1,720,963 research outputs found
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
Neuroengineering studies of fundamental behaviors and functions of neurons using electrode-based device
No full textTGPG[VGRGD(VGVPG)6]20WPC). Stemness and neuronal differentiation of the formed ORN spheroids were verified by performing quantitative polymerase chain reaction (qPCR) and immunocytochemistry (ICC) and there was no significant change of stemness and neuronal differentiation for ten spheroid cultivation days. In addition, physiological characteristics were maintained for ten spheroid cultivation days by monitoring the increase of intracellular calcium level of ORNs upon odorant stimulations. Finally, we successfully discriminated type and concentration of odorants by analyzing the generated electrical signals of ORNs upon odorant stimulations on the MEA.
In the Chapter 5, the thesis was competed with conclusion and implementation of the experimental results and the reference list.|신경세포는 인체의 수많은 세포의 활동을 조절하여 신체 활동을 내외부 상황에 따라 조절 및 통제하여 몸의 항상성을 유지하고 나아가 생명유지를 관장하는 신경계의 가장 기본적인 요소라 할 수 있다. 신경계는 뇌와 척추로 이루어진 중추신경계와 체성신경계와 자율신경계로 이루어진다. 중추신경계는 말초신경계에서 보내준 정보를 모아서 분석, 판단하여 결론에 따른 명령을 말초신경계에 보내 인체가 환경변화에 대한 적절한 반응을 일으킬 수 있도록 한다. 말초신경계는 5감(시각, 청각, 후각, 미각, 촉각) 정보를 중추신경계에 보고하고 중추신경계로 명령을 전달받아 실행한다. 이러한 정보의 감지 및 전달은 신경세포가 가진 고유의 전기적 신호 발생 및 전달 기능에 의해서 가능하다. 신경세포에서 전기적 신호는 신경세포 막에 위치하고 있는 전압 의존성 이온 통로에 의해 발생 및 전달되며 신체 전반에 위치하고 있는 각종 수용체에 의해 야기된다. 발생된 전기 신호는 시냅스라고 불리는 신경세포간의 특이한 구조에서 화학적인 방법으로 전달되며 신경세포의 축삭돌기 및 수상돌기의 해부학적 특징에 의해 먼 거리에 있는 신체와도 정보의 교환이 가능하며 뇌를 구성하는 복잡한 신경회로의 형성을 가능하게 한다. 이와 같이 인체 각 기관의 내적, 외적 환경 적응의 조절 기관인 신경계의 가장 핵심적인 요소인 신경세포는 적절한 개체 수 유지, 항상성 유지, 발달, 기능 유지를 위해 증식 및 분화를 거친다. 하지만 이러한 단계에서 장애가 발생하거나 적절한 진행이 이루어 지지 못 할 경우 신체 기능의 장애 및 나아가 생명활동에 영향을 줄 수 있다. 따라서 신경세포의 행동 및 신경세포의 전기적 신호에 대한 이해를 위해 각 요소를 모니터링 할 수 있는 연구가 필요하며 본 연구에서는 전극 기반의 측정 소자를 이용하여 신경세포의 증식과 분화를 실시간 모니터링 하고, 나아가 전기적 신호를 측정할 수 있는 시스템을 제작하고 쥐의 후각신경세포를 이용하여 인공코로 활용하는 실험을 수행하였다.
첫번째 결과챕터에서는 신경세포의 증식 및 분화를 측정할 수 있는 모니터링 시스템 제작 및 실험 결과에 대한 내용을 포함하였다. 세포 모니터링 시스템은 배양액 교체, 세포증식 및 세포분화 관찰에 발생하는 인력 및 시간 낭비를 줄이고, 실험에 사용되는 시약 및 각종 약품들의 소모를 줄이기 위한 목적으로 디자인 되었다. 이러한 문제를 해결하기 위해 세포를 배양하는 세포배양챔버는 반도체공정을 이용하여 제작하였으며 세포 배양에 필요한 배양액 및 시약은 세포배양 챔버의 외부에 위치하는 컴퓨터에 의해 자동으로 동작하는 시린지 펌프에 의해 주입 및 배출 되도록 제작하였다. 세포 모니터링 실험은 유사 신경세포인 PC12를 사용하였다. 전극 기반의 모니터링 소자의 실험 적합성을 확인하기 위해 서로 다른 PC12 개체수를 제작된 세포배양챔버에 배양하고 전기적 신호를 측정 한 결과 개체수가 증가함에 따라 저항신호가 유의미하게 증가하는 것을 확인하였다. 일주일 동안 성장배양액을 주입하였을 때 PC12의 개체수가 증가하는 것을 확인하였고 전극에서 측정되는 저항 신호도 세포가 증식하지 않는 세포배양챔버에서 측정되는 저항 신호에 비해 유의미하게 증가하는 것을 확인하였다. 마지막으로 PC12의 신경돌기 성장 모니터링 실험을 위해 세포배양챔버에 신경성장인자를 일주일 동안 주입한 후 신경돌기의 길이와 저항 값을 측정하였고 신경성장인자를 주입하지 않은 PC12 군의 저항 값과 비교한 결과 유의미한 증가를 확인하였다.
