• Mycobiology
• /
• v.45 no.4
• /
• pp.297-311
• /
• 2017

Saprolegniasis is one of the most devastating oomycete diseases in freshwater fish which is caused by species in the genus Saprolegnia including Saprolegnia parasitica. In this study, we isolated the strain of S. parasitica from diseased rainbow trout in Korea. Morphological and molecular based identification confirmed that isolated oomycete belongs to the member of S. parasitica, supported by its typical features including cotton-like mycelium, zoospores and phylogenetic analysis with internal transcribed spacer region. Pathogenicity of isolated S. parasitica was developed in embryo, juvenile, and adult zebrafish as a disease model. Host-pathogen interaction in adult zebrafish was investigated at transcriptional level. Upon infection with S. parasitica, pathogen/antigen recognition and signaling (TLR2, TLR4b, TLR5b, NOD1, and major histocompatibility complex class I), pro/anti-inflammatory cytokines (interleukin $[IL]-1{\beta}$, tumor necrosis factor ${\alpha}$, IL-6, IL-8, interferon ${\gamma}$, IL-12, and IL-10), matrix metalloproteinase (MMP9 and MMP13), cell surface molecules ($CD8^+$ and $CD4^+$) and antioxidant enzymes (superoxide dismutase, catalase) related genes were differentially modulated at 3- and 12-hr post infection. As an anti-Saprolegnia agent, plant based lawsone was applied to investigate on the susceptibility of S. parasitica showing the minimum inhibitory concentration and percentage inhibition of radial growth as $200{\mu}g/mL$ and 31.8%, respectively. Moreover, natural lawsone changed the membrane permeability of S. parasitica mycelium and caused irreversible damage and disintegration to the cellular membranes of S. parasitica. Transcriptional responses of the genes of S. parasitica mycelium exposed to lawsone were altered, indicating that lawsone could be a potential anti-S. parasitica agent for controlling S. parasitica infection.

• Journal of Life Science
• /
• v.18 no.4
• /
• pp.435-440
• /
• 2008

Random amplified polymorphic DNA (RAPD) markers were used to identify the genetic diversities among and within varieties and landraces of Rehmannia glutinosa. Polymorphic and reproducible bands were produced by 10 primers out of total 20 primers used in the experiment. In RAPD analysis of the 11 genotypes, 64 fragments out of 73 amplified genomic DNA fragments were polymorphic which represented an average 6.4 polymorphic fragments per primer. Number of amplified fragments with random primers ranged from 2 (OPA-1) to 13 (OPA-11) and varied in size from 200 bp to 1,400 bp. Especially, OPA-10, OPA-11 and OPA-19 primers showed specific bands for varieties of Korea Jiwhang and Jiwhang il ho, which could be useful for discriminating from other varieties and landraces of R. glutinosa. Percentage polymorphism ranged from a minimum of 50% (OPA-1) to a maximum of 100% (OPA-11), with an average of 87.7%. Similarity coefficients were higher in the genotypes of Korea Jiwhang and Jiwhang il ho than in other populations. In cluster analysis, genotypes of Korea Jiwhang, Jiwhang il ho, and Japanese accession were separated from those of other varieties and landraces. Average of genetic diversity within the population $(H_S)$ was 0.110, while average of total genetic diversity $(H_T)$ was 0.229. Across all RAPD makers the $G_{ST}$ value was 0.517, indicating that about 52% of the total genetic variation could be explained by RAPDs differences while the remaining 48% might be attributable to differences among samples. Consequently, RAPD analysis was useful method to discriminate different populations such as domestic varieties and other landraces. The results of the present study will be used to understand the population and evolutionary genetics of R. gllutinosa.

• Journal of Korean Neurosurgical Society
• /
• v.60 no.5
• /
• pp.577-583
• /
• 2017

