Information for Authors


About Freshwater Science

Freshwater Science is co-published by the Society for Freshwater Science (SFS) and the University of Chicago Press (UCP).

Freshwater Science
publishes articles that advance understanding and environmental stewardship of all types of inland aquatic ecosystems (lakes, rivers, streams, reservoirs, subterranean, and estuaries) and ecosystems at the interface between aquatic and terrestrial habitats (wetlands, riparian areas, and floodplains). Papers on aspects of estuarine and marine science that complement or add perspective to the understanding of freshwater ecosystems are appropriate. The editors welcome a wide range of topics, including: physical, chemical, and biological properties of lentic and lotic habitats; ecosystem processes; structure and dynamics of populations, communities, and ecosystems; ecology, systematics, and genetics of freshwater organisms, from bacteria to vertebrates; linkages between freshwater and other ecosystems and between freshwater ecology and other aquatic sciences; bioassessment, conservation, and restoration; environmental management; and new or novel methods for basic or applied research.

Submissions can range from full-length treatments to short papers. Short papers should tell a complete story and be supported by data. Reviews, meta-analyses, perspectives, and book reviews are welcome. Theoretical discussions and critical appraisals of rapidly developing research fields will be considered, as will articles that critically evaluate communication of scientific information to policy makers, resource managers, and the general public. Articles of interest to a broad audience that address environmental policy and applications of science to policy and management also are welcome. However, the journal publishes scholarly communications that are grounded in science rather than advocacy.

Special series of articles in Freshwater Science

Freshwater Science currently publishes regular articles, book reviews, special series of papers on particular themes, and articles in 4 special series:


Perspectives articles should express ideas, points of view, or comments on topics of interest to freshwater scientists. New and original papers or comments on items already published in the Journal of the North American Benthological Society (J-NABS) or Freshwater Science are welcome, as is speculation likely to stimulate worthwhile discussion. Alternative viewpoints should be instructive rather than merely contradictory or argumentative. Format and style may be less formal than for research papers; large data sets are not appropriate. Contact the Editor for further information.


BRIDGES is a forum for contrasting or complementary perspectives on new and emerging ideas in aquatic science. Clusters of short articles offering different perspectives within a topic area are welcome. Topics that build across disciplines are preferred, e.g., integrating public policy and science, improving communication among scientists and other communities, or linking scientific disciplines. BRIDGES fact sheets highlight the main points of each BRIDGES cluster using non-technical language to aid in the accessibility of BRIDGES issues. Authors or guest editors with ideas for topics should contact BRIDGES Editors, Ashley Moerke ( or Allison Roy (


Comments provide the opportunity to offer substantive comments, criticisms, or corrections related to articles published in Freshwater Science within the past year. Comments should be brief (≤3 pp.); tables and figures should be avoided. Contact the Editor for information.

FastTracked papers

Short papers with the potential for immediate impact (scientific, applied, management, or policy issues and Comments) can be FastTracked to ensure the most rapid turn-around time possible. Papers should be ≤8 pp. and must be accompanied by a cover letter that justifies the need for such handling. Contact the Editor for information.

History of the journal

The history of J-NABS was described in detail in 2005 by the journal’s first Editor, Rosemary J. Mackay, in her book Beneath the Surface: A history of the North American Benthological Society 1953 to 2003 (Mackay 2005). J-NABS was preceded by volumes 1–4 of Freshwater Invertebrate Biology, founded in 1981 by Jerry Kaster, who offered his journal to the North American Benthological Society in 1983. In 1986, the first issue of J-NABS (5/1), edited by Rosemary Mackay, was published. In 1997, the editorship passed to David Rosenberg, who brought the journal online in 2000. In 2005, Pamela Silver became the Editor of J-NABS. The role of J-NABS in advancing benthic science was detailed in a special 25th Anniversary Issue, published in 2010 (29/1; Silver and Steinman 2010 and papers therein). On 25 May 2011, the members of the North American Benthological Society (NABS) voted to change the name of their society to Society for Freshwater Science (SFS) and to change the title of the society’s journal from Journal of the North American Benthological Society (J-NABS) to Freshwater Science (FWS). On 2 December 2011, one day after the print publication of the 104th issue of J-NABS (30/4), the title of the journal changed officially to Freshwater Science.

