San-in District Research Articles

The distribution of the ABH secretors with myotonic dystrophy in San-In district of Japan.

The prevalence rate of myotonic dystrophy in San-in district of Japan was approximately 1∶46,000. The blood groups of 25 subjects, including 14 patients and 11 healthy relatives, were surveyed, which failed to present the maldistribution of secretors and non-secretors. The genetic linkage between the locus for myotonic dystrophy and the ABH-secretion locus was seen equilibrated. Some of the families permitted prenatal prediction.

Frequency of tuberous sclerosis in san-in district (Japan) and birth weight of patients with tuberous sclerosis

Fifty-two patients with tuberous sclerosis including 44 propositi were collected from 11 hospitals and 20 institutions in the San-in district. Of the 52 patients 44 were alive at the time of the study and the prevalence of tuberous sclerosis among the general population of the San-in district in October 1979 was estimated to be one in 31,000 (3.2 x 10(-5)), which was the highest value among the surveys in certain geographical areas. The frequency of tuberous sclerosis in live-births was estimated to be one in 24,000 (4.0 x 10(-5)). The frequency of the sporadic cases in live-births was one in 31,000 (3.2 X 10(-5) and the mutation rate was directly estimated to be 1.6 X 10(-5) per gene per generation. A difference between the parental age or birth order of the sporadic cases and those of controls was not detected. The mean birth weight for the tuberous sclerosis group was 2,834 g which was slightly less than the 2,985 g for their normal sibs. The frequency of low birth weight, less than 2,500 g, among the children with tuberous sclerosis was 30% (7/23), which was 4 times that in the general population (P less than 0.005). These facts suggest that the intrauterine growth is affected in a considerable number of the patients.

Mortality and causes of death of children with Down's syndrome in San-in District, Japan.

One hundred and fifty six children with Down's syndrome who were born during 1969–1978 in San-in district, Japan were traced for a period from one year to ten years. Mortality and survival as well as causes of death, if applicable were studied. The largest number of deaths were observed during the first year of life. The survival fraction at 5 years of age was 0.697±0.041. From ages 5 to 10, no death was observed. The most significant cause of death in children with Down's syndrome was cardio-respiratory diseases (80.5 per cent). Mortality was especially high in both winter and spring. No correlation was observed between the early deaths and the distributions of paternal and maternal age at childbirth.

Down's Syndrome. An Epideomiological and Genetical Study in San-in District, Japan

Down's Syndrome. An Epideomiological and Genetical Study in San-in District, Japan

Petrology of the Pliocene volcanic rocks in Sanin district with special reference to the genetic relationship between the alkaline basalt and the calc-alkaline andesite(Abstracts of Papers Submitted for the Meeting of the Society)

Petrology of the Pliocene volcanic rocks in Sanin district with special reference to the genetic relationship between the alkaline basalt and the calc-alkaline andesite(Abstracts of Papers Submitted for the Meeting of the Society)

本邦火山岩類のクロム含量 山陰西部・新生代火山岩類

The chromium contents of 50 rock samples, belonging to the Cenozoic volcanic rocks in the western part of the San-in distrct in west Japan, were determined by atomic absorption method. The volcanic province of this district is divided into Abu, Mishima and Otsu areas by the distribution of volcanic rocks. In Abu area the chromium contents of the alkaline rocks are 75-390 ppm and of the calc-alkaline rocks are 8-510 ppm, in Mishima area the alkaline rocks are 239-436 ppm, in Otsu area the tholeiitic rocks are 11-423 ppm and of the alkaline rocks are 120-508 ppm (high iron alkaline rocks are 120-185 ppm), resectively. From these data, the chromium contents of the volcanic rocks of the western part of the San-in district show the wide range of 8-510 ppm and the average value of 204 ppm. The chromium contents of the most of the rock samples have the tendency of the decreasing in the progress of crystallization differentiation. Although, as an exception in the case of co-existence of olivine and pyroxene, it is likely that chromium may concentrate in pyroxene rather than in early crystallized olivine. It is supposed that the alkaline rocks and calc-alkaline rocks are classified on the basis of the chromium contents of the olivine-bearing calc-alkaline rocks as an indicator.

