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Climate change has prompted nations, provinces, and cities to take actions to reduce anthropogenic sources of CO2 and other greenhouse gases. Accurate and consistent quantification of the emissions is required for both scientists and policymakers. Inventories of the CO2 emissions due to fossil fuel combustion are based on statistical data collected and reported by the emitters themselves and their quality is highly variable between countries. In principle, atmospheric measurements and inverse modeling could provide independent information to verify and evaluate these emissions. However, there are difficulties to separate the fossil fuel CO2 signal (FFCO2) from the signal of natural CO2 fluxes, in the atmospheric CO2 measurements from ground based continental networks. In this thesis, I aimed to improve the understanding of the potential of atmospheric 14CO2 measurements, one of the few tracers helping to separate FFCO2 from the signal of other CO2 sources, for the objective estimate of the fossil fuel emissions at national or provincial scales based on atmospheric inversion.I developed global inversion systems based on the global coarse-resolution (2.5°×3.75°) LMDZ atmospheric transport model, and on continental networks of atmospheric observations of CO2 and 14CO2, solving for the fossil fuel emissions at sub-continental / monthly scales in Europe and in China.In Chapter 2, I defined and quantified critical sources of modeling errors and their impact on the inversion of large-scale budget of the fossil fuel emissions when using a global inversion system and assuming FFCO2 data can be directly derived from 14CO2 measurements. The analysis highlighted the impact of ignoring the spatial distribution of the emissions and FFCO2 at a resolution higher than that of the transport model.In Chapter 3, I applied inversions with the system, assumptions and diagnostics of the modeling error from Chapter 2 in a series of Observing System Simulation Experiments to evaluate the skill of such an inversion system and of different virtual observation networks for estimating regional budgets of fossil fuel emissions in Europe. Results indicate that if assimilating continuous 2-week mean FFCO2 data from 17 existing 14CO2 European sites, the inversion would reduce the uncertainties in monthly fossil fuel emissions of western Germany by 30% compared to the assumed uncertainty in the inventories used as a prior knowledge in the Bayesian framework of the inversion. Using a larger network of 43 European sites that may be available in the future, up to 47% uncertainty reduction could be achieved for annual budgets of fossil fuel emissions for regions where the network would be the densest.In Chapter 4, I implemented a global isotopic inversion system that jointly assimilates atmospheric observations of CO2 and 14CO2 to simultaneously solve for fossil fuel emissions and natural CO2 fluxes over Europe and China. The purpose is to move beyond the assumption that variations in 14CO2 relate only to FFCO2 by accounting for non-fossil 14CO2 fluxes. The results confirm that 14CO2 data are useful to separate FFCO2 from the signal of natural fluxes at sites close to large emission regions, making 2-week mean 14CO2 data more efficient than daily CO2 data for estimating the emissions. ; Dans le contexte du réchauffement climatique, des états et des villes s'engagent à réduire