176,999 research outputs found
Functional characterisation of the novel histamine H(3) receptor agonist, VUF 5810, on the guinea-pig isolated ileum
No full textIt is known that the activation of prejunctionally-located histamine H3 receptors down-regulates the exocytotic acetylcholine release from the myenteric plexus and thus produces a negative control on the intestinal motility [1]. Most studies were performed by using the H3 receptor agonist (R) alpha-methylhistamine, which interferes also with the histamine H4 receptor, and the non-selective ligand histamine. Therefore, more selective compounds are requested for further characterisation of the different histamine receptor subtypes. We studied the effects of the immepip analog VUF 5810, a highly selective H3 receptor agonist previously characterised in SK-NM-C cells expressing the human H3 receptor protein, on the isolated guinea pig ileum. The agonistic effect was measured in terms of inhibition of electrical stimulation (0.1 Hz, 0.5 msec, 200-250 mA)-evoked muscle contractions, which are induced by endogenous acetylcholine.
The compound VUF 5810, as well as the H3/H4 agonists, immepip and (R) alpha-methylhistamine, induced a concentration-dependent reduction of the amplitude of the neurogenic response. All these agonists gave ~60% of maximum reduction of contractions, without affecting the contractile effect elicited by exogenous acetylcholine. The calculated pD2 value of VUF 5810 (8.22) was close to that of immepip (8.53) and ~10 times higher than that of MHA (7.61).
The putative H3 receptor antagonist, FUB 649, as well as the H3/H4 receptor antagonist, thioperamide, caused a rightward shift of the concentration-response curves of VUF 5810 (pA2 FUB 649: 8.55; thioperamide: 8.94), showing a sourmountable antagonism.
VUF 5810 did not cause any change in the basal tone of the preparations, even at 100 micromol, thus excluding any effect at H1 and H2 receptors.
These results suggest that VUF 5810 behaves as a full and potent agonist at prejunctional histamine receptors controlling the acetylcholine release from the myenteric plexus. The antagonistic effect of thioperamide and FUB 649 is consistent with the involvement of H3 receptors.
[1] Bertaccini et al., in: Leurs R., Timmerman H. (eds.), The histamine H3 receptor,
Elsevier Science B.V., Amsterdam, 1998, pp 59-111
Neuronal histamine H3 receptors mediate antisecretory effects in the isolated rat gastric fundus
No full text
Neuronal histamine H3 receptors mediate antisecretory effects in the rat isolated gastric fundus
No full textAppropriate Similarity Measures for Author Cocitation Analysis
No full textWe 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
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
Letter from R. R. Zellick, Assistant Trust Officer, Anglo California National Bank of San Francisco, to Joseph R. Goodman, October 2, 1942
No full textLetter from R. R. Zellick, Assistant Trust Officer at The Anglo California National Bank of San Francisco, to Joseph R. Goodman, regarding property owned by Dave Tatsuno. Zellick mentions a dispute between current tenants and Tatsuno, and that Tatsuno has asked Goodman to help locate trustworthy tenants.Personal correspondence, organizational records, government documents, publications, and other papers created or collected by Joseph R. Goodman documenting the forced removal and incarceration of Japanese Americans during World War II, as well as organized resistance to incarceration. Included in the collection are records of the Japanese Young Men's Christian Association and the Japanese American Citizens' League in San Francisco, including papers of the Japanese YMCA's executive secretary Lincoln Kanai; Sakai family papers; Goodman's correspondence to and from Japanese American incarcerees, organizations opposing forced removal and incarceration of Japanese Americans, the War Relocation Authority, and others; publications, photographs, and ephemera from the Topaz Relocation Center, where Goodman taught high school; War Relocation Authority records and publications; and newspaper clippings, pamphlets, and reports about forced removal and incarceration created by various government, religious, and civic organizations, in California and nationwide
Dispelling the Myths Behind First-author Citation Counts
No full textWe 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
Liftings for noncomplete probability spaces
No full textThe current state of knowledge concerning liftings for noncomplete probability spaces is discussed. This is a somewhat expanded version of the author's talk given at the 1991 Summer Conference on General Topology and Applications in Honor of Mary Ellen Rudin and Her Work.PT: S; CR: BURKE MR, IN PRESS P AM MATH S BURKE MR, 1991, ISRAEL J MATH, V73, P33 BURKE MR, 1992, ISRAEL J MATH, V79, P289 CARLSON T, THEOREM LIFTING CHRISTENSEN JPR, 1974, TOPOLOGY BOREL STRUC FREMLIN DH, 1989, HDB BOOLEAN ALGEBRAS, P877 INOESCUTULCEA A, 1966, 5TH P BERK S MATH ST, V2 IONESCUTULCEA A, 1967, CONTRIBUTIONS PROB 1, P63 IONESCUTULCEA A, 1969, TOPICS THEORY LIFTIN JECH TJ, 1978, SET THEORY JOHNSON RA, 1980, P AM MATH SOC, V80, P234 JUST W, IN PRESS T AM MATH S KUPKA J, 1983, INDIANA U MATH J, V32, P717 LOSERT V, 1983, LNM, V1080, P95 MAHARAM D, 1958, P AM MATH SOC, V9, P987 SHELAH S, 1983, ISRAEL J MATH, V45, P90 TALAGRAND M, 1982, P AM MATH SOC, V84, P379 VONNEUMANN J, 1931, CRELLES J MATH, V165, P109; NR: 18; TC: 0; J9: ANN N Y ACAD SCI; PG: 4; GA: BZ86BSource type: Electronic(1
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