Phil 7.17.2025

Exciting stage in Le Tour yesterday. on a “flat” stage yet.

Test out the new tire

Cycling in Uruguay: the inside guide

Effective One-Dimensional Reduction of Multicompartment Complex Systems Dynamics | Phys. Rev. X

  • A broad class of systems, including ecological, epidemiological, and sociological ones, are characterized by populations of individuals assigned to specific categories, e.g., a chemical species, an opinion, or an epidemic state, that are modeled as compartments. Because of interactions and intrinsic dynamics, the system units are allowed to change category, leading to concentrations varying over time with complex behavior, typical of reaction-diffusion systems. While compartmental modeling provides a powerful framework for studying the dynamics of such populations and describe the spatiotemporal evolution of a system, it mostly relies on deterministic mean-field descriptions to deal with systems with many degrees of freedom. Here, we propose a method to alleviate some of the limitations of compartmental models by capitalizing on tools originating from quantum physics to systematically reduce multidimensional systems to an effective one-dimensional representation. Using this reduced system, we are able not only to investigate the mean-field dynamics and their critical behavior, but we can additionally study stochastic representations that capture fundamental features of the system. We demonstrate the validity of our formalism by studying the critical behavior of models widely adopted to study epidemic, ecological, and economic systems.

Operation Overload’s underwhelming influence and evolving tactics – ISD

  • Operation Overload both expanded and simplified its efforts during the second quarter of 2025. It began posting on TikTok and made misleading claims about more countries, while also posting more frequently in English and concentrating on media impersonation. It also prioritized longer-term influence campaigns over election interference, targeting countries that have traditionally been in the crosshairs of Russian influence operations, like Ukraine and Moldova, more frequently than countries that held elections during the monitored period.
  • Social media platforms appear to have stepped up efforts to remove Operation Overload content, limiting its reach and impact. X removed 73 percent of sampled posts, compared to just 20 percent in the first quarter of 2025. On TikTok and Bluesky, removal rates were higher than 90 percent. This could reflect platforms’ increasing awareness of the operation or that its use of bots and other manipulation tactics is brazen enough to trigger automated moderation systems. ISD analysts did not see notable organic engagement among the remaining posts.
  • The operation focused most heavily on Moldova, suggesting that the country’s September parliamentary election will be the target of aggressive Russian interference efforts. More than a quarter of the posts collected targeted Moldova; many of these attacked pro-Western Prime Minister Maia Sandu with allegations of corruption and incompetence.

SBIRs

  • 9:00 standup
  • 12:00 NPS brainstorming
  • 4:00 SEG

GPT Agents