Direct Measurement of the Spectral Structure of Cosmic-Ray Electrons+Positrons in the TeV Region with CALET on the International Space Station

Detailed measurements of the spectral structure of cosmic-ray electrons and positrons from 10.6 GeV to 7.5 TeV are presented from over 7 years of observations with the CALorimetric Electron Telescope (CALET) on the International Space Station. The instrument, consisting of a charge detector, an imaging calorimeter, and a total absorption calorimeter with a total depth of 30 radiation lengths at normal incidence and a fine shower imaging capability, is optimized to measure the all-electron spectrum well into the TeV region. Because of the excellent energy resolution (a few percent above 10 GeV) and the outstanding e/p separation (10^{5}), CALET provides optimal performance for a detailed search of structures in the energy spectrum. The analysis uses data up to the end of 2022, and the statistics of observed electron candidates has increased more than 3 times since the last publication in 2018. By adopting an updated boosted decision tree analysis, a sufficient proton rejection power up to 7.5 TeV is achieved, with a residual proton contamination less than 10%. The observed energy spectrum becomes gradually harder in the lower energy region from around 30 GeV, consistently with AMS-02, but from 300 to 600 GeV it is considerably softer than the spectra measured by DAMPE and Fermi-LAT. At high energies, the spectrum presents a sharp break around 1 TeV, with a spectral index change from -3.15 to -3.91, and a broken power law fitting the data in the energy range from 30 GeV to 4.8 TeV better than a single power law with 6.9 sigma significance, which is compatible with the DAMPE results. The break is consistent with the expected effects of radiation loss during the propagation from distant sources (except the highest energy bin). We have fitted the spectrum with a model consistent with the positron flux measured by AMS-02 below 1 TeV and interpreted the electron+positron spectrum with possible contributions from pulsars and nearby sources. Above 4.8 TeV, a possible contribution from known nearby supernova remnants, including Vela, is addressed by an event-by-event analysis providing a higher proton-rejection power than a purely statistical analysis.

Changes in the Endophytic Bacterial Community of Brassica rapa after Application of Systemic Insecticides

Insecticides not only control target pests but also adversely affect non-target communities including humans, animals, and microbial communities in host plants and soils. The effect of insecticides on non-target communities, especially endophytic bacterial communities, remains poorly understood. Two phases of treatments were conducted to compare the trends in endophytic bacterial response after insecticide application. Endophytic bacteria were isolated at 2 and 4 weeks after germination. Most insecticide treatments showed a declining trend in bacterial diversity and abundance, whereas an increasing trend was observed in the control. Therefore, insecticide use negatively affected non-target endophytic bacterial communities. Bacillus spp. was mostly dominant in the early stage in both insecticide treatment and control groups. Nevertheless, in the matured stage, mostly bacteria including Pseudomonas spp., Priestia spp. were dominant in groups treated with high insecticide concentrations. Therefore, plants can regulate and moderate their microbiome during their lifecycle depending on surrounding environmental conditions.

Erratum: Charge-Sign Dependent Cosmic-Ray Modulation Observed with the Calorimetric Electron Telescope on the International Space Station [Phys. Rev. Lett. 130, 211001 (2023)]

This corrects the article DOI: 10.1103/PhysRevLett.130.211001.

Charge-Sign Dependent Cosmic-Ray Modulation Observed with the Calorimetric Electron Telescope on the International Space Station

We present the observation of a charge-sign dependent solar modulation of galactic cosmic rays (GCRs) with the Calorimetric Electron Telescope onboard the International Space Station over 6 yr, corresponding to the positive polarity of the solar magnetic field. The observed variation of proton count rate is consistent with the neutron monitor count rate, validating our methods for determining the proton count rate. It is observed by the Calorimetric Electron Telescope that both GCR electron and proton count rates at the same average rigidity vary in anticorrelation with the tilt angle of the heliospheric current sheet, while the amplitude of the variation is significantly larger in the electron count rate than in the proton count rate. We show that this observed charge-sign dependence is reproduced by a numerical "drift model" of the GCR transport in the heliosphere. This is a clear signature of the drift effect on the long-term solar modulation observed with a single detector.

Direct Measurement of the Cosmic-Ray Helium Spectrum from 40 GeV to 250 TeV with the Calorimetric Electron Telescope on the International Space Station

We present the results of a direct measurement of the cosmic-ray helium spectrum with the CALET instrument in operation on the International Space Station since 2015. The observation period covered by this analysis spans from October 13, 2015, to April 30, 2022 (2392 days). The very wide dynamic range of CALET allowed for the collection of helium data over a large energy interval, from ∼40  GeV to ∼250  TeV, for the first time with a single instrument in low Earth orbit. The measured spectrum shows evidence of a deviation of the flux from a single power law by more than 8σ with a progressive spectral hardening from a few hundred GeV to a few tens of TeV. This result is consistent with the data reported by space instruments including PAMELA, AMS-02, and DAMPE and balloon instruments including CREAM. At higher energy we report the onset of a softening of the helium spectrum around 30 TeV (total kinetic energy). Though affected by large uncertainties in the highest energy bins, the observation of a flux reduction turns out to be consistent with the most recent results of DAMPE. A double broken power law is found to fit simultaneously both spectral features: the hardening (at lower energy) and the softening (at higher energy). A measurement of the proton to helium flux ratio in the energy range from 60  GeV/n to about 60  TeV/n is also presented, using the CALET proton flux recently updated with higher statistics.

