Search

Abstract JSNS $$^2$$ 2 (J-PARC Sterile Neutrino Search at J-PARC Spallation Neutron Source) is an experiment that searches for sterile neutrinos via the observation of $$\bar{\nu }_{\mu } \rightarrow \bar{\nu }_{e}$$ ν ¯ μ → ν ¯ e appearance oscillations using muon decay-at-rest neutrinos. The JSNS $$^2$$ 2 experiment performed data taking from 2021. In this manuscript, a study of the accidental background is presented. The rate of the accidental background is ( $$9.29\pm 0.39) \times 10^{-8}$$ 9.29 ± 0.39 ) × 10 - 8 /spill with 0.75 MW beam power and comparable to the expected number of signal events.

Abstract JSNS $$^2$$ 2 (J-PARC Sterile Neutrino Search at J-PARC Spallation Neutron Source) is an experiment that is searching for sterile neutrinos via the observation of $${\bar{\nu }}_{\mu } \rightarrow {\bar{\nu }}_{e}$$ ν ¯ μ → ν ¯ e appearance oscillations using muon decay-at-rest neutrinos. Before dedicated data taking in the first-half of 2021, we performed a commissioning run for 10 days in June 2020. Using the data obtained in this commissioning run, in this paper, we present an estimate of the correlated background which imitates the $${\bar{\nu }}_{e}$$ ν ¯ e signal in a sterile neutrino search. In addition, in order to demonstrate future prospects of the JSNS $$^2$$ 2 experiment, possible pulse shape discrimination improvements towards reducing cosmic ray induced fast neutron background are described.

A total of 2 to 3 million tons of spring water flushes out from the foot of Mt. Fuji, the largest volcanic mountain in Japan. Based on the concept of piston flow transport, residence time of stored groundwater at Mt. Fuji was estimated at ∼ 15–30 years by the 36Cl ∕ Cl ratio (Tosaki et al., 2011). This range, however, represents the average residence time of groundwater that was mixed before it flushed out. To elucidate the route of groundwater in a given system, we determined signatures of direct impacts of rainfall on groundwater, using microbial, stable isotopic (δ18O), and chemical analyses (concentration of silica). Chemical analysis of the groundwater gave an average value of the water, which was already mixed with waters from various sources and routes in the subsurface environment. The microbial analysis suggested locations of water origin and paths. In situ observation during four rainfall events revealed that the stable oxygen isotopic signature obtained from spring water (at 726 m a.s.l., site SP-0 m) and shallow groundwater (at 150 m a.s.l., site GW-42 m), where the average recharge height from rainfall was 1700–1800 m, became greater than values observed prior to a torrential rain producing more than 300 mm of precipitation. The concentration of silica decreased after this event. In addition, the abundance of Bacteria in spring water increased, suggesting the influence of heavy rain. Such changes did not appear when rainfall was less than 100 mm per event. The above findings indicate a rapid flow of rain through the shallow part of the aquifer, which appeared within a few weeks of torrential rain extracting abundant microbes from soil in the studied geologic setting. Interestingly, we found that after the torrential rain, the abundance of Archaea increased in the deep groundwater at site GW-550 m, ∼ 12 km downstream of SP-0 m. However, chemical parameters did not show any change after the event. This suggests that strengthened piston flow caused by the heavy rain transported archaeal particles from the geologic layer along the groundwater route. This finding was supported by changes in constituents of Archaea, dominated by Halobacteriales and Methanobacteriales, which were not seen from other observations. Those two groups of Archaea are believed to be relatively tightly embedded in the geologic layer and were extracted from the environment to the examined groundwater through enforced piston flow. Microbial DNA can thus give information about the groundwater route, which may not be shown by analysis of chemical materials dissolved in the groundwater.

The genetic diversity of native chicken populations from Myanmar, Thailand, and Laos was examined by using 102 insertion and/or deletion (indels) markers. Most of the indels loci were polymorphic (71% to 96%), and the genetic variability was similar in all populations. The average observed heterozygosities (HO) and expected heterozygosities (HE) ranged from 0.205 to 0.263 and 0.239 to 0.381, respectively. The coefficients of genetic differentiation (Gst) for all cumulated populations was 0.125, and the Thai native chickens showed higher Gst (0.088) than Myanmar (0.041) and Laotian (0.024) populations. The pairwise Fst distances ranged from 0.144 to 0.308 among populations. A neighbor-joining (NJ) tree, using Nei’s genetic distance, revealed that Thai and Laotian native chicken populations were genetically close, while Myanmar native chickens were distant from the others. The native chickens from these three countries were thought to be descended from three different origins (K = 3) from STRUCTURE analysis. Genetic admixture was observed in Thai and Laotian native chickens, while admixture was absent in Myanmar native chickens.

The VHF electromagnetic noise intensity data at several stations in the Tohoku area of Japan during the period of a rather large (with magnitude of 7.2) earthquake (Miyagi-ken oki earthquake) taken place on 16 August 2005, are analyzed by means of different fractal analysis methods, including (1) spectral slope estimation, (2) multi-fractal detrended fluctuation analysis and (3) multi-fractal wavelet transform modulus maxima method. It seems to the authors that there is no definite analysis method for the analysis of any seismogenic phenomenon, so that the only way we have to take, is to apply different methods to the same data for the detailed comparison of the results. This comparison enables us to deduce the properties commonly observed by the above methods. Because the most important feature common to these three methods, is that significant changes in fractal scaling characteristics are observed just during the earthquake (mainly before the earthquake) only at one station of Kunimi. Finally, we can come to the definite conclusion on the self-organization of VHF emissions only at one station in the present case.

