1,720,990 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
In-situ label-free optical detection of cells cultured in 3D microincubators
No full textIn this work, we show that high aspect-ratio silicon microstructures can play, at the same time, the roles of a cell-selective three-dimensional microincubator for cell culture and optical label-free transducer of cell morphology mapping. Silicon microincubators, integrating a periodic array of narrow (5-μm-wide), deeply etched (50-μm-deep) gaps separated by 3-μm-thick silicon walls, are fabricated by electrochemical micromachining (ECM) technology [1], and used for culturing several both epithelial and mesenchymal cell lines. Fluorescence microscopy analyses highlight that the microincubator shows cell-selective capabilities, being mostly cells with mesenchymal phenotype able to actively colonize the deeply etched gaps and grow attached to the vertical silicon walls [2]. The microincubator also features reflectivity spectral properties typical of one-dimensional (1D) photonic crystals (PhCs) structures in the near infrared range, with high reflectivity regions separated by deep reflectivity notches. According to 1DPhC optical properties, the presence of cells inside the gaps of the microincubator strongly affects the reflectivity signal, which can be measured in-situ with a fiber-optic setup orthogonally to the silicon wall surface (x-y plane). By spatially mapping the reflected power spectrum in the vertical x-y plane, it is thus possible to infer on the extension of cells growing into the microincubator attached to silicon walls. In particular, the intensity ratio between reflectivity maximum and minimum at two different wavelengths around 1.55 μm is closely related to the cell spreading on the silicon wall inside the deeply etched gaps of the microincubator. These results clearly envisage future in-situ label-free analyses of cellular activities involving changes in cell morphology and/or adhesion (e.g. apoptosis), in a three-dimensional environment.
[1] M. Bassu, S. Surdo, L. M. Strambini, G. Barillaro, Adv. Funct. Mat., 22 (2012), 1222-1228;
[2] F. Carpignano, G. Silva, S. Surdo, V. Leva, A. Montecucco, F Aredia, A. Scovassi, S. Merlo, G. Barillaro, G. Mazzini, Plos ONE 7 (2012) DOI: 10.1371/journal.pone.0048556
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
Vertical High-Order 1D Silicon Photonic Crystals for Integrated Opto-Fluidic Microsystems
No full textHigh-Order One-Dimensional Silicon Micromachined Photonic Crystal with a Reflectivity Notch at λ~ 1.55 μm
No full textAppropriate 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
HIGH-ASPECT-RATIO PHOTONIC CRYSTALS FOR CAPILLARY OPTOFLUIDICS: TOWARDS DROP-AND-MEASURE PLATFORMS
No full textIn this work, a drop-and-measure optofluidic platform that exploits capillary microfluidic concepts to infiltrate high-aspect-ratio (HAR) one-dimensional (1D) silicon/air photonic crystals (PhCs), this latter being used as sensing ele-ments, is reported. The platform, which is fabricated by electrochemical micromachining (ECM) technology, is op-tically characterized by measuring PhC reflectivity spectra upon capillary infiltration of liquids with different refrac-tive indices into the PhC air-gaps. Fiber grooves integrated in the platform allow the measurements to be carried out using optical fibers positioned in front of the PhC. Good reliability, sensitivity, and limit of detection are obtained, with best sensitivity value of 310 nm/RIU and worst-case limit of detection of 10-3 RIU, which are comparable to pressure-driven state-of-the-art integrated refractometers
Recognition of human cells in a glass-silicon Fabry-Perot microcavity by spectral reflectivity measurements
No full textDispelling 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
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