Club convergence of per capita carbon emission: global insight from disaggregated level data

Abstract

This study aims to examine the convergence hypothesis of per capita carbon dioxide emission and its component such as coal, oil, and gas in the case of 53 countries covering the period of 1980 to 2016. In particular, we study whether countries are moving toward a common steady-state equilibrium condition in the per capita carbon emission or converging into different groups. To do so, this study used Phillips and Sul (Econometrica 75(6): 1771–1855, 2007, J Appl Econ 24(7): 1153–1185, 2009) technique. Our results show no evidence of convergence for full sample. However, our results support the evidence of two club convergence of total emission, emission from gas and petroleum consumption, while three clubs are noticed in case of per capita carbon dioxide emission from coal use. This invalidates the equality rule of participation of each country in climate change policy. Further, similar results emerge in case of total emission and petroleum where club 1 consists of mostly developed countries while club 2 has a large number of developing countries. Interestingly, we do not find any divergence behavior across all countries in the sample. We find that natural gas is the major component to drive the total carbon emission convergence in case of our sample countries.

https://ift.tt/2Irk2D5

Optimal path for controlling pollution emissions in the Chinese electric power industry considering technological heterogeneity

Abstract

The electric power industry is not only an important part in the Chinese economic system but also the key industry with the highest emissions of air pollutants in China. This paper aims to control the pollution emissions of the Chinese electric power industry and enhance its electric-generation capacity though pollution-emission allocation patterns and inefficiency elimination. The data envelopment analysis centralized allocation model (DEA-CA) under metafrontier framework is adopted to distribute pollution emissions and electric-generation capacity considering technological heterogeneity at regional and national levels. The empirical result shows that the emission reduction responsibility is directly proportional to regional power generation performance. The metafrontier framework allocates emission permits to combine the national and regional, which makes the adjustment of each province more reasonable. At last, the relationship between the aggregate optimal electricity capacity and the pollution emission control coefficient is shown to follow an inverted U-shape curve, which implies that a modest emission control policy might be more appropriate for the electric power industry to achieve the joint optimizing goal of electricity generation enhancement and pollution emission control.

https://ift.tt/2T8HOYB

An arbuscular mycorrhizal fungus ameliorates plant growth and hormones after moderate root damage due to simulated coal mining subsidence: a microcosm study

Abstract

Arbuscular mycorrhizal fungi (AMF) are obligate plant root symbionts delivering a range of benefits to the host plant such as improved nutrient acquisition and resistance to pathogens and abiotic stress. However, whether they can enhance the function of plant root systems damaged due to subsidence caused by excessive coal mining has not been well explored. In the present study, we investigated the effects of AMF using Funneliformis mosseae (FM) as the test fungus on maize (Zea mays L.) growth and hormone levels under different levels of root damage stress by simulating mining subsidence. The results show that plants treated with FM had more shoots, roots, mycorrhizal colonization and higher hyphal density than those without FM under the same simulated mining-induced subsidence conditions. In addition, plants treated with FM also possessed higher N, P, K, Ca, and Mg contents in the shoots and the roots and higher indole-3-acetic acid, gibberellin (GA), and cytokinin (CTK) contents in the roots, indicating that the mycorrhizal association promoted plant biomass and nutrient uptake. FM treatment was no longer beneficial when root damage due to mining-induced subsidence affected more than half of the roots. Soil SOC, AK, and TG were identified as key factors affecting GA, CTK, IAA, and ABA, and AMF can alter plant hormones directly via the hyphae and indirectly by altering soil physicochemical properties under root damage stress. Overall, our results provide baseline data for assessing the biological reclamation effects of AMF on coal mining-induced subsidence.

https://ift.tt/2IqtmHu

Higher mean platelet volume is associated with paediatric chronic spontaneous urticaria and with a more severe disease in the affected children

https://ift.tt/2GAZIxm

Higher mean platelet volume is associated with paediatric chronic spontaneous urticaria and with a more severe disease in the affected children

https://ift.tt/2GAZIxm

Melanoma-associated antigen-A and programmed death-ligand 1 expression are associated with advanced urothelial carcinoma

Abstract

Background

Melanoma-associated antigen-A (MAGE-A) and programmed-death ligand 1 (PD-L1) are present in urothelial carcinoma (UC). We assessed survival outcomes in patients with MAGE-A and PD-L1 expression.

Methods

MAGE-A and PD-L1 expression on neoplastic cells was analyzed using tissue microarrays from patients with UC. We compared differential expression between disease stage and grade. MAGE-A and PD-L1 co-expression was subcategorized. Fisher's exact test was done for categorical variables followed by univariable and multivariable analysis of recurrence-free survival (RFS) and progression-free survival (PFS).

Results

Co-expression of MAGE+/PD-L1+ was higher in advanced disease; however, only MAGE+/PD-L1− was associated with shorter RFS [hazard ratio (HR) 1.89; 95% confidence interval (CI) 1.19–2.99; p = .006]. MAGE+/PD-L1+ was associated with the worst PFS (HR 17.1; 95% CI 5.96–49.4; p ≤ .001). MAGE-A expression was more prevalent with high-grade (p = .015), and higher-stage ≥ pT2 (p = .001) disease. The 5-year RFS was 44% for MAGE+ versus 58% for MAGE− patients. On multivariable analysis, MAGE+ was also associated with shorter RFS (HR 1.55; 95% CI 1.05–2.30; p = .03). Similarly, MAGE+ was associated with shorter PFS (HR 3.12; 95% CI 1.12–8.68; p = .03).

Conclusion

MAGE-A and PD-L1 expression is increased in advanced disease and associated with shorter PFS. Furthermore, MAGE-A expression was significantly associated with higher-grade and -stage disease and associated with shorter RFS and PFS. The worse prognosis associated with MAGE-A+/PD-L1+ provides evidence that a combinatorial treatment strategy co-targeting MAGE/PD-L1 might be feasible. Further studies are needed to validate these findings.

https://ift.tt/2Ni7MUi

Diel-scale variation of dissolved inorganic carbon during a rainfall event in a small karst stream in southern China

Abstract

Metabolic processes of the submerged aquatic community (photosynthesis and respiration) play important roles in regulating diel cycles of dissolved inorganic carbon (DIC) and sequestering carbon in a karst stream. However, little is known of whether diel DIC cycling occurs during rainfall in a karst groundwater-fed stream, even though this question is critical for the accurate estimation of what may be a major terrestrial carbon sink. Here, we measured diel variations of water chemical composition in a small karst groundwater-fed stream in southwest China during a rainfall event to assess the influences of rainfall and rising discharge on DIC diel cycling and the potential carbon sink produced by in-stream metabolism. Our results show that water chemical composition at the source spring (CK site) is relatively stable due to chemostatic behavior during rising discharge after a rainfall period. This site lacked submerged aquatic vegetation and, thus, had no diel variations in water chemistry. However, diel cycles of all hydrochemical parameters occurred at a site 1.3 km downstream (LY site). Diel variations in pH, DO, and δ¹³C_DIC were inversely related to diel changes in SpC, DIC, Ca²⁺, and pCO₂. These results indicated that diel cycling of DIC due to in-stream metabolism of submerged aquatic community was still occurring during elevated discharge from rainfall. We estimate the carbon sink through the in-stream metabolism of the submerged aquatic community to be 5.6 kg C/day during the studied rainfall event. These results imply that submerged aquatic communities in a karst stream can significantly stabilize carbon originating from the carbonate rock weathering processes in karst areas.

https://ift.tt/2SfI1VB