leurs émissions de gaz à effet de serre et en particulier celles de CO2. Une quantification précise des émissions est nécessaire aux scientifiques et aux décideurs politiques. La qualité des inventaires des émissions dues à la consommation des combustibles fossiles, qui reposent sur des données statistiques compilées et rapportées par les émetteurs, reste très variable selon les pays. Les mesures atmosphériques et la modélisation inverse pourraient fournir une information indépendante pour la vérification de ces émissions. Il est cependant difficile de séparer le signal de CO2 fossile (CO2CF) du signal des flux naturels dans les mesures atmosphériques fournies par les réseaux continentaux de mesure au sol. L'objectif de ma thèse est d'améliorer la compréhension du potentiel des données de 14CO2, un des traceurs permettant de séparer le signal de CO2CF des autres sources de CO2, pour l'estimation objective des émissions fossiles aux échelles nationales par inversion atmosphérique.J'ai développé des systèmes d'inversions mondiaux basés sur le modèle de transport atmospherique LMDz à basse résolution (2.5° ×3.75°), et reposant sur des réseaux de mesure du CO2 et du 14CO2, résolvant les émissions fossiles à l'échelle subcontinentale / mensuelle en Europe et en Chine.Dans le Chapitre 2, j'ai défini et quantifié les sources d'erreurs de modélisationprincipales, puis analysé leur impact pour l'estimation des bilans d'émissions fossiles à grande échelle avec un système d'inversion mondial en faisant l'hypothèse que les données de CO2CF peuvent être directement déduites des données de 14CO2. Les analyses soulignent l'impact de la méconnaissance de la distribution spatiale des émissions de CO2 et du CO2CF aux résolutions spatiales plus fines que celle du modèle de transport.Dans le Chapitre 3, j'ai utilisé le système, les hypothèses et les diagnostics d'erreurs de modélisation du Chapitre 2 dans une série d'expériences avec des données synthétiques pour évaluer le potentiel d'un tel système d'inversion et de différents réseaux d'observation virtuels pour l'estimation les bilans régionaux d' émission fossile en Europe. Les résultats indiquent qu'en assimilant des moyennes sur 2 semaines de mesures CO2CF issues du réseau actuel de 17 sites 14CO2 en Europe, l'inversion réduirait l'incertitude sur les émissions mensuelles pour l'Ouest de l'Allemagne de 30% par rapport à l'incertitude supposée sur les inventaires utilisés comme connaissance a priori dans le cadre du formalisme Bayésien de l'inversion. En utilisant un réseau plus dense en Europe, constitué de 43 futurs sites, des réductions d'incertitude de 47% pourraient être réalisées pour les bilans annuels des émissions pour les régions où le réseau serait le plus dense.Dans le Chapitre 4, j'ai implémenté un système d'inversion global isotopique permettant d'assimiler conjointement des données atmosphériques de CO2 et de 14CO2 pour résoudre simultanément les émissions fossiles et les flux naturels de CO2 en Europe et en Chine. L'objectif est de dépasser l'hypothèse que les variations de 14CO2 ne sont liées qu'au CO2CF, en tenant compte ses flux de 14CO2 non fossiles. Les résultats confirment que les données de 14CO2 sont utiles pour séparer le CO2CF du signal des flux naturels près des régions fortement émettrices, rendant les données de 14CO2 moyennes sur 2 semaines plus efficaces que les données journalières de CO2 pour l'estimation des émissions.

