40 research outputs found

    Performance of hunting statistics as spatiotemporal density indices of moose (Alces alces) in Norway

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    Wildlife managers are often asking for reliable information of population density across larger spatial scales. In this study, we examined the spatiotemporal relationships between moose density as estimated by cohort analysis and the density indices (1) harvest density (HD; hunter kills per km2), (2) moose seen per unit effort (SPUE), seen moose density (SMD; seen moose per km2), and density of moosevehicle accidents (MVA density; e.g., traffic kills per km2) in 16 areas in Norway with 13–42 years of data. HD showed a close positive relationship with moose density both within and between regions. However, the temporal variation in HD was best explained as a delayed reflection of moose density and tended to overestimate its growth and decline. Conversely, SMD and SPUE were unable to predict the spatial variation in moose density with high precision, though both indices were relatively precise temporal reflectors of moose density. However, the SPUE tended to underestimate population growth, probably because of a decrease in searching efficiency with increasing moose density. Compared to the other indices, MVA density performed poor as an index of moose density within regions, and not at all among regions, but may, because of its independent source of data, be used to cross-check population trends suggested by other indices. Our study shows that the temporal trends in moose density can be surveyed over large areas by the use of cheap indices based on data collected by hunters and local managers, and supports the general assumption that the number of moose killed per km2 provides a precise and isometric index of the variation in moose density at the spatial scale of our study. cohort analysis; isometric index; management; monitoring; population reconstruction; precision; saturation; seen per unit effort (SPUE).Performance of hunting statistics as spatiotemporal density indices of moose (Alces alces) in NorwaypublishedVersio

    A Long Baseline Neutrino Oscillation Experiment Using J-PARC Neutrino Beam and Hyper-Kamiokande

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    Document submitted to 18th J-PARC PAC meeting in May 2014. 50 pages, 41 figuresDocument submitted to 18th J-PARC PAC meeting in May 2014. 50 pages, 41 figuresDocument submitted to 18th J-PARC PAC meeting in May 2014. 50 pages, 41 figuresHyper-Kamiokande will be a next generation underground water Cherenkov detector with a total (fiducial) mass of 0.99 (0.56) million metric tons, approximately 20 (25) times larger than that of Super-Kamiokande. One of the main goals of Hyper-Kamiokande is the study of CPCP asymmetry in the lepton sector using accelerator neutrino and anti-neutrino beams. In this document, the physics potential of a long baseline neutrino experiment using the Hyper-Kamiokande detector and a neutrino beam from the J-PARC proton synchrotron is presented. The analysis has been updated from the previous Letter of Intent [K. Abe et al., arXiv:1109.3262 [hep-ex]], based on the experience gained from the ongoing T2K experiment. With a total exposure of 7.5 MW ×\times 107^7 sec integrated proton beam power (corresponding to 1.56×10221.56\times10^{22} protons on target with a 30 GeV proton beam) to a 2.52.5-degree off-axis neutrino beam produced by the J-PARC proton synchrotron, it is expected that the CPCP phase ÎŽCP\delta_{CP} can be determined to better than 19 degrees for all possible values of ÎŽCP\delta_{CP}, and CPCP violation can be established with a statistical significance of more than 3 σ3\,\sigma (5 σ5\,\sigma) for 7676% (5858%) of the ÎŽCP\delta_{CP} parameter space

    Physics potential of a long-baseline neutrino oscillation experiment using a J-PARC neutrino beam and Hyper-Kamiokande

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    39 pages, 26 figures, submitted to PTE

    Hyper-Kamiokande Design Report

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    325 pages325 pagesOn the strength of a double Nobel prize winning experiment (Super)Kamiokande and an extremely successful long baseline neutrino programme, the third generation Water Cherenkov detector, Hyper-Kamiokande, is being developed by an international collaboration as a leading worldwide experiment based in Japan. The Hyper-Kamiokande detector will be hosted in the Tochibora mine, about 295 km away from the J-PARC proton accelerator research complex in Tokai, Japan. The currently existing accelerator will be steadily upgraded to reach a MW beam by the start of the experiment. A suite of near detectors will be vital to constrain the beam for neutrino oscillation measurements. A new cavern will be excavated at the Tochibora mine to host the detector. The experiment will be the largest underground water Cherenkov detector in the world and will be instrumented with new technology photosensors, faster and with higher quantum efficiency than the ones in Super-Kamiokande. The science that will be developed will be able to shape the future theoretical framework and generations of experiments. Hyper-Kamiokande will be able to measure with the highest precision the leptonic CP violation that could explain the baryon asymmetry in the Universe. The experiment also has a demonstrated excellent capability to search for proton decay, providing a significant improvement in discovery sensitivity over current searches for the proton lifetime. The atmospheric neutrinos will allow to determine the neutrino mass ordering and, together with the beam, able to precisely test the three-flavour neutrino oscillation paradigm and search for new phenomena. A strong astrophysical programme will be carried out at the experiment that will detect supernova neutrinos and will measure precisely solar neutrino oscillation

