ALBERT

Description: Phosphorylation of eukaryotic translation initiation factor 2α (eIF2α) by eIF2α family kinases is a conserved mechanism to limit protein synthesis under specific stress conditions. The baculovirus-encoded protein PK2 inhibits eIF2α family kinases in vivo, thereby increasing viral fitness. However, the precise mechanism by which PK2 inhibits eIF2α kinase function remains...

Description: The environmental conditions of Earth, including the climate, are determined by physical, chemical, biological, and human interactions that transform and transport materials and energy. This is the "Earth system": a highly complex entity characterized by multiple nonlinear responses and thresholds, with linkages between disparate components. One important part of this system is the iron cycle, in which iron-containing soil dust is transported from land through the atmosphere to the oceans, affecting ocean biogeochemistry and hence having feedback effects on climate and dust production. Here we review the key components of this cycle, identifying critical uncertainties and priorities for future research.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Jickells, T D -- An, Z S -- Andersen, K K -- Baker, A R -- Bergametti, G -- Brooks, N -- Cao, J J -- Boyd, P W -- Duce, R A -- Hunter, K A -- Kawahata, H -- Kubilay, N -- laRoche, J -- Liss, P S -- Mahowald, N -- Prospero, J M -- Ridgwell, A J -- Tegen, I -- Torres, R -- New York, N.Y. -- Science. 2005 Apr 1;308(5718):67-71.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉School of Environmental Sciences, University of East Anglia, Norwich NR47TJ, UK.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/15802595" target="_blank"〉PubMed〈/a〉

Description: Rapid industrialization and urbanization in developing countries has led to an increase in air pollution, along a similar trajectory to that previously experienced by the developed nations. In China, particulate pollution is a serious environmental problem that is influencing air quality, regional and global climates, and human health. In response to the extremely severe and persistent haze pollution experienced by about 800 million people during the first quarter of 2013 (refs 4, 5), the Chinese State Council announced its aim to reduce concentrations of PM2.5 (particulate matter with an aerodynamic diameter less than 2.5 micrometres) by up to 25 per cent relative to 2012 levels by 2017 (ref. 6). Such efforts however require elucidation of the factors governing the abundance and composition of PM2.5, which remain poorly constrained in China. Here we combine a comprehensive set of novel and state-of-the-art offline analytical approaches and statistical techniques to investigate the chemical nature and sources of particulate matter at urban locations in Beijing, Shanghai, Guangzhou and Xi'an during January 2013. We find that the severe haze pollution event was driven to a large extent by secondary aerosol formation, which contributed 30-77 per cent and 44-71 per cent (average for all four cities) of PM2.5 and of organic aerosol, respectively. On average, the contribution of secondary organic aerosol (SOA) and secondary inorganic aerosol (SIA) are found to be of similar importance (SOA/SIA ratios range from 0.6 to 1.4). Our results suggest that, in addition to mitigating primary particulate emissions, reducing the emissions of secondary aerosol precursors from, for example, fossil fuel combustion and biomass burning is likely to be important for controlling China's PM2.5 levels and for reducing the environmental, economic and health impacts resulting from particulate pollution.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Huang, Ru-Jin -- Zhang, Yanlin -- Bozzetti, Carlo -- Ho, Kin-Fai -- Cao, Jun-Ji -- Han, Yongming -- Daellenbach, Kaspar R -- Slowik, Jay G -- Platt, Stephen M -- Canonaco, Francesco -- Zotter, Peter -- Wolf, Robert -- Pieber, Simone M -- Bruns, Emily A -- Crippa, Monica -- Ciarelli, Giancarlo -- Piazzalunga, Andrea -- Schwikowski, Margit -- Abbaszade, Gulcin -- Schnelle-Kreis, Jurgen -- Zimmermann, Ralf -- An, Zhisheng -- Szidat, Sonke -- Baltensperger, Urs -- El Haddad, Imad -- Prevot, Andre S H -- England -- Nature. 2014 Oct 9;514(7521):218-22. doi: 10.1038/nature13774. Epub 2014 Sep 17.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉1] Laboratory of Atmospheric Chemistry, Paul Scherrer Institute (PSI), 5232 Villigen, Switzerland [2] State Key Laboratory of Loess and Quaternary Geology (SKLLQG), and Key Laboratory of Aerosol Chemistry and Physics, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710075, China [3]. ; 1] Department of Chemistry and Biochemistry, and Oeschger Centre for Climate Change Research, University of Bern, 3012 Bern, Switzerland [2] Laboratory of Radiochemistry and Environmental Chemistry, Paul Scherrer Institute (PSI), 5232 Villigen, Switzerland. ; Laboratory of Atmospheric Chemistry, Paul Scherrer Institute (PSI), 5232 Villigen, Switzerland. ; The Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, China. ; State Key Laboratory of Loess and Quaternary Geology (SKLLQG), and Key Laboratory of Aerosol Chemistry and Physics, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710075, China. ; 1] Laboratory of Atmospheric Chemistry, Paul Scherrer Institute (PSI), 5232 Villigen, Switzerland [2] European Commission, Joint Research Centre, Institute for Environment and Sustainability, Air and Climate Unit, Via Fermi, 2749, 21027 Ispra, Italy. ; Department of Earth and Environmental Sciences, University of Milano Bicocca, Piazza della Scienza 1, Milan 20126, Italy. ; Helmholtz Zentrum Munchen, German Research Center for Environmental Health (GmbH), Joint Mass Spectrometry Centre, Cooperation Group Comprehensive Molecular Analytics and Helmholtz Virtual Institute of Complex Molecular Systems in Environmental Health - Aerosol and Health (HICE), 85764 Neuherberg, Germany. ; 1] Helmholtz Zentrum Munchen, German Research Center for Environmental Health (GmbH), Joint Mass Spectrometry Centre, Cooperation Group Comprehensive Molecular Analytics and Helmholtz Virtual Institute of Complex Molecular Systems in Environmental Health - Aerosol and Health (HICE), 85764 Neuherberg, Germany [2] University of Rostock, Joint Mass Spectrometry Centre, Institute of Chemistry, Analytical Chemistry, 18015 Rostock, Germany. ; Department of Chemistry and Biochemistry, and Oeschger Centre for Climate Change Research, University of Bern, 3012 Bern, Switzerland. ; 1] Laboratory of Atmospheric Chemistry, Paul Scherrer Institute (PSI), 5232 Villigen, Switzerland [2].〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25231863" target="_blank"〉PubMed〈/a〉

