Korean larch(Larix olgensis)is one of the main tree species for aff orestation and timber production in northeast China.However,its timber quality and growth ability are largely infl uenced by crown size,structure and...Korean larch(Larix olgensis)is one of the main tree species for aff orestation and timber production in northeast China.However,its timber quality and growth ability are largely infl uenced by crown size,structure and shape.The majority of crown models are static models based on tree size and stand characteristics from temporary sample plots,but crown dynamic models has seldom been constructed.Therefore,this study aimed to develop height to crown base(HCB)and crown length(CL)dynamic models using the branch mortality technique for a Korean larch plantation.The nonlinear mixed-eff ects model with random eff ects,variance functions and correlation structures,was used to build HCB and CL dynamic models.The data were obtained from 95 sample trees of 19 plots in Meng JiaGang forest farm in Northeast China.The results showed that HCB progressively increases as tree age,tree height growth(HT growth)and diameter at breast height growth(DBH growth).The CL was increased with tree age in 20 years ago,and subsequently stabilized.HT growth,DBH growth stand basal area(BAS)and crown competition factor(CCF)signifi cantly infl uenced HCB and CL.The HCB was positively correlated with BAS,HT growth and DBH growth,but negatively correlated with CCF.The CL was positively correlated with BAS and CCF,but negatively correlated with DBH growth.Model fi tting and validation confi rmed that the mixed-eff ects model considering the stand and tree level random eff ects was accurate and reliable for predicting the HCB and CL dynamics.However,the models involving adding variance functions and time series correlation structure could not completely remove heterogeneity and autocorrelation,and the fi tting precision of the models was reduced.Therefore,from the point of view of application,we should take care to avoid setting up over-complex models.The HCB and CL dynamic models in our study may also be incorporated into stand growth and yield model systems in China.展开更多
Since the London fog in 1952, numerous epidemioLogical studies have revealed that both short-term and long-term exposure to air pollutants is associated with the development of diseases[1]. Up to date, the assessment ...Since the London fog in 1952, numerous epidemioLogical studies have revealed that both short-term and long-term exposure to air pollutants is associated with the development of diseases[1]. Up to date, the assessment of air quality on health and air quality standard establishment in developing countries were mainly relied on extrapolation based on the results from long-term cohort studies conducted in Europe and North America.展开更多
The mortality of trees across diameter class model is a useful tool for predicting changes in stand structure.Mortality data commonly contain a large fraction of zeros and general discrete models thus show more errors...The mortality of trees across diameter class model is a useful tool for predicting changes in stand structure.Mortality data commonly contain a large fraction of zeros and general discrete models thus show more errors.Based on the traditional Poisson model and the negative binomial model,different forms of zero-inflated and hurdle models were applied to spruce-fir mixed forests data to simulate the number of dead trees.By comparing the residuals and Vuong test statistics,the zero-inflated negative binomial model performed best.A random effect was added to improve the model accuracy;however,the mixed-effects zero-inflated model did not show increased advantages.According to the model principle,the zeroinflated negative binomial model was the most suitable,indicating that the"0"events in this study,mainly from the sample"0",i.e.,the zero mortality data,are largely due to the limitations of the experimental design and sample selection.These results also show that the number of dead trees in the diameter class is positively correlated with the number of trees in that class and the mean stand diameter,and inversely related to class size,and slope and aspect of the site.展开更多
简要介绍变系数模型,并以变系数Cox模型为例,通过实际数据分析展示其在医学和公共卫生领域的应用,为相关研究提供方法学参考。实例基于某疾病预防控制中心部分慢病管理数据,拟合变系数Cox模型,探索高血压人群中体重指数(body mass index...简要介绍变系数模型,并以变系数Cox模型为例,通过实际数据分析展示其在医学和公共卫生领域的应用,为相关研究提供方法学参考。实例基于某疾病预防控制中心部分慢病管理数据,拟合变系数Cox模型,探索高血压人群中体重指数(body mass index,BMI)与死亡风险之间的时变关联。结果显示,体重过低(BMI<18.5 kg/m^(2))与较高的死亡风险相关,但其关联程度随着随访时间的延长而逐渐减弱;超重(23 kg/m^(2)≤BMI<25 kg/m^(2))与较低的死亡风险相关,其关联程度随着随访时间的延长而逐渐减弱。变系数模型能够捕捉到暴露因素对于结局的影响如何随着其他变量的改变而变化,有助于更为全面地理解变量间的复杂关系,在医学和公共卫生研究中有很好的应用和推广价值。展开更多
