Has COVID-19 been the making of Open Science?

One outcome of the COVID-19 pandemic has been to put discussions about open research methods and practices, such as preprints, into the mainstream. Drawing on an recent analysis of the extent to which Open Science principles have been adopted during the COVID-19 pandemic, Lonni Besançon, Corentin Segalas, Clémence Leyrat, argue that while the pandemic has accelerated certain forms of Open Science, much work remains to be done to ensure that these principles are engaged with optimally

Open Science Saves Lives: Lessons from the COVID-19 Pandemic

In the last decade Open Science principles, such as Open Access, study preregistration, use of preprints, making available data and code, and open peer review, have been successfully advocated for and are being slowly adopted in many different research communities. In response to the COVID-19 pandemic many publishers and researchers have sped up their adoption of some of these Open Science practices, sometimes embracing them fully and sometimes partially or in a sub-optimal manner. In this article, we express concerns about the violation of some of the Open Science principles and its potential impact on the quality of research output. We provide evidence of the misuses of these principles at different stages of the scientific process. We call for a wider adoption of Open Science practices in the hope that this work will encourage a broader endorsement of Open Science principles and serve as a reminder that science should always be a rigorous process, reliable and transparent, especially in the context of a pandemic where research findings are being translated into practice even more rapidly

Étude de la mobilité du radium-226 en milieu naturel anthropisé par approches expérimentales et modélisation géochimique

