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In rural China, male offspring are traditionally regarded as the primary heirs of household assets, particularly land. This study examines the impact of offspring gender composition on long-term agricultural investment behavior, using commercial organic fertilizer application as an example of a strategic long-term investment in farmland. Based on cross-sectional data from 4090 rice farming households across 10 cities (counties) in Hubei province, collected between 2021 and 2023, this analysis identifies three key findings. First, the absence of male offspring significantly reduces long-term agricultural investments, a result that remains robust even when addressing potential endogeneity biases using instrumental variable techniques. Second, households without male heirs exhibit stronger present-oriented preferences and diminished social capital, which further hinder long-term agricultural investments. Third, the negative impact of not having male offspring is more pronounced when the current agricultural decision-maker is male and when land marketization is underdeveloped. These findings underscore the complex interplay between gender norms and agricultural behavior, revealing significant socioeconomic implications of inheritance practices. The study provides insights into addressing these challenges by emphasizing the importance of promoting gender equality and advancing land marketization to enhance equitable land use and support long-term agricultural investment.
The school–vacation cycle may have impacts on the psychological states of adolescents. However, little evidence illustrates how transition from school to vacation impacts students’ psychological states (e.g. depression and anxiety).
Aims
To explore the changing patterns of depression and anxiety symptoms among adolescent students within a school–vacation transition and to provide insights for prevention or intervention targets.
Method
Social demographic data and depression and anxiety symptoms were measured from 1380 adolescent students during the school year (age: 13.8 ± 0.88) and 1100 students during the summer vacation (age: 14.2 ± 0.93) in China. Multilevel mixed-effect models were used to examine the changes in depression and anxiety levels and the associated influencing factors. Network analysis was used to explore the symptom network structures of depression and anxiety during school and vacation.
Results
Depression and anxiety symptoms significantly decreased during the vacation compared to the school period. Being female, higher age and with lower mother's educational level were identified as longitudinal risk factors. Interaction effects were found between group (school versus vacation) and the father's educational level as well as grade. Network analyses demonstrated that the anxiety symptoms, including ‘Nervous’, ‘Control worry’ and ‘Relax’ were the most central symptoms at both times. Psychomotor disturbance, including ‘Restless’, ‘Nervous’ and ‘Motor’, bridged depression and anxiety symptoms. The central and bridge symptoms showed variation across the school vacation.
Conclusions
The school–vacation transition had an impact on students’ depression and anxiety symptoms. Prevention and intervention strategies for adolescents’ depression and anxiety during school and vacation periods should be differentially developed.
This study aims to explore the dynamics of leadership reconfiguration within emergent state-owned enterprises (SOEs), i.e., privately owned enterprises (POEs) that have been acquired by SOEs. From an institutional logic perspective, we argue that the emergence of these SOEs reflects a process in which POEs, previously dominated by market logic, incorporate state logic and transition to a hybrid form. However, this process presents a paradox for emergent SOEs: while a greater extent of reconfiguration of leadership helps them gain greater legitimacy in front of state-related institutional referents, it also results in greater conflicts between members adhering to different logics. To address this paradox, we theorize on the differences in the reconfigurations of the board and top management team (TMT) by respectively connecting their functions to institutional control and agency, two typical forms of institutional power. Our analysis reveals that emergent SOEs tend to experience reconfiguration more in the board while less in TMT. Furthermore, we find that these main effects are moderated by the industrial state-ownership density and acquirees' preacquisition political connections. Our study contributes to the SOE and M&A literature by highlighting the uniqueness of emergent SOEs arising from POE-to-SOE acquisitions. Additionally, we propose a strategy to reconcile legitimation and internal stabilizations during logic hybridizations, thereby contributing to the institutional logic literature.
