• Korean Journal of Soil Science and Fertilizer
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• v.29 no.2
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• pp.165-172
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• 1996

Symbiotic effectiveness and significance of Bradyrhizobium japonicum strains in five serogroups which were consisted of three corresponding serotype strains, respectively, indigenous to Korean soils were evaluated in terms of utility of strain serogroup for symbiotic improvement on soybean plant. The nodulation by rhizobia of each serogroup on four soybean cultivars(Danweonkong, Kwangkyo, Pangsakong, and Eunhakong) was good in order of USDA 123 > YCK 150 > YCK 117 > YCK 141 > USDA 110 serogroup members. Shoot dry weight of soybean was relatively high with USDA 110 serogroup members as well as with YCK 141 serogroup members, whereas the effectiveness of USDA 123 serogroup members was the lowest among the serogroups examined. In particular, Pangsakong among soybeans inoculated with five-serogroup members was positively outstanding on nodulation and shoot dry weight of the plant. Overall, symbiotic parameters of serogroup members associated with soybean plant such as nodule number, nodule mass, $N_2$ase activity, and shoot dry weight showed significantly different responses at level of 1% probability among both rhizobial serogroups and soybean cultivars, respectively. The rate in symbiotic similarity of the members of each serogroup from F-test ($$P{\leq_-}0.05$$) was 100% for nodule No., 90% for $N_2$ase activity. and 80% for soybean shoot dry weight. Taken together, the results indicated that the serological grouping of B. japonicum could be strongly useful for improving the symbiotic effectiveness hetween soybean and Rhizobium.

• The Journal of Internal Korean Medicine
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• v.29 no.4
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• pp.1011-1024
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• 2008

Objectives : The aim of this study was to assess the distribution of general characteristics and risk factors according to onset time in acute stroke patients. Methods : We studied hospitalized patients within 4 wks after the onset of stroke who were admitted to the Department of Internal Medicine at Kyunghee University Oriental Medical Hospital, Kyunghee University East-West Neo Medical Hospital, Kyungwon University Songpa Oriental Medical Hospital, Kyungwon University Incheon Oriental Medical Hospital, and Dongguk University Ilsan Oriental Medical Hospital from April 2007 to August 2008. The 24-hour day was divided into quartiles (6:00 to 12:00, 12:00 to 18:00, 18:00 to 24:00 and 24:00 to 6:00). We analyzed the general characteristics and risk factors according to onset time in acute stroke patients. Results : 468 subjects were included into the final analysis. 1. The most common time period for ischemic stroke onset was between 6:00 and 12:00. It demonstrated a 50% excess risk between 6:00 and 12:00. 2. On the demographic variables of the patients, the rate of hypertension was significantly higher from 18: 00 to 24: 00 than 24:00 to 6:00. 3. There was no significant difference of stroke type, Sasang constitution, or lifestyle between times. 4. According to the blood test, high density lipoprotein cholesterol was significantly higher at 24:00 to 6:00 and lower at 12:00 to 18:00 than other time-groups. 5. The patients diagnosed with metabolic syndrome were significantly more at 12:00 to 18:00 and fewer at 24:00 to 6:00. 6. Hypertension and coffee drinking showed close relationship with patients whose stroke occurred while awake in multivariate analysis. Conclusions : The above results showed that the overall tendency of acute stage cerebral infarction patients varied according to their onset time. These results can be utilized in the future as a basis material.

• Korean Journal of Environmental Agriculture
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• v.22 no.3
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• pp.185-191
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• 2003