Cosmic-Ray Boron Flux Measured from 8.4 GeV/n to 3.8 TeV/n with the Calorimetric Electron Telescope on the International Space Station

We present the measurement of the energy dependence of the boron flux in cosmic rays and its ratio to the carbon flux in an energy interval from 8.4  GeV/n to 3.8  TeV/n based on the data collected by the Calorimetric Electron Telescope (CALET) during ∼6.4  yr of operation on the International Space Station. An update of the energy spectrum of carbon is also presented with an increase in statistics over our previous measurement. The observed boron flux shows a spectral hardening at the same transition energy E_{0}∼200  GeV/n of the C spectrum, though B and C fluxes have different energy dependences. The spectral index of the B spectrum is found to be γ=-3.047±0.024 in the interval 25<E<200  GeV/n. The B spectrum hardens by Δγ_{B}=0.25±0.12, while the best fit value for the spectral variation of C is Δγ_{C}=0.19±0.03. The B/C flux ratio is compatible with a hardening of 0.09±0.05, though a single power-law energy dependence cannot be ruled out given the current statistical uncertainties. A break in the B/C ratio energy dependence would support the recent AMS-02 observations that secondary cosmic rays exhibit a stronger hardening than primary ones. We also perform a fit to the B/C ratio with a leaky-box model of the cosmic-ray propagation in the Galaxy in order to probe a possible residual value λ_{0} of the mean escape path length λ at high energy. We find that our B/C data are compatible with a nonzero value of λ_{0}, which can be interpreted as the column density of matter that cosmic rays cross within the acceleration region.

Observation of Spectral Structures in the Flux of Cosmic-Ray Protons from 50 GeV to 60 TeV with the Calorimetric Electron Telescope on the International Space Station

A precise measurement of the cosmic-ray proton spectrum with the Calorimetric Electron Telescope (CALET) is presented in the energy interval from 50 GeV to 60 TeV, and the observation of a softening of the spectrum above 10 TeV is reported. The analysis is based on the data collected during ∼6.2  years of smooth operations aboard the International Space Station and covers a broader energy range with respect to the previous proton flux measurement by CALET, with an increase of the available statistics by a factor of ∼2.2. Above a few hundred GeV we confirm our previous observation of a progressive spectral hardening with a higher significance (more than 20 sigma). In the multi-TeV region we observe a second spectral feature with a softening around 10 TeV and a spectral index change from -2.6 to -2.9 consistently, within the errors, with the shape of the spectrum reported by DAMPE. We apply a simultaneous fit of the proton differential spectrum which well reproduces the gradual change of the spectral index encompassing the lower energy power-law regime and the two spectral features observed at higher energies.

Direct Measurement of the Nickel Spectrum in Cosmic Rays in the Energy Range from 8.8 GeV/n to 240 GeV/n with CALET on the International Space Station

The relative abundance of cosmic ray nickel nuclei with respect to iron is by far larger than for all other transiron elements; therefore it provides a favorable opportunity for a low background measurement of its spectrum. Since nickel, as well as iron, is one of the most stable nuclei, the nickel energy spectrum and its relative abundance with respect to iron provide important information to estimate the abundances at the cosmic ray source and to model the Galactic propagation of heavy nuclei. However, only a few direct measurements of cosmic-ray nickel at energy larger than ∼3  GeV/n are available at present in the literature, and they are affected by strong limitations in both energy reach and statistics. In this Letter, we present a measurement of the differential energy spectrum of nickel in the energy range from 8.8  to 240  GeV/n, carried out with unprecedented precision by the Calorimetric Electron Telescope (CALET) in operation on the International Space Station since 2015. The CALET instrument can identify individual nuclear species via a measurement of their electric charge with a dynamic range extending far beyond iron (up to atomic number Z=40). The particle's energy is measured by a homogeneous calorimeter (1.2 proton interaction lengths, 27 radiation lengths) preceded by a thin imaging section (3 radiation lengths) providing tracking and energy sampling. This Letter follows our previous measurement of the iron spectrum [1O. Adriani et al. (CALET Collaboration), Phys. Rev. Lett. 126, 241101 (2021).PRLTAO0031-900710.1103/PhysRevLett.126.241101], and it extends our investigation on the energy dependence of the spectral index of heavy elements. It reports the analysis of nickel data collected from November 2015 to May 2021 and a detailed assessment of the systematic uncertainties. In the region from 20 to 240  GeV/n our present data are compatible within the errors with a single power law with spectral index -2.51±0.07.

