scholarly journals History dependence and the continuum approximation breakdown: the impact of domain growth on Turing’s instability

2017 ◽  
Vol 473 (2199) ◽  
pp. 20160744 ◽  
Author(s):  
Václav Klika ◽  
Eamonn A. Gaffney
Keyword(s):  
Domain Size ◽  
Turing Instability ◽  
Domain Growth ◽  
Continuum Approximation ◽  
Growing Domain ◽  
Spatial Frequencies ◽  
History Of ◽  
The Stability ◽  
The Impact ◽  
The Continuum

A diffusively driven instability has been hypothesized as a mechanism to drive spatial self-organization in biological systems since the seminal work of Turing. Such systems are often considered on a growing domain, but traditional theoretical studies have only treated the domain size as a bifurcation parameter, neglecting the system non-autonomy. More recently, the conditions for a diffusively driven instability on a growing domain have been determined under stringent conditions, including slow growth, a restriction on the temporal interval over which the prospect of an instability can be considered and a neglect of the impact that time evolution has on the stability properties of the homogeneous reference state from which heterogeneity emerges. Here, we firstly relax this latter assumption and observe that the conditions for the Turing instability are much more complex and depend on the history of the system in general. We proceed to relax all the above constraints, making analytical progress by focusing on specific examples. With faster growth, instabilities can grow transiently and decay, making the prediction of a prospective Turing instability much more difficult. In addition, arbitrarily high spatial frequencies can destabilize, in which case the continuum approximation is predicted to break down.

scholarly journals Устойчивость углеродной нанолуковицы в контакте с графитовой подложкой

2019 ◽  
Vol 45 (12) ◽  
pp. 9
Author(s):  
С.Ш. Рехвиашвили ◽  
М.М. Бухурова
Keyword(s):  
Theoretical Model ◽  
Interaction Potential ◽  
Interatomic Interaction ◽  
Continuum Approximation ◽  
Graphite Phase ◽  
Interatomic Interaction Potential ◽  
The Stability ◽  
The Continuum

AbstractA theoretical model describing the stability of a carbon nano-onion in the presence of a bulk catalytic graphite phase is constructed based on the continuum approximation of interatomic interaction potential and mechanics of deformed systems. It is shown that a carbon nano-onion becomes unstable when its radius exceeds double value of the radius of a fullerene C_60 molecule.

scholarly journals The effect of domain growth on spatial correlations

2016 ◽  
Author(s):  
Robert JH Ross ◽  
Christian A Yates ◽  
Ruth E Baker
Keyword(s):  
Differential Equations ◽  
Cell Motility ◽  
Ordinary Differential Equations ◽  
Cell Movement ◽  
Domain Growth ◽  
Continuum Approximation ◽  
Spatial Correlations ◽  
One Dimensional ◽  
Growing Domain ◽  
Pair Density

Mathematical models describing cell movement and proliferation are important research tools for the understanding of many biological processes. In this work we present methods to include the effects of domain growth on the evolution of spatial correlations between agent locations in a continuum approximation of a one-dimensional lattice-based model of cell motility and proliferation. This is important as the inclusion of spatial correlations in continuum models of cell motility and proliferation without domain growth has previously been shown to be essential for their accuracy in certain scenarios. We include the effect of spatial correlations by deriving a system of ordinary differential equations that describe the expected evolution of individual and pair density functions for agents on a growing domain. We then demonstrate how to simplify this system of ordinary differential equations by using an appropriate approximation. This simplification allows domain growth to be included in models describing the evolution of spatial correlations between agents in a tractable manner.

Financial Globalization as a Barrier to Democratic Consolidation: a North-South Model with Public Goods

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Gabriel Porcile
Keyword(s):  
Public Goods ◽  
Economic History ◽  
Capital Mobility ◽  
Democratic Consolidation ◽  
Empirical Literature ◽  
Financial Globalization ◽  
History Of ◽  
The Stability ◽  
The Impact

AbstractThis paper modifies the Acemoglu–Robinson model of the economic basis of democracy to discuss the impact of the international regime regulating capital flows on the consolidation and quality of democracy. Two regimes of capital mobility are considered, Bretton Woods and Rodrik’s hyperglobalization, in an international economy formed by an advanced North and a developing South. The model shows that hyperglobalization compromises the stability of democracy in the South by limiting the ability of the citizens to tax the elite and provide public goods which are critical for technical change and income distribution. At variance with the mainstream results, it is argued that financial globalization is a barrier to democratic consolidation. The model is consistent with key findings of the empirical literature on globalization and democracy, as well as with evidence from the economic history of Latin America.

