Acknowledgments

Authors may add an acknowledgements section at the end of their paper. This should be brief, and should not include thanks to anonymous referees and editors, or effusive comments. Grant or contribution numbers should be included in this section. Assistance from other writers, proof-readers and editors can also be acknowledged here. For initial submissions, if the acknowledgements section identifies the authors, we ask that you instead include this information in your cover letter or redact it to prevent double-blind review being compromised.

Author contributions

Authors may designate up to six equally contributing authors, up to six joint supervisors, and up to three corresponding authors. Any requests to include more equally contributing, supervising, or corresponding authors are reviewed by the Editor. 

• When applicable, equally contributing and jointly supervising authors should be clearly indicated in the manuscript, using the exact wording: ‘These authors contributed equally to this work’, or, ‘These authors jointly supervised this work’. 

• For corresponding authors the following wording should be used: ‘Corresponding author’ followed by ‘Correspondence to:’

• Authors may include a section entitled 'Author contributions' for any more detailed or nuanced statements.

For initial submissions, any author contributions statement can be included at the end of the cover letter or redacted to prevent double-blind review being compromised.

All authors listed must satisfy our criteria for authorship (see guidance on author responsibilities).

Competing interests

A competing interests statement is required for all submitted papers. If there is no conflict of interest, a statement declaring this must still be included in the paper.

Any statement must be explicit and unambiguous, describing any potential competing interest (or lack thereof) for each contributing author.

For initial submissions, if the competing interests section identifies the authors, we ask that you instead include this information in your cover letter and leave a redacted version in the manuscript to prevent double-blind review being compromised.

Statement templates:

Competing interests
The author(s) declare no competing interests.

Competing interests
X's work has been funded by A. He has received compensation as a member of the advisory board of B and owns stock in the company. He also has consulted for C and received compensation. Y and Z declare no potential conflict of interest.

Learn more about what we consider a competing interest in our policy guidelines.

Competing interests for Board Members/Collection Guest Editors

The journal’s Editorial Board members/Collection Guest Editors are expected to declare any interests that might influence, or be perceived to influence, their editorial activities. In particular, they should exclude themselves from handling manuscripts in cases where there is a conflict of interest, financial or otherwise. This may include—but is not limited to—having previously published with one or more of the authors, and sharing the same institution as one or more of the authors.

Board members/Guest Editors who are authors on a paper published by this journal are recommended to declare their association in the competing/conflicts of interests statement.

Statement templates:

• NAME SURNAME was a member of the Editorial Board of this journal at the time of acceptance for publication. The manuscript was assessed in line with the journal’s standard editorial processes, including its policy on competing interests.

• NAME SURNAME was a Collection Guest Editor for this journal at the time of acceptance for publication. The manuscript was assessed in line with the journal’s standard editorial processes, including its policy on competing interests.

Ethical statements

All authors must include the following two separate sections at the end of their manuscript, irrespective of the nature of the research reported:

• Ethical approval 

• Informed consent

Where these statements are not applicable, the authors should state so.

Ethical approval

When reporting a study that involved human participants, their data or biological material, authors should include a statement that confirms that the study was approved (or granted exemption) by the appropriate institutional and/or national research ethics committee (including the name of the ethics committee) and certify that the study was performed in accordance with the ethical standards as laid down in the 1964 Declaration of Helsinki and its later amendments or comparable ethical standards. If doubt exists whether the research was conducted in accordance with the 1964 Helsinki Declaration or comparable standards, the authors must explain the reasons for their approach, and demonstrate that an independent ethics committee or institutional review board explicitly approved the doubtful aspects of the study.

Authors must identify: (a) the committee that approved the research, and (b) confirm that all research was performed in accordance with relevant guidelines/regulations. Research involving human research participants must have been performed in accordance with the Declaration of Helsinki. If a study was granted exemption from requiring ethics approval, this should also be detailed in the manuscript (including the reasons for the exemption).

Examples of templates to be used when ethics approval has been obtained:

• All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. The study was approved by the Bioethics Committee of the Medical University of A (No. ...).

• This study was performed in line with the principles of the Declaration of Helsinki. Approval was granted by the Ethics Committee of University B (Date.../No. ...).