Editorial board

The quality of a journal rests with its Editorial Board. Freshwater Science Associate Editors oversee all aspects of the peer-review process. The Editorial Board is an international group of 30 to 40 subject-area experts chosen on the basis of their expertise, reviewing history, and demonstrated commitment to excellence and to the journal. Associate Editors are appointed for three-year terms, and many serve for more than one term. The current list of Associate Editors and contact information is available at


Manuscripts should be submitted via the Freshwater Science Online Submission and Tracking System. This site can be accessed directly at Detailed instructions are provided on the submission site. Please direct questions to the Editor: Pamela Silver, School of Science, Penn State Erie, Erie, Pennsylvania 16563 USA. E-mail:, phone: (814) 898-7132, fax: (814) 898-6213. Manuscripts must comply with Freshwater Science style and format. See Manuscript Preparation—General and Guide to Freshwater Science Style for details. Incomplete submissions or manuscripts that deviate significantly from Freshwater Science style and format will be returned to authors for revision before review.


Submissions should be accompanied by a covering letter that includes phone numbers of the corresponding author and e-mail addresses of ALL authors. The letter should describe the extent to which data, text, or illustrations have been used in existing or forthcoming papers or books, and should state an ability to pay page charges if the paper is published. In cases of financial hardship, authors should request assistance in their covering letter and contact the Editor directly. The letter must attest to the bona fide nature of data used in the study that exist only on a website and must describe steps taken for quality control. The URL must be provided in the manuscript. Authors should be able to provide a hard copy of the data on request.


All submissions will be assessed by rigorous peer review. The Editor reserves the right to reject, without review, manuscripts on topics outside the scope of Freshwater Science; with serious deficiencies in methods, study design, or analysis; with poor punctuation and structure; or of such limited scope that they lack relevance for an international audience. Manuscripts will be judged on the basis of scientific merit and quality of writing. Revised manuscripts that pass peer review will be forwarded to the Editor for further editing/revision and a final decision regarding publication. Information on the status of manuscripts can be obtained from the Freshwater Science Online Submission and Tracking System. Changes in contact information can be made online. Other inquiries should be addressed to the Editor.


Submit books for review to the Book Review Editor, E. F. Benfield (E-mail: Anyone wishing to review books for Freshwater Science should contact the Book Review Editor.

Page charges

To help defray the cost of publishing articles in Freshwater Science, accepted manuscripts are charged US$30.00/page for the first 13 pages and $50/page for every page thereafter.

Online supplemental files

Freshwater Science supports online supplemental text, image, data, video, and audio files that are linked to articles at no additional cost to authors.

Color images

A limited number of color images can be printed at no cost to authors. Color in the printed version of the journal should be requested only when it is essential to conveying an author’s message. Authors may choose to pay for publication of non-essential color images at a cost of US$150.00 per figure. Color versions of images printed in black and white can be made available as online supplemental files. Please contact the Editor for more information.

Open access

Open access publishing refers to electronic delivery of journal content to anyone with access to the internet. When an author publishes a manuscript in Freshwater Science and purchases open access, the article (abstract and full-text article) can be accessed at no cost by anyone in the world who can access the internet. The article file can be opened, read, or downloaded through search engines, the SFS/University of Chicago websites or JSTOR. The biggest advantage of open access is that it increases availability of articles, and therefore, increases the likelihood that an article will be read and cited. Open access articles have higher citation rates, greater impact, and are more likely to be used and built-upon by others than articles that are published in print only or that are locked behind subscription walls. Because much research is done and published by authors using public funds, many governmental agencies now require that authors find ways to make their articles open access (e.g., by purchasing open access at the time of publication [gold open access] or by submitting their article to PubMed Central or other public repositories [green open access]).


Open access articles carry no cost to readers, but these articles are not free to publish because all of the usual publishing costs except those for printing, binding, and mailing still exist. These costs include those associated with administration of the peer-review system, editorial services, typesetting/formatting, electronic tagging, and maintenance on the internet. Therefore, publishers charge authors a fee for gold open access. The fee for gold open access for articles published in Freshwater Science is $400 USD.


Authors whose research was funded by the National Institutes of Health, the Wellcome Trust, or the Medical Research Council (MRC UK) may submit their final accepted manuscript to PubMed Central or PubMed Central UK with release to the public 12 months after publication at no cost for NIH-funded research or 6 months after publication for Wellcome Trust-funded or MRC UK-funded research.