두번째 결과챕터에서는 후각신경세포를 구형배양하고 이를 분화시켜 인공코로 활용하는 실험 결과에 대한 내용을 포함하였다. 후각신경세포는 후각상피에 위치하고 있으며 외부로부터 들어오는 냄새분자를 인식하여 전기적 신호를 발생시킨다. 발생된 신호는 후각구에서 일차적으로 처리 된 후 뇌로 전달되고 냄새 인지가 이루어 진다. 후각신경세포는 이러한 일련의 냄새 인지과정에서 중요한 감지 역할을 한다. 따라서 후각신경세포의 냄새 인지 기작을 이해하기 위해 후각신경세포의 초대배양 기술이 개발되어 왔다. 따라서, 본 챕터에서는 초대배양한 후각신경세포를 다채널전극 시스템에 활용하여 인공코 시스템을 제작하였다. 기존의 초대배양기술에서의 후각신경세포는 단일층을 형성하여 세포 배양 기판에 붙어 분화를 시작하므로 실험을 통해 얻어진 후각신경세포의 보관이 불가능 하였으며 이는 인공코 실험에 있어서 해결해야 할 문제점이었다. 따라서 이러한 단점을 보완하기 위해 구형배양법을 도입하였다. 우선 쥐의 후각상피에서 분리 된 후각신경세포 전구체를 서로 다른 농도의 엘라스틴 유사 합성단백질이 코팅 된 배양접시에 배양하여 후각신경세포구형체의 형성 양상을 관찰하였고 코팅해야할 합성 단백질의 농도를 결정하였다. 세포가 구형체를 형성하는 기작을 확인하기 위해 원자현미경 및 주사전자현미경을 이용하여 엘라스틴 유사 합성단백질이 코팅된 표면을 관찰하였고 기존에 신경세포 코팅 물질로 사용되던 라미닌에 비해 표면 거칠기가 월등히 높음을 확인하였고, 증가한 거칠기가 세포의 구형 형성에 작용할 수도 있다는 사실을 확인하였다. 형성된 후각신경세포구형체를 10일 정도 배양하여도 세포의 생존도는 크게 감소하지 않음을 확인하였다. 또한 10일동안 배양한 후각신경세포구형체를 면역세포화학법 및 중합효소연쇄반응법을 이용하여 후각신경세포전구체가 가지고 있는 줄기세포의 특징을 유지하고 있음을 확인할 수 있었다. 다음으로 배양중이 후각신경세포구형체를 라미닌이 코팅된 세포배양접시에 분화 시켰을 떄, 후각신경세포 고유의 생리학적 특징을 가지는지 칼슘 이미징법을 통해 확인하였고 10일동안 후각신경세포구형체 상태로 배양하여도 후각신경세포는 냄새물질에 의해 활성화 되어 세포 내 칼슘 농도의 증가를 관찰 할 수 있었다. 또한 35일 동안 후각신경세포구형체를 극저온보관한 후 분화 시켰을 때도 냄새물질에 의해 증가하는 세포 내 칼슘 농도를 확인함에 따라 후각신경세포구형체 배양법을 이용하여 한달 여 동안 후각신경세포의 보관을 가능하게 한다는 사실을 확인하였다. 마지막으로 형성된 후각신경세포구형체를 64개의 채널을 가진 다채널전극 챔버에 분화하여 인공코 활용 실험을 수행하였다. 첫번째로 분화한 후각신경세포에 증가하는 IBMP를 주입하였을 때 발생하는 전기신호의 크기도 증가함을 확인할 수 있었다. 또한 분화한 후각신경세포에 isovaleric acid, citralva, IBMP를 주입하였을 때 발생한 전기신호의 패턴은 냄새물질 들 마다 확연히 다름을 확인할 수 있었다. 결과적으로 후각신경구형체를 이용해 냄새물질의 농도차와 냄새물질의 종류를 감지할 수 있는 시스템을 제작하였다.
본 연구에서 제작한 두 종류의 세포 측정 시스템을 이용하여 세포의 증식, 분화를 실시간 및 자동으로 모니터링 하였고, 후각신경세포의 기능을 활용하여 인공코 시스템으로 이용할 수 있는 가능성을 확인하였다. 개발되 장치를 하나의 시스템으로 통합한다면 줄기신경세포부터 성체신경세포까지 다양한 발달 단계에 있는 세포의 연구가 가능 할 것이고 또한 단일 신경세포부터 신경망의 전기적 신호 특성을 연구할 수 있는 장치로 활용 될 수 있을 것이라고 생각한다.This thesis was aimed at studying the behavior, differentiation, and chemical senses of neurons by developing devices that are capable of monitoring cellular behaviors and measuring extracellular signals of neurons. Chapter 1 introduces the academic contents and literature regarding to the thesis and Chapter 2 summarizes the materials and methods used in the thesis. Chapter 3 and Chapter 4 describes the development of a device to measure cellular behavior and differentiation, extracellular signals of olfactory receptor neurons (ORNs), respectively. Lastly, Chapter 5 represents conclusion and implementation of the thesis.