[Objective] The study aimed to investigate the synergistic effect of vegetable oil EC on chemical pesticides. [Method] Cottonseed oil EC and soybean oil EC were mixed with 20% imidacloprid EC and 0.5% avermectin WE re...[Objective] The study aimed to investigate the synergistic effect of vegetable oil EC on chemical pesticides. [Method] Cottonseed oil EC and soybean oil EC were mixed with 20% imidacloprid EC and 0.5% avermectin WE respectively, Schizaphis graminum were handled with dipped method,synergistic effects of vegetable oil EC on imidacloprid and avermectin were analyzed. [Result] Cottonseed oil EC and soybean oil EC had obvious synergistic effect on 20% imidacloprid EC and 0.5% avermectin WE. Corrected mortality of 20% imidacloprid EC＋cottonseed oil EC（0.10＋10.00, 0.10＋5.00, 0.10＋3.33 and 0.05＋10.00 ml/L）, 0.5% avermectin WE＋cottonseed oil EC（1.00＋10.00, 1.00＋5.00, 0.50＋10.00 and 0.50＋5.00 ml/L）and 20% imidacloprid EC＋soybean oil EC（0.10＋10.00, 0.10＋5.00, 0.10＋10.00 and 0.05＋5.00 ml/L） were all over 90%. [Conclusion] Considered from control effect and economy angle, the mixture of cottonseed oil EC or soybean oil EC with 20% imidacloprid EC, and the mixture of cottonseed oil EC with 0.5% avermectin WE could be used to control S. graminum.展开更多
Tropical cyclones are large-scale strong wind disturbance events that occur frequently in tropical and subtropical coastal regions and often bring catastrophic physical destruction to ecosystems and economic disruptio...Tropical cyclones are large-scale strong wind disturbance events that occur frequently in tropical and subtropical coastal regions and often bring catastrophic physical destruction to ecosystems and economic disruption to societies along their paths. Major tropical cyclones can infrequently move into the midaltitudes and inland areas. Ecologically, tropical cyclones have profound impacts on diversity, structure, succession and function of forest ecosystems. The ecological effects are both dramatic and subtle. The dramatic effects can be visible, noticeable and to some extent predictable over the short-term and relatively well documented in the literature. However, the subtle effects are often invisible, complex and at smaller scale relatively unpredictable in the long-term. Many factors, meteorologic, topographic and biologic, simultaneously interact to influence the complexity of patterns of damage and dynamics of recovery. I present a global synthesis on the effects of tropical cyclones on forest ecosystems and the complexity of forest responses, with particular attention on the response to large hurricanes in the neotropics and the temperate North America, and strong typhoons on the subtropical and temperate forests in the East and Southeast Asia. Four major aspects provide on organizational framework for this synthesis：（1） consistent damage patterns,（2） factors that influence response patterns and predict damage risks,（3） complexity of forest responses and recovery, and（4） the long-term effects. This review reveals highly variable and complex effects of tropical cyclones on forest ecosystems. A deep understanding of the synergistic effects of tropical cyclones is essential for effective forest management and biodiversity conservation.展开更多
Gastrectomy with radical lymph node dissection is the most promising treatment avenue for patients with gastric cancer. However, this procedure sometimes induces excessive intraoperative blood loss and requires periop...Gastrectomy with radical lymph node dissection is the most promising treatment avenue for patients with gastric cancer. However, this procedure sometimes induces excessive intraoperative blood loss and requires perioperative allogeneic blood transfusion. There are lasting discussions and controversies about whether intraoperative blood loss or perioperative blood transfusion has adverse effects on the prognosis in patients with gastric cancer. We reviewed laboratory and clinical evidence of these associations in patients with gastric cancer. A large amount of clinical evidence supports the correlation between excessive intraoperative blood loss and adverse effects on the prognosis. The laboratory evidence revealed three possible causes of such adverse effects: anti-tumor immunosuppression, unfavorable postoperative conditions, and peritoneal recurrence by spillage of cancer cells into the pelvis. Several systematic reviews and meta-analyses have suggested the adverse effects of perioperative blood transfusions on prognostic parameters such as all-cause mortality, recurrence, and postoperative complications. There are two possible causes of adverse effects of blood transfusions on the prognosis: Anti-tumor immunosuppression and patient-related confounding factors (e.g., preoperative anemia). These factors are associated with a worse prognosis and higher requirement for perioperative blood transfusions. Surgeons should make efforts to minimize intraoperative blood loss and transfusions during gastric cancer surgery to improve patients’ prognosis.展开更多
