• BMB Reports
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• v.51 no.7
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• pp.317-318
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• 2018

Plants are unable to relocate themselves to a more favorable location and thus have to deal with developmental programs and environmental cues wherever they happen to be. It is yet largely unknown how plant cells coordinate cellular activities and architectures to accomplish developmental processes and respond to environmental changes. By identifying and establishing a new cellular model system, we have discovered that two neighboring cell types in the abscission zone (AZ) of Arabidopsis flowers coordinate their activities to ensure a precise "cut" through a highly restricted area of plant tissue to bring about organ separation. From this perspective, we further discuss the essence of cellular coordination in AZ, the key molecules controlling the organ separation, and relevant implications.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2003.05a
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• pp.146-147
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• 2003

The free-living nematode, Caenorhabditis elegans (C. elegans) has been adopted as a multicellular biosensor of biological toxicity for alkylphenol, organotin compounds and heavy metals. To adopt as a biosensor, suitability to assess must be fulfilledthrough several criteria; the organism must be sensitive to the testing toxicants, easy to manage in the laboratory and available throughout the year. C. elegans widely used as a simple multicellular organism in developmental biology studies and satisfies all these criteria, and its culture conditions, developmental staging, anatomy and genetic properties are well defined. In addition, researchers can take advantage of the worm's short life cycle, low cost and little individual variation. Moreover, genomic sequencing of C. elegans has recently been completed. With these aspectsof the organism, C. elegans become a more potent model organism for basic and applied bioassays.

• Korean journal of applied entomology
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• v.55 no.1
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• pp.35-43
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• 2016

The temperature-dependent development of Metcalfa pruinosa overwintering eggs was investigated at ten constant temperatures (12.5, 15, 17.5, 20, 22.5, 25, 27.5, 30, 32.5, and $35{\pm}1^{\circ}C$, Relative Humidity 20~30%). All individuals collected before April 13, 2012 failed to develop into first instar larvae. In contrast, some individuals that were collected on April 11, 2013 successfully developed when reared under $20{\sim}32.5^{\circ}C$ temperature regimes. The developmental duration was shortest at $30^{\circ}C$ (13.3 days) and longest at $15^{\circ}C$ (49.6 days) in the fourth collected colony (April 26 2013). Developmental duration decreased with increasing temperature up to $30^{\circ}C$ and development was retarded at high-temperature regimes ($32.5^{\circ}C$). The lower developmental threshold was $10.1^{\circ}C$ and the thermal constant required to complete egg overwintering was 252DD. The Lactin 2 model provided the best statistical description of the relationship between temperature and the developmental rate of M. pruinosa overwintering eggs ($r^2=0.99$). The distribution of the developmental completion of overwintering eggs was well described by the 2-parameter Weibull function ($r^2=0.92$) based on the standardized development duration. However, the estimated cumulative 50% spring emergence dates of overwintering eggs were best predicted by poikilotherm rate model combined with the 2-parameter Weibull model (average difference of 1.7days between observed and estimated dates).

• Korean journal of applied entomology
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• v.50 no.4
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• pp.343-352
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• 2011

The developmental period of Laodelphax striatellus Fallen, a vector of rice stripe virus (RSV), was investigated at ten constant temperatures from 12.5 to $35{\pm}1^{\circ}C$ at 30 to 40% RH, and a photoperiod of 14:10 (L:D) h. Eggs developed successfully at each temperature tested and their developmental time decreased as temperature increased. Egg development was fasted at $35^{\circ}C$(5.8 days), and slowest at $12.5^{\circ}C$ (44.5 days). Nymphs could not develop to the adult stage at 32.5 or $35^{\circ}C$. The mean total developmental time of nymphal stages at 12.5, 15, 17.5, 20, 22.5, 25, 27.5 and $30^{\circ}C$ were 132.7, 55.9, 37.7, 26.9, 20.2, 15.8, 14.9 and 17.4 days, respectively. One linear model and four nonlinear models (Briere 1, Lactin 2, Logan 6 and Poikilotherm rate) were used to determine the response of developmental rate to temperature. The lower threshold temperatures of egg and total nymphal stage of L. striatellus were $10.2^{\circ}C$ and $10.7^{\circ}C$, respectively. The thermal constants (degree-days) for eggs and nymphs were 122.0 and 238.1DD, respectively. Among the four nonlinear models, the Poikilotherm rate model had the best fit for all developmental stages ($r^2$=0.98~0.99). The distribution of completion of each development stage was well described by the two-parameter Weibull function ($r^2$=0.84~0.94). The emergence rate of L. striatellus adults using DYMEX$^{(R)}$ was predicted under the assumption that the physiological age of over-wintered nymphs was 0.2 and that the Poikilotherm rate model was applied to describe temperature-dependent development. The result presented higher predictability than other conditions.

