1,721,228 research outputs found
Estabilidade das formulações de LNC ao longo do tempo - medidas de tamanho, PDI e PZ
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Effect of Nectar Composition on Bee Attraction for Onion Seed Production
No full textOnion is the second most cultivated vegetable crop in the world. Two types of onion varieties are usually grown around the world; open pollinated (OP) and first generation (F1) hybrids. Honey bees are the main pollinators of onion seed production, but owing to low attractiveness of flowers, pollination is often inadequate. Pollination problems result in low seed yields. Field observations indicate that F1 hybrid seed yields are much lower than open-pollinated varieties seed yields, with a decrease of up to 60%. Nectar is the most important floral reward offered by plants. Floral nectar composition has been studied as the potential cause of bee preferences in many species, among them onion. Nectar usually does not repel bees, but some nectar may be less attractive than nectar of competing flowers. Honeybees have distaste for onion flowers and avoid visiting them. Frequently, onion nectar potassium concentration and nectar sucrose concentration have been mentioned as potential causes of bee unattractiveness. Also, minor components of nectar such as phenols, amino acids, proteins, organosulfur compounds and alkaloids might directly affect bee foraging. There are differences in the chemical composition of nectar and floral morphology between open pollinated and F1 Hybrids and also within F1 Hybrids. These differences are correlated with the number of visits and seed yield. Therefore, it would be possible to select indirectly the most promising seed production lines analyzing nectar or floral morphological characters.EEA La ConsultaFil: Soto Vargas, Verónica Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Biología Agrícola de Mendoza; ArgentinaFil: Soto Vargas, Verónica Carolina. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Instituto de Biología Agrícola de Mendoza; ArgentinaFil: Silva, Maria Fernanda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Biología Agrícola de Mendoza; ArgentinaFil: Silva, Maria Fernanda. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Instituto de Biología Agrícola de Mendoza; ArgentinaFil: Galmarini, Claudio Romulo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria La Consulta; ArgentinaFil: Galmarini, Claudio Romulo. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Galmarini, Claudio Romulo. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias; Argentin
Determination of quercetin, gallic acid, resveratrol, catechin and malvidin in brazilian wines elaborated in the vale do São Francisco using liquid-liquid extraction assisted by ultrasound and GC-MS
Full text linkIn this work, a fast and simple methodology has been applied for the determination of gallic acid, resveratrol, catechin and malvidin in Brazilian wines by gas chromatography–mass spectrometry. The procedure included a stage of ultrasound-assisted liquid–liquid extraction and subsequent derivatization with N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) and GC-MS analysis. The limit of detection varied from 0.41 to 1.18 mgL−1 in all the analytes. The relative standard deviations calculated for 8.0 and 20 mgL−1 were 1.90 and 0.82 % for gallic acid, 3.08 and 1.22 % for catechin, 1.30 and 0.44 % for malvidin, 1.50 and 0.53 % for resveratrol, and 1.41 and 0.61 % for quercetin. The developed methodology was applied for the analysis of red wine samples collected in the São Francisco region, Bahia state, Brazil. Quercetin concentration varied from 2.4 to 3.0 mg L−1 , gallic acid 21.4–56.3 mgL−1 , resveratrol 1.5–5.9 mg L−1 , malvidin 15.3–32.2 mgL−1 , and catechin 11.71– 18.2 mgL−1 . The obtained concentrations are in agreement with those reported in the literature.Fil: De Souza Dias, Fábio. Universidade Federal do Recôncavo da Bahia; BrasilFil: Silva, Maria Fernanda. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Mendoza. Instituto de Biologia Agricola de Mendoza; ArgentinaFil: David, Jorge Mauricio. Universidade Federal Da Bahia. Instituto de Biologia; Brasil
Anthocyanins as markers for the classification of Argentinean wines according to botanical and geographical origin. Chemometric modeling of liquid chromatography-mass spectrometry data
