• Title/Summary/Keyword: Natural reproduction

검색결과 412건 처리시간 0.031초

차량시뮬레이터 및 아이카메라를 이용한 도로안전성 평가기법 개발 (Development of Road Safety Estimation Method using Driving Simulator and Eye Camera)

  • 도철웅;김원근
    • 한국도로학회논문집
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    • 제7권4호
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    • pp.185-202
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    • 2005
  • 본 연구에서는 현장 실험 조성의 제약을 극복하기 위해 3차원 가상현실(virtual reality)로 설계중인 도로를 모델링한 후, 피실험자가 Eye camera가 장착된 차량 시뮬레이터 (driving simulator)에 탑승하고 주행하면서 운전자가 행하는 선형변화에 대한 동적 반응 및 운전자의 시각행태에 대한 데이터를 획득하였다 본 실험에 적용된 차량시뮬레이터의 그래픽 모듈은 동역학 해석 모듈에 의해 얻어진 데이터를 기초로 하여 운동재현기와 가상환경의 일치감들 최대로 함으로써 피실험자로 하여금 차량시뮬레이터의 비현실성 및 부작용을 최소화하도록 하였다. 또한, Eye camera는 기존의 여타 장비와는 달리 운전자가 헬멧이나 렌즈 등 어떠한 부착장치도 착용하지 않고 실험할 수 있는 FaceLAB을 사용함으로써 운전자의 자연스러운 시각행태를 아무런 데이터 손실없이 획득하였다. 본 연구에서는 조사된 데이터를 바탕으로 도로 안전성을 평가하기 위해 차량 시뮬레이터, Eye camera방법을 통해 설계시 도로 기하구조 변화에 따라 운전자가 느끼는 안전성의 변화를 파악함으로써 도로 기하구조 조건과 안전성의 상관성을 명확하게 규명하고 이를 통해 운전자가 도로 주행시 편안하고 쾌적한 주행을 보장받을 수 있는 도로를 설계 단계에서부터 평가할 수 있는 방법을 제시하려고 한다.

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작은대칭이, Anodonta arcaeformis flavotincta의 유생 발생 중 숙주어류내에서 글로키디움 유생의 피낭 형성과정에 관한 연구 (Studies on the Glochidial Encystment in Host Fish during the development of Anodonta arcaeformis flavotincta)

  • 박갑만
    • 한국발생생물학회지:발생과생식
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    • 제2권1호
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    • pp.81-87
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    • 1998
  • 한국산 작은대칭이 (Anodonta arcaeformis flavotincta)의 유생발생 중 유생(glochidium)을 숙주어류인 붕어(carassius auratus)에 감염시켜 유생의 피낭형성과정(부착부위, 부착후 탈락가지의 시기)을 알아보기 위해, 주사전자현미경을 이용하여 관찰한 결과 다음과 같은 결론을 얻었다. 유생들은 30분내에 숙주어류의 니트러미, 구강 그리고 아가미에 부착되었다. 이 연구에서 유생이 부착된 숙주어류의 지느러미를 시간별로 관찰하였다. 유생의 부착률은 숙주어류의 가슴지느러미,꼬리지느러미, 배지느러미에 각각 30%, 22%, 17%였다. 피낭형성과정은 천천히 진행되었다. 1차 피낭형성은 24시간에서 27시간째에 이루어졌고, 그리고 5일 내지 6일째 유생은 숙주조직의 상피세포로 완전히 덮였다. 유패의 탈락과정은 숙주에 감염시킨후 8일째에 관찰되었다. 유생의 대부분은 15일 이내에 숙주어류의 피낭으로부터 탈락되었다. 유생이 숙주에 부착되기 전과 숙주어류의 피낭으로부터 탈락된 유패의 크기는 변화가 없었다.

