• Korean Journal of Animal Reproduction
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• v.10 no.1
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• pp.100-108
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• 1986

Eik-Nes (1966) reported that the mechanism of spermatogenesis is controlled by FSH and LH and maintaned normally in scrotum terperautre which is 3-5$^{\circ}C$ lower than body termperature. But Ojeda and Ramirez (1972) have described that the abdominal testis was shrinked severely and lost its normal function in congenital cryptorchidism or surgically induced cryptorchidism. Ramirez and Sawyer (1974) reported that the compensatory hypertorphy occured in the remaining testis of unilateral castration and the scrotal testis of unilateral cryptorchidism. Cunninham et al. (1978) reported that the serum FSH levle increased after unilateral castration. Frankel and Wright (1982) reported that the serum LH level was unchanged greatly after unilateral castration. Gomes and Jain (1976) reported that the serum testosterone level increased temporarily but not varied after unilateral castration. On the other hand, Kormano et al. (1964) reported that the serum FSH level in unilateral cryptorchidism rat was unchanged in contrast with the control and Risbirdger et al. (1981) reported that the serum LH level was unchanged till 2 weeks after operation and after then increased to 77%. Kim (1984) reported that the serum testosterone level was somewhat lower than that fo control group but there was't significant different. There were many different reports on hormone levels among different investigators when the immarue rats were castrated unilaterally or induced cryptorchidism unilaterally. Liang and Liang (1970) and Cunningham et al. (1978) described that there were no true compenastory hypertrophy in the remaining testis of unilateral castration and scrotal testis of unilateral testis of unilateral cryptorchidism in rat but they grew faster than that of control. Kormano et al.(1964), Damber et al.(1976), Cunningham et al.(1978) and Karpe et al.(1981) reported that the testis weight, germinal epithelia height and seminiferous tubules diameter developed continuously and similarily in the control, the remaining testis of unilateral castration and scrotal testis of unilateral cryptorchidism increased, however, in the abdominal testis of the unilateral cryptorchidism, they were much smaller than those of other groups. In observation of the histological changes in the seminiferous epithelium of control, remaining tesis of unilateral castration and scrotal testis of unilateral cryptorchidism differentiated and developed fully(Cunningham et al., 1978). However, the abdominal testis of unilateral crytorchidism degenerated severely and only the germ cells in early stage and Sertoli cells were found in the seminiferous tubules. (Damber et al., 1976, Gomes and Jain, 1976 and Karpe et al., 1981). By electron microscopic observation, Nagano (1963) and Leason and Leeson (1970) found that the abdominal testis of unilateral cryptorchidism was thicked in boundary tissue, increased lipid droplet in the Sertoli cell, disarranged axial filament complex and increased lipid inclusions in the Sertoli cell.

• Journal of Animal Science and Technology
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• v.45 no.5
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• pp.841-846
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• 2003

Landrace(L), Largewhite(Lw), Korean Native Pig(KNP) and commercial hybrid were experimented to determine holothane sensitivity, RYR gene mutation and quality profiles. In the results of halothane test, the incidence of halothane positive pigs was similar between L and Lw. But, the rate of dubious halothane positive type was higher in L than Lw. In hal-gene analysis, halothane-positive pigs(nn) were not found in any tested breed and heterotype(Nn) appeared only in one pig of L. Of the breed effect on the quality profiles, there were no differences in pH$_1$(pH at 1hr postslaughter), but pH$_{u}$(pH at 24hr postslaughter) was significantly higher in commercial hybrid and KNP than other breeds(p〈0.05). Color assessed by National Pork Producers Council(NPPC) and CIE L$^{*}$ was significantly paler in L breed than other breeds(p〈0.05). Significant differences were found in water holding capacity(WHC) and cooking loss in KNP(p〈0.05).

