Viet-Thi Tran

Philippe Ravaud

PhD Viet-Thi Tran -Md

PhD Philippe Ravaud -Md

COllaborative Open Platform E-cohorts for Research Acceleration in Trials and Epidemiology (COOPERATE)

Keywords:

Background

The current clinical research system relies on a "one-off" project-by project model involving a costly and time-wasting permanent construction and deconstruction of the research infrastructure. We propose a new model of research relying on collaborative principles: The COllaborative Open Platform (COOP') e-cohort.

Development

The COOP' e-cohort aims at building a large community of patients willing to participate in research by contributing to the generation of a large database of patient-reported data, passively enriched, at the individual level, by linkage with routinely collected care and/or medicoadministrative data. Approved teams can use the platform and benefit from already enrolled participants or collected data or add new online questionnaires to perform observational or interventional studies to answer a broad range of research questions.

Application

The Community of Patients for Research (ComPaRe) is a proof-of-concept COOP' e-cohort in the field of chronic conditions that was launched in 2017. As of April 2020, 36 000 patients have joined the project and contributed to more than 4 million data points. Patient-reported data will be enriched by linkage with the French national health system databases and with hospital data for patients receiving care in the Paris region. Since 2017, 150 researchers have used the platform for research projects. Three clinical trials nested in ComPaRe have been funded.

Conclusion

By moving from myriad independent studies to a large collaborative infrastructure of research, COOP' e-cohorts will accelerate the research process by avoiding the redundancy of many steps common to all research projects and by limiting waste of research.

Today's clinical research system is in crisis. An evolution toward a more efficient and sustainable model of research is necessary. In this paper, we discuss the limits of the current clinical research system and propose a new design to accelerate research in chronic conditions: the COllaborative Open Platform E-cohort for Research Acceleration in Trials and Epidemiology (COOPERATE, or COOP' e-cohort).

Limits of the current clinical research model

The current system relies on an inefficient "one-off" project model

The current clinical research system relies on a "one-off" project model [START_REF]Transforming Clinical Research in the United States: Challenges and Opportunities: Workshop Summary[END_REF]. Prospective studies, whether they are observational or interventional, start from scratch and require years to achieve full enrollment. After the publication of results, they are put away, resulting in a constant construction and deconstruction of the clinical research infrastructure [START_REF] Selby | Network news: powering clinical research[END_REF]. Avoiding this "oneoff" project model could spare the never-ending collection of the same data (e.g., a clinical trial collects an average 169 case report form pages [START_REF] Getz | Variability in Protocol Design Complexity by Phase and Therapeutic Area Drug Information[END_REF][START_REF] Getz | Clinical Trial Complexity: The National Academies of Sciences, Engineering and Medicine[END_REF]; with up to 80% of items collected not reported in final publications and already available from previous research [START_REF] Van Staa | Use of electronic healthcare records in large-scale simple randomized trials at the point of care for the documentation of value-based medicine[END_REF][START_REF] Coorevits | Electronic health records: new opportunities for clinical research[END_REF][START_REF] O'leary | Data collection in cancer clinical trials: Too much of a good thing?[END_REF][START_REF] Harel | Brief Report: Rethinking Data Collection for HIV Prevention Trials[END_REF]); reduce the burden of research for participants [START_REF] Naidoo | The research burden of randomized controlled trial participation: a systematic thematic synthesis of qualitative evidence[END_REF], and reduce the costs of research (e.g., a prospective cohort of 659 patients with myelodysplastic syndromes costs €22.05 M (€1.23 M per year) [START_REF] Lazzaro | Cost Description on a Cohort of 659 Patients with Adult MDS Included into the Italian Lazio Region Registry (the GROM-L)[END_REF][START_REF] Manolio | Enhancing the feasibility of large cohort studies[END_REF]).

The evidence is insufficiently robust

Most research studies are underpowered because they fail to recruit their original target within the time originally specified [START_REF] Campbell | Recruitment to randomised trials: strategies for trial enrollment and participation study. The STEPS study[END_REF]. This situation is not due to the unwillingness of patients to participate in research but rather to the lack of collaboration between researchers. For example, in rare diseases, 40% of prospective research studies involve a single centre with a limited number of participants (42 to 282 participants) [START_REF] Dechartres | Characteristics and Public Availability of Results of Clinical Trials on Rare Diseases Registered at Clinicaltrials[END_REF]. Beyond sample size, current data sources currently used in research may also have flaws. For example, a large proportion of results from recent observational studies relying on data collected for care or reimbursement purposes may be questioned because important missing covariates were not collected with careful measurement as part of a research protocol [START_REF] Ioannidis | Are mortality differences detected by administrative data reliable and actionable[END_REF].

The evidence does not reflect the "real world" and its relevance for patients is limited

In many clinical research studies, participants are often different from "real-world" people because they are mainly those who obtain care in large hospitals which participate in research [START_REF] Kaplan | Clinical trial discussion, referral, and recruitment: physician, patient, and system factors[END_REF]. Further, some inclusion/exclusion criteria used may limit the validity of findings from clinical research. For example, in clinical trials, older, obese or multimorbid patients are frequently excluded even though they represent an important proportion of patients for whom research conclusions will be applied [START_REF] Pestine | Representation of obese participants in obesity-related cancer randomized trials[END_REF][START_REF] Van Spall | Eligibility criteria of randomized controlled trials published in high-impact general medical journals: a systematic sampling review[END_REF][START_REF] Buffel Du Vaure | Exclusion of patients with concomitant chronic conditions in ongoing randomised controlled trials targeting 10 common chronic conditions and registered at ClinicalTrials.gov: a systematic review of registration details[END_REF].

Patients are also rarely involved in the elaboration and conduct of research, thus creating a gap between researchers' and patients' priorities. For osteoarthritis of the knee, 60% of trials test medications, whereas only 11% of patients consider that research on medications is of high priority [START_REF] Tallon | Relation between agendas of the research community and the research consumer[END_REF]. Outcomes chosen in clinical research may not be those considered important by patients. For example, in diabetes, only 18% of clinical trials used outcomes considered important by patients [START_REF] Gandhi | Patient-important outcomes in registered diabetes trials[END_REF].

The current system is built on a tournament model

Issues of the current clinical research model also come from researchers' mindsets and habits.

Especially, poor collaboration between people and institutions is responsible for redundant and fragmented research, small sample sizes and siloed research. The system is organized in silos by disease, specialty and/or methods used; with, for example, a distinct separation between qualitative and quantitative research and between interventional and observational designs.

Despite actions from institutions and scientific journals, principles of data sharing and open

research are rarely implemented in practice. Among the reasons, we may cite the disproportionate requirements from regulatory and governance bodies and/or the extensive efforts required by investigators (e.g., development of consent procedures that permit data sharing, de-identification of study data, creation of detailed code books, and support for end data users) to allow data sharing [START_REF] Salman | Increasing value and reducing waste in biomedical research regulation and management[END_REF][START_REF] Olfson | Incentivizing Data Sharing and Collaboration in Medical Research-The S-Index[END_REF]. However, beyond these reasons, we may argue that the current model of research is tainted by greed: investigators "play in a tournament" in which they compete for funding in a world in which small differences in innovation can be magnified into large differences in recognition, financial reward, and career advancement [START_REF] Olfson | Incentivizing Data Sharing and Collaboration in Medical Research-The S-Index[END_REF].

A new model for the clinical research infrastructure

To address these problems, we propose a new model for the clinical research infrastructure: the Collaborative Open Platform (COOP') e-cohort. In this paper, we present the general principles of COOP' e-cohorts and illustrate how they may be implemented in practice with examples from our proof-of-concept project: the Community of Patients for Research (ComPaRe) (Box

1 & 2).

Building a community of patients for research

Patient-powered research networks such as PatientsLikeMe have demonstrated that patients' motivation and engagement could accelerate research, minimize recruitment issues, and improve the relevance of findings [START_REF] Wicks | Accelerated clinical discovery using selfreported patient data collected online and a patient-matching algorithm[END_REF][START_REF] Kaye | From patients to partners: participant-centric initiatives in biomedical research[END_REF]. The concept of the COOP' e-cohort is to build a large community of patients willing to participate in research about their chronic conditions by contributing to the generation of a large database of patient-reported data that is passively enriched by other sources of data routinely collected during care or for collected medicoadministrative purposes.

In this community, patients go beyond "simple participation" and answers to online questionnaires. They become active members of the research community and are involved in every step of the research such as the governance of the program, the choice of projects to be conducted within the COOP e-cohort, the conception of all materials destined to participants, data analysis, or the dissemination of the project. Involvement of patients in research allows results to be more relevant and practicable, and ultimately, to be used by society [START_REF]The best research is produced when researchers and communities work together[END_REF]. In ComPaRe, we systematically ask participants about their expectations for participating in a large participative research project after their first year of participation. In 2018, among the 6089 participants who joined the cohort, 2692 (44%) wanted to participate beyond answering questionnaires. To meet these needs, we set up multiple interactive information technology interfaces that allowed patients to actively participate in the construction of the project. One example is to propose research ideas by using the online platform INSPIRE (https://inspirecompare.fr/). INSPIRE uses questionnaires with open-ended questions with which participants can propose research ideas, in their own words, without any health/research literacy requirements. Open-text data are analyzed by using natural language processing methods to generate a list of "research ideas" organized by themes and diseases that are accessible to all participants and researchers in ComPaRe. We also designed testing environments in which volunteer patients could review and propose modifications to all materials (information, questionnaires, etc.) destined for other patients.

Developing a large-scale recruitment strategy

To generate "real-world" data at scale, COOP' e-cohorts should rely on far-reaching recruitment strategies with the following:

-Minimal eligibility and exclusion criteria to generate evidence in a population of patients close to those who will benefit from the research, especially multi-morbid patients.

-Direct outreach to potential participants by using widespread advertising in general and social media and partner patient associations. This strategy avoids the potential pitfalls of relying on clinicians' referral for recruitment (e.g., their lack of time and resources to cope with the additional workload of research duties) [26,[START_REF] Andreeva | Comparison of the sociodemographic characteristics of the large NutriNet-Sante e-cohort with French Census data: the issue of volunteer bias revisited[END_REF]. Direct outreach strategies have been used in initiatives such as All of Us [26], the UK Biobank [START_REF] Collins | What makes UK Biobank special?[END_REF], and the Nutrinet-Santé study [START_REF] Hercberg | The Nutrinet-Sante Study: a web-based prospective study on the relationship between nutrition and health and determinants of dietary patterns and nutritional status[END_REF].

-Scalable recruitment strategies. "Low-cost" communication channels enabling outreach to a large number of potential participants should be favored. For example, in ComPaRe, we systematically add information about the research program to e-mails sent to patients who booked an appointment online in one of our partner hospitals, which allowed for the steady recruitment of 500 participants with diverse chronic conditions every month.

