New discovery of the oldest maize weevils in the world from Jomon potteries, Japan

The maize weevil (_Sitophilus zeamais_) and rice weevil (_Sitophilus oryzae_) are two of the most damaging insects for stored grains, and are characteristic species of ancient Japan. Both species and the granary weevil (_Sitophilus granarius_) are common elsewhere in the world, but the natural distribution of maize and rice weevils is restricted to the Old World^1^. Japanese archaeological records contain a few maize weevil fossils after the Middle Yayoi period (ca. 2000 aBP)^2^. However, since evidence of weevils was discovered as impressions in Jomon potsherds in 2004^3^, many weevil impressions have been found. The oldest is from the Late Jomon (ca. 4000 to 3200 aBP). These findings and other archaeological evidence suggest that the maize weevil invaded Japan from Korea, accompanying the spread of rice cultivation^4^. However, in 2010 we discovered older weevil impressions dating to ca. 9000 aBP. These specimens are the oldest harmful insects discovered from archaeological sites around the world. The new discovery is valuable for future entomological research because such specimens are absent from the fossil record. It is also archaeologically and culturally interesting because this provides evidence of harmful insects living in Jomon villages. However, the new discovery raises the question of what these weevils infested: did cereal cultivation exist 9000 years ago? We have no persuasive answer, but hope one will be provided by future interdisciplinary collaborations among geneticists, entomologists, and archaeologists

Revitalization of Kagoshima’s Historic Sites and Ruins Utilization Learned from Fudoki-no-Oka in Western Japan

application/pdf論文(Article)departmental bulletin pape

A new technique for MR elastography of the supraspinatus muscle: A gradient-echo type multi-echo sequence.

Magnetic resonance elastography (MRE) can measure tissue stiffness quantitatively and noninvasively. Supraspinatus muscle injury is a significant problem among throwing athletes. The purpose of this study was to develop an MRE technique for application to the supraspinatus muscle by using a conventional magnetic resonance imaging (MRI). MRE acquisitions were performed with a gradient-echo type multi-echo MR sequence at 100 Hz pneumatic vibration. A custom-designed vibration pad was used as a pneumatic transducer in order to adapt to individual shoulder shapes. In a gradient-echo type multi-echo MR sequence, without motion encoding gradient (MEG) that synchronizes with vibrations, bipolar readout gradient lobes achieved a similar function to MEG (MEG-like effect). In other words, a dedicated MRE sequence (built-in MEG) is not always necessary for MRE. In this study, 7 healthy volunteers underwent MRE. We investigated the effects of direction of the MEG-like effect and selected imaging planes on the patterns of wave propagation (wave image). The results indicated that wave images showed clear wave propagation on a condition that the direction of the MEG-like effect was nearly perpendicular to the long axis of the supraspinatus muscle, and that the imaging plane was superior to the proximal supraspinatus muscle. This limited condition might be ascribed to specific features of fibers in the supraspinatus muscle and wave reflection from the boundaries of the supraspinous fossa. The mean stiffness of the supraspinatus muscle was 10.6 ± 3.17 kPa. Our results demonstrated that using MRE, our method can be applied to the supraspinatus muscle by using conventional MRI