1,720,955 research outputs found
Phytotoxic effects of aqueous extracts of sunflower on seed germination and growth of Sinapis alba L., Triticum aestivum L. and Lolium multiflorum Lam.
No full textIn petridish and pot culture studies the phytotoxic effects of aqueous extracts
of leaves and stems of four sunflower cultivars (‘Oleko’, ‘Tellia’, ‘Sanbro’ and
‘Nutrasol’) were determined on the seed germination and plant growth of ‘Triticum
aestivum L., Sinapis alba L. and Lolium multiflorum Lam. In petridish bioassays, the
EC50 and EC90 levels showed that stems extracts were more inhibitory to seed
germination, radicle and hypocotyl length of S. alba than leaves extracts. There were
no significant differences among the sunflower cultivars. Aqueous extracts from
leaves and stems of cultivars ‘Tellia’ and ‘Sanbro’ inhibited the seed germination of L.
multiflorum but did not affect the seed germination of T. aestivum. In pot culture the
EC50 and EC90 levels showed that the stems extracts had highest allelopathic activity
than leaves extracts. Both stem and leaves extracts applied at the highest concentration
(12.5% w/v) completely suppressed the growth of S. alba and L. multiflorum plant
but had little effects on T. aestivum plant growth, especially using ‘Tellia’ extracts.
The bioavailability of aqueous extracts in sandy loam soil did not show significant
differences among the cultivars and type of extract with average values between
leaves and stems aqueous extracts of 25% and 37% for ‘Tellia’ and ‘Sanbro’,
respectively
Allelopathic potential of mugwort (Artemisia vulgaris L.) to control the Italian ryegrass (Lolium multiflorum Lam.) in winter wheat
No full textThe allelopathic potential of mugwort was evaluated in laboratory, glasshouse and field assays to control the Italian ryegrass (L. multiflorum) in winter wheat (Triticum aestivum L.). Extracts of mugwort inhibited the seed germination and radicle and hypocotyl lengths of Sinapis alba L. and followed the order: leaf extracts > stem extracts > rhizome extracts. The aqueous extract of aerial biomass (leaves + stems) of mugwort at the highest concentration (25% w/v) may be considered as a potent inhibitor of seed germination and plant growth of L. multiflorum. The application of aqueous extract on the soil surface as pre-emergence herbicide was found most effective for maximum efficacy against weeds. However, the bioactivity of mugwort extract in soil decreased with the increase in extract concentration. In field experiments, the mugwort extract (20% w/v) alone gave efficacy of 50% against L. multiflorum; furthermore, the dose of chlorsulfuron was reduced up to 80%, when aqueous extract were added in the spray solution. The mugwort extract alone or in mixture with chlorsulfuron significantly increased the wheat yield in the field. The extract of mugwort used as foliar bioherbicide did not control L. multiflorum
Allelopathic effects of Artemisia vulgaris L. (mugwort) on seed germination and growth of Sinapis alba L., Triticum aestivum L. and Lolium multiflorum Lam.
No full textThe aims of this study were to evaluate allelopathic potential of different plant tissues of A. vulgaris and their activity against wheat (T. aestivum) and L. multiflorum, respectively one of the main crop in Italy and its most problematic weed due to resistance to ACCase inhibiting herbicides
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
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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