Objective : Laminoplasty is an effective surgical method for treating cervical degenerative disease. However, postoperative complications such as kyphosis, restriction of neck motion, and instability are often reported. Despite sufficient preoperative lordosis, this procedure often aggravates the lordotic curve of the cervical spine and straightens cervical alignment. Hence, it is important to examine preoperative risk factors associated with postoperative kyphotic alignment changes. Our study aimed to investigate preoperative radiologic parameters associated with kyphotic deformity post laminoplasty. Methods : We retrospectively reviewed the medical records of 49 patients who underwent open door laminoplasty for cervical spondylotic myelopathy (CSM) or ossification of the posterior longitudinal ligament (OPLL) at Pusan National University Yangsan Hospital between January 2011 and December 2015. Inclusion criteria were as follows : 1) preoperative diagnosis of OPLL or CSM, 2) no previous history of cervical spinal surgery, cervical trauma, tumor, or infection, 3) minimum of one-year follow-up post laminoplasty with proper radiologic examinations performed in outpatient clinics, and 4) cases showing C7 and T1 vertebral body in the preoperative cervical sagittal plane. The radiologic parameters examined included C2-C7 Cobb angles, T1 slope, C2-C7 sagittal vertical axis (SVA), range of motion (ROM) from C2-C7, segmental instability, and T2 signal change observed on magnetic resonance imaging (MRI). Clinical factors examined included preoperative modified Japanese Orthopedic Association scores, disease classification, duration of symptoms, and the range of operation levels. Results : Mean preoperative sagittal alignment was $13.01^{\circ}$ lordotic; $6.94^{\circ}$ lordotic postoperatively. Percentage of postoperative kyphosis was 80%. Patients were subdivided into two groups according to postoperative Cobb angle change; a control group (n=22) and kyphotic group (n=27). The kyphotic group consisted of patients with more than $5^{\circ}$ kyphotic angle change postoperatively. There were no differences in age, sex, C2-C7 Cobb angle, T1 slope, C2-C7 SVA, ROM from C2-C7, segmental instability, or T2 signal change. Multiple regression analysis revealed T1 slope had a strong relationship with postoperative cervical kyphosis. Likewise, correlation analysis revealed there was a statistical significance between T1 slope and postoperative Cobb angle change (p=0.035), and that there was a statistically significant relationship between T1 slope and C2-C7 SVA (p=0.001). Patients with higher preoperative T1 slope demonstrated loss of lordotic curvature postoperatively. Conclusion : Laminoplasty has a high probability of aggravating sagittal balance of the cervical spine. T1 slope is a good predictor of postoperative kyphotic changes of the cervical spine. Similarly, T1 slope is strongly correlated with C2-C7 SVA.

• Journal of KIISE:Information Networking
• /
• v.36 no.4
• /
• pp.339-350
• /
• 2009

In wireless sensor networks, the limited battery resources of sensor nodes have a direct impact on network lifetime. To reduce unnecessary power consumption, it is often the case that only a minimum number of sensor nodes operate in active mode while the others are kept in sleep mode. In such a case, however, the network service can be easily unreliable if any active node is unable to perform its sensing or communication function because of an unexpected failure. Thus, for achieving reliable sensing, it is important to maintain the sensing level even when some sensor nodes fail. In this paper, we propose a new fault-tolerance scheme, called FCP(Fault-tolerant Coverage Preserving), that gives an efficient way to handle the degradation of the sensing level caused by sensor node failures. In the proposed FCP scheme, a set of backup nodes are pre-designated for each active node to be used to replace the active node in case of its failure. Experimental results show that the FCP scheme provides enhanced performance with reduced overhead in terms of sensing coverage preserving, the number of backup nodes and the amount of control messages. On the average, the percentage of coverage preserving is improved by 87.2% while the additional number of backup nodes and the additional amount of control messages are reduced by 57.6% and 99.5%, respectively, compared with previous fault-tolerance schemes.

• Asian Journal of Turfgrass Science
• /
• v.23 no.2
• /
• pp.253-264
• /
• 2009

The purpose of seed certification is to preserve the genetic purity and identity of seed varieties. This study is to provide information concerning seed certification procedures and certification standards of Kentucky bluegrass especially used in golf courses. We analyzed data from the seed certification standards of three states (Washington, Idaho and Oregon) in U.S.A. The certification processes both field inspection and laboratory requirement satisfying the minimum seed quality standards. The seed harvesting field must be propagated with the specified class of seeds and requires an adequate isolated distance from other crops. Moreover, the field should be clean and free from the objectionable weeds. The seed analysis tests include a germination rate, a percentage of pure seed, contents of other crop seed, weed seed, and inert matter. The certification standards of the certified seed and the sod quality seed showed general similarity in all three states. The certification standards of the sod quality seed should have less than 0.02% of maximum weed seed. The certified seed should have less than 0.3% of maximum weed seeds. Those certification standards of seed quality should guaranty the quality of turfgrass establishment of golf course.

• Korean Journal of Remote Sensing
• /
• v.34 no.6_1
• /
• pp.1119-1130
• /
• 2018

Soyang Lake has been contributing to economic growth by preventing flood damage in the metropolitan area, the water level in the middle to upper flow of lake has been greatly decreased due to the drought in 2015. In order to restore the existing flow rate, Bupyungbo has been built in Bupyeong-ri, Shin Nam-myeon, Inje-gun to cause artificial changes on the sedimentary environment of Bupyeong freshwater region. Therefore, this study intends to confirm the changes of sedimentary environment since Bupyeongbo has been utilized. For this study, we used the Sentinel-2 satellite image data periodically to measure the dimension of water according to the volume of water kept near Bupyung district and analyzed the particle size and the percentage of water content of the sediments through field study. The Sentnel-2 satellite images showed us how the water surface has been changed and that during the period from September 2017 to October 2018, the minimum and maximum area of water surface was observed in June 2018 and in January 2018, respectively. In addition, we find that the smaller being the particle size, the higher having the water content and that there is higher the correlation between the water content and the grain size of the sediment layer. Hereafter, if we will acquire the drone images at Bupyung district, we expect that we will be able to measure the distribution of sediments in the same area according to different time periods and observe various kinds of sediment through field work.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.7
• /
• pp.192-202
• /
• 2019

