Importance of Sulfate Aerosol in Evaluating the Relative Contributions of Regional Emissions to the Historical Global Temperature Change

During the negotiations of the KyotoProtocol the delegation of Brazil presentedan approach for distributing the burden ofemissions reductions among the Partiesbased on the effect of their cumulativehistorical emissions on the global-averagenear-surface temperature. The Letter tothe Parties does not limit the emissions tobe considered to be only greenhouse gas(GHG) emissions. Thus, in this paper weexplore the importance of anthropogenicSO_x emissions that are converted tosulfate aerosol in the atmosphere, togetherwith the cumulative greenhouse gasemissions, in attributing historicaltemperature change. We use historicalemissions and our simple climate model toestimate the relative contributions toglobal warming of the regional emissions byfour Parties: OECD90, Africa and LatinAmerica, Asia, and Eastern Europe and theFormer Soviet Union. Our results show thatfor most Parties the large warmingcontributed by their GHG emissions islargely offset by the correspondingly largecooling by their SO_x emissions. Thus,OECD90 has become the dominant contributorto recent global warming following itslarge reduction in SO_x emissions after1980.     

Analysing countries’ contribution to climate change: scientific and policy-related choices

This paper evaluates the influence of different policy-related and scientific choices on the calculated regional contributions to global climate change (the “Brazilian Proposal”). Policy-related choices include the time period of emissions, the mix of greenhouse gases and different indicators of climate change impacts. The scientific choices include historical emissions and model representations of the climate system. We generated and compared results of several simple climate models. We find that the relative contributions of different nations to global climate change—from emissions of greenhouse gases alone—are quite robust, despite the varying model complexity and differences in calculated absolute changes. For the default calculations, the average calculated contributions to the global mean surface temperature increase in 2000 are about 40% from OECD, 14% from Eastern Europe and Former Soviet Union, 24% from Asia and 22% from Africa and Latin America. Policy-related choices, such as time period of emissions, climate change indicator and gas mix generally have larger influence on the results than scientific choices. More specifically, choosing a later attribution start date (1990 instead of 1890) for historical emissions, decreases the contributions of regions that started emitting early, such as the OECD countries by 6 percentage points, whereas it increases the contribution of late emitters such as Asia by 8 percentage points. However, only including the fossil CO₂ emissions instead of the emissions of all Kyoto gases (fossil and land use change), increases the OECD contributions by 21 percentage points and decreases the contribution of Asia by 14 percentage points.     

Liquid chromatography-hydride generation-atomic absorption spectrometry for the speciation of tin in seafoods

Liquid chromatography with hydride generation atomic absorption spectrometry as the detection system was applied to the separation and determination of inorganic tin, tributyltin, dibutyltin, monobutyltin, diphenyltin and monophenyltin. A reversed phase C18 column and a methanol/water/acetic acid (70:27:3, v/v/v) mixture containing 0.05%(v/v) triethylamine and 0.1%(w/v) tropolone as the mobile phase (isocratic elution) were used. Extraction of organotins from the samples was carried out using methanol containing 0.05%(w/v) tropolone, a process that was repeated twice. The supernatants were shaken with water and dichloromethane in a separating funnel and the organic phase was collected and evaporated to dryness. When the method was applied to the speciation of tin in fresh and canned mussels, no organotins above the detection limits were identified in any of the samples, inorganic tin being the only species detected. The reliability of the procedure was checked by analyzing the total tin content of the samples by electrothermal atomic absorption spectrometry and by speciation of tin in a certified reference material, mussel tissue (CRM 477). The method can be used for environmental monitoring of organotins contaminated samples.     

A Gradient Study of 34 Elements in the Vicinity of a Copper-Nickel Smelter in the Kola Peninsula

Concentrations of 34 elements determined by ICP mass spectrometry were studied in surface soil and vegetation along a north–south gradient through the Pechenganickel smelter complex in Kola peninsula, northern Russia. Strong influence from the smelter was evident for Fe, Co, Ni, and Cu, mainly associated with dry deposition of large particles. Also for As, Se, Mo, Sb, Te, Bi, and Pb the smelter or associated sources appeared to be distinct contributors of contamination consisting presumably of smaller particles. Significant but less distinct effects leading to enhanced concentration levels were observed for P, S, V, Cr, Zn, and Tl. In the case of Mn, Rb, Sr, Cs, and Ba the concentrations in vegetation were generally lower near the source, which may be due to cation exchange with protons or heavy metal cations in the soil and subsequent leaching from the root zone. For Li, Be, B, Na, Mg, Al, Ca, Y, Cd, La, Th, and U no particular influence from the smelter complex was observed. Some characteristic differences observed in element concentrations in different plant species and between different years of Pinus sylvestris needles are discussed. The high concentrations observed for many trace elements in the humus horizon indicates that it acts as an active biogeochemical barrier against downward transport of these elements.     

