1,720,975 research outputs found
Dielectric behavior of lysozyme and ferricytochrome-c in water/ethylene-glycol solutions
No full textBiophys. J
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
Influence of urea on thermal denaturation of lysozyme investigated by optical and dielectric spectroscopies
No full textPhys. Chem. Chem. Phys
Elastic neutron scattering study of proton dynamics in glycerol
No full textA recent neutron scattering investigation on lysozyme embedded in glycerol-water mixtures has shown that solvent dynamics is crucial in determining the dynamical properties of the biomolecule itself (Biophys. J. 83 (2002) 1157). To better understand the role played by solvent, we have performed an elastic incoherent neutron scattering (INS) experiment as a function of the temperature on pure glycerol. To directly compare the dynamics of the solvated protein and that of the pure solvent, we settled the same experimental conditions and applied the same data analysis procedure as in Paciaroni et al. (Biophys. J. 83 (2002) 1157). By using a double-well model and taking into account for the global molecular diffusion, we exploited the measured intensity to estimate the mean square displacements (MSD) of glycerol hydrogen atoms. We found that the total MSD deviate from the low-temperature vibrational harmonic trend at approximately T = 235 K, consistent with the value of the critical temperature reported in literature (Phys. Rev. E 55 (1997) 3183). The present investigation suggests that the internal dynamics of glycerol molecules, i.e. the vibrations and reorientations of hydrogen atoms relative to the molecular centre of mass (c.o.m.), can be put in relationship with the protein dynamics
Modulation of hypersensitivity to oxidative DNA damage in ATM defective cells induced by potassium bromate by inhibition of the poly (ADP-ribose) polymerase (PARP)
No full textThe ataxia telangiectasia mutated (ATM) protein is a pivotal multifunctional protein kinase predominantly involved in DNA damage response, as well as in maintaining overall functional integrity of the cells. Apart from playing its major role in regulating the cellular response to DNA damage, ATM, when mutated, can additionally determine oxidative stress, metabolic syndrome, mitochondrial dysfunction and neurodegeneration.
In the present paper we aim to investigate the levels of oxidative stress potentially induced by the oxidising rodent renal carcinogen KBrO3 in ATM-defective lymphoblastoid cell lines (LCLs) established from four classical AT patients (with different ATM mutations), one AT variant with reduced hypersensitivity to X rays, obligate AT heterozygotes and wild type intrafamilial control. A possible modulatory involvement of PARP in potentially induced oxidative stress is also evaluated following its inhibition with 3-aminobenzamide (3-AB).
Treatments with KBrO3 clearly showed a marked hypersensitivity of the ATM-defective LCLs, including the AT variant. A marked and statistically significant reduction of KBrO3-induced chromosomal damage following inhibition of PARP by 3-AB, was observed in all AT LCLs, but not in those from the AT variant, AT heterozygotes and wild type intrafamilial control. This result is suggestive of a modulatory involvement of PARP in the hypersensitivity of ATM-defective cells to DNA oxidative damage
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
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