Climate change has prompted nations, provinces, and cities to take actions to reduce anthropogenic sources of CO2 and other greenhouse gases. Accurate and consistent quantification of the emissions is required for both scientists and policymakers. Inventories of the CO2 emissions due to fossil fuel combustion are based on statistical data collected and reported by the emitters themselves and their quality is highly variable between countries. In principle, atmospheric measurements and inverse modeling could provide independent information to verify and evaluate these emissions. However, there are difficulties to separate the fossil fuel CO2 signal (FFCO2) from the signal of natural CO2 fluxes, in the atmospheric CO2 measurements from ground based continental networks. In this thesis, I aimed to improve the understanding of the potential of atmospheric 14CO2 measurements, one of the few tracers helping to separate FFCO2 from the signal of other CO2 sources, for the objective estimate of the fossil fuel emissions at national or provincial scales based on atmospheric inversion.I developed global inversion systems based on the global coarse-resolution (2.5°×3.75°) LMDZ atmospheric transport model, and on continental networks of atmospheric observations of CO2 and 14CO2, solving for the fossil fuel emissions at sub-continental / monthly scales in Europe and in China.In Chapter 2, I defined and quantified critical sources of modeling errors and their impact on the inversion of large-scale budget of the fossil fuel emissions when using a global inversion system and assuming FFCO2 data can be directly derived from 14CO2 measurements. The analysis highlighted the impact of ignoring the spatial distribution of the emissions and FFCO2 at a resolution higher than that of the transport model.In Chapter 3, I applied inversions with the system, assumptions and diagnostics of the modeling error from Chapter 2 in a series of Observing System Simulation Experiments to evaluate the skill of such an inversion system and of different virtual observation networks for estimating regional budgets of fossil fuel emissions in Europe. Results indicate that if assimilating continuous 2-week mean FFCO2 data from 17 existing 14CO2 European sites, the inversion would reduce the uncertainties in monthly fossil fuel emissions of western Germany by 30% compared to the assumed uncertainty in the inventories used as a prior knowledge in the Bayesian framework of the inversion. Using a larger network of 43 European sites that may be available in the future, up to 47% uncertainty reduction could be achieved for annual budgets of fossil fuel emissions for regions where the network would be the densest.In Chapter 4, I implemented a global isotopic inversion system that jointly assimilates atmospheric observations of CO2 and 14CO2 to simultaneously solve for fossil fuel emissions and natural CO2 fluxes over Europe and China. The purpose is to move beyond the assumption that variations in 14CO2 relate only to FFCO2 by accounting for non-fossil 14CO2 fluxes. The results confirm that 14CO2 data are useful to separate FFCO2 from the signal of natural fluxes at sites close to large emission regions, making 2-week mean 14CO2 data more efficient than daily CO2 data for estimating the emissions. ; Dans le contexte du réchauffement climatique, des états et des villes s'engagent à réduire leurs émissions de gaz à effet de serre et en particulier celles de CO2. Une quantification précise des émissions est nécessaire aux scientifiques et aux décideurs politiques. La qualité des inventaires des émissions dues à la consommation des combustibles fossiles, qui reposent sur des données statistiques compilées et rapportées par les émetteurs, reste très variable selon les pays. Les mesures atmosphériques et la modélisation inverse pourraient fournir une information indépendante pour la vérification de ces émissions. Il est cependant difficile de séparer le signal de CO2 fossile (CO2CF) du signal des flux naturels dans les mesures atmosphériques fournies par les réseaux continentaux de mesure au sol. L'objectif de ma thèse est d'améliorer la compréhension du potentiel des données de 14CO2, un des traceurs permettant de séparer le signal de CO2CF des autres sources de CO2, pour l'estimation objective des émissions fossiles aux échelles nationales par inversion atmosphérique.J'ai développé des systèmes d'inversions mondiaux basés sur le modèle de transport atmospherique LMDz à basse résolution (2.5° ×3.75°), et reposant sur des réseaux de mesure du CO2 et du 14CO2, résolvant les émissions fossiles à l'échelle subcontinentale / mensuelle en Europe et en Chine.Dans le Chapitre 2, j'ai défini et quantifié les sources d'erreurs de modélisationprincipales, puis analysé leur impact pour l'estimation des bilans d'émissions fossiles à grande échelle avec un système d'inversion mondial en faisant l'hypothèse que les données de CO2CF peuvent être directement déduites des données de 14CO2. Les analyses soulignent l'impact de la méconnaissance de la distribution spatiale des émissions de CO2 et du CO2CF aux résolutions spatiales plus fines que celle du modèle de transport.Dans le Chapitre 3, j'ai utilisé le système, les hypothèses et les diagnostics d'erreurs de modélisation du Chapitre 2 dans une série d'expériences avec des données synthétiques pour évaluer le potentiel d'un tel système d'inversion et de différents réseaux d'observation virtuels pour l'estimation les bilans régionaux d' émission fossile en Europe. Les résultats indiquent qu'en assimilant des moyennes sur 2 semaines de mesures CO2CF issues du réseau actuel de 17 sites 14CO2 en Europe, l'inversion réduirait l'incertitude sur les émissions mensuelles pour l'Ouest de l'Allemagne de 30% par rapport à l'incertitude supposée sur les inventaires utilisés comme connaissance a priori dans le cadre du formalisme Bayésien de l'inversion. En utilisant un réseau plus dense en Europe, constitué de 43 futurs sites, des réductions d'incertitude de 47% pourraient être réalisées pour les bilans annuels des émissions pour les régions où le réseau serait le plus dense.Dans le Chapitre 4, j'ai implémenté un système d'inversion global isotopique permettant d'assimiler conjointement des données atmosphériques de CO2 et de 14CO2 pour résoudre simultanément les émissions fossiles et les flux naturels de CO2 en Europe et en Chine. L'objectif est de dépasser l'hypothèse que les variations de 14CO2 ne sont liées qu'au CO2CF, en tenant compte ses flux de 14CO2 non fossiles. Les résultats confirment que les données de 14CO2 sont utiles pour séparer le CO2CF du signal des flux naturels près des régions fortement émettrices, rendant les données de 14CO2 moyennes sur 2 semaines plus efficaces que les données journalières de CO2 pour l'estimation des émissions.