• Approval was obtained from the ethics committee of University C. The procedures used in this study adhere to the tenets of the Declaration of Helsinki.

• The questionnaire and methodology for this study was approved by the Human Research Ethics committee of the University of D (Ethics approval number: ...).

Example of the template to be used when ethics approval is not relevant:

• This article does not contain any studies with human participants performed by any of the authors.

Retrospective ethics approval

If a study has not been granted ethics committee approval prior to commencing, retrospective ethics approval usually cannot be obtained and it may not be possible to consider the manuscript for peer review. The decision on whether to proceed to peer review in such cases is at the Editor's discretion.

Ethics approval for retrospective studies
Although retrospective studies are conducted on already available data or biological material (for which formal consent may not be needed or is difficult to obtain) ethics approval may be required depending on the law and the national ethical guidelines of a country. Authors should check with their institution to make sure they are complying with the specific requirements of their country.
 

Ethics approval for case studies
Case reports require ethics approval. Most institutions will have specific policies on this subject. Authors should check with their institution to make sure they are complying with the specific requirements of their institution and seek ethics approval where needed. Authors should be aware to secure informed consent from the individual (or parent or guardian if the participant is a minor or incapable).
 

Informed consent

Authors should additionally include at the end of their manuscript confirming that informed consent was obtained from all participants and/or their legal guardians. If informed consent is not relevant, then the authors should simply state so: This article does not contain any studies with human participants performed by any of the authors.

All individuals have individual rights that are not to be infringed. Individual participants in studies have, for example, the right to decide what happens to the (identifiable) personal data gathered, to what they have said during a study or an interview, as well as to any photograph that was taken. This is especially true concerning images of vulnerable people (e.g. minors, patients, refugees, etc) or the use of images in sensitive contexts. In many instances, authors will need to secure written consent before including images.

Identifying details (names, dates of birth, identity numbers, biometrical characteristics (such as facial features, fingerprint, writing style, voice pattern, DNA or other distinguishing characteristics) and other information) of the participants that were studied should not be published in written descriptions, photographs, and genetic profiles unless the information is essential for scholarly purposes and the participant (or parent/guardian if the participant is a minor or incapable or legal representative) gave written informed consent for publication. Complete anonymity is difficult to achieve in some cases. Detailed descriptions of individual participants, whether of their whole bodies or of body sections, may lead to disclosure of their identity. Under certain circumstances consent is not required as long as information is anonymized and the submission does not include images that may identify the person.

Informed consent for publication should be obtained if there is any doubt. For example, masking the eye region in photographs of participants is inadequate protection of anonymity. If identifying characteristics are altered to protect anonymity, such as in genetic profiles, authors should provide assurance that alterations do not distort meaning.

Exceptions where it is not necessary to obtain consent:

• Images such as x rays, laparoscopic images, ultrasound images, brain scans, pathology slides unless there is a concern about identifying information in which case, authors should ensure that consent is obtained.

• Reuse of images: If images are being reused from prior publications, the Publisher will assume that the prior publication obtained the relevant information regarding consent. Authors should provide the appropriate attribution for republished images.

Consent and already available data and/or biologic material
Regardless of whether material is collected from living or dead patients, they (family or guardian if the deceased has not made a pre-mortem decision) must have given prior written consent. The aspect of confidentiality as well as any wishes from the deceased should be respected.

Data protection, confidentiality and privacy
When biological material is donated for or data is generated as part of a research project authors should ensure, as part of the informed consent procedure, that the participants are made aware what kind of (personal) data will be processed, how it will be used and for what purpose. In case of data acquired via a biobank/biorepository, it is possible they apply a broad consent which allows research participants to consent to a broad range of uses of their data and samples which is regarded by research ethics committees as specific enough to be considered “informed”. However, authors should always check the specific biobank/biorepository policies or any other type of data provider policies (in case of non-bio research) to be sure that this is the case.

