Discovery of nucleotide polymorphisms in the Musa gene pool by Ecotilling

Musa (banana and plantain) is an important genus for the global export market and in local markets where it provides staple food for approximately 400 million people. Hybridization and polyploidization of several (sub)species, combined with vegetative propagation and human selection have produced a complex genetic history. We describe the application of the Ecotilling method for the discovery and characterization of nucleotide polymorphisms in diploid and polyploid accessions of Musa. We discovered over 800 novel alleles in 80 accessions. Sequencing and band evaluation shows Ecotilling to be a robust and accurate platform for the discovery of polymorphisms in homologous and homeologous gene targets. In the process of validating the method, we identified two single nucleotide polymorphisms that may be deleterious for the function of a gene putatively important for phototropism. Evaluation of heterozygous polymorphism and haplotype blocks revealed a high level of nucleotide diversity in Musa accessions. We further applied a strategy for the simultaneous discovery of heterozygous and homozygous polymorphisms in diploid accessions to rapidly evaluate nucleotide diversity in accessions of the same genome type. This strategy can be used to develop hypotheses for inheritance patterns of nucleotide polymorphisms within and between genome types. We conclude that Ecotilling is suitable for diversity studies in Musa, that it can be considered for functional genomics studies and as tool in selecting germplasm for traditional and mutation breeding approaches

A Water Cherenkov Test Beam Experiment for Hyper-Kamiokande and Future Large-scale Water-based Detectors

Water Cherenkov and water-based particle detector technologies are used to realize multi-kiloton scale experiments such as the currently operating Super-Kamiokande experiment, the planned Hyper-Kamiokande experiment and the proposed THEIA detector and ESSnuSB detectors. These experiments are operated or proposed to study a broad range of physics including neutrino oscillations, nucleon decay, dark matter and neutrinoless double beta decay. The neutrino oscillations program will also include kiloton scale near or intermediate detectors used to study neutrino production and interactions in the absence of neutrino oscillations, such as the Hyper-K Intermediate Water Cherenkov Detector (IWCD). Realization of these physics programs will require new detector technologies and percent level calibration of detector responses and models of physics processes within the detector. Here we describe our intent to propose a 50~ton scale Water Cherenkov test experiment (WCTE) to be deployed in a North or East test beam experimental area. The experiment will include a secondary target located just upstream of the experiment in order to produce very low energy particle fluxes, including charged pions. The WCTE program will be carried out with the following objectives: - Operate and understand the performance of new detector technologies such as multi-PMTs, dichroicon wavelength-separating cones and water-based liquid scintillator in a fully integrated detector. - Study the performance of a <1 kiloton scale water Cherenkov detector with known particle fluxes, and test and develop calibration systems necessary for accurate modeling of a detector of this size. - Measure important physics processes for the modeling of water Cherenkov detector responses, including high-angle Cherenkov light production, pion scattering and absorption, and secondary neutron production in hadron scattering. We aim to start operation of the water Cherenkov test experiment in 2021-2022

J-PARC neutrino beamline upgrade technical design report

In this document, technical details of the upgrade plan of the J-PARC neutrino beamline for the extension of the T2K experiment are described. T2K has proposed to accumulate data corresponding to $2\times{}10^{22}$ protons-on-target in the next decade, aiming at an initial observation of CP violation with $3\sigma$ or higher significance in the case of maximal CP violation. Methods to increase the neutrino beam intensity, which are necessary to achieve the proposed data increase, are described

Indication of electron neutrino appearance from an accelerator-produced off-axis muon neutrino beam.

The T2K experiment observes indications of ν(μ) → ν(e) appearance in data accumulated with 1.43×10(20) protons on target. Six events pass all selection criteria at the far detector. In a three-flavor neutrino oscillation scenario with |Δm(23)(2)| = 2.4×10(-3)  eV(2), sin(2)2θ(23) = 1 and sin(2)2θ(13) = 0, the expected number of such events is 1.5±0.3(syst). Under this hypothesis, the probability to observe six or more candidate events is 7×10(-3), equivalent to 2.5σ significance. At 90% C.L., the data are consistent with 0.03(0.04) < sin(2)2θ(13) < 0.28(0.34) for δ(CP) = 0 and a normal (inverted) hierarchy