• Advances in Traditional Medicine
• /
• 제9권1호
• /
• pp.49-57
• /
• 2009

The antifertility activity of methanol extract of Cuscuta reflexa Roxb. stem (MECR) and Corchorus olitorius Linn. seed (MECO) were studied on male Swiss albino mice. The extracts were found to decrease sperm count, percentage of motile sperm and testosterone level in treated mice when compared with vehicle control after 17 days of treatment. The weight of gonads, epididymis were decreased whereas no significant changes of the body weight of mice were observed after methanol extract treatments. The fertility test showed 100% negative result in MECR and MECO treated mice at medium and high dose level of treatment. MECR and MECO in low (25 mg/kg and 15 mg/kg, respectively), medium (50 mg/kg and 20 mg/kg, respectively) and high (75 mg/kg and 25 mg/kg, respectively) dose level caused a simultaneous fall in testicular ${\Delta}5$-$3{\beta}$-hydroxy steroid dehydrogenase and glucose-6-phosphate dehydrogenase activities which are involved in testicular steroidogenesis. Total cholesterol and ascorbic acid content in testis were increased significantly in gonads. The activities of lactate dehydrogenase, malic dehydrogenase and ascorbic acid oxidase were reduced whereas that of carbonic anhydrase was increased significantly in the testis of MECR and MECO treated mice. All these observations indicate that the methanol extract of C. reflexa stem and C. olitorius seed produced antifertility activity in sexually matured male mice, which may be due to inhibition of gonadal steroidogenesis. This activity may be attributed due to the presence of flavonoids and steroids, respectively.

• Molecules and Cells
• /
• 제40권11호
• /
• pp.871-879
• /
• 2017

Levels of maturation-promoting factor (MPF) in oocytes decline after vitrification, and this decline has been suggested as one of the main causes of low developmental competence resulting from cryoinjury. Here, we evaluated MPF activity in vitrified mouse eggs following treatment with caffeine, a known stimulator of MPF activity, and/or the proteasome inhibitor MG132. Collected MII oocytes were vitrified and divided into four groups: untreated, 10 mM caffeine (CA), $10{\mu}M$ MG132 (MG), and 10 mM caffeine + $10{\mu}M$ MG132 (CA+MG). After warming, the MPF activity of oocytes and their blastocyst formation and implantation rates in the CA, MG, and CA+MG groups were much higher than those in the untreated group. However, the cell numbers in blastocysts did not differ among groups. Analysis of the effectiveness of caffeine and MG132 for improving somatic cell nuclear transfer (SCNT) technology using cryopreserved eggs showed that supplementation did not improve the blastocyst formation rate of cloned mouse eggs. These results suggest that maintaining MPF activity after cryopreservation may have a positive effect on further embryonic development, but is unable to fully overcome cryoinjury. Thus, intrinsic factors governing the developmental potential that diminish during oocyte cryopreservation should be explored.

• 한국컴퓨터정보학회논문지
• /
• 제19권12호
• /
• pp.349-357
• /
• 2014

우리나라는 세계에서 유례를 찾아보기 어려운 빠른 속도로 저출산과 더불어 고령화가 진행되어 가고 있다. 인구구조도 피라미드형 구조였으나, 최근에는 역피라미드형 구조가 되어감에 따라 생산인구 문제를 열악하게 만드는 요인으로 작용하고 있다. 노인일자리사업은 이러한 산업구조 역행의 일부를 대체하는 측면도 있지만, 노인의 경제적 측면과 신체적 측면 그리고 사회통합의 측면에서도 효과적인 지원체계가 마련되어져야 한다. 또한 다양한 일자리 창출 및 보급을 위한 노력도 함께 이루어져야 한다. 문화, 복지, 의료, 관광, 체험 등 서비스 분야에서 취약한 부분을 발굴하여 은퇴 전 가지고 있었던 기술과 경험이 활용될 수 있는 양질의 일자리가 만들어 지도록 해야 한다. 따라서 이 연구는 노인일자리사업의 효율화 방안을 위한 이론적 기초를 제공하였다는데 그 의의가 있다.

