• Title/Summary/Keyword: Nagasaki

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Floristics of bryophytes in Dongbaek-dongsan at Seonheul Gotjawal (선흘 곶자왈 동백동산의 선태식물상 연구)

  • Yim, Eun-Young;Moon, Myung-Ok;Sun, Byung-Yun;Nakanishi, Kozue
    • Korean Journal of Plant Taxonomy
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    • v.43 no.4
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    • pp.274-284
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    • 2013
  • This study presents a survey on the bryophytes in Dongbaek-dongsan located at Seonheul Gotjawal on the north-eastern face of Mt. Halla in Jeju Island, Korea. A total of 85 taxa belonging to the Bryophyta (22 families 44 genera 62 species), Marchantiophyta (12 families 16 genera 23 species) were found. Among them, 3 moss species, Diphyscium perminutum Takaki, Racomitrium japonicum Dozy & Molk., and Isopterygium minutirameum (M$\ddot{u}$. Hal.) A. Jaeger. were new additions to the bryophyte flora of Korea. The liverwort index was 27.0%. Predominant life-form was weft. The rates for the bryophytes dominating in mesic to hygric sites were higher than for the bryophytes mainly observed in xeric habitats. We considered that the composition and distribution of species are affected by the different environmental factors according to the evergreen broad-leaved forests, wetlands and exposed spaces. Moreover, the rocks were the substrate type that play a major role in providing the micro-habitats for bryophytes in this area. Particularly, the bryophytes of swamps in this area were very unique and various for its limited space and showed plant communities with mosaic spatial pattern, along with vascular plants. We suggest more detailed and comprehensive studies on the swamps where endemic fern Mankyua chejuense B. -Y. Sun, M. H. Kim & C. H. Kim inhabits to provide valuable information for the conservation and restoration of the species and habitats.

INFRARED SPECTRAL ENERGY DISTRIBUTION OF GALAXIES IN THE AKARI ALL SKY SURVEY: CORRELATIONS WITH GALAXY PROPERTIES AND THEIR PHYSICAL ORIGIN

  • Makiya, R.;Totani, T.;Takeuchi, T.T.;Nagashima, M.;Kobayashi, M.A.R.
    • Publications of The Korean Astronomical Society
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    • v.27 no.4
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    • pp.325-329
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    • 2012
  • We will report our recent study on the properties of more than 1,600 galaxies detected by the AKARI All-Sky Survey with physical quantities based on optical and 21-cm observations, to understand the physics determining the infrared spectral energy distribution (Totani et al., 2011). We discover a tight linear correlation for normal star-forming galaxies between the radiation field strength of dust heating (corresponding to dust temperature) and the galactic-scale infrared radiation field, $L_{TIR}/R^2$. This is the tightest correlation of dust temperature ever known, and the dispersion along the mean relation is 13% in dust temperature. This relation can be explained physically by a thin layer of heating sources embedded in a thicker, optically-thick dust screen. We also find that the number of galaxies sharply drops when galaxies become optically thin against dust-heating radiation, indicating that a feedback process to galaxy formation (e.g., by the photoelectric heating) is working when dust-heating radiation is not self-shielded on a galactic scale. We discuss implications from these findings for the $M_{H_I}$ -size relation, the Kennicutt-Schmidt relation, and galaxy formation in the cosmological context.

Comparison between Overall, Cause-specific, and Relative Survival Rates Based on Data from a Population-based Cancer Registry

  • Utada, Mai;Ohno, Yuko;Shimizu, Sachiko;Hori, Megumi;Soda, Midori
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.11
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    • pp.5681-5685
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    • 2012
  • Three kinds of survival rates are generally used depending on the purpose of the investigation: overall, cause-specific, and relative. The differences among these 3 survival rates are derived from their respective formulas; however, reports based on actual cancer registry data are few because of incomplete information and short follow-up duration recorded on cancer registration. The aim of this study was to numerically and visually compare these 3 survival rates on the basis of data from the Nagasaki Prefecture Cancer Registry. Subjects were patients diagnosed with cancer and registered in the registry between 1999 and 2003. We calculated the proportion of cause of death and 5-year survival rates. For lung, liver, or advanced stage cancers, the proportions of cancer-related death were high and the differences in survival rates were small. For prostate or early stage cancers, the proportions of death from other causes were high and the differences in survival rates were large. We concluded that the differences among the 3 survival rates increased when the proportion of death from other causes increased.

