Significant contrasts in aerosol acidity between China and the United States

Aerosol acidity governs several key processes in aerosol physics and chemistry, thus affecting aerosol mass and composition and ultimately climate and human health. Previous studies have reported aerosol pH values separately in China and the United States (USA), implying different aerosol acidity between these two countries. However, there is debate about whether mass concentration or chemical composition is the more important driver of differences in aerosol acidity. A full picture of the pH difference and the underlying mechanisms responsible is hindered by the scarcity of simultaneous measurements of particle composition and gaseous species, especially in China. Here we conduct a comprehensive assessment of aerosol acidity in China and the USA using extended ground-level measurements and regional chemical transport model simulations. We show that aerosols in China are significantly less acidic than in the USA, with pH values 1&ndash;2&nbsp;units higher. Based on a proposed multivariable Taylor series method and a series of sensitivity tests, we identify major factors leading to the pH difference. Compared to the USA, China has much higher aerosol mass concentrations (gas + particle, by a factor of 8.4 on average) and a higher fraction of total ammonia (gas + particle) in the aerosol composition. Our assessment shows that the differences in mass concentrations and chemical composition play equally important roles in driving the aerosol pH difference between China and the USA &ndash; increasing the aerosol mass concentrations (by a factor of 8.4) but keeping the relative component contributions the same in the USA as the level in China increases the aerosol pH by &sim;&thinsp;1.0&nbsp;units and further shifting the chemical composition from US conditions to China's that are richer in ammonia increases the aerosol pH by &sim;&thinsp;0.9 units. Therefore, China being both more polluted than the USA and richer in ammonia explains the aerosol pH difference. The difference in aerosol acidity highlighted in the present study implies potential differences in formation mechanisms, physicochemical properties, and toxicity of aerosol particles in these two countries. &nbsp;</p

Formal safety assessment based on relative risks model in ship navigation

Formal safety assessment (FSA) is a structured and systematic methodology aiming at enhancing maritime safety. It has been gradually and broadly used in the shipping industry nowadays around the world. On the basis of analysis and conclusion of FSA approach, this paper discusses quantitative risk assessment and generic risk model in FSA, especially frequency and severity criteria in ship navigation. Then it puts forward a new model based on relative risk assessment (MRRA). The model presents a risk-assessment approach based on fuzzy functions and takes five factors into account, including detailed information about accident characteristics. It has already been used for the assessment of pilotage safety in Shanghai harbor, China. Consequently, it can be proved that MRRA is a useful method to solve the problems in the risk assessment of ship navigation safety in practice

Path Analysis of Causal Factors Influencing Marine Traffic Accident via Structural Equation Numerical Modeling

Many causal factors to marine traffic accidents (MTAs) influence each other and have associated effects. It is necessary to quantify the correlation path mode of these factors to improve accident prevention measures and their effects. In the application of human factors to accident mechanisms, the complex structural chains on causes to MTA systems were analyzed by combining the human failure analysis and classification system (HFACS) with theoretical structural equation modeling (SEM). First, the accident causation model was established as a human error analysis classification in sight of a MTA, and the constituent elements of the causes of the accident were conducted. Second, a hypothetical model of human factors classification was proposed by applying the practice of the structural model. Third, with the data resources from ship accident cases, this hypothetical model was discussed and simulated, and as a result, the relationship path dependency mode between the latent independent variable of the accident was quantitatively analyzed based on the observed dependent variable of human behavior. Application examples show that relationships in the HFACS are verified and in line with the path developing mode, and resource management factors have a pronounced influence and a strong relevance to the causal chain of the accidents. Appropriate algorithms for the theoretical model can be used to numerically understand the safety performance of marine traffic systems under different parameters through mathematical analysis. Hierarchical assumptions in the HFACS model are quantitatively verified

A Hybrid Probabilistic Risk Analytical Approach to Ship Pilotage Risk Resonance with FRAM

Collision risk in ship pilotage process has complex characteristics that are dynamic, uncertain, and emergent. To reveal collision risk resonance during ship pilotage process, a hybrid probabilistic risk analysis approach is proposed, which integrates the Functional Resonance Analysis Method (FRAM), Dempster–Shafer (D–S) evidence theory, and Monte Carlo (MC) simulation. First, FRAM is used to qualitatively describe the coupling relationship and operation mechanism among the functions of the pilotage operation system. Then, the D–S evidence theory is used to determine the probability distribution of the function output in the specified pilotage scenario after quantitatively expressing the function variability, coupling effect, and the influence of operation conditions through rating scales. Finally, MC simulation is used to calculate the aggregated coupling variability between functions, and the critical couplings and risk resonance paths under different scenarios are identified by setting the threshold and confidence level. The results show that ship collision risk transmission is caused by function resonance in the pilotage system, and the function resonance paths vary with pilotage scenarios. The critical coupling ‘F2-F7(I)’ emerges as a consistent factor in both scenarios, emphasizing the significance of maintaining a proper lookout. The hybrid probabilistic risk analytical approach to ship pilotage risk resonance with FRAM can be a useful method for analysing the causative mechanism of ship operational risk

Homatula guanheensis sp. nov. (Teleostei: Nemacheilidae), a new species of loach from Henan Province, China

Homatula are peculiar taxa in China, distributed in the Yellow River, Yangtze River, Pearl River, Lancang River drainage and Red River. At present, 17 valid species have been already reported in China.Homatula guanheensis sp. nov., a new species, is described from the Guanhe River of the HanJiang River drainage (a tributary of the Yangtze River), Xixia County, Henan province, China. The species can be distinguished from its congeners by a combination of molecular divergence in the Cytochrome oxidase I (CO I) and Cytochrome b (Cyt b) genes and morphological characters, including a shallower body with a uniform depth, differences in the widths of vertical brown bars on the body, body scale distribution, length of the dorsal adipose crest of the caudal peduncle, and the form of the intestine

Schisandra sphenanthera Extract Facilitates Liver Regeneration after Partial Hepatectomy in Mice

ABSTRACT Liver regeneration after surgical liver resection is crucial for the restoration of liver mass and the recovery of liver function. Schisandra sphenanthera extract (Wuzhi tablet, WZ) is a preparation of an extract from the dried ripe fruit of Schisandra sphenanthera Rehd. et Wils, a traditional hepatoprotective herb. Previously, we found that WZ could induce liver regeneration-related genes against acetaminopheninduced liver injury. However, whether WZ can directly facilitate liver regeneration after liver resection remains unknown. We investigated whether WZ has potential in promoting liver regeneration after a partial hepatectomy (PHX) in mice. Remnant livers were collected 1, 1.5, 2, 3, 5, 7, and 10 days after PHX. Hepatocyte proliferation was assessed using the Ki-67 labeling index. Western blot analysis was performed on proteins known to be involved in liver regeneration. The results demonstrated that WZ significantly increased the liver-to-body weight ratio of mice after PHX but had no effect on that of mice after a sham operation. Additionally, the peak hepatocyte proliferation was observed at 1.5 days in PHX/WZ-treated mice but at 2 days in PHX/saline-treated mice, as evidenced by the Ki-67 positive ratio. Furthermore, WZ significantly increased the protein expression of ligand-induced phosphorylation of epidermal growth factor receptor and up-regulated cyclin D1, cyclin D-dependent kinase 4, phosphorylated retinoblastoma, and proliferating cell nuclear antigen protein expression and down-regulated the expression of cell cycle inhibitors p21 and p27 in the regenerative process after PHX. These results demonstrate that WZ significantly facilitates hepatocyte proliferation and liver regeneration after PHX