Basic medical insurance is the critical medical security system to realize common prosperity in China. This study explores the impact of basic medical insurance on elderly family income inequality in China using the China Family Panel Studies (CFPS) data in 2018. Our finding shows that basic medical insurance is significantly negatively correlated with elderly family income inequality, indicating basic medical insurance has a positive impact on narrowing the elderly family income inequality. The heterogeneity analysis shows that basic medical insurance has a more significant reduction effect among the eastern elderly and the younger elderly family. The results also suggest that health performance significantly mediates the relationship between basic medical insurance and elderly family income inequality. This study implies that the Chinese government should increase the proportion of basic medical insurance reimbursement and expand the scope of reimbursement for basic medical insurance to realize income fairness among elderly families.

International audience ; Natural gas use accounts for ≈38% of the fossil fuel CO 2 emissions in Europe, including the EU27 and UK (Eurostat, 2021). The share of this fossil fuel in the energy mix has been growing since 1990 at the expense of oil and coal, as it is viewed as a cleaner source of energy (IEA, 2021). The main sectors using natural gas are the built environment (residential, public and commercial buildings), the industry, and the electricity production (Eurostat, 2021). In addition to steadily growing natural gas use, the COVID-19 pandemic profoundly disrupted economic activities and the energy demand, beginning in early March of 2020. Specifically, the government policies restricted mobility and confined people at home during "lockdowns", and reduced or closed industrial and non-essential commercial activities, with impacts on gas use and pertaining CO 2 emissions. Although such impacts have been noted by recent reports (IEA, 2020a, 2020b), they have not yet been quantified and analyzed in detail. During the cold season period when the pandemic arrived in Europe, natural gas consumption is typically high due to the heating demand in the built environment, which represents 52% of the total gas consumption from all-sectors averaged over January to June. For both residential and commercial buildings, gas consumption is typically inversely proportional to daily air temperature when temperatures fall below a comfort threshold "critical

International audience ; Natural gas use accounts for ≈38% of the fossil fuel CO 2 emissions in Europe, including the EU27 and UK (Eurostat, 2021). The share of this fossil fuel in the energy mix has been growing since 1990 at the expense of oil and coal, as it is viewed as a cleaner source of energy (IEA, 2021). The main sectors using natural gas are the built environment (residential, public and commercial buildings), the industry, and the electricity production (Eurostat, 2021). In addition to steadily growing natural gas use, the COVID-19 pandemic profoundly disrupted economic activities and the energy demand, beginning in early March of 2020. Specifically, the government policies restricted mobility and confined people at home during "lockdowns", and reduced or closed industrial and non-essential commercial activities, with impacts on gas use and pertaining CO 2 emissions. Although such impacts have been noted by recent reports (IEA, 2020a, 2020b), they have not yet been quantified and analyzed in detail. During the cold season period when the pandemic arrived in Europe, natural gas consumption is typically high due to the heating demand in the built environment, which represents 52% of the total gas consumption from all-sectors averaged over January to June. For both residential and commercial buildings, gas consumption is typically inversely proportional to daily air temperature when temperatures fall below a comfort threshold "critical

