Invasive fusariosis (IF) is a frequently fatal disease as there are few antifungals to treat it, making the prevention of IF crucial. However, fusarium infections have not been as thoroughly studied ...as other common pathogenic fungi such as Aspergillus or Candida.
To investigate the epidemiology of IF in patients with haematological diseases in Japan and to elucidate the infectious route of fusarium infection.
We retrospectively analysed 29 IF cases in patients with haematological diseases from 2009 to 2019 in Japan. To discover the infectious source of IF, we performed an indoor environment survey targeted at indoor air and drain outlets in medical institutions and residences using culture-based and metagenomic methods. Finally, we performed aerosol- and droplet-mediated dispersion studies.
The epidemiological study showed that the primary pathogen of IF was Fusarium solani species complex (FSSC), and the most common species was Fusarium petroliphilum. Most patients were likely to develop IF during hospitalization. A fusarium culture was positive in 26 of 72 drain samples. Few fusarium were detected from air samples; by contrast, 29 of 108 isolates from the drain outlets were identified as fusarium. Furthermore, similar results were obtained in the metagenomic analysis. Interestingly, species belonging to FSSC were isolated from indoor drain outlets, which was similar to those of the IF patients. In the droplet-mediated dispersion study, eight to 17 colonies of fusarium were isolated.
Our study indicates that causative Fusarium spp. could inhabit drain outlets in hospitals or residences, and droplet-mediated fusarium dispersion is a potential cause of IF.
A new muon beam line, the muon science innovative channel, was set up at the Research Center for Nuclear Physics, Osaka University, in Osaka, Japan, using the 392 MeV proton beam impinging on a ...target. The production of an intense muon beam relies on the efficient capture of pions, which subsequently decay to muons, using a novel superconducting solenoid magnet system. After the pion-capture solenoid, the first 36° of the curved muon transport line was commissioned and the muon flux was measured. In order to detect muons, a target of either copper or magnesium was placed to stop muons at the end of the muon beam line. Two stations of plastic scintillators located upstream and downstream from the muon target were used to reconstruct the decay spectrum of muons. In a complementary method to detect negatively charged muons, the x-ray spectrum yielded by muonic atoms in the target was measured in a germanium detector. Measurements, at a proton beam current of 6 pA, yielded (10.4±2.7)×105muons per watt of proton beam power (μ+ and μ− ), far in excess of other facilities. At full beam power (400 W), this implies a rate of muons of (4.2±1.1)×108muonss−1 , among the highest in the world. The number of μ− measured was about a factor of 10 lower, again by far the most efficient muon beam produced. The setup is a prototype for future experiments requiring a high-intensity muon beam, such as a muon collider or neutrino factory, or the search for rare muon decays which would be a signature for phenomena beyond the Standard Model of particle physics. Such a muon beam can also be used in other branches of physics, nuclear and condensed matter, as well as other areas of scientific research.
JSNS Formula omitted (J-PARC Sterile Neutrino Search at J-PARC Spallation Neutron Source) is an experiment that is searching for sterile neutrinos via the observation of Formula omitted 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 Formula omitted signal in a sterile neutrino search. In addition, in order to demonstrate future prospects of the JSNS Formula omitted experiment, possible pulse shape discrimination improvements towards reducing cosmic ray induced fast neutron background are described.
JSNS
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
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
ν
¯
e
signal in a sterile neutrino search. In addition, in order to demonstrate future prospects of the JSNS
2
experiment, possible pulse shape discrimination improvements towards reducing cosmic ray induced fast neutron background are described.
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.
Abstract
Numerous particle physics experiments utilize gadolinium (Gd), a rare earth element with the most significant neutron capture cross-section among all elements, to detect anti-neutrinos via ...inverse beta decays or to remove neutron-induced background events. For example, to load Gd into water Cherenkov detectors, Gd2(SO4)3 · 8H2O is dissolved and rare event search experiments are required to screen for radioactive impurities in Gd2(SO4)3 · 8H2O before dissolution. This study developed a new method to rapidly measure the radium-226 (226Ra) concentration in Gd2(SO4)3 · 8H2O. This method requires only 3 days to measure a batch of samples, as opposed to the usual method using high-purity germanium detectors, which takes approximately 20 days after arrival. The detection limit for the measurement of 226Ra concentration in Gd2(SO4)3 · 8H2O is 0.43 mBq/kg. This method has been already used for Gd2(SO4)3 · 8H2O screening at the Super-Kamiokande Gd (SK-Gd) project, and it can be applied to future experiments.
In order to clarify the gamma -efficiency dependency of 4 pi beta - gamma efficiency functions, a series of 4 pi beta - gamma efficiency extrapolation measurements of a super(134)Cs source were ...carried out for a wide variety of gamma -geometries using a 4 pi beta (PS)-4 pi gamma detector configuration. As the source is situated in the plastic scintillator (PS) beta -detector, the gamma -efficiency of the system can be readily changed by extracting the beta -detector from the well-hole in a series of stages. For data acquisition and analyses, a list-mode two-parameter data acquisition system was employed. The forms of the extrapolation curves were monitored with decreasing gamma -geometry, eventually exhibiting a similar behavior to those obtained in a usual 4 pi beta - gamma coincidence counting system. The experimental results and considerations suggested that the gamma -geometry dependency of the efficiency functions were due to summing effects in the gamma -channel, and some qualitative remarks on the form of the extrapolation functions are given.
In order to clarify the γ-efficiency dependency of 4πβ-γ efficiency functions, a series of 4πβ-γ efficiency extrapolation measurements of a 134Cs source were carried out for a wide variety of ...γ-geometries using a 4πβ(PS)-4πγ detector configuration. As the source is situated in the plastic scintillator (PS) β-detector, the γ-efficiency of the system can be readily changed by extracting the β-detector from the well-hole in a series of stages. For data acquisition and analyses, a list-mode two-parameter data acquisition system was employed. The forms of the extrapolation curves were monitored with decreasing γ-geometry, eventually exhibiting a similar behavior to those obtained in a usual 4πβ-γ coincidence counting system. The experimental results and considerations suggested that the γ-geometry dependency of the efficiency functions were due to summing effects in the γ-channel, and some qualitative remarks on the form of the extrapolation functions are given.
Abstract
The Sterile Neutrino Search at the J-PARC Spallation Neutron Source (JSNS$^2$) experiment aims to search for sterile neutrino oscillations using a neutrino beam from muon decays at rest. The ...JSNS$^2$ detector contains 17 tons of 0.1$\%$ gadolinium (Gd) loaded liquid scintillator (LS) as a neutrino target. Detector construction was completed in the spring of 2020. A slow control and monitoring system (SCMS) was implemented for reliable control and quick monitoring of the detector operational status and environmental conditions. It issues an alarm if any of the monitored parameters exceed a preset acceptable range. The SCMS monitors the high voltage of the photomultiplier tubes, the LS level in the detector, possible LS overflow and leakage, the temperature and air pressure in the detector, the humidity of the experimental hall, and the LS flow rate during filling and extraction. An initial 10 days of data-taking with a neutrino beam was done following a successful commissioning of the detector and SCMS in 2020 June. In this paper, we present a description of the assembly and installation of the SCMS and its performance.
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