• Title/Summary/Keyword: history of natural number

Search Result 154, Processing Time 0.031 seconds

Chromosome number of myoga ginger (Zingiber mioga: Zingiberaceae) in Korea

  • IKEDA, Hiroshi;NAM, Bo-Mi;YAMAMOTO, Nobuko;FUNAKOSHI, Hidenobu;TAKANO, Atsuko;IM, Hyoung-Tak
    • Korean Journal of Plant Taxonomy
    • /
    • v.51 no.1
    • /
    • pp.100-102
    • /
    • 2021
  • The chromosome number of myoga ginger (Zingiber mioga (Thunb.) Roscoe: Zingiberaceae) has been reported as 2n = 22 for Chinese plants and 2n = 55 for Japanese plants. We checked the chromosome number of Z. mioga in plants collected in Jeollabuk-do and Jeollanam-do, Korea, and counted 2n = 44, the first report of this number for the species. As the basic chromosome number of Z. mioga is thought to be x = 11, Z. mioga plants in China, Korea, and Japan appear to be diploids, tetraploids, and pentaploids, respectively. In finding the tetraploid race of Z. mioga in Korea, we can hypothesize that the pentaploid race in Japan is derived through the fertilization of reduced gametes of the diploid race and unreduced gametes of the tetraploid race.

Classification of Place for Experiential Learning through Analysis of Previous Study and Actual Status of Elementary Schools in Gyeonggi-do about Science Experience Learning (과학체험학습에 관한 선행연구 및 경기도 지역 초등학교 운영실태 분석을 통한 다양한 과학체험학습장의 활용방안 모색)

  • Kwon, Nanjoo;Kwon, HyoekJae
    • Journal of Korean Elementary Science Education
    • /
    • v.38 no.1
    • /
    • pp.43-54
    • /
    • 2019
  • In order to organize various places for science experience study, this study gathered and analyzed prior research on science experience study and various science experience perated in school. To that end, a total of 162 relevant prior studies of literature published from 2000 to 2016 were collected and 2,201 cases of science experience study conducted in 2015 were collected and analyzed. The place where the science experiential learning was done is divided into three areas of natural ecology, cultural history, facility experiential learning study, and the characteristics of participating subjects are examined. In terms of the number of articles published in the field of science-related experiential learning areas, 83 ecological experience study sites (51.2%), facilities institution experience study sites 56 (34.6%), and cultural history experience study books 23 (14.2%). Through this study, it was found out that research tendency to analyze science - related attitudes became prominent by setting study subjects using natural objects around and learning to play while playing and playing in nature. There was also an analysis by subjects of participation in science related experience learning centers. Cultural history experiential learning field was significantly lower than previous studies. In the lower grades, nature ecological experience learning was mainly performed. Combining the above findings, it can provide implications for the development of science-related experience activities. First, it is necessary to develop a technology-related experience learning center using local community resources. Second, it is necessary to expand the culture and history experience learning center related to science. Third, we need an education support center to support the expansion and operation of such a technology-related cultural history learning center.

Natural Product Research in Dental Caries Prevention (임상가를 위한 특집 1 - 충치예방과 관련된 천연물(natural products) 연구의 현황)

  • Jeon, Jae-Gyu
    • The Journal of the Korean dental association
    • /
    • v.50 no.9
    • /
    • pp.544-551
    • /
    • 2012
  • Dental caries is a biofilm-related oral disease, and continues to afflict the majority of the world's population. Although fluoride, delivered in various modalities, remains the mainstay for the prevention of caries, additional approaches are required to enhance its effectiveness. Natural products have been used as a major source of innovative and effective therapeutic agents throughout human history, and have shown promise as a source of components for the development of new drugs. In addition. studies using natural products to prevent or treat oral diseases such as dental caries have received a great deal of attention. A number of compounds, such as epicatechin, allicin and sanguinarine, isolated from natural products, have also been investigated for their efficacy against oral microbial pathogens. However, the use of natural products as an anti-caries agent in clinical practice was controversial because of inadequate knowledge concerning their mechanisms of action and chemical characterization. This study focuses on the current knowledge of natural products in dental caries prevention and suggests natural products are importance sources for the prevention of dental caries.