In addition, because most patients with one chronic condition have (or will develop) multiple chronic conditions, all efforts directed to the recruitment of patients with a given condition will also contribute to the recruitment of patients with other conditions.

Sharing a common and permanent infrastructure for simpler and faster research

The core concept of the COOP' e-cohort is to result in a collaborative and permanent infrastructure for research.

-This single and shared research infrastructure, involving a mutualized participant and data pool, facilitates and accelerates research for all. In a COOP' e-cohort, approved researchers can access the platform, use any data already collected or actively collect new data (e.g., by the addition of new online questionnaires) to conduct a wide range of studies. A variety of designs are possible, ranging from observational studies [START_REF] Tran | Patients' views of wearable devices and AI in healthcare: findings from the ComPaRe e-cohort[END_REF]; online qualitative studies [START_REF] Tran | Taxonomy of the burden of treatment: a multicountry Web-based qualitative study of patients with chronic conditions[END_REF]; collective intelligence studies [START_REF] Tran | Patients' perspective on how to improve the care of people with chronic conditions in France: a citizen science study within the ComPaRe ecohort[END_REF]; development and validation of new patient-reported outcome measures (PROMs) [START_REF] Tran | Is My Patient Overwhelmed?: Determining Thresholds for Acceptable Burden of Treatment Using Data From the ComPaRe e-Cohort[END_REF], algorithms or scores; or even trials testing online tools, apps or educative programs, using cohort multiple randomized controlled trial designs [START_REF] Relton | Rethinking pragmatic randomised controlled trials: introducing the "cohort multiple randomised controlled trial" design[END_REF]) (Table ). Researchers using the COOP' e-cohorts benefit by 1) avoiding the numerous procedural and regulatory steps necessary to initiate a new project that have already been completed at the COOP' ecohort level; 2) participants already recruited; and 3) data already collected (Figure 1).

-The single and shared large infrastructure allows for reaching a critical size that opens possibilities not conceivable with smaller one-off projects such as obtaining regulatory authorizations for linkage with administrative and/or hospital databases.

-Shared participant pool. Participants are recruited once and contribute to multiple research projects. For example, a participant joining the cohort to accelerate research on asthma will also contribute to accelerating research on the participant's other conditions.

-Shared data pool. Data are collected once but are used for multiple purposes. All data collected by researchers are made available to others. The more nested projects, the richer the data and the fewer additional specific variables that will be needed for future projects. The common and shared infrastructure also solves most "technical" barriers for data sharing. No time and effort is required from researchers to document the data (documentation is automatically generated by the platform for all patient reported data) [START_REF] Perrier | The views, perspectives, and experiences of academic researchers with data sharing and reuse: A meta-synthesis[END_REF].

-The shared infrastructure of the COOP' e-cohort thus reduces some costs related to study size. Costs are related mainly to the maintenance of the infrastructure rather than "per-study" costs [START_REF] Sertkaya | Key cost drivers of pharmaceutical clinical trials in the United States[END_REF].

Multiple data sources

COOP' e-cohorts combine active data collection by using online questionnaires and the passive enrichment of these patient-reported data with data from other sources (Figure 2).

Active data collection

Active data collection involves mainly data reported by participants themselves with online self-reported questionnaires to capture PROMs and patient-reported experience measures (PREMs). Electronic data collection allows for a naturalistic and flexible follow-up of patients who can answer questionnaires where and when they choose, rather than "at the next visit". Data collected by online questionnaires may cover the following: 1) sociodemographic and clinical data (e.g., precise list of chronic conditions with diagnosis dates, all pharmacological and non-pharmacological treatments taken by patients); 2) PROMs or PREMs (e.g., burden of treatment, patient-reported adherence to medications); 3) stated preferences collected by using discrete choice experiments or case vignette tools; or 4) unstructured textual data collected by questionnaires with open-ended questions used to explore participants' perspectives on specific topics or engage them in the generation of new insights.

Self-reported questionnaires may target all participants from the COOP' e-cohort or sub-groups (or sub-cohorts) of patients determined, in real time, by their characteristics (i.e., patients who report that they have a new diagnosis of diabetes automatically join the specific cohort and receive online questionnaires related to diabetes).

For specific studies nested in the COOP' e-cohort, in addition to patient-reported data, for specific subgroups of patients, data collection may be expanded with the collection of biological samples to characterize the expression of chronic diseases from genomic, epigenetic, proteomic, transcriptomic and metabolomic perspectives.

Passive data enrichment

All patient-reported data are enriched by linkage at the individual level with external sources such as medico-administrative databases, hospital data warehouses, existing research registries or patients' own wearable devices. In ComPaRe, our enrichment strategy entails the systematic linkage of patient data with the following:

-Data from the French national health insurance system (SNDS), which covers about 98.8% of the French population from birth (or immigration) to death (or emigration). This database aggregates data from 1) the "Système National d'Information Inter Régimes de l'Assurance Maladie" (SNIIRAM), which includes exhaustive nationwide data on all healthcare encounters (physician or paramedical visits), medicines, medical devices, and lab tests (without results) reimbursed to patients; 2) the ""Programme de médicalisation des systèmes d'information" (PMSI), which includes exhaustive nationwide data on all hospitalizations in France (International Statistical Classification of Diseases and Related Health Problems, 10 th revision, codes for primary and associated diagnoses, date and duration, procedures, diagnostic-related groups, and cost coding);

3) the Centre d'épidémiologie sur les causes médicales de Décès (Cépi-DC), which includes exhaustive nationwide data on the date and cause of death for the French population.

-The Assistance Publique-Hôpitaux de Paris hospital data warehouses, which contain routinely collected care data (electronic health records, medical imaging data, pathology data and laboratory test results) for all patients hospitalized in the 39 university hospitals of the Paris region (about 8.8 M patients).

Advantages of such enrichment strategy are as follows: 1) the passive, accurate and no-burden collection of objective care data, thus restricting active data collection solely to essential PROMs and PREMs; 2) the minimization of attrition bias in cohorts (even if patients no longer respond to online questionnaires, researchers are still able to know about their care consumption, hospitalizations and vital status); and 3) the minimization of the number of missing important covariates when exploiting administrative databases for research purposes (here, researchers can fill in the gaps in important confounding variables absent from these datasets by using active data collection [START_REF] Ioannidis | Are mortality differences detected by administrative data reliable and actionable[END_REF]).

Creating a one-stop shop for research participation

The COOP' e-cohort represents a simple and identifiable entry point to participate in (multiple) research projects. For researchers, it eases the identification and recruitment of patients motivated to participate in their research. For patients, it facilitates 1) the identification and participation in research projects relevant to their interests and 2) the management of their data and consent across all research projects they participate in. For example, in ComPaRe, we propose a dynamic consent system whereby patients can easily see and modify their consent to 1) participate in the cohort, receive and answer online questionnaires, which is mandatory for participation; 2) link their data to external data (e.g., administrative or hospital databases); 3) be contacted for additional projects nested in the e-cohort and for their permission to be randomly selected to be approached for experimental interventions or to serve as control without further notice during participation in the e-cohort [START_REF] Da | Brief Report: Staged-informed Consent in the Cohort Multiple Randomized Controlled Trial Design[END_REF]; and 4) participate in specific nested studies.

A platform approach for research is not fundamentally new. Traditional cohorts have often been used as platform projects, with broad scientific objectives, intended to host ancillary projects.

Yet, data re-use and sharing (with researchers outside of the original team) was not often anticipated or clear for participants. The COOP' e-cohort changes this by giving participants clear information about data sharing and reuse, with a large number of researchers (not yet known), in order to answer a large number of research questions (not yet identified). In fact, the COOP' e-cohort aims at transposing in epidemiology and clinical research the model of sharing common large infrastructures for accelerated research. This model is the norm rather than the exception in most scientific fields (e.g., telescopes in astronomy, colliders in physics, -omics platform in biology).

Extending to other types of research

Last but not least, the COOP' e-cohort can also accelerate research "beyond its walls" by being a reservoir of patients willing to participate in research. This model resembles the Army of Women, a community of women willing to participate in research on breast cancer. Proposals submitted to the Army of Women and approved by the scientific committee are advertised in the community and women self-select and sign up for these studies. Since 2008, the Army of Women has accelerated 120 studies with 102,000 volunteers [START_REF] Susan | Army of Women: Dr Susan Love Research Foundation[END_REF][START_REF] Love | The Love/Avon Army of Women -Accelerating Research into the Etiology and Prevention of Breast Cancer[END_REF]. With a similar model, COOP' e-cohorts could jumpstart projects in not only clinical research but also basic and social sciences. For example, geneticists would be able to identify type 2 diabetes patients for whom both parents also had type 2 diabetes via a cross-sectional Web survey and invite them and a control population to participate in a genetic marker study outside of the e-cohort. Then, they could decide to collaborate with epidemiologists to link the collected data with long-term outcomes and response to treatment of patients, collected from patient-reported outcomes and administrative databases.

Potential challenges and solutions for COOP' e-cohorts

First, similar to all prospective cohorts, COOP' e-cohorts are threatened by missing follow-up data and attrition bias. However, this is mitigated by 1) linkage with administrative data (even if patients no longer respond to online questionnaires; important outcomes such as their care consumption, hospitalizations and vital status are still obtained by the passive enrichment of data with administrative data sources); and 2) the involvement of patients in the selection, design and analysis of studies conducted within the cohort, which has been shown to increase engagement in research [START_REF] Wicks | Accelerated clinical discovery using selfreported patient data collected online and a patient-matching algorithm[END_REF][START_REF] Wicks | Online platform to accelerate patient involvement in open instrument development[END_REF].

Regarding quality of data, online questionnaires allow for automatic checks in the data (including cross checks between data entered in multiple questionnaires). Forms are complete.

There are no data entry errors, Furthermore, linkage with administrative data allows for verifying the reliability of the information self-reported by patients. In the literature, use of online questionnaires has shown similar data quality as the use of paper questionnaires [START_REF] Touvier | Comparison between web-based and paper versions of a self-administered anthropometric questionnaire[END_REF], interviews by skilled interviewers [START_REF] Touvier | Comparison between an interactive web-based self-administered 24 h dietary record and an interview by a dietitian for large-scale epidemiological studies[END_REF], or with data obtained from administrative databases [START_REF] Andreeva | Comparison of the sociodemographic characteristics of the large NutriNet-Sante e-cohort with French Census data: the issue of volunteer bias revisited[END_REF][START_REF] Andreeva | Comparison of Dietary Intakes Between a Large Online Cohort Study (Etude NutriNet-Sante) and a Nationally Representative Cross-Sectional Study (Etude Nationale Nutrition Sante) in France: Addressing the Issue of Generalizability in E-Epidemiology[END_REF].

