This paper is the initial Position Statement of Evidence Synthesis International, a new partnership of organizations that produce, support and use evidence synthesis around the world. The paper (i) argues for the importance of synthesis as a research exercise to clarify what is known from research evidence to inform policy, practice and personal decision making; (ii) discusses core issues for research synthesis such as the role of research evidence in decision making, the role of perspectives, participation and democracy in research and synthesis as a core component of evidence ecosystems; (iii) argues for 9 core principles for ESI on the nature and role of research synthesis; and (iv) lists the 5 main goals of ESI as a coordinating partnership for promoting and enabling the production and use of research synthesis. Evidence synthesis uses formal explicit rigorous methods to bring together the findings of studies already completed and to provide an account of the totality of what is known from that pre-existing research. Evidence synthesis clarifies what is known and not known about a research question. It uses research methods to provide a statement about an evidence base. It is therefore a crucial step in the use of research findings in personal and public decision making.Evidence Synthesis International (ESI) is a new partnership of individual and umbrella organizations that produce, support and use evidence synthesis around the world. Our scope is broad, spanning education to human health, and environmental management to international development. We provide a global hub where evidence synthesis organizations meet to build and share capacities, resources and guidance, and enhance and advocate for the synthesis and use of research evidence in policy and practice decision making in all areas of human enterprise.ESI was established following an initial exploratory meeting held alongside the HTAi  annual meeting in Oslo in June 2015 and formally launched at the What Works Global Summit in London in September 2016. A foundational activity of the partnership was to develop a position statement on the shared principles and aims of ESI. This paper provides a background statement on the nature of evidence synthesis and a position statement on ESI’s principles and main areas of work. The ESI website [Research can be defined as critical social enquiry for public use . ResearcSystematic review is a broad term to cover a range of research methods to provide rigorous and transparent reviews of research. This may be describing what research has been undertaken in relation to a research question (mapping) and/or reviewing what is known from the findings of that research (synthesis to clarify the evidence base). ESI uses the term ‘synthesis’ in its name to cover this range of systematic review methods.Evidence synthesis can be defined as the review of what is known from existing research using systematic and explicit methods in order to clarify the evidence base and is the main focus of this journal. The research questions addressed and the methods used by such syntheses vary considerably, but they are all based on the principles of rigour and transparency. When reviews of research evidence are based on expert advice, expert panels and unsystematic methods, then the basis for the claims made by the reviews are uncertain. If reviews are not explicit and transparent in reporting their methods of review, then one cannot assess whether they have used rigorous methods that can justify the findings that they report.Effectiveness of health care interventions (Cochrane Collaboration)Policy and public funding recommendations in health Clinical practice recommendations in health )Effectiveness of social interventions in crime, education, social care and international development (The Campbell Collaboration).Environmental management and sustainability ).Preclinical and toxicological  studies (Systematic Review Center for Laboratory Experimentation (SYRCLE), Collaborative Approach to Meta-Analysis and Review of Animal Data from Experimental Studies (CAMARADES)).Global development and health A number of different organizations and collaborations have developed over the last 25 years to work on the synthesis of research in different topic areas, such as, for example:Other organizations have contributed to developing methods or building capacity to conduct or use evidence synthesis. For example, The Global Evidence Synthesis Initiative (GESI) aims to build capacity to conduct and use evidence syntheses in low- and middle-income country (LMIC) settings.Different users of research with varying perspectives  may have different questions they wish research to address. This user- and question-led approach has led to a diversity of approaches, paradigms and methods in primary research, ranging from questions (and associated methods) for the study of impact of interventions to questions of prevalence, process and meaning. This user- and question-led approach is also seen in evidence synthesis with an increasing range of single and multi-component methods including statistical empirical and conceptual synthesis.All forms of evidence synthesis are research at a ‘meta’ level as they are grounded in the analysis of pre-existing research. These synthesis methods can address a wide range of research questions including the prevalence of different phenomena, the evaluation of the impact of an intervention, the processes by which an intervention has an impact and the meaning of different experiences for people . This vaSystematic maps of research activity and synthesis of research findings can have many uses including to help prioritize research needs, encourage quality and completeness of execution and reporting of research, avoid duplication and reduce wastage of research effort . They caMECIR (Cochrane)  and MECCPRISMA Preferred Reporting Items for Systematic Reviews and Meta-Analyses RAMESES reporting standards for realist synthesis and meta narrative reviews ROSES Reporting standards for Systematic Evidence Syntheses in environmental research AMSTAR measurement tool to assess the methodological quality of systematic reviews ROBIS tool for assessing the risk of bias in systematic reviews As with all research, there needs to be clarity about how rigorous and transparent research needs to be in order to make justifiable evidence claims. In other words, what are the standards of quality, rigour and relevance that should be required for different types of evidence synthesis? There has therefore been the development of standards for the execution and reporting of evidence using several types of synthesis including, for example:These examples of tools to appraise or to report systematic reviews have mostly been developed for reviews of the evidence on the effectiveness of health interventions. There is however a much wider range of review methods. It is important to have plurality in methods but the lack of agreed terminology can limit methodological collaboration within and across disciplines.Many factors may influence how a policy, practice or personal decision is made. If research evidence is used to inform a decision, then evidence synthesis can provide an understanding of the whole of an evidence base, increase certainty regarding the findings from the evidence base and explore and resolve inconsistencies in the evidence base. The findings of a single or small subgroup of studies may not represent a full and accurate picture of what is known from all available research.The nature of the research evidence can vary considerably. Weiss, for example, distinguished between findings where empirical research findings were used instrumentally to inform decision making and new theories or concepts enlightened the thinking behind decision making . Weiss dResearch findings require interpretation to inform decision making, and this may require the use of further types of information. The processes of interpretation and use of other forms of evidence can also be made formal explicit and accountable (and themselves be subject to research).GRADE  : a systeCERQual : a transparent method for assessing the confidence of evidence from reviews of qualitative research .DECIDE (Tools for decision making and dissemination under development) project to develop and evaluate strategies for disseminating and supporting the uptake of guidelines by key decision makers in clinical practice .The INAHTA Product Type (IPT) Mark system which allows multi-lingual recognition and classification of different health technology assessment products, including HTA reports, mini-HTAs and rapid reviews .There is a developing interest in methods for enabling the dissemination and use of recommendations and guidelines. This includes the development of a range of tools to help clarify the process of moving from evidence to decision making, including for example:These strategies and methods to enable the use of research evidence raise issues about the applicability of research in different contexts and feedback on how research questions are framed and relate to user needs. There is a two-way interaction between users’ needs (demand or ‘pull’) for research evidence and the production (‘push’) of relevant research findings.The methods, standards, capacity and infrastructure available for evidence synthesis and its use raise not only technical methodological issues but also broader concerns about societal engagement with research. This includes power and agency that are reflected in questions about who should set research agendas, who should be involved in evidence synthesis and whether the scope, data, analysis, findings and recommendations sufficiently consider equity issues. The implications of omitting certain groups in society from research can lead to implications for resource allocation and perpetuate cycles of inequality –20. ReseResearch evidence is not produced in isolation. There is a two-way relationship between research being produced and it being requested and used . This caIf research is not undertaken, not undertaken well, is not relevant in focus for potential users of research or is not synthesized to provide an account of what is known from all available research, then the evidence is not likely to be used appropriately or effectively. Evidence is usually used to some extent and so evidence ecosystems exist even if they do not always function effectively. Synthesis is a key component of evidence ecosystems in creating and providing statements of what is known from research.Taking a systems approach can also help in planning the production and use of research. Different stakeholder and decision makers can be consulted about their priorities for research evidence. Synthesis can clarify what is known and not known and how further primary research can inform such users’ needs. Synthesis is therefore key in informing the prioritization, methods and use of primary research.Similarly, strategic choices can also be made about the balance of effort and investment in different parts of an ecosystem and help identify waste in research use and research production. Is there, for example, an appropriate balance between investments in the production of primary research and the synthesis of that research?As many organizations in different fields in different parts of the world are developing methods and infrastructure for evidence synthesis and use, the opportunity arises for shared learning and joint work. This could involve working together on principles, standards, methods, funding, teaching infrastructure and advocacy for synthesis. It could enable joint work, reduce duplication, optimize investment of effort, clarify variation in approaches and encourage innovation and development. ESI is a membership organization made up of organizations around the world that produce, support and use evidence syntheses. Some of the members of Evidence Synthesis International are umbrella organizations or networks in their own right. They have individual organizational members with a common purpose. Mention has already been made of GESI. This started as an initiative of the Alliance for Health Systems and Policy Research, the Campbell Collaboration, Cochrane, the EPPI-Centre and 3ie and now has a Secretariat, more partners and a network across 47 centres in 25 LMICs with a common concern to build capacity for conduct and use of evidence syntheses. It has also ensured the inclusion of evidence researchers from LMICs in the update of the Cochrane Handbook in 2018.Another example is the International Network of Agencies for Health Technology Assessment (INAHTA) which represents 50 not-for-profit health technology assessment agencies in 31 countries.across different sectors and to act as a hub for cross-sectoral collaboration.The aim of creating the ESI collaboration and this position statement is to provide a broader space and profile for these and other initiatives to work together to achieve our common aims. ESI respects the remit and responsibilities of these individual and umbrella organizations within their particular sectors  and in no way intends to duplicate their activities. Rather, the focus of ESI is to advocate for the importance of evidence synthesis Such a macro-level collaboration between research synthesis entities can advocate for and develop higher expectations internationally for better methods, standards, investment, capacity