1,721,016 research outputs found
Antioxidant compounds in some herbaceous aromatic plants
No full textFats and oils, contained in many foods and cosmetics, may easily deteriorate due to oxidative processes, causing both the development of off-flavours and the formation of free radicals, that may lead to various undesired chemical reactions. In order to prevent this process, some special synthetic substances, such as BHT (butylated hydroxytoluene) and BHA (butylated hydroxyanesole), sodium nitrate and nitrite, sulphites, are added to the products to be preserved, and often to their packaging materials. Lately, synthetic antioxidants have provided a point for criticism, in relation to the possible effects of their use on public health. Therefore, and in the widespread belief that natural products are anyway healthier and safer than synthetic ones, the importance of finding out vegetable compounds able to take effectively the role of conventional antioxidants, and their investigation and economical verification, is greatly increasing. Many medicinal and aromatic plants, especially those belonging to the Labiatae family, are already well known for their preservative properties, both in food and in cosmetic preparations. In many cases, they are species widely spread in spontaneous Mediterranean flora, and their exploitation is one of the few economical possibilities for some marginal lands. This work reviews the major botanical, agronomic and chemical aspects of some aromatic plants, considered to exert antioxidant activities
Vegetable extracts as natural sources of dyes
No full textAmong cosmetic and food additives, dyes are receiving, in the past two decades, the largest number of adverse criticism. As a matter of fact, more than a real technological tool (as for example antimicrobics and emulsifiers) they simply represent an answer of industry to market needs. The choice of natural colorants instead of synthetic ones is certainly due to healthy concerns, though real safety and healthiness of natural substances is not scientifically stated yet. Toxicological investigations about food colours, for example, are already performed all over the world, and every year they result in revisions, and often reductions, of their authorised maximum content. This kind of impulses, together with the modification of the requests from consumers, has caused a general lowering of industrial interest toward synthetic dyes. Therefore, the finding out and exploitation of naturally occurring dyes find strong motivations, that range from the field of food additivation to many other sectors, from cosmetics to clothes. The interest in all plants able to give pigments to be used by industry, is therefore increasing. Some of these plants are already known (Isatis, Rubia, Safflower), and before the worldwide spreading of synthetic dyes they were largely used with this purpose; the literature about this subject, however, also quotes many other species as potentially interesting, both coming from spontaneous Mediterranean flora and native of other areas. This work summarizes uses and prospects of several herbaceous species that could be useful natural dyes resources, which are already used by industry or that could be used in future
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
On the coexistence of LoRaWAN and legacy short range devices in unlicensed bands in Europe
No full textBio-agronomical evaluation of californian poppy (Eschscholtzia californica Cham.) in a semi-arid mediterranean environment
No full textCalifornian poppy (Eschscholtzia californica Cham.) is an annual or perennial herb belonging to the Papaveraceae family. The aerial parts of the plant are claimed to be endowed with gentle and non addictive hypnotic and tranquillising effects, and for this reason they are traditionally used as a sedative hypnotic or analgesic both for adults and children. In order to evaluate the suitability of the species to field cultivation in the Mediterranean semi-arid areas, a two year long experiment was performed in Sicily in 1999 and 2000. The seed of the plant was sown in both years on the first days of December in rows 50 cm apart. During the cultivation the most important morphological and production characteristics were evaluated. It was proven that effective cultivation of the species is possible under the conditions of the experimental area. After the first year a considerable number of plants self-seeded and vigorous growth of these plants was observed on the same plots. Data proved significant effect of the year on the behaviour of the plants, especially on plant height and number of branches. Differences between sown and self-seeded plants were registered evaluating their height, fruit and seeds mass
Cultivation trials of coriander (Coriandrum sativum L.) in a semi-arid mediterranean environment
No full textCoriander (Coriandrum sativum L. - family Apiaceae) fruits, commonly called "seeds," are used all over the world for flavouring many foods items. Unfortunately, most information about cropping techniques of coriander come from markedly different environments from the Mediterranean ones; it is worth, therefore, examining some of the most important aspects of this topic. In order to evaluate the possibility to grow coriander under semi-arid Mediterranean environments a field trial was performed in 1998/99 and 1999/2000. In both years, the experimental field was located in Sparacia (Cammarata- AG -Sicily). Coriander was sown, in rows 50 cm apart on December 4th, 1998 and December 7th, 1999. The harvest of seeds was performed in both years from the 10th to 20th of June, after reaching a thermic sum of 1586 and 1714 GDD (Growth Degree Days) respectively. Despite the very low rainfall (229 and 261 mm from sowing time to harvest in both years) the fruit yields were rather satisfactory, reaching 581.3 and 970.6 kg ha-1 (dry mass). In the case of the volatile oils the most important compounds detected in the fruits were linalool (24.8 to 31.7 %), α-pinene (27.5 to 26.1 %) and γ-terpinene (21.9 to 23.0 %)
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
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