Long-term exposure to ambient ozone and adult-onset asthma: A prospective cohort study.

BACKGROUND: The association between long-term exposure to ozone (O3) and adult-onset asthma (AOA) remains inconclusive, and analysis of causality is lacking. OBJECTIVES: To examine the causal association between long-term O3 exposure and AOA. METHODS: A prospective cohort study of 362,098 participants was conducted using the UK Biobank study. Incident cases of AOA were identified using health administrative data of the National Health Services. O3 exposure at participants' residential addresses was estimated by a spatio-temporal model. Instrumental variable (IV) modelling was used to analyze the causal association between O3 exposure and AOA, by incorporating wind speed and planetary boundary layer height as IVs into time-dependent Cox model. Negative control outcome (accidental injury) was also used to additionally evaluate unmeasured confounding. RESULTS: During a mean follow-up of 11.38 years, a total of 10,973 incident AOA cases were identified. A U-shaped concentration-response relationship was observed between O3 exposure and AOA in the traditional Cox models with HR of 0.917 (95% CI: 0.889, 0.946) for O3 at low levels (<38.17 ppb), and 1.198 (95% CI: 1.162, 1.236) for O3 at high levels (≥38.17 ppb). However, in the IV analysis we only found a statistically significant association between high-level O3 exposure and AOA risk, but not for low-level O3 exposure. No significant associations between O3 exposure and accidental injury were observed. CONCLUSION: Our findings suggest a potential causal relationship between long-term exposure to high-level ambient O3 and increased risks of AOA.

A High-Voltage-Specialized Direct-Current Triboelectric Nanogenerator for Air Purification.

Human health and the environment face significant challenges of air pollution, which is predominantly caused by PM2.5 or PM10 particles. Existing control methods often require elevated energy consumption or bulky high-voltage electrical equipment. To overcome these limitations, a self-powered, convenient, and compact direct current high-voltage triboelectric nanogenerator based on triboelectrification and electrostatic breakdown effects is proposed. By optimizing the structure-design of the direct current triboelectric nanogenerator and corresponding output voltage, it can easily achieve an output voltage of over 3 kV with a high charge density of 320 µC m-2 . A power management circuit is designed to overcome the influence of third domain self-breakdown, optimize 92.5% amplitude of voltage shake, and raise 5% charge utilization ratio. With a device size as tiny as 2.25 cm3 , it can continuously drive carbon nanowires to generate negative ions that settle dust within 300 s. This compact, simple, efficient, and safe high-voltage direct current triboelectric nanogenerator represents a promising sustainable solution. It offers efficient dust mitigation, fostering cleaner environments, and enhancing overall health.

New multi-source waste co-incineration and clustering park operating model for small- and medium-sized city: A case study in China.

With improvements in urban waste management to promote sustainable development, an increasing number of waste types need to be sorted and treated separately. Due to the relatively low amount of waste generated in small- and medium-sized cities, separate treatment facilities for each waste type lack scale, waste is treated at a high cost and low efficiency. Therefore, industrial symbiosis principles are suggested to be used to guide collaborative waste treatment system of multi-source solid wastes, and co-incineration is the most commonly used technology. Most existing studies have focused on co-incineration of one certain waste type (such as sludge or medical waste) with municipal solid waste (MSW), but the systematic design and the comprehensive benefits on a whole city and park level have not been widely studied. Taking the actual operation of a multi-source waste co-incineration park in south-central China as an example, this study conducted a detailed analysis of the waste-energy-water metabolism process of MSW, sludge, food waste, and medical waste co-incineration. The environmental and economic benefits were evaluated and compared with the single decentralized waste treatment mode. The results showed that the multi-source waste co-incineration and clustering park operating model was comprehensively superior to the single treatment mode, greenhouse gases and human toxicity indicators were decreased by 11.87% and 295.74%, respectively, and the internal rate of return of the project was increased by 29.35%. This mainly benefits from the synergy of technical system and the economies of scale. Finally, this research proposed policy suggestions from systematic planning and design, technical route selection, and an innovative management mode in view of the potential challenges.