and infrastructure in evidence synthesis and its use. One aspiration, for example, could be for a minimum percentage of research investment to be used for the synthesis of research. Another could be for agreed reporting standards across different topic and methods areas, as well as improved liaison to reduce duplication of effort. Another could be for all public bodies to have explicit policies on processes for the use of synthesized evidence in decision making. The work on evidence synthesis and use has the potential for an enormous positive impact on societies and there is much scope for greater engagement with, for example, international organizations involved in all areas of social and environmental policy. This position statement provides a starting point for such collaboration and the work of ESI.Systematic reviews and research synthesis (and their importance for the production and use of research findings) are central to the aims and values of ESI. The organization has therefore worked to create a set of principles for its work and goals for how this would be achieved. These principles were originally drafted by the initial instigators of ESI and then refined and developed by the authors of this paper as Members of the ESI Steering Group, the Board of Directors and the Secretariat.Evidence synthesis is a vital component in: (i) identifying what is known and not known from research; and (ii) using such research evidence to make well informed decisions.These are the shared principles underlying the work of ESI:2.Evidence synthesis should follow question-led formal methods that are rigorous, transparent and accountable.Evidence from appropriate research can be critical for individuals, groups and society in making informed decisions. In some cases, there is a lack of appropriate research evidence. Evidence synthesis can make this explicit and inform future primary research. Evidence synthesis provides a means to clarify what we know, what we do not know and what more we need to know. It can enable more strategic thinking about research use, research needs and research policy and planning.Research evidence may be able to inform and assist decision making by different groups and individuals in societies. For this to happen in an accountable way, there is a need for fit-for-purpose methods of evidence synthesis (bringing together what we know and how we know it) applied ethically, rigorously and transparently and completely reported. Individual research studies make up such evidence bases but should not be relied upon individually without situating them within the wider evidence base identified through systematic evidence synthesis.3.There should be formal processes to inform the transparent interpretation and use of the findings of evidence synthesis.Evidence synthesis is a form of research and so should conform to the expectations of research including the use of formal transparent methods. All research and its interpretation are driven by the questions being asked and their inherent perspectives  and so these should also be transparent. Evidence synthesis that is not rigorous, relevant and explicit and complete in method and reporting (such as expert literature reviews) or is driven by unspecified vested interests does not conform to the expectations of research. Synthesis that does not meet such appropriate evidence standards is not sufficient for making justifiable evidence claims and so should not be relied upon . There m4.Research paradigms, perspectives, questions, methods, data, analysis and interpretation and application may vary but all can be useful (fit for purpose) in different ways to different stakeholders and under different circumstances.In addition to methods for the synthesis of research, transparent processes are also required for the interpretation and application of evidence synthesis when making policy, practice and personal decisions. In order to enable the accountable use of evidence synthesis, the interpretation and application of that evidence  should be consistent and transparent.5.Interpretation and use of evidence synthesis may inform decision making in various ways, for example, through providing empirical data  or through ways of conceptualizing and understanding issues (enlightenment effect).Individuals and organizations may differ in their perspectives  and in the type of research questions considered appropriate, the methods used to address such questions and the purposes to which the research is put. Such variation exists in both primary research and research synthesis but does not undermine the logic and rationale of the production of evidence synthesis. Research evidence is constructed and interpreted within social perspectives. The transparent formal processes of principle 2 help clarify the perspectives being applied. Such transparency can also help clarify the way that different perspectives in society (including members of the public and users of services) participate in research production and use.6.Interpretation and use of evidence synthesis to inform decision making often involves the use of other evidence and information beyond research evidence.The application of evidence synthesis should be logical (within the perspectives within which it is being used), notwithstanding the nature of that evidence or whether the impact is empirical or conceptual. Evidence used selectively to support decisions made on other grounds is a symbolic use of evidence.7.The ability of evidence synthesis to provide rigorous evidence to inform the decisions of individuals, groups and societies is advanced by the study and development of evidence synthesis methodologies and capacity strengthening for the production and use of evidence synthesis.Evidence synthesis informs judgements made in decision making; it does not mechanically determine decision making. Decisions may be based on research evidence combined with many other factors such as values, tacit knowledge, available resources and local conditions and contexts. Transparency in the synthesis and use of research makes clear how different perspectives, values and types of information inform decision making.8.ESI will specify the social values it follows in terms of both research synthesis and research useMethods of evidence synthesis and processes for research use are not fixed; they are continually developing and require ongoing learning and training. There is a need for the ongoing development of methods to both undertake and study the synthesis and use of research.Ethical high-quality transparent rigorous fit-for-purpose methods of research and the avoidance of waste in research;Social justice, equity, social inclusion and the valuing of different perspectives in research production and its use;right.Research making an important contribution to societal decision making and access to research as a democratic societal 9.ESI will specify the principles for its own governanceThese social values include:Is a learning organization, open to different perspectives and experiences in evidence synthesisIs inclusive in working with those with similar aims and principles in using systematic approaches in the review and use of research evidence even if they may not in practice always fully meet those aims and principlesHas a governance and membership structure that is transparent, open, inclusive and democratic with its principles also reflected in the constituent membership organizationsIs open and transparent about its values and in its measures and performance in avoiding potential conflicts of interestHas no individual organization, or sector, role, topic or geographical focus dominating either the Board or the Sub-Committees of ESIOperationalizes these principles, monitors compliance and corrects any departure from them.These principles include developing a governance and membership structure that:In order to achieve the aims implicit in all the principles stated in this paper, ESI will advocate for increased political and financial support for the development and use of evidence synthesis in decision making. The move from a largely expert or ‘ad hoc’ use of evidence in many political and practice decision making processes to a more structured approach (as in principle 6) will, for example, require considerable political support. Advocacy  can help to engage such support. This might include, for example, the use of success stories from the global community of the beneficial effects of evidence-informed decision making. It may also include support for new organizations or networks for coordinating such efforts in new fields where those are not existing.Prioritizing research needsUndertaking systematic reviews such as systematic maps and synthesesComplete reporting and enabling access to such maps and synthesesInterpretations and application of research evidence including structured processes for advice and guidanceUnderstanding and use of overarching approaches to how evidence is required, produced, understood and used at individual, group, national and international levelsProviding access to approaches and models and sharing lessons learnt;Enabling tools, resources, and software to be accessible and usable by researchers globally including those with less resources and capacityResearch evidence is an important form of information in societal decision making. The conduct and use of evidence synthesis do not only require methods and capacity; it requires policies and systems by which it can be enabled, monitored, accessed, used and evaluated and integrated into broader systems for planning and decision making. Without these, evidence may not be used or might be used in a partial way that does not represent the totality of relevant evidence . Examples include infrastructure, policies and governance for:The aims and principles cannot be achieved without adequate resourcing. This may be achieved through additional funding of evidence ecosystems or a rebalancing of strategy and investment across such ecosystems . ESI’s aim is to attract funding for its members to achieve ESI’s goals. ESI will also require some funds in order to achieve its coordinating function.The development of joint methodological standards and terminology may reduce some duplication of effort whilst still allowing plurality in methods and perspectives and the scope for further innovation and development. Some standards may be shared whilst others may be specific to the topic, sector, stakeholder or perspective.The joint development of evidence synthesis methods may reduce duplication of effort whilst still allowing plurality and the scope for further innovation and methodological development. Evidence synthesis and use is a relatively new area of research and has developed most for examining evidence on the impact of interventions in health. As further questions, topics and perspectives from a wider group of stakeholders are addressed, new methods and approaches will continue to develop within a culture that encourages innovation and freedom to experiment.Undertaking the various forms of evidence synthesis requires specific skills, and these are changing as new forms of synthesis are developed. There is a need to learn from new areas and to develop capacity to undertake and understand different approaches to evidence synthesis for those involved in all levels of learning across all disciplines and topics. This might include ESI members working on mentorship and skills exchange programmes to enhance the quality of and access to work in this area internationally. It might also involve ESI member organizations collaborating to deliver training and capacity development in countries where evidence synthesis is emerging.The ability to understand the aims, approach and results of evidence synthesis can assist various stakeholders in their ability to commission and make use of evidence synthesis. There is also a broader societal role for knowledge of synthesis to be available to citizens in order to be able to facilitate engagement in democratic debates involving evidence. Those commissioning, conducting and using evidence synthesis can benefit from learning about how to engage with the variation in stakeholder needs and the legitimacy of evidence within decision making systems. For example, evidence synthesis researchers from the environmental field developed a five-step approach to engage stakeholders in evidence synthesis . SimilarESI has been founded to advocate for the importance of and to develop the capacity for undertaking research synthesis. In doing so, it is important to specify the principles and the goals of ESI. More broadly, the position statement can help develop a debate and further our thinking about what are the fundamental principles of research synthesis in research and in wider society.The position statement of principles and goals developed by ESI are inclusive and yet respectful of the variation in approach, perspective and responsibilities of its members. They have been developed to demonstrate our shared understanding of the value of evidence synthesis to society and our vision to have this value reflected in the policies, practices and resources utilized in all sectors and by all stakeholders internationally. The principles and goals will evolve over time as society’s needs change and as our sophistication and understanding of research synthesis develops.


