Kagawa Prefecture Research Articles

香川県の麦ほ地におけるオオスズメノカタビラの発生とその防除

香川県の麦ほ地におけるオオスズメノカタビラの発生とその防除

白亜紀花こう岩類の風化にともなう化学組成およびＳｒ・Ｎｄ同位体比組成の変化

We analyzed the changes of mineral, chemical and isotopic compositions of weathered Cretaceous granitic rocks from the Gozu Granite in the Gozu mountain, Niigata Prefecture, Kise Granodiorite in the Ina mountain, Nagano Prefecture, and Aji Granite in the Aji Peninsula, Kagawa Prefecture. The analyzed samples are fresh and weathered rocks and “masa” (sand originated from weathered granitic rocks) collected from the same outcrops for each granite. The change of mineral compositions of weathered granitic rocks is mainly characterized by the appearance of hematite and the increase of alteration degree of mafic minerals. Chemical composition of weathered granitic rocks is characterized by the depletion of major and trace elements. In particular, CaO and Na2O, which are partitioned mostly into plagioclase, and S are reduced extremely. Fe2O3/FeO ratios increase extremely with increasing weathering degree. Variations of total Fe and Cr contents dyring weathering are little. Rb/Sr ratios increase and Sr isotopic ratios change in progress of weathering. Nd isotopic compositions are almost maintained during weathering. The variation of Sr isotopic composition is generally caused by dissolution of minerals and isotope exchenge.

香川県東部地域における ミサゴ Ｐａｎｄｉｏｎ ｈａｌｉａｅｔｕｓ の営巣場所

Sixteen Osprey Pandion haliaetus nests were found during the 2002 breeding season in eastern Kagawa Prefecture (34°15-24′N, 134°5-17′E), Shikoku, Japan. Fourteen nests were situated on or near the tops of dead or alive pine trees Pinus spp, and two on the flat tops of radio towers. Thirteen of them were found within a small (4.5×2.5 km) hilly area.

Histopathological Changes Probably Associated with a Virus in Larval and Juvenile Marbled Sole Pleuronectes yokohamae

The seed production of marbled sole Pleuronectes yokohamae has been attempted at a hatchery in Kagawa Prefecture, Japan since 1989, while a subacute disease with a considerable amount of mortality occurred in larval and juvenile fish (24-69 days old) in 1989, 1990, 1991, 1997 and 2001. Diseased fish displayed edema, an abdominal distension due to ascites, and exophthalmia. The outbreak of the disease usually continued for 1 month or longer and the cumulative mortality was often over 40%. The evident histopathological features were the formation of multinuclear syncytia and following necrosis in the liver, renal tubules, pancreas and intestinal epithelium, and hemorrhage in the brain, choriocapillaries, stomach and skin. Electron microscopy of affected hepatocytes revealed formation of inclusion bodies consisting of crystalline arrays of virus particles (75-80 nm in diameter). These results suggest that the pathognomonic sign of the present disease is necrosis accompamied by the syncytial formation which would be associated with a virus infection.

中国・四国地方における上海便利用客の分布と流動

The aim of this study is to clarify distribution and flow patterns of air passengers from Okayama to Shanghai in the Chugoku and Shikoku District. The data on air passengers for this study are based on the survey in 2000by the author. The results of this study are summarized as follows:(1) There were many air passengers for Shanghai in big cities located around Okayama Airport, such as Okayama and kurashiki. The passengers were also generated in Kagawa Prefecture. Therefore, Seto-Ohashi Bridge expanded the sphere of the influence of Okayama Airport. Some passengers came from areas which may compete with Hiroshima Airport, such as Fukuyama and Hiroshima.(2) After getting off planes at Shanghai Airport, all passengers moved to the cities located in the eastern part of China. There wasn't any passengers moving to other countries. Many passengers moved to Shanghai. Some passengers visited Beijing or Nanjing. And, analyzing the relationship between the destinations of passengers and travel purposes, the author made it clear that there were two types of cities: one was the cities that passengers visited on business, and the other was the cities that passengers visited for sightseeing.(3) Finally, analyzing the relationship between the number of the destinations of passengers and travel purposes, the author made it clear that the passengers for sightseeing had many destinations and passengers on business had one destination.