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Egg Development and Morphology of Larva and Juvenile of the Oryzias latipes

  • Lee, Sung-Hun;Kim, Chun-Cheol;Koh, Soo-Jin;Shin, Lim-Soo;Cho, Jae-Kwon;Han, Kyeong-Ho
    • 한국발생생물학회지:발생과생식
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    • 제18권3호
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    • pp.173-178
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    • 2014
  • In order to monitor the developmental features of embryos, larvae, and juveniles of Oryzias latipes (Temminck and Schlegel), Oryzias latipes was caught in river of Shinduck-dong, Yeosu-si, Jeollanam-do, on May 2011, and experiments were carried out in Ichthyology laboratory at Chonnam National University. The blastodisc step was the first level for natural spawning. The optic vesicle, Kupffer's vesicle, myotome began to appear 75 hours 57 minutes later. After blastodisc development, the pectoral fins were made at 143 hours 37 minutes and the tail was separated started at the same time. Hatching was observed at 167 hours 27 minutes after blastodisc. The total length of the hatched larvae was 4.95~5.10 mm (mean, 5.01 mm), the mouth and anus were opened. Larvae used yolk completely after 3 days after hatching. The total length larvae was 5.45~5.56 mm (mean, 5.52 mm) after 8 days after hatching, and appeared the stems for tail. The stems pectoral, anal fin were showed after 14 days and the stems dorsal, ventral fin were appeared after 19 days. For 35 days after hatching, the total length of larvae 13.95~15.30 mm (mean, 14.64 mm), and at this time, fins and body were transferred like the adult Oryzias latipes.

2009개정 교육과정에서 과학과와 타교과의 성취기준 중복성에 대한 분석 (Analysis for the Duplication of Achievement Standards between Science and Other Subjects in the 2009 Revised National Curriculum)

  • 박재근
    • 과학교육연구지
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    • 제38권2호
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    • pp.231-243
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    • 2014
  • 이 연구의 목적은 2009개정 교육과정에서 과학과와 타 교과목들 사이에 제시된 성취기준의 중복성 문제를 살펴보고, 문제 해결을 위한 시사점과 개선 방안을 제안하는데 있다. 분석을 위한 내용 범주는 '우리 몸과 건강', '생물과 환경', '생식과 발', '생물의 다양성', '기술의 세계', 그리고 '자연재해' 등이고, 이들 범주에 제시된 과학과의 성취기준들이 실과, 사회, 체육, 도덕 교과와 중복되어 있다. 이 중 '우리 몸과 건강', '생물과 환경', '생물의 다양성', '자연재해' 범주의 성취기준은 교과목간 중복성이 높지 않은 것으로 분석되며, 이는 관련 교과목들이 공통적인 주제를 다루고 있지만 교육과정에 진술된 세부적인 성취기준들이 해당 교과목의 본질적인 특성을 비교적 잘 반영하여 분산되어 있기 때문이다. 이에 비해 '생식과 발생', '기술의 세계' 범주의 성취기준은 타 교과목과 중복성의 정도가 심각한 것으로 나타났다. 이러한 문제들에 대처하기 위해서는 관련 교과목들의 성취기준을 하나로 합치거나 통합하는 것과 같은 해결 방법을 모색해 보아야 하며, 또한 관련 교과교육 전문가들을 중심으로 성취기준의 적절성에 대한 범교과적인 논의와 조정을 통해 각 교과목의 정체성에 부합하는 성취기준 개발을 위해 노력해야 할 것으로 본다.

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Green Fluorescent Protein 발현 토끼 수정란의 핵이식에 의한 복제 (Cloning of Transgenic Rabbit Embryos Expressing Green Fluorescent Protein Gene by nuclear Transplantation)

  • 강태영;윤희준;노규진;이항;채영진;이효종
    • 한국수정란이식학회지
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    • 제15권2호
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    • pp.167-173
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    • 2000
  • The principal objective of this study was to clone transgenic embryos in order to improve the efficiency of transgenic animal production by the combination of microinjection and nuclear transplantation techniques. Mature female New Zealand White rabbits were superovulated by eCG and hCG treatments, fllowed by natural mating. Zygotes were collected from the oviducts at 18∼22 h after hCG injection by flushing with D-PBS containing 5% fetal calf serum(FCS). Two to three picoliters of green fluorescent protein(GFP) gene wa microinjected into male pronucleus. The foreign gene-injected zygotes were cultured in TCM-199 or RD medium containing 10% FCS with a monolayer of rabbit oviductal epithelial cells in a 5% CO2 incubator. The morulae expressing GFP gene were selected and their blastomeres were separated for the use of nuclear donor. Following nuclear transplantation of fluorescence-positive morula stage blastomeres, 13 (21.3%) out of 61 fused oocytes developed to blastocyst stage and all of the cloned blastocysts expressed GFP. The results indicate that the screening of transgene in rabbit embryos by GFP detection could be a promisible method for the preselection of transgenic embryos. Also the cloning of preselected transgenic embryos by nuclear transplantatin could be efficiently applied to the multiple production of transgenic animals.

