District Of Chongqing Research Articles

Investigation on Social Anxiety of Secondary Vocational Students

Objective: To investigate the status quo of social anxiety among secondary vocational students and the differences in demographic variables through the Communication Anxiety Scale (IAS) survey. Methods: A total of 890 students from a secondary vocational school in Changshou District of Chongqing were surveyed with the Communication Anxiety Scale (IAS) to understand the social anxiety of secondary vocational students. Results: The mean score of social anxiety of secondary vocational students was 45.25±9.32. The gender difference of social anxiety in secondary vocational students was significant (P<0.001). There was no significant difference in social anxiety of secondary vocational students in grade (P>0.05); The social anxiety of secondary vocational students was significantly different in household registration type (P<0.001); There was no significant difference in social anxiety between only children and non-only children (P>0.05). The difference of social anxiety in family income of secondary vocational students was very significant (P<0.001). Conclusion: The level of social anxiety of secondary vocational students is above the middle level. From the perspective of gender variables, there is a significant difference in the level of social anxiety between male and female students, and the level of social anxiety of male students is significantly lower than that of female students. In terms of grade variables, there was no significant difference in social anxiety in grade variables. From the perspective of the variable of residence type, social anxiety is significantly different between rural students and urban students. The level of social anxiety of rural students is higher than that of urban students. There is no significant difference between only-child and non-only-child in social anxiety. From the perspective of family income level, social anxiety is significantly different among different income families. Students from families with wages higher than the average social level had the lowest level of social anxiety, students from families with wages comparable to the average social level had higher levels of social anxiety, and students from families with wages lower than the average social level had the highest level of social anxiety.

Polymorphic Microsatellite Development, Genetic Diversity, Population Differentiation and Sexual State of Phytophthora capsici on Commercial Peppers in Three Provinces of Southwest China.

Pepper blight, caused by the oomycete pathogen Phytophthora capsici (P. capsici), is one of the most destructive soilborne diseases worldwide. Between 2019 and 2020, 235 single spore isolates of P. capsici were collected from 36 commercial pepper planting areas in Sichuan, Chongqing, and Guizhou provinces in China. A novel full set of 323 high-quality polymorphic microsatellites was obtained by resequencing 10 isolates. In total, 163 isolates with two alleles per microsatellite locus were used for population analysis and resulted in 156 genotypes on 10 microsatellite loci. The genetic diversity, population differentiation, principal component, genetic structure, and genetic relationships analyses showed an extensive variety of the P. capsici in Sichuan and Guizhou with clonal lineages, two shared genotypes, and no geographic differentiation. The population from Chongqing was differentiated from that of Sichuan and Guizhou and had the highest genetic diversity. There was no significant distinction between the populations of the two sampling years, but there was a small differentiation between the populations from bell peppers and hot peppers. The isolates from Southwest China were largely distant from the two reference isolates from the USA. The analysis of molecular variance showed that the major variance of the populations was within populations. The linkage equilibrium test, mating type composition, and oospore detection indicated that only P. capsici from the Jiulongpo district of Chongqing had appeared in sexual recombination. Overall, this study revealed that the high and complex genetic diversity population of P. capsici in Sichuan, Chongqing, and Guizhou with uneven geographic variation and limited sexual reproductive behavior in Chongqing, potentially driven by differences in the geographical environment, reproductive patterns, different cultivars, and artificial long-distance transfers. IMPORTANCE Phytophthora capsici, a notorious soilborne and rapidly evolving pathogen with a wide range of hosts, is a huge threat to pepper production worldwide. However, the detailed genetic structure and dynamics of P. capsici in most Chinese provinces are still unclear, even though China is the world's largest producer and consumer of peppers. Here, a novel full set of high-quality polymorphic microsatellites, obtained by genome resequencing data of 10 isolates from Southwest China, was provided for future population analyses. In this study, we further investigated and established the genetic structure, sexual recombination, geographic subdivisions, interannual stability, differentiation in different types of host peppers, and member relationships of P. capsici from three provinces in Southwest China. These results reveal the genetic structure and dynamics of P. capsici in three provinces of Southwest China and help us to execute more effective management strategies in the future.

