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ナイジェリアにおける多次元貧困―脆弱層に焦点をあてた家計レベルの分析 [全文の要約]
No full textこの博士論文全文の閲覧方法については、以下のサイトをご参照ください。https://www.lib.hokudai.ac.jp/dissertations/copy-guides
Historical Change in Primary Productivity in Ishikari Bay Reconstructed from Biogenic Si Content in the Sediment
No full textOrganic C, N, and biogenic Si (BSi) content, as well as C and N stable isotopes, in sediment cores were measured to elucidate the historical change in primary productivity at Ishikari Bay. The bay is characterized as an oligotrophic coastal water considerably influenced by riverine discharge from the Ishikari River, the second largest river in Japan. Layers with a high C content of 50 mg g−1 and a high C: N ratio of 25 were found in several cores, which coincided with a sedimentation age between the 1960s and 1970s. This was attributed to peat exposure to land surface and the delivery to the bay due to the intensive exploitation of land in the catchment area of the Ishikari River and the frequent floods of that time period. BSi content in the sediment layer may reflect change in the diatomaceous primary productivity in the surface euphotic zone. BSi content increased up to the present at the station nearest to the river mouth, indicating an increase in primary productivity by diatoms. However, the total nitrogen flux from the river has not changed significantly since the 1970s. The transparency in the river water has increased, suggesting a decrease in the loadings of suspended solids from the river due to the construction of revetment walls. Thus, light limitation has been relieved in the area near the river mouth. In semi-enclosed coastal areas, the sedimentary record of organic matter and BSi content may reflect historical changes in primary productivity and riverine influence
Three new species of gall-forming eriophyid mites (Acari: Eriophyidae) on the painted maple (Acer pictum Thunb.) from Japan
No full textThree eriophyid mites, Aceria circularis Yoshino & Kadono sp. nov., Aceria acutiuscula Yoshino & Kadono sp. nov., and Aculops vallecularis Yoshino & Kadono sp. nov., are described from Hokkaido, northern Japan. These species induce galls on the leaves of the painted maple, Acer pictum. Aceria. circularis and A. acutiuscula induce granular-shaped galls on the adaxial and abaxial sides of the leaves, respectively, and A. vallecularis induces groove-shaped galls on both sides of the leaves. Aceria galls on the adaxial and abaxial sides are remarkably similar, thus species status was tested by comparing the morphology and DNA sequences of the mitochondrial Cytochrome oxidase subunit I. Aceria mites from the adaxial and abaxial granular shaped-galls are morphologically distinct and phylogenetically separated, confirming that they constitute different species, which are herein formally described
