• Title/Summary/Keyword: Null

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Permutation-Based Test with Small Samples for Detecting Differentially Expressed Genes (극소수 샘플에서 유의발현 유전자 탐색에 사용되는 순열에 근거한 검정법)

  • Lee, Ju-Hyoung;Song, Hae-Hiang
    • The Korean Journal of Applied Statistics
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    • v.22 no.5
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    • pp.1059-1072
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    • 2009
  • In the analysis of microarray data with a small number of arrays, the most important task is the detection of differentially expressed genes by a significance test. For this purpose, one needs to construct a null distribution based on a large number of genes and one of the best way for constructing the null distribution for a small number of arrays is by means of permutation methods. In this paper we propose simple test statistics and permutation methods that are appropriate in constructing the null distribution. In a simulation study, we compare the null distributions generated by the proposed test statistics and permutation methods with the previous ones. With an example microarray data, differentially expressed genes are determined by applying these methods.

A Study on the Optimum Synthesis of Beam Patterns and Excitation Current Weights for Monopulse Tracking Linear Array Antennas (모노펄스 추적용 선형 배열 안테나 빔 패턴 및 여기 전류 가중치들의 최적 합성에 관한 연구)

  • Park, Eui-Joon
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.19 no.5
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    • pp.533-540
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    • 2008
  • In the sum and difference pattern synthesis problem of the equi-spaced monopulse tracking linear array antennas, an efficient numerical approach to deriving the relative excitation current weights of antenna elements is presented for the desired patterns. This method is based on the optimum perturbation of null points which are inherent to the Schelkunoffs polynomial representing the pattern array factor. Accordingly, opposite to the conventional method in which the excitation weights are directly optimized, this method is advantageous in that the patterns with the desired individual sidelobe levels(SLLs) and the corresponding excitation weights are easily synthesized by the control of null points. Furthermore, it is showed that two types of difference patterns can be synthesized as imposing the different initial values of null points in the optimization process. The proposed method is numerically validated by synthesizing the patterns with the arbitrary SLLs and substituting the extracted results into the array factor equation.

Predictive Role of Glutathione-S-transferase Gene Polymorphisms in Risk and Prognosis of Hepatocellular Carcinoma

  • Li, Cheng-Gang;Zhao, Zhi-Ming;Hu, Ming-Geng;Liu, Rong
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.7
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    • pp.3247-3252
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    • 2012
  • Aim: We conducted a prospective study in an Chinese population to detect associations of GSTM, GSTT and GSTP polymorphisms with hepatocellular carcinoma (HCC), and analyze roles in determining survival outcome. Methods: A prospective follow-up study was conducted with 476 HCC patients and 481 controls collected from May 2005 to May 2007. All patients were followed up until the end of Dec. 2011. GSTM1, GSTT1 and GSTP1 genotyping were performed by PCR-CTPP methods. Results: Null GSTM1 carriers had a 1.64 fold risk of HCC compared with non-null genotype, while GSTP1 Val/Val carriers had a 93% increased risk over the GSTP1 IIe/IIe genotype. The median follow-up time for the 476 patients was 34.2 months (range: 1 to 78 months). Individuals with null GSTM1 genotype had better survival of HCC than non-null genotype carriers (HR=0.71, 95%CI=0.45-0.95). Similarly, GSTP1 Val/Val genotypes had significant better survival than the GSTP1 IIe/IIe genotype (HR=0.34, 95%CI=0.18-0.65). Individuals carrying null GSTM1 and GSTP1 Val/Val who received chemotherapy had lower risk of death from HCC than those without chemotherapy. Conclusion: This study indicated carriage of null GSTM1 and GSTP1 Val/Val genotypes to have roles in susceptibility to and survival from HCC.

Analysis of the IP Spoofing Attack Exploiting Null Security Algorithms in 5G Networks

  • Park, Tae-Keun;Park, Jong-Geun;Kim, Keewon
    • Journal of the Korea Society of Computer and Information
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    • v.27 no.9
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    • pp.113-120
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    • 2022
  • In this paper, we analyze the feasibility of the IP spoofing attack exploiting null security algorithms in 5G networks based on 3GPP standard specifications. According to 3GPP standard specifications, the initial Registration Request message is not protected by encryption and integrity. The IP spoofing attack exploits the vulnerability that allows a malicious gNB (next generation Node B) to modify the contents of the initial Registration Request message of a victim UE (User Equipment) before forwarding it to AMF (Access and Mobility Management Function). If the attack succeeds, the victim UE is disconnected from the 5G network and a malicious UE gets Internet services, while the 5G operator will charge the victim UE. In this paper, we analyze the feasibility of the IP spoofing attack by analyzing whether each signaling message composing the attack conforms to the 3GPP Rel-17 standard specifications. As a result of the analysis, it is determined that the IP spoofing attack is not feasible in the 5G system implemented according to the 3GPP Rel-17 standard specifications.

