1,720,974 research outputs found
Endogenous Firing Patterns of Murine Spiral Ganglion Neurons
No full text Mo, Zun-Li and Robin L. Davis. Endogenous firing patterns of murine spiral ganglion neurons. J. Neurophysiol. 77: 1294–1305, 1997. Current-clamp recordings with the use of the whole cell configuration of the patch-clamp technique were made from postnatal mouse spiral ganglion neurons in vitro. Cultures contained neurons that displayed monopolar, bipolar, and pseudomonopolar morphologies. Additionally, a class of neurons having exceptionally large somata was observed. Frequency histograms of the maximum number of action potentials fired from 240-ms step depolarizations showed that neurons could be classified as either slowly adapting or rapidly adapting. Most neurons (85%) were in the rapidly adapting category (58 of 68 recordings). Measurements of elementary properties were used to define the endogenous firing characteristics of both neuron classes. Action potential number varied with step and holding potential, spike amplitude decayed during prolonged depolarizations, and spike frequency adaptation was observed in both rapidly and slowly adapting neurons. The apparent input resistance, spike amplitude decrement, and instantaneous firing frequency differed significantly between rapidly and slowly adapting neurons. Inward rectification was evaluated in response to hyperpolarizing constant current injections. Present in both electrophysiological classes, its magnitude was graded from neuron to neuron, reflecting differences in number, type, and/or voltage dependence of the underlying channels. These data suggest that spiral ganglion neurons possess intrinsic firing properties that regulate action potential number and timing, features that may be crucial to signal coding in the auditory periphery. </jats:p
Heterogeneous Voltage Dependence of Inward Rectifier Currents in Spiral Ganglion Neurons
No full text Mo, Zun-Li and Robin L. Davis. Heterogeneous voltage dependence of inward rectifier currents in spiral ganglion neurons. J. Neurophysiol. 78: 3019–3027, 1997. Inward rectification was characterized in neonatal spiral ganglion neurons maintained in tissue culture. Whole cell current and voltage-clamp techniques were used to show that the hyperpolarization-activated cationic ( I h) current underlies most or all of the inward rectification demonstrated in these neurons. The average reversal potential (−41.3 mV) and cesium sensitivity were typical of that found in other neurons and cell types. What was unique about the hyperpolarization-activated currents, however, was that the half-maximal voltages ( V 1/2) and slope factors ( k) that characterized I h current activation were graded from neuron to neuron. Voltage-clamp recordings made with standard bath and pipette solutions revealed V 1/2 values that ranged from −78.1 to −122.1 mV, with slope factors from 7.6 to 13.1. These gradations in the voltage-dependent features of the I h current did not result from variability in the recording conditions because independently measured Na+ current-to-voltage relationships were found to be uniform (peak current at −20 mV). Moreover, the range and average V 1/2 and slope values could be altered with activators [8-(4-chlorophenylthio) adenosine 3′,5′-cyclic monophosphate in combination with okadaic acid] or inhibitors { N-[2-(p-bromocinnamylamino)ethyl]-5-isoquinolinesulfonamide}of protein indicating that I h current heterogeneity most likely resulted from differential phosphorylation. </jats:p
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
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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