Heterogeneity Test Research Articles

Will Climate Endowment Affect the Improvement of Agricultural Production Efficiency? Evidence From Cities in Zhejiang Province, China

ABSTRACTClimate change poses constraints on nature‐based agricultural productivity, necessitating an understanding of urban agriculture's performance across varying climatic conditions. This study examines the impacts of temperature, precipitation, and evapotranspiration production potential on agricultural production efficiency using a pooled OLS model. The results show that there is a spatial pattern of alternating high and low agricultural production efficiency units, and in urban areas where agricultural production efficiency values hover around 0.5, there still exists significant potential for improvement. Through regression analysis, results show that the production potential of precipitation has a significantly positive impact on improving agricultural production efficiency. However, the effects of temperature production potential, evapotranspiration production potential, and insolation on agricultural production efficiency are either not significant or exhibit poor stability. The results of the heterogeneity test show that the effect of precipitation production potential on enhancing agricultural production efficiency varies between cities in northeastern and southwestern Zhejiang, with only a few cities experiencing significant benefits. Furthermore, the innovation of this study resides in its comprehensive application of management science, climatology, geography, and other interdisciplinary approaches to deeply explore the influences of different climatic resource endowments on agricultural production efficiency from a spatial perspective. This interdisciplinary research approach provides fresh insights into how urban agriculture can be optimized under complex and ever‐changing climatic conditions.

The Impact of Imported Timber Price Fluctuations on the Margins of Wood Forest Product Exports: Empirical Evidence from Provincial-Level Data in China

This paper adopts a comprehensive approach to integrating the wood forest product trade of China's provinces with the global market, utilizing over four million records of trade data from the Chinese Customs database and the United Nations Trade and Commerce database, creating a three-dimensional panel dataset structured by year—province—importing country. The paper decomposes the export trade share into extensive margin, quantity margin, and price margin, collectively referred to as the ternary margins of export, to analyze the impact of imported timber price fluctuations on these export margins of wood forest products. The findings indicate that fluctuations in imported timber prices increase uncertainty, thereby suppressing the growth of China's wood forest product export share, extensive margin, and quantity margin while increasing the price margin. Heterogeneity tests further reveal that the impact of imported timber price fluctuations is more pronounced for southern forest regions, labor-intensive wood products, and countries without a free trade agreement. Mechanism tests suggest that increasing forestry fixed asset investment intensity and enhancing timber supply capacity can help mitigate the uncertainty effects associated with imported timber price fluctuations. The paper proposes policy implications, including enhancing local timber supply resilience, strengthening government support for forestry, and reinforcing the supply chain.

Research on the Influence of Innovation Vouchers and Government Procurement on the Green Innovation of Small and Medium-sized Enterprises

This paper selects Chinese small and medium-sized board and Shanghai and Shenzhen A-share listed companies on GEM from 2018 to 2022 as research samples, and uses two-way fixed effect model to test the impact of two demand-side innovation policies, innovation voucher and government procurement, on green innovation of small and medium-sized enterprises and their combination mechanism. The study found that: (1) innovation vouchers and government procurement policies can promote green innovation of small and medium-sized enterprises, and there are synergistic effects between the two types of policies. After a series of robust tests, the results are still established. (2) Mechanism inspection shows that enterprise R & D investment and corporate social responsibility are the role mechanism of the combination of innovation voucher and government procurement policy affecting the green innovation of small and medium-sized enterprises.(3) Heterogeneity test shows that the two types of policies have a stronger role in promoting green innovation in non-state-owned enterprises. Based on the combination of policy tools, this paper expands the perspective of enterprise green innovation, which is of great significance to further rely on innovation policy tools to promote enterprise innovation.

Multiple thyroid disorders and risk of osteoporosis: a two-sample Mendelian randomization study.