香川県における宅地化の空間構造に関する研究

香川県における宅地化の空間構造に関する研究

Foot Rot of Ulluco Caused by Pythium aphanidermatum

Severe rot of stem bases caused by Pythium aphanidermatum was found on ulluco (Ullucus tuberosus) grown in Kagawa Prefecture, Japan, in September 1999. The name “foot rot of ulluco” is proposed for this new disease.

Butt Rot of Chamaecyparis obtusa (Sieb. et Zucc.) Endlicher Trees Caused by Perenniporia subacida in Shikoku District, Japan: Pathogen, Distribution of Damaged Trees in the Stand, and Soil Investigation

The rot of Chamaecyparis obtusa (hinoki) trees was studied in the northern part of Kagawa Prefecture, Japan. Among 158 hinoki examined, butt rot was found in 28.6, 58.3, and 100% of trees in the 29, 30, and 34-year-old stands, respectively. All trees with butt rot, and 11 trees without it had rotted roots. Thirteen hinoki were peeled by Cervus nippon (sika deer) and all of them were infected with butt rot. The maximum height of rot in deer-damaged trees was 2.6 m from the ground level, but was 1.9 m in undamaged trees. About eighty-two percent of rotted trees showed rotted areas of less than 40 cm2 on the cross section of stems at the ground level. White mycelia and black flecks sometimes appeared in the rotted wood. Basidiocarps of polyporaceous fungus were often found on felled logs and rotted stumps of hinoki and identified as Perenniporia subacida. Basidiomycetous fungus was isolated frequently from rotted wood of roots and stems, and determined to be P. subacida by comparative study on cultural characteristics. An inoculation experiment and wood-decay test proved that the fungus was the cause of the rot of hinoki. Few absorbing roots of living trees were found in the clayey subsurface soil of the high dry bulk density and the less soil aeration. Some absorbing roots had root rot and the rot spread from the base of the absorbing root to the central part of the woody root. This is the first report on the rot of hinoki caused by P. subacida in Japan.

Water Pollution of Irrigation Ponds in Kagawa Prefecture and Possible Alleviation by Increasing the Amount of Water

We analyzed the degree of pollution of the water in irrigation ponds in part of Kagawa prefecture and simulated the amount of nitrogen in water to evaluate the beneficial effect of dredging and excavation of the ponds. The average values of TN (Total Nitrogen), COD (Chemical Oxygen Demand) and TP (Total Phosphorus) throughout the period of analysis in 3 ponds exceeded the criteria values of irrigation water for paddy fields and the average values of the pH in all the ponds were also above those of the criteria. Moreover, a considerable degree of eutrophication was observed in 2 of 3 ponds which showed a high average chemical index. In the case of the pH, COD, TN and TP, 90, 58, 50 and 49% of all the water samples showed values above those of the criteria, respectively, while in the case of DO (Dissolved Oxygen), SS (Suspended Solids) and EC (Electric Conductivity), a small number of samples showed values exceeding those of the criteria. Simulation showed that the concentration of nitrogen in the water decreased by 25% and 40% with excavation, resulting in a total volume about 1.5 times as large as that presently. Simulation also showed that the TN concentration of 1.23 mg/L decreased to 1.13 mg/L, indicating that the TN concentration could be reduced by 10% without excavation, should the upper pond be excavated.

Seasonal changes of the testis in the raccoon dog, Nyctereutes procyonoides in Kagawa Prefecture, Japan

Seasonal changes of the testis in the raccoon dog, Nyctereutes procyonoides in Kagawa Prefecture, Japan

香川県坂出平野における上部更新統および完新統の層序と堆積環境

香川県坂出平野における上部更新統および完新統の層序と堆積環境

14. 香川県における夏期のブユ採集成績(第53回日本衛生動物学会東日本支部大会講演要旨)

14. 香川県における夏期のブユ採集成績(第53回日本衛生動物学会東日本支部大会講演要旨)

Distribution of the Oxytetracycline Resistance Determinant Tet 34 among Bacteria Isolated from Diseased Fish.

