• Title/Summary/Keyword: Reproduction number

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낙엽송인공림의 간벌강도에 따른 수종 및 임분구조 변화에 관한 연구 - 오대산국립공원 지역 - (Change of Tree Species and Stand Structure on the Different Thinning Intensities of Larix kaemferi Plantation -In Odaesan National Park-)

  • 엄태원
    • 한국환경생태학회지
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    • 제29권4호
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    • pp.580-589
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    • 2015
  • 1970년대 전국적인 조림정책으로 식재된 낙엽송인공림이 국립공원 내 위치하고 있어 이를 생태적으로 건전하고 종다양성이 풍부한 활엽수림으로 유도하고자 하였다. 이에 오대산국립공원내 월정사지역의 낙엽송림을 대상으로 2009년 밀도별(30%, 50%, 70%) 솎아베기(간벌) 후 2010년부터 2013년까지 활엽수의 천연갱신 양상을 조사하였다. 최근 2012년에서 2013년 사이에 새로이 유입된 흉고직경 2cm 이상의 수목은 없었으며 하층에 상당히 많은 양의 초본이 유입되었으며 이와 더불어 복자기나무, 층층나무, 국수나무, 고추나무 등의 교목성 치수들과 관목류들이 상당수 유입되고 있었다. 그러나 목본류의 많은 개체들이 초본과의 경쟁에서 도태되어 고사하고 새롭게 발생됨을 반복하고 있다. 30% 벌채구내의 치수의 발생량은 2013년 440개체로 매년 2배가량 증가하고 있다. 50% 벌채지 또한 목본류의 개체수는 증가하는 경향을 나타냈으며, 발생 1~2년만에 대부분의 개체들이 초본 및 조릿대와의 경쟁에서 도태되어 고사하고 있다. 70% 벌채지는 타 솎아베기(간벌) 시험구와 달리 2012년의 748개체서 오히려 감소한 608개체의 활엽수가 조사되었다. 이는 임상으로 전광이 유입되면서 조릿대의 번성, 두릅나무의 급격한 증가 때문인 것으로 나타났다. 초본류는 조릿대의 영향으로 거의 발생되지 않았다. 낙엽송인공림의 천연활엽수림으로 유도시 50%이상의 상층의 솎아베기(간벌) 밀도는 임상으로 전광을 유입시킴으로 조릿대와 초본류가 번성할 것을 고려하여 일정 수준 이상의 적정 밀도를 유지한 산림작업이 실시되어야 할 것이다.

1302년 아미타불복장 소화문협힐견(小花紋��纈絹) 염색기법 재현 (Reproduction of the Dyeing Technique Used for the Small Flower Pattern Clamp Resist Dyed Fine Tabby in Amitabha of 1302)

  • 최정임;심연옥
    • 헤리티지:역사와 과학
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    • 제52권2호
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    • pp.254-267
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    • 2019
  • 협힐(��纈)은 직물을 두 개 또는 그 이상의 조각한 목판 사이에 끼워 넣은 후 염색하여 무늬를 표현하는 방염(防染) 기법이다. 통일신라 흥덕왕 9년 복식금제(服飾禁制)에는 육두품녀(六頭品女)와 오두품녀(五頭品女)의 여러 가지 복식 품종에 협힐 사용을 금한다는 기록이 있다. 이것으로 미루어보아 협힐 직물이 당시 널리 사용되었으며 협힐 기법도 통일신라시대 또는 그 이전에 완성되었음을 추측할 수 있다. 그러나 문헌 자료에는 용어만이 언급되었을 뿐 염색 기법이나 정의에 대한 내용은 확인되지 않고 유물도 고려시대의 것만 극히 소량 남아 있어 협힐의 유형이나 특징을 알 수 없다. 공예 기술은 각 나라마다 정치 경제 사회 문화 등의 요인에 의해 변화하며 주변국과의 교류를 통해 발전한다. 따라서 본 논문은 주변국인 중국과 일본의 문헌 및 유물을 조사 분석하여 협힐 유형과 특징을 살펴보았다. 이를 통해 협힐은 국가별 특징보다 무늬를 나타낼 때 사용하는 색의 가짓수에 따라 단색(單色)과 다색(多色)으로 나누어지며, 무늬 구조에 따라 단독(單獨) 좌우대칭(左右對稱) 상하좌우대칭(上下左右對稱)으로 분류되는 것을 알 수 있었다. 또한 중국과 일본에서 전승 및 재현되고 있는 염색 기법의 사례를 연구한 결과 직물에 무늬가 잘 드러나도록 하기 위해서는 사용하는 색의 가짓수와 무늬의 특징에 맞추어 협힐판을 양각(陽刻) 투각(透刻) 음각(陰刻)으로 각각 다르게 조각하여야 하는 것을 확인하였다. 우리나라에서 무늬와 색이 온전히 남아 있는 유일한 유물인 1302년 아미타불복장 소화문협힐견을 실험 대상으로 삼고 염색 기법 사례 연구에서 얻어진 기초자료를 근거로 실증적 실험을 통해 협힐 기법을 재현하였다. 본 논문은 추후 계속 연구할 협힐 기법 재현에 활용될 기초자료를 구축하고, 전승되고 있지 않는 협힐 기법의 재현을 시도하여 기법의 특징을 확인한 것에 의의를 두고자 한다. 그리고 현대적인 무늬 염색 기법과 접목시켜 한국적 무늬 염색의 세계를 넓히며 재창조하는 데 보탬이 되길 기대한다.