International audience ; Natural gas use accounts for ≈38% of the fossil fuel CO 2 emissions in Europe, including the EU27 and UK (Eurostat, 2021). The share of this fossil fuel in the energy mix has been growing since 1990 at the expense of oil and coal, as it is viewed as a cleaner source of energy (IEA, 2021). The main sectors using natural gas are the built environment (residential, public and commercial buildings), the industry, and the electricity production (Eurostat, 2021). In addition to steadily growing natural gas use, the COVID-19 pandemic profoundly disrupted economic activities and the energy demand, beginning in early March of 2020. Specifically, the government policies restricted mobility and confined people at home during "lockdowns", and reduced or closed industrial and non-essential commercial activities, with impacts on gas use and pertaining CO 2 emissions. Although such impacts have been noted by recent reports (IEA, 2020a, 2020b), they have not yet been quantified and analyzed in detail. During the cold season period when the pandemic arrived in Europe, natural gas consumption is typically high due to the heating demand in the built environment, which represents 52% of the total gas consumption from all-sectors averaged over January to June. For both residential and commercial buildings, gas consumption is typically inversely proportional to daily air temperature when temperatures fall below a comfort threshold "critical

International audience ; Natural gas use accounts for ≈38% of the fossil fuel CO 2 emissions in Europe, including the EU27 and UK (Eurostat, 2021). The share of this fossil fuel in the energy mix has been growing since 1990 at the expense of oil and coal, as it is viewed as a cleaner source of energy (IEA, 2021). The main sectors using natural gas are the built environment (residential, public and commercial buildings), the industry, and the electricity production (Eurostat, 2021). In addition to steadily growing natural gas use, the COVID-19 pandemic profoundly disrupted economic activities and the energy demand, beginning in early March of 2020. Specifically, the government policies restricted mobility and confined people at home during "lockdowns", and reduced or closed industrial and non-essential commercial activities, with impacts on gas use and pertaining CO 2 emissions. Although such impacts have been noted by recent reports (IEA, 2020a, 2020b), they have not yet been quantified and analyzed in detail. During the cold season period when the pandemic arrived in Europe, natural gas consumption is typically high due to the heating demand in the built environment, which represents 52% of the total gas consumption from all-sectors averaged over January to June. For both residential and commercial buildings, gas consumption is typically inversely proportional to daily air temperature when temperatures fall below a comfort threshold "critical

International audience ; Natural gas use accounts for ≈38% of the fossil fuel CO 2 emissions in Europe, including the EU27 and UK (Eurostat, 2021). The share of this fossil fuel in the energy mix has been growing since 1990 at the expense of oil and coal, as it is viewed as a cleaner source of energy (IEA, 2021). The main sectors using natural gas are the built environment (residential, public and commercial buildings), the industry, and the electricity production (Eurostat, 2021). In addition to steadily growing natural gas use, the COVID-19 pandemic profoundly disrupted economic activities and the energy demand, beginning in early March of 2020. Specifically, the government policies restricted mobility and confined people at home during "lockdowns", and reduced or closed industrial and non-essential commercial activities, with impacts on gas use and pertaining CO 2 emissions. Although such impacts have been noted by recent reports (IEA, 2020a, 2020b), they have not yet been quantified and analyzed in detail. During the cold season period when the pandemic arrived in Europe, natural gas consumption is typically high due to the heating demand in the built environment, which represents 52% of the total gas consumption from all-sectors averaged over January to June. For both residential and commercial buildings, gas consumption is typically inversely proportional to daily air temperature when temperatures fall below a comfort threshold "critical

