• Korean Journal of Veterinary Research
• /
• v.43 no.2
• /
• pp.171-180
• /
• 2003

Certain hexavalent chromium compounds when administered via inhalation have the potential to induce lung injury in human and experimental animals. In present study, the inhalation effect of hexavalent chromium on morphological change and weight change of rat organ were investigated. Rats were exposed to hexavalent chromium ($Na_2CrO_4{\cdot}4H_2O$) at concentration of $0.36mg/m^3$ (group 1), $1.8mg/m^3$ (group 2), ascorbic acid and $1.8mg/m^3$ (group 3) and filtered air (group 0, control group) for I week, 2 weeks and 3 weeks. The weight of lung and kidney in group 2 and group 3 significantly higher than in control group at same exposure period. The epithilial cells of bronchiole in group 1, 2, 3 were more flatten than group 0. In the lung, the number of macrophage was significantly increased and morphologically changed macrophages were observed in group 1, 2, 3. The morphological change of the lung did not significant between group 2 and group 3, however, in group 1 was milder than in group 2 and group 3. The severity of morphological change were depend on exposure period in the lung. The morphological changes by hexavalent chromium of the liver and kidney were also observed These results suggest that inhalation of hexavalent chromium effects on not only respiratory organ, but also the liver and the kidney via blood stream.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.30 no.2
• /
• pp.108-120
• /
• 2004

Object : Patients with facial asymmetry accompanying mandibular prognathism have various causes and clinical features. So, it is difficult to find a satisfactory treatment method functionally and esthetically. Every traditional classification and interpretation to find etiopathogenesis and/or to establish ideal surgical modality has many limitations because it can't be applied simply to various conditions of patients with facial asymmetry accompanying mandibular prognathism. Therefore, we employ a new classification to interpret more details of the morphologic change of mandible and the spatial change of mandible and maxilla. Materials and Methods : Using panoramic X-ray films, PA cephalograms and submentovertex films of 126 patients diagnosed with facial asymmetry accompanying mandibular prognathism as resources, the following results were gathered after analyzing each characteristics through distributing the patterns according to the morphological mandibular asymmetry and mandibular and maxillary spatial asymmetry. Results : Almost frequency of morphological mandibular asymmetry was shown. In case of condyle-ramus elongation and body elongation group, it's frequency was the highest. Higher frequency of compensating vertical growth was shown on the side of over growing maxilla in case of vertical length difference between left and right condyle-ramus. On the other hand, higher frequency of no compensating vertical growth difference between left and right side was shown in case of no vertical length difference in condyle-ramus. Spatial mandibular asymmetry generally occurred when there was no morphological mandibular asymmetry. Correlation between condyle length difference and condyle-ramus length difference between left and right side was very high, but correlation between condyle length difference and body length difference, and correlation between condyle length difference and body vertical length difference was low. Conclusion : In case of patients with facial asymmetry accompanying mandibular prognathism, it is suggested that various pattern of facial asymmetry is occurred by the independent growth of each unit rather than dependent growth of other unit by major growth unit abnormality. Due to the untypical pattern and the various asymmetry occurring according to the changes of each mandibular growth unit, it is considered that an appropriate surgical method should be searched based on the accurate recognition of the each pattern for patients with facial asymmetry accompanying mandibular prognathism.

• Journal of Korean Society of Rural Planning
• /
• v.20 no.1
• /
• pp.13-26
• /
• 2014

The purpose of this study is to identify characteristics of the landscape changes in Gwangjyu city and Icheon city, the suburban areas on the outskirts of the Seoul metropolitan area, by focusing on the causes of the urban sprawl and the resultant morphological characteristics of landscape degradation. Particular attention has been given to the 'advantages for developing suburb including geographical proximity and land price', 'institutional regulation such as land-use regulation' and 'community solidarity' as drivers for possible introduction of external factors. The types of landscape change were divided into three, after having on-the-ground research on eleven chosen towns and interviews with head of a village: Overwhelming Change, Separated and Small-Scale Change. It was found that, in general, the quality of landscape was best for the small-scale change type, followed by separated and overwhelming change types. While the types of landscape change are correlated with the geographical proximity, its relevance with land regulation is relatively weak. The study found that imposing a land-use regulation as a means to prevent changes in suburban village landscape may not be fully effective. Also it analyzed that villages could better manage with keen interest the surrounding landscape if there is a high degree of solidarity within the village community. Therefore, the sense of community could play an important complementary role to land-use regulation which does not suffice in itself to manage suburban landscape.

