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Hokkaido University Collection of Scholarly and Academic Papers (135.521 recursos)

HUSCAP (Hokkaido University Collection of Scholarly and Academic Papers) contains peer-reviewed journal articles, proceedings, educational resources and any kind of scholarly works of Hokkaido University.

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Mostrando recursos 1 - 20 de 384

  1. Effects of time and environmental conditions on the quality of DNA extracted from fecal samples for genotyping of wild deer in a warm temperate broad-leaved forest

    Agetsuma-Yanagihara, Yoshimi; Inoue, Eiji; Agetsuma, Naoki
    Extraction of DNA from non-invasive samples (feces) has been used increasingly in genetic research on wildlife. For effective and reliable genetic analyses, knowledge about which samples should be selected in the field is essential. For this reason, we examined the process of DNA degradation in feces of deer. We collected fresh fecal pellets from three wild deer living in a warm temperate forest. We then assessed the effects of time (3, 5, and 10 days) under three environmental conditions (on the forest floor, on exposed ground, and inside the laboratory) on the rates of correct genotyping (CG), amplification failure (NA),...

  2. Spatial pattern of soil nitrogen availability and its relationship to stand structure in a coniferous-broadleaved mixed forest with a dense dwarf bamboo understory in northern Japan

    Inoue, Takahiro; Fukuzawa, Karibu; Watanabe, Tsunehiro; Yoshida, Toshiya; Shibata, Hideaki
    Natural disturbances create spatial patterns of the ecosystem processes and functions in natural forests. However, how dynamics and the spatial structure of forests relate to soil nitrogen dynamics is not well understood. We examined the spatial relationship between the distributions of canopy and understory species, and soil nitrogen dynamics in a natural coniferous-broadleaved mixed forest with a dense understory of Sasa dwarf bamboo in northern Japan. The O horizon was thick where coniferous litter predominated, and it was thin where broadleaved litter predominated. The soil water content was low in areas with a thick O horizon and a high abundance...

  3. Studies on the Development of Tubularia radiata and Tubularia venusta (Hydrozoa)

    NAGAO, Zen
    The development from the egg to the young polyp of Tubularia radiata and T. venusta is described. The developmental processes of the two species coincide in principle with each other. The cleavage is total and vertical until the fourth division , but some eggs of T. venusta cleave very irregularly and a syncytium is f ormed . The blastula is a modified coeloblastula. The gastrulation takes place, at first, by multipolar proliferation or by cell divisions like an inward proliferation and a solid mass of cells is formed, then the primary germ layers are differentiated by further cell divisions like...

  4. Notes on the Morphology of an Apodous Holothurian, Scoliodotella uchidai

    OGURO, Chitaru
    The present study concerns the internal morphology and histology of an apodous holothurian, Scoliodotella uchidai. Although the followings are noticeable features in this species, the general organization is along the line of the other apodous species ; unique combination of the alimentary canal and the mesenteries, non-winding small intestine, lack of outer connective tissue layer in the alimentary canal, and only one polian vesicle and stone canal. In recent years works were only fragmental in the field of holothurian morphology (Filice, 1950 ; Millott, 1950, 1953 ; Smith, 1962), though considerable number of inclusive works were carried out on this...


  6. On Three New Species of Cumacea, Crustacea, from Akkeshi Bay

    GAMO, Sigeo
    Three new species of Cumacea, Bodotria ovalis, B. serrulata and Cumella quadrispinosa described herein, were obtained from the collection of the cumaceans made by myself at Akkeshi Bay during the 15th to 20th of August in 1963 (Fig. 1)*. Before going further I have to express my gratitude to Professor Tune Sakai for his kind guidance. I must also tender my thanks to Professor Masao Iwasa of the Seikei University and to Professor Huzio Utinomi of the Seto Marine Biological Laboratory of the Kyoto University for their invaluable advice. I want to express my heartily thanks to Professor Atsuhiko Ichikawa...

