• 제목/요약/키워드: tropical Asia

검색결과 179건 처리시간 0.024초

한국-중국 북부지역에서 여름 강수량의 십년간 변동 (Interdecadal Change of Summer Rainfall in the Region of Korea and Northern China)

  • 최재원;차유미;김정윤;육일우
    • 한국지구과학회지
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    • 제38권1호
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    • pp.35-48
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    • 2017
  • 이 연구는 한국-중국 북부 지역($35^{\circ}-40^{\circ}N$, $110^{\circ}-130^{\circ}E$)에서 영역평균 된 여름(6-8월) 강수량의 증가경향이 1990년대 후반에 뚜렷하게 나타났음을 분석하였다. 따라서 한국-중국 북부지역에서 1998년 이후에 여름 강수량이 증가한 원인을 알아보기 위해 1998-2012년 평균과 1981-1997년 평균 사이에 종관환경에 대한 차를 분석하였다. 850 hPa 유선분석에서는 북태평양 지역과 호주 동쪽지역에서 거대한 고기압성 순환 아노말리가 강화되었다. 양반구에서 이러한 순환 아노말리에 의해 적도 중태평양으로부터 열대 서태평양에 편동풍 아노말리(무역풍 아노말리)가 강화되었다. 이는 라니냐 해에 나타나는 순환 패턴의 아노말리였다. 200 hPa 유선에서는 남 북태평양 모두에서 거대한 저기압성 순환 아노말리가 역시 강화되었다. 이러한 두 순환 아노말리에 의해 적도 중태평양 및 서태평양에서는 서풍의 아노말리가 강화되었다. 이는 1990년대 후반 이후 한국-중국 북부 지역에서 여름 강수량의 증가가 라니냐 패턴과 연관되었으며, 이 결과는 결국 워커 순환의 강화로 이어졌다. 또한 최근 동아시아 지역에서는 적도 서태평양과 동아시아 중위도 지역에서 상승한 기류가 아열대 서태평양지역에서 하강하는 지역 해들리 순환이 강화되었다.

아세아(亞細亞)에 있어서 흡충류감염(吸蟲類感染) 방어(防禦)를 위한 공중보건학적(公衆保健學的) 조치(措置) (Public Health Measures in Trematode Control in Asia)

  • 임한종
    • 농촌의학ㆍ지역보건
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    • 제13권1호
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    • pp.82-87
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    • 1988
  • 사람의 흡충류감염(吸蟲類感染)은 대부분(大部分) 열대(熟帶) 및 동부아세아지역(東部亞細亞地域) 여러 국가(國家)에서 발생(發生)한다. 주혈흡충증(住血吸蟲症), 간흡충증(肝吸蟲症), 태국간흡충증(泰國肝吸蟲症), 간흡충증(肝吸蟲症), 요꼬가와흡충증(吸蟲症), 이형이형흡충증(異型異型吸蟲症) 및 폐대흡충증(肺大吸蟲症)등은 어떤 일부(一部) 아세아국가(亞細亞國家)에 있어서 공중보건상(公衆保健上) 중요(重要)한 문제(間題)가 되어 있다. 이와 같은 패류매개성기생충감염(貝類媒介性寄生蟲感染)은 풍토병(風土病)을 일으키고 있다. 사람들의 생활습관은 풍토병을 일으키게될 원인이 될 뿐만 아니라 때로는 그 질병(疾病)을 유행(流行) 전파(傳播)시키는 기본적 요소가 되기도 한다. 주혈흡충을 제외한 흡충류감염은 우리가 중간숙주(中間宿主)을 먹었을때 그곳에 있었던 피낭유충(被囊幼蟲)에 의하여 감염이 이루어 진다. 식물(植物)의 생식(生殖)(간질(肝蛭), 폐대흡충(肺大吸蟲)), 게 및 가재 생식(폐흡충), 민물고기 생식(간흡충, 요꼬가와흡충, 이형이형흡충), 또는 우렁이 생식(극구흡충(棘口吸蟲)), 기타(몇가지 우연적감염(偶然的感染))등은 사람의 흡충류감염의 주 원인이 되는 것이다. 한편 주혈흡충 감염은 요염수원(汚染水源)에 접촉한 피부을 뚫고 들어온 쎌카리아 유충(幼蟲)에 노출되기 때문에 일어난다. 흡충류감염에 대하여 예방과 방어에 관한 공중보건학적 조치는 많다. 이들의 조치중에는 화학요법에 의한 감염원을 감소시키는 것, 패류숙주의 박멸, 만족할만한 위생시설의 비치, 급수시설, 보건교육, 진단기술의 보급, 환경관리 및 개선 등이 포함된다. 그러나 감염자들에 대한 화학요법은 가장 빠르고 효과적인 억제방법인 것으로 나타나고 있다. 흡충류감염을 예방하는데 있어서 가장 중요한 변화는 프라지콴텔과 같은 신약의 개발이었다. 프라지콴텔은 모든 종류의 주혈흡충, 간흡충, 폐흡충 및 여러가지 장내기생 흡충류등 사람의 병원성흡충류에 대한 치료제로서 가장 좋은 특효약이다. 흡충류감염이 중요한 보건문제가 되어 있는 곳에서는 그 예방과 억제책에 있어서 장단기계획(長短期計劃)을 수립하는 것이 좋을 것 같다. 단기는 집단화학요법을 조기에 실시하여야 하고 자기는 "비특이성 기구"로써, 예를들면 위생시설 및 급수시설의 설치, 보건교육등으로 감염을 감소시켜 감염유지 수준이하로 보지(保持)시키는 것이다. 이와같은 억제조치를 착실히 수행하기 위하여 많은일이 있다. 예를 들면 집단참여, 역학적 조사, 약물의 공급, 환경관리, 보건교육, 지역사회관련, 일차보건 진료와의 협조 및 재정후원등에 대하여 검토하고 연구하여야 할 것이다.

