Extinction, Nonlinear Dynamics, and Sociality

2020 ◽  
pp. 114-127
Author(s):  
Daniel Oro
Keyword(s):  
Nonlinear Dynamics ◽  
Stable State ◽  
Critical Threshold ◽  
Human Populations ◽  
Stable States ◽  
Statistical Tools ◽  
Warning Signals ◽  
Population Extinction ◽  
Critical Transitions

This chapter assesses how social feedbacks, and particularly runaway dispersal resulting from social copying, influence population extinction. Several forms of the logistic model are built to assess the role of density-dependent and cooperation mechanisms in the generation of nonlinearities in the path to extinction. Interestingly, transience to an extinction stable state may be delayed and may result in quasi-extinction population queues. Some empirical examples of quasi-extinction stable states are shown, including human populations. It is also explained how social sunk-cost effects—when individuals are trapped in a patch due to its momentum of suitability, social copying, or emotional drivers—can influence these quasi-extinction dynamics. The chapter also reviews several statistical tools for anticipating critical transitions and other nonlinear behaviours in populations. These tools include the early warning signals, which quantify when a critical threshold is approaching.

scholarly journals Catching Critical Transition in Engineered Systems

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Jin Huang ◽  
Tianchuang Meng ◽  
Yangdong Deng ◽  
Fanling Huang
Keyword(s):  
Early Warning ◽  
Multiple Scales ◽  
Stable State ◽  
Critical Threshold ◽  
Supporting Evidence ◽  
Critical Transition ◽  
Warning Signals ◽  
Early Warning Signals ◽  
Critical Transitions ◽  
Engineered Systems

A variety of engineered systems can encounter critical transitions where the system suddenly shifts from one stable state to another at a critical threshold. The critical transition has aroused vital concerns for its potentially disastrous impacts. We validate an often taken-for-granted hypothesis that the failure of engineered systems can be attributed to the respective critical transitions and show how early warning signals are closely associated with critical transitions. We demonstrate that it is feasible to use early warning signals to predict system failures. Our findings open a new path to forecast failures of engineered systems with a generic method and provide supporting evidence for the universal existence of critical transition in dynamical systems at multiple scales.

scholarly journals Several Indicators of Critical Transitions for Complex Diseases Based on Stochastic Analysis

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Gang Wang ◽  
Yuanyuan Li ◽  
Xiufen Zou
Keyword(s):  
Early Warning ◽  
Self Assembly ◽  
Disease Onset ◽  
Complex Diseases ◽  
Critical Threshold ◽  
Warning Signals ◽  
Early Warning Signals ◽  
Critical Transitions ◽  
Development And Differentiation ◽  
Quantitative Changes

Many complex diseases (chronic disease onset, development and differentiation, self-assembly, etc.) are reminiscent of phase transitions in a dynamical system: quantitative changes accumulate largely unnoticed until a critical threshold is reached, which causes abrupt qualitative changes of the system. Understanding such nonlinear behaviors is critical to dissect the multiple genetic/environmental factors that together shape the genetic and physiological landscape underlying basic biological functions and to identify the key driving molecules. Based on stochastic differential equation (SDE) model, we theoretically derive three statistical indicators, that is, coefficient of variation (CV), transformed Pearson’s correlation coefficient (TPC), and transformed probability distribution (TPD), to identify critical transitions and detect the early-warning signals of the phase transition in complex diseases. To verify the effectiveness of these early-warning indexes, we use high-throughput data for three complex diseases, including influenza caused by either H3N2 or H1N1 and acute lung injury, to extract the dynamical network biomarkers (DNBs) responsible for catastrophic transition into the disease state from predisease state. The numerical results indicate that the derived indicators provide a data-based quantitative analysis for early-warning signals for critical transitions in complex diseases or other dynamical systems.