Distribution of Heavy Metals in Bottom Mud of River. III. Bottom Mud of Prineipal Rivers in Japan

Distribution of Cu, Cr, Pb, Zn, Cd, Ni, and Hg in mud of Japanese rivers of first category was investigated with 178 mud samples from the mouth of 91 rivers, collected from August to September, 1973. The mud from the rivers in San-in district on the Japan Sea coast showed the lowest amount of all the heavy metals. The samples obtained from the Tsurumi or the Yodo River, near the industrial area, showed a very high concentration of all the metals. From the calculated values of the mean and standard deviation of each metal, it was considered that the higher these two values were, the more the river was polluted. The mean value of fignition loss was 5.03%. On the basis of this value, all the river were grouped into two classes. The first group had below 5.03% of ignition loss and the other with higher value. The mean and standard deviation of heavy metals of the former group were smaller than those of latter. Marked difference in concentration of Cd and Hg was observed between the two groups, while no difference was observed in the concentration of Ni. These results indicate that the mean of each metal in the first group river may be considered as approximate value for Japanese river mud in natural state.

Some Miocene Plant Fossils from Tottori and Shimane Prefectures, San-in District

Some Miocene Plant Fossils from Tottori and Shimane Prefectures, San-in District

On the Results of the Aeromagnetic Survey over San-in District

On the Results of the Aeromagnetic Survey over San-in District

ON THE LAND FORM AND TEPHROCHRONOLOGY OF MT. SAMBE, SAN-IN DISTRICT, WESTERN JAPAN

The author intends in this paper to offer some contributions on the chronology of Japanese Pleistocene, of which informative data have been few in San-in District. He made the geomorphological map of Mt. Sambe (Fig. 1), surveyed the volcanic ash beds (Fig. 2), and concluded that the volcanic evolution occurred as follows : 1. Ohda pumice flow, 2. Mt. Hikage lava dome, 3. Ukinuno-ike pumice flow and fall, 4. Mt. Ohira pyroclastic cone, 5. Mt. Sambe lava domes, 6. Shigaku pyroclastic flow. The eruptions of Ohda and Ukinuno-ike pumice flows also scattered the fall deposits of ash and pumice which covered the terraces, sand dunes and mountain slopes on the eastward areas. On the other hand, Mt. Daisen erupted ash and pumice beds, some of which are resemble to those of Mt. Sambe. Both the fall deposits of Mt. Sambe and Daisen are found overlapped each other on the terraces (Nogi terrace etc.) around Matsue City. They are easily identified, for some of them have distinct facies. Through interpreting these ash and pumice beds, the process of eruption can be known, and at the same time, terraces covered by these beds can be correlated with it (Fig. 3). Some of the fall deposits covered the palaeo-sand dunes in San-in District. For instance, volcanic ash contemporaneous to Ohda pumice flow covered Izumo palaeo-sand dunes (central part of Shimane Pref.). Ash and pumice beds of Mt. Daisen covered Tottori palaeo-sand dunes (eastern part of San-in District). In conclusion, the evolutions of Mt. Sambe, Mt. Daisen, palaeo-sand dunes and Nogi terrace can be correlated with each other as shown in Table 1, in which the formation of Nogi terrace was probably done during Riss-Wurm Interglacial Epoch.

The Quaternary system and topographic evolution around Lake Shinji and Nakaumi area, San-in District, Western Japan

The Quaternary system and topographic evolution around Lake Shinji and Nakaumi area, San-in District, Western Japan

Limnological study of the artificially constructed reservoirs in Tottori and Shimane Prefecture, San-in district.

Limnological study of the artificially constructed reservoirs in Tottori and Shimane Prefecture, San-in district.

ON THE TOPOGRAPHIES AND VOLCANIC ASH BEDS IN THE AREA SURROUNDING THE DAISEN VOLCANIC MOUNTAIN

The author surveyd the topographies and volcanic ash in the area surrounding Mt. Daisen, San-in disstrict, western Honshu. Up to present, it has been said that the terraces and uplands are scarcely developed in San-in district, but the author recognized the several series of fluvial, marine terraces and pyroclastic uplands, many of which are covered with volcanic ash several meters thick. The author's purpose in this survey was to make clear the condition of these terraces, uplands and volcanic ash, and to establish the geomorphic development in the area surrounding Mt. Daisen. The condition of volcanic ash beds are shown in Figs. 1-3, and distribution of terraces and pyroclastic uplands are in Figs. 5-7. The developing order of terraces and pyroclastic uplands were concluded by t-he correlation of volcanic ash beds covering them, some absolute dates of which were decided by Carbon-14. The geomorphic development derived from the above data is summarized in Table 1.

