• Title/Summary/Keyword: Contrast Sensitivity Function

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Transcallosal Ipsilateral Motor Pathway from the Unaffected Hemisphere in a Patient with Traumatic Brain Injury

  • Jang, Woo-Hyuk;Lee, Mi-Young;Kwon, Yong-Hyun;Jang, Sung-Ho
    • The Journal of Korean Physical Therapy
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    • v.26 no.3
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    • pp.216-219
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    • 2014
  • Purpose: We presented with a patient with traumatic brain injury who showed a transcallosal ipsilateral motor pathway from unaffected motor cortex to affected extremities, as evaluated by diffusion tensor tractography (DTT). Methods: One patient and six age-matched normal subjects were enrolled. A 42-year-old left hemiparetic male who suffered from brain injury by motor vehicle accident 9 years ago showed a leukomalactic lesion in the right corona radiata and parieto-temporal lobe. His left extremities were completely paralyzed initially, but recovered slowly over 2 years. At the time of the evaluation, he was able to grasp and release an object, and to walk with spastic gait pattern. DTT was performed using 1.5 T with a Synergy-L Sensitivity Encoding head coil. DTT was obtained with termination criteria of FA <0.2 and an angle change > $45^{\circ}c$. Results: The motor tracts of the unaffected (left) hemisphere of the patient and control subjects originated from the motor cortex and descended along the known corticospinal tract without any transcallosal tract. By contrast, the tract of the affected (right) hemisphere originated from the left premotor cortex, descended through the left corona radiata, and then crossed the mid-portion of the corpus callosum. The tract then descended through the known corticospinal tract pathway to the right medulla. Conclusion: We conclude that the transcallosal ipsilateral motor pathway from the unaffected hemisphere appeared to contribute to the motor recovery in this patient.

Model-Based Color- Image Halftoning Algorithm Using Dot-Pattern Database (도트 패턴 데이터 베이스를 이용한 모델 기반 칼라 영상 중간조 알고리즘)

  • Kim, Kyeong-Man;Song, Kun-Woen;Min, Gak;Kim, Jeong-Yeop;Ha, Yeong-Ho
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.38 no.2
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    • pp.208-217
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    • 2001
  • Model-based color image halftoning method using dot-pattern database is proposed for low-resolution color image printing. Dot-pattern database used in the proposed method is based on Blue-Noise Mask. The database consists of dot-patterns constructed by circular dot-overlap model according to each color value. In halftoning procedure, input color value is reproduced as the dot-pattern selected to minimize the difference between the color values of the original image and those of the printed image. Also, the contrast sensitivity function as a human visual model is used to improve the perceived quality of the printed image in dot-pattern selection. Thus, the proposed method can substantially reproduce the color values of the pixels in original image and obtain better image quality. In the experiment, the proposed method has less ΔΕ/Sub ab/ between the original image in monitor and the printed one than that of ED and BNM halftoning. This result approves that the proposed method reproduces better image quality.

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Regulation of the Korean Radish Cationic Peroxidase Promoter by Phytohormones and Other Reagents

  • Lee, Dong-Ju;Kim, Sung-Soo;Kim, Soung-Soo
    • BMB Reports
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    • v.32 no.1
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    • pp.51-59
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    • 1999
  • The Korean radish cationic peroxidase (KRCP) promoter, comprising nucleotides -471 to +704 relative to the transcriptional initiation site, was fused to the GUS gene and transformed to tobacco BY-2 cells. We examined how auxin (2,4-dichlorophenoxyacetic acid, 2,4-D), cytokinin (6-benzylaminopurine, BAP), gibberellic acid ($GA_3$), abscisic acid (ABA), methyl jasmonate (MeJA), and phosphatidic acid (PA) affect the GUS expression in the presence or absence of 2,4-D in a modified LS medium. Exogenous 2,4-D or BAP greatly decreased the GUS expression regulated by the KRCP promoter in a modified LS medium containing 0.2 mg/l 2,4-D. $GA_3$ increased the GUS expression and ABA completely reduced the inductive effect of $GA_3$. The GUS expression was also increased dose-dependently by plant defense regulators, MeJA and PA. In contrast to the above results, auxin deprivation from the modified LS medium increased the GUS expression after treatment with exogenous 2,4-D whereas BAP still greatly decreased the GUS expression dose-dependently. $GA_3$ or MeJA slightly decreased the GUS expression. The data suggest that auxin deprivation changes the sensitivity of the suspension cells to exogenous chemicals and that the regulation of the KRCP promoter by 2,4-D, $GA_3$, and MeJA is dependent on auxin, whereas the regulation by BAP is not. This study will be valuable for understanding the function and expression mode of the Korean radish cationic peroxidase in Korean radish.

