• 제목/요약/키워드: life-history ratio

검색결과 83건 처리시간 0.025초

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.

뇌졸중에 영향을 미치는 생활습관 요인 -흡연, 음주, 비만, 식습관을 중심으로- (The Lifestyle Factors in Stroke Etiology: Smoking, Alcohol Consumption, Obesity, Perception of Saltness)

  • 원종임;오희철
    • 한국전문물리치료학회지
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    • 제6권3호
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    • pp.82-93
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    • 1999
  • Stroke is a serious disease despite recent improvement in medical and surgical treatment. Hence, identification of modifiable risk factors for stroke is important. This case-control study was done to demonstrate that relationship between smoking, alcohol consumption, obesity, perception of saltness and the incidence of stroke and to identify that smoking, alcohol consumption, obesity and perception of saltness, after adjusting for age, hypertension. A structured interview was carried out from April 15, 1996 to May 3, 1996 in Yonsei Medical Center. The study group consisted of 59 neurologically confirmed stroke patients as the study group and 59 non-stroke patients as controls. Analysis of the data was done by means of ${\chi}^2$-test and logistic regression analysis. The results were as follows. In the study group: 1) Hypertension in males had a 10.2 odds ratio (p<0.05), cardiovascular disease in females had a 11.3 odds ratio (p<0.05) and a farnily history of stroke in males had a 3.1 odds ratio (p<0.05). 2) Females smoking one or more cigarettes had a 8.3 odds ratio (p<0.1), but males had no direct relationship with odds ratio of 1.5 (non-significant). 3) Alcohol consumption in males had a 0.4 odds ratio, and in females had a 0.8 odds ratio. The odds ratio was decreased in alcohol consumption group (non-significant). 4) Males with more than 20 cigarettes pack-years history had a 2.5 odds ratio (p<0.05), more than 25 Body Mass Index had a 3.1 odds ratio (p<0.05) and more than 220 ml ethanol weekly consumption had a 1.5 odds ratio (non-significant). 5) Female smokers had a 8.3 odds ratio (p<0.1), drinkers a 0.8 odds ratio and more than 25 Body Mass Iidex, a 43.1 odds ratio (p<0.05). 6) Females without saltness perception from a 0.5% salt solution had a 6.8 odds ratio (non-significant). 7) By logistic regression analysis independent risk factors for stroke in males were found to be hypertention, age, and obesity. The study was limited because number of subjects was too small for practical implications. However, like as other results, this study suggest that people should be advised to control hypertension, and obesity since these carry a risk of stroke.

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송현천에 서식하는 멸종위기어류 버들가지 Rhynchocypris semotilus (Pisces: Cyprinidae)의 생활사 (Life History of the Endangered Endemic Species, Rhynchocypris semotilus (Pisces: Cyprinidae) in the Songhyeoncheon (Stream), Korea)

  • 고명훈;한미숙;서형수
    • 한국어류학회지
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    • 제35권3호
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    • pp.160-170
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    • 2023
  • 멸종위기어류 버들가지 Rhynchocypris semotilus의 생태적 특징을 밝히기 위해 강원도 고성군 현내면의 송현천에서 2022년 4월부터 10월까지 생활사를 조사하였다. 4개 지점을 선정하여 7회 조사한 결과, 동소출현종은 10과 18종이 채집되었으며, 버들가지는 아우점종이었다. 버들가지는 송현천 중·상류의 바위와 큰돌, 수생식물로 이루어진 느린 여울부와 소에 주로 서식하고 있었다. 산란이 시작되는 5월에 전장빈도분포도로 버들가지의 연령을 추정하면, 전장 4~12 mm는 당년생 치어, 32~49 mm는 만 1년생, 50~65 mm는 만 2년생, 66~91 mm는 만 3년생, 92~116 mm는 만 4년생 이상으로 추정되었고, 5월부터 9월까지 급격한 성장을 보였다. 암컷과 수컷의 전장은 비교적 유사하였고, 암·수 성비(♂/♀)는 0.78이었다. 산란기는 5월부터 7월이며(수온은 17~21℃), 생식소는 전장 66 mm 이상인 만 3년생부터 성숙하였다. 5월의 생식소성숙도(GSI)는 평균 암컷 10.6±2.99%, 수컷 8.2±2.34%였고, 포란수는 평균 6,830±1,943개, 성숙란의 크기는 1.34±0.16 mm였다. 끝으로 버들가지의 생활사 특징을 버들치속과 연준모치속 어류와 비교·논의하였다.

