The structured flow on the brain's resting state manifold

Spontaneously fluctuating brain activity patterns emerge at rest and relate to brain functional networks involved in task conditions. Despite detailed descriptions of the spatio-temporal brain patterns, our understanding of their generative mechanism is still incomplete. Using a combination of computational modeling and dynamical systems analysis we provide a complete mechanistic description in terms of the constituent entities and the productive relation of their causal activities leading to the formation of a resting state manifold via the network connectivity. We demonstrate that the symmetry breaking by the connectivity creates a characteristic flow on the manifold, which produces the major empirical data features including spontaneous high amplitude co-activations, neuronal cascades, spectral cortical gradients, multistability and characteristic functional connectivity dynamics. The understanding of the brain's resting state manifold is fundamental for the construction of task-specific flows and manifolds used in theories of brain function such as predictive coding.

Soliton solutions for Hirota–Maxwell–Bloch system and its nonlocal form

This paper studies the Hirota–Maxwell–Bloch (H–MB) system and its nonlocal form. Based on the Darboux Transformations (DTs), for H–MB system, we present general double breathers, what is more, we take appropriate modulation frequency and position parameters to investigate the generative mechanism of rogue wave sequences and different periodic breather sequences. For nonlocal Hirota–Maxwell–Bloch (NH–MB) system, we discuss symmetry preserving and broken soliton solutions under zero background. Besides, we present nine combinations of dark and antidark soliton solutions under continuous waves background when PT-symmetry is broken.

Preferential Attachment and Fitness in the Evolution of the Brazilian Film Network

This study analyzes the network evolution, specifically that of the Brazilian film network. It examines two generative mechanisms that lie behind the network evolution: preferential attachment and fitness. The starting point is that preferential attachment and fitness may compete to shape the network evolution. We built a novel dataset with 974 Brazilian feature films released between 1995 and 2017 and used PAFit, a brand-new statistical method, to estimate the joint effects of preferential attachment and fitness on the evolution of the Brazilian film network. This study concludes that the network evolution is shaped by both preferential attachment and fitness. However, in the presence of fitness, the effects of preferential attachment on the network evolution become weaker. This means that the node ability to form ties in the Brazilian film network is mainly explained by its fitness. Besides, the preferential attachment assumes a sub-linear form. Costs, communication and managerial capabilities, and node age explain why nodes are unable to accumulate ties at rates proportional to their degree. Finally, preferential attachment and fitness manifest themselves heterogeneously, depending on either the type or the duration of the network. Preferential attachment drives the cast network evolution, whereas fitness is the main generative mechanism of the crew network. Actors and actresses rely on their status, privilege, and power to obtain future contracts (preferential attachment), whereas technical members are selected on the basis of their talent, skills, and knowledge (fitness). Due to node age or exit, preferential attachment becomes stronger in shorter networks.

Ligação Preferencial e Aptidão na Evolução da Rede de Filmes Brasileiros

This study analyzes the network evolution, specifically that of the Brazilian film network. It examines two generative mechanisms that lie behind the network evolution: preferential attachment and fitness. The starting point is that preferential attachment and fitness may compete to shape the network evolution. We built a novel dataset with 974 Brazilian feature films released between 1995 and 2017 and used PAFit, a brand-new statistical method, to estimate the joint effects of preferential attachment and fitness on the evolution of the Brazilian film network. This study concludes that the network evolution is shaped by both preferential attachment and fitness. However, in the presence of fitness, the effects of preferential attachment on the network evolution become weaker. This means that the node ability to form ties in the Brazilian film network is mainly explained by its fitness. Besides, the preferential attachment assumes a sub-linear form. Costs, communication and managerial capabilities, and node age explain why nodes are unable to accumulate ties at rates proportional to their degree. Finally, preferential attachment and fitness manifest themselves heterogeneously, depending on either the type or the duration of the network. Preferential attachment drives the cast network evolution, whereas fitness is the main generative mechanism of the crew network. Actors and actresses rely on their status, privilege, and power to obtain future contracts (preferential attachment), whereas technical members are selected on the basis of their talent, skills, and knowledge (fitness). Due to node age or exit, preferential attachment becomes stronger in shorter networks.

