Eucalyptus has become an important genus in China because it displays adaptability to a wide range of site conditions and produces pulp wood and veneer on short rotations. The aim of this study was to estimate genetic...Eucalyptus has become an important genus in China because it displays adaptability to a wide range of site conditions and produces pulp wood and veneer on short rotations. The aim of this study was to estimate genetic parameters and relationships and consider impli- cations for development of clonal forestry. We assessed growth traits, stem-branch characteristics, crown diameter and height of fresh branch for 20 Eucalyptus hybrid clones in China measured at the age of 44 months. Analysis of variance showed that there were significant differences in growth traits, height of fresh branch and stem straightness among clones. Significant differences in height, volume, crown diameter, height of fresh branch and branch size among replicates were also recorded. Coefficients of vari- ation ranged from 9.84 to 28.54 % for growth traits, 12.03 to 17.25 % for stem-branch characteristics, 18.26 % for crown diameter and 11.73 % for height of fresh branch. Estimates of repeatabilities for height, diameter at breastheight over bark, volume, crown diameter, height of fresh branch, stem straightness and branch size at clone mean level were 0.86, 0.80, 0.80, 0.54, 0.85, 0.77 and 0.44 respectively. Diameter at breast height over bark and height had strongly positive phenotypic and genotypic correlations with volume, ranging from 0.96 to 1.00. The positive genotypic and phenotypic correlations between growth traits and other studied traits suggested that fast growing clones always had bigger crown diameter, higher height of fresh branch, straighter stems and relatively smaller branches.展开更多
As a nonparametric method,the Kruskal-Wallis test is widely used to compare three or more independent groups when an ordinal or interval level of data is available,especially when the assump-tions of analysis of varia...As a nonparametric method,the Kruskal-Wallis test is widely used to compare three or more independent groups when an ordinal or interval level of data is available,especially when the assump-tions of analysis of variance (ANOVA) are not met.If the Kruskal-Wallis statistic is statistically signifi-cant,Nemenyi test is an alternative method for further pairwise multiple comparisons to locate the source of significance.Unfortunately,most popular statistical packages do not integrate the Nemenyi test,which is not easy to be calculated by hand.We described the theory and applications of the Kruskal-Wallis and Nemenyi tests,and presented a flexible SAS macro to implement the two tests.The SAS macro was demonstrated by two examples from our cohort study in occupational epidemiology.It provides a useful tool for SAS users to test the differences among three or more independent groups using a nonparametric method.展开更多
In the past few years, genome-wide association study (GWAS) has made great successes in identifying genetic susceptibility loci underlying many complex diseases and traits. The findings provide important genetic ins...In the past few years, genome-wide association study (GWAS) has made great successes in identifying genetic susceptibility loci underlying many complex diseases and traits. The findings provide important genetic insights into understanding pathogenesis of diseases. In this paper, we present an overview of widely used approaches and strategies for analysis of GWAS, offered a general consideration to deal with GWAS data. The issues regarding data quality control, population structure, association analysis, multiple comparison and visual presentation of GWAS results are discussed; other advanced topics including the issue of missing heritability, meta-analysis, setbased association analysis, copy number variation analysis and GWAS cohort analysis are also briefly introduced.展开更多
Continued advancement in the field of physical activity and health promotion relies heavily on the synthesis of rigorous scientific evidence.As such,systematic reviews and meta-analyses of randomized controlled trials...Continued advancement in the field of physical activity and health promotion relies heavily on the synthesis of rigorous scientific evidence.As such,systematic reviews and meta-analyses of randomized controlled trials have led to a better understanding of which intervention strategies are superior(i.e.,produce the greatest effects)in physical activity-based health behavior change interventions.Indeed,standard meta-analytic approaches have allowed researchers in the field to synthesize relevant experimental evidence using pairwise procedures that produce reliable estimates of the homogeneity,magnitude,and potential biases in the observed effects.However,pairwise meta-analytic procedures are only capable to discerning differences in effects between a select intervention strategy and a select comparison or control condition.In order to maximize the impact of physical activity interventions on health-related outcomes,it is necessary to establish evidence concerning the comparative efficacy of all relevant physical activity intervention strategies.The development of network meta-analysis(NMA)-most commonly used in medical-based clinical trials-has allowed for the quantification of indirect comparisons,even in the absence of direct,head-to-head trials.Thus,it stands to reason that NMA can be applied in physical activity and health promotion research to identify the best intervention strategies.Given that this analysis technique is novel and largely unexplored in the field of physical activity and health promotion,care must be taken in its application to ensure reliable estimates and discernment of the effect sizes among interventions.Therefore,the purpose of this review is to comment on the potential application and importance of NMA in the field of physical activity and health promotion,describe how to properly and effectively apply this technique,and suggest important considerations for its appropriate application in this field.In this paper,overviews of the foundations of NMA and commonly used approaches for conducting NMA are provided,followed by assumptions related to NMA,opportunities and challenges in NMA,and a step-by-step example of developing and conducting an NMA.展开更多
