Report on Distribution and Spawning of Small-scale Sillago, Sillago parvisquamis (family Sillaginidae), Based on Specimens from Yamaguchi Bay in Western Seto Inland Sea, Japan. <Article>

瀬戸内海山口湾で2005 ～ 2008 年に,絶滅危惧種アオギスSillago parvisquamis 8 標本(SP-YB1 ～ 8)を採集した。全長226.5 ～ 320.1mm,体長197.7 ～ 281.0mm,いずれも雌で,年齢はSP-YB1 ～ 6 が1才,SP-YB7 が3才,およびSP-YB8 は4才で,全個体が2004年級であった。卵巣の組織学的検討より,SP-YB1 ～ 7 では,最も発達した正常な卵母細胞は第三次卵黄球期か胚胞移動期で,排卵後濾胞細胞を有し,活発な産卵活動が確認された。釣りCPUE(個体数/3時間/ 人)は,2005 ～ 2012年では,5 ～ 7月は0.2(n=24),通年では0.1(n=49)であった。2004年級を主な対象とした2005 ～ 2006年の2年間では,5 ～ 7月は0.3(n=14),通年では0.2(n=23)であった。今回,標本に基づき山口湾を生息地および繁殖地として記載した。Small-scale sillago, Sillago parvisquamis, were collected from Yamaguchi Bay, western Seto Inland Sea, Japan. This species has been evaluated as an endangered species in Japan. Eight specimens (sample no. SPYB1-8) collected in 2005-2008 were 226.5-320.1 mm TL, 197.7-281.0 mm SL and were all adult females. The ages of SPYB1-6, 7, and 8 were 1, 3, and 4 years, respectively, and all individuals were of the 2004 class. Judging from ovarian histological samples, the most developed stage of normal oocytes in SPYB1-7 was the tertiary yolk globule stage or the migratory nucleus stage. All individuals had a lot of post-ovulatory follicles. Therefore, these two evidences indicate spawning. The catch per unit effort (CPUE) (indiv. / 3 hours / person) by fishing in 2005-2012 was 0.2 for the spawning season (n=24) and 0.1 for the whole year (n=49). For the 2004 class, CPUE in 2005-2006 was 0.3 for the spawning season (n=14) and 0.2 for the whole year (n=23). This is the detailed report of the distribution and spawning of Sillago parvisquamis based on specimens from Yamaguchi Bay

Structural basis for the fast phase change of Ge2Sb2Te5: Ring statistics analogy between the crystal and amorphous states

The three-dimensional atomic configuration of amorphous Ge2Sb2Te5 and GeTe were derived by reverse Monte Carlo simulation with synchrotron-radiation x-ray diffraction data. The authors found that amorphous Ge2Sb2Te5 can be regarded as "even-numbered ring structure," because the ring statistics is dominated by four- and six-fold rings analogous to the crystal phase. On the other hand, the formation of Ge–Ge homopolar bonds in amorphous GeTe constructs both odd- and even-numbered rings. They believe that the unusual ring statistics of amorphous Ge2Sb2Te5 is the key for the fast crystallization speed of the material

Controlling oxygen coordination and valence of network forming cations

Understanding the structure-property relationship of glass material is still challenging due to a lack of periodicity in disordered materials. Here, we report the properties and atomic structure of vanadium phosphate glasses characterized by reverse Monte Carlo modelling based on neutron/synchrotron X-ray diffraction and EXAFS data, supplemented by Raman and NMR spectroscopy. In vanadium-rich glass, the water durability, thermal stability and hardness improve as the amount of P2O5 increases, and the network former of the glass changes from VOx polyhedra to the interplay between VOx polyhedra and PO4 tetrahedra. We find for the first time that the coordination number of oxygen atoms around a V4+ is four, which is an unusually small coordination number, and plays an important role for water durability, thermal stability and hardness. Furthermore, we show that the similarity between glass and crystal beyond the nearest neighbour distance is important for glass properties. These results demonstrate that controlling the oxygen coordination and valence of the network-forming cation is necessary for designing the properties of glass