Response of accommodation and vergence to electro-holographic images.

Studies on measuring accommodation and vergence responses of human vision are important to evaluate three-dimensional (3D) display technologies. Electro-holography is expected to be an ideal 3D display. However, there has been little research on measuring responses to it. In this study, the static responses to electro-holographic images with a large visual field and correct stimuli were measured. In addition, responses to real objects were measured for comparison with those to displayed images. There were more subjects than in conventional studies for statistical analysis. The experimental results statistically confirmed the equivalence of the responses to electro-holographic images and those to real objects. Therefore, it was experimentally suggested that electro-holography enables human vision to perform correct accommodation and vergence responses in accordance with the depths.

Efficient establishment of primary fibroblast cultures from the hawksbill sea turtle (Eretmochelys imbricata).

The hawksbill sea turtle (Eretmochelys imbricata) is a critically endangered species at a risk of extinction. Preservation of the genomic and cellular information of endangered animals is important for future genetic and biological studies. Here, we report the efficient establishment of primary fibroblast cultures from skin tissue of the hawksbill sea turtle. We succeeded in establishing 19 primary cultures from 20 hawksbill sea turtle individuals (a success rate of 95%). These cells exhibited a fibroblast-like morphology and grew optimally at a temperature of 26°C, but experienced a loss of viability when cultured at 37°C. Chromosomal analysis using the primary cells derived here revealed that hawksbill sea turtles have a 2n = 56 karyotype. Furthermore, we showed that our primary cell cultures are free of several fish-related viruses, and this finding is important for preservation purposes. To our knowledge, this report is the first to describe primary cell cultures established from normal tissues of the hawksbill sea turtle. The results will contribute to the preservation of biodiversity, especially for the sea turtles that are critically endangered owing to human activities.