Effect of Glutathione S-Transferase Polymorphisms on the Antioxidant System (Glutathione S-Transferase 유전적 다형성이 항산화 체계에 미치는 영향)

  • Jeon, Gyeong-Im;Park, Eun-Ju
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.36 no.6
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    • pp.708-719
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    • 2007
  • Glutathione S-transferase genotypes GSTT1, GSTM1 and GSTP1 were characterized in 104 healthy male and female subjects and compared with parameters of oxidative stress at the level of DNA and lipids, with antioxidant enzymes, and with plasma antioxidants in smokers and non.smokers. Of the 104 subjects studied, 57.4% were GSTT1 present and 47.6% were GSTM1 present. The GSTP1 polymorphisms a and b were represented as follows: a/a, 75.5%; a/b, 21.6%; b/b type, 2.9%. The GSTT1 null genotype was associated with decreased glutathione in erythrocytes and elevated lymphocytes DNA damage. GST-Px was higher in GSTT1 null compared with GSTT1 present type. The homozygous GSTP1 genotype was not associated with any antioxidant status or DNA damage. The difference in plasma ${\alpha}$-carotene and erythrocytes GSH-Px and GST activities between smokers and non-smokers was detected in the GSTT1 null genotype. Plasma ${\gamma}$-tocopherol and ${\beta}$-carotene decreased significantly in smokers having GSTM1 null genotype. When GSTT1 and GSTM1 were combined, plasma lycopene and erythrocyte GST were reduced in smokers in both null types of these genes. As for GSTP1 genotype, plasma ${\alpha}$-carotene and erythrocytes GSH-Px decreased significantly in smokers with GSTP1 b/b, while erythrocytes GSH-Px activities decreased in smokers with GSTP1 a/b. The different ${\beta}$-carotene level between smokers and non-smokers was seen with both GSTP1 a/a and a/b genotype. It seems that polymorphisms in the phase II metabolizing enzyme glutathione S-transferase may be important determinants of commonly measured biomarkers.

Lymphocyte DNA damage and plasma antioxidant status in Korean subclinical hypertensive patients by glutathione S-transferase polymorphism

  • Han, Jeong-Hwa;Lee, Hye-Jin;Choi, Hee Jeong;Yun, Kyung Eun;Kang, Myung-Hee
    • Nutrition Research and Practice
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    • v.11 no.3
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    • pp.214-222
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    • 2017
  • BACKGROUND/OBJECTIVES: Glutathione S-transferase (GST) forms a multigene family of phase II detoxification enzymes which are involved in the detoxification of xenobiotics by conjugating substances with glutathione. The aim of this study is to assess the antioxidative status and the degree of DNA damage in the subclinical hypertensive patients in Korea using glutathione S-transferase polymorphisms. SUBJECTS/METHODS: We examined whether DNA damage and antioxidative status show a difference between GSTM1 or GSTT1 genotype in 227 newly diagnosed, untreated (systolic blood pressure $(BP){\geq}130mmHg$ or diastolic $BP{\geq}85mmHg$) subclinical hypertensive patients and 130 normotensive subjects (systolic BP < 120 mmHg and diastolic BP < 80 mmHg). From the blood of the subjects, the degree of the DNA damage in lymphocyte, the activities of erythrocyte superoxide dismutase, the catalase, and the glutathione peroxidase, the level of glutathione, plasma total radical-trapping antioxidant potential (TRAP), anti-oxidative vitamins, as well as plasma lipid profiles and conjugated diene (CD) were analyzed. RESULTS: Of the 227 subjects studied, 68.3% were GSTM1 null genotype and 66.5% were GSTT1 null genotype. GSTM1 null genotype had an increased risk of hypertension (OR: 2.104, CI: 1.38-3.35), but no significant association in GSTT1 null genotype (OR 0.982, CI: 0.62-1.55). No difference in erythrocyte activities of superoxide dismutase, catalase, or glutathione peroxidase, and plasma TRAP, CD, lipid profiles, and GSH levels were observed between GSTM1 or GSTT1 genotype. Plasma levels of ${\alpha}-tocopherol$ increased significantly in GSTT1 wild genotype (P < 0.05); however, plasma level of ${\beta}-carotene$ increased significantly in GSTT1 null genotype (P < 0.01). DNA damage assessed by the Comet assay was significantly higher in GSTM1 null genotype than wild genotype (P < 0.05). CONCLUSIONS: These results confirm the association between GSTM1 null genotype and risk of hypertension as they suggest that GSTM1 null genotype leads to an increased oxidative stress compared with wild genotype.