Full text linkA study of Argentinean red wines was performed by direct injection of untreated wine samples into a liquid chromatography–mass spectrometry system, processing the collected data with two chemometric algorithms: multivariate curve resolution with alternating least-squares and discriminant unfolded partial least-squares (D-UPLS). The objectives were: (1) the chemometric resolution of profiles in the modes represented by elution time and m/z ratio, (2) the discrimination of samples according to varietal and/or geographical origin, and (3) the identification of key compounds helping to perform sample discrimination. The results indicate that all wine varietals can be adequately discriminated, and also three wine producing regions (located in the east, south and north of the Cuyo region) were differentiated from the remaining regions. The applied chemometric models allowed the tentative identification of anthocyanin compounds as responsible for both type of discriminations, in the case of D-UPLS by employing the concept of variables importance in the projection.Fil: Pisano, Pablo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Química Rosario; ArgentinaFil: Silva, Maria Fernanda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mendoza. Instituto de Biología Agrícola de Mendoza; ArgentinaFil: Olivieri, Alejandro Cesar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Química Rosario; Argentin
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
Exploration of liquid chromatographic-diode array data for Argentinean wines by extended multivariate curve resolution
Full text linkSecond-order data were measured using high-performance liquid-chromatography with diode array detection (HPLC-DAD) for a number of wine samples, which were directly injected in the HPLC-DAD system without sample pre-treatment. The data were arranged in data matrices whose modes were elution time and UV–visible absorption wavelength, and processed by extended multivariate curve resolution coupled to alternating leastsquares (MCR–ALS). The individual data matrices were organized in a row-wise augmented data matrix sharing the time subspace, due to the high spectral similarity among several sample components. This required previous time alignment of the chromatograms using a suitable synchronization algorithm, in order to produce a bilinear augmented data matrix to be processed by MCR–ALS. The latter algorithm led to resolved component chromatograms and spectra, from which component scores could be estimated, which are proportional to the relative component concentrations in each studied sample. The matrix of sample scores was then submitted to principal component analysis, which was applied for data exploration according to grape varietal and geographical origin. The results showed that the present data generation and analysis are useful for the discrimination of all samples of the Malbec varietal from the remaining ones, but achieved partial success regarding geographical origin.Fil: Pisano, Pablo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Química Rosario; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Departamento de Química Analítica; ArgentinaFil: Silva, Maria Fernanda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mendoza. Instituto de Biología Agrícola de Mendoza; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias; ArgentinaFil: Olivieri, Alejandro Cesar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Química Rosario; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Departamento de Química Analítica; Argentin
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
High-throughput determination of phenolic compounds in virgin olive oil using dispersive liquid-liquid microextraction-CZE microextraction-capillary zone electrophoresis
No full textThis article reports a simple methodology using dispersive liquid-liquid microextraction (DLLME) combined with CZE. It has been applied for the simultaneous determination of phenolic compounds such as caffeic, gallic, vanillic, syringic, cinnamic, p-coumaric acids and oleuropein, apigenin, luteolin, 3-hydroxytyrosol, and tyrosol, in virgin olive oil (VOO). The optimized extraction conditions for 20 g of VOO were: extractant solvent: 400 L boric acid 30mMat pH 9.5; dispersive solvent: 300 L carbon tetrachloride; vortex: 8min; centrifugation: 3min. The composition of the BGE was optimized resulting in the selection of a solution made of 30mMboric acid at pH 9.5. As a strategy for on-line preconcentration a stacking step was applied, injecting a plug of water before sample injection. The short extraction time, centrifugation and electrophoretic steps allow the selective determination of phenolic compounds in VOO with satisfactory LODs (0.004-0.251 mg/kg), recoveries (89.4-101.0%), and RSD (less than 7.44% in peak area and less than 0.69% in migration time), compatible with the concentration levels present in the samples.Fil: Monasterio, Romina Paula. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnol.conicet - Mendoza. Instituto de Biologia Agricola de Mendoza; Argentina; Universidad Nacional de la Pampa. Facultad de Ciencias Exactas y Naturales. Departamento de Quimica; Argentina;Fil: Fernández, María de Los Ángeles. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Mendoza. Instituto de Biologia Agricola de Mendoza; Argentina;Fil: Silva, Maria Fernanda. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnol.conicet - Mendoza. Instituto de Biologia Agricola de Mendoza; Argentina
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