• The Korean Journal of Malacology
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• v.26 no.4
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• pp.267-273
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• 2010

From January to December 2007, we have investigated sediment types, environmental factors and density of clam Ruditapes philippinarum inhabited at Oeri, Naeri, Jonghyeon and Bangmiri tidal flats in Gyeonggi Bay off the west coast of Korea. Sediment types of Oeri and Jonghyeon were characterized with well sorted muddy sand. In contrast, Bangmiri tidal flat was mainly composed of poorly sorted gravelly muddy silt and Naeri was characterized with very poorly sorted muddy-sandy gravel. During the course of study, the surface water temperature, salinity, dissolved oxygen and pH ranged 3.2 to $27.0^{\circ}C$, 21.7 to 33.3 ‰, 5.6 to 12.7 mg/l and 7.36 to 8.82, respectively. The suspended solid (SS) ranged from 3.2 to 1,266.0 mg/l and chlorophyll-a level in the water column ranged $0.3-36.1{\mu}g/l$, respectively. The density of clam in the study areas was mainly determined by the harvesting activities rather than the types of substrate. Relatively higher density of clam was observed in Oeri and Bangmiri where the clam seeds were sowed by the villagers. Condition factor of clams were found to be higher in Oeri where the substrate sorting was better with higher level of chlorophyll a. It was believed that sediment types and the level of available food the two governing factors controlling the density and growth of clam in Gyeonggi Bay.

• Journal of Wetlands Research
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• v.23 no.3
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• pp.213-223
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• 2021

To understand the sedimentary environment of Scirpus planiculmis habitat (Myeongji and Eulsuk tidal flats) in the Nakdong Estuary, this study analyzed the statistical parameters (sorting, skewness, and kurtosis) of grain size data and the major (Al, Fe, Mn, Mg, Ca, Na, K, Ti, and P), minor (Li, Sc, V, Cr, Co, Ni, Cu, Zn, Sr, Zr, Cs, Pb, Th, and U), and rare earth elements (REEs) in sediment cores. For Myeongji, the sediment structure of the upper part of the cores was poorly sorted, more finely skewed, and more leptokurtic due to construction of the West gate. By contrast, the Eulsuk cores all differed due to the contrasting floodgate operation patterns of the West and East gates. The linear discriminate function (LDF) results corresponded to the statistical parameters for grain size. At the Eulsuk tidal flat (sites ES05 and ES11), elemental distributions were representative of Al-, Fe- and Ca-associated profiles, in which the elements are largely controlled by the accumulation of their host minerals (such as Na- and K-aluminosilicate and ferromagnesium silicate) and heavy detrital minerals at the sites. Detrital minerals including the aluminosilicates are major factors in the elemental compositions at ES05, diluting the REE contents. However, clay minerals and Fe-oxyhydroxides, as well as REE-enriched heavy minerals, appeared to be controlling factors of the elemental composition at ES11. Therefore, the mineral fractionation process is important in determining the elemental composition during sedimentation, which reflects the depositional condition of riverine-saline water mixing at both sites.

• Science of Emotion and Sensibility
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• v.23 no.3
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• pp.19-36
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• 2020

This study is aimed at analyzing the characteristics of adaptation to college life among freshmen of D University by utilizing the DEU-GRIT test. To achieve this, we examined differences in level of college life adaptation according to gender and major, and explored the characteristics of college life adaptation among college freshmen who were clustered based on their level of academic, social, emotional, and career adaptation, which is an important factor in adaptation to college life. Moreover, based on the DEU-GRIT test standards, we also explored the characteristics of their college life adaptation by sorting out low level groups of freshmen with difficulties adapting. The results demonstrated that male students had a higher level of emotional adaptation than female students, and that science and technology majors had higher levels of academic and emotional adaptation than students in the humanities and society majors. Furthermore, a cluster analysis based on 4 factor levels of college life adaptation showed that cluster 1 had a high level of adaptability to all factors, but cluster 3 had a low level of adaptability to all factors. Moreover, while cluster 2 showed a high level of emotional adaptation, cluster 4 showed a low level of emotional adaptation. On the other hand, a lower-standard group of DEU-GRIT tests showed that the level of academic adaptation and social adaptation was higher among female students than among male students. However, the overall level of college life, academic, and emotional adaptation were higher among science and technology students than among those majoring in humanities and social studies. In addition, a cluster analysis based on the level of 4 factors of college life adaptation of lower-standard groups showed that cluster 1 of the lower-standard groups had a high level of emotional adaptation, while cluster 2 of the lower-standard groups had a low level of emotional and career adaptation and a high level of academic and social adaptation. Also, cluster 3 of the lower-standard groups was found to have low levels of all factors, and cluster 4 of the lower-standard groups showed low levels of social and emotional adaptation and high levels of academic and career adaptation. This indicates that, in terms of social and emotional adaptation among freshmen, participation in psychological counseling programs tailored according to gender is necessary and, regarding the major, relative emotional intervention is required due to the high and low expectations of job prospects. In conclusion, the emotional and social adaptation to college life among the lower-level groups is likely to serve as a protective factor for college life adaptation, suggesting that specific intervention should be contemplated.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.3
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• pp.186-196
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• 2010

