1,721,063 research outputs found
Furanone Derivatives from Terrestrial Streptomyces spp.
No full textChemical investigation of the terrestrial Streptomyces sp. isolates GT2005/020 and ANK148 led to the isolation of two microbial furanone derivatives, 5-hydroxy-4-methylnaphtho[1,2-b]furan-3-one (1) and 4-hydroxy-5-methyl-furan-3-one (2), respectively, which have some similarity to quorum sensing molecules of the Al-2 type. In addition, the known compounds chalcomycin, ferulic acid, indole-3-acetic acid, uracil, thymine, 2'-deoxy-thymidin, monensin B (3), phencomycin, and l-acetyl-P-carboline were isolated. The structures of 1 and 2 were deduced from extensive studies of NMR (1D and 2D) and mass spectra. Additionally, the complete NMR shift assignments for monensin 13 (3) using H-H COSY, HMQC and HMBC experiments are reported here for the first time. We are describing the taxonomy and fermentation of the producing strains, the structure elucidation of the new metabolites and their bioactivity. [GRAPHICS] .Higher Education Commission of Pakistan (HEC
Scattering of Laguerre–Gaussian beam by a topological insulator cylinder coated with metamaterials
No full textA theoretical investigation is presented to study the orbital angular momentum (OAM) beam scattering from a topological insulator (TI) cylinder coated with metamaterials. To calculate the electromagnetic (EM) response of the scattered field, the field equations are modified using Laguerre–Gaussian (LG) potential and plane wave scattering. The response of the metamaterial coated geometry has been reported for Double positive (DPS), Double negative (DNG), Epsilon negative (ENG), and Mu negative (MNG) coating layers, respectively. The normalized bistatic echo widths for the TI cylinder also change by changing the topological charge (l), the radius of the metamaterial coated layer (b), source frequency (f), and beam waist radius (w0). Our result for LG00 beam exactly tones with plane wave scattering as a reference. Numerical results in the form of bistatic echo widths have been calculated. Besides, the prementioned parameters, the influence of OAM mode index on the bistatic echo width is also analyzed. It can be seen that OAM mode number plays major role in controlling the scattering amplitude and intensity
Analisis Faktor-Faktor Yang Mempengaruhi Audit Delay Pada Perusahaan LQ 45 Yang Terdaftar di Bursa Efek Indonesia Tahun 2013-2017
No full textPenelitian ini bertujuan untuk mengetahui pengaruh Ukuran KAP, Ukuran
Perusahaan, Profitabilitas, dan baik secara bersama-sama maupun secara sendirisendiri terhadap Audit Delay pada perusahaan LQ 45 yang terdaftar di Bursa Efek
Indonesia tahun 2013-2017.
Populasi dalam peneltian ini yaitu perusahaan LQ 45 di Indonesia yang
terdaftar di Bursa Efek Indonesia sejak tahun 2013–2017 yaitu sebanyak
65perusahaan pada tahun 2013 sampai 2017 dengan sampel diambil secara
purposive sampling sebanyak 20 perusahaan. Data yang dikumpulkan merupakan
data sekunder dengan metode dokumentasi. Sebelum dilakukan analisis data
terlebih dahulu diadakan pengujian prasyarat analisis yang meliputi uji normalitas,
uji linieritas, uji multikolinieritas, uji heteroskedastisitas dan uji autokorelasi.
Metode analisis data yang digunakan adalah analisis regresi linear sederhana dan
regresi linear berganda.
Hasil penelitian menunjukkan pada perusahaan LQ 45 yang terdaftar di
Bursa Efek Indonesia tahun 2013-2017 bahwa: 1) Ukuran KAP tidak mempunyai
pengaruh terhadap Audit Delay, 2) Ukuran Perusahaan tidak mempunyai pengaruh
terhadap Audit Delay, 3) Profitabilitas mempunyai pengaruh terhadap Audit
Delay, 4) Opini Auditor tidak mempunyai pengaruh terhadap Audit Delay, 5)
Ukuran KAP, Ukuran Perusahaan, Profitabilitas, dan Opini Auditor mempunyai
pengaruh secara bersama-sama terhadap Audit Delay, dan berdasarkan koefisien
determinasi sebesar 0,265, berarti variabel bebas tersebut secara bersama-sama
mempengaruhi 26,5% Audit Delay. Sebesar 73,5% ditentukan oleh variabel lain
yang tidak dibahas dalam penelitian ini
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
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