707 research outputs found

    Are EU spatial ex ante coexistence regulations proportional?

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    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

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    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,

    Direct Measurement of the Fermi Energy in Graphene Using a Double Layer Structure

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    We describe a technique which allows a direct measurement of the relative Fermi energy in an electron system using a double layer structure, where graphene is one of the two layers. We illustrate this method by probing the Fermi energy as a function of density in a graphene monolayer, at zero and in high magnetic fields. This technique allows us to determine the Fermi velocity, Landau level spacing, and Landau level broadening in graphene. We find that the N=0 Landau level broadening is larger by comparison to the broadening of upper and lower Landau levels.Comment: 5 pages, 4 figure

    Controlled Anisotropic Deformation of Ag Nanoparticles by Si Ion Irradiation

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    The shape and alignment of silver nanoparticles embedded in a glass matrix is controlled using silicon ion irradiation. Symmetric silver nanoparticles are transformed into anisotropic particles whose larger axis is along the ion beam. Upon irradiation, the surface plasmon resonance of symmetric particles splits into two resonances whose separation depends on the fluence of the ion irradiation. Simulations of the optical absorbance show that the anisotropy is caused by the deformation and alignment of the nanoparticles, and that both properties are controlled with the irradiation fluence.Comment: Submitted to Phys. Rev. Lett. (October 14, 2005

    Aligned gold nanorods in silica made by ion irradiation of core-shell colloidal particles

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    Colloidal particles with a 14 nm diameter Au core surrounded by a 72 nm thick silica shell have been irradiated with 30 MeV heavy ions. The shell deforms into an oblate ellipsoid, while the core becomes rod-shaped (aspect ratio up to 9) with the major axis along the beam. Optical extinction measurements show evidence for split plasmon bands, characteristic for anisotropic metal nanoparticles

    Satisfaction with caregivers during labour among low risk women in the Netherlands : the association with planned place of birth and transfer of care during labour

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    Background: The caregiver has an important influence on women's birth experiences. When transfer of care during labour is necessary, care is handed over from one caregiver to the other, and this might influence satisfaction with care. It is speculated that satisfaction with care is affected in particular for women who need to be transferred from home to hospital. We examined the level of satisfaction with the caregiver among women with planned home versus planned hospital birth in midwife-led care. Methods: We used data from the prospective multicentre DELIVER (Data EersteLIjns VERloskunde) cohort-study, conducted in 2009 and 2010 in the Netherlands. Women filled in a postpartum questionnaire which contained elements of the Consumer Quality index. This instrument measures 'general rate of satisfaction with the caregiver' (scale from 1 to 10, with cut-off of below 9) and 'quality of treatment by the caregiver' (containing 7 items on a 4 point Likert scale, with cut-off of mean of 4 or lower). Results: Women who planned a home birth (n = 1372) significantly more often rated 'quality of treatment by caregiver' high than women who planned a hospital birth (n = 829). Primiparous women who planned a home birth significantly more often had a high rate (9 or 10) for 'general satisfaction with caregiver' (adj.OR 1.48; 95% CI 1.1, 2.0). Also, primiparous women who planned a home birth and had care transferred during labour (331/553; 60%) significantly more often had a high rate (9 or 10) for 'general satisfaction' compared to those who planned a hospital birth and who had care transferred (1.44; 1.0-2.1). Furthermore, they significantly more often rated 'quality of treatment by caregiver' high, than 276/414 (67%) primiparous women who planned a hospital birth and who had care transferred (1.65; 1.2-2.3). No differences were observed for multiparous women who had planned home or hospital birth and who had care transferred. Conclusions: Planning home birth is associated to a good experience of quality of care by the caregiver. Transferred planned home birth compared to a transferred planned hospital birth does not lead to a more negative experience of care received from the caregiver
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