Photosynthetic Physiological Response to Drought Stress of Populus euphratica at Different Ages in Minqin

[Objectives]This study was conducted to investigate the photosynthetic physiological characteristics of Populus euphratica trees at different forest ages in the desert area of Minqin in response to drought stress.[Methods]With P.euphratica trees of different ages in Minqin as the research object,the water characteristics and photosynthetic physiological indexes(chlorophyll,soluble sugar,POD,SOD and MDA)were compared under different conditions.[Results]On the time gradient,the soil water contents of P.euphratica of different ages decreased continuously with the extension of irrigation stop time,but the decreases were small.Under the same stress treatment,the soil water contents of P.euphratica of different ages increased with the deepening of soil layer,but the differences were not significant(P>0.05).Under normal condition,the chlorophyll contents of P.euphratica at three ages gradually increased with the increase of age.The chlorophyll contents in leaves of P.euphratica at different ages were all lower under normal condition and higher under water stress.The changes of POD and SOD activity in leaves of P.euphratica at different ages under different conditions were basically the same,showing that the enzyme activity was higher under water stress than under normal under.The MDA contents in leaves of the young and middle P.euphratica forests were higher under water stress at 7 and 21 d than under normal condition,and the differences were not significant(P>0.05);and the MDA content in leaves of the mature P.euphratica forest was higher under water stress at 21 and 35 d than under normal condition.Drought stress has a certain effect on the photosynthetic physiological characteristics of P.euphratica.In summary,under drought stress,the chlorophyll content,SOD and POD activity,and MDA molar concentration in the leaves of P.euphratica were basically higher than under normal condition,indicating that P.euphratica could resist drought environment through osmotic adjustment and showed strong drought resistance.[Conclusions]This study provides a theoretical reference for the restoration,protection and reconstruction of natural P.euphratica forests in the desert area of Minqin.

Effect of Acetaldehyde on Oxidoreductases in Tissues of Rats at Different Ages

The toxicity of acetaldehyde and age related changes on oxidoreductases in the liver,brain, kidney, and musele of female albino rats (Wistar strain) were studied. The specific activities of lactate [LDH], isocitrate [ICDH (NAD/NADP)], succinate [SDH], malate [MDH], glutamate [GDH] and glucose-6-Phosphate [G-6-PDH] dehydrogenases were signifieantly inereased as a function of age. However, acetaldehyde treatment significantly inhibited oxidoreductases in the tissues of 21, 90 and 180 day old rats. Liver enzymes of young (21 days) rats exhibited greater sensitivity to acetaldehyde toxicity. Similar inhibition of oxidoreductases in brain and kidney of adult (180 days) rats treated with acetaldehyde was observed. LDH and GDH as compared to other enzymes studied showed higher susceptibility to acetaldehyde toxicity. The differential sensitivity of tissues and inhibition of oxidoreductases by acetaldehyde as a function of age could be attributed to hypoxic conditions, energy crisis, and mitochondrial structural changes. The results suggest that acetaldehyde affects oxidation of glucose via HMP shuni pathway, glycolytic pathway and Krebs cycle resulting in the impairment of carbohydrate metabolism

Willingness of People of Different Ages to Learn Online——Taking Guizhou Cadre Online Learning School as an Example

The method of statistical analysis is employed in this paper to research the interests of online cadre learners, including learners from administrative organizations directly governed by the provincial government, Zunyi city and the state-owned enterprises directly governed by the provincial government in 2011 through the courseware of Guizhou Cadre Online Learning School. The difference in willingness to study in this manner between people of differing ages is examined through data analysis.

The Influence of Depression on Different Age and Gender Groups in Bahawalpur

In Bahawalpur,a cross-sectional study assessed depression prevalence across age and gender groups,involving 442 participants from diverse socioeconomic backgrounds and settings.Utilizing the PHQ9 questionnaire,84%were found to meet depression levels.The findings revealed a higher incidence in females(88%)than males(79%),with the greatest disparity among young adults,particularly young women,due to factors like academic pressure and financial stress.School children had the lowest depression rates(68%),possibly due to better immunity.Elderly individuals exhibited more severe depression,likely related to aging and domestic challenges.The study’s findings highlight a significant variation in depression severity across different demographic groups,with an overall higher incidence in women.The research underscores the necessity for targeted mental health resources and interventions tailored to the specific needs of each demographic group.It also points to the importance of addressing academic and socioeconomic stressors to mitigate depression,particularly among young women.While the study provides valuable insights,it relies on self-reported data,which may introduce bias.Therefore,future research should include clinical assessments to validate these findings and ensure a more accurate representation of depression within the community.

