Takafumi Nakano

(K−, K+) reaction on nuclear targets at PK = 1.65 G

Abstract The forward-angle cross sections of the (K − , K + ) reaction on nuclear targets of C, Al, Cu, Ag and Pb have been measured at the K − incident momentum of 1.65 GeV/ c in a side range K + momentum. The obtained K + momentum spectrum for each target nucleus is characterized by a peak in the high-momentum region ( p K + > 0.95 GeV/ c ) and a broad bump in the low-momentum region ( p K + c ). A comparison of the measured spectrum with a DWIA calculation indicates that the quasifree process, K − (p) → K + Ξ − , is dominant in the high-momentum region. The target mass-number dependence of the cross section is well fitted with A α , where α is 0.38 ± 0.03 for the high-momentum region and 0.56 ± 0.02 for the low-momentum region. The result indicates that the quasifree process takes place at the peripheral of the target nucleus, whereas the two-step processes are dominant in the low-momentum region.

Production of a twin single hypernuclei and the Ξ−-nuclear interaction

Abstract An event accompanied by two single hyperfragments emitted from a Ξ− nuclear capture at rest was found in a nuclear emulsion. It is interpreted as a Ξ−-12C bound system decaying into either a) Λ4H + Λ9Be, b) Λ 4 H + Λ 9 Be ∗ or c) Λ 4 H ∗ + Λ 9 Be . The binding energy of the Ξ-12C system is obtained as a) 3.70−0.19+0.18 MeV, b) 0.62−0.19+0.18 MeV and c) 2.66−0.19+0.18 MeV, respectively. The system is considered as a Ξ− hypernucleus in the cases a) and c). In case b), this event and another event of the same type (Yokohama event) can both be interpreted as a decay from the Ξ-12C system in 2P state when a shallow Ξ−-nuclear potential is assumed.

A new sexannulate species of Orobdella (Hirudinida, Arhynchobdellida, Orobdellidae) from Yakushima Island, Japan

Abstract A new sexannulate species of the genus Orobdella Oka, 1895, Orobdella mononoke sp. n., is described on the basis of five specimens collected from Yakushima Island, Japan. Orobdella mononoke sp. n. differs from other sexannulate Orobdella species in its possessing the following combination of characters: dorsal surface bicolor in life, I–XIII, XXVII and caudal sucker grayish purple, XIV–XXVI amber, male gonopore at XI c11/c12, female gonopore at XIII b2, 8 + 1/2 between gonopores, tubular but bulbous at junction with crop gastroporal duct, epididymides in XV–XIX, and atrial cornua ovate. Phylogenetic analyses using nuclear 18S rDNA and histone H3, and mitochondrial COI, tRNACys, tRNAMet, 12S rDNA, tRNAVal and 16S rDNA markers show that Orobdella mononoke sp. n. is closely related to Orobdella esulcata Nakano, 2010 from Kyushu, Japan, and two species, Orobdella dolichopharynx Nakano, 2011 and Orobdella shimadae Nakano, 2011, from the Ryukyu Archipelago, Japan.

A new species of Orobdella (Hirudinida, Arhynchobdellida, Gastrostomobdellidae) and redescription of Orobdella kawakatsuorum from Hokkaido, Japan with the phylogenetic position of the new species.

Abstract A new quadrannulate Orobdella Oka, 1895 species, Orobdella koikei sp. n., is described on the basis of six specimens collected from Hokkaido, Japan. In addition, an emended description of quadrannulate Orobdella kawakatsuorum Richardson, 1975 is also provided. Orobdella koikei differs from other quadrannulate species of Orobdella in possessing the following combination of characters: color dorsally brown, IV uniannulate, male gonopore at XI b6, gastropore and female gonopore at XIII a1, 1/2 + 4 + 1/2 between gonopores, XXV triannulate, tubular but bulbous at junctions with gastropore and crop gastroporal duct, epididymides in XVII to XIX, and atrial cornua ovate. The phylogenetic position of the newly described species is estimated using mitochondrial COI, tRNACys, tRNAMet, 12S rDNA, tRNAVal and 16S rDNA markers. Orobdella koikei is a sister taxon of Orobdella kakawatsuorum according to the molecular phylogenetic analyses.

