6,081 research outputs found

    Stable non-standard imprecise probabilities

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    Stability arises as the consistency criterion in a betting interpretation for hyperreal imprecise previsions, that is imprecise previsions (and probabilities) which may take infinitesimal values. The purpose of this work is to extend the notion of stable coherence introduced in [8] to conditional hyperreal imprecise probabilities. Our investigation extends the de Finetti-Walley operational characterisation of (imprecise) prevision to conditioning on events which are considered "practically impossible" but not "logically impossible"

    Hint for axial-vector contact interactions in the data on e+e- -> e+e-(gamma) at centre-of-mass energies 192-208 GeV

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    For the first time the experiments ALEPH, DELPHI, L3 and OPAL have presented preliminary results for fermion-pair production in e+e- collisions on the full data set above the Z pole. A combined analysis of the Bhabha scattering measurements is performed to search for effects of contact interactions. In the case of two axial-vector (AA) currents the best fit to the data is 2.6 standard deviations away from the Standard Model expectation, corresponding to an energy scale Λ=10.3−1.6+2.8\Lambda = 10.3^{+2.8}_{-1.6} TeV for contact interactions. For other models no statistically significant deviations are observed, and the data are used to set lower limits at 95 % confidence level on the contact interaction scales ranging from 8.2 to 21.3 TeV, depending on the helicity structure.Comment: 6 pages, 1 table, 3 figure

    Z' Physics

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    The limits on extra neutral gauge bosons, which could be reached at LEP2, are reviewed. Exclusion and discovery limits are discussed for f\bar f and WW production.Comment: 20 pages Latex, 7 figures included by epsfig, Contribution to the Proceedings the workshop "Physics at LEP2", Geneva, 199

    The microbiota of Idaea inquinata developing on dry herbs

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    Idaea inquinata (Scopoli) (Lepidoptera: Geometridae, Idaeini) is a potential pest of stored food, mainly dry herbs. In this study, the role of diet in the shaping of the I. inquinata-associated bacterial community was investigated and its impact on insect performance (i.e., proportion of adult emergence and duration of postembryonic development). Larvae were reared on three diets with different nutritional compositions: (1) Matricaria chamomilla L. flowers, (2) Angelica archangelica L. roots, and (3) artificial diet. A DNA metabarcoding approach targeting V1-V2 and V4 regions of the bacterial 16S rRNA was adopted to characterize the bacterial communities associated with adults and larvae reared on different diets, and estimate their composition and diversity. The core microbiota of this species was found to include some bacterial genera commonly associated with Lepidoptera. When a coverage-based integration of rarefaction and extrapolation of Hill numbers was used to compare groups of samples, the microbial diversity (estimated as phylogenetic diversity) differed among individuals reared on different diets, and also between larvae vs. adults. The lowest taxon diversity was found associated with individuals reared on M. chamomilla. Larvae fed with this fiber-rich diet had also a significantly slower development. The composition of the microbial community varied among individuals with different diets, but not between adults vs. larvae. This study highlights the important role of diet in shaping I. inquinata microbiota, but also suggests that the microbiota of non-feeding adult moths could be partially inherited from larvae

    Project {\tt SANC} (former {\tt CalcPHEP}): Support of Analytic and Numeric calculations for experiments at Colliders

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    The project, aimed at the theoretical support of experiments at modern and future accelerators -- TEVATRON, LHC, electron Linear Colliders (TESLA, NLC, CLIC) and muon factories, is presented. Within this project a four-level computer system is being created, which must automatically calculate, at the one-loop precision level the pseudo- and realistic observables (decay rates and event distributions) for more and more complicated processes of elementary particle interaction, using the principle of knowledge storing. It was already used for a recalculation of the EW radiative corrections for Atomic Parity Violation [1] and complete one-loop corrections for the process e+e−→ttˉe^+ e^-\to t\bar{t} [2-4]; for the latter an, agreement up to 11 digits with FeynArts and the other results is found. The version of {\tt SANC} that we describe here is capable of automatically computing the decay rates and the distributions for the decays Z(H,W)→ffˉZ(H,W)\to f\bar{f} in the one-loop approximation.Comment: 3 Latex, Presented at ICHEP2002, Amsterdam, July 24-30, 2000; Submitted to Proceeding

