AIM: To study the dynamic character of aberration between the cornea and the ocular with aging, and to evaluate the symmetry of the aberrations between right and left eye in order to supply the data for clinic to do t...AIM: To study the dynamic character of aberration between the cornea and the ocular with aging, and to evaluate the symmetry of the aberrations between right and left eye in order to supply the data for clinic to do the refractive surgery reasonably. METHODS: This is a comparative case series study. 82 normal cases (164 eyes) including 37 females (74 eyes) and 45 males (90 eyes) were recruited through the routine examinations,Topolyzer and wavefront analysis. The average age was 25.9 +/- 5.0 years old (range 18 to 49 years old), and the mean spherical equivalent (SE) is -3.82 +/- 2.21D (range -1.00 to -6.00D). The changes of aberrations regarding age, the relationship between anterior corneal and total aberrations were analyzed,as well as the symmetry between right and left eyes by using Zernike terms. RESULTS: The Z (3) (1), RMS3 of corneal aberrations, Z (3) (1), Z (4) (0) RMS3 and RMS4 of ocular aberrations had a positive correlation with age. The zernike terms both in corneal and whole eye were significantly correlated between right and left eyes. CONCLUSION: The corneal horizontal coma, ocular horizontal coma and ocular spherical aberrations become to increase at the age of more than 40 years old. The dynamic change of aberration with aging, balance between corneal and ocular, and the symmetric character between left eye and right eye should be designed carefully in the treatment nomogram before the refractive surgery.展开更多
This research advocates for the construction of Climate Change Haven Communities across the Appalachian Region. The proposed development plan can be extended to the northern tier states across the US and also to the n...This research advocates for the construction of Climate Change Haven Communities across the Appalachian Region. The proposed development plan can be extended to the northern tier states across the US and also to the northern and mountainous regions of Europe and Asia. We present an analogy to the earlier climate change period of the Last Glacial Maximum/“Ice Age” in which these same northern regions of the planet were covered in ice sheets making them uninhabitable for most humans and many plant and animal species. In some significant ways, the Ice Age scenario can be a reverse-model for our current climate crisis. We also advocate strongly for the prevention of upscale real estate development projects in these same regions of the globe, as these will foreclose the possibility of safely sheltering the millions of persons who will be displaced by climate change over the next 5 to 10 years.展开更多
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
Language change is universally acknowledged and has become the major tenet of sociolinguistics. Language change occurs in different ways and places for different reasons. The social factors which language change is ti...Language change is universally acknowledged and has become the major tenet of sociolinguistics. Language change occurs in different ways and places for different reasons. The social factors which language change is tied to are complicated complex including: social class, sex, age and so on. Among them the first three are seen as fixed categories that remain stable in the research of language change and also are the factors will be discussed in this paper. The purpose of this piece of paper is to examine the language change affected by the three main social factors and the standardization and to provide a clear and helpful overview of the relationship of language change and society. It will also point out the weak points in every aspect therefore provides more insight to the further researches in this field.展开更多
Reconstructions of past climatic changes on the northeastern Tibetan Plateau(NETP) can provide insights into the Asian summer monsoon(ASM) variability. However, the regional climate changes on both orbital and suborbi...Reconstructions of past climatic changes on the northeastern Tibetan Plateau(NETP) can provide insights into the Asian summer monsoon(ASM) variability. However, the regional climate changes on both orbital and suborbital time scales since the late Glacial remain controversial. Here we present the results of high-resolution geochemical and grain-size analyses of a sediment core from Genggahai Lake, a small, shallow lake in this area. Changes of the accumulation rate of the core sediments show a similar trend with variations of the coarse fraction. Accordingly, the chronological framework is constructed using a grain-size age model. In addition, the histories of chemical weathering and aeolian activity since the late Glacial are reconstructed based on the Al/Ti ratios and coarse fractions, respectively. The results suggest that an enhanced chemical weathering and a weakened aeolian activity occurred on the NETP under a warmer, wetter climate during the early to mid-Holocene(11.3–6.3 ka cal BP), compared with the late Glacial(17.1–11.3 ka cal BP) and the late Holocene(6.3 ka cal BP to present), which responded mainly to the strengthened ASM on orbital time scale. In addition, the synchronous occurrences of weakened chemical weathering, low lake level and intense aeolian activity on suborbital time scale reflect several episodes of weakened ASM. Furthermore, these episodes largely coincide with the centennial-to millennial-scale cold events in the North Atlantic, which demonstrates the close connection between the ASM and the cooling at high latitudes.展开更多
Purpose: Cervical spine is considered to be the most moving part of vertebral column. It is located in a very important part of the body i.e. neck having some very important structures related to it. Any age related c...Purpose: Cervical spine is considered to be the most moving part of vertebral column. It is located in a very important part of the body i.e. neck having some very important structures related to it. Any age related changes occurring in such a part of vertebral column may lead to many disorders and disabilities. Complete familiarity of this entire region anatomically as well as radiologically is therefore of utmost importance for the diagnosis and management of such disorders. Aim of this work is to evaluate the frequency of age related degeneration in cervical spine in Saudi adult asymptomatic subjects using CT scan images. Methods: In this study, 105 cases of symptomless adults ranging between 18 - 90 years of age were included. The cases were classified into 3 groups;adult group (18 - 35 years old), middle age group (36 - 55 years old) and old age group (56 - 90 years old). Their CT scans were performed in the department of radiology, King Khalid Hospital, Al Kharj and studied for any age related changes. Results: The first age group category included 35 cases;20 had normal and 15 degenerative changes. The second category included 35 cases;3 had normal and 32 degenerative changes. The third category included 35 cases. Single had normal and 34 degenerative changes. Conclusion: Asymptomatic degenerative changes are common in the cervical spine after 30 years of age in Saudi adult asymptomatic subjects.展开更多
