We propose novel positive numerical integrators for approximating predator-prey models. The schemes are based on suitable symplectic procedures applied to the dynamical system written in terms of the log transformation of the original variables. Even if this approach is not new when dealing with Hamiltonian systems, it is of particular interest in population dynamics since the positivity of the approximation is ensured without any restriction on the temporal step size. When applied to separable M-systems, the resulting schemes are proved to be explicit, positive, Poisson maps. The approach is generalized to predator-prey dynamics which do not exhibit an M-system structure and successively to reaction-diffusion equations describing spatially extended dynamics. A classical polynomial Krylov approximation for the diffusive term joint with the proposed schemes for the reaction, allows us to propose numerical schemes which are explicit when applied to well established ecological models for predator-prey dynamics. Numerical simulations show that the considered approach provides results which outperform the numerical approximations found in recent literature.
Valentin Bellassen; Marion Drut; Federico Antonioli; Ružica Brečić; Michele Donati; Hugo Ferrer-Pérez; Lisa Gauvrit; Viet Hoang; Kamilla Knutsen Steinnes; Apichaya Lilavanichakul; Edward Majewski; Agata Malak-Rawlikowska; Konstadinos Mattas; An Nguyen; Ioannis Papadopoulos; Jack Peerlings; Bojan Ristic; Marina Tomić Maksan; Áron Török; Gunnar Vittersø; Abdoul Diallo;
Abstract The carbon and land footprint of 26 certified food products – geographical indications and organic products and their conventional references are assessed. This assessment goes beyond existing literature by (1) designing a calculation method fit for the comparison between certified food and conventional production, (2) using the same calculation method and parameters for 52 products – 26 Food Quality Schemes and their reference products – to allow for a meaningful comparison, (3) transparently documenting this calculation method and opening access to the detailed results and the underlying data, and (4) providing the first assessment of the carbon and land footprint of geographical indications. The method used is Life Cycle Assessment, largely relying on the Cool Farm Tool for the impact assessment. The most common indicator of climate impact, the carbon footprint expressed per ton of product, is not significantly different between certified foods and their reference products. The only exception to this pattern are vegetal organic products, whose carbon footprint is 16% lower. This is because the decrease in greenhouse gas emissions from the absence of mineral fertilizers is never fully offset by the associated lower yield. The climate impact of certified food per hectare is however 26% than their reference and their land footprint is logically 24% higher. Technical specifications directly or indirectly inducing a lower use of mineral fertilizers are a key driver of this pattern. So is yield, which depends both on terroir and farming practices. Overall, this assessment reinforces the quality policy of the European Union: promoting certified food is not inconsistent with mitigating climate change.
descriptionPublicationkeyboard_double_arrow_right Article 2018 Netherlands, Netherlands, United Kingdom, Italy, Netherlands, Italy, Netherlands Springer Science and Business Media LLC EC | ENVIROGENOMARKERS, EC | TICE
EC| ENVIROGENOMARKERS ,
Authors: Gianluca Campanella; Marc J. Gunter; Silvia Polidoro; Vittorio Krogh; +31 Authors
Gianluca Campanella; Marc J. Gunter; Silvia Polidoro; Vittorio Krogh; Domenico Palli; Salvatore Panico; Carlotta Sacerdote; Rosario Tumino; Giovanni Fiorito; Simonetta Guarrera; Licia Iacoviello; Ingvar A. Bergdahl; Beatrice Melin; Per Lenner; Theo M. de Kok; Panagiotis Georgiadis; Jos C. S. Kleinjans; Soterios A. Kyrtopoulos; H. Bas Bueno-de-Mesquita; Karen A. Lillycrop; Anne M. May; N. Charlotte Onland-Moret; Robert Murray; Elio Riboli; Monique Verschuren; Eiliv Lund; Nicolle A. Mode; Torkjel M. Sandanger; Valentina Fiano; Morena Trevisan; Giuseppe Matullo; Philippe Froguel; Paul Elliott; Paolo Vineis; Marc Chadeau-Hyam;
BackgroundObesity is an established risk factor for several common chronic diseases such as breast and colorectal cancer, metabolic and cardiovascular diseases; however, the biological basis for these relationships is not fully understood. To explore the association of obesity with these conditions, we investigated peripheral blood leucocyte (PBL) DNA methylation markers for adiposity and their contribution to risk of incident breast and colorectal cancer and myocardial infarction.MethodsDNA methylation profiles (Illumina Infinium® HumanMethylation450 BeadChip) from 1941 individuals from four population-based European cohorts were analysed in relation to body mass index, waist circumference, waist-hip and waist-height ratio within a meta-analytical framework. In a subset of these individuals, data on genome-wide gene expression level, biomarkers of glucose and lipid metabolism were also available. Validation of methylation markers associated with all adiposity measures was performed in 358 individuals. Finally, we investigated the association of obesity-related methylation marks with breast, colorectal cancer and myocardial infarction within relevant subsets of the discovery population.ResultsWe identified 40 CpG loci with methylation levels associated with at least one adiposity measure. Of these, one CpG locus (cg06500161) in ABCG1 was associated with all four adiposity measures (P = 9.07×10−8 to 3.27×10−18) and lower transcriptional activity of the full-length isoform of ABCG1 (P = 6.00×10−7), higher triglyceride levels (P = 5.37×10−9) and higher triglycerides-to-HDL cholesterol ratio (P = 1.03×10−10). Of the 40 informative and obesity-related CpG loci, two (in IL2RB and FGF18) were significantly associated with colorectal cancer (inversely, P < 1.6×10−3) and one intergenic locus on chromosome 1 was inversely associated with myocardial infarction (P < 1.25×10−3), independently of obesity and established risk factors.ConclusionOur results suggest that epigenetic changes, in particular altered DNA methylation patterns, may be an intermediate biomarker at the intersection of obesity and obesity-related diseases, and could offer clues as to underlying biological mechanisms.
