Livestock is a subsector of Pakistan agriculture which contributes approximately 56%of value addition in agriculture and nearly 11%to the gross domestic product(GDP).Livestock production makes a major contribution to ...Livestock is a subsector of Pakistan agriculture which contributes approximately 56%of value addition in agriculture and nearly 11%to the gross domestic product(GDP).Livestock production makes a major contribution to agriculture value added services.In order to highlight the actual performance of livestock production and livestock and poultry products,the study explored the relationship between agricultural GDP and livestock product output,including milk,beef,mutton,poultry meat,eggs,wool,hair,skins,hides and bones,in Pakistan over the 35 year period from 1980 to 2015.Time series data were collected from the National Food Security and Research,the Economic Survey of Pakistan and the Pakistan Bureau of Statistics(various publications).Livestock data were analysed using the ordinary least squares(OLS)method and the Augmented Dickey-Fuller(ADF)test,and the results were interpreted using the Johansen co-integration test.Our study found that the output of milk,fat,eggs,bones and mutton has a positive,significant relationship to the agricultural GDP of Pakistan,while the output of beef,poultry meat,wool,hair,skins and hides has a negative,insignificant relationship to the agricultural GDP of Pakistan.Therefore,the study suggests that the government of Pakistan initiates new funding schemes for the development of the livestock sector.展开更多
The study of population dynamics and their socioeconomic implications for a country or region fundamentally relies on continuous and complete demographic data disaggregated by age group and education level.However,lim...The study of population dynamics and their socioeconomic implications for a country or region fundamentally relies on continuous and complete demographic data disaggregated by age group and education level.However,limitations inherent in population survey frameworks often impede direct access to such data during non-census years or compromise its reliability.To address this gap,this study,harnessing the data from 2000,2010,and 2020 national censuses,employs a forward-backward iterative fitting approach utilizing the Discrete Population Equation to enable the reconstruction of age-and education-specific population counts for the years spanning 2000 to 2020.The reconstructed total population figures for non-census years show minimal discrepancy from the adjusted figures released by the National Bureau of Statistics,while the reconstructed age-specific population counts have successfully rectified discrepancies present in the officially published age structure demographics.Additionally,the study yields a sequential series of working-age population estimates,disaggregated by education level for individuals aged 15 to 64.展开更多
Severe population declines can reduce species to small populations, offering permissive conditions for deleterious processes. For example, following such events, species can become prone to inbreeding and genetic drif...Severe population declines can reduce species to small populations, offering permissive conditions for deleterious processes. For example, following such events, species can become prone to inbreeding and genetic drift which can lead to a loss of genetic diversity and evolutionary potentials. Hynobius chinensis is a poorly studied very rare and declining endangered amphibian species endemic to China in Changyang County. We investigated adult census population size by monitoring breeding populations from 2015 to 2018, developed microsatellite markers from the transcriptome and used them to investigate genetic diversity, and a population bottleneck in this species. We found H. chinensis in 4 different localities in a total area of 2.18 km^2 and estimated the overall adult census population size at 386–404 individuals. The adult census size（mean ± SE） per breeding pond ranged from 44 ± 6 to 141 ± 8 individuals and appeared smaller than that reported in closely related species in undisturbed habitats. We developed and characterized 13 microsatellite markers in total. Analysis of data at 7 loci（N = 118） in Hardy-Weinberg equilibrium gathered from the largest population showed that genetic diversity level was low. The average number of alleles per locus was 2.14. The observed and expected heterozygosities averaged 0.38 and 0.40, respectively. The inbreeding coefficient was –0.06. All tests performed to investigate a population bottleneck, i.e. The Garza-Williamson test, Heterozygosity excess test, Mode shift test of allele frequency, and effective population size estimates detected a population bottleneck. The contemporary and the historical effective population sizes were estimated at 36 and 234 individuals, respectively. We argue that as bottleneck effects, the studied population may have become prone to genetic drift and inbreeding, losing microsatellite alleles and heterozygosity. Our results suggest that populations of H. chinensismay have been extirpated in the study area.展开更多
In the Big Data era,Earth observation is becoming a complex process integrating physical and social sectors.This study presents an approach to generating a 100 m population grid in the Contiguous United States(CONUS)b...In the Big Data era,Earth observation is becoming a complex process integrating physical and social sectors.This study presents an approach to generating a 100 m population grid in the Contiguous United States(CONUS)by disaggregating the US cen-sus records using 125 million of building footprints released by Microsoft in 2018.Land-use data from the OpenStreetMap(OSM),a crowdsourcing platform,was applied to trim original footprints by removing the non-residential buildings.After trimming,several metrics of building measurements such as building size and build-ing count in a census tract were used as weighting scenarios,with which a dasymetric model was applied to disaggregate the American Community Survey(ACS)5-year estimates(2013-2017)into a 100 m population grid product.The results confirm that the OSM trimming process removes non-residential buildings and thus provides a better representation of population distribution within complicated urban fabrics.The building size in the census tract is found in the optimal weighting scenario.The product is 2.5Gb in size containing 800 million populated grids and is currently hosted by ESRI(http://arcg.is/19S4qK)for visualization.The data can be accessed via https://doi.org/10.7910/DVN/DLGP7Y.With the accel-erated acquisition of high-resolution spatial data,the product could be easily updated for spatial and temporal continuity.展开更多