• Journal of Ocean Engineering and Technology
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• v.24 no.6
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• pp.41-50
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• 2010

This study established a 3D ecosystem model composed of stratification considering the topographic heat accumulation effect and river outflow, and then applied this model to Jinhae, Masan Bay. Specifically, it reenacted the formation and developmental process of ODW according to the stratification by calculating the kinematic eddy viscosity and eddy diffusion coefficient of the stratification model. The results were used as input data for the ecosystem model and compared with DO, COD, I-N, and I-P, which is the standard index of ocean water quality. As a result, it was determined that COD and T-N are third grade and T-P is second grade standards for a natural environment.

• 한국노년학
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• v.31 no.2
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• pp.381-400
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• 2011

The purpose of this study is to develop the scale on Selection, Optimization, Compensation(SOC) model as successful aging strategies of Korean Elderly. In first phase of the study, 64 pilot items were collected from researcher's indepth interviews with a purposive sample group of 24 elderly people(16 items) and original SOC scale(48 items). To analyze the factor structure and to verify the validity of the scale, 592 questionnaires collected from survey were divided randomly into 300 developmental samples and 292 validity samples. The items were examined exploratory with developmental samples and confirmatory factor analysis with developmental samples. Two factor analysis supported four factor structure of the SOC consisted of 20 items. Four factors are as follows: 'Elective Selection', 'Loss-Based Selection', 'Opimization', 'Compensation'. The cronbach's alpha estimate of the scale was .930. This scale of four factor model exhibited good fit, assessed by overall fit measure criteria(TLI=.939, CFI=.947, RMSEA=.058). The result of analysis by item response theory for SOC scale is satisfatory. Also, SOC scale was significantly related to the two successful aging scales for Korean elderly and life satisfation scale(SWLS). These results proved the validity of the scale.

• Korean Journal of Radiology
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• v.22 no.6
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• pp.983-993
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• 2021

Objective: To investigate the image quality of ultralow-dose CT (ULDCT) of the chest reconstructed using a cycle-consistent generative adversarial network (CycleGAN)-based deep learning method in the evaluation of pulmonary tuberculosis. Materials and Methods: Between June 2019 and November 2019, 103 patients (mean age, 40.8 ± 13.6 years; 61 men and 42 women) with pulmonary tuberculosis were prospectively enrolled to undergo standard-dose CT (120 kVp with automated exposure control), followed immediately by ULDCT (80 kVp and 10 mAs). The images of the two successive scans were used to train the CycleGAN framework for image-to-image translation. The denoising efficacy of the CycleGAN algorithm was compared with that of hybrid and model-based iterative reconstruction. Repeated-measures analysis of variance and Wilcoxon signed-rank test were performed to compare the objective measurements and the subjective image quality scores, respectively. Results: With the optimized CycleGAN denoising model, using the ULDCT images as input, the peak signal-to-noise ratio and structural similarity index improved by 2.0 dB and 0.21, respectively. The CycleGAN-generated denoised ULDCT images typically provided satisfactory image quality for optimal visibility of anatomic structures and pathological findings, with a lower level of image noise (mean ± standard deviation [SD], 19.5 ± 3.0 Hounsfield unit [HU]) than that of the hybrid (66.3 ± 10.5 HU, p < 0.001) and a similar noise level to model-based iterative reconstruction (19.6 ± 2.6 HU, p > 0.908). The CycleGAN-generated images showed the highest contrast-to-noise ratios for the pulmonary lesions, followed by the model-based and hybrid iterative reconstruction. The mean effective radiation dose of ULDCT was 0.12 mSv with a mean 93.9% reduction compared to standard-dose CT. Conclusion: The optimized CycleGAN technique may allow the synthesis of diagnostically acceptable images from ULDCT of the chest for the evaluation of pulmonary tuberculosis.