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낙동강 권역의 하천 수면공간 및 수변환경이 수달의 출현에 미치는 영향분석 (Impacts of Aquatic and Riparian Environmental Factors on Eurasian Otter (Lutra lutra) Presence Characteristics in the Nakdong River Basin)

  • 신지훈;노백호
    • 한국환경과학회지
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    • 제26권12호
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    • pp.1341-1353
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    • 2017
  • This study aimed to identify the aquatic and riparian factors associated with the presence/absence of the Eurasian otter in the Nakdong river basin, where the species is relatively more abundant than other otter species. Environmental factors and presence records were collected. Geographical Information System technology and chi-square test were used to compare environmental gradients in aquatic and riparian factors between presence and absence sites. Aquatic habitat attributes were evaluated with natural riverside sandbars and channel crossing artificial structures, the ratio of channel width to alluvial plain width, riverbed substrate, and flow diversity. Riverbank characteristics, bank materials, man-made embankment types, and land use/land cover of inland and riverside areas were selected as riparian habitat attributes. Compared to the aquatic attributes, riparian attributes were highly significant when assessing otter presence and absence sites, suggesting that conservation of suitable riparian areas to provide maternity and resting areas for otter species is essential in the Nakdong river basin. None of the aquatic attributes examined were statistically significant when evaluating otter presence or absence. These results indicate that the presence of suitable riparian area for resting and reproduction habitats is more critical to the presence of Eurasian otter than food availability in aquatic areas. To inform implementation of effective conservation actions, broad-scale factors, such as watershed attributes, would be needed to further assess habitat conditions of the Eurasian otter.

Cyclic variations of gonad development of an air-breathing fish, Channa striata in the lentic and lotic environments

  • Al Mahmud, Nasim;Rahman, Hassan Md. Hafizur;Mostakim, Golam Mohammod;Khan, Mohd. Golam Quader;Shahjahan, Md.;Lucky, Nahid Sultana;Islam, M. Sadiqul
    • Fisheries and Aquatic Sciences
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    • 제19권1호
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    • pp.5.1-5.7
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    • 2016
  • The study was conducted to know the cyclic changes in gonadal maturation and to investigate the developmental stages of oocytes and testicular germ cells of an air-breathing fish, Channa striata. Fish were sampled monthly from lentic and lotic environments of three geographical locations of Bangladesh from December to November and the histological analysis of their gonad was done to evaluate the objectives. The highest mean GSI was $5.95{\pm}0.20$ for female in July and $0.14{\pm}0.01$ for male also in July showing that the gonadal development reached its peak during this month. The highest mean oocyte diameter was $1257.50{\pm}24.17{\mu}m$ observed in July implying that the oocyte reached maturity in this month. Histological study of ovary revealed the evidence of early yolk granule stage and late yolk granule stage from April to July. In case of male four stages of spermatogenesis were distinguished and spermatozoa were highly abundant in June and July. So the monthly pooled values of GSI and the analysis of gonadal histology indicated that the peak breeding season of C. striata occurred in July in the lentic and lotic environments. Samples collected from lentic and lotic habitats are suggestive of no difference in the development of the gonad. The results of the present study will be useful for selective breeding programme, conservation and sustainable fishery management of C. striata in its natural habitat.

Control of $Ca^{2+}$- Influx by $Ca^{2+}$/Calmodulin Dependent Protein Kinase II in the Activation of Mouse Eggs

