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Abstract: The selection of modeling and machining parameters for glass mould fabrication in ophthalmic lenses production, has required the definition of a theoretical–empirical model of the ground surface in order to predict the overall geometry errors of the surface. The accurate control of the geometrical errors and of the surface texture for the mould functional surface is crucial for the subsequent polishing operation, which is responsible for the final geometry, surface finish and cost. The basic hypotheses validation has been accomplished by measuring the micro-geometric parameters P, W and R and by characterizing the macro-geometry comparing the nominal profile and the measured profile. The correspondence among theoretical hypotheses and experimental results allows realistic predictions of the attainable surface texture during a contour grinding operation and the adoption of preventive actions in order to compensate the geometrical errors due to modeling and tool path generation parameters. [Copyright &y& Elsevier]

Copper can accumulate in agricultural topsoil through the use of Cu-based fungicides, which may harm soil organisms such as earthworms. This study aimed at reviewing the effects of copper on earthworms at different levels of biological organization, and to determine critical values of copper toxicity to earthworms using a meta-analysis and accounting for lethal and sub-lethal effects and different earthworm species and exposure conditions. Endpoints at the sub-individual level were more sensitive than at higher levels of organization. At the individual level, the most sensitive endpoints were reproduction and growth (hatching success, hatchling growth). Hormetic growth was clearly recognized at copper concentrations less than 80 mg kg−1 in dry soil. However, effects at the sub-individual level already occurred at lower concentrations. Considering all the exposure conditions, the calculated weighted means were 113 mg Cu kg−1 dry soil (95% CI -356; 582) for the LC 50 (lethal concentration for 50% of the exposed individuals), 94.6 mg Cu kg−1 dry soil (95% CI 14.0; 175) for the EC 50 reproduction, and 144 mg Cu kg−1 dry soil (95% CI -12.6; 301) for the EC 50 growth or weight change. When accounting for the origin of the soil, earthworms were five times more sensitive to copper (LC 50) in natural than in artificial soils. The different factors affecting Cu toxicity to earthworms explain the high variability of these values, making it difficult to derive thresholds. However, considering the potential negative effects of copper on earthworms, attention should be given to the more sustainable use of human-contributed copper in agricultural soils. [Display omitted] • Hormesis occurs for earthworm growth at concentrations below 80 mg Cu kg−1 dry soil. • But effects at the sub-individual level occur at lower concentrations. • Critical values (LC 50 , EC 50 reproduction, and EC 50 growth) of copper toxicity to earthworms are calculated. • Earthworms were more sensitive to copper in natural than in artificial soils. • Many factors influence Cu toxicity, making it difficult to derive thresholds. [ABSTRACT FROM AUTHOR]

[Display omitted] • Grasslands exhibit distinct taxonomic and functional profiles across regions. • Grasslands show consistent taxonomic and functional profiles despite management type. • Regions have a core microbiome of Firmicutes, Proteobacteria, and Actinobacteriota. • Soil pH influences microbial variability in taxonomic and functional profiles. • Nitrogen cycling potentials are influenced by region, soil pH, and organic carbon. Grasslands represent key functional ecosystems due to their global contribution to macronutrients cycling and their role as reservoirs of microbial diversity. The strategic importance of these habitats rests on their involvement in carbon and nitrogen fluxes from the atmosphere to the soil, while at the same time offering extensive sites for livestock rearing. In this study the management type, differentiated in pasture or meadow, was investigated as a variable for its possible effects on overall bacterial diversity and specific genes related to functional guilds. Its contribution was compared to that of other variables such as region, soil pH, and soil organic carbon, to rank their respective hierarchies in shaping microbial community structure. A latitudinal gradient across the European continent was studied, with three sampling groups located in Norway, France, and Northern Italy. The applied methods involved 16S DNA metabarcoding for taxonomic classification and determination of the relative abundance of the bacterial component, and quantitative PCR for the genetic determinants of bacterial and archaeal nitrification, intermediate or terminal denitrification, and nitrogen fixation. Results indicated that soil pH exerted the dominant role, affecting high taxonomy ranks and functions, along with organic carbon and region, with whom it partly covaried. In contrast, management type had no significant influence on microbial community structure and quantitative counts of functional genes. This suggests an ecological equivalence between the impacts of pasture and meadow practices, which are both perturbations that share the aspect of vegetation withdrawal by browsing or cutting, respectively. [ABSTRACT FROM AUTHOR]

