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Modelling free-fall motion and vortex flows through the use of Tracker software: an inquiry-based teaching learning sequence
No full textThis article presents a teaching–learning sequence based on the inquiry-based learning approach, designed to help high-school students gain a deeper understanding of the physical principles of the free fall of bodies and the role of viscous resistive forces. The activity, centred on the use of the open-source video analysis software Tracker, enables students to explore the motion of small-radius spheres of different masses and materials, and to experimentally infer the effect of air viscosity on the motion of a lightweight polystyrene ball by means of the Tracker’s built-in modelling tool. An extension of the activity is also proposed, focusing on the vortex-induced motion to provide a clearer explanation of the observed phenomena. The comparison of the motion laws of balls of different mass allows students to overcome common misconceptions related to dynamics and engage with fundamental aspects of fluid dynamics, which are often addressed only superficially in traditional instruction. The experiment is conceived not simply as a laboratory task, but as an educational experience aimed at developing scientific curiosity and critical autonomy through direct experimentation
Development of a versatile indoor framework for the measurement of tyre compound friction and wear
No full textMaximising tyre performance requires balancing conflicting targets, grip, wear resistance, and rolling efficiency, while accelerating development. In this context, tribological characterisation at compound level supports faster prototyping and reduces reliance on full-scale testing. Although standards for rubber friction testing exist, they are rarely followed in literature, and procedures are often underreported. This work addresses that gap by presenting the complete development of an experimental framework for rubber friction and wear testing, with particular focus on tyre tread compound, from the definition of functional requirements to the design of a novel linear friction tester and the implementation of a robust testing methodology. The Ground Rubber Interface Performance (GRIP) tester was designed for high versatility and cost-effectiveness. A key feature is the open-access architecture, which allows practical surface management and rapid retooling. A custom back-heating system ensures uniform specimen temperature even under varying test conditions. The methodology focuses on critical but overlooked aspects: specimen conditioning, surface rubberisation, and temperature control. Case studies demonstrate the repeatability of results and the system’s sensitivity to key input parameters. Additional tests confirm the platform’s adaptability to non-tyre tribological applications
Machine Learning Approaches to Assess Soil Microbiome Dynamics and Bio-Sustainability
No full textUnderstanding soil microbiota dynamics is essential for enhancing bio-sustainability in agriculture, yet the complexity of microbial communities hampers the prediction of their functional roles. Artificial intelligence (AI) and machine learning (ML) offer powerful tools to analyse high-dimensional microbiome data generated by high-throughput sequencing. Here, we apply unsupervised AI-based algorithms to uncover microbial patterns that are not immediately recognisable but are crucial for characterising the biological status of agricultural soils. Soil samples were collected from a site in Northern Italy managed under four strategies: conventional farming without organic matter (C), with organic matter (C + O), with beneficial microorganisms but without organic matter (M), and with both beneficial microorganisms and organic matter (M + O). Metagenomic amplicon sequencing of the 16S ribosomal RNA (rRNA) gene and the internal transcribed spacer (ITS) region was used to profile bacterial and fungal communities. Principal component analysis (PCA), k-means clustering, and t-distributed stochastic neighbour embedding (t-SNE) revealed coherent temporal trajectories in both datasets, with sampling time and crop presence emerging as dominant drivers of community assembly and only subtle compositional shifts attributable to treatments. Fungal communities exhibited higher plasticity and a stronger response to management than bacterial communities, which converged towards a stable oligotrophic core. Our findings highlight the complementary roles of fungal and bacterial guilds and show that unsupervised ML-based workflows provide an effective framework to disentangle temporal and treatment effects in complex microbiome datasets. This exploratory study lays the groundwork for future predictive models aimed at identifying microbial indicators of soil biological status and supporting bio-sustainable agronomic decisions
Development and external validation of a nomogram predicting cancer-specific mortality-free survival after trimodal therapy in muscle-invasive bladder cancer
