scholarly journals Local-global interactions and the role of mesoscopic (intermediate-range) elements in brain dynamics

2000 ◽  
Vol 23 (3) ◽  
pp. 401-401 ◽  
Author(s):  
Walter J. Freeman ◽  
Robert Kozma

A unifing theory of spatiotemporal brain dynamics should incorporate multiple spatial and temporal scales. Between the microscopic (local) and macroscopic (global) components proposed by Nunez, mesoscopic (intermediate-range) elements should be integral parts of models. The corresponding mathematical formalism requires tools of nonlinear dynamics and the use of aperiodic (chaotic) attractors. Some relations between local-mesoscopic and mesoscopic-global components are outlined.

2019 ◽  
Vol 7 (10) ◽  
pp. 1192-1204 ◽  
Author(s):  
M. C. Kirchmeier‐Young ◽  
H. Wan ◽  
X. Zhang ◽  
S. I. Seneviratne

1998 ◽  
Vol 08 (12) ◽  
pp. 2387-2407 ◽  
Author(s):  
Stefano Lenci ◽  
Giuseppe Rega

A method for controlling nonlinear dynamics based on avoiding homoclinic intersection is systematically implemented to perform a numerical analysis of the control induced modifications of the steady attractors and bifurcation scenario of a two-well impact system. The work is divided into two parts. This paper (Part I) deals with the analysis of the harmonic (reference) and global optimal excitations, which are both symmetric. The bifurcation diagrams obtained for increasing values of the excitation amplitude show there exist a "basic" attractor and other "complementary" solutions. The range of stability of the principal complementary attractors is numerically established, and the mechanisms leading to their disapperance are identified. The role of classical and nonclassical local bifurcations in determining the system response is emphasized. Chaotic attractors are seen to appear and disappear both by classical period doubling route to chaos and by sudden changes. Subductions, boundary and interior crises are repeatedly observed. By comparison of the system response under different excitations we obtain information on the performances of global control, which furnishes relatively low gain in terms of regularization but succeeds in controlling the whole phase space.


<em>Abstract.</em>—In this review, we argue that modeling salmonid populations needs to integrate multispecies dynamics to better address the keystone role of salmon in their ecosystems and management needs for co-occurring species. Despite several challenges of modeling salmon communities, including multiple threats, variable spatial and temporal scales, and different types of interspecific interactions, a number of modeling approaches are potentially available to examine interspecific interactions. We examine these choices in the context of the salmon communities, and discuss opportunities for improving multispecies models to successfully address the ecological and management questions facing salmon populations. To effectively integrate multiple species into salmonid population models, researchers should utilize relatively simple, transparent models that have the capability of examining parameter uncertainty and systematically adding complexity.


2021 ◽  
pp. 1-36

Abstract Like many coastal communities throughout the Mid-Atlantic region, relative sea level rise and accelerating instances of coastal nuisance flooding are having a tangible negative impact on economic activity and infrastructure in Annapolis, MD. The drivers of coastal nuisance flooding, in general, are a superposition of global, regional, and local influences that occur across spatial and temporal scales that determine water levels relative to a coastal datum. Most of the research to date related to coastal flooding has been focused on high impact episodic events, decomposing the global and regional drivers of sea level rise, or assessing seasonal to interannual trends in. In this study, we focus specifically on the role of short-duration (hours) meteorological wind forcing on water level anomalies in Annapolis, MD. Annapolis is an ideal location to study these processes because of the orientation of the coast relative to the prevailing wind directions, and the long record of reliable data observations. Our results suggest that three-, six-, nine-, and twelve-hour sustained wind forcing significantly influences water level anomalies in Annapolis. Sustained wind forcing out of the northeast, east, southeast and south is associated with positive water level anomalies, and sustained wind forcing out of the northwest and north is associated with negative water level anomalies. While these observational results suggest a relationship between sustained wind forcing and water level anomalies, a more robust approach is needed to account for other meteorological variables and drivers that occur across a variety of spatial and temporal scales.


2021 ◽  
Vol 14 (4) ◽  
Author(s):  
Zarai Besma ◽  
Walter Christian ◽  
Michot Didier ◽  
Montoroi Jean Pierre ◽  
Hachicha Mohamed

2008 ◽  
Vol 1 (2) ◽  
pp. 81-88 ◽  
Author(s):  
C. Zevenbergen ◽  
W. Veerbeek ◽  
B. Gersonius ◽  
S. Van Herk

2015 ◽  
Vol 120 ◽  
pp. 51-60 ◽  
Author(s):  
Yuval ◽  
Meytar Sorek–Hamer ◽  
Amnon Stupp ◽  
Pinhas Alpert ◽  
David M. Broday

Hydrobiologia ◽  
2008 ◽  
Vol 611 (1) ◽  
pp. 1-4 ◽  
Author(s):  
A. Razinkovas ◽  
Z. Gasiūnaitė ◽  
P. Viaroli ◽  
J. M. Zaldívar

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