Investigating the Relationship Between Self-Esteem and Stigma Among Young Adults With History of Suicide Attempts

Crisis ◽  
2016 ◽  
Vol 37 (4) ◽  
pp. 265-270 ◽  
Author(s):  
Meshan Lehmann ◽  
Matthew R. Hilimire ◽  
Lawrence H. Yang ◽  
Bruce G. Link ◽  
Jordan E. DeVylder
Keyword(s):  
Young Adults ◽  
Suicide Attempts ◽  
Self Esteem ◽  
High Risk Population ◽  
High Functioning ◽  
People With Mental Illness ◽  
History Of ◽  
The Individual ◽  
The Impact ◽  
The Relationship

Abstract. Background: Self-esteem is a major contributor to risk for repeated suicide attempts. Prior research has shown that awareness of stigma is associated with reduced self-esteem among people with mental illness. No prior studies have examined the association between self-esteem and stereotype awareness among individuals with past suicide attempts. Aims: To understand the relationship between stereotype awareness and self-esteem among young adults who have and have not attempted suicide. Method: Computerized surveys were administered to college students (N = 637). Linear regression analyses were used to test associations between self-esteem and stereotype awareness, attempt history, and their interaction. Results: There was a significant stereotype awareness by attempt interaction (β = –.74, p = .006) in the regression analysis. The interaction was explained by a stronger negative association between stereotype awareness and self-esteem among individuals with past suicide attempts (β = –.50, p = .013) compared with those without attempts (β = –.09, p = .037). Conclusion: Stigma is associated with lower self-esteem within this high-functioning sample of young adults with histories of suicide attempts. Alleviating the impact of stigma at the individual (clinical) or community (public health) levels may improve self-esteem among this high-risk population, which could potentially influence subsequent suicide risk.

Dietary Vitamin and Stability of Oral Anticoagulation: Proposal of a Diet with Constant Vitamin K1 Content

1997 ◽  
Vol 77 (03) ◽  
pp. 504-509 ◽  
Author(s):  
Sarah L Booth ◽  
Jacqueline M Charnley ◽  
James A Sadowski ◽  
Edward Saltzman ◽  
Edwin G Bovill ◽  
...  
Keyword(s):  
Dietary Intake ◽  
Vitamin K ◽  
High Performance ◽  
Case Reports ◽  
Food Composition ◽  
Dietary Guidelines ◽  
Dietary Vitamin ◽  
Vitamin K1 ◽  
The Stability ◽  
The Impact

SummaryCase reports cited in Medline or Biological Abstracts (1966-1996) were reviewed to evaluate the impact of vitamin K1 dietary intake on the stability of anticoagulant control in patients using coumarin derivatives. Reported nutrient-drug interactions cannot always be explained by the vitamin K1 content of the food items. However, metabolic data indicate that a consistent dietary intake of vitamin K is important to attain a daily equilibrium in vitamin K status. We report a diet that provides a stable intake of vitamin K1, equivalent to the current U.S. Recommended Dietary Allowance, using food composition data derived from high-performance liquid chromatography. Inconsistencies in the published literature indicate that prospective clinical studies should be undertaken to clarify the putative dietary vitamin K1-coumarin interaction. The dietary guidelines reported here may be used in such studies.

The Film World’s Cooperative Store: Institutions and Films of the 1930s and 1940s

2018 ◽  
Author(s):  
C. Claire Thomson
Keyword(s):  
World War Ii ◽  
Meat Products ◽  
Public Information ◽  
Early History ◽  
World War ◽  
International Context ◽  
German Occupation ◽  
History Of ◽  
The Uk ◽  
The Impact

This chapter traces the early history of state-sponsored informational filmmaking in Denmark, emphasising its organisation as a ‘cooperative’ of organisations and government agencies. After an account of the establishment and early development of the agency Dansk Kulturfilm in the 1930s, the chapter considers two of its earliest productions, both process films documenting the manufacture of bricks and meat products. The broader context of documentary in Denmark is fleshed out with an account of the production and reception of Poul Henningsen’s seminal film Danmark (1935), and the international context is accounted for with an overview of the development of state-supported filmmaking in the UK, Italy and Germany. Developments in the funding and output of Dansk Kulturfilm up to World War II are outlined, followed by an account of the impact of the German Occupation of Denmark on domestic informational film. The establishment of the Danish Government Film Committee or Ministeriernes Filmudvalg kick-started aprofessionalisation of state-sponsored filmmaking, and two wartime public information films are briefly analysed as examples of its early output. The chapter concludes with an account of the relations between the Danish Resistance and an emerging generation of documentarists.

