The effect of the stellar wind velocity on the eccentric-orbit binary model

The previous eccentric-orbit binary model for the recurrent X-ray sources is modified by taking account of the velocity field of the stellar wind. The resultant formula of the light curves for the X-ray sources may have an useful application to the observed X-ray sources.     

Correlation of the Hakkoda–Kokumoto Tephra, a widespread Middle Pleistocene tephra erupted from the Hakkoda Caldera, northeast Japan

Abstract A Middle Pleistocene widespread tephra referred to here as Hakkoda–Kokumoto Tephra (Hkd–Ku) has been newly recognized. Hkd–Ku, derived from the Hakkoda Caldera located in northernmost Honshu Is. of northeast Japan, covers much of Honshu Is. At the type locality in the proximal area, Hkd–Ku comprises Plinian pumice deposits and an immediately overlying ignimbrite. The fine vitric ash nature of the distal ash‐fall deposits of Hkd–Ku suggests that they are coignimbrite ash‐fall deposits. Hkd–Ku was identified using a combination of refractive indices and chemical compositions of major, trace and rare earth elements of glass shards, heavy mineral content, refractive indices of orthopyroxene and paleomagnetic polarity. On the basis of these properties, Hkd–Ku was identified in Oga and Boso Peninsulas and Osaka Plain, 830 km southwest of the source. Stratigraphic positions in Boso Peninsula and Osaka Plain within marine sediments that have a reliable chronology based on oxygen‐isotope, and litho‐, bio‐, magneto‐ and tephrostratigraphy indicate that the age of Hkd–Ku is ca 760 ka, positioned in the transition between marine oxygen‐isotope stages 19.1 and 18.4. The widespread occurrence of Hkd–Ku providing a tie line between many different Pleistocene sections over a distance of 800 km is a key marker horizon in the early part of the Middle Pleistocene. This tephra gives a time control point of ca 760 ka to marine sediments in the Oga Peninsula – where no datum plane exists between the Brunhes–Matuyama chron boundary and oxygen‐isotope stage 12 – and to the volcanostratigraphy of the Hakkoda Caldera. The distribution of Hkd–Ku showing emplacement of coignimbrite ash‐fall deposits in the area 830 km southwest of the source emphasizes the upwind transport direction, relative to the prevailing westerly winds, typical of other coignimbrite ash‐fall deposits in the Japanese islands.     

Tandem repeat arrays in the mitochondrial genome as a tool for detecting genetic differences among the ark shell Scapharca broughtonii

We found that tandem repeat (TR) arrays were present in the ark shell Scapharca broughtonii mitochondrial genome, and we demonstrated the efficiency of using this TR region as a tool for the detection of genetic differentiation. In samples collected from seven populations off the Japanese, Chinese, Russian and Korean coasts, five TR types with length ranging from 481 to 601 bp (base pairs) were found, as were 18 haplotypes (n = 155). All the Japanese samples from SD, IK, AM and KG, which represented four geographically distinct populations, had the same type of tandem repeat array, 481‐TR. All the samples from China and all but one sample from Russia had the same TR type, 511‐TR; these finding may be strong evidence that the ark shell populations in China and Russia are very similar. Based on a neighbor‐joining dendrogram of haplotypes, the Korean population was divided into two groups as follows: samples with haplotype H481‐3 and samples with haplotypes H601‐1, H601‐2, H601‐3 or H541‐1. Based on the haplotype diversity and nucleotide diversity, the Chinese, Russian and Korean populations showed a higher diversity than Japanese populations (P < 0.05).     

A New Juvenile Specimen of Lufengosaurus Huenei Young, 1941 (Dinosauria: Prosauropoda) from the Lower Jurassic Lower Lufeng Formation of Yunnan, Southwest China

Abstract: A skull and a series of associated cervical vertebrae (ZLJ0112) discovered from the Lower Lufeng Formation (Lower Jurassic) are determined as a juvenile specimen of Lufengosaurus huenei Young 1941 based on amended autapomorphies. Differences between ZLJ0112 and the holotype (sub-adult specimen) are considered as ontogenetic characteristic changes of L. huenei. Since some of these differences are present in other prosauropod dinosaurs (i.e., forms of the maxillary vascular foramen are irregular; the frontal contribution to the dorsal margin of the orbit is substantial; the frontal contribution to the supratemporal fossa is absent; the supratemporal fenestra is visible in lateral view; the supraoccipital inclined at 75 degrees; the parasphenoid rostrum lies level with the occipital condyle; the retroarticular process is short; the axial postzygapophysis project caudally beyond the end of the centrum) they may be common ontogenetic changes in prosauropod dinosaurs.