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Nutrient estimation in the Peruvian upwelling system based on a neural network approach
No full textInternational audienceThis study presents a regionally trained version of the “CArbonate system and Nutrients concentration from hYdrological properties and Oxygen using a Neural network” (CANYON) method, named CANYON-PU, for estimating primary macronutrients (phosphates, silicates, and nitrates) in the Peruvian Upwelling System (PUS). Using a neural network approach, the model was trained using extensive biogeochemical data spanning between 2003 and 2021, collected by the Peruvian Institute of Marine Research (IMARPE). Variables representing the low-frequency variability related to ENSO were introduced in the training and significantly improved the performance of the algorithm. The performance of CANYON-PU was validated against independent datasets and demonstrated an improvement in accuracy over the global CANYON model that struggled to represent the nutrient distribution in the PUS mainly due to the lack of samples in its training. Therefore, CANYON-PU successfully captured nutrient variability across different spatial and temporal scales, showcasing its applicability to diverse datasets, including high-frequency data such as profiling floats or gliders. This work highlights the effectiveness of neural networks for representing the nutrient distribution within highly variable ecosystems like the PUS
Comparative Analysis of Tropospheric Water Isotope Distributions on Mars and Earth: Insights into Ice Cloud Microphysical Processes and Storm Dynamics
No full textInternational audienceIsotopic analysis is a critical tool for understanding planetary water cycles and quantifying the role of distinct atmospheric processes. This study investigates the spatio-temporal distribution and controlling factors of the HDO/H₂O ratio in water vapor within the tropospheres of Earth and Mars, highlighting the similarities and differences in water vapor transport and phase changes on both planets.We found significant isotopic enrichment from ice sublimation on both planets, with a stronger effect observed on Mars due to longer ice-crystal residence times, lower atmospheric pressures, and substantial temperature fluctuations. In contrast, Earth's near-surface oceans buffer these isotopic variations. Quantifying ice sublimation effects through observational data could help improve the microphysical parameterization in atmospheric models.Moreover, during Mars's global dust storm, the D/H ratio markedly increased and propagated upward due to reduced condensation and the absence of liquid precipitation. In contrast, Earth-based observations during typhoon events indicate isotopic depletion propagating northward from tropical regions, driven primarily by raindrop evaporation within convective systems. Thus, storm events lead to opposite isotopic responses on Earth (depletion) and Mars (enrichment). Consequently, isotopic signals have considerable potential as proxies for reconstructing storm history and intensity across planetary environments.This comparative analysis underscores both shared and planet-specific aspects of tropospheric water cycling, supporting a unified conceptual framework that effectively explains isotopic distributions under differing planetary conditions. Our results may enhance climate and weather models by improving representations of cloud microphysics and atmospheric water transport, while offering new tools for interpreting past climate events based on isotopic evidence
The NPIS Model: A Standardized, Consensus-Based Framework for Evaluating Non-Pharmacological Interventions
No full textBackground. The term non-pharmacological intervention (NPI) refers to health prevention and care protocols supervised by healthcare professionals. However, no precise and widely adopted definition currently exists. Additionally, unlike drugs, NPIs lack a global evaluation framework due to the absence of consensus among stakeholders, driven by the heterogeneity of intervention content and study protocols. This heterogeneity limits scientific impact, hinders dissemination and continuous improvement of practices, and contributes to significant mistrust among professionals and users. Method. From 2022 to 2023, we conducted a consensus study, collaborating with over 1,000 stakeholders—including researchers, healthcare users, healthcare practitioners, health operators, scientific societies and health authorities—to co-construct a NPI definition along with a framework for evaluating NPIs that aligns with their specific characteristics and international health research standards. This framework—the NPIS Model—was developed under the guidance of a multidisciplinary committee of 22 experts through iterative, open, and documented exchanges across four stages: i) creation of an initial list of ethical and methodological items by a committee of 70 members, ii) refinement of this list by a committee of 300 members, iii) open voting on each item by 503 voters, and iv) consultation with 36 scientific societies and 14 health authorities. Findings. We reached a consensus defining an NPI as an "evidence-based, effective, personalized, non-invasive health prevention or care protocol, registered and supervised by a qualified professional". Based on this definition, we developed the NPIS Model, which includes 77 recommendations for evaluating NPIs—14 ethical and 63 methodological. Each recommendation received at least 80% agreement among voters. The recommendation are categorized into five types of studies: mechanistic, observational, prototypical, intervention, and implementation. To date, the NPIS Model has been endorsed by 31 scientific societies and three health authorities. Interpretation. The NPIS Model promotes transparency, methodological rigor, ethical standards, and transferability for NPI research, increasing the value of NPIs for researchers, healthcare practitioners, healthcare users, and health authorities