Given China’s rapid urbanisation, scale and global importance in climate mitigation, this study investigates how evidence is perceived and used to inform urban health and sustainability policies at central and local levels. Well-informed senior professionals in government/scientific agencies (12 in Beijing and 11 in Ningbo) were interviewed. A thematic analysis is presented using deductive and inductive coding. Government agency participants described formal remits and processes determining the scope and use of evidence by different tiers of government. Academic evidence was influential when commissioned by government departments. Public opinion and economic priorities were two factors that also influenced the use or weight of evidence in policymaking. This study shows that scientific evidence produced or commissioned by government was routinely used to inform urban health and sustainability policy. Extensive and routine data collection is regularly used to inform cyclical policy processes, which improves adaptive capacity. This study contributes to knowledge on the ‘cultures of evidence use’. Environmental governance can be further improved through increased data-sharing and use of diverse knowledge types.Sustainable development is best supported by intersectoral policies informed by a range of evidence and knowledge types ( The United Nations (UN) Habitat’s New Urban Agenda has focused attention on the potentially transformative role of cities for sustainable development across global settings . ThroughChina’s rapid industrialisation and economic growth since the early 1990s, coupled with increasing population, has resulted in greater environmental pressures and public expectations for quality of life. Urban populations more than doubled from the late 1970s to 2010 , with grThe study of evidence use by policymakers is emerging as a stand-alone field, while research on this topic has tended to occur in parallel across disciplines without cross-pollination of theory . AlthougTheory and empirical research suggest that evidence use is not a linear process and that expert knowledge may be one of many other considerations affecting policymaking . A generThe use of research evidence in China may differ from other countries given its high expenditure on research and development (R&D). China ranked second internationally in gross domestic expenditure on R&D in 2018, ranking first and second for such expenditure by government and higher education, respectively . Such spmay reflect the personal views of powerful leaders, the preferences of major interest groups, influential theories about economic development, assessments of what is needed to maintain the stability of the system, the ideas of prominent scientists, responses to rising public pressures, and so forth. play an important policy advisory role, and are sometimes included under the term ‘think-tank’. They are not necessarily independent, but can be seen as: stable and autonomous organisations that research and consult on policy issues to influence the policy process.: 453Official research institutions  and Ningbo (n = 11). Participants were purposively sampled by the Chinese research partners based on their professional networks to include those with knowledge of urban sustainability and health challenges and associated policy processes. Participants were recruited from the following types of organisations: municipal research and administration agencies, university departments, community service centres, and primary care services. Participants had professional expertise in the following areas: climate change; water, soil and air pollution; medicine, public health and epidemiology; urban planning; economic development; meteorology; and waste management.This study is based on a qualitative interview analysis. A total of 23 participants were interviewed in two Chinese (CUSSH partner) cities, Beijing (Interviews took place in Beijing (20–21 May 2019) and Ningbo (23–24 May 2019): they were semi-structured, audio-recorded and transcribed. Translators were present and they were members of the research team to aid with reflexivity and interpretation . Details4An overview of the health and sustainability evidence and governance structure described by participants is followed by three themes regarding the role of government priorities, the public and barriers in evidence generation and use.4.1This section reports foundational information regarding participants’ descriptions of the overarching governance system for environmental health in China, the routes through which evidence informs governance and the types of evidence described by participants. The following sections will build on this foundation to explore specific themes related to evidence use.4.1.1It’s powerful. […] If the central government have a policy, the local have to follow.Participants described environmental health governance in China as consisting of a hierarchical decision-making structure whereby priorities are determined centrally and filter down to ministries and other tiers of government . A partiCentral government’s key role in governance for environmental health was linked to these issues being ‘more sensitive’ and therefore ‘Chinese government attaches great importance to it.’they take some investigation to confirm if this is a real problem or not, then how to adjust their policy or their action plan to respond. To meet the concerns […].Policy priorities are first articulated at the annual joint meeting of the National People’s Congress and National Committee of the Chinese People’s Consultative Conference. Priorities are then communicated to the State Council to investigate and issue specific guidelines, through the overarching and subject-specific Five-Year Plans, via the cabinet-level ministries and supporting institutions. This process was described as a channel to integrate public opinions with research evidence. A Beijing health expert noted: Participants noted that specific issues proposed by representatives of the People’s Congress, at either national or local provincial levels, were taken seriously.Participants described how the National Development and Reform Commission, a macroeconomic management agency, had considerable power in determining land-use policies impacting urban health and sustainability. The 13th Five-Year Plan (2016–20), issued by the Commission, included the Healthy China agenda in the Green Development section, calling for green and environmentally friendly industries, resource conservation and other measures. The other relevant cabinet-level ministries for environment and health governance include the National Health Commission, which oversees the Centres for Disease Control and Prevention and the Ministry of Ecology and Environment. The 13th Five-Year Environment and Health Plan, developed by this ministry, was noted as underpinning the ministry’s work because it contained key measures for environmental sanitation: ‘this is why our subsequent work has been strongly supported’.In fact, it is not so easy to start, but the relative development in the past two years will be faster. In fact, the main reason is that the Chinese government attaches great importance to it. In fact, President Xi proposed a plan to build a beautiful China and ecological civilization, as well as a plan for a Healthy China 2030.The emergence and implementation of Healthy China 2030 was frequently referenced by interview participants. This national strategy has filtered down to impact the work of all environmental health  professionals, as one participant described: e.g. through increased use of health-impact assessments) using existing departmental budgets to progress the project.Interviews in Ningbo showed how the national agenda was implemented at the local level through the Healthy Ningbo 2030 project, described as a ‘government-led and social participation model [… that] has little to do with capital investment’. As part of a network of pilot projects across the country, Ningbo was required to set up a Leadership Committee of senior officials from city government departments, chaired by the mayor. The city aims to integrate health through all decision-making  were described as informing policy development and evaluating policy impact. Evidence was used to ‘prioritise’ air pollution control policies: First is, coal, burning coal because it’s the most polluted. Second would be the vehicles. And they decided this sequence based on surveillance data from the environmental department.Routine monitoring and surveillance data  or media reports of specific problems that were investigated by environmental health experts. In this way, ‘evidence’ in the forms of public and technical knowledge could be inserted into government decision-making if it were elevated in importance by public complaints.Participants frequently described how public opinion has directly influenced central government priorities and policy. Air pollution was commonly discussed in this regard, but also more specific environmental health incidents that received significant media exposure, public complaints and government reaction. Residents’ views were informed by their personal experiences  and because public opinion is not uniform: Government priorities and public opinion were interrelated. Government priorities determine which topics are investigated by researchers, and the findings inform subsequent policies.4.4There were several barriers to environment and health evidence being created or used by policymakers. Participants suggested that the transparency of policy goals and reporting meant that policy targets were not based on evidence, but instead were determined by what could be achieved. Privacy considerations and lack of data-sharing across departments sometimes obstructed evidence generation. Some participants noted that the fast pace of government policy reduced the use of evidence to inform air pollution control policies.if they publish this goal within the Five-Year Plan, they need to publish and measure the success.Meeting published environmental targets such as those for pollution reduction was described as important. A participant said that: One effect of this transparency was that policies should not be changed too frequently—‘you have to be very careful about it’—to avoid failing to meet the target. In another example, a participant noted that the policy target was carefully set to avoid failure: ‘you cannot set the threshold too high’. In these examples, participants described how the policy targets were not necessarily evidence based. Although targets were published and transparent, the process for determining these targets was ‘like a game’ and not widely known.if they do it manually the data might have been manipulated. Because we know this data, the air quality is not that good, but from the data it shows very good. The reason why, actually the local officials working in that monitoring station they can manipulate data. So now all these things have been in a way blocked.Transparency of goals and progress against them was notable across policy areas. Policy targets were described as being carefully monitored through environmental exposure data, although there was a perception that data manipulation had occurred in some cases. One participant noted that the local government agency had instituted a requirement for real-time public reporting of air quality data on a website to avoid any potential for data manipulation: because their weather data are as open to the public, but our health data are sometimes concerned about confidentiality.Although transparent public reporting was commonly referenced, data-sharing