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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
Action of capsaicin and related peptides on the ionic transport across the skin of Rana esculenta
No full textCapsaicin at low concentrations increases the short circuit current (SCC) across frog skin. Simultaneous measurements of both transepithelial fluxes of 22Na or 36Cl demonstrate that the SCC increase is due to stimulation of sodium active absorption. Capsaicin acts through the liberation of several peptides; thus these peptides were tested on the SCC across frog skin. Those more active are, in order of potency: Cyclic Calcitonin Gene Related Peptide (CGRP), Kassinin and Eledoisin, Substance P (SP) and Neurokinin A. Neurokinin B and Vasoactive Intestinal Peptide (VIP) have no effect. Also the actions of SP and CGRP are due mainly to stimulation of Na+ active absorption. A strict parallelism regarding the sensitivity to inhibitors (Naproxen, SQ22536 and CP96345) between SP, CGRP and Capsaicin strengthens the hypothesis that SP and CGRP are liberated by Capsaicin in this tissue
Interaction of pyrethroids with the ion transport pathways present in frog skin
No full textWe measured the ability of deltamethrin and permethrin to stimulate the ion transport operated by the frog skin. Ion transport was monitored by measuring the short-circuit current. Deltamethrin and permethrin, added to the fluid bathing the internal surface of the isolated frog skin, showed a seasonal feature and were more effective in increasing short-circuit current in the period between June and October. Transepithelial influxes and outfluxes of Na-22(+) and Cl-36(-) across symmetrical parts of the short-circuited skin were then measured. Deltamethrin was found to increase net Naf absorption and, to a lesser extent, Cl- secretion. The presence of a Cl- secretory mechanism is supported by two observations, those being that the short-circuit current value, recorded when deltamethrin and amiloride (inhibitor of NaC channels) were simultaneously present, was higher than that obtained in the presence of amiloride alone and that bumetanide, a classic inhibitor of Cl- secretion, completely inhibited the component of the Cl- outflux that was induced by the deltamethrin stimulation. The stimulations of short-circuit current respectively caused by deltamethrin (type II pyrethroid) and permethrin (type I) were comparable and similarly affected by indomethacin (an inhibitor of cyclooxygenase) and W7 (an inhibitor of the Ca2+/calmodulin system). These findings suggest that, in frog skin, the cellular mechanism of action of type I and type II pyrethroids is similar
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
The nature of Cl- secretion, induced by carbaryl, across the isolated skin of Rana esculenta.
No full text1. The pesticide carbaryl induces Cl- secretion through the isolated frog skin.
2. This effect is due to the activation of both processes responsible for this
phenomenon: (a) Na+/K+/2Cl- cotransport on the serosal membrane; (b) Cl-
selective channels on the external membrane. 3. Cl- outflux is inhibited by
bumetanide (10(-5) M) on the serosal side and by diphenylamine-2-carboxylic acid
(DPC) (10(-3) M) on the external side. 4. The DPC action is not mimicked by
Naproxen, a specific inhibitor of cyclooxygenase. 5. A comparison with
isoprenaline, demonstrates that the carbaryl action is, paradoxically, more
selective than that of isoprenaline. 6. This selectivity of carbaryl action on
Cl- permeability is confirmed by the fact that, unlike isoprenaline, carbaryl
does not affect the permeability of Na+ and thiourea
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