Environmental Kuznets Curves in the People’s Republic of China: turning points and regional differences

This paper examines the relationship between economic growth and environmental sustainability in the People’s Republic of China by empirically estimating environmental Kuznets curve (EKC) models using provincial-level panel data from 1985 to 2005. The results show that there exists an inverted-U shaped relationship as hypothesized by the EKC model between per capita income and per capita emissions (or discharges) in the cases of waste gas from fuel burning and waste water, with a turning point at per capita gross domestic product of $12,903 and$3,226, respectively, in 2005 purchasing power parity terms. This relationship does not hold in the case of waste gas from production or solid waste. The estimation results from the model allowing region-specific slope coefficients show that the EKCs of the more developed coastal region have a flatter rising portion with turning points occurring at a higher income level than those of the less developed central and western regions. The paper argues that this may reflect technology diffusion and leapfrogging and institution imitation across regions at different stages of development. Policy implications of these findings are discussed.environmental kuznets curve; EKC; China; economic growth; environmental sustainability

Higher water tariffs for less river pollution—evidence from Min River and Fuzhou City, People’s Republic of China

Upstream nonpoint source pollution has become a significant threat to urban drinking water safety in the People’s Republic of China. Payment for environmental services (PES) is seen as a promising mechanism to deal with the situation. In designing a sound PES, it is crucial to determine the willingness to pay (WTP) of urban beneficiaries for upstream water pollution controls. An analysis of household data from a contingent valuation survey conducted in Fuzhou in 2009 reveals that household income is the most important factor in determining respondents’ positions on water tariff increases as well as WTP under a PES scheme. Mean WTP varies from Yuan (CNY) –0.45 per cubic meter to CNY0.86 for different income groups. The overall mean WTP is estimated to be CNY0.21, which is equivalent to a 10% increase in the current tariff, with the 95% confidence interval at (CNY0.12, CNY0.31). The point estimate implies a total annual WTP of Fuzhou City equal to CNY22 million, which is 27% less than the contribution of Fuzhou to an ongoing government-financed PES. However, with continuous water tariff increases, affordability among low-income households might arise as an issue. This calls for subsidies targeting low-income households to be incorporated in water tariff reform.water tariff, river pollution, upstream nonpoint source pollution, payment for environmental services, willingness to pay, Min River, Fuzhou City, China

Recruiting Conventional Tree Architecture Models into State-of-the-Art LiDAR Mapping for Investigating Tree Growth Habits in Structure

Mensuration of tree growth habits is of considerable importance for understanding forest ecosystem processes and forest biophysical responses to climate changes. However, the complexity of tree crown morphology that is typically formed after many years of growth tends to render it a non-trivial task, even for the state-of-the-art 3D forest mapping technology-light detection and ranging (LiDAR). Fortunately, botanists have deduced the large structural diversity of tree forms into only a limited number of tree architecture models, which can present a-priori knowledge about tree structure, growth, and other attributes for different species. This study attempted to recruit Halle architecture models (HAMs) into LiDAR mapping to investigate tree growth habits in structure. First, following the HAM-characterized tree structure organization rules, we run the kernel procedure of tree species classification based on the LiDAR-collected point clouds using a support vector machine classifier in the leave-one-out-for-cross-validation mode. Then, the HAM corresponding to each of the classified tree species was identified based on expert knowledge, assisted by the comparison of the LiDAR-derived feature parameters. Next, the tree growth habits in structure for each of the tree species were derived from the determined HAM. In the case of four tree species growing in the boreal environment, the tests indicated that the classification accuracy reached 85.0%, and their growth habits could be derived by qualitative and quantitative means. Overall, the strategy of recruiting conventional HAMs into LiDAR mapping for investigating tree growth habits in structure was validated, thereby paving a new way for efficiently reflecting tree growth habits and projecting forest structure dynamics.Peer reviewe

The contribution of Alu exons to the human proteome.

BackgroundAlu elements are major contributors to lineage-specific new exons in primate and human genomes. Recent studies indicate that some Alu exons have high transcript inclusion levels or tissue-specific splicing profiles, and may play important regulatory roles in modulating mRNA degradation or translational efficiency. However, the contribution of Alu exons to the human proteome remains unclear and controversial. The prevailing view is that exons derived from young repetitive elements, such as Alu elements, are restricted to regulatory functions and have not had adequate evolutionary time to be incorporated into stable, functional proteins.ResultsWe adopt a proteotranscriptomics approach to systematically assess the contribution of Alu exons to the human proteome. Using RNA sequencing, ribosome profiling, and proteomics data from human tissues and cell lines, we provide evidence for the translational activities of Alu exons and the presence of Alu exon derived peptides in human proteins. These Alu exon peptides represent species-specific protein differences between primates and other mammals, and in certain instances between humans and closely related primates. In the case of the RNA editing enzyme ADARB1, which contains an Alu exon peptide in its catalytic domain, RNA sequencing analyses of A-to-I editing demonstrate that both the Alu exon skipping and inclusion isoforms encode active enzymes. The Alu exon derived peptide may fine tune the overall editing activity and, in limited cases, the site selectivity of ADARB1 protein products.ConclusionsOur data indicate that Alu elements have contributed to the acquisition of novel protein sequences during primate and human evolution