• 제목/요약/키워드: Madagascar

검색결과 20건 처리시간 0.028초

아프리카 마다가스카르산 석류석에 대한 보석광물학적 연구 (Gemological Studies on Garnet from Madagascar, Africa)

  • 김수현;장윤득;김종랑;김정진;김종근
    • 한국광물학회지
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    • 제21권1호
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    • pp.17-26
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    • 2008
  • 마다가스카르산 석류석은 편마암 내 변성광물로 산출되며 색상과 구성성분으로 로돌라이트, 자색 알만딘, 갈색 알만딘 세 그룹으로 분류할 수 있다. 자외선-가시광선 분광분석 결과, 로돌라이트와 자색 알만딘은 400, 428, 504, 521 및 572 nm 부근에서 강한 흡수피크를 보이는데 반해 갈색 알만딘은 433과 502 nm에서 주 흡수피크를 보였다. 적외선 분광분석 결과, $620{\sim}660\;cm^{-1}$ 영역에서 로돌라이트는 $640^{-1}$의 강한 단일 흡수피크가 관찰된 반면 갈색 알만딘은 $628\;cm^{-1}$$651\;cm^{-1}$ 두 개의 강한 흡수피크가 관찰되었고, 자색 알만딘은 $635\;cm^{-1}$$653\;cm^{-1}$에서 두개의 흡수피크가 약하게 관찰되었다. 알만딘에서 발견되지 않은 $3552\;cm^{-1}$ 특징적인 흡수피크가 로돌라이트에서는 관찰되었다. 따라서 로돌라이트와 알만딘은 비슷한 색상과 중첩된 굴절률로 인해 감별이 매우 어렵지만 자외선-가시광선 분광분석과 적외선 분광분석을 통해서는 로돌라이트와 알만딘간의 감별이 가능한 것으로 사료된다.

Transoceanic Propagation of 2011 East Japan Earthquake Tsunami

  • Choi, Byung Ho;Kim, Kyeong Ok;Min, Byung Il;Pelinovsky, Efim
    • Ocean and Polar Research
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    • 제36권3호
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    • pp.225-234
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    • 2014
  • The 2011 Tohoku earthquake triggered extremely destructive tsunami waves which propagated over the Pacific Ocean, Atlantic Ocean through Drake Passage and Indian Ocean respectively. A total of 10 tide-gauge records collected from the UNESCO/IOC site were analyzed through a band-pass digital filtering device to examine the observed tsunami characteristics. The ray tracing method and finite-difference model with GEBCO 30 arc second bathymetry were also applied to compare the travel times of the Tohoku-originated tsunami, particularly at Rodrigues in the Indian Ocean and King Edward Point in the Atlantic Ocean with observation-based estimates. At both locations the finite-difference model produced the shortest arrival times, while the ray method produced the longest arrival times. Values of the travel time difference however appear to be within tolerable ranges, considering the propagation distance of the tsunami waves. The observed tsunami at Rodrigues, Mauritius in the west of the Madagascar was found to take a clockwise travel path around Australia and New Zealand, while the observed tsunami at King Edward Point in the southern Atlantic Ocean was found to traverse the Pacific Ocean and then passed into the Atlantic Ocean through the Drake Strait. The formation of icebergs captured by satellite images in Sulzberger in the Antarctica also supports the long-range propagation of the Tohoku-originated tsunami.

Comparison of Adventitious Shoot Formation in Petiole Explant Cultures of 20 Cultivars of Catharanthus roseus

  • Lee, Soo-Young;Park, Pil-Son;Chung, Hwa-Jee;In, Dong-Soo;Park, Dong-Woog;Jang R. Liu
    • Journal of Plant Biotechnology
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    • 제5권1호
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    • pp.59-61
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    • 2003
  • Petiole explants from 20 cultivars of Catharanthus roseus were cultured on various shoot-inducing media to assess their competence for adventitious shoot formation. After eight weeks of culture on Murashige and Skoog' s medium supplemented with 4.4 $\mu\textrm{m}$6-benzyladenine and 0.5 $\mu\textrm{m}$ $\alpha$-naphthaleneacetic acid, petiole explants from 'Cooler Icy Pink' exhibited the greatest frequency of adventitious shoot formation at 40%, which was followed by 'Little Bright Eye'. By comparing with a previous study on assessment of competence for adventitious shoot formation in hypocotyl explant cultures of various cultures, it is indicated that the relative degree of their competence among cultivars varies to the organ used for the source of explant. Excised adventitious shoots were readily rooted on half-strength MS basal medium. Regenerated plantlets were successfully transplanted to potting soil and grown to maturity in a greenhouse.

