My research interests are focused on topological methods in statistics and machine learning. Topological data analysis refers to the analysis of data shape. My research spans from encoding of data into filtered simplicial complexes (topological representation), approximations of filtered simplicial complexes (sparsification), validation measures of unsupervised persistent homology, data benchmarks, efficient vector representations of persistent homology for supervised machine learning and applications of topological methods in biology and geophysics.

Academic article

• Benjamin Bergougnoux; Nello Blaser; Michael Ralph Fellows et al. (2025). On the parameterized complexity of lineal topologies (depth-first spanning trees) with many or few leaves. (external link)
• Nello Blaser; Erlend Raa Vågset (2025). Homology localization through the looking-glass of parameterized complexity theory. (external link)
• Benedicte Sjo Tislevoll; Monica Hellesøy; Oda Helen Eck Fagerholt et al. (2022). Early response evaluation by single cell signaling profiling in acute myeloid leukemia. (external link)
• Kristian Gundersen; Guttorm Alendal; Anna Oleynik et al. (2020). Binary time series classification with Bayesian convolutional neural networks when monitoring for marine gas discharges. (external link)
• Nello Blaser; Morten Brun (2018). Divisive Cover. (external link)
• Aurora Grefsrud; Nello Blaser; Trygve Buanes (2026). Calibrated and uncertain? Evaluating uncertainty estimates in binary classification models. (external link)
• Emmanuel Sam; Benjamin Bergougnoux; Petr Golovach et al. (2023). Kernelization for Finding Lineal Topologies (Depth-First Spanning Trees) with Many or Few Leaves. (external link)
• Morten Brun; Nello Blaser (2017). Filtered covers. (external link)
• Håvard G Frøysa; Shirin Fallahi; Nello Blaser (2018). Evaluating model reduction under parameter uncertainty. (external link)
• Lucius Bader; Stein-Erik Gullaksen; Nello Blaser et al. (2019). Candidate markers for stratification and classification in rheumatoid arthritis. (external link)
• Nello Blaser; Morten Brun (2019). Sparse Nerves in Practice. (external link)
• Morten Brun; Nello Blaser (2018). Sparse Filtered Nerves. (external link)
• Sonia Gavasso; Jonas Bull Haugsøen; Dimitrios Kleftogiannis et al. (2025). High-dimensional Immune Profiling Following Autologous Hematopoietic Stem Cell Transplantation in Relapsing-Remitting Multiple Sclerosis. (external link)
• Anna Oleynik; Maribel I. García-Ibáñez; Nello Blaser et al. (2020). Optimal sensors placement for detecting CO2 discharges from unknown locations on the seafloor. (external link)
• Nello Blaser; Morten Brun (2022). Relative Persistent Homology. (external link)
• Gerd Haga Bringeland; Nello Blaser; Kjell-Morten Myhr et al. (2020). Wearing-off at the end of natalizumab dosing intervals is associated with low receptor occupancy. (external link)