Consent to participate
For all research involving human subjects, freely-given, informed consent to participate in the study must be obtained from participants (or their parent or legal guardian in the case of children under 16) and a statement to this effect should appear in the manuscript. In the case of articles describing human transplantation studies, authors must include a statement declaring that no organs/tissues were obtained from prisoners and must also name the institution(s)/clinic(s)/department(s) via which organs/tissues were obtained. For manuscripts reporting studies involving vulnerable groups where there is the potential for coercion or where consent may not have been fully informed, extra care will be taken by the editor and may be referred to the Springer Nature Research Integrity Group.

Consent to publish
Individuals may consent to participate in a study, but object to having their data published in a journal article. Authors should make sure to also seek consent from individuals to publish their data prior to submitting their paper to a journal. This is in particular applicable to case studies. 

Availability of data/materials

An inherent principle of publication is that others should be able to replicate and build upon the authors' published claims. Therefore, a condition of publication is that authors are required to make materials, data and associated protocols promptly available to readers without undue qualifications. Any restrictions on the availability of materials or information must be disclosed to the publishing team at the time of submission. Any restrictions must also be disclosed in the submitted manuscript, including details of how readers can obtain materials and information. If materials are to be distributed by a for-profit company, this must be stated in the paper.

Supporting data must be made available to the journal and peer-reviewers at the time of submission for the purposes of evaluating the manuscript. Peer-reviewers may be asked to comment on the terms of access to materials, methods and/or datasets; the journal reserves the right to refuse publication in cases where authors do not provide adequate assurances that they can comply with the publication's requirements for sharing materials.

After publication, readers who encounter refusal by the authors to comply with these policies should contact the publishing team. In cases where we are unable to resolve a complaint, the matter may be referred to the authors' institution or funding institution and/or a formal statement of correction may be published, attached online to the publication, stating that readers have been unable to obtain necessary materials to replicate the findings.

All original articles should include a data availability statement. This should, wherever possible, include a link to and citation of any datasets analysed or generated in the study, when these are available in an appropriate public repository.

The preferred way to share datasets is via specialised public repositories, if one exists, or through a general data repository that can assure permanence and unique identification of deposited datasets.

Authors who make their datasets publicly available should use the most broadly supported and recognised repository for their research community. Public repositories that can be used by include:

• Dataverse — authors who do not have a preferred option can use the journal’s own repository, hosted by Dataverse. Deposition can be confidential during peer review and datasets released after acceptance of associated manuscripts for publication by the editorial team;

• Figshare;

• OpenICPSR;

• EASY (part of Data Archiving and Networked Services, DANS);

• Dryad;

• Open Science Framework.

Repositories for sensitive data that cannot be made public for individual privacy or other legitimate reasons include:

• UK Data Archive;

• ICPSR (Interuniversity Consortium for Political and Social Research).

Further repositories can be found here.

Some of these repositories offer authors the option to host data associated with a manuscript confidentially, and provide anonymous access to peer-reviewers before public release. Some of these repositories coordinate public release of the data with the journal's publication date. This option should be used when possible, but it is the authors' responsibility to communicate with the repository to ensure that public release is made promptly on the publication date. In the unlikely event there is no public repository to accommodate supporting datasets, they must be made available as Supplementary Information files that will be freely accessible on the journal website upon publication. In cases where it is technically impossible for such files to be provided to the journal, the authors must make the data available to the journal and peer-reviewers at submission, and directly upon request to any reader on and after the publication date, the authors providing a URL or other unique identifier in the manuscript.

The journal’s data availability policies are compatible with the standardised research data policies set out by Springer Nature.

Sharing datasets

A condition of publication is that authors are required to make materials, data and associated protocols promptly available to others without preconditions.

Datasets must be made freely available to readers from the date of publication, and must be provided to the journal and peer-reviewers at submission, for the purposes of evaluating the manuscript.

Citing datasets

Citing datasets in an equivalent way to citing journal articles and other types of publication helps enable researchers to earn appropriate credit for the collection and publication of datasets. Data citation also makes reuse and verification of scholarly research more efficient, and can help measure the impact and reuse of datasets. We recommend authors cite, in their reference list, any public datasets that are used or produced in any work described, provided the datasets have been assigned a persistent identifier. When citing datasets the format preferred by DataCite should be used, where persistent identifiers, such as digital object identifier (DOI) names, are displayed as linkable, permanent URLs. 