Phylogenetic position of gastrostomobdellid leeches (Hirudinida, Arhynchobdellida, Erpobdelliformes) and a new family for the genus Orobdella

Nakano, T., Ramlah, Z. & Hikida, T. (2012). Phylogenetic position of gastrostomobdellid leeches (Hirudinida, Arhynchobdellida, Erpobdelliformes) and a new family for the genus Orobdella. —Zoologica Scripta, 41, 177–185.

A New Species of the Genus Orobdella (Hirudinida: Arhynchobdellida: Gastrostomobdellidae) from Kumamoto, Japan, and a Redescription of O. whitmani with the Designation of the Lectotype

Orobdella whitmani has three syntype localities, Mt. Kinkazan, Gifu Pref., Mt. Kodaijiyama, Kyoto Pref. and Mt. Kimposan, Kumamoto Pref. The specimens from Mt. Kimposan can be distinguished from those from Mt. Kinkazan and Mt. Kodaijiyama by an annulation of somite XXVI, and possession of a tubular gastroporal duct. Specimens from Mt. Kimposan are described as representing a new species, Orobdella esulcata. Orobdella whitmani is redescribed with designation of a specimen from Mt. Kinkazan deposited at The University Museum, The University of Tokyo, as the lectotype.

Three species of land leeches from Taiwan, Haemadipsa rjukjuana comb. n., a new record for Haemadipsa picta Moore, and an updated description of Tritetrabdella taiwana (Oka)

Abstract Three species of land leeches, including a new combination Haemadipsa rjukjuana comb. n., a new record for Haemadipsa picta Moore, as well as an updated description for Tritetrabdella taiwana (Oka), are reported in this study. Morphological characters and DNA barcode analysis were used to identify these species. In addition, since Haemadipsa rjukjuana had been regarded as a variety of the Japanese land leech Haemadipsa japonica for a century, morphological differences between these two species were also compared.

A new species of Orobdella (Hirudinida, Arhynchobdellida, Orobdellidae) from Taipei, Taiwan

Abstract A new quadrannulate species of Orobdella, Orobdella ketagalan sp. n., from Taipei, Taiwan, is described. This is the first record of Orobdella and the family Orobdellidae from Taiwan. This new species possesses small, paired sperm duct bulbs in the male reproductive system. In addition to these bulbs, the following combination of characters distinguishes this new species from other quadrannulate species: somite IV uniannulate, male gonopore at XI b6, female gonopore at XIII a1, 1/2 + 4 + 1/2 between gonopores, simple tubular gastroporal duct, lacking epididymides, and undeveloped atrial cornua. Phylogenetic analyses using nuclear 18S rDNA and histone H3 as well as mitochondrial COI, 12S rDNA, tRNAVal, and 16S rDNA markers showed that Orobdella ketagalan is related to the two Ryukyu Archipelago species Orobdella dolichopharynx Nakano, 2011 and Orobdella shimadae Nakano, 2011.

A multifoil carbon polarimeter for protons between 20 and 84 MeV

A new type of polarimeter has been built for protons between 20 and 84 MeV. It is a ray trace type with a multifoil of carbon, multiwire proportional chambers and plastic scintillators. The polarimeter distinguishes between elastic and inelastic scattering from carbon foil and has a large solid angle acceptance (∼ 470 msr) from the carbon foil. The effective analyzing power and the effective efficiency for practical use are estimated at 0.84 and 1.7 × 10−4 in the vicinity of 60 MeV, respectively. To evaluate these values, cross sections and analyzing powers for p—C elastic scattering have been measured for laboratory scattering angles between 15° and 80° at 19 energies from 21.1 to 83.8 MeV.

A new quadrannulate species of Orobdella (Hirudinida, Arhynchobdellida, Orobdellidae) from central Honshu, Japan.

Abstract A new quadrannulate species of Orobdella, Orobdella masaakikuroiwai sp. n., from the mountainous region of central Honshu, Japan is described. This is only the second small species known within this genus, with a body length of less than 4 cm for mature individuals. Phylogenetic analyses using nuclear 18S rDNA and histone H3 as well as mitochondrial COI, tRNACys, tRNAMet, 12S, tRNAVal, 16S, and ND1 markers showed that Orobdella masaakikuroiwai sp. n. is the sister species of the quadrannulate Orobdella whitmani Oka, 1895. Phylogenetic relationships within Orobdella masaakikuroiwai sp. n. conducted using mitochondrial markers reveled a distinction between eastern and western phylogroups.