[Development of Positron Emission Tomography Scanners Based on Positology].

This article gives a commentary on the development of positron emission tomography scanners based on Positology which was proposed by Dr. Eiichi Tanaka. Circular detector rings of an equally spaced detector arrangement have a problem of linear sampling density distributions in the projections.

Parental exposure to low-dose X-rays in Drosophila melanogaster induces early emergence in offspring, which can be modulated by transplantation of polar cytoplasm.

In recent years there has been growing concern over the biological effects of low-dose X-rays, but few studies have addressed this issue. Our laboratory had observed flies (Drosophila melanogaster) irradiated with low-dose X-rays tend to emerge earlier than normal flies. This observation led us to quantitatively examine the effects of low-dose X-irradiation on development in the fly.