Taking the tobacco-growing area of Shashi Town,Liuyang City as the object,the number of registered,newly added and resigned tobacco farmers in each year,average age,number and proportion of tobacco farmers of differen...Taking the tobacco-growing area of Shashi Town,Liuyang City as the object,the number of registered,newly added and resigned tobacco farmers in each year,average age,number and proportion of tobacco farmers of different ages,number and proportion of tobacco farmers born in different eras,as well as planting scale and planting history of flue-cured tobacco in the last 10 years were analyzed statistically.The results showed that the number of tobacco farmers in Shashi Town showed a rapid decline trend from 2012 to 2018,while the average age continuously increased,and the average planting scale rose in a wave like way.From 2019 to 2021,the decline rate of the number of tobacco farmers slowed down,and the average planting scale continuously increased,while the aging of tobacco farmers accelerated.Meantime,the birth years of tobacco farmers were further concentrated in the 1960s,and they were mainly at the age of 50-59.The tobacco industry in Shashi Town of Liuyang City is facing the crisis of aging tobacco farmers and no successor of flue-cured tobacco planting,and it is predicted that the next 5-10 years will continue the change trend from 2019 to 2021.展开更多
In the present study, genetic parameters for longevity and genetic correlations with back fat （BF）, average daily gain （ADG）, and first mating age （FMA） were estimated from 19 300 Yorkshire and 18 378 Landrace s...In the present study, genetic parameters for longevity and genetic correlations with back fat （BF）, average daily gain （ADG）, and first mating age （FMA） were estimated from 19 300 Yorkshire and 18 378 Landrace sows from 12 farms derived from one breeding system. General linear models （GLM） were employed to estimate genetic correlations with heritability （h2）. Longevity was defined by six different parameters （i.e., traits） and heritability ranged from h2=0.13 to 0.16 （P〈0.05） in both swine breeds. Genetic correlations between different longevity definitions were positive and high （r=0.79 to 0.99; P〈0.05）. BF exhibited low positive genetic correlations （r=0.12 to 0.15; P〈0.05） with longevity traits identified in both pig breeds which were dependent on trait definition, whereas ADG and FMA showed weak negative genetic correlations with longevity traits. The influence of BF, ADG, and FMA on longevity traits was examined by dividing the production and reproductive traits into several numerical groups; the influence of each longevity trait was subsequently analyzed among the different groups. The results indicated BF was the best trait to improve longevity among BF, ADG, and FMA, which showed positive effects for almost all longevity traits. For Yorkshire sows, gilts with over 18 mm BF were most desirable; Landrace with 10.6-13 mm BF were suitable for longevity. ADG was not favorable for gilt selection, because the correlation between growth rate and longevity very low. For FMA, our results indicated gilts mating before 230 days exhibited a longer life span. Therefore, we suggest farmers should select for thicker back fat and mate at an earlier age to improve sow longevity.展开更多
AIM：To evaluate the influence of age and axial length（AL） on the position of the fovea in patients with high myopia（HM）.METHODS：In this prospective study,96 patients（186 eyes） with HM were consecutively recrui...AIM：To evaluate the influence of age and axial length（AL） on the position of the fovea in patients with high myopia（HM）.METHODS：In this prospective study,96 patients（186 eyes） with HM were consecutively recruited from the Third Affiliated Hospital of Nanchang University.DRI-OCT Atlantis,fundus imaging,and IOL Master were used in this study.Three indices were measured：the distance between the fovea and the optic nerve head（ONH） center（DFO）,the vertical distance between the fovea and the horizontal line pass of the ONH center（VDFO）,and the horizontal distance between the fovea and the vertical line pass of the ONH center（HDFO）.These measurements were used to analyze the effects of different age groups（A1,A2,A3 groups） and AL（AL1,AL2,AL3,AL4 groups） on these indices.RESULTS：The results showed that there was no statistical significance in DFO among the age and AL groups（F=0.46,0.37;P=0.62,0.76,respectively）.In HDFO,there was also no statistical significance among the age and AL groups（F=0.10,0.48;P=0.90,0.69,respectively）.In VDFO,however,the difference in the age and AL groups was statistically significant（F=3.21,3.12;P=0.04,0.02,respectively）.Thus,VDFO were correlated with age and AL（r=0.21,0.23,all P〈0.01）,while HDFO and DFO were not correlated with age and AL（r=0.30,P〉0.05）.CONCLUSION：In high myopia,the foveal position changes mainly in the vertical direction along with factors of age and AL.展开更多
