1,720,958 research outputs found
COMPARATIVE-STUDY ON RHEOLOGICAL PROPERTIES OF MYCELIAL BROTH IN FILAMENTOUS AND PELLETED FORMS
No full textPARTIAL-PURIFICATION AND CHARACTERIZATION OF BETA-HYDROXYBUTYRIC ACID DEHYDROGENASE OF A METHYLOTROPHIC BACTERIUM, PSEUDOMONAS-135
No full textAn intracellular enzyme, D(-)-beta-hydroxybutyric acid dehydrogenase involved in an intracellular poly-D(-)-beta-hydroxybutyric acid degradation was isolated from a facultative methylotrophic bacterium, Pseudomonas 135, grown on methanol as a sole carbon and energy source. This enzyme was partially purified to 11.6-fold by ammonium sulphate fractionation and a dye-affinity chromatography. The enzyme catalysed simultaneously the oxidation Of D(-)-beta-hydroxybutyric acid (Dbeta-HB) and the reduction of acetoacetate. The optimum pH was 8.5 for the oxidation reaction and 5.5-6.0 for the reduction reaction, and the enzyme was stable for 2 weeks at -20-degrees-C. The K(m) values for oxidation and reduction reactions were determined as 1.84 mm for Dbeta-HB, 0.244 mm for NAD+, 0. 319 mm for acetoacetate and 0.032 mm for NADH, respectively. It was also found that D-lactate and NADH significantly inhibited the oxidation reaction by competitive inhibition, and acetoacetate by non-competitive inhibition, respectively. The inhibition constants were determined as 1.49 mM for D-lactate, 0.196 mM for NADH and 1.82 mM for acetoacetate, respectively. According to an experiment with resting cells, it seemed that the enzyme was constitutive
EFFECT OF NUTRIENT DEFICIENCY ON ACCUMULATION AND RELATIVE MOLECULAR-WEIGHT OF POLY-BETA-HYDROXYBUTYRIC ACID BY METHYLOTROPHIC BACTERIUM, PSEUDOMONAS-135
No full textPseudomonas 135, a facultative methylotroph, was cultivated on methanol as a sole carbon and energy source for the accumulation of poly-beta-hydroxybutyric acid (PHB). The cells grew fairly well on minimal synthetic medium containing 0.5% (v/v) of methanol at pH 7.0 and 30-degrees-C. The maximum specific growth rate was determined to be 0.26-0.28 h-1 with a growth yield of 0.38 in the optimized growth medium. For stimulation of PHB accumulation in the cells, deficiency of nutrients such as NH4+, Mg2+ and PO43- was crucial even though cell growth was significantly suppressed. The PHB content of a 40-h culture was determined to be 37% of the total cell mass in NH4+-limited medium, 42.5% on Mg2+-deficient medium, and 34.5% on PO43- -deficient medium. The maximum content of PHB in the cells could reach 55% in NH4+-limited fed-batch culture. The average relative molecular eight determined by gel permeation chromatography was 3.7 x 1O(5) in NH4+-limited culture, 2.5 x 10(5) in Mg2+-deficient mediUm, and 3.1 x 10(5) in PO43--deficient medium. Polydispersity determined in each culture was relatively high (about 10-(11)). The solid PHB had a melting temperatue of 173-degrees-C
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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
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