Previous research has demonstrated that even minor changes in thyroid function are associated with an increased risk of osteoporosis (OP). However, the causal relationship between thyroid disorders and the development of OP remains unclear. To address this, we aim to investigate the connection between genetic predispositions to various thyroid disorders and OP using a two-sample Mendelian randomization (MR) approach. Instrumental variables (IVs) for multiple thyroid disorders were sourced from a large genome-wide association study (GWAS) meta-analysis dataset. Summary-level data for OP were obtained from the FinnGen consortium. Inverse variance weighting (IVW) methods served as the primary approach for MR analysis. Sensitivity analyses included MR-Egger regression, heterogeneity testing, multiple validity tests, and leaFve-one-out sensitivity tests. IVW analysis revealed a direct causal effect of hypothyroidism (OR = 1.105, 95% CI 1.023-1.194, P 0.011) and Hashimoto's thyroiditis (OR = 1.142, 95% CI 1.026-1.271, P 0.015) on OP. However, no direct causal association was found between hyperthyroidism (OR = 1.030, 95% CI 0.944-1.123, P 0.508) or thyroid cancer (OR = 0.971, 95% CI 0.898-1.051, P 0.469) and OP. Our MR analysis revealed a causal association between hypothyroidism, Hashimoto's thyroiditis, and OP. This highlights the significant impact of thyroid function on bone health. However, further longitudinal studies are needed to confirm these findings conclusively.

No causal association between serum vitamin D levels and bronchiectasis: A Mendelian randomization analysis.

Observational studies have reported an association between Vitamin D deficiency and an increased risk of bronchiectasis. This study aims to investigate the causal relationship between Vitamin D levels and bronchiectasis using a 2-sample Mendelian randomization (MR) analysis. Data from 2 genome-wide association studies (GWAS) based on European ancestry were analyzed: serum vitamin D levels (sample size = 441,291 [UK Biobank]) and bronchiectasis (sample size = 187,830 [cases = 1107, controls = 186,723; FinnGen]). Inverse-variance weighted (IVW) analysis was primarily used to assess the causal effect of 25(OH)D levels on bronchiectasis, supplemented by Mendelian randomization Egger regression (MR-Egger), weighted median, simple mode, and weighted mode analyses. Additionally, MR-Egger intercept test and MR-Pleiotropy Residual Sum and Outlier methods were implemented to determine pleiotropy, and Cochran's Q test was conducted for heterogeneity testing. Leave-one-out analysis and Bayesian weighted Mendelian randomization was also used to assess the robustness of the results. The MR analysis suggested no significant causal effects of serum 25(OH)D levels on bronchiectasis using the IVW method (odds ratio = 1.550; 95% confidence interval [CI]: 0.908-2.315; P = .120). These results were consistent across MR-Egger regression, weighted median, simple mode, and weighted mode analyses. No significant heterogeneity, pleiotropy, or bias was detected in instrumental variables. Additionally, no evidence supported the causal effects of bronchiectasis on serum vitamin D levels (β = -0.002, 95% CI: -0.007 to 0.003; P = .463). Our study found no significant causal association between serum 25(OH)D levels and bronchiectasis, in either direction. A larger sample-sized randomized controlled trial (RCT) is needed to further investigate this potential causal relationship.

Crocin Supplementation on Inflammation and Oxidative Stress: A Systematic Review and Meta-Analysis.

