Avoid mixing present and past tenses, especially in descriptions of experimental procedures. The abstract should be informative and not only indicate the general scope of the article but also state the main results obtained and conclusions drawn. It should be suitable for direct inclusion in abstracting journals and should not normally exceed 200 words. The introduction should state clearly the object of the work, its scope and the main advances reported, with brief references to relevant results of other workers. In long papers it is helpful to indicate the way in which the paper is arranged and the results are presented.
Good introductions are particularly important in long reviews.
Authors wishing to acknowledge assistance or encouragement from colleagues, special work by technical staff or financial support from organizations should do so in an unnumbered acknowledgments section immediately following the last numbered section of the paper. Subsections should be numbered 2.1, 2.2, 3.1, 3.2, etc. Where subsubsections are used they should be numbered 2.3.1, 2.3.2, etc. Authors should have their text carefully checked for ambiguities, inconsistencies and linguistic errors before submitting it for publication. This is particularly important for authors who are not writing in their first language.