Search results for " mineral"
showing 10 items of 541 documents
Carbohydrate and nutritional responses to stem girdling and drought stress with respect to understanding symptoms of Huanglongbing (HLB) in Citrus
2013
The most important worldwide problem in citrus production is the bacterial disease Huanglongbing (HLB; citrus greening) caused by phloem-limited bacterium Candidatus Liberibacter asiaticus. The earliest visible symptoms of HLB on leaves are vein yellowing and an asymmetrical chlorosis referred to as “blotchy mottle”, thought to be the result of starch accumulation. We tested the hypothesis that such visible symptoms are not unique to HLB by stem girdling 2-yr-old seedlings of two citrus rootstocks with and without drought stress in the greenhouse. After 31 d, girdling had little effect on shoot growth but girdling increased the relative growth rate of shoots in drought stressed trees. Starc…
Grafting suitability of Sicilian eggplant ecotypes onto Solanum torvum: Fruit composition, production and phenology
2013
The eggplant (Solanum melongena L.) is one of the most widely cultivated crops in tropical and temperate regions around the world and is suitable for propagation through grafting. In many parts of the world, grafting is a routine technique used in continuous cropping systems, because in the horticulture field is a sustainable technique that allows cultivators to overcome abiotic or biotic stress. The objective of this research was to evaluate the suitability at the grafting of four Sicilian eggplant ecotypes grown in open field in Sicily, Italy. Vegetables in general are a great source of minerals in the human diet and the eggplant (Solanum melongena L.) provides significant quantities of v…
Dynamics of carbon pools in a soil covered with different forest tree species after controlled heating and wetting
2012
Fire-induced soil heating deeply affects soil organic C pools and their dynamics. The objective of this study was to investigate, in a soil covered with different forest tree species (Eucalyptus camaldulensis, E. occidentalis, Pinus halepensis, and Cupressus sempervirens), the effect of controlled heating on C pools and C mineralization dynamics. Soil samples were heated under controlled condition in laboratory (160 and 380°C) and then wetted with distilled or sea water to simulate the extinction of wildfires. Soil organic C pools react to heating in different way depending on forest tree species. Total organic C was almost halved following the heating of soils at 380°C. Soil covered with P…
Evidences on alterations in skeleton composition and mineralization in a site-attached fish under naturally acidified conditions in a shallow CO2 vent
2021
Abstract Background Ocean acidification may affect fish mineralized structures (i.e. otoliths and skeleton). Methods Here, we compared the elemental composition of muscle and skeleton and the mineral features of skeleton in the site-attached fish Gobius bucchichi naturally exposed to high pCO2/low pH conditions in a shallow CO2 vent with fish of the same species exposed to normal pH. Results Overall, no skeleton malformations were found in both pH conditions, but among-site differences were found in the elemental composition. Interestingly, higher Ca/P values, inducing a moderate skeleton maturation, were found in fish exposed to acidified conditions than in controls. Conclusion Our finding…
Un approccio integrato allo studio delle "argille ceramiche" della Sicilia Centrale e Occidentale
2011
Iteratively reweighted least squares in crystal structure refinements
2011
The use of robust techniques in crystal structure multipole refinements of small molecules as an alternative to the commonly adopted weighted least squares is presented and discussed. As is well known, the main disadvantage of least-squares fitting is its sensitivity to outliers. The elimination from the data set of the most aberrant reflections (due to both experimental errors and incompleteness of the model) is an effective practice that could yield satisfactory results, but it is often complicated in the presence of a great number of bad data points, whose one-by-one elimination could become unattainable. This problem can be circumvented by means of a robust least-squares regression that…
New tailor-made bio-organoclays for the remediation of olive mill waste water
2013
A systematic study aimed at obtaining new organoclays for the treatment of Olive Mill Waste water (OMW) has been performed. Several organoclays have been prepared by loading different amounts of the biocompatible surfactant Tween20 onto the K10 montmorillonite (MMT). Complementary kinetic and equilibrium studies on the adsorption of the Tween20 onto the MMT have been carried out and the characterization of the new tailor-made bio-materials has been performed by means of the XRD and FT-IR measurements. Finally the prepared bio-organoclays have been successfully applied for the OMW remediation and they proved to be highly effective in decreasing the organic content (OC) to an extent that depe…
Synthetic and natural chromium bearing spinels: an optical spectroscopy study
2014
Four samples of synthetic chromium-bearing spinels of (Mg, Fe2+)(Cr, Fe3+)2O4 composition and four samples of natural spinels of predominantly (Mg, Fe2+)(Al, Cr)2O4 composition were studied at ambient conditions by means of optical absorption spectroscopy. Synthetic end-member MgCr2O4 spinel was also studied at pressures up to ca. 10 GPa. In both synthetic and natural samples, chromium is present predominantly as octahedral Cr3+ seen in the spectra as two broad intense absorption bands in the visible range caused by the electronic spin-allowed 4A2g → 4T2g and 4A2g → 4T1g transitions (U- and Y-band, respectively). A distinct doublet structure of the Y-band in both synthetic and natural spine…