The mechanism imparting salt tolerance to crop plants remains still unsolved, although soybean has been classified as a susceptible plant to NaCl. To determine optimum parameters on physiological responses for improving sensitivity of salinity in breeding program, soybean (Glycine max Merr., cv. "Gwan-gan") plants were grown in a greenhouse, treated 20 days after emergence for 7 days with NaCl at 0, 30, 60, and 90mM, corresponding to electric conductivity of 1.2, 4.4, 7.3, and 10.4 dS/m, respectively, and assessed 30 days after treatment. Chlorophyll contents were significantly decreased by NaCl ($0.4{\sim}1.0\;mg/g$) compared to control (1.2 mg/g). Photosynthesis rate by NaCl treatment at $0{\sim}90\;mM$ at flowering stage was ranged from 5.0 (control) to $9.6\;{\mu}mol/m^2/s$. Oxygen for respiration was consumed from 5.4 to $9.7\;{\mu}mol/m^2/s$ so that the ratio of $O_2$ (evolution:consumption) was increased with the increase of NaCl, indicating that $O_2$ consumption seems to go beyond $O_2$ evolution. Water potential of leaf at vegetative stage II was ranged from -0.6 to -1.8 MPa and the highest level was observed at mid-day. Water potential by salt stress was decreased with range of $-2.1{\sim}-2.7MPa$ compared to control. Transpiration was decreased from 17% to 20% by NaCl stress. Water vapor diffusing resistance of intercellular air space was affected significantly, increasing up to $16{\sim}24%$ compared to control by NaCl treatment. Salt-treated soybean tended to accumulate $Na^+$, specially in root, with reduced absorption of N, P, $K^+$, $Ca^{2+}$, and $Mg^{2+}$ contents. Free proline content of soybean leaf as affected by different NaCl concentrations was increased 4.2 times ($184{\sim}434\;{\mu}g/g$) more than control. NaCl also increased activities of nitrate reductase and peroxidase by $28{\sim}161%$ and $3{\sim}22%$, respectively. The results show that physiological characteristics of soybean plants during assay were useful as the best parameters of salt stress or salt tolerance test to improve sensitivity in screening and breeding program among cultivars or germplasms.

• Asia pacific journal of information systems
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• v.22 no.3
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• pp.53-74
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• 2012

A challenge in fostering virtual communities is the continuous supply of knowledge, namely members' willingness to contribute knowledge to their communities. Previous research argues that giving away knowledge eventually causes the possessors of that knowledge to lose their unique value to others, benefiting all except the contributor. Furthermore, communication within virtual communities involves a large number of participants with different social backgrounds and perspectives. The establishment of mutual understanding to comprehend conversations and foster knowledge contribution in virtual communities is inevitably more difficult than face-to-face communication in a small group. In spite of these arguments, evidence suggests that individuals in virtual communities do engage in social behaviors such as knowledge contribution. It is important to understand why individuals provide their valuable knowledge to other community members without a guarantee of returns. In virtual communities, knowledge is inherently rooted in individual members' experiences and expertise. This personal nature of knowledge requires social interactions between virtual community members for knowledge transfer. This study employs the social capital theory in order to account for interpersonal relationship factors and identity theory for individual and group factors that may affect knowledge contribution. First, social capital is the relationship capital which is embedded within the relationships among the participants in a network and available for use when it is needed. Social capital is a productive resource, facilitating individuals' actions for attainment. Nahapiet and Ghoshal (1997) identify three dimensions of social capital and explain theoretically how these dimensions affect the exchange of knowledge. Thus, social capital would be relevant to knowledge contribution in virtual communities. Second, existing research has addressed the importance of identity in facilitating knowledge contribution in a virtual context. Identity in virtual communities has been described as playing a vital role in the establishment of personal reputations and in the recognition of others. For instance, reputation systems that rate participants in terms of the quality of their contributions provide a readily available inventory of experts to knowledge seekers. Despite the growing interest in identities, however, there is little empirical research about how identities in the communities influence knowledge contribution. Therefore, the goal of this study is to better understand knowledge contribution by examining the roles of social capital and identity in virtual communities. Based on a theoretical framework of social capital and identity theory, we develop and test a theoretical model and evaluate our hypotheses. Specifically, we propose three variables such as cohesiveness, reciprocity, and commitment, referring to the social capital theory, as antecedents of knowledge contribution in virtual communities. We further posit that members with a strong identity (self-presentation and group identification) contribute more knowledge to virtual communities. We conducted a field study in order to validate our research model. We collected data from 192 members of virtual communities and used the PLS method to analyse the data. The tests of the measurement model confirm that our data set has appropriate discriminant and convergent validity. The results of testing the structural model show that cohesion, reciprocity, and self-presentation significantly influence knowledge contribution, while commitment and group identification do not significantly influence knowledge contribution. Our findings on cohesion and reciprocity are consistent with the previous literature. Contrary to our expectations, commitment did not significantly affect knowledge contribution in virtual communities. This result may be due to the fact that knowledge contribution was voluntary in the virtual communities in our sample. Another plausible explanation for this result may be the self-selection bias for the survey respondents, who are more likely to contribute their knowledge to virtual communities. The relationship between self-presentation and knowledge contribution was found to be significant in virtual communities, supporting the results of prior literature. Group identification did not significantly affect knowledge contribution in this study, inconsistent with the wealth of research that identifies group identification as an important factor for knowledge sharing. This conflicting result calls for future research that examines the role of group identification in knowledge contribution in virtual communities. This study makes a contribution to theory development in the area of knowledge management in general and virtual communities in particular. For practice, the results of this study identify the circumstances under which individual factors would be effective for motivating knowledge contribution to virtual communities.

