Study on the failure characteristics of sliding surface and stability analysis of inverted t-type retaining wall in active limit state.

This paper investigates the sliding surface failure characteristics, earth pressure distribution law and stability safety factor of inverted T-type retaining wall by using the finite element limit analysis software OptumG2, the effects of width of wall heel plate, width of wall toe plate, thickness of bottom plate, soil-wall interface friction angle, soil cohesion and soil internal friction angle of filling on the failure characteristics of sliding surface, the earth pressure distribution law and stability safety factor of retaining walls are analyzed, The stability safety factor of the retaining wall showed a gradually increasing trend as the width of wall heel plate and wall toe plate increased; as the bottom plate thickness increases, the stability safety factor of the retaining wall gradually increases; as the soil-wall interface element reduction coefficient rises, that is, the internal friction angle of the soil-wall gradually increases to the soil internal friction angle, the stability safety factor of the retaining wall gradually increases; as the soil cohesion and internal friction angle increase, the stability safety factor of the retaining wall progressively increases. The safety factor of retaining wall increases by 0.45 for every 0.5m increase in the width of the wall heel plate; the safety factor of the retaining wall increases by 0.29 when the width of the wall toe plate increases by 0.5m; for every 0.5m increase in the width of wall plate thickness, the safety factor of the retaining wall is increased by 0.62; for every 0.25 increase in soil-wall interface element reduction coefficient, the safety factor of the retaining wall increases by 0.29; for every increase of 5KPa in soil cohesion, the safety factor of the retaining wall increased by 1.16; for every 5° increases in soil internal friction angle, the safety factor of retaining wall increases by 0.6. The research is significant for studying the failure laws and stability of retaining walls and providing references for retaining wall design.

Fine mapping and cloning of a novel BrSCC1 gene for seed coat color in Brassica rapa L.

KEY MESSAGE: A novel BrSCC1 gene for seed coat color was fine mapped within a 41.1-kb interval on chromosome A03 in Brassica rapa and functionally validated by ectopic expression analysis. Yellow seed is a valuable breeding trait that can be potentiality applied for improving seed quality and oil productivity in oilseed Brassica crops. However, only few genes for yellow seed have been identified in B. rapa. We previously identified a minor quantitative trait locus (QTL), qSC3.1, for seed coat color on chromosome A03 in B. rapa. In order to isolate the seed coat color gene, a brown-seeded chromosome segment substitution line, CSSL-38, harboring the qSC3.1, was selected and crossed with the yellow-seeded recurrent parent, a rapid cycling inbred line of B. rapa (RcBr), to construct the secondary F2 population. Metabolite identification suggested that seed coat coloration in CSSL-38 was independent of proanthocyanidins (PAs) accumulation. Genetic analysis revealed that yellow seed was controlled by a single recessive gene, Seed Coat Color 1 (BrSCC1). Utilizing bulked segregant analysis (BSA)-seq and secondary F2 and F2:3 recombinants analysis, BrSCC1 was fine mapped within a 41.1-kb interval. By integrating gene expression profiling, genome sequence comparison, metabolite analysis, and functional validation through ectopic expression in Arabidopsis, the BraA03g040800.3C gene was confirmed to be BrSCC1, which positively correlated with the seed coat coloration. Our study provides a novel gene resource for the genetic improvement of yellow seeds in oilseed B. rapa.

Social Stigma and Depression among Asymptomatic COVID-19 Carriers in Shanghai, China: The Mediating Role of Entrapment and Decadence.

INTRODUCTION: Since the advent of 2019 novel coronavirus (COVID-19), the coexistence between social stigma and depression symptoms (depression hereafter) in COVID-19 patients has been mentioned, but the mechanisms involved remains unclear. This study aimed to explore how the stigma affects depression during the mid-pandemic period. METHODS: A cross-sectional survey using non-probability sampling was conducted among asymptomatic COVID-19 carriers in Shanghai, China (April 2022). An online questionnaire was used to obtain information on demographic characteristics and psychological traits. Logistic regression and path analysis were performed to analyze the depression risk factors and examine the mediation model, respectively. RESULTS: A total of 1283 participants (59.6% men) were involved in this study, in which 44.7% of carriers reported having depression. Univariate analyses found that education level (OR 0.575; 95% CI 0.448-0.737) and doses of vaccine (OR 1.693; 95% CI 1.042-2.750), were significantly associated with depression among asymptomatic carriers. The association between social stigma and depression was fully mediated by their feelings of entrapment and decadence (indirect effect = 0.204, p < 0.001; direct effect = -0.059, p = 0.058). The mediating role of entrapment between stigma and depression was moderated by age group (estimate = 0.116, p = 0.008). CONCLUSION: Mental health issues resulting from the COVID-19 pandemic are increasingly apparent in China and require urgent attention and responses. These findings provide new perspectives for the early prevention of depression in asymptomatic carriers.

The Mental Health and Syndemic Effect on Suicidal Ideation among Migrant Workers in China: A Cross-Sectional Study.