On the basis of the analysis of the standards for the city/town populationstatistics in the past censuses,the author makes a proportional analysis of the city/townpopulation according to the data obtained from the fou...On the basis of the analysis of the standards for the city/town populationstatistics in the past censuses,the author makes a proportional analysis of the city/townpopulation according to the data obtained from the fourth census,and points out the dis-crepancies in the standard for the the city/town population statistics used in the fourthcensus and proposes ways for their correction.展开更多
Population distribution and their temporal variation are a direct proxy of urbanization. This study evaluates the population density variation of China between 2000 and 2010 at the township level by using the data of ...Population distribution and their temporal variation are a direct proxy of urbanization. This study evaluates the population density variation of China between 2000 and 2010 at the township level by using the data of the fi fth and sixth national population censuses. The urbanization patterns of China in 2000 and 2010 are depicted based on the population densities at various levels and the urbanization process of China between 2000 and 2010 is then analyzed through a comparative approach. It also tries to visualize the population density dynamics and urbanization pattern variations of China at the township level.展开更多
The population of China has entered an era of low fertility and aging,with a slower growth rate in the last decade.This commentary briefly reviews demographic changes in China in the last seven decades with some impor...The population of China has entered an era of low fertility and aging,with a slower growth rate in the last decade.This commentary briefly reviews demographic changes in China in the last seven decades with some important years of change in mortality,fertility and urbanization,and discusses future trends according to the information provided by the 2020 Census.China has experienced“compressed”population change,and population aging will continue to advance,meanwhile the size of the population is expected to reach its peak in the near future.To prepare proper response to the challenges proactively,institutional change which adapts to population changes is necessary.展开更多
This paper uses the 2010 and 2020 Population Census micro-data to analyze relevant characteristics and trends over the decade.The analysis includes the following aspects:population size of rural children left-behind,t...This paper uses the 2010 and 2020 Population Census micro-data to analyze relevant characteristics and trends over the decade.The analysis includes the following aspects:population size of rural children left-behind,their age structure and sex composition,regional distribution,living arrangements,and educational development.The findings show that the population size of rural children left-behind remained large,and the likelihood of children being left-behind was closely related to age,with no significant difference by sex.An increasing proportion of rural children left-behind were cared for by grandparents as more mothers migrated between 2010 and 2020.Rural children left-behind no longer had an advantage in educational opportunities compared with average rural children.Over-age attendance was more prevalent among rural children left-behind than all rural children.Continuous attention should be paid to the issue of rural children left-behind and efforts should be made to address its root causes.展开更多
文摘Livestock is a subsector of Pakistan agriculture which contributes approximately 56%of value addition in agriculture and nearly 11%to the gross domestic product(GDP).Livestock production makes a major contribution to agriculture value added services.In order to highlight the actual performance of livestock production and livestock and poultry products,the study explored the relationship between agricultural GDP and livestock product output,including milk,beef,mutton,poultry meat,eggs,wool,hair,skins,hides and bones,in Pakistan over the 35 year period from 1980 to 2015.Time series data were collected from the National Food Security and Research,the Economic Survey of Pakistan and the Pakistan Bureau of Statistics(various publications).Livestock data were analysed using the ordinary least squares(OLS)method and the Augmented Dickey-Fuller(ADF)test,and the results were interpreted using the Johansen co-integration test.Our study found that the output of milk,fat,eggs,bones and mutton has a positive,significant relationship to the agricultural GDP of Pakistan,while the output of beef,poultry meat,wool,hair,skins and hides has a negative,insignificant relationship to the agricultural GDP of Pakistan.Therefore,the study suggests that the government of Pakistan initiates new funding schemes for the development of the livestock sector.
文摘The study of population dynamics and their socioeconomic implications for a country or region fundamentally relies on continuous and complete demographic data disaggregated by age group and education level.However,limitations inherent in population survey frameworks often impede direct access to such data during non-census years or compromise its reliability.To address this gap,this study,harnessing the data from 2000,2010,and 2020 national censuses,employs a forward-backward iterative fitting approach utilizing the Discrete Population Equation to enable the reconstruction of age-and education-specific population counts for the years spanning 2000 to 2020.The reconstructed total population figures for non-census years show minimal discrepancy from the adjusted figures released by the National Bureau of Statistics,while the reconstructed age-specific population counts have successfully rectified discrepancies present in the officially published age structure demographics.Additionally,the study yields a sequential series of working-age population estimates,disaggregated by education level for individuals aged 15 to 64.
