• 제목/요약/키워드: Study ability

Search Result 17,963, Processing Time 0.348 seconds

The Relations between Financial Constraints and Dividend Smoothing of Innovative Small and Medium Sized Enterprises (혁신형 중소기업의 재무적 제약과 배당스무딩간의 관계)

  • Shin, Min-Shik;Kim, Soo-Eun
    • Korean small business review
    • /
    • v.31 no.4
    • /
    • pp.67-93
    • /
    • 2009
  • The purpose of this paper is to explore the relations between financial constraints and dividend smoothing of innovative small and medium sized enterprises(SMEs) listed on Korea Securities Market and Kosdaq Market of Korea Exchange. The innovative SMEs is defined as the firms with high level of R&D intensity which is measured by (R&D investment/total sales) ratio, according to Chauvin and Hirschey (1993). The R&D investment plays an important role as the innovative driver that can increase the future growth opportunity and profitability of the firms. Therefore, the R&D investment have large, positive, and consistent influences on the market value of the firm. In this point of view, we expect that the innovative SMEs can adjust dividend payment faster than the noninnovative SMEs, on the ground of their future growth opportunity and profitability. And also, we expect that the financial unconstrained firms can adjust dividend payment faster than the financial constrained firms, on the ground of their financing ability of investment funds through the market accessibility. Aivazian et al.(2006) exert that the financial unconstrained firms with the high accessibility to capital market can adjust dividend payment faster than the financial constrained firms. We collect the sample firms among the total SMEs listed on Korea Securities Market and Kosdaq Market of Korea Exchange during the periods from January 1999 to December 2007 from the KIS Value Library database. The total number of firm-year observations of the total sample firms throughout the entire period is 5,544, the number of firm-year observations of the dividend firms is 2,919, and the number of firm-year observations of the non-dividend firms is 2,625. About 53%(or 2,919) of these total 5,544 observations involve firms that make a dividend payment. The dividend firms are divided into two groups according to the R&D intensity, such as the innovative SMEs with larger than median of R&D intensity and the noninnovative SMEs with smaller than median of R&D intensity. The number of firm-year observations of the innovative SMEs is 1,506, and the number of firm-year observations of the noninnovative SMEs is 1,413. Furthermore, the innovative SMEs are divided into two groups according to level of financial constraints, such as the financial unconstrained firms and the financial constrained firms. The number of firm-year observations of the former is 894, and the number of firm-year observations of the latter is 612. Although all available firm-year observations of the dividend firms are collected, deletions are made in the case of financial industries such as banks, securities company, insurance company, and other financial services company, because their capital structure and business style are widely different from the general manufacturing firms. The stock repurchase was involved in dividend payment because Grullon and Michaely (2002) examined the substitution hypothesis between dividends and stock repurchases. However, our data structure is an unbalanced panel data since there is no requirement that the firm-year observations data are all available for each firms during the entire periods from January 1999 to December 2007 from the KIS Value Library database. We firstly estimate the classic Lintner(1956) dividend adjustment model, where the decision to smooth dividend or to adopt a residual dividend policy depends on financial constraints measured by market accessibility. Lintner model indicates that firms maintain stable and long run target payout ratio, and that firms adjust partially the gap between current payout rato and target payout ratio each year. In the Lintner model, dependent variable is the current dividend per share(DPSt), and independent variables are the past dividend per share(DPSt-1) and the current earnings per share(EPSt). We hypothesized that firms adjust partially the gap between the current dividend per share(DPSt) and the target payout ratio(Ω) each year, when the past dividend per share(DPSt-1) deviate from the target payout ratio(Ω). We secondly estimate the expansion model that extend the Lintner model by including the determinants suggested by the major theories of dividend, namely, residual dividend theory, dividend signaling theory, agency theory, catering theory, and transactions cost theory. In the expansion model, dependent variable is the current dividend per share(DPSt), explanatory variables are the past dividend per share(DPSt-1) and the current earnings per share(EPSt), and control variables are the current capital expenditure ratio(CEAt), the current leverage ratio(LEVt), the current operating return on assets(ROAt), the current business risk(RISKt), the current trading volume turnover