  7. The Zoological Environs of the Akkeshi Marine Biological Station (With 7 text-figures and 4 plates)

    UCHIDA, Tohru; YAMADA, Mayumi; IWATA, Fumio; OGURO, Chitaru; NAGAO, Zen
    The Akkeshi Marine Biological Station of the Hokkaido University is located in Akkeshi on the Pacific coast of the easternmost part of Hokkaido, on 43°00'N. and 144°50'E. It was founded in 1931 for the biological research of marine animals and plants at that region and its vicinity, and since that time a number of works were made in different fields of research. The main reason why this place was chosen for institution of this station lies in the fact that the station has the rich fauna and flora which are distinctly different from those of other marine biological stations as...

  8. Polycelis akkeshi, a New Freshwater Planarian, from. Hokkaido

    ICHIKAWA, Atsuhiko; KAWAKATSU, Masaharu
    In 1952, during an investigation of freshwater planarians in Hokkaidö conducted by the senior author, A. Ichikawa, several specimens of white planarian were collected in the brooklet running through the compound adjoining the Akkeshi Marine Biological Station attached to the Faculty of Science of Hokkaido University, Akkeshi-chö, in eastern Hokkaidö. An examination of the material revealed that the worms belonged to the genus Polycelis. But the presence of an extraordinarily thick muscle zone surrounding the male antrum differentiates it from Polycelis sapporo (Ijima et Kaburaki), a most common unpigmented Polycelis species in Hokkaidö. Unfortunately, in this material, none of the...

  9. The Fauna of Akkeshi Bay : XXVI. Holothuroidea (With 7 text-figures)

    OGURO, Chitaru
    The present paper is a preliminary report on the holothurian fauna of Akkeshi Bay, based on the collection in 1955-1960. The specimens collected contain 3 actinopodous and 1 apodous species, of which the apodous holothurian is referable to a new species forming a new genus. In the following will be given some ecological notes on the former 3 wellknown species and the description of a new genus and a new species. Before proceeding further, the author wishes to express his cordial thanks to Professor Tohru Uchida, under whose direction this work has been carried out, for his kind guidance and...

  10. Studies on the Comparative Embryology of Nemerteans with Special Reference to Their Interrelationships

    IWATA, Fumio
    Up to the present time the phylogeny of the nemerteans has been mainly discussed from the _morphological point of view (Bürger, 1895 ; Friedrich, 1935; Hylbom, 1957) . The most important characteristics of the nemerteans used for consideration of the problem lie in the relative position of the nervous system in the body Wall. Bürger's conception was partly revised by Bergendal (1903), Friedrich (1935) and Hylbom (1957) . The latter reported a so-called phylogenetic tree of the Palaeonemertea, in which the questionable family Cephalothricidae was placed near the bottom of the group. It has been generally accepted that the palaeonemerteans...

  11. Hydroid Fauna of Japanese and its Adjacent Waters

    YAMADA, Mayumi
    This paper is a list of the hydroid species known from Japanese and its adjacent waters, from the Sea of Okhotsk to Formosa, with the synonymy, distribution and some notes for each species. The species here treated comprise the marine and brackish forms of the Orders Athecata (Anthomedusae) and Thecata (Leptomedusae), those of which only the medusa stage is known from Japan being excluded. The freshwater forms and the Order Limnomedusae are not treated in the list. The early literature on the hydroid fauna of Japanese waters appeared about a century ago, basing on the small collections of some foreigners....

  12. The Fauna of Akkeshi Bay : XXV. Gastropoda (With Plates I-V)

    HABE, Tadashige
    In 1955, the writer reported the bivalves and a tooth shell from Akkeshi Bay and its adjacent region. This is a report on the gastropodous species from the same region in which sixty-eight species are contained, including four new genera and six new species. The molluscan fauna of this area is characterized by the elements dwelling in the cold current and none of indicators of the warm current is found. But, some of them, such as Batillaria cumingii, Mitrella bella, Littorina brevicula and Ocenebra aclunca, may be regarded as the elements of the continental coastal fauna as they widely range...