Nonlinear cascade scattering of intense, tightly focused laser pulses by relativistic electrons is studied numerically in the classical approximation including radiation damping for the quantum parameter ⟨ℏω_{x ray}⟩/ϵ

Short-lived, ∼10 ps, deep plasma channels, with their lengths of ∼1 mm and diameters of ∼20 μm, are observed and characterized in Ar gas jets irradiated by moderate intensity, ∼10^{15–16} W/cm^{2}, laser pulses with a duration from subpicosecond to several picoseconds. The channels, upon 2D particle-in-cell simulations including ionization, fit well in the guiding of high intensity femtosecond laser pulses and, therefore, in laser wakefield acceleration with a controllable electron self-injection.

Introduction: We reported increased spleen tyrosine kinase (SYK) expression in kidney biopsies of patients with IgA nephropathy (IgAN) and that inhibition of SYK reduces inflammatory cytokines production from IgA stimulated mesangial cells. Methods: This study was a double-blind, randomized, placebo-controlled phase 2 trial of fostamatinib (an oral SYK inhibitor) in 76 patients with IgAN. Patients were randomized to receive placebo, fostamatinib at 100 mg or 150 mg twice daily for 24 weeks on top of maximum tolerated dose of renin-angiotensin system inhibitors. The primary end point was reduction of proteinuria. Secondary end points included change from baseline in estimated glomerular filtration rate (eGFR) and kidney histology. Results: Although we could not detect significant reduction in proteinuria with fostamatinib overall, in a predetermined subgroup analysis, there was a trend for dose-dependent reduction in median proteinuria (from baseline to 24 weeks by 14%, 27%, and 36% in the placebo, fostamatinib 100 mg, and 150 mg groups, respectively) in patients with baseline urinary protein-to-creatinine ratios (UPCR) more than 1000 mg/g. Kidney function (eGFR) remained stable in all groups. Fostamatinib was well-tolerated. Side effects included diarrhea, hypertension, and increased liver enzymes. Thirty-nine patients underwent repeat biopsy showing reductions in SYK staining associated with therapy at low dose (−1.5 vs. 1.7 SYK+ cells/glomerulus in the placebo group, P < 0.05). Conclusions: There was a trend toward reduction in proteinuria with fostamatinib in a predefined analysis of high risk patients with IgAN despite maximal care, as defined by baseline UPCR greater than 1000 mg/g. Further study may be warranted.

In association with a large solar flare on November 7, 2004, the solar neutron detectors located at Mt. Chacaltaya (5,250 m) in Bolivia and Mt. Sierra Negra (4,600 m) in Mexico recorded very interesting events. In order to explain these events, we have performed a calculation solving the equation of motion of anti-protons inside the magnetosphere. Based on these results, the Mt. Chacaltaya event may be explained by the detection of solar neutrons, while the Mt. Sierra Negra event may be explained by the first detection of very high energy solar neutron decay protons (SNDPs) around 6 GeV.

Abstract Antibody mediated rejection is a major cause of renal allograft loss. Circulating preformed donor specific antibodies (DSA) can result as a consequence of blood transfusion, pregnancy or prior transplantation. Current treatment strategies are limited due to partial or transient efficacy, adverse side-effects or patient unsuitability. Previous in vivo studies exploring autoimmune diseases have shown that spleen tyrosine kinase (SYK) signalling is involved in the development of pathogenic autoantibody. The role of SYK in allogenic antibody production is unknown, and we investigated this in a rodent model of sensitization, established by the transfusion of F344 whole blood into LEW rats. Two-week treatment of sensitized rats with selective SYK inhibitor fostamatinib strongly blocked circulating DSA production without affecting overall total immunoglobulin levels, and inhibition was sustained up to 5 weeks post-completion of the treatment regimen. Fostamatinib treatment did not affect mature B cell subset or plasma cell levels, which remained similar between non-treated controls, vehicle treated and fostamatinib treated animals. Our data indicate fostamatinib may provide an alternative therapeutic option for patients who are at risk of sensitization following blood transfusion while awaiting renal transplant.

Leukemic stem cells (LSCs) in chronic myeloid leukemia are resistant to imatinib and therefore are a cause of relapse. The authors show that IRAK1/4-NF-κB-PD-L1 signaling is critical to mediate imatinib resistance in LSCs and that combining imatinib with blocking this signalling pathway can eliminate LSCs.

Superconducting parametrons in the single-photon Kerr regime, also called KPOs, have been attracting increasing attention in terms of their applications to quantum annealing and universal quantum computation. It is of practical importance to obtain information of superconducting parametrons operating under an oscillating pump field. Spectroscopy can provide information of a superconducting parametron under examination, such as energy level structure, and also useful information for calibration of the pump field. We theoretically study the reflection spectroscopy of superconducting parametrons, and develop a method to obtain the reflection coefficient. We present formulae of the reflection coefficient, the nominal external and the internal decay rates, and examine the obtained spectra. It is shown that the difference of the populations of energy levels manifests itself as a dip or peak in the amplitude of the reflection coefficient, and one can directly extract the coupling strength between the energy levels by measuring the nominal decay rates when the pump field is sufficiently large.