This paper investigates the impact of maximum residue limit (MRL) standards of 2692 chemical substances regulated by 44 importing countries on China's agri-food exports, disaggregated at HS 8-digit product level over 2005-2021. We find that MRL standards for health-threatening chemical substances facilitate China's exports of agri-food products, while low-hazard MRLs impede trade. Furthermore, stricter MRL standards for health-threatening substances reduce the probability of exporting (extensive margin) while generating larger export values conditional on exporting (intensive margin). We also identify that the adjustments of fixed and variable compliance costs resulting from changes in health-threatening and low-hazard MRLs contribute to the heterogeneous responses on the extensive and intensive margins of exports.

OBJECTIVE:C-reactive protein (CRP) is increased in Parkinson's disease (PD). The CRP +1444C/T (rs1130864) polymorphism is located in the 3' untranslated region (3'-UTR) and is associated with serum CRP concentrations. We explored the relationship between the CRP +1444C/T polymorphism and susceptibility to PD.METHODS:A total of 1000 subjects from a Chinese population were recruited into this case-control study, including 500 PD patients and 500 healthy controls. The genotype of the CRP +1444C/T polymorphism was tested by Sanger sequencing, and the Hardy-Weinberg equilibrium (HWE) was assessed in the groups. The odds ratios and 95% confidence intervals were calculated to evaluate the strength of any correlations in allelic, dominant, recessive, and additive genetic models.RESULTS:The genotypic distribution of the CRP +1444C/T polymorphism was consistent with HWE in controls, and markedly different with cases. The CRP +1444C/T polymorphism was associated with increased PD risk in allelic and dominant models in the overall and male population, but not the female subgroup.CONCLUSION:The presence of a CRP +1444C/T polymorphism may be associated with an increased risk of PD in our Chinese population. Given the missing support for a role of this SNP in PD in the pre-existing GWAS, the SNP may not be genuinely associated with PD despite some positive candidate gene studies.

Parkinson's disease (PD) is the second most common progressive neurodegenerative disorder with complex etiology involving both genetic and environmental factors. Apolipoprotein E (ApoE) rs405509 ( - 219 T/G), a promoter SNP, controls the expression of APOE gene, and plays a modifier effect of APOE ezt on the susceptibility of Alzheimer's disease. In this study, we investigate the association between APOE rs405509 polymorphism and the susceptibility of PD in a Chinese population. A total of 1020 subjects were collected including 510 sporadic PD patients (mean age: 63.11 +/- 9.28 years) and 510 healthy control subjects (mean age: 62.97 +/- 9.09 years). APOE rs405509 polymorphism was genotyped using a TaqMan genotyping method. The Hardy-Weinberg Equilibrium (HWE) was calculated for the control group by Chi-square (chi 2) test. The strength of this association between the APOE rs405509 polymorphism and PD risk was evaluated with crude odds ratios (ORs) and 95 Wo confidence intervals (CIs) using a logistic regression analysis. The T allele frequency was 0.84 and 0.70 in the PD and control groups, respectively. T allele carriers of rs405509 were associated with an increased overall risk of PD and in male subjects in the allele, recessive, and additive genetic models. Similar results in female subjects were found in the allele and recessive genetic models. In conclusion, our study suggests that the APOE rs405509 T allele is correlated with increased susceptibility of PD in a Chinese population.

Epidemiological evidence of the relationship between vitamin D receptor (VDR) rs2228570 (Fokl) polymorphism and the susceptibility of Parkinson's disease (PD) is inconsistent, partially due to between-study variations in sample size, age, male/female ratio, and 25-OH vitamin D3 levels. Here, we examined the association between VDR rs2228570 polymorphism and PD risk in a Chinese population. A total of 940 subjects were included in this study, which consisted of 470 patients with sporadic PD (mean age: 62.65 +/- 9.34 years) and 470 healthy control subjects (mean age: 62.70 +/- 9.42 years). A TaqMan genotyping assay was applied to identify VDR rs2228570 polymorphism. The Hardy-Weinberg Equilibrium (HWE) was calculated for both groups with a Chi-square (chi 2) test. The sample power was calculated with Power V3.0. The crude odds ratios (ORs) and 95 % confidence intervals (CIs) for sporadic PD in relation to VDR rs2228570 polymorphism were calculated using a logistic regression analysis. The minor A allele frequency was 0.42 and 0.48 in the control and PD groups, respectively. A allele carriers of rs2228570 were associated with an increased overall risk of PD as well as early-onset PD (EOPD) in the allele and additive genetic models. Stratification analyses showed similar results in male subjects in the allele and additive genetic models, but only in the additive genetic model in female subjects. In conclusion, our study suggests that the VDR rs2228570 A allele is associated with an increased risk of PD in a Chinese population. Further investigations with larger sample sizes with consideration of gene-gene and gene-environment interaction are needed to further elucidate the role of vitamin D receptors in the development of PD.

The first paper presents an inter-temporal job search model and argues that both emigration and return of Chinese may be strategically planned as an optimal life-cycle residential location sequence. Particularly, it offers an explanation for two interesting phenomena in the context of Chinese immigration: (I) a substantial increase in both emigrants and returnees; (2) Returnees exhibit varying levels of educational degrees. The model attributes these phenomena to three facts: (1) China has a dual labor market with a higher paying modem sector; (2) the benefits of globalization accrue mainly to modem sector workers and; (3) the information revolution in US attracts China's most productive intellectuals.