Bioprocess Engineering Lab

I am Masashi K. Kajita, a senior assistant professor in the Department of Applied Chemistry and Biotechnology, Faculty of Engineering, University of Fukui. I work on problems in biophysics, mathematical biology, systems biology, and theoretical immunology, using mathematical models and data analysis.

Research themes

$Schematic: fraction of phosphorylated receptors versus V₁/V₂. When phosphorylation and dephosphorylation are saturated (zero-order), a slight difference between target and nontarget changes the response greatly.$

How cells process information

How immune cells distinguish molecules of very similar structure, studied as statistical information processing.

How mitochondria are positioned in cells

Why mitochondria are spaced nearly evenly along neuronal axons, explained by fluctuations in motion that depend on the ATP concentration.

Schematic: the disease state (normal WBC and CML cell counts), which cannot be observed directly, is inferred from clinical tests (WBC count and BCR-ABL1 (IS)).

Predicting disease course and treatment response

Using mathematical models to infer the disease state, which cannot be observed directly, from time series of routine clinical tests, and to predict treatment response early.

See Research for details and Publications for papers.

Recent work

We showed theoretically how mitochondria come to be spaced nearly evenly along neuronal axons. Because mitochondria produce ATP, two that come close raise the local ATP level and fluctuate more, while those apart tend to stay put; as a result they line up at nearly equal intervals without any direct interaction (Phys. Rev. Research 2024).

Simulation of mitochondria becoming evenly spaced from a random initial arrangement. Reproduced from the Supplemental Material of Kajita MK, Konishi Y, Hatakeyama TS, “Active thermodynamic force driven mitochondrial alignment,” Phys. Rev. Research 6, L022024 (2024), under CC BY 4.0. doi:10.1103/PhysRevResearch.6.L022024

Prospective students

For supervision and how research is done in the group, see Join us.

Bioprocess Engineering Laboratory, University of Fukui Kajita Group