• Kristian Gundersen; Anna Oleynik; Nello Blaser et al. (2021). Semi-conditional variational auto-encoder for flow reconstruction and uncertainty quantification from limited observations. (external link)
• Fekadu Yadetie; Xiaokang Zhang; Eileen Marie Hanna et al. (2018). RNA-Seq analysis of transcriptome responses in Atlantic cod (Gadus morhua) precision-cut liver slices exposed to benzo[a]pyrene and 17α-ethynylestradiol. (external link)
• Janne Estill; Cliff C. Kerr; Nello Blaser et al. (2018). The effect of monitoring viral load and tracing patients lost to follow-up on the course of the HIV epidemic in Malawi: A mathematical model. (external link)
• Simeon Sahani Mayala; Ida Ajvazi Herdlevær; Jonas Bull Haugsøen et al. (2022). GUBS: Graph-based unsupervised brain segmentation in MRI images. (external link)
• Gerd Haga Bringeland; Nello Blaser; Kjell-Morten Myhr et al. (2021). Wearing-off symptoms during standard and extended natalizumab dosing intervals: Experiences from the COVID-19 pandemic. (external link)
• Karina Dale; Mette Bjørge Müller; Zhanna Tairova et al. (2019). Contaminant accumulation and biological responses in Atlantic cod (Gadus morhua) caged at a capped waste disposal site in Kollevåg, Western Norway. (external link)
• Mitchell Black; Nello Blaser; Amir Nayyeri et al. (2022). ETH-Tight Algorithms for Finding Surfaces in Simplicial Complexes of Bounded Treewidth. (external link)
• Kareem Eldin Mohammed Ahmed; Håvard G Frøysa; Odd Andre Karlsen et al. (2018). Effects of defined mixtures of POPs and endocrine disruptors on the steroid metabolome of the human H295R adrenocortical cell line. (external link)
• Morten Brun; Nello Blaser (2019). Sparse Dowker nerves. (external link)
• Benedicte Sjo Tislevoll; Monica Hellesøy; Oda Helen Eck Fagerholt et al. (2023). Early response evaluation by single cell signaling profiling in acute myeloid leukemia. (external link)
• Odin Hoff Gardå; Nello Blaser (2025). RotaTouille: Rotation Equivariant Deep Learning for Contours. (external link)
• Nello Blaser; Morten Brun; Odin Hoff Gardå et al. (2025). Core Bifiltration. (external link)
• Nello Blaser; Morten Brun (2020). Relative Persistent Homology. (external link)
• Gerd Haga Bringeland; Lucius Bader; Nello Blaser et al. (2019). Optimization of receptor occupancy assays in mass cytometry: Standardization across channels with QSC beads. (external link)
• Marta Eide; Anders Goksøyr; Fekadu Yadetie et al. (2023). Integrative omics-analysis of lipid metabolism regulation by peroxisome proliferator-activated receptor a and b agonists in male Atlantic cod. (external link)
• Nello Blaser; Morten Brun; Lars Moberg Salbu et al. (2024). The parameterized complexity of finding minimum bounded chains. (external link)
• Nello Blaser; Barbara Bertisch; Roger D. Kouyos et al. (2017). Impact of screening and antiretroviral therapy on anal cancer incidence in HIV-positive MSM. (external link)