Study On The Same And Different Locations of Acupoints on Pulse (정경혈(正經穴) 중(中) 맥동처(脈動處)와 그 혈위(穴位)의 동이(同異)에 대(對)한 연구(硏究))

  • Jo, Hak-Jun;Lee, Pyeong-Jae
    • Journal of Korean Medical classics
    • /
    • v.20 no.4
    • /
    • pp.17-35
    • /
    • 2007
  • Objectives : To consider same or not the positions of acupoints on the meridian in the old acupuncture books. Methods: On the basis of old acu-books, We count the number of acupoints that are on pulse. Thru the three books-"Yijongkumkam(醫宗金鑑)","Chimkuhak 1st(鍼灸學-上)", Kyunghyulhakchongseo(經穴學叢書)"-We Compared the way of positioning of acupoints, also did on the location of acupoints, vein, vascular system, around the acupoints, based on the anatomical structures(esp. artery) Results : On the basis of old acu-books, the number of acupoints(only in the twelve meridian) on the pulse is 35, and the number of points not in the old books but on the pulse is 6, sum is 41 points. Comparion from Sambukuhu consultation method(三部九候診法) in "Somun(素問)", Some points, Taeyang(太陽, not in the twelve meridian), Yimun(耳門) and Koryo(Yimun and Koryo are in) are on pulse. Like Chonbu(天府) and Hyupbaek(俠白), We can feel the pulse on ulna side of biceps muscle, noton radial side. Shikdu(食竇) was described as on pulse in the "Chimkushimbopyokyul(鍼灸心法要訣)", but we could hardly feel it. Conclusions : It'll be right to add the Yimun(耳門) and Koryo to the points on pulse, of course two points are not in the twelve meridian. We must take the points Chonbu(天府) and Hyupbaek(俠白), on ulna side of biceps muscle. Shikdu(食竇) must be excepted, because we cannot feel the pulse in consultation.

  • PDF

Sensilla on the Aedeagi of the Genus Damaster (Insecta, Coleoptera, Carabidae)

  • Kim, Jung-Lark;Park, Sang-Ock;Tsukane Yamasaki
    • Animal cells and systems
    • /
    • v.3 no.1
    • /
    • pp.23-28
    • /
    • 1999
  • Sensilla on the aedeagi of 4 species under the genus Damaster were studied using scanning electron microscopy. A total of 37 types of sensilla were distinguished from the aedeagi of the species examined. The number of sensilla types was the largest in D. (Coptolabrus) smaragdinus branickii, 25, and 23 in D. (C.) jankowskii jankowskii. In D. (Acoptolabrus) gehinii gehinii and D. (Damaster) blaptoides blaptoides, 22 and 21 types of sensilla were found, respectively. External morphology and distribution patterns of sensilla were also described. The phylogenetic relationships among the species were discussed based on their distribution patterns.

  • PDF

Life History Traits and the Rate of Molecular Evolution in Galliformes (Aves)

  • Eo, Soo-Hyung
    • Journal of Ecology and Environment
    • /
    • v.31 no.1
    • /
    • pp.75-81
    • /
    • 2008
  • Rates of molecular evolution are known to vary widely among taxonomic groups. A number of studies, examining various taxonomic groups, have indicated that body size is negatively and clutch size is positively correlated with the rates of nucleotide substitutions among vertebrate species. Generally, either smaller body mass or larger clutch size is associated with shorter generation times and higher metabolic rates. However, this generality is subject to ongoing debate, and large-scale comparative studies of species below the Order level are lacking. In this study, phylogenetically independent methods were used to test for relationships between rates of the mitochondrial cytochrome b evolution and a range of life history traits, such as body mass and clutch size in the Order Galliformes. This analysis included data from 67 species of Galliformes birds and 2 outgroup species in Anseriformes. In contrast to previous studies, taxa were limited to within-Order level, not to Class or higher. I found no evidence to support an effect of life history traits on the rate of molecular evolution within the Galliformes. These results suggest that such relationship may be too weak to be observed in comparisons of closely related species or may not be a general pattern that is applicable to all nucleotide sequences or all taxonomic groups.

Estimation of fundamental natural period of vibration for reinforced concrete shear walls systems

