• Title, Summary, Keyword: Test of heterogeneity

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Current Evidence on the Relationship Between Two Polymorphisms in the NBS1 Gene and Breast Cancer Risk: a Meta-analysis

  • Zhang, Zhi-Hua;Yang, Lin-Sheng;Huang, Fen;Hao, Jia-Hu;Su, Pu-Yu;Sun, Ye-Huan
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.11
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    • pp.5375-5379
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    • 2012
  • Introduction: Published studies on the association between Nijmegen breakage syndrome 1(NBS1) gene polymorphisms and breast cancer risk have been inconclusive, and a meta-analysis was therefore performed for clarification. Methods: Eligible articles were identified by a search of MEDLINE and EMBASE bibliographic databases for the period up to March 2012. The presence of between-study heterogeneity was investigated using the chi-square-based Cochran's Q statistic test. When there was statistical heterogeneity, the random effects model was chosen; otherwise, fixed effects estimates were reported as an alternative approach. Results: A total of 11 eligible articles (14 case-control studies) were identified, nine case-control studies were for the 657del5 mutation (7,534 breast cancer cases, 14,034 controls) and five case-control studies were for the I171V mutation (3,273 breast cancer cases, 4,004 controls). Our analysis results indicated that the 657del5 mutation was associated with breast cancer risk (carriers vs. non-carriers: pooled OR =2.63, 95% CI: 1.76-3.93), whereas the I171V mutation was not (carriers vs. non-carriers: pooled OR =1.52, 95% CI: 0.70-3.28). Conclusion: The present meta-analysis suggests that the 657del5 gene mutation in the NBS1 gene plays a role in breast cancer risk, while the I171V mutation does not exert a significant influence.

Global prevalence of classic phenylketonuria based on Neonatal Screening Program Data: systematic review and meta-analysis

  • Shoraka, Hamid Reza;Haghdoost, Ali Akbar;Baneshi, Mohammad Reza;Bagherinezhad, Zohre;Zolala, Farzaneh
    • Clinical and Experimental Pediatrics
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    • v.63 no.2
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    • pp.34-43
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    • 2020
  • Phenylketonuria is a disease caused by congenital defects in phenylalanine metabolism that leads to irreversible nerve cell damage. However, its detection in the early days of life can reduce its severity. Thus, many countries have started disease screening programs for neonates. The present study aimed to determine the worldwide prevalence of classic phenylketonuria using the data of neonatal screening studies.The PubMed, Web of Sciences, Sciences Direct, ProQuest, and Scopus databases were searched for related articles. Article quality was evaluated using the Joanna Briggs Institute Critical Appraisal Evaluation Checklist. A random effect was used to calculate the pooled prevalence, and a phenylketonuria prevalence per 100,000 neonates was reported. A total of 53 studies with 119,152,905 participants conducted in 1964-2017 were included in this systematic review. The highest prevalence (38.13) was reported in Turkey, while the lowest (0.3) in Thailand. A total of 46 studies were entered into the meta-analysis for pooled prevalence estimation. The overall worldwide prevalence of the disease is 6.002 per 100,000 neonates (95% confidence interval, 5.07-6.93). The meta-regression test showed high heterogeneity in the worldwide disease prevalence (I2=99%). Heterogeneity in the worldwide prevalence of phenylketonuria is high, possibly due to differences in factors affecting the disease, such as consanguineous marriages and genetic reserves in different countries, study performance, diagnostic tests, cutoff points, and sample size.

Prognostic Value of β-catenin Expression in Breast Cancer Patients: a Meta-analysis

  • Zhang, De-Pu;Li, Xiao-Wei;Lang, Jing-He
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.14
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    • pp.5625-5633
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    • 2015
  • Background: ${\beta}$-catenin plays a crucial role in the progression of breast cancer (BC) and a prognostic role of in BC patients has been widely reported. However, controversy still remains. Materials and Methods: Identical search strategies were used to search relevant literature in electronic databases updated to July 1, 2014. Individual hazard ratios (HRs) and 95% confidence intervals (CIs) were extracted and pooled HRs with 95%CIs were used to evaluate the strength of association between positive ${\beta}$-catenin expression in different subcellular locations and survival results of BC patients. Subgroup and meta-regression analyses were performed to explore heterogeneity. Funnel plots of Begg's and Egger's linear regression test were used to investigate publication bias. Heterogeneity and sensitivity were also assessed. All the work was completed using STATA. Results: A total of 2,204 patients from 12 evaluative studies were finally included. Pooled HRs and 95%CIs suggested that ${\beta}$-catenin expression in cytoplasm/nucleus had an unfavorable impact on both overall survival (OS) (HR: 1.93, 95%CI: 1.40-2.65) and disease free survival (DFS)/ recurrent free survival (RFS) (HR: 1.60, 95%CI: 1.20-2.13) in BC patients. However, here was no significant association between ${\beta}$-catenin expression in the membranes with OS (HR: 0.65, 95%CI: 0.42-1.02) or DFS/RFS (HR: 0.66, 95%CI: 0.38-1.13). Publication bias was absent in all of the four outcomes. Sensitivity analysis revealed that the results of this meta-analysis were robust. Conclusions: Positive ${\beta}$-catenin expression in cytoplasm/nucleus rather than in membrane is a significant prognostic factor in patients with BC who have been surgically treated.

