Archivio della ricerca della Scuola Superiore Sant'Anna
Not a member yet
26957 research outputs found
Sort by
Orchestrating the Matrix: The Role of Glial Cells and Systemic Signals in Perineuronal Net Dynamics
No full text: Perineuronal nets (PNNs) are specialized, dense extracellular matrix structures that enmesh the cell bodies and dendrites of specific neurons, most notably inhibitory interneurons. Increasing evidence indicates that PNNs serve not merely as passive scaffolds but play an active and essential role in modulating synaptic plasticity and circuit physiology. They critically influence the timing of sensory system critical periods, as well as processes underlying learning, memory, and higher cognitive functions. Furthermore, dysregulation of PNN density and architecture have been associated with conditions like autism, neurodevelopmental disorders, schizophrenia and Alzheimer's disease. Since they are extensively involved in brain function, we discuss the multitude of regulatory factors that govern the formation, maturation, and remodeling of PNNs. In particular, we focus on both molecular and cellular brain-intrinsic mechanisms, highlighting the potential contributions of microglia and astrocyte derived factors. Additionally, we consider the influence of long-range signaling cues, including the metabolic status and peripheral hormones. Analysing this complex network of interactors, we try to highlight the role of PNNs beyond neural plasticity and brain function, in a broader whole-body physiological perspective
Constitutive Modeling of Creep–Fatigue Interaction in 1Cr-1Mo-0.25V Steel for Hold-Time Testing
No full textIn the field of energy production, creep–fatigue interaction is a typical failure mode that might compromise the structural integrity of both rotating equipment and pressure vessels. Common design practices approach the problem in a conservative way by using high safety factors, which typically results in additional costs for manufacturing companies. The aim of this article, in the framework of continuum damage mechanics approaches, is to present a novel fatigue damage-based constitutive law. The presented law is directly inspired by well-assessed creep-based rules, suggesting a similarity in the behavior. On the other hand, creep deformation and damage are calculated with a more recent approach. The identification of the model parameters was carried out by interpreting experimental results obtained from low-cycle fatigue and creep relaxation tests performed on a commonly used ferritic–martensitic steel for power generation rotor forgings. To validate the proposed models, they were used to estimate material life consumption when the material was subjected to fully reversed axial loading conditions with hold time under tensile load. Different loading conditions at different total strain ranges and hold times were simulated, and good agreement was found between the predicted and experimental life, thus confirming the validity of the proposed models
Corporate purpose and systemic innovation: intra-organisational dynamics to address societal challenges
No full textRecent literature increasingly suggests that embracing corporate purposeprovides companies with a competitive edge in driving systemicinnovations, which are crucial for addressing complex societalchallenges in our interconnected world. However, there is a dearth ofempirical research exploring the organisational mechanisms throughwhich corporate purpose facilitates systemic innovation. Our studyseeks to address this gap by qualitatively analysing internal documents,reports, and interviews with managers and founders of four Italianpurpose-driven companies. Our findings reveal three key intra-organisational dynamics enabled by corporate purpose: (1) strategicvision and alignment, (2) engagement, motivation, and creativity, and(3) trust and relational contracts – all of which facilitate theimplementation of systemic innovation. This research contributes toboth the grand challenges and organisational theory literature byoffering a deeper understanding of how corporate purpose can beeffectively leveraged to drive positive change. Additionally, it serves tostimulate new avenues of inquiry for management scholars and offerspractical insights for companies striving to address the contemporarychallenges of our society
Reconnecting the vagus nerve to the heart through nerve conduit preserves cardiac function in a minipig model of right cardiac vagotomy
No full textThe right vagus nerve is essential for cardiac homeostasis, and its intrathoracic resection can lead to postoperative cardiac complications. Strategies to restore vagal innervation after transection at the cardiac level remain lacking. Here, we show that early reconnection of the right vagus nerve using an implantable chitosan/poly-ε-caprolactone cuff-like nerve guidance conduit preserved cardiac mechanical function in adult male minipigs subjected to right cardiac vagotomy. Treated animals displayed improved global circumferential, longitudinal, and radial strains and reduced diastolic dyssynchrony. Histological analysis revealed partial repair with about 20% viable vagal fascicles, restoration of myocardial parasympathetic fibers, normalization of oxidative stress and aging markers, and prevention of interstitial fibrosis. These findings suggest that maintaining even limited vagal input prevents early cardiac remodeling by mitigating oxidative stress-induced premature senescence of cardiac cells. Reconnection of the right vagus nerve with chitosan/poly-ε-caprolactone cuff-like nerve guidance conduit may represent a therapeutic approach to preventing right vagotomy-induced heart failure after thoracic surgery or cardiothoracic transplantation
A Novel Underwater Robot with Carangiform Locomotion Achieved via Single Degree of Actuation and Magnetically Transmitted Traveling Wave
No full textThe phenomenon of the “traveling wave,” commonly observed in various organisms, involves a wave that propagates along the body, serving as a locomotion mechanism. Particularly, in aquatic environments, organisms such as fish and cetaceans utilize traveling waves to propel themselves through water, minimizing fluid drag and maximizing movement efficiency. Inspired by nature, robotics has extensively explored replicating such locomotion strategies. This work presents a fish robot with an innovative magnetic transmission system. The mechanism transforms the unidirectional rotation of a single motor into an oscillatory, phase-shifted movement across the modules of the kinematic chain, generating a traveling wave along the body. The robot's design and functionality are detailed, highlighting advancements in bio-inspired robotics for underwater applications, such as efficient and non-invasive monitoring and exploration of marine ecosystems. The fish robot achieved a swimming speed of approximately 2 body lengths per second (BL/s) with a tail-beat frequency of 3.24 Hz and a minimum Cost of Transport (CoT) of 5.33 J/(kg⋅m). Biomimetic robotics can play a key role in sustainable aquafarming, biodiversity conservation, and animal-robot interaction research, offering the potential to minimize ecosystem disruption and advance marine science