• Korean Journal of Heritage: History & Science
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• v.56 no.3
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• pp.214-232
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• 2023

Stromatolite at the Daegu Catholic University, Gyeongsan was designated as a natural monument in December 2009 because it was very excellent in terms of rarity, accessibility, preservation and scale. From the time of designation, the necessity of confirming the lateral extension of the stromatolite beds with the excavation of the surrounding area, and preparing a preservation plan was raised. Accordingly, the Cultural Heritage Administration conducted an investigation of the scale, production pattern, and weathering state of stromatolites with an excavation from April to December 2022, and based on this, suggested natural heritage values and conservation and use plans. The excavation was carried out in a 1,186m² area surrounding the exposed hemispherical stromatolite (approximately 30m2). Stromatolites are continuously distributed over the entire excavation area, and hemispherical stromatolites predominate in the eastern region, and the distribution and size of hemispherical domes tend to decrease toward the west. These characteristics are interpreted as a result of long-term growth in large-scale lakes, where stratiform or small columnar domes continued to grow and connect with each other, finally forming large domes. Consequently, large and small domes were distributed on the bedding plane in clusters like coral reefs. The growth of plants and lichens, as well as small-scale faults and joints developed on the stromatolite bedding surface, is the main cause of accelerated weathering. However, preservation treatment with chemicals as with dinosaur footprints or dinosaur egg fossil sites is not suitable due to the characteristics of stromatolites, and preservation with the installation of closed protection facilities should be considered. This excavation confirmed that the distribution, size and value of stromatolites are much larger and higher than at the time of designation as a natural monument. Therefore, additional excavation of areas by experts that could not be excavated due to the discovery of buried cultural properties (stone chamber tombs) and reexamination of the expansion designation of natural monuments are required.

• Economic and Environmental Geology
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• v.56 no.6
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• pp.715-728
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• 2023

Tracksite of pterosaurs, birds, and dinosaurs in Chungmugong-dong in Jinju was designated as a natural monument in 2011 and is known as the world's largest in terms of the number and density of pterosaur footprints. This site has been managed by installing protection buildings to conserve in 2018. About 17% of the footprints of pterosaur, theropod, and ornithopod in this site under management in the 2nd protection building are of great academic value, but observation of footprints has difficulties due to continuous physical and chemical damage. In particular, the accumulation of milk-white contaminants is formed by the gypsum and air pollutant complex. Gypsum remains evaporated with a plate or columnar shape in the process of water circulation around the 2nd protection building, and the dust is from through the inflow of the gallery windows. The aqueous solution of gypsum, consisting of calcium from the lower bed and sulfur from grass growth, is catchmented into the groundwater from the area behind the protection building. Pollen and a few minerals other constituents of contaminants, go through the gallery window, which makes it difficult to expel dust. To conserve the fossil-bearing beds from two contaminants of different origins, controlling the water and atmospheric circulation of the 2nd protection building and removing the contaminants continuously is necessary. When cleaning contaminants, the steam cleaning method is sufficiently effective for powder-shaped milk-white contaminants. The fossil-bearing bed consists of dark gray shale with high laser absorption power; the laser cleaning method accompanies physical loss to fossils and sedimentary structures; therefore, avoiding it as much as possible is desirable.

• Korean Journal of Agricultural Science
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• v.9 no.1
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• pp.303-313
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• 1982

