• Title/Summary/Keyword: Damage characteristics

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Estimation of the Moisture Maximizing Rate based on the Moisture Inflow Direction : A Case Study of Typhoon Rusa in Gangneung Region (수분유입방향을 고려한 강릉지역 태풍 루사의 수분최대화비 산정)

  • Kim, Moon-Hyun;Jung, Il-Won;Im, Eun-Soon;Kwon, Won-Tae
    • Journal of Korea Water Resources Association
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    • v.40 no.9
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    • pp.697-707
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    • 2007
  • In this study, we estimated the PMP(Probable Maximum Precipitation) and its transition in case of the typhoon Rusa which happened the biggest damage of all typhoons in the Korea. Specially, we analysed the moisture maximizing rate under the consideration of meteorological condition based on the orographic property when it hits in Gangneung region. The PMP is calculated by the rate of the maximum persisting 12 hours 1000 hPa dew points and representative persisting 12 hours 1000 hPa dew point. The former is influenced by the moisture inflow regions. These regions are determined by the surface wind direction, 850 hPa moisture flux and streamline, which are the critically different aspects compared to that of previous study. The latter is calculated using statistics program (FARD2002) provided by NIDP(National Institute for Disaster Prevention). In this program, the dew point is calculated by reappearance period 50-year frequency analysis from 5% of the level of significant when probability distribution type is applied extreme type I (Gumbel distribution) and parameter estimation method is used the Moment method. So this study indicated for small basin$(3.76km^2)$ the difference the PMP through new method and through existing result of established storm transposition and DAD(Depth-Area-Duration). Consequently, the moisture maximizing rate is calculated in the moisture inflow regions determined by meteorological fields is higher $0.20{\sim}0.40$ range than that of previous study. And the precipitation is increased $16{\sim}31%$ when this rate is applied for calculation.

The Occurrence of Rice Leaf-folder, Cnaphalocrocis medinalis (Lepidoptera : Crambidae) in Suwon and its Responses to Insecticides (혹명나방 개체군의 수원지역 발생 패턴 및 몇가지 약제에 대한 반응)

  • Park, Hong-Hyun;Cho, Jum-Rae;Park, Chang-Gyu;Kim, Kwang-Ho;Goh, Hyun-Gwan;Lee, Sang-Guei
    • Korean journal of applied entomology
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    • v.49 no.3
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    • pp.219-226
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    • 2010
  • This paper presents the occurrence and damage characteristics of the rice leaf-folder populations in the paddy fields of Dangsu-dong, Suwon from 2004 to 2007, and also reports the insecticide response of rice leaf-folder populations, which were collected from 2005 to 2006 in Korea and Vietnam. Laboratory measurements of the head capsule width and body length data enabled the identification of the rice leaf-folder larva stages collected in the field. The rice leaf-folder population in Suwon from 2004 to 2007 has a clear pattern consisting of two different group: the low and high density years. During the low density years (2004 and 2006), only one adult peak was noted in late August, with the damaged-hill percent less than 10% in late July, and the damaged-leaf percent around 2% in September. In contrast, during the high density years (2005 and 2007), two adult peaks were noted in early August and mid-September, with the damaged-hill percent was around 30% in late July, and the damaged-leaf percent 15 to 30% in September, which was beyond the economic injury level of rice leaf-folder. High correlations existed between the occurrence of rice leaf-folder in late July and early August and damages to rice during September. Based on these results, we suggest that the information on the rice leaf-folder population monitored by the adult density or damaged-hill percent in late July and early August would be very useful for predicting the damages later in the season for aiding in decision-making for timely control. In addition, the regional populations of rice leaf-folder showed the similar responses to the insecticides tested: high susceptibility to IGRs (tebufenozide and methoxyfenozide) and organophosphates (chlorpyrifos-methyl, pyridaphenthion), but relatively low to cartap.