Antibodies Against Hepatitis E Virus (HEV) in European Moose and White-Tailed Deer in Finland

Food and Environmental Virology - The main animal reservoirs of zoonotic hepatitis E virus (HEV) are domestic pigs and wild boars, but HEV also infects cervids. In this study, we estimated the...     

Artisanal fishers’ ethnobotany: from plant diversity use to agrobiodiversity management

Artisanal fishers interact with plants in many ways, and with different intensities. In spite of being characterized by fisheries, Caiçaras use plants with varied degrees of management, since the less intensive management actions, extraction of forest products, until intensively management actions through the cultivation of the agrobiodiversity. This study presents the results of different research projects and includes the North and the South regions of São Paulo state coast. The objective is to characterize the diversity of extracted and cultivated species by traditional fishers at Southeastern region of Brazilian Atlantic forest. Ethnobotanical surveys revealed a high diversity of plants known and used, ranging up to a richness of 272 species known in two communities for the South coast, most of them being native. However, depending on the management intensity, this diversity can be rather particularized: we found 68 varieties of cassava (Manihot esculenta Crantz) at North region and 58 varieties at the South region, with exclusive vernacular names. Through an ethnobotanical perspective, we compare and discuss the different dynamic systems underlying the relationships between fishers and plants. The diversity of cultivated plants is analyzed in depth, focusing on the historical importance of agriculture among people who are currently characterized as fishers. A schematic model is proposed to explain the dynamic systems operating in the relationships between fishers and plants.     

Antifungal activity of P3HB microparticles containing tebuconazole

In this study, tebuconazole (TEB)-loaded poly-3-hydroxybutyrate (P3HB)-based microparticles were developed and comprehensively characterized. TEB-loaded microparticles with the initial loading amounts of the fungicide of 10, 25, and 50% of the polymer mass (TEB 10, TEB 25, and TEB 50%) were prepared using emulsion technique. Encapsulation efficiency of TEB varied from 59 to 86%. As the loading amount was increased, the average diameter of microparticles increased too, from 41.3 to 71.7?µm, while zeta potential was not influenced by TEB loading, varying between –32.6 and –35.7?mV. TEB was gradually released from the microparticles to the model medium, and after 60?d, from 25 to 43% of TEB was released depending on the content of the encapsulated fungicide. The data obtained from in vitro TEB release were fitted to different mathematical models. It was shown that the release profiles of TEB could be best explained by the Zero-order, Higuchi, and Hixson–Crowell models. The antifungal activity of the P3HB/TEB microparticles against phytopathogenic fungi Fusarium moniliforme and Fusarium solani was demonstrated by in vitro tests conducted in Petri dishes. Thus, hydrophobic agrochemicals (TEB) can be effectively encapsulated into P3HB microparticles to construct slow-release formulations.     

An analysis of the dust deposition on solar photovoltaic modules

Environmental Science and Pollution Research - Solid particles impair the performance of the photovoltaic (PV) modules. This results in power losses which lower the efficiency of the system as well...     

Changes of turbidity during the phenol oxidation by photo-Fenton treatment

Turbidity presented by phenol solutions oxidized with Fenton reagent shows the tendency of a first order intermediate kinetics. Thus, turbidity can be considered a representative parameter of the presence of intermediate oxidation species, which are generated along the decomposition of toxic and reluctant contaminants, such as phenol. Moreover, that parameter presents a linear dependence with the catalyst dosage, but is also determined by the initial contaminant load. When analyzing the oxidation mechanism of phenol, it is found that the maximum turbidity occurs when the treatment is carried out at oxidant to phenol molar ratios R?=?4.0. These oxidation conditions correspond to the presence of a reaction mixture mainly composed of dihydroxylated rings, precursors of the muconic acid formation. The oxidation via “para” comprises the formation reactions of charge transfer complexes (quinhydrone), between the para-dihydroxylated intermediates (hydroquinone) and the para-substituted quinones (p-benzoquinone), which are quite unstable and reactive species, quickly decomposed into hydroxyhydroquinones. Working with oxidant ratios up to R?=?6.0, the maximum observed value of turbidity in the oxidized solutions is kept almost constant. It is found that, in these conditions, the pyrogallol formation is maximal, what is generated through the degradation of ortho-species (catechol and ortho-benzoquinone) and meta-substituted (resorcinol). Operating with ratios over R?=?6.0, these intermediates are decomposed into biodegradable acids, generating lower turbidity in the solution. Then, the residual turbidity is a function of the molar ratio of the ferrous ions vs. moles of oxidant utilized in the essays, that lets to estimate the stoichiometric dosage of catalyst as 20 mg/L at pH?=?3.0, whereas operating in stoichiometric conditions, R?=?14.0, the residual turbidity of water results almost null.