• 한국작물학회지
• /
• 제35권6호
• /
• pp.481-486
• /
• 1990

1988년도 강원도내 산간고랭지 등 국지적으로 발생한 랭해피해양상을 조사분석한 결과를 요약하면 다음과 같다. 1. 저온 경과시기는 지역간 차이는 있으나 7월 23일부터 8월 2일 사이로 감수분열기에 해당된 벼가 장해형 랭해를 유발하였다. 이때 최저극기온 횡성군 둔내면은 8.5$^{\circ}C$, 평창군 진부면은 5.7$^{\circ}C$였다. 2. 저온피해지역은 표고 300m 이상 산간고랭지가 대부분 해당되는 지역이었다. 3. 랭해피해지역의 임실비율이 80% 이상 되려면 감수분열기 13일간 평균기온 적산온도 285$^{\circ}C$, 최저기온 적산온도 2$25^{\circ}C$ 이상, 17$^{\circ}C$이하 지속일수 5일 이하로 경과하여야 함을 추정할 수 있었다. 4. 감수분열기 저온피해정도별 수량은 총재배면적 $\times$ 총피해품종면적/총면적 $\times$ 감수 분열제 피해면적/총피해품종면적 $\times$ 총예상수량 $\times$ 임실장해율로 산출할 수 있다.

• Journal of Preventive Medicine and Public Health
• /
• 제47권6호
• /
• pp.336-342
• /
• 2014

Objectives: Child mortality remains a critical problem even in developed countries due to low fertility. To plan effective interventions, investigation into the trends and causes of child mortality is necessary. Therefore, we analyzed these trends and causes of child deaths over the last 30 years in Korea. Methods: Causes of death data were obtained from a nationwide vital registration managed by the Korean Statistical Information Service. The mortality rate among all children aged between one and four years and the causes of deaths were reviewed. Data from 1983-2012 and 1993-2012 were analyzed separately because the proportion of unspecified causes of death during 1983-1992 varied substantially from that during 1993-2012. Results: The child (1-4 years) mortality rates substantially decreased during the past three decades. The trend analysis revealed that all the five major causes of death (infectious, neoplastic, neurologic, congenital, and external origins) have decreased significantly. However, the sex ratio of child mortality (boys to girls) slightly increased during the last 30 years. External causes of death remain the most frequent origin of child mortality, and the proportion of mortality due to child assault has significantly increased (from 1.02 in 1983 to 1.38 in 2012). Conclusions: In Korea, the major causes and rate of child mortality have changed and the sex ratio of child mortality has slightly increased since the early 1980s. Child mortality, especially due to preventable causes, requires public health intervention.

• 한국정보전자통신기술학회논문지
• /
• 제12권6호
• /
• pp.582-590
• /
• 2019

우리나라는 저출산·고령화가 진행함에 따라 전체 인구의 14%를 웃도는 고령사회에 진입함으로써 1인 세대의 증가라는 사회변화에 직면해 있다. 고령사회에서 1인 세대 증가로 인한 가스화재 사고를 예방할 수 있는 효과적인 방법은 컨트롤 밸브를 설치하여 설정시간이 지나면 강제적으로 가스를 차단하는 방법이다. 본 연구에서는 밸브 핸들을 돌리지 않고 택트 스위치를 눌러 모터를 이용하여 웜기어와 헬리컬 기어로 동력을 전달하여 밸브를 좌우 회전하여 개폐 할 수 있게 개발하였고, 컨트롤러와 탈부착이 쉽게 전용 밸브를 개발함으로써 조립 및 검사가 용이하고, 부품 수 및 제품 사이즈를 줄여 원가 절감을 통해 경쟁력을 강화할 수 있도록 개발하였다. 또한 내구성 시험을 통해 12초에 한 번씩 ON/OFF 반복하여 34시간 동안 10,000번을 수행하는 동안 안정적으로 동작 할 수 있도록하여 9년 이상을 사용할 수 있도록 개발하였다. 개발 방법은 Solid works와 Altium Designer 툴을 활용하여 기구 및 PCB 설계를 진행하였고, Firmware 개발은 IAR Embedded Workbench 환경에서 개발하였다.

• Asian-Australasian Journal of Animal Sciences
• /
• 제31권9호
• /
• pp.1387-1392
• /
• 2018

Objective: In a nucleus breeding scheme, the sire of dam's pathway plays an important role in producing genetic improvement. Selection proportion is the key parameter for predicting selection intensity, through truncating the normal distribution. Semen sexing using flow cytometry reduces the number of vials of sperm that can be obtained from a proved bull. In addition, a lower fertility of this kind of sperm is expected because of the lower sperm dosage in sex sorted semen. Both of these factors could affect the selection proportion in the sire of dam's pathway ($p_{SD}$). Methods: In the current study, through a deterministic simulation, effect of utilizing sex sorted semen on selection ($p_{SD}$) was investigated in three different strategies including 1: continuous use of sex sorted semen in heifers (CS), 2: the use of sex sorted semen for the first two (S2) and 3: the first (S1) inseminations followed by conventional semen. Results: Results indicated that the use of sex sorted semen has a negative impact on the sire of dams (SD) pathway due to increase in selection proportion. Consequently selection intensity was decreased by 10.24 to 20.57, 6.38 to 8.87 and 3.76 to 6.25 percent in the CS, S2, and S1 strategies, respectively. Conclusion: Considering the low effect of sexed semen on genetic improvement in dam pathways, it is necessary to consider the joint effect of using sex sorted semen on the sire and dams pathway to estimate about the real effect of sexed semen on genetic improvement in a nucleus breeding scheme.

