Prof. Takahiro Kenmotsu
Faculty of Life and Medical Sciences, Doshisha University, Japan
Double-strand breaks in genome-size DNA caused by photo-irradiation, gamma-rays and ultrasound
We evaluated double-strand breaks (DSBs) in genome-size DNA (T4 DNA; 166 kbp) caused by photo-irradiation and gamma-rays and ultrasound through a single DNA observation by fluorescence microscopy in a quantitative manner. Based on experimental results, DSBs were induced by two-step mechanism for the photo-irradiation. On the other hands, one- step mechanism led to DSBs for the irradiations of gamma-ray and ultrasound. Regarding the effect of ultrasound, it was found that DSBs were generated above a threshold power. It is stressed that the experimental methodology of single DNA observation serves as a useful tool for studying DSBs of genome-size DNA.
Takahiro Kenmotsu received the B.S. and M.S. from Okayama University of Science, Japan, in 1993 and 1995 and Dr. Sci. degrees from Graduate University for Advanced Studies, Japan, in 1999, respectively. He became a Lecturer at Kibi International University in 2004. He is currently a Professor in the Department of Biomedical Engineering, the Faculty of Life and Medical Sciences, Doshisha University. His current research interests include Biomedical and Life Sciences.
Prof. Takuo Yasunaga
Department of Bioscience and Bioinformatics, School of Computer Science and Systems Engineering, Kyushu Institute of Technology, Japan
Recent progress of cryo-electron tomography to elucidate life science and material science
Electron tomography is one of the most powerful techniques to elucidate three-dimensional (3D) nano-architecture in life science as well as material science. Notably, by combining with cryo-electron microscopy, quickly-frozen specimens supply us their structures under physiological and hydrated conditions. By this technique, we computationally reconstructed 3D cell organelles and their inside protein distributions from tilt-series of projection images taken by transmission electron microscopy. Other researchers have reported many program packages to reconstruct 3D objects and we have also developed an image processing package, Eos. Here we introduce current progress of electron tomography and cryo-microscopy and show the possibility to combine with simulation techniques and predict authentic physical properties or organism’s activities under the actual spatial distribution of materials.
Takuo Yasunaga received the B.S., M.S., and PhD (Science) from the University of Tokyo, Japan, in 1988, 1990, and 2001, respectively. He became a Research Associate at the University of Tokyo in 1992 and moved to Kyushu Insitute of Technology as an Associate Professor in 2001. He is currently a Professor in the Department of Bioscience and Bioinformatics, School of Computer Science and Systems Engineering, Kyushu Insitute of Technology. His current research interests include electron microscopy, image processing, and structural biology.
Prof. Tsukasa Aso
Department of Electronics and Computer Engineering, National Institute of Technology, Toyama College, Japan
Computing Research Center, High Energy Accelerator Research Organization (KEK), Japan
Introduction to Geant4 and Geant4-DNA
Geant4 offers comprehensive physics processes for radiation interactions with the capability of extending functions based on object-oriented technology. Geant4-DNA is a project for extending interactions to simulate DNA damage caused by radiations. This paper briefly describes the overview of Geant4 and Geant4-DNA.
Tsukasa Aso received the B.Sc., M.Sc., and Ph.D. degrees from Niigata University, Japan, in 1991, 1993 and 1996, respectively. He became a Research Associate, a Lecturer, and an Associate Professor at Toyama National College of Maritime Technology in 1996, 1999, and 2003, respectively. He is currently a Professor in the Department of Electronics and Computer Engineering, National Institute of Technology, Toyama College (NIT-Toyama). His current research interests include simulations for medical physics and radiation detection.