Pre-registration of studies
The journal encourages pre-registration of studies, where appropriate databases exist, as a means of making research more discoverable. Authors who have pre-registered their study in an independent registry (e.g. American Economic Association's registry for randomized controlled trials, Center for Open Science, Evidence in Governance and Politics (EGAP)  registry, and The Registry for International Development Impact Evaluations) are requested to indicate this clearly in the manuscript, such as in the abstract and an appropriate footnote.

Code sharing

We request that authors, where applicable, make available, to editors and reviewers, any previously unreported custom computer code used to generate results that are reported in the paper and central to its main claims. Upon publication, authors are encouraged to release custom computer code in a way that allows readers to repeat the published results. For all studies using custom code that is deemed central to the conclusions, a statement must be included in the paper (e.g. as a footnote), indicating whether and how the code can be accessed, including any restrictions to access.

Authors may supply code as Supplementary Information files or submit it to the journal’s own repository, hosted by Dataverse, when code must be kept private during peer review. Before final publication, however, authors are encouraged to release their code in a public repository that can assign it a DOI, such as Dataverse or Figshare. In addition, for sufficiently complex software, we recommend using an open version control system (VCS), such as GitHub, in combination with a DOI-providing repository to provide permanent access to a usable instance of code (information on how to archive GitHub code at figshare). Code with an assigned DOI may be formally cited and listed in the References section of the manuscript.

Data availability

All articles must include a ‘Data availability’ statement after the references section. Here ‘data’ refers to any materials or information that underpin a body of research, whether generated or analysed by the authors. ‘Data’ can be quantitative (e.g., numerical) or qualitative (e.g., interview transcripts, images etc) in nature. If no data were generated or analysed then this must be stated in the paper.

Data sharing

We encourage authors to deposit datasets or supporting information that underpin their study in a relevant public repository, where possible. In these cases, the ‘data availability’ statement should include a link to and citation of any deposited files (more guidance on repositories that are available can be found in our guidance on availability of materials and data).

We recognise it is not always possible to share research data publicly, for instance when individual privacy could be compromised, and in such instances data availability should still be stated in the manuscript along with any conditions for access.

For initial submissions, deposition of materials in a repository may result in the authors’ identities being visible, thereby undermining double-blind peer review. In such cases we recommend uploading materials as supplementary files via the submission system for the purposes of peer review. Deposition of materials and data can then take place later in the publication process.

Statement templates

Data availability statements can take one of the following forms (or a combination of more than one if required for multiple datasets):

1. The datasets generated during and/or analysed during the current study are available in the [NAME] repository, [PERSISTENT WEB LINK TO DATASETS]

2. The datasets generated during and/or analysed during the current study are available from the corresponding author on reasonable request.

3. All data generated or analysed during this study are included in this published article [and its supplementary information files].

4. The datasets generated during and/or analysed during the current study are not publicly available due [REASON(S) WHY DATA ARE NOT PUBLIC] but are available from the corresponding author on reasonable request.].

5. Data sharing is not applicable to this article as no datasets were generated or analysed during the current study.

6. The data that support the findings of this study are available from [THIRD PARTY NAME] but restrictions apply to the availability of these data, which were used under licence for the current study, and so are not publicly available. Data are however available from the authors upon reasonable request and with permission of [THIRD PARTY NAME].

More templates for data availability statements, including examples of openly available and restricted access datasets, are available here.

An example of a data availability statement can be found in the paper by Shutters et al. (2015).

While deposition of data in specialised public repositories (statement #1) is the preferred approach wherever possible, in principle all authors who generate or analyse research data are expected to comply with #4, which is the minimum journal policy.

The journal’s editorial team carries out appropriate checks to ascertain whether non-availability of data is for legitimate reasons.

Figures

Authors can include up to 12 display items (i.e. figures or tables) in total in their paper.

Figures that do not meaningfully complement or amplify ideas discussed in the main body of the article should not be included.

Figure legends

Figure legends should begin with a brief title sentence for the whole figure and continue with a short description of what is shown, for instance, in each panel in sequence, and any symbols used; methodological details should be kept to a minimum as much as possible.