Isolation of a Novel Endophytic Bacillus Strain Capable of Transforming Pentachlorophenol and Structure Determination of Pentachlorophenol Phosphate Using Single-Crystal X-ray Diffraction

A novel approach for the remediation of upland soils contaminated with pentachlorophenol (C₆HCl₅O; PCP) (1), a fungicide, wood perservative, and herbicide, through the exploitation of plant-endophytic bacteria may overcome the existing issues in bioaugmentaion and phytoremidiation. In this study, we isolated the endophytic Bacillus sp. strain PCP15 and determined its metabolite of PCP (1). This strain degraded 8.03 μmol L^-1 PCP (1) within 24 h and generated the novel metabolite PCP phosphate (3). The PCP15 strain showed nearly complete growth inhibition of 20 μmol L^-1 PCP (1). In contrast, PCP15 showed resistance to PCP phosphate (3), indicating that the phosphorylation of PCP, which has never previously been reported in organisms, contributed to the detoxification of PCP (1) in bacterial cells. Our results show the potential for practical application of this strain in hybrid remediation of PCP (1)-contaminated soils and reveal a novel PCP (1) detoxification mechanism in organisms.

Green manure incorporation accelerates enzyme activity, plant growth, and changes in the fungal community of soil

Green manure can sustain agricultural production, preserve biodiversity, and mitigate soil degradation caused by long-term application of chemical fertilizers. Moreover, the application of green manure can improve soil health through increased soil biological activities. Nevertheless, little attention has been paid to the effects of leguminous and non-leguminous plants on phosphorus- and carbon-related enzyme activities and fungal community composition in soil. In this study, a pot experiment was carried out to elucidate the effects of two green manures on plant growth promoting potential, phosphorus- and carbon-related enzyme activities, and soil fungal community composition. Two green manure treatments (Brassica juncea and hairy vetch), poultry compost and control (no amendment) were applied and soil samples were collected after incorporation of green manure and after plant harvest. The results revealed that plant growth with hairy vetch was significantly higher than that with B. juncea and poultry compost, and soil enzyme activities were markedly higher with hairy vetch than with B. juncea. Both green manure amendments altered the soil fungal community composition. It is possible that the incorporation of green manure into soil and their mineralization and decomposition were controlled by the carbon: nitrogen ratio of the manures and that these manures were easily degradable by soil fungi. In particular, the incorporation of leguminous (hairy vetch) green manure with a low carbon: nitrogen ratio resulted in better plant growth through fast mineralization. Our findings suggest that green manure incorporation is an effective practice and provides substantial benefits to the soil-plant system.

Measurement of the Iron Spectrum in Cosmic Rays from 10 GeV/n to 2.0 TeV/n with the Calorimetric Electron Telescope on the International Space Station

The Calorimetric Electron Telescope (CALET), in operation on the International Space Station since 2015, collected a large sample of cosmic-ray iron over a wide energy interval. In this Letter a measurement of the iron spectrum is presented in the range of kinetic energy per nucleon from 10  GeV/n to 2.0  TeV/n allowing the inclusion of iron in the list of elements studied with unprecedented precision by space-borne instruments. The measurement is based on observations carried out from January 2016 to May 2020. The CALET instrument can identify individual nuclear species via a measurement of their electric charge with a dynamic range extending far beyond iron (up to atomic number Z=40). The energy is measured by a homogeneous calorimeter with a total equivalent thickness of 1.2 proton interaction lengths preceded by a thin (3 radiation lengths) imaging section providing tracking and energy sampling. The analysis of the data and the detailed assessment of systematic uncertainties are described and results are compared with the findings of previous experiments. The observed differential spectrum is consistent within the errors with previous experiments. In the region from 50  GeV/n to 2  TeV/n our present data are compatible with a single power law with spectral index -2.60±0.03.

Non-target Impact of Dinotefuran and Azoxystrobin on Soil Bacterial Community and Nitrification

Pesticides to protect crops from pests are subject to rigorous risk assessment before registration in Japan. However, further information needs to be collected regarding the assessment of impacts on the natural environment. In particular, nitrifying bacteria play a role in converting ammonium salts to nitrates in soil. However, there is limited research covering the effects of insecticides on nitrification, despite several fungicides and herbicides have an inhibitory effect on nitrifying bacteria. Therefore, we investigated the effect of pesticides on the nitrification when applied to soil. The application of both pesticides promoted ammonia oxidation, and suppressed nitrite oxidation in a high-concentration treatment of dinotefuran. In addition, it was clarified that the diversity and species richness of soil bacteria was significantly reduced when the pesticides were applied to the soil, and that the specific soil bacteria (Metyhlotenera spp.) dominated the application of the pesticides.

Direct Measurement of the Cosmic-Ray Carbon and Oxygen Spectra from 10 GeV/n to 2.2 TeV/n with the Calorimetric Electron Telescope on the International Space Station

In this paper, we present the measurement of the energy spectra of carbon and oxygen in cosmic rays based on observations with the Calorimetric Electron Telescope on the International Space Station from October 2015 to October 2019. Analysis, including the detailed assessment of systematic uncertainties, and results are reported. The energy spectra are measured in kinetic energy per nucleon from 10  GeV/n to 2.2  TeV/n with an all-calorimetric instrument with a total thickness corresponding to 1.3 nuclear interaction length. The observed carbon and oxygen fluxes show a spectral index change of ∼0.15 around 200  GeV/n established with a significance >3σ. They have the same energy dependence with a constant C/O flux ratio 0.911±0.006 above 25  GeV/n. The spectral hardening is consistent with that measured by AMS-02, but the absolute normalization of the flux is about 27% lower, though in agreement with observations from previous experiments including the PAMELA spectrometer and the calorimetric balloon-borne experiment CREAM.