基金financially supported by the Chinese National Science and Technology Basic Work Program (No. 2014FY110100)the State Forestry Administration of China
文摘Severe population declines can reduce species to small populations, offering permissive conditions for deleterious processes. For example, following such events, species can become prone to inbreeding and genetic drift which can lead to a loss of genetic diversity and evolutionary potentials. Hynobius chinensis is a poorly studied very rare and declining endangered amphibian species endemic to China in Changyang County. We investigated adult census population size by monitoring breeding populations from 2015 to 2018, developed microsatellite markers from the transcriptome and used them to investigate genetic diversity, and a population bottleneck in this species. We found H. chinensis in 4 different localities in a total area of 2.18 km^2 and estimated the overall adult census population size at 386–404 individuals. The adult census size（mean ± SE） per breeding pond ranged from 44 ± 6 to 141 ± 8 individuals and appeared smaller than that reported in closely related species in undisturbed habitats. We developed and characterized 13 microsatellite markers in total. Analysis of data at 7 loci（N = 118） in Hardy-Weinberg equilibrium gathered from the largest population showed that genetic diversity level was low. The average number of alleles per locus was 2.14. The observed and expected heterozygosities averaged 0.38 and 0.40, respectively. The inbreeding coefficient was –0.06. All tests performed to investigate a population bottleneck, i.e. The Garza-Williamson test, Heterozygosity excess test, Mode shift test of allele frequency, and effective population size estimates detected a population bottleneck. The contemporary and the historical effective population sizes were estimated at 36 and 234 individuals, respectively. We argue that as bottleneck effects, the studied population may have become prone to genetic drift and inbreeding, losing microsatellite alleles and heterozygosity. Our results suggest that populations of H. chinensismay have been extirpated in the study area.
文摘In the Big Data era,Earth observation is becoming a complex process integrating physical and social sectors.This study presents an approach to generating a 100 m population grid in the Contiguous United States(CONUS)by disaggregating the US cen-sus records using 125 million of building footprints released by Microsoft in 2018.Land-use data from the OpenStreetMap(OSM),a crowdsourcing platform,was applied to trim original footprints by removing the non-residential buildings.After trimming,several metrics of building measurements such as building size and build-ing count in a census tract were used as weighting scenarios,with which a dasymetric model was applied to disaggregate the American Community Survey(ACS)5-year estimates(2013-2017)into a 100 m population grid product.The results confirm that the OSM trimming process removes non-residential buildings and thus provides a better representation of population distribution within complicated urban fabrics.The building size in the census tract is found in the optimal weighting scenario.The product is 2.5Gb in size containing 800 million populated grids and is currently hosted by ESRI(http://arcg.is/19S4qK)for visualization.The data can be accessed via https://doi.org/10.7910/DVN/DLGP7Y.With the accel-erated acquisition of high-resolution spatial data,the product could be easily updated for spatial and temporal continuity.
文摘On the basis of the analysis of the standards for the city/town populationstatistics in the past censuses,the author makes a proportional analysis of the city/townpopulation according to the data obtained from the fourth census,and points out the dis-crepancies in the standard for the the city/town population statistics used in the fourthcensus and proposes ways for their correction.
文摘Population distribution and their temporal variation are a direct proxy of urbanization. This study evaluates the population density variation of China between 2000 and 2010 at the township level by using the data of the fi fth and sixth national population censuses. The urbanization patterns of China in 2000 and 2010 are depicted based on the population densities at various levels and the urbanization process of China between 2000 and 2010 is then analyzed through a comparative approach. It also tries to visualize the population density dynamics and urbanization pattern variations of China at the township level.
文摘The population of China has entered an era of low fertility and aging,with a slower growth rate in the last decade.This commentary briefly reviews demographic changes in China in the last seven decades with some important years of change in mortality,fertility and urbanization,and discusses future trends according to the information provided by the 2020 Census.China has experienced“compressed”population change,and population aging will continue to advance,meanwhile the size of the population is expected to reach its peak in the near future.To prepare proper response to the challenges proactively,institutional change which adapts to population changes is necessary.
基金derivative products of the Seventh National Population Census research project called“Development Status of Children and Adolescents in China”and has received technical and financial support from the NBS/UNICEF/UNFPA Joint Data Project.
文摘This paper uses the 2010 and 2020 Population Census micro-data to analyze relevant characteristics and trends over the decade.The analysis includes the following aspects:population size of rural children left-behind,their age structure and sex composition,regional distribution,living arrangements,and educational development.The findings show that the population size of rural children left-behind remained large,and the likelihood of children being left-behind was closely related to age,with no significant difference by sex.An increasing proportion of rural children left-behind were cared for by grandparents as more mothers migrated between 2010 and 2020.Rural children left-behind no longer had an advantage in educational opportunities compared with average rural children.Over-age attendance was more prevalent among rural children left-behind than all rural children.Continuous attention should be paid to the issue of rural children left-behind and efforts should be made to address its root causes.