AIS 데이터에 기반한 LNGC의 운항 성능 추정 시뮬레이션 연구 (A Study on the Prediction of Sailing Performance for a LNGC based on the AIS Data)

  • 유영준;김재한;서민국
    • 대한조선학회논문집
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    • 제54권4호
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    • pp.275-285
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    • 2017
  • In order to predict the sailing performance of a LNGC during actual operation, it is necessary to consider not only the information about resistance, maneuverability etc. but also the information such as sea route and sailing scenario etc., comprehensively. In this paper, we propose a new approach to conduct the sailing simulation of a LNGC without full scale measurement data. Latitude, longitude, sea route, speed over ground, time in UTC obtained from AIS data are substituted for the measured data. By combining the model test results, design information, and AIS data, prediction of sailing performance is conducted from the coast of southern Taiwan to the coast of Madagascar. The simulation is verified by comparing the calculated time histories of RPM and power with those of measured RPM and power.

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.

Awareness of Breast Cancer Risk among Female University Students from 24 Low, Middle Income and Emerging Economy Countries

  • Peltzer, Karl;Pengpid, Supa
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권18호
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    • pp.7875-7878
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    • 2014
  • Background: The aim of this study was to investigate the awareness of breast cancer risk factors among female university students in 24 low, middle income and emerging economy countries. A cross-sectional survey was conducted with 10,242 undergraduate university students (mean age 20.7, SD=2.9) from 25 universities in 24 countries across Asia, Africa and the Americas. Using anonymous questionnaires the awareness of links between breast cancer and heredity, diet, overweight, exercise, alcohol use, smoking and stress was assessed. Results indicated that 35.4% of the women were not aware that any of these risk factors could influence breast cancer, 43.8% were aware of a genetic link, and only 12.5%, 10.9% and 10.6% correctly identified alcohol use, overweight and physical inactivity, respectively, as factors causing breast cancer. Moreover, 13.3% rated dietary fat and 11.5% fibre as influencing breast cancer; both low-fat and high-fibre diets may be weakly protective against breast cancer, and smoking (19.4%) and stress (13.5%), the most commonly chosen breast cancer lifestyle risk factors, have less clear impact on breast cancer. There were marked country differences, e.g., in regards of being aware of genetic causes of breast cancer risk in female students from Ivory Coast, India, Madagascar, Nigeria and Laos below 30% and female students from Pakistan, Singapore, Turkey, Grenada and Philippines 60 or more percent. This study provides insight in the breast cancer risk perception of young women, which can be utilized in breast cancer awareness and prevention programmes.

베릴륨 확산 처리 된 마다가스카르산 사파이어의 분광특성분석 (Spectroscopic Characteristics of Sapphire from Madagascar Diffused with Beryllium)

  • 정순희;안용길;서진교;박종완
    • 한국광물학회지
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    • 제22권2호
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    • pp.87-95
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    • 2009
  • 마다가스카르산 사파이어를 수평 알루미나 튜브의 전기로에서 대기중의 산화분위기 하에 $1650^{\circ}C$, 50시간의 조건으로 $Be^{2+}$의 확산 처리를 하였다. 자외선-가시광선 분광분석 결과는 각 시료 마다 차이는 있으나 전체적으로 $Fe^{2+}$에서 $Fe^{3+}$로 산화의 원인으로 청색이 옅어졌고 청자색 사파이어는 $Cr^{3+}$에 의한 분홍색이 나타났다. $Be^{2+}$의 확산 처리로 부분적인 갈색이 나타난 청색 사파이어에서는 진한 주황색 부분이 나타났고, 옥화메틸렌에 의한 침적실험 관찰 결과로 시료들의 가장자리에 주황색의 집중현상이 나타났음을 확인하였다. 또한 기존에 있던 내포물도 변화가 나타났다. 그러나 확산 처리 온도의 한계로 더 많은 양의 $Be^{2+}$의 확산이 이루어 지지는 못했다.

The Endophyte Curtobacterium flaccumfaciens Reduces Symptoms Caused by Xylella fastidiosa in Catharanthus roseus

