1,720,965 research outputs found
Distribution and molecular heterogeneity of galanin in human, pig, guinea pig, and rat gastrointestinal tracts.
No full textGalanin was measured by radioimmunoassay in whole thickness extracts of the
gastrointestinal wall from four species and in extracts from separate layers of
human small intestine. The immunoreactivity was characterized using gelchromatography and high-pressure liquid chromatography. Two antibodies were
employed, which were characterized as non-C-terminal (Gal 8) and C-terminal (Gal
9) using a C-terminal galanin 10-29 fragment. Substantial quantities of galanin
immunoreactivity were found, mainly localized at the muscle layer. Both
intramolecular and intermolecular heterogeneity was apparent. Two molecular forms
exist in humans (Kav 0.58, 0.69). The molecular heterogeneity in humans, rats,
and guinea pigs may be localized near the C-terminus of the galanin molecule. A
C-terminal extension of one human galanin form is likely (Kav 0.58). These
findings give radioimmunologic evidence for a neurocrine origin of galanin. The
chromatographic variations suggest that extrapolation of experimental result
Radioimmunoassay and intramural distribution of PHI-IR in human intestine.
No full textThe objective of this study was to develop a radioimmunoassay for PHI and use
this to assess its intramural distribution in the human intestine. The antibody
was harvested following immunization with porcine PHI conjugated to bovine serum
albumin by glutaraldehyde, and the iodinated PHI tracer was prepared by the
Iodo-gen method. The assay system showed no cross-reaction with other members of
the glucagon-secretin family of peptides and was sensitive to changes of PHI of 2
fmol/tube (95% confidence). High concentrations of immunoreactive PHI were found
in the human intestine, exclusively localized in the nonendocrine gut layers,
suggesting a possible neuroendocrinological or neurotransmitter role for PHI
Distribution of a novel pituitary protein (7B2) in mammalian gastrointestinal tract and pancreas.
No full textThe distribution of a novel pituitary protein (7B2) was determined in the
gastrointestinal tract and pancreas of four mammalian species (man, pig, guinea
pig, and rat) by a specific radioimmunoassay. The highest concentrations of
cross-reacting immunoreactive 7B2 (IR-7B2) were observed in the pancreas and the
proximal gut (antrum or duodenum). While the intestinal concentrations varied
widely among species, pancreatic IR-7B2 concentrations appeared to be similar in
all four species. In the rat, pancreatic islets were found to contain high
concentrations of IR-7B2 (5.73 +/- 0.14 fmol/islet, mean +/- SEM). Neonatal
capsaicin treatment and enteric nerve section did not affect the concentrations
of IR-7B2 in the rat intestine. Layer separation of human gut showed that IR-7B2
is mainly (71 +/- 8%) present in the epithelial fraction. Chromatographic
analysis of intestinal and pancreatic extracts from the four species on Sephadex
G-100 showed the presence of two immunoreactive peaks at Kav 0.3 and 0.6, but
there were both inter- and intraspecies variations in the proportions of the
larger and smaller molecular forms
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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