The rapid development of generative artificial intelligence (AI) systems, particularly those fuelled by increasingly advanced large language models, has raised concerns of their potential risks among policymakers globally. In July 2023, Chinese regulators enacted the Interim Measures for the Management of Generative AI Services (“the Measures”). The Measures aim to mitigate various risks associated with public-facing generative AI services, particularly those concerning information content safety and security. China’s approach to regulating AI to date has sought to address the risks associated with rapidly advancing AI technologies while fostering innovation and development. Tensions between these policy objectives are reflected in the provisions of the Measures. As Beijing moves towards establishing a comprehensive legal framework for AI governance, there will be growing interest in how China’s approach may influence AI governance and regulation at a global level.
In this paper, we propose a novel and highly effective variational Bayesian expectation maximization-maximization (VBEM-M) inference method for log-linear cognitive diagnostic model (CDM). In the implementation of the variational Bayesian approach for the saturated log-linear CDM, the conditional variational posteriors of the parameters that need to be derived are in the same distributional family as the priors, the VBEM-M algorithm overcomes this problem. Our algorithm can directly estimate the item parameters and the latent attribute-mastery pattern simultaneously. In contrast, Yamaguchi and Okada’s (2020a) variational Bayesian algorithm requires a transformation step to obtain the item parameters for the log-linear cognitive diagnostic model (LCDM). We conducted multiple simulation studies to assess the performance of the VBEM-M algorithm in terms of parameter recovery, execution time, and convergence rate. Furthermore, we conducted a series of comparative studies on the accuracy of parameter estimation for the DINA model and the saturated LCDM, focusing on the VBEM-M, VB, expectation-maximization, and Markov chain Monte Carlo algorithms. The results indicated that our method can obtain more stable and accurate estimates, especially for the small sample sizes. Finally, we demonstrated the utility of the proposed algorithm using two real datasets.
With the growing attention on large-scale educational testing and assessment, the ability to process substantial volumes of response data becomes crucial. Current estimation methods within item response theory (IRT), despite their high precision, often pose considerable computational burdens with large-scale data, leading to reduced computational speed. This study introduces a novel “divide- and-conquer” parallel algorithm built on the Wasserstein posterior approximation concept, aiming to enhance computational speed while maintaining accurate parameter estimation. This algorithm enables drawing parameters from segmented data subsets in parallel, followed by an amalgamation of these parameters via Wasserstein posterior approximation. Theoretical support for the algorithm is established through asymptotic optimality under certain regularity assumptions. Practical validation is demonstrated using real-world data from the Programme for International Student Assessment. Ultimately, this research proposes a transformative approach to managing educational big data, offering a scalable, efficient, and precise alternative that promises to redefine traditional practices in educational assessments.
Asymptotic expansions of the maximum likelihood estimator (MLE) and weighted likelihood estimator (WLE) of an examinee’s ability are derived while item parameter estimators are treated as covariates measured with error. The asymptotic formulae present the amount of bias of the ability estimators due to the uncertainty of item parameter estimators. A numerical example is presented to illustrate how to apply the formulae to evaluate the impact of uncertainty about item parameters on ability estimation and the appropriateness of estimating ability using the regular MLE or WLE method.
Stimulated Raman scattering is a third-order nonlinear optical effect that is not only effective for wavelength converting laser output, but also for single longitudinal-mode output due to the absence of spatial hole burning. Diamond is a prominent Raman-active medium that has significant potential for linewidth narrowing and wavelength converting lasers at high power levels due to its high thermal conductivity, long Raman frequency shift and wide spectral transmission range. In this work we utilize diamond in a resonantly mode-matched external cavity to achieve cascaded Raman conversion of a 1064 nm laser. By fine-tuning the length of this external cavity, we can obtain narrow linewidth emission at 1240 and 1485 nm. When operating at maximum power, the measured linewidths were more than twofold narrower than the linewidth of the fundamental field. In addition, the noise levels of the Stokes fields are lower than that of the fundamental field throughout the entire noise frequency range, and the intrinsic linewidth of the second Stokes field, which is expressed at the hertz level (~3.6 Hz), is decreased by approximately three orders of magnitude compared to that of the pump. This work represents the first measurement and analysis of the linewidth and noise characteristics of cascaded diamond Raman lasers and, significantly, offers a new means by which high-power, narrow linewidth laser output can be produced from wavelength-converted laser systems.
