Acceptability of self-collected vaginal samples for HPV testing in an urban and rural population of Madagascar

Objective: To evaluate the acceptability of self-collected vaginal samples for HPV testing in women living in rural and urban areas of Madagascar. Materials and Methods: Participants were recruited in a health care center (urban group) and smaller affiliated dispensaries (rural group). They were invited to perform unsupervised self-sampling for HPV testing and to answer a questionnaire on socio-demographic information, cervical cancer knowledge and self-sampling acceptability. Results: A total of 300 women were recruited. Median age was 44.1 years (range 29-65 years) in the urban group and 40.9 years (range 29-65 years) in the rural group. Urban women had improved knowledge on HPV, cervical cancer and cervical cancer screening (p<0.05) as compared to rural women. Urban women lived closer to a health care center (P<0.05), had fewer different sexual partners (P<0.05) and later first sexual intercourse (p=0.07). Unlike urban women, most rural women were married (p<0.05). Conclusion: Acceptability of self-sampling for HPV testing was similarly excellent in both groups despite their difference in terms of socio-demographic factors and knowledge about cervical cancer

Reducing uncertainties in decadal variability of the global carbon budget with multiple datasets

Conventional calculations of the global carbon budget infer the land sink as a residual between emissions, atmospheric accumulation, and the ocean sink. Thus, the land sink accumulates the errors from the other flux terms and bears the largest uncertainty. Here, we present a Bayesian fusion approach that combines multiple observations in different carbon reservoirs to optimize the land (B) and ocean (O) carbon sinks, land use change emissions (L), and indirectly fossil fuel emissions (F) from 1980 to 2014. Compared with the conventional approach, Bayesian optimization decreases the uncertainties in B by 41% and in O by 46%. The L uncertainty decreases by 47%, whereas F uncertainty is marginally improved through the knowledge of natural fluxes. Both ocean and net land uptake (B + L) rates have positive trends of 29 ± 8 and 37 ± 17 Tg C⋅y−2 since 1980, respectively. Our Bayesian fusion of multiple observations reduces uncertainties, thereby allowing us to isolate important variability in global carbon cycle processes

Recent Changes in Global Photosynthesis and Terrestrial Ecosystem Respiration Constrained From Multiple Observations

To assess global carbon cycle variability, we decompose the net land carbon sink into the sum of gross primary productivity (GPP), terrestrial ecosystem respiration (TER), and fire emissions and apply a Bayesian framework to constrain these fluxes between 1980 and 2014. The constrained GPP and TER fluxes show an increasing trend of only half of the prior trend simulated by models. From the optimization, we infer that TER increased in parallel with GPP from 1980 to 1990, but then stalled during the cooler periods, in 1990-1994 coincident with the Pinatubo eruption, and during the recent warming hiatus period. After each of these TER stalling periods, TER is found to increase faster than GPP, explaining a relative reduction of the net land sink. These results shed light on decadal variations of GPP and TER and suggest that they exhibit different responses to temperature anomalies over the last 35 years

The consolidated European synthesis of CO2emissions and removals for the European Union and United Kingdom : 1990-2018

Acknowledgements FAOSTAT statistics are produced and disseminated with the support of its member countries to the FAO regular budget. Philippe Ciais acknowledges the support of the European Research Council Synergy project SyG-2013-610028 IMBALANCE-P and from the ANR CLAND Convergence Institute. We acknowledge the work of the entire EDGAR group (Marilena Muntean, Diego Guizzardi, Edwin Schaaf and Jos Olivier). We acknowledge Stephen Sitch and the authors of the DGVMs TRENDY v7 ensemble models for providing us with the data. Financial support This research has been supported by the H2020 European Research Council (grant no. 776810).Peer reviewedPublisher PD

The consolidated European synthesis of CO2 emissions and removals for the European Union and United Kingdom: 1990–2020

