1,953 research outputs found

    mashpoint: browsing the web along structured lines

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    Large numbers of Web sites support rich data-centric features to explore and interact with data. In this paper we present mashpoint, a framework that allows distributed data-powered Web applications to linked based on similarities of the entities in their data. By linking applications in this way we allow browsing with selections of data from one application to another application. This sort of browsing allows complex queries and exploration of data to be done by average Web users using multiple applications. We additionally use this concept to surface structured information to users in Web pages. In this paper we present this concept and our initial prototyp

    Recent palaeoenvironmental evidence for the processing of hemp (Cannabis sativa L.) in eastern England during the medieval period

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    [FIRST PARAGRAPH] Hemp (Cannabissativa L.)— whose origins as a domesticated plant probably lie in C.Asia — has been cultivated in England since at least a.d.800 (and before this perhaps in the Roman Period), mainly for its ¿bre, which was used to make sails, ropes, ¿shing nets and clothes, as well as for the oil from hempseed. Hemp cultivation may have reached a peak during the early 16th century, when Henry VIII decreed that increased hemp production was required to supply the expanding navy. Evidence for the locations where the crop was cultivated and processed is available in several different forms, including written evidence in parish records and government reports, place-name evidence (e.g.Hempholme and some instances of Hempstead), and features on old maps, such as Hempis¿eld (hemp¿eld)

    Linked open government data: lessons from Data.gov.uk

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    The movement to publish government data is an opportunity to populate the linked data Web with data of good provenance. The benefits range from transparency to public service improvement, citizen engagement to the creation of social and economic value. There are many challenges to be met before the vision is implemented, and this paper describes the efforts of the EnAKTing project to extract value from data.gov.uk, through the stages of locating data sources, integrating data into the linked data Web, and browsing and querying it

    Kernel density classification and boosting: an L2 sub analysis

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    Kernel density estimation is a commonly used approach to classification. However, most of the theoretical results for kernel methods apply to estimation per se and not necessarily to classification. In this paper we show that when estimating the difference between two densities, the optimal smoothing parameters are increasing functions of the sample size of the complementary group, and we provide a small simluation study which examines the relative performance of kernel density methods when the final goal is classification. A relative newcomer to the classification portfolio is “boosting”, and this paper proposes an algorithm for boosting kernel density classifiers. We note that boosting is closely linked to a previously proposed method of bias reduction in kernel density estimation and indicate how it will enjoy similar properties for classification. We show that boosting kernel classifiers reduces the bias whilst only slightly increasing the variance, with an overall reduction in error. Numerical examples and simulations are used to illustrate the findings, and we also suggest further areas of research

    Nucleotide sequence from a ribosomal RNA transcription unit of Xenopus laevis

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    I have determined the sequence of the central part of a ribosomal transcription unit from Xenopus laevis, using the plasmid pXlr101. The sequence comprises over 200 bp at the 3' end of the 18S gene, the first internal transcribed spacer, the 5.8S gene, the second internal transcribed spacer, and over 100 bp at the 5' end of the 28S gene. The two transcribed spacers have G + C contents of over 80% and include long homopolymeric tracts of G or C (10-15 residues). ITS1 also has long tracts of purines containing several A residues. The Xenopus sequence is compared to other organisms where data is available. The gene sequences show a high level of homology with sequences from other eukaryotes and also some homology with the prokaryote E. coli. No sequence homology is found between the internal transcribed spacers of Xenopus and yeast (Saccharomyces). Tentative secondary structure models are proposed for the Xenopus sequence and again compared to possible models from other organisms. Secondary structure may be highly conserved within the mature rRNAs, even in regions where the primary sequence is variable between species. In the transcribed spacers one hairpin may be held in common by Xenopus and yeast but other secondary structures are not obviously conserved. I have attempted to characterise some ribosomal RNA precursors in Xenopus tissue culture cells by both 'Northern' transfers and SI nuclease protection mapping. Various artifacts limit the usefulness of these techniques in this system. However it is proposed that a putative '30S' precursor exists containing the RNA of 5.8S, ITS2 and 28S, and having the same 5' end as 5.8S rRNA. Evidence from the sequence supports the proposition that 5.8S rRNA in eukaryotes is structurally equivalent to the 5' end of 23S rRNA in E. coli The results lead to speculation of the relationship between rRNA processing in eukaryotes and E. coli

    Factors determining the home ranges of pet cats: A meta-analysis

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    Roaming pet cats Felis catus are a significant conservation issue because they may hunt, harass and compete with wildlife; spread disease, interbreed with cats in feral populations, and hybridise with wild native felids. Studies of the roaming behaviour of pet cats are often hampered by modest sample sizes and variability between cats, limiting statistical significance of the findings and their usefulness in recommending measures to discourage roaming. We resolved these difficulties through meta-analyses of 25 studies from 10 countries involving 469 pet cats to assess the influence of sex, whether a cat was desexed and housing density on roaming. A complementary linear mixed models approach used data on 311 individual animals from 22 studies and was also able to assess the influence of age and husbandry practices on roaming. This restricted sample gave greater statistical power than the meta-analyses. Meta-analyses found that: male pet cats had larger home ranges than females, desexing did not influence home range, and cats had larger home ranges when housing densities were low. The linear mixed models supported those results. They also indicated that animals ≥ 8 years old had smaller home ranges than younger cats. Cats fed regularly, provided with veterinary care and socialised with humans had similar home ranges to cats living in association with households but not provided for in some of these ways. Short of confinement, there is no simple measure owners can adopt to reduce roaming by their cats and prevent the associated environmental problems