Morphology and Development of Tetrastichus sp. (Hymenoptera: Eulophidae), Parasitizing Fallwebworm Pupae, Hyphantria cunea Drury (Lepidoptera: Arctiidae)

  • Lee, Hai-Poong;Kim, Il-Kwon;Lee, Ki-Sang
    • Animal cells and systems
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    • 제3권4호
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    • pp.369-374
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    • 1999
  • The life history and development of Tetrastichus sp. parasitizing fallwebworm pupa in Korea were studied. The mean lifetime fecundity was 94.7 with a maximum of 125, and the portion of female progeny averaged 90.3%. A male and a female lived for an average of 19.8${\pm}$4.5 and 21.7${\pm}$4.2 days, respectively. The duration of development for each stage was as follows: egg, 2 d; the 1st instar larva, 2${\pm}$1 d; the 2nd instar larva, 2${\pm}$1 d: the 3rd instar larva, 3${\pm}$1 d; the 4th instar larva, 6${\pm}$2 d; and pupa, 8${\pm}$2 d. Total developmental duration from hatching of the larva to adult emergence required 21.1${\pm}$3.7 d, and females took 1-2 days more than males in the incubator (28$^{\circ}C$, 70% RH, and 16:8 LD).

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Life Table Descriptions of Tetrastichus sp. (Hymenoptera: Eulophidae) on Hyphatria cunea Drury

  • Lee, Jang-Hoon;Lee, Ki-Sang;Lee, Hai-Poong
    • Animal cells and systems
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    • 제6권1호
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    • pp.19-22
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    • 2002
  • Life table studies were conducted in the laboratory for the eulophid gregarious pupal parasitoid, Tetrastichus sp., on Hyphantria cunea Drury at a constant temperature of 28.2$\pm$2$^{\circ}C$, 50-60% RH to evaluate their impact on the host and their potential biological control. Development of immature stage took 20.1$\pm$2.7 d: adult females lived for 23.2$\pm$2.2 (range, 16-27)d and produced a mean of 53.6$\pm$26.6 adult progeny per female, with a sex ratio of 1: 9.5 (M:F). The intrinsic rate of natural increase (r$_{m}$) was 0.178/ female/day; the net reproductive rate (R$_{o}$), 46.74; the capacity for increase (r$_{c}$) 0.177; the finite rate of increase (λ) 1.19/female/day; thus each female contributed 46.74 individuals to the population in a mean generation time of 21.6 d. Biological factors in determining the life history trait variation of the parasitoid were discussed.d.d.d.

멸종위기종 좀수수치 Kichulchoia brevifasciata의 산란기 특징 및 초기생활사 (Spawning Character and Early Life History of the Endangered Korean Dwarf Loach, Kichulchoia brevifasciata (Teleostei: Cobitidae))