Effects of rainfall and the slope gradient on the soil and water loss in a purple soil area

Soil and water losses in purple soil area is becoming an increasingly severe problem, bringing enormous challenges to environmental protection in rural areas. In this study, simulated rainfall experiments were conducted to analyse the effects of rainfall and the slope conditions on the soil and water loss. Purple soil from a typical slope in the Beibei District of Chongqing was selected as the experimental soil. Twenty rainfall scenarios with varying rainfall intensities and slope conditions were created in the simulation. The results indicate that the runoff initiation time shortened with an increased rainfall intensity and slope gradient. There was a logarithmic relationship between the effect of the rainfall amount on both the runoff intensity and sediment yield intensity. Generally, both the runoff and sediment yield showed a positive linear relationship with the rainfall intensity under different slope gradient conditions. In terms of the same rainfall intensity, both the runoff intensity and sediment yield intensity increased with the slope. Furthermore, a critical slope gradient for the soil and water loss was found between 20° and 25°. This study aimed to provide a reference for soil and water conservation research in a purple soil area.

Local Residents Becoming Local Tourists: Value Co-Creation in Chinese Wetland Parks during the COVID-19 Pandemic

Despite their ecological value, wetland parks can be expensive to preserve and maintain, so local governments endeavor to design financially sustainable models by exploiting the ecotourism value of wetland parks. This trend has been facilitated by telecommunication technologies that enable value co-creation. Unlike previous studies that primarily assume tourists to be outsiders far from home, this study addresses a unique situation: travel restrictions during the COVID-19 pandemic generated a unique ecotourism market for local residents. This study responds to the above issue by examining the factors responsible for local tourists’ value co-creation intention. Specifically, we drew on the theory of planned behavior to develop an extended model to address the research objective. The hypothesized model was empirically tested using an online survey of 386 local tourists who traveled to a wetland park in the Liangping district of Chongqing, China. Our results suggest that social norms, destination awareness, experience expectations, and facilitating conditions could affect local tourists’ attitudes, which further influences local customers’ value co-creation intention. Moreover, social norms, destination awareness, and experience expectations could affect local tourists’ perceived value of a wetland park, thus further influencing local customers’ value co-creation intention. In doing so, we made interesting insights and implications for ecotourism at a local level. Drawing on our survey in a specific wetland park, we highlight how local tourists’ attitude and perceived value positively affect their value co-creation intention and identify one more possible source of destination awareness: friends’ sharing of destination information and experience through social media. Practically, we suggest local tourism to offset the maintenance costs of wetland parks during the COVID-19 pandemic. That requires leveraging social norms and understanding residents’ expectations, in addition to improving infrastructure.

Construction and Application of 3D geological model of mianhuaba center in Wulong District of Chongqing Based on Depthlnsight

3D geological modeling plays an increasingly important role in the fields of mineral resources, energy, ecological geological environment and urban construction. With the continuous development of geological work and the increasing demand, many excellent 3D geological modeling software have emerged. In this paper, the 3D geological model of mianhuaba center in Wulong District of Chongqing City is completed based on Depthlnsight platform by using the 1:10000 measured topographic and geological map and integrating the geological profile, geophysical interpretation profile and borehole data. This model can be used to realize arbitrary direction and angle section cutting in the modeling area, and output the model geological profile with lithologic pattern to support the business work in the fields of engineering construction and resource exploration.

Preconception reproductive health and birth outcome cohort in Chongqing: the cohort profile

Birth cohort is an important platform to study the effect of early-life exposure on health outcome, but large cohorts to investigate the effect of preconception exposure, especially paternal exposure, on reproductive health and birth outcome are limited. The Preconception Reproductive Health and Birth Outcome Cohort (PREBIC) is a prospective birth cohort study which pays equal attention to the contribution of environmental, psychological, behavioral as well as other factors to reproductive health and adverse birth outcomes in both men and women in Chongqing, China. PREBIC started in 2019 and plans to recruit 20 800 reproductive-age couples with child-bearing willingness. Followed up was conducted to understand the conception status of the women within two years. Women in pregnancy would be visited at first, second, third trimesters and after delivery. The offspring would be monitored until 2 years old to understand the incidences of preterm birth, low birth weight, birth defects, neurodevelopmental disorders and other outcomes. Related information and biospecimen collections (including semen, peripheral blood, urine, placenta, umbilical cord, cord blood and oral swab) were scheduled in each period. By January 2022, PREBIC had recruited 8 698 participants from all 38 districts in Chongqing. The goal of PREBIC is to establish one of the largest prospective preconception birth cohorts covering both men and women, which might provide a unique insight to understand the effects of the full reproductive cycle on reproductive health and adverse outcomes, with especial emphasis on preconception exposures.