Abstract The aim of this work is to analyze the performance of the Overtopping Breakwater for Energy Conversion (OBREC), developed by the team of the University of Campania and installed at prototype scale in the port of Naples. It is a multifunctional coastal structure aimed to protect harbors and produce energy, based on the overtopping principle. This device has been preliminary analyzed by means of experimental and numerical investigations. This contribution provides for the first time an integrated assessment of the OBREC hydraulic and structural performance, by means of the measurements collected at the prototype installation and of numerical modelling i.e. methodologies not affected by the scale effects. The numerical model, developed in the openFOAM environment, is calibrated on the field data gathered during a storm event and is then applied to extend the information related to the OBREC response under the typical wave climate. The results obtained are proposed in terms of overtopping discharge rates and pressures acting along the OBREC profile, under several sea states. Based on these results some recommendations and indications regarding the optimal cross section design are given to maximize the energy production, without compromising the structural stability, and to promote the device exploitability.
descriptionPublicationkeyboard_double_arrow_right Article , Other literature type 2020 United Kingdom, Netherlands, Italy, Austria Springer Science and Business Media LLC EC | IMBALANCE-P, EC | ENGAGE, EC | ERA +6 projects
EC| IMBALANCE-P ,
EC| ENGAGE ,
EC| ERA ,
UKRI| How does global land-use change reshape ecological assemblages over time? ,
UKRI| GCRF Trade, Development and the Environment Hub ,
EC| PICASSO ,
UKRI| Revealing the interactions between global biodiversity change and human food security ,
EC| SIM4NEXUS ,
WT| Sustainable and Healthy Food Systems (SHEFS)
Authors: David Leclère; Michael Obersteiner; M. Barrett; Stuart H. M. Butchart; +54 Authors
David Leclère; Michael Obersteiner; M. Barrett; Stuart H. M. Butchart; Abhishek Chaudhary; Adriana De Palma; Fabrice DeClerck; Moreno Di Marco; Jonathan C. Doelman; M. Dürauer; Robin Freeman; Mike Harfoot; Tomoko Hasegawa; Stefanie Hellweg; Jelle P. Hilbers; Samantha L. L. Hill; Florian Humpenöder; Nancy Jennings; Tamás Krisztin; Georgina M. Mace; Haruka Ohashi; Alexander Popp; Andy Purvis; Aafke M. Schipper; Andrzej Tabeau; Hugo Valin; Hans van Meijl; Willem-Jan van Zeist; Piero Visconti; Rob Alkemade; Rosamunde E. A. Almond; G. Bunting; Neil D. Burgess; Sarah Cornell; Fulvio Di Fulvio; Simon Ferrier; Steffen Fritz; Shinichiro Fujimori; M. Grooten; Tom Harwood; Petr Havlik; Mario Herrero; Andrew J. Hoskins; Martin Jung; Tom Kram; Hermann Lotze-Campen; Tetsuya Matsui; Carsten Meyer; Deon Nel; Tim Newbold; Guido Schmidt-Traub; Elke Stehfest; Bernardo B. N. Strassburg; Detlef P. van Vuuren; Chris Ware; James E. M. Watson; Wenchao Wu; L. Young;
Increased efforts are required to prevent further losses to terrestrial biodiversity and the ecosystem services that it provides1,2. Ambitious targets have been proposed, such as reversing the declining trends in biodiversity3; however, just feeding the growing human population will make this a challenge4. Here we use an ensemble of land-use and biodiversity models to assess whether—and how—humanity can reverse the declines in terrestrial biodiversity caused by habitat conversion, which is a major threat to biodiversity5. We show that immediate efforts, consistent with the broader sustainability agenda but of unprecedented ambition and coordination, could enable the provision of food for the growing human population while reversing the global terrestrial biodiversity trends caused by habitat conversion. If we decide to increase the extent of land under conservation management, restore degraded land and generalize landscape-level conservation planning, biodiversity trends from habitat conversion could become positive by the mid-twenty-first century on average across models (confidence interval, 2042–2061), but this was not the case for all models. Food prices could increase and, on average across models, almost half (confidence interval, 34–50%) of the future biodiversity losses could not be avoided. However, additionally tackling the drivers of land-use change could avoid conflict with affordable food provision and reduces the environmental effects of the food-provision system. Through further sustainable intensification and trade, reduced food waste and more plant-based human diets, more than two thirds of future biodiversity losses are avoided and the biodiversity trends from habitat conversion are reversed by 2050 for almost all of the models. Although limiting further loss will remain challenging in several biodiversity-rich regions, and other threats—such as climate change—must be addressed to truly reverse the declines in biodiversity, our results show that ambitious conservation efforts and food system transformation are central to an effective post-2020 biodiversity strategy. To promote the recovery of the currently declining global trends in terrestrial biodiversity, increases in both the extent of land under conservation management and the sustainability of the global food system from farm to fork are required.
