1,799 research outputs found
Possibile impiego delle cellule staminali del fluido amniotico per la riparazione del danno polmonare in un modello animale per broncodiplasia: valutazione in vitro e in vivo
No full textIntroduction.
Since our knowledge on the replication and differentiating capability of the respiratory tract is still limited, the therapeutic potential of this system is quite unexplored. The respiratory disease in pediatric age concerns several pathologies among which broncopulmonary dysplasia (BPD) in neonate and premature newborns, asthma and cistyc fibrosys are the most studied because of their diffusion among children and their infaust prognosis.. In the last few years some studies have shown the possibility of deriving progenitors with various potential from the amniotic fluid. Amniocentesis is a widely accepted method for prenatal diagnosis; it is associated with low risk both for the mother and the fetus and overcomes the ethical problems commonly associated to other sources. Recently, it has been described that amniotic fluid stem (hAFS) cells, for their ability to differentiate to various lineages, could represent a good candidate for therapeutic applications. The recent characterization of hAFS and the consolidation of the techniques for intratracheal transplantation have shown new perspectives for gene and cell therapy applications. In particular, for these purposes hAFS cells should be genetically modified with a therapeutic gene and delivered systematically or injected directly into the tissue of interest.
Materials and methods
The in vitro phase has evaluated for the first time the possibility to infect hAFS with first generation E1-deleted adenoviral vectors, and the mantainence of the stemness and differentiating capability even after transduction with foreign gene sequences.
In the in vivo phase of the project we verified the pulmonary homing and the eventual engraftment of hAFS cells, after intratracheal administration, in a 60% O2 rat model presenting a respiratory disease similar to the one observed in human patients affected by broncopulmonary dysplasia (BPD) and cystic fibrosis. The symptoms were reproduced by using OXYCYCLER, with two pressurized rooms in which animals are exposed at controlled percentages of O2 and CO2. In this trial, hAFS cells have been infected AdHCMVsp1LacZ, a first generation E1 deleted viral vector transducing LacZ, the β-gal specific gene used as marker.
Results
At first, we investigated the feasibility of transducing hAFS cells with adenoviral vectors and to determine whether transduced stem cells retain the ability to differentiate into different lineages. Herein, we showed that hAFS cells could be efficiently infected by first generation adenovirus vectors. In addition, we demonstrated that infection and expression of two different marker genes, LacZ and EGFP, have no effect on cells phenotype and differentiation potential. In particular, on undifferentiated status, hAFS cells continued to express both the transgenes and stemness cell markers OCT4 and SSEA4 (stage-specific embryonic antigen 4). When cultured under mesenchymal conditions, infected cells could still differentiate into osteocytes and adipocytes expressing lineage specific genes.
Differently to what observed in embryonic stem cells, the amniotic fluid stem cells easily infect very efficiently. This could represent an excellent starting point for gene therapy studies in which a transient expression would be a necessary condition to the therapeutic approach.
In the in vivo phase we transplanted hAFS cells with an intratracheal administration in a rat model generated exposing newborns at 60% O2 for two weeks, reproducing in this way the chronic damage that can be seen in human patients affected by BPD. The results show that the model for chronic lung damage has been properly implemented; specific staining for lacZ performed three weeks post-transplant confirmed for hAFS cells a bronchiolar homing. After four weeks transplantation LacZ positive cells have been detected inside alveolis. Finally, an important phenomenon of damage repair was observed in the treated animals as compared to untreated controls
Automating the Layout of Analog Circuits: A Machine Learning-Based Approach
No full textProcesses are nowadays permeated by the usage of artificial intelligence (AI) techniques, aiming at boosting their efficiency and accessibility. Such extensive adoption of AI methods has been fueled by remarkable progress in the chip manufacturing industry, particularly through the reduction in transistor sizes and circuit components in general. These advancements have made available an enormous amount of computational power, enabling to advance the status of AI-based solutions, especially in fields such as natural language processing. Leveraging AI to accelerate and optimize chip design has, in turn, emerged as a critical research direction. Significant improvements have been reached in the digital circuits domain, especially with the adoption of automated learning-based frameworks. On the contrary, the field of analog circuit design, especially for what concerns the layout phase, continues to lag behind its digital counterpart in terms of automation, as it is affected by unique challenges originated from specific electric and topological constraints to abide by. As a result, the proposed solutions to streamline the layout procedure have seen limited applicability at the industrial level.
