1,722,178 research outputs found
A Secondary Metabolism Inducer of Saccharopolyspora erythraea ATCC 11635
Full text linkAbstract
A research has been carried out to investigate the time production and the chemical structure of a secondary metabolism inducer produced by Saccharopolyspora erythraea ATCC 11635. The inducer was found out to be produced around time which indicated a kind of "peak" of DO. The structural elucidation analysis showed that the inducer was a tetrahydrofuran derivate. In addition was a guanosine derivative, which was assumed to be ppGpp that is commonly present in a stresses condition.
Keywords: secondary metabolism inducer, Saccharopolyspora erythraea ATCC 1163
Considerations on the electromagnetic flow in Airy beams based on the Gouy phase
No full textWe reexamine the Gouy phase in ballistic Airy beams (AiBs). A physical interpretation of our analysis is derived in terms of the local phase velocity and the Poynting vector streamlines. Recent experiments employing AiBs are consistent with our results. We provide an approach which potentially applies to any finite-energy paraxial wave field that lacks a beam axis.This research was funded by the Spanish Ministry of Economy and Competitiveness under the project TEC2009-11635
A Secondary Metabolism Inducer of Saccharopolyspora erythraea ATCC 11635
No full textAbstract
A research has been carried out to investigate the time production and the chemical structure of a secondary metabolism inducer produced by Saccharopolyspora erythraea ATCC 11635. The inducer was found out to be produced around time which indicated a kind of "peak" of DO. The structural elucidation analysis showed that the inducer was a tetrahydrofuran derivate. In addition was a guanosine derivative, which was assumed to be ppGpp that is commonly present in a stresses condition.
Keywords: secondary metabolism inducer, Saccharopolyspora erythraea ATCC 1163
Diffraction-managed superlensing using metallodielectric heterostructures
No full textWe show that subwavelength diffracted wave fields may be managed inside multilayered plasmonic devices to achieve ultra-resolving lensing. For that purpose we first transform both homogeneous waves and a broad band of evanescent waves into propagating Bloch modes by means of a metal/dielectric (MD) superlattice. Beam spreading is subsequently compensated by means of negative refraction in a plasmon-induced anisotropic effective-medium that is cemented behind. A precise design of the superlens doublet may lead to nearly aberration-free images with subwavelength resolution in spite of using optical paths longer than a wavelength.This research was funded by the Spanish Ministry of Economy and Competitiveness under the project TEC2009-11635
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
Produksi-Anhidroeritromisin-A Dari Biakan Saccharopolyspora Erythraea ATCC 11635
No full textErythromycin has been used widely to prevent infection diseases which caused by Staphylococcus. However erythromycin is unstable and decomposed in an acid condition. This unstability erythromycin is conducted by due to a nucleophylic attack of the C6-hydroxyl group of erythromycin to its Cg-carbonyl group. This Decomposition can be avoided by modification the erythromycin structuresuch as omitting the C6-hydroxyl group. Biomodification for omitting the C6-hydroxyl group can be conducted by inhibition the activity of enoyl reductase in fourth step of the biosynthesis 6deoxyerythronolid-B. The inhibition process could carried out by an addition of an antimetabolite isonicotonic hidrazide (INH) into the fermentation of erythromycin production. By the enoyl reductase inhibition, the microbe will produce A6.7-Anhydroerythromycin-A which is more stable in an acid condition than erythromycin-A.
This research is to produce derivative A6.7 -Anhydroerythromycin-A by addition of INH into a culture of Saccharopolyspora erythraea ATCC 11635 in medium basal and Hutchinson. Selection of medium for fermentation of Sac. erythraea ATCC 11635 for A6.7-Anhydroerythromycin-A production was done out of two media: basal medium with palm oil and Hutchinson medium. The two media were treated with an additional 0,2% INH as an antimetabolite. Hutchinson medium yielded the highest product of A6.7-Anhydroerythromycin-A.
The FT-IR spectrometric analyzes of metabolite showed a stretching vibration of C=C conjugated group at wave number 1602,7 cm-l. This C=C
conju~ated vibration indicated the existence of double bond between C6 and
C7 (A .7), this confirmed that isolate-C contained A6.7-Anhydroerythromycin-A (the possibility of A6.7 was possitive).
Key words: enoyl reductase, L6,7-anhydroerythromycin-A, isoniazid (INH
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
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