• Journal of Families and Better Life
• /
• v.25 no.5
• /
• pp.167-183
• /
• 2007

The purpose of this study was to investigate the changes in infant-mother interactions and to measure infant-mother interaction, mutuality, and reciprocity at the 2nd and 6th postnatal monthperiods. Infant-mother interaction was assessed in the mornings, afternoons, and evenings in the 2nd and 6th postnatal months, by filming unstructured free play in the home and analyzing 28 of these infant-mother film recordingsusing two trained observers. This study can be summarized in five points. First, the separate frequency distribution of each category in MIIBR's maternal behavior was as follows: the frequencies of vocalization category, the kinesthetic exercise & physical contact category, the physical caregiving category, and theuse of play tool category. These all showed changes in the 6th postnatal month compared to the 2nd postnatal month. Second, the separate frequency distribution of each category in MIIBR's infant behavior was as follows: the frequencies of physical behavior category, the vocalization category, and the play behavior category. These also all showed changes in the 6th postnatal month compared to the 2nd postnatal month. Third, the mutuality and reciprocity of mother interaction decreased in the 2nd postnatal month compared to the 6th postnatal month. Fourth, mutuality and reciprocity in the infant interaction increased in 2nd postnatal month compared to the 6th postnatal month. Fifth, mutuality and reciprocity in the infant-mother interaction increased in 2nd postnatal month compared to the 6th postnatal month. In conclusion, it is evident that infant-mother interactions change over time. This study bears particular significance in setting a foundation for the theoretical basis of the interaction between infant and mother by observation.

• Korean Journal of Veterinary Research
• /
• v.37 no.4
• /
• pp.755-763
• /
• 1997

Recently new technologies for the establishment of high health herds are becoming efficient tools in the control of PRRS virus and secondary infections. Medicated early weaning(MEW) and nursery depopulation(ND) have shown to be one of the most successful procedures in the eradication and control of pathogens. Indirect evidence of the role of PRRSV in precipitating secondary infection comes from successful improvement in growth and in decreasing mortality on farms that have eliminated PRRSV through ND. Hence the present experiments were conducted in an effort to compare ND with MEW procedures as a means of eliminating PRRSV controlling secondary pathogens and improving performance of pigs in endemically infected swine herds. Following MEW and ND procedures practiced in the farms, some benefits obtained were as follows: 1. A decrease in PRRSV circulation in the nursery, but no entire elimination. 2. Decrease in the frequency of secondary bacteria and in the use of antibiotics. 3. Mycoplasma hyopneumoniae infection was prevented during the nursery stage. 4. ND protocol had a lower cost and management changes than MEW techniques. 5. Nursery performance was improved after the depopulation, cleaning and disinfection procedures, even though PRRSV still being cycled in the old nursery rooms. These studies revealed that the MEW and ND protocols are not always successful for PRRS virus elimination but it's great effect on control of secondary pathogens and improvement of performance make MEW and ND an efficient tools for the establishment of healthier and more efficient herds.

• Economic and Environmental Geology
• /
• v.29 no.2
• /
• pp.151-158
• /
• 1996

Rb-Sr isochron ages, Sr and Nd isotopic compositions were determined for late Cretaceous granophyre on the Haenam-Wando areas, the southwestern part of the Yeongdong-Kwangju depression in Korea. The granophyre in the Haenam-Wando areas are distributed in the shape of a resurgent cauldron. Five samples of Haenam granophyre give a defined Rb-Sr whole rock isochron age of $75.7{\pm}7.2Ma$ and Sr initial ratio of $0.70826{\pm}0.00020(2{\sigma})$. Plagioclase, orthoclase and whole rock of Haenam granophyre give a defined Rb-Sr whole rock-mineral isochron age of $67.0{\pm}5.8Ma$ and Sr initial ratio of $0.708880{\pm}0.00028(2{\sigma})$. Five samples of Wando granophyre give a defined Rb-Sr whole rock isochron age of $70.6{\pm}3.3Ma$ and Sr initial ratio of $0.70850{\pm}0.00088(2{\sigma})$. Eight samples of Haenam granophyre give a defined Nd isotope ratios of 0.512180~0.512259 and ${\varepsilon}Nd$ (T) values of -6.53~-8.15, ${\varepsilon}Sr$ (T) values of +51.49~+66.48 and model age of 1.28~1.60 Ga. Four samples of Wando granophyre give a defined Nd isotope ratios of 0.512228~0.512289 and ${\varepsilon}Nd$ (T) values of -6.74~-8.00, ${\varepsilon}Sr$ (T) values of +54.88~+78.98 and model age of 1.14~1.42 Ga.

