, ocean acidification) and ultimately to find carbon-based solutions or mitigation procedures (marine carbon removal). We present an extended database (SNAPO-CO2; Metzl et al., 2024c) with 24 700 new additional data for the period 2002 to 2023. The full database now includes more than 67 000 AT and CT observations along with basic ancillary data (time and space location, depth, temperature, and salinity) in various oceanic regions obtained since 1993 mainly in the framework of French research projects. This includes both surface and water columns data acquired in open oceans, coastal zones, rivers, the Mediterranean Sea, and either from time series stations or punctual cruises. Most AT and CT data in this synthesis were measured from discrete samples using the same closed-cell potentiometric titration calibrated with certified reference material, with an overall accuracy of ±4 µmol kg−1 for both AT and CT. The same technique was used on board for underway measurements during cruises conducted in the southern Indian and Southern oceans. The AT and CT data from these cruises are also added to this synthesis. The data are provided in one dataset for the global ocean (https://doi.org/10.17882/102337, Metzl et al., 2024c) that offers a direct use for regional or global purposes, e.g., AT–salinity relationships, long-term CT estimates, constraint and validation of diagnostics CT and AT reconstructed fields, ocean carbon and coupled climate–carbon models simulations, and data derived from Biogeochemical Argo (BGC-Argo) floats. These data can also be used to calculate pH, fugacity of CO2 (fCO2), and other carbon system properties to derive ocean acidification rates or air–sea CO2 fluxes
COMMENT DES ENSEIGNANTS DE GUADELOUPE CONÇOIVENT-ILS LA CONTEXTUALISATION DIDACTIQUE LORS D’ACTIVITÉS DE RÉSOLUTION DE PROBLÈMES ?
No full textAccepté pour publication - EMF 2025International audienceThis study explores the effects of didactic contextualization in mathematics through collaborations between middle and high school teachers. It focuses on the design of problem-solving activities adapted to territorial contexts. Using a mixed methodology, including interviews and classroom observations, the analysis focuses on contextualization choices drawn from French and Quebec textbooks. The expected results highlight the importance of pedagogical adjustments to meet the specific needs of students in their learning environment.Cette étude explore les effets de la contextualisation didactique en mathématiques dans les collaborations entre enseignants de collège et de lycée. Elle se concentre sur la conception d'activités de résolution de problèmes adaptées aux contextes territoriaux. En utilisant une méthodologie mixte, incluant des entretiens et des observations, l'analyse se focalise sur les choix de contextualisation tirés de manuels français et québécois. Les résultats attendus mettent en lumière l'importance des ajustements pédagogiques pour répondre aux besoins spécifiques des élèves dans leur environnement d'apprentissage
La fabrique de la ville caribéenne
No full textInternational audienceLa ville caribéenne constitue un objet d’étude singulier et méconnu. Ces établissements humains hétérogènes, parfois héritages des premiers temps coloniaux, concentrent les activités économiques et le pouvoir politiques. La ville attire par sa richesse et offre de multiples opportunités. La lecture de ce type d’espace est complexe, les contradictions abondent dans ces territoires sont composites, désarticulés, fragmentés, mouvants, entre violence et métissage. Insolents îlots de richesse voisinent avec de vastes poches de pauvreté et d’exclusion. C’est la ville refuge des démunis et des sans-logis et sans papiers, les invisibles, les plus vulnérables aux différents risques naturels récurrents. La ville caribéenne, d’aspect chaotique, juxtaposant des fragments de modernité et de doux exotiques anachroniques, objet social et vitrine politique, ouvre un champ d’investigation particulièrement riche. L’objectif de la présente étude est d’analyser les processus de fabrication de cette ville, de donner du sens à l’enchevêtrement de ces établissements humains qui font la ville, où les autoconstructions submergent au quotidien d’ordonnancement urbain projeté depuis les temps coloniaux ; d’où l’intérêt d’interroger les modes de d’organisation sociale initiées par les habitants
Are LSTM and conceptual rainfall-runoff models able to cope with limited training datasets under diverse hydrometeorological conditions?
No full textInternational audienceAs climate change exacerbates variability and non-stationarity in rainfall patterns, it is crucial to assess the predictive capabilities of forecasting models. Previous researches on rainfall-runoff modeling have focused on the impact of training dataset size on Artificial Neural Networks (ANNs) results, with limited consideration of hydrometeorological diversity. This study first evaluates the influence of the training dataset length (1 to 15 years) on performance of a Long Short-Term Memory (LSTM) and a traditional conceptual model, Superflex, across 10 validation years. Next, training years are categorized based on hydrometeorological diversity (wetter, standard, drier). This clustering allows for experiments where models are trained on data from similar or different clusters, enhancing understanding of how data diversity, and therefore climate change, can affect model performance. Results indicate that the LSTM model is highly sensitive to training length, showing poor performance with short datasets (below three years), reaches similar performance to Superflex around six training years on average, and overperforms with 15 years of training. Conversely, Superflex maintains rather constant performance levels regardless of the dataset length. LSTM model benefits from diverse 1 training data, achieving higher accuracy and reliability when trained on years with diverse hydrological typology. Despite their potential to outperform traditional models (with six or more training years on average), LSTM models are highly dependent on the quality and diversity of training data. In climate change scenarios, caution is needed when applying LSTM models to unfamiliar conditions, as their predictive accuracy may decline more rapidly than that of more traditional hydrological models
High prevalence and incidence of HSV-2 among people who inject drugs in Hai Phong, Vietnam, and risk factors associated with seroconversion
No full textInternational audienceAbstract Purpose Genital Herpes Simplex Virus-2 (HSV-2) epidemic is highly active worldwide and can be associated with severe morbidity and mortality. This study aimed to estimate the prevalence and incidence of HSV-2 infection among a vulnerable population of active heroin injectors in Hai Phong, Vietnam, and identify associated risk factors. Method Associations between HSV-2 infection and socio-demographic characteristics and sexual behaviors were explored in a univariable analysis of seroprevalence. Risk factors were defined using a multivariable Poisson regression accounting for time of follow-up. Results HSV-2 seroprevalence at baseline was 20.8% [95%CI: 17.8–22.2] for the 1281 men people who inject drugs (PWID), and 67.4% [95%CI: 60.1–74.1] for the 184 women PWID. For HSV-2 incidence, we accumulated a follow-up time of 1156.0 and 85.9 years for men and women, respectively. Standardised incidence rate was 4 [95%CI: 2.2–7.5] and 17.5 [95%CI: 5.7–53.8] infections per 100 person-years for men and women, respectively. Factors independently associated with HSV-2 seroconversion were HIV and injecting drug use for 5–10 years for men, and declared an uncontrolled HIV viral load and the use of street methadone. Conclusion High HSV-2 prevalence and incidence among PWID in Hai Phong point out the burden of sexually transmissible infections in this population. Together these results advocate for a reinforcement of HSV-2 care and prevention in this population and identify PWID as future beneficiaries of upcoming therapeutic/prophylactic vaccines