1,720,963 research outputs found
Oxidative damage and cell-programmed death induced in Zea mays L. by allelochemical stress
Full text linkThe allelochemical stress on Zea mays was analyzed by using walnut husk washing waters (WHWW), a by-product of Juglans regia post-harvest process, which possesses strong allelopathic potential and phytotoxic effects. Oxidative damage and cell-programmed death were induced by WHWW in roots of maize seedlings. Treatment induced ROS burst, with excess of H2O2 content. Enzymatic activities of catalase were strongly increased during the first hours of exposure. The excess in malonildialdehyde following exposure to WHWW confirmed that oxidative stress severely damaged maize roots. Membrane alteration caused a decrease in NADPH oxidase activity along with DNA damage as confirmed by DNA laddering. The DNA instability was also assessed through sequence-related amplified polymorphism assay, thus suggesting the danger of walnut processing by-product and focusing the attention on the necessity of an efficient treatment of WHWW
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
Postharvest treatment with chitosan affects the antioxidant metabolism and quality of wine grape during partial dehydration
Full text linkThe effectiveness of postharvest chitosan treatments on qualitative traits and antioxidant biochemical system during postharvest partial dehydration of "Sagrantino" grape has been studied, compared with ozone postharvest treatment. One % and 2% chitosan coatings delayed water loss but no difference in berry color or peel resistance during partial dehydration up to 30% mass loss (m. l.), was found among samples. The reducing sugar content rose straightly from 275 g L-1 (harvest), up to 445, 428, 411, and 390 g L-1, in 2% chitosan, 1% chitosan, water, and ozone, respectively. Malic acid, and consequently total acidity, increased progressively in all samples with higher values in ozone-and in chitosan-treated berries. In all samples, total polyphenol content rose already at 10% m. l., and 1% chitosan sample had the highest value. Postharvest treatments enhanced the activity of antioxidant enzymes, superoxide dismutase (SOD) and ascorbate peroxidase (APX), during partial dehydration process, whereas inhibited polyphenoloxidase (PPO) and lipoxygenase (LOX) activity, preventing polyphenol loss and avoiding membrane oxidation, as shown by lower malondialdehyde (MDA) accumulation
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
Overall quality and antioxidant enzymes of ready‐to‐eat ‘Purple Queen’ pomegranate arils during cold storage
Full text linkThis study evaluated the effectiveness of two different packaging systems, using micro-perforated (MPP) and
semipermeable (SP) films, on the physico-chemical and nutraceutical traits, microbial quality, and antioxidant
enzymatic system of ready-to-eat pomegranate (Punica granatum L.) arils (cultivar ‘Purple Queen’) stored at 5 °C
for 16 d. Statistically significant differences in gas composition and arils qualitative traits such as pH and titratable
acidity between the two packaging systems were found. Arils packaged in the SP system had higher
polyphenols and anthocyanins contents, followed by a high antioxidant activity, with a positive correlation
(r=0.610 and 0.940, respectively) among them. An increase in the activities of antioxidant enzymes, such as
superoxide dismutase, catalase, and ascorbate peroxidase, were registered in the arils in the SP system, with a
decrease in polyphenol oxidase and peroxidase activity involved in arils-browning. Overall, SP packaging could
be a valid system to preserve ready-to-eat arils within food chains that maintain high qualitative and nutraceutical
features up to 16 d of storage
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
The Effect of Chitosan Coating on the Quality and Nutraceutical Traits of Sweet Cherry During Postharvest Life
No full textThe effectiveness of a chitosan-coating treatment on the physical and chemical, nutraceutical, and sensorial traits of three sweet cherry cultivar (Prunus avium L., namely cvs. "Ferrovia," "Lapins," "Della Recca") harvested at the commercial ripening stage was evaluated. Fruits were treated with a 0.5 % chitosan coating, stored at 2 A degrees C for 14 days, and sampled weekly followed by storage at 24 A degrees C for 3 days to assess the shelf life of the fruit. Physical-chemical (weight loss, soluble solid content, and titratable acidity), nutraceutical (total polyphenol, anthocyanin, flavonoid, ascorbic acid content, antioxidant capacity), and sensory (fruit juiciness, sweetness, sourness, texture, and taste) evaluations were performed. A chitosan coating significantly reduced the water loss and delayed the changes in color, titratable acidity, ascorbic acid content, and respiration rate in a cultivar-dependent manner. Additionally, changes in the total polyphenol, anthocyanin, and flavonoid content and in the antioxidant capacity of the chitosan-coated sweet cherry fruits were delayed. This treatment extended the postharvest life, improved the storability, and enhanced the nutraceutical value of sweet cherry
Chitosan coating: A Postharvest treatment to delay oxidative stress in loquat fruits during cold storage
Full text linkLoquat is a non-climacteric fruit consumed fresh for its essential nutrients and phytochemical compounds. In this study, the effects of chitosan coating (1% w/v) on changes in the enzymatic antioxidant and membrane damage in three loquat selections (CREAFRC-S18; CREAFRC-S35 and CREAFRC-S36) and three loquat cultivars (Golden Nugget, Algerie and Nespolone rosso di Trabia) stored at 7 ◦C over 21 days were evaluated. Chitosan treatment enhanced the activities of superoxide dismutase, catalase and ascorbate peroxidase. Moreover, this treatment inhibited polyphenol oxidase and guaiacol peroxidase activities, extending the storage life of loquat. Chitosan also preserved membrane integrity by inhibiting lipoxygenase activity and malondialdehyde accumulation. Principal component analysis provided a global view of the responses of both loquat selections and cultivars to the postharvest chitosan coating and storage temperature. These findings suggest that chitosan treatment could be a valid tool for improving the activity of antioxidant enzymes, preserving the enzymatic browning of loquat fruits
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