Introduction: The first aim of this study was to isolate the dental tissue-derived stem cells from the dental follicle (DF), dental pulp (DP), and root apical papilla (RAP) of the extracted wisdom teeth. Second was to evaluate their characterization with the expressions of transcription factors and cell surface markers. Finally, their ability of the in vitro multi-lineage differentiations into osteogenic and adipogenic cells were compared, respectively. Materials and Methods: Dental tissues, including dental follicle, dental pulp, and root apical papilla, were separated in the extracted wisdom teeth. These three dental tissues were cultured in Dulbecco’s modified Eagle’s medium (DMEM) with supplements, respectively. After passage 3, the homogeneous shaped dental tissue-derived cells were analyzed the expression of transcription factors (Oct-4, Nanog and Sox-2) and cell surface markers (CD44, CD90 and CD105) with reverse transcription polymerase chain reaction (RT-PCR) and fluorescence-activated cell sorting (FACS) analysis. In order to evaluate in vitro multi-lineage differentiations, the culture media were changed to the osteogenic and adipogenic induction mediums when the dental tissue-derived cells reached to passage 3. The characteristics of these three dental tissue-derived cells were compared with immunohistochemistry. Results: During primary culture, heterogenous and colony formatted dental tissue-derived cells were observed in the culture plates. After passage 2 or 3, homogenous spindle-like cells were observed in all culture plates. Transcription factors and mesenchymal stem cell markers were positively observed in all three types of dental tissue-derived cells. However, the quantity of expressed transcription factors was most large in RAP-derived cells. In all three types of dental tissue-derived cells, osteogenic and adipogenic differentiations were observed after treatment of specific induction media. In vitro adipogenic differentiation was similar among these three types of cells. In vitro osteogenic differentiation was most strongly and frequently observed in the RAP-derived cells, whereas rarely osteogenic differentiation was observed in the DP-derived cells. Conclusion: These findings suggest that three types of human dental tissue-derived cells from extracted wisdom teeth were multipotent mesenchymal stem cells, have the properties of multi-lineage differentiations. Especially, stem cells from root apical papilla (SCAP) have much advantage in osteogenic differentiation, whereas dental follicle cells (DFCs) have a characteristic of easy adipogenic differentiation.

• Journal of Convergence for Information Technology
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• v.10 no.9
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• pp.222-228
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• 2020

The purpose of this study was to investigate activity participation level and functional disability based on ICF for the elderly aged over 65 years. Subjects were 100 senior citizens. We performed data collection using Korean Activity Card Sorting(KACS) and World Health Organization Disability Assessment Schedule 2.0(WHODAS 2.0). Data were analyzed using descriptive statistics, Pearson's correlation, multiple regression. As a result of the survey of activity participation levels, retained level of activity participation of instrumental activity was highest at 75.06%. Among the WHODAS 2.0 sub-domain, 'getting along with people', 'participation in society' had the most difficulties and 'self-care', 'life activities' were the lowest. An analysis of the correlation between the activity retention rate and functional disability showed that there was a significant negative correlation. Significant factors influencing functional disability were activity participation level of social activity, instrumental activity and main work(retirement). We confirmed that activity participation level was important factor on functional disability. Further, we need standardization study for generalization.