across government departments was a barrier for some public health activities. One environmental health expert had experience of monitoring air pollution, heatwaves and morbidity. There was cross-departmental collaboration to create a health warning system based on certain climatic conditions. There were some ‘data-sharing’ challenges: They can make better use of our monitoring or research data and we can do some accurate education for them. […] I think this is also a meaningful thing.However, they were able to cooperate to create the warning system. From their perspective, the value of the data was not necessarily to inform government policy but to support sensitive groups in the population to manage their own exposure: i.e. investigating issues pertaining to health and the environment.Other barriers or restrictions to sharing data across departments were bureaucratic—‘lack of a well-coordinated department’—but also related to non-health departments not being supported to work outside of their remit, the government is quite strong and they’re anxious to change this situation very, very, fast […].Finally, the pace of change in air pollution control was also described as a barrier to research evidence influencing policy. An interview participant in Beijing described the undesirable consequences of banning coal-burning for low-income residents who suffered health risks from excess cold in their homes. However, it was difficult to influence government with this evidence, particularly when such evidence ‘challenges’ its policy or plan. In terms of air pollution control: Thus, it was not possible to drive policy via evidence in that participant’s experience.5This investigation found that scientific evidence was routinely used to inform environment and health governance priorities, policies and decisions. Evidence was primarily viewed as data produced by government agencies, whose priorities were centrally defined, while the use of academic evidence was less clear from this study. Public opinion was described as increasingly shaping environmental governance priorities; however, community participation in policymaking was generally limited to voicing opinions through formal channels.Reflecting on the present findings of the ‘cultures of evidence use’ in China with findings in previous studies, a relatively large collection and use of environmental health data and a lower integration of diverse knowledge types in the Chinese cities can be noted. In order to consider the implications of these differences for China, including opportunities to strengthen governance capacities in this area, a framework for environmental governance by 5.1n = 23) of participants was relatively small, although the selection is based on well-informed and senior professionals working in government/scientific agencies. A clear repetition of the ideas discussed in the interviews indicated a point of saturation in terms of how evidence was used in the urban sustainability and health policy nexus. There were challenges with interpreting the meaning of the interview data, not only with regards language barriers but also understanding conflicting views. There are contradictory views in international academic and media discourse with coexisting accounts of China as a ‘reckless polluter’ and as ‘an emerging leader’ in global environmental mitigation  are likely to have influenced who participated, what they shared with the authors, and how those data were analysed and interpreted  as being opaque and driven by an aversion to failure. The central government controls what kinds of issues are researched and monitored and how the findings inform regulations, which may become more problematic in the longer term. The example of Beijing’s rapid decline in particulate matter since 2013 demonstrates the effectiveness of such centralised approaches  and trusted relationships primed to respond to a crisis. This paper identifies an area of improvement in adaptive capacity related to data-sharing, which was found to be limited across departments and to the wider public, although this is changing  would benefit from further investigation in order to increase the potential for cross-departmental collaboration and adaptive capacity. Strengthening these existing gaps could bolster the effectiveness of China’s environmental governance, leading to a responsiveness to environmental challenges that is lacking in other nations.https://doi.org/10.5334/bc.90.s1Supplemental data on the methods, reflections on the research process and key government documents for the Healthy Cities 2030 agenda can be accessed at: Supplementary material


Transmission electron microscopy is used to observe the morphological changes in colloidal gold nanoparticles and aggregation behavior of CS2 added to the colloidal gold nanoparticles’ solution. Raman spectroscopic analysis is further used to characterize the peaks of CS2, Cad and CS2-Cad molecules. Absorption spectroscopy is used to estimate the colorimetric differences and diffuse reflectance spectra of the samples. The sensing analysis is performed systematically in the presence and absence of CS2. CS2 added colloidal gold nanoparticles colorimetric sensor detected the BAs with a limit of detection (LOD) value of 50.00 µM. Furthermore, the developed sensor has shown an LOD of 50.00 µM for the detection of multiple BAs at a single time. The observed differences in the colorimetric and absorption signals indicate that the structure of BAs is converted to the dithiocarbamate (DTC)-BA molecule, due to the chemical reactions between the amine groups of BAs and CS2. Significantly, the developed colorimetric sensor offers distinct features such as facile fabrication approach, on-site sensing strategy, rapid analysis, visual detection, cost-effective, possibility of mass production, availability to detect multiple BAs at a single time and appreciable sensitivity. The developed sensor can be effectively used as a promising and alternative on-site tool for the estimation of BAs.Meat is often wasted due to the perceived concerns of its shelf life and preservation. Specifically, in meat formation, biogenic amines (BAs) are the major agents to spoil them. Herein, we have developed a carbon disulfide (CS All these substances are released from the amino acids (AAs), as they are disassembled from the proteins present inside the foods [Over the past few years, consumption of high-quality meat and meat products has been increasing steeply on a large scale ,2. Howevmmonia NH and biogethane CH, sulfurohe foods ,6. Amonghe foods . Principhe foods ,9.A low concentration of BAs produced from various types of food is essential to take action on gastric acid output and thermoregulation of the body; on the other hand, a high concentration of BAs is toxic to the body, which causes food poisoning or converts them to strong carcinogens . EspeciaCurrently, analysis of BAs in various food products is performed through various conventional instruments, such as high-performance liquid chromatography (HPLC), gas chromatography (GC) and capillary electrophoresis. These instruments can potentially measure BAs qualitatively and quantitatively with very high sensitivity and selectivity, but the price of the measurements is very expensive, and professional skills are required for the analysis, in which these instruments demand long-time consumption from the extraction, preprocessing and analysis ,15,16,17Another strategic method for the detection of BAs is surface plasmon resonance (SPR), which utilizes the charge density oscillation effect that occurred on the surface of the thin metal film. Chemical and physical changes that occurred on the fixed samples of the thin metal film can be measured through the resonance angle or the reflectance produced by the reducing reflexibility. Moreover, surface plasma wave conversion can happen during the absorption of light energy on the surface of the thin metal film ,21,22. BFrom these inferences, we can ascertain that traditional BA sensing techniques are time-consuming, and they are not suitable for the rapid and on-site detection of BAs. Thus, rapid, precise, accurate, consumer-friendly, cost-effective and on-site detection of the food quality is of utmost necessity for the safety and wellbeing of mankind globally. Over the past few years, significant attention has been made to maintain the quality and freshness of meat by developing novel detection techniques. Among the various types of sensing strategies, colorimetric sensing has been designated as a potential strategy for the efficient detection of BAs in meat and meat products.In this regard, colorimetric sensors based on the localized surface plasmon resonance (LSPR) effect of colloidal golds are developed, and various types of BAs are further determined. Colloidal golds were synthesized through a reduction reaction of gold ions with citric acids as stabilizers, and the detection of BAs was possible with particle aggregation effects. Combination possibility between different types of separate BAs and colloidal gold was determined and reactivity between a mixture of BAs and colloidal gold was further confirmed. Therefore, plasma absorption-based colorimetric sensors are expected as next generation sensors in food nutrition fields to effectively detect various types of BAs under different conditions.4∙3H2O; ≥99.9%), carbon disulfide , cadaverine , 1.4-diaminobutane (putrescine (Put); C4H12N2, ≥99.9%), histamine , tyramine , L-Histidine , L-lysine , L-Arginine  and L-Glutamine  were purchased from Sigma-Aldrich Chemicals, USA. Trisodium citrate dihydrate  was purchased from Kanto chemicals, Japan. Ultrapure water with a resistivity of 18.2 MΩ.cm was used for all the experimental procures and analysis.Gold (III) chloride trihydrate -Cad. To interpret the interactions and for the functionalization of CS2 and colloidal gold solution, CS2 was initially diluted with double the concentration of the target molecule. Further, 500.0 µL of the diluted solution was mixed with an equal amount of colloidal gold with an optical density value of 1, then the colloidal mixture was stirred for 10 min, this functionalization resulted in the fabrication of colloidal gold nanoparticles-based colorimetric sensor.Considering the molar ratio of the particles, CS2. BA samples viz Cad, Put, Him and Trm were prepared in three different types of mixture samples, in which sample 1 consists of Cad, Put and Trm, sample 2 consists of Cad, Put and Him, and sample 3 consists of Cad, Him and Trm. All these samples were prepared in the concentration range of 1.0 to 1000.0 µM. For the activation of the sensor, 500.0 µL of each sensing solution and the prepared BAs samples were mixed and kept under stirring for 10 min, later the absorbance spectrum of the samples was measured to ascertain the aggregation behavior of the colloidal gold.For the colorimetric sensing of BAs in distilled water, colloidal gold nanoparticles’ solution was mixed with and without CS−1. Colorimetric differences and UV-vis diffuse reflectance spectra of the samples were measured using ultraviolet-visible (UV-vis) spectrophotometer  in the range of 300–800 nm.Transmission electron microscopy  images were used to study the morphological changes in the colloidal gold solution. Raman spectroscopic analyses were performed using a Raman spectrometer  in the range of 300–2000 cm2 and colloidal gold nanoparticles was described in 2 mixture resulted in the occurring of interactions between the colloidal gold nanoparticles, CS2 and BAs. All these molecules, with their associated molecular interactions, lead to the aggregation of colloidal gold nanoparticle solution. Under the visible light, the colloidal gold solution itself emitted strong red light, due to the LSPR effect. Absorption spectra of colloidal gold particles showed a red shift due to the aggregation of the particles or the peak shift effect when the surrounding refraction rates of chemical or biological particles were attached to the surface of the gold particles [2 to the colloidal gold solution, characteristic changes were not observed in the color, representing that molecular interactions of the CS2 and the colloidal gold solution did not undergo any changes and both the molecules were properly mixed. Finally, with the addition of the selected BAs to the colloidal gold/CS2 colorimetric sensor, the color of the sensing solution has been changed to blue, which indicated the aggregation mechanism of the colloidal gold solution. 