    Probing neutrino non-standard interactions with atmospheric neutrino data

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    We have reconsidered the atmospheric neutrino anomaly in light of the laetst data from Super-Kamiokande contained events and from Super-Kamiokande and MACRO up-going muons. We have reanalysed the proposed solution to the atmospheric neutrino anomaly in terms of non-standard neutrino-matter interactions (NSI) as well as the standard nu_mu -> nu_tau oscillations (OSC). Our statistical analysis shows that a pure NSI mechanism is now ruled out at 99%, while the standard nu_mu -> nu_tau OSC mechanism provides a quite remarkably good description of the anomaly. We therefore study an extended mechanism of neutrino propagation which combines both oscillation and non-standard neutrino-matter interactions, in order to derive limits on flavour-changing (FC) and non-universal (NU) neutrino interactions. We obtain that the off-diagonal flavour-changing neutrino parameter epsilon and the diagonal non-universality neutrino parameter epsilon' are confined to -0.03 < epsilon < 0.02 and |epsilon'| < 0.05 at 99.73% CL. These limits are model independent and they are obtained from pure neutrino-physics processes. The stability of the neutrino oscillation solution to the atmospheric neutrino anomaly against the presence of non-standard neutrino interactions establishes the robustness of the near-maximal atmospheric mixing and massive-neutrino hypothesis. The best agreement with the data is obtained for Delta_m^2 = 2.3*10^{-3} eV^2, sin^2(2*theta) = 1, epsilon = 6.7*10^{-3} and epsilon' = 1.1*10^{-3}, although the chi^2 function is quite flat in the epsilon and epsilon' directions for epsilon, epsilon' -> 0.Comment: 26 pages, LaTeX file using REVTeX4, 1 table and 12 figures included. Added a revised analysis which takes into account the new 1489-day Super-Kamiokande and final MACRO data. The bound on NSI parameters is considerably improve

    Coherence as ultrashort pulse train generator

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    Intense, well-controlled regular light pulse trains start to play a crucial role in many fields of physics. We theoretically demonstrate a very simple and robust technique for generating such periodic ultrashort pulses from a continuous probe wave which propagates in a dispersive thermal gas media

    Assessing the effectiveness of the Birdsbesafe® anti-predation collar cover in reducing predation on wildlife by pet cats in Western Australia

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    Many pet cats hunt and, irrespective of whether or not this threatens wildlife populations, distressed owners may wish to curtail hunting while allowing their pets to roam. Therefore we evaluated the effectiveness of three patterned designs (simple descriptions being rainbow, red and yellow) of the anti-predation collar cover, the Birdsbesafe® (BBS), in reducing prey captures by 114 pet cats over 2 years in a suburban Australian context. The BBS offers a colourful indicator of a cat's presence and should therefore alert prey with good colour vision (birds and herpetofauna), but not most mammals with limited colour vision. We also interviewed the 82 owners of cats in the study about their experience using the BBS and their assessment of the behavioural responses of their cats. In the first year of the study, which focused on the effectiveness of different BBS colours, captures of prey with good colour vision were reduced by 54% (95% CL 43-64%) when cats were wearing a BBS of any colour, with the rainbow and red BBS more effective than the yellow when birds were prey. Captures of mammals were not reduced significantly. The second year assessed the rainbow BBS alone, and those data combined with rainbow data in the first year found a significant reduction of 47% (95% CL 43-57%) in capture of prey with good colour vision, with no effect of differences across years. We found no evidence that cats maintained a lower predation rate once the BBS was removed. Seventy-nine per cent of owners reported that their cats had no problems with the BBS and another 17% reported that their cats adjusted within 2 days. Fourteen owners reported that their cats spent more time at home and ate more while wearing the BBS. Two owners reported their cats stayed away from home more while wearing it. Sixty-four per cent of owners using the red collar, 48% using rainbow and 46% using yellow believed that it worked. Overall, 77% of owners planned to continue using the BBS after the study had finished. The BBS is an option for owners wishing to reduce captures of birds and herpetofauna by free-ranging cats, especially where mammalian prey are introduced pests. To date, the BBS is the only predation deterrent that reduces significantly the number of herpetofauna brought home. It is unsuitable where endangered mammalian prey or large invertebrates are vulnerable to predation by pet cats

    Confusing non-standard neutrino interactions with oscillations at a neutrino factory

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    Most neutrino mass theories contain non-standard interactions (NSI) of neutrinos which can be either non-universal (NU) or flavor-changing (FC). We study the impact of such interactions on the determination of neutrino mixing parameters at a neutrino factory using the so-called ``golden channels'' \pnu{e}\to\pnu{\mu} for the measurement of \theta_{13}. We show that a certain combination of FC interactions in neutrino source and earth matter can give exactly the same signal as oscillations arising due to \theta_{13}. This implies that information about \theta_{13} can only be obtained if bounds on NSI are available. Taking into account the existing bounds on FC interactions, this leads to a drastic loss in sensitivity in \theta_{13}, at least two orders of magnitude. A near detector at a neutrino factory offers the possibility to obtain stringent bounds on some NSI parameters. Such near site detector constitutes an essential ingredient of a neutrino factory and a necessary step towards the determination of \theta_{13} and subsequent study of leptonic CP violation.Comment: 23 pages, 5 figures, improved version, accepted for publication in Phs. Rev. D, references adde
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