112 research outputs found

    Discussion of Recent Decisions

    Get PDF

    Solving the degeneracy of the lepton-flavor mixing angle theta_atm by the T2KK two detector neutrino oscillation experiment

    Get PDF
    If the atmospheric neutrino oscillation amplitude, sin^2 2theta_atm is not maximal, there is a two fold ambiguity in the neutrino parameter space: sin^2 theta_atm>0.5 or sin^2 theta_atm<0.5. In this article, we study the impact of this degeneracy, the so-called octant degeneracy, on the T2KK experiment, which is a proposed extension of the T2K (Tokai-to-Kaimoka) neutrino oscillation experiment with an additional water cherenkov detector placed in Korea. We find that the degeneracy between sin^2 theta_atm= 0.40 and 0.60 can be resolved at the 3sigma level for sin^2 2theta_rct>0.12 (0.08) for the optimal combination of a 3.0^circ off-axis beam (OAB) at SK (L=295km) and a 0.5^circ OAB at L=1000km with a far detector of 100kton volume, after 5 years of exposure with 1.0(5.0) time 10^21 POT/year, if the hierarchy is normal. We also study the influence of the octant degeneracy on the capability of T2KK experiment to determine the mass hierarchy and the leptonic CP phase. The capability of rejecting the wrong mass hierarchy grows with increasing sin^2 theta_atm when the hierarchy is normal, whereas it is rather insensitive to sin^2 theta_atm for the inverted hierarchy. We also find that the 1sigma allowed region of the CP phase is not affected significantly even when the octant degeneracy is not resolved. All our results are obtained for the 22.5 kton Super-Kamiokande as a near detector and without an anti-neutrino beam.Comment: 23 pages, 9 figure

    Are we working towards global research priorities for management and conservation of sea turtles?

    Get PDF
    In 2010, an international group of 35 sea turtle researchers refined an initial list of more than 200 research questions into 20 metaquestions that were considered key for management and conservation of sea turtles. These were classified under 5 categories: reproductive biology, biogeography, population ecology, threats and conservation strategies. To obtain a picture of how research is being focused towards these key questions, we undertook a systematic review of the peer-reviewed literature (2014 and 2015) attributing papers to the original 20 questions. In total, we reviewed 605 articles in full and from these 355 (59%) were judged to substantively address the 20 key questions, with others focusing on basic science and monitoring. Progress to answering the 20 questions was not uniform, and there were biases regarding focal turtle species, geographic scope and publication outlet. Whilst it offers some meaningful indications as to effort, quantifying peer-reviewed literature output is ob viously not the only, and possibly not the best, metric for understanding progress towards informing key conservation and management goals. Along with the literature review, an international group based on the original project consortium was assigned to critically summarise recent progress towards answering each of the 20 questions. We found that significant research is being expended towards global priorities for management and conservation of sea turtles. Although highly variable, there has been significant progress in all the key questions identified in 2010. Undertaking this critical review has highlighted that it may be timely to undertake one or more new prioritizing exercises. For this to have maximal benefit we make a range of recommendations for its execution. These include a far greater engagement with social sciences, widening the pool of contributors and focussing the questions, perhaps disaggregating ecology and conservatio

    Recoilless Resonant Absorption of Monochromatic Neutrino Beam for Measuring Delta m^2_{31} and theta_{13}

    Full text link
    We discuss, in the context of precision measurement of Delta m^2_{31} and theta_{13}, physics capabilities enabled by the recoilless resonant absorption of monochromatic antineutrino beam enhanced by the M\"ossbauer effect recently proposed by Raghavan. Under the assumption of small relative systematic error of a few tenth of percent level between measurement at different detector locations, we give analytical and numerical estimates of the sensitivities to Delta m^2_{31} and sin^2 2theta_{13}. The accuracies of determination of them are enormous; The fractional uncertainty in Delta m^2_{31} achievable by 10 point measurement is 0.6% (2.4%) for sin^2 2theta_{13} = 0.05, and the uncertainty of sin^2 2theta_{13} is 0.002 (0.008) both at 1 sigma CL with the optimistic (pessimistic) assumption of systematic error of 0.2% (1%). The former opens a new possibility of determining the neutrino mass hierarchy by comparing the measured value of Delta m^2_{31} with the one by accelerator experiments, while the latter will help resolving the theta_{23} octant degeneracy.Comment: 23 pages, 3 figures, version to appear in New Journal of Physic