  • Lacava, Paulo Teixeira;Li, Wenbin;Araujo, Welington Luiz;Azevedo, Joao Lucio;Hartung, John Stephen
    • Journal of Microbiology
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    • 제45권5호
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    • pp.388-393
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    • 2007
  • Citrus variegated chlorosis (CVC) is a disease of the sweet orange [Citrus sinensis (L.)], which is caused by Xylella fastidiosa subsp. pauca, a phytopathogenic bacterium that has been shown to infect all sweet orange cultivars. Sweet orange trees have been occasionally observed to be infected by Xylella fastidiosa without evidencing severe disease symptoms, whereas other trees in the same grove may exhibit severe disease symptoms. The principal endophytic bacterial species isolated from such CVC-asymptomatic citrus plants is Curtobacterium flaccumfaciens. The Madagascar periwinkle [Citrus sinensis (L.)] is a model plant which has been used to study X. fastidiosa in greenhouse environments. In order to characterize the interactions of X. fastidiosa and C. flaccumfaciens, periwinkle plants were inoculated separately with C. flaccumfaciens, X. fastidiosa, and both bacteria together. The number of flowers produced by the plants, the heights of the plants, and the exhibited disease symptoms were evaluated. PCR-primers for C. flaccumfaciens were designed in order to verify the presence of this endophytic bacterium in plant tissue, and to complement an existing assay for X. fastidiosa. These primers were capable of detecting C. flaccumfaciens in the periwinkle in the presence of X. fastidiosa. X. fastidiosa induced stunting and reduced the number of flowers produced by the periwinkle. When C. flaccumfaciens was inoculated together with X. fastidiosa, no stunting was observed. The number of flowers produced by our doubly- inoculated plants was an intermediate between the number produced by the plants inoculated with either of the bacteria separately. Our data indicate that C. flaccumfaciens interacted with X. fastidiosa in C. roseus, and reduced the severity of the disease symptoms induced by X. fastidiosa. Periwinkle is considered to be an excellent experimental system by which the interaction of C. flaccumfaciens and other endophytic bacteria with X. fastidiosa can be studied.

이익공유를 고려한 유전자원 이용 사업 투자 의사결정 분석 (Analysis on the Investment in the Project using the Genetic Resources Considering the Benefit Sharing)

  • 홍원경;장희선;박호정
    • 자원ㆍ환경경제연구
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    • 제28권1호
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    • pp.95-120
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    • 2019
  • 나고야의정서의 발효로 유전자원을 이용하려는 기업들은 유전자원 이용 이익 공유방안을 제공국과 협상을 통해 결정해야 할뿐만 아니라 유전자원 이용 사업 자체에 대한 투자 의사를 결정해야 한다. 본 연구에서는 유전자원의 이용으로 인한 이익의 공유방안을 샤플리 밸류와 매출액 기준 일정 비율에 의한 방법을 통해 기업의 수익구조에 반영한 후 실물옵션기법을 이용해 유전자원 이용 프로젝트에 대한 경제성을 분석하였다. 그 결과 이익공유 비율과 할인율, 그리고 유전자원의 상품화 시기가 상기 두 분석 방법에 따른 투자임계가격의 순위에 영향을 미치는 것으로 나타났다. 협상을 통해 이익공유 방안에 대해 상호합의된 조건을 도출해야 하는 기업에게는 이와 같은 다양한 방법에 의한 접근과 분석이 협상 시 유용한 참고자료가 될 것이다.

선인장 및 다육식물 혼합식재 실태 및 광과 수분요구에 따른 식물의 분류 (Plant Grouping by Light and Watering of Cacti and Succulents Planting in a Pot and Its Current Situation)

  • 송천영;이상덕;임성희;김순재;이정식
    • 현장농수산연구지
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    • 제8권1호
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    • pp.30-42
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    • 2006
  • 합식에 주로 이용되는 선인장 종류는 용신목, 비모란, 백운각, 금황환, 소정, 방희환, 황금사, 환락, 희망환, 옹옥 및 노락 등 11개 정도 이고, 다육식물 종류로는 당인, 아악무, 성을녀, 금황성, 흑법사, 에케베리아 라우이, 파키포디움 라메리, 홍옥, 불야성 및 대봉각 등 10개 식물이었다. 선인장 비모란은 파라구아이, 용신목, 백운각, 황금사, 희망환 및 옹옥은 멕시코, 금황환과 소정은 브라질 남부, 환락과 노락은 페루가 원산지이고, 다육식물 중에서 당인, 아악무, 성을녀, 불야성 및 대봉각은 남아프리카, 금황성, 에케베리아 라우이, 홍옥 등은 멕시코, 흑법사는 그랜 캐나리아, 파키포디움 라메리는 마다가스카가 원산지였다. 대부분 선인장 및 다육식물은 무차광 또는 약간의 차광하에서도 잘 자라고, 홍옥과 아악무 등의 다육식물은 광도에 민감하지 않아서 광도에 가리지 않고 잘 자라는 것으로 조사되었다. 그러나 대부분 선인장 및 다육식물은 소량 및 보통관수를 요구하였다. 이와 같이 원산지와 생육조건인 수분과 광의 양이 다른 선인장 및 다육식물을 한 화분에 심어서 관리함으로서 발생되는 문제는 일부 식물이 적응하지 못하고 고사한다는 것이다. 따라서 식물의 수분 요구 및 광 등의 생리가 유사한 식물을 모아 심으면 고사율이 현저히 감소할 것으로 판단한다.