RESUMO
This study investigates the emergence of extreme events in two different coupled systems: the FitzHugh-Nagumo neuron model and the forced Liénard system, both based on time-varying interactions. The time-varying coupling function between the systems determines the duration and frequency of their interaction. Extreme events in the coupled system arise as a result of the influence of time-varying interactions within various parameter regions. We specifically focus on elucidating how the transition point between extreme events and regular events shifts in response to the duration of interaction time between the systems. By selecting the appropriate interaction time, we can effectively mitigate extreme events, which is highly advantageous for controlling undesired fluctuations in engineering applications. Furthermore, we extend our investigation to networks of oscillators, where the interactions among network elements are also time dependent. The proposed approach for coupled systems holds wide applicability to oscillator networks.
RESUMO
Alzheimer's disease (AD) is a devastating neurodegenerative disorder that affects millions of people worldwide. The characteristic pathological manifestation of AD includes the deposition of extracellular insoluble ß amyloid plaques and intracellular neurofibrillary tangles formed from hyperphosphorylated tau protein. Cost effective and minimally invasive peripheral blood-based biomarkers are critical for early AD diagnosis. Currently, the plasma based two fraction of ß amyloid peptide ratio (Aß42/40) and phosphorylated tau (p-tau) are considered as blood-based biomarkers for AD diagnosis. Recent research indicates that oxidative stress (OS) occurs prior to amyloid plaque (Aß) formation and abnormal tau phosphorylation in AD. The imbalance of the master antioxidant, glutathione (GSH), and prooxidants (iron, zinc, and copper)âplays a crucial role in AD neurodegeneration. We present peripheral blood-based OS related biomarkers that are mechanistically involved in the disease process and may serve as a novel screening tool for early detection of AD onset. This OS based approach may also provide a quick and cost efficient method to monitor the effects of disease-modifying therapies in AD clinical trials.