• Title/Summary/Keyword: day length

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Ecological Studies on Heading of Rice Plant I. The Response to Photoperiod of Major Rice Varieties (수도의 출수생태에 관한 연구 제1보 주요수도 품종의 일장반응)

  • 최경구;장영남;이성춘
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.28 no.2
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    • pp.151-163
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    • 1983
  • This study was conducted to investigate the responses to photoperiod of some Korean rice cultivars at four levels of the day length, 10, 12, 14 and 16 hours. Generally the days to heading were reduced in the short day length. Japonica varieties seemed to have shorter basic vegetative growth phase and, were more sensitive to day length, while Japonica crossed Indica varieties showed longer basic vegetative growth phase and, were less sensitive to day length. All tested varieties could be classified into 19 ecotypes based on the periods of the basic vegetative growth phase and the sensitivity to day length.

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Prediction of Parturition Day by Determination of Plasma Progesterone Concentrations in Companion Bitches 1. To Estimate of Prediction of Parturition Day (반려견에서 혈중 Progesterone 농도 측정에 의한 분만일 예측 1. 분만예정일의 산정)

  • Lee, Ju Hwan;Son, Chang Ho
    • Journal of Veterinary Clinics
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    • v.37 no.6
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    • pp.301-304
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    • 2020
  • The gestation period and parturition days were accurately predicted by measuring progesterone concentration in the plasma from 40 pregnant companion bitches. The mean length of the estrous cycle based on plasma progesterone concentrations were 8.14 ± 1.39 (Mean ± SD) days for proestrus, 9.19 ± 2.01 days for estrus, and 55.38 ± 1.96 days for diestrus phase, respectively. The gestation length from each based on the days was 65.61 ± 2.47 days from the first day of estrus after the first vaginal discharge, 63.21 ± 0.99 days from the day when plasma progesterone concentrations increase above 4.0 ng/ml, and 54.51 ± 3.51 days from the first day of diestrus, respectively. Therefore, the parturition day was estimated 65 days from the first day of estrus after the first vaginal discharge, 63 days from the day when plasma progesterone concentrations increase above 4.0 ng/ml, and 54 days from the first day of diestrus, respectively.

Ultrasonographic appearance of the gestational structures throughout accurately timed pregnancy in Korea Jin-do dogs II. Estimation of gestational age by measurement of the fetal and extra-fetal structures (진도개에서 임신일령에 따른 임신구조물의 초음파상 II. 태아 및 태아외구조물의 측정에 의한 임신일령의 추정)

  • Son, Chang-ho;Shin, Chang-rok;Kang, Byong-kyu;Choi, Han-sun
    • Korean Journal of Veterinary Research
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    • v.36 no.1
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    • pp.247-254
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    • 1996
  • Serial ultrasonographic examinations were performed on 9 pregnant Korea Jin-do dog from days 15 to 60 to determine the size of gestational structures throughout pregnancy. Gestational age was timed from the day of ovulation (Day 0), which was estimated to occur when plasma progesterone concentration was first increased above 4.0 ng/ml. Extra-fetal structures were measureable from days 17 to 49. Outer uterine diameter increased from $7.0{\pm}0.7$ ($mean{\pm}SD$)mm at day 17 to $54.0{\pm}2.2mm$ at day 49 and inner chorionic cavity diameter increased from $3.0{\pm}0.7mm$ at day 17 to $37.5{\pm}0.6mm$ at day 49. Uterine wall thickness increased from $2.8{\pm}0.4mm$ at day 17 to $8.3{\pm}0.5mm$ at day 49, placental thickness increased from $1.0{\pm}0.1mm$ at day 22 to $5.7{\pm}0.2mm$ at day 49 and length of chorionic cavity or zonary placenta increased from $5.5{\pm}1.3mm$ at day 20 to $52.3{\pm}2.2mm$ at day 49. Inner chorionic cavity diameter, outer uterine diameter and placental length each increased at a linear rate through day 37, after which time, each had a marked plateau in growth. Of the extra-fetal structures, inner chorionic cavity diameter was the most accurate for estimation of gestational age until day 37. Fetal structures were measureable from days l7 to 60. Crown-rump length, increased from $3.0{\pm}0.7mm$ at day 22 to $118.7{\pm}3.1mm$ at day 49, fetal body diameter increased from $4.0{\pm}0.7mm$ at day 25 to $55.8{\pm}1.7mm$ at day 60 and fetal head diameter increased from $4.3{\pm}0.6mm$ at day 26 to $29.8{\pm}0.8mm$ at day 60. Of the fetal structures, fetal head diameter was the most accurate for estimation of gestational age from day 37 until day 60.