• Asian-Australasian Journal of Animal Sciences
• /
• 제22권2호
• /
• pp.162-167
• /
• 2009

Reproductive abilities in beef cattle herds are receiving increased attention due to recent rises in production costs. To achieve more efficient management, a measure of fertility, namely the number of calves produced at k yr of age ($NCP_k$), was developed and its genetic parameters were estimated from Japanese Black cows by restricted maximum likelihood procedures. The k examined were distributed from 2 to 10 yr of age and $NCP_2$ averaged 1.077 calves over 43,536 cows. The averages increased by approximately 0.9 calf with each additional 1 yr increment in k. Heritabilities of $NCP_k$ were estimated to be low ranging from 0.083 to 0.162, which seemingly suggested a difficulty of genetic improvement. However, large genetic variation and high accuracy were observed in predicted breeding values of $NCP_k$. For example, the breeding values of $NCP_7$ were predicted between -0.303 and +0.213 with average accuracy of 0.607 for cows with observations. Genetic correlations among different k were generally high and positive (0.474 to 0.995). The analyses showed that at least $NCP_4$ was required to maintain the genetic correlations of 0.8 or higher with subsequent $NCP_k$. Also $NCP_5$ maintained the genetic correlations of 0.9 or higher with subsequent $NCP_k$ The results suggested some possibilities for $NCP_k$ to be a selection criterion considering its genetic variation, high accuracy and consistency with subsequent performance.

• 한국콘텐츠학회논문지
• /
• 제13권2호
• /
• pp.420-430
• /
• 2013

본 연구는 저출산 문제의 극복을 위한 정책으로 추진되고 있는 가족친화경영의 현황을 살펴보고 가족친화경영수준의 결정요인을 살펴보고자 하였다. 이를 위해 한국기업지배구조원의 ESG 평가모형에서 가족친화경영과 관련된 평가지표 및 평가결과를 활용하여 분석을 수행하였다. 분석결과 기업규모가 크고 부채비율이 낮으며 기업가치가 높은 기업일수록 가족친화경영에 적극적인 것으로 나타났으며 가족친화적 제도운영에 있어서는 종업원이나 정규직 직원 중 여성비율이 낮을수록 높게 나타나 기존의 연구와 다르게 나타났다. 그밖에 최대주주지분율이 높을수록 평가점수가 낮게 나타났다. 이러한 결과들은 우리나라 상장기업들이 아직까지 여성근로자의 고용규모에 비해 가족친화적 제도의 운영이 부족하며 가족친화경영의 활성화를 위해서는 최고경영진의 관심과 지원이 필수적이나 아직까지 우리 기업의 최대주주들은 이에 대해 적극적이지 않다는 의미로 해석된다.

• 한국초지조사료학회지
• /
• 제17권1호
• /
• pp.1-10
• /
• 1997

Unreduced (2n) gametes are meiotic products (pollen or egg) having a sporophytic (somatic) chromosome number, resulting from abnormalities during either microsporogenesis or megasporogenesis. They occur naturally at a low frequency in many plant species. Unreduced (2n) gametes in plants can be identified for four possible ways as follow i) pollen size and/or shape differences between haploid (n) and diploid (2n) pollen, ii) ploidy analysis (chromosome number) of progeny or meiotic analysis (presence of dyads andlor triads at the microspore stage), iii) progeny performance and fertility and iv) dosage of isozyme and DNA markers. Unreduced (2n) gametes can be an effective breeding tool in synthesizing new cultivars, providing a unique method to maximizing heterozygosity, i.e., transferring a large proportion of the non-additive genetic effects (intra- and inter- locus interactions) h m parent to offspring and can also be used to overcome infertility of interploidy crosses. Sexual polyploidization through 2n gametes has been a major route to the formation of naturally occurring polyploids. The three mechanisms of 2n pollen formation in potato have been discovered as follow: i) parallel spindles (ps) or tripolar spindles (ts), ii) premature cytokinesis (pc-I, pc-2) and iii) synaptic mutants (sy-2, sy-3, sy-4). Genetic analysis indicated that the mechanisms of 2n gamete formation were controlled by single recessive gene in potato, alfalfa, red clover, etc., and by two recessive genes in wheat. The use of 2n gametes which can efficiently transfer germplasm fiom wild relatives to cultivated species, especially fiom diploid to tetraploid could make a contribution to the improvement of germplasm base in breeding programs.