• Korean journal of applied entomology
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• v.52 no.2
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• pp.109-113
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• 2013

A greenhouse soil infested with an obligate nematode parasitic bacterium, Pasteuria penetrans, was used to test the effect of temperatures on the endospore attachment to root-knot nematode, Meloidogyne arenaria, juveniles (J2). Freshly hatched J2s were inoculated to the soil in petri dish and incubated under different temperatures of $20^{\circ}C$, $25^{\circ}C$, $30^{\circ}C$, and $35^{\circ}C$ for 7 days. The endospore attachment rates were 100% in all the temperatures, while the number of endospores attached per J2 was highest in $25^{\circ}C$ with 28.3 endospores/J2 followed by 20.2, 18.6, and 13.6 in $30^{\circ}C$, $20^{\circ}C$, and $35^{\circ}C$, respectively. When the soil was pre-treated under different temperatures before the J2 inoculation, the endospore attachment rates significantly decreased from 60% in room temperature to $25^{\circ}C$, 31.7, 8.3, 5.0, and 0% after the soil incubation in $-30^{\circ}C$, $4^{\circ}C$, $40^{\circ}C$, $50^{\circ}C$, and $100^{\circ}C$ for 10 days, respectively. The endospore numbers attached per J2 were 3.5, 4.3, 1, 1, and 0 when the soil was pre-treated in $-30^{\circ}C$, $4^{\circ}C$, $40^{\circ}C$, $50^{\circ}C$, and $100^{\circ}C$, respectively, which were lower than 5.3/J2 of room temperature treated soil. The P. penetrans isolate in the soil showed nematode species-specific endospore attachment characteristics with 100% attachment rate only on M. arenaria J2s while the rates were 0% on M. hapla and M. incognita J2s.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.6B
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• pp.565-575
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• 2011

The purpose of this study was to quantitatively evaluate the expression of both multi-metric qualitative habitat evaluation index (QHEI) and biological integrity index (IBI) for artificial structures eco-artificial fish reef (EAFR) for fishes asylum and habitat. Especially, both experimental evaluation and biological verification were performed in Water and Environmental Center's outdoor test-bed of Korea Institute of Construction Technology located in Andong-city, Gyeongsangbuk-do. The experimental conditions reflecting the situation of domestic river include the flow rate (e.g., $0.0{\sim}1.5m\;s^{-1}$), the width (e.g., 1.0~3.0 m), the depth (e.g., 0.05~0.70 m), and variable bed materials. Both QHEI and IBI were monitored for 8 months from May to December 2010. Whereas QHEI values were highest at experimental points of the E~F with an average of 83.1, those were lowest at B~C with an average of 78.1. However, QHEI values inside EAFR were more than 98.9, regardelss of space and time, and indicated more than the highest good of the state (Good) in the habitat. Overally, IBI values showed similar trend with QHEI, but were 44.2 in the winter dry season, compared to 32.8 of QHEI values. IBI values Also, IBI values inside EAFR were greater than those at the experimental channel by 5.7 to 11.4% and 18.7 to 34.8% in flow and stagnant conditions, respectively, indicating that EAFR can secure asylum and habitat for fish during the dry season. For comprehensive aquatic ecosystem assessment, the experimental channel showed generally fair conditions (Fair~Good), whereas EAFR showed good conditions (Good), suggesting that EAFR can be applied to aquatic ecosystem restoration and improvement.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.12
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• pp.1781-1786
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• 2011