Large-aperture gratings have significant applications in inertial confinement fusion, immersion lithography manufacturing and astronomical observation. Currently, it is challenging and expensive to manufacture sizable monolithic gratings. Therefore, tiled multiple small-aperture gratings are preferred. In this study, the impact of seam phase discontinuity on the modulation of the laser beam field was explored based on the measurement results of the Shenguang-II laser large-aperture multi-exposure-tiled grating. An innovative method for accurately calculating the phase jump of multi-exposure-tiled grating seams was proposed. An intensive electromagnetic field analysis was performed by applying rigorous coupled-wave analysis to a reasonably constructed micrometer-level periodic grating seam structure, and the phase jump appearing in millimeter-scale seams of large-aperture tiled gratings was obtained accurately.
Interlaminar delamination damage is a common and typical defect in the context of structural damage in carbon fiber-reinforced resin matrix composites. The technology to identify such damage is crucial for improving the safety and reliability of structures. In this paper, we fabricated carbon fiber-reinforced composite laminates with different degrees of delamination damage, conducted static load experiments on them and used femtosecond fiber Bragg grating sensors (fsFBG) to determine their structural state to investigate the effects of delamination damage on their performance. We constructed a model to identify damage based on the deep residual shrinkage network, and used experimental data to enable it to identify varying degrees of delamination damage to carbon fiber-reinforced composites with an accuracy of 97.98%.
Direct numerical simulations are performed to explore the evolution behaviour of the turbulent/non-turbulent interface (TNTI) in a temporally evolving turbulent plane jet, using the evolution equation for the TNTI surface area. A novel algorithm is used to calculate the surface area of the TNTI and entrainment flux. It is shown that the surface area remains relatively constant, which leads to the mean entrainment velocity being inversely proportional to the square root of time. On average, the effects of the stretching and curvature/viscous terms on the TNTI area roughly counterbalance each other, while the curvature/inviscid term associated with vortex stretching is virtually zero. More specifically, the stretching term contributes to the production of the surface area, while the curvature/viscous term is associated with a destruction in the surface area. The local effect of the curvature/viscous term exhibits high spatial intermittency with small-scale extreme/intense events, whereas the effect of the large-scale stretching term is more continuous. To shed light on the contribution of curvature/viscous term to the evolution of the surface area, we decompose it into three components. The effect of the curvature/normal diffusion term (the curvature/viscous dissipation term) in the bulging regions (the valley regions) mainly contributes to the production of the area. The continuous decrease of the average mean curvature is associated with the production of the bulging regions and the destruction of the valley regions. Finally, although the entrainment velocity is mainly dominated by the normal diffusion effect, all three components related to the viscous effect are indispensable to the production and destruction of the TNTI area. This numerical study contributes to a better understanding of the evolution of the TNTI area.
Paraquat, one of the most widely utilized herbicides globally, causes a significant environmental challenge due to its poor degradation rate and tendency to adsorb into clay interlayers. Several remediation methods have been proposed but their effectiveness remains suboptimal. The primary reason for this is the lack of microscopic understanding of paraquat–montmorillonite interactions. In this work molecular dynamics simulations were applied to study the interlayer structures and mobility of paraquat intercalated montmorillonite. Two stable hydration states were identified from the calculated immersion energy curve, which corresponded to a water content of 185 mgwater/gclay and 278 mgwater/gclay (the most stable). Paraquats remained in direct contact with the clay surface in both the anhydrous and hydrated states. At the water content of 185 mgwater/gclay, paraquats formed π-π stacking while at 278 mgwater/gclay, they were separated by a layer of water. Paraquat showed very small self-diffusion coefficients in the interlayer space of montmorillonite, indicating rather limited motions. The results in this work provide a basis for a better understanding of the interaction of paraquat with clay minerals.