This paper introduces a new method of calculating crown projection area(CPA),the area of level ground covered by a vertical projection of a tree crown from measured crown radii through numerical interpolation and inte...This paper introduces a new method of calculating crown projection area(CPA),the area of level ground covered by a vertical projection of a tree crown from measured crown radii through numerical interpolation and integration.This novel method and other four existing methods of calculating CPA were compared using detailed crown radius measurements from 30 tall trees of Eucalyptus pilularis variable in crown size,shape,and asymmetry.The four existing methods included the polygonal approach and three ways of calculating CPA as the area of a circle using the arithmetic,geometric and quadratic mean radius.Comparisons were made across a sequence of eight non-consecutive numbers(from 2 to 16)of measured crown radii for each tree over the range of crown asymmetry of the 30 trees through generalized linear models and multiple comparisons of means.The sequence covered the range of the number of crown radii measured for calculating the CPA of a tree in the literature.A crown asymmetry index within the unit interval was calculated for each tree to serve as a normative measure.With a slight overestimation of 2.2%on average and an overall mean error size of 7.9%across the numbers of crown radii that were compared,our new method was the least biased and most accurate.Calculating CPA as a circle using the quadratic mean crown radius was the second best,which had an average overestimation of 4.5%and overall mean error size of 8.8%.These two methods remained by and large unbiased as crown asymmetry increased,while the other three methods showed larger bias of underestimation.For the conventional method of using the arithmetic mean crown radius to calculate CPA as a circle,bias correction factors were developed as a function of crown asymmetry index to delineate the increasing magnitude of bias associated with greater degrees of crown asymmetry.This study reveals and demonstrates such relationships between the accuracy of CPA calculations and crown asymmetry and will help increase awareness among researchers and practitioners on the existence of bias in their CPA calculations and for the need to use an unbiased method in the future.Our new method is recommended for calculating CPA where at least four crown radius measurements per tree are available because that is the minimum number required for its use.展开更多
Low-velocity penetrating brain injury(LVPBI)caused by foreign bodies can pose life-threatening emergencies.Their complexity and lack of validated classification data have prevented standardization of clinical manageme...Low-velocity penetrating brain injury(LVPBI)caused by foreign bodies can pose life-threatening emergencies.Their complexity and lack of validated classification data have prevented standardization of clinical management.We aimed to compare the trans-base and trans-vault phenotypes of LVPBI to help provide guidance for clinical decision-making of such injury type.;A retrospective study on LVPBI patients managed at our institution from November 2013 to March 2020 was conducted.We included LVPBI patients admitted for the first time for surgery,and excluded those with multiple injuries,gunshot wounds,pregnancy,severe blunt head trauma,etc.Patients were categorized into trans-base and trans-vault LVPBI groups based on the penetration pathway.Discharged patients were followed up by outpatient visit or telephone.The data were entered into the Electronic Medical Record system by clinicians,and subsequently derived by researchers.The demography and injury characteristics,treatment protocols,complications,and outcomes were analyzed and compared between the two groups.A t-test was used for analysis of normally distributed data,and a Mann-Whitney U test for non-parametric data.A generalized linear model was further established to determine whether the factors length of stay and performance scale score were influenced by each factor.;A total of 27 LVPBI patients were included in this analysis,comprised of 13(48.1%)trans-base cases and 14(51.9%)trans-vault cases.Statistical analyses suggested that trans-base LVPBI was correlated with deeper wounds;while the trans-vault phenotype was correlated with injury by metal foreign bodies.There was no difference in Glasgow Coma Scale score and the risk of intracranial hemorrhage between the two groups.Surgical approaches in the trans-base LVPBI group included subfrontal(n=5,38.5%),subtemporal(n=5,38.5%),lateral fissure(n=2,15.4%),and distal lateral(n=1,7.7%).All patients in the trans-vault group underwent a brain convex approach using the foreign body as reference(n=14,100%).Moreover,the two groups differed in application prerequisites for intracranial pressure monitoring and vessel-related treatment.Trans-base LVPBI was associated with higher rates of cranial nerve and major vessel injuries;in contrast,trans-vault LVPBI was associated with lower functional outcome scores.;Our findings suggest that trans-base and trans-vault LVPBIs differ in terms of characteristics,treatment,and outcomes.Further understanding of these differences may help guide clinical decisions and contribute to a better management of LVPBIs.展开更多
基金finically supported by the National Twelfth Five-Year Science and Technology Plan ‘‘Breeding of High yield and High Resistance New Species of Eucalyptus’’(2012BAD01B0401),‘‘Genetic Research of Pulp Yield and Veneer of Eucalyptus urophylla Hybrid Clones’’(RITFYWZX201304)