This study was conducted to investigate the cause of microbiological contamination in yogurt and evaluate the effect of physicochemical treatment on the growth inhibition of Hanseniaspora uvarum isolated from yogurt. The yeast strain Hanseniaspora uvarum Y1 was subjected to heat and pH treatments. H. uvarum Y1 was killed at $70^{\circ}C$ and $80^{\circ}C$ after 15 min and survived in a wide pH range from pH 2 to 9. However, it did not survive under pH 1 and over pH 10. In a disk diffusion susceptibility test on H. uvarum Y1, a clear zone (5 mm) of growth inhibition was observed upon treatment with electrolyzed water. The effect of ozone gas on the growth of H. uvarum Y1 was evaluated by viable cell count. Initial cell numbers of $10^2$ and $10^3$ CFU/mL of H. uvarum Y1 were completely killed by treatment for 10 and 30 min, respectively. H. uvarum Y1 was also sterilized by microwave treatment for 1 min. When treated with gamma-irradiation, the rate of killing of H. uvarum Y1 was proportional to the irradiation dose. and complete killing occurred at a dose of 50 kGy.

• Food Science and Preservation
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• v.20 no.6
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• pp.854-862
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• 2013

We examined the quality characteristics and functionalities of Korean and Japanese spring Baechu cabbages and the kimchi prepared with them. To study the physiochemical properties of the cabbages and the kimchis, we measured their water content, pH, acidity, microbial counts, and springiness. On the third week of the kimchi fermentation at $5^{\circ}C$, their sensory properties and in vitro DPPH radical scavenging and anticancer activities using AGS human gastric cancer cells were determined. The Japanese Baechu contained 97.1% water, and the Korean Baechu, 92.4%. The comparison of the textures of the raw Baechu and the brined Baechu showed that the Korean Baechu had higher springiness scores than the Japanese Baechu. After four-week fermentation, the springiness score of the kimchi with Korean Baechu was 53.5%, significantly higher than the 41.4% of the kimchi with Japanese Baechu. The kimchi prepared with Korean Baechu had a low total bacterial count but higher Lactobacillus sp. and Leuconostoc sp. counts than the kimchi with Japanese Baechu. The kimchi prepared with Korean Baechu had the highest overall acceptability score in the sensory evaluation test. The DPPH radical scavenging activity of the kimchi with Korean Baechu was 83.2%, and that of the kimchi with Japanese Baechu, 46.1%. When the AGS human gastric cancer cells were treated with the kimchis, the kimchi prepared with Korean Baechu showed a 45% cancer cell growth inhibition rate, and the kimchi with Japanese Baechu, 26%, at 1 mg/mL of methanol extracts. At the 2 mg/mL concentration, the kimchis with Korean Baechu and Japanese Baechu showed 97% and 74% inhibition, respectively. The Korean Baechu showed better quality than the Japanese Baechu, and the kimchi prepared with the Korean Baechu showed better kimchi quality and functionality than the Japanese Baechu.