Phenology and Population Dynamics of Scirpus fluviatilis (Torr.) A. Gray in the Littoral Zone of the Upo Wetland (우포늪 연안대에서 매자기의 화력학과 개체군 변화)

  • Seo, Hye-Ran;Park, Sang-Yong;Oh, Kyung-Hwan
    • Journal of Wetlands Research
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    • v.11 no.3
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    • pp.49-59
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    • 2009
  • Seasonal changes of the growth characteristics and biomass of Scirpus fluviatilis, a aquatic emergent vascular plant, were investigated to reveal the phenology and the population dynamics and to provide the fundamental resources for the restoration counterplan of the wetland vegetation in the littoral zone of the Upo wetland, Changnyeong-gun, Gyeongsangnam-do, Korea from March 2006 to November 2006. Scirpus fluviatilis was distributed commonly in Upo, Mokpo, Sajipo, Jokjibyeol, and Topyeongcheon upstream and downstream of Upo wetland, and the density was highest in Mokpo. Distribution range for the water depth was 9~49cm, and the highest shoot density in 26~49cm, and the mean shoot density was $119/m^2$, and the mean shoot length was 122.3cm on May 28. The number of the tuber was $104.5/0.25m^2$, and the living tubers were 84.2%. The mean fresh biomass of the living tubers was 3.0g, and those of 1~4g was most as 57.9%. Germination rates of the living tubers was 43.8%, and the maximum rate was in 7~9g and more than 10g. In the pot cultivation, the shoot density of the germinated tubers and the dormant tubers were highest as 13.5 and 9.7, respectively in early August. In the field study, the shoot density had few change before typhoon damage, while the density increased abruptly in November after flooding accompanied with the typhoon 'Ewiniar'. The shoot length in the pot cultivation and in the field study were 100~116cm and 60~170cm, respectively in the growth-end. Biomass allocation rates into the stem, leaf, flower, and underground parts were 8.9%, 6.6%, 0%, and 84.5%, respectively in the pot cultivation of the germinated tubers, and those of the dormant tubers were 7.1%, 7.1%, 0%, and 85.8%, respectively. The tuber number increased to 1.4~4.1 times by the growth-end, so it is concluded that Scirpus fluviatilis is mostly propagated by the vegetative reproduction.

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Soil Characteristics of the Saprolite Piled Upland Fields at Highland in Gangwon Province (강원도 고랭지의 석비레 성토지 토양 특성)

  • Park, Chol-Soo;Jung, Yeong-Sang;Joo, Jin-Ho;Yang, Jae-E
    • Korean Journal of Soil Science and Fertilizer
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    • v.37 no.2
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    • pp.66-73
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    • 2004
  • As one of the typical farming practices in the sloped upland in Pyeongchang and Hongcheon area, application of piling with coarse saprolite materials has been practiced by farmers for several reasons such as reduction of damage by monocropping, better development of plant roots, and better drainage. However, adverse effect on application of coarse saprolite soil materials to environmental aspects should not be ignored. Therefore, this research was conducted to evaluate the physicochemical properties of coarse saprolite materials in upland fields in Pyeongchang area. According to particle size distribution of coarse saprolite materials, averaged gravel contents for Pyeongchang and Hongcheon county were 16.7 and 25.3%, respectively. There was no significant difference in gravel contents by soil depth, and CV values for each particle size ranged from 20 to 40%, which implied that application of coarse material with similar properties. When we compared CEC values of dressed soil with or without considering gravel content, CEC values decreased as increasing gravel contents. The penetration resistances were 0.04-7.48 MPa at the 0 to 10 cm surface soil, and 0.10 to 8.80 MPa at the depth below 11 cm. The bulk density of the soil was $1.15g\;cm^{-3}$ at the surface soil and 1.29 to $1.35g\;cm^{-3}$ at the soil depth below 10 cm. The organic matter content, cation exchange capacity, and avaliable $P_2O_5$ concentrations of soil in upland where piling with saprolite materials of Pyeongchang area applied were $12.4g\;kg^{-1}$, $7.1cmol_c\;kg^{-1}$, and $526mg\;kg^{-1}$, respectively. Cation exchange capacity was lower than that of averaged Korean upland soil, while available $P_2O_5$ concentration was relatively higher than that of averaged Korean upland, which indicated high input of various fertilizers.