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 aim of this ex vivo study was to test a novel three-dimensional (3D) automated computer-aided design (CAD) method (aCAD) for the computation of femoral angles in dogs from 3D reconstructions of computed tomography (CT) images. The repeatability and reproducibility of three manual radiography, manual CT reconstructions and the aCAD method for the measurement of three femoral angles were evaluated: (1) anatomical lateral distal femoral angle (aLDFA); (2) femoral neck angle (FNA); and (3) femoral torsion angle (FTA). Femoral angles of 22 femurs obtained from 16 cadavers were measured by three blinded observers. Measurements were repeated three times by each observer for each diagnostic technique. Femoral angle measurements were analysed using a mixed effects linear model for repeated measures to determine the levels of intra-observer agreement (repeatability) and inter-observer agreement (reproducibility). Repeatability and reproducibility of measurements using the aCAD method were excellent (intra-class coefficients, ICCs ≥ 0.98) for all three angles assessed. Manual radiography and CT exhibited excellent agreement for the aLDFA measurement (ICCs ≥ 0.90). However, FNA repeatability and reproducibility were poor (ICCs < 0.8), whereas FTA measurement showed slightly higher ICCs values, except for the radiographic reproducibility, which was poor (ICCs < 0.8). The computation of the 3D aCAD method provided the highest repeatability and reproducibility among the tested methodologies. [ABSTRACT FROM AUTHOR]

Abstract: The significantly growing use of Additive Manufacturing (AM) enables the fabrication of innovative parts, characterized by lightness and good mechanical properties. The biomedical field takes great advantage of these capabilities: in particular, the ability of producing porous or lattice structure-based parts allows to obtain prostheses with human bone like stiffness, with a positive influence in patient’s lifestyle. The knowledge of the mechanical behavior of materials used in AM and producible geometries is an essential requirement to profit and improve this characteristic: in particular, recent studies focus on the correlation between strength parameters and relative porosity of the part. In a previous work a set of tensile tests have been performed on different types of specimens, reproducing a set of corresponding emptying strategies, with different resulting porosity rates, and a linear predictive model has been proposed. Aim of this work is to integrate the already acquired data, providing an interpretation on previous results by numerical simulations: the influence of porosity rate on mechanical properties was investigated by performing both global and local Finite Element Analyses, finding out an explanation on inverse proportionality between material strength properties and porosity rate. The methodology proved to be a profitable way in the optimization of lattice structures for Additive Manufacturing. [Copyright &y& Elsevier]

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]

• In-depth understanding of the mechanical behavior of concrete. • Proposal of a procedure that combines 3D image techniques with FE modelling. • Exact geometric reconstruction of concrete at meso-level via the use of X-ray CT. • Adoption of an upgraded elasto-plastic damage model for the cement paste. • Sound prediction of damage triggering and evolution under generic stress states. The increasing attention to numerical issues related to material modeling is still a strong incentive to develop sound mechanical models that can explain material behavior up to failure. A procedure to handle a robust geometric meso-scale reconstruction of concrete materials is here proposed, based on X-ray Computed Tomography (CT-scan or X-ray CT). This study applies X-ray CT on ordinary concrete made with limestone aggregates. In this case the technique allows to acquire the overall inner geometry and distribution of the aggregates and also voids, thanks to the difference in material density of the components. Solid models have been generated with such technique and discretized in space to be numerically studied via the Finite Element (FE) method. The numerical results are compared with uniaxial compression tests on the same scanned specimens. For the numerical analyses a specific non-associated elasto-plastic constitutive behavior, coupled with damage, is developed for the cement matrix, whereas the coarse aggregates are treated as elastic. The mechanical characteristics of the components are gathered through a specific experimental campaign. The study confirms that a predictive simulation of damage triggering and evolution in concrete under generic 3D stress states requires the characterization of the continuum at a meso-scale level. Comparisons between numerical and experimental results proves the soundness of the proposed constitutive description to evaluate the brittle behaviour of cementitious materials and to satisfactorily simulate damage triggering under generic 3D stress states. [ABSTRACT FROM AUTHOR]