1,720,981 research outputs found
Evaluation of Bio-Pesticides on Integrated Management of Tomato Leafminer, Tuta absoluta (Meyrick) (Gelechiidae: Lepidoptera) on Tomato Crops in Western Shewa of Central Ethiopia
No full textDetermination of Oviposition Preference and Infestation Level of Tuta absoluta on Major Solanaceae Crops Under Glasshouse Conditions in Ethiopia
No full textCallosobruchus chinensis (L.) (Coleoptera: Bruchidae) Management on Stored Chickpea Using Botanicals in Amhara Region, Ethiopia
No full textMolecular evidence of Cotesia flavipes (Cameron) (Hymenoptera: Braconidae) establishment in Ethiopia
Full text linkCotesia flavipes (Cameron) is an Asian origin endo-larval parasitoid of cereal stemborers in the genera of Chilo, Sesamia and others. It was introduced into Kenya mainly for the control of Chilo partellus (Swinhoe) (Lepidoptera: Crambidae) from India, and North and South Pakistan. After introduction, the parasitoid was released in C. partellus prone areas of Eastern and Southern African countries. The establishment rate varies from country to country and region to region within the country. In Ethiopia, the parasitoid was not released, but for the first time recorded in 1999 as identified morphologically. Morphological traits in many instances lead to wrong taxonomic conclusion. Hence, molecular investigation was carried out to confirm whether the parasitoid recorded in Ethiopia is C. flavipes or not by running Polymerase Chain Reaction (PCR) of DNA fragments of C. flavipes collected from Ethiopia and other African and Asian countries. The PCR analysis using 16S gene (primer) indicated that C. flavipes collected from Ethiopia had similar bands with C. flavipes from other countries confirming the correctness of the morphological traits used to identify the parasitoid. Hence, the parasitoid recorded in 1999 in Ethiopia was Cotesia flavipes which was established without release. To partition the differences that could exist among the different populations of C. flavipes and possibly trace the origin of Ethiopian population, advanced molecular techniques such as restricted fragment polymorphism (RFLP) and sequencing will be recommended although the exercises are expensive
Evaluation of Calpurnia aurea leaf extracts as natural insect repellents for stored product insect pests in Ethiopia
No full textThe repellency of solvent extracts of Calpurnia aurea leaves was evaluated on the maize weevils and the red flour beetles. Nine-cm Whatman number 1 filter paper that is partitioned into treatment, neutral and non-treatment portions was used for the experiment. Each solvent extract treatment was applied at 2.5, 5 and 10% rates. Insects were released in the neutral portion, while the untreated part served as a control. A choice bioassay experimental method that is laid down in a completely randomized design within three replications was used. 5 and 10% rates of the polar solvent extracts of Calpurnia aurea leaves induced significantly (p < 0.05) higher percentage weevils and beetles repellency (≥50.00%) at 2 days after treatment than non-polar and partial polar solvent extract treatments and the untreated check. 10% dosage of Calpurnia aurea leaves’ polar solvent extract treatments caused 100% weevils and beetles repellency three days after treatment. Consequently, the polar solvent extracts of the tested plant were potent and could be used at 5 and 10% rates for the maize weevils and the red flour beetles’ management under farmers’ maize storage conditions. Nevertheless, their impact on cost-effectiveness, natural enemies and human beings needs additional study
Experimental Analysis of Ecomomic Action Level of Tomato Leafminer, Tuta absoluta Meyrick (Lepidoptera: Gelechiidae) on Tomato Plant under Open Field
No full text
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
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