The distribution of a newly cloned oxytetracycline (OTC) resistance determinant, Tet 34, was examined among bacterial strains isolated from diseased fish. We analyzed 33 OTC-resistant strains isolated from 1998 to 2000 in Kagawa Prefecture. Tet 34 was detected in 3 of the strains, which were grouped in the genus Vibrio. Minimum inhibitory concentrations (MICs) of the 3 strains were higher than 500 μg/ml in the presence of MgCl2, and 125 or 250 μg/ml in its absence. Tet 34 was found in chromosomal DNA in all positive strains. Polymerase chain reaction (PCR)-denaturing gradient gel electrophoresis of 16S rDNA revealed the 3 strains to have the same migration profiles. The sequences of their PCR products were also identical, suggesting that the species were the same. It was concluded that Tet 34 has been present since at least 1998, and the determinant occurs only in Vibrio species.

ため池公園の来訪者数に関する研究

This study aimed to make clear the main factors that affect the amount of visitors at irrigation pond parks based on the observed data at 27 ponds in Kagawa prefecture. As the results of multiple regression analysis and logit model analysis, the main factors were clarified, and also the projection models were established. Moreover, it became clear that the attribute of the irrigation pond itself, the situation of surrounding area and the maintenance were important factors though the content of park was also important.

Anthracnose of Nemesia strumosa Caused by Colletotrichum fuscum

Severe wilt with spots and/or leaf and stem blight were found on a scrophulariaceous flowering plant, Nemesia strumosa, grown in Kagawa Prefecture, Japan, in February 1999. Wilted plants had numerous lesions and died early. A mitosporic fungus isolated repeatedly from the diseased plants was identified as Colletotrichum fuscum and was demonstrated to cause the disease. N. strumosa is a new host for C. fuscum, which has been known to attack foxglove (Digitalis spp.). The present disease was named “anthracnose of N. strumosa” as a new disease.

Geographic differences in paralytic shellfish poisoning toxin profiles among Japanese populations of Alexandrium tamarense and A. catenella (Dinophyceae)

SUMMARY To reconsider whether toxin profile could be used as a marker for populations from different geographical areas, clonal isolates of the toxic dinoflagellates Alexandrium tamarense (Lebour) Balech and Alexandrium catenella (Whedon et Kofoid) Balech from Ofunato Bay (Iwate Prefecture), Atsumi Bay (Aichi Prefecture), Tanabe Bay (Wakayama Prefecture), Harima-Nada (Kagawa Prefecture), Uranouchi Bay (Kochi Prefecture), Hiroshima Bay (Hiroshima Prefecture) and Yamakawa Bay (Kagoshima Prefecture), which were identified on the basis of morphotaxonomy, immunological and molecular biological techniques, were subjected to analysis of paralytic shellfish poisoning toxins by high performance liquid chromatography-fluorometric method. All the isolates except A. tamarense OF152 from Ofunato Bay contained mainly N-sulfocarbamoyl toxins (C1 +2) with various amounts of derivatives, and a typical north-to-south trend of decreasing toxicity was observed. In both A. tamarense and A. catenella, toxin profiles were rather constant within a geographical area and divergent among different geographical areas. The toxin profiles of A. tamarense from Harima-Nada were well conserved among different bloom years. Toxin profile showed that isolates of A. tamarense from Ofunato Bay, A. tamarense from Harima-Nada isolated in 1988 and A. catenella from Uranouchi Bay were heterogeneous. However, only two or three groups of isolates with different toxin profiles were observed in a geographical region, suggesting that several representative isolates express the genotype in a given region. These observations confirmed that toxin composition could be used as a marker to discriminate different geographical populations of these species.