Saffron is the dried stigma of Crocus sativus L. flowers. The yellow-orange color of saffron comes from crocin, a water-soluble carotenoid that can be ingested. Crocin is known for its anti-inflammatory and antioxidant potential. It is believed to affect inflammation and oxidative stress, making it a promising therapeutic option. However, research on its impact is inconclusive. This meta-analysis aimed to assess the benefits of crocin supplementation and its specific effects on inflammation and oxidative stress markers. A comprehensive search of the literature was conducted up to February 2024 in PubMed/Medline, Scopus, and Web of Science to find suitable randomized clinical trials (RCTs). All participants were adults who were supplemented with crocin as part of the study intervention. The selected trials were subjected to heterogeneity tests using the I2 statistic. Random effects models were examined based on the heterogeneity tests, and the pooled data were calculated as weighted mean differences (WMD) with a 95% confidence interval (CI). Of the 519 papers that remain after duplications were removed, 13 eligible RCTs were included in the present meta-analysis. Our findings indicated that crocin supplementation significantly reduced c-reactive protein (CRP) levels (SMD: -0.50; 95%CI: -0.86 to -0.13; p = 0.008), tumor necrosis factor-α (TNF-α) (SMD: -1.96; 95%CI: -2.72 to -1.19; p < 0.001), and interleukin-6 (IL-6) (SMD: -3.52; 95%CI: -6.84 to -0.20; p = 0.03). Also, crocin supplementation led to a significant increase in total antioxidant capacity (TAC) (SMD: 1.48; 95%CI: 0.52 to 2.43; p = 0.002). Overall effect size showed that crocin intake failed to change the erythrocyte sedimentation rate (ESR) and malondialdehyde (MDA) levels significantly. Crocin reduces inflammatory markers and increases TAC. The effect of crocin on inflammatory markers was greater in a dose ≥ 30 mg/day and an intervention duration ≥ 12 weeks. However, more studies are needed for definitive conclusions.

Empowering sustainable development: revolutionizing agricultural green total factor productivity through rural digitalization

IntroductionThe rapid advancement of digital technology has catalyzed the emergence of “digital villages,” presenting both new opportunities and challenges for the digital transformation of agriculture. This transformation has become a core driving force behind sustainable agricultural development. This paper utilizes panel data from 30 provincial-level administrative regions of mainland China (excluding Tibet) for the period 2011 to 2020 to explore how digital rural development (DRD) impacts agricultural green total factor productivity (AGTFP) and examines its underlying mechanisms.MethodsRegarding variable measurement, the study employs the entropy weighting method to quantify the DRD and uses an extended Data Envelopment Analysis-Malmquist model to assess AGTFP. For the research approach, the study constructs a two-way fixed effects model to evaluate the impact of DRD on AGTFP and explores the underlying mechanisms. Specifically, the study conducts benchmark regression analysis, endogeneity tests, robustness tests, mechanism examinations, and heterogeneity tests.Results(1) DRD significantly enhances AGTFP, a conclusion that remains robust following the province-year clustering robust standard error estimates, winsorization tests, and excluding COVID-19-affected years. (2) Mechanistic analysis indicates that DRD primarily boosts AGTFP by promoting the development of digital inclusive finance (DIF) and facilitating the integration of primary, secondary, and tertiary industries (IPST). (3) Heterogeneity tests show that the positive impact of DRD on AGTFP is more pronounced in regions with higher levels of informatization and central regions of China.DiscussionTo harness DRD’s potential more effectively in fostering sustainable agricultural development, policymakers should concentrate on DIF and the IPST. Additionally, the government should pay close attention to disparities in informatization levels and resource allocation across regions and develop targeted strategies accordingly. Fundamentally, this study aims to elucidate China’s efficacy in rural digitalization and the green transformation of agriculture to an international audience. It seeks to provide insights and guidance on formulating more scientific, efficient, and sustainable strategies for agricultural development worldwide, thereby promoting green agricultural growth and supporting rural revitalization.

Genetic Discovery and Risk Prediction for Type 1 Diabetes in Individuals Without High-Risk HLA-DR3/DR4 Haplotypes.

