Parts Of Hokkaido Research Articles

Cost Effectiveness of Drive and Retrieve System in Hokkaido for Acute Ischemic Stroke Patient Treatment Using Geographic Information System

Background and Purpose: Although endovascular thrombectomy combined with recombinant tissue-type plasminogen activator is effective for treatment of acute ischemic stroke, regional disparities in implementation rates of those treatments have been reported. Drive and retrieve system, where a qualified neurointerventionist travels to another primary stroke center for endovascular thrombectomy, has been practiced in parts of Hokkaido, Japan. This study aims to simulate the cost effectiveness of the drive and retrieve system, which can be a method to enhance equality and cost effectiveness of treatments for acute ischemic stroke. Materials and methods: The number of patients who had acute ischemic stroke in 2015 is estimated. Those patients are generated according to the population distribution, and thereafter patient transport time is analyzed in the 3 scenarios (1) 60-minute drive scenario, (2) 90-minute drive scenario, in which the drive and retrieve system operates within 60-minute or 90-minute driving distance (3) without the system, using geographic information system. Incremental cost-effectiveness rate, quality-adjusted life years, and medical and nursing care costs are estimated from the analyzed transport time. Findings: The incremental cost-effectiveness rate by implementing the system was dominant. Cost reductions of $213,190 in 60-minute drive scenario, and $247,274 in the 90-minute scenario were expected, respectively. Such benefits are the most significant in Soya, Emmon, Rumoi, and Kamikawahokubu medical areas. Conclusions: The drive and retrieve system could enhance regional equality and cost effectiveness of ischemic stroke treatments in Hokkaido, which can be achieved using existing resources. Further studies are required to clarify its cost effectiveness from hospital perspective.

At-sea Occurrence and Historical Breeding of the Long-billed Murrelet(Brachyramphus perdix)in the Iburi Region, Hokkaido, Japan

The Long-billed Murrelet (Brachyramphus perdix) was previously considered to breed in Hokkaido, Japan, but the single 1961 historical nest record was recently found to be invalid, and small numbers observed during at-sea surveys off northeastern Hokkaido in 1996–2001 did not suggest breeding. In the Iburi Region of southern Hokkaido, small numbers of Long-billed Murrelets were observed at sea in May 2010 (n = 8) and May 2011 (n = 4), reflecting either local breeding, a stopover site during migration, or non-breeding individuals south of the breeding range during the breeding season. Single Long-billed Murrelets also were observed in October and December 2011, representing movements after the pre-basic molt. A historical record of a juvenile found in the forest about 20 km inland near the Chitose River in either 1913 or 1915 provides evidence of historical breeding in the Iburi Region and the best evidence so far of breeding in Japan, although breeding also may occur in the nearby southern Kuril Islands. At-sea and forest surveys are needed to better establish the status of and help conserve this declining species in the Iburi Region and other parts of Hokkaido.

Monthly maximum number of consecutive dry days in Japan and its reproducibility by a 5-km-mesh cloud-system resolving regional climate model

The geographical distribution of the Monthly maximum number of Consecutive Dry Days (MCDD) over Japan during June–October in 2002–2006 is investigated from observed raingauge data. In June and July, areas with low MCDD ( 10 days)] is found in inland areas [coastal areas of the Seto Inland Sea, southern Kanto, and parts of Hokkaido]. In September and October, low MCDD [high MCDD] is found on the Japan Sea side of Honshu [in Kyushu and coastal areas of the Seto Inland Sea]. The reproducibility of the MCDD by a 5-km-mesh cloud-system resolving regional climate model (NHM-5km) is statistically examined in numerical experiments with regional objective analysis data of the Japan Meteorological Agency. NHM-5km performs well in reproducing the features of the local geographical distribution and seasonal march of MCDD, although MCDD is slightly overestimated. The MCDD values averaged for 11 sub-regions of Japan are compared with observations, revealing a good agreement (correlation coefficient, 0.755; root mean square error, 1.49; mean error, 1.10). Moreover, annual variations in MCDD averaged over Japan are well reproduced by the model.

