Riparian areas are unique although often small component of the overall watershed landscape. The structure of riparian forests along Erdaobai River on the north slope of Changbai Mountain were investigated by using fi...Riparian areas are unique although often small component of the overall watershed landscape. The structure of riparian forests along Erdaobai River on the north slope of Changbai Mountain were investigated by using field data collected from eight sampling transects perpendicular to the Erdaobai River channel. Two kinds of species-area saturation curves were used to examine the relationship between species number and minimum sampling area. The results showed that riparian gymnosperms accounted for a high proportion of all gymnosperms in the Changbai Mountain Nature Reserve while riparian ferns and angiosperms accounted for a relatively low proportion. The average minimum sampling areas of riparian forest that included 60%, 80%, and 90% of the community species pool were about 85, 185, and 328 m 2 , respectively; while those for nonriparian forest were about 275, 390, and 514 m 2 , correspondingly.展开更多
Background Obsessive-compulsive disorder(OCD)is classified by the World Health Organization as 1 of the 10 most disabling conditions.However,nationally representative epidemiological data on OCD are not yet available ...Background Obsessive-compulsive disorder(OCD)is classified by the World Health Organization as 1 of the 10 most disabling conditions.However,nationally representative epidemiological data on OCD are not yet available in China.Aims To investigate the prevalence,comorbidity,role impairment and healthcare utilisation of OCD in China.Methods The present study used a multistage clustered area probability sample to obtain representative populationbased data of adults from 157 nationwide disease surveillance points across 31 provinces in China.Trained interviewers conducted face-to-face interviews with respondents to collect information based on the Composite International Diagnostic Interview 3.0.Data weighting was performed to account for differential selection probabilities and response rates,and to post-stratify the sample to ensure its representativeness of the population in China.Results A total of 28140 respondents(12537(44.55%)males and 15603(55.45%)females)completed the diagnostic interview.Two-thirds of the respondents with liftime OCD had comorbid mental disorders,with OCD typically emerging later than the comorbidities.The most common comorbidities were mood disorders(39.67%,odds ratio(OR):9.60,95%confidence interval(CI)7.35 to 12.53)and anxiety disorders(32.75%,OR:13.33,95%CI 10.14 to 17.52).Overall,588(weighted 58.19%)respondents with obsessions or compulsions experienced role impairment,which was most severe in those reporting unspecified symptoms.Only 46(6.74%)respondents with lifetime OCD and 28(6.48%)with 12-month OCD received any healthcare services for their conditions.Conclusions The weighted lifetime and 12-month prevalence of OCD were 2.43%and 1.63%,respectively.Most patients with OCD reported comorbid mental disorders and role impairment,but very few sought healthcare services.National programmes to expand service coverage and increase awareness of OCD are essential to meet healthcare needs in China.展开更多
The existing articulated arm coordinate measuring machines（AACMM） with one measurement model are easy to cause low measurement accuracy because the whole sampling space is much bigger than the result in the unstable...The existing articulated arm coordinate measuring machines（AACMM） with one measurement model are easy to cause low measurement accuracy because the whole sampling space is much bigger than the result in the unstable calibration parameters. To compensate for the deficiency of one measurement model, the multiple measurement models are built by the Denavit-Hartenberg＇s notation, the homemade standard rod components are used as a calibration tool and the Levenberg-Marquardt calibration algorithm is applied to solve the structural parameters in the measurement models. During the tests of multiple measurement models, the sample areas are selected in two situations. It is found that the measurement errors＇ sigma value（0.083 4 ram） dealt with one measurement model is nearly two times larger than that of the multiple measurement models（0.043 1 ram） in the same sample area. While in the different sample area, the measurement errors＇ sigma value（0.054 0 ram） dealt with the multiple measurement models is about 40% of one measurement model（0.137 3 mm）. The preliminary results suggest that the measurement accuracy of AACMM dealt with multiple measurement models is superior to the accuracy of the existing machine with one measurement model. This paper proposes the multiple measurement models to improve the measurement accuracy of AACMM without increasing any hardware cost.展开更多
An optimal validation of a thematic map would ideally require in-situ observations of a large sample of units specifically conceived for the map under validation.This is often not possible due to budget limitations.Th...An optimal validation of a thematic map would ideally require in-situ observations of a large sample of units specifically conceived for the map under validation.This is often not possible due to budget limitations.The alternative can be using photo-interpretation of high or very high resolution images instead of in-situ observations or using available data sets that do not fully comply with the ideal characteristics:unit size,reference date or sampling plan.This paper illustrates some examples of use of available data in the European Union.For land cover maps,the best existing data set is probably Land Use/Cover Areaframe Survey(LUCAS)that has been conducted by Eurostat on four occasions since 2001.Because LUCAS is based on systematic sampling,advantages and limitations of systematic sampling are discussed.A fine-scale population density map is presented as an example of a situation in which reference data on a statistical sample cannot be collected.展开更多
基金supported by the Ministry of Science and Technology of the People's Republic of China (2006BAD03A09)the Special Fund of State Key Laboratory of Urban and Regional Ecology
文摘Riparian areas are unique although often small component of the overall watershed landscape. The structure of riparian forests along Erdaobai River on the north slope of Changbai Mountain were investigated by using field data collected from eight sampling transects perpendicular to the Erdaobai River channel. Two kinds of species-area saturation curves were used to examine the relationship between species number and minimum sampling area. The results showed that riparian gymnosperms accounted for a high proportion of all gymnosperms in the Changbai Mountain Nature Reserve while riparian ferns and angiosperms accounted for a relatively low proportion. The average minimum sampling areas of riparian forest that included 60%, 80%, and 90% of the community species pool were about 85, 185, and 328 m 2 , respectively; while those for nonriparian forest were about 275, 390, and 514 m 2 , correspondingly.
