GWAS and Meta-QTL Analysis of Yield-Related Ear Traits in Maize.

Maize ear traits are an important component of yield, and the genetic basis of ear traits facilitates further yield improvement. In this study, a panel of 580 maize inbred lines were used as the study material, eight ear-related traits were measured through three years of planting, and whole genome sequencing was performed using the maize 40 K breeding chip based on genotyping by targeted sequencing (GBTS) technology. Five models were used to conduct a genome-wide association study (GWAS) on best linear unbiased estimate (BLUE) of ear traits to find the best model. The FarmCPU (Fixed and random model Circulating Probability Unification) model was the best model for this study; a total of 104 significant single nucleotide polymorphisms (SNPs) were detected, and 10 co-location SNPs were detected simultaneously in more than two environments. Through gene function annotation and prediction, a total of nine genes were identified as potentially associated with ear traits. Moreover, a total of 760 quantitative trait loci (QTL) associated with yield-related traits reported in 37 different articles were collected. Using the collected 760 QTL for meta-QTL analysis, a total of 41 MQTL (meta-QTL) associated with yield-related traits were identified, and 19 MQTL detected yield-related ear trait functional genes and candidate genes that have been reported in maize. Five significant SNPs detected by GWAS were located within these MQTL intervals, and another three significant SNPs were close to MQTL (less than 1 Mb). The results provide a theoretical reference for the analysis of the genetic basis of ear-related traits and the improvement of maize yield.

Hypoxia mitigation by manganese-doped carbon dots for synergistic photodynamic therapy of oral squamous cell carcinoma.

Photodynamic therapy (PDT) is widely used for cancer treatment due to its non-invasive and precise effectiveness, however, hypoxia in the tumor microenvironment greatly limits the efficacy of photodynamic therapy. Compared with conventional photosensitizers, carbon dots (CDs) have great potential. Therefore, developing a water-soluble, low-toxicity photosensitizer based on CDs is particularly important, especially one that can enhance the photodynamic efficacy using the tumor microenvironment to produce oxygen. Herein, manganese-doped carbon dot (Mn-CDs, ∼2.7 nm) nanoenzymes with excellent biocompatibility were prepared by a solvothermal method using ethylenediaminetetraacetic acid manganese disodium salt hydrate and o-phenylenediamine as precursors. TEM, AFM, HR-TEM, XRD, XPS, FT-IR, ζ potential, DLS, UV-Vis, and PL spectra were used to characterize the Mn-CDs. Cancer resistance was assessed using the CCK-8 kit, calcein AM versus propidium iodide (PI) kit, and the Annexin V-FITC/PI cell apoptosis assay kit. The obtained Mn-CDs have excellent near-infrared emission properties, stability, and efficient 1O2 generation. Notably, the manganese doping renders CDs with catalase (CAT)-like activity, which leads to the decomposition of acidic H2O2 in situ to generate O2, enhancing the PDT efficacy against OSCC-9 cells under 635 nm (300 mW·cm-2) irradiation. Thus, this work provides a simple and feasible method for the development of water-soluble photosensitizers with oxygen production, presenting good biosafety for PDT in hypoxic tumors.

Epistasis Activation Contributes Substantially to Heterosis in Temperate by Tropical Maize Hybrids.

Epistasis strongly affects the performance of superior maize hybrids. In this study, a multiple-hybrid population, consisting of three hybrid maize sets with varied interparental divergence, was generated by crossing 28 temperate and 23 tropical inbred lines with diverse genetic backgrounds. We obtained 1,154 tested hybrids. Among these tested hybrids, heterosis increased steadily as the heterotic genetic distance increased. Mid-parent heterosis was significantly higher in the temperate by tropical hybrids than in the temperate by temperate hybrids. Genome-wide prediction and association mapping was performed for grain weight per plant (GWPP) and days to silking (DTS) using 20K high-quality SNPs, showing that epistatic effects played a more prominent role than dominance effects in temperate by tropical maize hybrids. A total of 33 and 420 epistatic QTL were identified for GWPP and DTS, respectively, in the temperate by tropical hybrids. Protein-protein interaction network and gene-set enrichment analyses showed that epistatic genes were involved in protein interactions, which play an important role in photosynthesis, biological transcription pathways, and protein synthesis. We showed that the interaction of many minor-effect genes in the hybrids could activate the transcription activators of epistatic genes, resulting in a cascade of amplified yield heterosis. The multiple-hybrid population design enhanced our understanding of heterosis in maize, providing an insight into the acceleration of hybrid maize breeding by activating epistatic effects.

Development of high-resolution multiple-SNP arrays for genetic analyses and molecular breeding through genotyping by target sequencing and liquid chip.

