130,545 research outputs found
Comparison of induced and spontaneous atrial tachyarrhythmias in patients with a history of spontaneous atrial tachyarrhythmias
No full textThis retrospective study investigated whether induced episodes
could be used to predict the morphology of future spontaneous atrial episodes.
METHODS: Eighty-two patients (64 +/- 12 years; 77% male; CAD in 60%; left
ventricular ejection fraction 45 +/- 16%) with a history of atrial tachycardia
or atrial fibrillation (AT/AF) were implanted with a dual-chamber implantable
cardioverter defibrillator (ICD) and followed for 6 months. A total of 224
episodes of induced and spontaneous AT/AF were classified into type I, II, and
III according to the method of Israel et al. and then compared based on average
cycle length (CL) and atrial amplitude. Episodes were also grouped as
"pace-terminable" or "nonpace-terminable" based on the CL definition of Gillis
et al. RESULTS: The analysis of 121 induced episodes (from 80 patients) and 103
spontaneous episodes (from 43 patients) showed that within each arrhythmia type,
there were no significant differences in CL or mean amplitude between induced
and spontaneous episodes. Additional analysis of patients that had both induced
and spontaneous episodes (n = 41) showed 78% had at least one spontaneous
episode that matched the induced episode. Fifty-seven percent of spontaneous
episodes were considered to be pace-terminable based on CL. CONCLUSIONS: Our
data suggest that there is no significant difference between induced and
spontaneous episodes of AT/AF of the same type. The majority of patients had at
least one spontaneous episode of the same type as the induced episode, showing
that induced atrial arrhythmias may be useful in predicting the morphology of
future spontaneous episodes and in identifying patients potentially benefiting
from atrial antitachycardia pacing
MeSH term explosion and author rank improve expert recommendations
No full textInformation overload is an often-cited phenomenon that reduces the productivity, efficiency and efficacy of scientists. One challenge for scientists is to find appropriate collaborators in their research. The literature describes various solutions to the problem of expertise location, but most current approaches do not appear to be very suitable for expert recommendations in biomedical research. In this study, we present the development and initial evaluation of a vector space model-based algorithm to calculate researcher similarity using four inputs: 1) MeSH terms of publications; 2) MeSH terms and author rank; 3) exploded MeSH terms; and 4) exploded MeSH terms and author rank. We developed and evaluated the algorithm using a data set of 17,525 authors and their 22,542 papers. On average, our algorithms correctly predicted 2.5 of the top 5/10 coauthors of individual scientists. Exploded MeSH and author rank outperformed all other algorithms in accuracy, followed closely by MeSH and author rank. Our results show that the accuracy of MeSH term-based matching can be enhanced with other metadata such as author rank
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Scholarly Communication and Publishing Lunch and Learn Talk #11: The ULS Open Access Author Fee Fund
No full textAt the May 2014 talk, you will learn about the ULS Open Access Author Fee Fund--what it is, why we do it, how it works, and how the program is going so far
The R&D Tax Incentives
No full textThis article sets out some background information and reflections of the author on the R&D tax incentive schemes included in the Common Corporate Tax Base (CCTB) Proposal. In particular the author analyzes the stimulus to private R&D through ad hoc tax incentives included in the CCTB Proposal and dives into the actual provisions included in the Proposal highlighting the most relevant issues connected with their design and interpretation. Moreover, the author explores the interaction between the CCTB Proposal and the granting by Member States of domestic R&D tax incentives
Von der Nachrichtentechnik zur Informationstechnik: Vortraege d. NTG-Fachtagung anlaessl. d. VDE-Kongresses '86 am 14. u. 15. Oktober 1986 in Nuernberg
No full textIncludes 11 articlesAvailable from Bibliothek des Instituts fuer Weltwirtschaft, ZBW, Duesternbrook Weg 120, D-24105 Kiel C 142152 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman
Implantable dual-chamber defibrillator for the selective treatment of spontaneous atrial and ventricular arrhythmias: arrhythmia incidence and device performance.
No full textAtrial tachyarrhythmias are a common co-morbidity in patients with
an ICD indication. Recently introduced ICD's are equipped to independently
detect and treat atrial and ventricular tachyarrhythmias. The purpose of this
prospective study was to evaluate the incidence and termination of spontaneous
atrial and ventricular tachyarrythmias in patients with a history of atrial
tachyarrhythmias. METHODS AND RESULTS: Ninety patients, 70% male with an ICD
indication and history of atrial tachyarrhythmia (LVEF 45 +/- 6%, [AT/AF
indication 55 +/- 10, AT/VT 45 +/- 16], 46% CAD) were enrolled and 89 were
implanted with a VENTAK PRIZM AVT (Guidant). Spontaneous atrial and ventricular
tachyarrhythmias were printed and evaluated during an average follow-up period
of 272 +/- 72 days utilizing the stored intracardial electrogram function of the
device. Nineteen patients (21%) presented had only atrial tachyarrhythmias, 32
patients (36%) had both atrial and ventricular tachyarrhythmias and 18 patients
(20%) had only ventricular tachyarrhythmias. Patients with only atrial
tachyarrhythmias had a total of 3274 atrial episodes; 2002 terminated
spontaneously, 1264 were treated with ATP and 8 with shock therapy. ATP was
successful in 735 (58%) of 1264 episodes. Patients with both atrial and
ventricular tachyarrhythmias had 7277 documented atrial tachyarrhythmias, 5231
terminated spontaneously, 1153 of 2009 were terminated by ATP (57.4%) and 37 by
shock therapy (20 patient controlled). Atrial tachyarrhythmias identified as
atrial flutter (AT) by the atrial rhythm classification (ARC) algorithm had a
higher ATP conversion success rate than episodes identified as atrial
fibrillation (AF); 66.7% for AT and 26.4% for AF. Patients with only ventricular
tachyarrhythmias had 690 documented episodes, 401 terminated spontaneously, 248
(85.8%) were terminated by ATP and 41 by shock. CONCLUSION: Seventy-seven
percent of patients with an ICD indication had spontaneous atrial and/or
ventricular tachyharrhythmias within the first 6 months after ICD implantation.
ATP therapy terminated 58% of all atrial tachyarrhytmias and 66.7% of the atrial
flutters. The dual chamber ICD detected, classified and terminated all
ventricular tacharrhythmias appropriately
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