The influence of urban form compactness on CO2 emissions and its threshold effect: Evidence from cities in China.

Although compact urban form plays an important role in constraining emissions of carbon dioxide (CO2), the boundary for the impact of compact urban form on these emissions has nevertheless received little attention. We consequently applied the entropy weight method and several key landscape metrics to a dataset from 295 cities in China to quantify urban form compactness (UFC) between 2000 and 2015. The STIRPAT model then was employed to estimate the impact of UFC on CO2 emissions, and a panel threshold regression model was used to estimate threshold effects capable of limiting the impact of compact urban form on emissions. Although CO2 emissions increased sharply over the 15-year study period, a significant negative relationship between UFC and CO2 emissions was detected. Two thresholds of UFC were detected, and this allowed three categories to be differentiated: before the first threshold, between the two thresholds, and after the second threshold. These categories were respectively associated with no impact, strong impact, and weak impact of UFC on reduction of carbon emissions in the 295 cities. Carbon emissions reduction consequently becomes effective when the UFC exceeds the first threshold and effectiveness persists but at a reduced level when the UFC exceeds the second threshold. Further temporal analysis confirmed that an increasing number of mostly small- and medium-sized cities could constrain their future carbon emissions by adopting a compact urban form. Thus, government policies should emphasize UFC as a strategy to reduce CO2 emissions. Moreover, by defining the range of compact urban form that has the greatest impact on CO2 emissions, our study deepens the overall understanding of the influence of UFC on carbon emission reductions, so as to make contributions to the design of low-carbon cities.

[Socio-ecological risk analysis framework coupled with ecosystem services]. / 耦合生态系统服务的社会生态风险分析框架.

The strong coupling between society and ecosystem makes socio-ecological risks become the main object of risk management. As the link between ecological and social processes, ecosystem services (ESs) are the core variable in deconstructing the social-ecological risks and the crucial point in resolving the risks. We explored the concept and the internal formation mechanisms of socio-ecological risk combining ESs, and further put the cascade logic and evolution process of "real risk-risk perception-risk behavior". Based on driver-pressure-state-impact-response framework (DPSIR), we proposed a framework for analyzing socio-ecological risk, and expanded the content and methodology system of research and management practices related to socio-ecological risks. We proposed that socio-ecological risk research coupled with ESs should focus on: 1) exploring the transmission mechanism between ecosystem processes, ecosystem services, and human well-being; 2) exploring the response mechanism of social subject behavior and its impacts on ecosystem services and human well-being; 3) construction of a multi-scale assessment model for social ecological risks coupled with ESs. The socio-ecological risk analysis framework for coupled ecosystem services was based on the mutual feedback between human and nature to explore the logic of risk formation, evolution, and governance, which could provide ideas for clarifying the deep meaning of ecological problems and selecting pathways to resolve socio-ecological risks.

Integrated assessment and critical obstacle diagnosis of rural resource and environmental carrying capacity with a social-ecological framework: a case study of Liyang county, Jiangsu Province.

The contradiction among human being, resources, and environment has become a significant obstacle to achieving sustainable development, especially in rural areas subject to the spillover of urban development elements. With the immense strain of resources and environment, it is critical to assess whether human activities fall within the carrying capacity range of a natural ecosystem in a rural system. Taking the rural areas of Liyang county as an example, this study aims to assess the rural resource and environmental carrying capacity (RRECC) and diagnose its critical obstacles. Firstly, a social-ecological framework focusing on human-environment interaction was employed to construct the RRECC indicator system. Subsequently, the entropy-TOPSIS method was introduced to assess the performance of the RRECC. Finally, the obstacle diagnosis method was applied to identify the critical obstacles of RRECC. Our results show that the distribution of RRECC presents a spatial heterogeneity, with high- and medium-high-level villages primarily concentrated in the south of the study area, where there are abundant hills and ecological lakes. Medium-level villages are scattered throughout each town, and low and medium-low level villages are concentrated across all the towns. Moreover, the resource subsystem of RRECC (RRECC_RS) exhibits a similar spatial distribution to RRECC, while the outcome subsystem of RRECC (RRECC_OS) has a comparable quantity proportion of different levels to RRECC. Furthermore, the diagnosis results of critical obstacle vary between the town scale divided by administrative units and the regional scale divided by RRECC values. In detail, arable land occupied by construction is the main critical obstacle at the town scale, while the poor people in villages, people left-behind, and arable land occupied by construction are the main critical obstacles at the regional scale. Targeted differentiated improvement strategies for RRECC at regional scale from various perspectives of global, local, and single are proposed. This research can serve as a theoretical foundation for assessing RRECC and developing differentiated sustainable development strategies for the path forward to rural revitalization.