For a long time, China has large population, so the labor-intensive products become the comparative advantage.This paper analyzes the influences of population age structure's changes on the export commodity structure...For a long time, China has large population, so the labor-intensive products become the comparative advantage.This paper analyzes the influences of population age structure's changes on the export commodity structure of our country and draws conclusions.展开更多
Objective To determine the extent of the obesity epidemic in school‐aged Chinese children in 2010 and track the increasing trend in different socioeconomic regions over the preceding 25 years. Strategies for preventi...Objective To determine the extent of the obesity epidemic in school‐aged Chinese children in 2010 and track the increasing trend in different socioeconomic regions over the preceding 25 years. Strategies for preventing childhood obesity are suggested. Methods We used a dataset provided by the Chinese National Survey on Students’ Constitution and Health from 1985‐2010. Subjects were 7‐18‐year‐old students randomly selected from urban and rural areas in 30 provinces. Eight subgroups were created according to region and socioeconomic status. Results Increased rates of the epidemic (overweight and obesity combined) were greatest in large coastal cities‐32.6% and 19.1% among males and females, respectively. These rates has neared that of developed countries. Similar increases were found in all other regions, including the once poverty‐stricken rural west. The epidemic in most of the rural areas began after 2000, but has spread swiftly over the last decade. In 2010, it was estimated that 9.9% of Chinese school‐aged children and adolescents were overweight and that an additional 5.1% were obese, representing an estimated 30.43 million individuals. Conclusion The prognosis for China's childhood‐obesity epidemic is dire. To prevent childhood obesity, we suggest several strategies, including reasonable dietary intake, increase physical activity, a change in sedentary lifestyles and corresponding behavioral modifications.展开更多
Delingha is located in the northeast margin of Qaidam Basin.Bayin River alluvial proluvial fan is the main aquifer of Delingha,in which groundwater generally flows from north to south.The hydrochemistry results showed...Delingha is located in the northeast margin of Qaidam Basin.Bayin River alluvial proluvial fan is the main aquifer of Delingha,in which groundwater generally flows from north to south.The hydrochemistry results showed that two different hydrochemical evolution paths formed along southeast and southwest directions,respectively.Cl-Na type groundwater was formed in front of Gahai Lake,and SO_(4)·HCO_(3)-Na·Ca type groundwater was formed in front of Keluke Lake.The results of deuterium(D)and 18O revealed that the groundwater mainly originated from the continuous accumulation of precipitation during geological history under cold and humid climate conditions.In addition,results of ^(14)C indicated that the groundwater age was more than 1140 years,implying relatively poor renewal capability of regional groundwater.Moreover,our numerical modeling results showed that the regional groundwater level will continue to rise under the warm and humid climate conditions.展开更多
Social responses to climate change over human history have been widely discussed in academia over the last two decades. However, the transformation of the human–environment nexus crossing prehistoric and historic per...Social responses to climate change over human history have been widely discussed in academia over the last two decades. However, the transformation of the human–environment nexus crossing prehistoric and historic periods and the processes associated with it are not yet clearly understood. In this study, based on published works on radiocarbon dating, archaeobotany, zooarchaeology, and archaeological sites, together with a synthesis of historical documents and highresolution paleoclimatic records, we trace the extent to which human settlement patterns in the Hexi Corridor in northwestern China evolved in conjunction with climate change over the last 5,000 years. A total of 129 Neolithic, 126 Bronze Age, and 1,378 historical sites in the Hexi Corridor(n=1,633) were surveyed. Our results show that, in the Late Neolithic and Bronze Age periods(~2800–100 BC), climate change contributed to the transformation of subsistence strategies and the subsequent changes in human settlement patterns in the Hexi Corridor. The warm-humid climate in ~2800–2000 BC promoted millet agriculture and helped the Majiayao, Banshan, and Machang Cultures to flourish. The cold-dry climate in ~2000–100 BC resulted in the divergence and transformation of subsistence strategies in the Xichengyi–Qijia–Siba and Shajing–Shanma Cultures and in a shift in their settlement patterns. However, in the historical period(121 BC–AD 1911), human settlement patterns were primarily determined by geopolitics related to the alternating rule of regimes and frequent wars, especially in the Sui–Tang dynasties. We also find that trans-Eurasian cultural exchange since ~2000 BC improved social resilience to climate change in the Hexi Corridor, mediating the human–environment nexus there. Our findings may provide insights into how human societies reacted to climate change in arid and semi-arid environments over the long term.展开更多
Using high-precision zircon U-Pb ID-TIMS geochronology,tuffs from the Chang 9 shale and the Chang 7 shale were dated.The tuff in the Chang 9 shale is 241.47±0.17 Ma,which falls between the top tuff age of 241.06&...Using high-precision zircon U-Pb ID-TIMS geochronology,tuffs from the Chang 9 shale and the Chang 7 shale were dated.The tuff in the Chang 9 shale is 241.47±0.17 Ma,which falls between the top tuff age of 241.06±0.12 Ma and the bottom tuff age of 241.558±0.093 Ma in the Chang 7 shale.These reveal that the Chang 9 and Chang 7 shales are contemporaneous,belonging to the Ladinian stage of the Middle Triassic.This insight expands the region of the main source rock of Chang 7 to the northeast and will inform the search for the deep Chang 9 shale petroleum system,increasing the scope for exploring the Chang 7 shale system in northern Shaanxi.The research results clarify the relationship between the two sets of shale in the Yanchang Formation and redefine the distribution range of the Chang 7 shale in the Ordos Basin.At the same time,it shows that there is a cross-layer problem in the stratigraphic division of the Yanchang Formation in different regions,the high-precision U-Pb dating technology providing a reference for the fine stratigraphic correlation of other continental basins in the world.展开更多