Biochemical characterization of NADH:FMN oxidoreductase HcbA3 from Nocardioides sp. PD653 in catalyzing aerobic HCB dechlorination

Nocardioides sp. PD653 genes hcbA1, hcbA2, and hcbA3 encode enzymes that catalyze the oxidative dehalogenation of hexachlorobenzene (HCB), which is one of the most recalcitrant persistent organic pollutants (POPs). In this study, HcbA1, HcbA2, and HcbA3 were heterologously expressed and characterized. Among the flavin species tested, HcbA3 showed the highest affinity for FMN with a K _d value of 0.75±0.17 µM. Kinetic assays revealed that HcbA3 followed a ping-pong bi-bi mechanism for the reduction of flavins. The K _m for NADH and FMN was 51.66±11.58 µM and 4.43±0.69 µM, respectively. For both NADH and FMN, the V _max and k _cat were 2.21±0.86 µM and 66.74±5.91 sec^-1, respectively. We also successfully reconstituted the oxidative dehalogenase reaction in vitro, which consisted of HcbA1, HcbA3, FMN, and NADH, suggesting that HcbA3 may be the partner reductase component for HcbA1 in Nocardioides sp. PD653.

Multiple time-scale beats in aurora: precise orchestration via magnetospheric chorus waves

The brightness of aurorae in Earth’s polar region often beats with periods ranging from sub-second to a few tens of a second. Past observations showed that the beat of the aurora is composed of a superposition of two independent periodicities that co-exist hierarchically. However, the origin of such multiple time-scale beats in aurora remains poorly understood due to a lack of measurements with sufficiently high temporal resolution. By coordinating experiments using ultrafast auroral imagers deployed in the Arctic with the newly-launched magnetospheric satellite Arase, we succeeded in identifying an excellent agreement between the beats in aurorae and intensity modulations of natural electromagnetic waves in space called “chorus”. In particular, sub-second scintillations of aurorae are precisely controlled by fine-scale chirping rhythms in chorus. The observation of this striking correlation demonstrates that resonant interaction between energetic electrons and chorus waves in magnetospheres orchestrates the complex behavior of aurora on Earth and other magnetized planets.

Metabolite profiling reveals a complex response of plants to application of plant growth-promoting endophytic bacteria

Endophytic bacteria have been explored for their role in plant growth promotion, however, not much has been explored in cucumber. The metabolomic response of plants to application of such microbes also remains largely unknown. Thus, we investigated the application of endophytic bacteria to cucumber to infer their role in plant growth promotion and document metabolome response. The lowest healthy leaf-stalks were sampled from four differently sourced cucumber plants, and endophytic bacteria were isolated after surface disinfection. Initial plant growth-promoting (PGP) screening was performed to identify PGP strains out of numerous isolates, and five strains (Strains 4=Curtobacterium spp., 72=Brevibacillus spp., 167=Paenibacillus spp., 193=Bacillus spp., and 227=Microbacterium spp.) were selected based on their contribution to root growth compared with the control. The selected strains were further evaluated in pot experiments, axenic PGP trait assays, and metabolomic analysis. Results revealed that the selected isolates possessed different qualitative characteristics among indole acetic acid, siderophore production, phosphate solubilization, and 1-aminocyclopropane-1-carboxylate (ACC)-deaminase and nifH genes, and all isolates significantly enhanced plant growth in both pot experiments compared with the uninoculated control and fertilizer control. Metabolomic profiling revealed that both strains affected the plant metabolomes compared with the uninoculated control. Around 50 % of the metabolites explored had higher concentrations in either or both bacteria-applied plants compared with the uninoculated control. Differences were observed in both strains' regulation of metabolites, although both enhanced root growth near equally. Overall, endophytic bacteria significantly enhanced plant growth and tended to produce or induce release of certain metabolites within the plant endosphere.

Dissipation, dehalogenation, and denitration of chloroaromatic compounds by Nocardioides sp. strain PD653: Characterization of the substrate specificity

The substrate range of Nocardioides sp. strain PD653, capable of mineralizing hexachlorobenzene, was investigated based on the dissipation of substrates and the liberation of halogen ions. Strain PD653 dehalogenated 10 out of 18 halophenol congeners; however, it could dehalogenate only hexachlorobenzene out of seven halobenzene congeners tested. Moreover, dehalogenation activities were shown for chloronitrobenzenes, along with an increase in the number of substituted chlorine atoms except for 2,3,4,5-tetrachloro-1-nitrobenzene. These results suggested that this strain might be applicable to remediate soil contaminated with these persistent chloroaromatic compounds.

