Threshold effects of green technology application on sustainable grain production: Evidence from China

Sustainable production is considered as an important approach to solve the dilemma of food insecurity. Green technologies have made contributions to improving food production and reducing environmental pollution. Studying the effects of green technologies on sustainable food production has great significance. The paper started with the influence mechanism of green technology application on the green total factor productivity of grain (GTFPG). With the GTFPG, green technology efficiency change of grain (GECG) and green technical progress change of grain (GTCG) measured, threshold models were constructed to explore the nonlinear impacts of various green technologies on GTFPG and the influence paths. Results indicated that the differences of GTFPG among provinces in China were decreased mainly due to the changes of GTCG, while the regional differences of GECG remained small. The impacts of green technologies had threshold effects that depended on the ecological effects of green technologies in different application stages, and were significantly different in the major and non-major grain producing areas. Meanwhile, significant differences existed in the influence paths of green technologies. In the major grain producing areas, green technologies were more likely to improve GTFPG through the GTCG path; while in the non-major grain producing areas, the GECG path and the GTCG path were both important to improve GTFPG. The differences of green technologies' threshold effects and influence paths in the major and non-major grain producing areas were caused by regional technology preference, resource endowment and technology compatibility. This study emphasizes that the development of green technologies should fully consider the resource endowment and economic development of different regions, as well as the applicability and adoption rate of green technologies.

A New Sight of Influencing Effects of Major Factors on Cd Transfer from Soil to Wheat (Triticum aestivum L.): Based on Threshold Regression Model

Due to the high toxicity and potential health risk of cadmium (Cd), the influencing effects of major factors (like pH, OM, and clay, etc.) on Cd bioaccumulation and transfer from soil to crop grains are highly concerned. Multiple linear regression models were usually applied in previous literature, but these linear models could not reflect the threshold effects of major factors on Cd transfer under different soil environmental conditions. Soil pH and other factors on Cd transfer in a soil-plant system might pose different or even contrary effects under different soil Cd exposure levels. For this purpose, we try to apply a threshold regression model to analyze the effects of key soil parameters on Cd bioaccumulation and transfer from soil to wheat. The results showed that under different soil pH or Cd levels, several factors, including soil pH, organic matter, exchangeable Cd, clay, P, Zn, and Ca showed obvious threshold effects, and caused different or even contrary impacts on Cd bioaccumulation in wheat grains. Notably, the increase of soil pH inhibited Cd accumulation when pH > 7.98, but had a promotional effect when pH ≤ 7.98. Thus, threshold regression analysis could provide a new insight that can lead to a more integrated understanding of the relevant factors on Cd accumulation and transfer from soil to wheat. In addition, it might give us a new thought on setting regulatory limits on Cd contents in wheat grains, or the inhibitory factors of Cd transfer.

Does Clean Energy Use Have Threshold Effects on Economic Development? A Case of Theoretical and Empirical Analyses from China

Increasingly serious energy security and environmental problems have become the main constraints to China's economic development. Therefore, it is critical to explore the threshold effect of clean energy use on China's economic growth. Based on the panel data of 30 Chinese provinces from 2000 to 2019 and using energy intensity (EI) as the threshold variable, this study adopts a panel threshold model to explore the threshold effect of clean energy development on the economy. Empirical results indicate that clean energy has a significant threshold effect on economic development, with the threshold value of EI being 0.7655. When EI is less than 0.7655, clean energy development has a more positive effect on economic growth. When the EI exceeds 0.7655, the impact is significantly positive but with a smaller coefficient. EI weakens the role of clean energy development in promoting economic growth. After 2015, the EI of most provinces in the sample was below the threshold value, which indicates that in recent years, with the economic cost of developing clean energy decreasing, the role of clean energy development in promoting the economy has become more significant. Therefore, we propose policy implications to better promote the effect of clean energy development in promoting economic growth.

How Does Income Inequality Influence Environmental Regulation in the Context of Corruption? A Panel Threshold Analysis Based on Chinese Provincial Data

The question of how the income inequality of residents affects the level of environmental regulation in the context of official corruption was the core research issue of this study. We analyzed this problem using the panel threshold regression model from 26 provinces in China from 1995 to 2017. We found that when there is no official corruption, the widening of the residents’ income inequality promotes stricter environmental regulations; when the corruption problem is serious, the expansion of the residents’ income inequality leads to the decline in environmental standards; that is, the impact of residents’ income inequality on environmental regulation has a threshold effect due to corruption. In addition, the threshold effect due to corruption of all residents’ income inequality on environmental regulation is mainly generated by the urban residents’ income inequality and the urban–rural income inequality. This paper contributes to the literature that concentrates on the relationship between income inequality and environmental regulation, and shows that corruption is a key factor that can deeply influence that relationship. The research conclusion shows that increasing anti-corruption efforts can not only maintain national political stability, social fairness, and justice, but also be a powerful measure for environmental pollution governance.