Characteristics of Soil Organic Carbon and Total Nitrogen in Rubber Plantations Soil at Different Age Stages in the Western Region of Hainan Island

[Objective]The aim was to study on the characteristics of soil organic carbon and nitrogen in rubber （Hevea brasiliensis Muell-Arg） plantations at different age stages in the western region of Hainan Island,so as to evaluate the ecological benefits of rubber plantations and provide basic data for studying the effect of tropical land utilization/cover change on the global carbon and nitrogen cycle. [Method]The situs was in Danzhou city,western region of Hainan Island,and the samples were four kinds of rubber plantations soil at different ages and one kind of control check （pepper,Piper nigrum L.） soil. In this research,four quadrats were set up in each sample,and the size of each was 20 cm×20 cm. Four specimens were gathered from four layers of 0-15,15-30,30-45,45-60,and the average of them was the last analysis result of each sample. Soil density was measured by cutting ring method,soil containing and hygroscopic water was detected by oven drying method,soil organic carbon （SOC） was measured by low temperature heated outside potassium dichromate oxidation-colorimetry method,and soil total nitrogen （STN） was detected by semimicro Kjeldahl method. [Result]SOC contents of different layers in rubber plantations soil at different age stages （including the CK pepper soil,the same as below） varied little,and the content of SOC in surface layer （0-15 cm） was higher,while the underlayer （45-60 cm） was lower than the average value; there was significant difference in SOC content among different kinds of soil,and the content was of 6.03-7.78 g/kg,tapping young trees （7 years） CK pepper mature age trees （30 years） prophase of young trees （2 years） tapping trees （16 years）; there was no significant difference in SOC storage among different kinds of soil,and the storage was of 61.33-74.29 t/hm2,mature age trees （30 years） tapping young trees （7 years） prophase of young trees （2 years） CK pepper tapping trees （16 years）; there was significant difference in STN content among rubber plantations soil at different age stages,the content was of 410.86-664.14 mg/kg2,CK pepper tapping young trees （7 years） prophase of young trees （2 years） mature age trees （30 years） tapping trees （16 years）,and STN content of tapping trees （16 years） soil was extremely lowest; there was significant difference in C/N ratio among different kinds of soil,the ratio was of 10.94-14.47,and the ratio of tapping trees （16 years） mature age trees （30 years） tapping young trees （7 years） CK pepper prophase of young trees （2 years）. [Conclusion]There wasn＇t unhealthy effect of rubber trees planted in tropical area on the content and storage of SOC,the content of STN and the ratio of C/N. there was no significant difference between rubber plantations and CK pepper soil,and the effects of rubber plantation on soil carbon-nitrogen was similar to that of other tropical crops （such as pepper）.

Characterization of refuse landfill leachates of three different stages in landfill stabilization process

Landfill leachates with different ages （mature leachate, 11 years; semi-mature leachate, 5 years; fresh leachate, under operation） were collected from Laogang Refuse Landfill, Shanghai to characterize the colloid size distribution and variations of leachate. These leachates were separated using micro-filtration and ultra-filtration into specific size fractions, i.e., suspended particles （SP） （〉 1.2 μm）, coarse colloids （CC） （1.2-0.45 μm）, fine colloids （FC） （0.45 m, 5 kDa/1 kDa molecular weight （MW））, and dissolved organic matters （DM, 〈 5 kDa/1 kDa MW）. The specific colloids in each size fraction were quantified and characterized through chemical oxygen demands （COD）, total solid （TS）, pH, NH4^＋-N, total organic carbon （TOC） and fixed solid （FS）. It was found that COD, NH^4＋-N and TS in leachate decreased significantly over ages, while pH increased. The dissolved fractions （〈 5 kDa/1 kDa） dominated （over 50%） in three leachates in terms of COD, and the organic matter content in dissolved fraction of leachates decreased and the inorganic matter increased as the disposal time extended, with the TOC/COD ratio 30%-7%. Dissolved fractions decreased from 82% to 40% in terms of TOC as the disposal time extended, suggested that the organic matter remained in leachate would form into middle molecular weight substances during the degradation process.

