1,740 research outputs found
Recent QCD studies at the Tevatron
Since the beginning of Run II at the Fermilab Tevatron, the QCD physics groups of the CDF and D0 Collaborations have worked to reach unprecendented levels of precision for many QCD observables. This note summarizes important recent measurements with dataset corresponding to up to 8 fbâ1 of total integrated luminosity
Universality of Performance Indicators based on Citation and Reference Counts
We find evidence for the universality of two relative bibliometric indicators
of the quality of individual scientific publications taken from different data
sets. One of these is a new index that considers both citation and reference
counts. We demonstrate this universality for relatively well cited publications
from a single institute, grouped by year of publication and by faculty or by
department. We show similar behaviour in publications submitted to the arXiv
e-print archive, grouped by year of submission and by sub-archive. We also find
that for reasonably well cited papers this distribution is well fitted by a
lognormal with a variance of around 1.3 which is consistent with the results of
Radicchi, Fortunato, and Castellano (2008). Our work demonstrates that
comparisons can be made between publications from different disciplines and
publication dates, regardless of their citation count and without expensive
access to the whole world-wide citation graph. Further, it shows that averages
of the logarithm of such relative bibliometric indices deal with the issue of
long tails and avoid the need for statistics based on lengthy ranking
procedures.Comment: 15 pages, 14 figures, 11 pages of supplementary material. Submitted
to Scientometric
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
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
Advanced Ultrasonic Diagnosis of Extremity Trauma: The Faster Exam
Ultrasound is of prO)len accuracy in abdominal and thoracic trauma and may be useful to diagnose extremity injury in situations where radiography is not available such as military and space applications. We prospectively evaluated the utility of extremity , ultrasound performed by trained, non-physician personnel in patients with extremity trauma, to simulate remote aerospace or military applications . Methods: Patients with extremity trauma were identified by history, physical examination, and radiographic studies. Ultrasound examination was performed bilaterally by nonphysician personnel with a portable ultrasound device using a 10-5 MHz linear probe, Images were video-recorded for later analysis against radiography by Fisher's exact test. The average time of examination was 4 minutes. Ultrasound accurately diagnosed extremity, injury in 94% of patients with no false positive exams; accuracy was greater in mid-shaft locations and least in the metacarpa/metatarsals. Soft tissue/tendon injury was readily visualized . Extremity ultrasound can be performed quickly and accurately by nonphysician personnel with excellent accuracy. Blinded verification of the utility of ultrasound in patients with extremity injury should be done to determine if Extremity and Respiratory evaluation should be added to the FAST examination (the FASTER exam) and verify the technique in remote locations such as military and aerospace applications
EndCap Module Production for the ATLAS Silicon Tracker (SCT) at CERN and the University of Geneva
This note describes the infrastructure, procedure and quality assurance for the construction of approximately one third of the EndCap modules for the ATLAS Semiconductor Tracker (SCT) by groups at the University of Geneva and CERN
The role of mentorship in protege performance
The role of mentorship on protege performance is a matter of importance to
academic, business, and governmental organizations. While the benefits of
mentorship for proteges, mentors and their organizations are apparent, the
extent to which proteges mimic their mentors' career choices and acquire their
mentorship skills is unclear. Here, we investigate one aspect of mentor
emulation by studying mentorship fecundity---the number of proteges a mentor
trains---with data from the Mathematics Genealogy Project, which tracks the
mentorship record of thousands of mathematicians over several centuries. We
demonstrate that fecundity among academic mathematicians is correlated with
other measures of academic success. We also find that the average fecundity of
mentors remains stable over 60 years of recorded mentorship. We further uncover
three significant correlations in mentorship fecundity. First, mentors with
small mentorship fecundity train proteges that go on to have a 37% larger than
expected mentorship fecundity. Second, in the first third of their career,
mentors with large fecundity train proteges that go on to have a 29% larger
than expected fecundity. Finally, in the last third of their career, mentors
with large fecundity train proteges that go on to have a 31% smaller than
expected fecundity.Comment: 23 pages double-spaced, 4 figure
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
Does the arXiv lead to higher citations and reduced publisher downloads for mathematics articles?
An analysis of 2,765 articles published in four math journals from 1997 to
2005 indicate that articles deposited in the arXiv received 35% more citations
on average than non-deposited articles (an advantage of about 1.1 citations per
article), and that this difference was most pronounced for highly-cited
articles. Open Access, Early View, and Quality Differential were examined as
three non-exclusive postulates for explaining the citation advantage. There was
little support for a universal Open Access explanation, and no empirical
support for Early View. There was some inferential support for a Quality
Differential brought about by more highly-citable articles being deposited in
the arXiv. In spite of their citation advantage, arXiv-deposited articles
received 23% fewer downloads from the publisher's website (about 10 fewer
downloads per article) in all but the most recent two years after publication.
The data suggest that arXiv and the publisher's website may be fulfilling
distinct functional needs of the reader.Comment: Last updated May 02, 200
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