1,721,099 research outputs found
DNA origami as device at the nanoscale
No full textThe ability of synthetic DNA to self-assemble into a variety of nanostructures with different shapes, dimensions and functionality has been reported. In detail the powerful DNA origami technique uses short oligonucleotides staple strands to direct the folding of a long DNA scaffold strand into a programmed arrangment (Rothemund, 2006) producing a wide range of 2D and 3D nanostructures. Here we present switchable 2D and 3D DNA origami with a movable flap, whose opening movement is controlled by the hybridization status of a DNA sensor probe. The actuation is specifically triggered by the interaction between the ssDNA probe and the complementary ssDNA target and has been demonstrated using AFM, TEM, F\uf6rster resonance energy transfer, localized surface plasmon resonance tuning, colorimetric or chemiluminescent reactions (Torelli et al., 2014; Piantanida et al., 2015). Finally, we coupled 3D DNA origami intimately to the surface of a glass optical fiber. The detection scheme combines the intrinsic recognition abilities of the immobilized switchable DNA origami with a chemiluminescence signal collection coupled to a useful solid portable transducer. Based on our proof-of-principle, the proposed hybrid system can be a candidate for different applications, including point-of-care diagnostics or cellular in vivo biosensing (Torelli et al., 2017).ReferencesRothemund, P.W.K., 2006. Nature 440, 297-302.Piantanida, L., Naumenko, D., Torelli, E., Marini, M., Bauer, D.M., Fruk, L., Firrao, G., Lazzarino, M., 2015. Chem. Comm. 51, 4789-4792.Torelli, E., Marini, M., Palmano, S., Piantanida, L., Polano, C., Scarpellini, A., Lazzarino, M., Firrao, G., 2014. Small 10, 2918-2926.Torelli, E., Srivastava, K.S., Manzano, M., Marks, R.S., 2017, submitted
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
HoloLearn: Wearable Mixed Reality for People with Neurodevelopmental Disorders (NDD)
No full textOur research explores the potential of wearable Mixed Reality (MR) for people with Neuro-Developmental Disorders (NDD). The paper presents HoloLearn, a MR application designed in cooperation with NDD experts and implemented using HoloLens technology. The goal of HoloLearn is to help people with NDD learn how to perform simple everyday tasks in domestic environments and improve autonomy. An original feature of the system is the presence of a virtual assistant devoted to capture the user's attention and to give her/him hints during task execution in the MR environment. We performed an exploratory study involving 20 subjects with NDD to investigate the acceptability and usability of HoloLearn and its potential as a therapeutic tool. HoloLearn was well-accepted by the participants and the activities in the MR space were perceived as enjoyable, despite some usability problems associated to HoloLens interaction mechanism. More extensive and long term empirical research is needed to validate these early results, but our study suggests that HoloLearn could be adopted as a complement to more traditional interventions. Our work, and the lessons we learned, may help designers and developers of future MR applications devoted to people with NDD and to other people with similar needs
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