Influential cited references in FEMS Microbiology Letters: lessons from Reference Publication Year Spectroscopy (RPYS)

The journal FEMS Microbiology Letters covers all aspects of microbiology including virology. On which scientific shoulders do the papers published in this journal stand? Which are the classic papers used by the authors? We aim to answer these questions in this study by applying the Reference Publication Year Spectroscopy (RPYS) analysis to all papers published in this journal between 1977 and 2017. In total, 16 837 publications with 410 586 cited references are analyzed. Mainly, the studies published in the journal FEMS Microbiology Letters draw knowledge from methods developed to quantify or characterize biochemical substances such as proteins, nucleic acids, lipids, or carbohydrates and from improvements of techniques suitable for studies of bacterial genetics. The techniques frequently used for studying the genetic of microorganisms in FEMS Microbiology Letters' studies were developed using samples prepared from microorganisms. Methods required for the investigation of proteins, carbohydrates, or lipids were mostly transferred from other fields of life science to microbiology

The substantive and practical significance of citation impact differences between institutions: Guidelines for the analysis of percentiles using effect sizes and confidence intervals

In our chapter we address the statistical analysis of percentiles: How should the citation impact of institutions be compared? In educational and psychological testing, percentiles are already used widely as a standard to evaluate an individual's test scores - intelligence tests for example - by comparing them with the percentiles of a calibrated sample. Percentiles, or percentile rank classes, are also a very suitable method for bibliometrics to normalize citations of publications in terms of the subject category and the publication year and, unlike the mean-based indicators (the relative citation rates), percentiles are scarcely affected by skewed distributions of citations. The percentile of a certain publication provides information about the citation impact this publication has achieved in comparison to other similar publications in the same subject category and publication year. Analyses of percentiles, however, have not always been presented in the most effective and meaningful way. New APA guidelines (American Psychological Association, 2010) suggest a lesser emphasis on significance tests and a greater emphasis on the substantive and practical significance of findings. Drawing on work by Cumming (2012) we show how examinations of effect sizes (e.g. Cohen's d statistic) and confidence intervals can lead to a clear understanding of citation impact differences

Disruption indices and their calculation using web-of-science data:Indicators of historical developments or evolutionary dynamics?

Science and technology develop not only along historical trajectories, but also as next-order regimes that periodically change the landscape. Regimes can incur on trajectories which are then disrupted. Using citations and references for the operationalization, we discuss and quantify both the recently proposed “disruption indicator” and the older indicator for “critical transitions” among reference lists as changes which may necessitate a rewriting of history. We elaborate this with three examples in order to provide a proof of concept. We shall show how the indicators can be calculated using Web-of-Science data. The routine is automated (available at ) so that it can be upscaled in future research. We suggest that “critical transitions” can be used to indicate disruption at the regime level, whereas disruption is developed at the trajectory level. Both conceptually and empirically, however, continuity is grasped more easily than disruption

Metrics to evaluate research performance in academic institutions: A critique of ERA 2010 as applied in forestry and the indirect H2 index as a possible alternative

Excellence for Research in Australia (ERA) is an attempt by the Australian Research Council to rate Australian universities on a 5-point scale within 180 Fields of Research using metrics and peer evaluation by an evaluation committee. Some of the bibliometric data contributing to this ranking suffer statistical issues associated with skewed distributions. Other data are standardised year-by-year, placing undue emphasis on the most recent publications which may not yet have reliable citation patterns. The bibliometric data offered to the evaluation committees is extensive, but lacks effective syntheses such as the h-index and its variants. The indirect H2 index is objective, can be computed automatically and efficiently, is resistant to manipulation, and a good indicator of impact to assist the ERA evaluation committees and to similar evaluations internationally.Comment: 19 pages, 6 figures, 7 tables, appendice

A reverse engineering approach to the suppression of citation biases reveals universal properties of citation distributions

The large amount of information contained in bibliographic databases has recently boosted the use of citations, and other indicators based on citation numbers, as tools for the quantitative assessment of scientific research. Citations counts are often interpreted as proxies for the scientific influence of papers, journals, scholars, and institutions. However, a rigorous and scientifically grounded methodology for a correct use of citation counts is still missing. In particular, cross-disciplinary comparisons in terms of raw citation counts systematically favors scientific disciplines with higher citation and publication rates. Here we perform an exhaustive study of the citation patterns of millions of papers, and derive a simple transformation of citation counts able to suppress the disproportionate citation counts among scientific domains. We find that the transformation is well described by a power-law function, and that the parameter values of the transformation are typical features of each scientific discipline. Universal properties of citation patterns descend therefore from the fact that citation distributions for papers in a specific field are all part of the same family of univariate distributions.Comment: 9 pages, 6 figures. Supporting information files available at http://filrad.homelinux.or

At what institutions did Nobel laureates do their prize-winning work? An analysis of biographical information on Nobel laureates from 1994 to 2014

In this study we examined the institutions (and countries) the Nobel laureates of the three disciplines chemistry, physics and physiology/medicine were affiliated with (from 1994 to 2014) when they did the decisive research work. To be able to frame the results at that time point, we also looked at when the Nobel laureates obtained their Ph.D./M.D. and when they were awarded the Nobel Prize. We examined all 155 Nobel laureates of the last 21 years in physics, chemistry, and physiology/medicine. Results showed that the USA dominated as a country. Statistical analysis also revealed that only three institutions can boast a larger number of Nobelists at all three time points examined: UC Berkeley, Columbia University and the Massachusetts Institute of Technology (MIT). Researcher mobility analysis made clear that most of the Nobel laureates were mobile; either after having obtained their Ph.D./M.D. or after writing significant papers that were decisive for the Nobel Prize. Therefore, we distinguished different ways of mobility between countries and between institutions. In most cases, the researchers changed institutes/universities within one and the same country (in first position: the USA, followed, by far, by the United Kingdom, Japan and Germany)

Climate change and viticulture - a quantitative analysis of a highly dynamic research field

In this study, we analyzed the newly emerging research field of climate change in combination with viticulture. Our analyses have two objectives: First, the overall publication output and the growth of research on climate change and viticulture is presented and analyzed. We developed a sophisticated search query to cover the relevant literature as completely as possible and to exclude irrelevant literature. The time evolution of the publications of the research topic as well as the most contributing journals and countries of authors, and the major research areas are presented. Second, most important publications in the historical context of this field are identified. Both analyses are based on a carefully selected publication set of 1039 papers (articles, reviews, and conference proceedings) dealing with the implications of climate change for viticulture. The results reveal that the number of papers published per year dealing with climate change and viticulture shows a strong increase: Since around 2000, the number increased by a factor of ten, whereas in the same time period the overall number of papers increased by a factor of around two. We identified 14 citation classics which include fundamental early works of viticulture with a weak connection to climate change and more recent works with a stronger connection to climate change