基金funded by the special research project for non-profit public service of the Chinese Ministry of Health(grant number:201202022 to YH)the national twelfth five-year plan for science and technology support of the Chinese Ministry of Science and Technology(grant numbers:2012BAI01B01 to YH)+1 种基金the National Key R&D Program of China(grant numbers:2017YFC0907800 to YH and 2017YFC0907801 to GX)the Major Projects of the Health Commission of Hunan Province(grant number:W20241001 to YZ)。
文摘Background Obsessive-compulsive disorder(OCD)is classified by the World Health Organization as 1 of the 10 most disabling conditions.However,nationally representative epidemiological data on OCD are not yet available in China.Aims To investigate the prevalence,comorbidity,role impairment and healthcare utilisation of OCD in China.Methods The present study used a multistage clustered area probability sample to obtain representative populationbased data of adults from 157 nationwide disease surveillance points across 31 provinces in China.Trained interviewers conducted face-to-face interviews with respondents to collect information based on the Composite International Diagnostic Interview 3.0.Data weighting was performed to account for differential selection probabilities and response rates,and to post-stratify the sample to ensure its representativeness of the population in China.Results A total of 28140 respondents(12537(44.55%)males and 15603(55.45%)females)completed the diagnostic interview.Two-thirds of the respondents with liftime OCD had comorbid mental disorders,with OCD typically emerging later than the comorbidities.The most common comorbidities were mood disorders(39.67%,odds ratio(OR):9.60,95%confidence interval(CI)7.35 to 12.53)and anxiety disorders(32.75%,OR:13.33,95%CI 10.14 to 17.52).Overall,588(weighted 58.19%)respondents with obsessions or compulsions experienced role impairment,which was most severe in those reporting unspecified symptoms.Only 46(6.74%)respondents with lifetime OCD and 28(6.48%)with 12-month OCD received any healthcare services for their conditions.Conclusions The weighted lifetime and 12-month prevalence of OCD were 2.43%and 1.63%,respectively.Most patients with OCD reported comorbid mental disorders and role impairment,but very few sought healthcare services.National programmes to expand service coverage and increase awareness of OCD are essential to meet healthcare needs in China.
基金Supported by National Natural Science Foundation of China(Grant No.51265017)Jiangxi Provincial Science and Technology Planning Project,China(Grant No.GJJ12468)Science and Technology Planning Project of Ji’an City,China(Grant No.20131828)
文摘The existing articulated arm coordinate measuring machines（AACMM） with one measurement model are easy to cause low measurement accuracy because the whole sampling space is much bigger than the result in the unstable calibration parameters. To compensate for the deficiency of one measurement model, the multiple measurement models are built by the Denavit-Hartenberg＇s notation, the homemade standard rod components are used as a calibration tool and the Levenberg-Marquardt calibration algorithm is applied to solve the structural parameters in the measurement models. During the tests of multiple measurement models, the sample areas are selected in two situations. It is found that the measurement errors＇ sigma value（0.083 4 ram） dealt with one measurement model is nearly two times larger than that of the multiple measurement models（0.043 1 ram） in the same sample area. While in the different sample area, the measurement errors＇ sigma value（0.054 0 ram） dealt with the multiple measurement models is about 40% of one measurement model（0.137 3 mm）. The preliminary results suggest that the measurement accuracy of AACMM dealt with multiple measurement models is superior to the accuracy of the existing machine with one measurement model. This paper proposes the multiple measurement models to improve the measurement accuracy of AACMM without increasing any hardware cost.
文摘An optimal validation of a thematic map would ideally require in-situ observations of a large sample of units specifically conceived for the map under validation.This is often not possible due to budget limitations.The alternative can be using photo-interpretation of high or very high resolution images instead of in-situ observations or using available data sets that do not fully comply with the ideal characteristics:unit size,reference date or sampling plan.This paper illustrates some examples of use of available data in the European Union.For land cover maps,the best existing data set is probably Land Use/Cover Areaframe Survey(LUCAS)that has been conducted by Eurostat on four occasions since 2001.Because LUCAS is based on systematic sampling,advantages and limitations of systematic sampling are discussed.A fine-scale population density map is presented as an example of a situation in which reference data on a statistical sample cannot be collected.