ratio(TURNt), and the current dividend premium(DPREMt). In these control variables, CEAt, LEVt, and ROAt are the determinants suggested by the residual dividend theory and the agency theory, ROAt and RISKt are the determinants suggested by the dividend signaling theory, TURNt is the determinant suggested by the transactions cost theory, and DPREMt is the determinant suggested by the catering theory. Furthermore, we thirdly estimate the Lintner model and the expansion model by using the panel data of the financial unconstrained firms and the financial constrained firms, that are divided into two groups according to level of financial constraints. We expect that the financial unconstrained firms can adjust dividend payment faster than the financial constrained firms, because the former can finance more easily the investment funds through the market accessibility than the latter. We analyzed descriptive statistics such as mean, standard deviation, and median to delete the outliers from the panel data, conducted one way analysis of variance to check up the industry-specfic effects, and conducted difference test of firms characteristic variables between innovative SMEs and noninnovative SMEs as well as difference test of firms characteristic variables between financial unconstrained firms and financial constrained firms. We also conducted the correlation analysis and the variance inflation factors analysis to detect any multicollinearity among the independent variables. Both of the correlation coefficients and the variance inflation factors are roughly low to the extent that may be ignored the multicollinearity among the independent variables. Furthermore, we estimate both of the Lintner model and the expansion model using the panel regression analysis. We firstly test the time-specific effects and the firm-specific effects may be involved in our panel data through the Lagrange multiplier test that was proposed by Breusch and Pagan(1980), and secondly conduct Hausman test to prove that fixed effect model is fitter with our panel data than the random effect model. The main results of this study can be summarized as follows. The determinants suggested by the major theories of dividend, namely, residual dividend theory, dividend signaling theory, agency theory, catering theory, and transactions cost theory explain significantly the dividend policy of the innovative SMEs. Lintner model indicates that firms maintain stable and long run target payout ratio, and that firms adjust partially the gap between the current payout ratio and the target payout ratio each year. In the core variables of Lintner model, the past dividend per share has more effects to dividend smoothing than the current earnings per share. These results suggest that the innovative SMEs maintain stable and long run dividend policy which sustains the past dividend per share level without corporate special reasons. The main results show that dividend adjustment speed of the innovative SMEs is faster than that of the noninnovative SMEs. This means that the innovative SMEs with high level of R&D intensity can adjust dividend payment faster than the noninnovative SMEs, on the ground of their future growth opportunity and profitability. The other main results show that dividend adjustment speed of the financial unconstrained SMEs is faster than that of the financial constrained SMEs. This means that the financial unconstrained firms with high accessibility to capital market can adjust dividend payment faster than the financial constrained firms, on the ground of their financing ability of investment funds through the market accessibility. Futhermore, the other additional results show that dividend adjustment speed of the innovative SMEs classified by the Small and Medium Business Administration is faster than that of the unclassified SMEs. They are linked with various financial policies and services such as credit guaranteed service, policy fund for SMEs, venture investment fund, insurance program, and so on. In conclusion, the past dividend per share and the current earnings per share suggested by the Lintner model explain mainly dividend adjustment speed of the innovative SMEs, and also the financial constraints explain partially. Therefore, if managers can properly understand of the relations between financial constraints and dividend smoothing of innovative SMEs, they can maintain stable and long run dividend policy of the innovative SMEs through dividend smoothing. These are encouraging results for Korea government, that is, the Small and Medium Business Administration as it has implemented many policies to commit to the innovative SMEs. This paper may have a few limitations because it may be only early study about the relations between financial constraints and dividend smoothing of the innovative SMEs. Specifically, this paper may not adequately capture all of the subtle features of the innovative SMEs and the financial unconstrained SMEs. Therefore, we think that it is necessary to expand sample firms and control variables, and use more elaborate analysis methods in the future studies.