Genotyping platforms, as critical supports for genomics, genetics, and molecular breeding, have been well implemented at national institutions/universities in developed countries and multinational seed companies that possess high-throughput, automatic, large-scale, and shared facilities. In this study, we integrated an improved genotyping by target sequencing (GBTS) system with capture-in-solution (liquid chip) technology to develop a multiple single-nucleotide polymorphism (mSNP) approach in which mSNPs can be captured from a single amplicon. From one 40K maize mSNP panel, we developed three types of markers (40K mSNPs, 251K SNPs, and 690K haplotypes), and generated multiple panels with various marker densities (1K-40K mSNPs) by sequencing at different depths. Comparative genetic diversity analysis was performed with genic versus intergenic markers and di-allelic SNPs versus non-typical SNPs. Compared with the one-amplicon-one-SNP system, mSNPs and within-mSNP haplotypes are more powerful for genetic diversity detection, linkage disequilibrium decay analysis, and genome-wide association studies. The technologies, protocols, and application scenarios developed for maize in this study will serve as a model for the development of mSNP arrays and highly efficient GBTS systems in animals, plants, and microorganisms.

Flowering time regulation model revisited by pooled sequencing of mass selection populations.

Maize is one of the most broadly cultivated crops throughout the world, and flowering time is a major adaptive trait for its diffusion. The biggest challenge in understanding maize flowering genetic architecture is that the trait is confounded with population structure. To eliminate the effect, we revisited the flower time genetic network by using a tropical maize population Pop32, which was under mass selection for adaptation to early flowering time in China for six generations from tropical to temperate regions. The days to anthesis (DTA) of the initial (Pop32C0), intermedia (Pop32C3), and final population (Pop32C5) was 90.77, 84.63, and 79.72 days on average, respectively. To examine the genetic mechanism and identify the genetic loci underlying this rapid change in flowering time of Pop32, we bulked 30 individuals from C0, C3, and C5 to conduct the whole genome sequencing. And we finally identified 4,973,810 high-quality single nucleotide polymorphisms (SNPs) and 6,517 genes with allele frequency significantly changed during the artificial improvement process. We speculate that these genes might participate in the adaptive improvement process and control flowering time. To identify the candidate genes for flowering time from the gene set with allele frequency changed, we carried out weighted gene co-expression network analysis (WGCNA), and identified four co-expression modules that highly associated with the flowering time development, as well as constructed the co-expression network of key flowering time genes. Gene Ontology (GO) enrichment analysis revealed that the GO terms photosynthesis/light reaction, carbohydrate binding, auxin mediated signaling pathway, response to temperature stimulus that are closely connected with flowering time. Furthermore, targeted GWAS revealed the genes are significantly connected with the flowering time. qRT-PCR of four candidate genes GRMZM2G019879, GRMZM2G055905, GRMZM2G058158, and GRMZM2G171365 showed that their expression level is similar to the flowering time genes, which playing a key role in maize flowering time transition. This study revealed that the changes of flowering time in mass selection process may be strongly associated with the variations of allele frequency changes, and we identified some important candidate genes for flowering time, which will provide a new insight for the rapid improvement of maize important agronomic traits and promote the gene cloning of maize flowering time.

The Relationship Between Resilience and Mental Health in Chinese College Students: A Longitudinal Cross-Lagged Analysis.

The relationship between resilience and mental health was examined in three phases over 4 years in a sample of 314 college students in China. The present study aimed to gain insight into the reciprocal relationship of higher levels of resilience predicting lower levels of mental ill-being, and higher levels of positive mental health, and vice versa, and track changes in both resilience, mental ill-being and positive mental health over 4 years. We used the Depression Anxiety Stress, the Positive Mental Health, and the Resilience Scales. Results revealed that first-year students and senior year students experienced higher negative mental health levels and lower positive mental health levels than junior year students. Cross-lagged structural equation modeling analyses showed that resilience could significantly predict mental health status in the short term, namely within 1 year from junior to senior year. However, the predicting function of resilience for mental health is not significant in the long term, namely within 2 years from freshman to junior year. Additionally, the significant predicting function of individuals' mental health for resilience is fully verified for both the short and long term. These results indicate that college mental health education and interventions could be tailored based on students' year in college.

Measurement Invariance of the Depression Anxiety Stress Scales-21 Across Gender in a Sample of Chinese University Students.

The Depression Anxiety Stress Scales-21 (DASS-21) has three 7-item subscales (depression, anxiety, and stress). The current study aims assess the gender-based measurement invariance of the DASS-21 questionnaire in a Chinese university student sample from five different cities. The sample was composed of 13208 participants (62.3% female, mean age of 19.7 years, and SD age = 1.8). Multi-group confirmatory factor analysis supported full measurement invariance for the three subscales. The findings support the measurement invariance of DASS-21 scores across gender. Future research on the DASS should include additional validation across ethnicities and testing of all versions of the DASS.

The Spread and Development of Psychodrama in Mainland China.

The history of the popularization and research of psychodrama in the west has spanned more than 80 years since it was founded by J. L. Moreno in the 1930s. However, it was only in the 1990s that psychodrama was systematically introduced in mainland China. The historical process of the spread and development of psychodrama in China is complex; therefore, this study approached it from the perspectives of space and time and theoretical development. Considering four events as the critical time points, the history of psychodrama in China can be divided into four periods from a spatiotemporal perspective: pre-contact period, preparatory period, period of prosperity, and the period of new development. Based on the theoretical classification, three major branches of psychodrama in mainland China are represented by Gong Shu's Yi Shu psychodrama, Katherine Hudgins' therapeutic spiral model, and campus psychodrama developed by Chinese psychologists.

