Alexander Tong
Principal Investigator
About
Alexander Tong is a Principal Investigator at Aithyra, a research institute at the intersection of machine learning and life sciences led by Michael Bronstein and funded by the Boehringer Ingelheim Foundation. He works on generative modeling, deep learning, and optimal transport, with applications to cell and molecular biology. He received his PhD from Yale University in 2021, advised by Smita Krishnaswamy, after which he was a postdoc at Mila with Yoshua Bengio and then an assistant professor at Duke University.
Specialization
Publications
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Hacking Generative Perplexity: Why Unconditional Text Evaluation Needs Distributional Metrics
Antonio Franca, Alexander Tong
In ICML 2026 Workshop on Structured Probabilistic Inference & Generative Modeling (SPIGM)
July 2026
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Why Are DMD Students Lazy? Understanding the Copying Behavior in Few-Step Distillation
Shucheng Li, Iolo Jones, Alexander Tong†, Michael M. Bronstein†
In ICML 2026 Workshop on High-dimensional Learning Dynamics
July 2026
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MacroGuide: Topological Guidance for Macrocycle Generation
Alicja Maksymiuk, Alexandre Duplessis, Michael Bronstein, Alexander Tong, Fernanda Duarte, İsmail İlkan Ceylan
In ICML 2026
July 2026
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Strong Stochastic Flow Maps
Sam McCallum*, Zander W. Blasingame*, Timothy Herschell, Niklas Rindtorff, Alexander Tong†, James Foster†
In ICML 2026 Workshop on Structured Probabilistic Inference & Generative Modeling (SPIGM)
July 2026
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Autoregressive Boltzmann Generators
Danyal Rehman, Charlie B. Tan, Yoshua Bengio, Joey Bose, Alexander Tong
In ICML 2026 (Spotlight)
July 2026
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Beta cell-derived cholecystokinin drives obesity-associated pancreatic adenocarcinoma development
Cathy C. Garcia*, Aarthi Venkat*, Daniel C. McQuaid*, Sherry S. Agabiti, Alexander Tong, Boby Mathew, Rebecca L. Cardone, Rebecca Starble, Christian F. Ruiz, Christy Zheng, Akin Sogunro, Jeremy B. Jacox, Ken H. Loh, Richard G. Kibbey, Smita Krishnaswamy†, Mandar Deepak Muzumdar†
In Nature Communications
June 2026
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Entropy Across the Bridge: Conditional-Marginal Discretization for Flow and Schrödinger Samplers
Bruno Trentini, Dejan Stancevic, Michael M. Bronstein, Alexander Tong, Luca Ambrogioni
Preprint
May 2026
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Coupling Models for One-Step Discrete Generation
Fred Zhangzhi Peng, Avishek Joey Bose, Anru R. Zhang, Alexander Tong
Preprint
May 2026
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Don't Retrain, Align: Adapting Autoregressive LMs to Diffusion LMs via Representation Alignment
Fred Zhangzhi Peng, Alexis Fox, Anru R. Zhang, Alexander Tong
Preprint
May 2026
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FALCON: Few-step Accurate Likelihoods for Continuous Flows
Danyal Rehman, Tara Akhound-Sadegh, Artem Gazizov, Yoshua Bengio, Alexander Tong
In ICLR 2026 (Oral)
May 2026
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OXtal: An All-Atom Diffusion Model for Organic Crystal Structure Prediction
Emily Jin*, Andrei Cristian Nica*, Mikhail Galkin, Jarrid Rector-Brooks, Kin Long Kelvin Lee, Santiago Miret, Frances H. Arnold, Michael Bronstein, Avishek Joey Bose, Alexander Tong, Chenghao Liu
In ICLR 2026
May 2026
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Planner Aware Path Learning in Diffusion Language Models Training