With the aim to fully exploit the by-products obtained after the industrial extraction of starch from sweet potatoes, a cascading approach was developed to extract high-value molecules, such as proteins and pectins, and to valorize the solid fraction, rich in starch and fibrous components. This fraction was used to prepare new biocomposites designed for food packaging applications. The sweet potato residue was added to poly(3-hydroxybutyrate-co-3-hydroxyvalerate) in various amounts up to 40 wt % by melt mixing, without any previous treatment. The composites are semicrystalline materials, characterized by thermal stability up to 260 °C. For the composites containing up to 10 wt % of residue, the tensile strength remains over 30 MPa and the strain stays over 3.2%. A homogeneous dispersion of the sweet potato waste into the bio-polymeric matrix was achieved but, despite the presence of hydrogen bond interactions between the components, a poor interfacial adhesion was detected. Considering the significant percentage of sweet potato waste used, the biocomposites obtained show a low economic and environmental impact, resulting in an interesting bio-alternative to the materials commonly used in the packaging industry. Thus, according to the principles of a circular economy, the preparation of the biocomposites closes the loop of the complete valorization of sweet potato products and by-products.
The general objective of the MADFORWATER project is to develop an integrated set of technological and management instruments for the enhancement of wastewater treatment, treated wastewater reuse for irrigation and water efficiency in agriculture, with the final aim to reduce water vulnerability in selected basins in Egypt, Morocco and Tunisia. In particular, Work Package 3 “Adaptation of technologies for efficient water management and treated wastewater reuse in agriculture” aims to investigate several technological and non-technological solutions to enhance the use of treated waste water as alternative source of water for the irrigation sector, and to adapt them to the local contexts of Egypt, Morocco and Tunisia. Among the non–technological solutions, in Task 3.3 an agro physical (yield and water balance) - economic integrated model for land and water use optimization has been built and calibrated in the three case studies area of MADFORWATER, which are: the irrigated farming system in the Kafr-El- Sheikh Region in Egypt, the citrus farming system in Souss-Massa region in Morocco and the Nabeul Governorate in Tunisia. This deliverable presents the integrated model by describing the objective function to be maximized and the numerous physical (water resources availability, land use and climate change), technological, socio-economic (production costs, labour, prices) and water policy (pricing, licensing) constraints to be considered. In addition, the main outputs to be estimated have been identified, and the needed data to run the model that have been collected and used to calibrate it for the three case studies areas are also presented.
Abstract Microclimate change related events affect cities total environment and therefore citizens’ wellbeing. In a framework of urban resilience challenge, it is important to guarantee thermally comfortable conditions to dwellers in outdoors but also to preserve cultural heritage masterpieces for tourism and local socio-cultural identity. This work couples an innovative field monitoring at multiple scales and a validated numerical modelling effort to identify indoor and outdoor critical conditions at the present time and in the future, according to IPCC climate change forecast scenarios. The authors focused the attention on the overheating risk of Gubbio historical city center, in central Italy. Experimental data analysis highlights the microclimate granularity of the case study with detected temperature discrepancies up to 2.5 °C observed at pedestrian height during the hottest hour, i.e. 2p.m. Collected data are then used to validate the numerical models of (i) the most significant building of the city and (ii) its surroundings to investigate indoor/outdoor thermal comfort stress due to climate change and local overheating. The combined analysis shows that indoor operative temperature reaches 32 °C on average in 80 years, compared to the current 29 °C value. In the outdoors, apparent temperature increases by about 10 °C on 2100, being responsible for a serious threat compromising socio-cultural life, human health and outdoor and recreational activities.