Assessment of the professional dental cleaning knowledge, behavior and medical compliance among dentists, medical doctors and non-medical staffs: a cross sectional study in Chongqing, China

BackgroundThe professional dental cleaning (PDC) is an effective supplement that can make up for the lack of self-oral health care. Everyone should develop the habit of regular PDC. This study aimed to investigate the knowledge, behaviors and medical compliance of dentists, medical doctors and non-medical staffs about the PDC, identify the gaps, and provide information to help individuals develop healthy oral hygiene habit.Materials and methodsA web-based survey with 21 questions designed based on the characteristics, the PDC knowledge, behaviors, and medical compliance of respondents. A cross-sectional study was conducted in the main districts of Chongqing, China, in the period of September–November 2020. A total of 456 respondents including 153 dentists, 137 medical doctors and 166 non-medical staffs in 3 communities and 4 hospitals were sampled online with multistage sampling and surveyed. The data was analyzed by chi-square test using IBM SPSS Statistics v. 21.0.ResultsThe cognitive level and behavior of dentists on the PDC was significantly better than that of medical doctors and non-medical staffs (p = 0.000–0.044). The rates of not knowing “dental plaque” were 32.85% and 61.45%, of the medical doctors and non-medical staffs. Meanwhile, most of them had misunderstanding about effects of the PDC. They thought it would whiten teeth (72.99%, 80.72%), damage gums (16.79%, 19.88%) and teeth (15.33%, 21.69%), and create bigger gaps between teeth (24.82%, 33.13%). In terms of gum health and the PDC behavior, significant differences were observed, 23.53% of dentists experienced irritated gum bleeding in the last 12 months, 42.28% did not have their teeth cleaned professionally in the last 12 months, even 7.84% never had it before. Compared with it, in the same situation, the ratios of medical doctors and non-medical staffs were about 60% experiencing irritated gum bleeding, 69.34% and 77.71% not experiencing the PDC in the last 12 months, up to 33.58% and 45.18% never experienced it before. 41 respondents (8.99%) disagreed with the reasonable and necessary medical behaviors before the PDC.ConclusionPeople's understanding about the PDC was insufficient, and many people, included some dentists, had not developed the habit of regular dental cleaning. Our study provided a new understanding of the PDC among dentists, medical doctors, and non-medical staffs, which may help to improve their awareness and behavior of oral hygiene health, and establish the multidisciplinary collaborations between dentists and medical doctors.

Safety Evaluation of Slope Based on Factor Analysis-Taking Wanzhou District of Chongqing as an Example

Safety Evaluation of Slope Based on Factor Analysis-Taking Wanzhou District of Chongqing as an Example

Secondary organic aerosol formation and source contributions over east China in summertime