  • Yoon, Sook-Young;Kang, Da-Won;Bae, In-Ha
    • 한국발생생물학회지:발생과생식
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    • 제15권1호
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    • pp.31-39
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    • 2011
  • Change in intracellular $Ca^{2+}$-concentration ($[Ca^{2+}]_i$) is an essential event for egg activation and further development. $Ca^{2+}$ ion is originated from intracellular $Ca^{2+}$-store via inositol 1,4,5-triphosphate receptor and/or $Ca^{2+}$ influx via $Ca^{2+}$ channel. This study was performed to investigate whether changes in $Ca^{2+}$/calmodulin dependent protein kinase II (CaM KII) activity affect $Ca^{2+}$ influx during artificial egg activation with ethanol using $Ca^{2+}$ monitoring system and whole-cell patch clamp technique. Under $Ca^{2+}$ ion-omitted condition, $Ca^{2+}$-oscillation was stopped within 30 min post microinjection of porcine sperm factor, and ethanol-induced $Ca^{2+}$ increase was reduced. To investigate the role of CaM KII known as an integrator of $Ca^{2+}$- oscillation during mammalian egg fertilization, CaM KII activity was tested with a specific inhibitor KN-93. In the eggs treated with KN-93, ethanol failed to induce egg activation. In addition, KN-93 inhibited inward $Ca^{2+}$ current ($I_{Ca}$) in a time-dependent manner in whole-cell configuration. Immunostaining data showed that the voltage-dependent $Ca^{2+}$ channels were distributed along the plasma membrane of mouse egg and 2-cell embryo. From these results, we suggest that $Ca^{2+}$ influx during fertilization might be controlled by CaM KII activity.

꼬치동자개(Pseudobagrus brevicorpus)의 생태와 초기 생활사 (Ecology and Early Life History of Endangered Freshwater Fish, Pseudobagrus brevicorpus (Pisces: Bagridae))

  • 강언종;양현;이흥헌;조용철;김응오;임상구;방인철
    • 환경생물
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    • 제25권4호
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    • pp.378-384
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    • 2007
  • 멸종위기에 처한 우리나라 고유 담수어인 꼬치동자개 Pseudobagrus brevicorpus의 증식 복원을 위한 연구의 일환으로 생태와 초기생활사에 대해 조사하여 다음과 같은 결과를 얻었다. 꼬치동자개는 특정 조건에 밀집되어 개체군을 형성하며 서식밀도는 1.25개체 $m^{-2}$이었고, 생산력은 200$\sim$250개 마리$^{-1}$ 낮아 멸종위기 상황을 시사하였다. 산란은 자연산란 유도 결과 수초에 산란하는 것으로 추정되며 부화한 치어는 군집생활을 한다. 수정난은 약 50시간만에 부화하였으며, 부화 3일 후 난황이 거의 흡수되었고, 부화 8일 후에는 올챙이형으로 군집하며, 30일경에 어미와 같은 형태를 보이는 치어기로 성장하였다. 이러한 산란 생태와 관련하여 멸종위기에 처한 꼬치동자개의 증식 복원과 보존을 위한 방안들을 고찰하였다.

안면형상연구의 인간과학적 기초 연구 - 정기신혈(精氣神血)의 유체역학적(流體力學的) 해석을 중심으로 - (Fundamental Studies on Human Sciences by Facial Form Analysis - Based on Unit Fluid Model of Essence, Qi energy, Emotion, Blood -)

  • 김종원;이인선;김규곤;이용태;김경철;엄현섭;지규용
    • 동의생리병리학회지
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    • 제22권5호
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    • pp.1057-1061
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    • 2008
  • For the purpose of investigating the reasonable logics contained in physiognomy of east and old western medicine. hypothetical researches based on hydromechanics theory were performed concerning facial types of form and pathologic features, especially 4 types of Dr. Jisan-Essence, Qi energy. Emotional Activity and Blood(EQAB). In order to infer the functional relation between facial type forming and EQAB factors, EQAB were supposed as fluid grounded on their continual flowing or periodical change and pressure effect from its congestion. and a premise that there's a linear corresponding relationship between the appearance of organ and its physical conditions of its inner vessels is formed too. Through this work, the unit fluid model(UFM) of Essence can be assumed as circle shape formed by the high viscosity and surface tension, the UFM model of Qi energy as quadrangular shape by the scattering features to outer four directions, and the UFM of emotional activity as inverted triangular shape by the flippant and uprising features, and the UFM of blood as ellipsoid triangle by the heavy and descending features in spite of circulation. The shapes made from each UFM are reproduced in the process of human development and manifest respective facial shape through the self-reproduction method like fractal theory in the last. Conclusively. it is said that the facial form analysis method like EQAB type theory can be the useful methodology to understand the human pathological and physiological features in view of hydromechanics.