Causal association between long-term exposure to air pollution and incident Parkinson's disease.

Epidemiological evidence for long-term air pollution exposure and Parkinson's disease (PD) is controversial, and analysis of causality is limited. We identified 293,888 participants who were free of PD at baseline in the UK Biobank (2006-2010). Time-varying air pollution [fine particulate (PM2.5) and ozone (O3)] exposures were estimated using spatio-temporal models. Incident cases of PD were identified using validated algorithms. Four methods were used to investigate the associations between air pollution and PD, including (1) standard time-varying Cox proportional-hazard model; (2) Cox models weighted by generalized propensity score (GPS) and inverse-probability weights (IPW); (3) instrumental variable (IV) analysis; and (4) negative control outcome analysis. During a median of 11.6 years of follow-up, 1822 incident PD cases were identified. Based on standard Cox regression, the hazard ratios (95% confidence interval) for a 1 µg/m3 or ppb increase in PM2.5 and O3 were 1.23 (1.17, 1.30) and 1.02 (0.98, 1.05), respectively. Consistent results were found in models weighted by GPS and IPW, and in IV analysis. There were no significant associations between air pollution and negative control outcomes. This study provides evidence to support a causal association between PM2.5 exposure and PD. Mitigation of air pollution could be a protective measure against PD.

A Dual-Mode Triboelectric Nanogenerator for Efficiently Harvesting Droplet Energy.

Triboelectric nanogenerator (TENG) is a promising solution to harvest the low-frequency, low-actuation-force, and high-entropy droplet energy. Conventional attempts mainly focus on maximizing electrostatic energy harvest on the liquid-solid surface, but enormous kinetic energy of droplet hitting the substrate is directly dissipated, limiting the output performance. Here, a dual-mode TENG (DM-TENG) is proposed to efficiently harvest both electrostatic energy at liquid-solid surface from a droplet TENG (D-TENG) and elastic potential energy of the vibrated cantilever from a contact-separation TENG (CS-TENG). Triggered by small droplets, the flexible cantilever beam, rather than conventional stiff ones, can easily vibrate multiple times with large amplitude, enabling frequency multiplication of CS-TENG and producing amplified output charges. Combining with the top electrode design to sufficiently utilize charges at liquid-solid interface, a record-high output charge of 158 nC is realized by single droplet. The energy conversion efficiency of DM-TENG is 2.66-fold of D-TENG. An array system with the specially designed power management circuit is also demonstrated for building self-powered system, offering promising applications for efficiently harvesting raindrop energy.

Hyperhenrones: Prenylated α-pyrones with anti-inflammatory activity from Hypericum henryi.

Fourteen previously undescribed α-pyrone derivatives (1-14) together with four known analogs (15-18) were isolated from a traditional Chinese medicinal plant Hypericum henryi. Compounds (+)/(-)-1, 2, and 3 share a rare 6/6/4/6/6 polycyclic skeleton. Compound 14 was the first example of a 7,7-dimethyl-pyran-4-one moiety. Their structures were elucidated using comprehensive spectroscopic analyses and electronic circular dichroism calculations. The anti-inflammatory activities of 1-18 were screened in lipopolysaccharide-induced RAW264.7 cells. Among them, compounds 14, (+)-18, and (-)-18 exhibited inhibitory effects against nitric oxide production in LPS-induced RAW264.7 cells. Additionally, compound 14 suppressed the expression of cyclooxygenase-2 and inducible nitric oxide synthase in LPS-induced RAW264.7 cells. Furthermore, preliminary mechanism studies indicated that compound 14 suppressed the phosphorylation and degradation of the inhibitor of NF-κB, and this led to the inhibition of NF-κB activation.

