Identification of Sare0718 As an Alanine-Activating Adenylation Domain in Marine Actinomycete Salinispora arenicola CNS-205

BACKGROUND: Amino acid adenylation domains (A domains) are critical enzymes that dictate the identity of the amino acid building blocks to be incorporated during nonribosomal peptide (NRP) biosynthesis. NRPs represent a large group of valuable natural products that are widely applied in medicine, agriculture, and biochemical research. Salinispora arenicola CNS-205 is a representative strain of the first discovered obligate marine actinomycete genus, whose genome harbors a large number of cryptic secondary metabolite gene clusters. METHODOLOGY/PRINCIPAL FINDINGS: In order to investigate cryptic NRP-related metabolites in S. arenicola CNS-205, we cloned and identified the putative gene sare0718 annotated "amino acid adenylation domain". Firstly, the general features and possible functions of sare0718 were predicted by bioinformatics analysis, which suggested that Sare0718 is a soluble protein with an AMP-binding domain contained in the sequence and its cognate substrate is L-Val. Then, a GST-tagged fusion protein was expressed and purified to further explore the exact adenylation activity of Sare0718 in vitro. By a newly mentioned nonradioactive malachite green colorimetric assay, we found that L-Ala but not L-Val is the actual activated amino acid substrate and the basic kinetic parameters of Sare0718 for it are K(m) = 0.1164±0.0159 (mM), V(max) = 3.1484±0.1278 (µM/min), k(cat) = 12.5936±0.5112 (min(-1)). CONCLUSIONS/SIGNIFICANCE: By revealing the biochemical role of sare0718 gene, we identified an alanine-activating adenylation domain in marine actinomycete Salinispora arenicola CNS-205, which would provide useful information for next isolation and function elucidation of the whole cryptic nonribosomal peptide synthetase (NRPS)-related gene cluster covering Sare0718. And meanwhile, this work also enriched the biochemical data of A domain substrate specificity in newly discovered marine actinomycete NRPS system, which bioinformatics prediction will largely depend on

The Effects of Payment for Environmental Services on Environmental Improvement and Poverty Reduction: A Meta-Regression Analysis

Based on the empirical literature of the payments for environmental services (PES) projects for the environmental improvement and poverty reduction, this paper uses a meta-regression analysis method to study whether PES can achieve the effects of improving environmental quality and reducing poverty levels. For the meta-regression analysis, the literature was mainly searched by the Web of Science core journal database. The explanatory variables of meta-regression analysis are the hypothesis and related features of the models in the original literature by generally taking the binary dummy variables or categorical variables. The dependent variables used in this paper are environmental improvement and poverty reduction. The results show that PES projects based on private ownership rights are more conducive to poverty reduction and environmental improvement. If the country is a buyer of a PES project, it is more likely to achieve the effects of environmental enhancement and poverty alleviation. PES projects based on local conditions can also achieve a win–win situation for the two effects. The effects are more effective as policy implementation time is extended. The findings suggest that in developing countries, the government should set different PES projects according to different regions conditions, to promote project implementation through individual voluntary participation, and to achieve the dual purpose of environmental governance and poverty alleviation based on the expectation of long-term implementation of participant projects

Associations between Greenspaces and Individual Health: A Longitudinal Study in China

Using a longitudinal survey in China, this study identifies the effect of greenspaces on individual health in the aspects of self-rated health, mental health, feeling physical discomfort, and being hospitalized. The normalized difference vegetation index (NDVI) is used to measure the greenery cover of each city, and findings show that higher NDVI leads to the improvement of personal self-rated health status, and it also decreases the probability of being hospitalized, having symptoms of physical discomfort, and being lost in bad mood. The positive health effect of NDVI in the city is much more significant and larger for the middle-aged, the elderly, and the low-educated. The evidence of the three possible channels through which the NDVI of each city shows a positive correlation with individual physical and mental health is found. The increased NDVI in the city encourages residents to foster healthier habits (e.g., decreasing smoking or drinking, increasing sleeping hours), improves air quality and reduces air pollution in each city, and promotes the social cohesion of people, and so the health status of residents is enhanced. This study implies that increasing greenspaces in the city is an effective strategy to improve social welfare and residents’ health

The Effect of Urban Resilience on Residents’ Subjective Happiness: Evidence from China

This study aims to analyze the role of urban resilience in residents’ subjective happiness in China. Results show that the overall urban resilience is a critical factor in improving residents’ subjective happiness, and each sub-class resilience index of cities in the ecological, social, infrastructure, and economic aspects shows positive and significant correlations with residents’ subjective happiness. Heterogeneous results show that the effect of urban resilience is greater for residents with higher education or living in cities with larger population size. The mechanism results show that four possible channels are confirmed. The rise of urban resilience raises residents’ subjective happiness through increasing residents’ income or consumption, improving their health status, and raising their social trust or social integration. The main conclusion drawn from the empirical analysis is that raising urban resilience is an effective strategy to strengthen residents’ subjective happiness

Differences and Drivers of Urban Resilience in Eight Major Urban Agglomerations: Evidence from China

