1,720,967 research outputs found
KAJIAN PEMANFAATAN LIMBAH ORGANIK CAIR UNTUK PEMBIAKAN MASAL AGENS ANTAGONIS PSEUDOMONAS FLOURESCENS SERTA UJI POTENSINYA SEBAGAI BIO-PESTISIDA
No full textPseudomonas fluorescens has been well known as biological control agent for plant diseases control. The problem to apply the agents widely in the field or in the level of farmer is limited technology of mass production with low cost, due to the simple technology of propagation has not been yet available. The objective of this research is to study the potency of liquid organic wastes as media for mass production of P. fluorescens and to formulate them as bio-pesticide. The results showed that modification of coconut water to pH of 7.0 could be used as media for growing P. flourescens. The P. fluorescens also could grow well in livestock liquid waste by adding 10% meat extract. On the other hand, the liquid tofu waste and liquid compost waste became good media for growing of P. fluorescens by addition of 10% meat extract and 1.25% sugar. Tetes tebu will be very good media for P. fluorescens at 5% final concentration and by adding of 10% meat extract and 2.5% of sugar. The P. fluorescens showed high antagonistic effect to Ralstonia solanacearum and Sclerotium rolfsii in all of modified liquid organic wastes media. Survival and antagonisctic activity of P. fluorescens in modified organic liquid wastes stored at 5oC or room temperature were 12 weeks. In vivo antagonistic and plant growth promoting activity showed that P. fluorescens grown in liquid organic waste suppressed the incidence of stem rot diseases caused by Sclerotium rolfsii and increased the vigor of plant growth on watermelon. Formulation of the P. fluorescens grown in modified coconut water gave the best performance of P. fluorescens in supppressing of plant diseases and inducing plant growth. The product of BeMOR(e) (beneficial microorganism) from the result of this research will be proposed to be patente
Penapisan Aktinomiset Rizosfer Tanaman Liliaceae sebagai Agens Pengendali Hayati Fusarium oxysporum f. sp. cepae
Full text linkPenyakit moler yang disebabkan oleh Fusarium oxysporum f. sp. cepae merupakan salah satu penyakit penting pada tanaman bawang merah. Aktinomiset memiliki potensi sebagai agens pengendali hayati F. oxysporum f. sp. cepae karena kemampuannya dalam memproduksi senyawa bioaktif. Penelitian ini bertujuan mengevaluasi dan menyeleksi isolat-isolat aktinomiset yang dapat menekan pertumbuhan F. oxysporum f. sp. cepae dan memacu pertumbuhan tanaman bawang merah. Penelitian dibagi menjadi empat tahap, yaitu: isolasi, seleksi, karakterisasi, dan identifikasi isolat aktinomiset yang potensial. Sebanyak 43 isolat berhasil diisolasi dari tanaman Liliaceae dan sebanyak 14 isolat berhasil diseleksi berdasarkan hasil uji keamanan hayati. Hasil uji antagonisme menunjukkan bahwa 14 isolat menghasilkan penghambatan terhadap F. oxysporum f. sp. cepae sebesar 3.67%–53.67%. Di antara 14 isolat tersebut, sebanyak 13 isolat mampu memproduksi enzim kitinase dengan indeks kitinolitik sebesar 0.31–1.38. Lima isolat terpilih yaitu: ABF42, ABF59, ACF45, AEF35, dan AEF45, mampu melarutkan fosfat dan memproduksi IAA dengan konsentrasi 24.82–82.88 ppm, namun hanya tiga isolat yang mampu memfiksasi nitrogen. Berdasarkan sikuen gen 16S rRNA, lima isolat tersebut berturut-turut teridentifikasi sebagai: Streptomyces rameus, S. lydicus, S. panaciradicis, S. seoulensis, dan S. fuscichromogenes.Screening of Liliaceae Rhizosphere Actinomycetes as Biological Control Agents of Fusarium oxysporum f. sp. cepae
Fusarium basal rot caused by F. oxysporum f. sp. cepae is one of the major diseases of shallot in Indonesia. The use of biocontrol agents is one alternative method for controlling this disease. Actinomycetes isolates have the potential as biological control agents for F. oxysporum f. sp. cepae because of its ability to produce bioactive compounds. This study aims to evaluate and select actinomycete isolates with the ability to inhibit the growth of F. oxysporum f. sp. cepae and potentially promote the growth of shallot crops. The study was divided into four stages: i.e. isolation, selection, characterization, and identification of the potential isolates. Forty-three isolates of actinomycetes were successfully isolated from Liliaceae plants, and 14 isolates were selected based on the results of the biosafety test. Antagonism test showed that 14 isolates produced inhibition of F. oxysporum f. sp. cepae by 3.67%–53.67%. Among them, 13 isolates produced chitinase enzyme with a chitinolytic index of 0.31–1.38. Five selected isolates, i.e., ABF42, ABF59, ACF45, AEF35, and AEF45, were able to solubilize phosphate and produced IAA at the concentration range of 24.82–82.88 ppm, but only three isolates were able to grow on media without nitrogen. Based on the sequences of 16S rRNA, the five isolates were identified as Streptomyces rameus, S. lydicus, S. panaciradicis, S. seoulensis, dan S. fuscichromogenes
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
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