Prevalence of and factors associated with potentially redundant randomized controlled trials: a cross-sectional study.

OBJECTIVES: To investigate the prevalence of meta-analyses containing potentially redundant randomized controlled trials (RCTs) and the factors associated with the presence of redundancy. STUDY DESIGN AND SETTING: This is a cross-sectional study, based on a random sample of references (n = 4500) that were published during 2020 and 2021, indexed in PubMed, Embase, or the Cochrane Database of Systematic Reviews, and retrieved through comprehensive searches using terms about systematic reviews and meta-analysis. From each systematic review, one meta-analysis fulfilling all the following criteria, if available, was included in this study: (1) assessing the effect of the intervention on a primary outcome of the systematic review; (2) combining RCTs only. The primary outcome was prevalence of meta-analyses containing potentially redundant RCTs. Potentially redundant RCTs referred to the trials that started 1 year after the overall effect estimate from cumulative meta-analysis had been statistically robust, as determined by trial sequential analysis when appropriate. The number of potentially redundant trials (if any) in each eligible meta-analysis and the number of participants involved in those trials were documented and contrasted across groups. Logistic regression analysis was conducted to explore the factors associated with presence of potential redundancy. RESULTS: Of the 448 eligible meta-analyses, 57 (12.7%, 95% confidence interval (CI) 9.8-16.2%) contained potentially redundant RCTs. When limited to the 333 low-heterogeneity meta-analyses, the prevalence was 17.1% (95% CI 13.5-21.5%). The total number of potentially redundant RCTs was 295 (involving 85,385 participants), accounting for 38.5% of the RCTs (and 30.3% of the participants) included in the 57 meta-analyses. In these meta-analyses, the median number of potentially redundant RCTs and the participants involved were 2 (range: 1-50) and 352 (range: 17-26997), respectively. Potentially redundant RCTs were more likely to be present in the meta-analyses evaluating pharmaceutical intervention (odds ratio [OR] 2.31, 95% CI 1.16-4.49), assessing efficacy outcomes (OR 7.25, 95% CI 0.85-61.87), containing more than 5 RCTs (OR 6.47, 95% CI 3.22-12.99), or with the earliest RCT reporting statistically significant effect estimate (OR 5.30, 95% CI 2.64-10.64). CONCLUSION: This study found that 12.7% to 17.1% of recently published meta-analyses contained potentially redundant RCTs, highlighting the importance of conducting or examining systematic reviews of existing evidence to justify new RCTs. More importantly, the study identified some scenarios in which redundancy was more likely to occur and thus has implications for trialists, funding agencies, ethics committees, and journal editors.

Tailored Polypyrrole Nanofibers as Ion-to-Electron Transduction Membranes for Wearable K+ Sensors.

Conductive polymers are recognized as ideal candidates for the development of noninvasive and wearable sensors for real-time monitoring of potassium ions (K+ ) in sweat to ensure the health of life. However, the low ion-to-electron transduction efficiency and limited active surface area hamper the development of high-performance sensors for low-concentration K+ detection in the sweat. Herein, a wearable K+ sensor is developed by tailoring the nanostructure of polypyrrole (PPy), serving as an ion-to-electron transduction layer, for accurately and stably tracing the K+ fluctuation in human sweat. The PPy nanostructures can be tailored from nanospheres to nanofibers by controlling the supramolecular assembly process during PPy polymerization. Resultantly, the ion-to-electron transduction efficiency (17-fold increase in conductivity) and active surface area (1.3-fold enhancement) are significantly enhanced, accompanied by minimized water layer formation. The optimal PPy nanofibers-based K+ sensor achieved a high sensitivity of 62 mV decade-1 , good selectivity, and solid stability. After being integrated with a temperature sensor, the manufactured wearable sensor realized accurate monitoring of K+ fluctuation in the human sweat.

[Characteristics of Vertical Distribution and Environmental Factors of Antibiotics in Quaternary Sedimentary Column in Urban Areas].