  • 고명훈;방인철
    • 한국어류학회지
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    • 제26권2호
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    • pp.89-98
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    • 2014
  • 좀수수치 Kichulchoia brevifasciata의 산란기 특징 및 초기생활사 연구는 생물학적 특성 및 복원학적 기초자료를 확보하기 위하여 실시하였다. 산란기인 2011년 6월부터 7월까지 전라북도 고훙군 금산면에서 족대를 이용하여 채집한 후 산란기 특징을 분석하였고, 초기생활사는 성숙한 개체에 Ovaprim을 0.5 mL/kg 주사하여 성숙란을 얻은 후 건식법으로 인공수정 시켜 진행하였다. 성숙한 암컷은 전장은 46~76mm이고 GSI는 $9.6{\pm}3.77%$였고, 수컷은 전장 42~52mm이고 GSI는 $3.5{\pm}1.04%$였다. 성비는 0.1로 수컷이 매우 적었으며, 특별한 이차성징은 관찰되지 않았다. 포란수는 $69{\pm}35.3$개였으며, 산란된 성숙란은 담황색의 분리침성란으로 난경 $1.46{\pm}0.07mm$였다. 수정난은 수온 $25^{\circ}C$에서 66시간 후에 부화하였으며, 부화 직후 전기자어의 크기는 전장 $5.5{\pm}0.07mm$였다. 부화 후 6일째에는 전장 $9.0{\pm}0.29mm$로 난황을 모두 흡수하여 후기자어로 이행하였으며, 부화 후 17일째에는 전장 $12.6{\pm}0.24mm$로 모든 지느러미 기조가 정수가 되어 치어기로 이행하였다. 부화 후 80일째에는 전장 $33.0{\pm}2.19mm$로 체형과 체측반문이 비교적 성어와 유사하였다.

교통량 및 제설제 사용량에 따른 고속도로 포장의 공용수명 분석 (A Study to Analyze Service Life of Expressway Pavement according to Traffic Volumes and De-icing Chemicals)

  • 김찬우;안수한;박희영;이정훈;정철기
    • 한국도로학회논문집
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    • 제17권1호
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    • pp.35-41
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    • 2015
  • PURPOSES : The purpose of this study is to analyze the service life of expressway pavement based on both traffic volumes and use of deicing chemicals. METHODS : A database was built using expressway rehabilitation history information from over the last decade. In order to estimate the service life of expressway pavement, various analysis methods were considered, and a decision was made to perform analysis using a method based on an accumulated rehabilitation ratio. The service life of expressway pavement was then analyzed by classifying the scale of traffic volume and extent of de-icing chemicals used. RESULTS : The service life of PMA and SMA ranged from 7.8 to 10.6 years and from 9.9 to 12.0 years, respectively. The service life of JCP ranged from 16.0 to 22.2 years, and the service life of CRCP was 33.5 years on average. Results of assessing service life according to traffic volumes and de-icing chemicals showed that the lower the traffic volumes were, the greater the service life of PMA and JCP, and the less that de-icing chemicals were applied, the greater the service life of JCP. CONCLUSIONS : The dependence of expressway pavement service life on traffic volumes and de-icing chemicals makes it possible to apply LCCA for regional maintenance plans and cost-effective selection of expressway pavement type.

농촌지역 성인들의 혈청 총콜레스테롤치 및 관련요인 (Serum total Cholesterol Levels and Related Factors in a Rural Adult Population)

  • 안순기;감신;진대구;김종연;천병렬
    • Journal of Preventive Medicine and Public Health
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    • 제35권3호
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    • pp.255-262
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    • 2002
  • Objectives : To investigate the fetal cholesterol levels and related factors in a rural adult population. Methods : 3,207 adults(1,272 men and 1,935 women) were examined in 1997 Their heights, weights, and fasting serum total cholesterol levels were measured, and their body mass indices were calculated. A questionnaire interviewing method was used to collect risk factor data. Results : The mean value of total cholesterol were 190.5 mg/dl, and 198.8 mg/dl, and the age-adjusted prevalence rates for hypercholesterolemia (above 240 mg/dl) were 13.7% and 10.2%, in men and women, respectively. From simple analyses, age, educational level, coffee intake, amount of meat and food intake, waist circumference, waist-hip circumference ratio(WHR), and body mass index(BMI) were significant risk factors in men (p<0.05) relating to serum total cholesterol levels. In women, age, educational level, hypertension history, diabetes history, herbal drug history, amount of feed intake, alcohol consumption, waist circumference, WHR, BMI, and menopausal status were significant risk factors (p<0.05). In multiple linear regression analyses, waist circumference (p<0.01), BMI (p<0.01), and coffee intake (p<0.05) proved to be significant risk factors in men. Whereas, menopausal status (p<0.01), BMI (p<0.01), herbal drug history (p<0.01), amount of food intake (p<0.05), waist circumference (p<0.05), and alcohol consumption (p<0.05) were significant risk factors in women. Conclusions : The significant risk factors, for both men and women, relating to the serum total cholesterol were waist circumference and BMI. Thus, for the reduction of serum total cholesterol level, it is recommended that health education for the control of obesity should be implemented.

