Horizon scanning for South African biodiversity: A need for social engagement as well as science

Ambio - A horizon scan was conducted to identify emerging and intensifying issues for biodiversity conservation in South Africa over the next 5–10 years. South African biodiversity...     

Arsenate removal from underground water by polystyrene-confined hydrated ferric oxide (HFO) nanoparticles:effect of humic acid

Environmental Science and Pollution Research - Arsenic decontamination from groundwater is an urgent but still challenging task. Polystyrene-based hydrated ferric oxide (denoted as D201-HFO)...     

A data envelopment analysis approach to choose transport modes based on eco-efficiency

The main purpose of this paper is to use data envelopment analysis (DEA) as a support tool to establish a relative eco-efficiency measure for the different bioethanol transportation modes and to prioritize these different modes according to these figures. From a review of previous studies, we selected a set of attributes to be considered in DEA, and then experts were consulted about the importance of these attributes for this type of analysis in Brazil. To quantify the attributes, we established indicators and submitted them to DEA to evaluate the relative eco-efficiency to each available transportation mode for the case studied. The use of DEA established the guidelines to improve the transportation modes that were not considered 100?% relatively eco-efficient. These improvements could be achieved considering the percentage, reduction or growth for each of the attributes in the selected transportation mode. The proposed approach can help the Brazilian government to develop a plan to improve the bioethanol transportation infrastructure and can be used to propel short-term improvements in the highway transport of bioethanol, which could be useful given the Brazilian transportation context.     

Effect of Manufacturing Process and Xanthan Gum Addition on the Properties of Cassava Starch Films

The objective of this work was to manufacture biodegradable films by two different processes (casting and extrusion), from different combinations of cassava starch and xanthan gum. These films were produced by casting and by extrusion from six different starch-xanthan gum combinations (0, 2, 4, 6, 8 and 10% w/w), containing glycerol as plasticizer (20% w/w) and were also characterized according to their microstructure, optical, mechanical, and barrier properties. Scanning electron microscopy of the starch-xanthan gum extruded films showed reticulated surface and smooth interior, suggesting that xanthan was driven to the surface and gelatinized starch to the interior of the films during extrusion. Films manufactured by casting were entirely homogeneous. In general, casted films presented lower opacity and water vapor permeability and higher stress at break than films manufactured by extrusion. Xanthan gum addition affected mechanical properties of starch films, improving their stress and strain at break, especially for extruded samples, but these properties did not show stability at different RH conditions.     

Evolutionary Ecology in the 21st Century: New Concepts and Development Prospects

The ideas of the evolutionary ecology of the 20th century and its modern conceptual space are considered with regard to new knowledge of the contents of population and evolutionary synecology. The article proposes (1) a population cenotic approach to analyzing the covariation of cenopopulations of sympatric species and taxocenes in space and historical time; (2) an approach to assessing the intragroup morphological disparity in cenopopulations of sympatric species and taxocenes as a measure of morphogenetic stability. Consideration is given to experimental evolutionary ecology as a particular methodological area. Prospects for the formation of evolutionary ecology as an interdisciplinary applied science are discussed in view of the necessity of predicting regional biocenotic crises and rapid coevolutionary changes in biotic communities in a technogenic environment against the background of predicted unfavorable trends of climate changes.

     

Effects of walnut husk washing waters and their phenolic constituents on horticultural species

INTRODUCTION: The reuse of wastewaters for agricultural purposes is a common practice in many countries and is increasingly recommended by organizations that promote sustainable development. Yet, it is restricted by the potential negative impact of these materials on soil and crops. The aim of this study was therefore to evaluate the environmental impact of walnut husk washing waters (WHWW) and their organic fractions, in order to conceive their agricultural exploitation. DISCUSSION: Phytotoxicity tests and morphological investigations on representative plant species of horticultural interest indicated that WHWW and their organic fractions can elicit a concentration-dependent stimulating effect on the growth of radish, lettuce cv. cavolo Napoli with effects up to 165 %. An opposite inhibitory effect up to 70 % was observed on spinach and lettuce cv. Gentilina. Proapoptotic effects were observed by acridine orange/ethidium bromide assay in the species inhibited by WHWW treatment. High-performance liquid chromatography-mass spectrometry analysis of the WHWW revealed the presence of a main component which was extracted selectively in organic solvents and purified by preparative chromatography. Complete spectral analysis allowed identification as 4,8-dihydroxy-1-tetralone, commonly known as regiolone. Regiolone exhibited the same concentration-dependent activity on root elongation with a stimulation in the case of radish up to 135 % with respect to control. These results open perspectives in the exploitation of WHWW and the main phenolic constituent readily available by a straightforward isolation procedure as a natural fertilizer for specific crops.     

Seasonal and spatial changes of free and bound organic acids in total suspended particles in Guangzhou,China

The concentrations and compositions of free and bound organic acids in total suspended particles from typical urban, suburban and forest park sites of Guangzhou were determined in this study. The free form of organic acids (solvent extractable) in aerosols in Guangzhou varied with site and season. The suburban samples contained the highest contents of alkanoic, alkenoic and dicarboxylic acids. These findings were consistent with a higher supply of hydrocarbons and NOx in the suburban area. However, concentrations of aromatic acids were similar in the urban, suburban and forest park sites. Generally, winter season samples of the acids from anthropogenic sources contained more organic acids than summer season samples due to stronger removal by wet deposition in the summer. For the acids from botanic sources, the summer season samples were higher. In addition to the free acids, bound acids (solvent non-extractable) mainly formed by esterification of free acids were also found in the samples. In general, bound acids were higher than free acids. Esterification is mainly controlled by the pKa of organic acids and the atmospheric pH value. This explains why aromatic and dicarboxylic acids occur mainly as bound forms and why the samples from urban sites contained high levels of bound acids as the pH of rain water can reach 4.53.Concentrations of alkanoic and alkenoic acids in the aerosols of Guangzhou were much higher than those in the other areas studied.     

Influences of environmental regulations on skill premium: mediating effect of industrial structure optimization

Environmental Economics and Policy Studies - Environmental regulation could affect skill premium by affecting the relative supply and demand for skilled labor and non-skilled labor; meanwhile, it...