Antibiotics easily remain in sediments after migrating from the surface to the subsurface due to water-rock interactions, posing a risk of secondary release to groundwater. To investigate the vertical distribution characteristics and environmental impact factors of antibiotics, five 30 m quaternary sediment columns were drilled and stratified near the hospital, and five major classes of antibiotics and sulfonamide metabolites were tested and analyzed. The results showed that:① the antibiotic content in the sediments ranged from 3.05 to 107.03 µg·kg-1, and all of the target antibiotics were detected except lomefloxacin, of which ofloxacin and oxytetracycline were the most important antibiotics in the study area. ② The antibiotics did not show a strict downward trend in the vertical direction but varied with the lithological stratification. ③ Antibiotics were primarily deposited in the clay layer and varied with the fluctuation of the groundwater level. ④ The results of redundancy analysis between antibiotics and environmental factors suggested that pH and TOC controlled the fate and transformation of antibiotics through influencing the adsorption of antibiotics by sediments. The risk of antibiotic contamination from hospital wastewater seepage into the subsurface environment should be taken seriously.

Global analysis of iron metabolism-related genes identifies potential mechanisms of gliomagenesis and reveals novel targets.

AIMS: This study aimed to investigate key regulators of aberrant iron metabolism in gliomas, and evaluate their effect on biological functions and clinical translational relevance. METHODS: We used transcriptomic data from multiple cross-platform glioma cohorts to identify key iron metabolism-related genes (IMRGs) based on a series of bioinformatic and machine learning methods. The associations between IMRGs and prognosis, mesenchymal phenotype, and genomic alterations were analyzed in silico. The performance of the IMRGs-based signature in predicting temozolomide (TMZ) treatment sensitivity was evaluated. In vitro and in vivo experiments were used to explore the biological functions of these key IMRGs. RESULTS: HMOX1, LTF, and STEAP3 were identified as the most essential IMRGs in gliomas. The expression levels of these genes were strongly related to clinicopathological and molecular features. The robust IMRG-based gene signature could be used for prognosis prediction. These genes facilitate mesenchymal transformation, driver gene mutations, and oncogenic alterations in gliomas. The gene signature was also associated with TMZ resistance. HMOX1, LTF, and STEAP3 knockdown in glioma cells significantly reduced cell proliferation, colony formation, migration, and malignant invasion. CONCLUSION: The study presented a comprehensive view of key regulators underpinning iron metabolism in gliomas and provided new insights into novel therapeutic approaches.

F. prausnitzii-derived extracellular vesicles attenuate experimental colitis by regulating intestinal homeostasis in mice.

BACKGROUND: Emerging evidence has shown that extracellular vesicles (EVs) derived from gut bacteria play a crucial role in microbiota-host interactions. Here, we aimed to evaluate the attenuating effect of EVs derived from a reduced commensal bacterium, F. prausnitzii (Fp-EVs), in inflammatory bowel disease (IBD) on dextran sulfate sodium (DSS)-induced colitis in mice. RESULTS: Fp-EVs isolated by ultracentrifugation and typically exhibited a double concave disc shape with an average diameter of 172 nm. Fp-EVs treatment reduced DSS-induced weight loss, disease activity index (DAI) score, colon length shortening, histological damage, neutrophil infiltration and increased intestinal epithelial apoptotic cells in DSS-induced colitis mice. Fp-EVs upregulated the protein expression of zona occludens (ZO)-1 and Occludin and increased the ratio of Tregs in the colon tissue of colitis mice. Furthermore, Fp-EVs downregulated the expression of the proinflammatory cytokines interleukin-1ß (IL-1ß), IL-2, IL-6, IL-12a, IL-17a, Interferon-γ (IFN-γ), tumor necrosis factor - α (TNF-α), granulocyte-macrophage colony stimulating factor (GM-CSF) and upregulated the anti-inflammatory cytokines IL-4, IL-10, and transforming growth factor ß (TGF-ß) in DSS-treated mice. Moreover, Fp-EV treatment markedly reduced the phosphorylation of these proteins Nuclear factor-κB (NF-κB) and Mitogen activated protein kinase (MAPK), and regulated the expression of nuclear factor erythroid 2-related factor (Nrf2) and heme oxygenase-1 (HO-1). CONCLUSION: Our findings revealed that Fp-EVs attenuated DSS-induced colitis by modulating the intestinal mucosal barrier function and immunological profile. Our findings reveal that Fp-EVs attenuate DSS-induced colitis by modulating intestinal mucosal barrier function and the immunological profile.