Various precursor emissions and chemical mechanisms for secondary organic aerosol (SOA) formation were incorporated into a regional air quality model system (RAQMS) and applied to investigate the distribution, composition, and source contribution of SOA over east China in summer 2018. Model comparison against a variety of observations at a national scale demonstrated that the model was able to reasonably reproduce meteorological variables, O3 and PM2.5 concentrations, and the model simulated SOA concentration generally agreed with observations, with the overall NMB of 7.0% and R of 0.4 in 10 cities over east China. The simulated period-mean SOA concentrations of 4–15 μg m−3 were mainly distributed over the North China Plain (NCP), the middle and lower reaches of the Yangtze River and Chongqing district. SOA dominated organic aerosol (OA) over China in summertime (90%). The percentage contributions to SOA from ASOA (SOA produced from anthropogenic volatile organic compounds (AVOC)), BSOA (SOA produced from biogenic volatile organic compounds (BVOC)), DSOA (SOA produced from aqueous uptake of glyoxal and methylglyoxal) and S/I-SOA (SOA produced from semi-volatile and intermediate volatile organic compounds) were estimated to be 48.3%, 28.6%, 14.3%, and 8.8% respectively, over east China in summertime. In terms of domain and period average, ASOA contributed most to SOA (59%) in north China, while BSOA contributed most to SOA (37.3%) in northeast China. The percentage contribution of DSOA to SOA reached 21.5% in southwest China. S/I-SOA accounted for approximately 10% of SOA in most areas of east China. This study reveals that while AVOC dominates SOA formation on average over east China, the SOA source contributions differ considerably in different regions of China. BVOC makes the same contribution to SOA formation as AVOC in northeast China and southwest China, where forest coverage and BVOC emission are higher and anthropogenic emissions are relatively low, highlighting the significant role of BVOC in summer SOA formation in China.

Effects of social capital on farmers’ choices of climate change adaptation behavior in Dazu District, China

ABSTRACT This study explores the effects of social capital on farmers’ choices of climate change adaptation behavior in Dazu District, China. A total of 228 questionnaires were obtained from randomly sampled households. Social capital was divided into social networks, participation, reciprocity and trust. The adaptation behaviors in the study area were identified as crop adjustment, environmental improvement, financial management, and livelihood diversification. A boosted regression tree model was used to analyze the effects of different dimensions of social capital on farmers’ choices of climate change adaptation behavior. The results show that most farmers in Dazu District of Chongqing have adopted crop adjustment adaptation behavior. The social capital and socioeconomic characteristics of farmers have different impacts on different adaptation behaviors. Among social capital, the largest influence on climate change adaptation behavior is the degree of trust in the information of agricultural technology extension service centers, and the lowest influence is participation in rural cooperatives. In terms of socioeconomic characteristics, the largest impact on climate change adaptation behavior is agricultural income share, and the lowest impact is gender. The findings of this study can provide empirical support for governments to formulate effective policies to improve farmers’ climate change adaptation capabilities.

Association of self-reported snoring and hyperuricaemia: a large cross-sectional study in Chongqing, China

ObjectiveTo examine the relationship between self-reported snoring and hyperuricaemia in a large-scale population in Chongqing, China.SettingFace-to-face electronic questionnaire survey, physical examination and biological sample testing were conducted in 13 districts...

Nutrition Literacy of Middle School Students and Its Influencing Factors: A Cross-Sectional Study in Chongqing, China.

Nutrition literacy plays an important role in children's dietary habits and nutrition. This study aimed to analyse the status of nutrition literacy and its influencing factors amongst middle school students in Chongqing, China. “Nutrition literacy scale for middle school students in Chongqing” was used in 29 districts of Chongqing in September 2020. The scores of nutrition literacy and its' three sub-domains (functional, interactive and critical nutrition literacy) were divided into low and high groups based on their median scores. Binary logistic regression was used to measure the influencing factors of nutrition literacy. A total of 18,660 middle school students were included in this study. The median of nutrition literacy of middle school students was 61.68 (IQR = 14.37). Interactive nutrition literacy had the highest score (median = 70.00, IQR = 20.00), followed by functional nutrition literacy (median = 68.69, IQR = 14.14) and critical nutrition literacy (median = 45.83, IQR = 25.00). Students who were the minority (OR = 0.71, 95% CI = 0.637–0.785), in senior high school (OR = 0.51, 95% CI = 0.477–0.548), in rural areas (OR = 0.85, 95% CI = 0.790–0.911), receiving school meal support from the government (OR = 0.63, 95% CI = 0.591–0.664), with other caregivers' parenting (OR = 0.86, 95% CI = 0.805–0.914), with parents having a low level of education and with an abnormal BMI [thin (OR = 0.91, 95% CI = 0.837–0.990), overweight (OR = 0.87, 95% CI = 0.785–0.968), and obese (OR = 0.83, 95% CI = 0.767–0.902)] presented less probability of being a high level of nutrition literacy. Our results could assist public health authorities in developing strategies of nutrition literacy promotion for references and theoretical foundations.