Une paramétrisation stochastique du mélange induit par les ondes de gravité non orographiques pour le Modèle Climatique Planétaire de Mars
No full textInternational audienceThis paper presents a formalism of mixing induced by non‐orographic gravity waves (GWs) to integrate with the stochastic GWs scheme in the Mars Planetary Climate Model. We derive the formalism of GWs and their mixing under the same assumptions, integrating the two schemes within a unified framework. Specifically, a surface‐to‐exosphere parameterization of GW‐induced turbulence has been derived in terms of the eddy diffusion coefficient. Simulations show that the coefficient is on the order of 10⁴ to 10⁹ cm² s⁻¹ and a turbopause is at altitudes of 70–140 km, varying with seasons. The triggered mixing has minor effects on model temperatures, yet it substantially impacts upper atmospheric abundances. Simulations are consistent with observations from the Mars Climate Sounder and the Neutral Gas and Ion Mass Spectrometer. Mixing enhances the tracer transports in the middle and upper atmosphere, governing the dynamics of these regions. The scheme reveals how non‐orographic GW‐induced turbulence can regulate upper atmospheric processes, such as tracer escape.Cet article présente un formalisme du mélange induit par les ondes de gravité (OG) non orographiques afin de l’intégrer au schéma stochastique des OG dans le Modèle Climatique Planétaire de Mars. Nous dérivons le formalisme des OG et de leur mélange sous les mêmes hypothèses, en intégrant les deux schémas dans un cadre unifié. Plus précisément, une paramétrisation de la turbulence induite par les OG, de la surface à l’exosphère, a été formulée en termes de coefficient de diffusion turbulente. Les simulations montrent que ce coefficient est de l’ordre de 10⁴ à 10⁹ cm² s⁻¹ et qu’une turbopause se situe entre 70 et 140 km d’altitude, variant selon les saisons. Le mélange ainsi déclenché a un effet limité sur les températures du modèle, mais il influence fortement les abondances de la haute atmosphère. Les simulations sont cohérentes avec les observations du Mars Climate Sounder et du Neutral Gas and Ion Mass Spectrometer. Le mélange renforce le transport des traceurs dans la moyenne et la haute atmosphère, gouvernant la dynamique de ces régions. Ce schéma met en évidence la façon dont la turbulence induite par les OG non orographiques peut réguler les processus de la haute atmosphère, tels que l’échappement des traceurs
Prognostic Significance of Neutrophil-Lymphocyte Ratio in Salivary Gland Neoplasms : A Systematic Review
No full textInternational audienceImportance :Salivary gland tumors (SGTs) are rare and heterogeneous, necessitating improved prognostic tools to optimize patient management.Objective :To evaluate the prognostic value of the neutrophil-to-lymphocyte ratio (NLR) in distinguishing between benign and malignant SGTs, identifying tumor stage, and predicting survival and adverse events.Design :Systematic review conducted according to PRISMA guidelines.Setting :Published clinical studies from tertiary care centers and academic hospitals globally, retrieved from electronic databases (PubMed/MEDLINE, Embase, and Cochrane Library).Participants :Included studies focused on adult and pediatric patients with histologically-confirmed SGTs. Eligibility criteria encompassed all original research articles reporting NLR values related to diagnosis or prognosis of SGTs.Exposure :The exposure of interest was the NLR, evaluated pretreatment in relation to tumor type (benign vs malignant), tumor stage, survival, and adverse treatment outcomes.Main Outcome MeasuresPrimary outcome: prognostic performance of NLR regarding overall survival and disease stage.Results :Seventeen original studies were included, with a median cohort size of 123 patients (range: 20-1989). The mean NLR was 2.86 for distinguishing benign versus malignant SGTs, 2.23 for early-stage versus late-stage malignancy, and 3.62 across different malignant histologic subtypes. An NLR below the cutoff value of 2.51 was significantly associated with improved overall survival (P < .05). A higher cutoff of 3.95 correlated with the presence or absence of grade ≥3 adverse events (P < .05).Conclusions :NLR shows promise as a cost-effective, noninvasive biomarker to stratify malignancy risk, assess tumor stage, and predict prognosis and treatment-related toxicity in both adult and pediatric SGT populations.Relevance :These findings support the integration of NLR into routine pretreatment evaluation protocols for SGTs. Future prospective, multicenter studies are necessary to validate standardized cutoff values for clinical use and to further investigate its role in personalized treatment strategies
Libation rituals in Iron Age Iran? Unveiling the function of funerary pottery vessels at Sialk (Kashan) and Ghalekuti (Dailaman) through typology and organic residue analysis
No full textInternational audiencePottery vessels often comprise major burial goods, providing valuable information for reconstructing the past mortuary practices. However, because of the uncertainty of its function, which has been interpreted mostly through typological studies alone, the analytical potential of funerary pottery has not been fully exploited.This study applies organic residue analyses to funerary pottery vessels of the Necropolises of Sialk excavated in the 1930s and of Ghalekuti excavated in the 1960s. At Ghalekuti results demonstrated that the vessels retained remains of botanical and animal origin 1 . In particular, jars with tubular spouts, were likely specialised for botanical products. Interestingly, both carcass and dairy products from ruminant animals were processed in short-neck jars and bowls, including spouted bowls, suggesting their use in a liquid state. At Sialk, lipids were primarily identified as ruminant adipose fats. Dairy fats were found in only one Iron Age long-spouted pottery vessel, a type distinctive of the Iron Age period 2 .</div
Data-based estimates of ocean carbon uptake biased high from neglect of submonthly atmospheric pressure variability
