274 research outputs found
A case study of the Hirsch index for 26 non-prominent physicists
The h index was introduced by Hirsch to quantify an individual's scientific
research output. It has been widely used in different fields to show the
relevance of the research work of prominent scientists. I have worked out 26
practical cases of physicists which are not so prominent. Therefore this case
study should be more relevant to discuss various features of the Hirsch index
which are interesting or disturbing or both for the more average situation. In
particular, I investigate quantitatively some pitfalls in the evaluation and
the influence of self-citations.Comment: 13 pages, 3 figures, updated after extensive language editing, no
other changes to first versio
A bibliometric analysis of the Journal of Molecular Graphics and Modelling
This paper reviews the articles published in Volumes 2-24 of the Journal of Molecular Graphics and Modelling (formerly the Journal of Molecular Graphics), focusing on the changes that have occurred in the subject over the years, and on the most productive and most cited authors and institutions. The most cited papers are those describing systems or algorithms, but the proportion of these types of article is decreasing as more applications of molecular graphics and molecular modelling are reported
Webometric analysis of departments of librarianship and information science: a follow-up study
This paper reports an analysis of the websites of UK departments of library and information science. Inlink counts of these websites revealed no statistically significant correlation with the quality of the research carried out by these departments, as quantified using departmental grades in the 2001 Research Assessment Exercise and citations in Google Scholar to publications submitted for that Exercise. Reasons for this lack of correlation include: difficulties in disambiguating departmental websites from larger institutional structures; the relatively small amount of research-related material in departmental websites; and limitations in the ways that current Web search engines process linkages to URLs. It is concluded that departmental-level webometric analyses do not at present provide an appropriate technique for evaluating academic research quality, and, more generally, that standards are needed for the formatting of URLs if inlinks are to become firmly established as a tool for website analysis
Patient-reported depression measures in cancer: a meta-review
The patient-reported depression measures that perform best in oncology settings have not yet been identified. We did a meta-review to integrate the findings of reviews of more than 50 depression measures used in adults with, or recovering from, any type of cancer. We searched Medline, PsycINFO, Embase, and grey literature from 1999 to 2014 to identify 19 reviews representing 372 primary studies. 11 reviews were rated as being of high quality (defined as meeting at least 20 criteria in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement). The Hospital Anxiety Depression Scale (HADS) was the most thoroughly evaluated measure, but was limited by cutpoint variability. The HADS had moderate screening utility indices and was least recommended in advanced cancer or palliative care. The Beck Depression Inventory was more generalisable across cancer types and disease stages, with good indices for screening and case finding. The Center for Epidemiologic Studies Depression Scale was the best-weighted measure in terms of responsiveness. This meta-review provides a comprehensive overview of the strengths and limitations of available depression measures. It can inform the choice of the best measure for specific settings and purposes
Bias in the journal impact factor
The ISI journal impact factor (JIF) is based on a sample that may represent
half the whole-of-life citations to some journals, but a small fraction (<10%)
of the citations accruing to other journals. This disproportionate sampling
means that the JIF provides a misleading indication of the true impact of
journals, biased in favour of journals that have a rapid rather than a
prolonged impact. Many journals exhibit a consistent pattern of citation
accrual from year to year, so it may be possible to adjust the JIF to provide a
more reliable indication of a journal's impact.Comment: 9 pages, 8 figures; one reference correcte
Lamé Curve-based Spiral Tool Path Generation for Rough Milling
Automatic tool path generation for milling has been a subject of research for decades. The primary challenge in this area lies in simultaneously satisfying both geometric and technological constraints. Although various methods have been developed for spiral trajectory generation to meet these strict criteria, the potential of Lamé curves (also known as superellipses) has remained unexplored. This paper aims to address this gap by introducing a new algorithm that parametrises Lamé curves and transforms them into spirals using polar coordinate functions. The novel method generates a continuous tool path that smoothly fills the region between two closed boundaries without interrupting the cutting process. The algorithm was validated through case studies involving various pocket-like and island-like geometries. For the comparative analysis, two widely used strategies were selected as benchmarks: the traditional contour-parallel strategy and the advanced adaptive milling strategy. The simulation and cutting experiments conducted to analyse cutter engagement, tool load, and machining time demonstrated that the Lamé-based spiral paths achieved 1–44% improvements in machining time and 3–17% reductions in peak cutting force. These improvements are attributed to the smooth path curvature and the stable cutter engagement along the path, which enables effective tool load control. Although the strategy has certain geometric limitations, the results indicate that Lamé-based spirals offer a promising alternative for improving productivity and tool life in rough milling
Impact Factor: outdated artefact or stepping-stone to journal certification?