Emotional and Behavioral Changes and Related Factors of Firstborn School-Aged Compared to Same Age Only Children.

ObjectiveTo compare the emotional and behavioral characteristics of firstborn children during the pregnancy of a second child and only children of school-age in urban districts of Chongqing, China, and to explore the influencing factors of emotional and behavioral problems.MethodsWe recruited mothers of firstborn children and only children from two hospitals and one primary school using purposive sampling. Questionnaires and the Parental Child Behavior Checklist (CBCL) were used to collect basic information, family socioeconomic status, family atmosphere and emotional and behavioral characteristics of their children in the survey.ResultsThe sample consisted of 1,155 children, including 477 firstborn children and 678 only children. The average scores of internalizing (4.47), externalizing (6.05), total problems (22.04), and six emotional and behavioral of firstborn children were significantly lower than those of only children (p < 0.05). When adjusted for children's demographic, socioeconomic and family relationship covariates, the scores of firstborn children internalizing problems (β = −1.423, p = 0.000), externalizing problems (β = −0.661, p = 0.048), and total problems (β = −4.387, p = 0.000) were also significantly lower than those of only children. All children with more difficult parenting and development temperament, greater family economic pressure, poorer relationships between mother and child, less harmonious family atmosphere and father's permissive parenting style had more internalizing problems, externalizing problems and total problems (p < 0.05). Boys had more externalizing problems (β = 1.939, 95% CI = 1.380–2.497) and total problems (β = 4.908, 95% CI = 3.045–6.772) than girls.ConclusionFirstborn children had fewer emotional and behavioral problems than their counterparts who were only children. This research helps to understand the social impact of the implementation of the two-child policy in multiple dimensions.

Contribution of Infrastructure to the Township’s Sustainable Development in Southwest China

Townships in Southwest China are usually located in mountainous regions, which are abundant in natural and cultural landscape resources. There are additional requirements for the township’s sustainable development in these areas. However, insufficient infrastructures, due to limited resources, constrain the sustainable development of these townships. Sustainable contribution of infrastructure (SCOI) in this study is defined as the performance of infrastructure as a contribution to the coordinated development among economic, social, and environmental dimensions of township’s sustainable development. It is necessary to assess these infrastructures according to SCOI and provide choices for investment to maximize resource utilization. Therefore, an assessing model of SCOI with 26 general indicators was developed, which covers five most urgently needed infrastructures of these townships in Southwest China, including road transport, sewage treatment, waste disposal, water supply, and gas. In this model, quantitative and qualitative methods are combined to acquire different SCOI of each infrastructure. The result of the SCOI would be an important reference for infrastructure investment. A case study of Jiansheng Town, that is located in the Dadukou district of Chongqing, demonstrates the applicability of the model. It shows the assessing model of SCOI is efficient to identify the most valuable infrastructure that is appropriate for investment with the goal of township’s sustainable development. This study can provide insights for infrastructure investment and management in townships or areas.

The Positive Rate of Nucleic Acid Testing and the Epidemiological Characteristics of COVID-19 in Chongqing.

ObjectiveThe purpose of this study is to analyze the positive rate of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleic acid testing (NAT), cases of and deaths due to SARS-CoV-2, and the epidemiological characteristics of SARS-CoV-2 to identify high-risk populations.MethodsA retrospective study in Jiulongpo district of Chongqing was conducted by performing continuous observations of the frequency of SARS-CoV-2 NAT, analyzing the data of close contacts of patients and asymptomatic carriers, and collecting epidemiological data. Data were collected from January 20, 2020, when the first case of SARS-CoV-2 infection was reported, to March 26, 2020. Descriptive statistical analysis and Cochrane–Mantel–Haenszel analysis were used to compare the positive detection rates and positive diagnostic rates of different exposure groups.ResultsA total of 7,118 people received 10,377 SARS-CoV-2 nucleic acid tests in one district, and the SARS-CoV-2 positive rates were 0.40% (18/4446) and 0.15% (4/2672) in people receiving one and ≥ two nucleic acid tests (p = 0.06), respectively. Those with suspected cases (12.35%) and close contacts (8%) had higher positive rates than people tested at fever clinics (0.39%) (p < 0.001). The median latency (range) of cases was 5 (2, 9) days, and the median time from diagnosis to recovery was 22 (14, 25) days. One recovered patient received a positive test result at 28 days after recovery when she attempted to donate blood. Six clustered cases, including one patient who died, indicated persistent human-to-human transmission. One patient who was diagnosed after death was found to have infected 13 close contacts. People working in catering and other public service departments (36.36%) and people who are unemployed and retirees (45.45%) have an increased risk of infection compared with technical staff (9.09%) and farmers (9.09%).ConclusionThe total positive rate was low in the tested population, and more effective detection ranges should be defined to improve precise and differentiated epidemic control strategies. Moreover, in asymptomatic carriers, SARS-CoV-2 tests were positive after recovery, and patients with suspected SARS-CoV-2 infection who die may pose serious potential transmission threats.