Construction of Passing-Maneuver Model on Two-Lane Highway with Consideration of Road Surface and Visibility Conditions

Most national highways in rural parts of Hokkaido, Japan, are two-way, two-lane roads. On these highways, passing maneuvers that involve the use of the oncoming lane are frequently observed. Such passing is observed even when road surfaces are covered with compacted snow. To optimize speed and safety, simulated passing maneuvers have been conducted to make use of the oncoming lane of a two-way, two-lane highway. No such traffic simulations, however, have taken into consideration the surface conditions of roads in winter (e.g., snow-covered, icy, with poor visibility caused by snowfall and fog). In this study, a traffic flow simulation to model passing maneuvers that involved the oncoming lane was created through the use of values measured in a passing-maneuver field survey conducted on a two-lane road in summer and winter. The field values for the number of passing maneuvers, traffic volume, and speed distribution were compared with the simulation results. The outcomes confirmed that the difference between them was small. The sensitivity analysis results revealed that the number of passing maneuvers on surfaces covered with compacted snow under conditions of poor visibility did not increase as much as they did on dry surfaces, even when the traffic volume in the original lane was higher. The passing success rate tended to decrease with higher volumes of traffic in the oncoming lane, regardless of surface conditions.

Basal area growth and mortality of Betula maximowicziana affected by crown dieback in a secondary forest in Hokkaido, northern Japan

Since the late 1990s, decline of B. maximowicziana Regel has been observed in mature secondary forests in various parts of Hokkaido, northern Japan. To develop a method of thinning for large-timber production of B. maximowicziana, we measured basal area growth and the mortality of 217 trees during a four-year period (1999–2003) in a 90-year-old secondary forest with serious tree damage. We analyzed growth and mortality in relation to the degree of crown dieback (DC), symmetric and asymmetric competition from neighbors, and initial tree size. Individual basal area growth decreased with increasing DC, with increasing symmetric (two-sided) competition, and with decreasing initial tree size. During the four-year period, 4.1% of the observed trees died. Logistic regression analysis revealed that mortality rate increased with increasing DC and with increasing symmetric competition. These results suggest that both growth and mortality rates were affected by the same factors (i.e., DC and symmetric competition). We concluded that the resource for which individuals were competing at the study site was underground, most likely water. Modeled growth and mortality rates can be used to improve the management of damaged forests. A management plan for the damaged study site is proposed.

Home Range and Habitat Use of Brown Bears in the Southwestern Oshima Peninsula, Hokkaido