Bacterial diseases of flounder, Paralichthys olivaceus (넙치의 세균성(細菌性) 질병(疾病))

  • Kanai, Kinya
    • Journal of fish pathology
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    • v.6 no.2
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    • pp.197-204
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    • 1993
  • Flounder culture has been developed mainly in the western parts of japan, and, to date, following six bacterial diseases have been reported. Bacterial white enteritis occurs in 16 to 30-day-old flounder larvae and often causes mass mortality in seed production. Bacterium named Vibrio sp. INFL invades and multiplies in the mucosae of posterier part of intestine, and causes desquamative enteritis. Gliding bacterial disease occurs mostly in juvenile stage and in spring to summer. Diseased signs are partial discoloration and erosion of skin and fins. Histologically, epidermis are removed, and the causative bacterium, Flexibacter maritimus, multiplies on the surface of demis and invades into the muscular tissue. Vibriosis caused by Vibrio anguillarum and related organisum is one of the well-known diseases among marine fish. Outbreaks of the disease in flounder culture are relatively few, but mass mortalities in fingerlings due to the disease were reported. An outbreak of nocardiosis in the autumn of 1984 has been reported, but since then the disease scarcely occurred. The disease is characterized by formation of abscesses under the skin and white nodes in the gill, heart, spleen and kidney. Streptococcicosis occurs frequently in recent years. Beta-hemolytic streptococcus is the causative bacterium, which possesses the same biochemical and serological characteristics as $\beta$-streptococci isolated from some marine and freshwater fish, and is seemed to related to Streptococcus iniae. Edwardsiellosis is the disease that causes most damage in flounder culture in Japan. Characteristic symptoms are swelling of abdomen and intestinal protrusion from the anus due to accumulation of ascites. Edwardsiella tarda, a well-known pathogen of freshwater fish, is the causative bacterium of the disease.

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New Record of the Damselfish, Chromis fumea(Pisces : Pomacentridae) from Korea (한국산 자리돔속 어류 1 미기록종, Chromis fumea)

  • Kim, Yong-Uk;Koh, Jeong-Rak;Myoung, Jeong-Goo
    • Korean Journal of Ichthyology
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    • v.6 no.1
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    • pp.21-27
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    • 1994
  • The Damselfish, Chromis fumea, was originally described by Tanaka(1917) from Nagasaki, Japan. In the Korean waters, 27 specimens of Chromis fumea(Tanaka) were collected from Cheju-do, on April-August, 1993, and described herewith as new to the Korean fish fauna. Chromis fumea differs from Chromis notatus in having serrate preopercle, no distinctive black spot in pectoral base and caudal fin with a broad blackish band in each lobe. Yeonrnoo-ja-ri-dom is proposed as Korean name of Chromis fumea.

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Vertical and horizontal distributions of ellipsoidal Alexandrium (Dinophyceae) cysts in coastal sediment with special reference to paralytic shellfish poisoning caused by tsunamis -a case study of Osaka Bay(Japan) and the southern coast of the Korean Peninsula

  • Matsuoka, Kazumi;Yamamoto, Keigo;Akiyama, Satoshi;Kojima, Natsuhiko;Shin, Hyeon Ho
    • Korean Journal of Environmental Biology
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    • v.37 no.3
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    • pp.268-277
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    • 2019
  • Severe damages will result in human society, when several different critical natural phenomena coincide. One example relates to the resting cysts of Alexandrium species (dinoflagellates that cause paralytic shellfish poisoning), which are preserved in surface sediments throughout Osaka Bay, Japan. These cysts have been found to accumulate particularly densely in shallow areas in the inner parts of Osaka Bay, where a tsunami caused by an earthquake could occur any time. Damage by a tsunami could cause a change of the coastal ecosystems at Osaka Bay including the resuspension of surface sediments containing resting Alexandrium tamarense cysts and the subsequent redistribution of the cysts in newly deposited sediment. Under certain environmental conditions, these cysts could germinate and form dense blooms, leading to paralytic shellfish poisoning. Such a scenario could also affect other coastal areas, including the southern coast of the Korean Peninsula.