  13. Structural Complexity and Ecosystem Functions in a Natural Mixed Forest under a Single-Tree Selection Silviculture

    Yoshida, Toshiya; Naito, Sayoko; Nagumo, Misato; Hyodo, Natsumi; Inoue, Taiki; Umegane, Hiromitsu; Yamazaki, Haruka; Miya, Hisashi; Nakamura, Futoshi
    The objective of forest management has become broader, and it is essential to harmonize timber production with conservation of the forest ecosystem. Selection cutting is recognized as a major alternative of clear-cutting, because it can maintain the complexity and heterogeneity of a natural forest; however, its long-term evaluations are limited. This study compared various attributes of stand structures, which are indicators of biodiversity and ecosystem carbon stock between managed and unmanaged blocks (12.6 ha area in total) in a natural mixed forest in Hokkaido, the northernmost island of Japan. We found that 30 years' implementation of single-tree selection did not...

  14. Airborne basidiospores as an inoculum source of Typhula variabilis and the effect of hilling on the incidence of Typhula winter rot of carrots

    Ikeda, Sachiko; Hoshino, Tamotsu; Matsumoto, Naoyuki; Kondo, Norio
    Typhula winter rot on overwintering carrots caused by Typhula variabilis is a newly confirmed disease, and no practical control measure is yet available. To develop a control method, here we researched the infection period of T. variabilis and the time that winter rot appeared on carrots. Using spore traps, we found that basidiospore rain occurred from September to November before snowfall in Memuro, Hokkaido. In addition, carrot leaves collected in autumn had already been infected by T. variabilis. These epidemiological investigations revealed that the pathogen releases basidiospores to infect carrot leaves before snow cover, resulting in root decay under snow....

  15. Nemerteans from Sagami Bay (With Plates I-VII)

    Iwata, Fumio
    This report is based on the nemertean specimens which were collected by His Majesty the Emperor of Japan from eastern coasts of Sagami Bay and off Shimoda, between the tide marks or below it to the depth of 410 m, during the years from 1939 to 1956. The specimens are repre, sented by 21 species, of which 14 are new to science, including two new genera and 14 new species. Besides two new genera, a member of Drepanophorus has been first recorded from Japan. The specimens examined are all preserved in alcohol, appended with colour-films of Cerebratulus marginatus and Drepanophorus...

  16. The Fauna of Akkeshi Bay : XXIII. Enteropneusta (With 8 text-figures)

    Okuda, Shiro; Yamada, Mayumi

  17. The Fauna of Akkeshi Bay : XXII. Phoronidea (With 2 text-figures and 1 Plate)

    Uchida, Tohru; Iwata, Fumio

  18. Fauna of Akkeshi Bay : XXI. Pelecypoda and Scaphopoda (With Plates I-VII)

    Habe, Tadashige
    Here I deal with the molluscan shells collected by myself in 1949 and by the late Dr. Shiro Okuda in 1950 in the neighbourhood of Akkeshi Bay, Nemuro, Hanasaki and some other localities on the south-east coast of Hokkaido. These collections contain 54 species of bivalves and one species of tooth shell, including 4 new species which have been previously identified in error as the species of Northwest coast of America to this day. On the gastropodous molluscs, I will express in the another paper now under preparation. Before going further, I take pleasure to express my hearty thanks to...

  19. The Fauna of Akkeshi Bay : XIX. Littoral Pycnogonida (With Plates I and 11 text-figures)

    Utinomi, Huzio

  20. Development of teaching materials for international course students on the ancient forest culture of the Hokkaido University Campus

    Watanabe, Yoko; Moriya, Toyohito; Takakura, Jun; Satoh, Fuyuki; Koike, Takayoshi
    Many plant remains including pollen fossils, wooden artifacts and charred woods from Epi-Jomon culture (about 2000 years ago) to the Ainu culture period (about 400 years ago) have been excavated from the Hokkaido University Campus sites. Wood identification and pollen analysis have revealed the forest vegetation and wood utilization by ancient people, i.e., the ancient forest culture, for each era in this site. It is necessary to organize systematically the data concerning this ancient forest culture for showing an importance role of our campus as state property. Furthermore, the elucidation of the ancient forest culture is important because it can...

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