1,934 research outputs found
Integrated electrochemical device to screen for liver function at the point-of-care
Human Immunodeficiency Virus (HIV) and Tuberculosis (TB) continue to be a significant global burden, disproportionately affecting low- and middle-income countries (LMICs). While much progress has been made in treating these epidemics, this has led to a rise in liver complications, as patients on anti-retroviral therapies (to treat HIV) and anti-TBs (to treat TB) are at an increased risk of drug-induced liver injury (DILI). Therefore, patients on these medicines require consistent screening of liver function. But, due to logistical barriers, gold standard DILI screening fails to be executed at the point-of-care (POC) in LMICs. This thesis aims to fill a current and critical void in diagnosis and management of liver diseases in patients with HIV/AIDS and TB in these settings where conventional diagnostic approaches are prohibitively expensive.
To address this gap in technology and patient care, we have developed and optimized a robust, novel assay for on-site POC monitoring of liver health. We take an electrochemical approach to quantify the levels of alanine aminotransferase, a key biomarker of liver function, from whole blood samples. Additionally, we build a patient- and provider-centric platform for detection, aiming to minimize sample preparation steps and simplify the user experience. Furthermore, we use a computational approach to explore the impact of our technology at the POC in LMICs, quantifying both the efficacy and cost-effectiveness.
Using this technology, health care providers can assess patient liver health at the POC and make clinical decisions in real time. In the field this technology has the potential to impact HIV and TB patient treatment and improve patient quality of life
Studying the heterogeneity of European higher education institutions
The heterogeneity of the Higher Education (HE) Institutions is one of the main critical issues in the assessment of their performance. This paper adopts a multi-level and multi-dimensional perspective, combining national (macro) and institution (micro) level data, and measuring both research and teaching activity, using performance indicators derived from the European Tertiary Education Register, CWTS Leiden Ranking, and PATSTAT patent database. Clustering and efficiency analysis are combined to characterize the heterogeneity of national HE systems in European countries, and reveal the potential of using micro level data to characterize national level performance. Large differences are observed between the European countries, partially due to the fact that they are in different phases of their scientific (and economic) development and of the re-structuring of their HE systems. Evidence is found that universities specializing either in teaching or in research tend to have a higher efficiency than those institutions balancing research and teaching. Tradeoffs are observed between undergraduate and post-graduate activities, and a âMatthew cumulative effectâ seems in place on the European institutions analysed: high quality research is able to attract external funds that stimulate innovative and patenting activities that in turn are self-reinforcing to the scientific activities. The results reveal once more the limits and dangers of one-dimensional approaches to the performance of HEIs
The success-index: an alternative approach to the h-index for evaluating an individual's research output
Among the most recent bibliometric indicators for normalizing the differences among fields of science in terms of citation behaviour, Kosmulski (J Informetr 5(3):481-485, 2011) proposed the NSP (number of successful paper) index. According to the authors, NSP deserves much attention for its great simplicity and immediate meaningâ equivalent to those of the h-indexâwhile it has the disadvantage of being prone to manipulation and not very efficient in terms of statistical significance. In the first part of the paper, we introduce the success-index, aimed at reducing the NSP-index's limitations, although requiring more computing effort. Next, we present a detailed analysis of the success-index from the point of view of its operational properties and a comparison with the h-index's ones. Particularly interesting is the examination of the success-index scale of measurement, which is much richer than the h-index's. This makes success-index much more versatile for different types of analysisâe.g., (cross-field) comparisons of the scientific output of (1) individual researchers, (2) researchers with different seniority, (3) research institutions of different size, (4) scientific journals, etc
Open access increases citations of papers in ecology
Open access (OA) can effectively increase the accessibility and visibility of scientific articles and thus potentially confer them with citation advantages. Such an impact may be more pronounced in developing countries where the cost for journal subscription is comparably expensive and usually unaffordable. By comparing one OA article with one nonâOA article published in the same issue, we tested the impact of OA on citation advantages of articles published in 46 ecology journals indexed in the Journal Citation Reports (JCR). We compared OA to nonâOA articles published in the same issue of these journals, thereby controlling for potentially confounding effects of publication requirement and period. OA articles received significantly more citations than nonâOA articles, and this citation advantage of approximately one citation per year was sustained across publication years from 2009 to 2013. The OA citation advantage did not depend upon income of the country of origin of the citing scientists, and the OA citation advantage was found for citing scientists from North America, Europe, Asia, Africa, and Oceania, but not for Latin America. A total of 10 countries contributed more than 1000 citations each, and the OA citation advantage was found in all the 10 countries except Canada. Therefore, in ecology journals OA confers articles with citation advantages and such an impact accumulates with years and independent of the economic status of the countries. This information may guide decisions of scientific societies, journals, and individual authors as they weigh the relative costs and benefits of open electronic accessibility of scientific research
ResearchGate versus Google Scholar: Which finds more early citations?