Dynamic characteristics of cable vibrations in a steel cable-stayed bridge using nonlinear enhanced MECS approach

  • Wu, Qingxiong;Takahashi, Kazuo;Chen, Baochun
    • Structural Engineering and Mechanics
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    • v.30 no.1
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    • pp.37-66
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    • 2008
  • This paper focuses on the nonlinear vibrations of stay cables and evaluates the dynamic characteristics of stay cables by using the nonlinear enhanced MECS approach and the approximate approach. The nonlinear enhanced MECS approach is that both the girder-tower vibrations and the cable vibrations including parametric cable vibrations are simultaneously considered in the numerical analysis of cable-stayed bridges. Cable finite element method is used to simulate the responses including the parametric vibrations of stay cables. The approximate approach is based on the assumption that cable vibrations have a small effect on girder-tower vibrations, and analyzes the local cable vibrations after obtaining the girder-tower responses. Under the periodic excitations or the moderate ground motion, the differences of the responses of stay cables between these two approaches are evaluated in detail. The effect of cable vibrations on the girder and towers are also discussed. As a result, the dynamic characteristics of the parametric vibrations in stay cables can be evaluated by using the approximate approach or the nonlinear enhanced MECS approach. Since the different axial force fluctuant of stay cables in both ends of one girder causes the difference response values between two approach, it had better use the nonlinear enhanced MECS approach to perform the dynamic analyses of cable-stayed bridges.

Optimal Design Considerations of a Bus Converter for On-Board Distributed Power Systems

  • Abe, Seiya;Hirokawa, Masahiko;Shoyama, Masahito;Ninomiya, Tamotsu
    • Journal of Power Electronics
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    • v.9 no.3
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    • pp.447-455
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    • 2009
  • The power supply systems, which require low-voltage / high-current output has been changing from the conventional centralized power system to a distributed power system. The distributed power system consists of a bus converter and POL. The most important factor is the system stability in bus architecture design. The overlap between the output impedance of a bus converter input impedance of POL causes system instability and has been an actual problem. By increasing the bus capacitor, the system stability can be easily improved. However, due to limited space on the system board, the increasing of bus capacitors is impractical. An urgent solution of this issue is strongly desired. This paper presents the output impedance design for on-board distributed power system by means of three control schemes of a bus converter. The output impedance peak of the bus converter and the input impedance of the POL are analyzed and then conformed experimentally for stability criterion. Furthermore, the design process of each control schemes for system stability is proposed.

A DISCUSSION ON THE MAIN REASONS CAUSING THE MASS MORTALITY OF CORALS AND BENTHOS IN CONDAO ISLAND DURING OCTOBER 2005.

  • Son, Tong Phuoc Hoang;Khin, Lau Va;Ben, Hoang Xuan;Knee, Tan Chun;Ishizaka, Joji;Ransibrahmanakul, Varis;Tripathy, Sarat Chandra
    • Proceedings of the KSRS Conference
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    • v.1
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    • pp.463-466
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    • 2006
  • During Mid October of 2005 a mass mortality of the corals occurred surrounding Con Dao Islands (South Vietnam) where is the recognized as one of the most famous marine parks of Vietnam. Results from the field survey in October 2005 showed that the mass mortality of corals and benthos focused only on the North-West of the islands whereas there was almost no death recorded in the South - East parts. Based on field data it was assumed that an overlap between high water temperature ($>30^{\circ}C$) and low salinity (<25%o) during short term was the impact causing the situation. In this paper, we try to explain this phenomenon based on the hydrographical view together with analyzing ocean colour images. A coral bleaching warning system also is proposed for Condao site.

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Fatigue Strength Evaluation of Rusting Decayed Hull Steel Plate in Air and in Artificial Seawater Condition (선체의 부식쇠모강판의 대기중 및 해수중 피로강도평가에 관한 연구)

  • Kim, Won-Beom;Paik, Jeom-Kee;Iwata, Mitsumasa;Yajima, Hiroshi
    • Journal of the Society of Naval Architects of Korea
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    • v.43 no.4 s.148
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    • pp.467-475
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    • 2006
  • Fatigue strength of hull structural steel plate, extracted from longitudinal bulkhead of a 17-year-old ore/oil carrier for renewal, was investigated in air and in artificial seawater condition. The surface of the plate was covered with corrosion pits and they proved to be crack initiation sites by fractography using SEM. From this research, it was found that the evaluation method for fatigue strength of virgin mild steel plates in air and in artificial seawater can also be applied to the evaluation of the fatigue strength of mild steel plates those were long-term exposed to a corrosive environment and their surfaces had been rusted intensively.