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Studies on Eeological characteristies of Some Soybean (Glycine max(L.) Merr) Cultivars 2. Effects of Day Length on Flowering and Other Agronomic Characteristics (주요 대두품종의 생태적 특성에 관한 연구 제2보 일장조건이 개화 및 제특성에 미치는 영향)

  • 최경구;김진기;이성춘;이왕휴;전병기
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.25 no.4
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    • pp.59-65
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    • 1980
  • An attempt was made to survey soybean cultivars that were nonsensitive to the photoperiod for selection as possible breeding materials for wide area adaptable varieties. Fifty-five cultivars were subjected to different day length conditions. The number of days from sowing until flowering was shortened under short day length conditions, and late varieties tended to be more sensitive to day length than early varieties. The response to day length of the tested cultivars might be divided into three groups; low, intermediate and high degree, by their accelerated rate of flowering. Especially four varieties in the low responding group, Gembokin, Wirth, Wayne and Pi.54613 were identified to be nonsensitive to day lengths, that is, neutral varieties. They also showed little variation in morphological characteristics under different day length conditions.

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Determination of Phenolic acids and Flavonol Aglycone Contents in Orostachys japonicus A. Berger Grown under Various Cultivation Conditions

  • Jang, Sang-Hun;Lee, Sang-Gyeong;Kang, Jin-Ho;Park, Jong-Cheol;Shin, Sung-Chul
    • Korean Journal of Medicinal Crop Science
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    • v.14 no.5
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    • pp.311-316
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    • 2006
  • The content of four phonolic acids 1-4, and two flavonol aglycones 14 and 15 from Orostachysjaponicus A. Berger grown under night-break and day-length controlled experiments was estimated and compared with those in wild plants. The amount of the phenolic acids 1-4 and the flavonol aglycones 14 and 15 increased with increasing light irradiation under both the night-break and day-length control conditions. It was disclosed that the cultivation conditions such as the night-break and the day-length control were not adversely affect the production of phenolic acids and flavonols in Orostachys japonicus A. Berger extracts.

Ultrasonographic Appearance of the Gestational Structures Throughout Pregnancy in Shih-tzu bitches II. Estimation of Gestational Age by Measurement of the Fetal and Extra-fetal Structures (Shih-tzu견에서 임신일령에 따른 임신구조물의 초음파상 II. 태아 및 태아외구조물의 측정에 의한 임신일령의 추정)

  • 김방실;고진성;황순신;이순애;조양택;오기석;김성호;박인철;김종택
    • Journal of Veterinary Clinics
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    • v.21 no.2
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    • pp.143-148
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    • 2004
  • Serial ultrasonographic examination was daily performed on 12 pregnant Shih-tzu bitches from day 15 until parturition to determine the size of gestational structures. Gestational age was timed from the day of ovulation (day 0), which was estimated to occur when plasma progesterone concentration was first increased above 4.0 ng/ml. Extra-fetal structures were measurable from days 17 to 46. Outer uterine diameter increased from $9.9{\pm}0.4$ mm (Mean${\pm}$SD) at day 20 to $44.3{\pm}0.8$ mm at day 46 and inner chorionic cavity diameter increased from $7.2{\pm}0.2$ mm at day 17 to $36.9{\pm}1.5$mm at day 41. Length of chorionic cavity or zonary placenta increased from $6.6{\pm}0.4$ mm at day 21 to $46.4{\pm}0.9$ mm at day 44. Of the extra-fetal structures, inner chorionic cavity diameter was the most accurate for estimation of gestational age until day 38. Fetal structures were measurable from days 23 to 60. Crown-rump length increased from $3.9{\pm}0.3$ mm at day 23 to $55.2{\pm}3.3$ mm at day 41, fetal body diameter increased from $7.9{\pm}0.6$ mm at day 32 to $47.8{\pm}2$ mm at day 60, and fetal head diameter increased from $6.3{\pm}1.1$ mm at day 29 to $25.6{\pm}0.2$ mm at day 60. Of the fetal structures, fetal head diameter was the most accurate for estimation of gestational age from day 38 until day 60.

Effect of Microcurrent Electrostimulation on the Burn of Rats (미세전류 전기자극이 흰쥐의 화상에 미치는 영향)

  • Kim, Se-Hoon;Kim, Jung-Woo;Park, Jang-Sung
    • Journal of the Korean Academy of Clinical Electrophysiology
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    • v.6 no.1
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    • pp.81-89
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    • 2008
  • Purpose: This study aims to examine effect of microcurrent electrostimulation on burn healing by electric intensity and of which the electric intensity on the acute burn being cured with microcurrent electrostimulation therapy. Methods: 28 Sprague Dawley Rats is classified into a control group of 8 rats, an experimental group I of 10 rats and an experimental group II of 10 rats. The control group is not cured, the experimental group I is exposed to 10 Hz, and $100{\mu}A$ with microcurrent electrostimulation, and the experimental group II is exposed to 10 Hz, $300{\mu}A$ for 15 minutes a day. The next day, 2th, 4th, and 6th day after rats is burned. Result: There are not significant differences of length change of the burn cure between the control group, the experimental group I, and the experimental group II by a period. However, systematically hair follicle cell on the 2th day and epidermal cell on the 6th day turn up in the experimental group I, and the experimental group II. Inquiry: Nancy(1994) did not obtain the desired result when the skin of a pig is exposed to 0.1 Hz, and $100{\mu}A$ for wound healing. In the result of the study, when burn length is measured on the 2th, 4th, and 6th to see the length change of acute burn, there is not significant differences among 3 groups. Conclusion: Statistically, there is not significant differences of the length change between 3 groups. However, systematically the burn is cured faster in the experimental group I, and the experimental group II than in the contrast group.