The promoting effect and mechanism of MAD2L2 on stemness maintenance and malignant progression in glioma.

BACKGROUND: Glioblastoma, the most common primary malignant tumor of the brain, is associated with poor prognosis. Glioblastoma cells exhibit high proliferative and invasive properties, and glioblastoma stem cells (GSCs) have been shown to play a crucial role in the malignant behavior of glioblastoma cells. This study aims to investigate the molecular mechanisms involved in GSCs maintenance and malignant progression. METHODS: Bioinformatics analysis was performed based on data from public databases to explore the expression profile of Mitotic arrest deficient 2 like 2 (MAD2L2) and its potential function in glioma. The impact of MAD2L2 on glioblastoma cell behaviors was assessed through cell viability assays (CCK8), colony formation assays, 5-Ethynyl-2'-deoxyuridine (EDU) incorporation assays, scratch assays, and transwell migration/invasion assays. The findings from in vitro experiments were further validated in vivo using xenograft tumor model. GSCs were isolated from the U87 and LN229 cell lines through flow cytometry and the stemness characteristics were verified by immunofluorescence staining. The sphere-forming ability of GSCs was examined using the stem cell sphere formation assay. Bioinformatics methods were conducted to identified the potential downstream target genes of MAD2L2, followed by in vitro experimental validation. Furthermore, potential upstream transcription factors that regulate MAD2L2 expression were confirmed through chromatin immunoprecipitation (ChIP) and dual-luciferase reporter assays. RESULTS: The MAD2L2 exhibited high expression in glioblastoma samples and showed significant correlation with patient prognosis. In vitro and in vivo experiments confirmed that silencing of MAD2L2 led to decreased proliferation, invasion, and migration capabilities of glioblastoma cells, while decreasing stemness characteristics of glioblastoma stem cells. Conversely, overexpression of MAD2L2 enhanced these malignant behaviors. Further investigation revealed that MYC proto-oncogene (c-MYC) mediated the functional role of MAD2L2 in glioblastoma, which was further validated through a rescue experiment. Moreover, using dual-luciferase reporter gene assays and ChIP assays determined that the upstream transcription factor E2F-1 regulated the expression of MAD2L2. CONCLUSION: Our study elucidated the role of MAD2L2 in maintaining glioblastoma stemness and promoting malignant behaviors through the regulation of c-MYC, suggesting its potential as a therapeutic target.

Optimized O(α_{s}

The failure of observing the e^{+}e^{-}→J/ψJ/ψ events at B factories to date is often attributed to the significant negative order-α_{s} correction. In this work we compute the O(α_{s}^{2}) correction to this process for the first time. The magnitude of the next-to-next-to-leading order (NNLO) perturbative correction is substantially negative so that the standard nonrelativistic QCD prediction would suffer from an unphysical, negative cross section. This dilemma may be traced in the fact that the bulk contribution of the fixed-order radiative corrections stems from the perturbative corrections to the J/ψ decay constant. We thus implement an improved nonrelativistic QCD factorization framework, by decomposing the amplitude into the photon-fragmentation piece and the nonfragmentation piece. With the measured J/ψ decay constant as input, which amounts to resumming a specific class of radiative and relativistic corrections to all orders, the fragmentation-induced production rate can be predicted accurately and serves a benchmark prediction. The nonfragmentation type of the amplitude is then computed through NNLO in α_{s} and at lowest order in velocity. Both the O(α_{s}) and O(α_{s}^{2}) corrections in the interference term become positive and exhibit a decent convergence behavior. Our finest prediction is σ(e^{+}e^{-}→J/ψJ/ψ)=2.13_{-0.06}^{+0.30} fb at sqrt[s]=10.58 GeV. With the projected integrated luminosity of 50 ab^{-1}, the prospect to observe this exclusive process at Belle 2 experiment appears to be bright.