Studies on Yield-Forecast in Main Crops : XI. Analysis of grain production of rice plant in Chugoku district

Process of grain production of rice plant in Chugoku district was analized using the same data as shown in the preceding report. The results obtained were as follows: Close relation was observed between the ripening of grains (the yield per 1, 000 spikelet) and the number of spikelets per unit area, but it differed by locality, namely, the relation was negative in Okayama but positive in Tottori, and in Hiroshima the relation was positive when the number of spikelets per tsubo was less than 75 thousand and negative when much more than it, and in other localities clear relation was not seen. The yield per 1000 spikelet had close relation with the 1, 000 grain weight, and the 1, 000 grain weight had been influenced by air temperature in ripening stage, and these relations were marked in late varieties and also at San-in district. In general, sequential correlations were found to exist among the following factors which contribute toward the yield of rice grown in Chugoku district: grain yield ∝ number of spikelets ∝ number of panicles ∝ number of tillers ∝ number of secondary tillers.

THE IMPROVEMENT AND UTILIZATION OF FARM-LAND IN IZUMO PLAIN

Izumo Plain, situated on the coast of the Japan Sea, is the largest alluvial plain in the San-in District. In prewar times, dispersed settlement and a unique farming method under the large land-owner system made great features of the plain. In the end of last century, a farming method which required extremely hard labour was established on this plain. This method consisted in digging wet field deep, then heaping up the earth to make high ridges, upon which clovers (medicago denticulta) were planted for making green manure. Though it was hard for the farmers, this farming method was profitable on the part of the land-owners, so they had little intention to improve theirland. Their chief concern was to protect their land from frequent floods of the Hii River, and the energy of the farmers was directed to the river conservation works instead of land improvement. This is why this district has been so backward with respect to land-improvement. The conservation works of the Hii River were done from 1922 to 1944. After World War II, the first. attempt to improve the land was made on the lowest part of the plain on the coast of the lake. Encouraged by the successof this attempt coupled by the influence of the farm-land reform, farmers came to realize the importance of improving their land. So farm-land over 3, 200 ha was improved during the period from 1952 to 1957. First, dikes were formed along the lake coast, which prevented the salty lake water from coming into the fields. Then the water within was pumped away, and paddy fields were partitioned into 10 or 20 a. After the improvement, barley for beer-making is planted in some parts in place of clover which was commonly seen before the improvement, but this is not so widely known here. Orchards have shown a remarkable increase, but, when compared to the whole farm-land, they take only small part. Dairy in the wet fields, which is now being encouraged as a new type of agriculture, is experimentally adopted by a small number of farmers. Fodder culture is also restricted to only a small portion. In short, the rotation of rice and foddy culture does not go well. The commonest type of the utilization is single rice culture. Next to this, two-crop farming and horticulture are attempted in some place. The last one is dairy. These types, except the first one, are still on the experimental stage. This is caused by 1) farmers' inability to get accustomed to the new farming techniques (especially in raising milking cow), 2) lack of labourers, and 3) instability of the prices. For these reasons any effective utilization has not been observed. yet, though wet fields were changed into dry ones, except the only merit that the extremely hard labour of the farmers has been much reduced. For the future development of the land utilization, the following measures are to be desired. 1) The fields which still remain wet must be changed into dry ones by underground drainage. 2) For the ample supply of water and prevention of floods caused by the accumulation of sand, radical conservation works of the Hii must be performed. 3) A firm sale cooperative system directly connected with Osaka Metropolitan Market must be establi-shed. Both the agricultural cooperativeassociations and cooperative management of agriculture play agreat part for the realization of this purpose.

山陰地方(隠岐群島を含む)及びその付近海域のカニ類について

The western part of Japan proper facing the Japan Sea is called the Sanin District, in which the Oki Isls. Are also included in this paper. The writer has been studying the crab-fauna of this district and its adjacent waters in spare times of his onerous duties, as the result of which 90 species of crabs are shown in the list of this paper. Of them 6 species are fresh-water crabs, while 84 species are marine consisting of 3 nothern forms, 50 southern forms, and 31 intermediate forms. Among 50 southern forms 22 species are distributed further northwards, for instance, they are found in the list of crabs of Toyama Bay. The occurrence of southern forms, such as Calappa lophos, C. philargius, Ranina ranina, Paratymolus sexspinosus, Neptunus (Neptunus) sanguinolentus, N. (N.) pelagicus, Atergatis subdentatus, Eucrate crenata, Ommatocarcinus macgillivrayi, Plagusia dentipes and others in the Japan Sea side has never been recorded up to now. These peculialities of the distributions coincide with the course and its largeness of the warm current along the coast of this district.