This study was a descriptive study to investigate the factors influencing on self-esteem, ego resilience, impulsivity and life stress on smartphone addiction among college students. The subjects include college students in some areas. Data was collected in November and December, 2018. Total 231 college students were analyzed in the study. Collected data was analyzed in frequency, percentage, and t-test to examine differences in smartphone addiction according to general characteristics. Pearson's correlation was performed to examine correlations between smartphone addiction and main variables, and the factors influencing smartphone addiction were analyzed in multiple regression. The findings show that genera, satisfaction with college life, hours of using a smartphone, hours of using SNS, ego resilience, impulsivity, and life stress had significant effects on smartphone addiction. The study examined relations between general characters and smartphone addiction and found that the level of smartphone addiction was high in female college students, those who were not satisfied with college life, and used a smartphone and SNS for many hours. Ego resilience had negative correlations with smartphone addiction, and impulsivity and life stress had positive correlations with it. Multi-variate regression analysis results show that gender, ego resilience, and life stress were factors that had important influences on the smartphone addiction of college students, having explanatory power of 35.6%. In short, colleges and universities need to develop a school-level program to improve the college life of students and reduce their stress to the minimum and create an environment of encouraging them to grow power of controlling their lives so that they can prevent smartphone addiction.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.27 no.1
• /
• pp.67-73
• /
• 2021

The purpose of this study is to obtain a safe area for a passing vessel between anchored vessels by developing a model to predict the collision risk, frequent collisions occur between the anchored vessel and the passing vessel through the anchorage. For this, this study selected the southern anchorage of Busan port, which is the largest harbor in Korea, as the target area and extracted and analyzed VTS (Vessel Traffic Service) data during the period in which anchored vessels were the most waited. The ratio of D/L for each bearing was obtained to determine the safe distance (D) passes based on the length (L) of the passing vessel between anchored vessels. Based on the average domain of the D/L ratio distribution, the percentage of anchored vessels within the scope of the pre-studied ship's domain was analyzed to obtain a domain reflecting the degree of risk of VTSOs. Further research will evaluate and analyze the collision risk of a passing vessel using Domain-watch, the minimum safe distance between anchored vessels, and the safe domain of a passing vessel through anchorage, to develop a model for VTS to manage anchorages more efficiently and safely.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.22 no.2
• /
• pp.336-344
• /
• 2021

The purpose of this study was to identify the self-awareness of smartphone dependence among undergraduate students and their response to the same. The data was drawn from a survey on smartphone overdependence conducted by the Ministry of Science and information and communications technology (ICT) and the National Information Society Agency in 2017. The responses of 1,735 undergraduate students were analyzed by frequency, percentage, mean, standard deviation, minimum-maximum value, ��2-test, independent t-test, Pearson's correlation coefficient, and stepwise multiple regression analysis. The results indicated that 22.3% of participants were at risk of smartphone dependence, and 63.6% of them were unaware of their dependence on smartphones. The perception of smartphone dependence was significantly associated with a higher risk of smartphone dependence (��=.35, p=.000) and the increasing use of applications such as games (��=.19, p=.000), television/video (��=.11, p=.000), and learning (��=.11, p=.000). Of the participants with dependence awareness, only a few knew about the existence of centers to prevent smartphone and internet dependence. Moreover, they rarely utilized these centers. However, the participants felt the need for more counseling agencies (26.8%), programs for dealing with oneself (23.2%), information about smartphone dependence (14.9%), and help to overcome dependence (10.9%). These findings show the need to establish public services so that students can easily access correct information on smartphone dependence and address this problem.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.12
• /
• pp.660-671
• /
• 2020

This study is a descriptive survey study that attempted to confirm clinical nurses' consciousness of biomedical ethics, moral sensitivity, critical thinking deposition, and nursing ethics code of clinical nurses, as well as to identify the factors influencing the recognition of the nursing code of ethics. The general and ethical characteristics of the subject were calculated by frequency, percentage, mean, and standard deviation, and the difference for each variable according to the general and ethical characteristics was analyzed using SAS 9.4, independent t-test, and one-way ANOVA, and Scheffé test. The average, standard deviation, and the minimum and maximum values were used for the scores of each variable, and the correlation was determined using the Pearson correlation coefficient. Multiple regression was used to identify the factors that influence the recognition of the nurse's code of ethics. All variables showed significant correlations. Critical thinking deposition (p<.05) was the most influential variable in recognizing the code of ethics for nurses. Critical thinking deposition (p<.001), consciousness in biomedical ethics (p<.001), and moral sensitivity (p<.001) were shown to be affected in order, with 27.4% explaining power. Therefore, it is necessary to develop and apply educational programs to clinical nurses that can improve critical thinking, life and bioethics, and moral sensitivity.