PopRank: Ranking pages' impact and users' engagement on Facebook

Users online tend to acquire information adhering to their system of beliefs and to ignore dissenting information. Such dynamics might affect page popularity. In this paper we introduce an algorithm, that we call PopRank, to assess both the Impact of Facebook pages as well as users' Engagement on the basis of their mutual interactions. The ideas behind the PopRank are that i) high impact pages attract many users with a low engagement, which means that they receive comments from users that rarely comment, and ii) high engagement users interact with high impact pages, that is they mostly comment pages with a high popularity. The resulting ranking of pages can predict the number of comments a page will receive and the number of its posts. Pages impact turns out to be slightly dependent on pages' informative content (e.g., science vs conspiracy) but independent of users' polarization.Comment: 10 pages, 5 figure

Lithium disilicate posterior overlays: clinical and biomechanical features

The aim of this study was to evaluate the survival rate of lithium disilicate overlays in increasing occlusal vertical dimension (OVD) in the setting of minimally invasive techniques and the restoration thicknesses at different tooth sites. This is an observational study evaluating 43 lithium disilicate overlays (Lithium IPS e.max Press, Ivoclar Vivadent) on 8 patients, prepared with minimally invasive criteria over a follow-up period between 19 to 45 months (mean follow-up of 32 months). Occlusal vertical dimension's increase was planned using occlusal treatment plan and diagnostic wax-up. Prior to adhesive cementation, restoration thicknesses were measured with a caliber. The survival rate was calculated by Kaplan-Meier analysis. Restoration survival rates at 32 months were 97.7%. One infiltration was observed, no cases of fracture occurred. The greatest thickness in monolithic restorations was detected in the cusp sides of teeth, whereas the thinnest was highlighted in the central fossa. The average amount of dental tissue removed during preparation was 0.98 mm in non-functional cusps, 0.88 mm in functional cusps, and 0.57 mm in the central fossa. Lithium disilicate posterior overlays show an excellent complication-free survival rate, and the material allows for conservative restorations with minimum thickness. Monolithic lithium disilicate overlays feature a satisfying 32-month survival rate. The technique allows to perform restorations with a minimal removal of dental tissue, while limiting fractures over time. Its esthetical performance is excellent

flow curve prediction of zam100 magnesium alloy sheets using artificial neural network based models

Abstract A multivariable empirical model, based on an artificial neural network (ANN), was developed to predict flow curves of ZAM100 magnesium alloy sheets as a function of process parameters in hot forming conditions. Tensile tests were performed in a wide range of temperature and strain rate to collect the dataset used in the training and testing stages of the network. The generalization ability of the model was tested using both the leave-one-out cross-validation method and flow curves not belonging to the training set. The excellent fitting between experimental and predicted curves was proven the very good predictive capability of the model

in process control of rotational speed in friction stir welding of sheet blanks with variable mechanical properties

Abstract In the present work, an adaptive control constraint system was applied in the friction stir welding of AA6082 aluminum alloy with the aim of tailoring the mechanical properties of the sheet blank to the subsequent forming processes. To this purpose, blanks in the solution heat-treated and artificially aged (T6), and in the annealed (O) conditions were welded according to a well defined layout. Such in-process control strategy was based on the variation of the controlled variable (rotational speed of the pin tool) in order to keep the measured one (vertical force) constant during the welding stage of the process. To this end, a preliminary investigation on the effect of the rotational speed, varying from 1000 to 2500 rpm, on the vertical force during FSW was performed. The capability of the proposed approach in friction stir welding sheet blanks with variable mechanical properties along the welding line was proven

Health-Promoting Properties of Plant Products: The Role of Mycorrhizal Fungi and Associated Bacteria

The concept of food quality, traditionally based on nutritional and sensory properties, has recently acquired an additional meaning, referring to the health-promoting properties of plant products, that are ascribed to plant secondary metabolites called phytochemicals, primarily represented by polyphenolic compounds and glucosinolates. The diversity and content of phytochemicals in plant products are affected by different variables, such as plant genotype, agronomic factors, and arbuscular mycorrhizal fungi (AMF), which establish mycorrhizal symbioses with most crops, including cereals, legumes, vegetables, fruit trees, sunflower, cotton, and sugarcane. AMF and associated bacteria enhance plant growth and health, and affect the production of polyphenols and carotenoids, and the activity of antioxidant enzymes. The production of health-promoting phytochemicals was shown to be differentially modulated by different AMF isolates and bacterial strains, in several food plants, i.e., tomato, lettuce, strawberry, artichoke, maize, grapevine, sunflower. Here, we provide an overview of recent studies concerning the multiple roles played by AMF and associated bacteria in the modulation of the biosynthesis of plant secondary metabolites with health-promoting activity, and discuss the development of designed multifunctional consortia to be used in sustainable agriculture