2 solution upon the addition of CS2 and BAs. The reactions occurring in the colorimetric sensor could be ascertained based on the binding groups of the BAs. CS2 could not directly interfere with the colloidal gold solution, whereas colloidal gold/CS2 solution interfered with each other with the help of an amine group of BAs, which further lead to the formation of DTC. Generally, the binding group of BAs change from the amine group to DTC through the reaction with CS2. To lead the aggregation of colloidal gold nanoparticles for colorimetric sensing of BAs, two DTC molecules are required as CS2 could not directly bind to the colloidal gold nanoparticles. With the formation of DTC, the length of the molecules is increased, and the molecular interaction changes from electrostatic interaction between carboxyl and amine group to chemisorption between DTC and surface of colloidal gold nanoparticles [2 and BAs were further analyzed through obtained TEM analysis. The TEM image of the colloidal gold/CS2 solution , UV-vis spectroscopy analysis was performed by adding various concentrations of CS2 to the DTC-Cad  value was found to be 25.00 µM regardless of CS2. The observed differences in the colorimetric and absorption signals indicated that the structure of Cad was converted to the DTC-Cad molecule due to the chemical reactions between the amine groups of Cad and CS2. The formation of DTC-Cad resulted in the increase of the length of molecules and molecular interaction changes of the Cad binding group.In the case of colorimetric detection analysis of Cad in the presence and absence of CS2, Put showed the active section of the solution concentration between 50.00 and 500.00 µM with the colorimetric signals ranging from 44.37 to 72.03, whereas in the presence of CS2, an active section of the solution concentration ranged from 50.00 to 1000.00 µM with colorimetric signals ranging from 19.94 to 44.47. The LOD value for both the colloidal gold solutions was almost equal to 50.00 µM regardless of CS2. The representative colorimetric detection result of Put was similar to the Cad results. These similar phenomenologically resulted Cad and Put could be ascertained based on their chemical structures, as both the Put and Cad possess similar chemical structures. Put efficiently converted to DTC-Put, leading to the binding group transition. The colorimetric signals of Put were decreased when compared to Cad, due to the difference in the molecular length.2 were found to be apparent and distinctive, and the observed changes can be observed from the 2, the LOD value was found to be 5.00 µM; in this solution activation section was not clear, which depicted the dramatic increase in the colorimetric signals and peaks from 1.00 and 5.00 µM. This type of phenomenon was due to the relationship between the structure of Him and the colorimetric reaction process. Precisely, in Him two amine groups were combined with the colloidal gold suspension and attached to the imidazole ring [2, the LOD was increased to 10.00 µM with the expansion in the activation sites from 10.00 to 1000.00 µM with the colorimetric signals in the range from 11.17 to 60.02, which is quite similar to Cad and Put. This could be ascertained based on steric hindrance and the influence of the imidazole ring [2 was coupled with the amine group of His, this process can be the reason for getting a similar type of reaction to Cad and Put.In the presence of Him, colorimetric changes of the colloidal gold solution in the presence and absence of CSole ring . These sole ring . As both2, and the obtained findings were displayed in 2, LOD was found to be 250.00 µM and the colorimetric signal was increased from 250.00 to 500.00 µM. Nevertheless, the signal values were increased exceptionally at the same LOD value with the existence of CS2, this type of tendency could be due to the possibility of rapid π-π interactions and due to the increase of polarization differences in the benzene ring along with the structural change of amines through the CS2.Finally, the detection analysis of Trm was performed in the presence and absence of CS2 for the detection of BAs were confirmed through the absorption spectra analysis, the obtained spectra findings were illustrated in Changes in the plasmon spectrum of colloidal gold nanoparticles-based colorimetric sensors in the presence and absence of CSThe content of BAs generated by the decomposition of meat was gradually increasing based on the degree of decay concept, but the composition of BAs in the decomposed meat was changing either by the meat or with the changes in the environmental distribution ,36. Ther2, Cad, Put and Trm sample set showed LOD of 50.00 µM with signals of 8.95, whereas in the presence of CS2, signals showed a huge difference of up to 35.17 at the same limit of detection value The fabrication of the sensor is very simple.(ii)The developed colorimetric sensor detected the BAs within 10 min.(iii)The developed sensor can be efficiently used for the on-site analysis of BAs.(iv)The colorimetric sensor can be easily manufactured on the laboratory scale.(v)Mass production of the colorimetric sensor will be highly possible at the industrial scale.(vi)Notably, the developed sensor detects the multiple BAs at a single time.Compared to recently published reports , the fab2-based colorimetric sensor will bring novel insights and advancements for the fabrication of colorimetric sensors to detect various types of food pathogens.The developed sensor will be useful to detect BAs in various types of foods, particularly to detect the freshness of meat and meat products. Further, we anticipate that the developed colloidal gold/CS


Streptococcus pneumoniae. OPSI is a medical emergency that requires prompt diagnosis  and management with fluid resuscitation along with immediate administration of empirical antimicrobials. OPSI can be prevented by educating patients, vaccination, and antibiotic prophylaxis. This article summarizes the anatomy and physiology of the spleen and highlights its important functions. It primarily focuses on the pathophysiology of OPSI, its current management, and prevention strategies.The spleen is an intraperitoneal organ that performs vital hematological and immunological functions. It maintains both innate and adaptive immunity and protects the body from microbial infections. The removal of the spleen as a treatment method was initiated from the early 1500s for traumatic injuries, even before the physiology of spleen was properly understood. Splenectomy has therapeutic effects in many conditions such as sickle cell anemia, thalassemia, idiopathic thrombocytopenic purpura (ITP), Hodgkin’s disease, and lymphoma. However, it increases the risk of infections and, in some cases, can lead to a case of severe sepsis known as overwhelming post-splenectomy infection (OPSI), which has a very high mortality rate. Encapsulated bacteria form a major proportion of the invading organisms, of which the most common is  The spleen, a lymphoid aggregate, lies behind ribs 9-10 in the left hypochondriac region of the abdominal cavity where a part of it lies in the epigastric region. Thus, the largest organ of the lymphatic system is situated between the fundus of the stomach and the diaphragm. Being a highly vascular structure, the spleen appears spongy and reddish-purple in color. An adult human spleen is roughly the size of a clenched fist, although its size and weight vary, measuring about 10-12 cm (3.9-4.7 inch) vertically in the longest dimension while weighing 150-200 grams on average [Therapeutic splenectomy for malarial splenomegaly was performed as early as 1549 by Adriano Zaccaria. The first partial splenectomy dates back to 1590 and was performed by Franciscus Rosetti for war-related traumatized spleen [Staphylococcus aureus, Haemophilus influenzae, Streptococcus pneumoniae, and malarial parasites. Sepsis in asplenic patients is more likely to be caused by encapsulated organisms as they are more resilient to phagocytosis. The most dreadful complication of splenectomy is overwhelming post-splenectomy infection (OPSI), which is associated with significant morbidity and mortality rates.In 1911, Emil T Kocher stated that splenic injuries required the removal of the whole organ, and it had no adverse effects . This leScientific community and physicians are using a multidimensional approach to tackle the problem of OPSI. This approach involves patient education, the use of preoperative as well as postoperative vaccinations against specific organisms, prophylaxis with antibiotics, and the maintenance of a spleen registry following splenectomy. We aimed to review the existing literature on the topic and gather a comprehensive picture of splenectomy and the associated sequelae along with its management and preventive strategies.The SpleenEmbryologyDuring the sixth week of fetal development, the spleen develops from the left layer of dorsal mesogastrium in the cephalic part into multiple nodules that later fuse to form a lobulated spleen. In an adult spleen, notching of the superior border shows evidence of its multiple origins. During intrauterine life, the rotation of the stomach causes fusion of the left mesogastric surface with the peritoneum above the left kidney and, consequently, dorsal attachment of the lienorenal ligament. Cells required for the hematopoietic function of the spleen are supplied by the yolk sac and dorsal aorta. By the second trimester, the spleen is able to generate red and white blood cells into the blood circulation.LocationThe spleen lies posterior to the stomach and anterior to the left hemidiaphragm in the left hypochondriac region of the abdominal cavity, relatively below the left costal margin. It rests on the left colic (splenic) flexure, facing the left kidney and pancreatic tail medially and the diaphragm superiorly. Although it can descend up to pubic symphysis in certain disorders, a healthy normal spleen is usually not palpable in most individuals as it normally does not extend beyond the rib arch.Gross AnatomyThe spleen is encased in a weak fibroelastic connective tissue capsule that offers protection and expansion. The capsule further subdivides into smaller internal sections known as lobules. Being an intraperitoneal organ, all surfaces of the spleen are enveloped in the visceral peritoneum, except the hilum, which incorporates nerves, splenic vessels, and ligamentous attachments. The spleen has two surfaces: the diaphragmatic or lateral surface (smooth and convex) and the visceral or medial surface . The diaphragmatic surface shows imprints from ribs 9-11, while the visceral surface shows imprints from left colic flexure (colic area), stomach (gastric area), and left kidney . The spleen has three borders: superior (which bounds the gastric area), inferior , and anterior (which