Fred Zhangzhi Peng*, Zachary Bezemek*, Jarrid Rector-Brooks, Shuibai Zhang, Anru R. Zhang, Michael Bronstein, Avishek Joey Bose†, Alexander Tong†
In ICLR 2026 (Oral)
May 2026
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Topological Flow Matching
Kacper Wyrwal, Ismail Ilkan Ceylan, Alexander Tong
In ICLR 2026
May 2026
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Branched Schrödinger Bridge Matching
Sophia Tang, Yinuo Zhang, Alexander Tong, Pranam Chatterjee
In ICLR 2026
May 2026
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Flow matching for generative modelling in bioinformatics and computational biology
Alex Morehead*, Lazar Atanackovic*, Akshata Hegde*, Yanli Wang*, Frimpong Boadu*, Joel Selvaraj*, Alexander Tong, Aditi Krishnapriyan, Jianlin Cheng
In Nature Machine Intelligence
April 2026
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General Multimodal Protein Design Enables DNA-Encoding of Chemistry
Jarrid Rector-Brooks*, Théophile Lambert*, Marta Skreta*, Daniel Roth*, Yueming Long, Zi-Qi Li, Xi Zhang, Miruna Cretu, Francesca-Zhoufan Li, Tanvi Ganapathy, Emily Jin, Avishek Joey Bose, Jason Yang, Kirill Neklyudov, Yoshua Bengio, Alexander Tong, Frances H. Arnold, Cheng-Hao Liu
Preprint
April 2026
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MIOFlow 2.0: A Unified Framework for Inferring Cellular Stochastic Dynamics from Single Cell and Spatial Transcriptomics Data
Xingzhi Sun, João Felipe Rocha, Brett Phelan, Dhananjay Bhaskar, Guillaume Huguet, Yanlei Zhang, Alexander Tong, Ke Xu, Oluwadamilola Fasina, Mark Gerstein, Natalia Ivanova, Christine L. Chaffer, Guy Wolf, Smita Krishnaswamy
Preprint
March 2026
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Amortized Sampling with Transferable Normalizing Flows
Charlie B. Tan*, Majdi Hassan*, Leon Klein, Saifuddin Syed, Dominique Beaini, Michael M. Bronstein, Alexander Tong†, Kirill Neklyudov†
In NeurIPS 2025
December 2025
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Curly Flow Matching for Learning Non-gradient Field Dynamics
Katarina Petrović, Lazar Atanackovic, Viggo Moro, Kacper Kapuśniak, İsmail İlkan Ceylan, Michael Bronstein, Avishek Joey Bose†, Alexander Tong†
In NeurIPS 2025
December 2025
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Progressive Inference-Time Annealing of Diffusion Models for Sampling from Boltzmann Densities
Tara Akhound-Sadegh*, Jungyoon Lee*, Avishek Joey Bose, Valentin De Bortoli, Arnaud Doucet, Michael M. Bronstein, Dominique Beaini, Siamak Ravanbakhsh, Kirill Neklyudov†, Alexander Tong†
In NeurIPS (spotlight)
December 2025
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Foundations of Diffusion Models in General State Spaces: A Self-Contained Introduction
Vincent Pauline, Tobias Höppe, Kirill Neklyudov, Alexander Tong, Stefan Bauer, Andrea Dittadi
arXiv preprint
December 2025
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FORT: Forward-Only Regression Training of Normalizing Flows
Danyal Rehman, Oscar Davis, Jiarui Lu, Jian Tang, Michael Bronstein, Yoshua Bengio, Alexander Tong†, Avishek Joey Bose†
ICML GenBio Best Paper Award 2025
July 2025
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Scalable Equilibrium Sampling with Sequential Boltzmann Generators
Charlie B. Tan*, Avishek Joey Bose*, Chen Lin, Leon Klein, Michael M. Bronstein, Alexander Tong
In ICML 2025
July 2025
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Feynman-Kac Correctors in Diffusion: Annealing, Guidance, and Product of Experts
Marta Skreta*, Tara Akhound-Sadegh*, Viktor Ohanesian*, Roberto Bondesan, Alán Aspuru-Guzik, Arnaud Doucet, Rob Brekelmans, Alexander Tong†, Kirill Neklyudov†
In ICML 2025 (spotlight)
July 2025
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Defining and Benchmarking Open Problems in Single-Cell Analysis