  • Shatnawi, Anis S.;Al-Beddawe, Esra'a H.;Musmar, Mazen A.
    • Earthquakes and Structures
    • /
    • v.16 no.3
    • /
    • pp.295-310
    • /
    • 2019
  • This study attempts to develop new simplified approximate formulas to predict the fundamental natural periods of vibration (T) for bearing wall systems engaged with special reinforced concrete shear walls (RCSW) under seismic loads. Commonly, seismic codes suggested empirical formulas established by regression analysis of measured T for buildings during earthquake motions. These formulas depend on structure type, building height, number, height and length of SW, and ratio of SW area to base area of structure. In this study, a parametric investigation is performed for T of 110 selected models of bearing RCSW systems with varying structural height, configuration of horizontal plans including building width, number and width of bays, presence of middle corridors and core SWs. For this purpose, a 3D non-linear response time history (TH) analysis is implemented using ETABS v16.2.1. New formulas to estimate T are anticipated and compared with those obtained from formulas of IBC 2012 and ASCE/SEI 7-10. Moreover, the study examines responses of an arbitrarily two selected test model of 60 m and 80 m in height with presence of SWs having middle corridors. It is observed that the performance of the tested buildings is different through arising of considerable errors when using codes' formulas for estimating T. Accordingly, using the present proposed formulas exhibits more reasonable and safer design compared to codes' formulas. The results showed that equitable enhancement is promising to improve T formulas approaching enhanced and accurate estimation of T with reliable analysis, design, and evaluation of bearing RCSW systems.

Developmental Characteristics and Life History of the Korean Native Firefly, Pyrocoelia rufa

  • Kim, Jong-Gill;Kim, Keun-Young;Park, Young-Cheol;Park, Ji-Young;Kim, Sam-Eun;Jin, Byung-Rae;Lee, Sang-Mong;Lee, Jong-Eun;Lee, Ki-Yeol
    • International Journal of Industrial Entomology and Biomaterials
    • /
    • v.6 no.1
    • /
    • pp.69-72
    • /
    • 2003
  • Development and life history of the Korean native firefly, Pyrocoelia rufa, were investigated throughout the indoor rearing. Average size of egg with an oval shape was 1.7 m and the hatchability of egg of P. rufa was approximately 88.5%. The larvae were pupated at the ${5^th}$ instar and the body length of the matured larvae was 27.1 mm. The total periods of larval stage to the end of the 5$^{th}$ instar were approximately 104.7 days. Average pupal period was 10.3 days and average number of eggs oviposited by a female was 87.3 eggs. The body size of female in the pupa and adult was larger than that of male. The wings of female adult were deteriorated.

Developmental Characteristics and Life History of the Korean Native Fire-fly, Luciola lateralis

  • Kim, Jong-Gill;Kim, Sam-Eun;Park, Ji-Young;Yoon, Hyung-Joo;Park, Young-Cheol;Ohba Nobuyoshi;Jin, Byung-Rae;Noh, Si-Kap
    • International Journal of Industrial Entomology and Biomaterials
    • /
    • v.3 no.2
    • /
    • pp.141-147
    • /
    • 2001
  • To study the ecological characteristics of the Korean native firefly, Luciola lateralis, development and life history of L. lateralis were investigated throughout the indoor rearing. Average size of egg with an oval shape was 0.51${\times}$0.56 mm and an egg period of L. tateralis was approximately 25.8 days. The larvae were pupated at the 5$^{th}$ instar and the body length of the matured larvae was 15.8mm. The total periods of larval stage to the end of the $5^{th}$ instar were approximately 271.7 days. Pupae formed soil cocoon and average pupal period was approximately 28.7 days. Average number of eggs oviposited by a female was approximately 97. The body size of female in the pupa and adult were larger that of male.

  • PDF

Life History, Seasonal Occurrence and Natural Enemies of Caloptilia theivora (Lepidoptera: Gracillariidae) at Tea Tree Plantation (동백가는나방(Caloptilia theivora)의 생활사, 발생소장 및 천적의 종류)

  • 이승찬;김상수;김도익
    • Korean journal of applied entomology
    • /
    • v.34 no.3
    • /
    • pp.229-233
    • /
    • 1995
  • The life history, seasonal occurrence of larval population and natural enemies of Tea leaf roller (Caloptilia theivora (Walshingham) were investigated in field-age. C. theivora had 6 generations a year. The developmental periods from egg to adult emergence were 32.1~38.6 days in spring and fall, and 24.8~32.7 days in summer. The average longevities of adults were 8.4~14.5 days in spring and fall, and 6.3~8.6 days in summer. The average number of eggs laid by a female were 55~71 throughout the season. Larval population density of C. theivora showed 3~4 peaks from middle may in 1992 and 1993. However, population density of 194 was pretty low in early season and exhibited a peak in late September-early October. C. theivora overwintered in pupal stage on the leaves. Four hymenopterous parasitoids of C. theivora larvae were identified ; they are Stenomesius japonicus (Ashmead), Sympiesis ringoniellae Kamijo, Elasmus sp., and S. dolichogaster Ashmead which is dominant.

  • PDF