Quantification of land surface–atmosphere fluxes of carbon dioxide (CO2) and their trends and uncertainties is essential for monitoring progress of the EU27+UK bloc as it strives to meet ambitious targets determined by both international agreements and internal regulation. This study provides a consolidated synthesis of fossil sources (CO2 fossil) and natural (including formally managed ecosystems) sources and sinks over land (CO2 land) using bottom-up (BU) and top-down (TD) approaches for the European Union and United Kingdom (EU27+UK), updating earlier syntheses (Petrescu et al., 2020, 2021). Given the wide scope of the work and the variety of approaches involved, this study aims to answer essential questions identified in the previous syntheses and understand the differences between datasets, particularly for poorly characterized fluxes from managed and unmanaged ecosystems. The work integrates updated emission inventory data, process-based model results, data-driven categorical model results, and inverse modeling estimates, extending the previous period 1990–2018 to the year 2020 to the extent possible. BU and TD products are compared with the European national greenhouse gas inventory (NGHGI) reported by parties including the year 2019 under the United Nations Framework Convention on Climate Change (UNFCCC). The uncertainties of the EU27+UK NGHGI were evaluated using the standard deviation reported by the EU member states following the guidelines of the Intergovernmental Panel on Climate Change (IPCC) and harmonized by gap-filling procedures. Variation in estimates produced with other methods, such as atmospheric inversion models (TD) or spatially disaggregated inventory datasets (BU), originate from within-model uncertainty related to parameterization as well as structural differences between models. By comparing the NGHGI with other approaches, key sources of differences between estimates arise primarily in activities. System boundaries and emission categories create differences in CO2 fossil datasets, while different land use definitions for reporting emissions from land use, land use change, and forestry (LULUCF) activities result in differences for CO2 land. The latter has important consequences for atmospheric inversions, leading to inversions reporting stronger sinks in vegetation and soils than are reported by the NGHGI. For CO2 fossil emissions, after harmonizing estimates based on common activities and selecting the most recent year available for all datasets, the UNFCCC NGHGI for the EU27+UK accounts for 926 ± 13 Tg C yr−1, while eight other BU sources report a mean value of 948 [937,961] Tg C yr−1 (25th, 75th percentiles). The sole top-down inversion of fossil emissions currently available accounts for 875 Tg C in this same year, a value outside the uncertainty of both the NGHGI and bottom-up ensemble estimates and for which uncertainty estimates are not currently available. For the net CO2 land fluxes, during the most recent 5-year period including the NGHGI estimates, the NGHGI accounted for −91 ± 32 Tg C yr−1, while six other BU approaches reported a mean sink of −62 [] Tg C yr−1, and a 15-member ensemble of dynamic global vegetation models (DGVMs) reported −69 [] Tg C yr−1. The 5-year mean of three TD regional ensembles combined with one non-ensemble inversion of −73 Tg C yr−1 has a slightly smaller spread (0th–100th percentiles of [] Tg C yr−1), and it was calculated after removing net land–atmosphere CO2 fluxes caused by lateral transport of carbon (crop trade, wood trade, river transport, and net uptake from inland water bodies), resulting in increased agreement with the NGHGI and bottom-up approaches. Results at the category level (Forest Land, Cropland, Grassland) generally show good agreement between the NGHGI and category-specific models, but results for DGVMs are mixed. Overall, for both CO2 fossil and net CO2 land fluxes, we find that current independent approaches are consistent with the NGHGI at the scale of the EU27+UK. We conclude that CO2 emissions from fossil sources have decreased over the past 30 years in the EU27+UK, while land fluxes are relatively stable: positive or negative trends larger (smaller) than 0.07 (−0.61) Tg C yr−2 can be ruled out for the NGHGI. In addition, a gap on the order of 1000 Tg C yr−1 between CO2 fossil emissions and net CO2 uptake by the land exists regardless of the type of approach (NGHGI, TD, BU), falling well outside all available estimates of uncertainties. However, uncertainties in top-down approaches to estimate CO2 fossil emissions remain uncharacterized and are likely substantial, in addition to known uncertainties in top-down estimates of the land fluxes. The data used to plot the figures are available at https://doi.org/10.5281/zenodo.8148461 (McGrath et al., 2023)