• The Journal of the Korea Contents Association
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• v.14 no.5
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• pp.224-234
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• 2014

This study designed to nursing student's image of professional nurse before clinical practice using Q-methodology. Using Q-methodology, 43 nursing student sorted 34 statements selected professional nurse type. The statement positions on the sorting continuum were scored from +4(representing the highest level of agreement) through 0(at the neutral position on the continuum) through -4(representing the highest level of disagreement). Factor analysis of the data was undertaken using PC QUANL software to determine if any patterns were discernible. The three factors extracted eigenvalues greater than 1.0 and explained approximately 53.94% of the variation in responses(41.63, 7.41 and 4.9% respectively). The categories were labeled 'Nightingale's nursing philosophy type', 'Consideration of patient type' and 'Self-development type'. Twenty-two students who located to factor 1 "Nightingale's nursing philosophy type". Eleven students who located to factor 2 "Consideration of patient type". Three students sho located to the factor 3 "Self-development type". The significant differences found in the subjective structure of nursing student's image of professional nurse. The study results can be utilized in both an effective nursing education and clinical practice.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.38 no.6
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• pp.343-353
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• 2012

Objectives: This aim of this study was to effectively isolate mesenchymal stem cells (hSMSCs) from human submandibular skin tissues (termed hSMSCs) and evaluate their characteristics. These hSMSCs were then chemically induced to the neuronal lineage and analyzed for their neurogenic characteristics in vitro. Materials and Methods: Submandibular skin tissues were harvested from four adult patients and cultured in stem cell media. Isolated hSMSCs were evaluated for their multipotency and other stem cell characteristics. These cells were differentiated into neuronal cells with a chemical induction protocol. During the neuronal induction of hSMSCs, morphological changes and the expression of neuron-specific proteins (by fluorescence-activated cell sorting [FACS]) were evaluated. Results: The hSMSCs showed plate-adherence, fibroblast-like growth, expression of the stem-cell transcription factors Oct 4 and Nanog, and positive staining for mesenchymal stem cell (MSC) marker proteins (CD29, CD44, CD90, CD105, and vimentin) and a neural precursor marker (nestin). Moreover, the hSMSCs in this study were successfully differentiated into multiple mesenchymal lineages, including osteocytes, adipocytes, and chondrocytes. Neuron-like cell morphology and various neural markers were highly visible six hours after the neuronal induction of hSMSCs, but their neuron-like characteristics disappeared over time (24-48 hrs). Interestingly, when the chemical induction medium was changed to Dulbecco's Modified Eagle Medium (DMEM) supplemented with fetal bovine serum (FBS), the differentiated cells returned to their hSMSC morphology, and their cell number increased. These results indicate that chemically induced neuron-like cells should not be considered true nerve cells. Conclusion: Isolated hSMSCs have MSC characteristics and express a neural precursor marker, suggesting that human skin is a source of stem cells. However, the in vitro chemical neuronal induction of hSMSC does not produce long-lasting nerve cells and more studies are required before their use in nerve-tissue transplants.

• 한국해양학회지
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• v.30 no.5
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• pp.442-457
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• 1995

The relationships of environmental factors to the distribution patterns of the three species of ophiuroids, Ophiura kinbergi, O. sarsi and ). sarsi vadicola from Yellow Sea southeast seas and East Sea of Korea were studied to characterize their habitual niches. These three species chosen for study illustrated distinct niche and patterns according to their various preferences mainly for bottom water temperature, bottom water salinity and depth from seven environmental variables which were depth, bottom water temperature and salinity, density, bottom water oxygen content, grain size of the surface sediment, and sediment sorting coefficient. The results of habitat niche study mainly dealing with O. sarsi vadicola suggested that the optimum habitat rages were approximately 6$^{\circ}C$∼10$^{\circ}C$ in bottom temperature and 31%∼33.5% in bottom water salinity which also corresponded with the characteristic ranges of Yellow Sea Bottom Cold Water and higher probabilities of occurrence (more than 70%) were found in depth ranging from 100 to 200 m. In addition, the habitats of O. kinbergi and O. sarsi were compared with that of O. sarsi vadicola. Their ranges of habitat niches were found to have different niches in physical space of bottom water temperature, bottom water salinity and depth. Based on the distribution pattern of O. sarsi vadicola in the Yellow Sea, the ecological barrier which confined the distribution of benthic macro-invertebrates in southern Yellow Sea was determined to be the Yellow Sea Warm Current (approximately 34% < and 18$^{\circ}C$ in December) which occurs between 33$^{\circ}$ and 34$^{\circ}$N of southern Yellow Sea in winter time.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2000.11b
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• pp.210-218
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• 2000