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Model-based Dithering Using Dot Pattern Selection (도트 패턴 선택을 이용한 모델 기반 디더링)

  • Lee, Chae-Soo;Park, Yang-Woo;Uam, Tae-Uk;Jang, Joo-Seok;Ha, Yeong-Ho
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.38 no.3
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    • pp.247-257
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    • 2001
  • New methods are proposed for printing a full resolution image on a limited output device. The proposed algorithm uses a dot-pattern database that models overlapping phenomena among neighbor printing dots. To solve the problem of dot-overlap, the gray levels of dot-pattern sets were calculated using a circular dot-overlap model and then measured by a spectrometer. Thereafter, in order to improve the visual quality of the color dithering, the contrast sensitivity function of the human visual system was used. As a result, the optimal dot-pattern can be selected from the database. Consequently, the proposed algorithm can produce high quality images while using low-cost color devices.

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Modification of ERα by UFM1 Increases Its Stability and Transactivity for Breast Cancer Development

  • Yoo, Hee Min;Park, Jong Ho;Kim, Jae Yeon;Chung, Chin Ha
    • Molecules and Cells
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    • v.45 no.6
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    • pp.425-434
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    • 2022
  • The post-translational modification (e.g., phosphorylation) of estrogen receptor α (ERα) plays a role in controlling the expression and subcellular localization of ERα as well as its sensitivity to hormone response. Here, we show that ERα is also modified by UFM1 and this modification (ufmylation) plays a crucial role in promoting the stability and transactivity of ERα, which in turn promotes breast cancer development. The elevation of ufmylation via the knockdown of UFSP2 (the UFM1-deconjugating enzyme in humans) dramatically increases ERα stability by inhibiting ubiquitination. In contrast, ERα stability is decreased by the prevention of ufmylation via the silencing of UBA5 (the UFM1-activating E1 enzyme). Lys171 and Lys180 of ERα were identified as the major UFM1 acceptor sites, and the replacement of both Lys residues by Arg (2KR mutation) markedly reduced ERα stability. Moreover, the 2KR mutation abrogated the 17β-estradiol-induced transactivity of ERα and the expression of its downstream target genes, including pS2, cyclin D1, and c-Myc; this indicates that ERα ufmylation is required for its transactivation function. In addition, the 2KR mutation prevented anchorage-independent colony formation by MCF7 cells. Most notably, the expression of UFM1 and its conjugating machinery (i.e., UBA5, UFC1, UFL1, and UFBP1) were dramatically upregulated in ERα-positive breast cancer cell lines and tissues. Collectively, these findings implicate a critical role attributed to ERα ufmylation in breast cancer development by ameliorating its stability and transactivity.

Analysis of Elderly Driver's Visual Function (고령 운전자의 시각적 기능 분석에 관한 연구)

