• 제목/요약/키워드: early life history

검색결과 351건 처리시간 0.033초

실험실 사육에 의한 한국산 실고기과(Syngnathidae) 2종, 풀해마(Urocampus nanus)와 실고기(Syngnathus schlegeli)의 초기생활사 비교 (Comparative Early Life History of Two Pipefish, Urocampus nanus and Syngnathus schlegeli (Syngnathidae) in Laboratory Culture from Korea)

  • 이재환;김진구
    • 한국수산과학회지
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    • 제53권1호
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    • pp.83-89
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    • 2020
  • This study provides a detailed morphological description of larvae obtained from Urocampus nanus and Syngnathus schlegeli male brood fish over 20 days of culture in the laboratory. In both species, mating takes place when several males each spread their brood pouch like a wing to attract a female's attention. When the female begins to swim upward, the males follow her and receive her eggs in their brood pouches. Newborn larvae of U. nanus and S. schlegeli had already completed formation of dorsal and caudal fin rays, but not of pectoral fin rays. Pectoral fin rays were completely formed 15 days after release in S. schlegeli and 20 days after release in U. nanus. The ratio of caudal fin length to standard length increased until 8 days and decreased thereafter in S. schlegeli, while in U. nanus this ratio declined continuously after hatching. The larvae of the two species were very similar in external morphology, but well distinguished by the number of dorsal fin rays (15-16 in U. nanus vs. 39-43 in S. schlegeli), the presence of a membrane under the tail (absent in U. nanus vs. present in S. schlegeli), and the presence of melanophores in the dorsal fin (present in U. nanus vs. absent in S. schlegeli). Based on this study, U. nanus appears to be evolutionally more similar to pipefish than to seahorse.

Early Life History of Rhodeus Fish (R. uyekii and R. ocellatus) in the Nakdong River Water System

  • Park, Jae-Min;Han, Kyeong-Ho
    • 한국발생생물학회지:발생과생식
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    • 제22권1호
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    • pp.39-53
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    • 2018
  • The purpose of this study is to investigate the early life history of the Rhodeus fish, Rhodeus uyekii and R. ocellatus, in the Nakdong River to use as the preliminary data for the systematic study. The embryos used in the study were fertilized eggs (embryo) and larvae after artificial fertilization. The long diameter of the eggs of the R. uyekii was 3.39-3.97 mm (average $3.68{\pm}0.41mm$, n=30) and the short diameter was 1.36-1.55 mm (average $1.45{\pm}0.13mm$, n=30). The long diameter of the eggs of the R. ocellatus was 2.53-2.71 mm (average $2.62{\pm}0.12mm$, n=30) and the short diameter was 1.47-1.60 mm (average $1.53{\pm}0.09mm$, n=30). Hatching time was 48 hours for the R. uyekii and 50 hours for the R. ocellatus given that the average water temperature was $21.5^{\circ}C$. The hatched larvae were 4.95-5.00 mm (average $4.98{\pm}0.04mm$, n=5) for the R. uyekii and the total length was 3.66-3.69 mm (average $3.67{\pm}0.02mm$, n=5) for the R. ocellatus. R. uyekii was found to be 15.5-15.8 mm at total length (average $15.6{\pm}0.21mm$, n=5) on the 56 days after hatching with the number of dorsal fins being ⅲ-9, anal fins ⅲ-10, ventral fins ⅲ-5. The R. ocellatus was found to be 15.8-16.0 mm (average $15.9{\pm}0.14mm$, n=5) at total length on the 58 days with the number of dorsal fins being ⅲ-11, anal fins ⅲ-12 and ventral fins ⅲ-5 where the number of all fin stalks reached maximum.

미호종개 Iksookimia choii (Cobitidae)의 난 발생 및 자어 형태 발달 (Morphological Development of Egg and Larvae of Iksookimia choii (Cobitidae))

  • 송하윤;김우중;이완옥;방인철
    • 생태와환경
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    • 제41권1호
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    • pp.104-110
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    • 2008
  • 멸종위기 야생동식물이면서 천연기념물인 담수어류 미호종개의 난발생 과정 및 초기 생활사를 연구하였다. 성숙란은 인간 성선 자극호르몬(HCG) 10 IU $g^{-1}$을 주사하여 얻었으며, 습식번으로 수정하였다 수정란은 원형으로 투명한 황색을 띈 침성 점착란이었으며, 수정란의 직경은 $1.1\sim1.3mm$로 유구는 존재하지 않았다. 부화는 수온 평균 $25^{\circ}$에서 수정 후 24시간을 전후하여 시작하였다. 부화 직후 자어는 전각이 $2.5\sim2.7mm$ (평균 2.8 mm)로 입과 항문은 닫혀있었다. 부화 후 6일째 자어는 전장이 $4.7\sim5.4mm$(평균 5.1mm)로 꼬리 끝부분 척색이 $45^{\circ}$로 완전하게 굽어 후기 자어로 이행하였다. 부화 후 35일째 개체의 전장은 $20\sim22mm$ (평균 21.8 mm)로 모든 지느러미 가시와 줄기가 정수에 달하여 치어 단계로 이행하였다.