Two similar words, effectiveness and efficacy, have comparable insight and nearly describe analogous mea-ning for a screening test, yet clear understanding and perception of their diverse meanings will help clarify th...Two similar words, effectiveness and efficacy, have comparable insight and nearly describe analogous mea-ning for a screening test, yet clear understanding and perception of their diverse meanings will help clarify the basis of the differing conclusions about whether screening tests for different cancers reduce morbidity and mortality. Screening test may not be effective even when it sounds to be efficacious, on the other hand it should be efficacious when the test is effective.展开更多
Neighbourhood characteristics influence infant mortality above and beyond individual/household factors. In India, there are very few studies discussing the effects of neighbourhood characteristics on infant mortality....Neighbourhood characteristics influence infant mortality above and beyond individual/household factors. In India, there are very few studies discussing the effects of neighbourhood characteristics on infant mortality. This study examined the effect of neighbourhood socioeconomic characteristics on infant mortality using data from the India’s Third District Level Household Survey conducted in 2007-2008. Multilevel analyses applied on the representative sample of 168,625 nested within 14,193 communities using MCMC procedure. Results established that place of residence, neighbourhood socio-economic factors as important determinants of infant mortality. Overall, being born in affluent (OR: 0.79, p < 0.01), more educated (OR: 0.86, p < 0.01) and socially disadvantaged caste (OR: 0.83, p < 0.01) neighbourhood was associated with the significant reduction in hazards of infant death. The finding of this study suggests that effort should be made to reduce infant mortality in these high focus states by including policies which aim at improving infant survival in the neighbourhood that is economically and socially deprived.展开更多
基金supported by the National Key Research and Development Program of China(2017YFD0600401)the Fundamental Research Funds for the Central Universities(2572019CP08)
文摘Korean larch(Larix olgensis)is one of the main tree species for aff orestation and timber production in northeast China.However,its timber quality and growth ability are largely infl uenced by crown size,structure and shape.The majority of crown models are static models based on tree size and stand characteristics from temporary sample plots,but crown dynamic models has seldom been constructed.Therefore,this study aimed to develop height to crown base(HCB)and crown length(CL)dynamic models using the branch mortality technique for a Korean larch plantation.The nonlinear mixed-eff ects model with random eff ects,variance functions and correlation structures,was used to build HCB and CL dynamic models.The data were obtained from 95 sample trees of 19 plots in Meng JiaGang forest farm in Northeast China.The results showed that HCB progressively increases as tree age,tree height growth(HT growth)and diameter at breast height growth(DBH growth).The CL was increased with tree age in 20 years ago,and subsequently stabilized.HT growth,DBH growth stand basal area(BAS)and crown competition factor(CCF)signifi cantly infl uenced HCB and CL.The HCB was positively correlated with BAS,HT growth and DBH growth,but negatively correlated with CCF.The CL was positively correlated with BAS and CCF,but negatively correlated with DBH growth.Model fi tting and validation confi rmed that the mixed-eff ects model considering the stand and tree level random eff ects was accurate and reliable for predicting the HCB and CL dynamics.However,the models involving adding variance functions and time series correlation structure could not completely remove heterogeneity and autocorrelation,and the fi tting precision of the models was reduced.Therefore,from the point of view of application,we should take care to avoid setting up over-complex models.The HCB and CL dynamic models in our study may also be incorporated into stand growth and yield model systems in China.