More than 10% of patients with type 1 diabetes (T1D) do not have high-risk HLA-DR3 or -DR4 haplotypes with distinct clinical features, such as later onset and reduced insulin dependence. We aimed to identify genetic drivers of T1D in the absence of DR3/DR4 and improve prediction of T1D risk in these individuals. We performed T1D association and fine-mapping analyses in 12,316 non-DR3/DR4 samples. Next, we performed heterogeneity tests to examine differences in T1D risk variants in individuals without versus those with DR3/DR4 haplotypes. We further assessed genome-wide differences in gene regulatory element and biological pathway enrichments between the non-DR3/DR4 and DR3/DR4 cohorts. Finally, we developed a genetic risk score (GRS) to predict T1D in individuals without DR3/DR4 and compared with an existing T1D GRS. A total of 18 T1D risk variants in non-DR3/DR4 samples were identified. Risk variants at the MHC and multiple other loci genome wide had heterogeneity in effects on T1D dependent on DR3/DR4 status, and non-DR3/DR4 T1D had evidence for a greater polygenic burden. T1D-assocated variants in non-DR3/DR4 were more enriched for regulatory elements and pathways involved in antigen presentation, innate immunity, and β-cells and depleted in T cells compared with DR3/DR4. A non-DR3/DR4 GRS outperformed an existing risk score GRS2 in discriminating non-DR3/DR4 T1D from no diabetes (area under the curve 0.867; P = 7.48 × 10-32) and type 2 diabetes (0.907; P = 4.94 × 10-44). In total, we identified heterogeneity in T1D genetic risk dependent on high-risk HLA-DR3/DR4 haplotype, which uncovers disease mechanisms and enables more accurate prediction of T1D across the HLA background.

Creatine supplementation protocols with or without training interventions on body composition: a GRADE-assessed systematic review and dose-response meta-analysis.

Despite the robust evidence demonstrating positive effects from creatine supplementation (primarily when associated with resistance training) on measures of body composition, there is a lack of a comprehensive evaluation regarding the influence of creatine protocol parameters (including dose and form) on body mass and estimates of fat-free and fat mass. Randomized controlled trials (RCTs) evaluating the effect of creatine supplementation on body composition were included. Electronic databases, including PubMed, Web of Science, and Scopus were searched up to July 2023. Heterogeneity tests were performed. Random effect models were assessed based on the heterogeneity tests, and pooled data were examined to determine the weighted mean difference (WMD) with a 95% confidence interval (CI). From 4831 initial records, a total of 143 studies met the inclusion criteria. Creatine supplementation increased body mass (WMD: 0.86 kg; 95% CI: 0.76 to 0.96, I2 = 0%) and fat-free mass (WMD: 0.82 kg; 95% CI: 0.57 to 1.06, I2 = 0%) while reducing body fat percentage (WMD: -0.28 %; 95% CI: -0.47 to -0.09; I2 = 0%). Studies that incorporated a maintenance dose of creatine or performed resistance training in conjunction with supplementation had greater effects on body composition. Creatine supplementation has a small effect on body mass and estimates of fat-free mass and body fat percentage. These findings were more robust when combined with resistance training.

Milk adulteration testing and impact of farmers efficiency heterogeneity: A strategic analysis

Milk adulteration testing and impact of farmers efficiency heterogeneity: A strategic analysis

Genetic Association of Chronic Pains and Analgesics With Telomere Length: A Mendelian Randomization Study

Objective: The aim of this study was to explore the causal relationships between chronic pains (back pain, facial pain, general pain, headaches, knee pain, hip pain, neck/shoulder pain, stomach/abdominal pain) and analgesics (codeine, diclofenac, ibuprofen, morphine, paracetamol, tramadol) with telomere length using Mendelian randomization methods. Methods: In the study, various statistical methods including inverse variance weighted (IVW), Mendelian Randomization-Egger, weighted median, simple mode, and weighted mode were used to investigate the relationships between chronic pains, analgesics, and telomere length. Heterogeneity and pleiotropy tests were conducted to ensure the accuracy of the results. Results: The results of the IVW analysis revealed positive causal relationships between hip pain (odds ratio (OR): 1.145; 95% confidence interval (CI): 1.021–1.285; p = .020), and stomach/abdominal pain (OR: 1.100; 95% CI: 1.008–1.200; p = 0.033) with telomere length. Use of tramadol (OR: 0.074; 95% CI: 0.009–0.605; p = 0.015) had a negative causal relationships with telomere length. Conclusion: This study found positive associations between hip pain and stomach/abdominal pain with telomere length, and a negative association between tramadol and telomere length. However, no significant causal relationships were found with other types of chronic pains and analgesics. This could help develop healthier chronic pain treatments, avoiding the abuse of analgesics.

