43 research outputs found

    The impact of disease adaptation information on general population values for rheumatoid arthritis states

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    Economic evaluation of healthcare technologies uses values for hypothetical health states elicited from the general population rather than patients. However, they may not consider adaptation. This study explored the extent to which the general population changes their initial values, and the factors that influenced this change, after being informed about adaptation. Three rheumatoid arthritis (RA) states were used for illustration. Two respondent groups were interviewed. The Initially Uninformed Group initially valued the RA states. An adaptation exercise followed, where they listened to recordings of patients discussing how they adapted; they then valued the same states again. The Informed Group underwent the adaptation exercise before valuing the states. The difference between the valuations was examined using t-tests. A multivariate regression was developed to assess the factors that impacted individuals to change their initial values. After undergoing the adaptation exercise, the Initially Uninformed Group statistically increased their values for the RA states. When the second values of the Initially Uninformed Group were compared to the first values of the Informed Group, there were no statistical differences, implying that there was no interviewer effect. Younger and healthier individuals were more likely to increase their initial values after being informed about adaptation

    Genus Two Partition and Correlation Functions for Fermionic Vertex Operator Superalgebras I

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    We define the partition and nn-point correlation functions for a vertex operator superalgebra on a genus two Riemann surface formed by sewing two tori together. For the free fermion vertex operator superalgebra we obtain a closed formula for the genus two continuous orbifold partition function in terms of an infinite dimensional determinant with entries arising from torus Szeg\"o kernels. We prove that the partition function is holomorphic in the sewing parameters on a given suitable domain and describe its modular properties. Using the bosonized formalism, a new genus two Jacobi product identity is described for the Riemann theta series. We compute and discuss the modular properties of the generating function for all nn-point functions in terms of a genus two Szeg\"o kernel determinant. We also show that the Virasoro vector one point function satisfies a genus two Ward identity.Comment: A number of typos have been corrected, 39 pages. To appear in Commun. Math. Phy

    The energy spectrum of all-particle cosmic rays around the knee region observed with the Tibet-III air-shower array

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    We have already reported the first result on the all-particle spectrum around the knee region based on data from 2000 November to 2001 October observed by the Tibet-III air-shower array. In this paper, we present an updated result using data set collected in the period from 2000 November through 2004 October in a wide range over 3 decades between 101410^{14} eV and 101710^{17} eV, in which the position of the knee is clearly seen at around 4 PeV. The spectral index is -2.68 ±\pm 0.02(stat.) below 1PeV, while it is -3.12 ±\pm 0.01(stat.) above 4 PeV in the case of QGSJET+HD model, and various systematic errors are under study now.Comment: 12 pages, 7 figures, accepted by Advances in space researc

    Moon Shadow by Cosmic Rays under the Influence of Geomagnetic Field and Search for Antiprotons at Multi-TeV Energies

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    We have observed the shadowing of galactic cosmic ray flux in the direction of the moon, the so-called moon shadow, using the Tibet-III air shower array operating at Yangbajing (4300 m a.s.l.) in Tibet since 1999. Almost all cosmic rays are positively charged; for that reason, they are bent by the geomagnetic field, thereby shifting the moon shadow westward. The cosmic rays will also produce an additional shadow in the eastward direction of the moon if cosmic rays contain negatively charged particles, such as antiprotons, with some fraction. We selected 1.5 x10^{10} air shower events with energy beyond about 3 TeV from the dataset observed by the Tibet-III air shower array and detected the moon shadow at 40σ\sim 40 \sigma level. The center of the moon was detected in the direction away from the apparent center of the moon by 0.23^\circ to the west. Based on these data and a full Monte Carlo simulation, we searched for the existence of the shadow produced by antiprotons at the multi-TeV energy region. No evidence of the existence of antiprotons was found in this energy region. We obtained the 90% confidence level upper limit of the flux ratio of antiprotons to protons as 7% at multi-TeV energies.Comment: 13pages,4figures; Accepted for publication in Astroparticle Physic

    Are protons still dominant at the knee of the cosmic-ray energy spectrum?

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    A hybrid experiment consisting of emulsion chambers, burst detectors and the Tibet II air-shower array was carried out at Yangbajing (4,300 m a.s.l., 606 g/cm2^2) in Tibet to obtain the energy spectra of primary protons and heliums. From three-year operation, these energy spectra are deduced between 101510^{15} and 101610^{16} eV by triggering the air showers associated with a high energy core and using a neural network method in the primary mass separation. The proton spectrum can be expressed by a single power-law function with a differential index of 3.01±0.11-3.01 \pm 0.11 and 3.05±0.12-3.05 \pm 0.12 based on the QGSJET+HD and SIBYLL+HD models, respectively, which are steeper than that extrapolated from the direct observations of 2.74±0.01-2.74 \pm 0.01 in the energy range below 101410^{14} eV. The absolute fluxes of protons and heliums are derived within 30% systematic errors depending on the hadronic interaction models used in Monte Carlo simulation. The result of our experiment suggests that the main component responsible for the change of the power index of the all-particle spectrum around 3×10153 \times 10^{15} eV, so-called ``knee'', is composed of nuclei heavier than helium. This is the first measurement of the differential energy spectra of primary protons and heliums by selecting them event by event at the knee energy region.Comment: This paper has been accepted for publication Physics Letters B on October 19th, 2005. This paper has been accepted for publication Physics Letters B on October 19th, 200

    The impact of disease adaptation information on general population values for rheumatoid arthritis states

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    Economic evaluation of healthcare technologies uses values for hypothetical health states elicited from the general population rather than patients. However, they may not consider adaptation. This study explored the extent to which the general population changes their initial values, and the factors that influenced this change, after being informed about adaptation. Three rheumatoid arthritis (RA) states were used for illustration. Two respondent groups were interviewed. The Initially Uninformed Group initially valued the RA states. An adaptation exercise followed, where they listened to recordings of patients discussing how they adapted; they then valued the same states again. The Informed Group underwent the adaptation exercise before valuing the states. The difference between the valuations was examined using t-tests. A multivariate regression was developed to assess the factors that impacted individuals to change their initial values. After undergoing the adaptation exercise, the Initially Uninformed Group statistically increased their values for the RA states. When the second values of the Initially Uninformed Group were compared to the first values of the Informed Group, there were no statistical differences, implying that there was no interviewer effect. Younger and healthier individuals were more likely to increase their initial values after being informed about adaptation
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