An Overview of Regional Experiments on Biomass Burning Aerosols and Related Pollutants in Southeast Asia: From BASE-ASIA and the Dongsha Experiment to 7-SEAS

By modulating the Earth-atmosphere energy, hydrological and biogeochemical cycles, and affecting regional-to-global weather and climate, biomass burning is recognized as one of the major factors affecting the global carbon cycle. However, few comprehensive and wide-ranging experiments have been conducted to characterize biomass-burning pollutants in Southeast Asia (SEA) or assess their regional impact on meteorology, the hydrological cycle, the radiative budget, or climate change. Recently, BASEASIA (Biomass-burning Aerosols in South-East Asia: Smoke Impact Assessment) and the 7-SEAS (7- South-East Asian Studies) Dongsha Experiment were conducted during the spring seasons of 2006 and 2010 in northern SEA, respectively, to characterize the chemical, physical, and radiative properties of biomass-burning emissions near the source regions, and assess their effects. This paper provides an overview of results from these two campaigns and related studies collected in this special issue, entitled Observation, modeling and impact studies of biomass burning and pollution in the SE Asian Environment. This volume includes 28 papers, which provide a synopsis of the experiments, regional weatherclimate, chemical characterization of biomass-burning aerosols and related pollutants in source and sink regions, the spatial distribution of air toxics (atmospheric mercury and dioxins) in source and remote areas, a characterization of aerosol physical, optical, and radiative properties, as well as modeling and impact studies. These studies, taken together, provide the first relatively complete dataset of aerosol chemistry and physical observations conducted in the sourcesink region in the northern SEA, with particular emphasis on the marine boundary layer and lower free troposphere (LFT). The data, analysis and modeling included in these papers advance our present knowledge of source characterization of biomass-burning pollutants near the source regions as well as the physical and chemical processes along transport pathways. In addition, we raise key questions to be addressed by a coming deployment during springtime 2013 in northern SEA, named 7-SEASBASELInE (Biomass-burning Aerosols Stratocumulus Environment: Lifecycles and Interactions Experiment). This campaign will include a synergistic approach for further exploring many key atmospheric processes (e.g., complex aerosol-cloud interactions) and impacts of biomass burning on the surface-atmosphere energy budgets during the lifecycles of biomass burning emissions

The antioxidant response mechanism of flavonoids in ‘Tainong 1’ mango pulp under enhanced UV-B radiation

AbstractIn this study, UV-B radiation of 96 kJ·m−2·d−1 exposed to the ‘Tainong 1’ mango tree, and trees as the control group under natural lighting. The relative conductivity and the contents of MDA, superoxide anion, H2O2 were lower in the treatment group than in the control group before 60 DAF, and the opposite occurred after 60 DAF. The total flavonoid content in the treatment group was higher than that in the control group, but the opposite occurred later. The 60 DAF serves as the critical point. Before 60 DAF, the treatment enhanced the activity of each enzyme by inducing the upregulated expression of genes such as CHS, R02446, and CYP98A so that gallochol, leucoside, kaempferoside, quercetin, isoquercetin and luteolin, and then removed ROS through the reduction of flavonoids. After 60 DAF, the treatment enhanced the activity of each enzyme by inducing the upregulated expression of HCT and R02446, but the synthesized flavonoids are consumed by ROS. Meanwhile, ROS also accumulate continuously because of the enhanced continuous exposure of UV-B radiation. The downregulated expression of CYP75A led to a decline in enzyme activity. The accumulation rate of flavonoid compounds was lower than that of ROS, which led to ROS damage in pulp

The Pharmacological Effects of Lutein and Zeaxanthin on Visual Disorders and Cognition Diseases

Lutein (L) and zeaxanthin (Z) are dietary carotenoids derived from dark green leafy vegetables, orange and yellow fruits that form the macular pigment of the human eyes. It was hypothesized that they protect against visual disorders and cognition diseases, such as age-related macular degeneration (AMD), age-related cataract (ARC), cognition diseases, ischemic/hypoxia induced retinopathy, light damage of the retina, retinitis pigmentosa, retinal detachment, uveitis and diabetic retinopathy. The mechanism by which they are involved in the prevention of eye diseases may be due their physical blue light filtration properties and local antioxidant activity. In addition to their protective roles against light-induced oxidative damage, there are increasing evidences that L and Z may also improve normal ocular function by enhancing contrast sensitivity and by reducing glare disability. Surveys about L and Z supplementation have indicated that moderate intakes of L and Z are associated with decreased AMD risk and less visual impairment. Furthermore, this review discusses the appropriate consumption quantities, the consumption safety of L, side effects and future research directions

Cucumber mosaic virus coat protein modulates the accumulation of 2b protein and antiviral silencing that causes symptom recovery <i>in planta</i>

<div><p>Shoot apical meristems (SAM) are resistant to most plant viruses due to RNA silencing, which is restrained by viral suppressors of RNA silencing (VSRs) to facilitate transient viral invasion of the SAM. In many cases chronic symptoms and long-term virus recovery occur, but the underlying mechanisms are poorly understood. Here, we found that wild-type <i>Cucumber mosaic virus</i> (CMV^WT) invaded the SAM transiently, but was subsequently eliminated from the meristems. Unexpectedly, a CMV mutant, designated CMV^RA that harbors an alanine substitution in the N-terminal arginine-rich region of the coat protein (CP) persistently invaded the SAM and resulted in visible reductions in apical dominance. Notably, the CMV^WT virus elicited more potent antiviral silencing than CMV^RA in newly emerging leaves of infected plants. However, both viruses caused severe symptoms with minimal antiviral silencing effects in the <i>Arabidopsis</i> mutants lacking host RNA-DEPENDENT RNA POLYMERASE 6 (RDR6) or SUPPRESSOR OF GENE SILENCING 3 (SGS3), indicating that CMV^WT induced host RDR6/SGS3-dependent antiviral silencing. We also showed that reduced accumulation of the 2b protein is elicited in the CMV^WT infection and consequently rescues potent antiviral RNA silencing. Indeed, co-infiltration assays showed that the suppression of posttranscriptional gene silencing mediated by 2b is more severely compromised by co-expression of CP^WT than by CP^RA. We further demonstrated that CP^WT had high RNA binding activity leading to translation inhibition in wheat germ systems, and CP^WT was associated with SGS3 into punctate granules <i>in vivo</i>. Thus, we propose that the RNAs bound and protected by CP^WT possibly serve as templates of RDR6/SGS3 complexes for siRNA amplification. Together, these findings suggest that the CMV CP acts as a central hub that modulates antiviral silencing and VSRs activity, and mediates viral self-attenuation and long-term symptom recovery.</p></div