Geological and petrological studies on the late Cretaceous and early Paleogene igneous rocks in central San-in District, Southwest Japan (I)

Igneous and metamorphic rocks of the central San-in district can be classified into three groups, according to their stages of activities. They are: (1) The late Cretaceous volcanic rocks resulted by volcanic activities in three different stages and accompany dykes in their intrusive facies, (2) The late Cretaceous and early Paleogene intrusive rocks resulted from the plutonic activities in two different stages, (3) The late Cretaceous and early Paleogene metamorphic intrusive rocks which were re-metamor-phosed under plutonic activities of latter stage. The late Cretaceous volcanic rocks, composed largely of rhyolite, rhyodacite and andesite, have been known to distribute mainly on the westside of the “Sanbe-Hiroshima Structural Zone” whereas the late Cretaceous and early Paleogene intrusive rocks, composed largely of diorite, quartz diorite, aplitic granite and biotite granite, occupy chiefly on the east side of this structural zone. The geological structure of basement rocks, Paleozoic in age, seems to govern the late igneous activities of this district.

Mineralogical Study of Rock-alteration to Pottery Stone of Some Pottery Stone Deposits in San-in District

The pottery stone called “Toseki” is not defined mineralogically. And the process of rock-alteration to pottery stone is not studied yet.In San-in district, there are several localities of pottery stone which may be classified into following three types:I. Deposits produced by rock-alteration of pitchstone, which intrused into rhyolite-represented by Izushi pottery stone deposit in Hyogo prefecture.II. Deposits produced by rock-alteration of quartz porphyry-represented by Tanokouchi pottery stone deposit, Tottori prefecture.III. Deposits produced by rock-alteration of rhyolite-represented by Amabe pottery stone deposit, Kyoto prefecture.This paper concerns the geological and mineralogical studies of above three deposits stating in detail on the process of rock-alteration and also the mineralogical significance of pottery stone:(1) Pottery stone deposits are the products of the replacement and metamorphosis under the influence of epithermal solution rising up along the weak line of mother rock.During the process of deposition alkalies changed their position; Na2O being generally leached out because of its smaller molecular volume, while K2O codeposited with Fe on the circumference of pottery stone due to chemical migration giving lower quality ore so-called “Toraishi”.(2) Pottery stone, Toseki, is composed of SiO2 and Al2O3 as chief ingredient, whose analysis is 75-82% SiO2, 12-16% Al2O3, and 1-5% alklies (K2O+Na2O). It is white fine ore consisting mainly from quartz, sericite, halloycite and kaolinite, etc.

ON THE TYPES, GRADES, AND GEOGRAPHICAL PATTERNS OF SIGHT-SEEING RESORT IN JAPAN

There are many sight-seeing resorts in Japan, but the author thinks there are quite different types of them. Each resort has its own characteristic types of recreational activities. Big resorts are Atami spa, Beppu spa, Nikko, Fuji-Ha-kone, Seto Inland Sea National Park and others, but on the contrary, many small local resorts are found here and there as is the case in the central part of Chugoku region.The purpose of this geographical study is to set up some grades and to know geographical patterns of many sight-seeing resorts. Now, the results of this study are as follows;There are four grades of sight-seeing resorts in the centre of Chugoku region; namely (1) International resort (2) National resort (3) Local resort, and (4) Neighbouring resort. There are some international resorts in Sanyô district; they are Miyajima shrine, Hiroshima city, Iwakuni city, and so on; however, in San-in district there is no international resort.In the centre of Chugoku region, there are four national (ihcluding international resort) gight-seeing district, that is to say, there are (1) Hiroshima-Miyajima-Iwakuni, (2) Fukuyama-Tomo-Onomichi, (3) Tottori-Misasa spa and (4) Daisen-IzumoAfter the Second World War, transportation, (above all, bus, railway services) has made rapid progress. Some grades of the resorts became so apparent, and some fixed correlation and systematic combination between the sight-seeing resorts and their neighbouring resorts resulted from rapid progress of transportation.In the centre of Chugoku region there are many various landscapes, … mountainous, volcano, valley, sandy coast, rocky coast, lakeside, hot spring, religious, and urban, etc. Lake, seaside, volcano, hot spring, and religious landscapes are most attractive.In many sight-seeing regions, almost all of sight-seers are transient, and they (including almost all of foreigners) decide to go to some famous hot spring spa or some famous cities to take up one or two nights for their lodgings.

On the Informal Marriage in the San-in District

On the Informal Marriage in the San-in District