Showing papers by "University of Tsukuba published in 1974"

A Remark on Cauchy-Kowalevski's Theorem

Abstract: (where all the coefficients and / are analytic in a domain KcJ£), he has given the following result: in order that the Cauchy-Kowalevski theorem for (1.1) hold at every point in F, it is necessary and sufficient that the order of

Some Aspects on the Shimagare Phenomenon in the Subalpine Forests in the Kanto and Chubu Districts, Japan

Abstract: “Shimagare” or a phenomenon of blighted trees distributing in stripes is one of the characteristic features seen in the subalpine forests in Japan. The striped pattern of a group of withered trees in the subalpine forests is not only of great interest for those researchers of plant geography and plant ecology, but an important problem to be solved for the protection of nature and forest conservation. The Shimagare is uniquely observed in the subalpine coniferous forests, mainly consisting of Abies veitchii and Abies mariesii, partially mixed with Tsuga diversifolia and Picea hondoensis. The blighted forests present various shapes in the course of development, spots at the initial stage turning into arches and finally into stripes. From the fact that the Shimagare zones appear almost at the same altitude and on the slope facing in the same dierction, and further from the fact that the dead tree stripes move upward on the slope (or leeward) with the lapse of time, it is thought that the phenomenon has close relationship to the prevailing wind direction. To sum up the results of studies obtained so far on this subject, the Shimagare zone is distributed in the subalpine forests, ranging from the Kinki District to the northern part of the Kanto District in Japan; Oku-Nikko, Yatsugatake, Chichibu Koshin Kokkyo, Southern Alps, Central Alps, and Ohmine Mountains. Excepting for the Ohmine Mountains, where the lower limit of the distribution of Abies veitchii is low, this phenomenon appears at an altitude of higher than 2, 000m and mainly on the gentle slopes facing SW-SE. The investigation was carried out in the areas in the Chichibu Koshin Kokkyo Mountains, the Oku-Nikko Mountains and Akaishi Mountains by making use of aerial photographs and the field survey. Belt transects with a width of one meter for all trees with the diameter at breast height of more than 3cm were taken at a right angle at the center of the arch stripe of the Shimagare. At the same time, the height of trees, underbrush, density, and soil profiles were noted (Fig. 1). As a result of the present study, the following facts are clarified: 1) In all such mountains as stated above, the Shimagare phenomena are distributed on the gentle slopes facing SE-SW or failry flat ridge tops. It seems, therefore, that the distribution is related to the radiation, evaporation and prevailing wind direction. 2) The Shimagare strips are found only in the needle-leaved forest in sub-alpine regions. This fact, along with the movement, scale and shape of the Shimagare strips, is enough to make us believe that Abies veitchii and Abies mariesii are liable to be influenced by abrupt change of environments. 3) According to the meteorological observation carried out on the slope of Mt. Nantai, Oku-Nikko, the zone of the subalpin.e forests on the top of the mountain is characterized by the larger number of days with dense mist, frost, stronger wind, and greater cloudiness but by less precipitation than on the foot and mid-slope of the mountain. It can be said, therefore, that the relatively dry condition caused by the stronger wind on this zone might be one of the causes of the Shimagare phenomenon. 4) The soil in the Shimagare zone differs in thickness from place to place, but generally it is thin ranging from 4 to 30cm. The layer is mostly made up of humus underlain by the base rock. In the region, where the Shimagare is lacking, trees grow higher and the soil is thick. On the contrary, many trees fall dead in the Shimagare zone, probably because of the thin soil layer. 5) Comparing the prevailing wind direction estimated by the wind-shaped trees with the arrangement and shape of the Sh.imagare stripes, it was made clear that the direction of fallen trees and the direction of the movement of the Shimagare stripes have close relation to the prevailing southerly winds in spring, summer and autumn.

Hirstia domicola sp. n. from house dust in Japan and Surinam : Acarina : Sarcoptiformes, Pyroglyphidae

Abstract: The new species described here has been found in the dust of several houses in Japan and in two houses in Surinam. This new species differs from the single valid species of the genus Hirstia, H. chelidonis Hull, 1931 (=Dermatophagoides passericola Fain, 1964), in both sexes by the smaller size of the body and of the posterior legs; in the male by the relatively greater size of leg IV compared to leg III; in the female by the distinct sc1erotization of the cutic1e of the posterior region of the dorsum, especially around the d 5 and l 5 setae and immediately in front of the latter. ln 1950 and 1951, Sasa found from the sputum and urine of patients one female and one male mites, which were identified as Dermatophagoides sp. and D. saitoi (Sasa, 1947), respectively. It is presumed, however, that they are identical with the new species described in this paper. ln 1967 and 1970, Oshima found the fact that the mites of the present species abound· ed in house dust in Japan. The number of these mites ranged from 9 % to 18 % of total mites those existed in the house dust. In 1968, he described the present species and identified it with Mealia passericola (Fain, 1964) [=Hirstia chelidonis Hull, 1931J. Recently van Bronswijk also detected the present species in two houses in Surinam (Bronswijk, 1972). It was c1arified, however, that the present species was distinguished from H. chelidonis which materials are preserved in British rvluseum, and was new species. ** *s,~~~ : $ti8t*,~j;al2E~* CT 300-31 =!l:9ilt

An Econometric Analysis of Mitaka City in Tokyo

Abstract: In Japan, urbanization has rapidly raised the land prices in suburban area as a residencial town in recent years. Because of the lack of the fund for social overhead capital investment, local governments can't afford to newly purchase the required land for public use.The purposes of this paper are to analyze the economy of a suburban city, and to develop an operational method for city planning through the following three items, as the case study of Mitaka city in Tokyo.i) New econometric model building with two sets of distribution functions on population and land price, so called the second Mitaka model.ii) Long-term projection of Mitaka city by the model.iii) Quantitative analysis on the land available for public use in the period of the plan.It suggests that the above methods can connect micro indices consisted of physical plan on given point and/or mesh with macro economic indices, on i), and can analyze the feasibility of plan, more concretely, on ii) and iii).