Freshwater Science editorial policies and procedures

Message from the Editor

Freshwater Science expects that its Editor, Associate Editors, referees, and authors will adhere to the highest ethical and professional standards. Freshwater Science is committed to publishing the best possible papers. Its Editor and Associate Editors value both the quality and importance of the science and the quality of the communication of that science. The peer-review and editorial processes will be conducted in as timely a manner possible, but quality of an article will not be sacrificed for expediency. All papers are subject to peer and editorial review, and no paper will be published in print or online until it has been fully edited, copy edited, and polished. Freshwater Science embraces the philosophy that consistent service to authors based on personal interaction, constructive dialog, education of developing authors, and attention to detail will best serve the journal, its authors, readers, and the end-users of the science published in the journal.

Purpose and scope of the journal

Freshwater Science publishes timely, high-quality, peer-reviewed scientific research that promotes a better understanding and environmental stewardship of biological communities living in aquatic ecosystems, particularly streams, rivers, lakes, and wetlands. The scope of the journal is broad and encompasses basic and applied science in the many fields of aquatic science that are related to the biology, ecology, chemistry, geomorphology, and hydrology of this habitat and the organisms that live there.


Articles published in Freshwater Science should make a substantial contribution to the broad field of aquatic science either by contributing new knowledge or insights, improving understanding of the mechanisms or processes underlying patterns or phenomena, synthesizing existing knowledge, or showing how existing knowledge/understanding can be applied to improve environmental stewardship. Original research and hypotheses examined should be well developed and complete. Preliminary, partial, or pilot studies usually are inappropriate for Freshwater Science.

Editorial philosophy

Scientific merit. Scientific merit is the primary criterion applied to selection of manuscripts for publication in Freshwater Science. The journal publishes basic and applied science; studies that are descriptive, experimental (field-, model-, and laboratory-based), or theoretical; and reviews, meta-analyses, and perspectives/comments. Because the scope of the journal is broad, every effort is made to apply discipline-appropriate criteria during the review process. Material in manuscripts should advance the knowledge in a field rather than merely repeat well-established findings or patterns. Reports of studies designed to test causal hypotheses, synthesize information to develop or test theory, or fill specific knowledge gaps are especially welcome.


Freshwater Science does not restrict the length of manuscripts a priori, so manuscripts should tell a complete story and should not be partitioned among multiple small articles. Because Freshwater Science is an international journal, manuscripts presenting studies that are very limited in scope usually are not acceptable unless the work is placed into a context of relevance to a broad audience. Manuscripts that present policy- or management-related studies should be based on science and not on advocacy. Such studies should be presented in a manner that makes clear the relevance of the issue to an international audience.


The role of editing. Freshwater Science Editors and Associate Editors adhere to the philosophy that organization, clarity of presentation, writing style, and consistency in format enhances reader understanding and, therefore, the usefulness of articles and the reputations of their authors. Unclear writing and poorly formatted tables and figures can lead to misinterpretation or mistrust of results at worst and can be distracting at best. Manuscripts that are poorly prepared will be returned to authors without review. In cases where authors lack experience or for whom English is a second language, every effort will be made to provide editorial services and guidance to authors upon their request. All manuscripts will be thoroughly and carefully edited and copy edited to ensure that they are grammatically and factually correct and as concise as possible before they are published.

The peer-review/decision process

Manuscripts submitted to Freshwater Science are subject to peer review. Exceptions are invited book reviews and introductions to special series of articles that merely serve to introduce the theme of the series and the topics of individual papers in the series. Upon submission, articles will be screened to ensure that they are complete, meet the instructions for manuscript preparation, and are accompanied by a cover letter with all of the requested information. Once a submission passes this quality-control screening, manuscripts will be assigned to a subject-area Associate Editor, who will screen the article for appropriate scope and content and quality of preparation. Manuscripts that are inappropriate for Freshwater Science in terms of scope or topic or that are poorly prepared may be rejected without further review. Manuscripts that meet these initial tests will be sent for peer review, usually by two referees although more can be assigned at the discretion of the Associate Editor.


