133 research outputs found
Counting publications and citations: Is more always better?
Is more always better? We address this question in the context of
bibliometric indices that aim to assess the scientific impact of individual
researchers by counting their number of highly cited publications. We propose a
simple model in which the number of citations of a publication depends not only
on the scientific impact of the publication but also on other 'random' factors.
Our model indicates that more need not always be better. It turns out that the
most influential researchers may have a systematically lower performance, in
terms of highly cited publications, than some of their less influential
colleagues. The model also suggests an improved way of counting highly cited
publications
The elephant in the room: The problem of quantifying productivity in evaluative scientometrics
In a critical and provocative paper, Abramo and D'Angelo claim that commonly
used scientometric indicators such as the mean normalized citation score (MNCS)
are completely inappropriate as indicators of scientific performance. Abramo
and D'Angelo argue that scientific performance should be quantified using
indicators that take into account the productivity of a research unit. We
provide a response to Abramo and D'Angelo, indicating where we believe they
raise important issues, but also pointing out where we believe their claims to
be too extreme
Complications of peripheral arteriography:A new system to identify patients at increased risk
AbstractPurpose: The most quoted literature on arteriographic complications is based on self-reports collected during the mid 1970s. We sought to determine whether those results remain valid despite changes in arteriographic practice and whether patient subgroups at increased risk could be identified.Methods: Five hundred forty-nine consecutive patients were examined after arteriography and twice over 72 hours. Patients were telephoned at least 2 weeks later to identify delayed complications. The sample was divided into two groups to allow independent validation of suspected prognostic factors.Results: The rate of major complications was 2.9% (16/549), but varied from 0.7% to 9.1% among three strata of relative risk. Rates were highest in patients studied for suspected aortic dissection, mesenteric ischemia, gastrointestinal bleeding, or symptomatic carotid artery stenosis and lowest in patients with trauma or aneurysmal disease. Patients studied for claudication or limb-threatening ischemia had intermediate risk (2.0%). Within these strata, congestive heart failure and furosemide use were the only variables independently associated with a significantly increased complication rate.Conclusions: Previous reports have overestimated the risk of arteriography for trauma or aneurysm but substantially underestimate the risk for patients with other common conditions. Such stratified complication rates are essential to understand relative costs and benefits of arteriography and other vascular imaging modalities in specific clinical situations. (J VASC SURG 1995;22:787-94.
Mathematical models of population interactions with dispersal II: Differential survival in a change of habitat
AbstractThe paper considers a model of dispersing populations in the form of a system of nonlinear ordinary differential equations. Dispersal pressure is density dependent and a parameter measures the barrier strength. The model also incorporates a transition probability to allow for a risk in changing habitats. For the two-dimensional case, the region in parameter space for existence of a stable equilibrium solution is exactly determined, bounded in part by a branch of a hyperbola. For the n-dimensional case, similar, but less complete results are obtained
The Leiden Ranking 2011/2012: Data collection, indicators, and interpretation
The Leiden Ranking 2011/2012 is a ranking of universities based on
bibliometric indicators of publication output, citation impact, and scientific
collaboration. The ranking includes 500 major universities from 41 different
countries. This paper provides an extensive discussion of the Leiden Ranking
2011/2012. The ranking is compared with other global university rankings, in
particular the Academic Ranking of World Universities (commonly known as the
Shanghai Ranking) and the Times Higher Education World University Rankings.
Also, a detailed description is offered of the data collection methodology of
the Leiden Ranking 2011/2012 and of the indicators used in the ranking. Various
innovations in the Leiden Ranking 2011/2012 are presented. These innovations
include (1) an indicator based on counting a university's highly cited
publications, (2) indicators based on fractional rather than full counting of
collaborative publications, (3) the possibility of excluding non-English
language publications, and (4) the use of stability intervals. Finally, some
comments are made on the interpretation of the ranking, and a number of
limitations of the ranking are pointed out
Protein structures by spallation neutron crystallography
The capabilities of the Protein Crystallography Station at Los Alamos Neutron Science Center for determining protein structures by spallation neutron crystallography are illustrated, and the methodological and technological advances that are emerging from the Macromolecular Neutron Crystallography consortium are described
A Guide for Social Science Journal Editors on Easing into Open Science
Journal editors have a large amount of power to advance open science in their respective fields by incentivising and mandating open policies and practices at their journals. The Data PASS Journal Editors Discussion Interface (JEDI, an online community for social science journal editors: www.dpjedi.org) has collated several resources on embedding open science in journal editing (www.dpjedi.org/resources). However, it can be overwhelming as an editor new to open science practices to know where to start. For this reason, we created a guide for journal editors on how to get started with open science. The guide outlines steps that editors can take to implement open policies and practices within their journal, and goes through the what, why, how, and worries of each policy and practice. This manuscript introduces and summarizes the guide (full guide: https://osf.io/hstcx).<br/
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