文摘Eucalyptus has become an important genus in China because it displays adaptability to a wide range of site conditions and produces pulp wood and veneer on short rotations. The aim of this study was to estimate genetic parameters and relationships and consider impli- cations for development of clonal forestry. We assessed growth traits, stem-branch characteristics, crown diameter and height of fresh branch for 20 Eucalyptus hybrid clones in China measured at the age of 44 months. Analysis of variance showed that there were significant differences in growth traits, height of fresh branch and stem straightness among clones. Significant differences in height, volume, crown diameter, height of fresh branch and branch size among replicates were also recorded. Coefficients of vari- ation ranged from 9.84 to 28.54 % for growth traits, 12.03 to 17.25 % for stem-branch characteristics, 18.26 % for crown diameter and 11.73 % for height of fresh branch. Estimates of repeatabilities for height, diameter at breastheight over bark, volume, crown diameter, height of fresh branch, stem straightness and branch size at clone mean level were 0.86, 0.80, 0.80, 0.54, 0.85, 0.77 and 0.44 respectively. Diameter at breast height over bark and height had strongly positive phenotypic and genotypic correlations with volume, ranging from 0.96 to 1.00. The positive genotypic and phenotypic correlations between growth traits and other studied traits suggested that fast growing clones always had bigger crown diameter, higher height of fresh branch, straighter stems and relatively smaller branches.
基金supported by a grant from the National Basic Research Program of China (No. 2011CB503804)
文摘As a nonparametric method,the Kruskal-Wallis test is widely used to compare three or more independent groups when an ordinal or interval level of data is available,especially when the assump-tions of analysis of variance (ANOVA) are not met.If the Kruskal-Wallis statistic is statistically signifi-cant,Nemenyi test is an alternative method for further pairwise multiple comparisons to locate the source of significance.Unfortunately,most popular statistical packages do not integrate the Nemenyi test,which is not easy to be calculated by hand.We described the theory and applications of the Kruskal-Wallis and Nemenyi tests,and presented a flexible SAS macro to implement the two tests.The SAS macro was demonstrated by two examples from our cohort study in occupational epidemiology.It provides a useful tool for SAS users to test the differences among three or more independent groups using a nonparametric method.
基金supported by National Natural Science Foundation of China(No.81072389,81373102,81473070 and 81402765)Research Found for the Doctoral Program of Higher Education of China(No.20113234110002)+4 种基金Key Grant of Natural Science Foundation of the Jiangsu Higher Education Institutions of China(No.10KJA330034)College Philosophy and Social Science Foundation from Education Department of Jiangsu Province of China(No.2013SJB790059,2013SJD790032)Research Foundation from Xuzhou Medical College(No.2012KJ02)Research and Innovation Project for College Graduates of Jiangsu Province of China(No.CXLX13_574)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
文摘In the past few years, genome-wide association study (GWAS) has made great successes in identifying genetic susceptibility loci underlying many complex diseases and traits. The findings provide important genetic insights into understanding pathogenesis of diseases. In this paper, we present an overview of widely used approaches and strategies for analysis of GWAS, offered a general consideration to deal with GWAS data. The issues regarding data quality control, population structure, association analysis, multiple comparison and visual presentation of GWAS results are discussed; other advanced topics including the issue of missing heritability, meta-analysis, setbased association analysis, copy number variation analysis and GWAS cohort analysis are also briefly introduced.
文摘Continued advancement in the field of physical activity and health promotion relies heavily on the synthesis of rigorous scientific evidence.As such,systematic reviews and meta-analyses of randomized controlled trials have led to a better understanding of which intervention strategies are superior(i.e.,produce the greatest effects)in physical activity-based health behavior change interventions.Indeed,standard meta-analytic approaches have allowed researchers in the field to synthesize relevant experimental evidence using pairwise procedures that produce reliable estimates of the homogeneity,magnitude,and potential biases in the observed effects.However,pairwise meta-analytic procedures are only capable to discerning differences in effects between a select intervention strategy and a select comparison or control condition.In order to maximize the impact of physical activity interventions on health-related outcomes,it is necessary to establish evidence concerning the comparative efficacy of all relevant physical activity intervention strategies.The development of network meta-analysis(NMA)-most commonly used in medical-based clinical trials-has allowed for the quantification of indirect comparisons,even in the absence of direct,head-to-head trials.Thus,it stands to reason that NMA can be applied in physical activity and health promotion research to identify the best intervention strategies.Given that this analysis technique is novel and largely unexplored in the field of physical activity and health promotion,care must be taken in its application to ensure reliable estimates and discernment of the effect sizes among interventions.Therefore,the purpose of this review is to comment on the potential application and importance of NMA in the field of physical activity and health promotion,describe how to properly and effectively apply this technique,and suggest important considerations for its appropriate application in this field.In this paper,overviews of the foundations of NMA and commonly used approaches for conducting NMA are provided,followed by assumptions related to NMA,opportunities and challenges in NMA,and a step-by-step example of developing and conducting an NMA.