Contact efficiency optimization for tribovoltaic nanogenerators.

Energy harvesters based on the tribovoltaic effect that can convert mechanical energy into electricity offer a potential solution for the energy supply of decentralized sensors. However, a substantial disparity in output current, exceeding 106 times, exists between micro- and macro-contact tribovoltaic nanogenerators (TVNGs). To tackle this challenge, we develop a quantification method to determine the effective contact efficiency of conventional large-scale TVNGs, revealing a mere 0.038% for a TVNG of 1 cm2. Thus, we implement an optimization strategy by contact interface design resulting in a remarkable 65-fold increase in effective contact efficiency, reaching 2.45%. This enhancement leads to a current density of 23 A m-2 and a record-high charge density of 660 mC m-2 for the TVNG based on Cu and p-type silicon. Our study reveals that increasing the effective contact efficiency will not only address the existing disparities but also have the potential to significantly enhance the output current in future advancements of large-scale TVNGs.

The G protein-coupled receptor COLD1 promotes chilling tolerance in maize during germination.

The geographic range and yield of the staple crop maize (Zea mays L.) are both strongly limited by low-temperature conditions. One of the most economical and effective measures for improvement of maize production is chilling tolerance enhancement. In this study, a chilling-tolerance gene in maize, ZmCOLD1, was cloned and characterized. This gene encodes a G protein-coupled receptor that is localized to the plasma membrane and the endoplasmic reticulum. A single nucleotide polymorphism (SNP) in ZmCOLD1, SNP2738, was found to confer chilling tolerance and to have promoted maize adaptations during speciation from teosinte. Overexpression of the excellent haplotype ZmCOLD1Hap11 significantly enhanced chilling tolerance, whereas knocking down ZmCOLD1 increased sensitivity to low temperatures during the germination and seedling stages. ZmCOLD1 was associated with an influx of extracellular Ca2+, increases in abscisic acid content, and decreases in gibberellic acid and indole-3-acetic acid content under low temperatures during the germination stage. ZmCOLD1 interacted with the G protein α subunit ZmCT2 at the plasma membrane, and ZmCT2 interacted with ZmLanCL in the nucleus. These proteins are components of the chilling tolerance signaling pathway in maize that are triggered by abscisic acid and photosynthesis. These results offer novel strategies for improvement of chilling tolerance in key crop species.

Recent Progress of Advanced Materials for Triboelectric Nanogenerators.

Triboelectric nanogenerators (TENGs) have received intense attention due to their broad application prospects in the new era of internet of things (IoTs) as distributed power sources and self-powered sensors. Advanced materials are vital components for TENGs, which decide their comprehensive performance and application scenarios, opening up the opportunity to develop efficient TENGs and expand their potential applications. In this review, a systematic and comprehensive overview of the advanced materials for TENGs is presented, including materials classifications, fabrication methods, and the properties required for applications. In particular, the triboelectric, friction, and dielectric performance of advanced materials is focused upon and their roles in designing the TENGs are analyzed. The recent progress of advanced materials used in TENGs for mechanical energy harvesting and self-powered sensors is also summarized. Finally, an overview of the emerging challenges, strategies, and opportunities for research and development of advanced materials for TENGs is provided.

Discharge domains regulation and dynamic processes of direct-current triboelectric nanogenerator.