• PNF and Movement
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• v.7 no.1
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• pp.17-23
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• 2009

Purpose : To provide a convenient framework for PNF practice, we reviewed the relationship between ICF framework and PNF framework. Methods : We reviewed literatures related with ICF and PNF. Results : ICF model is useful tool for physical therapist who is working in PNF to identify the interactions the components of individual's health, especially the relationship between functioning and disability. A framework for PNF is philosophy which included the concept, functional approach. It is essential to identify primary activity limitation and causal impairment in PNF field and evaluate the their relationship. The ICF model can be used to classify the examination information. Next step is to prioritize the activity limitation and then evaluate the interrelationships among each components of the ICF framework. Conclusions : ICF model guides physical therapist in PNF practice to identify patient problems and evaluate the interrelationship of components of their health. This model is logical framework to directs functional approach as PNF philosophy to be approached the goal.

• Korean journal of applied entomology
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• v.51 no.4
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• pp.431-438
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• 2012

The developmental time of the nymphs of Myzus persicae was studied in the laboratory (six constant temperatures from 15 to $30^{\circ}C$ with 50~60% RH, and a photoperiod of 14L:10D) and in a green-pepper plastic house. Mortality of M. persicae in laboratory was high in the first(6.7~13.3%) and second instar nymphs(6.7%) at low temperatures and high in the third (17.8%) and fourth instar nymphs(17.8%) at high temperatures. Mortality was 66.7% at $33^{\circ}C$ in laboratory and $26.7^{\circ}C$ in plastic house. The total developmental time was the longest at $14.6^{\circ}C$ (14.4 days) and shortest at $26.7^{\circ}C$ (6.0 days) in plastic house. The lower threshold temperature of the total nymphal stage was $3.0^{\circ}C$ in laboratory. The thermal constant required for nymphal stage was 111.1DD. The relationship between developmental rate and temperature was fitted nonlinear model by Logan-6 which has the lowest value on Akaike information criterion (AIC) and Bayesian information criterion (BIC). The distribution of completion of each developmental stage was well described by the 3-parameter Weibull function ($r^2=0.95{\sim}0.97$). This model accurately described the predicted and observed occurrences. Thus the model is considered to be good for use in predicting the optimal spray time for Myzus persicae.

• Korean journal of applied entomology
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• v.43 no.4 s.137
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• pp.305-310
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• 2004

The development of Myzus persicae (Sulzer) was studied at temperatures ranging from 15 to $32.5^{\circ}C$ under $70{\pm}5\%$ RH, and a photoperiod of 16:8 (L:D). Mortality of 1st-2nd nymph was higher than that of 3rd-4th nymph at the most temperature ranges whereas at high temperature of $32.5^{\circ}C$, more 3-4nymph stage individuals died. The total developmental time ranged from 12.4 days at $15^{\circ}C$ to 4.9 days at $27.5^{\circ}C$, suggesting that higher the temperature, faster the development. However, at higher end temperature ranges of 30 and $32.5^{\circ}C$, the development took 5.0 and 6.3 days, respectively. The lower developmental threshold temperature and effective accumulative temperatures for the total immature stage were $4.9^{\circ}C$ and 116.5 day-degrees. The nonlinear shape of temperature related development was well described by the modified Sharpe and DeMichele model. When the normalized cumulative frequency distributions of developmental times for each life stage were fitted to the three-parameter Weibull function, attendance of shortened developmental times was apparent with pre-nymph, post-nymph, and total nymph stages in descending order. The coefficient of determination $r^2$ ranged between 0.87 and 0.94.