基金supported by the National Basic Research Program (973 program) of China (2011CB503802)the Gong-Yi Program of the Chinese Ministry of Environmental Protection (201209008)+2 种基金Shanghai Municipal Committee of Science and Technology (12dz1202602)Shanghai Health Bureau (GWDTR201212)the Scholarship Award for Excellent Doctoral Student granted by Ministry of Education (2011)
文摘Since the London fog in 1952, numerous epidemioLogical studies have revealed that both short-term and long-term exposure to air pollutants is associated with the development of diseases[1]. Up to date, the assessment of air quality on health and air quality standard establishment in developing countries were mainly relied on extrapolation based on the results from long-term cohort studies conducted in Europe and North America.
基金supported by the "948" Project of the State Forestry Administration of China(No.2013-4-66)
文摘The mortality of trees across diameter class model is a useful tool for predicting changes in stand structure.Mortality data commonly contain a large fraction of zeros and general discrete models thus show more errors.Based on the traditional Poisson model and the negative binomial model,different forms of zero-inflated and hurdle models were applied to spruce-fir mixed forests data to simulate the number of dead trees.By comparing the residuals and Vuong test statistics,the zero-inflated negative binomial model performed best.A random effect was added to improve the model accuracy;however,the mixed-effects zero-inflated model did not show increased advantages.According to the model principle,the zeroinflated negative binomial model was the most suitable,indicating that the"0"events in this study,mainly from the sample"0",i.e.,the zero mortality data,are largely due to the limitations of the experimental design and sample selection.These results also show that the number of dead trees in the diameter class is positively correlated with the number of trees in that class and the mean stand diameter,and inversely related to class size,and slope and aspect of the site.
基金Supported by Key Topics of Liaocheng University(x061005)Education Department of Shandong Province,Science and Technology Development Plan(J09Lc17)~~
文摘[Objective] The study aimed to investigate the synergistic effect of vegetable oil EC on chemical pesticides. [Method] Cottonseed oil EC and soybean oil EC were mixed with 20% imidacloprid EC and 0.5% avermectin WE respectively, Schizaphis graminum were handled with dipped method,synergistic effects of vegetable oil EC on imidacloprid and avermectin were analyzed. [Result] Cottonseed oil EC and soybean oil EC had obvious synergistic effect on 20% imidacloprid EC and 0.5% avermectin WE. Corrected mortality of 20% imidacloprid EC＋cottonseed oil EC（0.10＋10.00, 0.10＋5.00, 0.10＋3.33 and 0.05＋10.00 ml/L）, 0.5% avermectin WE＋cottonseed oil EC（1.00＋10.00, 1.00＋5.00, 0.50＋10.00 and 0.50＋5.00 ml/L）and 20% imidacloprid EC＋soybean oil EC（0.10＋10.00, 0.10＋5.00, 0.10＋10.00 and 0.05＋5.00 ml/L） were all over 90%. [Conclusion] Considered from control effect and economy angle, the mixture of cottonseed oil EC or soybean oil EC with 20% imidacloprid EC, and the mixture of cottonseed oil EC with 0.5% avermectin WE could be used to control S. graminum.