Malte Luecken*, Scott Gigante*, Daniel Burkhardt*, Robrecht Cannoodt, Daniel Strobl, Nikolay Markov, Luke Zappia, Giovanni Palla, Wesley Lewis, Daniel Dimitrov, Michael Vinyard, Daniel Magruder, Alma Andersson, Emma Dann, Qian Qin, Dominik Otto, Michal Klein, Olga Botvinnik, Louise Deconinck, Kai Waldrant, Bastian Rieck, Constantin Ahlmann-Eltze, Eduardo Da Veiga Beltrame, Andrew Benz, Carmen Bravo González-Blas, Ann Chen, Benjamin DeMeo, Can Ergen, Swann Floc'hlay, Adam Gayoso, Stephanie Hicks, Yuge Ji, Vitalii Kleshchevnikov, Gioele La Manno, Maximilian Lombardo, Romain Lopez, Dario Righelli, Hirak Sarkar, Valentine Svensson, Alexander Tong, Galen Xing, Chenling Xu, Jonathan Bloom, Angela Pisco, Julio Saez-Rodriguez, Drausin Wulsin, Luca Pinello, Yvan Saeys, Fabian Theis, Smita Krishnaswamy
In Nature Biotechnology, 2025
June 2025
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Generating Multi-Modal and Multi-Attribute Single-Cell Counts with CFGen
Alessandro Palma, Till Richter, Hanyi Zhang, Manuel Lubetzki, Alexander Tong, Andrea Dittadi, Fabian Theis
In ICLR 2025
May 2025
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Steering Masked Discrete Diffusion Models via Discrete Denoising Posterior Prediction
Jarrid Rector-Brooks, Mohsin Hasan, Zhangzhi Peng, Zachary Quinn, Chenghao Liu, Sarthak Mittal, Nouha Dziri, Michael Bronstein, Yoshua Bengio, Pranam Chatterjee, Alexander Tong†, Avishek Joey Bose†
In ICLR 2025
May 2025
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Meta Flow Matching: Integrating Vector Fields on the Wasserstein Manifold
Lazar Atanackovic*, Xi Zhang*, Brandon Amos, Mathieu Blanchette, Leo J. Lee, Yoshua Bengio, Alexander Tong, Kirill Neklyudov
In ICLR 2025
May 2025
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The Superposition of Diffusion Models Using the Itô Density Estimator
Marta Skreta*, Lazar Atanackovic*, Avishek Joey Bose, Alexander Tong, Kirill Neklyudov
In ICLR 2025 (spotlight)
May 2025
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geneRNIB: a living benchmark for gene regulatory network inference
Jalil Nourisa, Antoine Passemiers, Marco Stock, Berit Zeller-Plumhoff, Robrecht Cannoodt, Christian Arnold, Alexander Tong, Jason Hartford, Antonio Scialdone, Yves Moreau, Yang Li, Malte D. Luecken
In bioRxiv
April 2025
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Hidden sampling biases inflate performance in gene regulatory network inference
Marco Stock*, Florin Ratajczak*, Paul Bertin, Eva Hoermanseder, Yoshua Bengio, Jason Hartford, Pascal Falter-Braun, Matthias Heinig, Alexander Tong, Antonio Scialdone
Preprint (bioRxiv)
April 2025
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Path Planning for Masked Diffusion Model Sampling
Fred Zhangzhi Peng*, Zachary Bezemek*, Sawan Patel, Jarrid Rector-Brooks, Sherwood Yao, Alexander Tong†, Pranam Chatterjee†
arXiv preprint
February 2025
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Sequence-Augmented SE(3)-Flow Matching For Conditional Protein Backbone Generation
Guillaume Huguet*, James Vuckovic*, Kilian Fatras, Eric Thibodeau-Laufer, Pablo Lemos, Riashat Islam, Cheng-Hao Liu, Jarrid Rector-Brooks, Tara Akhound-Sadegh, Michael Bronstein, Alexander Tong†, Avishek Joey Bose†
In NeurIPS 2024
December 2024
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Metric Flow Matching for Smooth Interpolations on the Data Manifold
Kacper Kapusniak, Peter Potaptchik, Teodora Reu, Leo Zhang, Alexander Tong, Michael Bronstein, Avishek Joey Bose, Francesco Di Giovanni
In NeurIPS 2024
December 2024
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A Computational Framework for Solving Wasserstein Lagrangian Flows