This paper constructs an evaluation indicator system for urban resilience in China on four dimensions—economy, environment, society, and infrastructure. The evaluation indicator is used by the entropy weight method to measure the resilience levels of 138 cities in 8 urban agglomerations from 2005 to 2018. Using the Theil index and variance decomposition method, we explore the size and sources of urban resilience differences among the eight urban agglomerations from the dual perspectives of space and structure and employ geographic detectors to identify the driving factors behind their differences. The results show that although the overall resilience level of the eight urban agglomerations is not high, it shows an upward trend. The differences within the eight urban agglomerations are the main spatial sources of urban resilience differences and economic resilience is the main structural source of urban resilience differences. Moreover, economic resilience and social resilience have the greatest contribution and driving effect on the resilience differences of BTH, YRD, PRD, MYR, CC, GP, and HC urban agglomerations, but the difference in resilience of CP is mainly caused by the difference in infrastructure resilience. Compared with the single factor, the impact of the interaction of each factor is even greater

Differences and Drivers of Urban Resilience in Eight Major Urban Agglomerations: Evidence from China

This paper constructs an evaluation indicator system for urban resilience in China on four dimensions—economy, environment, society, and infrastructure. The evaluation indicator is used by the entropy weight method to measure the resilience levels of 138 cities in 8 urban agglomerations from 2005 to 2018. Using the Theil index and variance decomposition method, we explore the size and sources of urban resilience differences among the eight urban agglomerations from the dual perspectives of space and structure and employ geographic detectors to identify the driving factors behind their differences. The results show that although the overall resilience level of the eight urban agglomerations is not high, it shows an upward trend. The differences within the eight urban agglomerations are the main spatial sources of urban resilience differences and economic resilience is the main structural source of urban resilience differences. Moreover, economic resilience and social resilience have the greatest contribution and driving effect on the resilience differences of BTH, YRD, PRD, MYR, CC, GP, and HC urban agglomerations, but the difference in resilience of CP is mainly caused by the difference in infrastructure resilience. Compared with the single factor, the impact of the interaction of each factor is even greater

Sources of China’s Economic Growth: An Empirical Analysis Based on the BML Index with Green Growth Accounting

This study develops a biennial Malmquist–Luenberger productivity index that is used to measure the sources of economic growth by utilizing data envelopment analysis and the directional distance function. Taking restrictions on resources and the environment into account based on the green growth accounting framework; we split economic growth into seven components: technical efficiency change, technological change, labor effect, capital effect, energy effect, output structure effect and environmental regulation effect. Further, we apply the Silverman test and Li-Fan-Ullah nonparametric test in combination with kernel distribution to test for the counterfactual contributions at the provincial level in China from 1998 to 2012. The empirical results show that: (1) technological progress and TFP make positive contributions to economic growth in China, while technical efficiency drags it down; (2) the effect of output structure and CO2 emissions with environmental regulation restrain economic growth in some provinces; and (3) overall, physical capital accumulation is the most important driving force for economic take-off, irrespective of whether the government adopts environmental regulations

The Effect of Energy Quota Trading on Energy Saving in China: Insight from a Quasi-Natural Experiment

Saving energy is an important strategy to address the current energy crisis and environmental degradation. Regarding the pilot policy of the energy quota trading as a quasi-natural experiment by employing a difference-in-differences method, the purpose of this paper is to investigate the effect of this pilot policy on energy saving and its mechanisms based on city-level data in China from 2006 to 2020. We find that the energy quota trading policy can reduce the total energy consumption and energy consumption intensity of pilot cities, and the effect of the policy can gradually strengthen over time. The market-oriented reform of energy factor allocation can effectively promote energy saving and economic growth. These results are convincing through a series of robustness checks. The heterogeneity test shows that the energy quota trading has a significant energy saving effect on economically developed cities, densely populated cities and southern cities, but not in economically underdeveloped cities, sparsely populated cities and northern cities. Further mechanism inspection suggests that the pilot policy of energy quota trading mainly achieves energy conservation through industrial structure upgrading and green technology innovation. Our findings provide a valuable insight for China to control energy consumption and promote the high-quality development of the energy economy

The Effect of Urban Resilience on Residents’ Subjective Happiness: Evidence from China

This study aims to analyze the role of urban resilience in residents’ subjective happiness in China. Results show that the overall urban resilience is a critical factor in improving residents’ subjective happiness, and each sub-class resilience index of cities in the ecological, social, infrastructure, and economic aspects shows positive and significant correlations with residents’ subjective happiness. Heterogeneous results show that the effect of urban resilience is greater for residents with higher education or living in cities with larger population size. The mechanism results show that four possible channels are confirmed. The rise of urban resilience raises residents’ subjective happiness through increasing residents’ income or consumption, improving their health status, and raising their social trust or social integration. The main conclusion drawn from the empirical analysis is that raising urban resilience is an effective strategy to strengthen residents’ subjective happiness

Impacts of rail transit access on land and housing values in China: a quantitative synthesis

Rail transit investment has been viewed as a prominent policy instrument for local and regional development. However, little is known about to what extent the theorised changes in land and housing values arising from rail transit access can be substantiated by evidence in a large developing country context. This paper presents a quantitative review of empirical studies that analysed the impacts of rail transit access on land and housing values in China. We review empirical analyses in 67 studies from 1997 to 2018 for which we encode quantitative results along with a range of theoretically combinations of spatially contextual characteristics, data and methodological-design characteristics. The results show that there are significant variations in the size estimates of effects of rail transit access across studies. Such variations are associated with rail project types, data and methodological designs. Our study provides the insights on what has already been known and what needs to be known on evaluating real estate consequences of rail transit improvements in developing countries