Search results for "plasticity"
showing 10 items of 765 documents
Transumanesimo e postumanesimo alla luce della plasticità
2019
Postumanesimo e transumanesimo condividono la stessa idea: l’“uomo di oggi” è l’anticipazione di qualcosa di nuovo. I promotori di tali movimenti teorici sono convinti che la farmacologia, la nanotecnologia, la manipolazione genetica e le tecno-scienze plasmeranno una nuova umanità. L’essere umano si caratterizza, infatti, per un’elevata plasticità, concetto analizzato dalla pensatrice francese Catherine Malabou e che indica l’attitudine a dare e ricevere forma. Nella presente trattazione ci proponiamo di chiarire perché il principio di variazione plastica rappresenti il campo di battaglia fra la prospettiva teorica umanista e quella postumanista e, in secondo luogo, di delineare il diverso…
Three Effective Ways to Nurture Our Brain
2017
Abstract. A growing body of research suggests that physical activity, healthy eating, and music can, either directly or indirectly, have positive effects on our brain and cognition. More specifically, exercising and eating seem to enhance cognitive abilities, such as memory, creativity, and perception. They also improve academic performance and play a protective role from many degenerative diseases, including Alzheimer’s disease. Concerning music, research has shown that there exists a general positive relation between music aptitude and cognitive functioning. Furthermore, the presence of music seems to create a positive mood and a higher arousal, which translates into better performance i…
Tinnitus: a vision for research
2009
Tinnitus is classically defined as the perception of sound that has no external source. It was assumed to be primarily a disorder of the ear and has been linked to mechanisms equivalent to phantom pain; a pain sensation located to a no longer existing part of the body. Phantom pain is closely correlated with a cortical plasticity and with a reorganization of the somatosensory cortex. The end result is an alteration of neuronal activity, leading to tinnitus. Over the past decade, however, research on brain mechanisms of tinnitus has progressed rapidly, and insights have emerged into the possible neurological origins of tinnitus without any auditory dysfunction. Identification of the neurosci…
TERMODINAMICA, CAMPI QUANTICI E FUNZIONI MENTALI
2010
Nel tentativo di fornire spiegazioni esaurienti sul fenomeno della mente umana, il presente saggio scientifico di anatomia comparata e di fisiologia considera alcune tesi di fondo che si collegano a nuovi parametri fisici della realtà che ci circonda.
Weak forms of shakedown for elastic-plastic structures exhibiting ductile damage
2001
A special weak-form shakedown is studied for elastic-plastic internal-variable material models with nonlinear hardening, damageable elastic moduli and damageable yield surface, in the hypothesis of ductile damage, (i.e. damage induced by plastic strains), but the precise evolutive law of damage being left unspecified. Sufficient weak-form shakedown theorems are presented, one static and another kinematic, each assessing whether eventually plastic deformations cease together with their consequences, including ductile damage. A two-sided delimitation is provided, within which the weak-form shakedown safety factor can be located. An upper bound to the post-transient damage for a particular iso…
SHORT-TERM SYNAPTIC PLASTICITY IN MIGRAINE MOTOR CORTEX: EVIDENCE BY PRECONDITIONING OF HIGH-FREQUENCY REPETITIVE TRANSCRANIAL MAGNETIC STIMULATION (…
2011
Background: Brief 5Hz repetitive transcranial magnetic stimulation (rTMS) trains at 120% of the resting- motorthreshold (RMT) intensity determine in healthy subjects a potentiation of motor evoked potentials (MEPs), likely due to short-term presynaptic plasticity facilitation. We recently showed paradoxical intensity-dependent MEP changes to 5Hz rTMS in migraine with MEP facilitation at 110% and inhibition at 130% RMT. This provides evidence of both hyper-responsivity and self-limiting hyperexcitability capacity in migraine, likely due to earlier activation of inhibitory homeostatic plasticity mechanisms. To explore this, we applied in migraineurs cathodal transcranial Direct Current Stimul…
N6 -Methyladenosine Modification in Chronic Stress Response Due to Social Hierarchy Positioning of Mice
2021
Appropriately responding to stressful events is essential for maintaining health and well-being of any organism. Concerning social stress, the response is not always as straightforward as reacting to physical stressors, e.g., extreme heat, and thus has to be balanced subtly. Particularly, regulatory mechanisms contributing to gaining resilience in the face of mild social stress are not fully deciphered yet. We employed an intrinsic social hierarchy stress paradigm in mice of both sexes to identify critical factors for potential coping strategies. While global transcriptomic changes could not be observed in male mice, several genes previously reported to be involved in synaptic plasticity, l…
A method to transform a nonlocal model into a gradient one within elasticity and plasticity
2014
Abstract A method based on the principle of the virtual power (PVP) is presented, by which a mechanical problem of nonlocal elasticity, or plasticity, is transformed into one of gradient nature. Different Taylor series expansion techniques are applied to the driving local strain fields of the nonlocal problem, either full spatial expansion within the bulk volume, or uni-directional expansion along the normal to the thin boundary layer. This, at the limit when the boundary layer thickness tends to zero, makes the PVP of the nonlocal model transform itself into one featuring a counterpart gradient model. Also, for a class of “associated” nonlocal and gradient elasticity models (i.e. the kerne…
Consistent shakedown theorems for materials with temperature dependent yield functions
2000
The (elastic) shakedown problem for structures subjected to loads and temperature variations is addressed in the hypothesis of elastic-plastic rate-independent associative material models with temperature-dependent yield functions. Assuming the yield functions convex in the stress/temperature space, a thermodynamically consistent small-deformation thermo-plasticity theory is provided, in which the set of state and evolutive variables includes the temperature and the plastic entropy rate. Within the latter theory the known static (Prager's) and kinematic (König's) shakedown theorems - which hold for yield functions convex in the stress space - are restated in an appropriate consistent format…
Zum Wandel motorischer Einheiten bei Änderung des Aktivitätsmusters durch elektrische Reizung - Elektrostimulation und ihre klinischen Einsatzmöglich…
1989
Motoneuron and muscle fibers interact on the motor unit level, whereby discharge characteristics from the neuron imposed on the muscle seem to play a major role. Within the unit all muscle fibers are biochemically homogeneous and display a high degree of plasticity under different functional demands. To distinguish the existing different units rationals are listed that classify the units by physiological and histochemical parameters. Furthermore the review summarizes the available knowledge on the importance of activity patterns--as a biological principle--involved in the control of phenotypic expression of innervated and denervated muscle. The sequelae are shown of electrical stimulation o…