Distribution of Copepoda along 140°E in the Indian sector of the Southern Ocean

NORPAC net samplings at three stations along a south-north transect on ca. 140°E were conducted in the Indian sector of the Southern Ocean from March 10 to 12 in 2002 during the 43rd Japanese Antarctic Research Expedition. The survey was held to examine the community structure and abundance of Copepoda in the seasonal ice zone of the Southern Ocean. A total of 15 species of copepod were identified at the stations. For nine species of copepod, Microcalanus pygmaeus, Calanus simillimus, Rhincalanus gigas, Euchaeta antarctica, Clausocalanus laticeps, Scolecithricella minor, Metridia lucens, Haloptilus oxycephalus and Oithona frigida, disparities of the distributions between the south of the Southern Boundary (SB) and the north became apparent. As here was a distinct difference of, about 2°C, in the sea surface temperature between the south and north of the SB, these disparities were considered to be influenced by the difference in the physical structure in the ocean, in particular by the water temperature, which was driven by the SB. Among Calanoides acutus, Calanus propinquus, and R. gigas, the earlier copepodite stages were observed at higher latitudes at all stations. This trend was considered to be a result of the sea ice retreat, which caused a later spawning period for Copepoda. In addition, an interaction between the sea ice conditions and the community structure of copepod along 140°E was suggested

Unusual abundance of appendicularians in the seasonal ice zone(140°E ) of the Southern Ocean

During the 43rd Japanese Antarctic Research Expedition(JARE) cruise on March 10-12 in 2002, NORPAC net samplings at three stations along a south-north transect, ca. 140°E in the Indian sector were conducted to survey zooplankton community structure and abundance in the seasonal ice zone(SIZ) of the Southern Ocean. A total of fourteen species/taxa were identified from the three stations. While copepods were numerically dominant at two stations(79.9% and 93.1% respectively of total abundance), appendicularians were found to be numerically dominant(84.0% of total abundance) at the southernmost station. This dominance of Appendicularia at this station suggested that Appendicularia is possibly an integral part of the community structure of the zooplankton in the SIZ. The Southern Boundary(SB) on the 140°E transect was found to be located at ～64.30°S and the southernmost station was located south of the SB while the two other stations were located north of the SB. Some species, such as Rhincalanus gigas, Calanus simillimus, Amphipoda, Euphausiacea, and Polychaeta, had distribution patterns that correlated with the position of the SB, therefore the SB is considered important in influencing the distribution of the zooplankton and its community structure in the SIZ

Zooplankton distribution patterns in relation to the Antarctic Polar Front Zones Recorded by Continuous Plankton Recorder (CPR) during 1999/2000 Kaiyo Maru cruise

During the 8th Antarctic Expedition of the R/V Kaiyo Maru of the Japan Fisheries Agency, October 1999 to March 2000,a Continuous Plankton Recorder (CPR) was used to investigate zooplankton composition and abundance in the surface of the Indian sector of Southern Ocean between South Africa and Antarctica. Total zooplankton abundance ranged from 0 to 432 individuals/segment (a 5 nautical miles of the surface towing) (Mean±SD=69.7±83.5). Zooplankton abundance tended to be higher in the high latitudes than the Sub-Antarctic Front (SAF). Opposite correlations were observed between zooplankton and seawater temperature (negative), salinity (positive) and in vivo fluorescence value (positive) reflecting the higher abundance of zooplankton found in the cooler waters south of the SAF, which also have higher salinities and phytoplankton. Among twenty-nine species/taxa identified, cyclopoid copepod Oithona spp. were found throughout the transect, and accounted for 53.3% of total zooplankton abundance. Cluster analysis based on seventeen dominant zooplankton species/taxa revealed two groups and three ungrouped individual species/taxa at the 84% dissimilarity level. On the other hand, the cluster analysis based on the samples obtained in a 5 nautical miles indicated two major distinctive zooplankton community groups at 89% dissimilarity level. The main group included most segments in the Polar Frontal Zone (PFZ : region between SAF and the Polar Front) and Antarctic Zone (AZ : south of the Polar Front) with high zooplankton abundance while the second mainly group comprised lower latitude segment with low abundance (<100 individuals/segment)

DDBJ dealing with mass data produced by the second generation sequencer

DNA Data Bank of Japan (DDBJ) (http://www.ddbj.nig.ac.jp) collected and released 2 368 110 entries or 1 415 106 598 bases in the period from July 2007 to June 2008. The releases in this period include genome scale data of Bombyx mori, Oryzas latipes, Drosophila and Lotus japonicus. In addition, from this year we collected and released trace archive data in collaboration with National Center for Biotechnology Information (NCBI). The first release contains those of O. latipes and bacterial meta genomes in human gut. To cope with the current progress of sequencing technology, we also accepted and released more than 100 million of short reads of parasitic protozoa and their hosts that were produced by using a Solexa sequencer

βdecay of the 21/2^+ isomer in ^<93>Mo and level structure of ^<93>Nb

The γ rays associated with β decay of the 21/2^+ isomer in ^Mo (Ex=2.425 MeV, T_=6.85 h) were measured with a selective sensitivity to long-lived isomer decays. A new 1262-keV transition was found in the γ-γ coincidence measurement, and it was attributed to a transition in ^Nb, which is the daughter nucleus of the β decay of the ^Mo isomer, from the 2.753- to the 1.491-MeV levels. Accurate γ-ray intensity balances have determined the β-decay intensity from the ^Mo isomer to the 2.753-MeV level in ^Nb and placed no appreciable intensity for the previously reported β-decay branching to the 2.180-MeV level, for which a recent in-beam γ-ray experiment assigned to be I^π = 17/2^-. Based on the γ-ray intensities from the 2.753-MeV level, spin-parity assignment of this level was revised from 21/2^+ to 19/2^+. The observed β-decay intensity and the spin-parity assignment were explained by the jj-coupling shell model calculations