Kirill Neklyudov*, Rob Brekelmans*, Alexander Tong, Lazar Atanackovic, Qiang Liu, Alireza Makhzani
In ICML 2024
July 2024
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Iterated Denoising Energy Matching for Sampling from Boltzmann Densities
Tara Akhound-Sadegh*, Jarrid Rector-Brooks*, Avishek Joey Bose*, Sarthak Mittal, Pablo Lemos, Cheng-Hao Liu, Marcin Sendera, Siamak Ravanbakhsh, Gauthier Gidel, Yoshua Bengio, Nikolay Malkin, Alexander Tong
In ICML 2024
July 2024
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Learnable Filters for Geometric Scattering Modules
Alexander Tong*, Frederik Wenkel*, Dhananjay Bhaskar, Kincaid Macdonald, Jackson Grady, Michael Perlmutter, Smita Krishnaswamy, Guy Wolf
In IEEE Transactions on Signal Processing
June 2024
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SE(3)-Stochastic Flow Matching for Protein Backbone Generation
Avishek Joey Bose*, Tara Akhound-Sadegh*, Kilian Fatras, Guillaume Huguet, Jarrid Rector-Brooks, Cheng-Hao Liu, Andrei Cristian Nica, Maksym Korablyov, Michael Bronstein, Alexander Tong
In ICLR 2024 (Spotlight)
May 2024
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Improving and Generalizing Flow-Based Generative Models with Minibatch Optimal Transport
Alexander Tong*, Nikolay Malkin*, Guillaume Huguet, Yanlei Zhang, Jarrid Rector-Brooks, Kilian Fatras, Guy Wolf, Yoshua Bengio
In Transactions on Machine Learning Research (TMLR), 2024
May 2024
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A Heat Diffusion Perspective on Geodesic Preserving Dimensionality Reduction
Guillaume Huguet*, Alexander Tong*, Edward De Brouwer*, Yanlei Zhang, Guy Wolf, Ian Adelstein, Smita Krishnaswamy
In NeurIPS
December 2023
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DynGFN: Bayesian Dynamic Causal Discovery Using Generative Flow Networks
Lazar Atanackovic*, Alexander Tong*, Jason Hartford, Leo J. Lee, Bo Wang, Yoshua Bengio
In NeurIPS. Also presented at Frontiers4LCD Workshop @ NeurIPS 2022
December 2023
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Causal Inference in Gene Regulatory Networks with GFlowNet: Towards Scalability in Large Systems
Trang Nguyen, Alexander Tong, Kanika Madan, Yoshua Bengio†, Dianbo Liu†
In arXiv
October 2023
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Geodesic Sinkhorn for Fast and Accurate Optimal Transport on Manifolds
Guillaume Huguet*, Alexander Tong*, María Ramos Zapatero, Christpher J. Tape, Guy Wolf, Smita Krishnaswamy
In IEEE MLSP
September 2023
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Neural FIM for Learning Fisher Information Metrics from Point Cloud Data
Oluwadamilola Fasina*, Guillaume Huguet*, Alexander Tong, Yanlei Zhang, Guy Wolf, Maximilian Nickel, Ian Adelstein, Smita Krishnaswamy
In ICML
July 2023
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Graph Fourier MMD for signals on data graphs
Sam Leone, Alexander Tong, Guillaume Huguet, Guy Wolf, Smita Krishnaswamy
In SAMPTA
July 2023
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Single-Cell Analysis Reveals Inflammatory Interactions Driving Macular Degeneration
Manik Kuchroo*, Marcello DiStasio*, Eric Song*, Eda Calapkulu, Le Zhang, Maryam Ige, Amar H. Sheth, Abdelilah Majdoubi, Madhvi Menon, Alexander Tong, Abhinav Godavarthi, Yu Xing, Scott Gigante, Holly Steach, Jessie Huang, Guillaume Huguet, Janhavi Narain, Kisung You, George Mourgkos, Rahul M. Dhodapkar, Matthew J. Hirn, Bastian Rieck, Guy Wolf, Smita Krishnaswamy†, Brian P. Hafler†
In Nature Communications
June 2023
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Trellis tree-based analysis reveals stromal regulation of patient-derived organoid drug responses
María Ramos Zapatero*, Alexander Tong*, Jahangir Sufi, Petra Vlckova, Ferran Cardoso Rodriguez, Callum Nattress, Xiao Qin, Daniel Hochhauser, Smita Krishnaswamy, Christopher J. Tape