Conference lecture

• Xiaokang Zhang; Marta Eide; Odd Andre Karlsen et al. (2018). Modelling the chemical defensome networks --- a dynamic visualisation of the involved genes and interactions in two fish species and human. (external link)
• Fekadu Yadetie; Marta Eide; Sofie Söderström et al. (2017). PRECISION-CUT LIVER SLICES (PCLS) FOR TOXICOGENOMIC STUDIES IN ATLANTIC COD (Gadus morhua): THE dCOD 1.0 PROJECT. (external link)
• Fekadu Yadetie; Xiaokang Zhang; Eileen Marie Hanna et al. (2019). EFFECTS OF SELECTED ENVIRONMENTAL ESTROGENS ON EXPRESSION OF FIBROBLAST GROWTH FACTOR SIGNALING PATHWAY GENES IN THE LIVER OF ATLANTIC COD (GADUS MORHUA) IN VIVO AND EX VIVO. (external link)
• Anders Goksøyr; Guttorm Alendal; Libe Aranguren Abadía et al. (2018). dCOD 1.0: DECODING THE SYSTEMS TOXICOLOGY OF ATLANTIC COD (GADUS MORHUA). (external link)
• Kristian Gundersen; Anna Oleynik; Nello Blaser et al. (2019). Bayesian convolutional neural networks as a tool to detect discharges of pollutants to marine waters through time series classification. (external link)
• Guttorm Alendal; Anna Oleynik; Nello Blaser et al. (2018). The need for proper environmental statistics to design adequate monitoring for offshore geological storage of CO2 projects.. (external link)
• Marta Eide; Xiaokang Zhang; Odd Andre Karlsen et al. (2019). The chemical defensome of Atlantic cod (Gadus morhua). (external link)
• Nello Blaser; Shirin Fallahi; Håvard G Frøysa (2017). Model reduction under parameter uncertainty. (external link)
• Marta Eide; Xiaokang Zhang; Odd Andre Karlsen et al. (2018). Modelling The Chemical Defensome Networks - A Comparative Dynamic Visualisation Of The Involved Genes And Interactions In Two Fish Species And Humans. (external link)
• Nello Blaser; Eileen Marie Hanna; Morten Brun et al. (2018). Discovering pathway perturbations with topological edge set enrichment analysis (TESEA). (external link)
• Natacha Galmiche; Helwig Hauser; Thomas Spengler et al. (2021). Revealing Multimodality in Ensemble Weather Prediction. (external link)
• Marta Eide; Xiaokang Zhang; Odd Andre Karlsen et al. (2018). Modelling the chemical defensome network - a dynamic visualisation of the involved genes and pathways in two fish species and humans. (external link)
• Fekadu Yadetie; Xiaokang Zhang; Eileen Marie Hanna et al. (2018). RNA-seq analysis of transcriptome responses in Atlantic cod (Gadus morhua) precision cut liver slices exposed to benzo[a]pyrene and 17α-ethynylestradiol. (external link)
• Nello Blaser (2017). Topological Data Analysis in Epidemiology. (external link)
• Nello Blaser; Morten Brun (2017). An attempt at using topology for classification. (external link)
• Nello Blaser; Morten Brun (2017). Divisive cover classification. (external link)
• Marta Eide; Anders Goksøyr; Fekadu Yadetie et al. (2020). A multi-omics approach to study Ppar-mediated regulation of lipid metabolism in Atlantic cod (Gadus morhua). (external link)
• Zhanna Tairova; Mette Helen Bjørge Müller; Jan Ludvig Lyche et al. (2017). Adverse effects in Atlantic cod (Gadus morhua) due to environmental exposure to pollutant mixtures from the Oslofjord, Norway. (external link)
• Kristian Gundersen; Anna Oleynik; Guttorm Alendal et al. (2018). Combining Models and Machine Learning Techniques to Design Leak Detection Monitoring. (external link)
• Fekadu Yadetie; Xiaokang Zhang; Eileen Marie Hanna et al. (2018). RNA-seq analysis of transcriptome responses in Atlantic cod (Gadus morhua) precision cut liver slices exposed to benzo[a]pyrene and 17α-ethynylestradiol. (external link)
• Kristian Gundersen; Anna Oleynik; Hans J. Skaug et al. (2018). Machine Learning in CO2 leak detection. (external link)
• Fekadu Yadetie; Xiaokang Zhang; Eileen Marie Hanna et al. (2019). Toxicogenomic responses in Atlantic cod (Gadus morhua) after treatment with selected environmental contaminants in vivo and ex vivo. (external link)
• Nello Blaser; Shirin Fallahi; Håvard G Frøysa (2017). Model reduction under parameter uncertainty. (external link)
• Anders Goksøyr; Guttorm Alendal; Libe Aranguren-Abadía et al. (2019). dCOD 1.0: DECODING THE SYSTEMS TOXICOLOGY OF ATLANTIC COD (GADUS MORHUA) – HIGHLIGHTS SO FAR. (external link)
• Nello Blaser; Morten Brun (2020). Relative Persistent Homology. (external link)
• Karina Dale; Mette Helen Bjørge Müller; Zhanna Tairova et al. (2019). Biological responses of Atlantic cod (Gadus morhua) exposed to polycyclic aromatic hydrocarbons and perfluoroalkyl substances. (external link)
• Morten Brun; Nello Blaser (2019). Sparse Nerves in Practice. (external link)
• Zhanna Tairova; Mette Helen Bjørge Müller; Jan Ludvig Lyche et al. (2018). Adverse health effects related to chemical exposure in Atlantic cod (Gadus morhua) from Norwegian fjords. (external link)

Master’s thesis

• Nello Blaser; Audun Ljone Henriksen; Martin Møller Greve (2023). Learning Acquisition Functions for Cost-aware Bayesian Optimization. (external link)
• Leander Jacob Nielsen Eikås; Martin Møller Greve; Nello Blaser et al. (2024). Machine learning for early detection of structure loss in the Czochralski process. (external link)