한강 수계 보통천에 서식하는 좀구굴치 Micropercops swinhonis의 난발생 및 자치어 형태발달 (Morphological of Development Eggs, Larvae and Juveniles Micropercops swinhonis in Botongcheon Stream Hangang River)

  • 박재민;한경호
    • 한국어류학회지
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    • 제35권3호
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    • pp.151-159
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    • 2023
  • 이 연구는 한강 수계 보통천에 서식하는 좀구굴치의 초기생활사를 규명하고 근연종과 유연관계를 비교하였다. 좀구굴치의 수정란은 타원형으로 평균 난경은 장경 1.23 mm, 단경 0.85 mm 였다. 수온 20.6℃에서 부화 시간은 179시간이 소요되었다. 부화자어의 크기는 전장 3.82~4.08 mm로 입과 항문이 완전히 발달하지 않았다. 후기자어기는 부화 후 18일째 전장 7.97~8.43 mm로 척색말단 끝부분이 45°로 완전히 휘어졌다. 치어기는 부화 후 29일째 전장 9.83~10.8 mm로 지느러미 줄기 수는 정수에 달하였다. 연구 결과 좀구굴치는 난 크기, 부화자어 크기, 유영형태에서 근연종과 차이를 보였다. 후기자어 이행시기와 제1등지느러미 발달 시기는 비교한 근연종 중 가장 느렸고, 크기는 큰 특징을 보여 초기생활사에서 근연종과의 차이점을 확인할 수 있었다.

20세기 초 유럽의 아동중심 교육철학에 따른 학습환경 개념에 대한 고찰 (A Study on the Concept of Learning Environment According to the Philosophy of Child-Centered Education in Europe in the Early 20th Century)

  • 류호섭
    • 교육시설 논문지
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    • 제24권1호
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    • pp.11-22
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    • 2017
  • The main purpose of this research is to consider educational environment, concept, and spatial organization and its characteristic based on the early 20th century European child-centered educational philosophy. For this process, the study of the following have been done : 1) Literature review, which includes educational ideology, perspective of child development of Maria Montessori, Rudolf Steiner, Peter Peterson, and Celestin Freinet. 2) Comparisons of spatial organization and classrooms of schools operated with the educational philosophy of mentioned philosophers from above. These schools have classrooms(or multi-purpose space near classroom) contained self-directed individual learning space, group and collaborative learning space, and training space of practical life. These configuration of learning space intended 1) learning based on individual child's interest, experience 2) developing of responsibility based on freedom 3) sociality and community spirit of children.

Nature Death Act -Taiwan Experience-

  • Lai, Enoch Y.L.
    • 한국호스피스완화의료학회:학술대회논문집
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    • 한국호스피스완화의료학회 2008년도 하계학술대회
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    • pp.19-21
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    • 2008
  • Hospice movement in Taiwan emerged early in 1983. There was a nurse visiting terminal cancer patients by herself in Taipei city. It was ceased after one year. This stage of hospice movement might be called as "compassionate era". In early 1990, the first in-patient hospice ward was set up in north Taiwan. She demonstrated high touch in the high technology medical atmosphere. There was a great echo in Taiwan society to this action. In the following years, quite a few new hospice settings were founded. Medical professionals were aroused again to talk and think about life and death, dignity of dying and holistic care. This stage of hospice movement might be called as "ethical stage". Around 2000, obstructions were discovered in our development. We do need system and rules. Standard of setting and care, Curriculum of education and training, Accreditation system and specialist system and Nature Death Act are some of the systems we approached. This stage of hospice movement might be called as "Act stage". Among the "Act stage", the Nature Death Act is actually the mile stone in our history. What listed below are the translated one for the reference:

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북방종개 Cobitis pacifica(Pisces: Cobitidae)의 배 발생과 초기생활사 (Embryonic Development and Early Life History of the Northern Loach, Cobitis pacifica (Pisces: Cobitidae))

