• Parasites, Hosts and Diseases
• /
• v.34 no.1
• /
• pp.21-26
• /
• 1996

An experimental study was carried out to observe the effects of radiation on the infectivity of metacercariae of Gymnophalloines seoi to C3H mice. Oysters, the second intermediate host, were collected from an endemic area, and non-irradiated control, metacercaria-irradiation, and oyster-irradiation groups were prepared . One hundred metacercariae were infected orally to each mouse, and worm recovery rate was compared by groups at 7th day post-infection. In the metacercaria-irradiation group, the worm recovery rate was significantly reduced at radiation doses higher than 200 Gy, and the number of intrauterine eggs significantly reduced at doses over 50 Gy. In the oyster- irradiation group, 50 Gy significantly reduced both the worm recovery rate and number of uterine eggs. In the two groups, no worm was recovered at 1,000 Gy irradiation. Conclusively, irradiation of oysters with 200-1,000 Gy was effective to control infectivity of metacercariae to C3H mice, and could be adopted as a control measure for gymno-phalloidiasis.

• Journal of Korean Home Economics Education Association
• /
• v.24 no.2
• /
• pp.51-62
• /
• 2012

This research examined the method and amount changes of recommended protein intakes(RPI) for male and female adult, and pregnant lactating women from 1962's Recommended Dietary Allowances for Korean(KRDA) to 2010's Dietary Reference Intakes for Koreans(KDRIs) revised. As male and female adult's RPI calculation, factorial method was applied until 1989 KRDA, after that nitrogen balance study was applied. Basal factor in factorial method was standard protein(egg or milk protein) requirement or obligatory nitrogen(protein) loss. On the other hand, basal factor in nitrogen balance study was minimum dietary protein requirement to maintain nitrogen equilibrium balance(nitrogen intake = nitrogen excretion). Adjusting factors of RPI were stress and/or protein requirement difference among people. The RPI of male adults were 50~80 g/day, that of female adults were 45~70 g/day. The additional RPI of pregnant women were 10~30 g/day, were calculate based upon the extra protein needs caused by unborn child development. The pregnant women's additional RPI of 2010's KDRIs revised in the periods of first, second, and third trimester were 0, 15, 30 g/day, respectively. The additional RPI of lactation women were 20~30 g/day, were calculated based upon the extra protein needs caused by maternal milk secretion.

• Journal of Embryo Transfer
• /
• v.18 no.1
• /
• pp.35-41
• /
• 2003

Three experiments were performed to develop an optimal culture system of in-vitro derived porcine embryos. In experiment 1, embryos were cultured in two different basic culture media (NCSU-23 and PZH) supplemented with BSA (4mg/ml), FBS (10%), PVA (3mg/ml). Although no difference on the percentage of embryos developed to blastocysts was found (P>0.05), more 2-cell embryos (59.5% vs. 44.7 to 52.0%) were obtained when embryos were cultured in NCSU-23 added with BSA. In experiment 2, identical treatment was conducted using PZM medium. More (P<0.05) 2-cell embryos (54.4% vs. 40.7 to 44.5%) and blastocysts (12.5% vs. 5.8 to 9.0) were produced when embryos were cultured in PZM added with BSA (4mg/ml). In experiment 3, embryos were cultured in media as follows; 1) NCSU-23 without BSA for 192 hours; 2) NCSU-23 with BSA for 192 hours; 3) NCSU-23 with BSA for 96 h and then subsequently injected with FBS into culture drops. Although no difference on the percentage of embryos developed to blastocysts was found (P>0.05), more 2-cell embryos (63.8 to 69.2% vs. 52.0%) were obtained when embryos were cultured both in NCSU-23 added with BSA throughout culture duration and in FBS supplemented medium. In conclusion, no difference was found when porcine preimplantation embryos were cultured in NCSU-23 added with various macromolecules. However, when PZM medium was used, PZM medium supplemented with BSA showed more potential to support embryo development. Finally, FBS supplemented into culture drop 96h post-insemination did not show any benefits on embryo development.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.28 no.2
• /
• pp.202-210
• /
• 1983