• Asian-Australasian Journal of Animal Sciences
• /
• v.17 no.3
• /
• pp.366-370
• /
• 2004

One hundred and sixty day-old Hainan chicks were randomly allotted into eight pens to investigate the effect of different dietary concentrations of chromium (Cr) in the form of chromium chloride, and different dosages of florfenicol on humoral immune responses by determining antibody titers to Newcastle disease (ND) vaccines using the hemagglutination inhibition test. The results indicated that ND antibody titers were significantly higher in chicks receiving Cr at low (5 mg/kg feed) and middle (10 mg/kg feed) dose compared with the control (p<0.01). However, ND antibody titers were significantly decreased in chicks receiving Cr at a high dosage of 500 mg/kg feed (p<0.01), though the ND antibody titers of the early days (d 21 and d 28 of age) were higher than that of the control group. It is suggested that excessive Cr intake has detrimental effects on ND antibody production in chicks. No significantly lower response was measured in chicks that received florfenicol at a low dosage of 50 mg/kg feed (p>0.05), but the ND antibody titers were significantly decreased in chicks receiving 200 and 400 mg/kg feed of the drug (p<0.01). The ND antibody titers of group receiving 200 mg/kg feed of florfenicol plus 10 mg/kg Cr were slightly higher than that of the group receiving single florfenicol of 200 mg/kg although, no significant differences were observed between these two treatments. It is suggested that the humoral immune response impaired by florfenicol (200 mg/kg feed) could not be significantly reversed by Cr (10 mg/kg feed).

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.50 no.4
• /
• pp.335-342
• /
• 2017

Oysters Crassostrea gigas are a globally popular shellfish for human consumption. As filter-feeding bivalve mollusks, oysters may harbor many microorganisms and chemicals that could pose potential human health risks. The objective of this study was to investigate the suitability of cultured oysters for raw consumption or use in seafood products by measuring concentrations of harmful microorganisms and chemicals in their flesh. Microbial concentrations in cultured oysters were found to be: $1.0{\times}10^2-6.0{\times}10^4CFU/g$ (viable cell counts), not detected $(ND)-5.4{\times}10^3CFU/g$ (coliform bacteria), $ND-1.3{\times}10^2CFU/g$ (E. coli), and $ND-4.6{\times}10^3CFU/g$ (Vibrio parahaemolyticus). Other pathogenic bacteria, including Enterohemorrhagic E. coli (EHEC), Listeria monocytogenes, Staphylococcus aureus, and Salmonella spp., were not detected in any samples. Heavy metal concentrations of cultured oysters were ND-0.239 mg/kg (total mercury), ND-1.091 mg/kg (lead), ND-0.968 mg/kg (cadmium). The concentrations of benzo(a)pyrene ranged from $0.280-0.880{\mu}g/kg$. Paralytic shellfish poison ranged from ND-0.58 mg/kg, while diarrhetic shellfish poison was not detected. No radioactivity was detected. These results suggest that oysters intended for raw consumption or use in seafood products should be subjected to chemical and biological controls.

• Horticultural Science & Technology
• /
• v.28 no.5
• /
• pp.895-898
• /
• 2010

A new light pink spray-mum, 'Noble ND' was bred by crossing 'Mona Lisa', a white anemone type flower, and 'Dark Weldon', a pink anemone type flower in October, 2004. The growth and flowering characteristics were investigated in forcing, natural, and retarding cultures from 2006 to 2007. The 'Noble ND' was a medium-flowering fall-mum with light pink anemone type flower and had 9.2 flowers per stem, with 4.8 cm flower diameter in natural culture. The number of days to flowering and flowers per plant was 57 and 7.4, respectively, in forcing culture of 'Noble ND', whereas the number of days to flowering was 48 in retarding culture.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.36 no.5
• /
• pp.386-391
• /
• 2010

Introduction: Bone resorption is a unique function of osteoclasts. Osteoclasts are a specialized macrophage polykaryon whose differentiation is regulated principally by macrophage colony-stimulating factors, receptor activator of nuclear factor ${\kappa}B$ ligand (RANK) ligand, osteoprotegerin (OPG), and interleukins (IL). Reflecting the integrin-mediated signals, osteoclasts develop a specialized cytoskeleton that allows it to establish an isolated micro-environment between itself and the bone, wherein matrix degradation occurs by a process involving proton transport. The levels of IL-1, IL-6, OPG, and prostaglandin $E_2$ ($PGE_2$) expression were evaluated to study the correlations between dental implant teeth and the adjacent teeth. Materials and Methods: The exudate of the gingival crevice acquired from dental implants, adjacent teeth, opposite teeth and contralateral teeth of 24 patients. Results: 1. The levels of IL-1, IL-6, OPG and $PGE_2$ expression in dental implant teeth were higher than those of the contralateral teeth. 2. IL-1 revealed a higher expression level in the adjacent teeth than in dental implant teeth. 3. The dental implant teeth and adjacent teeth did not show a remarkable difference in the level of IL-1 expression. 4. All the other cytokines were strongly expressed in the dental implant compared to the adjacent teeth. Conclusion: These results suggest that there might be close correlation between dental implant teeth and adjacent teeth in terms of the expressions of cytokines that affect the development and regulation of osteoclasts.

