Title: A directional proposal to solve a chronobiological problem
Authors: Yolanda Larriba - University of Valladolid (Spain) [presenting]
Cristina Rueda - University of Valladolid (Spain)
Miguel Fernandez - Universidad de Valladolid (Spain)
Shyamal Peddada - National Institute of Environmental Health Sciences (United States)
Abstract: Biological processes, such as cell cycle, circadian clock or blood pressure, are governed by oscillatory systems whose components exhibit periodic patterns over time. The study of these periodic patterns, or rhythms, and how they change under different conditions, is called chronobiology. An interesting problem in chronobiology is to reconstruct the temporal order at which samples were taken, when it is unknown. For instance, when dealing with human organ biopsies or autopsies, the exact time of the day (e.g. 11:00 A.M.) at which each sample was taken is often unrecorded, as it might suppose a risk for health or a cost increase. A directional proposal is proposed to analyse chronobiological rhythms. The intrinsic circular nature of these data suggests a mathematical formulation in the circular space and the use of circular statistics. The specific problem described above, the temporal order estimation, is solved as a circular order aggregation problem within the framework of a general methodology based on order restrictions. In particular, we recover the temporal order among different cell cycle stages for unsynchronized single cell RNA-seq (scRNA-seq) transcriptome data. Simulation experiments are also illustrated to validate the procedure.