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Effect of natural plant extract (Abelmo) on action mechanism and hair growth activities in C57BL/6 mice (C57BL/6 마우스에서 천연 식물성추출물(아벨모)의 발모효능 및 작용 메카니즘)

  • Park, Sang-Oh;Park, Byung-Sung;Noh, Ga-Yeong
    • Journal of the Korean Applied Science and Technology
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    • v.31 no.4
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    • pp.653-662
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    • 2014
  • This study was determined the hair growth effect and mode of action of a complex extract (abelmo), extracted from various natural plants including Acorus calamus var. angustatus. 30 six-week old C57BL/6 mice were randomly assigned into three treatment groups with ten mice per treatment group repeatedly. The treatment group is a control group, and was classified into saline-applied, minoxidil 5%-applied, and abelmo-applied groups. Hair growth started from the abelmo-applied and minoxidil 5% -applied groups on the 9th day, compared to the saline-applied group. Hair growth rate was 17.06% and 19.15% in those two groups, respectively, and the abelmo-applied group's hair growth rate was higher. The density, length and thickness of hair were significantly higher in the order of abelmo-applied group, minoxidil 5%-applied group and saline-applied group on the 9th day, and hair root was strongly maintained in the abelmo-applied group. The density, length and thickness of hair in the abelmo-applied group were significantly higher by 599.8, 122.2 and 181.8% on the 9th day compared to the saline-applied group, and 166.7, 171.4 and 200.2% on the 12th day, and 136.6, 216.9 and 180.7%, respectively on the 15th day. As for hair follicle and the length of hair shaft from the dosal skin histopathology manifestation, the abelmo-applied group was more excellent than the saline-applied group and minoxidil 5%-applied group. This result actually confirmed the fact that abelmo promotes hair growth and strongly maintains hair root simultaneously.

Rice Varieties Adaptable to the Temperature and Day-Length Conditions of the Major Rice Production Area in North Korea

  • Woonho Yang;Shingu Kang;Dae-Woo Lee;Jong-Seo Choi
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2022.10a
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    • pp.172-172
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    • 2022
  • The heading response of 40 genotypes, originated from South Korea, North Korea, and northern China, was tested under the temperature and day-length conditions of thirteen major rice production area in North Korea, with aims to select adaptable varieties to the given environment and crop period for each region. To simulate regional environment, seven-day mean temperature with 10℃ daily temperature range and day-length for each region were imposed at a weekly interval in the walk-in phytotrons. Olbyeo1, Olbyeo2 and Sonbong9 originated from North Korea, Kenjiandao3 and Nongdae3 from northern China, and Joun from South Korea demonstrated the earliest heading stage depending on the regional environment. Thirty-four varieties reached heading stage within the regional safe marginal heading date (SMHD) under Haeju and Sariwon conditions while 16-17 varieties reached the stage under Wonsan, Changjon, Supung, and Yongyon environment. Some of the middle and mid-late maturing varieties originated from South Korea could reach heading stage within SMHD under the temperature and day-length conditions of Kaesong, Haeju, Sariwon, Nampo, and Pyongyang located in west-southern plain. Majority of early maturing varieties, but not middle or mid-late ones, showed heading stage within SMHD under the conditions of Singye, Anju, Kusong and Sinuiju. Only some early maturing varieties demonstrated heading stage within SMHD under Yongyon, Changjon and Wonsan environment. These results provide basic information on the varieties able to complete their normal life cycle under the regional environment in North Korea. It it further suggested that yield performance of the selected varieties for each region in this study be tested to select high yielding rice varieties adaptable to North Korean environment.

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Screening for Day Length Response Character in Soybean (대두 일장반응 형질의 선발)

  • 권신한;원종락;김재리
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.25 no.3
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    • pp.31-34
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    • 1980
  • In order to evaluate the day length sensitivity of soybean lines, Korean native and other varieties were planted in different dates from May 4 to July 13. With early plantings flowering was delayed and little differences of flowering time among lines were observed with the early plantings as compared with those of late plantings. The positive relationship between number of days to flowering from plantings on May 4 and July 13 was found and screening for the day length sensitivity is recommended to plant either on the beginning of Mayor mid-July in the middle part of Korean peninsular. Among the soybean lines tested several day neutral lines were observed.

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