Instability and Collapse in Discrete Wave Equations

2005 ◽  
Vol 5 (3) ◽  
pp. 223-241
Author(s):  
A. Carpio ◽  
G. Duro
Keyword(s):  
Continuum Limit ◽  
Wave Equations ◽  
Numerical Solutions ◽  
Blow Up ◽  
Theoretical Predictions ◽  
Initial States ◽  
The Impact ◽  
The Continuum

AbstractUnstable growth phenomena in spatially discrete wave equations are studied. We characterize sets of initial states leading to instability and collapse and obtain analytical predictions for the blow-up time. The theoretical predictions are con- trasted with the numerical solutions computed by a variety of schemes. The behavior of the systems in the continuum limit and the impact of discreteness and friction are discussed.

A Left History of Liquorice: What It Means to Write "Left" History

2019 ◽  
Vol 23 (1) ◽  
Author(s):  
Bryan D. Palmer
Keyword(s):  
Historical Study ◽  
Right Wing ◽  
Special Edition ◽  
Political Climate ◽  
Historical Approach ◽  
History Of ◽  
The Impact

This article is part of a special Left History series reflecting upon changing currents and boundaries in the practice of left history, and outlining the challenges historians of the left must face in the current tumultuous political climate. This series extends a conversation first convened in a 2006 special edition of Left History (11.1), which asked the question, “what is left history?” In the updated series, contributors were asked a slightly modified question, “what does it mean to write ‘left’ history?” The article charts the impact of major political developments on the field of left history in the last decade, contending that a rising neoliberal and right-wing climate has constructed an environment inhospitable to the discipline’s survival. To remain relevant, Palmer calls for historians of the left to develop a more “open-ended and inclusive” understanding of the left and to push the boundaries of inclusion for a meaningful historical study of the left. To illustrate, Palmer provides a brief materialist history of liquorice to demonstrate the mutability of left history as a historical approach, rather than a set of traditional political concerns.

IMPACT OF GOVERNMENT DEBT ON FINANCIAL SECURITY OF UKRAINE

2017 ◽  
Author(s):  
Olena Pikaliuk ◽  
◽  
Dmitry Kovalenko ◽  
Keyword(s):  
Economic Development ◽  
Public Debt ◽  
Positive Impact ◽  
The State ◽  
Financial Security ◽  
State Budget ◽  
The Public ◽  
Debt Security ◽  
The Stability ◽  
The Impact

One of the main criteria for economic development is the size of the public debt and its dynamics. The article considers the impact of public debt on the financial security of Ukraine. The views of scientists on the essence of public debt and financial security of the state are substantiated. An analysis of the dynamics and structure of public debt of Ukraine for 2014-2019. It is proved that one of the main criteria for economic development is the size of public debt and its dynamics. State budget deficit, attracting and using loans to cover it have led to the formation and significant growth of public debt in Ukraine. The volume of public debt indicates an increase in the debt security of the state, which is a component of financial security. Therefore, the issue of the impact of public debt on the financial security of Ukraine is becoming increasingly relevant. The constant growth and large amounts of debt make it necessary to study it, which will have a positive impact on economic processes that will ensure the stability of the financial system and enhance its security.

THEORETICAL AND PRACTICAL BASES OF THE CONCEPT OF SOCIO LINGUISTICS

2020 ◽  
Vol 5 (3) ◽  
pp. 20-24
Author(s):  
Durdona Karimova ◽  
Keyword(s):  
Sociolinguistic Competence ◽  
History Of ◽  
The Impact

This article discusses the theoretical and practical foundations of the concept of sociolinguistics and the importance of this field in the study of the impact of society on language. It also describes the views of linguists in this regard, the history of the origin and development of the filed, its connection with other disciplines, and explains in detail the sociolinguistic issues with practical examples.In addition, the terms as macro-sociolinguistics and micro-sociolinguistics and sociolinguistic competence are explained.

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