Regarding non-representativeness, online studies are known to recruit younger, more educated and more often female participants [START_REF] Andreeva | Comparison of the sociodemographic characteristics of the large NutriNet-Sante e-cohort with French Census data: the issue of volunteer bias revisited[END_REF]. As a result, COOP' e-cohorts are not a suitable resource for deriving generalizable disease prevalence and incidence rates. However, they are appropriate for other purposes (e.g., analytical epidemiology, development of novel patientreported outcomes, interventional studies, etc.). In fact, the experience of the Nutrinet-Santé ecohort and the first data collected in ComPaRe have shown that the direct outreach strategy allows for recruiting participants with diverse sociodemographic backgrounds, including socioeconomically disadvantaged individuals who are usually difficult to reach and retain in long-term epidemiologic studies [START_REF] Kesse-Guyot | Participant profiles according to recruitment source in a large Web-based prospective study: experience from the Nutrinet-Sante study[END_REF].

Finally, concerning regulatory approval, our experience with the ComPaRe e-cohort in

France has been well received from all regulatory actors in France. In fact, using data from a cohort to answer multiple research questions was a similar problem as the use of hospital data for research purposes, and COOP' e-cohorts were therefore in line with the definition of "Entrepôt de données" (data warehouse).

Discussion

In this article, we propose a new infrastructure for clinical research, the COOP' e-cohort, with the following features: The COOP' e-cohort offers some advantages in comparison to other existing infrastructures aiming at accelerating clinical research. In contrast to registries and registry trials, it offers extreme flexibility in the data collected and does not require the pre-existence of a registry for a given disease [START_REF] Lauer | The randomized registry trial--the next disruptive technology in clinical research?[END_REF]. A platform cohort may also be easier to set up than a large international prospective clinical research network that uses hospital information systems as the main source of data [START_REF] Rachel | Using Electronic Health Record Data in Pragmatic Clinical Trials: NIH HCS collaboratory[END_REF]. Indeed, it is simpler to "import" data from different international health information systems within an existing e-cohort (in which specific data are purposefully collected) than harmonizing all information systems from hospitals, internationally (and to develop ad-hoc specific data-collection forms). Finally, different from patient communities such as PatientsLikeMe, data are collected regularly for all participants, which allows for robust longitudinal studies [START_REF] Van Der Eijk | Using online health communities to deliver patient-centered care to people with chronic conditions[END_REF].

This new infrastructure is a tool for not just researchers; it is also designed to be a motivator to "re"-put patients at the centre of research. Thus, besides the structural advantages we present, the COOP' e-cohort may also have the power to improve transparency and quality in research because all patients involved will have the most interest in ensuring that research is rigorous and complete. Some challenges will need to be addressed. Especially, the current academic funding systems is challenged. Indeed, the current systems rely on a project-by-project funding that is incompatible with a shared and common infrastructure for research. It will be necessary to imagine a participative research model in which researchers using the infrastructure devote a fraction of their funds for its maintenance. Also, current models of research governance will be challenged. How to make a patient democracy work? Should we look for representative patients or use regular large polls to gain the opinion of patients?

To conclude, we propose to move from a model of clinical research involving myriad small independent studies, each requiring specific funding, recruitment and data collection, to a large collaborative infrastructure of research able to combine data from different sources to answer any research question.

Box 1: Objectives of the COOP' e-cohort

The COOP' e-cohort uses a shared infrastructure for research for the following aims:

-Accelerate research within and outside of the cohort -Reduce the costs of research -Facilitate regulatory, procedural and logistics efforts required for research -Reduce waste of research via the mutualization of data -Reduce the burden of research for participants -Forego silos in research and encourage multidisciplinary projects ComPaRe (https://compare.aphp.fr) is a proof of concept for a COllaborative Open Platform (COOP') e-cohort in the field of chronic conditions. Patients join ComPaRe to donate some of their time to accelerate research on chronic conditions. They answer regular online questionnaires (using patient-reported outcome measures [PROMs], patient-reported experience measures [PREMs] or questionnaires with open-ended questions), suggest ideas for new research, and can participate in the set-up or analysis of research projects. For researchers, ComPaRe offers the ability to quickly set up new projects with PROMs or PREMs in the field of chronic conditions. Aim:

-To evaluate the impact of chronic conditions and their management on patients' lives -To answer various research questions on specific chronic conditions or treatments -To evaluate the importance of multi-morbidity and its consequences for patients. Expected number of participants: 100 000 (10,000 per year) over 10 years. Currently, 36,000 participants have joined the project since January 2017. Eligibility to enter ComPaRe: Eligible participants are adults ≥ 18 years old with at least one chronic condition defined as a condition requiring regular health care for at least 6 months. Recruitment strategy: Patients are informed that the project exists by the following:

-Partner researchers, physicians and national medical societies -Systematic invitation of people who 1) booked their medical appointment online in partner hospitals and 2) consented to receive information on research (approximately 500 participants per month) -Advertisement on social networks (approximately 2000 followers on various social media) -A general media campaign (TV, radio, newspapers) -Snowball sampling method

Characteristics measured at inclusion:

-Socio-demographic characteristics -Chronic conditions (including year of diagnosis) based on chronic conditions listed in the International Statistical Classification of Diseases and Related Health Problems 10 th version, and International Classification of Primary Care, 2 nd edition -Long-term treatments for patients (start/end date, dosage) -Disabilities -Anthropometric data: self-measured weight and height -Tobacco use, alcohol consumption Follow-up with patient-reported outcomes:

-Example of PROMs collected regularly for all patients in the cohort:

• Quality of life using the EQ5D [START_REF] Johnson | Valuation of EuroQOL (EQ-5D) health states in an adult US sample[END_REF] • Treatment burden using the Treatment Burden Questionnaire [START_REF] Tran | Development and description of measurement properties of an instrument to assess treatment burden among patients with multiple chronic conditions[END_REF] • Adherence to medications for each drug taken by the patient [START_REF] Sidorkiewicz | Development and validation of an instrument to assess treatment adherence for each individual drug taken by a patient[END_REF] • Patients' self-evaluation of their symptoms with the Measure Your Medical Outcome Profile [52] -Example of PROMs used in specific "sub-cohorts":

• Vitiligo cohort: severity of disease with the Vitiligo Impact Patient Scale [START_REF] Salzes | The Vitiligo Impact Patient Scale (VIPs): Development and Validation of a Vitiligo Burden Assessment Tool[END_REF] • Diabetes cohort: problem areas in diabetes with the Problem Areas in Diabetes questionnaire [START_REF] Welch | The Problem Areas in Diabetes Scale. An evaluation of its clinical utility[END_REF] Enrichment of patient-reported data with other data sources (planned) -Linkage with the French National Health System databases (SNDS), which covers data on hospital stays, patients' diagnoses and reimbursement of medications (characterized by their Anatomical Therapeutic Chemical code), medical procedures, laboratory tests and medical or paramedical visits and information on participants' vital status -Linkage with hospital data warehouses (electronic health records, biological and imaging data) for patients receiving care in the Paris region -Linkage with patients' own wearable devices (smartphones, smart-watches, etc.) -Specific collection of biological data Patients' participation in research:

-44% of participants want to do more than simply answer online questionnaires. They are willing to test questionnaires, participate in data analysis, be active in the recruitment of new participants etc. -1500 participants have contributed to INSPIRE and have proposed at least one research idea, for a total of 2000 research ideas.

Example of projects that are possible by using ComPaRe

-Help for recruitment (in clinical or fundamental research or social sciences etc.). Potential eligible participants can be targeted by using all data collected in the cohort and invited by e-mail for studies outside of ComPaRe. -Observational studies (cross-sectional or longitudinal). We evaluated the proportion of patients who considered their burden of treatment unacceptable [START_REF] Tran | Is My Patient Overwhelmed?: Determining Thresholds for Acceptable Burden of Treatment Using Data From the ComPaRe e-Cohort[END_REF]. -Online citizen science studies. We engaged patients with chronic conditions to generate ideas on how to improve their care by using an open-ended question "If you had a magic wand, what would you change in your care?" [32] -Development of new PROMs. We are developing a new measure to assess the burden of treatment for Vitiligo. -Nested randomized trials. PaNaM is a cohort multiple randomised controlled trial aimed at evaluating the impact of a virtual patient navigator on mortality, hospitalization rates and burden of treatment for multi-morbid patients

-

  A model for patient-centered research -A model facilitating the reusability of tools and data: data are collected once for multiple purposes -A model to answer questions currently not tackled by "classical" clinical research -Flexibility and rapid data collection from e-epidemiology -Common strata for all clinical research projects simplifying the comparison or synthesis of data -A model reducing the incremental cost of studies and the time to set up new projects

Box 2 :

 2 Community of Patients for Research (ComPaRe)

Table : Example of studies and design that can be conducted within COOP' e-cohorts Studies/designs that can be conducted within COOP' e-cohorts Fields/domains for which COOP' e-cohorts could support recruitment

 :

	-Analytical epidemiology aimed at inferring	-Comparative effectiveness research
	associations between exposures and	studies aimed at evaluating
	outcomes using observational studies	drugs/devices in trials
	(cross-sectional, prospective, retrospective)
	relying mainly on PROM and PREM data
		-Clinical research requiring face-to-face
		contact and/or biological samples
	-Comparative effectiveness research studies
	such as:
	o Emulated trials in which	-Identifying participants for basic
	interventions are defined by data	science studies (genetics, immunology,
	from medico-administrative or	etc.)
	hospital databases and evaluation
	involves using PROMs
	o Trials assessing online interventions
	(e.g., educational videos, online
	educative programs) assessed by
	using PROMs
	o Bring Your Own Device (BYOD)
	trials in which the intervention is,
	for example, a smartphone app to be
	downloaded and is assessed by
	using PROMs
	-Development of new PROMs and PREMs
	-Development of predictive models or
	algorithms based on PROMs/PREMs
	-Online surveys with open-ended questions
	aimed at exploring new concepts
	-Online collective intelligence studies aimed
	at generating ideas on a given concept

-Social science studies involving patients with chronic conditions

Acknowledgments

The authors thank Aurélie Malon, Isabelle Pane, Elise Diard, Solene Gouesbet, Carolina Riveros, Nicole Pitcher, Razak Ellafi and all members of the ComPaRe team; Laura Smales (BioMedEditing, Toronto, Canada) for editing, and Elise Diard for help in drafting figures.

Funding

ComPaRe was funded by the Assistance Publique-Hôpitaux de Paris (APHP) and Paris Descartes University

Competing interests

The authors declare no competing interests and no financial associations that may be relevant or seen as relevant to the submitted manuscript.