Associate Editors will solicit reviews from referees chosen on the basis of expertise, availability, and willingness to conduct a review. Authors are encouraged to suggest appropriate referees, but Associate Editors are not obligated to choose referees suggested by authors. Authors also may identify referees who should not be asked to review their manuscript. Referees will be asked to complete their reviews within four weeks when possible. After the desired number of reviews has been received, Associate Editors will make an initial decision regarding whether to reject a manuscript, reject a manuscript with an invitation for extensive revision and resubmission as a new manuscript, or recommend the manuscript for revision and consideration for acceptance. In most cases, Associate Editors will provide their own critique and analysis of the manuscript. As part of this process, they will provide guidance to authors regarding how to respond to referee comments and suggestions (e.g., rectifying conflicting requests or advice) during revision.


Manuscripts recommended for revision will be returned to the authors. The expected turn-around period for revisions is four months or less. Authors may request extensions if there are extenuating circumstances, but prolonged delays may result in rejection or another round of reviews in light of new developments in the field. Associate Editors will check all revisions carefully to ensure that all referee comments have been addressed. Authors are encouraged to submit a detailed matrix with their revision showing how each reviewer comment has been addressed. In some cases, Associate Editors might request a new round of reviews, e.g., if the revisions have substantially altered the content or revealed new problems. Associate Editors also might request further revisions before making a final recommendation to the Editor.

After a manuscript is recommended for publication

The final decision to accept a manuscript rests with the Editor. When the Associate Editor is satisfied that the scientific and technical details of a manuscript meet Freshwater Science standards, s/he will notify the author and forward the manuscript to the Editor. The Editor will ensure that the manuscript meets Freshwater Science style and format requirements and will edit the manuscript for grammatical correctness, clarity, readability, conciseness, and organization. The extent of the editing will vary with the quality of the presentation of the manuscript. The Editor also will check all factual details, rectify the text, tables, and figures for factual consistency, and check all bibliographic details. The edited manuscript will be returned to the author for final corrections. The author is expected to verify the changes, make any required corrections, and return the manuscript to the editor for final polishing. The polished manuscript will be sent to the Copy Editor, who will check the manuscript for typographical and spelling details, verify the Literature Cited, and check again for factual consistency. The final manuscript will then be sent for typesetting and publication. Authors are required to read and request necessary changes to proofs. The editor also will read and annotate the proofs, and verify that corrections have been made in the revised proofs. Any changes requested by the authors at this point may result in a fee and delay in publication.


Fully corrected proofs (final version) will be published immediately in the online version of the journal. The date of online publication is provided in the heading of the article as a reference in case of questions regarding precedence of publication. The printed journal is published quarterly (March, June, September, and December 1). All printed articles are identical to their electronic versions.

Ethical and other considerations

Plagiarism. Plagiarism is intellectual property theft and will not be tolerated. Freshwater Science defines plagiarism as the unauthorized use of written, spoken, or graphical material belonging to someone other than the author(s) of a manuscript. Material that is quoted directly from another source should be placed in quotation marks and the page on which the quotation can be found should be listed in the citation. Paraphrased material also must be accompanied by a citation and page reference or a notation of personal communication. In general, extensive use of quotations and paraphrasing is strongly discouraged. Material and data already published by an author in another paper or publicly available report, whether printed or electronic, also may not be quoted, summarized, repeated, or paraphrased without proper attribution.


In the event that plagiarism, whether intentional or inadvertent, is discovered, the incident should be reported immediately to the Editor who will verify the facts of the incident and contact the author for an explanation. The author will be given an opportunity to explain the situation and to correct the problem in a manuscript or to retract a published paper. Should an author decline to correct the problem in a manuscript, the manuscript will be rejected for plagiarism without possibility of resubmission. Further action might be taken depending on the circumstances. Should an author decline to retract a published paper, the Editor will publish a retraction.


Dual publication. Dual publication is defined as publishing an article or parts of an article in more than one journal or venue. Authors are required to verify that manuscripts or parts of manuscripts, including methods sections and data, submitted to Freshwater Science have not been submitted or published elsewhere. Freshwater Science regards material published in a format that is publicly available (e.g., rejected manuscripts that remain available in discussion format on other journal web sites) as published elsewhere. Government reports that have been extensively modified for publication as a journal article usually are exceptions to this rule. Doctoral dissertations and Master’s theses generally are exceptions to this rule. Graduate students are encouraged to consult their graduate institutional policy regarding publishing their theses and dissertations. Authors who are unsure whether they might be in violation of this policy are encouraged to contact the Editor or Associate Editor for clarification.