scholarly journals Early warning signals in complex ecosystems

2015 ◽  
Vol 6 (2) ◽  
pp. 2507-2542 ◽  
Author(s):  
I. S. Weaver ◽  
J. G. Dyke
Keyword(s):  
Early Warning ◽  
Warning Signal ◽  
Ecosystem Model ◽  
Robust Methods ◽  
Stable States ◽  
Warning Signals ◽  
Early Warning Signals ◽  
Critical Transitions ◽  
Rapid Changes ◽  
External Driving

Abstract. Given the potential for elements of the Earth system to undergo rapid, hard to reverse changes in state, there is a pressing need to establish robust methods to produce early warning signals of such events. Here we present a conceptual ecosystem model in which a diversity of stable states emerge, along with rapid changes, referred to as critical transitions, as a consequence of external driving and non-linear ecological dynamics. We are able to produce robust early warning signals that precede critical transitions. However, we show that there is no correlation between the magnitude of the signal and magnitude or reversibility of any individual critical transition. We discuss these findings in the context of ecosystem management prior to and post critical transitions. We argue that an understanding of the dynamics of the systems is necessary both for management prior and post critical transitions and the effective interpretation of any early warning signal that may be produced for that system.

scholarly journals Anticipating Critical Transitions in Psychological Systems using Early Warning Signals: Theoretical and Practical Considerations

2020 ◽  
Author(s):  
Fabian Dablander ◽  
Anton Pichler ◽  
Arta Cika ◽  
Andrea Bacilieri
Keyword(s):  
Early Warning ◽  
Stable State ◽  
Critical Slowing Down ◽  
Future Research ◽  
Frequency Noise ◽  
Alternative Stable State ◽  
Warning Signals ◽  
Early Warning Signals ◽  
Slowing Down ◽  
Critical Transitions

Many real-world systems can exhibit sudden shifts from one stable state to another, and the theory of dynamical systems points to the existence of generic early warning signals that precede such shifts. Recently, psychologists have begun to conceptualize mental disorders such as depression as an alternative stable state, and suggested that early warning signals based on the phenomenon of critical slowing down might be useful for predicting sudden transitions into depression or other psychiatric disorders. Harnessing the potential of early warning signals requires us to understand their limitations as well as the factors influencing their performance in practice. In this paper, we (a) review limitations of early warning signals based on critical slowing down to better understand when they can and cannot occur, and (b) study the conditions under which early warning signals may anticipate critical transitions in online-monitoring settings by simulating from a bistable dynamical system, varying crucial features such as sampling frequency, noise intensity, and speed of approaching the tipping point. We find that, in sharp contrast to their reputation of being generic or model-agnostic, whether early warning signals occur or not strongly depends on the specifics of the system. We also find that they are very sensitive to noise, potentially limiting their utility in practical applications. We discuss the implications of our findings and provide suggestions and recommendations for future research.

LANDSLIDE RISK MANAGEMENT IN THE COASTAL ZONE OF THE KUIBYSHEV RESERVOIR DUE THE DESIGN OF HIGH-SPEED LINE "MOSCOW-KAZAN"

2017 ◽  
Author(s):  
Nikolai Petrov ◽  
Nikolai Petrov ◽  
Inna Nikonorova ◽  
Inna Nikonorova ◽  
Vladimir Mashin ◽  
...  
Keyword(s):  
High Speed ◽  
Computational Models ◽  
Stable State ◽  
Landslide Risk ◽  
Kuibyshev Reservoir ◽  
Stepped Surface ◽  
The Stability ◽  
Landslide Slope ◽  
The Village

High-speed railway "Moscow-Kazan" by the draft crosses the Volga (Kuibyshev reservoir) in Chuvashia region 500 m below the village of New Kushnikovo. The crossing plot is a right-bank landslide slope with a stepped surface. Its height is 80 m; the slope steepness -15-16o. The authors should assess the risk of landslides and recommend anti-landslide measures to ensure the safety of the future bridge. For this landslide factors have been analyzed, slope stability assessment has been performed and recommendations have been suggested. The role of the following factors have been analyzed: 1) hydrologic - erosion and abrasion reservoir and runoff role; 2) lithologyc (the presence of Urzhum and Northern Dvina horizons of plastically deformable rocks, displacement areas); 3) hydrogeological (the role of perched, ground and interstratal water); 4) geomorphological (presence of the elemental composition of sliding systems and their structure in the relief); 5) exogeodynamic (cycles and stages of landslide systems development, mechanisms and relationship between landslide tiers of different generations and blocks contained in tiers). As a result 6-7 computational models at each of the three engineering-geological sections were made. The stability was evaluated by the method “of the leaning slope”. It is proved that the slope is in a very stable state and requires the following measures: 1) unloading (truncation) of active heads blocks of landslide tiers) and the edge of the plateau, 2) regulation of the surface and groundwater flow, 3) concrete dam, if necessary.