Our study aimed to develop and validate a nomogram to assess talaromycosis risk in hospitalized HIV-positive patients. Prediction models were built using data from a multicentre retrospective cohort study in China. On the basis of the inclusion and exclusion criteria, we collected data from 1564 hospitalized HIV-positive patients in four hospitals from 2010 to 2019. Inpatients were randomly assigned to the training or validation group at a 7:3 ratio. To identify the potential risk factors for talaromycosis in HIV-infected patients, univariate and multivariate logistic regression analyses were conducted. Through multivariate logistic regression, we determined ten variables that were independent risk factors for talaromycosis in HIV-infected individuals. A nomogram was developed following the findings of the multivariate logistic regression analysis. For user convenience, a web-based nomogram calculator was also created. The nomogram demonstrated excellent discrimination in both the training and validation groups [area under the ROC curve (AUC) = 0.883 vs. 0.889] and good calibration. The results of the clinical impact curve (CIC) analysis and decision curve analysis (DCA) confirmed the clinical utility of the model. Clinicians will benefit from this simple, practical, and quantitative strategy to predict talaromycosis risk in HIV-infected patients and can implement appropriate interventions accordingly.
This study is dedicated to achieving efficient active noise control in a supersonic underexpanded planar jet, utilizing control parameters informed by resolvent analysis. The baseline supersonic underexpanded jet exhibits complex wave structures and substantial high-amplitude noise radiations. To perform the active control, unsteady blowing and suction are applied along the nozzle inner wall close to the exit. Employing both standard and acoustic resolvent analyses, a suitable frequency and spanwise wavenumber range for the blowing and suction is identified. Within this range, the control forcing can be significantly amplified in the near field, effectively altering the original sound-producing energetic structure while minimizing far-field amplification to prevent excessive noise. A series of large-eddy simulations are further conducted to validate the control efficiency, demonstrating an over 10 dB reduction in upstream-propagated screech noise. It is identified that the present unsteady control proves more effective than steady control at the same momentum coefficient. The controlled jet flow indicates that the shock structures become more stable, and the stronger the streamwise amplification of the forcing, the more likely it is to modify the mean flow characteristics, which is beneficial for reducing far-field noise radiation. Spectral proper orthogonal decomposition analysis of the controlled flow confirms that the control redistributes energy to higher forcing frequencies and suppresses large-scale antisymmetric and symmetric modes related to screech and its harmonics. The findings of this study highlight the potential of resolvent-guided control techniques in reducing noise in supersonic underexpanded jets and provide a detailed understanding of the inherent mechanisms for effective noise reduction through active control strategies.
Sea-ice deformation is concentrated at linear kinematic features such as ridges and leads. Ridging and leads opening processes are highly related to sea-ice fracture. Different rheology models have been successfully applied in various scenarios. However, most of the approaches adopted are based on continuum mechanics that do not explicitly model fracture processes. There are emerging needs for a more physically informed modelling methods that explicitly address fracture at the kilometre scale. In pursuing this objective, in this paper we explored the potential of applying a promising mesh free numerical method, peridynamics (PD), in modelling ice floe (~km) fractures. PD offers a physically and mathematically consistent theory through which spontaneous emergence and propagation of cracks can be achieved. The integral nature of the governing equations in PD remains valid even if a crack appears. We numerically investigated in this paper the tensile fracture (e.g. lead opening) of an elastic heterogenous ice floe. The modelling results were compared with published numerical results obtained by another numerical method. The potentials and challenges of PD in this application are discussed and summarized.
