1,720,959 research outputs found
Microsomal protein mediates a pH-dependent fusion of liposomes to rat brain microsomes
No full textThe fusion between rat brain microsomes and liposomes is investigated by measuring the release of octadecylrhodamine B (R18) fluorescence selj-quenching. In the experimental conditions used in this work, the method allows a rapid and quantitative
evaluation of the mixing ofmicrosome and liposome lipid phases. The decrease of pH below 7 produces an extensive fusion between microsomes and acidic phospholipid liposomes. Microsomal protein is necessary for fusion, which is inactivated by
exposure of microsomes to pronase. Therefore, H+ -induced fusion differs from Ca2+-induced fusion since the latter does not require microsomal protein. The pretreatment of microsomes with trinitrobenzenesulfonic acid (TNBS) in non penetrating conditions
does not affect the extent of fusion. On the other hand, N ethoxycarbonyl-2-ethoxy- 1,2-dihydroquinoline (EEDQ), a reagent able to react with carboxyl groups, causes an extensive inactivation of fusion. Therefore, the H+ -induced fusion described here depends on some microsomal protein and may have physiological significance because it occurs at pH values present in the living celi. H+-dependent fusion can be also considered as a means to enrich membranes in some selected lipid
Transport of phosphatidylserine from microsmes to the inner mitochondrial membrane in brain tissue
No full textPhosphatidylserine was labeled by incubating rat
brain homogenates with [3-I4C]serine in the presence of
Ca2+ (base-exchange conditions). Some labeled phosphatidylethanolamine
also forms, in spite of the inhibition of
Ca" on phosphatidylserine decarboxylase. Phosphatidylserine
labeling and decarboxylation also occur on incubating
a mixture of purified mitochondria and microsomes,
suggesting that no soluble factors are necessary for the synthesis
and the decarboxylation of phosphatidylserine. Ca2+
favors the transfer of phosphatidylserine from microsomes
(where it forms) to mitochondria (where it is decarboxylated).
The specific radioactivity of the phosphatidylserine
transferred to mitochondria is higher than that of microsoma1
phosphatidylserine. This finding supports the hypothesis
that the lipid is compartmentalized in microsomes
and that radioactive, newly synthesized phosphatidylserine
is much better exported than the bulk of microsomal phospholipid.
Key Words: Phosphatidylserine-Base-exchange
reactions-Phosphatidylserine decarboxylase-Mitochondria-
Microsomes-Brain. Corazzi L. et al. Transport of
phosphatidylserine from microsomes to the inner mitochondrial
membrane in brain tissue. J. Neurochem. 60,50-
56 (1 993)
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
- …
