1,722,591 research outputs found
Development of a Novel Index to Characterise Arterial Physiology Using Ultrasound Imaging
No full textJoel Ward1*, Xinhao Cheng2*, Pierfrancesco Lapolla1, Anirudh Chandrashekar1, Ashok Handa1, Robin Cleveland2# and Regent Lee2#
*, # Authors contributed equally
Nuffield Department of Surgical Sciences, University of Oxford
Department of Engineering Science, Unviersity of Oxford
Introduction
Abdominal aortic aneurysms (AAA) are associated with features of systemic inflammation and endothelial dysfunction. Flow mediated dilatation (FMD), measured remotely at the brachial artery, is a recognised non-invasive measurement for endothelial function. We had previously reported FMD to be a predictor of AAA growth. We hypothesised that other physical characteristics of the brachial artery wall correlate with AAA growth.
Methods
In a prospectively recruited cohort of patients with AAAs (Oxford Abdominal Aortic Aneurysm Study), brachial wall motion captured from ultrasound data was analysed. We developed a novel image analysis method (UK patent priority filing P255395GB) to extract a ‘brachial artery relaxation index’ (BARI), and examined BARI in the context of AAA and its correlation with future aneurysm growth.
Results
Preliminary results were promising with clear differentiation between patients at the extreme spectrum of prospective AAA growth. However, there was no difference in BARI between age and sex matched healthy volunteers and OxAAA patients (n=15 each, p=0.77). In the entire OxAAA Study cohort (n=126) no differences was observed in BARI between aneurysms of different diameters (30-40mm vs 40-55mm vs >55mm, ANOVA p=0.99). Furthermore, no correlation between BARI and future aneurysm growth was observed (p=0.5).
Discussion
Image based analyses of vasculature is important in the context of AAAs. We developed a novel analysis method to extract characteristics of arterial wall motion as a proposed biomarker and tested its utility in the context of AAA disease. This serves as a model for future collaborative research in an inter-disciplinary approach
Smart-phone-based electrochemical sensor for environmental applications
Get PDFWe demonstrated a mobile phone sensing platform, MoboSens, with integrated plug-n-play microelectronic ionic sensor that performs electrochemical measurement by using audio jack of a smart phone. This platform was used to measure nitrate concentration using a few microliter liquid samples on field along with providing geospatial map locations through a wireless network. This compact MoboSens platform (~65 gram), based on a smart phone, is able to detect nitrate concentration in water with a detection limit of 0.2 ppm within 1 minute. The nitrate ion detection on MoboSens platform is performed by a microfabricated microfluidic sensor utilizing a cyclic voltammetry based electrochemical process. The stability of the measurements was verified by performing the experiments under varying temperature, pH and ion interference conditions. The mobile phone app reports the quantitative nitrate sensing results along with user-input metadata. The results can be automatically saved on secure cloud servers or can be pushed on public social media, e.g., Twitter. Finally, the digital sensing information can be retrieved with geospatial information tagged on an internet map service, e.g., Bing Map, for public sharing and viewing. We tested this lab-on-a-chip mobile sensing platform for field water quality measurement and confirmed our mobile sensing results with other existing analytical testing methods.Submission published under a 24 month embargo labeled 'U of I only', the embargo will last until 2017-05-01The student, Xinhao Wang, accepted the attached license on 2015-04-06 at 20:48.The student, Xinhao Wang, submitted this Thesis for approval on 2015-04-06 at 20:59.This Thesis was approved for publication on 2015-04-13 at 17:03.DSpace SAF Submission Ingestion Package generated from Vireo submission #7797 on 2015-07-22 at 14:17:38Made available in DSpace on 2015-07-22T22:33:12Z (GMT). No. of bitstreams: 2
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Previous issue date: 2015-04-13Embargo set by: Seth Robbins for item 79842
Lift date: 2017-07-22T22:34:16Z
Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD systemU of I Only Restriction Lifted for Item 79842 on 2017-07-23T09:15:19Z
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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
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