1,721,016 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
Exploring Cell Biodiversity
Full text linkBrain tissue is a really complex system composed of different cell types that change in shape and size. A single neuron itself has a cell body, dendrites and an axon. About 80% of cerebral tissue consists of water molecules that are confined (intra and extra cellular) in its disordered biologic networks. Using neutron scattering on IN13 we are able to explore hydrogens (H) dynamics in time scale at about 40 ps and in size scale at about 1 Å. Such characteristic make it suitable to investigate brain tissue heterogeneity exploiting hydrogens as a probe since major constituent of macromolecules and water. Elastic neutron scattering (ENS) gives information about means square displacement (MSDs) and flexibility (inversely proportional to k force constant) associable at complex and disordered system as cellular tissue. Cell paste with water extra cellular removed of E. coli bacteria, yeast (fungus), glioma 9L and PC12 cancer cell from rat was investigated by ENS. Preliminary results show that MSDs increase as a function of temperature and that k force constant value is strongly dependent on cellular biodiversity. The smaller is the k force constant the bigger are the flexibility associated to the system, consequently increasing the dynamic
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
Exploring cell biodiversity - Neutron scattering investigation of water diffusion in complex system
No full textScientists from biophysics, biology and medicine fields are interested in exploring and characterizing topologically cerebral tissue in order to diagnostic different diseases which affect brain in many patients [1-3].
One of the most diffuse diagnostic techniques is dMRI (diffusion magnetic resonance imaging) which extracts information about heterogeneity and asymmetries in brain tissue studying water diffusion dynamics (~80% mass constituent of tissues). The experimental limit of this technique is related to the acquisition time, TA, of the order of milliseconds. Water molecules diffuse within micrometre distance using TA as diffuse time (Eistein equation D~2TA). Cells have micrometric size and they consist in many organelles surrounded by water molecules essentially, therefore dMRI lose information concerning interaction between water molecules and extra/intra cellular material.
Such limit, from physical point of view, means that dMRI gets out information on an average diffusion coefficient, losing information of local motions. Nevertheless, many works show that the diffusion properties of water molecules in brain tissue are not in agreement with classical free-like diffusion (Fick law). Although, several models have been proposed to describe such a discrepancy, an univocal physical interpretation of water dynamics in brain is still not achieved [4-13].
Aims of PhD project
Neutron scattering technique gives access to space scale of the order of interatomic distances and dynamics in ps-ns time scale. It is particular sensitive to highly enriched H macromolecules, such as water. Thus, neutron scattering may offer a unique tool to overcome the dMRI experimental limit. Recently studies of quasi-elastic neutron scattering (QENS) on cerebral tissue of bovine and mice have shown that it is possible to distinguish two water pools in cerebral tissues: the first one having a behaviour similar to bulk water (called free-like water) with a diffusion coefficient similar to free water (Dw=2.3*10-5 cm2/s) and a second one showing a reduced diffusion coefficient probably due to interactions with intra and extra cellular material [14-15]. The project aims at addressing the following points:
• Joint complementary QENS and dMRI investigation;
• Proton dynamics of water at different degrees of confinement. Comparison of dMRI and QENS on phantoms;
• Proton dynamics in glioma at different degrees of malignancy
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
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
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