In Cell
June 2023
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Understanding Graph Neural Networks with Generalized Geometric Scattering Transforms
Michael Perlmutter, Alexander Tong, Feng Gao, Guy Wolf, Matthew Hirn
In SIAM Journal on Mathematics of Data Science (SIMODS), 2023
May 2023
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Learning Transcriptional and Regulatory Dynamics Driving Cancer Cell Plasticity Using Neural ODE-Based Optimal Transport
Alexander Tong*, Manik Kuchroo*, Shabarni Gupta, Aarthi Venkat, Beatriz P. San Juan, Laura Rangel, Brandon Zhu, John G. Lock, Christine L. Chaffer, Smita Krishnaswamy
In BioRxiv
April 2023
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Manifold Interpolating Optimal-Transport Flows for Trajectory Inference
Guillaume Huguet*, D. S. Magruder*, Alexander Tong*, Oluwadamilola Fasina, Manik Kuchroo, Guy Wolf, Smita Krishnaswamy
In NeurIPS
December 2022
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Immune Cells and Their Inflammatory Mediators Modify Beta Cells and Cause Checkpoint Inhibitor-Induced Diabetes
Ana Luisa Perdigoto, Songyan Deng, Katherine C. Du, Manik Kuchroo, Daniel B. Burkhardt, Alexander Tong, Gary Israel, Marie E. Robert, Stuart P. Weisberg, Nancy Kirkiles-Smith, Angeliki M. Stamatouli, Harriet M. Kluger, Zoe Quandt, Arabella Young, Mei-Ling Yang, Mark J. Mamula, Jordan S. Pober, Mark S. Anderson, Smita Krishnaswamy, Kevan C. Herold
In JCI Insight 7(17), e156330, 2022
June 2022
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Multiscale PHATE identifies multimodal signatures of COVID-19
Manik Kuchroo*, Jessie Huang*, Patrick Wong*, Jean-Christophe Grenier, Dennis Shung, Alexander Tong, Carolina Lucas, Jon Klein, Daniel Burkhardt, Scott Gigante, Abhinav Godavarthi, Benjamin Israelow, Tianyang Mao, Ji Eun Oh, Julio Silva, Takehiro Takahashi, Camila D. Odio, Arnau Casanovas-Massana, John Fournier, Yale IMPACT Team, Shelli Farhadian, Charles S. Dela Cruz, Albert I. Ko, F. Perry Wilson, Julie Hussin†, Guy Wolf†, Akiko Iwasaki†, Smita Krishnaswamy†
In Nature Biotechnology
June 2022
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Embedding Signals on Knowledge Graphs with Unbalanced Diffusion Earth Mover's Distance
Alexander Tong, Guillaume Huguet, Dennis Shung, Amine Natik, Manik Kuchroo, Guillaume Lajoie, Guy Wolf, Smita Krishnaswamy
In ICASSP
May 2022
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A sandbox for prediction and integration of DNA, RNA, and protein data in single cells
Malte D Luecken, Daniel B Burkhardt, Robrecht Cannoodt, Christopher Lance, Aditi Agrawal, Hananeh Aliee, Ann T Chen, Louise Deconinck, Angela M Detweiler, Alejandro Granados, Shelly Huynh, Laura Isacco, Yang Joon Kim, Sunil Kuppasani, Heiko Lickert, Aaron McGeever, Honey Mekonen, Joaquin Caceres, Maurizio Morri, Michaela Mueller, Norma F Neff, Sheryl Paul, Kaylie Schneider, Scott Steelman, Michael Sterr, Dan J Treacy, Alexander Tong, Alexandra-Chloé Villani, Guilin Wang, Jia Yan, Ce Zhang, Angela O Pisco, Smita Krishnaswamy, Fabian J Theis, Jonathan M Bloom
In NeurIPS Datasets and Benchmarks
December 2021
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MURAL: An Unsupervised Random Forest-Based Embedding for Electronic Health Record Data
Michal Gerasimiuk*, Dennis L. Shung*, Alexander Tong, Adrian J. Stanley, Machael Shultz, Jeffrey Ngu, Loren Laine, Guy Wolf, Smita Krishnaswamy
In IEEE Big Data
December 2021
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Multimodal data visualization and denoising with integrated diffusion
Manik Kuchroo*, Abhinav Godavarthi*, Alexander Tong, Smita Krishnaswamy, Guy Wolf
In IEEE MLSP
September 2021