Multifunctional food waste fertilizer having the capability of Fusarium-growth inhibition and phosphate solubility: A new horizon of food waste recycle using microorganisms

Organic waste, including food leftovers and trade refuse, has been explored for its use as a nutrient source through a multitude of techniques. Composting; the dominant method, is criticized due to exhaustion of nutrients used for simultaneous microbial growth. Drying of food waste to low moisture levels, besides keeping the nutrition intact, offers the potential of growing desirable phyto-beneficial-cum-functional microbes, which can have additional benefits. Consequently, isolation of fungus from soil was carried out followed by characterization for confrontation against Fusarium, phosphate solubilization and utilization of food waste material. The food waste material was collected from University of Yamanashi Restaurant and dried up to approximately 3.8% moisture using Hitachi Household Garbage Dryer & Processor (ECO-B25). A pot experiment, growing Lactuca sativa (lettuce) and Brassica rapa, in selected fungal isolate-inoculated food waste material was conducted comparing with that of chemical, and organic fertilizer besides uninoculated food waste material. Results showed that one strain UY2015_11 (identified as Aspergillus niger) significantly inhibited the growth of Fusarium besides solubilizing hardly available iron, and calcium-type phosphates. Similarly, in a 13-week incubation experiment, mineralization of nitrate nitrogen from the food waste and fungal strain UY2015_11-inoculated food waste, was 23.9% and 17.0%, respectively. Later pot experiment indicated that the strain UY2015_11-inoculated dried food waste material showed same vegetable growth as chemical and organic fertilizer (rapeseed oil cake). Concluding, Aspergillus niger strain UY2015_11 isolated from soil inhibited the growth of Fusarium and solubilized hardly phosphate. Moreover, the strain UY2015_11 inoculated low moisture-food waste material showed the same vegetable growth as chemical and organic fertilizer (rapeseed oil cake).

Changes in endophytic bacterial communities during different growth stages of cucumber (Cucumis sativus L.)

Endophytic bacterial diversity in plants presents the level of interaction between culturable and non-culturable endophytic bacteria, thereby providing an appropriate insight into the endophytic environment. This study was conducted to determine the trend of culturable and non-culturable endophytic bacteria at two different sites encompassing four consecutive growth stages. For culturable endophytic bacteria, isolation was carried out using the dilution plate technique, and the obtained colonies were compared using PCR-restriction fragment length polymorphism (RFLP). Different RFLP-types were identified to their nearest neighbour using 16S rRNA sequencing. The non-culturable endophytic bacterial diversity was obtained by next generation sequencing. Results suggested a similar trend among the culturable and non-culturable bacteria for observed operational taxonomic units and diversity indices. It is noticeable that the endophytic bacteria inhabiting in stage 1 disappeared, and instead, different endophytic bacteria appeared. Moreover, the temporal persistence of certain culturable and non-culturable bacteria was also observed. In conclusion, the endophytic bacterial diversity in cucumber initially increased with the plant growth and then decreased at a later stage. Furthermore, it was suggested that plants regulate the number and diversity of endophytes throughout the lifecycle of plants.

Direct Measurement of the Cosmic-Ray Proton Spectrum from 50 GeV to 10 TeV with the Calorimetric Electron Telescope on the International Space Station

In this paper, we present the analysis and results of a direct measurement of the cosmic-ray proton spectrum with the CALET instrument onboard the International Space Station, including the detailed assessment of systematic uncertainties. The observation period used in this analysis is from October 13, 2015 to August 31, 2018 (1054 days). We have achieved the very wide energy range necessary to carry out measurements of the spectrum from 50 GeV to 10 TeV covering, for the first time in space, with a single instrument the whole energy interval previously investigated in most cases in separate subranges by magnetic spectrometers (BESS-TeV, PAMELA, and AMS-02) and calorimetric instruments (ATIC, CREAM, and NUCLEON). The observed spectrum is consistent with AMS-02 but extends to nearly an order of magnitude higher energy, showing a very smooth transition of the power-law spectral index from -2.81±0.03 (50-500 GeV) neglecting solar modulation effects (or -2.87±0.06 including solar modulation effects in the lower energy region) to -2.56±0.04 (1-10 TeV), thereby confirming the existence of spectral hardening and providing evidence of a deviation from a single power law by more than 3σ.

Potential use of endophytic root bacteria and host plants to degrade hydrocarbons

Microbe-assisted phytoremediation depends on competent root-associated microorganisms that enhance remediation efficiency of organic compounds. Endophytic bacteria are a key element of the root microbiome and may assist plant degradation of contaminants. The aim of this study was to investigate the application of four hydrocarbon-degrading endophytic strains previously isolated from an oil sands reclamation area. Strains EA1-17 (Stenotrophomonas sp.), EA2-30 (Flavobacterium sp.), EA4-40 (Pantoea sp.), and EA6-5 (Pseudomonas sp.) were inoculated in white sweet clover growing on soils amended with diesel at 5,000, 10,000, and 20,000 mg·kg^-1. Our results indicate that plant growth inhibition caused by diesel fuel toxicity was overcome in inoculated plants, which showed significantly higher plant biomass. Analysis of soil F2 and F3 hydrocarbon fractions also revealed that these soils were remediated by inoculated plants when diesel was applied at 10,000 mg·kg^-1 and 20,000 mg·kg^-1. In addition, quantification of hydrocarbon-degrading genes suggests that all bacterial strains successfully colonized sweet clover plants. Overall, the endophytic strain EA6-5 (Pseudomonas sp.), which harbored hydrocarbon-degrading genes, was the most effective candidate in phytoremediation experiments and could be a strategy to increase plant tolerance and hydrocarbon degradation in contaminated (e.g., diesel fuel) soils.

