Bryan Laraway | Searcharxiv

arXiv2025

Why we need all the organisms: an exploration of the Monarch knowledge graph to aid mechanism discovery

Research done using model organisms has been fundamental to the biological understanding of human genes, diseases and phenotypes. Model organisms provide tractable systems for experiments to enhance understanding of biological mechanisms conserved across the evolutionary tree. Decades of model organism research has generated vast amounts of data; however, this data is split across many domains, organisms, and biological fields of research. Knowledge graphs (KGs) are a computational way to aggregate and compile disparate information in a parsable format. By unifying data across studies, organisms and time points, KG researchers can create novel targeted hypotheses. Here we demonstrate how model organisms are connected to humans and other organisms through genes, diseases and phenotypes allowing for a broader understanding of genetic biology than just one organism alone can provide. Utilizing resources such as the Monarch KG is a great way to reduce redundant experiments and find directions previously unexplored.

q-bio.QM↗

arXiv2022

A method for comparing multiple imputation techniques: a case study on the U.S. National COVID Cohort Collaborative

Healthcare datasets obtained from Electronic Health Records have proven to be extremely useful to assess associations between patients' predictors and outcomes of interest. However, these datasets often suffer from missing values in a high proportion of cases and the simple removal of these cases may introduce severe bias. For these reasons, several multiple imputation algorithms have been proposed to attempt to recover the missing information. Each algorithm presents strengths and weaknesses, and there is currently no consensus on which multiple imputation algorithms works best in a given scenario. Furthermore, the selection of each algorithm parameters and data-related modelling choices are also both crucial and challenging. In this paper, we propose a novel framework to numerically evaluate strategies for handling missing data in the context of statistical analysis, with a particular focus on multiple imputation techniques. We demonstrate the feasibility of our approach on a large cohort of type-2 diabetes patients provided by the National COVID Cohort Collaborative (N3C) Enclave, where we explored the influence of various patient characteristics on outcomes related to COVID-19. Our analysis included classic multiple imputation techniques as well as simple complete-case Inverse Probability Weighted models. The experiments presented here show that our approach could effectively highlight the most valid and performant missing-data handling strategy for our case study. Moreover, our methodology allowed us to gain an understanding of the behavior of the different models and of how it changed as we modified their parameters. Our method is general and can be applied to different research fields and on datasets containing heterogeneous types.

cs.AI↗