bounds the colic area). The splenic hilum is found inferomedial to the gastric area. The pancreatic tail leaves an impression between the hilum and colic area. Three ligaments originating from adjacent viscera connect with the spleen. Out of them, two ligaments approach the splenic hilum as they are traversed by the transmitted vascular supply of the spleen. These ligaments include the gastrosplenic ligament (which connects splenic hilum with greater gastric curvature) and the splenorenal ligament (which bridges splenic hilum with left kidney). The latter transmits splenic artery and vein whereas the former contains short gastric vessels and left gastroepiploic arteries and veins. Lastly, the spleen is supported by the phrenicocolic ligament, which takes its origin from the colon and is regarded as sustentaculum lienis.Microscopic Anatomy and Functions of the SpleenKnowledge of the microscopic anatomy of the spleen is vital for the understanding of its functions. The dense irregular connective tissue of the capsule gives numerous septa called trabeculae that extend into the parenchyma of the spleen. Myoepithelial cells are found in the capsule as well as in the trabeculae, which contract to pump stored blood into the circulatory system whenever the body is in need, i.e., during intense physical activity or severe hemorrhage. The parenchyma of the spleen (pulp) contains two different types of tissues, termed white and red pulp, each with unique functions. The white pulp, constituting 25% of the total splenic volume, is primarily lymphocytic. It is mainly composed of periarteriolar lymphoid sheaths  and lymphatic nodules (B-cells). The remaining 75% of the splenic volume is occupied by the red pulp, which incorporates splenic venous sinuses, cords (of Billroth), and perisinusoidal macrophages. Separating white and red pulp is the marginal zone that filters pathogens out of the blood and presents them to the lymphocytes residing in white pulp . A schemChanges in Splenic Function with Advancing AgeInadequate defense mechanism against encapsulated bacteria during the early and later years of life is a consequence of a natural process involving splenic cellular maturation, which occurs during the first two decades of life. The concentration of follicles diminishes as individual ages, particularly after the third decade, until they are atrophic by the eighth decade of life. This indicates that the immunological function of the spleen deteriorates with age .SplenectomySplenectomy, or the surgical removal of the spleen, is usually considered a life-saving procedure in traumatized individuals, certain hematological disorders, malignant conditions, and for the sake of diagnostic purposes . GloballInfections Following SplenectomyAlthough the presence of spleen is not imperative for the survival of human beings, its removal still has consequences. Until 1952, when King and Schumacher revealed the risk of OPSI, the spleen was considered an unnecessary organ and a spleenless existence was thought to be quite safe . The facCapnocytophaga canimorsus and Bordetella holmesii [Babesia parasites [Splenectomy can be immediately followed by reactive thrombocytosis and leukocytosis. The former usually resolves within 6-12 months, whereas the latter may persist for many years following the removal of the spleen . Leukocyholmesii , 22, andarasites ,24.Overwhelming post-splenectomy infectionThe major long-term complication of splenectomy is OPSI, also known as post-splenectomy sepsis syndrome, which is defined as a generalized non-specific flu-like prodrome followed by rapid deterioration to full-blown fulminant septic shock within 24-48 hours of the onset . AlthougThe period of highest risk for infections is during the first 3 years post-splenectomy; however, the risk remains elevated throughout an individual’s lifespan, indicated by the reported occurrence of cases of fulminant infection 20 years after splenectomy . ChildreNeisseria meningitidis and Haemophilus influenzae (type b) are also common etiologic agents [Pseudomonas aeruginosa, Capnocytophaga canimorsus, Bartonella spp., and Babesia spp. [Escherichia coli (E. coli) to be the most prevalent in post-splenectomy bacteremia; but it may be a regional phenomenon [In the late 1990s and early 2000s, pneumococcus was considered the predominant cause of infection post-splenectomy (57-87%). However, recent studies suggest that c agents ,29. Lesssia spp. . Pneumocsia spp. . Howeverenomenon . This mienomenon .OPSI is a medical emergency as rapid cardiovascular collapse and death have been reported to occur within 12-24 hours of the onset of symptoms . It starInitially, the condition may be difficult to diagnose. However, any splenectomized individual with symptoms like fever, chills, diarrhea, and vomiting should be assessed for OPSI. Individuals suffering from severe sepsis or septic shock must be evaluated in accordance with the international guidelines  along wiPrevention of post-splenectomy infectionDespite adequate treatment, the mortality rate pertaining to OPSI remains high. This highlights the importance of implementing preventive strategies in the effective management of splenectomized individuals. The British Committee for Standards in Haematology has set guidelines for the prevention and treatment of infections in the asplenic or hyposplenic population, which can be divided roughly into three categories: patient education, vaccination, and prophylaxis with antibiotics .Patient EducationA vast majority (85%) of splenectomized individuals are not aware of their increased susceptibility to infectious diseases and the need to take relevant health precautions . InadequVaccinationHaemophilus influenza type b (Hib), meningococcal, and annual influenza vaccinations [All asplenic individuals must receive pneumococcal, inations . These vinations ,41. Keepinations .Antibiotic ProphylaxisStreptococcus pneumoniae declined [In the 1980s, two controlled trials evaluated the effectiveness of prophylactic penicillin in the pediatric population with sickle cell disease where rates of infection with declined ,44. Oraldeclined . In contdeclined . Initialdeclined . Table 6declined .Benefits of Having a Spleen RegistryIn a cross-sectional survey, Wang J. et al. reported higher rates of adherence to current post-splenectomy guidelines among patients who had been registered in the Victorian Spleen Registry. They also reported reduced incidences of infections among this cohort . In anotTherapeutic removal of the spleen is currently widely carried out in hematological and oncological disorders. The removal of the spleen leaves the body defenseless against many infections as the body’s ability to opsonize bacteria is weakened. The individual becomes susceptible to a variety of respiratory, urinary, and meningeal infections. Seeding of bacteria from infection sites can lead to bacteremia and a severe case of sepsis knows as OPSI. Due to its rapid progression and high mortality rate, OPSI is considered a serious medical emergency. The timely identification of OPSI, its immediate management, and vigilant care of splenectomized patients provides them with a better chance of survival.Haemophilus influenza type b (Hib), meningococcal, and annual influenza vaccinations along with prophylactic antibiotics  as these measures have been found effective in decreasing the incidence of post-splenectomy infections. The formation of a spleen registry has also been found beneficial in reducing infection rates. Further research is needed to improve the current prevention and treatment strategies for OPSI and thereby improve the quality of life of high-risk (splenectomized or asplenic) patients.In order to reduce post-splenectomy infections, patient education, vaccination, and prophylactic antibiotics are of prime importance. Splenectomized patients who are aware of the dangers that infections could cause are likely to be more careful and adherent to precautionary measures. All asplenic individuals must receive pneumococcal,


N = 887 individuals indicated their attitudes towards vaccination and their intention to vaccinate before and after watching a television (TV) discussion. The presence and absence of forewarning, outnumbering and rebuttal were manipulated between subjects; participants also indicated their individual issue involvement. We obtained no evidence that outnumbering mitigates damage from denialism, even when advocates served as multiple sources. However, forewarning about the false-balance effect mitigated deniers’ negative effects. Moreover, the protective effect was independent of rebuttal and issue involvement. Thus, forewarnings can serve as an effective, economic and theory-driven strategy to counter science denialism in public discussions, at least for highly educated individuals such as university students.In mass media, the positions of science deniers and scientific-consensus advocates are repeatedly presented in a balanced manner. This false balance increases the spread of misinformation under the guise of objectivity. Weight-of-evidence strategies are an alternative, in which journalists lend weight to each position that is equivalent to the amount of evidence that supports the position. In public discussions, journalists can invite more advocates of scientific consensuses than science deniers (outnumbering) or they can employ warnings about the false-balance effect prior to the discussions (forewarning). In three pre-registered laboratory experiments, we tested the efficacy of outnumbering and forewarning as weight-of-evidence strategies to mitigate science deniers’ influence on individuals’ attitudes towards vaccination and their intention to vaccinate. We explored whether advocates’ responses to science deniers  and audiences’ issue involvement moderate the efficacy of these strategies. A total of  Therefore, the forewarning hypothesis expects that when individuals read a general explanation of the false-balance effect, denial messages’ damage will be mitigated compared with a control group.Another weight-of-evidence strategy is to warn the audience prior to the discussion. In line with inoculation theory , 1961b, involvement-as-moderator research question explores whether and how the audience’s issue involvement will moderate weight-of-evidence strategies’ efficacy.Some extant findings challenge the idea that weight-of-evidence strategies are a universal approach to counter science denialism in public discussions. First, forewarnings are found to be more effective with highly involved audiences, but also have a greater chance of backfiring with these specific audiences . Moreoverebuttal-as-moderator research question explores whether and how weight-of-evidence strategies’ efficacy will depend on rebuttal messages’ presence. We refer to the failure to deliver a rebuttal as advocate silent.Second, the two outlined weight-of-evidence strategies’ efficacy may depend on whether an advocate responds to the denier’s claim with a counter message, that is, whether or not a rebuttal is present. If science deniers present misinformation, and advocates respond with rebuttal messages , then weIn three preregistered laboratory experiments, we tested the efficacy of outnumbering (Experiments 1–3) and forewarning (Experiments 2 and 3) to counter the damage from science denialism in public discussions Figure . Thus, vaspredicted.org: http://aspredicted.org/blind.php?x=jp7az5.In this experiment, we tested the outnumbering hypothesis by assessing whether a relatively higher number of advocates for science compared with deniers effectively reduces damage from science denialism. Experiment 1 uses the relative