Primiparas만 Perceptions of Their Delivery Experience and Their Maternal-Infant Interaction : Compared According to Delivery Method (초산모의 분만유형별 분만경험에 대한 지각과 모아상호작용 과정에 관한 연구)

  • 조미영
    • Journal of Korean Academy of Nursing
    • /
    • v.20 no.2
    • /
    • pp.153-173
    • /
    • 1990
  • One of the important tasks for new parents. especially mothers, is to establish warm, mutually affirming interpersonal relationships with the new baby in the family, with the purpose of promoting the healthy development of the child and the wellbeing of the whole family. Nurses assess the quality of the behavioral characteristics of the maternal-infant interaction. This study examined the relationships between primiparas pereptions of their delivery experience and their maternal infant interaction. It compared to delivery experience of mothers having a normal vaginal delivery with those having a casearean section. The purpose was to explore the relationships between the mother's perceptions of her delivery experience with her maternal infant interaction. The aim was to contribute to the development of theoretical understanding on which to base care toward promoting the quality of maternal-infant interaction. Data were collected directly by the investigator and a trained associate from Dec. 1, 1987 to March 8, 1988. Subjects were 3 random sample of 62 mothers, 32 who had a normal vaginal delivery and 30 who had a non-elective cesarean section (but without other perinatal complications) at three general hospitals in Seoul. Instruments used were the Stainton Parent -infant Interaction Scale(1981) and the Marut and Mercer Perception of Birth Scale(1979). The first observations were made in the delivery room (for vaginally delivered mothers only), followed by day 1, day 2, day 3, and 2 weeks, 4 weeks, 6 weeks and 8 weeks after birth, for a total of 7-8 contacts(Cesarean section mothers were observed on days 4 and 5 but the data not used for analysis). Observations in the hospital were made during the hour prior to scheduled feedings. The infant was placed beside the mother. Later contacts were made at home. Data analysis was done by computer using as SPSS program and indulded X² test, paired t-test, t-test, and Pearson Correlation coefficient ; the results were as follows. 1. Mothers who had a normal vaginal delivery tended to perceive the delivery experience more positively than cesarean section mothers(p=0.002). The finding supported the hypothesis I that perception of delivery would vary according to the method of delivery. Mothers' perceptions of birth were classified into three dimensions, labor, delivery and the bady. There was a significantly different and positive perception by the vaginally delivered mothers to the delivery experience(p=0.000) but no differences for labor or the bady according to the delivery method(p=0.096, p=0.389), 2. Mothers who had a normal vaginal delivery had higher average maternal-infant interaction scores(p=0.029) than mothers who had a cesarean section. There were similar higher scores for the 1st day(p=0.042), 2nd day (p=0.009), and the 3rd day(p=0.006) after delivery but not for later times. The findings supported the hypothesis Ⅱ that there would be differences in maternal-infant interaction for mothers having vaginal and cesarean section deliveries. However these differences deccreased section deliveries. However these differences decreased over time . by eight weeks the scores for vaginal delivery mothers averaged 8.1 and for cesarean section mothers, 7.9. 3. The more highly positive the pereption of the delivery experience, the higher the maternal-infant interaction score for all subjects(F=.3206, p=.006). The findings supported the hypothesis Ⅲ that there would be correlations between perceptions of delivery and maternal-infant interaction. The maternal infant interaction was highest when the perception of the bady and deliery was positive(r=.4363, p=.000, r=.2881, p=.012). No correlations between perceptions of labor and maternal-infant interaction were found(p=0.062). 4. The daily maternal-infant interaction score for the initial contact after birth to 8 weeks postpartum had the lowest average score 5.20 and the highest 7.98(in a range of 0-10). This subjects group of mothers needed nursing intervention to promote their maternal- infant interaction. The daily scores for the maternal-infant over the period of eight weeks. However, there were significantly different increases in maternal-infant interaction only from the first to second day(p=0.000) and from the fourth to sixth weeks after birth(P=0.000). 5. When the eight items of maternal-infant interaction were evaluated separately, “Expresses feelings about her role as mother” had the highest average score, 1.64(ina range of 0-3)and “Speaks to baby” the lowest, 0.9. All items, with the possible exception of “Expresses feelings about her role as mother”, suggested the subjects' need of nursing intervention to promote maternal-infant interaction. 6. There were positive correlations between certain general charateristis, namely, both a higher economic status(p=0.002) and breast feeding(p=0.202) and maternal - infant interaction. There were positive correlations between a mother's confidence in her role as a mother and the perception of the birth experience(p=0.004). For mothers who had a cesarean section, a positive perception of the birth experience was related to the duration of her marriage(p=0.010), a wanted pregnancy (P=0.030) and her confidence in her role as a mother(p=0.000). Pereptions of birth for mothers who had a normal vaginal delivery were positive than those for mothers who had a cesarean section. The level of maternalinfant interaction for mothers delivered vaginally was higher than for cesarean section mothers. The relationship between perception of birth and materanalinfant interaction was confirmed. Cesarean section has an impact on the mother's perceived experience of birth which, in turn, is positively related to maternal-infant in turn, is positively related to maternal-infant interaction. Nursing intervention to enhance maternal-infant interaction should begin in prenatal classes with an exploration of the potential impact of cesarean section on the perceptions of the birth experience and continue throughout the perinatal and post-natal periods to promote the mother's ability to control with this crisis experience and to mobilize social support. Nursing should help transform a relatively negatively perceived experience into an accepted, positively perceived and self affirming experience which enhances the maternal-infant relationship.

