1,721,099 research outputs found
Aeroelastic Stability of a Hingeless Rotor Blade in Hover Using Finite Elements Based on Large Deflection Theory
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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
A poly(β-amino ester) of spermine and poly(ethylene glycol) diacrylate as a gene carrier
No full textVectors are vital aspect of gene delivery system which decides the success of gene therapy. Efficient transfection with minimum or no toxicity, are two principal aims of any gene delivery system. In this our study, we rationally developed biodegradable water soluble poly(β-amino ester) (PAE) based on spermine (SPR) and poly (ethylene glycol) (PEG), by Michael-type addition reaction and further studied for its potential as a gene carrier. Confirmation of synthesized PAE was done by proton NMR spectroscopy. In gel retardation assay, the PAEs have shown good DNA binding ability over wide range of polyplexes. The addition of PEG over SPR resulted in a novel PAE with higher degree of safety and transfection efficiency as compared with polyethylenimine 25K (PEI) when studied in 293T human kidney carcinoma cells.N
Receptor-mediated gene delivery using chitosan derivatives in vitro and in vivo
No full textThe development of an efficient targeted gene delivery system into cells is an important strategy for the advancement of gene therapy. The targeted gene delivery system is especially important in non-viral gene transfer which shows the relative low transfection efficiency. And it also opens the possibility of selective delivery of therapeutic plasmids to specific tissues. Chitosan has been investigated as a non-viral vector because it has several advantages such as biocompatibility, biodegradability and low toxicity with high cationic potential. However, low specificity and low transfection efficiency of chitosan need to be overcome prior to clinical trial. In this review, we focused on the specific ligand modification of chitosan for enhancement of cell specificity and transfection efficiency via receptor-mediated endocytosis in vitro and in vivo. Copyright © 2007 WILEY-VCH Verlag GmbH & Co. KGaA.N
Reconstruction of High-Frequency Lunar Digital Elevation Model using Shape from Shading
No full textThis paper deals with a procedure to reconstruct a lunar surface based on fusion of Shape from Shading with absolute depth information exploited from Lunar Orbiter Laser Altimeter data. The generation of accurate lunar digital elevation model which contains altitude and terrain shape of mission area is critical for lunar exploration mission design. The photoclinometric approach with Shape from Shading yields dense, high-frequency information while range scanning data from Lunar Orbiter Laser Altimeter complements the photoclinometric reconstruction with low-frequency, large scale reliable depth information. The proposed Shape from Shading algorithm utilizes the laser altimetry data as initial guess and iteratively calculates the high-frequency altitude information from high resolution image. The high-frequency depth variation caused by small crater and boulder is recovered by applying Shape from Shading
Degradable polyethylenimines as gene carriers
No full textGene therapy is a powerful treatment for inborn and acquired diseases. The development of safe and effective gene delivery systems is a great challenge to make the human gene therapy a reality. Viral vectors have been commonly employed due to the high transfection efficiency, however, their application to the human body is often frustrated by immunogenicity, potential infectivity, complicated production, and inflammation. Non-viral vectors have been widely proposed as safer alternatives to viral vectors by reason of unique advantages such as less immune reaction against repeated administration, ease of synthesis, cell/tissue targeting, unrestricted plasmid size, and low cost. Among non-viral systems, cationic polymers have gained increasing attention because they can easily form self-assembly with DNA. Polyethylenimine (PEI) is one of the most popular cationic polymers investigated in non-viral gene therapy due to its ability to generate elevated levels of gene expression in vitro and in vivo compared to another non-viral carriers. However, the PEI showed high cytotoxicity, which depends on the molecular weight of the PEI. Recently, the degradable PEIs were synthesised to have high transfection efficiency with low cytotoxicity. The present review describes recent progress on the development of degradable PEIs as non-viral vectors. The present paper also summarises structure of degradable PEIs-transfection relationship to provide a novel insight with respect to this type of gene delivery system. First, linear degradable polymers based on linear PEIs are represented. Second, branched polymers based on branched PEIs are discussed. Third, grafted degradable copolymers based on branched PEIs are explained.N
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
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