On the basis of the geomorphology, paleosol, paleoclimate and loess age, major changes of the Loess Plateau were studied. There are five major changes in the evolution of the Loess Plateau in China. Among them, the fi...On the basis of the geomorphology, paleosol, paleoclimate and loess age, major changes of the Loess Plateau were studied. There are five major changes in the evolution of the Loess Plateau in China. Among them, the first, second, third and fourth major changes have taken place since the formation of the Loess Plateau, and the fifth major change will happen in 100 years. The first major change, which occurred at about 2.50 Ma BP, was a transition from red earth plateau to the Loess Plateau, and reflects the climate from the warm-sub-humid to the alteration between cold-and-dry and warm-and-humid. The driving force of this first major change was climate. The second major change, which took place at about 1.60 Ma BP, was a vital transition of the main rivers in this area from non-existence to existence, and represented an important change on the Loess Plateau's neotectonic uplift from the slow rising to periodically accelerated rising, and making the river's erosion go from feeble to strong. The driving force of the second major change is tectonic uplift. The third major change which occurred at about 150 ka, was a great transition of the Yellow River's inpouring from a lake outlet to a sea outlet. At that time, the Yellow River cut the Sanmen Gorge. The transition led to the transformation of loess material from internal transportation to external transportation. The driving force of the third major change was running water erosion. The fourth one that occurred at about 1.1 ka was a change of the Loess Plateau from natural erosion to erosion accelerated by human influences. The driving force of the fourth major change is mainly human activities. The fifth major change, which is the opposite change to the fourth one, in which the motive power is human activity, too.展开更多
Hyperlipidemia prevention intervention for behavior change was conducted on subjects in their 30s and 40s to evaluate changes in health behavior and investigate the effectiveness of these changes, with respect to earl...Hyperlipidemia prevention intervention for behavior change was conducted on subjects in their 30s and 40s to evaluate changes in health behavior and investigate the effectiveness of these changes, with respect to early prevention and improvement of disease. Subjects were middle-aged individuals aged 30 - 49, suffering from serum lipid abnormalities. Intervention designed to affect behavior change was implemented for 3 weeks in 11 employees (nine males, two females) at five workplaces. Intervention mainly consisted of improving self-efficacy. The study’s purpose was explained and the written consent was obtained from subjects. Subjects filled questionnaires (characteristics, history of present illness, health behavior, self-efficacy scale for prevention of hyperlipidemia, etc.) both before and after intervention. Subjects recorded their physical activity using accelerometers and dietary intake photographically. Each subject created realistic behavior goals and recorded their progress using self-monitoring charts. Data were analyzed using descriptive statistics;therefore, pre- and post-intervention data were compared. Physical activity and achievement rate of goals during the first week and over the next 2 - 3 weeks were compared. Health behavior scores showed modification of behavior in a desirable direction after intervention compared with those before intervention. No significant difference in self-efficacy before and after intervention was observed. However, the subscale for diet was significantly higher after intervention compared with that before intervention. Steps, total calories, and activity calories were increased in the second and third weeks compared with those in the first week. Three weeks of intervention resulted in health behavior changing in a desirable direction. We infer that intervention in the form of self-monitoring using accelerometers that make physical activity visible was effective in leading to behavior change.展开更多
Background:Forest is the largest biomass carbon(C)pool in China,taking up a substantial amount of atmospheric carbon dioxide.Although it is well understood that planted forests(PFs)act as a large C sink,the contributi...Background:Forest is the largest biomass carbon(C)pool in China,taking up a substantial amount of atmospheric carbon dioxide.Although it is well understood that planted forests(PFs)act as a large C sink,the contribution of human management to C storage enhancement remains obscure.Moreover,existing projections of forest C dynamics suffer from spatially inconsistent age and type information or neglected human management impacts.In this study,using developed PF age and type maps and data collected from 1371 forest plantation sites in China,we simulated biomass C stock change and quantified management impacts for the time period 2010-2050.Results:Results show that future forest biomass C increment might have been overestimated by 32.5%-107.5% in former studies.We also found that age-related growth will be by far the largest contributor to PF biomass C increment from 2010 to 2050(1.23±0.002 Pg C,1 Pg=10^(15) g=1 billion metric tons),followed by the impact of human management(0.57±0.02 Pg C),while the contribution of climate is slight(0.087±0.04 Pg C).Besides,an additional 0.24±0.07 Pg C can be stored if current PFs are all managed by 2050,resulting in a total increase of 2.13±0.05 Pg C.Conclusions:Forest management and age-related growth dominate the biomass C change in PFs,while the effect of climatic factors on the accumulation is minor.To achieve the ambitious goal of forest C stock enhancement by 3.5 Pg from 2020 to 2050,we advocate to improve the management of existing forests and reduce the requests for more lands for forest expansion,which helps mitigate potential conflicts with agricultural sectors.Our results highlight that appropriate planning and management are required for sustaining and enhancing biomass C sequestration in China’s PF.展开更多