number of advocates present as a social cue, that is, while the relative number of advocates and deniers varies, only one person per group serves as a speaker . The chosen effect size of the power analysis was informed by effect sizes of previous research on the false-balance effect /(maximum possible score – minimum possible score)] × 100; SDage = 2.71) for all participants. All participants correctly identified the hypothetical debate’s content; thus, no participant was excluded from the analyses. No evidence of differences between conditions in prior attitudes towards vaccination or prior intention to get vaccinated was found . The Supplementary Information contains detailed descriptive data on all experiments (Supplementary Method).Eighty percent of the full sample was female, with a mean age of 20.71  = 0.11, p = .737, η2p = .001, intention: F = 0.19, p = .661, η2p = .002. We repeated confirmatory analyses with preregistered control variables, and the pattern of results did not differ (Supplementary Tables 5 and 6).However, contrary to the expectations on the outnumbering hypothesis, we obtained no evidence that the presence of a higher proportion of science advocates at the debate mitigated deniers’ influence on individuals’ attitudes or intention; interaction effects from outnumbering with time on attitude: F = 4.68, p = .033, η2p = .046. That is, inviting more advocates than deniers marginally reduced damage from deniers when a rebuttal was delivered, F = 3.10, p = .081, though this trend was reversed when the advocate remained silent, F = 1.69, p = .196. The interaction effect was only marginally significant concerning individuals’ intention .Additional explorative analyses revealed no evidence that the outnumbering strategy’s effects depend on the audience’s issue involvement (Supplementary Table 7). Furthermore, we found no evidence that the willingness to donate to a fictitious initiative that supports anti-vaccination campaigns differed between either the rebuttal or outnumbering conditions  with a power of .80 in a mixed within-between ANOVA . The effect size of the power analysis was chosen to detect conventionally small effect sizes  while the experimental group read an explanatory text about false balance in media reports Figure .In addition to the measures in Experiment 1 Table . Thus, iSDage = 2.26) for all participants. 99.5% correctly answered the question about the debate’s content, with 80% recalling the exact number of advocates and 82.3% recalling the exact number of deniers who were present at the debate. Thus, we repeated the primary analyses with a sample containing only those participants who recalled the correct information, with differences in the full sample reported below. No evidence of differences existed between conditions in prior attitudes, intention to get vaccinated or confidence .Seventy-seven percent of the full sample was female, with a mean age of 19.96  = 0.27, p = .605, η2p = .001; intention to get vaccinated: F = 0.15, p = .703, η2p < .001 or confidence: F = 1.35, p = .246, η2p = .004, not even when analysed as a function of whether or not a rebuttal was delivered  = 7.52, p = .006, η2p = .019; intention: F = 14.75, p < .001, η2p = .037; confidence: F = 10.44, p = .001, η2p = .027.Contrary to the findings in Experiment 1 and contradicting the rebuttal-as-moderator hypothesis, no evidence existed that a higher proportion of advocates present in the debate mitigated deniers’ influence on individuals’ attitude towards vaccination: F1, 38 = 0.27, Confirmatory analyses were repeated with preregistered control variables (Supplementary Tables 5–6 and 8) and with a reduced sample containing only participants who provided correct answers to all three questions of the attention check (Supplementary Table 9–11), obtaining the same patterns of results.Further exploration of the ANOVA models revealed no evidence that forewarning’s efficacy was a function of whether or not a rebuttal was delivered Tables . We alsoAs in Experiment 1, we again found no evidence that outnumbering increases the audience’s resistance to science denialism. Thus, in the third experiment, we aimed to increase outnumbering’s persuasive power by adding another mechanism by which outnumbering potentially can work. Moreover, we aimed to replicate findings from Experiment 2 regarding the forewarning hypothesis.http://aspredicted.org/blind.php?x=wk8nc8.In the previous experiments, only one denier and one advocate spoke during the discussion, regardless of the relative number of guests present during the debate. Thus, outnumbering was expected to work as a social cue. In this experiment, we tested another possible mechanism: outnumbering by delivering multiple rebuttal sources. With this change, we aimed to test whether inviting a greater number of science advocates compared with deniers is an effective weight-of-evidence strategy when all participants take part in the conversation. This additional effect can be expected only when the advocates do not remain silent. Thus, we preregistered the rebuttal-as-moderator hypothesis. Moreover, we preregistered the forewarning hypothesis, explored the rebuttal-as-moderator research question for forewarning and explored the involvement-as-moderator research question for both weight-of-evidence strategies. We preregistered the experiment at The experimental setup was identical to Experiments 1 and 2, with deviations reported below.N = 368 to detect an interaction effect (minimum effect size of interest of d = 0.20) with a power of .80 in a mixed within-between ANOVA . The effect size of the power analysis was chosen to detect conventionally small effect sizes  for all participants. In the end, 99.5% of the sample passed the content question, 82.3% correctly recalled the number of advocates and 85.1% correctly recalled the number of deniers who were present at the debate. Thus, we again repeated the primary analyses with a reduced sample and reported differences to the full sample. No evidence existed of differences between conditions in prior intentions to get vaccinated or prior confidence in vaccination, all ps ≥ .160 in 2 × 2 × 2 ANOVA. However, a difference did exist between conditions in individuals’ prior attitudes towards vaccination, as revealed through a significant three-way interaction, F = 4.08, p = .044, η2p = .010, in the 2 × 2 × 2 ANOVA . Details of the interaction effect are reported in Supplementary Figure 1. To increase the findings’ robustness, the primary analysis of individuals’ attitudes was repeated using postvalues at T2, controlled for values at T1, rather than difference scores. Differences are reported below.Sixty-seven percent of the sample was female, with a mean age of 22.96 years  = 2.10, p = .148, η2p = .005; intention to get vaccinated: F = 2.44, p = .119, η2p = .006, or confidence: F = 0.81, p = .369, η2p = .002, not even when analysed as a function of rebuttal  = 6.92, p = .009, η2p = .018; confidence: F = 8.76, p = .003, η2p = .022. This trend also was observed for individuals’ attitudes; however, the benefit from using forewarning remained not significant for this outcome, F = 1.11, p = .293, η2p = .003.Even with all advocates speaking, we again found no evidence for the outnumbering hypothesis, nor for the rebuttal-as-moderator hypothesis: A higher proportion of advocates did not mitigate the denier’s influence on individuals’ attitudes towards vaccination: F1, 88 = 2.10Confirmatory analyses were repeated with preregistered control variables (Supplementary Tables 5 and 6 and 8) and a sample adjusted for failing attention (Supplementary Tables 9–11). In addition, and due to differences in initial attitude values between conditions, we repeated the ANOVA for individuals’ attitudes using the attitude at T2 as a dependent variable controlling for attitude at T1, rather than difference scores (Supplementary Table 12). The patterns of results did not differ.We found no evidence that forewarning’s efficacy was a function of whether a rebuttal was delivered Tables , 3, 4 orIn the preregistration, we also planned to analyse whether the effects from forewarning and rebuttal were mediated by the denier’s perceived expertise. However, we accidentally did not ensure causal ordering because perceived expertise was measured after the dependent variables. We thus refrain from conducting this analysis.Again, the forewarning mitigated the damage from vaccine denialism messages on the audience’s specific attitudinal beliefs, that is, vaccination safety and trust in institutions. Moreover, it mitigated the damage to the audience’s intention to vaccinate. Thus, forewarnings proved to be a helpful weight-of-evidence strategy against misinformation. As a limitation, and contrary to Experiment 2, we found no significant mitigating effect from forewarnings on the damage to the audience’s general attitudes towards vaccination. Despite our efforts to increase the persuasive strength of adding more advocates via the multiple-source mechanism, we again found no evidence that outnumbering mitigates science denialism damage from public discussions.The results from these three experiments provide some new insights into how editors and journalists can support the evidence-based voice of science when they invite science advocates and deniers to a public discussion. The results also showed that it is necessary to use such measures consciously, as in all three experiments, the science denier damaged study participants’ vaccination-related attitudes and intention, and reduced their confidence in vaccines’ safety and efficacy. While the damage can be mitigated through clever rebuttals from the advocate , nor when lots of advocates served as multiple information sources (Experiment 3). Thus, the outnumbering strategy remained ineffective in the present experiments, even in audiences that, following dual-process theories, are likely to be persuaded by such peripheral cues.The unexpected inefficacy of this weight-of-evidence strategy may be a result of the numeric relation between the majority and minority. Studies show that individuals are persuaded by a consensus when majorities become overwhelming . The numAnother potential concern with the materials used in this study is the dependence on multiple sources. One of the very first studies about the multiple-source effect by Harkins and Petty  found thThis study has several limitations. First, consistent with other survey experiments of this kind , the finGiven the results, editors, journalists and other mass media outlets should invest some effort in providing forewarnings as an effective weight-of-evidence strategy. No evidence was obtained that the efficacy of forewarnings depends on advocates’ delivery of specific rebuttals in the discussion or the audience’s issue involvement. Therefore, we suggest that warning audiences about false-balance reporting prior to debates can serve as a theory-driven, economic and effective weight-of-evidence strategy to support advocates for science in public discussions about scientific topics. To increase the generalisability of the findings, future studies will benefit from analysing the efficacy of weight-of-evidence strategies as a function of varying sample characteristics and participants’ perceived authority of the user of these strategies.https://doi.org/10.17605/OSF.IO/SEFQU.The materials, data and syntax supporting the findings of this study are archived in the Open Science Framework’s public database and are available to anyone: The additonal file for this article can be found as follows:10.5334/joc.125.s1Supplementary Information.Supplementary Method and Supplementary Results.