The authors have no association with commercial entities that could be viewed as having an interest in the general area of the submitted manuscript.

List of boxes and tables

List of figures


Qinyuan Qu

Guijian Liu

Emmanuel Henry

David Point

Jérôme Chmeleff

Ruoyu Sun

Jeroen E Sonke
email: jeroen.sonke@get.omp.eu

Jinbin Chen
email: jbchen@tju.edu.cn

Tin stable isotopes in magmatic-affected coal deposits: Insights in the geochemical behavior of tin

Keywords: tin, tin isotopes, magma intrusion, binary mixing models, redox states

Tin (Sn) is a redox-sensitive element and geochemically incompatible that accumulates in evolved magmas and associated hydrothermal fluids. Here, a Sn stable isotope approach is used to characterize sources and geochemical behaviors of Sn in magmatic intruded coal deposits by combining with petrographic and elemental analysis. Sn isotope ratios of twelve coal samples with various magmatic-affected degrees show a δ 120/118 Sn variation from -0.06 to 0.22‰ (2σ of 0.07‰, relative to NIST 3161a). Basing on Sn isotope data and geochemical characteristics of the samples, we suggest binary source mixing and redox state related isotope shift as two mechanisms accounting for the isotope variations. The first mechanism is an admixture of magmatic-hydrothermal fluids, characterized by high δ 120/118 Sn, into coal deposits with low δ 120/118 Sn. A binary mixing model is used to estimate Sn contributions of the two end-members.

The second process results in a positive isotope shift caused by an oxidation of sample states when they are affected by magmatic intrusions. In fact, magmatic intrusions could trigger the oxidation

Introduction

Magmatic intrusion is a commonly occurred process in coal deposit and severely affects the safety and productivity of coal mining [START_REF] Finkelman | Influence of an igneous intrusion on the inorganic geochemistry of a bituminous coal from Pitkin County, Colorado[END_REF][START_REF] Querol | Geological controls on the mineral matter and trace elements of coals from the Fuxin basin, Liaoning Province, northeast China[END_REF]. The intrusions are highly firm and thus are difficult to mine through. The emplacements usually form joints and fractures that may cause instabilities of initial coal roofs and walls. Furthermore, the thermal energy carried by magmatic intrusions can alter coals into cokes, and release methanes and carbon monoxides, causing risks of spontaneous combustion and outbursting [START_REF] Golab | Changes in geochemistry and mineralogy of thermally altered coal, Upper Hunter Valley, Australia[END_REF]. Tin (Sn) could be used as a proxy for magmatic intrusion in coal deposit. Sn is a redox-sensitive element with two main oxidized states Sn (II) and Sn (IV) and able to behave as a chalcophile or lithophile element in magmatic intruded coal deposits [START_REF] Qu | Geochemistry of tin (Sn) in Chinese coals[END_REF][START_REF] Teng | Non-traditional stable isotopes:retrospective and perspective[END_REF][START_REF] Wang | Tin isotope fractionation during magmatic processes and the isotope composition of the bulk silicate Earth[END_REF][START_REF] Witt-Eickschen | The geochemistry of the volatile trace elements As, Cd, Ga, In and Sn in the Earth's mantle: New evidence from in situ analyses of mantle xenoliths[END_REF]. Despite the generally low concentration of Sn in coals (2 μg/g, [START_REF] Dai | Geochemistry of trace elements in Chinese coals: a review of abundances, genetic types, impacts on human health, and industrial utilization[END_REF][START_REF] Ketris | Estimations of Clarkes for Carbonaceous biolithes: World averages for trace element contents in black shales and coals[END_REF], magmatic activities might deliver variable amounts of Sn from melts, magmatic-differentiated hydrothermal fluids into coals [START_REF] Haapala | Magmatic and Postmagmatic Processes in Tin-mineralized Granites: Topaz-bearing Leucogranite in the Eurajoki Rapakivi Granite Stock, Finland[END_REF][START_REF] Taylor | The behavior of tin in granitoid magmas[END_REF]. As a result, Sn levels in magmatic-affected coals could be elevated by several folds compared to the background coals [START_REF] Dai | Factors controlling geochemical and mineralogical compositions of coals preserved within marine carbonate successions: a case study from the Heshan Coalfield, southern China[END_REF][START_REF] Dai | Geochemistry of trace elements in Chinese coals: a review of abundances, genetic types, impacts on human health, and industrial utilization[END_REF][START_REF] Sun | Geochemistry of trace elements in coals from the Zhuji Mine, Huainan Coalfield, Anhui, China[END_REF]. However, the sources and migration pathways of Sn in magmatic-affected coal deposits are still rarely investigated.

High-precision measurement of Sn stable isotope ratios in last decade offers a new way to constrain the sources and geochemical processes of Sn. Tin has 10 stable isotopes with a relatively large mass difference: 112 Sn, 114 Sn, 115 Sn, 116 Sn, 117 Sn, 118 Sn, 119 Sn, 120 Sn, 122 Sn and 124 Sn. Up to now, only few studies reported Sn isotopic compositions. Significant isotope fractionations up to 0.40‰ in δ 124/116 Sn have been observed in a laboratory-controlled electrolytic plating experiment between Sn (II) and Sn (IV) ions [START_REF] Wang | Experimental evidence for fractionation of tin chlorides by redox and vapor mechanisms[END_REF]. Magmatic differentiation has been suggested to cause small, but significant Sn isotope fractionation as well. For example, [START_REF] Creech | Tin stable isotope analysis of geological materials by double-spike MC-ICPMS[END_REF] found ~0.3‰ difference in δ 122/118 Sn between basalt and granite during the differentiation of magmas. Even larger Sn isotope fractionation was observed by [START_REF] Yao | Sn-isotope fractionation as a record of hydrothermal redox reactions[END_REF] where the later formed stannite (Cu2FeSnS4) is lighter than the earlier formed cassiterite (SnO2) by ~2‰ in δ 124/116 Sn. The distinguishable isotope signatures of different magmatic components and the discerned fractionation trajectories during magmatic differentiation processes provide an opportunity to trace the Sn behavior in magmatic-affected coals.

Here, a series of coal samples taken from a magmatic-affected coal deposit in China were measured for their Sn isotope ratios along with elemental and petrographic parameters. Our objectives are 1) to investigate whether Sn isotope ratios are distinguishable among coals affected by varying degrees of magmatic intrusion, 2) to trace Sn behaviors in magmatic-affected coals, and 3) to quantify the contributions of Sn from different sources.

Materials and Methods

Study area

Zhuji Coalmine locates in the north of Huainan Coalfield, China (Fig. 1). The coal seams deposited in the Permo-Carboniferous Period, and the fractures and faults highly developed in the coalmine. The largest fault is the NWW-NW extending Minglongshan Fault, which cut through the coalmine from the east to the west. The faults were considered to be formed in the Indosinian orogeny at 257-205 Ma [START_REF] Song | Identification of structure and its dynamics control of Huainan coalfield[END_REF][START_REF] Yang | Characterization of intrusive rocks and REE geochemistry of coals from the Zhuji Coal Mine, Huainan Coalfield, Anhui, China[END_REF].

The coal seams in Zhuji Coalmine suffered from multi-stage magmatic intrusions, forming a series of magma intruded coals [START_REF] Sun | Geochemistry of trace elements in coals from the Zhuji Mine, Huainan Coalfield, Anhui, China[END_REF][START_REF] Yang | Characterization of intrusive rocks and REE geochemistry of coals from the Zhuji Coal Mine, Huainan Coalfield, Anhui, China[END_REF]. Fig 1C graphically presented the general area of the magmatic emplacement. According to the U-Pb dating of zircons, the magma intrusion mainly occurred in the Late Yanshanian stage (~110 Ma). The pre-developed faults and fractures acted as effective pathways for the magmatic intrusion [START_REF] Chen | Mineralogical and geochemical responses of coal to igneous intrusion in the Pansan Coal Mine of the Huainan coalfield, Anhui, China[END_REF][START_REF] Yang | Characterization of intrusive rocks and REE geochemistry of coals from the Zhuji Coal Mine, Huainan Coalfield, Anhui, China[END_REF].

Samples and regents

Twelve samples were taken from coal seams of Zhuji Coalmine [START_REF] Sun | Geochemistry of trace elements in coals from the Zhuji Mine, Huainan Coalfield, Anhui, China[END_REF]. The sample locations and other detailed information were respectively shown in Fig 1 andTable 1. More details about the stratigraphic characteristics and the intrusion of the coal seams were described in the study of [START_REF] Sun | Geochemistry of trace elements in coals from the Zhuji Mine, Huainan Coalfield, Anhui, China[END_REF] and [START_REF] Yang | Characterization of intrusive rocks and REE geochemistry of coals from the Zhuji Coal Mine, Huainan Coalfield, Anhui, China[END_REF]. An international coal standard SARM 20 (CRPG) was used in this study for sample digestion recovery verification.

Teflon Savillex® beakers were used throughout the experiment for sample processing and storage. The beakers were previously cleaned by aqua regia (HNO3: HCl=1:2, analytical grade) and HF (50%, v/v), and further rinsed by ultrapure water from a Milli-Q system (Millipore, France). For the whole sample processing and measurement, the bi-distilled HNO3 and HCl, and ultrapure H2O2 and HF (Merck, German) were used.

Mineralogical and Elemental analysis

The mineral composition of the samples was determined by an X-ray diffractometer (XRD, Philips X'Pert PRO, Japan, with diffraction angle ranging between 3° and 60°. The mineral phases were identified by the Jade 6.0 (Philips, Netherland).

The ash yield (Ad) of the coals was analyzed following the GB/T211-2008. 0.05g of air-dried coal powder (200 mesh) was taken with a porcelain boat and ashed in the Muffle furnace.

The heating temperature was set to 815°C and kept for 2hs. After the heating procedure, the Ad was calculated as following:

Ad=ma/mi*100%, where the ma was the mass of the ash yield after the furnace and the mi the initial mass of the coal.

The concentrations of major elements (Na, K, Ca, Mg, Fe, Al, Si and Ti) and trace elements (La, Th, U, Pb, Zn, Cd, Sb, Rb, Cr, Mn, Cu, Sr, Ba, Nb, Mo, Ni, Co, V and Zr) were measured by X-ray fluorescence and high resolution-inductively coupled plasma mass spectrometry (Element-XR, Thermo-Scientific Inc.), respectively. For the HR-ICP-MS measurement, 0.05 g of each sample was digested by acid mixture of HNO3: H2O2: HF (8mL: 2mL: 2mL) within a microwave system (Mars 5, CEM Inc.). The heating program was set as 120℃-15min-1200W, 150℃-10min-1200W and 190℃-30min-1800W. The digested solution was cooled down to room temperature and transferred to the Savillex beakers. Then, the sample solutions were dried at 70℃ and re-dissolved in 10 mL 2% HNO3 and 0.01% HF (v/v) before trace element measurement and subsequent Sn purification by column chromatography. An indium (In) internal standard (Lot#56875, Merck Inc.) was used to monitor the signal stability during the HR-ICP-MS analysis.

