arXiv Machine Learning

Escaping the Phylogenetic Trap: Persistent Homology Enables Cross-Species Ion Channel Classification via Multimodal Graph Neural Networks

The paper investigates how phylogenetic leakage can inflate performance estimates for protein classifiers, particularly in venom ion‑channel target prediction. By treating cross‑species prediction as a structured distribution shift, the authors compare five structural inductive biases using a multimodal graph neural network that fuses ESM‑2 embeddings with a disulfide‑aware attention mechanism. Persistent‑homology representations, which capture backbone geometry through topological descriptors, outperform other biases under a leave‑one‑taxon‑out protocol, achieving 63.4% accuracy versus 54‑55% for other geometric priors and 30% for a sequence‑only baseline.

arXiv Computation and Language
Sep 7

Self-Supervised Lexical Representation Learning for Fast, Large-Scale Phylogenetic Inference

The paper presents a fully self‑supervised contrastive learning framework that learns lexical representations from raw IPA‑transcribed wordlists without any cognacy annotations or expert input. Using a dual contrastive objective—word‑level and language‑level losses—the model produces word representations that enable fast computation of pairwise language distances and the inference of a global phylogenetic tree for 3,399 language varieties. The resulting tree achieves a generalized quartet distance competitive with baselines while requiring only minutes of computation on a standard notebook GPU, and the representations also capture diachronic concept stability.

By Tim Wientzek
arXiv Machine Learning
Sep 7

Self-Supervised Pretraining of Molecular Graph Encoders with LeJEPA

The study investigates whether self‑supervised pretraining improves molecular graph neural networks by adapting the LeJEPA architecture to molecular graphs. While pretraining enhances learned representations and a frozen probe outperforms random initialization on tasks such as ogbg‑molhiv, it does not consistently boost finetuning performance across different data splits. Combining pretrained embeddings with 1024‑bit Morgan fingerprints yields modest gains, indicating that pretraining provides complementary information best exploited at the feature level.

By Micha{\l} Kulczykowski, Rafa{\l} {\L}ab\k{e}dzki
arXiv Machine Learning
Jun 16

Learning Topological Representations for Molecular Dynamics

arXiv:2606. 14737v1 Announce Type: cross Abstract: Molecular dynamics (MD) simulations generate trajectories in a high-dimensional configuration space whose analysis critically depends on molecular descriptors, typically handcrafted observables or learned kinetic embeddings.

By Dominik Geng, Florian Graf, Martin Uray, Roland Kwitt
arXiv AI
Sep 25

SMILESGNN: Interpretable Clinical Toxicity Prediction via SMILES-Graph Cross-Attention Fusion

SMILESGNN is a multimodal architecture that fuses a SMILES Transformer encoder with a GATv2 graph encoder through cross‑attention, enabling interpretable clinical toxicity predictions. The model retains an explicit graph branch, allowing GNNExplainer to identify substructures linked to toxicity. On the ClinTox dataset it achieves an AUC‑ROC of 0.987 and F1 of 0.906 with only 0.4 M parameters, while on Tox21 it attains a mean AUC‑ROC of 0.750, comparable to strong single‑modality baselines.

By Quang Minh Nguyen, Thuy Quynh Nguyen, Duc Minh Le, Ho Nhat Minh Nguyen, Thanh Long Dai Doan, Trong Nghia Nguyen
arXiv Machine Learning
2d ago

Fragment-Level Graph Encoding for Interpretable Molecular Property Prediction

The paper introduces a fragment‑level graph encoding for molecular property prediction, using BRICS decomposition to represent molecules as graphs of synthetically meaningful fragments. This change of input representation allows any message‑passing GNN and post‑hoc attribution method to produce explanations at the functional‑group level, matching atom‑level accuracy on smaller graphs. Experiments across multiple architectures, tasks, and explainers show that fragment‑level encoding recovers known pharmacophores more reliably than post‑hoc aggregation of atom‑level explanations.

By Rafael Lopes Almeida (School of Pharmacy, University of Eastern Finland, Kuopio, Finland), Ina P\"ohner (School of Pharmacy, University of Eastern Finland, Kuopio, Finland)