  • 이완옥;김경환;백재민;강용진;전형주;김치홍
    • 생태와환경
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    • 제44권1호
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    • pp.1-8
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    • 2011
  • 미꾸리과 어류에 속하는 우리나라 고유종인 북방종개를 강원도 고성군 북천에서 채집하여 난발생과정과 초기 생활사를 연구하였다. 채집된 성숙한 북방종개를 호르몬(LHRH-a, HCG) 주사하여 채란하고 건식법으로 수정 시켰다. 수정란은 원형이었고 엷은 흰색을 띠는 분리침성란이며, 난경은 $1.09{\pm}0.04\;mm$ (n=20) 이었다. 수온 $21.0{\sim}24.0^{\circ}C$에서 수정 후 48시간 전후하여 부화하였으며, 부화자어의 크기는 전장 $2.87{\pm}0.05\;mm$ (n=20) 이었다. 부화 4 일 후에는 전장 $6.86{\pm}0.10\;mm$ (n=10)로 성장하였고, 난황이 거의 흡수되고 입과 항문이 열렸다. 부화 14 일 후에는 전장 $10.71{\pm}0.34\;mm$ (n=10)로 자라고 대부분의 지느러미 기조가 출현하였으며 반문이 나타났다. 부화 26일 후에는 전장 $14.88{\pm}0.45\;mm$ (n=10)로 자라고 모든 지느러미의 기조수가 정수에 도달하여 치어기로 이행되었다. 부화 80일 후에는 전장 $33.3{\pm}1.25\;mm$ (n=10)로 성장하였으며, 반문의 모양과 외부형태가 성어와 유사하였다. 북방종개의 배 발생 및 초기생활사 특정은 다른 미꾸리과 어류들과 큰 차이를 보이지 않았으며, 추후 고유종의 복원연구에 기초자료를 제공하였다.

한국산 대만나방(나비목: 솔나방과)의 생태적 특성 (Ecological Characteristics of Paralebeda plagifera femorata (Lepidoptera: Lasiocampidae) in Korea)

  • 심상준;이기영;황환준;한상섭;변봉규
    • 한국응용곤충학회지
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    • 제39권2호
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    • pp.83-87
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    • 2000
  • 최근 강원도 원주 등지에서 은행나무에 큰 피해를 주었던 대만나방의 생활사를 1998년부터 1999년까지 조사하였다. 현재까지 우리 나라에서는 자세히 보고된 바 없는 알, 유충, 번데기 및 성충의 형태적 특징과 각 충태별 기간 및 생태적 특성을 조사하였다. 대만나방은 연 1회 발생하였으며, 6령충으로 기주식물의 가지에서 월동하였다. 유충은 총 9령을 거치며, 종령유충은 6월하순경에 가지에서 은행잎 2-3장을 엮은뒤 갈색실을 토하여 고치를 틀고 그 속에서 번데기가 되었다. 성충은 7월초순부터 8월초순에 걸쳐 우화하였으며 우화최성기는 7월하순이었다. 교미한 암컷은 평균 205개의 알을 난괴형태로 산란하였으며, 산란장소는 가지, 줄기, 또는 잎의 가장자리였다.

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An observational population based study on dysmenorrhea and its risk factors

  • Kotagasti, Tabassum;Rias, Nishad
    • 셀메드
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    • 제5권3호
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    • pp.18.1-18.4
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    • 2015
  • Dysmenorrhea is the most common gynecological disorder in women of reproductive age. The prevalence of menstrual pain is relatively high and has been shown to be related to many factors like age, age at menarche, menstrual cycle regularity, parity, cigarette smoking, and dietary habits etc. This study was conducted to determine the possible link between dysmenorrhea and the factors related to it. We investigated the associated risk factors that could influence menstrual pain. This Cross Sectional Study was conducted at Dept. of OBG, NIUM, Bangalore. The study consisted of 230 women between the ages of 20 - 49 years. Included volunteers were newly married, nulliparious and parous women. The detailed reproductive history was recorded and was analyzed statistically. It was observed that there were only two factors that were influencing Dysmenorrhea namely the early age at menarche and increase parity. It was hypothesis that earlier start to reproductive life in some way decreases the sensitivity of the uterus to prostaglandin, whereas delayed menarche and postponing reproductive life increase sensitivity of the uterus to prostaglandins and cause severe menstrual pain. It is concluded that early age at menarche and high parity decrease menstrual pain.

Laparoscopic management of early primary peritoneal pregnancy: a case report

  • Koo, Hwa-Seon;Bae, Ju-Youn;Kang, Inn-Soo;Koong, Mi-Kyoung;Kim, Hye-Ok;Cha, Sun-Hwa;Choi, Min-Hye;Kim, Ji-Young;Yang, Kwang-Moon
    • Clinical and Experimental Reproductive Medicine
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    • 제38권2호
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    • pp.109-114
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    • 2011
  • Peritoneal pregnancy is an implantation in the peritoneal cavity exclusive of tubal, ovarian, or intra-ligamentary implantations. This is a rare obstetric complication with high maternal mortality and even higher perinatal mortality, and secondary type was most common. Risk factors for peritoneal pregnancy are previous history of extrauterine pregnancy or tubal surgery pelvic post-inflammatory status or presence of an intrauterine device. As it is a life-threatening condition, expectant management carries a risk of sudden life-threatening intra-abdominal bleeding and a generally poor fetal prognosis. So, when it is recognized, immediate termination of pregnancy is usually recommended. Early diagnosis of peritoneal pregnancy is difficult, but is important by their life threatening progress course to patients. Recently, we experienced primary peritoneal pregnancy which meets both the original and modified criteria. In this paper, we reported the case of early diagnosed and successfully treated peritoneal pregnancy despite of their diagnosis was incidentally.