6,844 research outputs found

    Should Europe Further Strengthen Intellectual Property for Plant Breeders? An Analysis of Seed Industry Proposals

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    This paper illustrates the potential negative effects of increasing the scope of plant breeders' rights (PBR) protection, as has been proposed for Europe by leading plant breeding firms. Such a policy could increase the costs for varietal development for breeding companies, particularly if their access to varieties of the market leader is constrained. This is represented as an asymmetrical increase in breeders' cost functions in a simple model of endogenous quality choice under price competition. Increased scope of IPR protection leads to increased profits for the leading breeding company but decreases in varietal quality and both farm and overall profits.intellectual property rights, product differentiation, plant breeding, genetic diversity, Research and Development/Tech Change/Emerging Technologies, L13, O34, Q16,

    Spurious Eccentricities of Distorted Binary Components

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    I discuss the effect of physical distortion on the velocities of close binary components and how we may use the resulting distortion of velocity curves to constrain some properties of binary systems, such as inclination and mass ratio. Precise new velocities for 5 Cet convincingly detect these distortions with their theoretically predicted phase dependence. We can even use such distortions of velocity curves to test Lucy's theory of convective gravity darkening. The observed distortions for TT Hya and 5 Cet require the contact components of those systems to be gravity darkened, probably somewhat more than predicted by Lucy's theory but clearly not as much as expected for a radiative star. These results imply there is no credible evidence for eccentric orbits in binaries with contact components. I also present some speculative analyses of the observed properties of a binary encased in a non-rotating common envelope, if such an object could actually exist, and discuss how the limb darkening of some recently calculated model atmospheres for giant stars may bias my resuts for velocity-curve distortions, as well as other results from a wide range of analyses of binary stars.Comment: 14 pp, 2 tables, 12 fig; under review by Ap

    The Rulebook

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    In this course, Mythology and the Movies, students were assigned the creation of a 20-30 page graphic novel. Graphic novels are an excellent form for presenting mythological stories and many of the graphic novels available today address the same theoretical issues the class was studying. The graphic novel created for this assignment had to contain an original story that the student wrote and illustrated and it had to demonstrate one of the class mythological themes: metamorphosis, creation and origin, chaos and order, time, the quest, fate and chance, difference, or the Other . Students used photographs, their own drawings, clip art, LEGO minifigures, action figures, and 3D computer generated images to illustrate their works.https://repository.upenn.edu/showcase_comics/1020/thumbnail.jp

    From/To: Charles Van Eaton (Chalk\u27s reply filed first)

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    A Not-So Equitable Allocation: The Need for an Environmental Cost Principle

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    Potential impacts of genetic use restriction technologies (GURTs) on agrobiodiversity and agricultural production systems

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    Development and application of GURT as an appropriation mechanism may potentially have considerable impact on agriculture, the environment and the food security of rural areas in developing countries. Positive impacts may include increased investments in breeding as a result of increased intellectual property protection. Increased investments may contribute to higher yields and more advanced varieties, and thus to increased food production, a more sustainable production, and better consumer products. Potential negative impacts have been identified as well. These may require further discussion and close attention by regulatory authorities

    On the maximal halfspace depth of permutation-invariant distributions on the simplex

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    We compute the maximal halfspace depth for a class of permutation-invariant distributions on the probability simplex. The derivations are based on stochastic ordering results that so far were only showed to be relevant for the Behrens-Fisher problem.Comment: 14 pages, 3 figure

    Microseismic Monitoring Developments in Hydraulic Fracture Stimulation

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    The last decade has seen a significantly increased interest in microseismic monitoring by the hydrocarbon industry due to the recent surge in unconventional resources such as shale-gas and heavy-oil plays. Both hydraulic fracturing and steam injection create changes in local pore pressures and in situ stresses and thereby brittle failure in intact rock plus additional slip/shearing in naturally fractured rock. Local rock failure or slip yields an acoustic emission, which is also known as a microseismic event. The microseismic cloud represents thus a volumetric map of the extent of induced fracture shearing, opening and closing. Microseismic monitoring can provide pertinent information on in situ reservoir deformation due to fluid stimulation, thus ultimately facilitating reservoir drainage. This paper reviews some of the current key questions and research in microseismicity, ranging from acquisition, processing to interpretation

    Modelling the spread of American foulbrood in honeybees

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    We investigate the spread of American foulbrood (AFB), a disease caused by the bacterium Paenibacillus larvae, that affects bees and can be extremely damaging to beehives. Our dataset comes from an inspection period carried out during an AFB epidemic of honeybee colonies on the island of Jersey during the summer of 2010. The data include the number of hives of honeybees, location and owner of honeybee apiaries across the island. We use a spatial SIR model with an underlying owner network to simulate the epidemic and characterize the epidemic using a Markov chain Monte Carlo (MCMC) scheme to determine model parameters and infection times (including undetected ‘occult’ infections). Likely methods of infection spread can be inferred from the analysis, with both distance- and owner-based transmissions being found to contribute to the spread of AFB. The results of the MCMC are corroborated by simulating the epidemic using a stochastic SIR model, resulting in aggregate levels of infection that are comparable to the data. We use this stochastic SIR model to simulate the impact of different control strategies on controlling the epidemic. It is found that earlier inspections result in smaller epidemics and a higher likelihood of AFB extinction
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