Month: November 2020

Engineering self-organized criticality in living cells

Blai Vidiella, Antoni Guillamon, Josep Sardanyés, Victor Maull, Nuria Conde-Pueyo, Ricard Solé

Complex dynamical fluctuations, from molecular noise within cells, collective intelligence, brain dynamics or computer traffic have been shown to display noisy behaviour consistent with a critical state between order and disorder. Living close to the critical point can have a number of adaptive advantages and it has been conjectured that evolution could select (and even tend to) these critical states. One way of approaching such state is by means of so called self-organized criticality (SOC) where the system poises itself close to the critical point. Is this the case of living cells? It is difficult to test this idea given the enormous dimensionality associated with gene and metabolic webs. In this paper we present an alternative approach: to engineer synthetic gene networks displaying SOC behaviour. This is achieved by exploiting the presence of a saturation (congestion) phenomenon of the ClpXP protein degradation machinery in E. coli cells. Using a feedback design that detects and then reduces ClpXP congestion, a critical motif is built from a two-gene network system, where SOC can be successfully implemented. Both deterministic and stochastic models are used, consistently supporting the presence of criticality in intracellular traffic. The potential implications for both cellular dynamics and designed intracellular noise are discussed.

Read the full article at: www.biorxiv.org

Benford’s law and the 2020 US presidential election: nothing out of the ordinary

You may have noticed that not everyone agrees with the outcome of the 2020 US Presidential election. But looking beyond the ALL CAPS TWEETS of Donald Trump, one claim circulating on social media is that some of Joe Biden’s votes look suspicious because they don’t adhere to “Benford’s law “.

So do the claims stack up? In short, no – but the reasons are interesting.

Read the full article at: physicsworld.com

The Computational Boundary of a “Self”: Developmental Bioelectricity Drives Multicellularity and Scale-Free Cognition

Michael Levin

Front. Psychol

All epistemic agents physically consist of parts that must somehow comprise an integrated cognitive self. Biological individuals consist of subunits (organs, cells, and molecular networks) that are themselves complex and competent in their own native contexts. How do coherent biological Individuals result from the activity of smaller sub-agents? To understand the evolution and function of metazoan creatures’ bodies and minds, it is essential to conceptually explore the origin of multicellularity and the scaling of the basal cognition of individual cells into a coherent larger organism. In this article, I synthesize ideas in cognitive science, evolutionary biology, and developmental physiology toward a hypothesis about the origin of Individuality: “Scale-Free Cognition.” I propose a fundamental definition of an Individual based on the ability to pursue goals at an appropriate level of scale and organization and suggest a formalism for defining and comparing the cognitive capacities of highly diverse types of agents. Any Self is demarcated by a computational surface – the spatio-temporal boundary of events that it can measure, model, and try to affect. This surface sets a functional boundary – a cognitive “light cone” which defines the scale and limits of its cognition. I hypothesize that higher level goal-directed activity and agency, resulting in larger cognitive boundaries, evolve from the primal homeostatic drive of living things to reduce stress – the difference between current conditions and life-optimal conditions. The mechanisms of developmental bioelectricity – the ability of all cells to form electrical networks that process information – suggest a plausible set of gradual evolutionary steps that naturally lead from physiological homeostasis in single cells to memory, prediction, and ultimately complex cognitive agents, via scale-up of the basic drive of infotaxis. Recent data on the molecular mechanisms of pre-neural bioelectricity suggest a model of how increasingly sophisticated cognitive functions emerge smoothly from cell-cell communication used to guide embryogenesis and regeneration. This set of hypotheses provides a novel perspective on numerous phenomena, such as cancer, and makes several unique, testable predictions for interdisciplinary research that have implications not only for evolutionary developmental biology but also for biomedicine and perhaps artificial intelligence and exobiology.

Read the full article at: www.frontiersin.org

Conference on Complex Systems 2020 – online

We are looking up to a very exciting Conference.
There are 20 world-class famous plenary/invited speakers.
There are over 325 accepted presentations, in oral, lightning, and poster presentations.
Over 55 countries are represented, more than any previous CCS meeting.

A round table discussion on COVID-19 is currently being planned with well-known participants.
Representatives from Journals of the European Physical Society and Complexity
will present information to all prospective authors.

On Friday December 4, a very exciting session is planned for young researchers,
with tutorials, didactic presentations, contests, puzzles, etc. etc All registered participants
in CCS2020 may attend !

More at: ccs2020.web.auth.gr