Freshwater Science will consider for publication manuscripts that have been posted in a recognized not-for-profit preprint archive (such as arXiv, bioRxiv, and PeerJ PrePrints).


Associate Editors and referees who suspect that an author might be in violation of this policy are encouraged to request copies of previously published materials or to contact the Editor for guidance. In the event of discovery that a paper published in Freshwater Science was previously or subsequently published elsewhere, the Editor will publish a retraction of the paper, and further action might be taken, depending on the circumstances.


Voucher specimens. Voucher specimens are preserved organisms (or parts thereof) that serve as a future reference for a name used in a scientific publication. Voucher specimens ensure the credibility and endurance of research results because they document the identity of study organisms. Therefore, although not required for publication in Freshwater Science, the preservation of voucher specimens is recognized by the Editorial Board as one of the most important author responsibilities when publishing research. Accordingly, the Board has adopted the following policy statement: “Authors are encouraged to designate, properly prepare, label, and deposit high-quality voucher specimens and cultures documenting their research in an established permanent collection and to cite the repository in publication.”


Species distribution records. Authors are encouraged to place all species distribution records in a publicly accessible database such as the national Global Biodiversity Information Facility (GBIF) nodes ( or data centers endorsed by GBIF, including BioFresh (


Criteria for authorship. All persons listed as authors of a manuscript must have made a substantial intellectual and scientific contribution to the manuscript by: 1) conceiving, designing, or implementing the study, 2) analyzing or interpreting the data, or 3) writing the manuscript. Potential authors who have not contributed in one of these ways to the paper should not be included, although their contribution can and should be recognized in the Acknowledgements section. All authors of a multi-author paper must read and approve of the manuscript and revisions. Changes to the list of authors or the order of authors during the peer-review and publication process must be approved in writing by all parties involved. This approval should be sent to the Editor prior to publication of an article.


Use of human or animal subjects or studies involving endangered species. All uses of human or animal subjects in research published in Freshwater Science must conform to all institutional, regional, or national ethical and legal standards that apply. The Editor reserves the right to consider animal welfare as part of the decision to publish a study.


Acknowledgements. Freshwater Science expects all authors to acknowledge the individuals or institutions that provided intellectual, financial, and logistic support for their work. Authors should provide grant numbers and contract numbers as appropriate. Any individuals who contributed substantially to the work or manuscript but who are ineligible as authors (e.g., field or laboratory technicians, developers of software used in the research, landowners who provided access to research sites, laboratory discussion groups) also should be recognized. Referees contribute substantial time and effort to reviewing, and their constructive criticism of manuscripts and any other contributions should be acknowledged when appropriate. Permit numbers or statements regarding conformity with ethical standards should be included when appropriate. Last, any required disclaimers, contribution numbers, or explanations of order of authorship should be included in Acknowledgements.


Financial disclosure. Authors are required to disclose any substantive financial interests in the publication of a paper at the time the manuscript is submitted.


Conflicts of interest. The integrity of the peer-review process requires that the Editor, Associate Editors, and referees disclose any conflicts of interest before agreeing to handle or review a manuscript. All manuscripts, reviews, and decisions are privileged and should be kept confidential.


Errors. All manuscripts will be carefully edited to ensure that they are well-written, technically correct, and that all facts presented in the text are supported by data presented in tables, figures, and appendices. However, ultimately, authors are responsible for the content of their papers and should be diligent during the preparation and editing stages. Content published in online-only appendices and files usually is not edited by Freshwater Science personnel, so authors should be particularly diligent about checking these files for accuracy and completeness. In the event that an error is discovered after an article has been published, authors are urged to contact the Editor and to publish an erratum. Errata are not subject to page charges unless they exceed 1 page in length. Errata are permanently associated with the original article when published in the electronic version of the journal.


A manuscript submitted for publication in this journal will not have been previously published and will not be simultaneously submitted for publication elsewhere. By submitting a manuscript, an author agrees that the copyright to that article will be transferred to the Society for Freshwater Science (SFS), if and when the article is accepted for publication. Assignment of copyright is not required from an author who is employed by a government organization that does not permit such agreements. The copyright covers the exclusive right to reproduce and distribute the article in all forms, including, but not limited to, translations, photographic reproductions, microfilm, electronic form, or other reproductions of similar nature.