Tin stable isotope analysis

A two-step chromatographic method modified from [START_REF] Wombacher | Stable isotope compositions of cadmium in geological materials and meteorites determined by multiple-collector ICPMS[END_REF] and [START_REF] Yi | Indium and tin in basalts, sulfides, and the mantle[END_REF] was adapted to separate Sn from digested solutions (Table 2). An anion-exchange resin AG 1-X8 (100-200 mesh, Bio-rad Inc.) was firstly employed to separate Sn and Cd from major elements of the digested solutions using a 10 mL polypropylene column (Bio-rad Inc.). Before the sample loading, the digested solution was dried at 70℃ and then re-dissolved by 5mL 3M HCl. In addition, 100μL HF (3M, v/v) was added into the re-dissolved solution to prevent Sn hydrolysis.

The final eluents of AG 1-X8 were collected for the following TRU-spec resin separation (#TRU-B50-A, 100-150μm, Eichrom Inc.). After the two-step chromatographic purification, the final eluents were concentrated and re-dissolved into a 3 mL solution for the isotope measurement by using a MC-ICP-MS (Neptune, Thermo Finnigan). Before the isotope measurement, a Sn recovery verification was performed on the HR-ICP-MS. A coal standard SARM 20 was processed along with the samples. The Sn recovery for SARM 20 after digestion and chromatographic purification was better than 90%. The procedural blanks were negligible compared to the Sn mass in standards and samples.

The stable isotope ratios of Sn were determined by a multi-collector inductively coupled plasma mass spectrometer (MC-ICP-MS, Neptune, Thermo Finnigan) at Geosciences Environnement Toulouse Laboratory. The instrument equipped with a Jet sample cone and H skimmer cone. A PFA micro-nebulizer and Scott type double pass spray chamber were used to introduce the sample solutions. The sample uptake rate was approximately 100 μL/min. The sample solutions were kept at 30 ng/mL doped with 60 ng/mL of Sb, which generated ~1V signal intensity of 120 Sn. Six Sn isotopes ( 116 Sn, 117 Sn, 118 Sn, 119 Sn, 120 Sn and 122 Sn), and two Sb isotopes

Mathematic simulation

Based on a binary mixing model, the Sn input from two source end-members were simulated.

The simulation was performed by a Monte Carlo approach used by [START_REF] Jiskra | Mercury deposition and re-emission pathways in boreal forest soils investigated with Hg isotope signatures[END_REF]. A Pseudo-Random Function (i=1 to 1000) was settled as the iteration number and the computational processes were operated as the following equations:

where j referred to the Sn source members, fj referred to the Sn fraction of each source, Ij referred to Sn isotope values of each source member, Isample referred to the δ 120/118 Sn measured for each sample. Isotope values of Ij were taken from the samples which showed the most positive or negative isotope variations. The computation was performed on the platform of Matlab (R2016b, Mathworks).

Results and discussion

Mineralogical analysis

The XRD spectrums of coal samples were presented in Fig. 3. For easy comparison, the samples were re-ordered based on their intensity ratios of the highest peak and the mean spectrum background (S/N). The highest S/Ns were found in coal samples #12-5-7, #15-5-7 and #16-4-5, with a value of 93.02, 15.22 and 14.01, respectively. For the samples with high S/N, quartz was dominant mineral followed by biotite, muscovite, amesite and chamosite. The lowest S/N value was seen in samples #15-5-11 (2.44). Their dominant minerals were kaolinite followed by sulfide and carbonates. The varied mineral assemblage between the high S/N samples and the low S/N sample suggested that the samples experienced different forming processes. The high S/N sample were probably intruded by magmatic materials, because the biotite, muscovite, amesite and chamosite were common minerals found in metamorphosed or igneous rocks [START_REF] Aarnes | Contact metamorphic devolatilization of shales in the Karoo Basin, South Africa, and the effects of multiple sill intrusions[END_REF][START_REF] Andreani | Aluminum speeds up the hydrothermal alteration of olivine[END_REF][START_REF] Dai | Mineralogical and compositional characteristics of Late Permian coals from an area of high lung cancer rate in Xuan Wei, Yunnan, China: Occurrence and origin of quartz and chamosite[END_REF][START_REF] Dai | Occurrence and origin of minerals in a chamosite-bearing coal of Late Permian age, Zhaotong, Yunnan, China[END_REF], whereas the low S/N samples were commonly found in the normally deposited coals [START_REF] Chou | Sulfur in coals: A review of geochemistry and origins[END_REF][START_REF] Pinetown | Quantitative evaluation of minerals in coal deposits in the Witbank and Highveld Coalfields, and the potential impact on acid mine drainage[END_REF].

Ash yield (Ad) was a common index to evaluate the non-volatile mineral proportions of the samples (mainly alumino-silicates) (Table 1). Sample #12-7-5, #15-5-7 and #16-4-5, showed the highest Ad (78.53% for #12-7-5, 51.87% for #15-5-7 and 46.85% for 16-4-5), according with their S/Ns. In contrast, sample with the lowest S/N ratios showed the lowest ash yield (10.53% for #15-5-11). The high correlation between the ash yield and S/N was probably caused by the magmatic intrusions of the coal deposit, as magma intrusions usually accompanied with a significantly increase of silicates.

Elemental analysis

The high mineral content samples

Three samples (#12-7-5, #16-4-5 and #15-5-7) would be mainly discussed in the following elemental concentration comparison as they were the most represented high mineral content samples. Relative to the elemental backgrounds of Huainan coal and Chinese coal averages [START_REF] Chen | Mineralogical and geochemical responses of coal to igneous intrusion in the Pansan Coal Mine of the Huainan coalfield, Anhui, China[END_REF]; [START_REF] Dai | Geochemistry of trace elements in Chinese coals: a review of abundances, genetic types, impacts on human health, and industrial utilization[END_REF]), higher levels of Na, Mg, Al, Si, Ba, Sr, Cr, Mn, Nb, Th, Rb and Zr were found in the three samples (Cthis study> both CHuainan and CChinese), whereas Fe was depleted (Fig. 4). However, compared with the other samples of this study, the highest Fe levels were shown in the three samples. Among the enriched element collection, Na, Al, Si were elements according with the higher proportions of quartz and minor minerals in the samples; Nb, Zr, Sr, Ba, Rb and La were geochemically incompatible elements, which usually concentrated in the highly differentiated magma melts or fluids; Mn and Rb were the elements with the highest enrichment coefficient (ECs) in this study, 2.8-16.5 of Rb and 1.9-4.6 of Mn. In the studies of magmatic intruded coal deposits [START_REF] Golab | Changes in geochemistry and mineralogy of thermally altered coal, Upper Hunter Valley, Australia[END_REF][START_REF] Querol | Geological controls on the mineral matter and trace elements of coals from the Fuxin basin, Liaoning Province, northeast China[END_REF], intensely increase of Mn in coals (Table 1S, Supplementary Material) was usually interpreted as precipitation of carbonates, which were caused by reactions of CO and CO2 from magmatic fluids altered coals. Rb, Sr, Ba, Ca and Mg were usually the main cations of the carbonates and they were able to substitute with each other. Furthermore, in #15-5-7, chalcophile elements of Pb, Zn, Cd, Sb, Cu and Mo were more enriched than that of #12-7-5 and #16-4-5 and other samples. The differences of elemental associations between #12-7-5, #16-4-5 and #15-5-7 demonstrated that #15-5-7 experienced a more S-rich intrusion than #12-7-5 and #16-4-5. Therefore, it could be concluded that #12-7-5, #16-4-5 and #15-5-7 affected by the magmatic intrusions, which were more likely the magmatic hydrothermal fluids than the melts, and the fluids intruded #15-5-7 were more reduced than that intruded #12-7-5 and #16-4-5.

To make a further explanation of why it was more probably of the hydrothermal fluids intrusion than magmatic melts, an alumina saturation index A/CNK (molar Al2O3/ (CaO+Na2O+K2O)) was introduced [START_REF] Clarke | The Origins of Strongly Peraluminous Granitoid Rocks[END_REF][START_REF] Gao | Distinction between S-type and peraluminous I-type granites: Zircon versus whole-rock geochemistry[END_REF]. Basing on the published data [START_REF] Yang | Characterization of intrusive rocks and REE geochemistry of coals from the Zhuji Coal Mine, Huainan Coalfield, Anhui, China[END_REF], we calculated the A/CNKs of the intrusive melt of Zhuji coalmine and compared the values with the coal samples. The A/CNKs of the three samples with the highest possibilities of magma intrusion were 3.87 (#12-7-5), 7.08 (#16-4-5) and 8.50 (#15-5-7), while the intrusive melt ranged between 0.60-1.41, comparable to a peraluminous granite [START_REF] Clarke | The Origins of Strongly Peraluminous Granitoid Rocks[END_REF][START_REF] Clarke | The mineralogy of peraluminous granites: a review[END_REF][START_REF] Pérez-Soba | Petrogenesis of highly fractionated I-type peraluminous granites: La Pedriza pluton (Spanish Central System)[END_REF]. Since the much higher A/CNKs of the coals than the intrusive melts, the samples were not likely directly intruded by magmatic melts, but the hydrothermal fluids. This was also supported by [START_REF] Clarke | The mineralogy of peraluminous granites: a review[END_REF], who considers that rock samples with A/CNK >> 1 could be caused by the interaction with hydrothermal fluids from silicate melts.

The low mineral content samples

Relative to the average of Huainan coals (22.1%, [START_REF] Chen | Geochemistry of environmentally sensitive trace elements in Permian coals from the Huainan coalfield, Anhui, China[END_REF], six samples showed lower Ad (10.53-21.99%). Among the six samples, #15-5-11 showed the lowest Ad of 10.53%, demonstrating that coal organics dominated in the sample. #16-4-4 showed the highest ash yield of the six samples, probably owing to an enriched iron minerals (Fe 1.22%).

According to the mineralogy and elemental analysis, it was observed that the Ad and Mn level were sensitive indicators to reflect variations of magmatic impact on the samples. Therefore, we considered that three samples were severely affected by magmatic intrusions (#12-7-5, #16-4-5 and #15-5-7, Ad>50% and Mn>200μg/g), while the other samples were less possible affected by the intrusions.