scholarly journals Bub1 mediates cell death in response to chromosome missegregation and acts to suppress spontaneous tumorigenesis

2007 ◽  
Vol 179 (2) ◽  
pp. 255-267 ◽  
Author(s):  
Karthik Jeganathan ◽  
Liviu Malureanu ◽  
Darren J. Baker ◽  
Susan C. Abraham ◽  
Jan M. van Deursen
Keyword(s):  
Cell Death ◽  
Chromosome Segregation ◽  
Physiological Role ◽  
Mitotic Checkpoint ◽  
Critical Threshold ◽  
Wild Type ◽  
Checkpoint Protein ◽  
Chromosome Missegregation ◽  
Mitotic Checkpoint Protein

The physiological role of the mitotic checkpoint protein Bub1 is unknown. To study this role, we generated a series of mutant mice with a gradient of reduced Bub1 expression using wild-type, hypomorphic, and knockout alleles. Bub1 hypomorphic mice are viable, fertile, and overtly normal despite weakened mitotic checkpoint activity and high percentages of aneuploid cells. Bub1 haploinsufficient mice, which have a milder reduction in Bub1 protein than Bub1 hypomorphic mice, also exhibit reduced checkpoint activity and increased aneuploidy, but to a lesser extent. Although cells from Bub1 hypomorphic and haploinsufficient mice have similar rates of chromosome missegregation, cell death after an aberrant separation decreases dramatically with declining Bub1 levels. Importantly, Bub1 hypomorphic mice are highly susceptible to spontaneous tumors, whereas Bub1 haploinsufficient mice are not. These findings demonstrate that loss of Bub1 below a critical threshold drives spontaneous tumorigenesis and suggest that in addition to ensuring proper chromosome segregation, Bub1 is important for mediating cell death when chromosomes missegregate.

scholarly journals Methane, oxygen, photosynthesis, rubisco and the regulation of the air through time

2008 ◽  
Vol 363 (1504) ◽  
pp. 2745-2754 ◽  
Author(s):  
Euan G Nisbet ◽  
R. Ellen R Nisbet
Keyword(s):  
Greenhouse Gas ◽  
Greenhouse Warming ◽  
Biological Productivity ◽  
Stable States ◽  
Mixing Ratios ◽  
The Past ◽  
Glacial Epoch ◽  
Air Control ◽  
Carbon Gases

Rubisco I's specificity, which today may be almost perfectly tuned to the task of cultivating the global garden, controlled the balance of carbon gases and O 2 in the Precambrian ocean and hence, by equilibration, in the air. Control of CO 2 and O 2 by rubisco I, coupled with CH 4 from methanogens, has for the past 2.9 Ga directed the global greenhouse warming, which maintains liquid oceans and sustains microbial ecology. Both rubisco compensation controls and the danger of greenhouse runaway (e.g. glaciation) put limits on biological productivity. Rubisco may sustain the air in either of two permissible stable states: either an anoxic system with greenhouse warming supported by both high methane mixing ratios as well as carbon dioxide, or an oxygen-rich system in which CO 2 largely fulfils the role of managing greenhouse gas, and in which methane is necessarily only a trace greenhouse gas, as is N 2 O. Transition from the anoxic to the oxic state risks glaciation. CO 2 build-up during a global snowball may be an essential precursor to a CO 2 -dominated greenhouse with high levels of atmospheric O 2 . Photosynthetic and greenhouse-controlling competitions between marine algae, cyanobacteria, and terrestrial C3 and C4 plants may collectively set the CO 2  : O 2 ratio of the modern atmosphere (last few million years ago in a mainly glacial epoch), maximizing the productivity close to rubisco compensation and glacial limits.