Can the Opening of Public Data Improve the Quality of Urban Employment?-- Evidence from China

In the era of digital economy, the opening of public data holds significant importance as a pivotal means to maximize the utilization of data elements and enhance the quality of urban employment. Leveraging urban-level data spanning from 2011 to 2021 in China, this study employs a Multi-period DID method to systematically investigate the mechanisms underlying the impact of public data openness on urban employment quality.The empirical findings reveal that the openness of public data markedly elevates the quality of urban employment. Notably, these results persist even after rigorous robustness and endogeneity tests, ensuring the reliability and validity of our conclusions.A deeper analysis further unveils that the opening of public data enhances urban employment quality through various mechanisms, including increased urban innovation investment, advancements in digital finance, and the upgrading of industrial structures. Additionally, heterogeneity tests demonstrate that the impact of public data openness policies is particularly pronounced in coastal regions and larger cities, highlighting the differential effects across geographical and urban scales.The insights gained from this study offer crucial policy implications for accelerating the opening of public data and enhancing the quality of urban employment, ultimately contributing to the high-quality economic development of our cities and nations.

Causal relationship between immune cells, inflammatory cytokines, metabolites, and erectile dysfunction: a two-sample Mendelian randomization study.

Previous studies have investigated the association between immune inflammation, metabolism and erectile dysfunction (ED). However, these studies are limited by biases, confounding factors, and reverse causality, failing to establish causality. We conducted a two-sample Mendelian randomization (MR) study to elucidate the causal relationships between immune cells, inflammatory cytokines, plasma metabolites, and the risk of ED. Data on 91 inflammatory cytokines (n=14,736), 731 immune phenotypes (n=3,757) and 1,400 circulating metabolites (n=8,000) were obtained from genome-wide association studies (GWAS) as exposures, while ED data were sourced from the Integrative Epidemiology Unit (IEU) Open GWAS database (n=223,805) as outcomes. A two-sample MR analysis was performed to determine the relationships between exposures and outcomes. The inverse variance weighted (IVW) method was used as the primary MR analysis approach, supplemented by additional methods. Sensitivity analyses, including Cochran's Q test for heterogeneity and MR-Egger intercept for horizontal pleiotropy, were conducted to assess the robustness of the MR results. At a significance level of P<0.01, we identified 12 factors associated with ED: five immune cells, one inflammatory cytokine, two metabolites, and four metabolite ratios. Specifically, CD19 on immunoglobulin D- (IgD-) CD38+ B cells [odds ratio (OR) =1.17; 95% confidence interval (CI): 1.06-1.30], CD4 on terminally differentiated CD4+ T cells (OR =1.07; 95% CI: 1.02-1.12), CD25 on IgD+ CD38dim B cells (OR =1.05; 95% CI: 1.01-1.09), CD25 on IgD+ CD24- B cells (OR =1.04; 95% CI: 1.01-1.07), and IgD on IgD+ B cells (OR =0.88; 95% CI: 0.79-0.97) were associated with ED. Among inflammatory cytokines, only elevated levels of urokinase-type plasminogen activator (uPA) significantly reduced the risk of ED (OR =0.83; 95% CI: 0.73-0.95). Six metabolites, including glycerol levels (OR =1.30; 95% CI: 1.08-1.56), aspartate to N-acetylglucosamine to N-acetylgalactosamine ratio (OR =1.21; 95% CI: 1.07-1.37), cholesterol to taurocholate ratio (OR =1.23; 95% CI: 1.07-1.42), 4-methyl-2-oxopentanoate to 3-methyl-2-oxobutyrate ratio (OR =1.26; 95% CI: 1.07-1.48), alpha-ketoglutarate to kynurenine ratio (OR =0.86; 95% CI: 0.76-0.96), and X-16964 levels (OR =1.24; 95% CI: 1.06-1.45) were significantly associated with ED. Sensitivity analyses did not reveal any heterogeneity or pleiotropy. Our MR analysis indicates that immune inflammation and metabolism have both inducing and protective effects on ED risk. These findings provide new insights for clinicians regarding the treatment and prevention of ED. Additionally, our study offers novel insights into the pathogenesis of ED.