Effect of Silicate-Coated Rice Seed on Healthy Seedling Development and Bakanae Disease Reduction when Raising Rice in Seed Boxes (벼 상자육묘에서 규산코팅볍씨의 건묘육성과 벼키다리병 경감효과)

  • Kang, Yang-Soon;Kim, Wan Jung;Roh, Jae-Hwan
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.62 no.1
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    • pp.1-8
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    • 2017
  • We investigated the effect of silicate coating of rice seeds on bakanae disease incidence and the quality of seedlings raised in seedling boxes and transplanted into pots. The silicate-coated rice seed (SCS) was prepared as follows. Naturally infested rice seeds not previously subjected to any fungicidal treatment were dressed with a mixture of 25% silicic acid at pH 11 and 300-mesh zeolite powder at a ratio of 50 g dry seed - 9 mL silicic acid - 25 g zeolite powder. The following nursery conditions were provided : Early sowing, dense seeding in a glass house with mulching overnight and no artificial heating, which were the ideal conditions for determining the effect on the seed. The nursery plants were evaluated for Gibberella. fujikuroi infection or to determine the recovery to normal growth of infected nursery plants in the Wagner pot. Seedlings emerged 2-3 days earlier for the SCS than they did for the non-SCS control, while damping-off and bakanae disease incidence were remarkably reduced. Specifically, bakanae disease incidence in the SCS was limited to only 7.8% for 80 days after sowing, as compared to 91.6% of the non-SCS control. For the 45-days-old SCS nursery seedlings, the fresh weight was increased by 11% and was two times heavier, with only mild damage compared to that observed for non-SCS. Even after transplanting, SCS treatment contributed to a lower incidence of further infections and possibly to recovery of the seedlings to normal growth as compared to that observed in symptomatic plants in the pot. The active pathogenic macro-conidia and micro-conidia were considerably lower in the soil, root, and seedling sheath base of the SCS. In particular, the underdeveloped macro-conidia with straight oblong shape without intact septum were isolated in the SCS ; this phenotype is likely to be at a comparative etiological disadvantage when compared to that of typical active macro-conidia, which are slightly sickle-shaped with 3-7 intact septa. A active intact conidia with high inoculum potential were rarely observed in the tissue of the seedlings treated only in the SCS. We propose that promising result was likely achieved via inhibition of the development of intact pathogenic conidia, in concert with the aerobic, acidic conditions induced by the physiochemical characteristics associated with the air porosity of zeolite, alkalinity of silicate and the seed husk as a carbon source. In addition, the resistance of the healthy plants to pathogenic conidia was also important factor.

Ultrasonic Properties on Building Stones, Characteristics of Structural Deformation and Conservation States of the Sanctuary in Wat Phou Temple of Champasak, Lao PDR (라오스 밧푸 주사원의 보존현황과 석재의 초음파 물성 및 구조적 변형특성)

  • Lee, Chan Hee;Shin, Hyo Cheol;Han, Doo Roo
    • Journal of Conservation Science
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    • v.33 no.6
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    • pp.399-416
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    • 2017
  • The 'Wat Phou and Associated Ancient Settlements within the Champasak Cultural Landscape' of Laos was designated as a UNESCO World Cultural Heritage in 2001. The uppermost structure of the Sanctuary in Wat Phou has been destroyed and being variably damaged, maintenance is required through scientific and systematic diagnosis. The Sanctuary of Wat Phou was constructed mainly using sandstones and bricks. There are physical damages including fracture, break out, exfoliation and interval as well as biological damages by lichen, mosses and weeds. According to the ultrasonic velocity measurement and property evaluation of the sandstones of the Sanctuary in Wat Phou, weathering index of the eastern side sandstones is 0.10 to 0.74 (mean 0.36), showing MW grade. Southern and northern side sandstones have relatively higher properties with average weathering indices of 0.30 and 0.32. The results of slope analysis of the Sanctuary, indicated that the 4th spot in the southern side has the largest slope of $5^{\circ}W$, seemingly due to the unstable ground around the Sanctuary. Based on the relative level measurement and past drawings, the Sanctuary is verified to have been located on ground with a certain slope rather than flatland. The ground of the southern side is inclined $1.51^{\circ}$ more than that of the northern side, which will affect the structural stability of the temple. The interval width of the selected southern spot is the largest with an average width of 159.5 mm, and the largest width is 328.3 mm at the top, since the width increases above rather than below, seemingly due to the unequal subsidence of the ground. Constant maintenance for conservation is required for the structural stability of the Sanctuary in Wat Phou, which was partly collapsed and has also suffered physical damage.