Social stock for metal determines secondary or recoverable resources to a certain extent.Top-down analysis method for the studying of metal in social stock was given.Influences of metal consumption under three circums...Social stock for metal determines secondary or recoverable resources to a certain extent.Top-down analysis method for the studying of metal in social stock was given.Influences of metal consumption under three circumstances,that is keeping constant,varying in a linear trend and in an exponential trend,on one kind of metal’s social stock,recyclable ratio and average age were analyzed.Al-contents and Cu-contents in social stock for China during the period 2006-2009 were calculated.The results reveal that Al-contents and Cu-contents in social stock kept increasing and reached 88.9 million tons and 51.4 millions tons in 2009,respectively,their average recyclable ratios are 1.45% and 0.30%,and the average ages are 4.65 years and 6.89 years,respectively.The recyclable ratios and average ages of Al-contents and Cu-contents in social stock will rise in future along with the decline of the increasing rate of aluminum consumption and copper consumption.展开更多
AIM: To estimate the prevalence and risk factors for vitreous floaters in the general population. ·METHODS: An electronic survey was administered through a smartphone app asking various demographic and health que...AIM: To estimate the prevalence and risk factors for vitreous floaters in the general population. ·METHODS: An electronic survey was administered through a smartphone app asking various demographic and health questions, including whether users experience floaters in their field of vision. Multivariate logistic regression analysis was used to determine risk factors. ·RESULTS: A total of 603 individuals completed the survey, with 76% reporting that they see floaters, and 33% reporting that floaters caused noticeable impairment in vision. Myopes were 3.5 times more likely (P =0.0004), and hyperopes 4.4 times more likely (P =0.0069) to report moderate to severe floaters compared to those with normal vision. Floater prevalence was not significantly affected by respondent age, race, gender, and eye color. ·CONCLUSION: Vitreous floaters were found to be a very common phenomenon in this non -clinical general population sample, and more likely to be impairing in myopes and hyperopes.展开更多
Focusing on the 18 counties along “One River and Two Tributaries” region, and based on the data from China 3nl, 4th and 5th population censuses, this article has analyzed the time and spatial changing patterns of th...Focusing on the 18 counties along “One River and Two Tributaries” region, and based on the data from China 3nl, 4th and 5th population censuses, this article has analyzed the time and spatial changing patterns of the population in this region. The analyses show that since the 3nl population census, total population, average age and total birth rate have all changed considerably: ① Total population has grown, fast, with most counties' annual average growth rate of more than 10. ② In terms of the region's average age, in 2000 the age in the 18 counties is younger than 30 years old. ③ Compared with the 3nl population census, labor force by the 5th census is much younger. ④ Countermeasures are proposed to control population by controlling birth rate as the result of the local resident's quality improvement by education.展开更多
Jersey bull calves and steers produce high quality meat;however, the growth rate of Jersey bull calves for veal and beef are low in comparison to other dairy breeds. This could be improved by crossbreeding with beef b...Jersey bull calves and steers produce high quality meat;however, the growth rate of Jersey bull calves for veal and beef are low in comparison to other dairy breeds. This could be improved by crossbreeding with beef breeds. In the current study, the veal and beef production of Jersey and Fleckvieh × Jersey (F × J) bull calves and steers were compared. Bull calves were reared intensively for veal up to a carcass weight not exceeding 100 kg, or as steers for beef to 21 months of age. In both veal and steer production systems, the