1,720,978 research outputs found
Training-to-Beat bioreactor for investigating Engineered Cardiac Tissues: design, development & validation
Full text linkIn last the decades, advances relevant to the generation of 3D Engineered Cardiac Tissues (ECTs) have been made. In reason of this, ECTs are now considered a great promise for in vitro studies of cardiac development, disease and, eventually, for strategies for the repair of the structure and function of the injured myocardium. Among the several physical stimuli which have been exploited to improve the functionality and maturation of ECTs, a preeminent role has been ascribed to mechanical stimulation. Appropriate mechanical stimulation can be recreated and maintained within bioreactors, which are devices/platforms devoted to mimic the physiological milieu in a monitored/controlled culture environment, where the engineered constructs can be properly stimulated. One main limitation of the bioreactor-based strategy for cardiac tissue engineering applications is that the devices which are currently used are meant to passively apply to ECTs a stimulus predefined by the user, regardless of their level of maturation along the duration of the in vitro culture. In this scenario, and trying to overcome current limitations, a novel bioreactor design has been conceived for the investigation of 3D ECTs with a biomimetic approach. Technically, the here proposed bioreactor is capable (1) to apply native-like or pathologic mechanical stimuli (cyclic strain) by means of a reliable linear actuator operating in a wide range of strains and frequencies, and (2) to monitor in real-time both chemo-physical parameters (e.g. oxygen tension, pH) of the milieu and the mechanical stiffness of ECTs by means of dedicated sensors, eventually adapting the stimulation to the actual stage of maturation of the constructs. As a proof of concept, a first experimental campaign has been carried out with a double aim: (1) to verify the bioreactor feasibility in delivering mechanical cyclical stimulation to 3D fibrin-based, ring shaped Engineered Cardiac Tissues (ECTs); (2) to assess the effect of cyclic strain on tissue maturation, contractility and modification on its mechanical properties. In detail, the bioreactor platform has been preliminarily tested to verify protocols for hold on, sterilization, and control of the delivered mechanical stimuli. Firstly, the suitability of the bioreactor platform in culturing ad-hoc designed constructs, in terms of ease of use and capability in setting the stimulation parameters, has been tested. Then, the observed maturation of ring shaped ECTs subject to sinusoidal cyclic strain within the bioreactor has confirmed the potency of the proposed approach and the instrumental role of mechanical stimulation in ECTs maturation and in the development of an adult-like cardiac phenotype responsive to electrical excitation. Even if further validation steps are required before the implementation of culture strategy fully adaptive in terms of mechanical stimuli applied to the engineered cardiac constructs, the developed bioreactor represents a valuable proof of concept for, in its most advanced operational mode, biomimetic culturing of engineered cardiac construct
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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