• Journal of Animal Science and Technology
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• v.50 no.4
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• pp.465-474
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• 2008

The amount of telomeric DNA was quantified across different breeds(Landrace, Duroc, Yorkshire and Berksire), at different ages(90 days old and 180 days old) and among sexes(male and female) in pigs raised at the Performance Testing Station of Korea Swine Association, Jinkyo, Korea. The telomeric DNA amount was quantified by Quantitative Fluorescence In Situ Hybridization(Q-FISH) using a porcine telomeric DNA probe on interphase nuclei of lymphocytes. Analysis revealed that the amount of telomeric DNA on the pig lymphocytes was found to decrease with age. The quantity of telomeres significantly differed among breeds at 90 days of age. The colored breeds such as Berkshire and Duroc had higher amount of telomeric DNA than the Yorkshire and Landrace breed. In addition, the amount of telomeric DNA in male lymphocytes was significantly higher than that of females. In the correlation coefficients between the telomere quantity and their productive traits; average daily gain, loin percent and index value were positively correlated, whereas body length, feed efficiency and back fat thickness correlated negatively. However, the correlation coefficients were very low and not significant. Therefore, this study suggests that the amount of telomeres on lymphocytes can be considered as a physiological marker but not as a productive marker in pig.

• The Journal of Engineering Geology
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• v.4 no.2
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• pp.153-168
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• 1994

The status of groundwater development in Chungnam was studied with geological characteristics according to the measured data of Korean Rural Development Corporation. The data of 212 survey wells were used for the relation between catchment area and water discharge, and the data of 344 development wells for the relationships between well depth and discharge, between casing depth and discharge, between rock type and discharge, and the relation with lineaments density. The relationship between the catchment area and discharge does not show any special trend, and it is understood that groundwater of hard rock mass is not so much influenced by the surface catchment area. The relationship between well depth and discharge shows two different trends; discharge increasing with depth for alluvial groundwater, but no certain trend between depth and discharge for groundwater of hard rock zone. Discharge increases linearly with the casing depth, and it is reliable because the casing was installed in the weathered zone against well destruction. Generally the rock type does not show any difference of discharge, but the crystalline rocks such as granite and gneiss yield a little more discharge than the more porous rocks such as sedimentary rock or schist. It suggests that the effect of fracture zone is a major governing factor. In Hongsong and Puyo, there are similar in rock type and casing depth, but the big difference in average discharge. The big discharge of Hongsong is concordant with the higher intersection density and longer length of lineament in Hongsong than those of Puyo. Therefore the groundwater development strategy should be focused on the micro topography analysis and geophysical survey for the understanding of the fracture zone rather than catchment area or rock type.

• Applied Microscopy
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• v.22 no.2
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• pp.84-96
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• 1992

This study was carried out to examine the $H^+$ transport mechanism by observing the properties of cellular membrane having an ${\alpha}$ type of carbonic anhydrase (CA)-containing cells in turtle urinary bladder. The urinary bladder consists of a heterogenous population of cells. As a result of fine observation with traditional thin-section electron microscopy. the bladder epithelium has three different cell types on mucosal surface. They are a basal cell, a granular cell and a third type of CA-rich cell. The CA-rich cells are divided into two distinct smaller groups within them and called them ${\alpha}$ type and ${\beta}$ type of CA cells. The ${\alpha}$ type of CA cells are responsible for the proton secretion using the proton pumps on the apical plasma membrane, while the ${\beta}$ type of CA cells secrete bicarbonate via an oppositely-directed proton pumps in their basolateral plasma membrane. After performing the freeze-fracture technique, it was shown that there were distributed a large number of intramembranous particles having a special structure on the apical membrane of ${\alpha}$ type of CA-rich cells in the process of their $H^+$ secretion. In turtle bladder ${\alpha}$ type of CA-rich cells, this particle was the only prominent structure in the apical membrane. These intramembrane rod-shaped particles probably represent the integral membrane components of the proton pump. This result may explain that carbonic anhydrase within epithelial cell of urinary bladder takes part in formation of $H^+$ and bicarbonate, that active transport of $H^+$ is done, and that the reabsorption of bicarbonate suggests transport mechanism containing $H^+$ secretion. However, it seems that more studies are required for considering their regular transport pathway.

• Journal of Science Education
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• v.37 no.2
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• pp.389-404
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• 2013

This study aimed to explore elementary teachers' beliefs about science teaching, science learning and the nature of science and consistency among these beliefs. Data was collected by using an open questionnaire and semi-structured individual interview. Teachers' beliefs were classified as traditional beliefs and constructivist beliefs. Traditional beliefs were further divided into content knowledge-centered beliefs and procedural knowledge-centered beliefs. The result showed that a relatively large number of teachers among the total 30 teachers had traditional beliefs about science teaching, science learning, and the nature of science(respectively 60.0%, 66.7%, 83.3%). Most of traditional beliefs were identified as content knowledge-centered beliefs. The proportion of teachers with consistent beliefs for all three aspects was 40.0%, the proportion of those with consistent beliefs for two of them (those with related beliefs) was 53.3%, the proportion of those with different beliefs for them (those with divergent belief) was 6.7%. Most of the teachers with the consistent beliefs had the content knowledge-centered beliefs of traditional beliefs. Although constructivism has been widely emphasized in science education from the 1980's, the rate of the teachers with the consistent beliefs in constructivism was as low as 6.7%.

