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Validation of general linear modeling for identifying factors associated with Quality of Life: A comparison with structural equation modeling
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作者 Naoko Kumagai Motonori Hatta +1 位作者 Yashiyasu Okuhara Hideki Origasa 《Health》 2013年第11期1884-1888,共5页
Purpose: General linear modeling (GLM) is usually applied to investigate factors associated with the domains of Quality of Life (QOL). A summation score in a specific sub-domain is regressed by a statistical model inc... Purpose: General linear modeling (GLM) is usually applied to investigate factors associated with the domains of Quality of Life (QOL). A summation score in a specific sub-domain is regressed by a statistical model including factors that are associated with the sub-domain. However, using the summation score ignores the influence of individual questions. Structural equation modeling (SEM) can account for the influence of each question’s score by compositing a latent variable from each question of a sub-domain. The objective of this study is to determine whether a conventional approach such as GLM, with its use of the summation score, is valid from the standpoint of the SEM approach. Method: We used the Japanese version of the Maugeri Foundation Respiratory Failure Questionnaire, a QOL measure, on 94 patients with heart failure. The daily activity sub-domain of the questionnaire was selected together with its four accompanying factors, namely, living together, occupation, gender, and the New York Heart Association’s cardiac function scale (NYHA). The association level between individual factors and the daily activity sub-domain was estimated using SEM?and GLM, respectively. The standard partial regression coefficients of GLM and standardized path coefficients of SEM were compared. If?these coefficients were similar (absolute value of the difference -0.06 and -0.07 for the GLM and SEM. Likewise, the estimates of occupation, gender, and NYHA were -0.18 and -0.20, -0.08 and -0.08, 0.51 and 0.54, respectively. The absolute values of the difference for each factor were 0.01, 0.02, 0.00, and 0.03, respectively. All differences were less than 0.05. This means that these two approaches lead to similar conclusions. Conclusion: GLM is a valid method for exploring association factors with a domain in QOL. 展开更多
关键词 general liner modelING LATENT Variable Standardized Path COEFFICIENT Standard Partial Regression COEFFICIENT Structural Equation modelING
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单变量多因素观察性资料主要影响因素的逐步筛选 被引量:7
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作者 保宏翔 刘丹红 +1 位作者 杨鹏 徐勇勇 《中国卫生统计》 CSCD 北大核心 2007年第1期33-35,42,共4页