    Protein Content and Oil Composition of Almond from Moroccan Seedlings: Genetic Diversity, Oil Quality and Geographical Origin

    Get PDF
    The protein and oil content and the fatty acid profile of the kernels of selected almond genotypes from four different Moroccan regions were determined in order to evaluate the kernel quality of the plant material of these different regions. The ranges of oil content (48.7–64.5 % of kernel DW), oleic (61.8–80.2 % of total oil), linoleic (11.4–27.0 %), palmitic (5.6–7.7 %), stearic (1.3–3.1 %), and palmitoleic (0.4–0.9 %) acid percentages agreed with previous results of other almond genotypes, but the protein content (14.1–35.1 % of kernel DW) showed that some genotypes had higher values than any previously recorded in almond. Some genotypes from mountainous regions showed kernels with very high oil content as well as high and consistent oleic and linoleic ratio, establishing a possible differentiation according to the geographical origin. These differences may allow establishing a geographical denomination for almond products. In terms of genetic diversity, oleic and linoleic acids were confirmed to be the most variable components of almond oil chemical composition among genotypes. Additionally, the genotypes with extreme favorable values, such as high protein content, could be incorporated into an almond breeding program aiming at an increase in kernel quality.Peer ReviewedPrunus amygdalusProtein contentOil contentFatty acidsQualityGenetic resourcesBreedingPublishe

    Expression analysis of Clavata1-like and Nodulin21-like genes from Pinus sylvestris during ectomycorrhiza formation

    Get PDF
    The ecology and physiology of ectomycorrhizal (EcM) symbiosis with conifer trees are well documented. In comparison, however, very little is known about the molecular regulation of these associations. In an earlier study, we identified three EcM-regulated Pinus expressed sequence tags (EST), two of which were identified as homologous to the Medicago truncatula nodulin MtN21. The third EST was a homologue to the receptor-like kinase Clavata1. We have characterized the expression patterns of these genes and of auxin- and mycorrhiza-regulated genes after induction with indole-3-butyric acid in Pinus sylvestris and in a time course experiment during ectomycorrhizal initiation with the co-inoculation of 2,3,5-triiodobenzoic acid, an auxin transport inhibitor. Our results suggest that different P. sylvestris nodulin homologues are associated with diverse processes in the root. The results also suggest a potential role of the Clv1-like gene in lateral root initiation by the ectomycorrhizal fungus

    Green turtles (Chelonia mydas) foraging at Arvoredo Island in Southern Brazil: Genetic characterization and mixed stock analysis through mtDNA control region haplotypes

    Get PDF
    We analyzed mtDNA control region sequences of green turtles (Chelonia mydas) from Arvoredo Island, a foraging ground in southern Brazil, and identified eight haplotypes. Of these, CM-A8 (64%) and CM-A5 (22%) were dominant, the remainder presenting low frequencies (< 5%). Haplotype (h) and nucleotide (π) diversities were 0.5570 ± 0.0697 and 0.0021 ± 0.0016, respectively. Exact tests of differentiation and AMOVA ΊST pairwise values between the study area and eight other Atlantic foraging grounds revealed significant differences in most areas, except Ubatuba and Rocas/Noronha, in Brazil (p > 0.05). Mixed Stock Analysis, incorporating eleven Atlantic and one Mediterranean rookery as possible sources of individuals, indicated Ascension and Aves islands as the main contributing stocks to the Arvoredo aggregation (68.01% and 22.96%, respectively). These results demonstrate the extensive relationships between Arvoredo Island and other Atlantic foraging and breeding areas. Such an understanding provides a framework for establishing adequate management and conservation strategies for this endangered species
    • 

    corecore