1,720,962 research outputs found
Anion-linked polymerization of the tetrameric hemoglobin from Scapharca inaequivalvis. Characterization and functional relevance.
No full textSubunit-association and functional properties in the hemocyanin of the squid Todarodes sagittatus.
No full textThe association-dissociation behaviour in Todarodes sagittatus hemocyanin has been studied by sedimentation velocity measurements
at different pH values and in the absence and presence of a
number of anions and cations. In the absence of salts the sedimentation
pattern is dominated (about 1002) by a relatively low M.W.
species (20 S), while 10 mM CaCl2 and increasing pH (above 65)
stabilize a larger (30 S) species.
The above data are used as a basic to explain some physiological questions concerning
the nutritional habits of these animals
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
Structural and functional effects of selective chemical modifications of Scapharca inaequivalvis haemoglobins in relation to their unique assembly.
No full textRefolding pathway and association intermediates of glutamate dehydrogenase from tthe hyperthermophile Pyrococcus furiosus
No full textI.F.= 3.24
Oxidation reaction of Scapharaca inaquivalvis hemoglobins with nitrate
No full textThe oxidation reaction with nitrite of the dimeric and tetrameric hemoglobins from the mullosc Scapharca inaequivalvis has been studied kinetically and at equilibrium. In line with previous findings obtained with ferricyanide as oxidant, in both proteins the stable oxidation product is a hemichrome, although the nitrite-methemoglobin complex is formed in significant amount when excess nitrite is employed. The reaction kinetics are characterized by a lag period followed by an autocatalytic phase, as in the case of human hemoglobin. However, with respect to human hemoglobin, in the two molluscan proteins the lag phase is prolonged significantly due to the instability of their met-form, an obligatory intermediate for the onset of autocatalysis. All the data obtained in spectrophotometric, EPR and sedimentation velocity experiments under a variety of experimental conditions conform to the reaction mechanism proposed for human hemoglobin (Spagnuolo et al., Biochim. Biophys. Acta 911 (1987) 59-63) provided hemichrome formation and nitrite binding are taken into account. © 1988
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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