Geospatial epidemiology of Toxoplasma gondii infection in livestock, pets, and humans in China, 1984-2020.

Undercooked or raw meat containing cyst-stage bradyzoites and oocyst-contaminated pets are presumed to constitute a major source of human toxoplasmosis. As the geospatial epidemiology of Toxoplasma gondii (T. gondii) infection in livestock, pets, and humans is rarely studied in China, we undertook a geospatial analysis using GIS visualization techniques. The present study retrieved information from the PubMed, China National Knowledge Infrastructure, and Baidu Scholar databases from 1984 up to 2020. All the data about the seroprevalence of T. gondii in livestock (sheep and goats, pigs, cattle and yaks), pets (cats, dogs), and humans in China were collected. Geospatial epidemiology of T. gondii infection in these hosts was performed using GIS. Results revealed that the estimated pooled seroprevalence of T. gondii was ranged from 3.98 to 43.02% in sheep and goats in China, 0.75 to 30.34% in cattle and yaks, 10.45 to 66.47% in pigs, 2.50 to 60.00% in cats, 0.56 to 27.65% in dogs, and 0.72 to 23.41% in humans. The higher seroprevalences of T. gondii were observed in sheep and goats in the districts of Chongqing, Zhejiang, and Beijing. The infection rates of T. gondii in cattle and yaks were higher in Guizhou, Zhejiang, and Chongqing. Also, the pigs from Chongqing and Guizhou were most severely infected with T. gondii. For cats, the districts of Shanxi, Hebei, and Yunnan had higher seroprevalences of T. gondii and, the infections among dogs were higher in Yunnan and Hebei as well. Furthermore, higher infection pressure of T. gondii exists in the districts of Taiwan and Tibet in humans. The geographical and spatial distribution of toxoplasmosis indicated that infection with T. gondii was widely spread in China, with a wide range of variations among the different hosts and regions in the country. Our results suggested that livestock and pets are not only a reservoir for the parasite but also a direct source of T. gondii infection for humans. It is important to control T. gondii infections in these animals that would reduce the risk of toxoplasmosis in humans.

