By comparing the long-term tree-ring growths at various geographic scales, we can make clear the effects of environmental variations on tree growth, and get an understanding of the responses of forest ecosystems to th...By comparing the long-term tree-ring growths at various geographic scales, we can make clear the effects of environmental variations on tree growth, and get an understanding of the responses of forest ecosystems to the possible changes in global and regional climate. Radial tree-ring growth of Picea schrenkiana and its relationship to air temperature and precipitation were investigated across longi- tude transects on the north slopes of the Tianshan Mountains in northwestern China. Tree-ring samples were collected and residual chronologies were developed for three different regions along a gradient of decreasing precipitation from west to east. Response-function analysis was conducted to quantify the relationships between tree-ring chronologies and climate variables, such as monthly mean temperature and monthly precipitation from 1961 to 1998, using the PRECON software program. The statistical characteristics of the chronologies showed that the three chronologies constructed in this study con- tained significant environmental signals and were well suitable to reveal the impacts of climatic change on tree growth and forest productivity. Annual ring-width variations were similar among the three sites, but the variability was greatest in the east. This research showed that the growth trends of Picea schrenkiana in the Tianshan Mountains have not followed a uniform pattern. Response-function analy- sis indicated that there were significant correlations between tree growth and climatic factors in all the three regions, among which precipitation was the principal. With decreasing precipitation, the response of tree-ring widths to increasing temperature changed from a positive to a negative correlation. As for precipitation, the positive relationship to tree-ring width always dominates. It could be expected that with increased temperature and decreased precipitation, the importance of precipitation to tree growth would increase, and the response of tree growth to environmental changes would also increase. This study emp展开更多
Objective To determine whether smoking increases the risk for developing metabolic syndrome （MetS） in Chinese men.Methods A total of 693 men with no MetS at baseline were followed for 2.9‐5.5 years.Subjects were di...Objective To determine whether smoking increases the risk for developing metabolic syndrome （MetS） in Chinese men.Methods A total of 693 men with no MetS at baseline were followed for 2.9‐5.5 years.Subjects were divided into nonsmokers,ex‐smokers,and current smokers according to baseline smoking status.Results After adjusting for age,education level,alcohol intake,fasting plasma insulin,HOMA‐IR index,and BMI at baseline and weight change,current smokers were dose‐dependently associated with increased risk for developing new MetS compared with nonsmokers.The odds ratio （OR） was 2.131 （95% CI,1.264,3.592;P0.01） for the NCEPIII definition or 3.083 （95% CI,1.807,5.295;P0.01） for the JCDCG definition of MetS.Ex‐smokers who had quit for ≥13 years significantly decreased the risk for developing new MetS defined by the JCDCG definition.Compared with nonsmokers,current smokers were significantly associated with increased incidence of hypertriglyceridemia and low HDL‐C.Conclusion Smoking is a risk factor for developing MetS in Chinese men after adjusting for age,education level,alcohol intake,fasting plasma insulin,HOMA‐IR,BMI,and weight change.This could be due to an increased incidence of dyslipidemia.Smoking cessation for 13 years decreased the risk for developing MetS defined by the JCDCG definition.展开更多
Plant height and tillering are crucial factors determining rice plant architecture and influencing rice grain production. In this study, rnulti-tillering dwarf1 （mtdl）, a stable multi-tiller and dwarf mutant, was sc...Plant height and tillering are crucial factors determining rice plant architecture and influencing rice grain production. In this study, rnulti-tillering dwarf1 （mtdl）, a stable multi-tiller and dwarf mutant, was screened from the ethylmethane sulfonate-treated japonica rice variety Wuyunging7. Compared with the wild type, mtdl mutant exhibited pleiotropic phenotypes, including dwarf- ism, more tillers, brittle culms and delayed heading date. By employing map-based cloning strategy, the gene MTD1 was finally mapped to an approximately 66-kb region on the short arm of chromosome 9. Sequencing results showed that the gene LOCOsO9g02650 （BC12） in mtdl mutant had a single nucleotide substitution （G to A）, which gen- erated a premature translation stop. Over-expressing MTD1/BC12 coding sequ（nce rescued all the phenotypes of mtdl mutants including plant height and tillers, which confirms that BC12 is the mutated gene in mtdl mutant. Quantitative reverse tran,-eription-PCR analysis showed that MTDI/BCI2 could negatively regulate the expression of MONOCULM 1, IDEAL PLANT ARCHITECTURE1 and Tillering and Dwarf 1, and control rice tillering. Remark- ably, a-amylase activity analysis and gibberellic acid （GA） treatment showed that the dwarf phenotype of mtdl mutant was dependent on GA biosynthesis pathway. These results facilitated to further uncover the molecular mechanism of the growth and development in rice.展开更多