• Food Science and Preservation
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• v.20 no.6
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• pp.751-759
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• 2013

There is increasing interest in freshly cut products, that is, foods produced without washing and cutting. In this study, the quality of freshly cut sliced Deodeok was compared with that of what based on its washing methods. In bubble washing, the Deodeok rises to the water surface apace and is broken into centimeter sizes. Microbubble washing calls for the production of a great number of 0.1 mm-sized bubbles in anions-bearing water and their passing through a trumpet-shaped hole at a high pressure. To compare the product deterioration rates of the specimens, they were stored at $10^{\circ}C$ for 10 days. In the specimens washed with the control method and with hand washing, the deterioration rate was 80%; and in the specimens washed with bubble and microbubble washing, 20~30%. The L-value (an index of browning) was higher in the bubble and microbubble washing than in the control and the hand washing, which implies that browning was minimized during the storage. As for the viable cell and coliform group counts that were measured during the storage, the specimens washed with the control method showed the highest values. In contrast, the specimens washed with microbubble washing showed the lowest values. In the sensory test, the specimens washed with microbubble were highest in storage preference. In conclusion, the Deodeok that was stored after it was washed with microbubble washing was found to have had the best quality.

• Journal of The Korean Dental Society of Anesthesiology
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• v.14 no.1
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• pp.17-27
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• 2014

Background: Various medical emergency situations can occur during dental practices. Cardiac arrest is known to comprise approximately 1% of emergency situation. Thus, it is necessary for dentists to be able to perform cardiopulmonary resuscitation (CPR) to increase the chance of saving patient's life in emergency situation. In this paper, we conducted a survey study to evaluate to what extent dentists actually understood CPR practice and if they had experience in handling emergency situations in practice. Method: The survey was done for members of the Korean Dental Society of Anesthesiology (KDSA), who had great interest in CPR and for whom survey-by-mail was convenient. We had selected 472 members of the KDSA with a dental license and whose office address and contact information were appropriate, and sent them a survey questionnaire by mail asking about the degree of their CPR understanding and if they had experience of handling emergency questions before. Statistical analyses -frequency analysis, chi-square test, ANOVA, and so on- were performed by use of IBM SPSS Statistics 19 for each question. Result: Among 472 people, 181 responded (38.4% response rate). Among the respondents were 134 male and 47 female dentists. Their average age was $40.4{\pm}8.4$. In terms of practice type, there were 123 private practitioners (68.0%), 20 professors (11.0%), 16 dentists-in-service (8.8%), 13 residents (specialist training) (7.2%) and 9 military doctors (5%). There were 125 dentists (69.1%) who were specialists or receiving training to be specialist, most of whom were oral surgeon (57, 31.5%) and pediatric dentists (56, 30.9%). There were 153 people (85.0%) who received CPR training before, and 65 of them (35.9%) were receiving regular training. When asked about the ratio of chest pressure vs mouth-to-mouth respiration when conducting CPR, 107 people (59.1%) answered 30:2. However, only 27.1% of them answered correctly for a question regarding CPR stages, C(Circulation)- A(Airway)- B(Breathing)- D(Defibrillation), which was defined in revised 2010 CPR practice guideline. Dentists who had experience of handling emergency situations in their practice were 119 (65.6%). The kinds of emergency situations they experienced were syncope (68, 37.6%), allergic reactions to local anesthetic (44, 24.3%), hyperventilation (43, 23.8%), seizure (25, 13.8%), hypoglycemia (15, 8.3%), breathing difficulty (14, 7.8%), cardiac arrest (11, 6.1%), airway obstruction (6, 3.3%), intake of foreign material and angina pectoris (4, 2.2%), in order of frequency. Most respondents answered that they handled the situation appropriately under the given emergency situation. In terms of emergency equipment they had blood pressure device (70.2%), pulse oximetry (69.6%), Bag-Valve-Mask (56.9%), emergency medicine (41.4%), intubation kit (29.8%), automated external defibrillator (23.2%), suction kit (19.3%) and 12 people (6.6%) did not have any equipment. In terms of confidence in handling emergency situation, with 1-10 point scale, their response was $4.86{\pm}2.41$ points. The average point of those who received regular training was $5.92{\pm}2.20$, while those who did not was $4.29{\pm}2.29$ points (P<0.001) Conclusion: The result showed they had good knowledge of CPR but the information they had was not up-to-date. Also, they were frequently exposed to the risk of emergency situation during their dental practice but the level of confidence in handling the emergency situation was intermediate. Therefore, regular training of CPR to prepare them for handling emergency situation is deemed necessary.