A Study on Correlation between Heterogeneity Index and Mechanical Properties of Igneous Rocks using 3D X-ray Computed Tomography Image (3차원 X-ray CT 영상을 이용한 화성암 불균질 지수와 역학적 특성과의 상관관계에 대한 연구)

  • Jeong, Yeon Jong;Kim, Kwang Yeom;Yun, Tae Sup
    • Tunnel and Underground Space
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    • v.27 no.5
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    • pp.333-342
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    • 2017
  • In this study, the heterogeneity of internal structure of various igneous rocks acquired in Korea was quantified and correlated with the seismic velocity and the point load strength. Three-dimensional X-ray Computed Tomography (CT) was used to obtain information on the internal structure of the rock specimen, and the representative unit length (LR) was calculated by applying a statistical technique to the CT images. We also proposed an estimation equation to predict the mechanical properties of rocks from the relationship between LR, acoustic velocity and point load strength. In the proposed method, it is shown that the characterization of internal structure of rocks could be utilized as an indirect index to account for the mechanical behavior of rocks by substituting physical laboratory testing for non-destructive test.

Lack of Any Association of GST Genetic Polymorphisms with Susceptibility to Ovarian Cancer - a Meta-analysis

  • Han, Li-Yuan;Liu, Kui;Lin, Xia-Lu;Zou, Bao-Bo;Zhao, Jin-Shun
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.15
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    • pp.6131-6136
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    • 2014
  • Objective: Epidemiology studies have reported conflicting results between glutathione S-transferase Mu-1 (GSTM1), glutathione S-transferase theta-1 (GSTT1) and glutathione S-transferase pi-1 (GSTP1) and ovarian cancer (OC) susceptibility. In this study, an updated meta-analysis was applied to determine whether the deletion of GSTM1, GSTT1 and GSTP1 has an influence on OC susceptibility. Methods: A published literature search was performed through PubMed, Embase, Cochrane Library, and Science Citation Index Expanded database for articles published in English. Pooled odds ratios (ORs) and 95% confidence intervals (95%CIs) were calculated using random or fixed effects models. Heterogeneity between studies was assessed using the Cochrane Q test and $I^2$ statistics. Sub-group analysis was conducted to explore the sources of heterogeneity. Sensitivity analysis was employed to evaluate the respective influence of each study on the overall estimate. Results: In total, 10 published studies were included in the final analysis. The combined analysis revealed that there was no significant association between GSTM1 null genotype and OC risk (OR=1.01, 95%CI: 0.91-1.12). Additionally, there was no significant association between GSTT1 genetic polymorphisms and OC risk (OR=0.98, 95% CI: 0.85-1.13). Similalry, no significant associations were found concerning the GSTP1 rs1695 locus and OC risk. Meanwhile, subgroup analysis did not show a significant increase in eligible studies with low heterogeneity. However, sensitivity analysis, publication bias and cumulative analysis demonstrated the reliability and stability of the current meta-analysis. Conclusions: These findings suggest that GSTs genetic polymorphisms may not contribute to OC susceptibility. Large epidemiological studies with the combination of GSTM1 null, GSTT1 null and GSTP1 Ile105Val polymorphisms and more specific histological subtypes of OC are needed to prove our findings.

Adjustment of heterogeneous variance by milk production level of dairy herd (젖소군의 유생산 수준별 이질성 분산 보정)

  • Cho, Kwang-Hyun;Lee, Joon-Ho;Park, Kyung-Do
    • Journal of the Korean Data and Information Science Society
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    • v.25 no.4
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    • pp.737-743
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    • 2014
  • This experiment was conducted to compare heterogeneity for the variance in dairy cattle population and to induce homogeneity of variance using 502,228 performance test records of dairy cattle. The estimates of heritability for milk yields, fat yields and protein yields were 0.28, 0.26 and 0.24, respectively and the estimate of average breeding value by birth year was lower in HV (heterogenous variance) model than in animal model, collectively. The average breeding values of milk yields, fat yields and protein yields for 545 sire bulls applicable to the criteria of interbull MACE programme were 453.54kg, 10.75kg and 14.33kg, respectively and when the heterogeneity was adjusted they were 432.06kg, 10.15kg and 13.40kg, respectively, which were lower in all milk traits collectively. In animal model, coefficients of phenotypic correlation between dataset I and II were 0.839 in milk yields, 0.821 in fat yields, and 0.837 in protein yields, while in HV model, they were 0.841 in milk yields, 0.820 in fat yields, and 0.836 in protein yields, showing similar results in 2 models. When compared using animal model and HV model, the regression coefficient for ratio of number of daughters by calving year of milk yields increased from 15.157 to 16.105 and that of fat yields increased from =0.227 to =0.196, but that of protein yields decreased from 0.630 to 0.586.