基金supported by the Natural Science Foundation of China (32071758)the Fundamental Research Funds for the Central Universities of China (No. 2572020BA01)
文摘This paper introduces a new method of calculating crown projection area(CPA),the area of level ground covered by a vertical projection of a tree crown from measured crown radii through numerical interpolation and integration.This novel method and other four existing methods of calculating CPA were compared using detailed crown radius measurements from 30 tall trees of Eucalyptus pilularis variable in crown size,shape,and asymmetry.The four existing methods included the polygonal approach and three ways of calculating CPA as the area of a circle using the arithmetic,geometric and quadratic mean radius.Comparisons were made across a sequence of eight non-consecutive numbers(from 2 to 16)of measured crown radii for each tree over the range of crown asymmetry of the 30 trees through generalized linear models and multiple comparisons of means.The sequence covered the range of the number of crown radii measured for calculating the CPA of a tree in the literature.A crown asymmetry index within the unit interval was calculated for each tree to serve as a normative measure.With a slight overestimation of 2.2%on average and an overall mean error size of 7.9%across the numbers of crown radii that were compared,our new method was the least biased and most accurate.Calculating CPA as a circle using the quadratic mean crown radius was the second best,which had an average overestimation of 4.5%and overall mean error size of 8.8%.These two methods remained by and large unbiased as crown asymmetry increased,while the other three methods showed larger bias of underestimation.For the conventional method of using the arithmetic mean crown radius to calculate CPA as a circle,bias correction factors were developed as a function of crown asymmetry index to delineate the increasing magnitude of bias associated with greater degrees of crown asymmetry.This study reveals and demonstrates such relationships between the accuracy of CPA calculations and crown asymmetry and will help increase awareness among researchers and practitioners on the existence of bias in their CPA calculations and for the need to use an unbiased method in the future.Our new method is recommended for calculating CPA where at least four crown radius measurements per tree are available because that is the minimum number required for its use.
基金This project was supported by the Xiangya Medical Big Data Foundation,the Natural Science Foundation of Hunan Province of China(Grant No.2018JJ2649)Health and Family Planning Commission of Hunan Province(Grant No.B2019191).
文摘Low-velocity penetrating brain injury(LVPBI)caused by foreign bodies can pose life-threatening emergencies.Their complexity and lack of validated classification data have prevented standardization of clinical management.We aimed to compare the trans-base and trans-vault phenotypes of LVPBI to help provide guidance for clinical decision-making of such injury type.;A retrospective study on LVPBI patients managed at our institution from November 2013 to March 2020 was conducted.We included LVPBI patients admitted for the first time for surgery,and excluded those with multiple injuries,gunshot wounds,pregnancy,severe blunt head trauma,etc.Patients were categorized into trans-base and trans-vault LVPBI groups based on the penetration pathway.Discharged patients were followed up by outpatient visit or telephone.The data were entered into the Electronic Medical Record system by clinicians,and subsequently derived by researchers.The demography and injury characteristics,treatment protocols,complications,and outcomes were analyzed and compared between the two groups.A t-test was used for analysis of normally distributed data,and a Mann-Whitney U test for non-parametric data.A generalized linear model was further established to determine whether the factors length of stay and performance scale score were influenced by each factor.;A total of 27 LVPBI patients were included in this analysis,comprised of 13(48.1%)trans-base cases and 14(51.9%)trans-vault cases.Statistical analyses suggested that trans-base LVPBI was correlated with deeper wounds;while the trans-vault phenotype was correlated with injury by metal foreign bodies.There was no difference in Glasgow Coma Scale score and the risk of intracranial hemorrhage between the two groups.Surgical approaches in the trans-base LVPBI group included subfrontal(n=5,38.5%),subtemporal(n=5,38.5%),lateral fissure(n=2,15.4%),and distal lateral(n=1,7.7%).All patients in the trans-vault group underwent a brain convex approach using the foreign body as reference(n=14,100%).Moreover,the two groups differed in application prerequisites for intracranial pressure monitoring and vessel-related treatment.Trans-base LVPBI was associated with higher rates of cranial nerve and major vessel injuries;in contrast,trans-vault LVPBI was associated with lower functional outcome scores.;Our findings suggest that trans-base and trans-vault LVPBIs differ in terms of characteristics,treatment,and outcomes.Further understanding of these differences may help guide clinical decisions and contribute to a better management of LVPBIs.