Exosome-Producing Follicle Associated Epithelium Is Not Involved in Uptake of PrPd from the Gut of Sheep (Ovis aries): An Ultrastructural Study

In natural or experimental oral scrapie infection of sheep, disease associated prion protein (PrPd) often first accumulates in Peyer's patch (PP) follicles. The route by which infectivity reaches the follicles is unknown, however, intestinal epithelial cells may participate in intestinal antigenic presentation by delivering exosomes as vehicles of luminal antigens. In a previous study using an intestinal loop model, following inoculation of scrapie brain homogenate, inoculum associated PrPd was detected by light microscopy shortly (15 minutes to 3.5 hours) after inoculation in the villous lacteals and sub-mucosal lymphatics. No PrPd was located within the follicle-associated epithelium (FAE), sub-FAE domes or the PP follicles. To evaluate this gut loop model and the transportation routes in more detail, we used electron microscopy (EM) to study intestinal tissues exposed to scrapie or control homogenates for 15 minutes to 10 days. In addition, immuno-EM was used to investigate whether exosomes produced in the FAE may possess small amounts of PrPd that were not detectable by light microscopy. This study showed that the integrity of the intestinal epithelium was sustained in the intestinal loop model. Despite prominent transcytotic activity and exosome release from the FAE of the ileal PP in sheep, these structures were not associated with transportation of PrPd across the mucosa. The study did not determine how infectivity reaches the follicles of PPs. The possibility that the infectious agent is transported across the FAE remains a possibility if it occurs in a form that is undetectable by the methods used in this study. Infectivity may also be transported via lymph to the blood and further to all other lymphoid tissues including the PP follicles, but the early presence of PrPd in the PP follicles during scrapie infection argues against such a mechanism

WG ECOSTAT report on common understanding of using mitigation measures for reaching Good Ecological Potential for Heavily Modified Water Bodies - Part 3: Impacted by drainage schemes

Hydromorphological alterations for drainage are widespread pressures on water bodies in Europe. Because of the importance of the water uses relying on drainage schemes, such as agriculture and urban areas, not all necessary restoration measures can be taken without significant adverse effect on the water use. Therefore many of the affected water bodies have been designated as heavily modified (HMWB). Still, in a substantial number of these water bodies, some mitigation measures should be taken to reach Good Ecological Potential (GEP). This report presents responses of European countries on a detailed questionnaire distributed in 2015 on the impacts of land drainage on the water environment and the measures that can mitigate those impacts. The questionnaire also included questions on impacts of flood prevention, presented in the accompanying report “Part 2: Impacted by flood protection structures”. A key objective of the questionnaire was to compare the understanding of impacts caused by drainage to continuity, hydrological regime, morphological alterations and aquatic biology. Information was requested on 1) national definitions of drainage and existing guidelines, 2) water uses and regulatory regimes linked to drainage, 3) hydromorphological alterations due to drainage and their assessment, and 4) mitigation measures. A list of mitigation measures and their definition is presented. In total, 20 countries responded to the questions on land drainage. Key findings of the exercise are as follows: • Comparing the mitigation expected for good ecological potential by different countries provided a good basis for identifying similarities and differences between those countries’ standards for good ecological potential. It also provided a valuable opportunity for the exchange of information. • It is possible to reach a harmonized understanding between countries of the environmental objective for HMWBs impacted by drainage. • There is no common EU wide definition of the term drainage, although a common understanding exists of what it entails. • There are several methods to detect impacts from hydromorphological pressures and many countries do not have methods to detect all the parameters affected by drainage. • There is no common understanding on minimum ecological requirements for GEP related to impacts from drainage. • The standard for ecological potential seems to vary between water bodies and countries and few countries have a national definition on significant impact on water use. • There are some indications that the majority of countries probably rule-out mitigation measures when considering (often site-specific) evaluating criteria. • It would be interesting to compare different countries’ national methods to a common and comparable set of water bodies/catchments impacted by drainage. Such an exercise would be valuable in further identifying and elaborating on emerging good practice, implementation of measures in practice and possibly also for handling multiple pressures and intercalibrated Ecological Quality Ratios/Methods related to e.g. pollution in a comparable way. Key recommendations for next steps presented in the conclusions of this report include: • A generalised framework for deciding on the mitigation required for good ecological potential should be developed to achieve further harmonisation of GEP. Such a generalised framework can be used to supplement CIS Guidance no. 4 on HMWB. • The existing approach should be further developed to allow for harmonizing the levels/requirements of ecological potential based on mitigation measures. • Future exercises under the Common Implementation Strategy should use the common technical terminology and mitigation measures provided in this report. • Harmonized hydromorphological classification methods should be developed in order to have a comparable assessment of the hydromorphological alterations due to drainage, among the different countries. • More common understanding on ecological minimum criteria for GEP should be developed. • Countries should exchange and establish transparent criteria for deciding if mitigation would have a significant effect on drainage and benefits for society. • Reasons for ruling out measures should be made clear and more transparent . It is recommended to compare the outcomes produced by countries’ national methods by applying them to a comparable set of heavily modified water bodies included in generic cases. Consideration should then be given to incorporating the results of both exercises into a good practice guideJRC.D.2-Water and Marine Resource

Geochemical analysis of soil in the central Barents Region

This atlas is the culmination of one of the most comprehensive environmental geochemical studies ever undertaken on a regional scale. It covers some of the most polluted, and some of the most pristine areas in Europe. It provides data for many elements for which the media concerned have not previously been analysed on a large regional scale and demonstrates that many of these are part of the emission spectra from industries within the area covered. It casts light on many processes governing the distribution of elements in the biosphere, pedosphere and geosphere, questioning some established theories and confirming others. It represents both an end and a beginning, in that the data are now available for use in studies related to toxicological impacts on plants, animals and humans, remediation of polluted areas, the scientific basis for action levels, baseline assessments for new development projects and other fields

Hydropower and Fish: A Roadmap for Best Practice Management: IEA Hydro Report on Annex XIII - Hydropower and Fish

The development of a hydropower facility has, in nearly all cases, some impact on natural river flows and the wider environment. This impact often includes the effect on fish, most notably curtailment of migration routes and changes to their natural habitat and ecosystem services fish is dependent on. The general relationship between fish and hydropower development and management has been the subject of extensive research for many years. However, most of the previous work has been based on a limited number of species, with the applicability of results on a global scale difficult to justify. With the further development of hydropower planned on a global scale, a program of international collaborative research is justified. This document identifies emerging best practices for managing hydropower and fish, by addressing relevant measures to mitigate changes in hydro-morphological conditions, water quality and quantity due to hydropower development. Where relevant, some of the most mature solutions are described as providing safe two-way connectivity for fish past barriers created by hydropower infrastructures. As such, it serves as a valuable resource for practitioners in the hydropower sector by providing a clear pathway toward viable solutions to the identified challenges for fish and hydropower