Description: Black or elemental carbon (EC), including soot and char, are byproducts of anthropogenic fossil-fuel and biomass burning, and also of wildfires. EC, and particularly soot, strongly affects atmospheric chemistry and physics and thus radiative forcing; it can also alter regional climate and precipitation. Pre-industrial variations in EC as well as its source areas and controls however, are poorly known. Here we use a lake-sediment EC record from China to reconstruct Holocene variations in soot (combustion emissions formed via gas-to-particle conversion processes) and char (combustion residues from pyrolysis) measured with a thermal/optical method. Comparisons with sedimentary charcoal records (i.e., particles measured microscopically), climate and population data are used to infer variations in biomass burning and its controls. During the Holocene, positive correlations are observed between EC and an independent index of regional biomass burning. Negative correlations are observed between EC and monsoon intensity, and tree cover inferred from arboreal pollen percentages. Abrupt declines in temperature are also linked with widespread declines in fire. Our results 1) confirm the robustness of a relatively new method for reconstructing variations in EC; 2) document variations in regional biomass burning; 3) support a strong climatic control of biomass burning throughout the Holocene; and 4) indicate that char levels are higher today than at any time during the Holocene.

Description: This paper addresses the stabilization problem for a class of genetic regulatory networks (GRNs) with mixed delays which include both the finite distributed time delay and the discrete time delay. The adaptive feedback control scheme is adopted to achieve the global asymptotic stability for the GRNs. By resorting to the integral partitioning technique and the delay fractioning approach, a novel Lyapunov–Krasovskii functional is constructed, and some sufficient criteria are established to ensure the closed-loop GRNs to be globally asymptotically stable. The conditions obtained are in the form of matrix inequalities and easy to be solved by resorting to the standard softwares in the Matlab. Finally, a numerical example is given to demonstrate the applicability and efficiency of the proposed approach.