Concentration and isotope variations of Sn

Sn levels and δ 120/118 Sn values of the studied coals were listed in Table 1. The Sn levels ranged between 0.94 and 4.48 μg/g, with an average of 2.06 μg/g. High Sn levels were found in coals with the highest Ad (#12-7-5 4.48 μg/g, #15-5-7 2.28μg/g and #16-4-5 2.12 μg/g), while the lowest Sn level was found in sub-bituminous coal #15-5-11 (0.94 μg/g) with the lowest Ad. δ 120/118 Sn of the coals ranged from -0.06‰ to 0.22‰ (±0.07, 2σ).

Below we propose two major mechanisms to explain the observed variations of Sn isotopes in coals: 1) a mixing of Sn isotope from different sources; 2) Sn isotope fractionation caused by redox changes. With the current data, we were unable to identify which mechanism was dominant.

However, it was likely that both mechanisms were responsible for the Sn isotope variation observed.

Possible contributing sources of Sn

As was shown in Fig. 5, a linear correlation could be fitted between 1/Sn concentrations and δ 120/118 Sn values (r=0.64). This correlation suggested that the Sn isotope variations in the coals might be controlled by the mixing of two end-members with different δ 120/118 Sn. The two end-members were most likely the Sn carried by the intruded magmatic hydrothermal fluids and the Sn from the original deposited coals. In this study, the magmatic affected samples (#12-5-7, #15-5-7 and #16-4-5) had higher δ 120/118 Sn values (0.09-0.22‰), and the most represented coal samples (#15-5-11 and #16-4-4) had the lowest δ 120/118 Sn variations (-0.04‰ and -0.06‰).

Based on the mineralogical and elemental evidences, the samples with the higher δ 120/118 Sn values were affected more by magmatic-intrusion, and thus a higher fraction of magmatic-derived Sn was expected in these samples. As a chalcophile and lithophile element, Sn showed the highest affinities with either oxygen or sulfur at different redox states. According to the study of Badullovich et al. (2019), the species of Sn depended on the levels of f (O2) of the intruded magmatic materials. In coal deposits, Sn could associated with alumino-siliates, sulfide minerals (mainly pyrite (FeS)) or coal organic matters [START_REF] Qu | Geochemistry of tin (Sn) in Chinese coals[END_REF]. In this study, the f (O2) of #12-7-5 and #16-4-5 were obviously higher than #15-5-7. Thus, the Sn in #12-7-5 and #16-4-5 were most likely in Sn(IV)-O form, whereas the Sn in #15-5-7 more possible occurred as Sn(II)-S. In contrast, the samples with the lowest δ 120/118 Sn ratios (#15-5-11 and #16-4-4) were unlikely affected by magmatic-intrusion as they had lower Ad and mineral contents. Due to the studies of Sn modes of occurrence in coals, the Sn in low Ad coals could either associated with the coal organics to form functional groups or associated with sulfide minerals, such as FeS and Cu2FeSnS3. In our study, the Sn in #15-5-11 was mostly likely associated with the coal organic, while the Sn in #16-4-4 more tended to associate with sulfide minerals, as there was a high level of Fe (1.22%).

The Sn isotope variations of the coals in this study was further compared with other published Sn isotope ratios (Fig. 6). Sn isotope variations of magmatic rocks were more positive with respect to the samples from other geochemical reservoirs, indicating an enrichment of heavy Sn isotopes in earth mantle and crust. The most positive coal δ 120/118 Sn (#12-7-5 and #16-4-5) corresponded closely to the isotopic ranges of the highly-evolved acidic magmatic rocks, which was supported by [START_REF] Yang | Characterization of intrusive rocks and REE geochemistry of coals from the Zhuji Coal Mine, Huainan Coalfield, Anhui, China[END_REF]. Sample #15-5-11 and #16-4-4, which had the most negative δ 120/118 Sn variations, were observed on the upper limit of the isotopic range of sulfide-associated Sn minerals (Cu2FeSnS3) (-0.06 to -0.56‰). Since the Sn in coals could either associated with the coal organic sulfur or sulfide minerals , the negative δ 120/118 Sn in #15-5-11 and #16-4-4 may therefore indicate a partial coordination of Sn (II) by the coal organic and sulfide minerals respectively.

A binary mixing model was applied to estimate the contributions of the two end-members (magmatic hydrothermal fluids and original coal deposit) to the Sn budget in coals. In this model, published δ 120/118 Sn of granite was used to represent the Sn end-member in magmatic hydrothermal fluids (Fig. 6), since it was considered that no isotope fractionation occured during Sn crystallization of silicates [START_REF] Badullovich | Tin isotopic fractionation during igneous differentiation and Earth's mantle composition[END_REF]. For the δ 120/118 Sn of the other end-member (coal organics), the upper limit of stannite isotope variation (Fig. 6), which was close to the isotope variation of #16-4-4 and #15-5-11, was used to represent the Sn coordinated to S. Based on the following equations ( 5) and ( 6), Sn contributions by the two end-members in each coal samples were calculated. The detailed calculations were listed in the Supplementary Material Table S2 (csv file).

According to the simulation, the Sn input carried by the magmatic sourced hydrothermal fluids contributed 86% (±9.5%, 1σ) of the Sn in the sample with the most positive isotope variation (#12-7-5), while only 14% (±11.5%, 1σ) of the Sn in the sample from the coal organics (#15-5-11). The detailed calculation results could be seen in the Supporting material.

Isotope variations of Sn caused by redox changes

In addition to the mixing of Sn from two geochemical reservoirs, changes in redox states of Sn in coals could be responsible for the isotope variation of this study as well, since redox changes between Sn (II) and Sn (IV) had been proved to cause small, but detectable isotope fractionation [START_REF] Wang | Experimental evidence for fractionation of tin chlorides by redox and vapor mechanisms[END_REF]. In this study, an oxidation of magmatic affected coal seams probably happened because comparing to the reductive coal deposition environment (usually Sn occurred as Sn (II)-S), the intruded magmatic hydrothermal fluids could be more oxic when it had a high oxygen fugacity (f (O2)). According to the calculation by [START_REF] Badullovich | Tin isotopic fractionation during igneous differentiation and Earth's mantle composition[END_REF], Sn could occur as Sn (IV) in magmatic liquids at f (O2) of Fayalite-Magnetite-Quartz (FMQ) and temperature of ~1200 °C. In this study, since the temperature of hydrothermal fluids partitioning from melts was usually lower than 800 °C, and trace amount of biotite and muscovite (usually Fe (III) rich) were detected in the hydrothermal fluid impacted samples, the f (O2) of the samples were apparently higher than the estimation of Badullovich et al. Therefore, the hydrothermal fluids were able to transfer the initial organic associated Sn (II) to oxidized Sn (IV) and contribute isotope shifts of Sn isotopes in this study.

To evaluate redox condition of the coal samples, a series of well-developed paleo-redox proxies, V/(V+Ni), Mn/Cr and V/Cr [START_REF] Hatch | Relationship between inferred redox potential of the depositional environment and geochemistry of the Upper Pennsylvanian (Missourian) Stark Shale Member of the Dennis Limestone, Wabaunsee County[END_REF][START_REF] Jones | Comparison of geochemical indices used for the interpretation of palaeoredox conditions in ancient mudstones[END_REF][START_REF] Nico | Redox dynamics of mixed metal (Mn, Cr, and Fe) ultrafine particles[END_REF][START_REF] Rimmer | Geochemical paleoredox indicators in Devonian--Mississippian black shales, central Appalachian Basin (USA)[END_REF], were examined in this study. High V/Cr ratios (>2) in coals were thought to empirically indicate dysoxic conditions, and V/(V+Ni) (>0.2) predict dysoxic to euxinic conditions. Mn and Cr were considered as a pair of elements with reverse behaviors of solubility in both oxic and reducitive conditions. It was usually considered that the higher ratios of Mn/Cr, the more reductive the condition was. As shown in Fig. 7A, the samples were re-ordered by their drill hole locations. A profile of δ 120/118 Sn of the samples were compared with the three paleo-redox proxies (Fig 7A). They were also compared with Ad, Na and Si (Fig 7B ), which were characteristic properties for magmatic intrusions. It was striking to find that all three redox proxies indicated relatively more oxic conditions for the samples with the most positive δ 120/118 Sn (#12-7-5 and #16-4-5) than the less positive δ 120/118 Sn (#15-5-7), and the samples with the most negative δ 120/118 Sn (#15-5-11 and #16-4-4) (Fig. 7A). Furthermore, positive correlations were found particularly between the most positive δ 120/118 Sn samples and the contents of Ad, Na and Si (Fig. 7B), which were characteristic properties for magmatic intrusions. Combing the two sets of evidences, we suggested that the magmatic hydrothermal fluid intrusion into coal seams might have shifted the redox conditions of coals to be more oxic, and also the redox states of the Sn in the coals.

The magmatic hydrothermal fluids intrusion could change the redox states of Sn in coals through a Sn re-mobilization process [START_REF] Golab | Changes in geochemistry and mineralogy of thermally altered coal, Upper Hunter Valley, Australia[END_REF]. Carrying with large amounts of thermal energy and mineral contents, the intruded fluids were able to alter the coals by either pyrolyzation or mineral contamination [START_REF] Dai | Geochemistry of the late permian No. 30 coal seam, Zhijin coalfield of southwest China: influence of a siliceous low-temperature hydrothermal fluid[END_REF]. The former could partially decompose the coal organic matters and sulfide minerals, leading to a volatilization of the associated Sn. The latter demonstrated that a material exchange took place between the coals and the fluids, and partial Sn of the coals could be leached out by the fluid. Hence, a Sn re-mobilization happened while the coals was intruded by a magmatic hydrothermal fluids.