The study was conducted to find out the concentrations of sex hormones and the contents of metabolites in serum, and the changes of weights and tissues on ovary, thyroid gland and adrenal gland according to gestation period in rabbit. The results were summarized as follows: 1. The ovary weights were increased significantly with the time e lapse after gestation and recovered normally at 5 days after parturition. In the histological changes of ovary, the lutein cells were hypertrophied and the secretory granules were increased actively until 3 weeks after gestation, and then a trophied thereafter. 2. The thyroid gland weights at all observation times were higher than those in control group, and the significance was recognized at 1, 3 and 4 weeks after gestation. The histological features of the secretory epithelium were the hyper trophic and columnar condition stimulating the functional state from 1 week after gestation. 3. The adrenal gland weights in experimental group were recognized significantly at 4 weeks after gestation, but showed higher than those in control group at all observation times. The zona fasciculata and zona reticularis of the gland showed the slight hypertrophic condition, but the zona glomeerulosa and adrenal medulla did not find out any particular changes. 4. The serum concentrations of progesterone and LH reached a peak level at 2 weeks and 1 week after geestation respectively, and rapidly began to decline thereafter. 5. The serum concentrations of estradiol-$17{\beta}$ and FSH were not detected below 20.0 pg/ml and 1.3 mIU/ml respectively. 6. The contents of total protein and non-protein nitrogen nitrogen were decreased gradually with the time elapse after gestation, but the significant differences were recognized from 3 weeks. 7. The total lipids were not changed markedly until 3 weeks, but increased significantly at 4 weeks after gestation and at 5 days after parturition. 8. The serum cholesterol tended to be decreased until 3 weeks, but increased at 4 weeks after gestation and at 5 days after parturition. 9. The serum calcium showed a continuous decrease during the gestation period, but the significant differences were recognized at 3 and 4 weeks. The serum phosphorus also had a significant decrease at 4 weeks after gestation.

• Korean Journal of Agricultural Science
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• v.17 no.1
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• pp.34-44
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• 1990

The study was carried out to elucidate the effects of ovarian function on the thyroid gland, adrenal gland and uterus in female rats. One hundred and forty-four mature female rats were allotted into the three groups ; ovariectomized group, estradiol treated group and intact control group. The ovaries of 48 heads of rats were completely removed. Forty eight heads of rats were administered with $200{\mu}g$ of estradiol benzoate every 48 hours. Serum estradiol-$17{\beta}$ and progesterone levels were determined with radioimmunoassay method at 3, 6, 12, 24 hours and 5, 10, 15 days after treatment. The rats were necropsied to measure weights of thyroid gland, adrenal gland and uterus and to examine the histological changes in the organs. The results obtained were as follows ; 1. Serum estradiol-$17{\beta}$ levels were rapidly decreased below 27.20pg/ml 18 hours after ovariectomy. In estradiol treated rats the levels were rapidly increased 18 hours after treatment, but thereafter slowly decreased. The significant differences in the estradiol level were found between the group at every observation time. 2. Serum progesterone levels were significantly decreased after ovariectomy and estradiol injection. The lowest level was found in the group of ovariectomized rats. 3. The weights of thyroid glands decreased in ovariectomized rats rather than in intact rats 5 days after treatment. The weights tended to increase after estradiol injection but significant differences between the groups were seen on 10th and 15th days. 4. In the histological findings of thyroid glands, follicular epithelial cells were changed to be squamous 5 days after ovariectomy and accompanied pyknosis 10 days and karyorrhexis 15 days after ovariectomy. On the contrary follicular epithelial cells were changed to be columnar with hypertrophy 10 days after estradiol injection. 5. The significant differences in adrenal gland weights were recognized between all the groups 5 and 15 days after treatment in ovariectomized rats were lighter than intact rats and the adrenal gland weights were rather heavier in estradiol treated rats. 6. The days after ovariectomy the adrenal glands were atrophied accompanying with pyknosis in the cortical cells of zona fasciculata. The cells in zona fasciculata and zona reticularis started to hypertrophy 5 days after estradiol injection, but no changes were found in the zona glomerulosa of adrenal cortex and in the adrenal medulla. 7. The significant differences in uterus weights were recognized between the groups at each observation time. After ovariectomy the uterus weights decreased rapidly but after estradiol injection they increased rapidly. 8. Through histological examination of uterus, the atrophy and degeneration started to occur in endometrium and lamina propria 12 hours after ovariectomy, and in myometrium one day after ovariectomy, and the changes progressed rapidly after that. On the contrary, the myometrium was proliferated and hypertrophied from 12 hours after estradiol-$17{\beta}$ injection.