1,721,007 research outputs found
Muscarinic receptor modulation of GABA-mediated giant depolarizing potentials in the neonatal rat hippocampus
No full text1. The whole-cell patch clamp technique was used to study the role of muscarinic receptors in regulating the frequency of giant depolarizing potentials (GDPs) in CA3 hippocampal neurones in slices from postnatal (P) P1-P8 rats.
2. Atropine (1 mu M) reduced the frequency of GDPs by 64.2 +/- 2.9%. The acetylcholinesterase inhibitor edrophonium (20 mu M) increased the frequency of GDPs in a developmentally regulated way. This effect was antagonized by the M1 muscarinic receptor antagonist pirenzepine.
3. In the presence of edrophonium, tetanic stimulation of cholinergic fibres induced either an enhancement of GDP frequency (179 +/- 79%) or a membrane depolarization (27 +/- 16 mV) associated with an increase in synaptic noise. These effects were presented by atropine.
4. Application of carbachol (3 mu M) produced an increase in GDP frequency that at P5-P6 was associated with a membrane depolarization and an increase in synaptic noise. These effects were prevented by atropine, pirenzepine (3 mu M) and bicuculline (10 mu M).
5. In the presence of pirenzepine, carbachol reduced GDP frequency by 50 +/- 4%. Conversely, in the presence of methoctramine (3 mu M), carbachol enhanced GDP frequency by 117 +/- 4%.
6. It is concluded that endogenous acetylcholine, through the activation of M1 receptors, enhances the release of gamma-aminobutyric acid (GABA), in a developmentally regulated way. On the other hand, carbachol exerts both an up- and downregulation of GABA release through the activation of M1 and M2 receptors, respectively
Modeling of surface myoelectric signals, Part I: Model implementation
No full textIEEE TRANS. ON BIOMEDICAL ENG
I registri del Pagatorato delle soldatesche e dei tesorieri della legazione di Avignone e del Contado Venassino nell'Archivio di Stato di Roma (1562-1791)
No full textCaria Nardi, I registri del Pagatorato délie soldatesche e dei tesorieri della Legazione di Avignone e del Contado Venassino nell'Archivio di Stato di Roma (1562-1791), p. 15-120.
I 262 registri che costituiscono l'archivio del Pagatorato della Legazione di Avignone e del Contado Venassino (anni : 1562-1791), fondo conservato nell'Archivio di Stato di Roma, non sono che una delle quindici serie del fondo delle Tesorerie provinciali dello Stato pontificio. In realtà lo studio analitico della documentazione ha rivelato l'atipicità della serie avignonese nel panorama delle tesorerie provinciali, tanto da motivare una rettifica della denominazione del fondo.
La peculiarità della tesoreria avignonese consiste sia nella particolare collocazione geografica, che nel precipuo connotato di presidio militare. Si tratta infatti esclusivamente di scritture contabili dei tesorieri depositari
(v. retro) della città e della legazione, del tesoriere di Carpentras e del Contado Venassino, del collaterale e pagatore delle soldatesche. Le uscite sono inerenti alle spese di mantenimento del presidio, le entrate provengono dal centro e dalle comunità del Contado. Correda l'inventario un indice dei nomi di persona con la qualifica rivestita.Nardi Carla. I registri del Pagatorato delle soldatesche e dei tesorieri della legazione di Avignone e del Contado Venassino nell'Archivio di Stato di Roma (1562-1791). In: Mélanges de l'École française de Rome. Italie et Méditerranée, tome 107, n°1. 1995. pp. 15-120
Increased density of M1 receptors in the hippocampus of juvenile rats chronically deprived of NGF.
No full textBinding studies were used to assess the changes in affinity and/or number of M1 muscarinic receptors in hippocampi from juvenile rats chronically deprived of NGF. NGF deprivation was obtained by implanting into right ventricle at postnatal day 2 (P2) hybrydoma cells secreting high levels of monoclonal antibodies against NGF (alphaD11). Parenteral myeloma cells (P3U) were used as controls. Competition experiments were used to characterise the [3H]-PNZ binding sites in membrane preparations of hippocampi from rats sacrificed at P15. [3H]-PNZ bound M1 receptors both in P3U and alphaD11 group as shown by displacing potency order of antagonists: TLZ=4-DAMP>PNZ>p-F-HHSiD>MTC. The deprivation of NGF for two weeks significantly increased the number of M1 receptors without changing the Ki values of antagonists with exception of methoctramine which showed an increase in affinity in alphaD11 group. Similar changes in binding parameters were already observed after the first week of anti-NGF treatment. In contrast, a treatment for a week with implant at postnatal day 15 failed to produce any changes in M1 binding parameters. These results provide further physiological evidence for developmentally regulated modulatory role of NGF in the cholinergic function in the hippocampus
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
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