1,720,961 research outputs found
Plantation Development Policies and Strategies in Facing the Opportunities and Challenges of the New Normal Plantation Sector
No full textMateri ini disampaikan pada webinar yang diselenggarakan oleh Pascasarjana Universitas Medan Area dengan Tema "The Future Strategies Of Estate Crops In The New Normal
". Adapun pembicara pada webinar ini adalah Dr. Antarjo Dikin, Prof. John McCarthy, Dr. Shri Dewi, Dr. Mulia Panusunan Nasution, Prof. Phuong Ho Ngoc, dan Dr. Mohd Zukime B. Mat Junoh - This material was presented in a webinar organized by the Graduate University of Medan Area with the theme "The Future Strategies Of Estate Crops In The New Normal
". The speakers at this webinar are Dr. Antarjo Dikin, Prof. John McCarthy, Dr. Shri Dewi, Dr. Mulia Panusunan Nasution, Prof. Phuong Ho Ngoc, and Dr. Mohd Zukime B. Mat Junoh
Development of a Biopesticide for the Control of Schyzophyllum Commune Fr., a Pathogen of Oil Palm Seeds
Get PDFAn effective and efficient biopesticide produced from antagonistic bacteria was developed for the control of Schizophyllum commune Fr., an important seedborne pathogen of oil palm causing brown germ and seed rot disease. Fifty two out of 265 bacterial isolates were found to inhibit the growth of S. commune in dual culture assay and 14 out of these 52 isolates produced antimicrobial substances and inhibited the growth of S. commune. Finally, 2 isolates, Burkholderia multivorans RU50 and Microbacterium testaceum RU7 were confirmed to produce a broad spectrum of antimicrobial substances in liquid media containing neopeptone plus lactose (1:1) and peptone plus maltose (1:1) respectively that were able to suppress S. commune and other species of fungi. The mixture of equal amount of supernatant containing antimicrobial substances from both bacterial species resulted in the potential biopesticide. The potential biopesticide destroyed cell organs of the fungus. It contained pyrrolnitrin, phenylpyrrol, phenazine and 5 unknown compounds. It had a minimum inhibitory concentration (MIC) value of 1:65 in the liquid form and 1:310 in freeze dried powder form. It was also resistant to heat at 60oC for 2 hours, stable under irradiation of UV light at 312 nm for 5 hours, stable in sodium chloride solution up to 10%, stable on variable of pH 4-9 and had a shelf life of up to one year at 26±2oC and 5-10oC. Application of this biopesticide with a dilution of 1:4 with distilled water, as seed treatment to oil palm seeds was effective for the control of S. commune using vacuum infiltration at 400 mm Hg Vac. for 2 minutes or seed dipping for 30 minutes for non-germinating oil palm seeds. Oil palm seeds coated with the freeze dried talcum powder inhibited the colonization of S. commune on the seeds. Oil palm seeds treated with this biopesticide increased seed germination up to 77%
Biological Control of Schizophyllum Commune Fr. the Seedborne Pathogen of Oil Palm with Antagonistic Bacteria
Get PDFSchizophyllum commune Fr. is one of the most important seedborne
pathogens of oil palm. This pathogen can be isolated from fermented fruits,
germinated seeds, rotten fruits and infected seeds. The fungus produced
papery and leathery compact white mycelia on both sides of the agar plates
and often produced basidiocarps (diameter less than 2 cm) with gills on
culture plates. The mycelia produced clamp connections with some hyphae
having spinulose projections. The width of the hyphae was 2 to 4 μ. Spores
produced from basidiocarp were hyaline, cylindrical and single-celled. S.
commune grew on PDA medium added 50 g/L of NaCl at 30-35oC optimum
temperature but the mycelia became dormant at 45oC. The fungus grew on
PDA medium at pH 5 to 6 and was resistant to 1% sodium hypochloride.Inoculation of S. commune Fr. on non germinating oil palm seeds by
contact was found to cause a significant decrease of seed germination to
64.3%. Mycelia covered the germ pores of seeds and penetrated the germ
pore to reach the surface of seed kernel. Inoculation of non germinating
seeds produced abnormal seedlings, inhibition of germ tube elongation and
brown discoloration of plumule and radicle. Inoculation of germinating
seeds resulted in stunted growth of seedlings, decreased root growth and
reduction in both fresh and dry weights.
Histological study of the infected seeds indicated that the mycelia
penetrated the rotted fruit to reach the testa through germ pores. Mycelium
was unable to directly penetrate the endocarp. In advanced seed infection,
white mycelia colonized the surface of seed kernel. Mycelia infected the
surface of the testa without formation of ‘appressorium’ to support
absorption to the surface of the kernel nor produced ‘haustorium’ for
absorption of nutrient from the host.
Eight out of 40 bacterial isolates from rotten fruits and infected seeds were
found to inhibit the radial growth of S. commune in the range 42.9–79.8%
and spore germination. The 8 antagonistic bacterial isolates were clustered
into 5 species by Biolog® Identification System and they were Bacillus thermoglucosidasius, Burkholderia cepacia, Pseudomonas aeruginosa,
Serratia marcescens and Serratia sp.
B. cepacia and Serratia sp. grew on NA medium containing 4% and 6% salt
concentration respectively. Both species were able to grow on Nutrient Agar
(NA) medium that were incubated at 40oC. Both species grew on NA
medium containing 0.5% and 2% sodium hypochloride respectively. Both B.
cepacia and Serratia sp. grew on NA medium with pH range 4-8.
Dipped vacuum treatment of antagonistic bacteria at 400 mm Hg vac. for 2
minutes significantly reduced the internal infection of the inoculated non
germinating oil palm seeds. B. cepacia and Serratia sp. significantly
increased percentage of seed germination. Dipped vacuum treatment was
also used to treat inoculated germinating seeds at 150 mm Hg Vac. for 2
minutes. The results showed that B. cepacia reduced seedling infection
Diversity and characterisation of nematodes associated with potato production in Indonesia with focus on potato cyst nematodes
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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
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