Direct-current triboelectric nanogenerators arising from electrostatic breakdown can eliminate the bottleneck problem of air breakdown in conventional triboelectric nanogenerators, offering critical benefits of constant-current output, resistance to electromagnetic interference, and high output power density. Previous understanding is that its output characteristics are described by a capacitor-breakdown model or dictated by one or two discharge domains in direct-current triboelectric nanogenerators. Here, we demonstrate that the former holds only for ideal conditions and the latter cannot fully explain the dynamic process and output performance. We systematically image, define, and regulate three discharge domains in direct-current triboelectric nanogenerators, then a "cask model" is developed to bridge the cascaded-capacitor-breakdown dynamic model in ideal conditions and real outputs. Under its guidance, the output power is increased by an order of magnitude within a wide range of resistive loads. These unexplored discharge domains and optimization methods revolutionize the output performance and potential applications of direct-current triboelectric nanogenerators.

A Diagnostic Classifier Based on Circulating miRNA Pairs for COPD Using a Machine Learning Approach.

Chronic obstructive pulmonary disease (COPD) is highly underdiagnosed, and early detection is urgent to prevent advanced progression. Circulating microRNAs (miRNAs) have been diagnostic candidates for multiple diseases. However, their diagnostic value has not yet been fully established in COPD. The purpose of this study was to develop an effective model for the diagnosis of COPD based on circulating miRNAs. We included circulating miRNA expression profiles of two independent cohorts consisting of 63 COPD and 110 normal samples, and then we constructed a miRNA pair-based matrix. Diagnostic models were developed using several machine learning algorithms. The predictive performance of the optimal model was validated in our external cohort. In this study, the diagnostic values of miRNAs based on the expression levels were unsatisfactory. We identified five key miRNA pairs and further developed seven machine learning models. The classifier based on LightGBM was selected as the final model with the area under the curve (AUC) values of 0.883 and 0.794 in test and validation datasets, respectively. We also built a web tool to assist diagnosis for clinicians. Enriched signaling pathways indicated the potential biological functions of the model. Collectively, we developed a robust machine learning model based on circulating miRNAs for COPD screening.

Sperm mobility is predictive of the relative genetic contribution among competing mating geese, as determined by microsatellite genotype identification of potential sires.

The low reproductive efficiency (RE) of geese limits their production in the poultry industry. To select ganders with high breeding potential, the effect of 3 sperm mobility ranks (SMRs; high-, medium-, and low-SMR) on the RE of naturally mating geese was determined. To exclude the confounding effect of social rank (SR) on RE in naturally mating flocks, a 2-factor nested experimental design was used to differentiate the effects of SMR and SR on RE. Twenty-seven ganders and 135 geese (Zi geese, Anser cygnoides L.) at approximately 1 yr of age were divided into 3 flocks, each of which included the 3 SMR groups. Each SMR group included 3 ganders and 15 female geese. Relative genetic contribution (RGC) is defined as the number of offspring sired by 1 male as a percentage of the entire goslings in each flock, and it was used to compare the differences in RE among ganders. The frequency of agonistic behavioral interactions (ABIs) among the ganders was video recorded in each SMR group, and the SR of each gander was determined. In total, 1,026 eggs were incubated, and 609 goslings hatched. Parent-offspring relationships among 771 individuals from the 2 generations were identified using 20 microsatellite markers, and the RGC was calculated. Results showed that the SMR and SR had significant effects on RGC in naturally mating geese (P = 0.001 and P = 0.000, respectively). Significant differences in RGC were observed among the high- and medium- and low-SMR groups, with average RGCs of 14.3, 10.6, and 8.4%, respectively. The high-SMR group had the highest RGCs in each flock, and the ganders with high SR had the highest RGCs among the 3 SMRs. The study showed that in a naturally mating geese population, selecting for the sperm mobility traits of a gander can effectively improve the RE.