1,720,966 research outputs found
Effects of extracellular Ca2+ on membrane and seal resistance in patch-clamped rat thalamic and sensory ganglion neurons
No full textWe studied the effects of [Ca2+]ext changes on seal resistance in patch-clamp experiments. Recordings were made on rat peripheral and thalamic neurons. Increasing [Ca2+]ext from 0.5 to 4.5 mM, reduced the ionic currents evoked at potentials from -100 to +50 mV, in cell-attached recordings, in all the neurons tested. The effect was greater at negative potentials. The change in seal conductance (deltaG) decreased with higher resistance seals and became very low over 1 Gohm (<0.5 nS). However, the ratio deltaG/G(0.5 Ca2+) rose from close to 0 up to 0.6, indicating that Ca2+ has a stronger effect when the microelectrode and the membrane are sealed more tightly. These findings suggest that changes in seal resistance may be misleading in experiments in which extracellular Ca2+ changes are used
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
The voltage-dependent nonselective cation current in human red blood cells studied by means of whole-cell and nystatin-perforated patch-clamp techniques
No full textAbstractHuman red blood cells (RBC) can be studied by means of whole-cell and nystatin-perforated patch-clamp techniques. In 85% of the whole-cell experiments (n=86) and 69% of the perforated-patch recordings (n=13), steps to positive potentials, from a holding potential of 0 mV, induced a slow-activating non-inactivating persistent outward current which reverted at about 0 mV. The current activation phase fitted well with a two-component exponential curve. Half-maximal conductance was reached at about 42 mV. Na+ and K+ carried this current, which was not affected by 20 nM charybdotoxin or 20 mM TEA, but was reduced following a partial substitution of extracellular Cl− by tartrate. This current has characteristics similar to the single-channel currents already described in RBC and may be involved in the rapid adaptations of these cells in the circulation
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
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