  • PDF

Ecological Characteristic between the Re-introduction Population and the Original Population (Jojong Stream, Sudong Stream) of Zacco koreanus in the Bongseonsa Stream, Korea (봉선사천의 참갈겨니(Zacco koreanus) 재도입 개체군과 원개체군(조종천, 수동천) 간 생태학적 특징)

  • Wang, Ju-Hyoun;Choi, Jun-Kil;Lee, Hyuk-Je;Lee, Hwang-Goo
    • Korean Journal of Environment and Ecology
    • /
    • v.31 no.6
    • /
    • pp.537-548
    • /
    • 2017
  • The purpose of this study was to investigate the species composition and the aquatic environment of Jojong Stream and Sudong Stream, which were the original habitats of Zacco koreanus population and restored population re-introduced in Bongseonsa Stream. It also compared and analyzed the states of the growth and reproductive ability of Z. koreanus habiting in each of the three streams. The investigation was conducted in June 2016 which was known as the spawning season of Z. koreanus. The results of the physical aquatic environments showed the slight differences in altitude, width and depth of water among three streams, but the bottom structure was found to be quite different in the composition of the boulder, cobble, and pebble among the streams. The result of the physicochemical aquatic environment analysis showed that there were no significant differences in water temperature, pH, DO, BOD, and EC among the three stream. In the fish fauna investigation, 530 individuals of 11 species of 3 families were collected in Bongseonsa Stream, 293 individuals of 12 species of 4 families were collected in Jojong Stream, and 361 individuals of 11 species of 4 families were collected in Sudong Stream. All three streams were dominated by Z. koreanus and Z. platypus. Six Korean endemic species appeared in each of the three streams, showing the high occurrence rate of indigenous species of 50.0% or more. The aggregation index analysis revealed that the mean dominance index ranged from 0.63 (${\pm}0.05$, BS) to 0.72(${\pm}0.01$, JJ), mean diversity index from 1.55 (${\pm}0.06$, JJ) to 1.78 (${\pm}0.11$, BS), mean evenness index from 0.71 (${\pm}0.03$, JJ) to 0.76 (${\pm}0.02$, BS), and mean richness index from 1.61 (${\pm}0.33$, JJ) to 1.73 (${\pm}0.24$, SD). The result indicated that the observed differences between the stream community indices were statistically nonsignificant. The similarity analysis showed that 75.4% similarity was divided into two groups of A and B and that the fish fauna on each analyzed point was similar. The quantitative habitat evaluation index (QHEI) analysis showed that the average value of QHEI was 151.0 (${\pm}46.0$), which means that it was a suboptimal habitat environment. The result of length-weight analysis of Z. koreanus populations showed that the regression coefficient b of the restoration population and the original habitat population were at 3.0 or higher while the condition factor had a positive slope. Moreover, it was found that the slopes of the regression coefficient b and condition factor of the original habitat population were larger than the restored population. The analysis of the length frequency distribution of the Z. koreanus population revealed that all three streams maintained the stable life cycle although it was found that the growth rate of the original habitat population was faster than the restored population in the one-year-old class. The result of the gonadosomatic index (GSI) analysis showed that the GSI median value of the Z. koreanus population in the restored habitat Bongseonsa Stream was higher than the population in the original habitat Jojong Stream and Sudong Stream for both of males and females.

