Hepatitis A Virus: State of the Art

Hepatitis A is the most common among all hepatitis worldwide in spite of an efficient vaccine and improved hygiene. Shellfish-borne outbreaks are still of major concern causing hundreds of cases and huge economical losses in the present context of global food trade. Hepatitis A virus (HAV) is a unique picornavirus with many differences in its molecular biology including both its incapacity to induce the inhibition of the cellular protein synthesis and a highly biased and deoptimized codon usage with respect the cell. The final goal of this intriguing strategy seems to be the need for a fine-tuning control of the translation kinetics, particularly at the capsid coding region, and the underlying mechanism is the use of a right combination of common and rare codons to allow a regulated ribosome traffic rate thus ensuring the proper protein folding. Capsid folding is critical to warrant a high environmental stability for a virus transmitted through the fecal–oral route with long extracorporeal periods.     

On international equity in reducing emissions from deforestation

Reducing emissions from deforestation and forest degradation (REDD) can be an effective and efficient means of mitigating climate change. However, the perceived equity in the distribution of financial incentives for REDD could also emerge as a critical issue in international negotiations. The design of reference levels, which provide the benchmark for crediting emissions reductions, affects the economic incentives for national participation in a REDD mechanism and thus the overall willingness to reach an agreement on REDD. This paper compares the equity impacts of five proposed reference level designs using a partial-equilibrium model. Tradeoffs among equity, environmental effectiveness and cost-efficiency indicate the proposals trigger similar aggregate emissions reductions but lead to different outcomes in efficiency and alternative measures of equity. If equity across countries is measured as the financial incentive provided relative to a country's forest carbon stock, then a REDD mechanism compensating a uniform share of at-risk carbon stocks is the most equitable. On the other hand, if equity is evaluated as the financial incentive relative to the opportunity costs of participating in REDD, then the most equitable approach would be compensating emissions reductions but withholding a part of the payments to compensate for carbon stocks, which also encourages broader country participation under our model.     

Economy-wide impacts of climate change: a joint analysis for sea level rise and tourism

While climate change impacts on human life have well defined and different origins, the interactions among the diverse impacts are not yet fully understood. Their final effects, however, especially those involving social-economic responses, are likely to play an important role. This paper is one of the first attempts to disentangle and highlight the role of these interactions. It focuses on the economic assessment of two specific climate change impacts: sea-level rise and changes in tourism flows. By using a Computable General Equilibrium (CGE) model the two impacts categories are first analysed separately and then jointly. Considered separately, in 2050, the forecasted 25 cm. of sea level rise imply a GDP loss ranging from (−) 0.1% in South East Asia to almost no loss in Canada, while redistribution of tourism flows – which in terms of arrivals favours Western Europe, Japan, Korea and Canada and penalises all the other world regions – triggers GDP losses ranging from (−) 0.5% in Small Island States to (−) 0.0004% in Canada. GDP gainers are Australia, New Zealand, Western Europe, Middle East and South Asia. The impact of sea level rise and tourism were simulated jointly and the results compared with those of the two disjoint simulations. From a qualitative point of view, the joint effects are similar to the outcomes of the disjoint exercises; from a quantitative perspective, however, impact interaction does play a significant role. In six cases out of 16 there is a detectable (higher than 2% and peaking to 70%) difference between the sum of the outcomes in the disjoint simulation and the outcomes of the joint simulations. Moreover, the relative contribution of each single impact category has been disentangled from the final result. In the case under scrutiny, demand shocks induced by changes in tourism flows outweigh the supply-side shock induced by the loss of coastal land.

An efficient simultaneous degradation of sulfamethoxazole and trimethoprim by photoelectro-Fenton process under non-modified pH using a natural citric acid source: study of biodegradability,ecotoxicity, and antibacterial activity

Environmental Science and Pollution Research - In this work, the use of natural organic wastes (orange and lemon peels) as sources of citric acid was evaluated along with the application of the...     

SARS-CoV-2 surveillance in indoor and outdoor size-segregated aerosol samples

Environmental Science and Pollution Research - We aimed to determine the presence of SARS-CoV-2 RNA in indoor and outdoor size-segregated aerosol samples (PM10-2.5, PM2.5). Five outdoor daily...     

Effects of Combined Exposure to Formaldehyde and PM2.5 on the Brain of Balb/c Mice Asthma Model

Epidemiological studies have shown that there is a link between asthma and brain damage,but toxicological studies have not fully confirmed yet,especially the effects of asthma on the brain. In this study,at first,we explore the effects of asthma on the brain through the establishment of an allergic asthma model. Then PM_(2.5),a typical outdoor air pollutant and formaldehyde,a typical indoor air pollutant were selected to be closer to the true environment and find whether there is any synergism between them. In this study,an ovalbumin( OVA)-sensitized mice asthma model was established. 30 male Balb/c mice were randomly divided into 5 groups:( 1) saline control group,( 2) OVA-sensitized group,( 3) OVA-combined with formaldehyde exposure group,( 4) OVA-combined with PM_(2.5) exposure group,( 5) Combination of OVA,formaldehyde and PM_(2.5) exposure group. The mice were inhaled with formaldehyde or/and instilled with PM_(2.5) from day 1 to 18. The mice asthma model was developed by OVA sensitization and challenge. The mice were sensitized with OVA+Al( OH)3( 5 mg OVA and 175 mg Al( OH)3 in 30 m L saline each time) or saline( 30 m L saline each time) by intraperitoneal injection on day 1,7 and 14.This was then followed by an aerosol challenge in 1% OVA( 30 min·d~(-1)) from day 19 to 25( 7 times) using an ultrasonic nebulizer. On the 26 th day,the organ coefficient of mice brain was counted,then the contents of oxidative stress of mice brain were measured,including reactive oxygen species( ROS),glutathione( GSH) and malondialdehyde( MDA),and the concentrations of NF-κB and interleukin-1β( IL-1β) were detected by using ELISA kits.Detection of interleukin-6( IL-6) was made with immunohistochemical method. Histological assay for brain was also conducted. In our results,all the OVA treated groups showed a significant increase of ROS and a significant decrease of GSH contents when compared with the control group. Except OVA-sensitized group,other OVA treated groups also showed a significant increase of MDA contents when compared with the control group,and MDA contents of OVA-sensitized group showed significant change when compared to the combined exposure group. In ROS and GSH,combined exposure showed some joint effect compared with single exposure. When OVA was applied in combination with formaldehyde and PM_(2.5),NF-κB was activated. And all the OVA treated groups showed increased levels of IL-1β and IL-6 compared with the control group. And the combined exposure showed an aggravated effect when compared with OVA-sensitized group. Histopathological observation of the hippocampus in mice brain clearly showed the difference of eosin( EO) stained neurons in the combined exposure group compared with the control group and OVA-sensitized group. The pyramidal neurons of the mice with allergic asthma exposed to formaldehyde and/or PM_(2.5) had been reduced in number,the cells were swollen and the dendrites had disappeared. Allergic asthma can cause damage to the brain through oxidative stress. Exposure to formaldehyde and PM_(2.5) will increase the damage caused by allergic asthma to the brain,which may be mediated by oxidative stress and NF-κB activation.This promotes the release of the inflammatory factors,resulting in increased inflammation.     

Methods for selenium removal from contaminated waters: a review

Environmental Chemistry Letters - Worldwide contamination of waters by metals, metalloids, and organometallic pollutants is a major health issue. In particular, the occurrence of the selenium...