1,721,149 research outputs found
PHYSIOLOGICAL RESPONSES OF WHITE GRAPE BERRIES TO SUNLIGHT EXPOSURE
Full text linkReflectance spectroscopy was used in 2013, to investigate about varietal behaviors to different agronomics condition: (i) composition and quantification of pigments by using non-invasive method; (ii) photosynthetic pigments assessment by new reflectance indices (iii) how different microclimatic bunch conditions could affect the appearance of sunburn. The experiment was performed in the Regional Research Station of Riccagioia (Lombardy region, Northern Italy), at the University of Milan, on 16 white grape accessions, during 3 phenological stages: pre-veraison (77 BBCH), veraison (81 BBCH) and harvest (89 BBCH). New specific indices for the evaluation and estimation of photosynthetic pigments were proposed on the basis of grape berry reflectance spectra. Validations with classical extraction analysis were done. About 200 berries were analyzed (over 1000 reflectance spectra were collected). First the chlorophyll a and b absorption maxima in the reflectance spectra were established: 675 and 650 nm respectively. These new equations are also able to discriminate between chlorophyll a and b. Indeed, the wavelengths of major interest for their absorption detection were identified. If chlorophyll quantifications were achieved directly from reflectance spectra, for carotenoids the absorption bands did not allow good reflectance correlations. Nonetheless, thanks to the physiological relation of photosynthetic pigments, the chlorophyll/carotenoid ratio was used to estimate carotenoid content. Because their proportion changes during berry development, the index coefficients can be adapted in relation to the BBCH phenological stage. These indices demonstrated good correlations with the destructive quantifications.
Also, the degradation intensity of the chlorophyll was different from that of the carotenoid during maturation, leading to a change in their absorption proportion throughout ripening. This finding allows suggesting that in white berries, the colour change during berry development is not related to the activation of a specific biosynthetic pathway, but is mostly the result of catabolic processes.
Chardonnay and Riesling showed different susceptibility to sunburn. The results suggest that for each variety, the timing of leaf removal during the day is fundamental to reducing the appearance of brown color in the berry skin. In Chardonnay it would be better to avoid any leaf removal especially in pre-veraison, in the morning. Because Riesling was more susceptible during the afternoon, it would be recommendable to remove leaves, if necessary, during the early morning.
The aims of the last two years (2014-2015) data collection were: (i) to evaluate phenolics in Riesling and Chardonnay berries in response to sunlight exposure under different irrigation regimes; (ii) to study the relation of water stress to sunburn appearance. The experiment was carried out in the Columbia Crest vineyards (Columbia Valley, Washington State, USA). Chardonnay and Riesling berries were collected from two different vineyards. Two different irrigation regimes were applied in both vineyards. Full irrigation (FI): vines were irrigated to replace 100% crop evapotranspiration, from fruit set to harvest, with no water stress imposed. Deficit irrigation (DI): vines were irrigated to maintain a moderate water stress (stem water potential (stem) at midday between -0.7 and -1 MPa) from fruit set to harvest. For compositional analysis two cluster exposures were considered: one exposed to direct sunlight (sun), and the other totally shaded from sunlight (shade). Skin flavonol, flavan3ol and proanthocyanidin content were analysed by HPLC methods. Total tannins were measured by spectrophotometer. Six temperature/light sensors per irrigation treatment were randomly installed on 3 sun and 3 shade bunches. In terms of absolute concentration in both varieties, several statistical tests indicate greater amount of variance accounted for by the effect exposure and phenological stages, and their interaction. No effect was due to the irrigation, in both varieties. Chardonnay had much higher flavanol concentration than Riesling. Chardonnay had much higher flavanols in the pre- veraison than during ripening. In Chardonnay the amount of monomers, dimers, trimers and polymers was greater in sun exposed berries than in shaded berries. Unlike in Chardonnay, in Riesling no flavan3ols monomers were detected by HPLC during the pre-veraison and veraison. In Riesling the amount of monomers, dimers and trimers was greater in sun exposed berries than in shaded berries. In both varieties flavonol concentrations were much higher in sun exposed berries than in shaded berries, with absolute much higher concentration in Chardonnay. Flavonols increased during ripening, especially in the sun in both Chardonnay and Riesling. Under similar light conditions the difference in temperature within the two irrigation treatments in the sun, could be due to the less vigorous canopy of DI plants compared with FI plants, which overall lead to greater cluster exposure, in both varieties. Nonetheless, the temperatures were always lower in FI and higher in DI, supporting the hypothesis of a possible no (or little) effect on flavonol biosynthesis. Shaded-bunch temperatures were always lower as compared to sun exposed ones, as direct solar heating did not occur in the shaded-conditions
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Reconstruction of the distal finger with partial second toe transfers by means of an exteriorised pedicle
No full textThis study reports the outcome of a series of ten microsurgical fingertip reconstructions with partial toe transfers in which the vascular pedicle was exteriorised and subsequently excised after the transfer had become established. The aim of this technique was to provide better aesthetic and functional outcomes. The technique was successful and without complication in nine of the ten patients who had excellent functional and aesthetic outcomes. Arterial thrombosis resulted in partial necrosis of the fingertip in the other cas
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