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Data-Driven Learning of Geometric Scattering Networks
Alexander Tong*, Frederik Wenkel*, Kincaid MacDonald, Smita Krishnaswamy, Guy Wolf
In IEEE MLSP. Also presented at ML4M Workshop @ NeurIPS 2020
September 2021
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Diffusion Earth Mover's Distance and Distribution Embeddings
Alexander Tong*, Guillaume Huguet*, Amine Natik*, Kincaid MacDonald, Manik Kuchroo, Ronald Coifman, Guy Wolf, Smita Krishnaswamy
In ICML. Also presented at LMRL Workshop @ NeurIPS 2020
July 2021
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Quantifying the effect of experimental perturbations in single-cell RNA-sequencing data using graph signal processing
Daniel B. Burkhardt*, Jay S. Stanley*, Alexander Tong, Ana Luisa Perdigoto, Scott A. Gigante, Kevan C. Herold, Guy Wolf, Antonio J. Giraldez, David van Dijk, Smita Krishnaswamy
In Nature Biotechnology
June 2021
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POT: Python Optimal Transport
Remi Flamary, Nicolas Courty, Alexandre Gramfort, Mokhtar Z Alaya, Aurelie Boisbunon, Stanislas Chambon, Laetitia Chapel, Adrien Corenflos, Kilian Fatras, Nemo Fournier, Leo Gautheron, Nathalie T H Gayraud, Hicham Janati, Alain Rakotomamonjy, Ievgen Redko, Antoine Rolet, Antony Schutz, Vivien Seguy, Danica J Sutherland, Romain Tavenard, Alexander Tong, Titouan Vayer
In JMLR
June 2021
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Fixing Bias in Reconstruction-based Anomaly Detection with Lipschitz Discriminators
Alexander Tong, Guy Wolf, Smita Krishnaswamy
Journal version in Journal of Signal Processing Systems (2021). Presented at IEEE MLSP 2020 (*Best Student Paper Award*).
June 2021
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Abstract 2839: Understanding the mesenchymal-to-epithelial transition and its drivers in triple-negative breast cancer with continuous normalizing flows
Alexander Tong, Beatriz P. San Juan, Brandon Zhu, Christine L. Chaffer, Smita Krishnaswamy
AACR
April 2021
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Uncovering the Folding Landscape of RNA Secondary Structure with Deep Graph Embeddings
Egbert Castro, Andrew Benz, Alexander Tong, Guy Wolf†, Smita Krishnaswamy†
In IEEE Big Data. Also at GRLB Workshop @ ICML 2020
December 2020
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Interpretable Neuron Structuring with Graph Spectral Regularization
Alexander Tong*, David van Dijk*, Jay S. Stanley III, Matthew Amodio, Kristina Yim, Rebecca Muhle, James Noonan, Guy Wolf, Smita Krishnaswamy
In IDA Also presented at RLGM Workshop @ ICLR 2019
October 2020
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TrajectoryNet: A Dynamic Optimal Transport Network for Modeling Cellular Dynamics
Alexander Tong, Jessie Huang, Guy Wolf, David van Dijk, Smita Krishnaswamy
In ICML. Also at LMRL Workshop @ NeurIPS 2019
July 2020
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Interpolating Optimal Transport Barycenters of Patient Manifolds
Alexander Tong, Smita Krishnaswamy
In ISMB
July 2020
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Finding Archetypal Spaces Using Neural Networks
David van Dijk*, Daniel B. Burkhardt*, Matthew Amodio, Alexander Tong, Guy Wolf, Smita Krishnaswamy
In IEEE Big Data
December 2019
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Fixing Bias in Reconstruction-based Anomaly Detection with Lipschitz Discriminators
Alexander Tong, Guy Wolf, Smita Krishnaswamy
In Journal of Signal Processing Systems
May 2019
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Allocate-On-Use Space Complexity of Shared-Memory Algorithms
James Aspnes, Bernhard Haeupler, Alexander Tong, Philipp Woelfel
In DISC
October 2018