1,720,977 research outputs found
Deep Tissue Hemodynamic Monitoring Using Diffuse Optical Probes
No full textTo see what is happening under our skin using light would have been a dream, as there are many strong absorbers and scatterers that act as hindrances for imaging purpose. Although light penetrates the skin a little and it is possible to image and monitor superficial blood flow using light illumination, it remains as a challenge to probe deep tissue (roughly 0.1, 3.0 cm) using light alone. In this chapter, we describe the challenges and recent achievements of diffuse optical methods to probe deep tissue, running the gamut from diffuse optical spectroscopy (DOS) and diffuse optical tomography (DOT) to recently developed diffuse speckle contrast analysis (DSCA). Diffuse optics has opened up a new possibility of non-invasive diagnosis of lesions in deep tissue. In addition, the usage of light makes diffuse optics-based device compatible with other conventional medical devices such as CT and MRI as well as some implanted device such as pace maker. Moreover, diffuse optics-based device is relatively cost-effective and portable. These merits could limitlessly extend its application to primary care unit, bedside monitoring, and operation theater as an optimal modality for probing hemodynamic parameters in microvasculature in deep tissue. © Springer Science+Business Media Singapore 2016. All rights reserved.1
Application of coherent light in measuring optical property and blood perfusion
No full textCoherent light source is widely utilized in biomedical study. In this thesis, the coherent light is mainly applied for measuring the optical property and in vivo blood perfusion.
An interesting physiological phenomenon, coherent backscattering (CBS) is introduced. People have found many biomedical applications of CBS related technologies. Through our study, the illumination beam size on the sample is shown to affect the CBS phenomenon significantly when its diameter is small.
The coherent light source is highly auto-correlated in time domain. The electric field temporal autocorrelation function of the light will decay faster when the photons are collided with moving particles, such as the in vivo red blood cells. This is the foundation of many optical modalities for blood perfusion measurement, such as diffuse correlation spectroscopy (DCS). A software correlator based DCS system is introduced in this thesis. We validate its performance by a flow-controlled phantom. Interesting in vivo data is also demonstrated.
To simplify DCS system, a novel optical modality for deep tissue blood perfusion measurement, diffuse speckle contrast analysis (DSCA) is introduced for the first time by the author. DSCA brings several advantages in instrumentation and data processing, which may find significant clinical applications. Relative validation results against our home made DCS system are demonstrated.
There are already several existing optical modalities for blood perfusion measurement in the market, such as laser Doppler Flowmetry and laser speckle contrast imaging. In this thesis, the working principles of these existing optical blood perfusion monitoring technologies are studied and compared in details. The relationship and comparison among these optical technologies are discussed in details.
In summary, this dissertation introduces some biomedical applications of the coherent light, especially in optical property measurement and blood perfusion mornitoring.Doctor of Philosophy (SCBE
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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