Basing on the analysis of δ 120/118 Sn variations of the samples and Sn geochemistry in hydrothermal fluid affected coals, we proposed a conceptual model to explain the mechanism of the possible δ 120/118 Sn variations. As was discussed above, the chemical species of Sn highly depended on the levels of f (O2). In oxidizing condition, Sn usually associated with O in Sn(IV)-O, while under reducing condition, Sn was in Sn (II) and had a high affinity with S. Since Sn(IV)-O had much shorter bond length (~2.18Å) than Sn(II)-S (~2.48Å), the heavier Sn isotopes were more likely enriched in Sn(IV)-O species with shorter and stiffer chemical bonds [START_REF] Badullovich | Tin isotopic fractionation during igneous differentiation and Earth's mantle composition[END_REF][START_REF] Bigeleisen | Calculation of Equilibrium Constants for Isotopic Exchange Reactions[END_REF][START_REF] Gürel | Characterization of vibrational and mechanical properties of quaternary compounds Cu2ZnSnS4 and Cu2ZnSnSe4 in kesterite and stannite structures[END_REF][START_REF] She | Sn isotope fractionation during volatilization of Sn (IV) chloride: laboratory experiments and quantum mechanical calculations[END_REF][START_REF] Yao | Sn-isotope fractionation as a record of hydrothermal redox reactions[END_REF]. In this study, since the organic matters of #15-5-11 and #16-4-4 accounted for 80% to 90% of the total coals, most of the Sn in the samples should associate with the reduced organic matters and thus a more negative isotope shift of δ 120/118 Sn was observed. For #12-7-5 and #16-5-4, as they were affected by magmatic hydrothermal fluids with high f (O2), the Sn of the initial coals could be either oxidized to Sn (IV) or leached out, resulting in an enrichment of heavier Sn isotopes in the residue phase. For sample #15-5-7, because it was intruded by a S-rich hydrothermal fluid, a negative δ 120/118 Sn isotope shift relative to #12-7-5 and #16-4-5 could be observed.

Summarily, the mixing of two end-members and the redox changes that could both fractionate Sn isotopes were proposed to explain the isotope variations of the coals. However, considering the similar Sn content (ppm level) in coals and magma fluid (e.g. MORB) and the lack of direct evidence, we were not able to distinguish the effect of redox change from magmatic input on Sn isotope variation at this stage, further systematic study was thus needed to better constrain Sn isotope fractionation during hydrothermalism.

Conclusions

In this study, Sn stable isotope variations in twelve coals with various magmatic-affected degrees from a coal deposit of China vary from -0.06 to 0.22‰ in δ 120/118 Sn. The Sn stable isotope variations demonstrate clear difference between the magmatic affected samples (0.20 to 0.22‰) and the normally deposited coals (-0.04 to -0.06‰). Two possible interpretations are suggested to explain the isotopic variation of the samples. The first, the isotope variation is attributed to a mixture of magmatic hydrothermal fluids and coal deposits with different Sn isotope ratios, as demonstrates by the linear relationship between Sn and its isotopes in a mixing diagram. The second, an oxidation of the coal seams probably take place when they are intruded by the magmatic hydrothermal fluids. In fact, the higher oxidation states of the intruded coals leads to an enrichment of heavy Sn isotopes. This enrichment can be roughly explained by the relatively shorter bond length of Sn (IV)-O than Sn (II)-S. Both of the two geochemical processes were considered responsible for the variation determined in this study. Finally, our work shows that Sn isotope ratios are useful tools for investigating Sn geochemical behavior in different Earth reservoirs and during redox-sensitive processes. [START_REF] Yamazaki | Feasibility studies of Sn isotope composition for provenancing ancient bronzes[END_REF]2013). The black rectangle refers the median and the black diamond refers the outlier. For comparison purposes, all the Sn isotope ratios were converted to δ 120/118 Sn relative to NIST 3161a. Tin isotope differences between reference solutions used in the literatures and NIST 3161a were corrected using the values measured by [START_REF] She | Sn isotope fractionation during volatilization of Sn (IV) chloride: laboratory experiments and quantum mechanical calculations[END_REF]. Fig. 7 A) The spatial distribution of δ 120/118 Sn, V/Cr, V/(V+Ni) and Mn/Cr. The sample order on the vertical axis represents the locations of the drill holes from west to east. The shadowed rectangle highlights the samples which were probably affected by magmatic hydrothermal solution. The empirical thresholds of V/Cr and V/(V+Ni) for redox states were from [START_REF] Hatch | Relationship between inferred redox potential of the depositional environment and geochemistry of the Upper Pennsylvanian (Missourian) Stark Shale Member of the Dennis Limestone, Wabaunsee County[END_REF], [START_REF] Nico | Redox dynamics of mixed metal (Mn, Cr, and Fe) ultrafine particles[END_REF] and [START_REF] Rimmer | Geochemical paleoredox indicators in Devonian--Mississippian black shales, central Appalachian Basin (USA)[END_REF]. Mn/Cr only quanlitatively indicates redox state changes as Mn and Cr behave inversely in terms of solubility under oxic and reduced contions [START_REF] Jones | Comparison of geochemical indices used for the interpretation of palaeoredox conditions in ancient mudstones[END_REF][START_REF] Rimmer | Geochemical paleoredox indicators in Devonian--Mississippian black shales, central Appalachian Basin (USA)[END_REF]. B) The spatial distribution of δ 120/118 Sn, ash content, Si and Na concentrations. These samples were firstly reported in the study of [START_REF] Sun | Geochemistry of trace elements in coals from the Zhuji Mine, Huainan Coalfield, Anhui, China[END_REF] Table 2 Procedures for Sn separation from coal matrix (modified from [START_REF] Wombacher | Stable isotope compositions of cadmium in geological materials and meteorites determined by multiple-collector ICPMS[END_REF][START_REF] Yi | Indium and tin in basalts, sulfides, and the mantle[END_REF] Operation Solvents

(

  121 Sb, 123 Sb) and126 Te were simultaneously collected by L4-H4 Faraday cups. One sample run consisted of 35 measurements with 8s integration time of each scan.Mass bias of the MC-ICP-MS was corrected by an internal NIST 3102a Sb standard and NIST 3161a Sn standard-sample bracketing method. For the internal correction, an exponential law was used to obtain the mass bias factor β (equation 1) which was then applied to correct the measured Sn isotope ratios: where the rSb and RSb respectively refer the true and observed isotopic ratios of internal Sb standard solution. The 123 Sb/ 121 Sb refers the mass ratio of two Sb isotopes. A natural abundance ratio of 123 Sb/ 121 Sb = 0.7480 proposed by Meija et al. (2016) was used to represent the true ratio of the Sb standard solution. The corrected Sn isotope ratios of the samples were expressed as δ 120/118 Sn (‰). where the r sample and r standard represented the Sn isotopic ratios of the samples and standard NIST 3161a Sn solution. For the measured isotopic variations, 120 Sn and 118 Sn were selected for the calculation because they were the most abundant Sn isotopes with the highest precision. The one-day continuous measurement of the isotope ratios of the NIST standard was shown in Fig.2. A long-term reproducibility for of δ 120/118 Sn of the SARM 20 was 0.07 ‰ (2σ, n=17, Fig 2).

Fig. 1 A

 1 Fig. 1 A) Location of Huainan Coalfield, B) Main faults in Huainan Coalfield, and C) Locations of minor faults and sample drilling holes, and magma intrusion boundaries of coal seam No.4, No.5 and No.7 in Zhuji Coal Mine, Huainan Coalfield

Fig. 5

 5 Fig.5Linear regression between 1/Sn concentration (g µg -1 ) and δ 120/118 Sn suggesting a mixing of two endmembers, the dashed zone were range of data within 95% confidential intervals

Table 1

 1 Sample information

	Sample a Coal seam	Depth (m)	Degree of the coalification b	Ad (%)	Total Sn in sample (μg/g)	δ 120/118 Sn (‰)	2SD
	12-7-5	Seam	1182.6	Natural Coke	78.53	4.48	0.22	0.07
	16-4-5	Seam	1107.42-1106.77 Bituminous	46.85	2.12	0.20	0.07
	16-4-8	Seam	1041.42-1038.78 Bituminous	27.66	1.85	0.17	0.07
	16-4-4	Seam	1121.40-1116.92 Bituminous	21.99	1.65	-0.06	0.07
	7-8-5	Seam	1105.82-1104.52 Bituminous	37.95	2.28	0.00	0.07
	12-6-7	Seam	1018.40-1017.15 Bituminous	15.79	1.60	0.02	0.07
	15-5-7	Seam	1080.7-1079.98 Natural Coke	51.87	2.49	0.09	0.07
	15-5-11 Seam	987.75	Sub-bituminous 10.53	0.94	-0.04	0.07
	16-5-4	Seam	1125.22-1122.92 Bituminous	31.63	1.63	0.08	0.07
	16-5-8	Seam	1050.50-1046.90 Bituminous	17.99	1.95	0.06	0.07
	20-4-8	Seam	1064.10	Bituminous	17.68	2.09	0.10	0.07
	17+1-4 Seam	1121.25-1117.80 Bituminous	10.53	1.61	0.06	0.07
	a.

Acknowledgement

This study was supported by the Natural Science Foundation of China (No. 41625012, U1612442, 41561134017 and 41961144028) and National Key Research and Development Program of China (No. 2019YFC1804400). We acknowledge financial and logistic support from the Laboratoire de Géosciences Environnement Toulouse, Observatoire Midi-Pyrénées, CNRS/IRD/Université Paul Sabatier Toulouse III, France.