Movement, home range, and habitat use of 10 (7 M and 3 F) brown bears (Ursus arctos yesoensis) were investigated by radiotracking in southwestern Oshima Peninsula, Hokkaido, from May 1987 through May 1990. The annual home-range size was 28.1-39.1 km2 for 1 female. Male home-range size was larger than that of females, although no males were monitored throughout the year. Lower deciduous natural forest areas such as beech-oak (Fagus crenata)-(Quercus monoglica var. grosseserrata) forest and maple-linden (Acer mono)-(Tilia japonica) forest were used by bears intensively, but subalpine areas such as sasa-birch (Sasa kurilensis or S. senanensis)-(Betula ermani) forest and sasa community were rarely used and usage was restricted. Food availablilty could influence the habitat selection by the bears. Int. Conf. Bear Res. and Manage. 9(1):319:325 Hokkaido brown bears have been killed indiscriminately for more than 120 years. Especially during the period of 1966 through 1989, the spring prophylactic killing system was in force, and many bears were killed as pests and as game animals. Forest and field areas have been developed without considerations of bear habitat maintenance. As a result of these pressures, conspicuous extinction or near extinction had occurred by the 1980s in northern Hokkaido (Aoi 1990) and in areas such as the Shakotan Peninsula and the Yoichidake-Eniwa mountain area (Hokkaido Government 1986). However, recent bear damage to livestock and crops still occurs in other parts of Hokkaido (Hokkaido Government 1986). It is obvious that with the control kill alone, damages will continue to occur until the bear population drops to near extinction. Since mid 1970, about one-fourth of the total brown bear damage in Hokkaido has occurred (annually) in the Oshima Peninsula (Hokkaido Government 1986), which occupies only about 9% of the island. As this area is a peninsula, characterized by having a very long boundary between bear range and human residential areas, troubles and conflicts between people and bears are apt to occur. Moreover, habitat development on the Oshima Peninsula could have a major influence on bear habitat and population maintenance on Hokkaido. Biological information such as brown bear home range and habitat use is required for proper habitat management. The first successful brown bear radio-telemetry study in Hokkaido, Japan, was initiated in southwestern Oshima Peninsula in 1987. In this paper, I present preliminary information on movement, home range, and habitat use of Hokkaido brown bears in the deciduous forest of this area. I thank K. Maita and S. Kojima for their devoted field assistance. I thank also M. Yoneda, H. Abe, T. Aoi, H. Kudo, and T. Akasaka for their helpful advice and suggestions. Y. Maruko, A. Kishikawa, J. Yamazaki, T. Tsuizuki, G. Suzuki, N. Sato, T. Sato, and K. Takahashi, who are the members of the Hokkaido Hunting Society, kindly cooperated with the study. T. Tsubota, K. Yamamoto, Y. Kamada, and the members of the Brown Bear Research Group of Hokkaido University also provided devoted field assistance. Y. Sawamura and K. Kudo provided assistance in aerial radio location. The Matsumae District Forestry Office of Hokkaido also gave facilities for investigations. K. Kanagawa cooperated with the English. This research was partly funded by the Japan Environmental Agency. Asahi Broadcasting Co., Iwanami Productions Inc, and Tokyo Broadcasting System Inc. also provided financial assistance.

The geographical distribution of the potential for seed germination and seedling establishment ofPinus densiflora in Japan as influenced by soil and air temperatures

The geographical distribution ofPinus densiflora forests in Japan was examined in relation to the seed germination and seedling establishment information obtained from laboratory experiments, field observations and field experiments. The laboratory experiments indicated that seed germination can occur in all areas of Japan because effective cumulative soil temperatures reaches to 75 °C · day everywhere. However, the field observations and field experiments suggested that seedling establishment is impossible in the northern, eastern and central parts of Hokkaido because the effective cumulative air temperature at a height of 6 cm over bare ground is less than 2 000 °C · day. These results agree approximately with the actual geographical distribution ofP. densiflora forest, which can not be found under natural circumstances in these areas.

Method of judging copper deficiency from the concentration of soluble copper in soils and the copper: Iron ratio in wheat plants

Abstract With the increasing acreage of wheat in Hokkaido, Cu deficiency has become a problem in various parts of Hokkaido since 1979. Cu deficiency was found in some brown forest soils, peat soils and andosols, whose total Cu concentration ranged from 5.5 to 22 ppm. Sterility of wheat plants was seen in soils whose soluble Cu concentration (soil: 0.1 N HOratio, 1 : 5) was lower than 0.15 ppm (mineral soils) or 0.2-0.25 ppm (peat soils). No clear relationship was observed between the humus content and concentration of soluble Cu. It was difficult to determine Cu deficiency from the concentration of Cu in the tops of wheat plants. On the other hand, it was found that wheat plants deficient in Cu tended to have a high concentration of Fe. The Cu : Fe ratio in all wheat plants which were made sterile through Cu deficiency was 0.003 to 0.01, whereas the same ratio in fructified wheat plants was mostly 0.01 to 0.1. Thus, the Cu :Fe ratio in wheat plants can serve as a useful parameter in judging whether or not...

