1,720,972 research outputs found
An observational assessment of aortic deformation during infrarenal and complex endovascular aortic aneurysm repair
No full textObjective: Real-time aortic deformation during endovascular aortic aneurysm repair (EVAR) has not been reported. Successful EVAR relies on predicting intraoperative aortic-endograft deformation from preoperative imaging. Correct prediction is essential, because malalignment of endografts decreases patient survival. We describe intraoperative aortic deformation during infrarenal EVAR and complex fenestrated/branched EVAR (F/BEVAR), relating deformation to preoperative anatomy and follow-up outcomes. Methods: A multicenter, retrospective cohort of aortic aneurysm patients undergoing operation between January 2019 and February 2021, substratified by repair, infrarenal EVAR (n = 50), F/BEVAR (n = 80), and iliac branch graft with F/B/EVAR (IBG + F/B/EVAR; n = 27), were compared using software-based nonrigid two- and three-dimensional aortic deformational intraoperative assessment (CYDAR). Preoperative computed tomography reconstructions of aortic and iliac tortuosities were assessed against intraoperative deformation, the primary outcome, and related to perioperative and follow-up adverse outcomes. Results: All treatment groups had low preoperative visceral aortic tortuosity; the EVAR group had higher iliac tortuosity (1.43 ± 0.05; P = .018). Intraoperative aortic visceral deformation was consistently cranial and anterior; IBG + F/B/EVAR patients had the largest magnitude deformation (superior mesenteric artery, EVAR 5.1 ± 0.9 mm; F/BEVAR 4.4 ± 0.4 mm; IBG 8.3 ± 1.2 mm; P = .004). Celiac artery, superior mesenteric artery, and bilateral renal artery deformations were correlated (R = 0.923-0.983). Iliac deformation was variable in magnitude and direction. Preoperative tortuosity was not correlated with the magnitude of intraoperative deformation nor was deformation magnitude related to endograft instability during follow-up, including endoleak development, reinterventions, or visceral vessel complications. Conclusions: The aorta deforms consistently during EVAR at the visceral aortic segment but unpredictably at the iliac bifurcation. Aortoiliac deformation is unrelated to adverse perioperative outcomes, branch instability, or reinterventions during short-term follow-up
PREDATION BY DUGESIA POLYCHROA (PLATYHELMINTHES: TRICLADIDA) PREVENTS THE ESTABLISHMENT OF PHYSA ACUTA (GASTROPODA: PULMONATA) IN HARD-SUBSTRATUM HABITATS
No full textDespite half a century of research on planarian-gastropod interactions, the population-level impact
of planarian predation on littoral pulmonates is not well known.We have quantified the predation of the common
lacustrine planaria Dugesia polychroa Schmidt on the ubiquitous snail Physa acuta Drap., a potential keystone
grazer in benthic littoral communities, in a high-replicate laboratory experiment. Planarian predation
pressure was maintained constant, and experimental populations of P. acuta were size-structured simulating
young-rich small groups (re)colonising the habitat (e.g. after release from predation). D. polychroa caused a
quick (week 2) reduction in the density of hatchlings and juveniles, followed by significant reduction in the
numbers of young (at the onset of reproductive age) and larger, reproductive-age adults (week 3). Planarias
did not have any effect on the size of reproductive-age large adults, but oviposition decreased significantly in
week 2, and all P. acuta populations in planarian-present aquaria went extinct within six weeks. Dugesiidinduced
extinction mainly occurred by precluding population turnover. The results strongly suggest that
active predation by D. polychroa on P. acuta can be high under some environmental conditions, effectively preventing
the (re)establishment of small, colonising populations of P. acuta in hard-substratum habitats
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe 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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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