1,721,190 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
Intrinsic map dynamics exploration for uncharted effective free-energy landscapes
Full text linkWe describe and implement a computer-assisted approach for accelerating the exploration of uncharted effective free-energy surfaces (FESs). More generally, the aim is the extraction of coarse-grained, macroscopic information from stochastic or atomistic simulations, such as molecular dynamics (MD). The approach functionally links the MD simulator with nonlinear manifold learning techniques. The added value comes from biasing the simulator toward unexplored phase-space regions by exploiting the smoothness of the gradually revealed intrinsic low-dimensional geometry of the FES
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
Computational exploration of water structure and dynamics at heterogeneous interfaces
Full text linkThe goal of this thesis is to completely understand the dynamical behavior of
water at different heterogeneous interfaces through statistical mechanics and
computational methods. The molecular processes described here has been focused
for past few decades, since the advent of experimental techniques to probe
interfacial water molecules. A central theme throughout the thesis is to have
quantitative understanding of water dynamics and structural interactions at the
microscopic level. This work has immense importance in the field of analytical
chemistry, surface science and biophysics.
We first describe the model for the intercalation process of a probe molecule in
the chromatographic system. This study is relevant for industrial HPLC techniques,
however complete microscopic level understanding of this process is still not
completely understood. The effect of various solvent concentrations and phase
thickness on the process of intercalation of acridine orange (probe) has been studied.
An extension to this work is the thermodynamic model for intercalation
of organic compounds based on experimentally known partition coefficient data.
Another interesting process is related with the vibrational spectroscopic feature of
water at hydroxylated silica surface. A lot of experimental studies has been
done to probe vibrational feature of water at solid interface and relate it to H-bonding
structure at these interfaces. Most of these results focused on the vibrational
feature in the streching frequency regime of water but we focused on the vibrational
bending mode of water close to the bare hydroxylated silica surface. This study
demonstrate the importance of higher order multipoles to capture the precise
spectroscopic description. Both the above studies are discuss in great detail in chapter IV.
Other interesting system we studied is the allosteric proteins, which mainly includes
Dimeric Scapharca Hemoglobin and Tetrameric human hemoglobin. This study mainly focus
on the role of water molecules close to protein surface and disentangle the coupled
dynamics of ligand and water molecules at the interface. Finally, we will describe
the quaternary structural transition T to R in tetrameric human hemoglobin. This
work is described in chapter V of this thesis
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
How mitogen-activated protein kinases recognize and phosphorylate their targets: A QM/MM study
Full text linkMitogen-activated protein kinase (MAPK) signaling pathways play an essential role in the transduction of environmental stimuli to the nucleus, thereby regulating a variety of cellular processes, including cell proliferation, differentiation, and programmed cell death. The components of the MAPK extracellular activated protein kinase (ERK) cascade represent attractive targets for cancer therapy, as their aberrant activation is a frequent event among highly prevalent human cancers. To understand how MAPKs recognize and phosphorylate their targets is key to unravel their function. However, these events are still poorly understood because of the lack of complex structures of MAPKs with their bound targets in the active site. Here we have modeled the interaction of ERK with a target peptide and analyzed the specificity toward Ser/Thr-Pro motifs. By using a quantum mechanics/molecular mechanics (QM/MM) approach, we propose a mechanism for the phosphoryl transfer catalyzed by ERK that offers new insights into MAPK function. Our results suggest that (1) the proline residue has a role in both specificity and phospho transfer efficiency, (2) the reaction occurs in one step, with ERK2 Asp 147 acting as the catalytic base, (3) a conserved Lys in the kinase superfamily that is usually mutated to check kinase activity strongly stabilizes the transition state, and (4) the reaction mechanism is similar with either one or two Mg 2+ ions in the active site. Taken together, our results provide a detailed description of the molecular events involved in the phosphorylation reaction catalyzed by MAPK and contribute to the general understanding of kinase activity.Fil: Turjanski, Adrian. National Institutes of Health; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; ArgentinaFil: Hummer, Gerhard. National Institutes of Health; Estados UnidosFil: Gutkind, J. Silvio. National Institutes of Health; Estados Unido
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