Rethinking Proxy War Theory in IR: A Critical Analysis of Principal–Agent Theory

This paper explores the question of what drives proxy alignment in war and argues that current proxy war scholarship needs further thinking to go beyond focusing on the principal–agent theory and individual actors’ motivation analysis. Rather, there is a need to look at the generative mechanisms of proxy alignment as a process that constitutes patterns of friend–enemy relations. The paper argues securitization patterns from domestic to regional and international levels drive actors to re-evaluate their positions and define their enemies and friends. This is a process of securitization alignment and confluence, which serves as a generative mechanism for proxy alignment in a conflict. Securitization alignment is based on a convergence of securitizations by different actors that create a friend–enemy dynamic and convergence of security interests between actors. The confluence of securitizations from the domestic level to regional and beyond also connects actors across different levels to be in alignment and impact the conflict.

Diagnostic Analysis of the Generative Mechanism of Extratropical Cyclones in the Northwest Pacific and Northwest Atlantic

We investigated the early-stage development of cyclones occurring in the strong baroclinic regions in the Northwest Pacific and the Northwest Atlantic based on European Center for Medium-range Weather Forecasts Re-Analysis-Interim (ERA-Interim) data. The composite background conditions corresponding to the cyclones on the onset day are characterized by upper troposphere divergence of westerly jet ahead of a trough, low troposphere convergence of westerly jet behind a trough, and strong meridional air temperature gradient (baroclinicity) both in the Northwest Pacific and the Northwest Atlantic, but with stronger baroclinicity in the Northwest Pacific. The composite velocity and temperature fields of the cyclone on the onset day show a clear horizontal front and a westward and northward vertical tilting of cyclonic circulation to the cold zone. The composite Northwest Pacific cyclone filed on the onset day has a warm core, whereas the composite Northwest Atlantic cyclone field has a cold core in the low troposphere. The leading adiabatic processes that contribute to the developing of the cold core cyclone in the Northwest Atlantic on the onset day is the temperature advection, while stronger vertical motion induces stronger adiabatic warming in the Northwest Pacific cyclones, which has a significant contribution to the development of warm core cyclones on the onset day.

THE GENERATIVE MECHANISM OF SECONDARY SCHOOL STUDENTS’ OCCUPATIONAL EXPECTATIONS IN THE BALTIC COUNTRIES: INFLUENCE OF FAMILY, SCHOOL, AND INDIVIDUAL SCIENCE LEARNING ACHIEVEMENT

Gender, learning achievements, parents’ occupational status, social-economic backgrounds, and a few traits of schools affect students’ occupational expectations. However, no research had integrated the above factors to investigate the generative mechanism of students’ occupational expectations. After combining student-level and school-level PISA 2018 datasets, two-level latent covariate modeling was used to find the generative mechanism of students’ occupational expectations in the Baltic countries. The mechanism had its primary concern to understand roles parents’ occupational status and individual science learning achievement played on students’ occupational expectations. The results indicate that the generative mechanism of students’ occupational expectations of Lithuania, Estonia, and Latvia are the power model, the maternal model, and the science learning achievement pattern, respectively. It suggests one parent having high occupational status is to mold children’s high-skilled occupational expectations, and it would be better the mother is the higher occupational status parent. It highlights the importance of strengthening adult education, especially that aimed at families with both parents of low occupational status. It disapproves of a mother being a full-time housewife. It may impede her children from having ambitions for high-skilled jobs. Keywords: occupational expectation, PISA 2018 datasets, science learning achievement, two-level latent covariate model

A New Insight into Understanding Urban Vitality: A Case Study in the Chengdu-Chongqing Area Twin-City Economic Circle, China

Addressing the issues caused by urbanization through urban vitality theory has elicited increasing attention in social environment research. However, few studies focus on vitality itself, such as the generative mechanism of urban vitality (GMUV) and the identification of key factors to vitality improvement. Therefore, a new insight into vitality is presented in this study through the exploration of GMUV based on partial least squares structural equation modeling (PLS-SEM). Concretely, the GMUV and the key factors to vitality improvement are analyzed and identified based on nighttime lights data, points of interest, and the statistical data of the Chengdu-Chongqing Area Twin-City Economic Circle in China. The results show that external representations and internal elements constitute the structural basis of the GMUV and that environmental vitality and social vitality are the key factors to enhance vitality. Finally, suggestions on improving regional vitality are provided to urban policymakers. This study may promote a better understanding of vitality, and the proposed vitality evaluation model may serve as a reference for other regions.