226Ra, a radioactive decay product of 238U and the most prevalent naturally occurring isotope of radium leads to many environmental issues in various industries due to its half-life of 1600 years: hydrothermal energy, seawater desalination and zircon production among others. The most impacted industries are the extractive ones: shale oil and gas production, coal, phosphate and uranium extraction. 226Ra remains in tailings from U mines and its mobility is controlled by retention mechanisms: sorption on mineral surfaces (iron oxy-hydroxydes, phyllosilicates, zeolites) and organic matter, or by the formation of solid solutions (sulfate minerals such as barite and carbonate minerals). The average concentration in lithospheric rocks being 32Bq / kg, or 1ppt, the identification of the retention mechanisms of this radionuclide at the scale of the material sampled in the field is made difficult because it is an ultra-trace element. Sequential extractions are commonly used to assess the retention of trace elements, but this technique is subject to experimental and analytical artefacts which are exacerbated in the case of an ultra-trace element. In this work, geochemical modeling of sequential extractions experiments has indeed shown that this technique leads to biased interpretations, particularly in the case of 226Ra which is remobilized during the different extraction steps. In order to have a better understanding of the retention of 226Ra and its distribution in heterogeneous and fine-grained materials, including mine tailings, a new approach has been developed. This approach combines alpha autoradiography, chemical elemental cartographies and mineralogical characterizations obtained on petrographic thin sections. A direct global analysis of the activity of the sample at the petrographic thin section scale is thus possible. This method was first qualified on model samples containing a single synthetic or natural mineral playing an important role in the retention of 226Ra in the natural environment. It was then tested on an assemblage of three of the main minerals responsible for the retention, namely: barite, clay minerals and iron oxy-hydroxydes. Finally, it was applied to U-mine tailings. A first set of samples comes from the French post-mining storage sites of Bellezane, where the tailings are stored under a solid cover, and from Bois Noirs Limouzat, which uses a liquid cover. A second set of tailings sample comes from the on-going ore processing facility of McClean Lake, Canada, which uses a tailings neutralization process by barite precipitation. The results show that barite is the main trap of 226Ra via the formation of a solid solution (Ba, Ra)SO4 in all these tailings from different sites. Over a few years, with or without neutralization by barite precipitation, it appears that this solid solution tends towards a recrystallization equilibrium which controls the concentration of 226Ra in solution. These results will subsequently be integrated into reactive transport type modeling to predict the long-term behavior of these tailings.Le 226Ra, descendant radioactif de l’238U et isotope majoritaire naturellement présent sur Terre, suscite de nombreuses problématiques environnementales en raison de sa demi-vie de 1600 ans dans des industries variées : hydrothermalisme, désalinisation de l’eau de mer et production de zircon par exemple ; mais surtout dans les industries extractives : pétrole et gaz de schiste, charbon, phosphate et uranium. Le 226Ra est retenu au sein des résidus de traitement des mines d’U et sa mobilité est contrôlée par les mécanismes de sorption à la surface de minéraux (oxy-hydroxydes de fer, phyllosilicates, zéolithes), ou de la matière organique ou par la formation de solutions solides (minéraux sulfatés comme la barytine et minéraux carbonatés). La concentration moyenne dans les roches lithosphériques étant de 32 Bq/kg, soit 1 ppt, l’identification des mécanismes de rétention de ce radionucléide à l’échelle du matériau échantillonné sur le terrain est rendue difficile par son caractère ultra-trace. Les extractions séquentielles, technique classique pour le suivi des éléments traces, peuvent être sujettes à de nombreux artefacts exacerbés pour les éléments ultra-traces. Dans le cadre de ce travail, une modélisation géochimique d’expériences de lixiviations séquentielles a en effet montré que cette technique conduit à des interprétations biaisées en particulier dans le cas du 226Ra, soumis à de nombreux mécanismes de remobilisation aux différentes étapes de lixiviation. Afin de mieux comprendre les processus de rétention du 226Ra et la distribution de celui-ci dans les matériaux hétérogènes et finement divisés, dont font partie les résidus de traitement de l’extraction minière, une nouvelle approche a été développée couplant autoradiographie alpha, cartographies chimiques élémentaires et caractérisations minéralogiques obtenues entre autres par MEB/EDS sur lames minces pétrographiques. Une analyse globale directe de l’ensemble de l’activité de l’échantillon à l’échelle de la lame mince pétrographique est ainsi possible. Cette méthode a été qualifiée tout d’abord sur des échantillons de référence contenant un seul minéral synthétique ou naturel jouant un rôle important dans la rétention du 226Ra en milieu naturel, puis à un assemblage de trois des principaux minéraux responsables de la rétention, à savoir : barytine, minéraux argileux et oxy-hydroxydes de fer. Enfin, elle a été directement appliquée à des résidus de traitement. Un premier corpus est issu des sites français de stockage post-miniers de Bellezane, où les résidus de traitement sont stockés sous couverture solide, et de Bois Noirs Limouzat, qui utilise une couverture liquide. Sont également considérés des résidus du site en activité de traitement de minerai de McClean Lake, au Canada, qui utilise un processus de neutralisation des résidus par précipitation de barytine

Étude de la mobilité du radium-226 en milieu naturel anthropisé par approches expérimentales et modélisation géochimique