• Economic and Environmental Geology
• /
• v.37 no.6 s.169
• /
• pp.613-629
• /
• 2004

Contamination of groundwater by volatile organic compounds (VOCs) was investigated for 168 groundwater wells in Ulsan area to study the natural attenuation of organic compounds in the aquifers. As groundwater contamination by VOCs is closely related to land use, 168 groundwater samples were classified into 4 different groups; agricultural, forestry, industrial, and residential & business. From analysis 65 out of 168 groundwater samples contained more than one VOC. Analysis of samples were performed fir 36 halogenated aliphatic hydrocarbons and 25 petroleum hydrocarbons set up by NAWQA of US geological survey. Twelve petroleum hydrocarbons were detected in 26 groundwater wells, but their concentrations were less than 1.5 g/L except for MTBE. Twenty three chlorinated aliphatic hydrocarbons, composed of 11 methanes, 6 ethanes and 6 ethenes, were detected in 63 groundwater samples. The range of methanes concentration was $ND\~330\;/gL,\;ethanes\;ND\~84\;gL$, and PCE and their derivatives $ND\~62\;g/L$. As the study area was comprised of the aerobic/denitrification zones and $Fe^{+3}$ redox condition, most of petroleum hydrocarbons were degraded well, while halogenated hydrocarbons were slowly biodegradation.

• The Journal of the Petrological Society of Korea
• /
• v.20 no.4
• /
• pp.191-206
• /
• 2011

The emplacement ages, whole-rock geochemistry and Sr-Nd isotopic compositions of granitoid rocks from Cheongju area, South Korea, were investigated for delineating their petrogenetic link to the Jurassic Daebo granitoid rocks. Zircon crystals were collected from the diorite, biotite granite and acidic dyke samples in a single outcrop. Cross-cutting relationships show that the emplacement of diorite was postdated by the intrusion of biotite granite. Both rocks have been subsequently intruded by acidic dyke. The U-Pb isotopic compositions of zircon from the diorite, biotite granite, and acidic dyke were measured using a SHRIMP-II ion microprobe, yielding the crystallization ages of $174{\pm}2Ma$, $170{\pm}2Ma$, and $170{\pm}5Ma$, respectively, with 95% confidence limits ($t{\sigma}$). The emplacement ages are consistent with those determined from the above relative ages. The major and trace element patterns of the rocks are consistent with those of the Jurassic Daebo granitoid rocks, possibly suggesting a subduction-related I-type granite. The geochemical signature is, however, betrayed by the Sr and Nd isotopic compositions of these rocks. The isotopic signatures suggest that the rocks were produced either by the partial melting of lower-crust or by the mantle-derived magma contaminated by the basement rocks during its ascent and/or emplacement. In addition, the inherited ages of zircons of the rocks (ca. 2.1, 1.8, 0.8 and 0.4 Ga) suggest a possible assimilation with crustal rocks from the Gyeonggi massif and Ogcheon metamorphic belt.

• Resources Recycling
• /
• v.27 no.3
• /
• pp.8-15
• /
• 2018

Solvent extraction behavior of light rare earth elements (Pr, Nd) and medium rare erath elements (Tb, Dy) in the HCl-PC88A-kerosene extraction system was investigated in order to separate high-purity light rare earths (Pr, Nd) and medium rare earths (Tb, Dy) in the mixed rare earth chloride solution. In the batch test step, it was confirmed that the separation efficiency was good when the extractant concentration (PC88A) was 0.5 M, the equilibrium pH after extraction was 0.8 to 1.0 (initial pH 1.3 of the feed), the concentrations of hydrochloric acid in scrubbing solution was set as 0.1 M, the concentrations of hydrochloric acid in stripping solution was set as 2.0 M or more. Based on the experimental data obtained from the batch test, the mixer-settler was composed as follows; 4 stages of extraction, 8 stages of scrubbing, 4 stages of stripping, and 3 stages of pickling organic solution. The Mixer-settler was operated for 180 hours, and the operating conditions were continuously adjusted to obtain the high-purity light/medium rare earths. Finally, the purity of light (Pr, Nd) and medium rare earth elements (Tb, Dy) was reached as 3 N class.