Biotype differentiation in the Typhula ishikariensis complex and their allopatry in Hokkaido.

Typhula ishikariensis isolates were collected from various parts of Hokkaido. There were two genetically different groups which did not mate with each other; one was termed biotype A, and the other was further divided into two by cultural characteristics, i.e., biotypes B and C. Biotype A was identical to T. ishikariensis and T. ishikariensis var. ishikariensis. Biotype B was not identical to T. idahoensis or T. ishikariensis var. idahoensis. Biotype C was similar to T. ishikariensis var. canadensis. Biotype A tended to occur inland where deep snow cover lasts for a long time. Biotype B was obtained mainly from the coastal regions where snow cover is thin and short in time. The distribution of biotype C was irregular. Taxonomic significance of the genetics and allopatry in the T. ishikariensis complex is discussed.

Distribution of Shrikes (Laniidae) in Hokkaido

The authoer has studied distributions of three kinds of shrikes (Laniidae), i. e., the Bull-headed Shrike Lanius bucephalus, the Red-tailed Shrike L. cristatus that commonly breed in Hokkaido, and the Grey Shrike L. excubitor that visits there in the winter season. The study has been conducted by means of field surveys by the author, his questionaries to and interviews with ornithologists and bird watchers, and refering to the published papers by other schalars. Each area where these species were recorded is indicated by a circle drawn on the map of Hokkaido on the scale of 50, 000. Moreover, distributions of the shrikes in Sapporo and Koshimizu areas were studied in detail. The results are as follows.1. It was confirmed that the Bull-headed and the Red-tailed Shrikes were distributed almost entirely over Hokkaido, though the former was somewhat than was the latter. In the northern and eastern parts of Hokkaido, the density of both shrikes was very low.2. The grey shrike was recorded at many areas every year. The recorded period covered up to 10 months in a year with the exception of records in June and September. This species usually visited the coastal areas along the Ochotsk Sea in autumn and disappeared in spring and reached peak in number before and after February.3. From the detailed field surveys in Sapporo and Koshimizu, the bull-headed shrike was found to have wider in habitat preference, from open land to the foot of a mountain, than in the Red-tailed Shrike which was found mostly in open land.4. The Bull-headed Shrike has been considered as a summer visitor to Hokkaido, but a few individuals might have stayed in Hokkaido during the winter.

北海道における日本脳炎の疫学的研究

Sero-epizootiological studies were performed on Japanese encephalitis (JE) in wild and domestic animals in Hokkaido. The relation of climatic factors to JE outbreaks was also investigated.1. Hemagglutination-inhibiting (HI) antibodies against both Nakayama and JaGAr-01 strains were found in 9 (1.5%) of 593 swine sera collected in different parts of Hokkaido in 1970. All the 9 sera were among those collected in the southern part (Hiyama district) of Hokkaido. Two of them were senitive to 2-ME.2. A total of 12 pools of mosquitoes belonging to Aedes vexans nipponii, Culex pipiens pallens, and Anopheles sinensis were collected in the the Hiyama district. No virus was isolated from any of them.3. Neutralizing antibody to the JaGAr-01 strain was detected from 48 (7.8%) of 604 bovine sera collected in different parts of Hokkaido by means of the microtiter method. The positive rate decreased gradually northward and became higher in accordance with the advance in age.4. Sera were collected from 35 wild birds, 87 rodents, and 28 bats in Hokkaido in 1970. All of them were negative for the microneutralization test with the JaGAr-01 strain.5. Climatic conditions for effect were investigated on the outbreak of JE in domestic animals by using the ten-day records of air temperature and precipitation over a period from April to October. An epizootic of JE occurred in a year when the mean ten-day temperature was 20°C or higher in summer, although it varied in size with the duration of the mean temperature. Precipitation was also found to affect JE infection of pigs in Hon shu, but such was not clearly demonstrated in Hokkaido.

