1,720,966 research outputs found
Olive Wastes as a High-Potential by-Product: Variability of Their Phenolic Profiles, Antioxidant and Phytotoxic Properties
No full textThe global world olive oil industry produces large amounts of wastes and wastewaters. However, the disposal of these polluting by-products is a significant environmental problem owing to their high polyphenolic compounds. In order to learn possible ways of exploiting this waste, we investigated the phytochemical profiles, the phytotoxicity and the antioxidant activities of olive wastes (leaves, mill wastewater (OMWW) and mill solid waste (OMSW)). Leaf extracts exhibited the highest phytotoxic and antioxidant effects, which are mainly due to its phenolic content. The chromatographic profiles depicted eleven phenolic compounds belonging to secoiridoids, phenyl alcohols, phenolic acids, phenylethanoid glycoside, and flavonoids. Hydroxytyrosol and oleuropein were the main components in leaf methanol and OMWW extracts, respectively, exhibiting an amount of 13.05 and 4.39 mg/g DW. These results will help to demonstrate the possibility of utilizing olive wastes, particularly the leaf, as an inexpensive natural product, in food and agricultural applications. Graphic Abstract: [Figure not available: see fulltext.]
Allelopathic potential and phenolic allelochemicals discrepancies in Ficus carica L. cultivars
No full textThe phytotoxic effect of some tree species could act as an ecological filter through chemical production that influences plant growth of other species. Despite this widespread interest, few studies have investigated the allelopathic effect of some Moraceae species, while this mechanism has not been studied in Ficus carica. To address this research, we attempted to identify the allelopathic mechanisms of thirteen local preserved fig cultivars on the germination and seedling growth of common weeds and standard target species. The results stated that all fig extracts displayed significant phytotoxic impact, and the degree of inhibition was appeared to be dependent on the cultivars and target species. In general, leaf extracts were more toxic and significantly influenced the seedling elongations, as compared to twig extracts. It was clearly marked that the germination and growth of weed species were totally affected by leaf aqueous and methanol extracts of cultivars Kahli and Bouhouli, respectively, at 40 g/L and 6 g/L. The phytochemical analysis through high performance liquid chromatography detected similar profile among cultivars but with a significant disparity in phenolic composition. Among the identified compounds, rutin is the major flavonoid compound recorded in cv. Zidi and was highly accumulated in leaf rather than in twig. It was obvious that the different fig cultivars or even their tissues can be characterized and clustered in three groups based on their allelopathic potential and phenolic compounds
Physiological mechanisms and adaptation strategies of Lactuca sativa L. in response to Olea europaea L. and Ficus carica L. allelochemicals
Full text linkAgro-industrial wastes of Ficus carica L. and Olea europaea L. represent great sources of bioactive phenolic compounds that would be actively involved in sustainable development. Most of these wastes possess a valuable source of phytotoxic compounds that would be used as potential bioherbicides, but their function and mechanisms of action in cultivated crops remain far to be understood. In this study, we investigate the biochemical and physiological mechanisms of action of fig and olive allelochemicals extracts in lettuce as a model plant for weed species studies. Results revealed that these allelochemicals triggered an oxidative stress through cell membrane damage in lettuce roots and leaves, which was mitigated by various adaptive responses. Therefore, an intricate defense system was implicated by the increase of enzymatic and non-enzymatic antioxidants in lettuce tissues. This adaptive physiological response was highly correlated with the regulation of the phenylpropanoid pathway through the distinguished activation of phenylalanine ammonia-lyase by 98% and phenolic accumulation by 85% under olive and fig leaves aqueous extracts. The outcomes of this study will help understanding the response of cultivated crop to fig and olive phenolic compounds that can be selective in their actions, or the plants can be selective in their responses
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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