Research on the Effect of the Control Methods of Irrigation Water on the Growth and Yield of Paddy Rice. (한발기에 있어서 용수관리 방법이 수도생육과 그 수량에 미치는 영향에 관한 연구)

  • 김시원
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.13 no.1
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    • pp.2177-2190
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    • 1971
  • This experiment was made to determienthe effect of various soil moisture contents in simulated drought conditions on different stages of rice growth. The drought conditions were developed at such three rice-growing stages as transplanting, immediately after transplanting and young ear forming. Three different lengths of drought periods, which are ten days, twenty days and thirty days, were applied for each growing stage of rice. The rice variety used this experiment is Nong-rim 29. This experiment was conducted at the university farm of the Kon-Kuk University during the period of $1968{\sim}1970$. Three reprications for each of 12 treatments and split plot design were employed in this study. Bottomless wood square boxes, $1^m{\times}1^m{\times}1^m$, were burried in the test plot and box top was covered with poloyethylene sheets to avoid natural rainfall drops. Standard plots were irrigated continuously with a water depth of 40mm/day and those of drought treatments were irrigated continuously up to the beginning of the planned drought period, and they were irrigated again with a depth of 40mm/day up to the maturing stage of rice. Other methods for rice raising followed those methods developed by the Field Crops Experiment Station of the Office of Rural Development. During this experiments, climatic conditions in regard to rainfalls, sunshine hours, and temperatures were observed. According to this observation, those values measured deviate slightly from the annual means. However the growing condition of rice plants were normal. The pH value of irritation water is nearly neutral, and soils in the test plots are relatively fertile, being similar to ordinary paddy soils. Analysis of variances for number of stalks, plan-height, ear sprouting date, length of stalks, ear length, number of ears per plant, fertility, grain weitght, weight of plant, and yield were carried out. The variances for plant height, ear sprouting date, length of stalk ear length, and yield has statistical significance under drought treatments applied at three different growing stages. The variance showing the effect of lengths of drought period is highly significant for all the treatments studied except that of grain weight. The interaction between drought periods and drought treatments at different growing stages is significant for plant height, stalk length, ear length, number of ears, fertility and yield, these results indicated that droughts at different growing stages have influence on plant height, ear length, yield, and length of drought period also has strong influence on all factors studied except grain weight. The combination of drought treatments at different rice growing stages and lengths of drought periods has different effects on various agronomic characteristics, including yield. Plant height under drought treatment practiced at transplanting stage is the lowest, and drought treatment applied immediately after transplanting resulted in the least number of stalks. The effect of different lengths of drought periods on plant height and number of stalks depends signis ficantly on increasing days of drought. Ear sprouting date tends to be delayed for one or two days undedrought treatments at transplanting period and with increasing days of drought. Better yield is secured in drought treatment applied immediately after transplanting. Adverse effect war observed when drought treatment was applied at ear forming period. These effects may be attributed to the alternation of irrigation and drought causing vigorous root activity. In general, yield linearly decreases as the length of the drought period increases. The results obtained in this study demonstrate that, in order to mimimize damage due to drought, and, to save irrigation water, paddy fields, immediately after transplanting, may be not irrigated, since there is sufficient moisture in the soil, and that sufficient irrigation water should be applied again in the ear forming stage of rice plant.

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Effects of Patriotism on Product Evaluation: Focused on the Mediating Effects of Consumer Ethnocentrism (애국심이 제품평가에 미치는 영향: 소비자 자민족중심주의의 매개효과를 중심으로)