A review of Garfield's journal impact factor and its specific implementation
as the Thomson Reuters Impact Factor reveals several weaknesses in this
commonly-used indicator of journal standing. Key limitations include the
mismatch between citing and cited documents, the deceptive display of three
decimals that belies the real precision, and the absence of confidence
intervals. These are minor issues that are easily amended and should be
corrected, but more substantive improvements are needed. There are indications
that the scientific community seeks and needs better certification of journal
procedures to improve the quality of published science. Comprehensive
certification of editorial and review procedures could help ensure adequate
procedures to detect duplicate and fraudulent submissions.Comment: 25 pages, 12 figures, 6 table
askMEDLINE: a free-text, natural language query tool for MEDLINE/PubMed
BACKGROUND: Plain language search tools for MEDLINE/PubMed are few. We wanted to develop a search tool that would allow anyone using a free-text, natural language query and without knowing specialized vocabularies that an expert searcher might use, to find relevant citations in MEDLINE/PubMed. This tool would translate a question into an efficient search. RESULTS: The accuracy and relevance of retrieved citations were compared to references cited in BMJ POEMs and CATs (critically appraised topics) questions from the University of Michigan Department of Pediatrics. askMEDLINE correctly matched the cited references 75.8% in POEMs and 89.2 % in CATs questions on first pass. When articles that were deemed to be relevant to the clinical questions were included, the overall efficiency in retrieving journal articles was 96.8% (POEMs) and 96.3% (CATs.) CONCLUSION: askMEDLINE might be a useful search tool for clinicians, researchers, and other information seekers interested in finding current evidence in MEDLINE/PubMed. The text-only format could be convenient for users with wireless handheld devices and those with low-bandwidth connections in remote locations
Proof over promise: towards a more inclusive ranking of Dutch academics in Economics & Business
The Dutch Economics top-40, based on publications in ISI listed journals, is - to the best of our knowledge - the oldest ranking of individual academics in Economics and is well accepted in the Dutch academic community. However, this ranking is based on publication volume, rather than on the actual impact of the publications in question. This paper therefore uses two relatively new metrics, the citations per author per year (CAY) metric and the individual annual h-index (hIa) to provide two alternative, citation-based, rankings of Dutch academics in Economics & Business. As a data source, we use Google Scholar instead of ISI to provide a more comprehensive measure of impact, including citations to and from publications in non-ISI listed journals, books, working and conference papers.
The resulting rankings are shown to be substantially different from the original ranking based on publications. Just like other research metrics, the CAY or hIa-index should never be used as the sole criterion to evaluate academics. However, we do argue that the hIa-index and the related citations per author per year metric provide an important additional perspective over and above a ranking based on publications in high impact journals alone. Citation-based rankings are also shown to inject a higher level of diversity in terms of age, gender, discipline and academic affiliation and thus appear to be more inclusive of a wider range of scholarship
Combined 1H-Detected solid-state NMR spectroscopy and electron cryotomography to study membrane proteins across resolutions in native environments
Membrane proteins remain challenging targets for structural biology, despite much effort, as their native environment is heterogeneous and complex. Most methods rely on detergents to extract membrane proteins from their native environment, but this removal can significantly alter the structure and function of these proteins. Here, we overcome these challenges with a hybrid method to study membrane proteins in their native membranes, combining high-resolution solid-state nuclear magnetic resonance spectroscopy and electron cryotomography using the same sample. Our method allows the structure and function of membrane proteins to be studied in their native environments, across different spatial and temporal resolutions, and the combination is more powerful than each technique individually. We use the method to demonstrate that the bacterial membrane protein YidC adopts a different conformation in native membranes and that substrate binding to YidC in these native membranes differs from purified and reconstituted system
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