Initial Risk Assessment of Acetanilide in OECD High Production Volume Chemical Program

  • Park, Hye-Youn;Park, Yoonho;Sanghwan Song;Kwon, Min-Jeoung;Koo, Hyun-Ju;Jeon, Seong-Hwan;Na, Jin-Gyun;Park, Kwangsik
    • Toxicological Research
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    • 제18권1호
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    • pp.13-22
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    • 2002
  • In Korea, 2,320 tonnes of acetanilide were mostly wed as intermediates for synthesis in phar-maceuticals or additives in synthesizing hydrogen peroxide, varnishes, polymers and rubber. Only small amount of 120 kg were wed as a stabilizer for hydrogen peroxide solution for hair colouring agents in 1998. Readily available environmental or human exposure data do not exist in Korea at the present time. However, potential human exposures from drinking water, food, ambient water and in work places are expected to be negligible because this chemical is produced in the closed system in only one company in Korea and the processing factory is equipped with local ventilation and air filtering system. Acetanilide could be distributed mainly to water based on EQC model. This substance is readily biodegradable and its bioaccumulation is low. Acute toxicity of acetanilide is low since the L $D_{50}$ of oral exposure in rats is 1,959 mg/kg bw. The chemical is not irritating to skin, but slightly irritating to the eyes of rabbits. horn repeated dose toxicity, the adverse effects in rats were red pulp hyperplasia of spleen, bone marrow hyperplasia of femur and decreased hemoglobin, hematocrit and mean corpuscular hemoglobin concentration. The LOAEL for repeated dose toxicity in rats was 22 mg/kg/day for both sexes. Acetanilide is not considered to be genotoxic. In a reproductive/developmental toxicity study, no treatment-related changes in precoital time and rate of copulation, impregnation, pregnancy were shown in all treated groups. The NOAELs for reproduction and developmental toxicity (off-spring toxicity) are considered to be 200 mg/kg bw/day and 67 mg/kg bw/day, respectively. Ecotoxicity data has been generated in a limited number of aquatic species of algae (72 hr- $E_{b}$ $C_{50}$; 13.5 mg/l), daphnid (48hr-E $C_{50}$ > 100 mg/l) and fish (Oryzias latipes, 96hr-L $C_{50}$; 100 mg/l). Form the acute toxicity values, the predicted no effect concentration (PNEC) of 0.135 mg/1 was derived win an assessment factor of 100. On the basis of these data, acetanilide was suggested as currently of low priority for further post-SIDS work in OECD.in OECD.D.

Genomic Polymorphism Analysis using Microsatellite Markers in Gyeongju Donggyeong Dogs

  • Kim, Seung-Chang;Kim, Lee-Kyung;Choi, Seog-Kyu;Park, Chang-Min;Park, Sun-Ae;Cho, Yong-Min;Lim, Dajeong;Chai, Han-Ha;Lee, Seung-Hwan;Lee, Ji-Woong;Sun, Sang-Soo;Choi, Bong-Hwan
    • Reproductive and Developmental Biology
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    • 제36권4호
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    • pp.243-248
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    • 2012
  • This study was conducted to find a useful marker for gene polymorphism analysis using Microsatellite marker (MS marker) in Gyeongju Donggyeong dog. Twenty three MS marker analyzed the genetic features of DNA using 100 Gyeongju Donggyeong dogs in Gyeongju area. It was performed multiplex PCR with 3 set primer divided 9, 10 and 4 by analysis of conditions among MS markers. The results were calculated heterozygosity, polymorphic information content (PIC), allele frequency and number of allele at each locus using Microsatellite Toolkit software and Cervus 3.0 program. Total 148 alleles were genotyped to determine and average 6.43 alleles was detected. FH3381 had the highest of 15 alleles and FH2834 had the lowest of 2 alleles. Expected heterozygosity had a wide range from 0.282 to 0.876 and had average value of 0.6496. Also, Observed heterozygosity had a more wide range from 0.200 to 0.950 and had average value of 0.6404. PIC had range from 0.262 to 0.859 and average PIC was calculated 0.606. Especially, FH2998 represented the highest rate of observed heterozygosity of 0.950 and FH3381 represented the highest rate of expected heterozygosity of 0.876 and PIC of 0.859. The use of these markers was considered to be useful to study genetic traits of Gyeongju Donggyeong dog.

