1,721,041 research outputs found
Effect of aggregation state, temperature and phospholipids on photobleaching of photosynthetic pigments in spinach Photosystem II core complexes
No full textPhotosystem II (PSII) complex activity is known to decrease under strong white light illumination, and this photoinhibition phenomenon is connected to the photobleaching of the PSII photosynthetic pigments. In this work the pigment photobleaching has been studied on PSII core complexes, by observing the effects of different factors such as the aggregation state (PSII monomers and dimers were used), temperature (20°C and 10°C temperatures were tested) and the presence of the exogenous phospholipids (cardiolipin and phosphatidylglycerol). In particular, PSII resistance against white light stress was studied by means of UV/VIS Absorption and Fluorescence Emission measurements. It was found that PSII dimers resulted more resistant against photobleaching and that lower temperature reduces the pigment photodestruction. Moreover, the presence of phosphatidylglycerol or cardiolipin enhanced the PSII resistance to the photobleaching phenomenon, mainly at lower temperatures
Herbicides affect fluorescence and electron transfer activity of spinach chloroplasts, thylakoid membranes and isolated Photosystem II
No full textIn this work, studies on the effects produced by atrazine, terbutryn or diuron onto spinach photosynthetic materials were performed by observing changes in fluorescence emission and in electron transfer activities of the bio-samples in the presence of such herbicides; chloroplasts, thylakoids, Photosystem II-enriched thylakoids (BBYs) and isolated Photosystem II (PSII) were employed. This approach evidenced differences in the herbicide-photosynthetic material interactions going up-down from chloroplasts to proteins. Rapid emission increments were detected for chloroplasts and thylakoids, in particular in the presence of terbutryn; no remarkable emission increment was recorded when BBYs or PSII were used for this assay. The dependences of the chloroplast and thylakoid emission intensities upon herbicide concentration were investigated with responses even at concentrations below 10-7 M. The influence of lowering the temperature was also tested, and stabilizing effects on the resistances of the bio-samples against herbicides were recorded. Furthermore, Hill Reaction-based colorimetric assays were performed to monitor the electron transfer activities of the bio-samples in the presence of herbicides, after brief incubations. As results, chloroplasts and thylakoids resulted to be sensitive tools in responding to concentrations even lower than 10-7 M of most herbicides; nevertheless, an interesting sensitivity to herbicides was also observed for PSII
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
Isolation and characterization of lipids strictly associated to PSII complexes: focus on cardiolipin structural and functional role
No full textIn this work, lipid extracts from spinach membrane fragments enriched in Photosystem II (PSII) and from spinach PSII dimers were analyzed,
by means of Thin Layer Chromatography (TLC) and Electro-Spray Ionization Mass Spectrometry. Cardiolipin found in association with PSII was
isolated and purified by preparative TLC, then characterized by mass and mass–mass analyses. Cardiolipin structures with four unsaturated C18
acyl chains and variable saturation degrees were evidenced. Structural and functional effects of different phospholipids on PSII complexes were
investigated by Fluorescence, Resonance Light Scattering and Oxygen Evolution Rate measurements. An increment of PSII thermal stability was
observed in the presence of cardiolipin and phosphatidylglycerol
COMPARISON OF DIFFERENT SHEAR TEST CONFIGURATIONS FOR JOINED CERAMICS AND CMCS
No full textIn book of abstracts and oral presentatio
JOINING OF DIFFERENT MATERIALS FOR ENERGY PRODUCTION: FUSION ENERGY, SOFC
No full textAbstract book and poster presentatio
Chemical Profile of the Carpino Broad Bean by Conventional and Innovative Physicochemical Analyses
No full textA detailed chemical characterization of a typical Apulian legume, the Carpino broad bean, was obtained. Crude proteins, moisture, phosphorus, ash and energy content were evaluated on starting seeds, half-ripening beans and final products. Stable isotope ratios (15N/14N and 13C/12C), major (Ca, Mg, Na and K) and trace metals (Zn, Mo, Mn, Cu, Fe, Cr, Cd, Ni and Co) were also assessed. Moreover, information on a large number of metabolites was obtained by 1H high-resolution magic-angle spinning nuclear magnetic resonance spectroscopy. The data revealed that Carpino broad bean dry seeds supply adequate protein and energy content, 28.1% and 326kcal, respectively, being also a good source of macro- and microelements. In particular, the iron content was 46.0mg/kg: this potentially provides about 33% of the recommended daily allowance by a 100g serving. Moreover, the analyzed samples seem to lack elements considered potentially harmful for health. Practical Applications: The Carpino broad bean is a native faba bean cultivar, traditionally cultivated in small quantities in Gargano (Southern Italy). It is commonly considered a traditional food product with interesting nutritional properties. At present, the Carpino broad bean has still not received an official European label as typical product, but it is a Slow Food presidium, this remarks its considerable socio-cultural, nutritional and environmental values. Even if restricted to a limited geographic area, this typical and appreciable cultivation should be protected from extinction, preserving territory identity and working techniques; therefore, it is essential to explore ways to prove the Carpino broad bean quality and peculiarities, starting from a physicochemical characterization, that has not been presented in detail until now, and that could be a considerable basis for an official valorization of this product, for instance, for the attainment of EU Protected Designation of Origin/Protected Geographical Indication (EU PDO/PGI) labels
SHEAR STRENGTH TESTS OF JOINED ADVANCED CERAMICS AND C/C COMPOSITES
No full textIn "Book of abstracts" and oral presentatio
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
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