This weblog is typically avoiding all things health-related, and because that's a mess that can swallow you whole, but this is from the Santa Fe Institute. Along with the Complexity Hub in Vienna, and sometimes the RIKEN Institute in Japan, the Santa Fe Institute is the premier institution in the world for those interested in the other side of the cutting edge of science, where the rules haven't been written yet, and all the departments kind sound like each other:
Western diets pose greater risk of cancer and inflammatory bowel disease
Jul 2024, phys.org
From SFI's new outpost in Ireland: They examined Mediterranean, high-fiber, plant-based, high-protein, ketogenic, and Western diets, to underscore the detrimental effects of the Western diet, characterized by high fat and sugar intake, compared to the benefits of diets rich in plant-based and high-fiber foods. By contrast, it finds that a Mediterranean diet, high in fruits, vegetables, is effective in managing conditions such as cardiovascular disease, IBD, and type 2 diabetes.
via APC Microbiome Ireland, an SFI Research Centre at University College Cork, and Teagasc: Fiona C. Ross et al, The interplay between diet and the gut microbiome: implications for health and disease, Nature Reviews Microbiology (2024). DOI: 10.1038/s41579-024-01068-4
How higher-order interactions can remodel the landscape of complex systems
Oct 2024, phys.org
Higher-order interactions can lead to deeper "basins of attraction," which are collections of starting points that end up at the same state as the system moves forward in time. If the system were a pendulum, the lowest point is an attractor, and every possible starting point is in the basin of attraction because they all eventually converge there.If the system were a brain working through a complicated math problem, then the thought processes that lead to a solution—hopefully the correct one—are in the basin of attraction. A deeper basin means that the solutions are more stable—that is, starting points get to the bottom faster or more quickly recover from small perturbations.But even though the basins get deeper, they become narrower. What starting points do end up in the basin get there faster, but overall, fewer starting points lead to the bottom.
via Santa Fe Institute: Yuanzhao Zhang et al, Deeper but smaller: Higher-order interactions increase linear stability but shrink basins, Science Advances (2024). DOI: 10.1126/sciadv.ado8049.
This one is old as hell:
Aging societies more vulnerable to collapse, suggests analysis
Dec 2023, phys.org
This new study shows that pre-modern states faced a steeply increasing risk of collapse within the first two centuries after they formed."This approach is commonly used to study the risk of death in aging humans, but nobody had the idea to look at societies this way."In humans, the risk of dying doubles approximately every six to seven years after infancy. As that exponential process compounds with great age, few people survive more than 100 years. The authors show that it works differently for states. Their risk of termination rises steeply over the first two centuries but then levels off, allowing a few to persist much longer than usual.They found a similar pattern all over the world from European pre-modern societies to early civilizations in the Americas to Chinese dynasties. (Gulps in American)
via Santa Fe Institute: Marten Scheffer et al, The vulnerability of aging states: A survival analysis across premodern societies, Proceedings of the National Academy of Sciences (2023). DOI: 10.1073/pnas.2218834120
RIKEN calling in:
Chaotic dynamics in the brain may enable probabilistic thinking
Jul 2024, phys.org
Even when watching a blank screen with no sound, neurons in the cortex fluctuate spontaneously. Some experiments suggest that this spontaneous activity corresponds to the brain ruminating over imagined possible scenarios—perhaps based on sensory inputs the brain has been presented with in the past, and that this activity follows chaotic dynamics.The pair fed a computational neural network, driven by chaotic dynamics, with sensory inputs about an object's location."One neuron would fire for the object being in the north, another for it being in the northeast, and so on." At any one moment, because of the chaos, the firing neuron can change irregularly. But when averaged over time, the frequency of neurons firing mapped to the correct probability for the object's location."In our model, the ultimate probabilistic distribution is robust and gives nearly optimal results, despite the chaos."
via RIKEN: Yu Terada et al, Chaotic neural dynamics facilitate probabilistic computations through sampling, Proceedings of the National Academy of Sciences (2024). DOI: 10.1073/pnas.2312992121
Post Script: Spoken like someone who works at RIKEN: "Today's AI is very good, but it's not blowing our minds"
Exploring the evolution of social norms with a supercomputer
Aug 2024, phys.org
RIKEN meets the Max Planck Institute for Evolutionary Biology; you're in some sh** now:
Thye've created an arena of natural selection (artificial selection) for social norms, so they fight it out and see who wins. This is hard because the norms added to the model, the more complex the interactions. But that's ok, because they used RIKEN's Fugaku, one of the fastest supercomputers worldwide.
They analyzed the reputation dynamics among all 2,080 norms of a natural complexity class, the so-called "third-order norms."The research shows that cooperative norms are difficult to sustain if the population consists of a single well-mixed community. However, if the population is subdivided into several smaller communities, cooperative norms evolve more easily.The most successful norm in the simulations is particularly simple. It views cooperation as universally positive and defection as generally negative—except when defection is used as a means to discipline other defectors.It suggests that the structure of a population significantly influences which social norms prevail and how durable cooperation is.
via RIKEN Center for Computational Science and Max Planck Institute for Evolutionary Biology in Plön: Yohsuke Murase et al, Computational evolution of social norms in well-mixed and group-structured populations, Proceedings of the National Academy of Sciences (2024). DOI: 10.1073/pnas.2406885121
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