ResearchGate has launched its own citation index by extracting citations from documents uploaded to the site and reporting citation counts on article profile pages. Since authors may upload preprints to ResearchGate, it may use these to provide early impact evidence for new papers. This article assesses the whether the number of citations found for recent articles is comparable to other citation indexes using 2675 recently-published library and information science articles. The results show that in March 2017, ResearchGate found less citations than did Google Scholar but more than both Web of Science and Scopus. This held true for the dataset overall and for the six largest journals in it. ResearchGate correlated most strongly with Google Scholar citations, suggesting that ResearchGate is not predominantly tapping a fundamentally different source of data than Google Scholar. Nevertheless, preprint sharing in ResearchGate is substantial enough for authors to take seriously
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
A New Approach to Analyzing Patterns of Collaboration in Co-authorship Networks - Mesoscopic Analysis and Interpretation
This paper focuses on methods to study patterns of collaboration in
co-authorship networks at the mesoscopic level. We combine qualitative methods
(participant interviews) with quantitative methods (network analysis) and
demonstrate the application and value of our approach in a case study comparing
three research fields in chemistry. A mesoscopic level of analysis means that
in addition to the basic analytic unit of the individual researcher as node in
a co-author network, we base our analysis on the observed modular structure of
co-author networks. We interpret the clustering of authors into groups as
bibliometric footprints of the basic collective units of knowledge production
in a research specialty. We find two types of coauthor-linking patterns between
author clusters that we interpret as representing two different forms of
cooperative behavior, transfer-type connections due to career migrations or
one-off services rendered, and stronger, dedicated inter-group collaboration.
Hence the generic coauthor network of a research specialty can be understood as
the overlay of two distinct types of cooperative networks between groups of
authors publishing in a research specialty. We show how our analytic approach
exposes field specific differences in the social organization of research.Comment: An earlier version of the paper was presented at ISSI 2009, 14-17
July, Rio de Janeiro, Brazil. Revised version accepted on 2 April 2010 for
publication in Scientometrics. Removed part on node-role connectivity profile
analysis after finding error in calculation and deciding to postpone
analysis
Articles by Latin American Authors in Prestigious Journals Have Fewer Citations
Background: the journal Impact factor (IF) is generally accepted to be a good measurement of the relevance/quality of articles that a journal publishes. in spite of an, apparently, homogenous peer-review process for a given journal, we hypothesize that the country affiliation of authors from developing Latin American (LA) countries affects the IF of a journal detrimentally.Methodology/Principal Findings: Seven prestigious international journals, one multidisciplinary journal and six serving specific branches of science, were examined in terms of their IF in the Web of Science. Two subsets of each journal were then selected to evaluate the influence of author's affiliation on the IF. They comprised contributions (i) with authorship from four Latin American (LA) countries (Argentina, Brazil, Chile and Mexico) and (ii) with authorship from five developed countries (England, France, Germany, Japan and USA). Both subsets were further subdivided into two groups: articles with authorship from one country only and collaborative articles with authorship from other countries. Articles from the five developed countries had IF close to the overall IF of the journals and the influence of collaboration on this value was minor. in the case of LA articles the effect of collaboration (virtually all with developed countries) was significant. the IFs for non-collaborative articles averaged 66% of the overall IF of the journals whereas the articles in collaboration raised the IFs to values close to the overall IF.Conclusion/Significance: the study shows a significantly lower IF in the group of the subsets of non-collaborative LA articles and thus that country affiliation of authors from non-developed LA countries does affect the IF of a journal detrimentally. There are no data to indicate whether the lower IFs of LA articles were due to their inherent inferior quality/relevance or psycho-social trend towards under-citation of articles from these countries. However, further study is required since there are foreseeable consequences of this trend as it may stimulate strategies by editors to turn down articles that tend to be under-cited.Fundação de Amparo Ă Pesquisa do Estado de SĂŁo Paulo (FAPESP)Conselho Nacional de Desenvolvimento CientĂfico e TecnolĂłgico (CNPq)Latin Amer & Caribbean Ctr Hlth Sci Informat, BIREME PAHO WHO, SĂŁo Paulo, BrazilUniversidade Federal de SĂŁo Paulo, DIS Dept Informat Med, SĂŁo Paulo, BrazilUniversidade Federal de SĂŁo Paulo, DIS Dept Informat Med, SĂŁo Paulo, BrazilFAPESP: 05/57665-8CNPq: 2006-0919Web of Scienc
Bibliometrics of systematic reviews : analysis of citation rates and journal impact factors
Background:
Systematic reviews are important for informing clinical practice and health policy. The aim of this study was to examine the bibliometrics of systematic reviews and to determine the amount of variance in citations predicted by the journal impact factor (JIF) alone and combined with several other characteristics.
Methods:
We conducted a bibliometric analysis of 1,261 systematic reviews published in 2008 and the citations to them in the Scopus database from 2008 to June 2012. Potential predictors of the citation impact of the reviews were examined using descriptive, univariate and multiple regression analysis.
Results:
The mean number of citations per review over four years was 26.5 (SD +/-29.9) or 6.6 citations per review per year. The mean JIF of the journals in which the reviews were published was 4.3 (SD +/-4.2). We found that 17% of the reviews accounted for 50% of the total citations and 1.6% of the reviews were not cited. The number of authors was correlated with the number of citations (r = 0.215, P =5.16) received citations in the bottom quartile (eight or fewer), whereas 9% of reviews published in the lowest JIF quartile (<=2.06) received citations in the top quartile (34 or more). Six percent of reviews in journals with no JIF were also in the first quartile of citations.
Conclusions:
The JIF predicted over half of the variation in citations to the systematic reviews. However, the distribution of citations was markedly skewed. Some reviews in journals with low JIFs were well-cited and others in higher JIF journals received relatively few citations; hence the JIF did not accurately represent the number of citations to individual systematic reviews
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