scholarly journals Path-dependent institutions drive alternative stable states in conservation

2018 ◽  
Vol 116 (2) ◽  
pp. 689-694 ◽  
Author(s):  
Edward W. Tekwa ◽  
Eli P. Fenichel ◽  
Simon A. Levin ◽  
Malin L. Pinsky
Keyword(s):  
Renewable Resources ◽  
Path Dependence ◽  
Alternative Stable States ◽  
Stable State ◽  
Empirical Support ◽  
Stable States ◽  
Alternative Stable State ◽  
Important Challenge ◽  
Quantitative Analyses ◽  
Path Dependent

Understanding why some renewable resources are overharvested while others are conserved remains an important challenge. Most explanations focus on institutional or ecological differences among resources. Here, we provide theoretical and empirical evidence that conservation and overharvest can be alternative stable states within the same exclusive-resource management system because of path-dependent processes, including slow institutional adaptation. Surprisingly, this theory predicts that the alternative states of strong conservation or overharvest are most likely for resources that were previously thought to be easily conserved under optimal management or even open access. Quantitative analyses of harvest rates from 217 intensely managed fisheries supports the predictions. Fisheries’ harvest rates also showed transient dynamics characteristic of path dependence, as well as convergence to the alternative stable state after unexpected transitions. This statistical evidence for path dependence differs from previous empirical support that was based largely on case studies, experiments, and distributional analyses. Alternative stable states in conservation appear likely outcomes for many cooperatively managed renewable resources, which implies that achieving conservation outcomes hinges on harnessing existing policy tools to navigate transitions.

scholarly journals An Empirical Study to Determine the Role of Credit in the Betterment of the Farmers’ Life: A Study with Special Reference to Cachar District of Assam

2021 ◽  
Vol 6 (1) ◽  
pp. 36-47
Author(s):  
Subhash Sinha ◽  
Vanlalchhawna
Keyword(s):  
Factor Analysis ◽  
Regression Analysis ◽  
Financial Institutions ◽  
Statistical Tools ◽  
Agricultural Credit ◽  
Rural People ◽  
Rural Sector ◽  
The Impact ◽  
Structured Questionnaire

The study focuses on the significance of agricultural credit that can bring change in the life of farmers and rural people. The rural sector is mostly neglected and lacks adequate finance that’s needed to back the sector. However, there are certain financial institutions that work for the welfare of the sector and lend credit facilities to farmers and associated people, for their wellbeing. The current study majorly recognizes the impact and benefits of these credit facilities in improving the situation of farmers at several unnoticed places, including Cachar district. The present study is exploratory in nature. It has explored the role of credit in farmer’s life. The data was collected through a structured questionnaire from 283farmers of Cachar district. The statistical tools applied for the study were “Exploratory Factor Analysis (EFA)”, and “Multiple regression analysis.” The factors identified were Economic Development, Agro Development and Family and Social Development. It was found that there is a significant role of credit in the development of all the three factors.

scholarly journals Microtubules: A network for solitary waves

2017 ◽  
Vol 82 (5) ◽  
pp. 469-481 ◽  
Author(s):  
Slobodan Zdravkovic
Keyword(s):  
Nonlinear Dynamics ◽  
Differential Equation ◽  
Nonlinear Differential Equation ◽  
Solitary Waves ◽  
Discrete Approximations ◽  
Mathematical Methods ◽  
In Cells

In the present paper we deal with nonlinear dynamics of microtubules. The structure and role of microtubules in cells are explained as well as one of models explaining their dynamics. Solutions of the crucial nonlinear differential equation depend on used mathematical methods. Two commonly used procedures, continuum and semi-discrete approximations, are explained. These solutions are solitary waves usually called as kink solitons, breathers and bell-type solitons.

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