Seisei-Gakkan, a Private Middle School in Sakaide, Kagawa

In 1886 a new school, Seisei-Gakkan, was founded in Sakaide, Kagawa Prefecture by Katsutaro Kamada and others. The aim of the school was to provide middle-school level education to the children from primary schools, who had been deprived of the chance to study at that level of education due to the Promulgation of Middle School Order in 1886.The school is said to have given a general education with an emphasis on using English-language materials, although the curriculum is no longer accessible, nor is the list of the textbooks used in the school. We can, however, guess which textbooks were used through the Regulations of Hanyo English Club, which had been established a few months before Seisei-Gakkan. It is probable that Seisei-Gakkan staff made reference to the regulations of the club when they designed the school's curriculum, since one of the founders of the club joined the teaching staff of Seisei-Gakkan.The school closed in 1893. During the seven-year operation they invited from the metropolitan area six headmasters, among whom we can identify the name of Sentaro Nishida, who later moved to Matsue Middle School in Shimane and became a reliable colleague of Lafcadio Hearn. In Nishida's diaries we can find how warmly he was welcomed to the school.Seisei-Gakkan thus successfully played the role of a substitute public middle school until the establishment of the two prefectural middle schools in Takamatsu and Marugame in 1893.

Basic Studies on the Cultivation and Breeding of Brewers' Rice in Kagawa Prefecture. Effect of the selection for leaf color on the protein content and some other brewing characteristics in late generation.

オオセト×山田錦およびオオセト×松山三井の組み合わせにおける雑種初期世代からの葉色に対する選抜が後代のタンパク質含有率や他の酒米特性に及ぼす影響について検討した.F2集団の出穂期における葉色値(SPAD-502型による読み取り値)は正規分布に似た連続変異を示し,その分散から推定した広義の遺伝率は,オオセト×山田錦0.517,オオセト×松山三井0.397であった.F2からF5まで,出穂期の葉色が濃い方(H群)と淡い方(L群)へ選抜を続けた結果,F6系統のタンパク質含有率はH群の方がL群よりも有意に高くなった.平均値で比較した稈長+穂長はH群の方がL群より長く,1000粒重はH群の方が軽かった.また,H群の方が出穂期迄日数は短く,心白粒発現率は高かった.F6系統における葉色値とタンパク質含有率との間には有意な正の相関関係が認められた.ただし,H群内には葉色値とタンパク質含有率との関係が異なる二つのグループが存在した.葉色値のF5-F6親子相関は有意であった.これらより,酒米の品種育成においても雑種初期世代における出穂期の葉色はタンパク質含有率に対する選抜指標として有効と判断した.

An Approach to Enviromental Evaluation using Binary Data of the Butterfly Community on Environment Preservation Areas and Natural Parks in Kagawa Prefecture

An Approach to Enviromental Evaluation using Binary Data of the Butterfly Community on Environment Preservation Areas and Natural Parks in Kagawa Prefecture

Association between life events, subjective health status and health practices in a rural population

A survey has been conducted on subjective health status, experience of life events in recent 1 year, and health practices in the rural of Kagawa prefecture. The survey was performed from March 1995 to May 1995 with 4,013 participants, aged 40 to less than 80. The proportion of respondents who recognized their physical conditions as good decreased with age. However, the proportion of respondents who recognized their life satisfaction as good increased with age. 'Health-related' life events were the most common experienced life events for both male and female. The proportion of respondents who had life events of type 'family', 'financial', 'at workplace or job', 'in the community', and 'others' decreased with age. Men had higher proportion of 'at workplace or job' life events. The higher proportion of respondents who experienced life events recognized their subjective health status poor. For male, it observed that poor physical health status had significant association with experience of type 'in the community' and 'environmental' life events. Poor mental health status significantly associated with experience of type 'at workplace and job' life events for male, and with 'health-related' and 'family' life events for female. Poor life satisfaction significantly associated with 'at workplace or job' and 'in the community' life events for male, and with 'health related' and 'family' life events. Higher proportion of the respondents who experienced life events and recognized their subjective health status poor had low health practice scores. Logistic regression analysis showed that experience of life events and poor subjective health status had significant association with the poor health practices, especially with 'body weight changed' for both male and female.