Comparison of Treatment Effect of Resperidone on First-Episode Schizophrenia Patients at Different Ages and its Influencing Factor Analysis

Objectives To explore the treatment effect of risperidone on patients with firstepisode schizophrenia at different ages and analyze its influencing factors.Methods fifty cases of adult patients with the first-episode schizophrenia(adult group)and forty cases of juvenile patients with the firstepisode schizophrenia(juvenile group)treated in our hospital from March 2013 to March 2015 were selected for oral administration of risperidone.The clinical efficacy,adverse effect,brief psychiatric rating scale(BPRS)score before and after the therapy,brain-derived neurotrophic factor(BDNF)and blood lipid level were compared between the two groups after eight weeks’treatment with risperidone,and meanwhile,the multivariable linear regression analysis was performed to the related factors possibly influencing the efficacy of risperidone.Results The difference of total effective rate between the adult group(86%)and the juvenile group(82.5%)was not significant(P>0.05).The total score of BPRS,TC,TG,and LDL-C levels in the two groups after the treatment were significantly decreased compared with that before the treatment,while BDNF was significantly increased.The difference of inter-group comparison was significant before and after the treatment(P>0.05).However,the comparison difference between two groups was not significant before and after the treatment(P>0.05).The multivariable linear regression equation was used to analyze the longer duration of untreated psychosis(DUP),BPRS total score before treatment and BDNF levels that influence the efficacy of risperidone on patients with schizophrenia.Conclusion the treatment efficacy of risperidone on adult patients and juvenile patients with first-episode schizophrenia was similar and it was safe and effective.The DUP,BPRS total score before treatment and BDNF levels were associated with the efficacy of risperidone.

N,P,and K characteristics of different age groups of temperate coniferous tree species in northwestern China

This study chose dominant tree species including Picea crassifolia,Pinus armandii and Pinus tabuliformis which are distributed in Qilian Mountains,Xiaolongshan Mountains,and Bailongjiang River.According to the different tree species,ages and components,we sampled leaves,branches,stems,and roots,and measured the contents of Nitrogen,Phosphorus,Potassium,along with soil fertility.The changes of N,P,and K contents in the different tree species were studied,and the relationship between nutrient content and environmental factors was analyzed.The results indicated that the content of P in all three species was the lowest(0.039–0.28 g kg),while N content was the highest(0.095–1.72 g kg).As the terminal organ of nutrient transport,the nutrient content of leaves was the highest.P.armandii(0.45 g kg) had a higher nutrient concentration than P.tabulaeformis(0.19 g kg) and P.crassifolia(0.29 g kg).The nutrient content of each species was highest in a young forest,but lowest in a mature forest.The nutrient content of all three tree species was significantly affected by soil nutrient content,and negatively correlated with available soil nutrients.

Welfare effects of rural-urban land conversion on different aged land-lost farmers:exemplified in Wuhan city

Rural-urban land conversion is a universal phenomenon in the rapid process of economic development and urban growth.The welfare of farmers who lost their farmland attracted a widespread concern within the society and academia.However,further research about differentiated policies according to the characteristics of different farmer groups is still need to be conducted.This article divides the land-lost farmers into three age groups:younger than 45,45-65,and more than 65.It proposes a welfare index system including eight functional areas based on different age groups of affected farmers,taking four districts of Wuhan City as case study area.Fuzzy mathematics method is used to derive the aggregated welfare effect index.Our analysis show that the overall welfare levels of land-lost farmers of all age groups declined,but with a varying degree,with the level of welfare in those farmers who are 45-65 years old,younger than 45 years old,and older than 65 years old decreased by 18.7%,16.6%,and 12.7%,respectively.The direction and degree of effects on the functional activity index varies among different groups.Economic conditions,living environment,health,and social participation of all age groups decrease while social security and housing conditions increase.On the other hand,development opportunities,social communication,and leisure have different changing directions in different age stages.These results call for differentiated and tailor-made compensation policies for land-lost farmers,towards improving the welfare levels of all farmers and reduce the disparity among them.

A Different Opinion on the Geological Age of the Longzhaogou and Jixi Groups of Eastern Heilongjiang, China

The age of the Longzhaogou and Jixi Groups of coal measures in eastern Heilongjiang were previouslyconsidered to be Jurassic or mainly Jurassic. But there occur Middle Barremian-Early Albian Aucellina(bivalvia) fossils in the Upper Yunshan Formation of the Longzhaogou Group and the Lower Chengzihe For-mation of the Jixi Group, and the Qihulin Formation of the Longzhaogou Group yields Early Cretaceousbivalve and ammonite fossils. Consequently, the geological ages of the two groups are mainly, or even all, Ear-ly Cretaceous.