Locally adaptive intelligent interpolation for population distribution modeling using pre-classified land cover data and geographically weighted regression (지표피복 데이터와 지리가중회귀모형을 이용한 인구분포 추정에 관한 연구)

  • Kim, Hwahwan
    • Journal of the Korean association of regional geographers
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    • v.22 no.1
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    • pp.251-266
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    • 2016
  • Intelligent interpolation methods such as dasymetric mapping are considered to be the best way to disaggregate zone-based population data by observing and utilizing the internal variation within each source zone. This research reviews the advantages and problems of the dasymetric mapping method, and presents a geographically weighted regression (GWR) based method to take into consideration the spatial heterogeneity of population density - land cover relationship. The locally adaptive intelligent interpolation method is able to make use of readily available ancillary information in the public domain without the need for additional data processing. In the case study, we use the preclassified National Land Cover Dataset 2011 to test the performance of the proposed method (i.e. the GWR-based multi-class dasymetric method) compared to four other popular population estimation methods (i.e. areal weighting interpolation, pycnophylactic interpolation, binary dasymetric method, and globally fitted ordinary least squares (OLS) based multi-class dasymetric method). The GWR-based multi-class dasymetric method outperforms all other methods. It is attributed to the fact that spatial heterogeneity is accounted for in the process of determining density parameters for land cover classes.

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Effect of Cognitive Behavioral Therapy (CBT) for Perinatal Depression: A Systematic Review and Meta-Analysis (산전우울 임부를 위한 인지행동치료 프로그램의 효과: 체계적 문헌고찰 및 메타분석)

  • Shin, Hyeon-Hee;Shin, Yeong-Hee;Kim, Ga-Eun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.11
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    • pp.271-284
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    • 2016
  • This study was carried out to evaluate the efficacy of CBT for perinatal depression through systematic literature review and meta-analysis. The following databases were used to search the literature: CINAHL, PubMed, EMBASE, Koreamed, Library of Korean Congress, KISS, and Korean Academic Publication Database. Keywords included 'perinatal depression,' 'pregnant women,' and 'cognitive behavioral therapy,' and the evaluated articles were published up to May 2016. Using the R program, the effect size of perinatal depression and anxiety were calculated by random-effects model. The heterogeneity of the effect size was analyzed by data moderator analysis using the meta-ANOVA. Furthermore, the funnel plot, Egger's regression test, fail-safe N, trim-and-fill test, and publication bias analysis were conducted and used to verify the results. Out of the 180 selected articles, 16 clinical trial studies were meta-analyzed. Each articles were evaluated for the risk of bias by the checklist of SIGN; the overall risk of bias was low. The effect size of CBT for perinatal depression was Hedges' g=-0.55 (95% CI: -0.76~-0.33), which was a moderate level, while for anxiety reduction, Hedges' g=-0.20 (95% CI: -0.48~-0.08) and it was not statistically significant. Heterogeneity or risk of publication bias were low. This meta-analytic study found that CBT is moderately effective in reducing perinatal depression in pregnant women.

Intelligent management system for tunnel under construction using ITIS (Intelligent Tunnelling Information System)

  • Kim Changyong;Hong Sungwan;Bae Gyujin;Kim Kwangyeom
    • 한국지구물리탐사학회:학술대회논문집
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    • pp.170-175
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    • 2003
  • Ground and rock mass considered in tunnelling have characteristics such as uncertainty, heterogeneity and structural complexity because they have been formed undergoing various geological events for a long period. So, it is difficult for engineers to predict behaviors of rock mass in tunneling. In the paper the authors describe the development of an integrated expert system prototype for site investigation, design and construction in tunnelling and introduce the case applying this system to the tunnel construction site under construction. Geostructure Research Group in Korea Institute of Construction Technology (KICT) has developed the system during the past 4 years. The system mainly consists of several modules which is related to the design, construction and management of tunnelling. The test site, Neung-dong tunnel is located in Ulsan, Korea. The geology map shows it may confront big fault zone whose width is over kilometres. With the networking system of ITIS, various information of face mapping, monitoring and other construction task can be transmitted into the database and GIS Server at real time. And necessary analyses can be carried out with the modules equipped in the system.

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Constitutive Model for a Confined Concrete Cylinder with an Unbonded External Steel Jacket

  • Roh, Young-Sook
    • Architectural research
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    • v.17 no.1
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    • pp.41-48
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    • 2015
  • Early investigations focused mainly on manipulating the confinement effect to develop a reinforced concrete column with lateral hoops. Based on this legacy model, Li's model incorporated the additional confinement effect of a steel jacket. However, recent experiments on plain concrete cylinders with steel jackets revealed relatively large discrepancies in the estimates of strength enhancement and the post-peak behavior. Here, we describe a modified constitutive law for confined concrete with an unbonded external steel jacket in terms of three regions for the loading stage. We used a two-phase heterogeneous concrete model to simulate the uniaxial compression test of a $150mm{\times}300mm$ concrete cylinder with three thicknesses of steel jackets: 1.0 mm, 1.5 mm, and 2.0 mm. The proposed constitutive model was verified by a series of finite element analyses using a finite element program. The damaged plasticity model and extended Drucker-Prager model were applied and compared in terms of the level of pressure sensitivity for confinement in 3D. The proposed model yielded results that were in close agreement with the experimental results.