Nesting habits shape feeding preferences and predatory behavior in an ant genus

We tested if nesting habits influence ant feeding preferences and predatory behavior in the monophyletic genus Pseudomyrmex (Pseudomyrmecinae) which comprises terrestrial and arboreal species, and, among the latter, plant-ants which are obligate inhabitants of myrmecophytes (i.e., plants sheltering so-called plant-ants in hollow structures). A cafeteria experiment revealed that the diet of ground-nesting Pseudomyrmex consists mostly of prey and that of arboreal species consists mostly of sugary substances, whereas the plant-ants discarded all the food we provided. Workers forage solitarily, detecting prey from a distance thanks to their hypertrophied eyes. Approach is followed by antennal contact, seizure, and the manipulation of the prey to sting it under its thorax (next to the ventral nerve cord). Arboreal species were not more efficient at capturing prey than were ground-nesting species. A large worker size favors prey capture. Workers from ground- and arboreal-nesting species show several uncommon behavioral traits, each known in different ant genera from different subfamilies: leaping abilities, the use of surface tension strengths to transport liquids, short-range recruitment followed by conflicts between nestmates, the consumption of the prey’s hemolymph, and the retrieval of entire prey or pieces of prey after having cut it up. Yet, we never noted group ambushing. We also confirmed that Pseudomyrmex plant-ants live in a kind of food autarky as they feed only on rewards produced by their host myrmecophyte, or on honeydew produced by the hemipterans they attend and possibly on the fungi they cultivate.     

Environmental assessment of different advanced oxidation processes applied to a bleaching Kraft mill effluent

Basic research on remediation of polluted sediment by leaching has, to date, been carried out exclusively with suspended material. For economic reasons, only solid-bed leaching is applicable to large-scale processes. Abiotic and microbial solid-bed leaching were comparatively studied in a percolator system using ripened and therefore permeable heavy metal polluted river sediment. In the case of abiotic leaching, sulfuric acid was supplied to the sediment by circulating water; the lower the pH of the percolating water, the higher the percolation flow, and the lower the solid-bed height was, the faster the heavy metals were solubilized. However, the pH and percolation flow are subjected to restrictions: strongly acidic conditions result in dissolution of mineral components, and the percolation flow must not exceed the bed permeability. And a high solid bed is an economic requirement. In the case of bioleaching, elemental sulfur added to the sediment was oxidized to sulfuric acid within the package which, in turn, solubilized the heavy metals. Here, the percolation flow and the solid-bed height did not affect the rate of metal solubilization. Solid-bed leaching on a larger scale will thus be much more efficient applying bioleaching with sulfur as the leaching agent than abiotic leaching with sulfuric acid.     

Exploring the possibility of a systematic and generic approach to social sustainability

There is a growing need to understand how existing concepts and tools for sustainability relate to each other and to a robust, trans-disciplinary systems perspective for sustainability. As a response, a group of scientists, including some of the authors, have developed a framework based on backcasting from sustainability principles over the last 20 years – the Framework for Strategic Sustainable Development (FSSD), also known as The Natural Step Framework. The intent of this study is to scrutinize the existing framework as regards its social dimension. The study demonstrates dichotomies and lack of robustness and proposes a way forward to make the social dimension of the FSSD more cohesive as well as operational.     

An approach to assessing sustainability integration in strategic decision systems for product development

This article aims to explore a new approach to assess company decision systems regarding sustainability-related communication and decision support between senior management and product development levels. The assessment approach was developed in theory and its applicability was directly tested in action research in two small and medium-sized companies and two large companies. The results were validated against experiences made by two management consultancies. Our study indicates that successful companies should: (i) integrate sustainability into business goals and plans, backed up by suitable (ii) internal incentives and disincentives and (iii) decision support tools. Our study also indicates that the new assessment approach can be used as a template to assess the current state of sustainability integration in company decision systems.