Conference poster

• Eileen Marie Hanna; Nello Blaser; Morten Brun et al. (2018). Persistent homology and network analyses reveal key gene interactions affected by environmental pollutants in Atlantic cod. (external link)
• Karina Dale; Mette Helen Bjørge Müller; Zhanna Tairova et al. (2019). Biological responses of Atlantic cod (Gadus morhua) exposed to polycyclic aromatic hydrocarbons (PAHs) and perfluoroalkyl substances (PFASs). (external link)
• Eileen Marie Hanna; Xiaokang Zhang; Shirin Fallahi et al. (2019). A draft metabolic reconstruction of Atlantic cod (Gadus morhua) liver. (external link)
• Kristian Gundersen; Nello Blaser; Guttorm Alendal et al. (2017). Assessment of Topological Data Analysis and Machine Learning Technologies as Tools for Seep Detection. (external link)
• Marta Eide; Xiaokang Zhang; Odd Andre Karlsen et al. (2018). MODELLING THE CHEMICAL DEFENSOME NETWORKS - a comparative visualisation of the defense genes and interactions in two fish species and human. (external link)
• Anders Goksøyr; Malin Celander; Guttorm Alendal et al. (2017). dCod 1.0: decoding the systems toxicology of Atlantic cod (Gadus morhua). (external link)
• Siri Øfsthus Goksøyr; Anders Goksøyr; Odd Andre Karlsen et al. (2017). dCod 1.0 decoding the systems toxicology of Atlantic cod. (external link)
• Anders Goksøyr; Guttorm Alendal; Libe Aranguren-Abadía et al. (2019). dCOD 1.0: DECODING THE SYSTEMS TOXICOLOGY OF ATLANTIC COD (GADUS MORHUA) – HIGHLIGHTS SO FAR. (external link)
• Anna Oleynik; Kristian Gundersen; Guttorm Alendal et al. (2018). Mathematical methods for detection and localization of CO2 leaks. (external link)
• Nello Blaser; Morten Brun; Lucius Bader et al. (2018). Diagnosing rheumatoid arthritis with mass cytometry using topological data analysis. (external link)
• Kristian Gundersen; Anna Oleynik; Nello Blaser et al. (2020). Reconstruction of Currents Based on Sparse Observations with Deep Learning. (external link)
• Morten Blørstad; Berent Ånund Strømsnes Lunde; Nello Blaser (2024). Stable Update of Regression Trees. (external link)
• Xiaokang Zhang; Marta Eide; Odd Andre Karlsen et al. (2019). THE CHEMICAL DEFENSOME OF ATLANTIC COD (GADUS MORHUA): HOW DOES IT DIFFER FROM DEFENSOME NETWORKS IN OTHER TELEOST SPECIES?. (external link)
• Nello Blaser; Shirin Fallahi; Håvard G Frøysa (2017). Model reduction under parameter uncertainty. (external link)
• Heebah Saleem; Sergey Alyaev; Nello Blaser et al. (2025). Latent Diffusion For Text Generation and its Application in Geology. (external link)

Academic book chapter

• Natacha Galmiche; Helwig Hauser; Thomas Spengler et al. (2021). Revealing Multimodality in Ensemble Weather Prediction. (external link)
• Morten Brun; Nello Blaser (2008). Sparse Nerves in Practice. (external link)

Lecture

• Eileen Marie Hanna; Xiaokang Zhang; Marta Eide et al. (2019). A draft metabolic reconstruction of Atlantic cod (Gadus morhua) liver: how to and what for?. (external link)
• Nello Blaser (2019). Machine Learning in Mathematical Modeling. (external link)
• Nello Blaser (2017). Clinical trials for biomarker detection and evaluation - opportunities, benefits and challenges - The biostatistician’s view. (external link)

Journal corrigendum

• Benedicte Sjo Tislevoll; Monica Hellesøy; Oda Helen Eck Fagerholt et al. (2023). Author Correction: Early response evaluation by single cell signaling profiling in acute myeloid leukemia (Nature Communications, (2023), 14, 1, (115), 10.1038/s41467-022-35624-4). (external link)

Professional article

• Kristian Gundersen; Anna Oleynik; Nello Blaser et al. (2020). Semi Conditional Variational Auto-Encoder for Flow Reconstruction and Uncertainty Quantification from Limited Observations. (external link)

See a complete overview of publications in Cristin.