10 research outputs found

    Rhythms and Evolution: Effects of Timing on Survival

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    The evolution of metabolism regulation is an intertwined process, where different strategies are constantly being developed towards a cognitive ability to perceive and respond to an environment. Organisms depend on an orchestration of a complex set of chemical reactions: maintaining homeostasis with a changing environment, while simultaneously sending material and energetic resources to where they are needed. The success of an organism requires efficient metabolic regulation, highlighting the connection between evolution, population dynamics and the underlying biochemistry. In this work, I represent organisms as coupled information-processing networks, that is, gene-regulatory networks receiving signals from the environment and acting on chemical reactions, eventually affecting material flows. I discuss the mechanisms through which metabolism control is improved during evolution and how the nonlinearities of competition influence this solution-searching process. The propagation of the populations through the resulting landscapes generally point to the role of the rhythm of cell division as an essential phenotypic feature driving evolution. Subsequently, as it naturally follows, different representations of organisms as oscillators are constructed to indicate more precisely how the interplay between competition, maturation timing and cell-division synchronisation affects the expected evolutionary outcomes, not always leading to the \"survival of the fastest\"

    Dynamical Models of Biology and Medicine

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    Mathematical and computational modeling approaches in biological and medical research are experiencing rapid growth globally. This Special Issue Book intends to scratch the surface of this exciting phenomenon. The subject areas covered involve general mathematical methods and their applications in biology and medicine, with an emphasis on work related to mathematical and computational modeling of the complex dynamics observed in biological and medical research. Fourteen rigorously reviewed papers were included in this Special Issue. These papers cover several timely topics relating to classical population biology, fundamental biology, and modern medicine. While the authors of these papers dealt with very different modeling questions, they were all motivated by specific applications in biology and medicine and employed innovative mathematical and computational methods to study the complex dynamics of their models. We hope that these papers detail case studies that will inspire many additional mathematical modeling efforts in biology and medicin

    Effects of non-linearities and disorder in systems with multiple absorbing states. A perspective for modeling the dynamics of complex ecosystems.

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    Interacting particle systems are a particular class of stochastic processes where single degrees of freedom interact through probabilistic rules defined over a graph which reflects the spatial topology of the model. From the statistical mechanics point of view these models are of particular interest since they are genuinely out-of-equilibrium processes and introduce new universality classes and dynamical phase transitions. Among these processes, systems with absorbing states are characterized by points in the state-space in which the dynamics becomes trivial and, once reached, cannot be leaved. Because of the several possible interpretations, these models have found many applications in different areas of science: from condensed matter Physics to Biology, from Ecology to Sociology and Finance and also, in their quantum versions, to quantum control theory. Despite their importance for possible applications, though, a unified understanding of these systems is still lacking. In theoretical ecology, many open fundamental questions about the dynamics of ecosystems provide the cue for a further development of the theory of interacting particle systems. In particular, in this thesis we will address three main topics: i) Spontaneous neutral symmetry breaking. A central problem in ecology is the elucidation of the mechanisms responsible for biodiversity and stability. Neutral theory provides gross patterns in accord with empirical observations, but its validity is still highly debated. In particular, it is not clear how this theory can originate the observed non-neutral dynamics. Within a completely species-symmetric theory, we demonstrate that nonlinear dynamics can lead to a stationary state characterized by both stability and biodiversity by spontaneously breaking the neutral symmetry. ii) Habitat heterogeneities. It is known that habitat can have a great impact on the dynamics of species. In its most basic level of abstraction, its effects can be mimicked by an interacting particle system in a quenched random external field that locally breaks the species symmetry. We propose here an effective solution of the model in the long-times limit. iii) Role of boundary conditions. For non-equilibrium systems near a critical point, little is known about the role of the boundary conditions to the global phase diagram of the system. We analyze here a paradigmatic non-equilibrium critical model with mixed symmetry-preserving boundary conditions

    Three Risky Decades: A Time for Econophysics?

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    Our Special Issue we publish at a turning point, which we have not dealt with since World War II. The interconnected long-term global shocks such as the coronavirus pandemic, the war in Ukraine, and catastrophic climate change have imposed significant humanitary, socio-economic, political, and environmental restrictions on the globalization process and all aspects of economic and social life including the existence of individual people. The planet is trapped—the current situation seems to be the prelude to an apocalypse whose long-term effects we will have for decades. Therefore, it urgently requires a concept of the planet's survival to be built—only on this basis can the conditions for its development be created. The Special Issue gives evidence of the state of econophysics before the current situation. Therefore, it can provide excellent econophysics or an inter-and cross-disciplinary starting point of a rational approach to a new era

    An Initial Framework Assessing the Safety of Complex Systems

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    Trabajo presentado en la Conference on Complex Systems, celebrada online del 7 al 11 de diciembre de 2020.Atmospheric blocking events, that is large-scale nearly stationary atmospheric pressure patterns, are often associated with extreme weather in the mid-latitudes, such as heat waves and cold spells which have significant consequences on ecosystems, human health and economy. The high impact of blocking events has motivated numerous studies. However, there is not yet a comprehensive theory explaining their onset, maintenance and decay and their numerical prediction remains a challenge. In recent years, a number of studies have successfully employed complex network descriptions of fluid transport to characterize dynamical patterns in geophysical flows. The aim of the current work is to investigate the potential of so called Lagrangian flow networks for the detection and perhaps forecasting of atmospheric blocking events. The network is constructed by associating nodes to regions of the atmosphere and establishing links based on the flux of material between these nodes during a given time interval. One can then use effective tools and metrics developed in the context of graph theory to explore the atmospheric flow properties. In particular, Ser-Giacomi et al. [1] showed how optimal paths in a Lagrangian flow network highlight distinctive circulation patterns associated with atmospheric blocking events. We extend these results by studying the behavior of selected network measures (such as degree, entropy and harmonic closeness centrality)at the onset of and during blocking situations, demonstrating their ability to trace the spatio-temporal characteristics of these events.This research was conducted as part of the CAFE (Climate Advanced Forecasting of sub-seasonal Extremes) Innovative Training Network which has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 813844

    A complex systems approach to education in Switzerland

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    The insights gained from the study of complex systems in biological, social, and engineered systems enables us not only to observe and understand, but also to actively design systems which will be capable of successfully coping with complex and dynamically changing situations. The methods and mindset required for this approach have been applied to educational systems with their diverse levels of scale and complexity. Based on the general case made by Yaneer Bar-Yam, this paper applies the complex systems approach to the educational system in Switzerland. It confirms that the complex systems approach is valid. Indeed, many recommendations made for the general case have already been implemented in the Swiss education system. To address existing problems and difficulties, further steps are recommended. This paper contributes to the further establishment complex systems approach by shedding light on an area which concerns us all, which is a frequent topic of discussion and dispute among politicians and the public, where billions of dollars have been spent without achieving the desired results, and where it is difficult to directly derive consequences from actions taken. The analysis of the education system's different levels, their complexity and scale will clarify how such a dynamic system should be approached, and how it can be guided towards the desired performance
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