mean birth weight of F × J bull calves was higher (P < 0.001) than Jersey bull calves, i.e. 33.5 ± 1.2 kg vs. 27.9 ± 1.2 kg and (33.4 ± 0.9 kg vs. 26.9 ± 0.9 kg, respectively. The body weight of Jersey and F × J veal calves at 6 months of age differed (P < 0.01) being 163.5 ± 3.9 and 180.6 ± 4.0 kg respectively. This could be attributed to a higher (P < 0.01) average daily gain (ADG) of 0.82 ± 0.02 kg/day for F × J compared to 0.73 ± 0.02 kg/day for Jersey bull calves. Marketing age in the veal production system differed (P < 0.001) with Jersey and F×J bull calves marketed at 7.1 ± 0.1 and 6.3 ± 0.1 months of age, respectively. End live weight at 21 months of age of Jersey and F × J differed (P < 0.01) being 322.6 ± 13.4 and 441.4 ± 14.9 kg respectively. This was due to a higher (P < 0.01) average daily gain in F × J vs. Jersey steers, i.e. 0.64 ± 0.02 and 0.46 ± 0.0 kg/day, respectively. Fleckvieh × Jersey steers had a higher (P < 0.01) carcass weight at 21 months of age being 206.5 ± 8.9 kg vs. 157.9 ± 8.6 kg respectively. These results indicated the potential of improving beef production characteristics of the Jersey cattle through crossbreeding.展开更多
Purpose:To evaluate the relationship between axial length(AL)and spherical equivalent refraction(SER)in Chinese children.Methods:This hospital-based cross-sectional study included 1208 eyes(from 617 Chinese boys and 5...Purpose:To evaluate the relationship between axial length(AL)and spherical equivalent refraction(SER)in Chinese children.Methods:This hospital-based cross-sectional study included 1208 eyes(from 617 Chinese boys and 591 Chinese girls),ranging between 2 and 12 years.All subjects were divided into subgroups according to the spherical equivalent refraction(SER)(hyperopia,emmetropia,and myopia)and age(2–6 years,7–9 years,and 10–12 years).Comparisons were made between age,sex,and SER groups.Multiple linear regression analysis was used to evaluate the correlation of AL and SER for all groups.Results:The mean AL and SER were significantly different among the three age groups:2–6 years group(AL:22.241.59 mm;SER:0.732.67 D);7–9 years group(AL:23.491.10 mm;SE:-0.681.97 D)and 10–12 years group(AL:24.331.02 mm;SER:-1.721.86 D).Boys showed longer AL compared with the girls(23.661.51 mm vs 23.051.32 mm).However,as for SER,the girls(0.702.17 D)showed smaller SER(more myopia)compared with the boys(0.42.48 D).After adjusting for age and sex,the SER tended to decrease(became more myopic)1.23 D(95%CI:1.15–1.30D)with a 1 mm increase of AL.Among the different SER groups,the SER tended to become more myopic per mm of AL by 1.09 D(95%CI:0.97–1.21D)for the myopia group,1.38 D(95%CI:1.23–1.54 D)for the hyperopia group,and 0.05 D(95%CI:0.02–0.08 D)for the emmetropic group.In addition,an increase of 1 mm elongation of AL showed a decrease of SER by 1.05 D(95%CI:0.90–1.20 D)among 2–6-year-olds,by 1.40 D(95%CI:1.30–1.51 D)among 7–9-year-olds,and by 1.37 D(95%CI:1.21–1.52 D)among 10–12-year-olds.As for sexual differences,the girls 1.68 D,(95%CI:1.57–1.79 D)showed a more significant myopic shift of SER with a 1 mm increase of AL compared with the boys(0.94 D,95%CI:0.84–1.04 D).Conclusions:Our results indicated a strong linear relationship between SER and AL and an early-rising trend of myopia in Chinese children.展开更多
基金Supported by Science and Technology Project of Changsha Tobacco Company(20-22B02).
文摘Taking the tobacco-growing area of Shashi Town,Liuyang City as the object,the number of registered,newly added and resigned tobacco farmers in each year,average age,number and proportion of tobacco farmers of different ages,number and proportion of tobacco farmers born in different eras,as well as planting scale and planting history of flue-cured tobacco in the last 10 years were analyzed statistically.The results showed that the number of tobacco farmers in Shashi Town showed a rapid decline trend from 2012 to 2018,while the average age continuously increased,and the average planting scale rose in a wave like way.From 2019 to 2021,the decline rate of the number of tobacco farmers slowed down,and the average planting scale continuously increased,while the aging of tobacco farmers accelerated.Meantime,the birth years of tobacco farmers were further concentrated in the 1960s,and they were mainly at the age of 50-59.The tobacco industry in Shashi Town of Liuyang City is facing the crisis of aging tobacco farmers and no successor of flue-cured tobacco planting,and it is predicted that the next 5-10 years will continue the change trend from 2019 to 2021.