Functional mixed effects clustering with application to longitudinal urologic chronic pelvic pain syndrome symptom data.

By clustering patients with the urologic chronic pelvic pain syndromes (UCPPS) into homogeneous subgroups and associating these subgroups with baseline covariates and other clinical outcomes, we provide opportunities to investigate different potential elements of pathogenesis, which may also guide us in selection of appropriate therapeutic targets. Motivated by the longitudinal urologic symptom data with extensive subject heterogeneity and differential variability of trajectories, we propose a functional clustering procedure where each subgroup is modeled by a functional mixed effects model, and the posterior probability is used to iteratively classify each subject into different subgroups. The classification takes into account both group-average trajectories and between-subject variabilities. We develop an equivalent state-space model for efficient computation. We also propose a cross-validation based Kullback-Leibler information criterion to choose the optimal number of subgroups. The performance of the proposed method is assessed through a simulation study. We apply our methods to longitudinal bi-weekly measures of a primary urological urinary symptoms score from a UCPPS longitudinal cohort study, and identify four subgroups ranging from moderate decline, mild decline, stable and mild increasing. The resulting clusters are also associated with the one-year changes in several clinically important outcomes, and are also related to several clinically relevant baseline predictors, such as sleep disturbance score, physical quality of life and painful urgency.

Sporicidal mechanism of the combination of ortho-phthalaldehyde and benzyldimethyldodecylammonium chloride as a disinfectant against the Bacillus subtilis spores.

Previous studies have shown that the combination disinfectant, Ortho-phthalaldehyde and benzyldimethyldodecylammonium chloride (ODB), can effectively kill a variety of microorganisms, such as Escherichia coli, Staphylococcus aureus, and Candida albicans. To observe the sporicidal ability and mechanism of ODB for spores, Bacillus subtilis spores were used as the research object in this experiment. TEM images revealed that ODB destroyed the integrity of the coat, cortex, and inner membrane of the spores after 0.5-h treatment, and the nuclear material was also broken and exuded after 4-h treatment. The broken structure led to the release of dipicolinic acid (DPA) in large amount. The results show that B. subtilis spores can be effetely killed by ODB through destroying the structure of the spores.

Effect of polyhexamethylene biguanide functionalized silver nanoparticles on the growth of Staphylococcus aureus.

Polyhexamethylene biguanide (PHMB) was used as a stabilizing ligand to synthesize uniform silver nanoparticles (Ag NPs). The effects and action mechanism of PHMB functionalized Ag NPs (Ag NPs-PHMB) on the growth of the Gram-positive bacteria Staphylococcus aureus were investigated. The results showed that a high concentration Ag NPs-PHMB could be obtained and prepared particles were fairly uniform. Prepared Ag NPs-PHMB enhanced the bactericidal effect and the log kill reached 5.06 when S. aureus was exposed to Ag NPs-PHMB for 20 min. Ag NPs-PHMB caused damage to cell wall, a decrease in the membrane fluidity, and leakage of K+, Mg2+, ATP and proteins from the cell, eventually leading to the death of S. aureus.

Toxicity and Metal Corrosion of Glutaraldehyde-Didecyldimethylammonium Bromide as a Disinfectant Agent.

The wide use of disinfectants has prompted resistance from the microbiome which will in turn reduce the bactericidal effect of disinfectants. Hence, glutaraldehyde (GA) and didecyldimethylammonium bromide (DDAB) were used to develop a combination disinfectant with high stability and antimicrobial effects, which was named GA-DDAB combination disinfectant (GD). The bactericidal mechanism against Escherichia coli was studied in our earlier work. In this study, we focused on GD's bactericidal efficacy in both the laboratory and environment, the genetic toxicity to mouse lymphoma L5178Y TK+/- cells, acute peroral toxicity in mice, and its metal corrosion properties with a view to providing theoretical support for developing a high-efficiency, low toxicity, and weakly corrosive disinfectant for general use.