In the first experiment, we aimed to develop a device that is capable of measuring the proliferation and neurite outgrowth of cells with a miniaturized real-time manner through automatic injection and withdrawal of media and nerve growth factor (NGF). In order to realize miniaturization of the device, a microfluidic chamber was fabricated by combining electrode patterned glass substrate and polydimethylsiloxane (PDMaster) cell culture chamber. PC12 cells were cultured for seven days in the fabricated device and proliferation of the cells was analyzed using impedance of the electrodes. In addition, NGF was injected into the cell culture chamber using a syringe pump which was automatically driven by the custom-made software, and the neurite outgrowth was successfully measured for seven days by measuring the impedance change.
In order to understand the characteristics of electrical signals generation in the olfactory receptor neurons (ORNs) upon odorants stimulation, extracellular electrical signals of ORNs were measured and analyzed by developing ORN spheroid culture technique combined with multi electrode array (MEA). ORN spheroids culture technique has been developed to overcome the vulnerability and stability of the dissociated ORN precursors in the conventional culture method. Spherical aggregation of the cells was formed by culturing the dissociated rat ORN precursors on a plate pre-treated with recombinant protein (REPopenChapter Ⅰ. Introduction
1.1 Neurons 1
1.1.1 Overview of neurons 1
1.1.2 Anatomical characteristics of neurons 3
1.1.3 Electrical signals of neurons 5
1.1.4 Proliferation and differentiation of neurons 8
1.2 Measurement of neuronal behaviors and electrical signals of neurons 10
1.2.1 Measurement of neuronal behaviors 10
1.2.2 Measurement of electrical signals of neurons 11
1.3 Electrodes and transducers 13
1.4 MechanisMaster of measuring cell behaviors and electrical signals 15
1.4.1 Impedance detection system 15
1.4.2 Role of microelectrodes 16
1.4.3 The extracellular space 17
1.4.4 Neuron-electrode interface 19
Chapter Ⅱ. Materials and Methods
2.1 Materials 23
2.1.1 Chemicals and iteMaster in Fab 23
2.1.2 Experimental Animals 23
2.1.3 Cells 23
2.1.4 Recombinant protein 24
2.1.5 Antibodies and Reagents 25
2.2 Methods 25
2.2.1 Fabrication of the cell monitoring device 25
2.2.2 Measurement of impedance using electrode device 26
2.2.3 Dissociated culture of the rat ORN precursors 27
2.2.4 Generation of ORN precursor spheroids 27
2.2.5 Atomic force microscopy analysis 28
2.2.6 Scanning electron microscope analysis 29
2.2.7 Viability assay 29
2.2.8 Immunocytochemistry 29
2.2.9 qRT-PCR 30
2.2.10 Calcium imaging 31
2.2.11 Measurement of electrical signals of ORNs using MEA 32
2.2.12 Principal component analysis 33
Chapter Ⅲ. Detection of PC12 proliferation and neuronal differentiation
3.1 Background 39
3.1.1 Measurement of neuronal proliferation and neurite outgrowth 40
3.1.2 Rationale 41
3.2 Results 42
3.2.1 Design of the cell monitoring device 42
3.2.2 Fabrication of the cell monitoring device 44
3.2.3 Test of syringe pump 46
3.2.4 Overview of the impedance measurement 48
3.2.5 Measurement of PC12 proliferation 50
3.2.6 Measurement of PC12 differentiation 54
3.3 Summary 59
Chapter Ⅳ. Development of bioelectronics nose using rat ORN
4.1 Background 60
4.1.1 Bioelectronic nose 60
4.1.2 Cell-based bioelectronics nose 62
4.1.3 Olfactory receptor neuron 63
4.1.4 Rationale 66
4.2 Results 67
4.2.1 Formation of ORN precursor spheroids 67
4.2.2 Characterization of ORN precursor spheroids 72
4.2.3 Differentiation of ORN precursor spheroids and characterization 74
4.2.4 Physiological characterization of ORN precursor spheroids 77
4.2.5 Measurement of extracellular electrical signals of ORNs 82
4.2.5.1 Measurement of odorant concentration 82
4.2.5.2 Discrimination of odorants 92
4.3 Summary 104
Chapter Ⅴ. Conclusions and implications 105
References 109
Summary (국문 요약) 116DOCTORdCollectio
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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