Month: November 2024

Limits on inferring T cell specificity from partial information

James Henderson, Yuta Nagano, Martina Milighetti, and Andreas Tiffeau-Mayer

PNAS 121 (42) e2408696121

The specificity of cellular immune responses is determined by the binding of T cell receptors (TCRs) to diverse ligands, yet due to their vast diversity, most TCRs lack experimentally validated binding partners. To overcome this gap requires understanding the recognition code linking receptors and ligands. Here, we introduce an information theoretic approach to rank TCR features by their relevance to predicting specificity and bound how accurately T cell specificity can be predicted from partial information. By identifying informative features, our work provides a rational basis for prioritizing matches in TCR databases and for developing machine learning models to predict TCR–ligand interactions.

Read the full article at: www.pnas.org

How Is AI Changing the Science of Prediction?

With lots of data, a strong model and statistical thinking, scientists can make predictions about all sorts of complex phenomena. Today, this practice is evolving to harness the power of machine learning and massive datasets. In this episode, co-host Steven Strogatz speaks with statistician Emmanuel Candès about black boxes, uncertainty and the power of inductive reasoning.

Read the full article at: www.quantamagazine.org

Spontaneous Emergence of Agent Individuality through Social Interactions in LLM-Based Communities

Ryosuke Takata, Atsushi Masumori, Takashi Ikegami

We study the emergence of agency from scratch by using Large Language Model (LLM)-based agents. In previous studies of LLM-based agents, each agent’s characteristics, including personality and memory, have traditionally been predefined. We focused on how individuality, such as behavior, personality, and memory, can be differentiated from an undifferentiated state. The present LLM agents engage in cooperative communication within a group simulation, exchanging context-based messages in natural language. By analyzing this multi-agent simulation, we report valuable new insights into how social norms, cooperation, and personality traits can emerge spontaneously. This paper demonstrates that autonomously interacting LLM-powered agents generate hallucinations and hashtags to sustain communication, which, in turn, increases the diversity of words within their interactions. Each agent’s emotions shift through communication, and as they form communities, the personalities of the agents emerge and evolve accordingly. This computational modeling approach and its findings will provide a new method for analyzing collective artificial intelligence.

Read the full article at: arxiv.org

Strategic Sacrifice: Self-Organized Robot Swarm Localization for Inspection Productivity

Sneha Ramshanker, Hungtang Ko, Radhika Nagpal

Robot swarms offer significant potential for inspecting di- verse infrastructure, ranging from bridges to space stations. However, effective inspection requires accurate robot localization, which demands substantial computational resources and limits productivity. Inspired by biological systems, we introduce a novel cooperative localization mech- anism that minimizes collective computation expenditure through self- organized sacrifice. Here, a few agents bear the computational burden of localization; through local interactions, they improve the inspection pro- ductivity of the swarm. Our approach adaptively maximizes inspection productivity for unconstrained trajectories in dynamic interaction and environmental settings. We demonstrate the optimality and robustness using mean-field analytical models, multi-agent simulations, and hard- ware experiments with metal climbing robots inspecting a 3D cylinder.

Read the full article at: ssr.princeton.edu

Peer interaction dynamics and L2 learning trajectories during study abroad: A longitudinal investigation using dynamic computational Social Network Analysis

Paradowski, M.B., Whitby, N., Czuba, M. & Bródka, P. (2024). Language Learning. DOI: 10.1111/lang.12681

This is the first application in second language acquisition of quantitative Social Network Analysis reconstructing a complete learner network with repeated (three) measurement points. Apart from the empirical contribution showcasing exciting findings from an intensive study-abroad Arabic program, the text can also serve as a primer of centrality metrics, providing in-depth explanation of the most commonly used centrality measures in network science – to the best of our knowledge, the first such 101 in applied linguistics. The materials, dataset, as well as code are all openly available on OSF and IRIS.

Abstract

Using computational Social Network Analysis (SNA), this longitudinal study investigates the development of the interaction network and its influence on the second language (L2) gains of a complete cohort of 41 U.S. sojourners enrolled in a 3-month intensive study-abroad Arabic program in Jordan. Unlike extant research, our study focuses on students’ interactions with alma mater classmates, reconstructing their complete network, tracing the impact of individual students’ positions in the social graph using centrality metrics, and incorporating a developmental perspective with three measurement points. Objective proficiency gains were influenced by predeparture proficiency (negatively), multilingualism, perceived integration of the peer learner group (negatively), and the number of fellow learners speaking to the student. Analyses reveal relatively stable same-gender cliques, but with changes in the patterns and strength of interaction. We also discuss interesting divergent trajectories of centrality metrics, L2 use, and progress; predictors of self-perceived progress across skills; and the interplay of context and gender.

Read the full article at https://onlinelibrary.wiley.com/doi/10.1111/lang.12681