The instantaneous total mortality rate(Z) of a fish population is one of the important parameters in fisheries stock assessment. The estimation of Z is crucial to fish population dynamics analysis,abundance and catch ...The instantaneous total mortality rate(Z) of a fish population is one of the important parameters in fisheries stock assessment. The estimation of Z is crucial to fish population dynamics analysis,abundance and catch forecast,and fisheries management. A catch curve-based method for estimating time-based Z and its change trend from catch per unit effort(CPUE) data of multiple cohorts is developed. Unlike the traditional catch-curve method,the method developed here does not need the assumption of constant Z throughout the time,but the Z values in n continuous years are assumed constant,and then the Z values in different n continuous years are estimated using the age-based CPUE data within these years. The results of the simulation analyses show that the trends of the estimated time-based Z are consistent with the trends of the true Z,and the estimated rates of change from this approach are close to the true change rates(the relative differences between the change rates of the estimated Z and the true Z are smaller than 10%). Variations of both Z and recruitment can affect the estimates of Z value and the trend of Z. The most appropriate value of n can be different given the effects of different factors. Therefore,the appropriate value of n for different fisheries should be determined through a simulation analysis as we demonstrated in this study. Further analyses suggested that selectivity and age estimation are also two factors that can affect the estimated Z values if there is error in either of them,but the estimated change rates of Z are still close to the true change rates. We also applied this approach to the Atlantic cod(G adus morhua) fishery of eastern Newfoundland and Labrador from 1983 to 1997,and obtained reasonable estimates of time-based Z.展开更多
Cell lines with high passage numbers exhibit alterations in cell morphology and functions.In thepresent work,C2C12 skeletal muscle cells with either low(<20)or high(>60)passage numbers(identified as l-C2C12 or h...Cell lines with high passage numbers exhibit alterations in cell morphology and functions.In thepresent work,C2C12 skeletal muscle cells with either low(<20)or high(>60)passage numbers(identified as l-C2C12 or h-C2C12,respectively)were used to investigate the apoptotic response to H2O2 as a function ofculture age h-C2C12.We found that older cultures(h-C2C12 group)were depleted of mitochondrial DNA(mtDNA).When we analyzed the behavior of Bad,Bax,caspase-3 and mitochondrial transmembrane potential,we observed that cells in the h-C2C12 group were resistant to H2O2 induction of apoptosis.We propose seriallycultured C2C12 cells as a refractory model to H2O2-induced apoptosis.In addition,the data obtained in thiswork suggest that mtDNA is required for apoptotic cell death in skeletal muscle C2C12 cells.展开更多
The care of the elderly is both a human basic human rights and a manifestation of social civilization. "Family pension" has always been the main pension model in China for thousands of years. However, with the trans...The care of the elderly is both a human basic human rights and a manifestation of social civilization. "Family pension" has always been the main pension model in China for thousands of years. However, with the transformation of social structure and population structure, the traditional "family pension" model is facing increasing challenges. While other emerging "institutions pension", "community pension" and failed to become a "family pension" alternative options, the role is limited. With the development of a variety of integrated technology, a new integrated technology based on the wisdom of the pension model began to emerge, wisdom pension as a new pension model has been in China with a preliminary attempt, it can maximize the elimination of the Chinese labor force The risk of population loss, the greatest extent to meet the needs of the elderly, the risk of dealing with old age, improve pension efficiency, and give the elderly equalization of power and ability, so as to fundamentally enhance the subjectivity of the elderly. But as a new exploration, but also faced with manyproblems, it is worth our in-depth thinking.展开更多
Through comparing the data collected in different time, this paper explores the changes of Chinese compliments and compliment responses during the recent fifteen years, and also studies the differences of compliments ...Through comparing the data collected in different time, this paper explores the changes of Chinese compliments and compliment responses during the recent fifteen years, and also studies the differences of compliments and compliment responses among different genders and generations as well as different cultures in order to have a better communication and to better adapt in these rapidly developed world.展开更多
The climatic change since the Little Ice Age recorded in the Dunde Ice Cap is presentedin this paper. There have been three cold periods and three warm periods since 1400AD.Among them, the coldest one was in the 17th ...The climatic change since the Little Ice Age recorded in the Dunde Ice Cap is presentedin this paper. There have been three cold periods and three warm periods since 1400AD.Among them, the coldest one was in the 17th century. Many evidences verified the three coldand warm variations recorded in the Dundc Ice Cap. But it was found from the comparison between the Dunde Icc Cap climatic record and thewinter temperature record in Shanghai that there was a temporal dfference in climatic changebetween East China and West China. The general trend is that the cooling and warmingprocesses in West China were earlier than that in East China. In the Dunde Ice Cap, it isnow in an anomalous warm period, while it is not as warm as in Dunde Ice Cap recordaccording to the winter temperature in Shanghai. In addition to the possible cause of temporaldifference in climatic change between West China and East China, another possible cause isthat the greenhouse effect of CO_2 may already be recognizable in the Dunde Ice Cap arealocated in Western China in land of the middle latitude.展开更多
This study analyzes change in carbon storage by applying forest growth models and final cutting age to actual and potential forest cover for six major tree species in South Korea. Using National Forest Inventory data,...This study analyzes change in carbon storage by applying forest growth models and final cutting age to actual and potential forest cover for six major tree species in South Korea. Using National Forest Inventory data, the growth models were developed to estimate mean diameter at breast height, tree height, and number of trees for Pinus densiflora, Pinus koraiensis, Pinus rigida, Larix kaernpferi, Castanea crenata and Quercus spp. stands. We assumed that actual forest cover in a forest type map will change into potential forest covers according to the Hydrological and Thermal Analogy Groups model. When actual forest cover reaches the final cutting age, forest volume and carbon storage are estimated by changed forest cover and its growth model. Forest volume between 2010 and 2110 would increase from 126.73 to 157.33 m^3 hm^-2. Our results also show that forest cover, volume, and carbon storage could abruptly change by 2060. This is attributed to the fact that most forests are presumed to reach final cutting age. To avoid such dramatic change, a regeneration and yield control scheme should be prepared and implemented in a way that ensures balance in forest practice and yield.展开更多