The CALorimetric Electron Telescope (CALET) on the International Space Station: Results from the First Two Years of Operation

The CALorimetric Electron Telescope (CALET) space experiment, which has been developed by Japan in collaboration with Italy and the United States, is a high-energy astroparticle physics mission on the International Space Station (ISS). The primary goals of the CALET mission include investigation of possible nearby sources of high-energy electrons, detailed study of galactic cosmic-ray acceleration and propagation, and search for dark matter signatures. With a long-term observation onboard the ISS, the CALET experiment measures the flux of cosmic-ray electrons (including positrons) up to 20 TeV, gamma-rays to 10 TeV, and nuclei up to 1,000 TeV based on its charge separation capability from Z = 1 to 40. Since the start of science operation in mid-October, 2015, a continuous observation has been maintained without any major interruptions. The number of triggered events over 10 GeV is nearly 20 million per month. By using the data obtained during the first two-years, here we present a summary of the CALET observations: 1) Electron+positron energy spectrum, 2) Nuclei analysis, 3) Gamma-ray observation with a characterization of the on-orbit performance. The search results for the electromagnetic counterparts of LIGO/Virgo gravitational wave events are also discussed.

Biodegradability and biodegradation pathways of chlorinated cyclodiene insecticides by soil fungi

An aerobic dieldrin-degrading fungus, Mucor racemosus strain DDF, and two aerobic endosulfan-degrading fungal strains, Mortierella sp. strains W8 and Cm1-45, were isolated from soil contaminated with organochlorine pesticides. Strain DDF degraded more than 90% dieldrin during 10-days of incubation at 25°C and showed the production of a small amount of aldrin trans-diol. Moreover, strain DDF reduced levels of aldrin trans-diol while producing unknown metabolites that were determined to be aldrin trans-diol exo- and endo-phosphates. On the other hand, Mortierella sp. strains W8 and Cm1-45 degraded more than 70% and 50% of α and β-endosulfan, respectively, over 28 days at 25°C, in liquid cultures containing initial concentrations of 8.2 µM of each substance. Only a small amount of endosulfan sulfate, a persistent metabolite, was detected in the both cultures, while these strains could not degrade endosulfan sulfate when this compound was provided as the initial substrate. Both strains generate endosulfan diol as a first step in the degradation of endosulfan, then undergo further conversion to endosulfan lactone.

Extended Measurement of the Cosmic-Ray Electron and Positron Spectrum from 11 GeV to 4.8 TeV with the Calorimetric Electron Telescope on the International Space Station

Extended results on the cosmic-ray electron + positron spectrum from 11 GeV to 4.8 TeV are presented based on observations with the Calorimetric Electron Telescope (CALET) on the International Space Station utilizing the data up to November 2017. The analysis uses the full detector acceptance at high energies, approximately doubling the statistics compared to the previous result. CALET is an all-calorimetric instrument with a total thickness of 30 X_{0} at normal incidence and fine imaging capability, designed to achieve large proton rejection and excellent energy resolution well into the TeV energy region. The observed energy spectrum in the region below 1 TeV shows good agreement with Alpha Magnetic Spectrometer (AMS-02) data. In the energy region below ∼300  GeV, CALET's spectral index is found to be consistent with the AMS-02, Fermi Large Area Telescope (Fermi-LAT), and Dark Matter Particle Explorer (DAMPE), while from 300 to 600 GeV the spectrum is significantly softer than the spectra from the latter two experiments. The absolute flux of CALET is consistent with other experiments at around a few tens of GeV. However, it is lower than those of DAMPE and Fermi-LAT with the difference increasing up to several hundred GeV. The observed energy spectrum above ∼1  TeV suggests a flux suppression consistent within the errors with the results of DAMPE, while CALET does not observe any significant evidence for a narrow spectral feature in the energy region around 1.4 TeV. Our measured all-electron flux, including statistical errors and a detailed breakdown of the systematic errors, is tabulated in the Supplemental Material in order to allow more refined spectral analyses based on our data.

Energy Spectrum of Cosmic-Ray Electron and Positron from 10 GeV to 3 TeV Observed with the Calorimetric Electron Telescope on the International Space Station

First results of a cosmic-ray electron and positron spectrum from 10 GeV to 3 TeV is presented based upon observations with the CALET instrument on the International Space Station starting in October, 2015. Nearly a half million electron and positron events are included in the analysis. CALET is an all-calorimetric instrument with total vertical thickness of 30 X_{0} and a fine imaging capability designed to achieve a large proton rejection and excellent energy resolution well into the TeV energy region. The observed energy spectrum over 30 GeV can be fit with a single power law with a spectral index of -3.152±0.016 (stat+syst). Possible structure observed above 100 GeV requires further investigation with increased statistics and refined data analysis.

Air shower simulation for WASAVIES: warning system for aviation exposure to solar energetic particles

WASAVIES, a warning system for aviation exposure to solar energetic particles (SEPs), is under development by collaboration between several institutes in Japan and the USA. It is designed to deterministically forecast the SEP fluxes incident on the atmosphere within 6 h after flare onset using the latest space weather research. To immediately estimate the aircrew doses from the obtained SEP fluxes, the response functions of the particle fluxes generated by the incidence of monoenergetic protons into the atmosphere were developed by performing air shower simulations using the Particle and Heavy Ion Transport code system. The accuracy of the simulation was well verified by calculating the increase count rates of a neutron monitor during a ground-level enhancement, combining the response function with the SEP fluxes measured by the PAMELA spectrometer. The response function will be implemented in WASAVIES and used to protect aircrews from additional SEP exposure.