BACKGROUND: Migrant workers are in a socially disadvantaged position and thus suffer from more stress and mental health disorders, resulting in a high risk of suicidal ideation. This study aimed to explore the association between psychosocial problems and suicidal ideation, and the syndemic effect of concurrent psychosocial problems on suicidal ideation among migrant workers. METHODS: We conducted a cross-sectional study and recruited 1805 migrant workers in Shenzhen, China. Each participant completed a self-administered questionnaire to report sociodemographic information and mental health status. Univariate and multivariate logistic regression were used to explore the association between psychosocial variables and suicidal ideation, and their syndemic effect on suicidal ideation. RESULTS: The prevalence of suicidal ideation among migrant workers was 7.5%. All selected psychosocial variables were independently associated with suicidal ideation. Multivariate logistic regression analysis showed that three psychosocial variables were associated with suicidal ideation: anxiety (ORm: 1783, 95% CI: 1.089-2.920), entrapment (ORm: 2.064, 95% CI: 1.257-3.388), and defeat (ORm: 2.572, 95% CI: 1.612-4.103). Various mental health issues can exist simultaneously to increase the risk of suicidal ideation (AOR: 5.762, 95% CI: 3.773-8.802). Workers with more psychosocial problems were more likely to have suicidal ideation. CONCLUSIONS: The association between poor mental health and suicidal ideation should not be overlooked among migrant workers. The co-occurring or syndemic effect of psychosocial problems may increase the risk of suicidal ideation.

The Impact of Social Network Site Addiction on Depression in Chinese Medical Students: A Serial Multiple Mediator Model Involving Loneliness and Unmet Interpersonal Needs.

The use of social network sites (SNSs) is inevitable in daily life. Everyone is likely to be addicted to SNSs, especially medical students. This study is aimed to assess the degree of SNS addiction and its relation to psychosocial factors such as depression, loneliness and unmet interpersonal needs among Chinese medical students. The cross-section survey was conducted from March to May in 2018 in Shanghai Jiao Tong University School of Medicine. Of the total 1067 participants, 33.18% had an SNS addiction, 87.7% of the participants used SNSs every day during last month and 53.42% of the participants used SNSs for at least an hour per day during the last week. SNS addiction is positively related with depression both directly and indirectly. The mediating roles of loneliness and unmet interpersonal needs on the relationship between SNS addiction and depression are significant. For the well-being of medical students, efforts should be taken to prevent them from becoming addicted to SNSs.

A content analysis of e-cigarette related calls to the Shanghai health hotline, for the period 2014-2019.

INTRODUCTION: The health hotline (12320) of Shanghai, not only offers residents information about health knowledge, policies and regulations, but also serves as a channel for public supervision on health issues. This study explored the content of calls towards the Shanghai health hotline (SHH) related to e-cigarettes. METHODS: The call sheets related to e-cigarette received by SHH were collected from 2014 to 2019. Voice conversations were recorded by the management system of SHH and the telephone operators then converted the recordings into text to collect the information of residents. We used a natural language processor, ROST-CM6.0 to clean up and create words dictionaries and analyzed the text using a text-mining method to identify themes and other useful details. RESULTS: Among the 491 call sheets, 87.4% were for consultation and 7.5% for complaint. The issue that Shanghai citizens were concerned about most was 'whether the e-cigarette belongs to the jurisdictional scope of the Amendment', and 76.6% of the call sheets were related to this particular concern. Other concerns were 'whether e-cigarettes are harmful or not' (9.4%), 'can e-cigarettes help people quit smoking or have side effects' (6.1%), 'whether e-cigarettes can be sold openly in shopping malls and where can we buy e-cigarettes' (2.2%) and 'can minors buy e-cigarettes' (1.0%). CONCLUSIONS: The number of call sheets about e-cigarettes received by SHH has seen a significant increase since the Amendment was implemented with questions primarily focused on 'if electronic cigarettes belong to the scope of tobacco control'.

Identification and validation of major and minor QTLs controlling seed coat color in Brassica rapa L.

Seed coat color is an important agronomic trait in Brassica rapa. Yellow seeds are a desirable trait for breeding oilseed Brassica crops. To identify quantitative trait loci (QTLs) that condition seed coat color in B. rapa, we used a population of recombinant inbred lines (RILs) derived from crossing 09A001, a standard rapid-cycling (RcBr) inbred line of B. rapa L. ssp. dichotoma with yellow seeds, with 08A061, an inbred line of heading Chinese cabbage with dark brown seeds. Using two phenotypic scoring methods, we detected a total of nine QTLs distributed on four chromosomes (Chrs.), A03, A06, A08, and A09, that explained 3.17 to 55.73% of the phenotypic variation for seed color. To validate the effects of the identified QTLs in the RIL population, chromosome segment substitution lines (CSSLs) harboring the chromosomal segment carrying the candidate QTL region from 08A061 were selected, and two co-localized major QTLs, qSC9.1 and qSCb9.1, and one minor QTL, qSC3.1, were successfully validated. The validated QTL located on Chr. A03 appears to be a new locus underlying seed coat color in B. rapa. These findings provide additional insight that will help explain the complex genetic mechanisms underlying the seed coat color trait in B. rapa.