A Study on the Conversion to Feed Stuff from Cellulosic Biomass (섬유질자원(纖維質資源)의 사료(飼料) 전환(轉換))

  • Lee, Ke-Ho;Sung, Chang-Geun;Chung, Kyu-Ok
    • Applied Biological Chemistry
    • /
    • v.27
    • /
    • pp.29-46
    • /
    • 1984
  • To utilize several species of hard wood as raw materials of feed products, fermentation characteristics of cellulosic substrates to single cell protein was investigated, and results were summarized as follows. Among the microorganisms investigated, Tricoderma viride was selected as one of the most cellulolytic. Mixed culture of fungi did not show a synergistic effect on cellulose degradation. When the fungi were cultured at $28^{\circ}C$ for 7 days in a medium containing wheat bran 25 g, cellulose 0.25 g, proteose peptone 0.025 g and tween 800.025 g, cellulotic activities on carboxy methyl cellulose and filter paper reached maximum at 12 hr. The alkali treatment resulted in increased degradation of substrate from 13 to 18% when treated with enzymes for 12h, and reducing sugar formation increased with decreased size of substrates. Glucose was a very good feedback inhibitor of the enzyme from T.viride than that of xylose. When the substrate was rehydrolyzed, hydrolysis rate was 31% to reducing sugars within 12 hr. Quantative anlysis with HPLC showed the ratio of glucose to xylose in sugar syrups as 1.77 to 1. For the purpose of producing cellulosic-single cell protein from the sawdust of mulberry tree, 15 strains of xylose-assimilating yeast were isolated from 42 samples of rotten woods and compost soils and examined for their ability to utilize xylose. Then three strains were selected by their strong xylose-assimilating activities. The cultivative condition, the growth characteristics, and protein and nucleic acid productivities of three strains were investigated. The results obtained were, 1. Wood hydrolysate of mulberry tree was assimilated by 5 strains of CHS-2, CHS-3, ST-40, CHS-12 and CHS-13. 2. The optimum initial pH and temperature for the growth of strain CHS-13 were 4.4 and $30^{\circ}C$. 3. The specific growth rate of strain CHS-13 was $0.23h^{-1}$ and generation time was 3.01 hrs at the optimum condition. 4. CHS-13 strain assimilated 81 % of sugar in wood hydrolysate. 5. CHS-13 strain was identified as Candida guilliermondii var. guilliermondii 6. When the CHS-13 strain was cultured in the wood hydrolysate containing yeast extract, L-protein content was increased with yeast extract concentration. 7. The L-protein and nucleic acid yields from wood hydrolysate were 0.73 mg/ml and $4.92{\times}10^{-2}\;mg/ml$ respectively. 8. An optimal nucleic acid content of CHS-13 strain was observed in the medium containing 0.2% of yeast extract.

  • PDF

Operation and Perception on Dietary Life Education and Nutrition Counseling of Elementary School in Chungbuk Province (충북지역 초등학교 영양교사의 식생활 교육과 영양상담 운영실태 및 인식)

  • Kim, Myoung-Sil;Kim, Hye Jin;Lee, Young Eun
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.42 no.12
    • /
    • pp.2049-2067
    • /
    • 2013
  • The purpose of this study is to present a more effective nutrition education activation plan. As a result of investigating the dietary education operating situation, 58.9% underwent direct education, and 89.5% underwent food life education through traditional food culture succeeding business operation. The results from investigating the recognition regarding dietary education are as follows. The activation level by education types was as low as 2.24 points, the necessity was as high as 4.54 points, the difficult point in performing food life education was 'overwork' with 4.43 points, and the teaching activity ability level was 'can effectively prepare a teaching guidance plan' at 2.96 points. As a result of investigating the nutrition consultation operating situations, 62.8% underwent it and all of the students as well as some parents and teachers performed it. The consumed time per consultation for effective nutrition consultation was 10~20 minutes, the required education equipment and data were 'consultation program' with 40.3%, and the important content during consultation was 'contents related to eating habits' with 70.5%, which was recognized as the most important.