文摘AIM: To study the dynamic character of aberration between the cornea and the ocular with aging, and to evaluate the symmetry of the aberrations between right and left eye in order to supply the data for clinic to do the refractive surgery reasonably. METHODS: This is a comparative case series study. 82 normal cases (164 eyes) including 37 females (74 eyes) and 45 males (90 eyes) were recruited through the routine examinations,Topolyzer and wavefront analysis. The average age was 25.9 +/- 5.0 years old (range 18 to 49 years old), and the mean spherical equivalent (SE) is -3.82 +/- 2.21D (range -1.00 to -6.00D). The changes of aberrations regarding age, the relationship between anterior corneal and total aberrations were analyzed,as well as the symmetry between right and left eyes by using Zernike terms. RESULTS: The Z (3) (1), RMS3 of corneal aberrations, Z (3) (1), Z (4) (0) RMS3 and RMS4 of ocular aberrations had a positive correlation with age. The zernike terms both in corneal and whole eye were significantly correlated between right and left eyes. CONCLUSION: The corneal horizontal coma, ocular horizontal coma and ocular spherical aberrations become to increase at the age of more than 40 years old. The dynamic change of aberration with aging, balance between corneal and ocular, and the symmetric character between left eye and right eye should be designed carefully in the treatment nomogram before the refractive surgery.
文摘This research advocates for the construction of Climate Change Haven Communities across the Appalachian Region. The proposed development plan can be extended to the northern tier states across the US and also to the northern and mountainous regions of Europe and Asia. We present an analogy to the earlier climate change period of the Last Glacial Maximum/“Ice Age” in which these same northern regions of the planet were covered in ice sheets making them uninhabitable for most humans and many plant and animal species. In some significant ways, the Ice Age scenario can be a reverse-model for our current climate crisis. We also advocate strongly for the prevention of upscale real estate development projects in these same regions of the globe, as these will foreclose the possibility of safely sheltering the millions of persons who will be displaced by climate change over the next 5 to 10 years.
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.
文摘Language change is universally acknowledged and has become the major tenet of sociolinguistics. Language change occurs in different ways and places for different reasons. The social factors which language change is tied to are complicated complex including: social class, sex, age and so on. Among them the first three are seen as fixed categories that remain stable in the research of language change and also are the factors will be discussed in this paper. The purpose of this piece of paper is to examine the language change affected by the three main social factors and the standardization and to provide a clear and helpful overview of the relationship of language change and society. It will also point out the weak points in every aspect therefore provides more insight to the further researches in this field.
基金This research was supported by the Strategic Priority Research Program of Chinese Academy of Sciences (Grant No. XDA20090000)the National Natural Science Foundation of China (Grants 41901103)the Foundation for Excellent Youth Scholars of "Northwest Institute of Eco-Environment and Resources", CAS
文摘Reconstructions of past climatic changes on the northeastern Tibetan Plateau(NETP) can provide insights into the Asian summer monsoon(ASM) variability. However, the regional climate changes on both orbital and suborbital time scales since the late Glacial remain controversial. Here we present the results of high-resolution geochemical and grain-size analyses of a sediment core from Genggahai Lake, a small, shallow lake in this area. Changes of the accumulation rate of the core sediments show a similar trend with variations of the coarse fraction. Accordingly, the chronological framework is constructed using a grain-size age model. In addition, the histories of chemical weathering and aeolian activity since the late Glacial are reconstructed based on the Al/Ti ratios and coarse fractions, respectively. The results suggest that an enhanced chemical weathering and a weakened aeolian activity occurred on the NETP under a warmer, wetter climate during the early to mid-Holocene(11.3–6.3 ka cal BP), compared with the late Glacial(17.1–11.3 ka cal BP) and the late Holocene(6.3 ka cal BP to present), which responded mainly to the strengthened ASM on orbital time scale. In addition, the synchronous occurrences of weakened chemical weathering, low lake level and intense aeolian activity on suborbital time scale reflect several episodes of weakened ASM. Furthermore, these episodes largely coincide with the centennial-to millennial-scale cold events in the North Atlantic, which demonstrates the close connection between the ASM and the cooling at high latitudes.
文摘Purpose: Cervical spine is considered to be the most moving part of vertebral column. It is located in a very important part of the body i.e. neck having some very important structures related to it. Any age related changes occurring in such a part of vertebral column may lead to many disorders and disabilities. Complete familiarity of this entire region anatomically as well as radiologically is therefore of utmost importance for the diagnosis and management of such disorders. Aim of this work is to evaluate the frequency of age related degeneration in cervical spine in Saudi adult asymptomatic subjects using CT scan images. Methods: In this study, 105 cases of symptomless adults ranging between 18 - 90 years of age were included. The cases were classified into 3 groups;adult group (18 - 35 years old), middle age group (36 - 55 years old) and old age group (56 - 90 years old). Their CT scans were performed in the department of radiology, King Khalid Hospital, Al Kharj and studied for any age related changes. Results: The first age group category included 35 cases;20 had normal and 15 degenerative changes. The second category included 35 cases;3 had normal and 32 degenerative changes. The third category included 35 cases. Single had normal and 34 degenerative changes. Conclusion: Asymptomatic degenerative changes are common in the cervical spine after 30 years of age in Saudi adult asymptomatic subjects.