Depuis de nombreuses années la philosophe Catherine Larrère et l'agronome Raphaël Larrère proposent une réflexion originale et convaincante sur la pensée écologique. Cette fois, ils interrogent la pertinente de la collapsologie 1 . Encadré d'une stimulante introduction et d'une conclusion un peu rapide, trois thématiques (« De la crise écologique à l'Anthropocène » ; « Le catastrophisme : un nouveau grand récit » ; « Quelle place pour la collapsologie dans la pensée écologique ») balisent la thèse selon laquelle la collapsologie n'auraient aucun fondements scientifiques et politiques et serait, en fait, une pensée contre-positive. Il faut par conséquent mettre en garde l'ensemble des écologistes contre l'innocuité politique de cette vision 2 , son positionnement ambigu 3 pour finalement « dénoncer l'imposture » (p. 15) de la collapsologie et des collapsologues La position centrale des auteurs peut se résumer sous la maxime suivante : « le pire n'est pas certain et que les possibles restent ouverts. » (p. 15) [START_REF] Jean-Pierre | Simplismes de l'écologie catastrophiste[END_REF] . Au contraire, C. et R. Larrère souhaitent promouvoir une écologie qui prendrait davantage en compte l'incertitude de l'avenir. Ainsi, plus ouvert, le futur serait moins marqué par le poids des risques écologiques. Pour les auteurs, l'« ontologie » (p. 14) des collapsologistes se présente comme une vision déterminée de l'histoire du système Terre. À partir d'une interprétation extensive des faits scientifiques, les théoriciens de l'effondrement décrivent une perspective historique catastrophiste de l'avenir. C. et R. Larrère remettent à la fois en cause ce « récit unique » (p. 58) -la seule trajectoire sera celle de l'effritement du monde social -et l'unicité du chemin pour faire face à ce futur -l'anticipation de la contraction du monde par une adaptation immédiate et radicale (décroissance, sobriété, etc.). La collapsologie aurait mal interprété les données scientifiques alarmistes, produisant une vision déterministe du devenir (p. 81-83) et aboutissant à l'inaction politique : la « certitude de l'effondrement inéluctable permet le diagnostic d'impuissance » (p. 83). Cela faciliterait le développement d'une oligarchie économique et politique, renforçant les inégalités sociales et les comportements individualistes adoptant « des réactions privées et dépolitisées 1 ». Les auteurs font l'effort de restituer le contexte des idées qui a pu permettre l'émergence de cette notion : avec les phases du développement durable et de l'Anthropocène, mais en oubliant de rappeler la permanence de l'idée de catastrophe dans le discours écologiste 2 . Ils mettent en évidence une pédagogie de la catastrophe qui a influencé différentes conceptions de l'avenir. C'est un discours qui, en s'appuyant sur certaines sources scientifiques, insiste sur la possibilité de l'effondrement d'un système. Pour illustrer leur propos, les auteurs mobilisent l'exemple de l'effondrement forestier à la fin du XIX e siècle, processus lent mais localisé, ayant été maîtrisé par l'intervention de l'État. Dans ce cas, la catastrophe a été mobilisée comme moyen de mettre en scène la situation critique, en réduisant la temporalité de la situation, ce qui permet d'insister sur la mise en place de processus de réaction rapide des politiques publiques. Il n'y aurait donc pas de situations d'effondrement ingérable. Ensuite, ils critiquent la peur de la catastrophe. L'heuristique de la peur est mobilisée par de nombreux philosophes (Hans Jonas, Günther Anders) comme une méthode de compréhension et d'action face à la catastrophe. On peut alors développer une obligation morale afin de l'éviter : c'est une injonction à l'action. Pourtant, cette transformation de l'action n'est possible qu'après avoir accepté que de la catastrophe est déjà bien engagé. Pour les collapsologues, la catastrophe est une réalité inévitable -un effondrement global, complet et synchrone -qu'il faut anticiper par une adaptation radicale de nos modes de vie. La transformation touche à la fois nos manières de nous représenter notre place dans le monde (notamment dans les rapports avec les non humains), mais aussi notre relation au monde dans l'ensemble de nos pratiques sociales. Or, C. et R. Larrère insistent sur sa probabilité [START_REF]Ce faisant, ils procèdent à un contre-sens sur la démonstration philosophique d'Anders, qui ne fait pas de la catastrophe nucléaire une possibilité[END_REF] . C'est pourquoi ils s'appuient sur le travail de Jean-Pierre Dupuy 4 , en insistant sur l'hypothèse qu'il y a et il y aura une diversité des possibilités d'avenir. L'imprévisibilité de l'avenir est sans cesse évoquée, au risque d'apparaître comme l'expression d'une conviction chère aux auteurs. Enfin, les auteurs mènent une charge sévère contre les propositions politiques des collapsologues. Ceux-ci n'auraient pas pris la mesure de la nécessité de théoriser la transition à partir des institutions publiques, préférant valoriser la construction de communautés locales résilientes. C. et R. Larrère soulignent à juste titre l'absence de réflexion sur les institutions étatiques (p. 126 et s.). Mais ils oublient eux-mêmes le rôle central des instances supra-nationales tout, comme la capacité de ces institutions à garder dans le temps leur capacité d'intervention (maintien des outils régaliens, capacité de financements, de sécurisation 5 …). On peut regretter les nombreuses lacunes théoriques et méthodologiques des auteurs qui limitent la démonstration 6 . Tout d'abord, le corpus sur lequel s'appuie les auteurs se concentre sur deux livres : le best-seller de Servigne Pablo et Raphaël Stevens paru en 2015 et celui d'Yves Cochet de 201 1 . Ainsi réduite, la collapsologie se trouve amputée d'une série d'autres livres, d'auteurs et de courants (D. Orlov, F. Vargas, C. Morel Darleux, M. Commaret, P. Pantel, R. Gori, R. Hopkins, D. Bourg…), qui, s'ils partagent le sentiment de l'urgence écologique, proposent d'autres interprétations (parfois plus nuancées, comme L. Aillet, A. Bernier, Y. Citton, R. Duterme, V. Mignerot, J. Rasmi, L. Testot…), d'autres pistes d'action, d'autres perspectives futures. Ensuite, les auteurs insistent sur l'importance des possibles futurs, en se basant sur la valorisation rapide d'expérimentations exemplaires. Paradoxalement, ils s'appuient sur les mêmes initiatives que celles des écrits collapsologistes : permaculture, villes en transition, écoféminisme 2 … Mais les collapsologues videraient ces initiatives de leur sens politique -l'attente de la fin est inévitable et donc, il n'y a plus qu'à s'adapter. Ils défendraient ainsi une vision individualiste, voir libertarienne, qui ne se préoccupe ni de combattre l'État et encore moins le capitalisme. Dans le même mouvement, C. et R. Larrère estiment que les collapsos tenteraient de récupérer les mouvements sociaux les plus actifs (ZAD, Villes en transition, etc.). Mais ce serait une reprise hâtive, simplement déclarative et surtout opportuniste. Signalons aussi que la mobilisation de ces expérimentations se fait sans sources empiriques solides (mis à part quelques ouvrages de seconde main, ayant peu d'ancrages sociologiques). Enfin, on peut regretter la portée performative du discours critique. Dénoncer la collapsologie, ses limites et ses incohérences devrait permettre de promouvoir une autre perspective écologique. Or, on se retrouve face à un appel assez vague sur la nécessité d'adopter des mesures de gestions appropriées, en invoquant une sorte de bon sens qui ne tardera pas à émerger… Il est dommage que le livre ne nous donne pas à voir quelquesunes des lignes d'actions à la hauteur des enjeux 3 . C. et R. Larrère demeurent accrochés à une vision continuiste du projet de développement humain. Ainsi, bien souvent, la thématique de la catastrophe est construite à travers le prisme de catastrophe anciennes (ponctuelles, localisées, aux effets limités -comme le cas des Amérindiens). Cette posture contribue à minimiser la dimension globale (tous les peuples) de la catastrophe actuelle. S'ils parlent bien du réchauffement climatique, c'est pour insister sur les conséquences localisées de ce réchauffement. S'ils évoquent bien l'effondrement du vivant, ils n'insistent pas tellement sur les conséquences que cela aura sur les milieux humains, en raison de l'interdépendance des conditions de vie des acteurs humains et non humain. Ce discours entretient l'illusion de la nature commune entre les catastrophes anciennes et celle de la catastrophe globale et systématique actuelle. Ils maintiennent ainsi cet étrange décalage entre l'acceptation des situations d'effondrements (biodiversité, climat, sol…) -qu'ils ne contestent pas -et la minimisation des conséquences de l'enchaînement cumulé de ces catastrophes -en les segmentant et les individualisant, de manière à produire un discours rationnel sur chacune d'elle. Ce que le livre reflète, c'est davantage une posture prise par les deux auteurs. Car si « Le pire n'est pas certain », il n'est donc pas complètement exclu. Prendre la décision de travailler à partir de l'incertitude ou de la certitude du pire, désigne l'expression d'une volonté. Elle s'inscrit dans la rationalité moderne qui tient avant tout à insister sur la perfectibilité de l'homme et de ses actes (d'où le silence sur la question du conflit et de la 1 Cochet Yves, Avant l'effondrement, Paris, LLL, 2019 2 Mais même cette dimension serait affaiblie par les discours collapsologistes, qui auraient tendance à réduire l'écoféminisme à la féminité qui habiterait chaque homme… Intervention de R. Larrère, 30 novembre 2020, Programme Cit'in. [START_REF]Ce faisant, ils procèdent à un contre-sens sur la démonstration philosophique d'Anders, qui ne fait pas de la catastrophe nucléaire une possibilité[END_REF] Dans certains entretiens, ils insistent sur le développement de solutions techniques assez localisées, par exemple pour lutter contre l'érosion de certains écosystèmes, au niveau local, voir références ci-dessus. violence par exemple). Elle veut à tout prix maintenir une vision positiviste et positive. S'il s'agissait d'interroger « l'aveuglement catastrophiste », il est dommage que les auteurs n'aient pas, au moins pendant quelques pages, adoptés une posture réflexive sur leur propre myopie. Par conséquent, si la trame du livre proclame qu'il existe malgré tout une part d'incertitude, si le pire n'est pas certain, il reste néanmoins probable que les « possibles ouverts » risquent de se réduire au fur et à mesure des situations d'effondrement et de l'inertie des décisions publiques et des habitudes intellectuelles. Bruno Villalba AgroParisTech, Printemps Bruno.villalba@agroparistech.fr

Villalba

  Bruno, recension Catherine Larrère, Raphaël Larrère, Le pire n'est pas certain. Essai sur l'aveuglement catastrophiste, Premier Parallèle, 2020, in Natures Sciences Sociétés 29, 4, 487-503 (2021) © NSS-Dialogues, Hosted by EDP Sciences, 2022 https://doi.org/10.1051/nss/2022012 Larrère Catherine, Larrère Raphaël, Le pire n'est pas certain. Essai sur l'aveuglement catastrophiste, Paris, Premier Parallèle, 2020.

La collapsologie est un néologisme inventé, « avec une certaine autodérision », par Pablo Servigne et Raphaël Steven (Comment tout peut s'effondrer, petit manuel de collapsologie à l'usage des générations présentes Paris, Seuil,

2015). Il est issu du latin lapsus qui signifie chute et du verbe to collapse, qui signifie s'effondrer. C'est « l'exercice transdisciplinaire d'étude de l'effondrement de notre civilisation industrielle, et de ce qui pourrait lui succéder, en s'appuyant sur les deux modes cognitifs que sont la raison et l'intuition, et sur des travaux scientifiques reconnus. » (Servigne et Steven, 2015, p. 253).[START_REF] Hicham-Stéphane | La fin du monde et de l'humanité. Essai sur la généalogie du discours écologique[END_REF] Larrère C., Larrère R., « La collapsologie est politiquement inoffensive », https://www.lesinrocks.com/2020/09/10/idees/idees/la-collapsologie-est-politiquement-inoffensive/ 10 octobre 2020.[START_REF]Ce faisant, ils procèdent à un contre-sens sur la démonstration philosophique d'Anders, qui ne fait pas de la catastrophe nucléaire une possibilité[END_REF] Voir même sa collusion avec les idées néo-libérales : Larrère C., Larrère R., « Les collapsologues sont dans un rapport de convergence avec le pouvoir », https://usbeketrica.com/article/larrere-lescollapsologues-sous-estiment-l-etat, 06 octobre 2020.[START_REF] Jean-Pierre | Simplismes de l'écologie catastrophiste[END_REF] Une thèse déjà défendue, avec concision : Larrère C., Larrère R., « Les transitions écologiques à Cerisy », Natures Sciences Sociétés, vol. 24(3), 2016, 242-250.