Effect of Early Pregnant Heifer as Donor on the Ovum Pick-Up Derived Oocyte Aspiration and Embryo Production (초기 임신우의 공란우 활용이 초음파 유도 난자 채취 및 수정란 생산에 미치는 영향)

  • Jin, Jong-In;Kwon, Tae-Hyeon;Choi, Byeong-Hyun;Kim, Sung-Soo;Jo, Hyun-Tea;Bang, Jae-Il;Kim, Sam-Chul;Cho, Kyu-Woan;Lee, Jung-Gyu;Kong, Il-Keun
    • Journal of Embryo Transfer
    • /
    • v.26 no.1
    • /
    • pp.19-25
    • /
    • 2011
  • This study was carried out to evaluate the effect of early pregnant cow as donor for Ovum Pick-Up (OPU) derived oocyte aspiration and embryo production in Holstein heifers. Four non-pregnant and 2 pregnant Holstein heifers were used as donor and then carried out total 17 OPU session for 10 weeks (2 times per week). Recovered cumulus-oocyte-complexes (COCs) were classified into 4 grade by oocyte cytoplasm and cumulus cells and matured in vitro in TCM-199 supplemented with 10% FBS, 10 mg/ml FSH and 1 mg/ml estradiol in 5% $CO_2$ and over 99% humidity for 24 h. After 24 h co-incubation with post-thaw sperm, the presumed zygotes were cultured in CR1aa medium with 4 mg/ml BSA for 3 days and then changed CR1aa medium with 10% of FBS for another 3~4 days. The Mean number of aspirated follicles and collected oocytes in the early stage pregnant and non-pregnant heifers were $13.0{\pm}4.3$ and $10.6{\pm}3.9$, $5.4{\pm}3.4$ and $7.7{\pm}3.6$ per session, respectively. Rate of collected oocyte from aspirated follicles were 59.2% and 50.5%, respectively. The average number of good quality oocytes (Grade I and II) in the early stage pregnant and non-pregnant heifers was $3.7{\pm}2.7$ and $4.9{\pm}2.6$ (Mean${\pm}$SD). Cleavage and blastocyst developmental rates in Grade I and II were 22.2% and 25.5%, and then $1.7{\pm}0.9$ and $1.4{\pm}1.1$ blastocyst per session, respectively. In conclusion, OPU technology can be used in early stage pregnant and non-pregnant heifers without any problem and so applied OPU derived embryo production to maximize the ability of genetically valuable females.

Ecological Characteristics of Local Collections of Cyperus serotinus Rottb. and Their Geographical Differentiation (너도방동산이 지방수집종(地方蒐集種)들의 생태적(生態的) 특성(特性) 및 그의 생리적(生理的) 분화(分化)에 관한 연구(硏究))

  • Seong, Ki-Yeong;Kwon, Yong-Woong
    • Korean Journal of Weed Science
    • /
    • v.3 no.1
    • /
    • pp.14-22
    • /
    • 1983
  • To study ecological characteristics of Cyperus serotinus occuring in Korea its propagules were collected from 6 locations from the northern part to the southern part of Korea (Chuncheon, Suweon, Iri, Jeonju, Gwangju, Milyang) in 1981, cultured and replanted 4 times (May 20, June 5, June 20, July 5) in 1982. They flowered from August 10 to August 29 in the plants planted on May 20 and from August 22 to September 4 in the plants planted on July 5. Plant height, number of tillers and top fresh weight were 85-100cm, 375-1,500 tillers/$m^2$ and 500-1,750g/$m^2$, respectively, when they were planted on May 20, and 58-67cm, 300-625 tillers/ $m^2$ and 125-250g/$m^2$, respectively, when they were planted on July S. Weight of seeds and number of rhizomes per plant were 20-50g/$m^2$ and 20.75-61, respectively, whey, they were planted on May 20, and 5-17.5g/$m^2$ and 51.5-80.25 when they were planted on July 5. Local collections showed. the same morphological characteristics at the level of species identification, but there existed variations among the local collections. Cyperus serotinus from Chuncheon and Suweon were longer in the length of inflorescence, than those from Gwangju and Milyang and rhizomes from Chuncheon and Suweon were thicker than the others. Each of local collections may be regarded as different ecotype based on the above mentioned differences in morphology, growth and flowering response to the planting date. The results appear to imply that Cyperus serotinus weeds occuring in various locations of Korea are different one another in competitive ability with rice crop.

