2025
SmallData Seminar Series: Research Presentations from Jana Naue & Martin Wolkewitz
In this seminar, our SmallData Associated Researchers will give a 30 minute presentation of their work on small data and explore how it connects with other projects across the Collaborative Research Center. Each seminar will feature an open Q&A session.
Institute of Forensic Medicine, Medical Center – University of Freiburg
Analyzing trace material is one of the main tasks in a laboratory of Forensic Molecular Biology. The standard method is to determine the individual DNA profile (‘genetic fingerprint’) to connect a trace to a person. However, there is additional information in the DNA that can reveal more information about the circumstances of the crime or help to narrow down the pool of possible contributors if a trace cannot be connected to a reference profile.
In this seminar, I will first shortly introduce general methods and requirements to perform casework in a forensic laboratory.
In the main part, I will present my primary research area, ‘Forensic Epigenetics’, with a closer look at two applications: chronological age prediction and body fluid identification. I will explain the biological background and the current state of the art of analysis and data interpretation for application in a forensic case. Next to the wet lab measurements of DNA methylation levels, dry lab work, including bioinformatics pipelines and mathematical models/ machine learning (e.g., Random Forest regression and classification), is an important step of inferring chronological age and body fluid from trace material.
I will also discuss the performed research on limitations and challenges due to the analysis of forensic material. Especially, technical limitations and stochastic effects due to low quantity and quality of sample materials have to be considered. Furthermore, analyzing only a few markers, having unknown background information, and having missing or challenging reference data can also influence the reliability of data and model interpretation.
Methodological aspects of the emulated target trial approach to optimize treatment strategies for a rare pediatric disease
Martin Wolkewitz (SmallData Associated Researcher) & Derek Hazard
Institute of Medical Biometry and Statistics, Division Methods in Clinical Epidemiology, Faculty of Medicine and Medical Center – University of Freiburg
A significant challenge in the treatment of rare diseases is the need to understand the effects of medical interventions and to identify the subgroups that stand to benefit most from these treatments. The additional complexities introduced by time-varying treatment initiation further compound the challenges inherent to this field. Randomized controlled trials represent the gold standard for causal inference; however, they are often infeasible due to ethical, logistical, or financial constraints, in addition to a lack of available patients with a rare disease. In view of this challenge, we demonstrate how emulated target trials methods provide an alternative for analyzing such scenarios using data from a study into children with a rare combined immunodeficiency.
The example study is predicated on the assumption that the treatment is beneficial for all patients, provided that they survive the adverse effects of the procedure. This introduces an additional layer of complexity, as some patients may be too ill to derive benefit from the procedure, while others may be too healthy to justify the potential risks associated with the procedure itself. The emulated target trial will be contrasted with multi-state and machine learning approaches in order to compare analysis strategies to identify the most suitable patients for treatment in this highly complex setting.