1,721,284 research outputs found
Post-harvest foliar-applied Fe(II)-sulfate promotes Fe nutrition of pear trees grown in calcareous soil
No full textThe effectiveness of post-harvest foliar-applied Fe(II)-sulfate was assessed and indices were tested for precocious prognosis of Fe-chlorosis in field-grown pear trees. In a commercial pear (Abbé Fétel/BA 29) orchard, Fe-induced chlorotic trees were sprayed in early autumn with a Fe(II)-sulfate heptahydrate solution and compared with water-sprayed control trees. Leaf Fe concentration was higher in senescent and abscised leaves of Fe-sprayed trees, indicating that Fe was taken up. However, phytotoxic symptoms occurred and leaves fell earlier than in untreated trees. Fe(II)-sulfate spray increased Fe concentration of flower buds and fruiting spur leaves as well as leaf Chl values. Yield was increased in sprayed trees by about 13%, mostly associated with a higher fruit number per tree rather than fruit size, indicating an improved fruit set. We hypothesize that a fraction of the absorbed Fe contributed to sustain Fe requirements of the newly formed organs as from growth resumption. Summer leaf SPAD readings were positively correlated with Fe concentration of flower buds, fruiting spur leaves and, in particular, with senescent and abscised leaves. Our findings suggest the effectiveness of the post-harvest foliarly applied Fe(II)-sulfate to improve Fe nutrition of pear trees the following season. Rather than inducing a temporary re-greening, our approach is based on the fact that high Fe-rates sprayed before leaf fall may contribute to increase Fe pools within perennial organs. We propose utilizing leaf Fe concentration of senesced and abscised leaves as a predictive tool for the diagnosis of the Fe-chlorosis occurrence in pear trees
Preparation and [2 + 3] cycloaddition of thienyl isocyanates with trimethylsilyl azide: One-pot synthesis of thienyltetrazolin-5-ones
No full textEfforts to prepare thienyl isocyanates by thermal reactions of thenoyl chlorides with trimethylsilyl azide (TMSA) led preferentially to the formation of 1,4-disubstituted tetrazolin-5-ones, arising by interaction of the initially formed thienyl isocyanate with TMSA. In fact, 2-thenoyl chloride and benzo[6]thiophene-2-carbonyl chloride reacted with 1 equiv. TMSA in refluxing carbon tetrachloride to give 1-(2-thienyl or benzo[b]thienyl)-4-(2-thenoyl or benzo[b]thiophenecarbonyl)tetrazolin-5-one 4d, e, whereas 3-thenoyl chloride led to 1-(3-thienyl)-4-trimethylsilyltetrazolin-5-one adduct II which was converted, after hydrolytic desilylation, to 1-(3-thienyl)tetrazolin-5(4H)-one 4c. Similar reactions, carried out with more than two equiv. of TMSA, led in all cases to the formation of the corresponding 1-heteroaryltetrazolin-5-one 4a-c via the corresponding silylated tetrazolin-5-ones II, whereas at room temp. such reactions gave essentially thenoyl azides which, after elimination of the excess TMSA, were thermally converted to the corresponding thienyl isocyanates 3 in fairly good yields
Percutaneous coronary intervention in dextrocardia: a case report and a brief review of the literature.
No full textRoot growth dynamic and plant performance of nectarine trees amended with biochar and compost
No full textA 2-year experiment was carried out outdoor on 1-year-old nectarine trees (Big Top grafted on Adesoto 101 Puebla (P. insititia) grown in large ((similar to)0.5 m(3)) pots filled with a sandy and poorly fertile soil in which, with 4 replicates, the following soil-applied amendment strategies were compared: a) unamended control; b) biochar (16.4 g kg(-1) (d.w.)); c) compost (40.0 g kg(-1) (d.w.)) and d) biochar mixed with compost, at the same rates of the previous two strategies. Only the first two strategies received mineral fertilizers. We monitored root growth dynamic and assessed tree growth, nutritional status, leaf photosynthetic rate, yield, fruit quality, tree architecture and tree biomass partitioning. Our findings demonstrate that benefits on soil properties and tree growth were mainly attributable to the addition of compost and, to a less extent, by biochar alone (mostly without significant effects), indicating that perennial agro-ecosystems may not immediately respond to biochar application. Strategies influenced root physiology rather than morphology or biomass, as a possible adaptation to the changed growing conditions. However, root growth pattern did not reflect the aboveground tree performance. Compost extended root lifespan and increased photosynthetic leaf efficiency, while biochar reduced root survivorship and increased root turnover, signifying that amendment strategies modify C fixation and alter C budget partitioning within tree organs. The PCA analysis suggests that biochar-induced benefits on tree yield could presumably occur over time. Tree physiology and performance were not outperformed by the mixture of the two amendments, likely because compost hindered potential synergism with biochar. While we conclude that the contemporaneous addition of biochar and compost may not always reflect additive responses on plant performance, we speculate that these matrices can be conveniently combined in the sustainable management of nectarine trees with the aim to replace mineral inputs, preserve soil fertility and fight climate changes
Fertilizzazione dei sistemi colturali frutticoli
No full textLa concimazione delle specie frutticole passa attraverso il bilancio dei nutrienti, con il quale si determinano le esigenze della specie e le disponibilità del terreno. La tecnica di gestione del suolo e l'epoca di fertilizzazione devono rendere massima l'efficienza di utilizzo dei nutrienti. Casi studio relativi alla coltivazione dell'arancio in Sicilia, del melo in Alto Adige, del pero nel ferrarese, del pesco in Romagna e di astoni di melo in vivaio, completano l'argomento, portando esempi pratici legati alle varie caratteristiche del territorio
Investigation of the water-induced reorganization of polycaprolactone-poly(fluoroalkylene oxide)-polycaprolactone triblock copolymer films by angle-dependent X-ray photoelectron spectroscopy
No full textThe water-induced reorganization of a series of poly(caprolactone)-poly(fluoroalkylene oxide)-poly(caprolactone) (PCL-PFPE-PCL) thin film surfaces was studied by angle-dependent X-ray photoelectron spectroscopy (XPS). The reorganization was studied as a function of polymer chain length, water exposure time, and XPS sampling depth. The prepared films were exposed to water and then frozen in liquid nitrogen to preserve the surface composition during XPS analysis. The XPS results showed the PFPE block segment length influenced the extent and rate of segment reorganization at the surface. The detected changes were shown to be reversible upon re-exposure to air and the effect of liquid-nitrogen freezing was determined to be negligible
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
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