• Journal of Science Education
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• v.41 no.1
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• pp.80-97
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• 2017

The purpose of this study was to develop understanding-oriented materials based on backward course design model and analyze their effects on 'biology and environment' unit of elementary school science. Backward Design starts from a specification of learning outcomes and decisions on methodology and syllabus are developed from the learning outcomes. This method has a strength maintaining consistency between educational contents-evaluation-learning activities and also promoting student's authentic understanding. The 78 students 6th graders participated in this experiments. Data was collected using project activities, the science academic emotion scale and academic achievement. The collected data was analyzed by t-test and ANCOVA analysis using the SPSS 23 statistical program. The following major conclusions were drawn on the basis of data analysis. First, the experimental group showed a relatively accurate understanding of the contents of science but they could not produce creative output in two project activities. Second, the interaction effect of the instruction based on backward curriculum design and science academic emotion was not significant statistically. Third, the experimental group showed a significant improvement in the academic achievement of 'biology and environment' unit.

• Journal of The Korean Society of Grassland and Forage Science
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• v.19 no.3
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• pp.281-290
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• 1999

The bacterial isopentenyl transferase (ipt) gene involved in cytokinin biosynthesis was fused with 35S promoter of cauliflower mosaic virus (CaMV) and introduced into tobacco plants (Nicotiana tabacum L. cv. Samsun) via Agrobacterium-mediated transformation. As expected, ipt gene was constitutively expressed in all tissues of transgenic plants. Several primary transgenic plants were obtained that expressed different level of transcripts for ipt gene. Three of transgenic plants with different expression level of ipt gene were selected and selfed to obtain homozygous line for further analysis. A number of interesting phenotypic changes such as viviparous leaves, delayed senescence, larger axillary shoots, an abundance of tiny shoots at the apex and a release of lateral buds, were observed in transgenic plants. Chlorophyll content was 1.5- t.o 4-fold higher in transgenic plants as compared with non-transformed plants. These results indicate that the cytokinin synthesized in transgenic plants could improve forage crop yield by delay of leaf senescence and increase of leaf number.

• Korean Journal of Food Science and Technology
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• v.43 no.6
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• pp.675-682
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• 2011

This study was conducted to monitor the concentrations of 24 anti-impotence drugs and their analogues in various foods and dietary supplements, with the aim of ensuring the safety of the foods and supplements. The measurements were done in 226 samples using high performance liquid chromatography/photodiode array detector (HPLC/PDA) and liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). Five male sexual function enhancing products have been detected as follows: acethylvardenafil (21,476 mg/kg; 15 mg/capsule from one sample), sildenafil (52,778 mg/kg, 29 mg/capsule in one sample; 71,535 mg/kg, 48 mg/capsule in one sample), and tadalafil (9,772-55,545 mg/kg, 6-33 mg/capsule in four samples). A sustainable monitoring of anti-impotence drugs and their analogues in various foods and dietary supplement is recommended.

• Korean Journal of Food Science and Technology
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• v.43 no.6
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• pp.747-753
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• 2011

It is commonly believed that black soybean (Glycine max: BB) prevents and alleviates hair loss. However, few studies have directly assessed the effect of BB on hair growth. We presently evaluated the mitosis induction on dermal papillae cell and mitogenic effect on NIH3T3 cells in vitro. To elucidate the hair growth promoting effect in vivo, anagen induction and hair restoration were examined in a shaving model of C57BL/6 mice. We also conducted biochemical analysis of blood plasma. Significant stimulation of dermal papillae and NIH3T3 cell proliferation were observed by treatment of BB in a dose-dependent manner. BB markedly promoted hair growth and significantly improved blood total antioxidant capacity and reduced lipid peroxidation and triglyceride level. These results suggest that BB has hair growth promoting effect and it is a potent candidate for the prevention of hair loss.