Authors are responsible for obtaining permission to publish any figures or illustrations that are protected by copyright, including figures published elsewhere, or downloaded from the internet, and pictures taken by professional photographers. The sources and copyright information must be included in the legends.

Key points

• Figures should be numbered separately with Arabic numerals in the order of occurrence in the text of the manuscript. One- or two-column format figures are required. When appropriate, figures should include error bars. A description of the statistical treatment of error analysis should be included in the figure legend;

• Figure lettering should be in a clear, sans-serif typeface (for example, Helvetica); the same typeface in the same font size should be used for all figures in a paper. Use symbol font for Greek letters. All display items should be on a white background, and should avoid excessive boxing, unnecessary colour, spurious decorative effects (such as three-dimensional 'skyscraper' histograms) and highly pixelated computer drawings. The vertical axis of histograms should not be truncated to exaggerate small differences. Labelling must be of sufficient size and contrast to be readable, even after appropriate reduction. The thinnest lines in the final figure should be no smaller than one point wide;

• Figures divided into parts should be labelled with a lower-case bold a, b, and so on, in the same type size as used elsewhere in the figure. Lettering in figures should be in lower-case type, with only the first letter of each label capitalized. Units should have a single space between the number and the unit, and follow SI nomenclature (for example, ms rather than msec) or the nomenclature common to a particular field. Thousands should be separated by commas (1,000). Unusual units or abbreviations should be spelled out in full or defined in the legend. Scale bars should be used rather than magnification factors, with the length of the bar defined on the bar itself rather than in the legend. In legends, please use visual cues rather than verbal explanations such as "open red triangles";

• Unnecessary figures should be avoided: data presented in small tables or histograms, for instance, can generally be stated briefly in the text instead. Figures should not contain more than one panel unless the parts are logically connected; each panel of a multipart figure should be sized so that the whole figure can be reduced by the same amount and reproduced at the smallest size at which essential details are visible;

• Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Image integrity and standards

All digitised images submitted with the final revision of the manuscript should be 300 DPI if possible.

A certain degree of image processing is acceptable for publication (and for some experiments, fields and techniques is unavoidable), but the final image must correctly represent the original data and conform to community standards. The guidelines below will aid in accurate data presentation at the image processing level; authors must also take care to exercise prudence during data acquisition, where misrepresentation must equally be avoided. Manuscripts should include an 'equipment and settings' section with their Methods that describes for each figure the pertinent instrument settings, acquisition conditions and processing changes, as described in this guide.

• Authors should list all image acquisition tools and image processing software packages used. Authors should document key image-gathering settings and processing manipulations in the Methods;

• Images gathered at different times or from different locations should not be combined into a single image, unless it is stated that the resultant image is a product of time-averaged data or a time-lapse sequence. If juxtaposing images is essential, the borders should be clearly demarcated in the figure and described in the legend;

• The use of touch-up tools, such as cloning and healing tools in Photoshop, or any feature that deliberately obscures manipulations, is to be avoided;

• Processing (such as changing brightness and contrast) is appropriate only when it is applied equally across the entire image and is applied equally to controls. Contrast should not be adjusted so that data disappear. Excessive manipulations, such as processing to emphasise one region in the image at the expense of others (for example, through the use of a biased choice of threshold settings), is inappropriate, as is emphasizing experimental data relative to the control.

When submitting revised final figures upon conditional acceptance, authors may be asked to submit original, unprocessed images.

Tables

Please submit tables in your main article document in an editable format, and not as images. Tables that include statistical analysis of data should describe their standards of error analysis and ranges in a table legend.

Papers can include no more than 12 display items in total (e.g., figures or tables). 

Equations

Equations and mathematical expressions should be provided in the main text of the paper. Equations that are referred to in the text are identified by parenthetical numbers, such as (1), and are referred to in the manuscript as "equation (1)".

For submissions in a .doc or .docx format please ensure that all equations are provided in an editable Word format. These can be produced with the equation editor included in Microsoft Word.

Copyright permission

The author bears the responsibility for checking whether material submitted is subject to copyright or ownership rights (e.g., figures, tables, photographs, illustrations, trade literature and data). The author will need to obtain permission to reproduce any such items (and cover any resulting payments) under a CC-BY license, and include these permissions with their final submission. Where use is restricted, the editorial office must be informed with the final submission of the material.