226Ra, a radioactive decay product of 238U and the most prevalent naturally occurring isotope of radium leads to many environmental issues in various industries due to its half-life of 1600 years: hydrothermal energy, seawater desalination and zircon production among others. The most impacted industries are the extractive ones: shale oil and gas production, coal, phosphate and uranium extraction. 226Ra remains in tailings from U mines and its mobility is controlled by retention mechanisms: sorption on mineral surfaces (iron oxy-hydroxydes, phyllosilicates, zeolites) and organic matter, or by the formation of solid solutions (sulfate minerals such as barite and carbonate minerals). The average concentration in lithospheric rocks being 32Bq / kg, or 1ppt, the identification of the retention mechanisms of this radionuclide at the scale of the material sampled in the field is made difficult because it is an ultra-trace element. Sequential extractions are commonly used to assess the retention of trace elements, but this technique is subject to experimental and analytical artefacts which are exacerbated in the case of an ultra-trace element. In this work, geochemical modeling of sequential extractions experiments has indeed shown that this technique leads to biased interpretations, particularly in the case of 226Ra which is remobilized during the different extraction steps. In order to have a better understanding of the retention of 226Ra and its distribution in heterogeneous and fine-grained materials, including mine tailings, a new approach has been developed. This approach combines alpha autoradiography, chemical elemental cartographies and mineralogical characterizations obtained on petrographic thin sections. A direct global analysis of the activity of the sample at the petrographic thin section scale is thus possible. This method was first qualified on model samples containing a single synthetic or natural mineral playing an important role in the retention of 226Ra in the natural environment. It was then tested on an assemblage of three of the main minerals responsible for the retention, namely: barite, clay minerals and iron oxy-hydroxydes. Finally, it was applied to U-mine tailings. A first set of samples comes from the French post-mining storage sites of Bellezane, where the tailings are stored under a solid cover, and from Bois Noirs Limouzat, which uses a liquid cover. A second set of tailings sample comes from the on-going ore processing facility of McClean Lake, Canada, which uses a tailings neutralization process by barite precipitation. The results show that barite is the main trap of 226Ra via the formation of a solid solution (Ba, Ra)SO4 in all these tailings from different sites. Over a few years, with or without neutralization by barite precipitation, it appears that this solid solution tends towards a recrystallization equilibrium which controls the concentration of 226Ra in solution. These results will subsequently be integrated into reactive transport type modeling to predict the long-term behavior of these tailings.Le 226Ra, descendant radioactif de l’238U et isotope majoritaire naturellement présent sur Terre, suscite de nombreuses problématiques environnementales en raison de sa demi-vie de 1600 ans dans des industries variées : hydrothermalisme, désalinisation de l’eau de mer et production de zircon par exemple ; mais surtout dans les industries extractives : pétrole et gaz de schiste, charbon, phosphate et uranium. Le 226Ra est retenu au sein des résidus de traitement des mines d’U et sa mobilité est contrôlée par les mécanismes de sorption à la surface de minéraux (oxy-hydroxydes de fer, phyllosilicates, zéolithes), ou de la matière organique ou par la formation de solutions solides (minéraux sulfatés comme la barytine et minéraux carbonatés). La concentration moyenne dans les roches lithosphériques étant de 32 Bq/kg, soit 1 ppt, l’identification des mécanismes de rétention de ce radionucléide à l’échelle du matériau échantillonné sur le terrain est rendue difficile par son caractère ultra-trace. Les extractions séquentielles, technique classique pour le suivi des éléments traces, peuvent être sujettes à de nombreux artefacts exacerbés pour les éléments ultra-traces. Dans le cadre de ce travail, une modélisation géochimique d’expériences de lixiviations séquentielles a en effet montré que cette technique conduit à des interprétations biaisées en particulier dans le cas du 226Ra, soumis à de nombreux mécanismes de remobilisation aux différentes étapes de lixiviation. Afin de mieux comprendre les processus de rétention du 226Ra et la distribution de celui-ci dans les matériaux hétérogènes et finement divisés, dont font partie les résidus de traitement de l’extraction minière, une nouvelle approche a été développée couplant autoradiographie alpha, cartographies chimiques élémentaires et caractérisations minéralogiques obtenues entre autres par MEB/EDS sur lames minces pétrographiques. Une analyse globale directe de l’ensemble de l’activité de l’échantillon à l’échelle de la lame mince pétrographique est ainsi possible. Cette méthode a été qualifiée tout d’abord sur des échantillons de référence contenant un seul minéral synthétique ou naturel jouant un rôle important dans la rétention du 226Ra en milieu naturel, puis à un assemblage de trois des principaux minéraux responsables de la rétention, à savoir : barytine, minéraux argileux et oxy-hydroxydes de fer. Enfin, elle a été directement appliquée à des résidus de traitement. Un premier corpus est issu des sites français de stockage post-miniers de Bellezane, où les résidus de traitement sont stockés sous couverture solide, et de Bois Noirs Limouzat, qui utilise une couverture liquide. Sont également considérés des résidus du site en activité de traitement de minerai de McClean Lake, au Canada, qui utilise un processus de neutralisation des résidus par précipitation de barytine