No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, scanning, or otherwise, except as described below, without permission in writing from the University of Chicago Press ( Copying of articles is not permitted except for personal and internal use, to the extent permitted by Section 107 or 108 of the US Copyright Act. Requests for permission for other kinds of copying, such as copying for general distribution, for advertising or promotional purposes, for creating new collective works or for resale, and all other inquiries, should be directed to the University of Chicago Press (


An author may make an article published by SFS available on a personal web page without requesting permission. The source of the article must be cited, and SFS must be identified as the copyright owner. For further information on author’s rights, please consult the University of Chicago Press Guidelines for Journal Authors’ Rights at




A manuscript submitted Copyrighted material published in the Journal of the North American Benthological Society or in Freshwater Science may be copied or otherwise reused without permission only at the extent permitted by Sections 107 and 108 of the U.S. Copyright Law. Permission to copy articles for personal, internal, classroom, or library use may be obtained from the Copyright Clearance Center ( For all other uses, such as copying for general distribution, for advertising or promotional purposes, for creating new collective works, or for resale, please contact Permissions Coordinator, Journals Division, University of Chicago Press, 1427 E. 60th St., Chicago, IL 60637 USA. Fax: 773-834-3489. E-mail Articles in the public domain may be used without permission, but it is customary to contact the author.

Instructions for Manuscript Assembly

General layout

Type and double space all materials including literature cited, table headings, tables, appendices, and figure legends. Leave 2.5-cm margins on all text pages. Do not justify the right-hand margin.


Number all pages and lines and assemble in the order: title page, abstract and key words, text, acknowledgements, literature cited, appendices, figure captions, tables. Figures should be submitted as separate individual files.


Title page

The title page begins with an abbreviated title (running head) of ~40 characters, followed by the actual title of ≤15 words; names and addresses of authors; footnotes to show e-mail addresses, changes of address, and author to whom correspondence should be addressed if not 1st author.


The abstract states succinctly (<5% of text) the purpose, methods, results, and conclusions of the research. It is followed by 6-12 key words for indexing purposes, listed in order of decreasing importance.

Main text

Text has central main headings; side subheadings are separate for second level, but part of the paragraph for third level.

References cited in the text

References in the text are cited by author and date: e.g., Smith (1960) or (Smith 1960). Do not cite abstracts or manuscripts in review. Multiple citations should be separated by commas and given in chronological order. Use et al. after name of 1st author for citations having >2 authors.


URLs may be used for data that exist only on a web site, but the letter of submittal (see above) must attest to the bona fide nature of the data and briefly describe the steps taken for quality control. Authors should be prepared to prepare a hard copy on request.


Acknowledgements, under a central heading, include special publication numbers when appropriate.

Literature Cited

Literature Cited, under a central heading, lists references in alphabetical order of 1st (2nd, 3rd) authors, regardless of date. Do not type authors' names entirely in upper-case letters. Use both sizes of letters in the following style:


Case, A. B., and C. D. Yan. 1983. Arctic periphyton. Journal of Arctic Ecology 9:8-15.


Gann, E. F., G. H. King, and I. J. Hall. 1980. Feeding by benthic invertebrates. Pages 6–11 in K. L. Gee (editor). Productivity in lakes. Lansing Press, Lansing, Ohio.


Kerr, K. L. 1985. River management. 2nd edition. Seaton Publishing Company, Chicago, Illinois.


For technical reports, cite the hardcopy version in preference to the URL. Technical reports not part of a numbered series need an address of availability (either postal or URL). Use the most current URL.


To download the Freshwater Science EndNote style output file, visit


Tables are double spaced on separate sheets; long tables should be typed on several pages rather than being photoreduced to fit a single page. Use lower-case letters to indicate footnotes. Tables must be editable and in MSWord format.


Figures should be in electronic format and all fonts should be sized to be >8 pt in the printed version (see Guide to Freshwater Science Style). Please use sans serif font.

Online-only material

Very large tables or appendices and supplemental files (figures, photographs, video/audio files, and supplemental data files) can be uploaded via the Freshwater Science Online Submission and Tracking System and linked to the published manuscript. The existence of such files should be mentioned in the cover letter and all files should be referenced in the manuscript. Please edit these files carefully for accuracy and completeness because they are not subject to standard editing procedures.