Juvenile myelomonocytic leukemia (JMML) is a rare aggressive myelodysplastic/myeloproliferative neoplasm of early childhood, initiated by RAS-activating mutations. Genomic analyses have recently described JMML mutational landscape; however, the nature of JMML-propagating cells (JMML-PCs) and the clonal architecture of the disease remained until now elusive. Combining genomic , Colony forming assay and xenograft studies, we detect the presence of JMML-PCs that faithfully reproduce JMML features including the complex/nonlinear organization of dominant/minor clones, both at diagnosis and relapse. Further integrated analysis also reveals that although the mutations are acquired in hematopoietic stem cells, JMML-PCs are not always restricted to this compartment, highlighting the heterogeneity of the disease during the initiation steps. We show that the hematopoietic stem/progenitor cell phenotype is globally maintained in JMML despite overexpression of CD90/THY-1 in a subset of patients. This study shed new lights into the ontogeny of JMML, and the identity of JMML-PCs, and provides robust models to monitor the disease and test novel therapeutic approaches. NRAS, KRAS) or RAS-pathway regulators  [in vitro proliferation of monocyte-macrophage colonies in the absence of exogenous colony stimulating factor [Juvenile myelomonocytic leukemia (JMML) is a rare and aggressive childhood myelodysplastic/myeloproliferative neoplasm (MDS/MPN) thought to be initiated by the activation of the RAS signal transduction pathway due to germline or somatic mutations in genes encoding RAS  or the clonal evolution in JMML, those being, all crucial steps to improve the management of children with JMML.Although this syndrome is predominantly characterized by granulo-monocytic lineage involvement, JMML also shows evidence of multilineage involvement . ThromboPatient-derived xenografts (PDX) provide an invaluable tool to functionally assess tumor samples for leukemia-propagating cell potential. However, limited data are available concerning the capacity of primary JMML PDX to engraft in immunodeficient mice, and whether addition of exogenous human GM-CSF is required for JMML to engraft is not clear –16. MoreIn this paper, we aimed to address these questions by using a combination of whole-exome and targeted deep next-generation sequencing, single-cell colony analysis, and cell sorting as well as xenotransplantation experiments with 17 JMML samples obtained from 15 patients.PTPN11 , NRAS , KRAS , or other genes (n = 3). An additional patient (#123) had a germline PTPN11 p.N308T mutation, in line with Noonan syndrome features.The cohort included 36 patients with JMML  aged 3 months to 13 years (median 2.2 years)  were collected in a diagnostic setting. All children’s samples were obtained after parents had given their written informed consent. This study was approved by the institutional review board of the French Institute of Health and Medical Research (INSERM) (IORG0003254) in accordance with the Helsinki declaration.JMML patient samples  was obtained from intrafamilial BM transplantation donors. The collection and use of these samples were approved by the Institutional Review Board of “Hôpitaux Universitaires Paris Nord Val-de-Seine,” Paris 7 University, AP-HP), (IRB: 00006477), in accordance with the Helsinki declaration.BM of healthy age-matched children (−/− (NSG) mice and NOD/SCID/IL2rγ−/−/IL-3/GM/SF (NSG-S) mice were originally a kind gift of Dr Leonard Shultz (The Jackson Laboratory) and since then have been bred at the Francis Crick Institute Biological Resource facility. These mice were genotypes on arrival and on regular basis thereafter using the genotypic protocols provided by the Jackson laboratory.All animal experiments were performed at the Francis Crick Institute in accordance with UK Home Office and CRICK guidelines and were undertaken under the Home Office project license PLL 70/8904. NOD/SCID/IL2rγ−/− (NSG) mice and NOD/SCID/IL2rγ−/−/IL-3/GM/SF (NSG-S) mice (aged 8–12 weeks old), sex matched/patient  received a sublethal dose of radiation (350–375 cGy) from a cesium-137 source. Direct intra-BM injection was performed in the tibia with 15 × 103 BM CD34+ cells from patients and healthy donors. Number of mice injected per samples varied between samples and were dependent on the primary cells available (from two to six mice). Neither exclusion criteria nor randomization were performed. The investigator was not blind to the group. Engraftment was assessed at sacrifice (6–12 weeks) and the BM cells  were immuno-phenotyped for the presence of mCD45, hCD45, hCD33, hCD19, and hCD3  cell populations. Live cells were stained and sorted on hCD45 phenotype using FACS Aria SORP  or sorted by magnet isolation using EasySep™ Mouse/Human chimera isolation kit . Isolated CD45+ cells were washed in PBS and plated into methylcellulose as mentioned below and/or pelleted in order to later perform genomic analysis or used for secondary transplantation experiment. In addition, one pelvis, one lobe of lung and the spleen were fixed for immunochemistry/immunofluorescence and 105 cells from harvested BM were cytospinned, and then fixed in methanol on a slide for later analysis using May–Grunwald–Giemsa staining. For secondary transplantation, between 1 and 3.7 × 106, human CD45+ cells were injected into sublethally irradiated recipient mice (NSG or NSG-S).Prior to transplantation, NOD/SCID/IL2rγhttp://www.ebi.ac.uk/arrayexpress, Accession number E-MTAB-6461 (patients) and E-MTAB-6467 (xenograft samples). For SNP/CGH array: Accession numbers E-MTAB-3729 (SNP array) and E-MTAB-6468 (CGH + SNP array).Whole genome sequencing data were available via ArrayExpress database: p value < 0.05. Statistical value is provided in each figure.Differences between groups were tested using the Mann–Whitney test (two groups) or by using multivariable one-way ANOVA unpaired analysis corrected for multiple comparisons (multiple groups). All analyses were performed with Prism software. version 6.0 . Statistical significance was defined as Supplementary material and methods section is available in supplementary information including reagents and resources used in this paper (see Table n = 31) (Supplementary Table n = 19). Hematopoietic stem cells (HSCs), multipotent progenitors (MPPs), lymphoid-primed multipotent progenitors (LMPPs), common myeloid progenitors (CMPs), granulocyte-macrophage progenitors (GMPs), and megakaryocyte-erythroid progenitors (MEPs) were identified using multiparametric FACS analyses based on previously defined markers [PTPN11-mutated JMML, which also showed a larger percentage of myeloid progenitors compared with healthy BM within the CD34+CD38+ compartment  of JMML cases showing ectopic CD90 expression in more than 30% of the GMP cells. This was confirmed as a transcriptional deregulation by RNAseq analysis (data not shown).This analysis also revealed an aberrant upregulation of CD90/Thy1 expression within the CD34ion Fig. , and couIn order to functionally assess the leukemia-propagating cell potential, xenotransplantation of cells from 15 genetically defined JMML was performed Table . ConsistIn compliance with UK Home Office guidelines, we first investigated, using samples from a small cohort of four patients , we could not evidence a higher engraftment capacity of the CD90high JMML samples tested  of detection compared with only 1 out of 11 in NSG-S. Only one patient sample (#109) did not engraft in either mouse models. Two samples that were not engrafted in NSG at 12 weeks, engrafted in NSG-S mice at 6 weeks. However, in all other cases, engraftment was detected in both models Fig. . The kin+ cell infiltration after transplantation with some of the JMML samples , into the matching mouse strain. In order to understand whether human cytokines present in NSG-S would increase engraftment in secondary mice, one JMML sample (#92), first engrafted in an NSG mouse, was cross-transplanted into an NSG-S mouse. In all cases, successful secondary engraftment was obtained at 12 weeks Fig. .Contrary to what was observed with primary transplants, engraftment was slightly decreased following secondary transplantation in NSG-S compared with NSG mice despite the longer time-lapse in NSG compared with NSG-S mice (12 + 12 weeks for NSG versus 6 + 12 weeks for NSG-S) suggesting that the self-renewing JMML-PCs are less sensitive to human cytokines.Overall, our data evidence the presence of self-renewing JMML-PCs and confirm the robustness of both mouse models in promoting engraftment and maintaining JMML-PCs, although NSG mice present some advantages in terms of survival times.Having proven the presence of self-renewing JMML-PCs in JMML samples, we next investigated the nature of these cells. HSC, MPP, LMPP, CMP, and GMP subfractions were sorted from five JMML patients and injected separately into NSG mice. NSG mice were preferred to NSG-S mice since we wanted to reveal JMML long-term propagating cells. In most patients from whom JMML cells engrafted, xenografts confirmed the presence of JMML-PCs in the more immature HSC/MPP compartment. Intriguingly, more committed cells, such as LMPP/CMP/GMP, were also able to propagate the disease, demonstrating the JMML-PC capacity of the mature compartment Fig. . From thThe mutational landscape of JMML xenografts, investigated by WES, was compared with the patient sample pre transplantation  assays, performed before and after engraftment in mice Fig. .Fig. 4ClTwo groups of JMML could be delineated according to their clonal architecture. A majority of patients (12/15) presented at diagnosis with either a single (3/12), or several mutations co-existing in a unique JMML clone (9/12), as demonstrated by CFC analysis and/or postulated from elevated VAF (>30%) for all variants (data not shown). This was consistent with a linear pattern of mutation acquisition, although in most cases, the order of acquisition of mutations could not be determined since they were all present in each clone that could be studied , JMML showed nonlinear progression with several subclones co-existing at diagnosis Fig. .n = 2) or branched (n = 3) clonal evolution, targeted sequencing of sorted fractions evidenced the presence of all mutations in the HSC or CD34+CD38− compartment, as well as in more differentiated fractions, with frequencies mirroring those found in the bulk of mononucleated cells , direct sequencing of human engrafted CD45+ cells and CFC analysis out of the mice revealed that the clonal architecture of the native JMML sample (whether at diagnosis or relapse) was maintained in mice  of the three patients with a branched clonal architecture at diagnosis subsequently relapsed. Patient 66’s JMML displayed branched evolution from a one Fig. . Whateveice Fig. .NRAS-mutated founder clone with a major subclone having acquired mutations in RAC2 and NACAD and a minor subclone harboring two distinct mutations in NF1  confirmed the capacity of most JMML samples to engraft in immunodeficient mice , 16. InjOur data demonstrate the robustness of the JMML xenotransplantation model and show that both mouse models not only reproduce major JMML clinical features, but also respect the native clonal architecture in all three major genetic groups of sporadic JMML. Such findings are in sharp contrast with what has been reported for AML , 20 or TInterestingly, whatever the initiating genetic lesion, GM-CSF expressed by NSG-S mice leads to a rapid myeloid expansion, contributing to the aggressive nature of the malignancy, but does not have a significant long-term effect on self-renewing JMML-PCs. Importantly, NSG-S mice also do not seem to induce a bias in clonality compared with NSG, contrary to what might have been expected if human GM-CSF preferentially “overstimulated” specific subclones. This highlights that, although GM-CSF hypersensitivity is a well-known hallmark of JMML, it is more likely a consequence favoring the granulo-monocytic expansion than a causative abnormality in JMML-PCs. This is consistent with the lack of activating GM-CSF mutation in JMML –9 and suIntegration of the hematopoietic cellular hierarchy with clonal evolution by analyzing isolated stem cell and progenitor fractions, showed that the complete JMML mutational profile is already present with a high allelic burden in the HSC/LMPP compartment, consistent with early clonal dominance. In chronic myelomonocytic leukemia, an MPN resembling JMML but occurring in adults , such anhigh JMML samples. Further work will be needed to determine the potential biological or clinical relevance of the upregulation of this marker in some patients.Finally, this study highlighted an aberrant overexpression of CD90 in a subset of patients. CD90/Thy-1 is a cell surface glycoprotein involved in cell adhesion and cell communication in numerous cell types. Although CD90 is considered a major marker of HSC pluripotency and a surrogate marker for HSCs, we could not evidence a higher engraftment capacity in these CD90In conclusion, our data provides new evidence of JMML heterogeneity, unveiling a complex clonal architecture and different JMML-PCs. This heterogeneity could not be explained by the pattern of genetic alterations nor by the initiating cell in which mutations arise. In addition, we show here that, by faithfully recapitulating both the key clinical features and unbiased clonal architecture of the disease, xenotransplanted mice could provide an invaluable model for further research and testing of new candidate treatments, which are urgently needed in this still mostly incurable disease.Supplementary data