• Korean Journal of Applied Biomechanics
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• v.15 no.4
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• pp.55-66
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• 2005

The present study used a video analysis system to quantify the kinematical data of step shoot motion by male university handball players. From the results of analyzing dynamic variables of step shoot motion according to shooting direction were drawn conclusions as follows. 1. The height of release was proportional to the height of players, and the height of release appeared low in left-side attacks. This is probably because the left-right-throwing angle is larger in left-side attacks than that in center attacks and right-side attacks and, as a result, the throwing arm is lowered down in throwing. 2. The leftward inclination angle of the body was larger in order of right-side attacks > center attacks > left side attacks. 3. Players' throwing form was close to three quarter style in left-side attacks. In center and right-side attacks, the arm was somewhat more upright but still it was more three quarter style than overhand style. 4. The front-rear throwing angle at the moment of release was much higher in right-side attacks than in left-side ones. This is probably because the point of time for releasing the ball is usually late in right-side attacks and, as a result, the front-rear throwing angle becomes quite large. 5. The contribution of body parts on the ball speed was higher in order of the forearm > upper arm, hand > shoulder joint. 6. In players whose distance between the two legs at the moment of release, their body usually did not incline to the side much. Thus it is considered necessary to correct the right leg in their shooting motion. 7. According to the result of analyzing throwing form, the speed of the ball at the moment of leaving the hand was faster in right-side attacks than in left-side and center attacks.

• The Korean Journal of Nuclear Medicine Technology
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• v.21 no.1
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• pp.15-22
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• 2017

Purpose During Brain SPECT study, critical factor for proper study with $^{99m}Tc-ECD$ or $^{99m}Tc-HMPAO$ is one of the important causes to patent's movement. It causes both improper diagnosis and examination failure. In this study, we evaluated the effect of Dynamic Continuous Mode Acquisition compared to Step and Shoot Mode to raise efficacy and reject the data set with movement, as well as, be reconstructed in certain criteria. Materials and Methods Deluxe Jaszczak phantom and Hoffman 3D Brain phantom were used to find proper standard data set and exact time. Step and Shoot Mode and Dynamic Continuous Mode Acquisition were performed with SymbiaT16. Firstly, Deluxe Jaszczak phantom was filled with $Na^{99m}TcO_4$ 370 MBq and obtained in 60 minutes to check spatial resolution compared with Step and Shoot Mode and Dynamic Continuous Mode. The second, the Hoffman 3D Phantom filled with $Na^{99m}TcO_4$ 74 MBq was acquired for 15 Frame/minutes to evaluate visual assessment and quantification. Finally, in the Deluxe Jaszczak phantom, Spheres and Rods were measured by MI Apps program as well as, checking counts with the frontal lobe, temporal lobe, occipital lobe, cerebellum and hypothalamus parts was performed in the Hoffman 3D Brain Phantom. Results In Brain SPECT Study, using Dynamic Continuous Mode rather than current Step and Shoot Mode, we can do the reading using the 20 to 50 % of the acquired image, and during the test if the patient moves, we can remove unneeded image to reduce the rate of restudy and reinjection. Conclusion Dynamic Continuous Mode in Brain study condition enhances effects compared to Step and Shoot Mode. And also is powerful method to reduce reacquisition rate caused by patient movement. The findings further indicate that it suggest rejection limit to maintain clinical value with certain reconstruction factors compared with Tomo data set. Further examination to improve spatial resolution, SPECT/CT should be the answer for that.

• Journal of Plant Biotechnology
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• v.35 no.1
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• pp.75-80
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• 2008

In vitro culture of shoot tip of garlic (Allium sativium L. cv. Seosan) was carried out to find medium condition of the induction of multiple shoots and bulbing for muliproduction of virus-free seed bulbs. For this work, tank culture was introduced. In shoot tip culture on MS solid medium the induction of multiple shoots and bulbing were better by adding 3% sucrose than 8%. Supplementation with 2mg/L 2ip and 0.2 mg/L IAA in this medium was effective. Three point three shoots including 2.7 bulbs were formed from a shoot tip after cultivation for 30 days on this medium. Bulbing of garlic in liquid culture with plastic water tank of 20L supplied air at the side of the lower part was better by adding 3% sucrose than 8% by subculture for 45 days with shoots obtained from shoot tip culture for 30 days on soid MS medium. Shoot growth was vigorous at 3% sucrose however bulb growth was more effective on the medium of 8% sucrose. Because of the effectiveness on solid medium added 3% sucrose, 2 mg/L 2ip and 0.2 mg/L IAA for initial production of multi-shoot in stem tip culture and the effectiveness in liquid culture with water tank for growth of bulbs, the method of two-step culture could be introduced for the multiple production of seed bulb of high quality. It was more desirable by supply of 0.2 mg/L BA and 0.02 mg/L NAA at tank culture time. But growth of the bulbs became poor by increasing concentration of NAA of the medium.

