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Several cell populations have been reported to possess intestinal stem cell (ISC) activity during homeostasis and injury-induced regeneration. Here, we explored inter-relationships between putative mouse ISC populations by comparative RNA-sequencing (RNA-seq). The transcriptomes of multiple cycling ISC populations closely resembled Lgr5+ ISCs, the most well-defined ISC pool, but Bmi1-GFP+ cells were distinct and enriched for enteroendocrine (EE) markers, including Prox1. Prox1-GFP+ cells exhibited sustained clonogenic growth in vitro, and lineage-tracing of Prox1+ cells revealed long-lived clones during homeostasis and after radiation-induced injury in vivo. Single-cell mRNA-seq revealed two subsets of Prox1-GFP+ cells, one of which resembled mature EE cells while the other displayed low-level EE gene expression but co-expressed tuft cell markers, Lgr5 and Ascl2, reminiscent of label-retaining secretory progenitors. Our data suggest that the EE lineage, including mature EE cells, comprises a reservoir of homeostatic and injury-inducible ISCs, extending our understanding of cellular plasticity and stemness.

Revised legislation and bans on imports of waste electrical and electronic equipment (WEEE) into many Asian countries for treatment are driving the need for more efficient WEEE fractionation in Europe by expanding the capacity of treatment plants and improving the percentage recovery of materials of economic value. Data from a key stakeholder survey and consultation are combined with the results of a detailed literature survey to provide weighted matrix input into multi-criteria decision analysis calculations to carry out the following tasks: (a) assess the relative importance of 12 process options against the 6 industry-derived in-process economic potential criteria, that is, increase in product quality, increase in recycling rate, increase in process capacity, decrease in labour costs, decrease in energy costs and decrease in disposal costs; and (b) rank 25 key technologies that have been selected as being the most likely to benefit the efficient sorting of WEEE. The results indicate that the first stage in the development of any total system to achieve maximum economic recovery of materials from WEEE has to be the selection and application of appropriate fractionation process technologies to concentrate valuable components such as critical metals into the smallest possible fractions to achieve their recovery while minimising the disposal costs of low-value products. The stakeholder-based study has determined the priority for viable technical process developments for efficient WEEE fractionation and highlighted the economic and technical improvements that have to be made in the treatment of WEEE. [ABSTRACT FROM AUTHOR]

A comparison of the implementation of extended producer responsibility (EPR) to packaging waste and waste electrical and electronic equipment (WEEE) is presented for a representative sample of eleven European Union countries based on five indicators: stakeholders and responsibilities; compliance mechanisms; role of local authorities; financing mechanisms and merits and limitations, with four countries selected for more detailed case study analysis. Similarities, trends and differences in national systems are highlighted with particular focus on the role of local authorities and their relationship with obligated producers and the effect on the operation and success of each system. The national systems vary considerably in design, in terms of influence of pre-existing policy and systems, methods of achieving producer compliance (multiple or single collective schemes), fee structures, targets, waste stream prioritization and local authority involvement. Differing approaches are evident across all member states with respect to the role played by local authorities, responsibility apportioned to them, and the evolution of working relationships between obligated producers and municipalities. On the whole, EPR for packaging and WEEE has been successfully implemented throughout Europe in terms of Directive targets. It is, however, clear that the EPR systems currently in application across Europe differ primarily due to contrasting opinion on the legitimacy of local authorities as stakeholders and, in some cases, a fear on the part of industry of associated costs. Where local authorities have been engaged in the design and implementation of national systems, existing infrastructure used and defined roles established for producers and local authorities, results have been significantly more positive than in the cases where local authorities have had limited engagement. [ABSTRACT FROM PUBLISHER]

A comparison of the implementation of extended producer responsibility (EPR) to packaging waste and waste electrical and electronic equipment (WEEE) is presented for a representative sample of eleven European Union countries based on five indicators: stakeholders and responsibilities; compliance mechanisms; role of local authorities; financing mechanisms and merits and limitations, with four countries selected for more detailed case study analysis. Similarities, trends and differences in national systems are highlighted with particular focus on the role of local authorities and their relationship with obligated producers and the effect on the operation and success of each system. The national systems vary considerably in design, in terms of influence of pre-existing policy and systems, methods of achieving producer compliance (multiple or single collective schemes), fee structures, targets, waste stream prioritization and local authority involvement. Differing approaches are evident across all member states with respect to the role played by local authorities, responsibility apportioned to them, and the evolution of working relationships between obligated producers and municipalities. On the whole, EPR for packaging and WEEE has been successfully implemented throughout Europe in terms of Directive targets. It is, however, clear that the EPR systems currently in application across Europe differ primarily due to contrasting opinion on the legitimacy of local authorities as stakeholders and, in some cases, a fear on the part of industry of associated costs. Where local authorities have been engaged in the design and implementation of national systems, existing infrastructure used and defined roles established for producers and local authorities, results have been significantly more positive than in the cases where local authorities have had limited engagement.