These experiments were conducted to study the relationship among agronomic traits, varietal variation of grain-filling periods and the effect of environmental conditions on the grain-filling in the ten selected barley cultivars. The varietal variation of grain-filling periods was of significance: Tokak had the similar increment in both greenhouse and field plot, Suweon two row was believed to be an cultivar with short grainfilling period. Cultivars with higher grain-filling rates tended to. have significantly lower ash content. Ash content of a cultivar tended to be lower when grown under favorable condition. At maturity, the time of development of yellow or dark pigment at the crease base could be a possible criterion for physiological maturity determination. However, this requires further study. Average grain-filling period in the different conditions was constant, but varietal differences were 9 days in the greenhouse and 5 days in the field. The grain moisture content was not constant in accordance to both cultivars and growing conditions. Average accelerated days for heading and ripening periods were very constant in comparision with field and vinyl mulching suggests that the selected materials will be useful for genetic study on grain-filling periods. The cultivars and grown conditions with higher accumulated temperature per $100^{\circ}C$ from early grain-filling had larger grain-filling rates and heavier 1000 grain weight. This study showed that if the variation among and within cultivars is to be minimized, the greenhouse and vinyl mulching plots could be useful for genetic study on grain-filling periods in $BC_1$ and $F_2$ segregation.

• Journal of Animal Science and Technology
• /
• v.49 no.4
• /
• pp.451-458
• /
• 2007

This study was to investigate the effectiveness of pre-weaning injection of gonadotropin and scheduled fixed-time insemination on sow fertility. Sows were randomly assigned to receive gonadotropin 2 days before weaning, 1 day after weaning or none as control. In gonadotropin treated groups, half of sows were inseminated twice at 24 and 36 hours after onset estrus and half of sows were inseminated twice at scheduled fixed-time. Weaning to onset of estrus was the shortest in lactating sows injected with gonadotropin prior to weaning. Liter size was significantly higher in AI groups after detection of estrus, compared to fixed-time AI group. Results of these experiments indicated that injection of gonadotropin in lactating sows could initiate the final follicular development, and has potential to enhance the reintegration of estrus. Further researches are needed to define the relationship between reduced interval of wean to onset estrus and enhanced fertility in lactating sows.

• Korean Journal of Poultry Science
• /
• v.39 no.4
• /
• pp.291-295
• /
• 2012

The use of methylacetamide (MA) as a cryoprotective agent for freezing Korean Native Black rooster Ogye semen was examined with artificial insemination. The diluted Ogye semen with HS-1 was subjected for 2 step dilution method of cryopreservation in which the final concentration of MA was adjusted to 7.5%. The sperm viability after thawing was reduced from $95.17{\pm}0.93%$ to $55.93{\pm}1.38%$ which was confirmed by live-death analysis based on Fluorescence-Activated Cell Sorting (FACS). The rates of fertilized eggs with fresh or frozen-thawed semen were reduced from $94.98{\pm}3.93%$ to $66.36{\pm}8.43%$ at day 7 with significant difference. However, the hatching rates of experiments at day 21 did not shown difference between $92.64{\pm}2.33%$ and $90.45{\pm}8.05%$ (P<0.05). With these results, the utilization of MA for freezing of Ogye spermatozoa could affect on viability of frozen-thawed semen but not on the fertility of lain eggs and hatchability of fertilized eggs and also provide possible tools of freezing for poultry genetic resource conservation.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.50 no.6
• /
• pp.406-410
• /
• 2005

This study was conducted to establish the efficient protocols of the germination and cryopreservation of dehisced Korean ginseng seeds for long-term germ­plasm conservation. $GA_3$ and BA treated on seed for 24 hr facilitated germination at 5 and $10^{\circ}C$. Germination percentage of desiccated seeds was decreased under moisture content (MC) of below $7.2\%$. Dehisced ginseng seeds were dried under airflow of laminar floor cabinet and seed drying room. The high levels (more than $90\%$) of germination after cryogenic exposure were obtained after drying under vertical airflow of laminar floor for 12-30 hours (MC $10.6{\~}7.2\%$). Decrease in germination percentage of ginseng seeds due to desiccation damage and freezing injury was observed at MC of below $7.2\%$ and of above $12.1\%$, respectively. Therefore, MC of ginseng seeds need to be controlled with a range of $8{\~}10\%$ to avoid damages from both desiccation and freezing.