文摘For a long time, China has large population, so the labor-intensive products become the comparative advantage.This paper analyzes the influences of population age structure's changes on the export commodity structure of our country and draws conclusions.
文摘Objective To determine the extent of the obesity epidemic in school‐aged Chinese children in 2010 and track the increasing trend in different socioeconomic regions over the preceding 25 years. Strategies for preventing childhood obesity are suggested. Methods We used a dataset provided by the Chinese National Survey on Students’ Constitution and Health from 1985‐2010. Subjects were 7‐18‐year‐old students randomly selected from urban and rural areas in 30 provinces. Eight subgroups were created according to region and socioeconomic status. Results Increased rates of the epidemic (overweight and obesity combined) were greatest in large coastal cities‐32.6% and 19.1% among males and females, respectively. These rates has neared that of developed countries. Similar increases were found in all other regions, including the once poverty‐stricken rural west. The epidemic in most of the rural areas began after 2000, but has spread swiftly over the last decade. In 2010, it was estimated that 9.9% of Chinese school‐aged children and adolescents were overweight and that an additional 5.1% were obese, representing an estimated 30.43 million individuals. Conclusion The prognosis for China's childhood‐obesity epidemic is dire. To prevent childhood obesity, we suggest several strategies, including reasonable dietary intake, increase physical activity, a change in sedentary lifestyles and corresponding behavioral modifications.
基金This work was supported by the National Natural Science Foundation of China(41672243)the China Geological Survey Program(DD20160291,DD20189270).
文摘Delingha is located in the northeast margin of Qaidam Basin.Bayin River alluvial proluvial fan is the main aquifer of Delingha,in which groundwater generally flows from north to south.The hydrochemistry results showed that two different hydrochemical evolution paths formed along southeast and southwest directions,respectively.Cl-Na type groundwater was formed in front of Gahai Lake,and SO_(4)·HCO_(3)-Na·Ca type groundwater was formed in front of Keluke Lake.The results of deuterium(D)and 18O revealed that the groundwater mainly originated from the continuous accumulation of precipitation during geological history under cold and humid climate conditions.In addition,results of ^(14)C indicated that the groundwater age was more than 1140 years,implying relatively poor renewal capability of regional groundwater.Moreover,our numerical modeling results showed that the regional groundwater level will continue to rise under the warm and humid climate conditions.
基金This study was supported by the National key R&D Program of China(Grant 2018YFA0606402)the Strategic Priority Research Program of Chinese Academy of Sciences,Pan-Third Pole,Environment Study for a Green Silk Road(Pan-TPE)(grant no.XDA20040101)+2 种基金the second Tibetan Plateau Scientific Expedition and Research Program(STEP)(Grant No.SQ2019QZKK2201)the Improvement on Competitiveness in Hiring New Faculties Funding Scheme(4930900)Direct Grant for Research 2018/19(4052199)of the Chinese University of Hong Kong.
文摘Social responses to climate change over human history have been widely discussed in academia over the last two decades. However, the transformation of the human–environment nexus crossing prehistoric and historic periods and the processes associated with it are not yet clearly understood. In this study, based on published works on radiocarbon dating, archaeobotany, zooarchaeology, and archaeological sites, together with a synthesis of historical documents and highresolution paleoclimatic records, we trace the extent to which human settlement patterns in the Hexi Corridor in northwestern China evolved in conjunction with climate change over the last 5,000 years. A total of 129 Neolithic, 126 Bronze Age, and 1,378 historical sites in the Hexi Corridor(n=1,633) were surveyed. Our results show that, in the Late Neolithic and Bronze Age periods(~2800–100 BC), climate change contributed to the transformation of subsistence strategies and the subsequent changes in human settlement patterns in the Hexi Corridor. The warm-humid climate in ~2800–2000 BC promoted millet agriculture and helped the Majiayao, Banshan, and Machang Cultures to flourish. The cold-dry climate in ~2000–100 BC resulted in the divergence and transformation of subsistence strategies in the Xichengyi–Qijia–Siba and Shajing–Shanma Cultures and in a shift in their settlement patterns. However, in the historical period(121 BC–AD 1911), human settlement patterns were primarily determined by geopolitics related to the alternating rule of regimes and frequent wars, especially in the Sui–Tang dynasties. We also find that trans-Eurasian cultural exchange since ~2000 BC improved social resilience to climate change in the Hexi Corridor, mediating the human–environment nexus there. Our findings may provide insights into how human societies reacted to climate change in arid and semi-arid environments over the long term.