This thesis provides a wide range of techniques for generating the layout of analog integrated circuits, with a specific focus on leveraging reinforcement learning (RL) for floorplanning, along with pathfinding and deterministic approaches for efficient routing. We start with a dual development of a floorplanning engine, one combining RL and simulated annealing (SA) and another solely on RL mimicking the SA search process. An obstacle-avoiding rectilinear Steiner tree global routing system is also proposed and integrated with the floorplanning engine into an existing procedural layout generation framework for finalizing layouts. We demonstrate the effectiveness of learning-based approaches in exploring a large solution space better than metaheuristic techniques, while also reducing runtimes compared to manually crafted layouts. Then, to improve generalization and transferability, we devise a novel floorplanning solution that combines relational graph convolutional neural networks (R-GCNs) with RL to scale layout generation to more complex circuits. Devices are placed on a discretized grid, providing greater flexibility for the RL agent to optimize circuit area and proxy wirelength metrics. Moreover, we propose a plug-and-play integration based on a beam search strategy to enhance the RL inference process, allowing for flexible objective weighting tailored to specific use cases and addressing congestion without policy finetuning. Lastly, we present a routing-aware version of the floorplanning engine, which builds upon the R-GCN RL approach. This enhanced framework leverages a novel U-Net policy, dynamic routing resource estimation, and revised reward scheme for delivering routing-ready floorplans. A prototype A* rip-up and reroute analog routing engine is also proposed, allowing the generation of complete layouts, showing how this novel framework consistently outperforms previous methods in both routability and placement performance.Processes are nowadays permeated by the usage of artificial intelligence (AI) techniques, aiming at boosting their efficiency and accessibility. Such extensive adoption of AI methods has been fueled by remarkable progress in the chip manufacturing industry, particularly through the reduction in transistor sizes and circuit components in general. These advancements have made available an enormous amount of computational power, enabling to advance the status of AI-based solutions, especially in fields such as natural language processing. Leveraging AI to accelerate and optimize chip design has, in turn, emerged as a critical research direction. Significant improvements have been reached in the digital circuits domain, especially with the adoption of automated learning-based frameworks. On the contrary, the field of analog circuit design, especially for what concerns the layout phase, continues to lag behind its digital counterpart in terms of automation, as it is affected by unique challenges originated from specific electric and topological constraints to abide by. As a result, the proposed solutions to streamline the layout procedure have seen limited applicability at the industrial level.