基金supported by National Natural Science Foundation of China(31370483)a University Research Award from Texas A&M University-Kingsville
文摘Tropical cyclones are large-scale strong wind disturbance events that occur frequently in tropical and subtropical coastal regions and often bring catastrophic physical destruction to ecosystems and economic disruption to societies along their paths. Major tropical cyclones can infrequently move into the midaltitudes and inland areas. Ecologically, tropical cyclones have profound impacts on diversity, structure, succession and function of forest ecosystems. The ecological effects are both dramatic and subtle. The dramatic effects can be visible, noticeable and to some extent predictable over the short-term and relatively well documented in the literature. However, the subtle effects are often invisible, complex and at smaller scale relatively unpredictable in the long-term. Many factors, meteorologic, topographic and biologic, simultaneously interact to influence the complexity of patterns of damage and dynamics of recovery. I present a global synthesis on the effects of tropical cyclones on forest ecosystems and the complexity of forest responses, with particular attention on the response to large hurricanes in the neotropics and the temperate North America, and strong typhoons on the subtropical and temperate forests in the East and Southeast Asia. Four major aspects provide on organizational framework for this synthesis：（1） consistent damage patterns,（2） factors that influence response patterns and predict damage risks,（3） complexity of forest responses and recovery, and（4） the long-term effects. This review reveals highly variable and complex effects of tropical cyclones on forest ecosystems. A deep understanding of the synergistic effects of tropical cyclones is essential for effective forest management and biodiversity conservation.
文摘Gastrectomy with radical lymph node dissection is the most promising treatment avenue for patients with gastric cancer. However, this procedure sometimes induces excessive intraoperative blood loss and requires perioperative allogeneic blood transfusion. There are lasting discussions and controversies about whether intraoperative blood loss or perioperative blood transfusion has adverse effects on the prognosis in patients with gastric cancer. We reviewed laboratory and clinical evidence of these associations in patients with gastric cancer. A large amount of clinical evidence supports the correlation between excessive intraoperative blood loss and adverse effects on the prognosis. The laboratory evidence revealed three possible causes of such adverse effects: anti-tumor immunosuppression, unfavorable postoperative conditions, and peritoneal recurrence by spillage of cancer cells into the pelvis. Several systematic reviews and meta-analyses have suggested the adverse effects of perioperative blood transfusions on prognostic parameters such as all-cause mortality, recurrence, and postoperative complications. There are two possible causes of adverse effects of blood transfusions on the prognosis: Anti-tumor immunosuppression and patient-related confounding factors (e.g., preoperative anemia). These factors are associated with a worse prognosis and higher requirement for perioperative blood transfusions. Surgeons should make efforts to minimize intraoperative blood loss and transfusions during gastric cancer surgery to improve patients’ prognosis.
文摘Two similar words, effectiveness and efficacy, have comparable insight and nearly describe analogous mea-ning for a screening test, yet clear understanding and perception of their diverse meanings will help clarify the basis of the differing conclusions about whether screening tests for different cancers reduce morbidity and mortality. Screening test may not be effective even when it sounds to be efficacious, on the other hand it should be efficacious when the test is effective.
文摘Neighbourhood characteristics influence infant mortality above and beyond individual/household factors. In India, there are very few studies discussing the effects of neighbourhood characteristics on infant mortality. This study examined the effect of neighbourhood socioeconomic characteristics on infant mortality using data from the India’s Third District Level Household Survey conducted in 2007-2008. Multilevel analyses applied on the representative sample of 168,625 nested within 14,193 communities using MCMC procedure. Results established that place of residence, neighbourhood socio-economic factors as important determinants of infant mortality. Overall, being born in affluent (OR: 0.79, p < 0.01), more educated (OR: 0.86, p < 0.01) and socially disadvantaged caste (OR: 0.83, p < 0.01) neighbourhood was associated with the significant reduction in hazards of infant death. The finding of this study suggests that effort should be made to reduce infant mortality in these high focus states by including policies which aim at improving infant survival in the neighbourhood that is economically and socially deprived.