Distribution of Bacterial Species in Soil with a Vegetational Change from Japanese Black Pine (Pinus thunbergii) to Black Locust (Robinia pseudoacacia)

The effects of a nitrogen-fixing tree, black locust (Robinia pseudoacacia), on the distribution of bacterial species were examined in a Japanese black pine (Pinus thunbergii) and black locust-dominated area. DNA was extracted from the soil at depths of 0-5 and 5-10 cm, collected at the border between a Japanese black pine-dominated forest and a black locust-dominated forest, and the distribution of bacterial species was investigated by denaturing gradient gel electrophoresis (DGGE). The bacterial communities did not differ between the two forests. The distribution of some bacterial species correlated significantly with soil pH, soil carbon [C], soil nitrogen [N], and soil N/phosphate [P], but not with soil C/N or soil P. The distributional relationships between ectomycorrhizal (ECM) fungal species and bacterial species were also analyzed. A positive correlation was observed between the distribution of some ECM fungi and bacterial species. These bacteria may have some interactions with ECM fungi in the field.

Biodegradation of endosulfan by Mortieralla sp. strain W8 in soil: Influence of different substrates on biodegradation

To examine the bioremediation potential of Mortierella sp. strain W8 in endosulfan contaminated soil, the fungus was inoculated into sterilized and unsterilized soil spiked with endosulfan. Wheat bran and cane molasses were used as substrates to understand the influence of different organic materials on the degradation of endosulfan in soil. Strain W8 degraded α- and β-endosulfan in both sterilized and unsterilized soil. In unsterilized soil with wheat bran+W8, α- and β- endosulfan were degraded by approximately 80% and 50%, respectively after 28 d incubation against the initial endosulfan concentration (3 mg kg(-1) dw). The corresponding values for α- and β-endosulfan degradation with wheat bran only were 50% and 3%. Endosulfan diol metabolite was detected after 14 d incubation in wheat bran+W8 whereas it was not found with wheat bran only. Production of endosulfan sulfate, the main metabolite of endosulfan, was suppressed with wheat bran+W8 treatment compared with wheat bran only. It was demonstrated that wheat bran is a more suitable substrate for strain W8 than cane molasses. Wheat bran+W8 is a superior fungus and substrate mix for bioremediation in soil contaminated with endosulfan.

Isolation and identification of dieldrin-degrading Pseudonocardia sp. strain KSF27 using a soil-charcoal perfusion method with aldrin trans-diol as a structural analog of dieldrin

We isolated a novel aerobic dieldrin-degrading bacterium from an enrichment culture in a soil-charcoal perfusion system. Enrichment culture using a soil-charcoal perfusion system was an effective way to obtain microorganisms that degrade recalcitrant compounds. The soil-charcoal perfusion was performed using aldrin trans-diol, which was a metabolite of dieldrin. Aldrin trans-diol had higher bioavailability (2.5 mg/l) than dieldrin (0.1-0.25 mg/l), therefore it is possible for microorganisms to utilize it as a substrate in soil. After 100 days of circulation and three exchanges of the medium, the enriched charcoal was harvested and a bacterium isolated. The isolate was designated as strain KSF27 and was found to be closely related to Pseudonocardia spp. as determined by 16S rRNA sequencing analysis. Strain KSF27 degraded aldrin trans-diol by 0.05 μmol/l from an initial concentration of 25.5 μmol/l. The metabolite of aldrin trans-diol was detected by HPLC/MS and determined to be aldrindicarboxylic acid based on retention time and the MS fragment. Moreover, strain KSF27 degraded dieldrin from 14.06 μmol/l to 2.01 μmol/l over a 10-day incubation at 30°C. This strain degraded dieldrin and other persistent organochlorine pesticides, such as α-endosulfan, β-endosulfan, endosulfan sulfate, heptachlor, heptachlor epoxide and chlordecone.

Biodegradation of dieldrin by a soil fungus isolated from a soil with annual endosulfan applications

An aerobic dieldrin-degrading fungus, Mucor racemosus strain DDF, was isolated from a soil to which endosulfan had been annually applied for more than 10 years until 2008. Strain DDF degraded dieldrin to 1.01 microM from 14.3 microM during a 10-day incubation at 25 degrees C. Approximately 0.15 microM (9%) of aldrin trans-diol was generated from the dieldrin degradation after a 1-day incubation. The degradation of dieldrin by strain DDF was detected over a broad range of pH and concentrations of glucose and nitrogen sources. Extracellular fluid without mycelia also degraded dieldrin. Strain DDF degraded not only dieldrin but also heptachlor, heptachlor epoxide, endosulfan, endosulfan sulfate, DDT, and DDE. Endosulfan sulfate and heptachlor were degraded by 0.64 microM (95%) and 0.75 microM (94%), respectively, whereas endosulfan and DDE were degraded by 2.42 microM (80%) and 3.29 microM (79%), respectively, and DDT and heptachlor epoxide were degraded by 6.95 microM (49.3%) and 5.36 microM (67.5%), respectively, compared with the control, which had a concentration of approximately 14 microM. These results suggest that strain DDF could be a candidate for the bioremediation of sites contaminated with various persistent organochlorine pesticides including POPs.