Effects of Caffeine on Maturation-Promoting Factor (MPF) Activity in Bovine Oocytes and on the Development of Somatic Cell Nuclear Transfer Embryos in White-Hanwoo

  • Lee, Joon-Hee;Lee, Hee-Gyu;Baik, Sang-Ki;Jin, Sang-Jin;Moon, Song-Yi;Eun, Hye-Ju;Kim, Tae-Suk;Ko, Yeoung-Gyu;Kim, Sung-Woo;Park, Hae-Geum;Park, Soo-Bong
    • Reproductive and Developmental Biology
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    • 제36권4호
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    • pp.261-267
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    • 2012
  • The technique of SCNT is now well established but still remains inefficient. The in vitro development of SCNT embryos is dependent upon numerous factors including the recipient cytoplast and karyoplast. Above all, the metaphase of the second meiotic division (MII) oocytes have typically become the recipient of choice. Generally high level of MPF present in MII oocytes induces the transferred nucleus to enter mitotic division precociously and causes NEBD and PCC, which may be the critical role for nuclear reprogramming. In the present study we investigated the in vitro development and pregnancy of White-Hanwoo SCNT embryos treated with caffeine (a protein kinase phosphatase inhibitor). As results, the treatment of 10 mM caffeine for 6 h significantly increased MPF activity in bovine oocytes but does not affect the developmental competence to the blastocyst stage in bovine SCNT embryos. However, a significant increase in the mean cell number of blastocysts and the frequency of pregnant on 150 days of White-Hanwoo SCNT embryos produced using caffeine treated cytoplasts was observed. These results indicated that the recipient cytoplast treated with caffeine for a short period prior to reconstruction of SCNT embryos is able to increase the frequency of pregnancy in cow.

Estimation of Inbreeding Levels and Its Effect on Growth Performances of Calves in Hanwoo and Chikso (Korea Brindle) Cattle Population

  • Park, Yong-Soo;Jeong, Dae-Jin;Choy, Yun-Ho;Choi, Tea-Jeong;Lee, Chang-Woo;Choi, Jae-Woun;Lee, Ji-Hong
    • Reproductive and Developmental Biology
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    • 제37권3호
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    • pp.123-127
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    • 2013
  • The objective of this study was to compare the effects of the levels of inbreeding on body weight traits between two breed populations, Hanwoo and Korea Brindle cattle. Birth weight (BW), weaning weight (WW), body weight at 6 months of age (W6) and yearling weight (YW). Records of 1,745 calves (1,513 from Hanwoo, and 232 from Korea Brindle calves) were collected from Livestock Research Institutes in Kangwon, Gyeongbuk and Chungbuk provinces. The least squares means (LSM) and their standard errors for BW, WW, W6 and YW were $25.4{\pm}0.1$ kg, $81.0{\pm}1.8$ kg, $146.1{\pm}3.7$ kg and $291.5{\pm}2.4$ kg, respectively in Hanwoo calves and $22.6{\pm}0.3$ kg, $79.9{\pm}2.3$ kg, $137.6{\pm}4.6$ kg and $249.3{\pm}6.6$ kg, respectively in Korea Brindle calves. Pedigree data showed that 14.8% (316 out of 2131) of Hanwoo was inbred and the average inbreeding coefficient was 0.0209 (2.09%). Inbreeding coefficients of ten calves out of 316 total inbred Hanwoo calves were 12.5% or higher, whereas those of the other 306 calves were less than 12.5%. In both breeds, calves were divided into three groups of inbreeding classes - highly inbred group($F{\geq}0.125$), lowly to medially inbred group(0

Thymocyte Differentiation is Regulated by a Change in Estradiol Levels during the Estrous Cycle in Mouse