    A Bayesian multivariate factor analysis model for evaluating an intervention by using observational time series data on multiple outcomes

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    A problem that is frequently encountered in many areas of scientific research is that of estimating the effect of a non-randomized binary intervention on an outcome of interest by using time series data on units that received the intervention (‘treated’) and units that did not (‘controls’). One popular estimation method in this setting is based on the factor analysis (FA) model. The FA model is fitted to the preintervention outcome data on treated units and all the outcome data on control units, and the counterfactual treatment-free post-intervention outcomes of the former are predicted from the fitted model. Intervention effects are estimated as the observed outcomes minus these predicted counterfactual outcomes. We propose a model that extends the FA model for estimating intervention effects by jointly modelling the multiple outcomes to exploit shared variability, and assuming an auto-regressive structure on factors to account for temporal correlations in the outcome. Using simulation studies, we show that the method proposed can improve the precision of the intervention effect estimates and achieve better control of the type I error rate (compared with the FA model), especially when either the number of preintervention measurements or the number of control units is small. We apply our method to estimate the effect of stricter alcohol licensing policies on alcohol-related harms

    Biogeography and ecology of geographically distant populations of sibling Cryptocephalus leaf beetles

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    Different populations of two closely related species, Cryptocephalusflavipes and C. bameuli, from western (Alps, Apennines and Pyrenees) and central Europe (Poland, Ukraine and Pannonia) were analysed. On the basis of DNA sequences from two genes, cox1 and ef1-alpha, distinctiveness of both species was confirmed. Nevertheless, possible hybrids were identified in Carpathian mountains. We found a significant genetic differentiation among populations of C. flavipes and C. bameuli from distant regions but a high genetic similarity between populations of C. bameuli from north and south of the Carpathians. Demographic estimates suggest a past population expansion in the case of C. bameuli and a recent one for C. flavipes, possibly occurred during Pleistocene and Holocene, respectively. Distribution modelling showed that C. flavipes is typically present in the mountain systems, whereas C. bameuli is associated with hilly areas of central and eastern Europe. Based on the present data, Last Glacial Maximum refugia of both species were located in the Alpine region and Black Sea coasts, but on different elevations. The characterization of the insect diet, through a DNA metabarcoding approach targeting the trnL plant intron, demonstrated a significant differentiation of food preferences between the two species, as well as between geographic populations within the species

    Cattle and Sheep Mixed Grazing 1: Species Equivalence

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    The effects of mixed grazing of cattle and sheep depend on stocking rate (SR) and species ratio (Nicol, 1997). Calculations of SR and species ratio require the use of species equivalence. Equivalents are often estimated in terms of intake requirements calculated on the basis of LW0.75. Freer (1981) stated that LW0.9 would be more appropriate for comparisons of intake requirements for maintenance of sheep and cattle. Nonetheless, Nolan & Connolly (1977) stated that the equivalence is system-specific and depends on the species being considered. The objective of this experiment was to estimate species equivalence for the evaluation of the introduction of sheep into a cattle dairy system based on grazing in temperate Mexico

    Three Dimensional Annihilation Imaging of Antiprotons in a Penning Trap

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    We demonstrate three-dimensional annihilation imaging of antiprotons trapped in a Penning trap. Exploiting unusual feature of antiparticles, we investigate a previously unexplored regime in particle transport; the proximity of the trap wall. Particle loss on the wall, the final step of radial transport, is observed to be highly non-uniform, both radially and azimuthally. These observations have considerable implications for the production and detection of antihydrogen atoms.Comment: Invited Talk at NNP03, Workshop on Non-Neutral Plasmas, 200
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