The effects of decompressive craniectomy on cerebral blood flow volume and brain metabolism in different aged patients with severe traumatic brain injury

Objective To explore effects of decompressive craniectomy on cerebral blood flow volume and brain metabolism in different aged patients with severe traumatic brain injury. Methods 71 cases were divided into three groups according age: group A( 【 30 years) ,group B ( 30 ～ 50 years) 。

Have the Covid-19 Lockdowns Made Lasting Changes to Everyday Life? Evidence from UK Time Use Surveys

This paper asks whether the turbulence of the Covid-19 lockdowns has left enduring changes to everyday life in the UK which are unlikely to have happened,up to now,in the absence of the pandemic.The analysis disaggregates the UK population by gender,and into age groups and income bands,specifies whose lives were changed during the lockdowns,and exactly how.It is argued that most changes from pre-to post-lockdowns have been spurts in longer-running trends driven by the UK demographic,housing,economic and political contexts.The exceptions,the sole genuine lockdown legacies that the analysis leaves,are the normalisation of working from home and an increase in total time spent doing paid work.

Rhizospheric microbial communities are driven by Panax ginseng at different growth stages and biocontrol bacteria alleviates replanting mortality

The cultivation of Panax plants is hindered by replanting problems, which may be caused by plantdriven changes in the soil microbial community. Inoculation with microbial antagonists may efficiently alleviate replanting issues. Through high-throughput sequencing, this study revealed that bacterial diversity decreased,whereas fungal diversity increased, in the rhizosphere soils of adult ginseng plants at the root growth stage under different ages. Few microbial community, such as Luteolibacter, Cytophagaceae, Luteibacter, Sphingomonas,Sphingomonadaceae, and Zygomycota, were observed; the relative abundance of microorganisms, namely,Brevundimonas, Enterobacteriaceae, Pandoraea, Cantharellales, Dendryphion, Fusarium, and Chytridiomycota,increased in the soils of adult ginseng plants compared with those in the soils of 2-year-old seedlings. Bacillus subtilis 50-1, a microbial antagonist against the pathogenic Fusarium oxysporum, was isolated through a dual culture technique. These bacteria acted with a biocontrol efficacy of 67.8%. The ginseng death rate and Fusarium abundance decreased by 63.3% and 46.1%, respectively, after inoculation with B. subtilis 50-1. Data revealed that microecological degradation could result from ginseng-driven changes in rhizospheric microbial communities;these changes are associated with the different ages and developmental stages of ginseng plants. Biocontrol using microbial antagonists alleviated the replanting problem.

Biomass and Nutrient Accumulation Characteristics of Young Stands of Alnus cremastogyne

To investigate plant biomass and nutrient distribution and accumulation in organs of Alnus cremastogyne at different ages from 1 to 4 years, the biomass, N, P, K, Ca, Mg, Fe and Zn were tested. The results showed that the average biomass of the whole tree and the biomass of leaf, branch, stem, and root were in positive correlation with tree age, but the growth rate of biomass had a decreasing trend with the tree age increasing, and only the biomass proportion of the trunk in the whole individual plant showed an increasing trend with age. The contents of nutrient elements in organs showed an order of N 〉 Ca 〉 K 〉 Mg 〉 P 〉 Fe 〉 Zn ; and the contents of N, P and K were higher in the leaf than in other organs, and the contents of Ca, Mg and Fe in the root were higher than in other organs. The accumulations of N, P, K, Ca, Mg and Zn were the highest in the trunk, and that of Fe was the highest in the root. The annual net accumulations of N, P, K, Ca and Mg in the average trees from 1 to 4 years old were 17.07, 40.79, 95.82 and 106.71 g, respectively, and the annual net accumulations of microelements （Fe and Zn） were 335.04, 577.26, 1267 and 1525.27 mg, respectively.

Size-and leaf age-dependent effects on the photosynthetic and physiological responses of Artemisia ordosica to drought stress

Drought is one of the most significant natural disasters in the arid and semi-arid areas of China.Populations or plant organs often differ in their responses to drought and other adversities at different growth stages.At present,little is known about the size-and leaf age-dependent differences in the mechanisms of shrub-related drought resistance in the deserts of China.Here,we evaluated the photosynthetic and physiological responses of Artemisia ordosica Krasch.to drought stress using a field experiment in Mu Us Sandy Land,Ningxia Hui Autonomous Region,China in 2018.Rainfall was manipulated by installing outdoor shelters,with four rainfall treatments applied to 12 plots(5 m×5 m).There were four rainfall levels,including a control and rainfall reductions of 30%,50%and 70%,each with three replications.Taking individual crown size as the dividing basis,we measured the responses of A.ordosica photosynthetic and physiological responses to drought at different growth stages,i.e.,large-sized(>0.5 m^(2))and small-sized(≤0.5 m^(2))plants.The leaves of A.ordosica were divided into old leaves and young leaves for separate measurement.Results showed that:(1)under drought stress,the transfer efficiency of light energy captured by antenna pigments to the photosystem II(PSII)reaction center decreased,and the heat dissipation capacity increased simultaneously.To resist the photosynthetic system damage caused by drought,A.ordosica enhanced its free radical scavenging capacity by activating its antioxidant enzyme system;and(2)growth stage and leaf age had effects on the reaction of the photosynthetic system to drought.Small A.ordosica plants could not withstand severe drought stress(70%rainfall reduction),whereas large A.ordosica individuals could absorb deep soil water to ensure their survival in severe drought stressed condition.Under 30%and 50%rainfall reduction conditions,young leaves had a greater ability to resist drought than old leaves,whereas the latter were more resistant to severe drought stress.The response of A.ordosica photosynthetic system reflected the trade-off at different growth stages and leaf ages of photosynthetic production under different degrees of drought.This study provides a more comprehensive and systematic perspective for understanding the drought resistance mechanisms of desert plants.