• The Korean Journal of Malacology
• /
• v.27 no.4
• /
• pp.345-351
• /
• 2011

Comparison of different morphological characteristics of bivalves is very useful for distinguishing species. Therefore, this study used a morphometric approach to document patterns of phenotypic change through the specimens of family Pinnidae inhabiting the bottom sediments at the coasts of An Thoi Archipelago (south-eastern Gulf of Thailand), in that way excluding intraspecific variations among different populations along a wide geographical range. It was revealed that individuals determined as Pinna trigonium separated from specimens of Pinna nigra and Atrina vexillum at high level, but P. nigra and A. vexillum were the single species A. vexillum, as it is assumed now. Also, it was found that both groups of P. trigonium individuals and A. vexillum specimens divided into tree subgroups unified the specimens with the similar morphometric parameters: small, medium and large within the populations, though there were no evident divisions into subgroups in the size distributions of the populations. In addition to the interspecific morphological variations, the species also showed significant intraspecific morphological variations even in the same population. Most probable reason for the appearance of the intraspecific morphological variations and division of all specimens into size-specific subgroups in the population is the fact that the growth of Pinnidae bivalves is not isometric.

• Proceedings of the Korean Powder Metallurgy Institute Conference
• /
• 2000.11a
• /
• pp.48-48
• /
• 2000

• 대한치주과학회:학술대회논문집
• /
• 2001.12a
• /
• pp.52-52
• /
• 2001

• Proceedings of the Korean Society of Crop Science Conference
• /
• 1999.05a
• /
• pp.51-52
• /
• 1999

• Proceedings of the Korean Powder Metallurgy Institute Conference
• /
• 2003.10a
• /
• pp.125-125
• /
• 2003

• Journal of the Korean Geographical Society
• /
• v.40 no.4 s.109
• /
• pp.416-427
• /
• 2005

This paper aims to investigate morphological changes of deltaic barrier islands in the Nakdong Estuary and especially their spatial variations after barrage construction. We analyzed shorelines, geometrical centroids, and areas to reveal the changes of barrier islands. Here, we suggest three interesting points from this study. First, each individual barrier island in the Nakdong estuary goes through a different stage of the geomorphic cycle. The frontal barrier islands such as Sinja-do and Doyo-deung grow because they are located in front of the gates of the barrage. Sediments in water out of the gates are moved to offshore and then reworked by coastal processes such as waves and tides. Second, on the contrary, Baekhap-deung located behind Doyo-deung now diminishes indicating that sediments mainly move to the frontal growing island. Third, there is no morphological change in several barrier islands far away from the main flow of the Nakdong river such as Jinwoo-do, Daema-deung, and Jangja-do. In conclusion, barrier islands in the Nakdong estuary show distinct spatial variations. As a barrier island is closer to the main channel or is in the frontal location, there happens a very dynamic change in the morphology of the island.

• Journal of Aquaculture
• /
• v.12 no.4
• /
• pp.255-266
• /
• 1999

The early development, growth, and morphological changes of Tiger puffer Takifugu rubripes are described on the basis of a seres of a series of reared specimens. Detailed o수 the early developmental stages are illusrtated withe special reference to morphological transformation. Egg and sperm of puffer fish Takifugu rubripes were obtained from mature adults under natural conditions, ferilized artificially and incubated in the laboratory. The incubation period of fertilizd eggs was 160 to 180 hours at a temperature of $15.1~ 18.0^{\circ}C$. Larvae were fed successively with rotifer, Artemia nauplii and artificial food for 90 days. The mean total length of newly-hatched larvae was about 2.8mm. Mouth opening occurred on the 1- day yolk-sac larvae and initial feeding was observed on th 4-5 days after hatching . The morphological transitions from the larvae to juvenile and juvenile and juvenile to young stages occurred when fish reached about 10mm in total length(about 30 days after hatching) and about 32mm in total length(about 60days after hatching) , respectively. The coefficient of variation in total length distribution increased with growth. Following the appearance of its peak at the size of about 18mm in total length, the coefficient value declined. Many changes in proportion of the body parts to total length were observed at about 9~10mm and 30~33mm in total length, corresponding to the transformations from larvae to juvenile and from juvenile to young, respectively. Also one big morphological change was observed at about 18mm in total length that divide the juvenile stage into two sub-stages.