More detailed advice on rights and permissions can be found here.

It is very likely you will need to seek permission to reproduce third party material unless you include in your submission items that are:

• Not subject to copyright (e.g. where the term of copyright has expired);

• Covered by a copyright exception (please see our requirements regarding the use of material under copyright exceptions);

• Or, obtained from places that set out their terms and conditions for re-use without requiring you to apply to them for permission (e.g. a valid creative commons license, the UK's Government's 'Open Government License' or website terms and conditions).

Permissions clearance can be time-consuming and also, in some instances, expensive. We recommend obtaining permissions as early in the manuscript preparation process as is feasible to avoid delays later on.

Please add any necessary acknowledgments to the typescript, preferably in the form of an Acknowledgments section at the end of the paper.

Legend templates

The sources and copyright of photographs, figures, illustrations, in the accompanying captions must be included in figure legends (where applicable), using the following formula:

Images that you do have permission to reproduce under a CC-BY license:

Figure 1. Figure title. Description of what is in the image/key points. This figure is covered by the Creative Commons Attribution 4.0 International License. Reproduced with permission of NAME; copyright © NAME, all rights reserved.

Images that you do NOT have permission to reproduce under a CC-BY license:

Figure 1. Figure title. Description of what is in the image/key points. This figure is not covered by the Creative Commons Attribution 4.0 International License. Reproduced with permission of NAME; copyright © NAME, all rights reserved.

For a published example, see this paper.

Supplementary information

Supplementary Information (or appendices) may be submitted with the manuscript and will be sent to referees during peer review. It is published online with accepted manuscripts.

We do not permit supplementary information/appendices that follow straight on from the main article text – either the material should be absorbed into the main text, or the information should be uploaded separately as a single supplementary file.

We request that authors avoid ‘data not shown’ statements. Where possible, if an author is able to do so, we consider it best practice to deposit any supplementary information (particularly for supporting data, tables, or figures) in an public repository, or the journal’s own.

Any data necessary to evaluate the claims of the paper that are not available via a public depository should be provided as one single Supplementary Information file.

Supplementary Information is not edited, typeset or proofed, so authors should ensure that it is clearly and succinctly presented at initial submission, and that the style and terminology conform to the rest of the paper.

Please note that modification of Supplementary Information after the paper is published requires a formal correction, so authors are encouraged to check their Supplementary Information carefully before submitting the final version.

The guidelines below detail the creation, citation and submission of Supplementary Information. Publication may be delayed if these are not followed correctly.

• Multiple pieces of Supplementary Information should be combined and supplied as a single file, or supplied separately (e.g. supplementary videos, spreadsheets [.csv or .xlsx] or data files);

• Designate each item as Supplementary Table, Figure, Video, Audio, Note, Data, Discussion, Equations or Methods, as appropriate. Number Supplementary Tables and Figures as, for example, "Supplementary Table S1". This numbering should be separate from that used in tables and figures appearing in the main article. Supplementary Note or Methods should not be numbered; titles for these are optional;

• Refer to each piece of supplementary material at the appropriate point(s) in the main article. Be sure to include the word "Supplementary" each time one is mentioned. Please do not refer to individual panels of supplementary figures;

• Use the following examples as a guide (note: abbreviate "Figure" as "Fig." when in the middle of a sentence): "Table 1 provides a selected subset of the most interesting examples. The entire list of 96 countries can be found as Supplementary Table S1 online." "The decision tree used in the study considers various options (see Supplementary Fig. S2 online). Figure 2 shows...";

• Remember to include a brief title and legend (incorporated into the file to appear near the image) as part of every figure submitted, and a title as part of every table;

• File sizes should be as small as possible, with a maximum size of 50 MB, so that they can be downloaded quickly.

• With the exception of spreadsheet, audio and video files, please submit the Supplementary Information as a single combined PDF if possible (in the order figures, tables and text). If necessary, we can also accept any of these formats: txt; .gif; .html; doc; .jpg; .swf; .mov; .xls; .pdf; .ppt; .wav.