393 research outputs found

    Bridging the gap between social tagging and semantic annotation: E.D. the Entity Describer

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    Semantic annotation enables the development of efficient computational methods for analyzing and interacting with information, thus maximizing its value. With the already substantial and constantly expanding data generation capacity of the life sciences as well as the concomitant increase in the knowledge distributed in scientific articles, new ways to produce semantic annotations of this information are crucial. While automated techniques certainly facilitate the process, manual annotation remains the gold standard in most domains. In this manuscript, we describe a prototype mass-collaborative semantic annotation system that, by distributing the annotation workload across the broad community of biomedical researchers, may help to produce the volume of meaningful annotations needed by modern biomedical science. We present E.D., the Entity Describer, a mashup of the Connotea social tagging system, an index of semantic web-accessible controlled vocabularies, and a new public RDF database for storing social semantic annotations

    THE 1995 THROUGH 1998 PRICING PERFORMANCE OF MARKET ADVISORY SERVICES FOR WHEAT

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    The purpose of this research report is to present an evaluation of advisory service pricing performance from 1995 through 1998 for wheat. The average net advisory price across all 24 wheat programs in 1995 is 3.79perbushel,3.79 per bushel, 0.18 above the market benchmark price. The range in 1995 is 3.01to3.01 to 4.71 per bushel. The average net advisory service price for 23 wheat programs in 1996 is 3.82perbushel,3.82 per bushel, 0.13 below the market benchmark. The range in 1996 is 2.74to2.74 to 4.94 per bushel. The average net advisory price for all 20 wheat programs in 1997 is 2.64perbushel,2.64 per bushel, 0.58 below the market benchmark. The range in 1997 is 1.34to1.34 to 3.90 per bushel. Finally, the average net advisory price across all 21 services in 1998 is 2.36perbushel,2.36 per bushel, 0.54 below the market benchmark. The range in 1998 is 1.34to1.34 to 3.33 per bushel.Marketing,

    Isospin asymmetry and type-I superconductivity in neutron star matter

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    It has been argued by Buckley et. al.(Phys. Rev. Lett. 92, 151102, 2004) that nuclear matter is a type-I rather than a type-II superconductor. The suggested mechanism is a strong interaction between neutron and proton Cooper pairs, which arises from an assumed U(2) symmetry of the effective potential, which is supposed to originate in isospin symmetry of the underlying nuclear interactions. To test this claim, we perform an explicit mean-field calculation of the effective potential of the Cooper pairs in a model with a simple four-point pairing interaction. In the neutron star context, matter is very neutron rich with less than 10% protons, so there is no neutron-proton pairing. We find that under these conditions our model shows no interaction between proton Cooper pairs and neutron Cooper pairs at the mean-field level. We estimate the leading contribution beyond mean field and find that it is is small and attractive at weak coupling.Comment: 7 pages, 2 figure

    1998 PRICING PERFORMANCE OF MARKET ADVISORY SERVICES FOR CORN AND SOYBEANS

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    The purpose of this research report is to present an evaluation of advisory service pricing performance in 1998 for corn and soybeans. Specifically, the average price received by a subscriber to an advisory service is calculated for corn and soybean crops harvested in 1998. The average net advisory price across all 23 corn programs is 2.17perbushelsevencentsbelowthemarketbenchmarkprice.Thenetadvisorypricesforcornrangefromaminimumof2.17 per bushel - seven cents below the market benchmark price. The net advisory prices for corn range from a minimum of 1.93 per bushel to a maximum of 2.51perbushel.Theaveragenetadvisorypriceacrossall22soybeanprogramsis2.51 per bushel. The average net advisory price across all 22 soybean programs is 5.82 per bushel - four cents less than the market benchmark. The net advisory prices for soybeans range from a minimum of 5.11perbusheltoamaximumof5.11 per bushel to a maximum of 6.58 per bushel.Marketing,

