1,720,981 research outputs found
Variability in Crithmum maritimum L. Essential Oils’ Chemical Composition: PCA Analysis, Food Safety, and Sustainability
Full text linkIn this study, four accessions of Crithmum maritimum L., not previously studied, collected in Isola delle Femmine (Italy) (S43), Croatia (S44), Montenegro (S45), and Israel (S46) were investigated. The volatile profile of essential oils was evaluated using GC–MS and 38 compounds were identified. All the analyzed samples show a composition characterized essentially by monoterpene hydrocarbons (94.0–97.6%), with limonene, γ-terpinene, β-phellandrene, α-pinene, and p-cymene as the principal compounds. In addition, a comprehensive review of the composition of C. maritimum essential oils that have been studied thus far was conducted. To evaluate the similarity between samples, principal component analysis (PCA) and Hierarchical Cluster Analysis (HCA) were utilized. To evaluate the possibility of addressing food value to natural species that can strengthen sustainable food policies, it appears necessary to consider the previous safety of the dietary intake of C. maritimum. A matrix plot analysis of the content of dillapiole, a toxic constituent, in the samples was performed. The results of the statistical analysis show the presence of six clusters indicating some differences between C. maritimum accessions from different locations. Regarding dillapiole content, the four accessions discussed in this paper showed dillapiole values of less than 2%, suggesting the healthiness of sea fennel from these locations, while the highest values were found in samples from France, Portugal, and Tunisia
The chemical composition of the aerial parts essential oil of Ammi crinitum Guss. (Apiaceae) endemic of Sicily (Italy)
No full textAmmi L. is a small genus of economically important plants belonging to Apiaceae family that includes only six taxa. In the present study the chemical composition of the essential oil from aerial parts of Ammi crinitum Guss., a very rare plant, endemic of Sicily, was analyzed by GC–MS. No previously paper has been published on this species. The results showed the presence of large quantity of monoterpene hydrocarbons with sabinene (63.9%), as the most abundant component. Other metabolites present in good quantity were γ-terpinene (8.0%), and 4-terpineol (3.7%). Based on the composition of the essential oil of all the other Ammi taxa, several considerations have been carried out
The chemical composition of the aerial parts essential oil of Lonas annua (L.) Vines & Druce (Asteraceae)
No full textLonas annua (L.) Vines & Druce (Asteraceae), commonly known as African Daisy or Yellow Ageratum is a rare therophyte native to northwestern Africa (Algeria, Morocco, and Tunisia) and Italy (Sicily and Sardinia). In the present study, the chemical composition of the essential oil from aerial parts of Lonas annua was analyzed by GC-MS. No one report has been previously published on the essential oil of this species. The results showed the presence of large quantity of two unusual metabolites 2,3-dihydrofarnesol (41.64%), and acenaphthene (36.18%). Chemotaxonomic considerations were carried out in order to confirm the phylogenetic reconstructions of Anthemideae
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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