重庆喀斯特生境中桢楠种群结构与动态特征

PDF HTML阅读 XML下载 导出引用 引用提醒 重庆喀斯特生境中桢楠种群结构与动态特征 DOI: 10.5846/stxb202106171607 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 重庆市自然科学基金项目（cstc2020jcyj-msxmX0244）；中央高校基本科研业务费专项（XDJK2020B037）；国家自然科学基金项目（31500399） Population structure and dynamic characteristics of Phoebe zhennan S. Lee in karst areas of Chongqing Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:桢楠是我国珍稀渐危树种，国家二级保护植物，野生多散生于海拔1500 m以下的亚热带常绿阔叶林中。而喀斯特生境岩石裸露、土壤浅薄贫瘠、岩溶干旱频发，理论上并不适合喜湿耐荫且喜酸性土壤的桢楠生长及幼苗更新。因此重庆市大足区和永川区喀斯特生境中的天然桢楠种群可能存在一定的更新困难。为明确这两个桢楠种群的生存现状及动态特征，采用野外调查法，从径级结构、静态生命表、存活曲线、结构动态及分布格局等方面分析桢楠种群结构及其数量动态规律，以期预测种群未来发展趋势，为喀斯特地区桢楠种群的保护、群落更新及植被恢复提供理论基础。结果表明：（1）大足区桢楠种群的年龄结构趋于稳定型，而永川区桢楠种群的年龄结构为增长型。两地区幼苗充足但死亡率高。（2）静态生命表及相关曲线分析显示，两个桢楠种群存活数量总体上随径级增大而减少；两个桢楠种群的生存期望值在不同径级间存在波动，大足区桢楠种群在第Ⅱ径级而永川区则是第Ⅳ径级期望值最高。（3）两个种群的存活曲线均为Deevey-Ⅲ型，即幼树死亡率较高，并且种群的增长速度较为缓慢。（4）大足区种群为随机分布，永川区种群为集群分布；种群各生长发育阶段均为集群分布，但聚集强度随着龄级的增加而减弱。桢楠种群在喀斯特地区生长周期长，天然更新能力较强但对外部干扰敏感。建议加强对幼苗的抚育工作，提高幼苗存活率，促进桢楠种群的自然更新和恢复。 Abstract:Phoebe zhennan S. Lee is a rare and endangered tree species in China, a nationally protected secondary plant. It is mostly scattered in the wild in subtropical evergreen broad-leaved forests below 1500 m above sea level. As the primary populations are almost destroyed, the existing resources are limited and scattered. Karst habitat has exposed rocks, shallow and barren soil and frequent drought. In theory, it is not suitable for the growth and seedling regeneration of P. zhennan, which likes humidity, shade and acid soil. Therefore, it may be difficult to renew the natural P. zhennan population in karst habitats in Dazu District and Yongchuan District of Chongqing. To explore the survival status and distribution model of the two P. zhennan populations, the field survey method is used to analyze the structure and the dynamic law of the populations and their quantity, by assessing the diameter structure, static life table, survival curve, structural dynamics and distribution pattern. It is hoped that the future development trend of the population can be predicted, and the theoretical basis for the protection, community renewal and vegetation restoration of the karst area will be provided. The results showed that:(1) the age structure of P. zhennan population in Dazu District tended to be a stable type, while it was an increase type in Yongchuan District. Both areas had abundant seedlings but with high mortality rates. (2) The individual numbers of both populations of P. zhennan generally decreased with the diameter class increased. The life expectation of the two P. zhennan populations fluctuated between different diameter classes. It was the highest in the diameter class Ⅱ in the population of P. zhennan in Dazu District, while it highest in the diameter class Ⅳ in Yongchuan District.(3) Both populations had Deevey-Ⅲ type survival curves, that was, the mortality of young trees was relatively high, and a relatively low population growth rate. (4) The population in Dazu District was randomly distributed, while that of the Yongchuan District was consolidated. P. zhennan were clustered populations at the growth and development stage, but their strength weakened with the growth of the age group. The population of P. zhennan in the karst region had a long growing time, a strong capacity for natural regeneration but sensitive to external disturbances. It is suggested to enhance seedling selection and improve seedling survival to promote natural renewal and restoration of P. zhennan population. 参考文献 相似文献 引证文献

Iodine nutrition level and thyroid function in pregnant women in the Yongchuan district of Chongqing