The lithosphere of Mars

La partie externe, rigide, et froide d'une planète est conventionnellement appelée lithosphère. Lorsque la lithosphère est soumise à des charges telles qu'un volcan ou un calotte polaire, elle dévie de son état initial et se fléchie. Ce mécanisme de compensation génère deux principaux observables, détectables depuis l'orbite: des anomalies gravimétriques et des variations topographiques. Ces données peuvent être couplées à un modèle géophysique, afin de déterminer la densité et composition de la charge, ainsi que l'épaisseur élastique de la lithosphère (Te). Te est directement liée à l'état thermique de l'intérieur et fournie des contraintes cruciales afin de déterminer l'évolution géologique de la planète. Cette thèse caractérise l'évolution thermo-mécanique de la lithosphère de Mars au cours des temps géologiques, en s'appuyant sur des données gravimétriques, topographiques, et radars. Dans une première partie, nous présentons une analyse de Broquet & Wieczorek (2019) sur la signature gravitationnelle de 18 volcans Martiens. Nous modélisons la déformation de la lithosphère sujette à leurs charges et comparons le signal gravitationnel théorique associé, aux observations. La densité apparente moyenne obtenue est de 3200 ± 200 kg m-3, ce qui est représentatif d'un basalte riche en fer, tel qu'échantillonné par les météorites basaltiques Martiennes. Te était fine, 3.2 Ga) se sont formés, et implique que la lithosphère était peu rigide et fine, à l'aube de l'histoire géologique de la planète. A l'inverse, nous obtenons que les plus jeunes volcans ( 3.2 Ga, 0.5 to 7.4 km) formed. This implies that the lithosphere was hot and thin early in geologic history. Conversely, most younger and larger prominent constructs within the Tharsis and Elysium provinces (< 3 Ga, 5.8 to 21.9 km) were emplaced on a colder and thicker lithosphere, 30 to 100 km, which is consistent with the bulk of their emplacement occurring later in geologic history. In the second part, we discuss a study by Broquet et al. (2020) that analyzes the flexure of the lithosphere beneath the north polar cap, and present results for the south polar cap. The polar caps are geologically young (< 10 Ma) and transparent to sounding radars, giving us a unique insight into their composition and the present-day geodynamic response of the lithosphere. We show that the lithosphere is thick and cold at the north and south poles, with Te larger than 330 and 175 km, respectively. In the absence of in situ heat flow measurements, the derived Te provide the best estimates for the present-day thermal state of Mars. Our inferred compositions suggest that, for reasonable dust contents, about 10 vol% CO2 ice is mixed within the north polar deposits, the rest being water ice. The south polar cap potentially harbors lots of CO2 ice (up to 38 vol%). Like on Earth, where the composition of buried ices gives hints on the climatic evolution, having CO2 ice at the poles pole will help improve scenarios for the climate and orbital evolution of Mars. In the last part, we discuss the thermo-mechanical properties and composition of the crust and lithosphere on a global scale. Based on a gravity analysis, we show that the bulk density of the surface varies laterally, with an average of about 2500 ± 370 kg m-3. This value is significantly lower than what was found for the volcanic regions, which suggests that the subsurface has been heavily reworked by sedimentary processes that either modified the material composition or generated significant porosity. Alternatively, we propose that the crust could be felsic-rich, and not basaltic in composition. Based on a comparison of our Te estimates to that obtained from thermal evolution models of Mars, we constrain that more than half of the planet's bulk abundance in radiogenics are located in the crust. For nominal compositional models, only thermal models with an average crustal thickness of 60 km fit our range of Te. These constraints will help to determine how the InSight local estimate on the crustal thickness relates to the global scale properties, and what is the bulk composition of the planet