  • PDF

Effects of Activation Treatments and Culture Condition on In Vitro Development of Caprine In Vivo and In Vitro Oocytes (재래산양의 체내 및 체외유래 난자의 활성화 처리방법 및 배양조건이 단위발생란의 체외발달에 미치는 영향)

  • Park H. S.;Kim T. S.;Lee Y. H.;Jung S. Y.;Lee M. Y.;Jin J. I.;Park J. K.;Lee J. S.;Kim C. H.
    • Reproductive and Developmental Biology
    • /
    • v.28 no.3
    • /
    • pp.181-185
    • /
    • 2004
  • This study was conducted to examine whether activation treatments, source of oocytes and culture conditions affect in vitro developmental ability of caprine oocytes. Mature Korean native goats were pretreated with intravaginal CIDR for 10 days. The goats were then treated with a single intramuscular injection of 1,000 IU PMSG on Day 8 or twice daily injection of a total of 70 mg FSH for 3 days from Day 8 of CIDR insertion for superovulation. All the goats were injected with 10 mg PGF/sub 2a/ on Day 8 and 400 IU hCG on Day 10 of CIDR. Oocytes were surgically collected by oviduct flushing(in vivo maturation) or direct follicle aspiration(in vitro maturation) through mid-ventral incision at 35 h after hCG injection. Fifteen to twenty oocytes were placed in TCM-199 medium containing 25 mM Hepes and hormones under mineral oil at 39℃ in a humudified atmosphere of 5% CO₂ in air for 22 to 24 h. After maturation, the oocytes were activated by electric stimulation or ionomycin + 6-DMAP. The activated oocytes were then cultured in M16, TCM-199 and mSOF media supplemented with proteins at 39℃ for 6 to 7 days. Activation treatments did not affect cleavage of the oocytes. The cleavage rates were 64.1% (41/64) in oocytes activated by electric stimulation and 76.5% (218/285) in oocytes activated by ionomycin + 6-DMAP. The proportion of development to blastocyst was 15.6% (34/218) in oocytes activated by ionomycin + 6-DMAP, but activation by electric stimulation did not support embryos developed beyond morula stage. There were no differences in the cleavage rates of activated oocytes experiencing in vivo (86.8%, 66/76) and in vitro maturation (69.0%, 127/184). However, the development rate to blastocyst stage was significantly (P<0.05) higher for oocytes matured in vivo (50.0%, 33/66) compared to in vitro (0.8%, 1/127). Culture conditions did not affect the cleavage of -activated oocytes. The cleavage rates were 51.6% (49/95) in M16, 64.3% (18/28) in TCM-199 and 81.0% (145/179) in mSOF, respectively. By contrast, the development rate of activated oocytes to stage was greater (P<0.05) for oocytes cultured in mSOF medium (23.4%, 34/145) than in M16 or TCM-199 (0.0%). Our results suggest that source of oocytes and culture conditions are major factors affecting in vitro development of caprine parthenogenetic oocytes.

Seedling - Emergence of Rice, Weedy Rice, and Echinochloa species Sown before Wintering and in the Early Spring (월동전(越冬前) 초춘(初春)에 파종(播種)한 재배(栽培)벼, 잡초성(雜草性)벼 및 피의 출현특성(出現特性))

  • Kwon, Y.W.;Lee, B.W.;Kim, D.S.
    • Korean Journal of Weed Science
    • /
    • v.16 no.2
    • /
    • pp.88-99
    • /
    • 1996
  • In recent years dry direct-seeding of rice has been encouraged by the government and increasingly practiced by farmers in Korea. This has been bringing up an increased occurrence of weedy rites. Some farmers in the southern region dare to sow the rice before winter after harvest, while most farmers wish to sow as early as possible in the spring to secure the growing period, and to disperse the intensive labor in early May. The purpose of this study was to determine the feasibility of moving the sowing of rice to an earlier date under dry direct-seeding, and to elucidate the nature of emergence of an old strain of rice, weedy rites, and barnyardgrasses tinder this farming practice and their adaptive competence over present cultivate. The presently recommended rice cultivar, Dongjinbyo and an old rice strain, Dadajo which prevailed in early 1900s, almost could not emerge from soil deeper than 6cm and could emerge to only 5.3% at best from 1cm deep loamy soil field when the seeds were sown on Nov. 28. However, two strains of weedy rites being weedy for over 200 years emerged by 17.0 to 63.0% from the loamy and sandy clay loam field 1 to 6cm deep. Emergence of the weedy rites was greater in the loamy soil and at a shallow depth, and negligible from the soil depth of 9cm. Barnyardgrasses sown on Nov. 28 emerged by 13.4 to 51 % from the 1 to 3cm deep loamy soil, and 8.6 to 46.7% from the 1cm deep sandy clay loam. Echinochloa crus-galli var. crus-galli emerged more than var. praticola, and var. oryzicola least. Most of the non-emerged barnyardgrasses seem to have entered secondary dormancy. Seeding rice a month earlier than the season lowered the emergence of Dongjinbyo by ca. 10, 18, and 26%, respectively at 1, 3, and 6cm soil depths, indicating that moving the seeding date a month earlier is impractical. The old strain, Dadajo sown in the soil at a depth of 6cm responded similarly. However, the strain has shown a significantly higher ability in emergence from 9cm deep soil. Weedy rices sown a month earlier A month earlier sown weedy rices have shown very similar emergence rates at various soil depths to those sown on May 1. Barnyardgrasses have also shown similar emergence rates when sown between April 3 and May 1. Like barnyardgrasses, the old strain and weedy rices apparantly posessed a greater adaptability to emerge under lower temperatures, and from deeper soil ; Dongjinbyo${\leq}$ Echinochloa species in that order. However, emergence- speed under lower temperature(sown on April 3) was faster in the order of weedy rice

