1,720,957 research outputs found
NMR of 133Cs+ in stretched hydrogels: one-dimensional, z- and NOESY spectra, and probing the ion’s environment in erythrocytes
No full text(133)Cs nuclear magnetic resonance (NMR) spectroscopy was conducted on (133)Cs(+) in gelatin hydrogels that were either relaxed or stretched. Stretching generated a septet from this spin-7/2 nucleus, and its nuclear magnetic relaxation was studied via z-spectra, and two-dimensional nuclear Overhauser (NOESY) spectroscopy. Various spectral features were well simulated by using Mathematica and the software package SpinDynamica. Spectra of CsCl in suspensions of human erythrocytes embedded in gelatin gel showed separation of the resonances from the cation inside and outside the cells. Upon stretching the sample, the extracellular (133)Cs(+) signal split into a septet, while the intracellular peak was unchanged, revealing different alignment/ordering properties of the environment inside and around the cells. Differential interference contrast light microscopy confirmed that the cells were stretched when the overall sample was elongated. Analysis of the various spectral features of (133)Cs(+) reported here opens up applications of this K(+) congener for studies of cation-handling by metabolically-active cells and tissues in aligned states
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
Advanced NMR Spectral Characteristics Used in Biochemical Studies of Anisotropic Media and Cells
Full text linkThe theme of this thesis was to quantify possible sources of adenosine triphosphate (ATP) hydrolysis in the human red blood cell (RBC). Understanding the consumption of ATP in RBCs provides insight into its energy demands, and those of other cell types and the body as a whole. The main sources of ATP hydrolysis investigated included: (i) the Na+,K+-ATPase (NKA); and (ii) cell membrane flickering (CMF) of RBCs. In addition to these studies, we developed mathematical models of RBC systems and the experimental techniques used. Many of these models described spectral characteristics of NMR spectra, including: (i) chemical shift differences induced by shift reagents (SRs); (ii) dynamic nuclear polarisation (DNP) NMR; and (iii) z-spectra of quadrupolar nuclei contained in stretched hydrogels. In each of these cases, experimental data were acquired, and methods were then developed to estimate model parameter values. This included (a) examined the NMR chemical shift differences induced on 23Na+ by the SR,TmDOTP, as functions of Na+ and other competing ions; (b) the mathematical description of the decay of magnetisation of hyperpolarised nuclei (achieved using DNP) as observed using 13C NMR spectroscopy; (c) the application of Bayesian analysis and Markov chain Monte Carlo (MCMC) methods to estimate the relaxation rate constants of the z-spectra of quadrupolar nuclei contained in stretched gels; (d) measurement of the stoichiometric relationship between the rate at which Na+ ions are transported across the RBC membrane by the NKA to its indirect consumption rate of glucose and (e) an exploration into the origin of CMF in human RBCs using both an experimental approach and mathematical modelling. Overall, this work ruled out a number of potential sources of ATP hydrolysis in the RBC, and provided several model frameworks that describe metabolic systems in the human RBC, and various NMR spectral characteristics
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
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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