    Physics Potentials with the Second Hyper-Kamiokande Detector in Korea

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    We have conducted sensitivity studies on an alternative configuration of the Hyper-Kamiokande experiment by locating the 2nd Hyper-Kamiokande detector in Korea at ∌\sim1100− -\ 1300 km baseline. Having two detectors at different baselines improves sensitivity to leptonic CP violation, neutrino mass ordering as well as nonstandard neutrino interactions. There are several candidate sites in Korea with greater than 1 km high mountains ranged at an 1−-3 degree off-axis angle. Thanks to larger overburden of the candidate sites in Korea, low energy physics, such as solar and supernova neutrino physics as well as dark matter search, is expected to be improved. In this paper sensitivity studies on the CP violation phase and neutrino mass ordering are performed using current T2K systematic uncertainties in most cases. We plan to improve our sensitivity studies in the near future with better estimation of our systematic uncertainties

    Physics potentials with the second Hyper-Kamiokande detector in Korea

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    Hyper-Kamiokande consists of two identical water-Cherenkov detectors of total 520 kt, with the first one in Japan at 295 km from the J-PARC neutrino beam with 2.5 degrees off-axis angles (OAAs), and the second one possibly in Korea at a later stage. Having the second detector in Korea would benefit almost all areas of neutrino oscillation physics, mainly due to longer baselines. There are several candidate sites in Korea with baselines of 1000-1300 km and OAAs of 1 degrees-3 degrees. We conducted sensitivity studies on neutrino oscillation physics for a second detector, either in Japan (JD x 2) or Korea (JD + KD), and compared the results with a single detector in Japan. Leptonic charge-parity (CP) symmetry violation sensitivity is improved, especially when the CP is non-maximally violated. The larger matter effect at Korean candidate sites significantly enhances sensitivities to non-standard interactions of neutrinos and mass ordering determination. Current studies indicate the best sensitivity is obtained at Mt. Bisul (1088 km baseline, 1.3 degrees OAA). Thanks to a larger (1000 m) overburden than the first detector site, clear improvements to sensitivities for solar and supernova relic neutrino searches are expected

    Evaluation of suitable conditions for natural regeneration of Picea jezoensis on fallen logs

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    The abundance of Picea jezoensis, a major conifer tree species in Hokkaido, northern Japan, is currently decreasing due to the lack of suitable conditions for recruitment and intensive harvests. To contribute to the development of sustainable forest management in Hokkaido, suitable substrates for natural regeneration of P. jezoensis were evaluated during a 4-year experimental study using seed additions in a natural coniferous forest. The environmental conditions (moss height, log hardness, extent of the humus layer, and light conditions) of fallen logs were measured. Moss height was categorized into three groups: 0 mm, Bark; 0 - 20 mm, Mthin; and ≄ 20 mm, Mthick. The germination rates of P. jezoensis were highest on Mthin, intermediate on Bark, and lowest on Mthick. Survival rates were low on Mthick, did not differ between Bark and Mthin, and increased with enhanced light. Growth increased with light, but the root allocation of seedlings was not affected by any environmental conditions. From these results, we determined that fallen logs with no or thin moss cover under bright conditions were most suitable for P. jezoensis regeneration. We discussed the generality of our results in relation to a co-occurring tree species in Hokkaido and the results of other regions

    Effects of surface and light conditions of fallen logs on the emergence and survival of coniferous seedlings and saplings

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    We surveyed the germination number (N cs) of 2-year and a 1-year survival of Abies sachalinensis and Picea jezoensis seedlings and saplings on 29 fallen logs from 2004 to 2005 in a natural coniferous forest in Hokkaido, northern Japan, in relation to the surface and light conditions of fallen logs. Moss height (H moss), log hardness (Hardness), and the area of fallen log (Area) were measured as the surface conditions by each 1-m block from bottom to top of all fallen logs. The relative photosynthetic photon flux density (rPPFD) 10 cm above the tallest seedling in each block was measured as the light condition. In addition, the height of the tallest seedling or sapling in each block (H max), the difference between a height of each seedling and sapling and the H max (Shading), and a height of seedlings and saplings in 2004 (H ini) were considered. N cs of A. sachalinensis was affected by Hardness and Area, whereas N cs of P. jezoensis was affected by H moss, Hardness, Area, H max, and rPPFD. The survival of seedlings (height < 5 cm) and saplings (5 cm ≀ height < 50 cm) were affected by H ini, rPPFD, and shading for both species. However, the survival of P. jezoensis saplings was more sensitive to decrease in rPPFD and increase of shading than that of A. sachalinensis. Therefore, seedling emergence was influenced by surface conditions, whereas survival was affected by light conditions. Furthermore, P. jezoensis emergence and survival were more sensitive to surface and light conditions than that of A. sachalinensis
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