    DO AGRICULTURAL MARKET ADVISORY SERVICES BEAT THE MARKET? EVIDENCE FROM THE WHEAT MARKET OVER 1995-1998

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    The purpose of this report is to address two basic performance questions for market advisory services in wheat: 1) Do market advisory services, on average, outperform an appropriate market benchmark? and 2) Do market advisory services exhibit persistence in their performance from year-to-year? Data on wheat net price received for advisory services, as reported by the AgMAS Project, are available for the 1995, 1996, 1997 and 1998 crop years. Not only do market advisory programs in wheat consistently fail to "beat the market," their performance is significantly worse than the market. On average, market advisory service performance is about $14 per acre below benchmark revenue, an economically non-trivial amount by any reasonable standard. The predictability results provide little evidence that future advisory service pricing performance can be predicted from past performance.Marketing,

    Conditioning with spatio-temporal patterns: Constraining the contribution of the hippocampus to configural learning

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    The conditions under which the hippocampus contributes to learning about spatio-temporal configural patterns are not fully established. The aim of Experiments 1–4 was to investigate the impact of hippocampal lesions on learning about where or when a reinforcer would be delivered. In each experiment, the rats received exposure to an identical set of patterns (i.e., spotted + morning, checked + morning, spotted + afternoon and checked + afternoon); and the contexts (Experiment 1), times of day (Experiment 2), or their configuration (Experiments 3 and 4) signalled whether or not a reinforcer would be delivered. The fact that hippocampal damage did not disrupt the formation of simple or configural associations involving spatio-temporal patterns is surprising, and suggests that the contribution of the hippocampus is restricted to mediated learning (or updating) involving spatio-temporal configurations

    Leptonic contribution to the bulk viscosity of nuclear matter

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    For beta-equilibrated nuclear matter we estimate the contribution to the bulk viscosity from purely leptonic processes, namely the conversion of electrons to and from muons. For oscillation frequencies in the kiloHertz range, we find that this process provides the dominant contribution to the bulk viscosity when the temperature is well below the critical temperature for superconductivity or superfluidity of the nuclear matter.Comment: 15 pages, LaTeX, new appendix and general clarifications in response to referee comment

    Landsat Data Continuity Mission (LDCM) Ascent and Operational Orbit Design

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    For the past 40-years, Landsat Satellites have collected Earth's continental data and enabled scientists to assess change in the Earth's landscape. The Landsat Data Continuity Mission (LDCM) is the next generation satellite supporting the Landsat science program. LDCM will fly a 16-day ground repeat cycle, Sun-synchronous, frozen orbit with a mean local time of the descending node ranging between 10:10 am and 10:15 am. This paper presents the preliminary ascent trajectory design from the injection orbit to its final operational orbit. The initial four burn ascent design is shown to satisfy all the LDCM mission goals and requirement and to allow for adequate flexibility in re-planning the ascent

    Flux tubes and the type-I/type-II transition in a superconductor coupled to a superfluid

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    We analyze magnetic flux tubes at zero temperature in a superconductor that is coupled to a superfluid via both density and gradient (``entrainment'') interactions. The example we have in mind is high-density nuclear matter, which is a proton superconductor and a neutron superfluid, but our treatment is general and simple, modeling the interactions as a Ginzburg-Landau effective theory with four-fermion couplings, including only s-wave pairing. We numerically solve the field equations for flux tubes with an arbitrary number of flux quanta, and compare their energies. This allows us to map the type-I/type-II transition in the superconductor, which occurs at the conventional kappa = 1/sqrt(2) if the condensates are uncoupled. We find that a density coupling between the condensates raises the critical kappa and, for a sufficiently high neutron density, resolves the type-I/type-II transition line into an infinite number of bands corresponding to ``type-II(n)'' phases, in which n, the number of quanta in the favored flux tube, steps from 1 to infinity. For lower neutron density, the coupling creates spinodal regions around the type-I/type-II boundary, in which metastable flux configurations are possible. We find that a gradient coupling between the condensates lowers the critical kappa and creates spinodal regions. These exotic phenomena may not occur in nuclear matter, which is thought to be deep in the type-II region, but might be observed in condensed matter systems.Comment: 14 pages, improved discussion of the effects of varying the neutron/proton condensate ratio; added reference
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