This study aims to investigate thyroid function-associated parameters and the incidence of thyroid disorders in pregnant women, with the overarching aim to ensure that pregnant women do not develop said disorders due to aberrant iodine levels during the course of pregnancy. A total of 300 pregnant women who underwent routine check-ups at the Yongchuan Hospital Affiliated to Chongqing Medical University from January to December 2021 were enrolled. Venous blood and morning urine were collected. Serum thyroid-stimulating hormone (TSH), free thyroxine (FT4), and free triiodothyronine (FT3) were determined by chemiluminescence immunoassay. Urinary iodine concentration (UIC) was detected by arsenic cerium catalytic spectrophotometry. Thyroid disorders were extrapolated from the measured parameters. The overall median UIC was 203 μg/L, which was within normal range. Subgroup analysis revealed that the median UIC in the first trimester was 187.5 μg/L, 211.8 μg/L in the second trimester, and 239.9 μg/L in the third trimester. However, based on the WHO criteria, 32%, 30%, and 18% of pregnant women were iodine deficient during their first, second, and third trimester, respectively. The proportion of women with iodine deficiency in the first and second trimesters was higher compared to the third trimester (P < 0.05). Serum FT3 and FT4 concentrations were higher in subjects in their first and second trimester versus the third trimester, while serum TSH levels were lower in subjects in their first and second trimester versus the third trimester (P < 0.05). The TSH concentration in subjects with inadequate iodine intake (UIC < 150 μg/L) was lower compared to subjects with adequate iodine intake (UIC 150 - 249 μg/L), but higher than in subjects with more than adequate intake (UIC 250 - 499 μg/L) and excess iodine intake (UIC ≥ 500 μg/L) (P < 0.05). TSH concentration and UIC were positively correlated (r = 0.1945, P = 0.0007), while no relationship was observed between UIC and FT3 and FT4 serum levels (r1 = -0.0593, P1 = 0.3053; r2 = -0.0149, P2 = 0.7968). There was no significant difference in FT3 and FT4 concentration between different UIC strata (P > 0.05). The incidence of thyroid disease during pregnancy in iodine-deficient women was greater compared to pregnant women with adequate iodine intake (P < 0.05) and higher in subjects in the more than adequate as well as excessive iodine intake cohorts (P < 0.05). The iodine nutritional intake by pregnant women in Yongchuan District, Chongqing, was generally sufficient to meet developmental and metabolic needs. However, about a third of women in their first and second trimester exhibited iodine deficiency. Iodine deficiency was associated with an increased incidence of thyroid diseases. In clinical practice, the UIC of pregnant women should be measured during key stages in the pregnancy to prevent the manifestation of thyroid diseases.

Land Geoparcel-Based Spatial Downscaling for the Microwave Remotely Sensed Soil Moisture Product

The spatial downscaling of soil moisture (SM) provides a technical tool to solve the problem of coarse resolution of passive microwave products. However, conventional methods are developed based on the kilometer scale grid pixels of remote sensing images. The regular rough grids will lead to the mixing and uncertainty of SM information. In this paper, we formulate a novel land geoparcel-based spatial downscaling technique for the Soil Moisture Active Passive (SMAP) satellite products. It is developed by combining XGBoost (eXtreme Gradient Boosting) machine learning algorithm with the support of geoparcel vector data and a variety of auxiliary raster data. The downscaling effect is evaluated by using SMAP 9km products and site measured data in Tongnan District of Chongqing, China. The experiments show that the geoparcel-based downscaling method maintains the dynamic range of the original SM product, and conserves energy before and after downscaling. It is proved that our method effectively increases the spatial details of the original SM product with complete spatial coverage. The comparison and analysis with the ground verification data demonstrate that the formalized procedure with geoparcel-based spatial downscaling allows better results than those of using km-scale regular grids.

Investigation on the Operation Status of Community-Based Rehabilitation Station in a District of Chongqing.

Objective Investigate and analyze the current operation status of the community-based rehabilitation station in a district of Chongqing to provide some reference schemes for improving the construction of the community-based rehabilitation system for Chongqing. Methods Self-designed questionnaires were issued to 36 community-based rehabilitation stations in a district of Chongqing to investigate the human resources status, service projects, service methods, and other aspects of the community-based rehabilitation stations. Results The community-based rehabilitation station lacks the participation of medical rehabilitation personnel, and only 33.3% of the community-based rehabilitation stations are composed of multidisciplinary human resources of medical and community staff. Community-based rehabilitation services focus on supply education and publicity (86.11%), and rehabilitation treatment services are not fully involved in the community-based rehabilitation service (44.44%). The methods of community-based rehabilitation services are mainly posters and other publicity activities (94.44%), and the community-based rehabilitation service methods are not highly goal-oriented. Conclusion The survey found some problems to be improved in the construction and operation of grass-roots community-based rehabilitation stations in Chongqing. Community-based rehabilitation stations should enrich the human resources and technology of medical rehabilitation, become an extension of the restoration of community health institutions, and promote the high-quality development of community-based rehabilitation.