BACKGROUND: One of the most cost-effective treatments for secondary prevention of stroke and other non-communicable diseases is a long-term medication regimen. However, the complexities of medication adherence extend far beyond individual behavior change, particularly in low- and middle-income countries. The purpose of this study was to examine stakeholder perspectives on barriers to medication adherence for stroke patients in Beijing, China, identifying opportunities to improve care and policy in resource-constrained settings. METHODS: We conducted a qualitative, phenomenological analysis of data obtained from 36 individuals. Participants were patients; caregivers; healthcare providers; and representatives from industry and government, purposively selected to synthesize multiple perspectives on medication management and adherence for stroke secondary prevention in Beijing, China. Data was analyzed by thematic analysis across iterative coding cycles. RESULTS: Four major themes characterized barriers on medication adherence, across stakeholders and geographies: limitations driven by individual patient knowledge / attitudes; lack of patient-provider interaction time; lack of coordination across the stratified health system; and lack of affordability driven by high overall costs and limited insurance policies. CONCLUSIONS: These barriers to medication management and adherence suggest opportunities for policy reform and local practice changes, particularly for multi-tiered health systems. Findings from this study in Beijing, China could be explored for applicability in other low- and middle-income countries with urban centers serving large geographic regions. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12913-021-06789-3.

International audience ; As the COVID-19 virus spread over the world, governments restricted mobility to slow transmission. Public health measures had different intensities across European countries but all had significant impact on people's daily lives and economic activities, causing a drop of CO2 emissions of about 10% for the whole year 2020. Here, we analyze changes in natural gas use in the industry and gas distribution to the built environment during the first half of year 2020 with daily gas flows data from pipeline and storage facilities in Europe. We find that reductions of industrial gas use reflect decreases in industrial production across most countries. Surprisingly, natural gas use in the built environment also decreased despite most people being confined at home and cold spells in March 2020. Those reductions that we attribute to the impacts of COVID-19 remain of comparable magnitude to previous variations induced by cold or warm climate anomalies in the cold season. We conclude that climate variations played a larger role than COVID-19 induced stay-home orders in natural gas consumption across Europe.

International audience ; As the COVID-19 virus spread over the world, governments restricted mobility to slow transmission. Public health measures had different intensities across European countries but all had significant impact on people's daily lives and economic activities, causing a drop of CO2 emissions of about 10% for the whole year 2020. Here, we analyze changes in natural gas use in the industry and gas distribution to the built environment during the first half of year 2020 with daily gas flows data from pipeline and storage facilities in Europe. We find that reductions of industrial gas use reflect decreases in industrial production across most countries. Surprisingly, natural gas use in the built environment also decreased despite most people being confined at home and cold spells in March 2020. Those reductions that we attribute to the impacts of COVID-19 remain of comparable magnitude to previous variations induced by cold or warm climate anomalies in the cold season. We conclude that climate variations played a larger role than COVID-19 induced stay-home orders in natural gas consumption across Europe.

International audience ; As the COVID-19 virus spread over the world, governments restricted mobility to slow transmission. Public health measures had different intensities across European countries but all had significant impact on people's daily lives and economic activities, causing a drop of CO2 emissions of about 10% for the whole year 2020. Here, we analyze changes in natural gas use in the industry and gas distribution to the built environment during the first half of year 2020 with daily gas flows data from pipeline and storage facilities in Europe. We find that reductions of industrial gas use reflect decreases in industrial production across most countries. Surprisingly, natural gas use in the built environment also decreased despite most people being confined at home and cold spells in March 2020. Those reductions that we attribute to the impacts of COVID-19 remain of comparable magnitude to previous variations induced by cold or warm climate anomalies in the cold season. We conclude that climate variations played a larger role than COVID-19 induced stay-home orders in natural gas consumption across Europe.

International audience ; As the COVID-19 virus spread over the world, governments restricted mobility to slow transmission. Public health measures had different intensities across European countries but all had significant impact on people's daily lives and economic activities, causing a drop of CO2 emissions of about 10% for the whole year 2020. Here, we analyze changes in natural gas use in the industry and gas distribution to the built environment during the first half of year 2020 with daily gas flows data from pipeline and storage facilities in Europe. We find that reductions of industrial gas use reflect decreases in industrial production across most countries. Surprisingly, natural gas use in the built environment also decreased despite most people being confined at home and cold spells in March 2020. Those reductions that we attribute to the impacts of COVID-19 remain of comparable magnitude to previous variations induced by cold or warm climate anomalies in the cold season. We conclude that climate variations played a larger role than COVID-19 induced stay-home orders in natural gas consumption across Europe.