Bird investigation in Hokkaido (1965)

In May and June, 1965, the author made five bird surveys in less known parts of Hokkaido. These are reported here under the headings: 1. Notes on birds along Shiretoko Peninsula (May), 2. Sea-bird survey of Kojima I., off Matsumae (May), 3. Observations of birds of Rishiri I. (June), 4. Bird survey of Cape Esan (May, June) and 5. Birds of Soya area and Rishiri. They are sea bird observations (pelagic census and breeding colonies) and notes on land birds.1. Along Shiretoko peninsula, sea bird colonies were observed from ship at some distance. The main colony was on the west-side cliffs at Iwaobetsu chiefly consisting of some hundreds of Larus schistisagus and Phalacrocorax capillatus with Ph. pelagicus and Cepphus carbo, etc. There were a few other smaller ones but they could not be observed at close range. According to local observer, Mr. Yoshida, there appears to be some colonies of Uria aalge, Lunda cirrhata, Cerorhinca monocerata, and breeding of Fratercula and Brachyramphus marmoratus, possibly also Phalacrocorax urile is suggestive. Summer records so far known for Brachyramphus are listed and two birds were encountered this time. A flock of scores of Larus crassirostris were observed near the tip of the peninsula but the breeding was not confirmed. According to Yoshida, he saw chicks of Histrionicus with an adult bird in June, 1963. A White-tailed Sea Eagle was seen on a pack ice with some Larus schistisagus; it breeds at several places of the peninsula. Two Japanese Robins, Erithacus akahige, were unexpectedly found at rocky tip of the peninsula where there were no vegetations and some snow was remaining. Offshore census of sea birds is given in tables.2. Kojima I. is situated in 139°50'E, 41°20'N, 20km. WSW of Matsumae, the southwesternmost tip of Hokkaido. It is a small volcanic island with a coastal line of about 7km., surrounded by steep cliffs and inhabited only by lighthouse keeper family. The breeding species consisted of Larus crassirostris, Uria aalge, Cerorhinca monocerata, Cepphus carbo and Phalacrocorax capillatus, as on Teuri I. (Kuroda, 1963). Many nest burrows of Cerorhinca were found excavated (by a dog of the lighthouse) and this puffin was apparently decreasing (but increasing at Teuri I.) judging from remains of nests on which grasses were already growing. Gull eggs were still being taken by fishermen and thus protection of the whole island is hoped. The time (May 14) was too early (the season was 10-14 days in retard this year) for Uria aalge which we saw only a few, but on May 31 some hundreds were seen by Mr. Saito. On the island some passerines on migration (both leaving winter bird such as Turdus naumanni and arriving summer birds such as Muscicapa narcissina were found). Scattered Cerorhinca and some flocks of Puffinus griseus and P. carneipes were seen in this sea area and a huge migrating flock of about 3, 000 birds (probably of the latter species) were flying northwestward off Cape Shirakami in an endless line. A flock of 300 birds of this species (definitely identified) had been observed on May 7 all making west the Tsugaru Strait.3. Rishiri and Rebun Is. (See also 5.) situated at a little north of 45N°, west of Wakkanai, northern end of Hokkaido, were visited June 7-9, staying on Rishiri. Cerorhinca was found scattered on the sea between Wakkanai and the islands and many were non-breeding birds without the bill-nob. A small number of Puffinus tenuirostris was seen confined off Wakkanai, a great flock of about 1, 500 of P. griseus consisting of numerous small groups was making a circular movements over the sea area between Rishiri and Rebun,

On Relation between Frost Penetration and Frost Heave

Frost heave and its damages are the most important factors affecting road in a cold area.Neumerous data have been obtained from the investigation of frost penetration and heaving of roads in all parts of Hokkaido over a period of several years.This paper contains following items.(1) Relationship between frost penetration and freezing index.(2) Investigation of ratio of replacement based on the frost heave and penetration studies.