目的探讨如何用单变量分析的一般线性模型(GLM-Univariate)方法筛选“单变量多因素观察性资料”的主要影响因素。方法以住院患者病案首页数据中住院费用的影响因素分析为例,比较逐步回归方法与GLM-Univari-ate方法的优劣。结果逐步回归... 目的探讨如何用单变量分析的一般线性模型(GLM-Univariate)方法筛选“单变量多因素观察性资料”的主要影响因素。方法以住院患者病案首页数据中住院费用的影响因素分析为例,比较逐步回归方法与GLM-Univari-ate方法的优劣。结果逐步回归方法可能导致的主要问题是庞杂的哑变量处理和计算结果对哑变量赋值方法的高度依赖性,且不能分析因素的整体效应。GLM-Univariate不仅能克服上述问题,而且可以通过方差分析表中各因素(协变量)的P值和效应值η2大小,逐步筛选出主要影响因素和协变量,并建立相应的回归方程。结论GLM-Univariate过程可以完成单变量多因素观察性资料主要影响因素的筛选,并能够分析因素之间和因素与协变量间的交互效应,较逐步回归方法更为适宜。 展开更多
关键词 观察性资料 一般线性模型 逐步回归
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海南主要陆域自然保护地兰科植物多样性与生境的关联分析 被引量:10
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作者 周康 张哲 +4 位作者 宋希强 李大程 陈枳衡 张中扬 李霖明 《广西植物》 CAS CSCD 北大核心 2022年第8期1337-1356,共20页
为了掌握海南主要陆域自然保护地内野生兰科植物的物种多样性现状以及制约其发展的关键生境因子,对该地区进行兰科植物资源调查并分析兰科植物多样性的空间分布格局,进一步采用典范对应分析(CCA)探索生境因子对兰科植物组成的影响,最后... 为了掌握海南主要陆域自然保护地内野生兰科植物的物种多样性现状以及制约其发展的关键生境因子,对该地区进行兰科植物资源调查并分析兰科植物多样性的空间分布格局,进一步采用典范对应分析(CCA)探索生境因子对兰科植物组成的影响,最后运用广义线性模型(GLM)框架下的负二项回归拟合兰科植物丰富度和多度对生境变异的响应。结果表明:(1)共发现兰科植物67属193种,为海南兰科植物分布的绝对中心。(2)水平方向上,霸王岭兰科植物丰富度高但居群相对拥挤,而五指山最大的海拔落差带来了更加多样化的小生境类型和宽阔的生存空间,孕育了种类丰富且分布均匀的兰科植物资源。(3)垂直方向上,中海拔地区兰科植物种类最为丰富且种间竞争较为激烈,高海拔地区则存在明显的优势类群。(4)海拔变化对兰科植物物种组成变异有着非常高的解释率,而喀斯特和河谷地貌的显著影响也不容忽视。(5)多因子综合作用共同影响着兰科植物的多样性,其中坡度、河谷地貌、喀斯特地貌的显著正效应和枫香林的显著负效应受其他协变量的影响较小,是驱动兰科植物丰富度和多度变化的关键生境因子。综上所述,中高海拔地区以及特殊地貌(如河谷和喀斯特地貌)应作为兰科植物多样性的优先保护区域。 展开更多
关键词 兰科植物多样性 生境 典范对应分析 广义线性模型 自然保护地
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Detection of QTL(quantitative trait loci) associated with wood density by evaluating genetic structure and linkage disequilibrium of teak 被引量:1
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作者 Vivek Vaishnav Shamim Akhtar Ansari 《Journal of Forestry Research》 SCIE CAS CSCD 2019年第6期2247-2258,共12页
To find the quantitative trait loci associated with wood density in teak(Tectona grandis L.f.), 21 co-dominant markers including 13 site specific recombinase and 8 EST-based co-dominant markers designed from lignin bi... To find the quantitative trait loci associated with wood density in teak(Tectona grandis L.f.), 21 co-dominant markers including 13 site specific recombinase and 8 EST-based co-dominant markers designed from lignin biosynthesis genes were applied to 174 teak plus tree clones at the National Germplasm Bank, Chandrapur,India. The germplasm bank exhibited 10.6% coefficient of variation for wood densities with 84.5 ± 31.3 genetic polymorphism(%). The highly panmictic set of genotypes(FST= 0.035 ± 0.004) harbored 96.47 ± 0.40 genetic variability(%). The average allelic frequency of the 21 codominant markers was 0.65 ± 0.11 with 12.9% pairs of loci in significant LD(p\0.05, R^2 values [ 0.1), confirming their suitability for a strong marker-trait association study. The marker CCoAMT-1 was significantly(p\0.01) associated with wood density showing stability by both GLM and MLM models and explained 4.3% of the phenotypic effect. The marker from the EST representing CCoAMT can be further developed for gene-assisted selection of elite genotypes of teak with greater wood density. Therefore, we believe that the report will help accelerate the genetic improvement and advance the breeding program of the species. 展开更多