基金supported by the Research Program of the Research Institute of Petroleum Exploration and Development of the Changqing Oilfield(Grant No.J2019168)。
文摘Using high-precision zircon U-Pb ID-TIMS geochronology,tuffs from the Chang 9 shale and the Chang 7 shale were dated.The tuff in the Chang 9 shale is 241.47±0.17 Ma,which falls between the top tuff age of 241.06±0.12 Ma and the bottom tuff age of 241.558±0.093 Ma in the Chang 7 shale.These reveal that the Chang 9 and Chang 7 shales are contemporaneous,belonging to the Ladinian stage of the Middle Triassic.This insight expands the region of the main source rock of Chang 7 to the northeast and will inform the search for the deep Chang 9 shale petroleum system,increasing the scope for exploring the Chang 7 shale system in northern Shaanxi.The research results clarify the relationship between the two sets of shale in the Yanchang Formation and redefine the distribution range of the Chang 7 shale in the Ordos Basin.At the same time,it shows that there is a cross-layer problem in the stratigraphic division of the Yanchang Formation in different regions,the high-precision U-Pb dating technology providing a reference for the fine stratigraphic correlation of other continental basins in the world.
文摘On the basis of the geomorphology, paleosol, paleoclimate and loess age, major changes of the Loess Plateau were studied. There are five major changes in the evolution of the Loess Plateau in China. Among them, the first, second, third and fourth major changes have taken place since the formation of the Loess Plateau, and the fifth major change will happen in 100 years. The first major change, which occurred at about 2.50 Ma BP, was a transition from red earth plateau to the Loess Plateau, and reflects the climate from the warm-sub-humid to the alteration between cold-and-dry and warm-and-humid. The driving force of this first major change was climate. The second major change, which took place at about 1.60 Ma BP, was a vital transition of the main rivers in this area from non-existence to existence, and represented an important change on the Loess Plateau's neotectonic uplift from the slow rising to periodically accelerated rising, and making the river's erosion go from feeble to strong. The driving force of the second major change is tectonic uplift. The third major change which occurred at about 150 ka, was a great transition of the Yellow River's inpouring from a lake outlet to a sea outlet. At that time, the Yellow River cut the Sanmen Gorge. The transition led to the transformation of loess material from internal transportation to external transportation. The driving force of the third major change was running water erosion. The fourth one that occurred at about 1.1 ka was a change of the Loess Plateau from natural erosion to erosion accelerated by human influences. The driving force of the fourth major change is mainly human activities. The fifth major change, which is the opposite change to the fourth one, in which the motive power is human activity, too.
文摘Hyperlipidemia prevention intervention for behavior change was conducted on subjects in their 30s and 40s to evaluate changes in health behavior and investigate the effectiveness of these changes, with respect to early prevention and improvement of disease. Subjects were middle-aged individuals aged 30 - 49, suffering from serum lipid abnormalities. Intervention designed to affect behavior change was implemented for 3 weeks in 11 employees (nine males, two females) at five workplaces. Intervention mainly consisted of improving self-efficacy. The study’s purpose was explained and the written consent was obtained from subjects. Subjects filled questionnaires (characteristics, history of present illness, health behavior, self-efficacy scale for prevention of hyperlipidemia, etc.) both before and after intervention. Subjects recorded their physical activity using accelerometers and dietary intake photographically. Each subject created realistic behavior goals and recorded their progress using self-monitoring charts. Data were analyzed using descriptive statistics;therefore, pre- and post-intervention data were compared. Physical activity and achievement rate of goals during the first week and over the next 2 - 3 weeks were compared. Health behavior scores showed modification of behavior in a desirable direction after intervention compared with those before intervention. No significant difference in self-efficacy before and after intervention was observed. However, the subscale for diet was significantly higher after intervention compared with that before intervention. Steps, total calories, and activity calories were increased in the second and third weeks compared with those in the first week. Three weeks of intervention resulted in health behavior changing in a desirable direction. We infer that intervention in the form of self-monitoring using accelerometers that make physical activity visible was effective in leading to behavior change.
文摘Background:Forest is the largest biomass carbon(C)pool in China,taking up a substantial amount of atmospheric carbon dioxide.Although it is well understood that planted forests(PFs)act as a large C sink,the contribution of human management to C storage enhancement remains obscure.Moreover,existing projections of forest C dynamics suffer from spatially inconsistent age and type information or neglected human management impacts.In this study,using developed PF age and type maps and data collected from 1371 forest plantation sites in China,we simulated biomass C stock change and quantified management impacts for the time period 2010-2050.Results:Results show that future forest biomass C increment might have been overestimated by 32.5%-107.5% in former studies.We also found that age-related growth will be by far the largest contributor to PF biomass C increment from 2010 to 2050(1.23±0.002 Pg C,1 Pg=10^(15) g=1 billion metric tons),followed by the impact of human management(0.57±0.02 Pg C),while the contribution of climate is slight(0.087±0.04 Pg C).Besides,an additional 0.24±0.07 Pg C can be stored if current PFs are all managed by 2050,resulting in a total increase of 2.13±0.05 Pg C.Conclusions:Forest management and age-related growth dominate the biomass C change in PFs,while the effect of climatic factors on the accumulation is minor.To achieve the ambitious goal of forest C stock enhancement by 3.5 Pg from 2020 to 2050,we advocate to improve the management of existing forests and reduce the requests for more lands for forest expansion,which helps mitigate potential conflicts with agricultural sectors.Our results highlight that appropriate planning and management are required for sustaining and enhancing biomass C sequestration in China’s PF.
