• Title/Summary/Keyword: Madagascar

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

  • Kim, Su-Hyun;Jang, Yun-Deuk;Kim, Jong-Rang;Kim, Jeong-Jin;Kim, Jong-Gun
    • Journal of the Mineralogical Society of Korea
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    • v.21 no.1
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    • pp.17-26
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    • 2008
  • The Madagascar garnets wear mainly found as a porphyroblast in gneiss and classified into rhodolite, purple almandine, and brown almandine based on compositional characteristics and color. UV-visible analysis strong absorption bands, 400, 428, 504, 521, and 572 nm, were observed for rhodolite and purple almandine, and main absorption bands of 433 and 502 nm observed for brown almandine. For FT-IR analysis a strong absorption band of $640\;cm^{-1}$ was observed for rhodolite, two strong bands of 628 and $651\;cm^{-1}$ observed for brown almandine, and two weak absorption bands of 635 and $653\;cm^{-1}$ observed for purple almandine. Single distinct absorption band, $3552\;cm^{-1}$, was observed only for rhodolite. It is possible to distinguish rhodolite from purple or brown almandine by considering overall characteristics of the rhodolite such as color, RI, UV-visible absorption, FTIR absorption etc.

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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    • v.36 no.3
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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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    • v.5 no.1
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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.

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

  • You, Youngjun;Kim, Jaehan;Seo, Min-Guk
    • Journal of the Society of Naval Architects of Korea
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    • v.54 no.4
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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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    • v.14 no.3
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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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    • v.15 no.18
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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.

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

  • Jung, Soon-Hee;Ahn, Yong-Kil;Seo, Jin-Gyo;Park, Jong-Wan
    • Journal of the Mineralogical Society of Korea
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    • v.22 no.2
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    • pp.87-95
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    • 2009
  • The spectroscopic characteristics of the diffusion of beryllium into sapphire are investigated by UV-Vis and FTIR spectroscopy. The $Be^{2+}$ diffused samples are observed in an immersion filled with methylene iodide. The blue colors were fainteddue tochanges of iron's electrovalence ($Fe^{2+}$${\rightarrow}$$Fe^{3+}$) after heat treatment in an oxidation atmosphere and the pink color appeared due to $Cr^{3+}$ in case of violet sapphire. The blue sapphire containing light brown showed yellow orange color due to reaction of beryllium with trace elements during the beryllium diffusion. From analysis of immersion filled with methylene iodide, we could demonstrate to show yellow orange with concentrated color in the rim of samples. Also, there were some changes to the pre-existed inclusions.

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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    • v.45 no.5
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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.

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

  • Hong, Wonkyung;Jang, Heesun;Park, Hojeong
    • Environmental and Resource Economics Review
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    • v.28 no.1
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    • pp.95-120
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    • 2019
  • As the Nagoya Protocol has been in effect since 2014, firms that invest in projects related with the genetic resources should establish methods to share the benefits arising from using genetic resources with the country providing such resources. The objective of this paper is to investigate the factors that affect the genetic resources related investment decisions under the Nagoya Protocol. Specifically, we construct the model of Sharpley value and benefit sharing rate in order to consider the results of benefit sharing with a providing country under the Real Options, and simulate the model in the context of Madagascar Banana project. The results show that the product time to market, benefit sharing rate, and discount rate significantly influence the investment decisions.

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

  • Song, C.Y;Lee, S.D.;Lim, S.H.;Kim, S.J.;Lee, J.S.
    • Journal of Practical Agriculture & Fisheries Research
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    • v.8 no.1
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    • pp.30-42
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    • 2006
  • This experiment was conducted to investigate current situation and plant grouping by light and watering of mingled several cacti and succulents in a pot. The main 11 cacti are consist of Myrtillocactus geometrizans (Mart.) Cons., Gymnocalycium mihanovichii var. friedrichii Werd., Marginatocereus marginatus(DC.) Backbg., Eriocactus leninghausii (Hge. Jr.) Backbg, Notocactus scopa (Spreng.) Berg., Lobivia nealeana Backbg., Mammillaria elongata var. intertexta (DC.) SD., Pseudoespostoa (Vp1.) Backbg., Mammillaria albilanata Backbg., Mammillaria klissingiana Bod. and Espostoa lanata (HBK.) Br. & R. The main 10 succulents are Kalanchoe thyrsifolia Harv., Portulacaria afra var. foliis-variegatis Jacobs., Crassula perforata Thunbg., Echeveria pulvinata Rose, Aeonium arboreum cv. atropurpureum., Echeveria lauii Moran & J. Meyran, Pachypodium lamerei Drake, Sedum rubrotinctum cv. Aurora Boom., Aloe mitriformis Mill., and Euphorbia coerulescens Haw. The cacti were native to Mexico, Brazil, Peru, Paraguay, Ecuador, etc. The sucullents were native to Mexico, Africa, Gran Canaria, Madagascar, etc. Most of all the cacti and sucullents in the experiment are growing well under full sun or light shade, however Portulacaria afra var. foliis-variegatis Jacobs, and Sedum rubrotinctum cv. Aurora Boom. did not influenced by light. And all the plants require a little or moderate watering. Thus, planting by similar required water and light, when growing in a pot of several cacti and succulents, might be decreased the rate of death causing by their different plant physiology.