Month: August 2023

The emergence of dynamic networks from many coupled polar oscillators: a paradigm for artificial life

Alessandro Scirè & Valerio Annovazzi-Lodi 

Theory in Biosciences volume 142, pages 291–299 (2023)

This work concerns a many-body deterministic model that displays life-like properties such as emergence, complexity, self-organization, self-regulation, excitability and spontaneous compartmentalization. The model portraits the dynamics of an ensemble of locally coupled polar phase oscillators, moving in a two-dimensional space, that under certain conditions exhibit emergent superstructures. Those superstructures are self-organized dynamic networks, resulting from a synchronization process of many units, over length scales much greater than the interaction range. Such networks compartmentalize the two-dimensional space with no a priori constraints, due to the formation of porous transport walls, and represent a highly complex and novel non-linear behavior. The analysis is numerically carried out as a function of a control parameter showing distinct regimes: static pattern formation, dynamic excitable networks formation, intermittency and chaos. A statistical analysis is drawn to determine the control parameter ranges for the various behaviors to appear. The model and the results shown in this work are expected to contribute to the field of artificial life.

Read the full article at: link.springer.com

Heterogeneity Extends Criticality

Carlos Gershenson

While studying rank dynamics, we have found a universal pattern across a broad variety of phenomena: more relevant elements change their rank slower than the majority of elements. Our hypothesis was that this temporal heterogeneity provides a balance between robustness (slow) and adaptability (fast) similar to criticality, but without the need of fine-tuning parameters. With this motivation, we have studied the effect of different types of heterogeneity (structural, temporal, and functional) in complex systems, and shown that each of these “extend” criticality. We have also used heterogeneity as a simple strategy to improve search algorithms. A question remains open: how to find “optimal” heterogeneity?

Watch at: vimeo.com

Evolution of priorities in strategic funding for collaborative health research. A comparison of the European Union Framework Programmes to the program funding by the United States NIH

David Fajardo-Ortiz, Bart Thijs, Wolfgang Glanzel, Karin R. Sipido

The historical research-funding model, based on the curiosity and academic interests of researchers, is giving way to new strategic funding models that seek to meet societal needs. We investigated the impact of this trend on health research funded by the two leading funding bodies worldwide, i.e. the National Institutes of Health (NIH) in the United States, and the framework programs of the European Union (EU). To this end, we performed a quantitative analysis of the content of projects supported through programmatic funding by the EU and NIH, in the period 2008-2014 and 2015-2020. We used machine learning for classification of projects as basic biomedical research, or as more implementation directed clinical therapeutic research, diagnostics research, population research, or policy and management research. In addition, we analyzed funding for major disease areas (cancer, cardio-metabolic and infectious disease). We found that EU collaborative health research projects clearly shifted towards more implementation research. In the US, the recently implemented UM1 program has a similar profile with strong clinical therapeutic research, while other NIH programs remain heavily oriented to basic biomedical research. Funding for cancer research is present across all NIH and EU programs, and in biomedical as well as more implementation directed projects, while infectious diseases is an emerging theme. We conclude that demand for solutions for medical needs leads to expanded funding for implementation- and impact-oriented research. Basic biomedical research remains present in programs driven by scientific initiative and strategies based on excellence, but may be at risk of declining funding opportunities.

Read the full article at: arxiv.org

Opinion Dynamics Explain Price Formation in Prediction Markets

Valerio Restocchi, Frank McGroarty, Enrico Gerding and Markus Brede
Entropy 2023, 25(8), 1152; DOI: 10.3390/e25081152

Prediction markets are heralded as powerful forecasting tools, but models that describe them often fail to capture the full complexity of the underlying mechanisms that drive price dynamics. To address this issue, we propose a model in which agents belong to a social network, have an opinion about the probability of a particular event to occur, and bet on the prediction market accordingly. Agents update their opinions about the event by interacting with their neighbours in the network, following the Deffuant model of opinion dynamics. Our results suggest that a simple market model that takes into account opinion formation dynamics is capable of replicating the empirical properties of historical prediction market time series, including volatility clustering and fat-tailed distribution of returns. Interestingly, the best results are obtained when there is the right level of variance in the opinions of agents. Moreover, this paper provides a new way to indirectly validate opinion dynamics models against real data by using historical data obtained from PredictIt, which is an exchange platform whose data have never been used before to validate models of opinion diffusion.

Read the full article at: www.mdpi.com

Evolution “On Purpose” Teleonomy in Living Systems. Edited by Peter A. Corning, Stuart A. Kauffman, Denis Noble, James A. Shapiro, Richard I. Vane-Wright and Addy Pross

A unique exploration of teleonomy—also known as “evolved purposiveness”—as a major influence in evolution by a broad range of specialists in biology and the philosophy of science.

The evolved purposiveness of living systems, termed “teleonomy” by chronobiologist Colin Pittendrigh, has been both a major outcome and causal factor in the history of life on Earth. Many theorists have appreciated this over the years, going back to Lamarck and even Darwin in the nineteenth century. In the mid-twentieth century, however, the complex, dynamic process of evolution was simplified into the one-way, bottom-up, single gene-centered paradigm widely known as the modern synthesis. In Evolution “On Purpose,” edited by Peter A. Corning, Stuart A. Kauffman, Denis Noble, James A. Shapiro, Richard I. Vane-Wright, and Addy Pross, some twenty theorists attempt to modify this reductive approach by exploring in depth the different ways in which living systems have themselves shaped the course of evolution.

Evolution “On Purpose” puts forward a more inclusive theoretical synthesis that goes far beyond the underlying principles and assumptions of the modern synthesis to accommodate work since the 1950s in molecular genetics, developmental biology, epigenetic inheritance, genomics, multilevel selection, niche construction, physiology, behavior, biosemiotics, chemical reaction theory, and other fields. In the view of the authors, active biological processes are responsible for the direction and the rate of evolution. Essays in this collection grapple with topics from the two-way “read-write” genome to cognition and decision-making in plants to the niche-construction activities of many organisms to the self-making evolution of humankind. As this collection compellingly shows, and as bacterial geneticist James Shapiro emphasizes, “The capacity of living organisms to alter their own heredity is undeniable.”

More at: mitpress.mit.edu