Fitts' Law is modulated by movement history.

Fitts' Law is one of the most robust and well-studied principles in psychology. It holds that movement time (MT) for target-directed aiming movements increases as a function of target distance and decreases as a function of target width. The purpose of this study was to determine whether Fitts' Law is affected not only by the demands of the target on the current trial but also by the requirements for performance on the previous trial. Experiments 1 and 2 examined trial-to-trial effects of varying target width; Experiment 3 examined trial-to-trial effects of varying target distance. The findings from Experiments 1 and 2 showed that moving a finger or cursor towards a large object on a previous trial shortened the movement time on the current trial, whereas the opposite occurred with a small object. In contrast, target distance on the previous trial had no effect on movement time on the current trial. These findings suggest that performance on trial n has a clear and predictable effect on trial n+1 (at least for target width) and that Fitts' Law as it is normally expressed does not accurately predict performance when the width of the target varies from trial to trial.

Association between hair cortisol concentration and perceived stress in female methamphetamine addicts.

OBJECTIVE: The present study aims to explore whether hair cortisol concentration is associated with explicit stress or implicit stress in female methamphetamine addicts. METHODS: Hair samples were collected from 51 female methamphetamine addicts from inpatient addiction treatment programs. Perceived stress was assessed by both explicit and implicit measures through the Perceived Stress Scale (PSS) and the Implicit Association Test (IAT), respectively. RESULTS: The positive relationship between hair cortisol concentration with D-scores of the IAT reached statistically significant difference. A marginal correlation between hair cortisol concentration and scores of the PSS was observed. Additionally, linear regression analysis indicated that D-scores of the IAT are strongly predictive of hair cortisol concentration. CONCLUSION: Hair cortisol concentration is strongly related to implicit stress but only weakly related with explicit stress.

Personal value orientations as mediated predictors of mental health: A three-culture study of Chinese, Russian, and German university students.

Previous studies of traditional and modern value orientations in individuals found mediated predictive relationships of these values on particular mental disorders. The aim of this study with samples from three countries (Germany, Russia, and China) is to extend findings on mental health (MH) and value orientations to broader MH indicators and two types of mediators, i.e. social support and resilience in accordance to a theory of values and modernization/postmodernization. The multisite study was conducted in the three countries. A path-model with traditional values predicting MH mediated by social support, and modern values predicting MH mediated by resilience was tested in all three countries. As expected, value orientations were for the most part strongest in China, followed by Russia and Germany. Structural equation modeling supported the assumption of mediated prediction of MH by value orientations by and large. The traditional value benevolence predicts social support whereas the modern value self-direction predicts resilience. Value orientations are a sensitive tool to empirically describe cross-cultural differences. The findings indicate that personal value orientations are meaningful predictors of MH. The analysis of personal values shows promise in linking public health, cross-cultural and modernization issues.

Estudios previos sobre orientaciones de valores tradicionales y modernos encontraron relaciones predictivas mediadas con trastornos mentales particulares. El objetivo de este estudio con muestras procedentes de tres países (Alemania, Rusia y China) es ampliar los resultados indicadores más amplios de salud mental (SM) y dos tipos de mediadores (apoyo social y resiliencia), de acuerdo a la teoría de los valores y la modernización/postmodernización. Se probó en los tres países un path-model con valores tradicionales prediciendo la SM mediada por el apoyo social y valores modernos prediciendo la SM mediada por la resiliencia. Como era de esperar, las orientaciones de valores eran en su mayor parte más fuertes en China, seguido por Rusia y Alemania. Modelos de ecuaciones estructurales apoyaron la hipótesis de la predicción de la SM mediada por las orientaciones de valores en general. La benevolencia de valores tradicionales predice el apoyo social, mientras que el valor autodirección moderna predice la resiliencia. Las orientaciones de valores constituyen una herramienta sensible para describir empíricamente las diferencias interculturales. Los resultados indican que las orientaciones de valores personales son predictores significativos de la SM. El análisis de los valores personales se muestra prometedor en la salud pública transcultural y cuestiones de modernización.

The Mini-IPIP Scale: psychometric features and relations with PTSD symptoms of Chinese earthquake survivors.

The present purpose was to validate the Mini-IPIP scale, a short measure of the five-factor model personality traits, with a sample of Chinese earthquake survivors. A total of 1,563 participants, ages 16 to 85 years, completed the Mini-IPIP scale and a measure of posttraumatic stress disorder (PTSD) symptoms. Confirmatory factor analysis supported the five-factor structure of the Mini-IPIP with adequate values of various fit indices. This scale also showed values of internal consistency, Cronbach's alphas ranged from .79 to .84, and McDonald's omega ranged from .73 to .82 for scores on each subscale. Moreover, the five personality traits measured by the Mini-IPIP and those assessed by other big five measures had comparable patterns of relations with PTSD symptoms. Findings indicated that the Mini-IPIP is an adequate short-form of the Big-Five factors of personality, which is applicable with natural disaster survivors.