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The characterization of nutrient and biostimulant effects in crops is complex and needs rigorous evaluations. In this study, we evaluated morphological and molecular responses induced by microalgae (Chlorella vulgaris and Scenedesmus quadricauda) extracts in Beta vulgaris L. The two microalgae extracts were firstly characterized by CNS, Fourier transform infrared spectroscopic analysis (FT-IR), and carbon-13 nuclear magnetic resonance (13C NMR). Seedlings were grown in Hoagland’s solution under controlled conditions. After 5 days of growth, 2 mL L−1 (1 mg Corg L−1) and 4 mL L−1 (2 mg Corg L−1) of the two microalgae extracts were added to the Hoagland solution. Roots were sampled 36 h after treatments. Inductively coupled plasma spectrometry (ICP-OES) and nanofluidic real-time PCR (OpenArray system) were used for sample profiling. Fifty-three sugar beet genes putatively involved in sulfate starvation were tested in treated and untreated samples. Root morphological traits were measured by means of a scanner-based image analysis system. Multivariate statistical analysis revealed no significant changes in the ionomic profile of Hoagland’s solutions treated with the two microalgae extracts with respect to that of the untreated solution. At the molecular level, microalgae extract supplies upregulated many of the evaluated genes. Functional categorization revealed these genes to be related to various biological pathways and processes including primary and secondary metabolism and intracellular transport. At the morphological level, the treated seedlings showed significantly higher values for root traits related to soil exploration and nutrient uptake, such as total root length, fine root length (diameter < 0.5 mm), and number of root tips, than the untreated plants. These data indicate that microalgae extracts have biostimulant effects on the expression of root traits and genes related to nutrient acquisition in sugar beet. [ABSTRACT FROM AUTHOR]

The free-form technologies, recently introduced in the manufacturing process of ophthalmic lenses, allow the production of high performance and custom progressive addition lenses (PALs). In this work a method for the parametric design and analysis of PAL, based on discrete shape modelling, is proposed. Both the optical (e.g. power and addition) and the geometrical (e.g. inset, corridor length, amplitude of the distance and near vision area) parameters have been taken into account. In addition the method developed for the analysis of surface optical properties, especially with regard to the astigmatic surface power, has proved an essential tool for the analysis of results. Moreover the exchange data formats for the CNC manufacturing process were described. The influence of different parameters on the optical properties are analyzed and discussed. In this context a key role on the resultant optical properties of the designed PAL is covered by the distribution of the curves in the intermediate area and by the curvature equation along the corridor. Surface power and astigmatic surface power show similar behaviour to other commercial progressive additional lens but, moreover, the designer can specify the distribution of astigmatism in the intermediate region. Compared to the methods proposed in literature, this one shows more opportunities in the design parameters definition and allows highly customized lens, designed on the main habits of the wearer. Finally the method was applied to the manufacturing process of glass mould for PAL and the results of optical parameters measurements are proposed. [ABSTRACT FROM AUTHOR]

Several simple models, such as conicoid models, are usually adopted to describe the surfaces of the human crystalline lens; unfortunately they do not provide a continuous junction between the anterior and the posterior surface of the lens and then they cannot qualify for biomechanical simulation. Vice versa, more complex mathematical models give a continuous junction between the anterior and the posterior surface, but do not provide a geometrical or optical interpretation of the coefficients of the model. In this work we propose a continuous curvature lens model in which the coefficients are derived by geometrical constraints. In this way, both the continuity in the junction zone and a geometrical-physical interpretation of the coefficient involved in the model are obtained. Shape, volume and curvature of the proposed model were compared with four models presented in the literature: two independent conic equations, two interdependent figuring conicoid equations, conic patches model and modulated hyperbolic cosine. [ABSTRACT FROM AUTHOR]

Carrot cells were grown in cultures supplemented with two hormones [2,4-dichlorophenoxyacetic acid (2,4-D) and 6-benzylaminopurine (6BAP)] and two humic fractions extracted from earthworm faeces, one with high acidity and a low apparent molecular size (<3500) and the other with low acidity and a large molecular size. 2,4-D stimulated growth through an effect on cell enlargement, while the strongly acidic humic fraction (0.2 mg l) and the weakly acidic fraction (1 mg l) were both less effective. With 4-16 h of pre-incubation, the highly acid humic fraction, mainly alone, induced the best increase in protein content; the effect of the weakly acid humic fraction and the hormones was generally less important. The two humic fractions also differed in their influence on glutamate dehydrogenase activity. After 2 h of pretreatment, the highly acidic fraction increased glutamate dehydrogenase activity, while the other fraction did not affect it. After 4-16 h of pre-incubation, the activity of this enzyme was still not influenced by these humic fractions. The presence of the two hormones did not interfere with the humic matter effects. Glutamine synthetase activity was not affected by a pre-incubation of up to 4 h with the two humic fractions, but it was stimulated after 8-16 h of pre-incubation. A 2,4-D+6BAP mixture stimulated glutamine synthetase activity (from +12 to +50%). Again, the presence of the hormones did not interfere with the effects induced by the humic fractions. After 16 h of pre-incubation, phosphoenolpyruvate carboxylase activity was increased by the highly acidic humic fraction (+93%) and by both humic fractions together (+34%). An explanation of the different incubation times necessary for the humic fractions to exert stimulatory effects on these enzymes is proposed here. The regulatory properties of the strongly acidic humic fraction appeared to depend on the combination of high acidity (expecially carboxylic C) with low molecular size. [ABSTRACT FROM AUTHOR]

Leaf explants of Nicotiana plumbaginifolia were compared in cultures supplemented with hormones or humic substances (extracted from faeces of Allolobophora caliginosa) of various molecular complexity and concentration. The results showed that the humic substances (F, F, and T) at the concentration of 1 mg C l produced greater leaf explants than those grown in the control. Furthermore, humic fractions like gibberellic alone induced a rhizogenic activity in leaf explants. Quantitative differences were also observed in the peroxidase activity induced in Nicotiana plumbaginifolia by humic matter (F, F, and T). In addition, the Nicotiana sp. tissue treated with humic fractions revealed, in the esterase enzyme pattern, the appearance of the 2a band, which was attributable to indoleacetic acid, since its profile was consistent with those obtained from tissues treated with indoleacetic acid. These differences demonstrate that humic substances exhibited a hormone-like behaviour, but no evidence of a relationship between biological activities and chemical characteristics of humus substances was found. [ABSTRACT FROM AUTHOR]

An energy dispersive X-ray fluorescence method for trace element analysis in plants (leaves and roots) is presented. The method is characterized by the use of a secondary target excitation, thin specimen, and microwave acid digestion. The accuracy is about 10% and the sensitivity is in the range 10-50 ng/cm. The analysis time (from dry sample to concentration data) is about 4×10 s. The effects of Cr in sewage sludge on barley seedling growth is presented. [ABSTRACT FROM AUTHOR]