The immune cells causative role in lung cancer: Mendelian randomization study

BackgroundsLung cancer (LC) is the leading cause of cancer-related deaths in China, with its incidence and mortality rates rising annually. Various studies have demonstrated disparities in immune cell counts and profiles between LC patients and healthy individuals. However, the existence of a causal link remains largely uncertain. To explore the potential causal association between immune cells and LC risk, a Mendelian randomization (MR) approach was employed.MethodsEmploying immune cell genome-wide association study (GWAS) data from a public database (n = 731 subjects) and Lung Cancer Genome Research Consortium's GWAS dataset (n = 492,803 participants), unconventional genetic loci remarkably associated with the significant abundance of 731 types of immune cells were extracted according to preset threshold points as instrumental variables. The primarily analytical strategy involved the inverse variance weighting (IVW) method, with the effect size estimates expressed as odds ratio (OR) and 95% CI. The robustness of the findings was assessed through a leave-one-out sensitivity analysis, heterogeneity test, horizontal gene pleiotropy test, MR-PRESSO and MR-Egger.ResultsThe MR analysis identified a significant association between 18 distinct immune cell types and lung cancer risk. MR analysis revealed that 7 types of immune cells, including CD20 on IgD − CD38 − B cell, CD20 on switched memory B cell, IgD on IgD + CD24 + B cell, BAFF − R on IgD − CD38 + B cell, CD39 + resting CD4 regulatory T cell Absolute Count, CD127 on CD45RA + CD4 + T cell, CD8 on Effector Memory CD8 + T cell, displayed a protective effect against lung cancer development. Conversely, 11 other immune cells populations were positive associated with an increased lung cancer risk. In contrast, reverse MR analysis indicated that the lung cancer risk was linked to 11 immune cells, with 2 types of immune cells (CD25 on IgD − CD27 − B cell, CD4 + T cell %leukocyte) showing a are positive correlation with cancer development, whereas 9 types of immune cells appeared to be inversely regulated. These findings collectively imply that specific immune cell populations may play critical roles in either promoting or suppressing the initiation and progression of lung cancer.ConclusionThe findings of this study offer fresh insights into the underlying biological mechanisms governing lung cancer development, thereby opening new avenues for future research in the domain of LC. The identification of specific immune cell subsets with protective or promoting roles provides crucial leads for preventive and therapeutic strategies. These insights have the potential to enhance early detection methods and inform the development of more effective treatment approaches, ultimately benefiting patient outcomes and improving the overall management of lung cancer.