基金Supported by Knowledge Innovation Project of Chinese Academy of Sciences (Grant No. KZCX1-10-05) Key Program from the National Natural Science Foundation of China (Grant No. 90102009)
文摘By comparing the long-term tree-ring growths at various geographic scales, we can make clear the effects of environmental variations on tree growth, and get an understanding of the responses of forest ecosystems to the possible changes in global and regional climate. Radial tree-ring growth of Picea schrenkiana and its relationship to air temperature and precipitation were investigated across longi- tude transects on the north slopes of the Tianshan Mountains in northwestern China. Tree-ring samples were collected and residual chronologies were developed for three different regions along a gradient of decreasing precipitation from west to east. Response-function analysis was conducted to quantify the relationships between tree-ring chronologies and climate variables, such as monthly mean temperature and monthly precipitation from 1961 to 1998, using the PRECON software program. The statistical characteristics of the chronologies showed that the three chronologies constructed in this study con- tained significant environmental signals and were well suitable to reveal the impacts of climatic change on tree growth and forest productivity. Annual ring-width variations were similar among the three sites, but the variability was greatest in the east. This research showed that the growth trends of Picea schrenkiana in the Tianshan Mountains have not followed a uniform pattern. Response-function analy- sis indicated that there were significant correlations between tree growth and climatic factors in all the three regions, among which precipitation was the principal. With decreasing precipitation, the response of tree-ring widths to increasing temperature changed from a positive to a negative correlation. As for precipitation, the positive relationship to tree-ring width always dominates. It could be expected that with increased temperature and decreased precipitation, the importance of precipitation to tree growth would increase, and the response of tree growth to environmental changes would also increase. This study emp
基金funded by the Major Program of Shanghai Municipality for Basic Research (08dj1400601)the National Natural Science Foundation of China (30971121)the Key Project of Science and Technology of Shanghai (09DZ1950202)
文摘Objective To determine whether smoking increases the risk for developing metabolic syndrome （MetS） in Chinese men.Methods A total of 693 men with no MetS at baseline were followed for 2.9‐5.5 years.Subjects were divided into nonsmokers,ex‐smokers,and current smokers according to baseline smoking status.Results After adjusting for age,education level,alcohol intake,fasting plasma insulin,HOMA‐IR index,and BMI at baseline and weight change,current smokers were dose‐dependently associated with increased risk for developing new MetS compared with nonsmokers.The odds ratio （OR） was 2.131 （95% CI,1.264,3.592;P0.01） for the NCEPIII definition or 3.083 （95% CI,1.807,5.295;P0.01） for the JCDCG definition of MetS.Ex‐smokers who had quit for ≥13 years significantly decreased the risk for developing new MetS defined by the JCDCG definition.Compared with nonsmokers,current smokers were significantly associated with increased incidence of hypertriglyceridemia and low HDL‐C.Conclusion Smoking is a risk factor for developing MetS in Chinese men after adjusting for age,education level,alcohol intake,fasting plasma insulin,HOMA‐IR,BMI,and weight change.This could be due to an increased incidence of dyslipidemia.Smoking cessation for 13 years decreased the risk for developing MetS defined by the JCDCG definition.
基金supported by the National Natural Science Foundation of China (31401464, 31201183)Zhejiang Provincial Natural Science Foundation of China (Y3110194, LY16C130001)+1 种基金China Postdoctoral Science Foundation (2014M561108)the Open Foundation from Zhejiang Provincial Top Key Discipline of Biology (KFJJ2014006)
文摘Plant height and tillering are crucial factors determining rice plant architecture and influencing rice grain production. In this study, rnulti-tillering dwarf1 （mtdl）, a stable multi-tiller and dwarf mutant, was screened from the ethylmethane sulfonate-treated japonica rice variety Wuyunging7. Compared with the wild type, mtdl mutant exhibited pleiotropic phenotypes, including dwarf- ism, more tillers, brittle culms and delayed heading date. By employing map-based cloning strategy, the gene MTD1 was finally mapped to an approximately 66-kb region on the short arm of chromosome 9. Sequencing results showed that the gene LOCOsO9g02650 （BC12） in mtdl mutant had a single nucleotide substitution （G to A）, which gen- erated a premature translation stop. Over-expressing MTD1/BC12 coding sequ（nce rescued all the phenotypes of mtdl mutants including plant height and tillers, which confirms that BC12 is the mutated gene in mtdl mutant. Quantitative reverse tran,-eription-PCR analysis showed that MTDI/BCI2 could negatively regulate the expression of MONOCULM 1, IDEAL PLANT ARCHITECTURE1 and Tillering and Dwarf 1, and control rice tillering. Remark- ably, a-amylase activity analysis and gibberellic acid （GA） treatment showed that the dwarf phenotype of mtdl mutant was dependent on GA biosynthesis pathway. These results facilitated to further uncover the molecular mechanism of the growth and development in rice.