L'impresa sociale per la crescita del territorio. L'esperienza di Hermete

Il lavoro socio-educativo può essere declinato nella sua operatività in diversi modi. Nell’articolo si racconta l’approccio sviluppato da Hermete, cooperativa del veronese, le sue peculiarità organizzative e la scelta di radicarsi in un territorio circoscritto. Nella seconda parte, viene presentato un progetto di comunità e le comprensioni di metodo avvenute durante le varie attivit

Arbuscular Mycorrhizal Fungi and Associated Microbiota as Plant Biostimulants: Research Strategies for the Selection of the Best Performing Inocula

Arbuscular mycorrhizal fungi (AMF) are beneficial soil microorganisms establishing mutualistic symbioses with the roots of the most important food crops and playing key roles in the maintenance of long-term soil fertility and health. The great inter- and intra-specific AMF diversity can be fully exploited by selecting AMF inocula on the basis of their colonization ability and efficiency, which are aaffected by fungal and plant genotypes and diverse environmental variables. The multiple services provided by AMF are the result of the synergistic activities of the bacterial communities living in the mycorrhizosphere, encompassing nitrogen fixation, P solubilization, and the production of phytohormones, siderophores, and antibiotics. The tripartite association among host plants, mycorrhizal symbionts, and associated bacteria show beneficial emerging properties which could be efficiently exploited in sustainable agriculture. Further in-depth studies, both in microcosms and in the field, performed on different AMF species and isolates, should evaluate their colonization ability, efficiency, and resilience. Transcriptomic studies can reveal the expression levels of nutrient transporter genes in fungal absorbing hyphae in the presence of selected bacterial strains. Eventually, newly designed multifunctional microbial consortia can be utilized as biofertilizers and biostimulants in sustainable and innovative production systems

Deformation behavior of pre-painted steel sheets

Abstract The present work aims at studying the tensile behaviour of a hot-dip galvanized Z100 steel sheet, coated with a silicone-modified polyester resin. To this purpose, the pre-painted steel sheet was subjected to interrupted tensile tests at different strain levels in order to evaluate the elongation capability of both paint coating and steel sheet. The occurrence of superficial damages on paint coating was detected and the damage evolution before the sample fracture was analyzed. Furthermore, the thinning of each layer of the pre-painted sheet was also evaluated as a function of strain levels. Before the onset of necking, the degree of thinning on the different layers is almost uniform, whilst, once the necking was reached, a noticeable reduction in the thickness of both paint and steel sheet can be observed in the central zone of tensile sample

Buckling behavior of 3D printed composite isogrid structures

Abstract Different 3D printed composite isogrid structures in polyamide reinforced with 20% in weight of short carbon fiber were manufactured by means of fused deposition modeling process. Six configurations were realized varying the rib width and the rib thickness of the structures. The isogrid panels were tested under compressive load in order to investigate the effect of geometric parameters on the buckling behavior, in terms of strength and specific strength. Different failure modes were identified, depending on geometric parameters: global and local buckling. Finally, optical microscopy was carried out in order to analyze the fractured ribs after buckling. It was demonstrated that the configurations which result in the highest strength are not the same of those providing the highest specific strength

Improved thrombin binding aptamer analogues containing inversion of polarity sites: structural effects of extra-residues at the ends

In this paper, we report the investigations, based on NMR, molecular modelling, CD measurements and electrophoresis, of thrombin binding aptamer (TBA) analogues containing an extra-residue at the 3’-end or at both the ends of the original TBA sequence, linked through 3’–3’ or 5’–5’ phosphodiester bonds. The data indicate that most of the modified aptamers investigated adopt chair-like G-quadruplex structures very similar to that of the TBA and that stacking interactions occur between the 3’–3’ or 5’–5’ extra residues and the deoxyguanosines of the upper G-tetrad. A comparison of the thermodynamic data of TBA-A and TBA-T containing a 3’–3’ extra residue and their canonical versions clearly indicates that the 3’–3’ phosphodiester bond is fundamental in endowing the modified aptamers with remarkably higher thermal stabilities than the original TBA