• Journal of Embryo Transfer
• /
• v.21 no.2
• /
• pp.163-168
• /
• 2006

The present study was carried out to investigate in vitro development and post-thawed survivability of bovine embryos according to different ovary transport temperatures. Bovine ovaries were collected at a local slaughterhouse and were transported at 4 different temperature categories to laboratory: $7{\sim}10^{\circ}C\;(T1),\;11{\sim}17^{\circ}C\;(T2),\;18{\sim}25^{\circ}C\;(T3)$ and above $26^{\circ}C$ (control group). The cumulus-oocyte-complexes aspirated from ovaries were in vitro matured, fertilized and cultured. The rates of maturation (to metaphase II), cleavage and development to blastocysts were compared among treatment groups. Furthermore, frozen-thawed blastocysts were in vitro cultured to compare the survivability among groups. The maturation rates in the T1, T2 and T3 groups ($60.0{\sim}68.2%$) were significantly lower than that in the control group (81.8%, p<0.05). The cleavage rates in the T1 and T2 groups (52.6 and 54.5%) were significantly lower than that in the control group (83.6%, p<0.05). However, there was no difference in the development rate to blastocysts among all groups ($27.9{\sim}33.0%$, p>0.05). The survivability of frozen-thawed embryos was significantly lower in the T1 group (46.2%) than those in the T2, T3 and control groups ($68.8{\sim}7.13%$, p<0.05). In conclusion, the results suggest that ovary transport temperature at $26^{\circ}C$ may be optimal for the better in vitro development and the survival of frozen-thawed embryos produced in vitro Furthermore, exposure of ovary to temperature below $10^{\circ}C$ during transport may significantly decrease both in vitro development and survivability of frozen-thawed blastocysts.

• Journal of agricultural medicine and community health
• /
• v.31 no.2
• /
• pp.177-185
• /
• 2006

Objectives: This study was carried out with 31, 519(16,653 boys, 14,857 girls) of elementary school students to investigate the prevalence of obesity at a district in Gwangju City. It can be applied to develope an educational program of the obesity control as basic data in this local area Methods: The data collected from May, 2004 to July, 2004 were analyzed by SAS PC+ 8.0 program. Children were selected depending on criteria from obesity index (%) by using physical index (height, body weight), and then subjects were classified into one of three groups according to the degree of obesity: mild(20~29.9%), moderate(30~49.9%), and severe($?50%{\cdot}$) obesity. Results: It showed that male elementary school students were higher and heavier than female elementary school students(p< .001) in every grade except the 4th grade(height) and the 6th grade ( body weight). The obesity rates of male students(11.6%) showed higher(p< .001) than those of female students(8.8%). Specially the 4th grade elementary school boys were higher than any other groups in obesity(13.7%). As a whole, the prevalence of obestiy showed mild(5.9%), moderate(3.8%), and severe(0.6%). Male students showed higher rate of obesity than those of female students. The obesity of male students showed higher rate than that of female students except 2-3rd grade elementary school students(p< .001). The obesity of 4~6th grade elementary school students showed higher rate than those of 1~3rd grade students(p< .001). Conclusions: The obesity rates of male students are higher than that of female students, and the obesity rates of 4~6th grade students are higher than those of 1-3rd grade students in the elementary school. Additionally, these results suggest that the program may be needed to prevent obesity of children.

• Journal of Bio-Environment Control
• /
• v.30 no.4
• /
• pp.320-327
• /
• 2021

Freezing damage to fruit trees is frequently occurring due to cold in winter and low temperature in spring to abnormal weather caused by global warming. In particular, the freezing injury of deciduous fruit trees is highly dependent on the developmental stages of the flower buds. And the cold resistance is weakened as the growth progresses, so it is most vulnerable period from flowering to petal fall(post-bloom). Therefore, this study was conducted to analyze the cause of the freezing injury caused by severe low temperature to 'Fuji', which has a late flowering period more than 'Hongro' in April 2020. We investigated freezing injury rate in 'Fuji' and 'Hongro' apple trees damaged by natural low temperature at Boeun-gun, Chungbuk province in Korea. In addition, flower buds in the same developmental stage (tight cluster) were treated artificially low temperature to investigate the injury rate for accurate comparative analysis between varieties, and to analyze the soluble sugar and hormone contents in the flower buds. As a result of survey in natural low temperature, 'Fuji' had a higher injury rate than 'Hongro' in both orchards, and in particular, B orchard 'Fuji' had the highest injury rate of 60.5%. Also there were significantly difference in the freezing injury rate between 'Fuji' and 'Hongro' in artificially low temperature treatments. As a result of analyzing the soluble sugar contents in 'Hongro' was higher than 'Fuji'. Also ABA, IAA and SA contents were more increased in the damaged tissue than in the normal flower buds by low temperature treatments. Consequently, it was assumed that the freezing injury was closely related to soluble sugar contents in the flower buds. In particular, the freezing injury rate was negatively correlated with the sorbitol contents.