  • Kim, Jung Bok;Hwang, Jeong Hee;Chu, Byoung Sun
    • The Korean Journal of Vision Science
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    • v.20 no.4
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    • pp.505-511
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    • 2018
  • Purpose : This study investigated the visual functions of drivers aged over 65 year olds and drivers aged 50~65 year olds. In addition, difference of visual functions between professional drivers and normal drivers were investigated. Methods : Forty Driver aged over 65 year olds and 67 drivers aged less than 67 year olds were participated. All participants had more than 5 years of driving experiences and had no ocular pathology. Demographic data(gender, job, age, body condition) and visual functions such as contrast sensitivity(CS), stereopsis, glare recovery time and discomfort glare index were measured. Results : Constrast sensivity under photopic condition was higher with bus driver group. In addition, difference of CS at 12cpd and 18cpd were signifcantly different between normal drivers(1.57) and bus drivers(1.70) (p<0.05). There was no significant difference for glare recovery time, despite of trend of longer recovery time with age. Discomfort glare index was significantly different that normal drivers with more than 65 year olds had 3, taxi and truck driver presented almost 5 index score (p<0.05). Conclusion : Analysis of visual function of elderly drivers, it was confirmed that their visual functions decreased with age. Therefore, visual function tests such as CS, discomfort glare index and stereopsis in addition to current available test may need to be considered for drivers aged over 65.

The Study of Near-field Scanning Microwave Microscope for the Nondestructive Detection System (비파괴 측정을 위한 근접장 마이크로파 현미경 연구)

  • Kim, Joo-Young;Kim, Song-Hui;Yoo, Hyun-Jun;Yang, Jong-Il;Yoo, Hyung-Keun;Yu, Kyong-Son;Kim, Seung-Wan;Lee, Kie-Jin
    • Journal of the Korean Society for Nondestructive Testing
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    • v.24 no.5
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    • pp.508-517
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    • 2004
  • We described a near-field scanning microwave microscope which uses a high-quality dielectric resonator with a tunable screw. The operating frequency is f=4.5 5GHz. The probe tip is mounted in a cylindrical resonant cavity coupled to a dielectric resonator We developed a hybrid tip combining a reduced length of the tapered part with a small apex. In order to understand the function of the probe, we fabricated three different tips using a conventional chemical etching technique and observed three different NSMM images for patterened Cr films on glass substrates. We measured the reflection coefficient of different metal thin film samples with the same thickness of 300m and compared with theoretical impedance respectly. By tuning the tunable screw coming through the top cover, we could improve sensitivity, signal-to-noise ratio, and spatial resolution to better than $1{\mu}m$. To demonstrate the ability of local microwave characterization, the surface resistance of metallic thin films has been mapped.

Phenotypic Suppression of Rad53 Mutation by CYC8 (CYC8에 의한 rad53 돌연변이의 표현형 억제에 대한 연구)

  • Park, Kyoung-Jun;Choi, Do-Hee;Kwon, Sung-Hun;Kim, Joon-Ho;Bae, Sung-Ho
    • Korean Journal of Microbiology
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    • v.46 no.2
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    • pp.122-126
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    • 2010
  • RAD53 functions as an effector kinase of checkpoint pathways in Saccharomyces cerevisiae, which plays a central role to regulate many downstream cellular processes in response to DNA damage. It also involves in transcriptional activation of various genes including RNR genes which encode the key enzyme required for dNTP synthesis. In this study, we identified CYC8 as a suppressor for the hydroxyurea sensitivity of $rad53{\Delta}$ mutation. $Rad53{\Delta}$ mutant transformed with a multi-copy plasmid containing CYC8 showed increased hydroxyurea resistance. In contrast, TUP1 which forms a complex with CYC8 did not function as a suppressor. In the case of mutations, both $cyc8{\Delta}$ and $tup1{\Delta}$ suppressed hydroxyurea sensitivity of $rad53{\Delta}$. Since CYC8 can propagate as a prion in yeast, overexpression of CYC8 induced misfolding of the normal CYC8 proteins, resulting in dominant cyc8-phenotype. Therefore, it is suggested that CYC8 can act as a multi-copy suppressor due to its prion property. It was observed that the levels of RNR transcription were increased in the yeast strains containing either multi-copies of CYC8 gene or $cyc8{\Delta}$ mutation, suggesting that the increased level of RNR will elevate the intracellular pools of dNTPs, which, in turn, suppress the phenotype of $rad53{\Delta}$ mutation.

