A Comparative Structural Bioinformatics Analysis of the Insulin Receptor Family Ectodomain Based on Phylogenetic Information

The insulin receptor (IR), the insulin-like growth factor 1 receptor (IGF1R) and the insulin receptor-related receptor (IRR) are covalently-linked homodimers made up of several structural domains. The molecular mechanism of ligand binding to the ectodomain of these receptors and the resulting activation of their tyrosine kinase domain is still not well understood. We have carried out an amino acid residue conservation analysis in order to reconstruct the phylogeny of the IR Family. We have confirmed the location of ligand binding site 1 of the IGF1R and IR. Importantly, we have also predicted the likely location of the insulin binding site 2 on the surface of the fibronectin type III domains of the IR. An evolutionary conserved surface on the second leucine-rich domain that may interact with the ligand could not be detected. We suggest a possible mechanical trigger of the activation of the IR that involves a slight ‘twist’ rotation of the last two fibronectin type III domains in order to face the likely location of insulin. Finally, a strong selective pressure was found amongst the IRR orthologous sequences, suggesting that this orphan receptor has a yet unknown physiological role which may be conserved from amphibians to mammals

How will climate change modify river flow regimes in Europe?

Worldwide, flow regimes are being modified by various anthropogenic impacts and climate change induces an additional risk. Rising temperatures, declining snow cover and changing precipitation patterns will interact differently at different locations. Consequently, in distinct climate zones, unequal consequences can be expected in matters of water stress, flood risk, water quality, and food security. In particular, river ecosystems and their vital ecosystem services will be compromised as their species richness and composition have evolved over long time under natural flow conditions. This study aims at evaluating the exclusive impacts of climate change on river flow regimes in Europe. Various flow characteristics are taken into consideration and diverse dynamics are identified for each distinct climate zone in Europe. In order to simulate present-day natural flow regimes and future flow regimes under climate change, the global hydrology model WaterGAP3 is applied. All calculations for current and future conditions (2050s) are carried out on a 5' × 5' European grid. To address uncertainty, bias-corrected climate forcing data of three different global climate models are used to drive WaterGAP3. Finally, the hydrological alterations of different flow characteristics are quantified by the Indicators of Hydrological Alteration approach. Results of our analysis indicate that on the European scale, climate change can be expected to modify flow regimes remarkably. This is especially the case in the Mediterranean (due to drier conditions with reduced precipitation across the year) and in the boreal climate zone (due to reduced snowmelt, increased precipitation, and strong temperature rises). In the temperate climate zone, impacts increase from oceanic to continental. Regarding single flow characteristics, strongest impacts on timing were found for the boreal climate zone. This applies for both high and low flows. Flow magnitudes, in turn, will be predominantly altered in the Mediterranean but also in the Northern climates. At the end of this study, typical future flow regimes under climate change are illustrated for each climate zone

Assessing future changes in pan-European environmental flows

The potential river flow-driven impact of change on aquatic and riparian ecosystems at the pan-European scale under various climatological and development scenarios was assessed using a methodology based conceptually on the Range of Variability Approach (RVA) using the Indicators of Hydrological Alteration (IHA): a desk-top technique for assessing if environmental flow requirements. This paper presents an adaptation of the IHA approach using monthly flows. European and Mediterranean river networks were modelled as ~35,000 cells (0.5° longitude x 0.5° latitude). For each cell, modelled monthly flows were generated for an ensemble of 10 future climate change scenarios. These scenarios consist of combinations of two climate scenarios (IPCM4 and MIMR) and four socio-economic water-use scenarios (each with a main driver of economy, policy, security, or sustainability), projected for 2050s. IHA-styled statistics were calculated. By tailoring the RVA, acceptable baseline environmental flow ranges and departures from these of the projected hydrological regimes were assessed and coded using a traffic-light system (green for environmental flows met, amber minor variation, red major variation). For the first time, the results show spatial patterns of flow change and associated potential river ecosystem impacts across the wider European continent. Importantly, the findings indicate that climate change may be a more influential driver than water-use change in determining future river ecosystem healt

European scenario studies on future in-stream nutrient concentrations

Large-scale water quality issues have recently become the focus of policy and research. To gain insight into large-scale water quality issues, a scenario analysis was carried out for Europe using the continental water quality model WorldQual with total nitrogen and phosphorus as example pollutants. Future nitrogen and phosphorus loadings and instream concentrations were simulated for an “economy first” scenario and compared to contemporary conditions. Results indicate that future total nitrogen (TN) loadings are likely to decrease in most parts of central Europe by 5 to 25 kg ha-1 year-1 due to land-use change in the form of reduced cropland area as a result of technological changes, as well as improvements in land-use management based on higher efficiencies of application rates. Climate change has less impact on TN loadings, but an increase of future in-stream concentrations is accompanied by reduced river discharge. Future total phosphorus (TP) loadings are similar to contemporary loadings for all of Europe. In-stream TP concentrations do not change in northern and eastern Europe. In central Europe, concentrations increase little (by one class). In a few regions,such as northern Spain, very high changes (up to more than three classes) are apparent as a result of reduced river discharge

Projected flow alteration and ecological risk for pan-European rivers

Projection of future changes in river flow regimes and their impact on river ecosystem health is a major research challenge. This paper assesses the implications of projected future shifts in river flows on in-stream and riparian ecosystems at the pan-European scale by developing a new methodology to quantify ecological risk due to flow alteration (ERFA). The river network was modelled as 33 668 cells (5′ longitude × 5′ latitude). For each cell, modelled monthly flows were generated for an ensemble of 10 scenarios for the 2050s and for the study baseline (naturalized flows for 1961–1990). These future scenarios consist of combinations of two climate scenarios and four socio-economic water-use scenarios (with a main driver of economy, policy, security or sustainability). Environmental flow implications are assessed using the new ERFA methodology, based on a set of monthly flow regime indicators (MFRIs). Differences in MFRIs between scenarios and baseline are calculated to derive ERFA classes (no, low, medium and high risk), which are based on the number of indicators significantly different from the baseline. ERFA classes are presented as colour-coded pan-European maps. Results are consistent between scenarios and show that European river ecosystems are under significant threat with about two-thirds at medium or high risk of change. Four main zones were identified (from highest to lowest risk severity): (i) Mediterranean rim, southwest part of Eastern Europe and Western Asia; (ii) Northern Europe and northeast part of Eastern Europe; (iii) Western and Eastern Europe; and (iv) inland North Africa. Patterns of flow alteration risk are driven by climate-induced change, with socio-economics as a secondary factor. These flow alterations could be manifested as changes to species and communities, and loss of current ecosystem functions and services

Envisioning the future of water in Europe - the SCENES project

The aim of this article is to describe the background and main elements of the SCENES project (Water Scenarios for Europe and Neighbouring States) together with the approach for selecting, constructing and evaluating water scenarios up to 2050. SCENES is a multi-faceted integrated project that aims to address the complex questions about the future of Europe’s water resources. It takes an integrated approach by combining and balancing the many dimensions of Europe’s water futures, including hydrological, ecological, economic, cultural, social, climatic, financial and other dimensions. The project is implemented in three phases. In the first phase (fast-track) largely extant scenarios are selected, and readily available information on drivers and policies information assembled and run through an existing quantitative model of pan-European water availability. In the second phase more refined scenarios are developed at both the pan-European and regional scales, with scenario panels providing ‘enriched’ scenarios. The third phase involves a synthesis of the information and dissemination of the project outputs to external stakeholders and end-users. In the SCENES project an evaluation of the participatory scenario processes is carried out giving us new information on the functioning of the science-policy interface, and on the challenges the European water management may confront in the future