Are EU spatial ex ante coexistence regulations proportional?

The EU is currently struggling to implement coherent coexistence regulations on genetically modified (GM) and non-GM crops in all member states. While it stresses that any approach needs to be “proportionate to the aim of achieving coexistence”, very few studies have actually attempted to assess whether the proposed spatial ex ante coexistence regulations (SEACERs) satisfy this proportionality condition. In this article, we define proportionality as a functional relationship which is weakly increasing in the incentives for coexistence. We propose a spatial framework based on an existing landscape and introduce the new concept of shadow factor as a measure for the opportunity costs induced by SEACERs. This enables comparing the proportionality of (i) rigid SEACERs which are based on large isolation distances imposed on GM farmers versus (ii) flexible SEACERs based on pollen barrier agreements between neighboring farmers. Our theoretical and empirical findings argue for flexibility as rigid SEACERs violate the proportionality condition and, hence, are not consistent with the objectives of the EU.policy analysis, GIS, shadow factor, Agricultural and Food Policy, Crop Production/Industries,

Economics of spatial coexistence of genetically modified and conventional crops: Oilseed rape in Central France

Europe is currently struggling to implement coherent coexistence regulations on genetically modified (GM) and non-GM crops in all EU Member States. We conduct simulations with the software ArcView® on a GIS dataset of a hypothetical case of GM herbicide tolerant oilseed rape cultivation in Central France. Our findings show that rigid coexistence rules, such as large distance requirements, may impose a severe burden on GM crop production in Europe. These rules are not proportional to the farmers’ basic incentives for coexistence and hence not consistent with the objectives of the European Commission. More alarming, we show that in densely planted areas a domino-effect may occur. This effect raises coexistence costs and even adds to the non-proportionality of rigid coexistence regulations. Instead, we show that flexible measures would be preferable since they are proportional to the incentives for coexistence and, hence, less counterproductive for European agriculture.regulation, GIS modelling, domino-effect, Crop Production/Industries,

Permeability correction factor for fractures with permeable walls

Enhanced Geothermal Systems (EGS) are based on the premise that heat can be extracted from hot dry rocks located at significant depths by circulating fluid through fracture networks in the system. Heated fluid is recovered through production wells and the energy is extracted in a heat exchange chamber. There is much published research on flow through fractures, and many models have been developed to describe an effective permeability of a fracture or a fracture network. In these cases however, the walls of the fracture were modelled as being impermeable. In this paper, we have extended our previous work on fractures with permeable walls, and we introduce a correction factor to the equation that governs fracture permeability. The solution shows that the effective fracture permeability for fractures with permeable walls depends not only on the height of the channel, but also on the wall permeability and the wall Reynolds number of the fluid. We show that our solution reduces to the established solution when the fracture walls become impermeable. We also extend the discussion to cover the effective permeability of a system of fractures with permeable walls.R. Mohais, C. Xu, P. A. Dowd, and M. Han

New fossils from Jebel Irhoud, Morocco and the pan-African origin of Homo sapiens

Fossil evidence points to an African origin of Homo sapiens from a group called either H. heidelbergensis or H. rhodesiensis. However, the exact place and time of emergence of H. sapiens remain obscure because the fossil record is scarce and the chronological age of many key specimens remains uncertain. In particular, it is unclear whether the present day ‘modern’ morphology rapidly emerged approximately 200 thousand years ago (ka) among earlier representatives of H. sapiens1 or evolved gradually over the last 400 thousand years2. Here we report newly discovered human fossils from Jebel Irhoud, Morocco, and interpret the affinities of the hominins from this site with other archaic and recent human groups. We identified a mosaic of features including facial, mandibular and dental morphology that aligns the Jebel Irhoud material with early or recent anatomically modern humans and more primitive neurocranial and endocranial morphology. In combination with an age of 315?±?34 thousand years (as determined by thermoluminescence dating)3, this evidence makes Jebel Irhoud the oldest and richest African Middle Stone Age hominin site that documents early stages of the H. sapiens clade in which key features of modern morphology were established. Furthermore, it shows that the evolutionary processes behind the emergence of H. sapiens involved the whole African continent

Evaluation and use of a spatio-temporal model of cropping system effects on gene escape from transgenic oilseed rape varieties. Example of the GENESYS model applied to three co-existing herbicide tolerance transgenes

International audienc

Evaluation and use of a spatio-temporal model of cropping system effects on gene escape from transgenic oilseed rape varieties. Example of the GENESYS model applied to three co-existing herbicide tolerance transgenes

International audienc

Occurrence of genetically modified oilseed rape seeds in the harvest of subsequent conventional oilseed rape over time

International audienceIs returning to a conventional crop possible after growing a genetically modified (GM) variety? Oilseed rape volunteers in oilseed rape crops can cause seed admixture in the harvest. Farmers who desire to go back to conventional varieties after growing genetically modified varieties must comply with the 0.9% threshold of GM material in the harvest if they are to declare it as non-GM for food and feed use in Europe. The farm-scale GM platforms set up in France in 1995 were used to estimate the amount of GM seeds in the harvest of a conventional variety grown 3–8 years later in the same field. We show that over time the rate of GM seeds admixture in the harvest largely exceeded the European threshold in 6 out of 18 cases. In one case, the GM level was as high as 18%. However, it varied considerably according to the varieties used. These findings are discussed in the light of studies about seed shedding, seed dormancy and survival in the soil which are suggested to be the main source of large differences among GM varieties, which ultimately determines the frequency of volunteer plants growing amongst and harvested in admixture with the sown crop. These findings are equally discussed in light of differences of growth habit and potential competitiveness between conventional varieties responsible for different seed output by volunteers. To help cope with coexistence over time, we discuss appropriate uses of varieties and crop management in order to prevent seed admixtur