This thesis provides a wide range of techniques for generating the layout of analog integrated circuits, with a specific focus on leveraging reinforcement learning (RL) for floorplanning, along with pathfinding and deterministic approaches for efficient routing. We start with a dual development of a floorplanning engine, one combining RL and simulated annealing (SA) and another solely on RL mimicking the SA search process. An obstacle-avoiding rectilinear Steiner tree global routing system is also proposed and integrated with the floorplanning engine into an existing procedural layout generation framework for finalizing layouts. We demonstrate the effectiveness of learning-based approaches in exploring a large solution space better than metaheuristic techniques, while also reducing runtimes compared to manually crafted layouts. Then, to improve generalization and transferability, we devise a novel floorplanning solution that combines relational graph convolutional neural networks (R-GCNs) with RL to scale layout generation to more complex circuits. Devices are placed on a discretized grid, providing greater flexibility for the RL agent to optimize circuit area and proxy wirelength metrics. Moreover, we propose a plug-and-play integration based on a beam search strategy to enhance the RL inference process, allowing for flexible objective weighting tailored to specific use cases and addressing congestion without policy finetuning. Lastly, we present a routing-aware version of the floorplanning engine, which builds upon the R-GCN RL approach. This enhanced framework leverages a novel U-Net policy, dynamic routing resource estimation, and revised reward scheme for delivering routing-ready floorplans. A prototype A* rip-up and reroute analog routing engine is also proposed, allowing the generation of complete layouts, showing how this novel framework consistently outperforms previous methods in both routability and placement performance
Myocarditis. Reply
No full textTo the Editor: In the review article on myocarditis by Basso (Oct. 20 issue),(1) the author recommends invasive coronary angiography for diagnostic workup in patients with suspected myocarditis in order to rule out underlying coronary artery disease (CAD).(1) Strong evidence suggests that noninvasive coronary computed tomographic angiography (CCTA) has similar diagnostic accuracy and is associated with a lower incidence of adverse events than invasive coronary angiography in patients with chronic coronary syndrome.(2) In fact, recent guidelines on the management of chest pain(3) and prevention of sudden cardiac death(4) recommend CCTA as a class I indication, which should be preferred over . .
La casa pubblica. Storia dell’Istituto Autonomo Case Popolari di Torino
No full textRecensione del volume "La casa pubblica. Storia dell’Istituto Autonomo Case Popolari di Torino", di Daniela Adorni, Maria D’Amuri, Davide Tabor, Roma, Viella, 201
Erosion de la nature, stratification de l'humain. Tournant ontologique et écologie sémiotique
No full textThe article “Érosion de la nature, stratification de l’humain: Tournant ontologique et écologie sémiotique” by Pierluigi Basso Fossali explores the interplay between ecological thought and semiotics, emphasizing the ontological challenges posed by the relationship between nature and culture. The author critiques the oversimplification of nature as a static regulatory principle, advocating instead for a dynamic semiotic ecology that acknowledges the interdependence of cultures, environments, and symbolic systems. The text highlights the necessity of rethinking environmental discourse through a multi-layered perspective that transcends traditional dichotomies, such as nature versus culture, while embracing the epistemological contributions of diverse civilizations. By integrating the notions of resistance, translation, and intersubjectivity, the article argues for a pluralistic understanding of ecological frameworks as both cultural constructs and practical paradigms for addressing global environmental challenges
Experimental evaluation of lateral transfer functions and structural modes of two-wheeled vehicles
No full textThe dynamic behaviour of two-wheeled vehicles is simulated by means of powerful multi-body codes in which the vehicle is described as a system ofrigid bodies with elastic suspensions and tires [l]. The structural modes of vibration of motorcycle and scooter chassis are usually neglected, but they may bave a significant influence on severa! features of vehicle's behaviour such as comfort, shockabsorption and braking, which are related to dynamics in the symmetry piane, and handling and stability, which are related to out-of-plane dynamics [2]. The purposes of this research program are: the identificati an of the structural modes of vibrati an of two-wheeled vehicles, the measurement of the latera) transfer functions (between latera! accelerations and latera! tire forces) and, eventually, the integration of experimental modal analysis with multi-body simulation. Structural moda! analysis of the vehicle's subsystems (such as chassis, forks and tires [3]) and ofthe whole vehicle was carried out.