Test for comparing the associations of multiple exposures with a common outcome

IntroductionWith advancement of medicine, alternative exposures or interventions are emerging with respect to a common outcome, and there are needs to formally test the difference in the associations of multiple exposures. MethodsThe paper proposes a duplication method-based multivariate Wald test in the Cox proportional hazard regression model to test the difference in the associations of multiple exposures with a same outcome. This method applies to continuous or categorical exposures. For illustration, the method was applied to compare the associations between alignment to two different dietary patterns (Alternative Healthy Eating Index-2010 [AHEI-2010] and reversed empirical dietary inflammatory pattern [rEDIP]), either as continuous or quartile exposures, and incident chronic diseases, defined as a composite of cardiovascular disease, cancer, and diabetes, in the Health Professional Follow-up Study (HPFS). Relevant sample codes in R that implement the proposed approach are provided. The present analysis was conducted in 2024. ResultsWith a median follow-up of 22 years, there were a total of 14,427 chronic disease incidences among N=43,185 men included in the HPFS analysis. The hazard ratios (HRs) [95% confidence interval] per increment from the 10th to the 90th percentile for incident chronic disease were 0.83 [0.79, 0.87] for AHEI-2010 and 0.76 [0.73, 0.80] for rEDIP. Although the 95% CIs were overlapped for each exposure, the proposed test was well powered to detect the difference (p=0.005). ConclusionsThe proposed duplication-method-based approach offers a flexible, formal statistical test for heterogeneity in the associations of multiple exposures with the common outcome with minimal assumptions.

Hybrid management of aberrant subclavian artery: A systematic review and meta-analysis.

To elucidate the short- and long-term mortality, morbidity, and endoleak incidences in the hybrid management of aberrant subclavian artery (ASA). A systematic review and meta-analysis of 99 articles comprising n = 272 cases using PRISMA were supplemented by Cohen's Kappa for assessor consistency. The analysis involved a random-effect model, odds ratios (ORs) with 95% confidence intervals, tests of heterogeneity, and probability. This review was registered with the International Prospective Register of Systematic Reviews (CRD42023405011). The 30-day mortality was 4.6% (95% CI: 1.4%-14.4%) with an overall mortality of 7.3% (95% CI: 2.9%-18.7%) demonstrating a 1.2% increase in mortality per decade of life beyond 60 years. The reported morbidity was 7.6% (95% CI: 3.7%-15.7%) and higher in males albeit higher age (p < .05) (67vs 59 years). The endoleak incidence stood at 7.8% (95% CI: 3.3%-18.3%) with Type-I the as prominent (48%). Rupture presentation was in 3%, whilst esophageal fistulation (n = 2/3) was associated with morbidity of 66%. Treatment varied, with TEVAR and carotid-subclavian bypass being the most common modality of the choice. The median follow-up was 12 months (IQR, 1-60 months). The observed incidence of mortality, morbidity, and endoleak shows the current role of the hybrid approach in managing ASA. These results emphasize the critical role of detailed surgical planning, combined endovascular and open expertise, and the necessity for a common registry to monitor long-term outcomes.

The arch myth: investigating the impact of flat foot on vertical jump height: a systematic review and meta-analysis

ObjectiveThe necessity to exclude flat foot when selecting athletes is a controversial issue. This study aimed to investigate whether flat foot affects vertical jump.MethodsThe quality of the literature was assessed using the observational study quality assessment tool provided by the Joanna Briggs Institute (JBI) Centre for Evidence-Based Health Care in Australia. Meta-analysis, heterogeneity testing, sensitivity analysis, subgroup analysis, and forest plot were conducted using Review Manager 5.4.ResultsIn the end, 9 articles met the meta-analysis criteria. Due to the heterogeneity of the studies, only vertical jump height was used as an indicator for meta-analysis. Meta-analysis results showed low heterogeneity among studies (I2 = 6%, P = 0.39), and the combined effect size showed no significant difference in jumping height between flat foot and normal foot (P = 0.73, ES = 0.13, 95%CI [-0.58, 0.83]). Subgroup analyses showed no significant differences in jump heights between flat and normal foot in either the adolescent subgroup (ES = 0.07, 95% CI [-1.04, 1.18]) or the adult subgroup (ES = 0.16, 95% CI [-0.76, 1.08]). Subgroups were divided according to training background, and jump height was unaffected by flat foot in both athletes (ES = -0.08, 95%CI [-1.07, 0.90]) and amateur (ES = 0.34, 95%CI [-0.67, 1.35]).ConclusionOverall, flat foot do not affect vertical jump height, although flat foot have different vertical jump biomechanics. This study breaks the bias that flat foot have poorer athletic performance. The meta-analysis has been registered with PROSPERO under registration number CRD42023481326.

