1,720,976 research outputs found
Biochar Addition to the Loam Soil of Soybean Fields Can Reduce Trifluralin Usage in Velvetleaf Control
No full textBiochar, made by the pyrolysis of various organic materials such as plants, can amend soil physicochemical properties and improve the efficiency of pre-planted incorporated (PPI) herbicides. The excessive consumption of PPI herbicides results in environmental predicaments; improving the PPI herbicides’ efficacy by changing the soil’s biological properties might solve this problem. Trifluralin, a PPI, is recommended against annual broadleaf weeds such as velvetleaf in soybean fields. In the present study, the treatments included normal soil (NS) (sand 30% + silt 35% + clay 35%) and manipulated soil (MS) (sand 27% + silt 32% + clay 32% + biochar 9%). Two blocks of NS received the recommended dose (RD) (1.7 L/ha) (NS + RD) and a reduced dose (1.2 L/ha) (NS + ReD) of trifluralin. Meanwhile, the block of MS was exposed to the reduced dose (MS + ReD) of trifluralin. Two days after the herbicide treatments, the seeds of Abutilon theophrasti were sown. Then, seven days after sowing, the growth of the weeds was monitored and the weed control percentage was calculated using the arcsine model based on observed data. The results showed that the NS + RD was the most effective treatment in velvetleaf control (100%), followed by MS + ReD (93.5%) with no significant difference. The NS + ReD treatment resulted in 81% weed control showing significant differences with the NS + RD and MS + ReD. Thus, it seems that biochar acts as a neutral buffer and decreases the necessity of PPI herbicide application in soybean fields. Biochar application can potentially reduce soil contamination, weed resistance, environmental pollution, and the adverse effects of PPI herbicides on the soil microbial population
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
Relaxed predation hinders development of anti‐predator behaviors in an aposematic beetle
No full textDispelling 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
Sexual dimorphism of Colorado beetle, Leptinotarsa decemlineata (Coleoptera: Chrysomelidae) in the west and northwest of Iran by geometric morphometric method
No full textThe males and females of Colorado beetles do not reveal clear dimorphism and therefore they have high resemblance so that recognition of the sexes by simple eye is too difficult. In order to study sexual dimorphism in Colorado beetle, three geographical populations were collected from potato fields in Ardabil, Bahar and Hamedan regions by manual method and direct observation in the summer of 2012. Fore and hind wings were separated and 7 and 8 landmarks were orderly selected for the fore and hind wings at the end and angle of veins. Geometric coordinate of landmarks were converted to shape and size variables as comparison factors between the sexes. Wings relative variations were determined separately in male and female and it revealed variations of wing shape in evolutionary process. Multivariate analysis based on the results of regression of shape variables showed fore wing had allometry and hind wing had not allometry. Two way MANOVA analysis was conducted for observation of shape differences (base on average of shape variables) and size differences. The analysis showed that there were significant differences in shape of fore wing between the sexes
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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