Stochastic fluctuations of permittivity coupling regulate seizure dynamics in partial epilepsy

Partial epilepsy is characterized by recurrent seizures that arise from a localized pathological brain region. During the onset of partial epilepsy, the seizure evolution commonly exhibits typical timescale separation phenomenon. This timescale separation behavior can be mimicked by a paradigmatic model termed as Epileptor, which consists of coupled fast-slow neural populations via a permittivity variable. By incorporating permittivity noise into the Epileptor model, we show here that stochastic fluctuations of permittivity coupling participate in the modulation of seizure dynamics in partial epilepsy. In particular, introducing a certain level of permittivity noise can make the model produce more comparable seizure-like events that capture the temporal variability in realistic partial seizures. Furthermore, we observe that with the help of permittivity noise our stochastic Epileptor model can trigger the seizure dynamics even when it operates in the theoretical nonepileptogenic regime. These findings establish a deep mechanistic understanding on how stochastic fluctuations of permittivity coupling shape the seizure dynamics in partial epilepsy,and provide insightful biological implications.

Maritime network dynamics before and after international events

Investigating the influence of international events on global maritime networks is a challenging task that must comprehensively incorporate geographical, political, and maritime sciences. Understanding global maritime network dynamics is an initial and critical step in this investigation. This study proposes an automatic identification system(AIS)-based approach to understanding maritime network dynamics before and after international events. In this approach, a spatiotemporal modeling method is introduced to measure the similarity in shipping trends before and after international events. Then, a spatiotemporal analytic framework is proposed to understand the maritime network dynamics by grouping similar situation, and assessing possible indirect effects within a network. Finally, three case studies of international events, military conflict, lifted economic sanctions, and government elections, were used to investigate the observed network dynamics possibly affected by international events. The results indicate that container, tanker, and bulk shipping between India and its connected countries all declined more than 69% after military conflicts between India and Pakistan in August 2015. Tanker shipping between Iran and the United Arab Emirates increased 51% after economic sanctions on Iran were lifted. Container shipping between Sri Lanka and Singapore, Malaysia, and India increased more than 74% after the general election in Sri Lanka. These investigations demonstrate the feasibility of the proposed approach in assessing the possible effects of international events on maritime network dynamics.

Dynamical fluctuations in fragmentation reactions in a Boltzmann-Langevin approach

Based on the isospin-dependent Boltzmann-Langevin model,the dynamical fluctuations in the fragmentation reaction of^(112)Sn+^(112)Sn are investigated.The quadrupole moment and octupole moment with zero magnetic quantum number have large fluctuations in the early time of the collisions.The dynamical fluctuations in momentum space show a strong dependence on the incident energy.The effects of using different fluctuations on the fragment cross sections are also studied in the fragmentation reactions.The results by using Q_(20)+Q_(30)fluctuation have a better agreement with the experimental data.Calculations using Q_(20)+Q_(30)fluctuation produce more proton-rich and neutron-rich nuclei than those using Q_(20)fluctuation only.Besides,the difference between the production cross sections of fragments calculated by using Q_(20)and Q_(20)+Q_(30)fluctuations is larger in the vicinity of the projectile.These results present that the dynamical fluctuations may affect the whole dynamical process of fragmentation reactions including the production of fragments,due to the nonlinear nature of the Boltzmann-Langevin equation.

Dynamic alterations of amplitude of low-frequency fluctuations in patients with chronic neck pain

Background:The pathogenesis of neck pain in the brain,which is the fourth most common cause of disability,remains unclear.Furthermore,little is known about the characteristics of dynamic local functional brain activity in cervical pain.Objective:The present study aimed to investigate the changes of local brain activity caused by chronic neck pain and the factors leading to neck pain.Methods:Using the amplitude of low-frequency fluctuations(ALFF)method combined with sliding window approach,we compared local brain activity that was measured by the functional magnetic resonance imaging(fMRI)of 107 patients with chronic neck pain(CNP)with that of 57 healthy control participants.Five pathogenic factors were selected for correlation analysis.Results:The group comparison results of dynamic amplitude of low-frequency fluctuation(dALFF)variability showed that patients with CNP exhibited decreased dALFF variability in the left inferior temporal gyrus,the middle temporal gyrus,the angular gyrus,the inferior parietal marginal angular gyrus,and the middle occipital gyrus.The abnormal dALFF variability of the left inferior temporal gyrus was negatively correlated with the average daily working hours of patients with neck pain.Conclusions:The findings indicated that the brain regions of patients with CNP responsible for audition,vision,memory,and emotion were subjected to temporal variability of abnormal regional brain activity.Moreover,the dALFF variability in the left inferior temporal gyrus might be a risk factor for neck pain.This study revealed the brain dysfunction of patients with CNP from the perspective of dynamic local brain activity,and highlighted the important role of dALFF variability in understanding the neural mechanism of CNP.

A Dynamic Model of Sensibility Analysis in Project Evaluation

The study on multi-faCtor Sensibility analysis problem in project evaluation, [1]-I4] gave the static models respectively. In order to raise the practicality and reliability of sensibility analysis,we propoes a dynamic model in this paper. Comparing with the above, our model has four special features. First, it is suitable for us to optimize and control the Proceeding Project and evaluate the completed Project as well. Second, it offers quantitative measures of sensitivity formulas. Third,it can evaluate project dynamically so that it can obtain much higher precision and reliability . Fourth,it can deal with Problem which involved in cost of capital fluctuation.