scholarly journals A Computer Simulation Study of Anatomy Induced Drift of Spiral Waves in the Human Atrium

2015 ◽  
Vol 2015 ◽  
pp. 1-15 ◽  
Author(s):  
Sanjay R. Kharche ◽  
Irina V. Biktasheva ◽  
Gunnar Seemann ◽  
Henggui Zhang ◽  
Vadim N. Biktashev
Keyword(s):  
Wall Thickness ◽  
Simulation Study ◽  
Sudden Change ◽  
Spiral Wave ◽  
Spiral Waves ◽  
Human Atrium ◽  
Atrial Wall ◽  
Anatomical Structures

The interaction of spiral waves of excitation with atrial anatomy remains unclear. This simulation study isolates the role of atrial anatomical structures on spiral wave spontaneous drift in the human atrium. We implemented realistic and idealised 3D human atria models to investigate the functional impact of anatomical structures on the long-term (∼40 s) behaviour of spiral waves. The drift of a spiral wave was quantified by tracing its tip trajectory, which was correlated to atrial anatomical features. The interaction of spiral waves with the following idealised geometries was investigated: (a) a wedge-like structure with a continuously varying atrial wall thickness; (b) a ridge-like structure with a sudden change in atrial wall thickness; (c) multiple bridge-like structures consisting of a bridge connected to the atrial wall. Spiral waves drifted from thicker to thinner regions and along ridge-like structures. Breakthrough patterns caused by pectinate muscles (PM) bridges were also observed, albeit infrequently. Apparent anchoring close to PM-atrial wall junctions was observed. These observations were similar in both the realistic and the idealised models. We conclude that spatially altering atrial wall thickness is a significant cause of drift of spiral waves. PM bridges cause breakthrough patterns and induce transient anchoring of spiral waves.

scholarly journals Role of atrial wall thickness in wave-dynamics of atrial fibrillation

PLoS ONE ◽  
2017 ◽  
Vol 12 (8) ◽  
pp. e0182174 ◽  
Author(s):  
Jun-Seop Song ◽  
Jin Wi ◽  
Hye-Jeong Lee ◽  
Minki Hwang ◽  
Byounghyun Lim ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Wall Thickness ◽  
Atrial Wall ◽  
Wave Dynamics

scholarly journals Deleterious mutation accumulation and the long-term fate of chromosomal inversions

PLoS Genetics ◽  
2021 ◽  
Vol 17 (3) ◽  
pp. e1009411
Author(s):  
Emma L. Berdan ◽  
Alexandre Blanckaert ◽  
Roger K. Butlin ◽  
Claudia Bank
Keyword(s):  
Adaptive Evolution ◽  
Simulation Study ◽  
Feedback Loop ◽  
Deleterious Mutation ◽  
Adaptive Divergence ◽  
Deleterious Mutations ◽  
Dynamic Features ◽  
Chromosomal Inversions

Chromosomal inversions contribute widely to adaptation and speciation, yet they present a unique evolutionary puzzle as both their allelic content and frequency evolve in a feedback loop. In this simulation study, we quantified the role of the allelic content in determining the long-term fate of the inversion. Recessive deleterious mutations accumulated on both arrangements with most of them being private to a given arrangement. This led to increasing overdominance, allowing for the maintenance of the inversion polymorphism and generating strong non-adaptive divergence between arrangements. The accumulation of mutations was mitigated by gene conversion but nevertheless led to the fitness decline of at least one homokaryotype under all considered conditions. Surprisingly, this fitness degradation could be permanently halted by the branching of an arrangement into multiple highly divergent haplotypes. Our results highlight the dynamic features of inversions by showing how the non-adaptive evolution of allelic content can play a major role in the fate of the inversion.

Abusive head trauma (AHT) outcome at long-term follow-up and the role of elective neurosurgical approach: A report of 22 cases

2013 ◽  
Author(s):  
Francesca Menegazzo ◽  
Melissa Rosa Rizzotto ◽  
Martina Bua ◽  
Luisa Pinello ◽  
Elisabetta Tono ◽  
...  
Keyword(s):  
Head Trauma ◽  
Abusive Head Trauma ◽  
Long Term Follow Up

The Second Start of Transformation in Ukraine?

2014 ◽  
pp. 30-52 ◽  
Author(s):  
L. Grigoryev ◽  
E. Buryak ◽  
A. Golyashev
Keyword(s):  
Economic Growth ◽  
Armed Conflict ◽  
Political Crisis ◽  
Investment Climate ◽  
Institutional Reforms ◽  
Personal Consumption ◽  
Governance Quality ◽  
Political Turmoil

The Ukrainian socio-economic crisis has been developing for years and resulted in the open socio-political turmoil and armed conflict. The Ukrainian population didn’t meet objectives of the post-Soviet transformation, and people were disillusioned for years, losing trust in the state and the Future. The role of workers’ remittances in the Ukrainian economy is underestimated, since the personal consumption and stability depend strongly on them. Social inequality, oligarchic control of key national assets contributed to instability as well as regional disparity, aggravated by identity differences. Economic growth is slow due to a long-term underinvestment, and prospects of improvement are dependent on some difficult institutional reforms, macro stability, open external markets and the elites’ consensus. Recovering after socio-economic and political crisis will need not merely time, but also governance quality improvement, institutions reform, the investment climate revival - that can be attributed as the second transformation in Ukraine.

Thoughts on the Long-Term Strategy, Science and Democracy

2006 ◽  
pp. 4-19 ◽  
Author(s):  
L. Abalkin
Keyword(s):  
Strategy Development ◽  
Russian Science ◽  
Global Trends ◽  
The World ◽  
World Development ◽  
Crucial Condition

The article covers unified issues of the long-term strategy development, the role of science as well as democracy development in present-day Russia. The problems of budget proficit, the Stabilization Fund issues, implementation of the adopted national projects, an increasing role of regions in strengthening the integrity and prosperity of the country are analyzed. The author reveals that the protection of businessmen and citizens from the all-embracing power of bureaucrats is the crucial condition of democratization of the society. Global trends of the world development and expert functions of the Russian science are presented as well.

Development of Social and Economic Forecasting and Ideas of A. Anchishkin

2013 ◽  
pp. 143-155
Author(s):  
A. Klepach ◽  
G. Kuranov
Keyword(s):  
Economic Planning ◽  
Special Role ◽  
Economic Management ◽  
Economic Forecasting ◽  
Russian Economy ◽  
World Economic ◽  
Long Term Forecasting ◽  
Working Out

The role of the prominent Soviet economist, academician A. Anchishkin (1933—1987), whose 80th birth anniversary we celebrate this year, in the development of ideas and formation of economic forecasting in the country at the time when the directive planning acted as a leading tool of economic management is explored in the article. Besides, Anchishkin’s special role is noted in developing a comprehensive program of scientific and technical progress, an information basis for working out long-term forecasts of the country’s development, moreover, his contribution to the creation of long-term forecasting methodology and improvement of the statistical basis for economic analysis and economic planning. The authors show that social and economic forecasting in the period after 1991, which has undertaken a number of functions of economic planning, has largely relied on further development of Anchishkin’s ideas, at the same time responding to new challenges for the Russian economy development during its entry into the world economic system.

Sign in / Sign up

Export Citation Format

Share Document