All Things in Moderation? Threshold Effects in Adolescent Extracurricular Participation Intensity and Behavioral Problems

BACKGROUND

School-based extracurricular activity participation is one of the primary avenues for prosocial activity engagement during adolescence. In this study, we test the "overscheduling hypothesis" or whether the negative relationship between structured activity intensity (ie, hours) and adolescent bullying and fighting levels off or declines at moderate to high intensity (ie, threshold effects).

METHODS

This study uses the Dane County Youth Survey (N = 14,124) to investigate the relationship between school-based extracurricular activity participation intensity and bullying perpetration and physical fighting and whether there are threshold effects of activity participation intensity.

RESULTS

The results indicate that there is a negative relationship between extracurricular activity participation intensity and bullying perpetration and physical fighting and that there are threshold effects in these relationships at 3 to 4 hours per week. Results also suggest that low-income adolescents engage in more fighting than other youth and the negative relationship between activity participation intensity and physical fighting was mainly concentrated among low-income adolescents.

CONCLUSIONS

School-based extracurricular activity participation-in moderation (ie, up to 3-4 hours per week)-may provide a positive, supportive context that could be a promising prevention strategy for bullying and fighting. Implications for future research on how school-based extracurricular activity participation intensity benefits adolescent functioning are discussed.

The Impact of Reducing Psychiatric Beds on Suicide Rates

There has been ongoing debate regarding the impact of reductions in psychiatric beds on suicide rates, and the potential effect of reallocation of acute hospital funding to community-based mental health programs and services. Computer simulation offers significant value in advancing such debate by providing a robust platform for exploring strategic resource allocation scenarios before they are implemented in the real world. We report an application that demonstrates a threshold effect of cuts to psychiatric beds on suicide rates and the role of context specific variations in population, behavioral, and service use dynamics in determining where that threshold lies. Findings have important implications for regional decision-making regarding resource allocation for suicide prevention.

Prevalence of vitamin D deficiency in girls with idiopathic central precocious puberty

The relationship between vitamin D deficiency and idiopathic central precocious puberty (ICPP) has been recently documented. In this study, 280 girls diagnosed with ICPP and 188 normal puberty control girls of similar ages were enrolled and retrospectively studied. The ICPP group had significantly lower serum 25-hydroxyvitamin D (25[OH]D) levels than the control group. Furthermore, a nonlinear relationship was found between serum 25[OH]D and ICPP, and a cut-off point for serum 25[OH]D was found at 31.8 ng/ml for ICPP with and without adjusting the different confounding factors. Girls with serum 25[OH]D ≥ 31.8 ng/ml had a lower odds ratio (unadjusted: OR 0.36, 95% CI 0.15 to 0.83, P < 0.05; height and weight adjusted: OR 0.44, 95% CI 0.18 to 1.08, P = 0.072; BMI adjusted: OR 0.36, 95% CI 0.16 to 0.84, P < 0.05). The ICPP subjects with 25[OH]D deficiency had a higher body mass index (BMI) than the subjects from the two other subgroups. Correlation analysis showed that vitamin D level is correlated with BMI and some metabolic parameters in the ICPP group. Our study suggested that vitamin D status may be associated with ICPP risk and may have a threshold effect on ICPP.

A base triple in the Tetrahymena group I core affects the reaction equilibrium via a threshold effect

Previous work on group I introns has suggested that a central base triple might be more important for the first rather than the second step of self-splicing, leading to a model in which the base triple undergoes a conformational change during self-splicing. Here, we use the well-characterized L-21 ScaI ribozyme derived from the Tetrahymena group I intron to probe the effects of base-triple disruption on individual reaction steps. Consistent with previous results, reaction of a ternary complex mimicking the first chemical step in self-splicing is slowed by mutations in this base triple, whereas reaction of a ternary complex mimicking the second step of self-splicing is not. Paradoxically, mechanistic dissection of the base-triple disruption mutants indicates that active site binding is weakened uniformly for the 5'-splice site and the 5'-exon analog, mimics for the species bound in the first and second step of self-splicing. Nevertheless, the 5'-exon analog remains bound at the active site, whereas the 5'-splice site analog does not. This differential effect arises despite the uniform destabilization, because the wild-type ribozyme binds the 5'-exon analog more strongly in the active site than in the 5'-splice site analog. Thus, binding into the active site constitutes an additional barrier to reaction of the 5'-splice site analog, but not the 5'-exon analog, resulting in a reduced reaction rate constant for the first step analog, but not the second step analog. This threshold model explains the self-splicing observations without the need to invoke a conformational change involving the base triple, and underscores the importance of quantitative dissection for the interpretation of effects from mutations.