Donor Human Milk Fat Content Is Associated with Maternal Body Mass Index.

Introduction: Donor human milk is increasingly being utilized for both preterm and term infants when mother's milk is unavailable. With the rising prevalence of maternal overweight and obesity, it is crucial to evaluate the relationship between maternal body mass index and the fat and energy content of donor human milk. Objectives: To assess the impact of maternal body mass index on human milk fat content. Methods: A cross-sectional study was carried out using retrospective data from women who made their first human milk donation at ≥15 days postpartum at a human milk bank in São Paulo, Brazil, from January 2018 to December 2020. Data of sociodemographic, obstetric, health, and anthropometric measures were collected by the human milk bank staff. Milk fat and energy content were determined using the crematocrit test. Analysis of variance and multiple linear regression were used to compare means of crematocrit and fat. We determined the p-values using a test of heterogeneity and linear trend and presented the one with the lower p-value. Results: Most donors were between 25 and 35 years old, had higher education, were employed, and lived with a partner. At the time of milk donation, 40.9% of women were overweight or obese. The fat (1.09 g/dL) and energy (9.83 kcal/dL) content of human milk were higher in obese donor compared with eutrophic donors. Conclusions: The fat and energy content of human milk were associated with maternal body mass index, suggesting the potential value for selective use of high fat and high calorie donor milk for very low birthweight or premature infants.

Green credit policy and firm’s labor productivity: evidence from Chinese heavily-polluting enterprises

Taking the “Green Credit Guidelines” (also known as “Green Credit Policy”, GCP) in 2012 as a quasi-natural experiment, this study adopts the panel datasets between 2010 and 2019 for Chinese manufacturing firms listed publicly to examine the effects of GCP on the labor productivity of Chinese heavily-polluting companies. The findings indicate that: (1) Upon introducing GCP, it can improve labor productivity of Chinese heavily-polluting companies, a result of the promotion effect of GCP on commercial credit and technological innovation. (2) The implementation of GCP can enhance the commercial credit of Chinese heavily-polluting enterprises and relieve its financing constraints to some degree. (3) The implementation of GCP can further the innovation activities of Chinese heavily-polluting companies and realize the re-test of the “Porter effect”. (4) The heterogeneity test indicates that GCP exerts a pronounced promoting influence on state-owned and large heavily-polluting enterprises in eastern China. Those conclusions are still valid after robustness tests. This research offers empirical evidence and policy wisdom for promoting the green conversion of manufacturing enterprises.

Explicating the Role of Agricultural Socialized Services on Chemical Fertilizer Use Reduction: Evidence from China Using a Double Machine Learning Model

Reducing chemical usage, particularly chemical fertilizers, is a crucial measure for advancing sustainable agricultural development. This study utilized field survey data from 894 maize farmers across three northeastern provinces of China. A double machine learning modeling framework was established to empirically examine the impact and mechanism of agricultural socialized services on chemical fertilizer use of farm households. The model addresses numerous stringent constraints of conventional causal inference models and effectively mitigates the “curse of dimensionality” issue. Current research indicates that agricultural socialized services can substantially decrease chemical fertilizer use among farmers. Further investigation reveals that these services facilitate this reduction by enhancing the mechanization level, promoting the use of organic fertilizers, and providing a labor substitution effect. The region heterogeneity test indicates that the impact of agricultural socialized services is more pronounced in Liaoning and Heilongjiang provinces geographically. Regarding the heterogeneity analysis of food crop income levels, agricultural socialized services can decrease chemical fertilizer use among farmers more effectively with elevated food crop income levels. Consequently, the findings imply that the socialization of agricultural services has substantial potential to be an effective chemical fertilizer reduction strategy to support the agricultural green transition, which can be enhanced through promoting the degree of mechanization, organic fertilizer application, and labor division and specialization.