关键词 Association mapping Expressed sequence tags(EST) general LINEAR model(glm) Linkage disequilibrium(LD) Lignin Mixed LINEAR model(MLM) Principal co-ordinate analysis(PCoA)
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气候变化对巨柏适宜生境分布的潜在影响和预测
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作者 吴茹茹 刘美珍 +4 位作者 谷仙 常馨月 郭立月 蒋高明 祁如意 《植物生态学报》 CAS CSCD 北大核心 2024年第4期445-458,共14页
随着全球气候变化,植物的生长和生存模式均受到影响。预测气候变化下物种潜在的地理分布范围变化,是判断该物种如何响应气候变化的重要手段,有助于制定科学的物种保护策略。巨柏(Cupressus gigantea)是雅鲁藏布江中游末段及主要支流尼... 随着全球气候变化,植物的生长和生存模式均受到影响。预测气候变化下物种潜在的地理分布范围变化,是判断该物种如何响应气候变化的重要手段,有助于制定科学的物种保护策略。巨柏(Cupressus gigantea)是雅鲁藏布江中游末段及主要支流尼洋河近江河段河岸带的特有物种,也是国家一级重点保护植物,其分布范围主要在朗县至米林市丹娘乡的雅鲁藏布江两岸及尼洋河河谷的巨柏公园,生存受到区域自然资源开发和气候变化的明显影响。该研究基于巨柏当前地理分布数据、地形因子、当前及未来气候条件下的环境因子数据,利用最大熵(MaxEnt)模型、广义线性模型(GLM)和广义相加模型(GAM)与ArcGIS空间分析分别对西藏当前及未来2081-2100年2种气候变化情景(高排放模式SSP5-8.5和低排放模式SSP1-2.6)下的巨柏生境适宜性进行模拟分析。研究结果表明:(1)巨柏的潜在地理分布范围较狭窄,适生区集中分布在加查县至米林市的雅鲁藏布江两岸和米林市至工布江达县的尼洋河两岸,在隆子县、贡嘎县、错那县等地呈零星分布;(2)对巨柏潜在地理分布影响较大的环境因子有最冷季平均气温、温度季节性、昼夜温差月均值和海拔,适宜范围分别为-1.62-2.14℃、565.29-603.78、11.66-12.97℃和2898-3550 m;(3)三种模型模拟结果均表明与潜在地理分布面积相比,未来气候变化情景下巨柏的总适生区面积呈现扩大的趋势,且SSP5-8.5情景下巨柏适生区面积的扩增程度明显高于SSP1-2.6气候情景;(4)与当前适生区质心相比,未来情景下的巨柏适生区质心整体呈向西南偏移的趋势,巨柏的分布区也呈向藏西南雅鲁藏布江中游方向较高海拔迁移的趋势。该研究探究了巨柏生长的关键影响因子及巨柏对气候的响应状况,对巨柏保护具有十分重要的科学意义和实践指导价值。 展开更多
关键词 气候变化 巨柏 潜在分布区模拟 最大熵模型 广义线性模型 广义相加模型 适生分析
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Microenvironmental time-activity patterns in Chongqing,China 被引量:1
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作者 Yu ZHAO Shuxiao WANG +3 位作者 Gangcai CHEN Fei WANG Kristin AUNAN Jiming HAO 《Frontiers of Environmental Science & Engineering》 SCIE EI CSCD 2009年第2期200-209,共10页
An investigation using recall questionnaires was conducted in winter and autumn 2006 to evaluate the time-activity patterns in Chongqing,China.The average time spent in seven microenvironments(MEs)including outdoors,t... An investigation using recall questionnaires was conducted in winter and autumn 2006 to evaluate the time-activity patterns in Chongqing,China.The average time spent in seven microenvironments(MEs)including outdoors,transit,living room,bedroom,kitchen,classroom/office,and other indoors were found to be about 3.5,1.1,2.5,9.7,1.4,4.2,and 1.7 h per day,respectively.According to the results of a nonparametric test,the sampling period and day of week were significant for the variation of the time spent in all MEs except for transit and outdoors.The time budget was analyzed using a general linear model(GLM),which exhibited significant variability by demographic factors such as gender,age,residence,education,and household income. 展开更多
关键词 time-activity patterns MICROENVIRONMENT general linear model(glm) CHONGQING China
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