  • Lee, Hyojin;Kim, Heejung;Chung, Yiwa;Kim, Jinhee;Yang, Hyunwon
    • 한국발생생물학회지:발생과생식
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    • 제17권4호
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    • pp.441-449
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    • 2013
  • Recent study showed that T cells in the immune organs and peripheral blood are influenced by estradiol, leading to a dysfunction of the immune system. However, little is known about the thymic-gonadal relationship during the estrous cycle in mouse. Therefore, the purpose of this study was to elucidate the mechanism by which a change in estradiol levels during the estrous cycle regulates the development of T cells in the mouse thymus. Six-week-old ICR mice were used and divided into four groups, including diestrous, proestrous, estrous, and metestrous. We first confirmed that ER-${\alpha}$ and - ${\beta}$ estrogen receptors were expressed in thymic epithelial cells, showing that their expression was not different during the estrous cycle. There was also no significant difference in thymic weight and total number of thymocytes during the estrous cycle. To determine the degree of thymocyte differentiation during the estrous cycle, we analyzed thymocytes by flow cytometry. As a result, the percentage of CD4+CD8+ double-positive (DP) T cells was significantly decreased in the proestrous phase compared to the diestrous phase. However, CD4+CD8- or CD4-CD8+ (SP) T cells were significantly increased in the proestrous phase compared to the diestrous phase. In addition, the percentage of CD44+CD25- (DN1) T cells was significantly decreased in the estrous phase compared to other phases, whereas the percentages of CD44+CD25+ (DN2), CD44-CD25+ (DN3), and CD44-CD25- (DN4) were not changed during the estrous cycle. These results indicate that the development of thymocytes may arrest in the DP to SP transition stage in the proestrous phase displaying the highest serum level of estradiol. This study suggests that a change in estradiol levels during the estrous cycle may be involved in the regulation of thymocyte differentiation in the mouse thymus.

Effect of Pregnancy on Lactation Milk Value in Dairy Buffaloes

  • Khan, Sarzamin;Qureshi, Muhammad Subhan;Ahmad, Nazir;Amjed, Muhammad;Durrani, Fazali Raziq;Younas, Muhammad
    • Asian-Australasian Journal of Animal Sciences
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    • 제21권4호
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    • pp.523-531
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    • 2008
  • Buffalo are a major source of milk production, contributing 12.1% in the World and 38.0% in Asia. The buffaloes are kept under peri-urban farming systems to produce milk for urban populations. Breeding is delayed in these herds to get more economic benefit because farmers believe that the pregnancy decreases milk production. The lactation milk value has been studied in this paper as an economic indicator. Complete milk yield records of 3,304 buffaloes was collected from a group of state farms. Economic traits including lactation yield, lactation length, calving interval (CI), dry period and milk yield per day of calving interval (MYPDCI) were derived from the data. The animals were grouped according to parity number (1-3), service period (G1 to G4, conceiving during <150, 150-200, 200-300 and >300 days post calving) and yield levels (HMY>2,500; MMY 2,001-2,500; and LMY 1,500-2,000 liters/ lactation). To study the effect of pregnancy on milk composition a research trial was conducted at a medium size private dairy farm, using forty lactating buffaloes of three yield levels and four service period groups, as described already. Milk was sampled on alternate weeks and analyzed for fat and protein contents (%). For quantifying the value of milk produced during a lactation period, the value corrected milk (VCM) was determined and converted to lactation milk value (LMV). Group means were compared for varicous parameters. Highest milk yield ($2,836.50{\pm}15.68$ liters/lactation) was recorded in the HMY animals of G4 group while lowest milk yield of $1,657.04{\pm}8.34$ liters/lactation was found in LMY of G1. Lactation was significantly increased with the extending of service period. The shortest dry period was recorded in HMY, parity 1, G1 animals and the longest in parity 2, MMY, G4.The CI was shortest in HMY, parity 1, and G1 animals and longest in LMY, parity 3, G4 buffaloes. The HMY, parity 2, G1 buffaloes showed the highest MYPDCI and the lowest value was recorded ($6.53{\pm}0.17$ vs. $2.76{\pm}0.04$ liter/day) for LMY, parity 1, G4 buffaloes. The VCM decreased with the delayed conception. This decreasing trend was higher in respect of the total yield but decrease in the VCM was smaller due to the increasing levels of fat and protein in the milk. The gap between the various production classes was reduced based on the VCM as compared with the yield per day of CI. LMV showed a consistent decline with extending service period in all three production groups. The study suggests that CI increased with delayed conception, showing a consistent trend in the low, moderate and high yielding buffaloes. There was a coherent declining pattern of milk yield with delaying conception, associated with prolonged CI. An animal conceiving at a later stage of lactation showed a decline in financial returns of 24 to 27% compared with those conceiving earlier.