경남 진주에서 여치 Gampsocleis sedakovi abscura Walker의 생활사에 관한 연구 (Life Cycle of Gampsocleis sedakovi abscura Walker (Orthoptera:Tettigoniidae) in Jinju, Gyeongnam)

  • 윤철호;박정규
    • 농업생명과학연구
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    • 제44권1호
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    • pp.43-49
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    • 2010
  • 본 연구는 경남 진주에서 여름철에 풀숲에서 아름다운 소리를 들려주는 정서곤충의 한 종류인 여치(Gampsocleis sedakovi abscura Walker)에 관한 생활사를 3년간 (2005~2007)에 조사한 결과이다. 여치는 1년에 1세대 발생하며, 성충의 몸길이는 암컷이 60 mm정도이며 수컷은 50 mm정도이었다. 몸의 색깔은 녹색 또는 암갈색의 두 종류가 있었다. 땅 속에서 알 상태로 월동하며, 야외에서 3월 상순부터 약충을 볼 수 있었으며 성충의 우화 최성기는 7월 상순이었다. 야외에서 알기간이 269일, 약충기간이 88일로 성충이 되기까지 357일이 걸렸다. 3년간 평균 산란기간은 63일이었고, 산란수는 평균 94개였다. 평균수명은 암컷이 90일, 수컷이 82일이었으며, 성비는 암컷이 52%이었다. 일일 중 성충의 우화는 오전 8시에서 10시 사이가 가장 많았다.

하이브리드 차량 네트워크를 위한 연결성 분석기의 설계 및 구현 (Design and implementation of a connectivity analyzer for the hybrid vehicular network)

  • 이정훈;김철민;권상철
    • 한국공간정보시스템학회 논문지
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    • 제10권3호
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    • pp.45-54
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    • 2008
  • 텔레매틱스 네트워크 구성을 위한 유용한 가이드라인과 정보를 제공하기 위하여 본 논문은 현재 운영되고 있는 택시 텔레매틱스 시스템으로부터 수집된 실제 이동이력 데이터를 바탕으로 하이브리드 텔레매틱스 네트워크에 있어서의 연결성 분석기를 설계하고 구현한다. 본 설계에 따라 구현된 분석기는 다양한 인자들을 고려한 시뮬레이션에 의해 1) 각각의 차량의 위치를 추적하고, 2) 차량의 타입, 즉, 게이트웨이 또는 일반 노드인지를 설정하며, 3) 특정시간에 한 노드가 모바일 게이트웨이에 연결 될 수 있는지 판단하고 4) 차량의 상태추적에 의해 연결의 단절 시간을 계산한다. 무선 전송거리와 게이트웨이 비율 등의 성능인자를 고려한 이 분석을 통해, 셀룰러 네트워크와 애드혹 네트워크가 결합된 하이브리드 네트워크에서 각 노드의 연결성과 연결 단절시간에 대한 사전분석을 시행할 수 있으며 이에 의해 효율적인 모바일 게이트웨이의 밀도와 버퍼 공간의 양을 결정할 수 있다.

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