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New Method Reveals Delayed Interactions in Living Systems

A novel approach helps understand how living things interact over time.

― 5 min read


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Table of Contents

Scientists study how different living things interact to understand their behaviors and movements. Whether it's birds flying together or cells moving in our bodies, these interactions can influence their actions significantly. This article looks at a new way of figuring out how these interactions happen, especially when they aren't immediate, meaning there’s a delay in communication between the units involved.

The Importance of Movement

Movement is a crucial part of life. It helps animals search for food and mates, and it also enables cells to respond to their environment. This movement can be quick, like a bird dodging a predator, or slow, like white blood cells moving to fight infection. Understanding how these different forms of life communicate while they move can tell us a lot about their behavior and help us influence their actions.

The Challenge of Measuring Interactions

One of the significant challenges in studying these movements is determining how units interact with each other over time. For example, if two cells are in the same area, their behavior can affect each other, even if they don't touch. Sometimes, these interactions are delayed, as when one cell releases a signal that another cell picks up later on. Traditional methods often look only at immediate interactions, which can lead to misunderstandings about how these units truly behave.

New Methodology

To tackle the problem of delayed interactions, researchers have developed a new method that combines the ideas of Maximum Entropy and Dynamic Modeling. This method allows scientists to analyze how units interact over time, even when there's a delay between their actions.

Maximum Entropy Principle

The maximum entropy principle is a mathematical approach that helps scientists predict how systems behave under uncertainty. By using this principle, researchers can estimate the most likely interactions that would occur given the available data. This method can provide a more accurate picture of the interactions at play.

Dynamic Modeling

Dynamic modeling looks at how systems change over time. By combining it with the maximum entropy approach, scientists can create a more holistic view of interactions. This means they can consider not just what happens at a single moment, but how things evolve over time.

Application of the New Method

The new method has been tested on both synthetic data generated by computer models and real-world data from experiments involving cell migration. These tests have shown that the method can reliably identify both the strength of the interactions and the time it takes for those interactions to occur.

Synthetic Data Testing

Scientists first applied their method to synthetic datasets, basically simulated scenarios that mimic real life. They created two main models, the Heisenberg-Kuramoto model and the Vicsek model, which simulate how groups of units interact. By comparing the predicted interactions to the actual data from these models, researchers verified that their new method could accurately infer the interactions.

Real-World Testing

The truly exciting part came when researchers used their method on real-world data from experiments studying how immune cells, like dendritic cells, move in response to chemical signals. In these experiments, scientists recorded the movement of cells over time as they responded to a chemical gradient. Using their new method, the researchers could identify how long the influence of one cell's movement affected another, even when the effects were not immediately observable.

Findings and Implications

The results from both synthetic and real-world data showed that the new method is effective in uncovering delayed interactions. It revealed that not only do cells influence each other, but the duration of this influence can extend over a longer period than previously thought.

The Role of Time in Interactions

One key finding from the research is that the interactions among units are not just immediate but can span across time. For example, a cell’s movement can be influenced by the actions of other cells days or minutes before. This finding emphasizes the importance of considering time when studying interactions.

Overcoming Previous Limitations

Traditional methods often required instantaneous interactions, which limited their effectiveness in many biological contexts. This new approach allows for a broader understanding of how units influence each other over time, providing a more accurate model of biological systems.

Broader Impact on Science

The ability to accurately model interactions over time has significant implications for various fields, including biology, ecology, and medicine. By understanding the timing of interactions, scientists can improve their predictions about how cells behave in different environments, which could lead to better treatments for diseases or more successful conservation efforts.

Conclusion

In summary, the new method developed for analyzing delayed interactions in dynamic systems shows great promise in enhancing our understanding of how living things communicate and behave. This approach opens up new opportunities for research and application in many fields, from medical science to environmental sustainability. The findings not only highlight the importance of timing in interactions but also provide a more accurate framework for understanding the complex behaviors of different life forms.

Original Source

Title: Inverse modeling of time-delayed interactions via the dynamic-entropy formalism

Abstract: Although instantaneous interactions are unphysical, a large variety of maximum entropy statistical inference methods match the model-inferred and the empirically-measured equal-time correlation functions. Focusing on collective motion of active units, this constraint is reasonable when the interaction timescale is much faster than that of the interacting units, as in starling flocks, yet it fails in a number of counter examples, as in leukocyte coordination (where signalling proteins diffuse among two cells). Here, we relax this assumption and develop a path integral approach to maximum-entropy framework, which includes delay in signalling. Our method is able to infer the strength of couplings and fields, but also the time required by the couplings to completely transfer information among the units. We demonstrate the validity of our approach providing excellent results on synthetic datasets of non-Markovian trajectories generated by the Heisenberg-Kuramoto and Vicsek models equipped with delayed interactions. As a proof of concept, we also apply the method to experiments on dendritic migration, where matching equal-time correlations results in a significant information loss.

Authors: Elena Agliari, Francesco Alemanno, Adriano Barra, Michele Castellana, Daniele Lotito, Matthieu Piel

Last Update: 2024-07-10 00:00:00

Language: English

Source URL: https://arxiv.org/abs/2309.01229

Source PDF: https://arxiv.org/pdf/2309.01229

Licence: https://creativecommons.org/licenses/by/4.0/

Changes: This summary was created with assistance from AI and may have inaccuracies. For accurate information, please refer to the original source documents linked here.

Thank you to arxiv for use of its open access interoperability.

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