1,720,961 research outputs found
Pengaruh samping aplikasi deltametrin terhadap Artropoda predator penghuni permukaan tanah di pertanaman kedelai
No full textSide Effects of Deltamethrin Application to The Ground Surface Dwelling Predatory Arthropods on Soybean Field. Side effects of deltamethrin to the ground surface dwelling predatory arthropods were studied on soybean field in Cianjur during July to October 1998. Insecticide was applied 1-4 times. Predator abundance was observed by setting pitfall traps. The results showed that application of deltamethrin reduced the abundance of ground-surface predatory arthropods, especially lycosid and linyphiid spiders, carabid beetle and formicid. Reductions of predator abundance on the plots treated with deltamethrin were around 35% to 41%. There was no significant difference on the predator abundance among the plots treated with the insecticide at difference frequencies. Observations after application showed that predator abundance on the treated plots recovered one week after application. Deltamethrin application to the soybean with dense crown (38 and 52 days after planting) did not reduce predator abundance, especially within three day range after application. However, negative effects of deltamethrin application at early vegetative growth stage (10 days after planting) on the reduction of predator abundance continued by harvesting. The abundance of detritivorous arthropods was not affected by deltamethrin application.</p
Pengaruh samping aplikasi deltametrin terhadap Artropoda predator penghuni permukaan tanah di pertanaman kedelai
Full text linkSide Effects of Deltamethrin Application to The Ground Surface Dwelling Predatory Arthropods on Soybean Field. Side effects of deltamethrin to the ground surface dwelling predatory arthropods were studied on soybean field in Cianjur during July to October 1998. Insecticide was applied 1-4 times. Predator abundance was observed by setting pitfall traps. The results showed that application of deltamethrin reduced the abundance of ground-surface predatory arthropods, especially lycosid and linyphiid spiders, carabid beetle and formicid. Reductions of predator abundance on the plots treated with deltamethrin were around 35% to 41%. There was no significant difference on the predator abundance among the plots treated with the insecticide at difference frequencies. Observations after application showed that predator abundance on the treated plots recovered one week after application. Deltamethrin application to the soybean with dense crown (38 and 52 days after planting) did not reduce predator abundance, especially within three day range after application. However, negative effects of deltamethrin application at early vegetative growth stage (10 days after planting) on the reduction of predator abundance continued by harvesting. The abundance of detritivorous arthropods was not affected by deltamethrin application.</jats:p
Statistik demografi Menochilus sexmaculatus (Fabricius) (Coleoptera: Coccinellidae) pada Aphis craccivora Koch (Hemiptera: Aphididae)
No full textInformasi mengenai statistik demografi Menochilus sexmaculatus (Fabricius) pada Aphis craccivora Koch penting bagi pengembangan strategi pengendalian hama yang lebih efektif dan ramah lingkungan. Tujuan percobaan ini adalah menentukan statistik demografi (peluang hidup (kesintasan), keperidian (fekunditas), tingkat pertumbuhan, laju reproduksi, lama hidup), biologi, dan morfometrik dari M. sexmaculatus pada mangsa A. craccivora. Sebanyak 15 pasang imago M. sexmaculatus yang didapatkan dari pertanaman kacang panjang di Situgede, Bogor dipelihara di dalam kurungan yang didalamnya terdapat 3 polybag tanaman kacang panjang (terserang A. craccivora sebagai pakan imago). Seratus telur (6 kelompok telur) dikumpulkan dari kurungan pemeliharaan imago dan dipelihara pada wadah plastik (diameter atas 6,7 cm, diameter bawah 4,9 cm, tinggi 6,3 cm) per 1 kelompok telur. Larva yang keluar dari telur dipisahkan setiap individu ke dalam 1 wadah dan pemeliharaan dilakukan hingga imago menghasilkan telur kembali dan mati. Nilai rata-rata dan simpangan baku dari 5 parameter statistik demografi ditentukan dengan metode Jacknife. Peluang hidup dan keperidian disajikan dalam bentuk kurva. Kumbang M. sexmaculatus memiliki ukuran tubuh rata-rata imago jantan 7,32 × 5,94 mm dan betina 8,63 × 6,98 mm. M. sexmaculatus berpotensi sebagai agens pengendali bagi hama A. craccivora. Potensi ini didukung oleh kemampuan reproduksi yang tinggi (R0 35,72 ± 1,10 individu/betina/generasi dan GRR 128,85 ± 3,02 individu/generasi), laju pertambahan populasi yang cepat (r 0,20 ± 0,002 individu/betina/hari), T yaitu 18,16 ± 0,04 hari
PELEPASAN DAN PEMANGSAAN KUMBANG JELAJAH PAEDERUSFUSCIPES (COLEOPTERA:STAPHYLINIDAE) TERHADAP TELUR DAN LARVA HELICOVERPA ARMIGERA (LEPIDOPTERA: NOCTUIDAE)
No full textPaederus fuscipes is an important predators in soybean fields, including toward Helicoverpa armigera. Predation evaluation using a cage are very common, giving significant suppressed the exposed pest population. However, predation evaluation in open space is rarely conducted. This study was to investigate the dispersal capability of P. fuscipes, and to evaluate the effectiveness of the beetle release in the predation on H. Armigera eggs and larvae. Observations were made in a soybean field in Mekarwangi Village, Cianjur, during soybean planting season in 2005 and 2006. In the dispersal study, all beetles were collected from the field and tagged on the elitra. As many as 1187 tagged beetle were released. The dispersal was observed in the area within a radius of 40 m from the release point. In the predation study, eggs and larvae of H.armigera from laboratory rearing were used as the prey. Soybean plots with exposed prey were treated by releasing the beetle with different densities, i. e., 100-400 beetles, and a control. The released beetles were from laboratory rearing and beetles were collected from the field. The study indicated that the tagged beetles that were released to the soybean field actively move but their dispersal were relatively slow. Until 5 days after release, most beetles were remain in the area surrounding release point, within a radius of 5 m. Release of predators to the soybean field, suppressed H. armigera egg and larva populations for both vegetative and generative stages, but were not significantly different between treatment and control plots, except for the egg population on vegetative stage. It indicates that population of the natural predator in soybean field were very complex and potential to be used for controling pest populations. Thus, it is important to manage soybean field that can support the role of predators in the field
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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