Comparative study on semen quality of one- and two-year-old ganders during the entire reproductive season

Aim: To evaluate the characteristics of semen produced by one- and two-years old White Italian ganders duringentire reproductive season, in order to clarify whether the young ganders are responsible for a low fertility rate in yougeese. Methods: Males were kept individually in cages under natural light. Semen was collected by dorso-abdonhal massage three times a week and routine examination was performed. Results: The mean ejaculate volume (2and 1.6 mL, respectively) and sperm concentration (323 and 281 × 10~6/mL, respectively) in one-year-old gandwere higher than those of two-year-old ones. The percentages viable spermatozoa of one- and two-year-old gandwere similar (91.4 and 92.3%, respectively), but the percentage of normally formed viable spermatozoa was signicantly higher in the older ganders than in the younger (47.8 and 42.9%, respectively, P < 0.05). Conclusion:The semina from one- or two-year-old Ganders were similar in regard to volume, sperm density and sperm motility,the percentage of normally formed viable spermatozoa, which is critical for fertilization, was significantly higher inolder ganders. It appears that the ganders are responsible for the low fertility rate in young geese.

Migrant Workers Age-Group Productivity Gap Is Key to Verifying Lewis Turning Point in Chin＊

This paper uses age-related productivity gaps to analyze the Lewis turning point in China. The age-related productivity gap implies that under same wage rate, older and less productive rural laborers working in cities will earn less than the reservation wage. Thus, they may elect instead to return to the countryside. Therefore, this paper argues that while the supply of younger, high-productivity migrant workers fails demand and Lewis turning point emerges, there still exists a high volume of lower-productivity rural surplus labor.

An Empirical Study on Self-Efficacy of Online Learning of Overseas Chinese Children in Europe

In the post-Covid-19 pandemic era,it is more difficult for some Chinese schools in Europe to provide online extra classes for overseas Chinese children after school hours,as they did previously.To meet students'multifaceted learning needs,online extra classes teaching,including online Chinese language classes and some online art classes,is increasingly being offered as a supplement to the diversity of teaching activities in Chinese schools in Europe,with the ultimate goal of improving the learning abilities of overseas Chinese children while relieving pressure on teaching resources in schools.Children’s learning self-efficacy in online extracurricular courses has its own uniqueness,which can be considered from three dimensions,including learning confidence,learning ability,and self-assessment ability.This study aims to examine the factors influencing the self-efficacy of overseas Chinese children and to make optimization suggestions for better teaching methods.In search of that,an online questionnaire survey with 127 participants from overseas Chinese children aged􀀘to􀀔􀀘was collected.The findings indicate that the role of learning confidence in overseas Chinese children outweighs their learning ability and self-assessment ability.Gender and age have a negligible effect on self-efficacy but have an impact on learning confidence.Chinese schools in Europe do not need to show gender differences when conducting classroom activities in online teaching to improve the online self-efficacy of Chinese children,and efforts should also be made to keep the courage of older students to trial and error.Teachers are expected to investigate more aspects of their students'personalities in future classrooms rather than sticking to a consistent and unchanging teaching model.

Research on the Gender and Age Differences of Middle School Students＇ Shame Sense

In order to ensure the existence of the gender and age differences of middle school students＇ shame, 1258 Shanghai middle school students are surveyed with the help of the Middle school students＇ shame measurement scale with the combination of delaminating and random sampling. The results of questionnaire show that there are significant gender differences in middle school students＇ shame and the average scores of male students＇ shame are higher than those of female students. Besides, there does exist significant age differences in middle school students＇ shame, but it is not simple linear relationship between the feeling of shame and ages. The feeling of shame reaches maximum at the age of 14 and intervention should be given at this age, which young students feel sensitive most. It is suggested that collective remission of the shame should be offered to middle school students with the methods such as physical exercises, persuasion etc.