1,720,976 research outputs found
Ultrasound-assisted extraction of phytohormones from vermicompost.
No full textVermicompost (VC) is the by-product of the joint actions between earthworms and microorganisms living within them and is traditionally used as organic fertilizer. It is postulated that phytohormones are the “magic compounds” in VC that made them such good fertilizers. Chemical characterization of phytohormones in VC is seldom reported. Our aim is to develop an efficient extraction method for the simultaneous extraction of different classes of phytohormones in VC using ultrasound-assisted extraction (UAE). The efficiency of this technique was compared with the classical mix-stirring (MSt) method. Nine phytohormones from three different classes: trans-zeatin (Z), kinetin (K), indole-3-acetic acid (IAA), N6-[2-Isopentyl]adenine (iP), N6-Benzyladenine (BA), N6-Isopentenyladenosine (iPR), (+)-Abscisic Acid (ABA), 4-[3-Indolyl]butyric Acid (IBA) and 1-Naphthaleneacetic Acid (NAA) were screened in this project. Systematic optimization was conducted based on the various parameters. Compared to MSt, UAE proved to be more time efficient and was able to achieve higher recovery with lesser solvent usage. The optimized conditions for UAE were using either MeOH- or EtOH-water-acetic acid, 80:20:1, v/v/v, with no significant difference between them, 40min extraction time and solvent to sample ratio of 16:1. These extraction parameters were applied on a qualitative study of 500g real VC sample and iP was detected under LC-MS.Bachelor of Science in Biomedical Science
Classification Of The Malaysian Banana Varieties Using Retrotransposon Markers
Full text linkRetrotransposons are the most common class of eukaryotic transposable elements
that make up over 50% of nuclear DNA found in many plants with large and
complex genomes. The long terminal repeat (LTR) retrotransposons have a high
degree of autonomy and encode at least five distinct protein components, which are
required for their movement in the genome. We have exploited the repetitive,
dispersed nature of many LTR-containing retrotransposon families for the
visualization of genomic polymorphism (genome constitution) and the visualization
of varieties polymorphism (varieties classification). The IRAP-PCR (Inter-
Retrotransposon Amplified Polymorphism-Polymerase Chain Reaction) markers are
generated by the proximity of two LTRs or reverse transcriptase CRT) genes using
outward-facing primers annealing to LTR target sequence. This method could
distinguish between banana genome constitution (A and B genome) and varieties.
This method can track new insertion of retrotransposon in banana tissue culture
materials. The evolution of Malaysian bananas can also be tracked using this
phylogenetic analysis. Since the method is PCR-based, it may allow the detection
and isolation of the active, newly inserted retrotransposon copies easily, by analyzing the subsequent generations within an otherwise genetically homogeneous material.
This method is applicable to other plants with dispersed families of LTR retrotransposons
where either the LTR or nearby internal sequences are known
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
LTR retrotransposons and tandem repeats in Musa genomes and their contribution to Musa diversity and genome evolution
No full textEThOS - Electronic Theses Online ServiceGBUnited Kingdo
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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