• Molecules and Cells
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• v.44 no.10
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• pp.746-757
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• 2021

Plant somatic cells can be reprogrammed into a pluripotent cell mass, called callus, which can be subsequently used for de novo shoot regeneration through a two-step in vitro tissue culture method. MET1-dependent CG methylation has been implicated in plant regeneration in Arabidopsis, because the met1-3 mutant exhibits increased shoot regeneration compared with the wild-type. To understand the role of MET1 in de novo shoot regeneration, we compared the genome-wide DNA methylomes and transcriptomes of wildtype and met1-3 callus and leaf. The CG methylation patterns were largely unchanged during leaf-to-callus transition, suggesting that the altered regeneration phenotype of met1-3 was caused by the constitutively hypomethylated genes, independent of the tissue type. In particular, MET1-dependent CG methylation was observed at the blue light receptor genes, CRYPTOCHROME 1 (CRY1) and CRY2, which reduced their expression. Coexpression network analysis revealed that the CRY1 gene was closely linked to cytokinin signaling genes. Consistently, functional enrichment analysis of differentially expressed genes in met1-3 showed that gene ontology terms related to light and hormone signaling were overrepresented. Overall, our findings indicate that MET1-dependent repression of light and cytokinin signaling influences plant regeneration capacity and shoot identity establishment.

• Korean Journal of Plant Resources
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• v.36 no.6
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• pp.562-570
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• 2023

The droplet-vitrification technique for cryopreservation has proven successful across a diverse range of germplasm, ensuring safe and effective long term preservation. In this study, we investigate an effective cryopreservation protocol using the droplet-vitrification technique for shoot tips of Freesia hybrida cultivars 'Sunny Gold' and 'Sweet Lemon'. To determine optimal conditions for Freesia cryopreservation, we employed a carefully selected standard procedure along with additional treatments and alternative solutions. For 'Sunny Gold', the highest regrowth rate of 24% was achieved when shoot tips underwent dehydration with PVS3 solution for 120 minutes before direct immersion in liquid nitrogen (LN) for 1 hour, coupled with a standard protocol involving a two-step preculture with 0.3 M - 0.5 M sucrose, loading with C4 for 40 minutes, and unloading with 0.8 M sucrose for 40 minutes. In the case of 'Sweet Lemon,' regrowth of cryopreserved shoot tips was observed with dehydration treatments, including PVS2 (A3) for 60 minutes and PVS3 (B1) for 60 minutes, as well as longer exposure. The results reflect the distinct sensitivity of shoot tips to chemical toxicity and osmotic stress in these two genotypes. This study provides valuable evidence to consistently enhance the effectiveness of cryopreservation methods for the long-term conservation of Freesia germplasm.

• Korean Journal of Plant Tissue Culture
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• v.22 no.3
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• pp.127-130
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• 1995

Japanese pepper (Zanthoxylum piperitum Dc.) tree of selected genotype was propagated by a two-step method. Among the media tested, BTM promoted shoot height growth and DKW revealed as superior to micro-canopy increment Multiple shoot formation was greatest when the single shoot were subcultured on medium containing 0.89 $\mu$M BA alone. The numbers of survival shoots could be markedly increased by acclimatization of the multiplied shoots itself in plastic Petridish (punctured with pin on the top) for two weeks and subsequently transplanting each shoot onto peat plug system. After transplanting the micropropagules onto pots, prickliness characteristics seem to be transmitted to all plane produced from selected genotype.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.5
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• pp.394-406
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• 2004