  • Hong, Sung-Tai;Kang, Dong-Kyoon
    • Journal of Distribution Research
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    • v.15 no.2
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    • pp.71-99
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    • 2010
  • Most of studies on patriotism in the marketing area have focused on ethnocentric tendencies observed in consumption behaviors. On the contrary, there have been few empirical studies on how patriotism in the general sense, indicating affection for, attachment to, and pride in the country, influences consumers' evaluation of domestic and foreign products. Given the current situation that marketing activities appealing to people's patriotism is increasing, this is somewhat surprising. Thus, this study examined empirically how patriotism influences people's evaluation of domestic and foreign products. In addition, we tested whether consumer ethnocentrism works as an intervening variable in the relation between patriotism and product evaluation. The empirical analysis was conducted through a questionnaire survey of undergraduate and graduate students at universities in Seoul. The survey asked about the respondents' patriotism, consumer ethnocentrism, domestic product evaluation, foreign product evaluation, and demographical characteristics. In foreign product evaluation, the respondents were requested to evaluate Chinese and Japanese products. Email was used to send and recover the questionnaires, and 135 replies were used in the analysis. Major findings from the empirical analysis are as follows. First, a significant relationship was observed between patriotism and domestic product evaluation. That is, patriotic participants evaluated domestic products more favorably. On the other hand, no significant relationship was observed between patriotism and foreign product evaluation(See Table 1-1 and 1-2). Next, the effect of patriotism on domestic product evaluation was mediated by consumer ethnocentrism. However, whether the effect of patriotism on domestic product evaluation is mediated by consumer ethnocentrism partially or fully was different according to product(See Table 2-1 and 2-2). Lastly, we tried to analyze the relation between consumer ethnocentrism and product evaluation and comparing the results with findings of previous researches. According to the results, a significant relationship was observed between consumer ethnocentrism and domestic product evaluation but not between consumer ethnocentrism and foreign product evaluation. The meanings of this study are as follows. First, there have been few marketing studies that investigated the relation between patriotism and product evaluation. Thus, this study is meaningful in that it supplemented the limitation of previous research. Second, consumer ethnocentrism was found to mediate the relation between patriotism and domestic product evaluation. Considering the absence of previous research that examined the role of consumer ethnocentrism as an intervening variable, this study is significant in that it expanded the scope of research on consumer ethnocentrism. Third, from the practical aspect, the results of this study suggest that marketing appealing to patriotism is effective in stimulating consumers' purchase and consumption of domestic products. Accordingly, such a marketing strategy is expected to be effective in protecting domestic markets from imported goods and overseas brands and to increase demands for domestic products and brands. However, there is the question of whether the effect of patriotism based marketing strategies in promoting demand for domestic products would persist. That is, this study could not find a significant relation between patriotism and foreign product evaluation, and this means that the increase in patriotism for the home country does not damage people's view to the quality of foreign products negatively. Accordingly, without change in people's perception of foreign products, it is highly likely that the increase in demand for domestic products or brands induced by patriotism elevated at a specific time or situation may not last long. Fourth, the results of this study suggest that the patriotism level may influence consumers' choice behavior toward retailers strongly connected to a specific country or region. That is, consumers with high level patriotism may hesitate or avoid using a retailer associated with some foreign country. Fifth, according to the results of this study, when people's patriotism is stimulated by a specific social situation or event, it can be an opportunity for domestic franchise brands to increase their market performance such as sales and market share and, at the same time, for foreign franchise brands to experience adversities. Therefore, during a period like the Olympic Games or the World Cup when people's sense of belonging or attachment to their country is heightened, domestic franchise brands need to make marketing activities that may lead market opportunities to substantial results and foreign franchise brands to cope with such adversities. Sixth, consumers' brand choice is often made in retail stores. It has been demonstrated by numerous studies that in store stimuli such as point of purchase display can affect consumers' behavior. Considering this, domestic brands facing competition with foreign brands should make continuous efforts to enhance the market performance of their products through developing in store stimuli that can stimulate consumers' patriotism. Finally, based on the major findings of this study, both academic and practical issues were discussed. Suggestions for future studies were provided.

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The Improvement Effect of Pinus densiflora Forest Disturbed by Human Trampling in the Solbat Neighborhood Park, Gangbuk-gu, Seoul (서울시 강북구 솔밭근린공원 소나무림 답압 피해 개선사업 효과 연구)