基金supported by the grants from the National Swine Industry Technology System,China (CARS-36)the Guangdong Modern Agricultural Industry Technology System,Chinathe project from the Ministry of Science and Technology of China (2014 FY120800 and 2013 GA790001)
文摘In the present study, genetic parameters for longevity and genetic correlations with back fat （BF）, average daily gain （ADG）, and first mating age （FMA） were estimated from 19 300 Yorkshire and 18 378 Landrace sows from 12 farms derived from one breeding system. General linear models （GLM） were employed to estimate genetic correlations with heritability （h2）. Longevity was defined by six different parameters （i.e., traits） and heritability ranged from h2=0.13 to 0.16 （P〈0.05） in both swine breeds. Genetic correlations between different longevity definitions were positive and high （r=0.79 to 0.99; P〈0.05）. BF exhibited low positive genetic correlations （r=0.12 to 0.15; P〈0.05） with longevity traits identified in both pig breeds which were dependent on trait definition, whereas ADG and FMA showed weak negative genetic correlations with longevity traits. The influence of BF, ADG, and FMA on longevity traits was examined by dividing the production and reproductive traits into several numerical groups; the influence of each longevity trait was subsequently analyzed among the different groups. The results indicated BF was the best trait to improve longevity among BF, ADG, and FMA, which showed positive effects for almost all longevity traits. For Yorkshire sows, gilts with over 18 mm BF were most desirable; Landrace with 10.6-13 mm BF were suitable for longevity. ADG was not favorable for gilt selection, because the correlation between growth rate and longevity very low. For FMA, our results indicated gilts mating before 230 days exhibited a longer life span. Therefore, we suggest farmers should select for thicker back fat and mate at an earlier age to improve sow longevity.
基金Supported by the Research and Development Project of Science and Technology of the Jiangxi Province(No.20171BBG70100)the Ophthalmic Innovation Project of Nanchang City(No.2016114)
文摘AIM：To evaluate the influence of age and axial length（AL） on the position of the fovea in patients with high myopia（HM）.METHODS：In this prospective study,96 patients（186 eyes） with HM were consecutively recruited from the Third Affiliated Hospital of Nanchang University.DRI-OCT Atlantis,fundus imaging,and IOL Master were used in this study.Three indices were measured：the distance between the fovea and the optic nerve head（ONH） center（DFO）,the vertical distance between the fovea and the horizontal line pass of the ONH center（VDFO）,and the horizontal distance between the fovea and the vertical line pass of the ONH center（HDFO）.These measurements were used to analyze the effects of different age groups（A1,A2,A3 groups） and AL（AL1,AL2,AL3,AL4 groups） on these indices.RESULTS：The results showed that there was no statistical significance in DFO among the age and AL groups（F=0.46,0.37;P=0.62,0.76,respectively）.In HDFO,there was also no statistical significance among the age and AL groups（F=0.10,0.48;P=0.90,0.69,respectively）.In VDFO,however,the difference in the age and AL groups was statistically significant（F=3.21,3.12;P=0.04,0.02,respectively）.Thus,VDFO were correlated with age and AL（r=0.21,0.23,all P〈0.01）,while HDFO and DFO were not correlated with age and AL（r=0.30,P〉0.05）.CONCLUSION：In high myopia,the foveal position changes mainly in the vertical direction along with factors of age and AL.
基金Project (71003018) supported by the National Natural Science Foundation of ChinaProject (N110402003) supported by the Fundamental Research Funds for the Central Universities,China
文摘Social stock for metal determines secondary or recoverable resources to a certain extent.Top-down analysis method for the studying of metal in social stock was given.Influences of metal consumption under three circumstances,that is keeping constant,varying in a linear trend and in an exponential trend,on one kind of metal’s social stock,recyclable ratio and average age were analyzed.Al-contents and Cu-contents in social stock for China during the period 2006-2009 were calculated.The results reveal that Al-contents and Cu-contents in social stock kept increasing and reached 88.9 million tons and 51.4 millions tons in 2009,respectively,their average recyclable ratios are 1.45% and 0.30%,and the average ages are 4.65 years and 6.89 years,respectively.The recyclable ratios and average ages of Al-contents and Cu-contents in social stock will rise in future along with the decline of the increasing rate of aluminum consumption and copper consumption.
文摘AIM: To estimate the prevalence and risk factors for vitreous floaters in the general population. ·METHODS: An electronic survey was administered through a smartphone app asking various demographic and health questions, including whether users experience floaters in their field of vision. Multivariate logistic regression analysis was used to determine risk factors. ·RESULTS: A total of 603 individuals completed the survey, with 76% reporting that they see floaters, and 33% reporting that floaters caused noticeable impairment in vision. Myopes were 3.5 times more likely (P =0.0004), and hyperopes 4.4 times more likely (P =0.0069) to report moderate to severe floaters compared to those with normal vision. Floater prevalence was not significantly affected by respondent age, race, gender, and eye color. ·CONCLUSION: Vitreous floaters were found to be a very common phenomenon in this non -clinical general population sample, and more likely to be impairing in myopes and hyperopes.