  • PDF

Performance State and Improvement Countermeasure of Primary Health Care Posts (보건진료소(保健診療所)와 업무실태(業務實態)와 개선방안(改善方案))

  • Park, Young-Hee;Kam, Sin;Han, Chang-Hyun;Cha, Byung-Jun;Kim, Tae-Woong;Gie, Jung-Aie;Kim, Byong-Guk
    • Journal of agricultural medicine and community health
    • /
    • v.25 no.2
    • /
    • pp.353-377
    • /
    • 2000
  • This study was performed to investigate the performance state and improvement countermeasure of Primary Health care Posts(PHPs). The operation reports of PHPs(1996 330 PHPs, 1999 313 PHPs) located in Kyongsangbuk-Do and data collected by self-administered questionnaire survey of 280 community health practitioners(CHPs) were analyzed. The major results were as follows: Population per PHP in 1999 decreased in number compared with 1996. But population of the aged increased in number. The performance status of PHP in 1999 increased compared with 1996. A hundred forty one community health practitioners(50.4%) replied that the fiscal standing of PHP was good. Only 1.4% replied that the fiscal standing of PHP was difficult. For the degree of satisfaction in affairs, overall of community health practitioners felt proud. The degree of cooperation between PHP and public health institutions was high and the degree of cooperation of between PHP and private medical institutions was high. The degree of cooperation between PHP and Health Center was significantly different by age of CHP, the service period of CHP, and CHP's service period at present PHP. Over seventy percent of CHPs replied that they had cooperative relationship with operation council, village health workers, community organization. CHPs who drew up the paper on PHP's health activity plan were 96.4 % and only 11.4% of CHPs participated drawing up the report on the second community health plan. CHPs who grasped the blood pressure and smoking status of residents over 70% were 88.2%, 63.9% respectively and the grasp rate of blood pressure fur residents were significantly different according to age and educational level of CHP. CHPs received job education in addition continuous job education arid participated on research program in last 3 years were 27.5%, respectively. CHPs performed the return health program for residents in last 3years were 65.4%. Over 95% of CHPs replied that PHPs might be necessary and 53.9% of CHPs replied that the role of PHPs should be increased. CHPS indicated that major reasons of FHPs lockout were lack of understanding for PHP and administrative convenience, CHPs were officials in special government service governors intention of self-governing body. CHPs suggested number of population in health need such as the aged and patients with chronic disease, opinion of residents, population size, traffic situation and network in order as evaluation criteria for PHP and suggested results of health performance, degree of relationship with residents, results of medical examination anti treatment, ability for administration and affairs in order as evaluation criteria for CHP. CHPs replied that the important countermeasures for PHPs under standard were affairs improvement of PHPs and shifting of location to health weakness area in city. Over 50% of CHPs indicated that the most important thing for improvement of PHPs was affairs adjustment of CLIP. And CHPs suggested that health programs carried out in priority at PHP were management of diabetes mellitus and hypertention. home visiting health care, health care for the aged. The Affairs of BLIP should be adjusted to satisfy community health need and health programs such as management of diabetes mellitus and hypertention, home visiting health care, health care for the aged should be activated in order that PHPs become organization reflecting value system of primary health care.

  • PDF