基金Supported by the USDA Cooperative State Research,Education and Extension Service,Hatch Project(No.0210510)the National Natural Science Foundations of China(Nos.31270527,40801225)+1 种基金the Natural Science Foundation of Zhejiang Province(No.LY13D010005)the Young Academic Leaders Climbing Program of Zhejiang Province(No.pd2013222)
文摘The instantaneous total mortality rate(Z) of a fish population is one of the important parameters in fisheries stock assessment. The estimation of Z is crucial to fish population dynamics analysis,abundance and catch forecast,and fisheries management. A catch curve-based method for estimating time-based Z and its change trend from catch per unit effort(CPUE) data of multiple cohorts is developed. Unlike the traditional catch-curve method,the method developed here does not need the assumption of constant Z throughout the time,but the Z values in n continuous years are assumed constant,and then the Z values in different n continuous years are estimated using the age-based CPUE data within these years. The results of the simulation analyses show that the trends of the estimated time-based Z are consistent with the trends of the true Z,and the estimated rates of change from this approach are close to the true change rates(the relative differences between the change rates of the estimated Z and the true Z are smaller than 10%). Variations of both Z and recruitment can affect the estimates of Z value and the trend of Z. The most appropriate value of n can be different given the effects of different factors. Therefore,the appropriate value of n for different fisheries should be determined through a simulation analysis as we demonstrated in this study. Further analyses suggested that selectivity and age estimation are also two factors that can affect the estimated Z values if there is error in either of them,but the estimated change rates of Z are still close to the true change rates. We also applied this approach to the Atlantic cod(G adus morhua) fishery of eastern Newfoundland and Labrador from 1983 to 1997,and obtained reasonable estimates of time-based Z.
基金supported by the NationalResearch Council of Argentina(CONICET)and theUniversidad Nacional del Sur,Argentina.
文摘Cell lines with high passage numbers exhibit alterations in cell morphology and functions.In thepresent work,C2C12 skeletal muscle cells with either low(<20)or high(>60)passage numbers(identified as l-C2C12 or h-C2C12,respectively)were used to investigate the apoptotic response to H2O2 as a function ofculture age h-C2C12.We found that older cultures(h-C2C12 group)were depleted of mitochondrial DNA(mtDNA).When we analyzed the behavior of Bad,Bax,caspase-3 and mitochondrial transmembrane potential,we observed that cells in the h-C2C12 group were resistant to H2O2 induction of apoptosis.We propose seriallycultured C2C12 cells as a refractory model to H2O2-induced apoptosis.In addition,the data obtained in thiswork suggest that mtDNA is required for apoptotic cell death in skeletal muscle C2C12 cells.
文摘The care of the elderly is both a human basic human rights and a manifestation of social civilization. "Family pension" has always been the main pension model in China for thousands of years. However, with the transformation of social structure and population structure, the traditional "family pension" model is facing increasing challenges. While other emerging "institutions pension", "community pension" and failed to become a "family pension" alternative options, the role is limited. With the development of a variety of integrated technology, a new integrated technology based on the wisdom of the pension model began to emerge, wisdom pension as a new pension model has been in China with a preliminary attempt, it can maximize the elimination of the Chinese labor force The risk of population loss, the greatest extent to meet the needs of the elderly, the risk of dealing with old age, improve pension efficiency, and give the elderly equalization of power and ability, so as to fundamentally enhance the subjectivity of the elderly. But as a new exploration, but also faced with manyproblems, it is worth our in-depth thinking.
文摘Through comparing the data collected in different time, this paper explores the changes of Chinese compliments and compliment responses during the recent fifteen years, and also studies the differences of compliments and compliment responses among different genders and generations as well as different cultures in order to have a better communication and to better adapt in these rapidly developed world.
文摘The climatic change since the Little Ice Age recorded in the Dunde Ice Cap is presentedin this paper. There have been three cold periods and three warm periods since 1400AD.Among them, the coldest one was in the 17th century. Many evidences verified the three coldand warm variations recorded in the Dundc Ice Cap. But it was found from the comparison between the Dunde Icc Cap climatic record and thewinter temperature record in Shanghai that there was a temporal dfference in climatic changebetween East China and West China. The general trend is that the cooling and warmingprocesses in West China were earlier than that in East China. In the Dunde Ice Cap, it isnow in an anomalous warm period, while it is not as warm as in Dunde Ice Cap recordaccording to the winter temperature in Shanghai. In addition to the possible cause of temporaldifference in climatic change between West China and East China, another possible cause isthat the greenhouse effect of CO_2 may already be recognizable in the Dunde Ice Cap arealocated in Western China in land of the middle latitude.
基金supported by"Developing Forest Management Model for Climate Change Adaptation"(FE 0100-2009-01)provided by the Korea Forest Research Institutesupported by"Climate Change Correspondence Program"(2014001310008)provided by Ministry of Environment,Korea
文摘This study analyzes change in carbon storage by applying forest growth models and final cutting age to actual and potential forest cover for six major tree species in South Korea. Using National Forest Inventory data, the growth models were developed to estimate mean diameter at breast height, tree height, and number of trees for Pinus densiflora, Pinus koraiensis, Pinus rigida, Larix kaernpferi, Castanea crenata and Quercus spp. stands. We assumed that actual forest cover in a forest type map will change into potential forest covers according to the Hydrological and Thermal Analogy Groups model. When actual forest cover reaches the final cutting age, forest volume and carbon storage are estimated by changed forest cover and its growth model. Forest volume between 2010 and 2110 would increase from 126.73 to 157.33 m^3 hm^-2. Our results also show that forest cover, volume, and carbon storage could abruptly change by 2060. This is attributed to the fact that most forests are presumed to reach final cutting age. To avoid such dramatic change, a regeneration and yield control scheme should be prepared and implemented in a way that ensures balance in forest practice and yield.