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Time trend of malaria in relation to climate variability in Papua New Guinea

  • Park, Jae-Won;Cheong, Hae-Kwan;Honda, Yasushi;Ha, Mina;Kim, Ho;Kolam, Joel;Inape, Kasis;Mueller, Ivo
    • Environmental Analysis Health and Toxicology
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    • 제31권
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    • pp.3.1-3.11
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    • 2016
  • Objectives This study was conducted to describe the regional malaria incidence in relation to the geographic and climatic conditions and describe the effect of altitude on the expansion of malaria over the last decade in Papua New Guinea. Methods Malaria incidence was estimated in five provinces from 1996 to 2008 using national health surveillance data. Time trend of malaria incidence was compared with rainfall and minimum/maximum temperature. In the Eastern Highland Province, time trend of malaria incidence over the study period was stratified by altitude. Spatio-temporal pattern of malaria was analyzed. Results Nationwide, malaria incidence was stationary. Regionally, the incidence increased markedly in the highland region (292.0/100000/yr, p =0.021), and remained stationary in the other regions. Seasonality of the malaria incidence was related with rainfall. Decreasing incidence of malaria was associated with decreasing rainfall in the southern coastal region, whereas it was not evident in the northern coastal region. In the Eastern Highland Province, malaria incidence increased in areas below 1700 m, with the rate of increase being steeper at higher altitudes. Conclusions Increasing trend of malaria incidence was prominent in the highland region of Papua New Guinea, while long-term trend was dependent upon baseline level of rainfall in coastal regions.

Estimation of Design Wave Height for the Waters around the Korean Peninsula

  • Lee, Dong-Young;Jun, Ki-Cheon
    • Ocean Science Journal
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    • 제41권4호
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    • pp.245-254
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    • 2006
  • Long term wave climate of both extreme wave and operational wave height is essential for planning and designing coastal structures. Since the field wave data for the waters around Korean peninsula is not enough to provide reliable wave statistics, the wave climate information has been generated by means of long-term wave hindcasting using available meteorological data. Basic data base of hindcasted wave parameters such as significant wave height, peak period and direction has been established continuously for the period of 25 years starting from 1979 and for major 106 typhoons for the past 53 years since 1951 for each grid point of the North East Asia Regional Seas with grid size of 18 km. Wind field reanalyzed by European Center for Midrange Weather Forecasts (ECMWF) was used for the simulation of waves for the extra-tropical storms, while wind field calculated by typhoon wind model with typhoon parameters carefully analyzed using most of the available data was used for the simulation of typhoon waves. Design wave heights for the return period of 10, 20, 30, 50 and 100 years for 16 directions at each grid point have been estimated by means of extreme wave analysis using the wave simulation data. As in conventional methodsi of design criteria estimation, it is assumed that the climate is stationary and the statistics and extreme analysis using the long-term hindcasting data are used in the statistical prediction for the future. The method of extreme statistical analysis in handling the extreme vents like typhoon Maemi in 2003 was evaluated for more stable results of design wave height estimation for the return periods of 30-50 years for the cost effective construction of coastal structures.