차세대 염기서열 분석법을 이용한 방어(Seriola quinqueradiata)의 microsatellite 마커의 개발 및 유전적 특성 분석 (Development and Genetic Diversity Analysis of Microsatellite Markers Using Next-generation Sequencing in Seriola quinqueradiata)

  • 동춘매;이미난;김은미;박중연;김군도;노재구
    • 생명과학회지
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    • 제30권3호
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    • pp.291-297
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    • 2020
  • 본 연구는 차세대 염기서열 분석법(NGS)을 이용하여 방어의 microsatellite 마커를 개발하고, 개발된 마커를 이용하여 방어 집단의 유전적 특성을 분석하기 위해 수행되었다. 차세대 염기서열 분석 장비인 Illumina Hiseq2500를 이용하여 총 28,873,374개의 read들을 얻어 assembly를 수행한 결과, 전체의 약 1.6%에 해당하는 466,359개의 read들이 assembly 되었으며, 이 read들의 총 길이는 7,247,216,874 bp로 확인되었다. 크기가 518 bp 이상이 되는 contig는 30.729개로 나타났으며, 이 중 microsatellite 영역을 포함하는 contig 132개(0.43%)를 1차로 선별하고, PCR 증폭 여부 및 유전자형 분석을 통해 microsatellite 후보 60개를 2차로 선별하였다. 그 중 방어집단의 마커로서 유용한 15개의 microsatellite 마커를 선택하였다. 방어집단을 대상으로 개발된 15개의 microsatellite 마커로 분석한 결과, 관찰된 유효 대립유전자수(NA)는 평균 18.5(11~30)로 나타났다. 평균 관측치 이형접합도(HO)와 평균기대치 이형접합도(HE)는 각각 0.812(0.431~0.972)와 0.896(0.782~0.949)으로 나타났다. 다형성이 관찰된 모든 microsatellite 마커 간의 연관불평형은 나타나지 않았으며, 해산어의 평균 HE 값인 0.79 이상의 수치를 나타내었다. 따라서 본 연구에서 개발된 15개의 microsatellite 마커는 방어 집단의 유전적 다양성 분석에 유용할 것으로 사료된다.

멸종위기 종인 남생이(Mauremys reevesii)의 동면 여부에 따른 기초 번식생리의 계절적 변동 (Seasonal Changes in the Basic Reproductive Physiology of the Endangered Reeves' Turtle (Mauremys reevesii) Based on Hibernation or Nonhibernation)

  • 정유정;김일훈;구교성;송재영;강신근;박대식
    • 한국환경생태학회지
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    • 제30권6호
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    • pp.977-985
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    • 2016
  • 환경부 지정 멸종위기 II급 종인 남생이의 복원을 위하여 개체증식 프로그램들을 개발해왔지만, 남생이의 번식생리에 대한 이해는 여전히 부족한 상태이다. 본 연구에서는 2014년 11월부터 2015년 10월 사이에 동면을 한 개체와 동면을 하지 않은 개체를 이용하여 성호르몬, 여포와 알의 수와 크기, 암 수간의 행동상호작용의 계절적 변화를 연구하였다. 비록 동면 여부에 따라 다소의 편차는 있었지만, 암컷의 혈청 에스트라디올 농도는 7월부터 증가하기 시작하여 8월-10월에 최고 농도를 보였으며, 수컷의 테스토스테론의 농도는 8-9월에 최고 농도를 보였으며, 3월에 가장 낮았다. 동면을 한 암컷들은 5월초에서 7월 중순 사이에 완전히 발달한 알을 가지고 있었으며, 산란은 6월 초순부터 7월 하순 사이에 이루어졌다. 반면, 동면을 하지 않은 암컷들은 이른 4월부터 이른 6월 사이와 8월 중순에서 11월 하순 사이에 알을 가지고 있었으며, 산란은 6월초, 10월 중순, 2월 초에 이루어졌다. 이러한 결과는 동면이 여포와 알의 정상적인 발달에 매우 중요한 역할을 함을 보여준다. 행동연구에서 암 수간의 구애행동을 포함하는 행동상호작용은 8월 하순부터 증가되어 10-11월에 최대를 보였다. 연구결과는 남생이의 짝짓기 기간이 성호르몬의 증가와 직접 연계되어 있지만, 여포와 알의 발달은 그렇지 않다는 것을 보여준다. 이러한 연구결과는 멸종위기종인 남생이의 성공적인 번식프로그램을 운영하는데 매우 중요하게 사용될 것으로 판단된다.