Since the SSC(soluble solid contents) and titratable acidity of fruit are highly concerned to the taste, the need for measuring them by non-destructive technology such as NIR(Visual and Near-infrared) spectroscopy is increasing. Specially, in order to grade the quality of each fruit with a sorter at sorting and packing facilities, technologies for online measurement satisfying the tolerance in terms of accuracy and speed should be developed. Many researches have been done to develop devices to measure the internal qualities of fruit such as SSC, titratable acidity, firmness, etc. with the VIS(Visual)/NIR(Near Infrared) reflectance spectra. The distributions of the SSC, titratable acidity, firmness, etc. are different with respect to the position and depth of fruit, and generally the VIS/NIR light can interact with fruit in a few millimeters of pathlength, and it is very difficult to measure the qualities of inner flesh of fruit. Therefore, to measure the average concentrations of each quality factor such as SSC and titratable acidity with the reflectance-type NIR devices, the spectra of fruit at several positions should be measured. Recently, the interest about the transmittance-type VIS/NIR devices is increasing. NIR light can penetrate through the fruit about 1/10-1/1,000,000 %. Therefore, very intensive light source and very sensitive sensor should be adopted to measure the transmitted light spectra of intact fruit. The ultimate purpose of this study was to develop a device to measure the transmitted light spectra of intact fruit such as apple, pear, peach, etc. With the transmittance-type VIS/NIR device, the feasibility of measurement of the SSC and titratable acidity in intact fruit cultivated in Korea was tested. The results are summarized as follows; A simple measurement device which can measure the transmitted light spectra of intact fruit was constructed with sample holder, two 500W-tungsten halogen lamps, a real-time spectrometer having a very sensitive CCD array sensor and optical fiber probe. With the device, it was possible to measure the transmitted light spectra of intact fruit such as apple, pear and peach. Main factors affecting the intensity of transmitted light spectra were the size of sample, the radiation intensity of light source and the integration time of the detector. Sample holder should be designed so that direct light leakage to the probe could be protected. Preprocessing method to the raw spectrum data significantly influenced the performance of the nondestructive measurement of SSC and titratable acidity of intact fruit. Representative results of PLS models in predicting the SSC of peach were SEP of 0.558 Brix% and R2 of 0.819, and those in predicting titratable acidity were SEP of 0.056% and R2 of 0.655.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.4 no.2
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• pp.107-116
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• 1999

To study the characters of surface sediment and to describe the seasonal depositional environment as a result of sedimentation process off Byun-San Peninsula, a total 61 samples of surface sediment (32 samples in summer; 29 samples in winter) were collected and analysed. A digitized depth data from sea chart and echosounding profiles along five trans-sections were helpful for understanding the morphological factors. The types classified by the characters of surface sediment are type I (sand, S), type II (silty sand, zS), and type ill (sandy silt, sZ). Mean grain size varies from 2.11 to 7.81 ${\Phi}$. The positive-skewness shows the typical tide-dominated environment. The sediment type of the northwestern stations is medium sand and the sorting value is 0.5~1.4 ${\Phi}$ of well/moderately sorted. Meanwhile, other stations are composed of muddy sands and sandy muds transported from rivers and offshore. These sediment types toward inshore change gradually from silty sand to sandy silt. According to the C/M diagram, there are three major transport modes of sediment: bed load (Mode A), graded suspension (Mode B), and suspension (Mode C), correlating with north-eastern sandy area, middle part of silty-sand area, and southern sandy-silt area, respectively. The result of Principal Component Analysis shows also similar pattern of sediment types. In result, sediment texture of type III tends to be finer and more poorly-sorted than that of type II and sediment facies are correlateed with sedimentation process.