The Study on the Reduction of Patient Surface Dose Through the use of Copper Filter in a Digital Chest Radiography (디지털 흉부 촬영에서 구리필터사용에 따른 환자 표면선량 감소효과에 관한 연구)

  • Shin, Soo-In;Kim, Chong-Yeal;Kim, Sung-Chul
    • Journal of radiological science and technology
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    • v.31 no.3
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    • pp.223-228
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    • 2008
  • The most critical point in the medical use of radiation is to minimize the patient's entrance dose while maintaining the diagnostic function. Low-energy photons (long wave X-ray) among diagnostic X-rays are unnecessary because they are mostly absorbed and contribute the increase of patient's entrance dose. The most effective method to eliminate the low-energy photons is to use the filtering plate. The experiments were performed by observing the image quality. The skin entrance dose was 0.3 mmCu (copper) filter. A total of 80 images were prepared as two sets of 40 cuts. In the first set (of 40 cuts), 20 cuts were prepared for the non-filter set and another 20 cuts for the Cu filter of signal + noise image set. In the second set of 40 cuts, 20 cuts were prepared for the non-filter set and another 20 cuts for the Cu filter of non-signal image (noisy image) with random location of diameter 4 mm and 3 mm thickness of acryl disc for ROC signal at the chest phantom. P(S/s) and P(S/n) were calculated and the ROC curve was described in terms of sensitivity and specificity. Accuracy were evaluated after reading by five radiologists. The number of optically observable lesions was counted through ANSI chest phantom and contrast-detail phantom by recommendation of AAPM when non-filter or Cu filter was used, and the skin entrance dose was also measured for both conditions. As the result of the study, when the Cu filter was applied, favorable outcomes were observed on, the ROC Curve was located on the upper left area, sensitivity, accuracy and the number of CD phantom lesions were reasonable. Furthermore, if skin entrance dose was reduced, the use of additional filtration may be required to be considered in many other cases.

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Study on Image Quality Assessment in Whole Body Bone Scan (전신 뼈검사에서의 영상 평가 연구)

  • Kwon, Oh Jun;Hur, Jae;Lee, Han Wool;Kim, Joo Yeon;Park, Min Soo;Roo, Dong Ook;Kang, Chun Goo;Kim, Jae Sam
    • The Korean Journal of Nuclear Medicine Technology
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    • v.19 no.1
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    • pp.30-36
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    • 2015
  • Purpose Whole body bone scan, which makes up a largest percentage of nuclear medicine tests, has high sensitivity and resolution about bone lesion like osteomyelitis, fracture and the early detection of primary cancer. However, any standard for valuation has not yet been created except minimum factor. Therefore, in this study, we will analysis the method which show a quantitative evaluation index in whole body bone scan. Materials and Methods This study is conducted among 30 call patients, who visited the hospital from April to September 2014 with no special point of view about bone lesion, using GE INFINIA equipment. Enumerated data is measured mainly with patient's whole body count and lumbar vertabrae, and the things which include CNR (Contrast to Noise ratio), SNR (Signal to Noise ratio) are calculated according to the mean value signal and standard deviation of each lumbar vertabrae. In addition, the numerical value with the abdominal thickness is compared to each value by the change of scan speed and tissue equivalent material throughout the phantom examination, and compared with 1hours deleyed value. Completely, on the scale of ten, 2 reading doctors and 5 skilled radiologists with 5-years experience analysis the correlation between visual analysis with blind test and quantitative calculation. Results The whole body count and interest region count of patients have no significant correlation with visual analysis value throughout the blind test(P<0.05). There is definite correlation among CNR and SNR. In phantom examination, Value of the change was caused by the thickness of the abdomen and the scan speed. And The poor value of the image in the subject as a delay test patient could be confirmed that the increase tendency. Conclusion Now, a standard for valuation has not been created in whole body bone scan except minimum factor. In this study, we can verify the significant correlation with blind test using CNR and SNR and also assure that the scan speed is a important factor to influence the imagine quality from the value. It is possible to be some limit depending on the physiology function and fluid intake of patient even if we progress the evaluation in same condition include same injection amount, same scan speed and so on. However, that we prove the significant evaluation index by presenting quantitative calculation objectively could be considered academic value.

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