文摘Focusing on the 18 counties along “One River and Two Tributaries” region, and based on the data from China 3nl, 4th and 5th population censuses, this article has analyzed the time and spatial changing patterns of the population in this region. The analyses show that since the 3nl population census, total population, average age and total birth rate have all changed considerably: ① Total population has grown, fast, with most counties' annual average growth rate of more than 10. ② In terms of the region's average age, in 2000 the age in the 18 counties is younger than 30 years old. ③ Compared with the 3nl population census, labor force by the 5th census is much younger. ④ Countermeasures are proposed to control population by controlling birth rate as the result of the local resident's quality improvement by education.
文摘Jersey bull calves and steers produce high quality meat;however, the growth rate of Jersey bull calves for veal and beef are low in comparison to other dairy breeds. This could be improved by crossbreeding with beef breeds. In the current study, the veal and beef production of Jersey and Fleckvieh × Jersey (F × J) bull calves and steers were compared. Bull calves were reared intensively for veal up to a carcass weight not exceeding 100 kg, or as steers for beef to 21 months of age. In both veal and steer production systems, the mean birth weight of F × J bull calves was higher (P < 0.001) than Jersey bull calves, i.e. 33.5 ± 1.2 kg vs. 27.9 ± 1.2 kg and (33.4 ± 0.9 kg vs. 26.9 ± 0.9 kg, respectively. The body weight of Jersey and F × J veal calves at 6 months of age differed (P < 0.01) being 163.5 ± 3.9 and 180.6 ± 4.0 kg respectively. This could be attributed to a higher (P < 0.01) average daily gain (ADG) of 0.82 ± 0.02 kg/day for F × J compared to 0.73 ± 0.02 kg/day for Jersey bull calves. Marketing age in the veal production system differed (P < 0.001) with Jersey and F×J bull calves marketed at 7.1 ± 0.1 and 6.3 ± 0.1 months of age, respectively. End live weight at 21 months of age of Jersey and F × J differed (P < 0.01) being 322.6 ± 13.4 and 441.4 ± 14.9 kg respectively. This was due to a higher (P < 0.01) average daily gain in F × J vs. Jersey steers, i.e. 0.64 ± 0.02 and 0.46 ± 0.0 kg/day, respectively. Fleckvieh × Jersey steers had a higher (P < 0.01) carcass weight at 21 months of age being 206.5 ± 8.9 kg vs. 157.9 ± 8.6 kg respectively. These results indicated the potential of improving beef production characteristics of the Jersey cattle through crossbreeding.
基金the National Natural Science Foundation of China(Grant No.81800869 to Xiaoning Yu).
文摘Purpose:To evaluate the relationship between axial length(AL)and spherical equivalent refraction(SER)in Chinese children.Methods:This hospital-based cross-sectional study included 1208 eyes(from 617 Chinese boys and 591 Chinese girls),ranging between 2 and 12 years.All subjects were divided into subgroups according to the spherical equivalent refraction(SER)(hyperopia,emmetropia,and myopia)and age(2–6 years,7–9 years,and 10–12 years).Comparisons were made between age,sex,and SER groups.Multiple linear regression analysis was used to evaluate the correlation of AL and SER for all groups.Results:The mean AL and SER were significantly different among the three age groups:2–6 years group(AL:22.241.59 mm;SER:0.732.67 D);7–9 years group(AL:23.491.10 mm;SE:-0.681.97 D)and 10–12 years group(AL:24.331.02 mm;SER:-1.721.86 D).Boys showed longer AL compared with the girls(23.661.51 mm vs 23.051.32 mm).However,as for SER,the girls(0.702.17 D)showed smaller SER(more myopia)compared with the boys(0.42.48 D).After adjusting for age and sex,the SER tended to decrease(became more myopic)1.23 D(95%CI:1.15–1.30D)with a 1 mm increase of AL.Among the different SER groups,the SER tended to become more myopic per mm of AL by 1.09 D(95%CI:0.97–1.21D)for the myopia group,1.38 D(95%CI:1.23–1.54 D)for the hyperopia group,and 0.05 D(95%CI:0.02–0.08 D)for the emmetropic group.In addition,an increase of 1 mm elongation of AL showed a decrease of SER by 1.05 D(95%CI:0.90–1.20 D)among 2–6-year-olds,by 1.40 D(95%CI:1.30–1.51 D)among 7–9-year-olds,and by 1.37 D(95%CI:1.21–1.52 D)among 10–12-year-olds.As for sexual differences,the girls 1.68 D,(95%CI:1.57–1.79 D)showed a more significant myopic shift of SER with a 1 mm increase of AL compared with the boys(0.94 D,95%CI:0.84–1.04 D).Conclusions:Our results indicated a strong linear relationship between SER and AL and an early-rising trend of myopia in Chinese children.