  • Kwon, Ki-Young;Han, Bong-Ho;Park, Seok-Cheol;Choi, Jin-Woo
    • Journal of the Korean Institute of Landscape Architecture
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    • v.40 no.5
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    • pp.148-159
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    • 2012
  • The purpose of this study is to validate the effect of improvement such measures as fence installation or planting of bush and herbaceous plants taken from Pinus densiflora forest in Solbat Neighborhood Park in Seoul, which was damaged by stamping. The study was conducted in 2005 and 2010 in order to analyze changes in planting types, planting structure of Pinus densiflora forest, soil hardness, cross-sectional structure of soil, and physicochemical characteristics of soil. It was also measured by the growth of the branches and the diameter of Pinus densiflora, comparing before and after the improvement to study the effect of restoring Pinus densiflora forest damaged by stamping. When it comes to a change in planting type, Pinus densiflora forest without underlay was reduced from 48.5% in 2005 to 6.8% in 2010. Pinus densiflora forest with bush and herbaceous plants was increased dramatically from 7.4% to 46.8%. Regarding planting structure, in most area of the subject site, Pinus densiflora forest without under layer was transformed into the one with bush and herbaceous plants including Rhododendron mucronulatum, Rhododendron schippenbachii, Hemerocallis fulva, Aceriphyllum rossii, Hosta plantaginea growing in a wide area. The soil in the Solbat Neighborhood Park was very stiff with soil hardness of $54.8kg/cm^2$ in average. After the improvement efforts made in the Park in 2010, the soil hardness was mostly less than $4kg/cm^2$, being in a good condition with little influence on the growth of plants. When it comes to the cross-sectional structure of soil, litter layer didn't exist in 2005 because of stamping and the organic matter layer was only 1.0cm thick, which provided an unfavorable condition for plant growth. However, after improvement, litter layer was formed up to 3.0cm and thickness of the organic matter layer also went up to 1.5~8.0cm in 2010 because the damage from stamping was reduced. Concerning the physicochemical characteristic of soil, in 2005 soil showed pH 5.76~6.70, organic matter content 7.15~10.55%, and available phosphorus 9.38~26.47mg/kg, having no big problems as a soil environment for growth of Pinus densiflora. 15 trees of Pinus densiflora were selected to see branch growth and it was found that the branches tended to grow better after improvement. 70 trees of Pinus densiflora from various grades of soil hardness also were selected to identify changes of diameter growth. In most cases, it was analyzed that Pinus densiflora grew better after improvement. After conducting this study, it was validated that such measures as fence installation or planting of bush and herbaceous plants to restore Pinus densiflora Forest damaged by stamping were effective in improving growth of Pinus densiflora.

Cellular Antioxidant Activity and Whitening Effects of Dendropanax morbifera Leaf Extracts (황칠나무 잎 추출물의 세포 항산화 활성과 미백활성 측정)

  • Park, Su Ah;Park, Jun;Park, Chan Il;Jie, Young Jong;Hwang, Yun Chan;Kim, Yong Hyun;Jeon, So Ha;Lee, Hye Mi;Ha, Ji Hoon;Kim, Kyeong Jin;Park, Soo Nam
    • Microbiology and Biotechnology Letters
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    • v.41 no.4
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    • pp.407-415
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    • 2013
  • In this study, we investigated the antioxidant activities on HaCaT and the whitening effects on B16F1 melanoma cells of Dendropanax morbifera leaf extract. In an antioxidative activity assay using HaCaT cells, the ethyl acetate ($50{\mu}g/ml$) and aglycone fractions ($25{\mu}g/ml$) of the D. morbifera leaf extract didn't exhibit any characteristics of cytotoxicity. When HaCaT cells were exposed to a single large dose ($800mJ/cm^2$) of UVB, the extracts protected the cells against UVB radiation. When HaCaT cells were treated with 10 mM $H_2O_2$ and $4{\mu}M$ rose bengal, the ethyl acetate ($6.25{\sim}50{\mu}g/ml$) and aglycone ($6.25{\sim}25{\mu}g/ml$) fractions protected the cells against oxidative damage in a concentration dependent manner. When the whitening effects of D. morbifera leaf extract were tested in melanoma B16/F1 cells treated with the a-melanocyte stimulating hormone (${\alpha}$-MSH), the extracts inhibited ${\alpha}$-MSH-stimulated intra/extracellular melanogenesis in a concentration dependent manner. The inhibitory effects of the ethyl acetate and aglycone fractions of D. morbifera leaf extract were 21% and 44% at $25{\mu}g/ml$, respectively. Both are more effective than arbutin (15% at $25{\mu}g/ml$) which is known as a whitening agent. These results indicate that fractions of the D. morbifera leaf can function as cell protectants and natural antioxidants in biological systems, particularly skins exposed to UV radiation by quenching and/or scavenging $^1O_2$ and other ROS, and protecting cells against ROS. In addition, fractions of the D. morbifera leaf can be applied to new whitening cosmetics because of their inhibitory effects on ${\alpha}$-MSH stimulated melanogenesis in B16F1 melanoma cells.