9,439 research outputs found

    Envisat - taking the measure of North Atlantic storms

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    Envisat carries a number of sensors able to provide quantitative information on raining clouds: AATSR delivers information on cloud microphysics (particle size, temperature etc.), MWR-2 gives columnar totals for liquid and vapour forms of water, and RA-2 yields rain rate and wind speed. This paper examines the complementarity of these sensors, with a focussed study on significant rain events in the N. Atlantic, covering both coherent large storms and fronts with smaller scale structure. The difference in liquid water estimates from the infra-red and passive systems appears to be related to the temperature and sizes of drops being detected

    Isolated Photons in Deep Inelastic Scattering

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    Photon radiation at large transverse momenta at colliders is a detailed probe of hard interaction dynamics. The isolated photon production cross section in deep inelastic scattering was measured recently by the ZEUS experiment, and found to be considerably larger than theoretical predictions obtained with widely used event generators. To investigate this discrepancy, we perform a dedicated parton-level calculation of this observable, including contributions from fragmentation and large-angle radiation. Our results are in good agreement with all aspects of the experimental measurement.Comment: 4 pages, 3 figure

    Jurisprudential and Economic Justifications for Gene Sequence Patents

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    This Article introduces the scientific background necessary to understand the practice of gene sequence patenting from a technical perspective. This Part will dispel a number of misconceptions related to the practice of gene sequence patenting, specifically what a gene patent represents and the limited bundle of exclusionary rights a gene sequence patent provides. This Part will also explain, from a technical perspective, the difference between non-patent eligible native DNA sequences and patent eligible man-made cDNA gene sequences. Part III introduces and attempts to synthesize the century-long products of nature doctrine, which supplies the standard for composition patent eligibility under section 101 of the patent statute. Additionally, this Part includes a discussion of the heightened utility standards promulgated by the USPTO and adopted by the In re Fisher court, which has severely limited the practice of patenting upstream subject matter such as gene fragments and ESTs. Part IV of this Article constructs an alternative standard for patent eligibility of genetic composition claims which simultaneously applies an information preemption analysis in concert with a functional and physical difference analysis under the products of nature doctrine. This Part further explains Judge Sweet’s erroneous application of the “markedly different” standard under the products of nature doctrine to only the informational character of native DNA and the cDNA sequences claimed in Myriad’s patents. Part V of this Article introduces the underlying patent prospect theory used to justify the granting of patent rights. This Part describes the theory of the tragedy of the anticommons and its application to the biotechnology industry. In doing so, this Part introduces theories which suggest that the proliferation of patents in areas of upstream research, such as gene sequences, may amplify the risk of the tragedy of the anticommons. Part V further explains how factors such as large public agency control of upstream subject matter, enforcement costs on patent holders, and the stricter utility requirements promulgated by the USPTO all act to mitigate anticommons effects. Finally, this Part provides an overview of mitigating options, such as a statutory experimentation defense and expanded march-in rights, available to Congress to help stave off any threat of an anticommons market malfunction

    Correlations in local measurements on a quantum state, and complementarity as an explanation of nonclassicality

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    We consider the classical correlations that two observers can extract by measurements on a bipartite quantum state, and we discuss how they are related to the quantum mutual information of the state. We show with several examples how complementarity gives rise to a gap between the quantum and the classical correlations, and we relate our quantitative finding to the so-called classical correlation locked in a quantum state. We derive upper bounds for the sum of classical correlation obtained by measurements in different mutually unbiased bases and we show that the complementarity gap is also present in the deterministic quantum computation with one quantum bit.Comment: 15 pages, 4 figures, references adde

    Profiling of aminoxyTMT-labeled bovine milk oligosaccharides reveals substantial variation in oligosaccharide abundance between dairy cattle breeds.

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    Free milk oligosaccharides are bioactive molecules that function as prebiotics and prevent infections that commonly afflict developing infants. To date, few publications have examined the factors affecting bovine milk oligosaccharide production among cattle in the dairy industry. Here we have applied a high-throughput isobaric labeling technique to measure oligosaccharide abundances in milk collected from Danish Holstein-Friesian and Jersey dairy cattle by liquid chromatography-mass spectrometry. With a total of 634 milk samples, this collection represents the largest sample set used for milk oligosaccharide profiling in the current literature. This study is also the first to use isobaric labeling for the purpose of measuring free oligosaccharides in a real sample set. We have identified 13 oligosaccharides that vary significantly by breed, with most structures being more abundant in the milk of Jersey cattle. The abundances of several oligosaccharides were increased in second-parity cows, and correlations between the abundances of oligosaccharide pairs were identified, potentially indicating similarities in their synthetic pathways. Fucosylated oligosaccharide structures were widely identified among both breeds. Improving our understanding of oligosaccharide production will aid in developing strategies to recover these compounds from processing streams and may enable their use as a functional ingredient in foods for infants and adults

    Positive P simulations of spin squeezing in a two-component Bose condensate

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    The collisional interaction in a Bose condensate represents a non-linearity which in analogy with non-linear optics gives rise to unique quantum features. In this paper we apply a Monte Carlo method based on the positive P pseudo-probability distribution from quantum optics to analyze the efficiency of spin squeezing by collisions in a two-component condensate. The squeezing can be controlled by choosing appropiate collision parameters or by manipulating the motional states of the two components.Comment: 5 pages, 2 figures. Submitted to Phys. Rev.
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