Glutathione-S-transferase (GSTM1, GSTT1) Null Phenotypes and Risk of Lung Cancer in a Korean Population

  • Piao, Jin-Mei;Shin, Min-Ho;Kim, Hee Nam;Cui, Lian-Hua;Song, Hye-Rim;Kweon, Sun-Seog;Choi, Jin-Su;Kim, Young-Chul;Oh, In-Jae;Kim, Kyu-Sik
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.12
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    • pp.7165-7169
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    • 2013
  • Purpose: The aim of this study was to evaluate any association of GSTM1 and GSTT1 null genotypes with the risk of lung cancer in a South Korean population. Methods: We conducted a large-scale, population-based case-control study including 3,933 lung cancer cases and 1,699 controls. Genotypes of GSTM1 and GSTT1 were determined using real-time polymerase chain reaction. Results: In logistic regression analysis adjusted for age and smoking, we did not find any association between GSTM1 or GSTT1 and LC risk in women. However, in men, the GSTM1 and GSTTI null genotypes were borderline associated with risk (OR=1.18, 95% CI=0.99-1.41 for GSTM1, OR=1.18, 95% CI=0.99-1.41 for GSTT1), and combined GSTM1 and GSTT1 null genotypes conferred an increased risk for LC in men (OR=1.39, 95% CI=1.08-1.78). The OR for the GSTT1 null genotype was greater in subjects aged 55 years old or younger (OR=1.45, 95% CI=1.09-1.92 for men; OR=1.36, 95% CI=0.97-1.90 for women), than in those over age 55 (OR=1.03, 95% CI=0.83-1.27 for men; OR=0.86, 95% CI=0.66-1.12 for women) in both genders (p for interaction <0.05). Conclusions: In the Korean population, the GSTM1 and GSTT1 null genotypes are risk factors for LC in men; the GSTT1 null genotype has a more prominent effect on LC risk in younger people (age 55 years and under) than in older individuals.

Analysis of the Optical Measurement Error Induced by Vibration of the Optical Measurement Tower for Large Mirrors (대구경 반사경 광학측정용 타워의 진동에 의한 광학측정오차 분석)

  • Kang, Pilseong;Kim, Ohgan;Ahn, Hee Kyung;Yang, Ho-Soon
    • Korean Journal of Optics and Photonics
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    • v.28 no.6
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    • pp.281-289
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    • 2017
  • In the present research, the optical measurement error induced by vibration of the optical measurement tower for large mirrors at KRISS (Korea Research Institute of Standards and Science) is investigated. The vibrations of the tower structure, the interferometer, and the null lens are measured while the surface errors of the 600-mm-diameter on-axis aspheric mirror are measuring, under various environmental conditions. The increase of surface error induced by alignment error with respect to vibration is analyzed. As a result, the interferometer and the null lens, which are located on the top of the tower, are highly sensitive to vibration. Additionally, the surface error of the mirror is strongly increased when the vibration directions of the interferometer and the null lens are different. To reduce the alignment error and the surface error induced by vibration, the tower structure should be improved, to be insensitive to low-frequency vibration. Alternatively, optical measuring under stable conditions by vibration monitoring can improve the reliability of the surface error measurement.

Breeding of Green Soybean Strain with Green Cotyledon and Tetra Null Genotype (Tetra null 유전자형과 녹색종피 및 자엽을 가진 콩 계통 육종)

  • Sarath Ly;Jeong Hwan Lee;Hyeon Su Oh;Se Yeong Kim;Jin Young Moon;Jong Il Chung
    • Journal of Life Science
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    • v.33 no.8
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    • pp.632-638
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    • 2023
  • A soybean cultivar with a green seed coat and cotyledon contains high levels of lutein, which is beneficial for eye health. Plus, antinutritional components such as lipoxygenase, Kunitz trypsin inhibitor (KTI), lectin and stachyose exist in the mature seed. The genetic elimination of these antinutritional factors is a necessary step in green soybean breeding. This research was conducted to improve a new green soybean line with the green cotyledon and tetra null genotype (lox1lox2lox3tilers2) in terms of lipoxygenase, KTI, lectin and stachyose. We used five germplasms to develop a breeding population. A total of 69 F2 seeds were obtained from the cross of parent 1 and parent 2, and from those, 21 F2 seeds were selected that had the green seed coat color, and which were free of lectin protein. Next, four F2 plants with the green seed coat and tetra null genotype were selected from the breeding population derived from four genotypes. The absence of lipoxygenase, KTI and lectin proteins was confirmed in the F5 strain. The breeding line has a green seed coat, green cotyledon and white hilum color. The 100-seed weight and stachyose content for the breeding line were 30.7 g and 2.40 g/kg, respectively. The line selected in this study could be used as a cultivar or parent to improve colored soybean cultivars through the removal of antinutritional components such as lip- oxygenase, KTI, lectin and stachyose.