Reports of Drawida (Oligochaeta: Moniligastridae) from far East Asia

  • Blakemore, Robert J.;Lee, Seunghan;Seo, Hong-Yul
    • Journal of Species Research
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    • 제3권2호
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    • pp.127-166
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    • 2014
  • Moniligastrids are an important yet often ignored earthworm group commonly found in cultivated soils, especially paddy, in the tropical East. Seven new taxa are: Drawida koreana austri, D. koreana nanjiro, D. koreana shindo, D. odaesan, D. jeombongsan, D. companio and D. csuzdii Blakemore spp. or sub-spp. nov. from Korea. Drawida csuzdii is the first new species from North Korea since Lumbricidae Eisenia koreana (Zicsi, 1972). Historical East Asian moniligastrids are reviewed chronologically and Drawida barwelli (Beddard, 1886), D. japonica (Michaelsen, 1892) and D. siemsseni Michaelsen, 1910 are compared on their museum types. These three taxa were thought similar and related to D. nepalensis Michaelsen, 1907 and its possible synonym D. burchardi Michaelsen, 1903 (priority!) and both of these to prior D. uniqua (Bourne, 1887). Indian Drawida calebi Gates, 1945 is compared to new material of D. japonica from Japan, and D. willsi Michaelsen, 1907 to the new sub-species of D. koreana Kobayashi, 1938 from Korea. Where available, mtDNA COI gene barcodes are provided to help objective determinations and a phylogram is provided with outgroup Ocnerodrilidae Eukerria saltensis (Beddard, 1895) itself found in rice paddy/irrigation. The challenge now is comparison of all early taxa in their various homelands in order to assess the genetic variability and taxonomic boundaries acceptable, especially for unpigmented D. barwelli and also for pink/grey D. japonica and blue/grey D. koreana. A checklist of moniligastrids is appended showing 22 species from China (including Hainan and Taiwan), 21 from Korea, nine from Japan and the Drawida ghilarovi Gates, 1969 species-complex from far eastern Russian (Siberia). Recent Drawida dandongensis Zhang & Sun, 2014 from Sino-Korean border is misdescribed and cannot be meaningfully compared to any other Drawidas.

Centella asiatica extract prevents visual impairment by promoting the production of rhodopsin in the retina

  • Park, Dae Won;Jeon, Hyelin;So, Rina;Kang, Se Chan
    • Nutrition Research and Practice
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    • 제14권3호
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    • pp.203-217
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    • 2020
  • BACKGROUND/OBJECTIVE: Centella asiatica, also known as Gotu kola, is a tropical medicinal plant native to Madagascar, Southeast Asia, and South Africa. It is well known to have biological activities, including wound healing, anti-inflammatory, antidiabetic, cytotoxic, and antioxidant effects. The purpose of this study was to determine the efficacy of extracts of C. asiatica against age-related eye degeneration and to examine their physiological activities. MATERIALS/METHODS: To determine the effects of CA-HE50 (C. asiatica 50% EtOH extract) on retinal pigment cells, we assessed the cytotoxicity of CoCl2 and oxidized-A2E in ARPE-19 cells and observed the protective effects of CA-HE50 against N-methyl-N-nitrosourea (MNU)-induced retinal damage in C57BL/6 mice. In particular, we measured factors related to apoptosis and anti-oxidation and the protein levels of rhodopsin/opsin. We also measured glucose uptake to characterize glucose metabolism, a major factor in cell protection. RESULTS: Induction of cytotoxicity with CoCl2 and oxidized-A2E inhibited decreases in the viability of ARPE-19 cells when CA-HE50 was administered, and promoted glucose uptake under normal conditions (P < 0.05). In addition, CA-HE50 inhibited degeneration/apoptosis of the retina in the context of MNU-induced toxicity (P < 0.05). In particular, CA-HE50 at 200 mg/kg inhibited the cleavage of pro-caspase-3 and pro-poly (ADP-ribose)-polymerase and maintained the expressions of nuclear factor erythroid 2-related factor 2 and heme oxygenase-1 similar to normal control levels. Rhodopsin/opsin expression was maintained at a higher level than in normal controls. CONCLUSION: A series of experiments confirmed that CA-HE50 was effective for inhibiting or preventing age-related eye damage/degeneration. Based on these results, we believe it is worthwhile to develop drugs or functional foods related to age-related eye degeneration using CA-HE50.