A split-plot designed experiment including four rice varieties and 10 nitrogen levels was conducted in 2003 at the Experimental Farm of Seoul National University, Suwon, Korea. Before heading, hyperspectral canopy reflectance (300-1100nm with 1.55nm step) and nine crop variables such as shoot fresh weight (SFW), leaf area index, leaf dry weight, shoot dry weight, leaf N concentration, shoot N concentration, leaf N density, shoot N density and N nutrition index were measured at 54 and 72 days after transplanting. Grain yield, total number of spikelets, number of filled spikelets and 1000-grain weight were measured at harvest. 14,635 narrow-band NDVIs as combinations of reflectances at wavelength ${\lambda}l\;and\;{\lambda}2$ were correlated to the nine crop variables. One NDVI with the highest correlation coefficient with a given crop variable was selected as the NDVI of the best fit for this crop variable. As expected, models to predict crop variables before heading using the NDVI of the best fit had higher $r^2$ (>10\%)$ than those using common broad- band NDVI red or NDVI green. The models with the narrow-band NDVI of the best fit overcame broad- band NDVI saturation at high LAI values as frequently reported. Models using NDVIs of the best fit at booting showed higher predictive capacity for yield and yield component than models using crop variables.

• Journal of Plant Biology
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• v.32 no.4
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• pp.313-322
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• 1989

A system was established for induction of multi-shoots and plant regeneration from mesophyll protoplasts of alfalfa, Medicago sativa L. cv. Vernal. Different hormonal effects were tested at each step of protoplast culture, i.e. cell division in modified Kao's liquid medium (K566-7). calli formation on SH semi solid medium, and multi-shoot regeneration from calli on SHa and SHb solid media. Frequency of multi-shoots and plant regeneration was affected by various combinations of phytohormones in final step. The evaluation of multi-shoots induction systems via protoplast culture was discused.

• Progress in Medical Physics
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• v.13 no.4
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• pp.181-186
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• 2002

The IMRT planning depends on the algorithm of each planning system and MLC performance of each Linac system. Yonsei Cancer Center introduced an IMRT System at the beginning of February, 2002. The system consists of CORVUS (Nomos, U.S.A.) treatment planning system, LANTIS, PRIMEVIEW and PRIMART (Siemens, U.S.A) linac system. The optimization of CORVUS planning system with PRIMART is an important task to make a desirable quality treatment plan. Our Step ＆ Shoot IMRT system uses Finite Size Pencil Beams (FSPB) dose model, simulated annealing optimization algorithm and IMFAST segmentation algorithm. We constructed treatment plans for four different patient cases with two basic beamlet sizes, 1.0$\times$1.0 $\textrm{cm}^2$ and 0.5$\times$1.0 $\textrm{cm}^2$, and four intensity steps, 5%, 10%, 20%, 33%. Each case's plan was evaluated with the dose volume histograms of target volumes and delivery efficiencies. The patient case of small target volume is sensitive at the change of intensity map's segmentation and it highlighted an effective treatment plan at marrow intensity step and small basic projection beamlet.

• Korean Journal of Plant Resources
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• v.28 no.6
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• pp.697-703
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• 2015

Twenty apple germplasm accessions from the Korean Genebank were successfully cryopreserved using two-step freezing to back up genetic resources maintained by field collections. This study examined the morphological and genetic stability of cryopreserved dormant apple buds that were stored in liquid nitrogen, and then rewarmed and regrown. Whole plants were regenerated directly from dormant buds through budding without an intermediary callus phase. The cryopreserved buds produced high levels of shoot formation (76.2-100%), similar to those of noncryopreserved buds (91.3-100%), with no observed differences between cryopreserved and noncryopreserved materials. Three of the twenty cryopreserved apple germplasm accessions were used to assess morphological and genetic stability. No differences in morphological characteristics including shoot length, leaf shape, leaf width/length ratio, and root length were observed between controls (fresh control and noncryopreserved) and cryopreserved plantlets. The genetic stability of regenerants (before and after cryopreservation) was investigated using inter simple sequence repeat (ISSR) markers. The ISSR markers produced 253 bands using four primers, ISSR 810, SSR 835, ISSR 864, and ISSR 899. These markers showed monomorphic banding patterns and revealed no polymorphism between the mother plant and regenerants before and after cryopreservation, suggesting that cryopreservation using two-step freezing does not affect the genetic stability of apple germplasm. These results show that two-step freezing cryopreservation is a practical method for long-term storage of apple germplasms.