Emotion regulation, as a typical “top-down” emotional self-regulation, has been shown to play an important role in children’s oppositional defiant disorder (ODD) development. However, the association between other self-regulation subcomponents and the ODD symptom network remains unclear. Meanwhile, while there are gender differences in both self-regulation and ODD, few studies have examined whether their relation is moderated by gender. Five hundred and four children (age 6–11 years; 207 girls) were recruited from schools with parents and classroom teachers completing questionnaires and were followed up for assessment six months later. Using moderation network analysis, we analyzed the relation between self-regulation and ODD symptoms, and the moderating role of gender. Self-regulation including emotion regulation, self-control, and emotion lability/negativity had broad bidirectional relations with ODD symptoms. In particular, the bidirectional relations between emotion regulation and ODD3 (Defies) and between emotion lability/negativity and ODD4 (Annoys) were significantly weaker in girls than in boys. Considering the important role of different self-regulation subcomponents in the ODD symptom network, ODD is better conceptualized as a self-regulation disorder. Each ODD symptom is associated with different degrees of impaired “bottom-up” and “top-down” self-regulation, and several of the associations vary by gender.
Skeletal muscle is of great importance for human activity and quality of life, as its loss contributes greatly to immobilisation, especially for aged individuals. An increased dietary intake of antioxidant vitamins may be beneficial for muscle loss because of ageing. However, the quantitative relationship between total antioxidant capacity (TAC) of antioxidant vitamins and muscle mass is undetermined. Totally, 4009 participants from the National Health and Nutrition Examination Survey (NHANES) were included. Multivariate linear regression analysis was performed with demographic, lifestyle and dietary intake adjustment factors. The dose saturation effect was also determined by a saturation effect analysis. Subgroup analysis was performed for age and sex. In the fully adjusted model, per unit increase of dietary TAC was associated with an increase of 0·018 g/kg appendicular lean mass (95 % CI 0·007, 0·029), 0·014 g/kg trunk lean mass (95 % CI 0·004, 0·024) and 0·035 g/kg total lean mass (95 % CI 0·014, 0·055). TAC was associated with a decrease of 0·004 kg/kg total percent fat (95 % CI −0·006, −0·002), 0·005 kg/kg trunk percent fat (95 % CI −0·007, −0·002) and 0·003 kg/m2 BMI (95 % CI −0·006, −0·001) at the same time. Subgroup analysis indicated that women and adults < 50 years may experience the most significant association between TAC and skeletal muscle mass. We revealed a positive correlation between TAC and lean body mass and a negative association between TAC and body fat and BMI. Saturation values were found among people aged 40–59 years. Age and sex mediate these associations.
Folate metabolism is involved in the development and progression of various cancers. We investigated the association of single nucleotide polymorphisms (SNP) in folate-metabolising genes and their interactions with serum folate concentrations with overall survival (OS) and liver cancer-specific survival (LCSS) of newly diagnosed hepatocellular carcinoma (HCC) patients. We detected the genotypes of six SNP in three genes related to folate metabolism: methylenetetrahydrofolate reductase (MTHFR), 5-methyltetrahydrofolate-homocysteine methyltransferase reductase (MTRR) and 5-methyltetrahydrofolate-homocysteine methyltransferase (MTR). Cox proportional hazard models were used to calculate multivariable-adjusted hazard ratios (HR) and 95 % CI. This analysis included 970 HCC patients with genotypes of six SNP, and 864 of them had serum folate measurements. During a median follow-up of 722 d, 393 deaths occurred, with 360 attributed to HCC. In the fully-adjusted models, the MTRR rs1801394 polymorphism was significantly associated with OS in additive (per G allele: HR = 0·84, 95 % CI: 0·71, 0·99), co-dominant (AG v. AA: HR = 0·77; 95 % CI: 0·62, 0·96) and dominant (AG + GG v. AA: HR = 0·78; 95 % CI: 0·63, 0·96) models. Carrying increasing numbers of protective alleles was linked to better LCSS (HR10–12 v. 2–6 = 0·70; 95 % CI: 0·49, 1·00) and OS (HR10–12 v. 2–6 = 0·67; 95 % CI: 0·47, 0·95). Furthermore, we observed significant interactions on both multiplicative and additive scales between serum folate levels and MTRR rs1801394 polymorphism. Carrying the variant G allele of the MTRR rs1801394 is associated with better HCC prognosis and may enhance the favourable association between higher serum folate levels and improved survival among HCC patients.