우리나라 미기록 식물: 고깔닭의장풀(Commelina benghalensis L.)과 큰닭의장풀(C. diffusa Burm. f.) (Two new records for the Korean flora: Commelina benghalensis L. and C. diffusa Burm. f. (Commelinaceae))

  • 김찬수;김수영
    • 식물분류학회지
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    • 제41권1호
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    • pp.58-65
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    • 2011
  • 우리나라 미기록 종인 닭의장풀과(Commelinaceae)의 고깔닭의장풀(Commelina benghalensis L.)과 큰닭의장풀(Commelina diffusa Burm. f.) 2종이 제주도의 저지대에서 채집되었다. 고깔닭의장풀은 불염포의 밑 부분이 합생하여 깔때기 모양을 하고 폐쇄화를 갖는다는 점에서 나머지의 다른 종들과 구분이 된다. 큰닭의장풀은 삭과가 3개의 과피편으로 되어 있고, 불염포상 총포편이 피침형이면서 심장저 또는 원저라는 점에서 나머지 다른 종들과 구분된다. 염색체수는 고깔닭의장풀이 2n = 2x = 22(2배체)이며, 염색체 크기가 1.25-2.70 ${\mu}m$로 매우 작았고, 큰닭의장풀은 2n = ca. 100 이상으로 정확한 수를 알 수 없었다. 이 종들은 지금까지는 아시아와 아프리카의 열대 및 아열대에 분포하여 우리나라보다 남쪽에만 분포하는 것으로 알려져 왔다.

Molecular phylogenetic relationship of the family Colchicaceae (Liliales)

  • Thi, Nguyen Pham Anh;Kim, Jung-Sung;Kim, Joo-Hwan
    • 한국자원식물학회:학술대회논문집
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    • 한국자원식물학회 2012년도 정기총회 및 춘계학술발표회
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    • pp.19-19
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    • 2012
  • The Colchicaceae comprising 250 species and 15-19 genera of rhizomatous or cormous perennials, the moderate sized family in Liliales, distributes widely through the temperate and tropical areas of Africa, Asia and North America. The division of two subfamilies in Colchicaceae is still unclear because of different results in previous studies. Moreover, sister taxa of this family has not been determined. In genus level, it was uncertain that whether expand circumscription of three genera of Colchicum, Gloriosa, and Wurmbea which are include Androcymbium, Littonia and Onixotis, respectively, is reasonable or not. In this study, three coding genes of atpB, matK and rbcL were analyzed to reconstruct phylogenetic relationship of Colchicaceae and both of maximum parsimony (MP) and Bayesian analysis were conducted. Among three genes, matK region was most variable and provided more parsimony-informative sites, whereas the atpB and rbcL regions were similar in the variation and number of informative characters. Monophyly of Colchicaceae was strongly supported and it was divided into two subfamilies (Wurmbeoideae and Uvulariodeae). Uvularia-Disporum clade, comprises the subfamily Uvularioideae, is a sister of the rest Colchicaceae and subsequently differentiated Burchardia was a sister within subfamily Wurmbeoideae. Burchadia was used to be supposed to be a sister of the family in the previous studies. It was clear the monophyly and phylogenetic relationship among six tribes sensu Vinnersten and Manning (2007) within the family. In addition, the expanded circumscription of three genera was also strongly supported; Colchicum-Androcymbium (BP99), Wurmbea-Onixotis (BP100), and Littonia-Gloriosa (BP100). Here, we propose a re-circumscription among taxa of Colchicaceae.