No full textCurrent estimates of the global ocean carbon sink based on measurements of CO2 fugacity are inconsistent with those obtained from global ocean biogeochemistry models. Here we investigate how this gap might be partially closed by more fully accounting for submonthly variability in observation-based estimates. While these estimates compute the air-sea CO2 flux based on hourly wind speed, other variables have only monthly resolution. Thus they neglect some high-frequency variability from short-term events such as storms. To evaluate this error, we compare fluxes at different temporal resolutions between 2009 and 2018. We find that accounting for hourly variations in atmospheric pressure and daily variations in sea surface temperature decreases the global carbon uptake estimate by 5% (0.12 Pg C yr-1) which is driven by the submonthly covariance between wind speed and atmospheric pressure, particularly in the southern extratropics. This represents 25% of the average gap between observationbased and model estimates
Chronology of mobile pastoralists settlements and dairy exploitation in neolithic Iran through compound-specific radiocarbon analyses of archaeological pottery
No full textInternational audienceAgropastoralism developed in southwest Asia in the 9th millennium BC. The Zagros mountains in Iran are one of the centres of goat domestication. The management of caprine herds and the climatic constraints of this region led to the development of pastoralism with seasonal mobility. The temporary campsites of mobile pastoral groups, which were probably occupied on several occasions, generally include ceramic and lithic materials that are not very distinctive. The dearth of organic materials conventionally used for 14 C dating provides challenges in establishing the chronology of the settlements. Therefore, the development of CSRA of lipids in ceramic vessels provides a unique alternative to resolve the chronology of such campsites. We study first the lipid preservation in about 400 ceramics from Neolithic permanent settlements, open-air campsites, and cave campsites of pastoral groups. It showed a reliance on both carcasses and dairy products of their caprine herds. The overall low lipid preservation led to performing 14C measurements on less than 100 µg of C of lipids in ceramic, which diverged from the routine method with sample sizes over 200 µg of C. We therefore employed the EA-GIS interface linked to ECHoMICADAS to do gas measurements on single lipid. Despite the relatively low precision obtained on the measurements, we were able to: (1) provide chronological context to prospection surveys in the Zagros; (2) show a reuse of three open-air and cave campsites across several centuries or millennia; (3) demonstrate dairy exploitation in the ceramic vessels by pastoral groups in the Zagros mountains was already established during the 7th millennium BC
Development of agropastoralism in Southwest Asia. Cross-dating of archaeological ceramics by radiocarbon and archaeomagnetic dating
No full textInternational audienceThe ERC-StG AGROCHRONO project studies the development of agropastoralism in the Indo-Iranian borderlands. The objectives are to specify the chronological, cultural, economic and environmental framework in which the first agropastoral populations in the region developed from the 7 th millennium BC onwards
Segmentation d'images spectrales de fluorescence X sur la base d'une dissimilarité s'appuyant sur la perte de vraisemblance
No full textNational audienceX-ray fluorescence (XRF) imaging generates large spectral images, recording an energy spectrum at each pixel. It is used in the study of ancient materials to systematically determine homogeneous areas whose XRF determines the elemental composition of the materials. Clustering of such data is tricky because of their volume due to the number of pixels as well as the number of emission energies, undermining methods such as hierarchical clustering. In a previous work, we proposed a hierarchical classification under proximity constraint using a dissimilarity based on a weighted Euclidean distance of χ² between spectra. But this method presented apparent artifacts. In this communication, we take a modeling approach by representing the XRF photon emission by Poisson distributions. This model allows us to propose a dissimilarity based on a difference in log-likelihood and a pseudo-inertia criterion linked to deviance. This new approach is applied to real and simulated datasets. The results obtained show that this criterion is well adapted to the hierarchical clustering of XRF images and outperforms the method using the χ² distance.L’imagerie par fluorescence de rayon-X (XRF) génère des images spectrales de grande taille, enregistrant un spectre d’énergie en chaque pixel. Elle est utilisée en particulier dans l’étude des matériaux anciens afin de déterminer systématiquement des zones homogènes, la fluorescence de rayon-X permettant de déterminer la composition élémentaire des matériaux. Le clustering de telles données est délicat à cause de leur volumétrie, aussi bien en nombre de pixels qu’en nombre d’énergie d’émission, mettant à mal des méthodes comme la classification hiérarchique. Dans un précédent travail, nous avons proposé une classification hiérarchique sous contrainte de proximité utilisant une dissimilarité basée sur la distance euclidienne pondérée du χ² entre les spectres. Mais cette méthode présentait des artefacts manifestes. Dans la présente communication, nous poussons l’exploitation dumodèle posant l’émission de photons XRF par une loi de Poisson en chaque canal. Ceci nous permet de proposer une dissimilarité basée sur une différence de log-vraisemblance et un critère de pseudo-inertie lié à une déviance. Cette nouvelle approche a été appliquée sur des jeux de données réelles et simulées. Les résultats obtenus montrent que ce critère est bien adapté à la segmentation hiérarchique d’images XRF et surpasse en qualité la méthode utilisant la distance du χ²