1,722,678 research outputs found
Leupeptin, an inhibitor of ca-dependent proteases, retards the kinase-irreversible, ca-dependent loss of calcium current in perfused snail neurons
No full textRaspberry Diseases
No full text4 p. Photographs.This archival publication may not reflect current scientific knowledge or recommendations. Current information available from the University of Minnesota Extension: https://www.extension.umn.edu.Behrendt, Chad J.. (2000). Raspberry Diseases. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/93625
Calcineurin, a calcium-dependent phosphatase, enhances ca- mediated inactivation of ca current in perfused snail neurons
No full textParasitic Diseases of Tomato
No full text2 pages. Illustrated.This archival publication may not reflect current scientific knowledge or recommendations. Current information available from the University of Minnesota Extension: https://www.extension.umn.edu.Describes tomato diseases that are common in Minnesota and how to identify and control them.University of Minnesota Extension Service.Behrendt, Chad J.; Gould, S.L.. (1998). Parasitic Diseases of Tomato. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/51483
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
Kinetics of calcium-dependent inactivation of calcium current in voltage-clamped neurones of Aplysia californica
No full textCa currents flowing during voltage-clamp depolarizations were examined in axotomized Aplysia neurones under conditions that virtually eliminated other currents. Moderate to large currents exhibited a two-component time course of relaxation that can be approximated reasonably well by the sum of two exponentials. The rapid phase (tau 1 approximately equal to 70 ms at 0 mV) plus the slower phase (tau 2 approximately equal to 300 ms at 0 mV) ride upon a steady, non-inactivating current, I infinity. Conditions that diminish the peak current amplitude, such as reduced stimulus depolarization, inactivation remaining from a prior depolarization, or partial blockade of the Ca conductance by Cd, slowed both phases of inactivation, and all selectively eliminated the tau 1 phase, such that weak currents exhibited only the slower phase of decline. Injection of EGTA slowed both phases of inactivation, decreased the extent of the tau 1 phase, and increased the intensity of I infinity and of the current during the tau 2 phase. For a given voltage, the rate of inactivation increased as the peak current strength was increased, and decreased as the peak current strength was decreased. For a given peak current the rate of inactivation decreased as depolarization was increased. The relation of inactivation to prior Ca2+ entry was essentially linear for small currents, but decreased in slope with time during strong currents. The relation also became shallower with increasing depolarization, suggesting an apparent decrease in the efficacy of Ca in causing inactivation at more positive potentials. The basic kinetics of Ca current inactivation along with experimentally induced changes in those kinetics were simulated with a binding-site model in which inactivation develops during current flow as a function of the entry and accumulation of free Ca2+. This demonstrated that a single Ca-mediated process can account for the two-component time course of inactivation, and that the nearly bi-exponential shape need not arise from two separate processes. The two-component time course emerges as a consequence of a postulated hyperbolic reaction between diminishing probability of channels remaining open and the accumulation of intracellular free Ca2+. The occurrence of a single- or a two-component time course of inactivation thus appears to depend on the levels of internal free Ca2+ traversed during current flow
Spatio-temporal characteristics of ca-2+ dispersal following its injection into aplysia neurons
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