Structural moda! analysis of the whole vehicle is very interesting, since the identified moda! parameters (natura! frequencies, mode shapes) are related to vehicle stability and handling. When performing moda! testing of the whole vehicle, constraints similar to the ones caused by the contact between the rolling tire and the road bave to be introduced. Far this reason the modal analysis was carried out exciting one tire with a special equipment and with the other tire in free condition or in contact with a rough surface. The structural modification method was then used to correlate the results achieved in the two testing conditions and to simulate the constraints that are present when the tire rolls on the road. Moda! analysis was carried out with global methods and results are presented in terms of lateral transfer functions of significant points ( e.g. handle-bars), natural frequencies, damping factors and mode shapes. Finally the influence of structural behaviour on stability and handling is
discusse d. The different ranges of motorcycle and scooter modes are highlighted and the effect of low frequency torsi an modes of scooters is discussed too
Application of the Half-Order Derivative to Impedance Control of the 3-PUU Parallel Robot
No full textThis paper presents an extension of impedance control of robots based on fractional cal-culus. In classical impedance control, the end-effector reactions are proportional to the end-effector position errors through the stiffness matrix K, while damping is proportional to the first-order time-derivative of the end-effector coordinate errors through the damping matrix D. In the proposed approach, a half-derivative damping is added, proportional to the half-order time-derivative of the end-effector coordinate errors through the half-derivative damping matrix HD. The discrete-time digital implementation of the half-order derivative alters the steady-state behavior, in which only the stiffness term should be present. Consequently, a compensation method is proposed, and its effectiveness is validated by multibody simulation on a 3-PUU parallel robot. The proposed approach can be considered the extension to MIMO robotic systems of the PDD1/2 control scheme for SISO mechatronic systems, with potential benefits in the transient response performance
Photoinduced Multicomponent Reactions
No full textThe combination of multicomponent approaches with light-driven processes opens up new scenarios in the area of synthetic organic chemistry, where the need for sustainable, atom- and energy-efficient reactions is increasingly urgent. Photoinduced multicomponent reactions are still in their infancy, but significant developments in this area are expected in the near future
Criteria for Selecting Optimal Nitrogen Fertilizer Rates for Precision Agriculture
No full textYield rates vary spatially and maps produced by the yield monitor systems are evidence of the degree of withinfield variability. The magnitude of this variability is a good indication of the suitability of implementing a spatially variable management plan. Crop simulation models have the potential to integrate the effects of temporal and multiple stress interaction on crop growth under different environmental and management conditions. The strength of these models is their ability to account for stress by simulating the temporal interaction of stress on plant growth each day during the season. The objective of paper is to present a procedure that allows for the selection of optimal nitrogen fertilizer rates to be applied spatially on previously identified management zones through crop simulation modelling. The integration of yield maps, remote sensing imagery, ground truth measurements, electrical resistivity imaging allowed for the identifications of three distinct management zones based on their ability to produce yield and their stability over time (Basso et al., 2009). After validating the model, we simulated 7 N rates from 0 to 180 kg N/ha with a 30 kg N/ha increment. The model results illustrate the different N responses for each of the zone. The analysis allowed us to identify the optimal N rate for each of the zone based on agronomic, economic and environmental sustainability of N management
Innovare «dal basso» le politiche attive tra formazione e lavoro: un’analisi delle esperienze italiane
No full textIl rapporto tra formazione e lavoro è centrale nella strategia europea ma l’emergenza occupazionale attuale impone un ripensamento delle politiche. L’analisi delle transizioni ha evidenziato che il successo del lavoratore non dipende solo dalle competenze possedute ma anche dalla capacità di attivare e combinare risorse identitarie e sociali in un momento in cui le carriere si fanno più frammentate e incerte, con elevati rischi di intrappolamento, over-education e over skilling. Ciò ha contribuito a una crescente assunzione di responsabilità dei sistemi educativi,
valorizzando la dimensione formale e informale dei processi di apprendimento. Pur in assenza di analisi puntuali, la valutazione delle recenti politiche attive nel paese, come il Progetto Neet o Youth Guarantee, conferma però i deficit delle politiche top down e incoraggia l’ampliamento
del dibattito sull’innovazione partendo da esperienze alternative di tipo bottom up. Il contributo individua i tratti di iniziative «dal basso», riflettendo criticamente sulle loro caratteristiche di innovazione e sul rapporto tra formazione ed employability
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