No full textIntroduction: We developed and externally validated a novel population-based model for predicting cancer-specific mortality free survival (CSM-FS) in trimodal therapy (TMT)-treated muscle-invasive bladder cancer (MIBC) patients, and we compared its performance to that of AJCC categories. Methods: Within the SEER database (2004–2021), we identified MIΒC patients treated with TMT (n = 1801). The population was randomly divided into development (n = 900, 50%) and external validation (n = 901, 50%) cohorts. Univariable Cox-regression models addressing CSM were fitted. Subsequently, the most parsimonious model with the best validation metrics was selected. Accuracy, calibration, and decision curve analyses (DCAs) tested the novel nomogram relative to the AJCC staging within the external validation cohort. Results: Age at diagnosis, sex, median household income, T stage, N stage, and tumor size qualified for inclusion in the nomogram predicting CSM-FS. In external validation cohort, the accuracy of the novel nomogram predictions at two vs. three vs. four years after TMT was 0.70 vs. 0.67 vs. 0.66, respectively. Conversely, AJCC staging accuracy was 0.57 vs. 0.56 vs. 0.55 for the same timepoints. The novel nomogram predictions were well calibrated relative to observed CSM-FS rates. Finally, in DCAs the novel nomogram outperformed AJCC staging at all three timepoints. Conclusion: The novel nomogram for TMT-treated patients outperformed AJCC-based predictions of CSM-FS, when accuracy and DCAs represented the benchmarks of interest. However, its predictive accuracy is not ideal
Gonadic cycle and environmental modulation of P450 aromatase localization in Cerastoderma glaucum ovary from Monastir Bay
No full text: The gonadic cycle of bivalve molluscs is highly variable and depends on several factors, including the geographical location and environmental conditions of the populations. The aim of this study was to analyse the gonadic cycle of Cerastoderma glaucum female by monitoring a population sampled in Monastir Bay (Tunisia) over a period of 13 months, correlating histological analyses of the ovary with environmental parameters. In addition, we studied the localisation of P450 aromatase, a key enzyme involved in the biosynthesis of 17β-estradiol, to understand its possible role in regulating the oogenesis process. Histological analysis of the ovary revealed the constant presence of oocytes at different stages of maturation, suggesting an asynchronous reproductive cycle, in which the reproductive phase of C. glaucum is continuous throughout the year, without periods of quiescence, and is characterized by three main reproductive events: one in spring, the most significant in summer and a final one in autumn. Environmental factors such as temperature appear to support the progression of gametogenesis, while salinity appears to influence the gamete release phase. Finally, the distribution of aromatase showed a clear correlation with oocyte maturation stages, suggesting a direct involvement of the enzyme in the progression of the female gonadal cycle. Aromatase expression therefore appears to respond to environmental changes, such as variations in water temperature, suggesting a possible mechanism of environmental regulation of reproductive function
Evolution of the aorta after valve replacement in bicuspid aortic valves: results at mid-term follow-up
No full textAim: Bicuspid aortic valve (BAV) is a common congenital heart defect often associated with ascending aorta dilation. Current guidelines suggest surgical intervention for diameters ≥45 mm in conjunction with surgical aortic valve replacement (SAVR). However, the optimal management of ascending aortas measuring 40–44 mm remains under debate. This study aims to evaluate the evolution of aortic diameter in patients with BAV and ascending aorta diameters between 40 and 44 mm undergoing aortic valve replacement, assessing whether a conservative approach is justified. Method: We conducted a retrospective observational study, analysing 88 patients with BAV who underwent SAVR between January 2012 and December 2018. Patients were divided into two groups based on preoperative ascending aorta diameters: <40 mm (Group 1, n=15) and the ≥40 and <45 mm (Group 2, n=11). Follow-up of at least 5 years included aortic dilation rates, survival, and reoperation rates. Results: No significant differences were observed in aortic dilation between the two groups during follow-up, with overall annual dilation rates of 0.2±0.07 mm/year. Survival rates were 86.3% for Group 1 and 81.9% for Group 2, with no reoperations required in either group. Conclusions: Patients with BAV and ascending aorta diameters of 40–44 mm do not require prophylactic aortic replacement during AVR, provided they undergo regular follow-up. These findings support current guidelines advocating conservative management for ascending aorta diameters in this range. However, in younger patients or those nearing the 45 mm threshold, surgical replacement may still be considered to pre-empt future complications
Forme di tutela previdenziale per la disabilità
No full textIl contributo analizza in chiave critica le attuali tutele previdenziali connesse alla disabilità, sia rispetto alla cura della salute sia rispetto alla riduzione della capacità di lavoro, interrogandosi altresì sulle incertezze derivati, in questo ampbito, dalle nuove norme sulla disabilità ex d.lgs. 62/2024