The Role of Barite in the Post-Mining Stabilization of Radium-226: A Modeling Contribution for Sequential Extractions

Barite is ubiquitous and known to incorporate 226Ra through the formation of a solid-solution. In U mining mill tailings, barite is one of the dominant sulfate-binding minerals. In such environments, sequential extractions are generally used to identify the U- and 226Ra-binding phases and their associated reactivity. To better decipher the main processes governing the behavior of 226Ra during such sequential extractions, a geochemical model was developed with PHREEQC mimicking the sequential extraction of U and 226Ra from Bois-Noirs Limouzat U mine tailings, France. The model results were compared with a dataset produced by an experimental sequential extraction from the same mine tailings and including data on the solids and selective extraction results with the major elements, U and 226Ra. The simulations reproduced the results of the experimental chemical extractions accurately, with iron oxyhydroxides being the major U binding phase. However, the modeling indicated rather that barite would be the main 226Ra binding phase, instead of the iron oxyhydroxides identified by the experimental extractions. This is consistent with the 226Ra concentration measured in pore water, but in disagreement with the direct interpretation of the sequential extractions. The direct interpretation disregarded the role of barite in the geochemical behavior of 226Ra because barite was not specifically targeted by any of the extraction steps. However, the modeling showed that the dissolution of 226Ra-binding barite by reactants would lead to a 226Ra redistribution among the clay minerals, resulting in a skew in the experimental results. Similar results were achieved by referring simply to the bulk mineralogy of the tailings. This study highlights the importance of considering the mineralogy, mineral reactivity and retention capacity for more realistic interpretation of sequential extractions. Moreover, this paper provides new perspectives on the long-term consequences of these mill tailings in which barite controls the geochemical behavior of the 226Ra

Vaccination rates and COVID-19 cases: a commentary of “Increases in COVID-19 are unrelated to levels of vaccination across 68 countries and 2947 counties in the United States.”

The manuscript from Subramanian and Kumar shows a lack of vaccine efficacy on Covid Incidence. However, this paper suffers major pitfalls : inadequate outcome, lack of confounding factors, inadequate time period (7 days), inclusion/exclusion criteria not respected, causal inference from inappropriate data, and erroneous interpretation of the data. We comment on these issues in detail and show that Subramanian and Kumar’s paper is flawed and misleading

Re: Subramanian and Kumar. Vaccination rates and COVID-19 cases.

The manuscript from Subramanian and Kumar shows a lack of vaccine efficacy on Covid Incidence. However, this paper suffers major pitfalls : inadequate outcome, lack of confounding factors, inadequate time period (7 days), inclusion/exclusion criteria not respected, causal inference from inappropriate data, and erroneous interpretation of the data. We comment on these issues in detail and show that Subramanian and Kumar’s paper is flawed and misleading.</p

Quantifying 226Ra activity in a complex assemblage of 226Ra-bearing minerals using alpha autoradiography and SEM/EDS

International audienceRa-226 is an ultra-trace element with important environmental implications for many industries (including water treatment and oil and mineral extraction). Its extremely low concentrations in natural environments do not allow for direct observation and measurement of the Ra-226-bearing minerals governing Ra-226 mobility. To better understand the retention processes for Ra-226 in rocks and soil, a synthesized assemblage of Ra-226-doped minerals was made, combining montmorillonite, ferrihydrite and barite. A new methodology was developed using alpha activity maps acquired using alpha autoradiography, and elemental maps by using SEM/EDS. These maps were processed using a global approach, considering the entirety of the signal. The comparison of the alpha activity map and the elemental map enabled a correlation to be established between the Ra-226 activity and the chemical composition and identification of the main Ra-226-bearing mineral of the assemblage, from which we were able to estimate the contribution of each mineral to the total activity of the assemblage, and to quantify the Ra-226-activity for each mineral. This methodology makes it possible to link mineralogy and occurrence of Ra-226 at the scale of the mineral (tens of mu m). It can be applied to natural samples, including fine-grained samples with a complex mineralogy