1,720,963 research outputs found
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
Medical Imaging of Magnetic Micromotors Through Scattering Tissues
Get PDFMicro- and nanorobots (MNRs) are small autonomous devices capable of performing complex tasks and have been demonstrated for a variety of non-invasive biomedical
applications, such as tissue engineering, drug delivery or assisted fertilization. However, translating such approaches to an in vivo environment is critical. Current
imaging techniques do not allow localization and tracking of single or few micromotors at high spatiotemporal resolution in deep tissue.
This thesis addresses some of these limitations, by exploring the use of two optical-based techniques (IR and photoacoustic imaging (PAI)) and a combination of both US
and PAI. First, we employ an IR imaging setup to visualize mobile reflective micromotors under scattering phantoms and ex vivo mouse skull tissues, without
using any labels. The reflective micromotor reflects more than tenfold the light intensity of a simple particle. However, the achieved penetration depth was ca. 100 μm
(when using ex vivo tissues), limiting this technique to superficial biomedical applications. In this regard, PAI plays a role that combines the advantages of US such
as penetration depth and real-time imaging with the molecular specificity of optics. For the first time, in this thesis, this method is evaluated for dynamic process
monitoring, in particular for tracking single micromotor in real-time below ~1 cm deep phantom and ex vivo tissue.
However, the precise function control of MNRs in living organisms, demand the combination of both anatomical and functional imaging methods. Therefore, in the
end, we report the use of a hybrid US and PA system for the real-time tracking of magnetically driven micromotors (single and swarms) in phantoms, ex vivo, and in vivo
(in mice bladder and uterus), envisioning their application for targeted drug-delivery. This achievement is of great importance and opens the possibilities to employ medical
micromotors in a living organism and perform a medical task while being externally controlled and monitored.:ABSTRACT 1
1 INTRODUCTION 5
1.1 Motivation 5
1.2 Background 7
1.2.1 Microrobotics 7
1.2.2 Medical Imaging 9
1.3 Objectives and Structure of Thesis 12
2 FUNDAMENTALS 15
2.1 Optical Imaging 15
2.1.1. Reflection-based Imaging 17
2.1.2. Fluorescence-based Imaging 18
2.1.1 Light-Tissue Interaction 20
2.2 Photoacoustic Imaging 23
2.2.1 Theory 23
2.2.2 Implementation 25
2.3 Ultrasound Imaging 26
2.3.1 Theory 26
2.3.2 Implementation 28
3 MATERIALS AND METHODS 30
3.1 Fabrication of Magnetic Micropropellers 30
3.1.1 3D Laser Lithography of Polymeric Resin 30
3.1.2 Self-assembly of SiO2 Particles 31
3.1.3 Electron Beam Evaporation 32
3.1.4 Surface Functionalization 33
3.2 Fabrication of Phantom Tissue and Microfluidic Channels 34
3.2.1 Fabrication of PDMS-Glycerol Phantom 34
3.2.2 Fabrication of Agarose Phantom 35
3.2.3 Phantom based on Ex vivo Tissues (Chicken Breast and Mice Skull) 36
3.2.4 Microfluidic Channel Platform 37
3.3 Sample Characterization 38
3.3.1 Optical Microscopy 38
3.3.2 Scanning Electron Microscopy 38
3.4 Magnetic Actuation 39
3.4.1 Magnetic Force 39
3.4.2 Magnetic Torque 39
3.5 Ethic Statement for Mice Experiments 41
4 OPTICAL IMAGING OF MICROROBOTS 42
4.1 Concept of Reflective Micromotors 42
4.2 Fabrication of Reflective Micromotors 44
4.3 IR Imaging Actuation Setup 45
4.4 Actuation and Propulsion Performance below Phantom 47
4.5 Actuation and Propulsion Performance below Ex Vivo Skull Tissue 50
4.6 Actuation and Propulsion Performance in Blood 51
5 PHOTOACOUSTIC IMAGING OF MICROROBOTS 55
5.1 Absorbers for Deep Tissue Imaging 55
5.2 Absorber Micromotor Design and Fabrication 56
5.3 Photoacoustic Imaging Setup 58
5.4 Actuation Performance below Phantom Tissue 60
5.5 Actuation Performance below Ex Vivo Tissue 65
6 HYBRID ULTRASOUND AND PHOTOACOUSTIC IMAGING 67
6.1 Hybrid Ultrasound/Photoacoustic System 68
6.2 Fabrication and Characterization of Micromotors 69
6.3 Actuation and Propulsion Performance below Phantom 69
6.4 Actuation and Propulsion Performance below Ex Vivo Tissues 71
6.5 Actuation and Propulsion Performance in Mice 72
6.5.1 Swimming of Micromotors in Bladder 72
6.5.2 Actuation of Micromotors in Uterus 74
6.5.3 3D Multispectral Imaging 76
6.5.4 Towards Targeted Drug Delivery 77
7 SUMMARY AND PERSPECTIVES 80
7.1 Summary 80
7.2 Future Perspectives 83
7.2.1 Contrats Enhancing Labels 84
7.2.2 Novel Imaging Concepts 85
8 REFERENCES 88
9 APPENDIX 105
List of Figures 105
List of Tables 107
Abbreviations 108
List of Publications 109
Acknowledgements 110
Selbstständigkeitserklärung 111
Curriculum Vitae 11
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
Author Under Sail The Imagination of Jack London, 1893-1902
No full textIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
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