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Long-range Transport Mechanisms of Asian Dust associated with the Synoptic Weather System

  • Kim, Yoo-Keun;Lee, Hwa-Woon;Moon, Yun-Seob;Song, Sang-Keun
    • Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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    • 제10권S_4호
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    • pp.197-206
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    • 2001
  • The long-range transport mechanisms of Asian dust were analyzed based on the synoptic weather system and numerical simulation by using NCEP/NCAR reanalysis and TOMS data during the periods of 1996-2001. We classified the whole weather types of eastern Asia during spring and created the representative weather types during the yellow sand events using cluster analysis and weather charts for the last 6 years(1996~2001). These long-range transport mechanisms were related to various pressure patterns including high and low, trough and ridge, and upper-level fronts. Case studies of the yellow sand events have performed by the simulation of MM5 with meteorological elements such as the horizontal wind of u and v component, potential temperature, potential vorticity, and vertical circulation during the episodic days(2~8 March 2001). In addition, the origin of the long-range transport was examined with the estimation of backward trajectory using HYSPLIT4 Model. In this paper, we concluded that three weather types at 1000 hPa, 850 hPa, 500 hPa, and 300 hPa levels were classified respectively. The dominant features were the extending continental outflow from China to Korea at 1000 hPa and 850 hPa levels, the deep trough passage and cold advection at 500 hPa and 300 hPa levels during the yellow sand events. And also, we confirmed the existence of pola $r_tropical jets in the upper-level, the behavior of potential vorticity over Korea, the estimation of potential vorticity through vertical cross section, and the transport of yellow sand through backward trajectories.es.

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Antioxidant value and Antiproliferative Efficacy of Mitragynine and a Silane Reduced Analogue

  • Goh, Teik Beng;Yian, Koh Rhun;Mordi, Mohd Nizam;Mansor, Sharif Mahsufi
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권14호
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    • pp.5659-5665
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    • 2014
  • Background: To investigate the antioxidant value and anticancer functions of mitragynine (MTG) and its silane-reduced analogues (SRM) in vitro. Materials and Methods: MTG and SRM was analyzed for their reducing power ability, ABTS radical inhibition and 1,1-diphenyl-2-picryl hydrazylfree radicals scavenging activities. Furthermore, the antiproliferation efficacy was evaluated using MTT assay on K 562 and HCT116 cancer cell lines versus NIH/3T3 and CCD18-Co normal cell lines respectively. Results: SRM and MTG demonstrate moderate antioxidant value with ABTS assay (Trolox equivalent antioxidant capacity (TEAC): $2.25{\pm}0.02$ mmol trolox / mmol and $1.96{\pm}0.04$ mmol trolox / mmol respectively) and DPPH ($IC_{50}=3.75{\pm}0.04mg/mL$ and $IC_{50}=2.28{\pm}0.02mg/mL$ respectively). Both MTG and SRM demonstrate equal potency ($IC_{50}=25.20{\pm}1.53$ and $IC_{50}=22.19{\pm}1.06$ respectively) towards K 562 cell lines, comparable to control, betulinic acid (BA) ($IC_{50}24.40{\pm}1.26$). Both compounds showed concentration-dependent cytototoxicity effects and exert profound antiproliferative efficacy at concentration > $100{\mu}M$ towards HCT 116 and K 562 cancer cell lines, comparable to those of BA and 5-FU (5-Fluorouracil). Furthermore, both MTG and SRM exhibit high selectivity towards HCT 116 cell lines with selective indexes of 3.14 and 2.93 respectively compared to 5-FU (SI=0.60). Conclusions: These findings revealed that the medicinal and nutitional values of mitragynine obtained from ketum leaves that growth in tropical forest of Southeast Asia and its analogues does not limited to analgesic properties but could be promising antioxidant and anticancer or chemopreventive compounds.