Author: cxdig

Behavior-based dependency networks between places shape urban economic resilience

Takahiro Yabe, Bernardo Garcia Bulle Bueno, Morgan Frank, Alex Pentland, Esteban Moro

Urban economic resilience is intricately linked to how disruptions caused by pandemics, disasters, and technological shifts ripple through businesses and urban amenities. Disruptions, such as closures of non-essential businesses during the COVID-19 pandemic, not only affect those places directly but also influence how people live and move, spreading the impact on other businesses and increasing the overall economic shock. However, it is unclear how much businesses depend on each other in these situations. Leveraging large-scale human mobility data and millions of same-day visits in New York, Boston, Los Angeles, Seattle, and Dallas, we quantify dependencies between points-of-interest (POIs) encompassing businesses, stores, and amenities. Compared to places’ physical proximity, dependency networks computed from human mobility exhibit significantly higher rates of long-distance connections and biases towards specific pairs of POI categories. We show that using behavior-based dependency relationships improves the predictability of business resilience during shocks, such as the COVID-19 pandemic, by around 40% compared to distance-based models. Simulating hypothetical urban shocks reveals that neglecting behavior-based dependencies can lead to a substantial underestimation of the spatial cascades of disruptions on businesses and urban amenities. Our findings underscore the importance of measuring the complex relationships woven through behavioral patterns in human mobility to foster urban economic resilience to shocks.

Read the full article at: arxiv.org

Lake Como School on Complex Networks Theory, Methods, and Applications

May 27-31, 2024
Villa del Grumello,
Como, Italy

Many real systems can be modeled as networks, where the elements of the system are nodes and interactions between elements are edges. An even larger set of systems can be modeled using dynamical processes on networks, which are in turn affected by the dynamics. Networks thus represent the backbone of many complex systems, and their theoretical and computational analysis makes it possible to gain insights into numerous applications. Networks permeate almost every conceivable discipline —including sociology, transportation, economics and finance, biology, and myriad others — and the study of “network science” has thus become a crucial component of modern scientific education.

The school “Complex Networks: Theory, Methods, and Applications” offers a succinct education in network science. It is open to all aspiring scholars in any area of science or engineering who wish to study networks of any kind (whether theoretical or applied), and it is especially addressed to doctoral students and young postdoctoral scholars. The aim of the school is to deepen into both theoretical developments and applications in targeted fields.

Read the full article at: ntmh.lakecomoschool.org

Scaling deep learning for materials discovery

Amil Merchant, Simon Batzner, Samuel S. Schoenholz, Muratahan Aykol, Gowoon Cheon & Ekin Dogus Cubuk 
Nature (2023)

Novel functional materials enable fundamental breakthroughs across technological applications from clean energy to information processing1,2,3,4,5,6,7,8,9,10,11. From microchips to batteries and photovoltaics, discovery of inorganic crystals has been bottlenecked by expensive trial-and-error approaches. Concurrently, deep-learning models for language, vision and biology have showcased emergent predictive capabilities with increasing data and computation12,13,14. Here we show that graph networks trained at scale can reach unprecedented levels of generalization, improving the efficiency of materials discovery by an order of magnitude. Building on 48,000 stable crystals identified in continuing studies15,16,17, improved efficiency enables the discovery of 2.2 million structures below the current convex hull, many of which escaped previous human chemical intuition. Our work represents an order-of-magnitude expansion in stable materials known to humanity. Stable discoveries that are on the final convex hull will be made available to screen for technological applications, as we demonstrate for layered materials and solid-electrolyte candidates. Of the stable structures, 736 have already been independently experimentally realized. The scale and diversity of hundreds of millions of first-principles calculations also unlock modelling capabilities for downstream applications, leading in particular to highly accurate and robust learned interatomic potentials that can be used in condensed-phase molecular-dynamics simulations and high-fidelity zero-shot prediction of ionic conductivity.

Read the full article at: www.nature.com

Evolution and sustainability: gathering the strands for an Anthropocene synthesis

compiled and edited by Peter Søgaard Jørgensen, Timothy M. Waring and Vanessa P. Weinberger

PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY B, BIOLOGICAL SCIENCES
How did human societies evolve to become a major force of global change? What dynamics can lead societies on a trajectory of global sustainability? The astonishing growth in human population, economic activity, technological capacity and environmental impact – together known as the Anthropocene – has brought these questions to the fore. In this theme issue, we bring together the major elements of a theory of human evolution and sustainability on Earth. We show how diverse theories and approaches help to understand the past, present and future evolution of the Anthropocene, and discover new opportunities for moving towards sustainability. Collectively, the work provides the basis for an evolutionary synthesis of the human predicament on planet Earth.

Read the Special Issue at: royalsocietypublishing.org

The vulnerability of aging states: A survival analysis across premodern societies

The vulnerability of aging states: A survival analysis across premodern societies
Marten Scheffer, Egbert H. van Nes, Luke Kemp, Timothy A. Kohler, Timothy M. Lenton,  and Chi Xu

PNAS 120 (48) e2218834120

Humans become increasingly fragile as they age. We show that something similar may happen to states, although for states, the risk of termination levels off as they grow older, allowing some to persist for millennia. Proximate causes of their demise such as conquest, coups, earthquakes, and droughts are easy to spot and have received significant attention. However, our results suggest that unraveling what shapes resilience to such events is equally important if we are to understand state longevity and collapse. Risk of termination rises over the first 200 y, inviting a search for mechanisms that can undermine resilience at this timescale.

Read the full article at: www.pnas.org