Distribution of ectomycorrhizal and pathogenic fungi in soil along a vegetational change from Japanese black pine (Pinus thunbergii) to black locust (Robinia pseudoacacia)

The nitrogen-fixing tree black locust (Robinia pseudoacacia L.) seems to affect ectomycorrhizal (ECM) colonization and disease severity of Japanese black pine (Pinus thunbergii Parl.) seedlings. We examined the effect of black locust on the distribution of ECM and pathogenic fungi in soil. DNA was extracted from soil at depths of 0-5 and 5-10 cm, collected from the border between a Japanese black pine- and a black locust-dominated forest, and the distribution of these fungi was investigated by denaturing gradient gel electrophoresis. The effect of soil nutrition and pH on fungal distribution was also examined. Tomentella sp. 1 and Tomentella sp. 2 were not detected from some subplots in the Japanese black pine-dominated forest. Ectomycorrhizas formed by Tomentella spp. were dominant in black locust-dominated subplots and very little in the Japanese black pine-dominated forest. Therefore, the distribution may be influenced by the distribution of inoculum potential, although we could not detect significant relationships between the distribution of Tomentella spp. on pine seedlings and in soils. The other ECM fungi were detected in soils in subplots where the ECM fungi was not detected on pine seedlings, and there was no significant correlation between the distribution of the ECM fungi on pine seedlings and in soils. Therefore, inoculum potential seemed to not always influence the ECM community on roots. The distribution of Lactarius quieticolor and Tomentella sp. 2 in soil at a depth of 0-5 cm positively correlated with soil phosphate (soil P) and that of Tomentella sp. 2 also positively correlated with soil nitrogen (soil N). These results suggest the possibility that the distribution of inoculum potential of the ECM fungi was affected by soil N and soil P. Although the mortality of the pine seedlings was higher in the black locust-dominated area than in the Japanese black pine-dominated area, a pathogenic fungus of pine seedlings, Cylindrocladium pacificum, was detected in soil at depths of 0-5 and 5-10 cm from both these areas. This indicates that the disease severity of pine seedlings in this study was influenced by environmental conditions rather than the distribution of inoculum potential.

Sex-related differences in the renal disposition of the acidic metabolite of clentiazem in rat

1. Sex-related differences in the renal excretion of the acidic compounds (+)-(2S,3S)-8-chloro-2,3,4,5-tetrahydro-3-hydroxy-2-(4-hydroxyphenyl)-4-oxo-1,5-benzothiazepin-5-acetic acid (MA4; one of the acidic metabolites of clentiazem), probenecid (PB) and methotrexate (MTX) have been investigated in the 7-week-old male and female Sprague-Dawley rat using an in vivo renal clearance technique. 2. The extent of plasma protein binding of MA4, PB and MTX was approximately 96, 95 and 65%, respectively, and it did not differ significantly between the male and female rat. On the other hand, the unbound renal clearance (CLrf) of MA4 in the female was approximately 300 times higher than that in male, and the ratio of this clearance to the glomerular filtration rate (GFR) was approximately 10, suggesting that MA4 undergoes extensive active renal secretion in the female. Furthermore, the CLrf/GFR ratio was significantly decreased by co-administration of PB. In contrast, no sex-related difference in the renal excretion of PB could be detected because its CLrf was very low and reabsorption contributed extensively to its renal disposition. The CLrf/GFR for MTX was approximately 2.5 but did not differ significantly between the male and female. 3. The renal organic anion transport systems in rat show sex-related differences and have different substrate-specific characteristics.

[Prevalence of cervical and cerebral atherosclerosis and silent brain infarction in patients with multivessel coronary artery disease]

OBJECTIVES

This clinical study investigated the prevalence of cervical and cerebral atherosclerosis and silent brain infarction in patients with coronary artery disease.

METHODS

Cervical and cerebral magnetic resonance angiography(MRA) was performed in 133 patients (98 males, 35 females, mean age 65.3 years) with suspected coronary artery disease, who were divided into a zero- and one-vessel disease group(n = 71) and a two- and three-vessel disease group(n = 62) depending on the number of major coronary branches with 75% or more stenosis. The MRA lesion was defined as more than 50% stenosis. Magnetic resonance imaging(MRI) of the brain was performed within 1 week of MRA in 78 patients without symptomatic stroke and atrial fibrillation. Silent brain infarction on MRI was defined as a focal high intensity area on T2-weighted images larger than 3 mm.

RESULTS

The prevalence of MRA lesions was significantly greater in the two- and three-vessel group than in the zero- and one-vessel group(53% vs 14%, p < 0.01). The prevalence of MRI lesion was significantly higher in the two- and three-vessel group than in the zero- and one-vessel group(77% vs 36%, p < 0.01). The size and number of the MRI lesions were also significantly greater in the two- and three-vessel group than in the zero- and one-vessel group(p < 0.01). Neither age nor percentage of male gender was different between the groups. Diabetes mellitus was the common risk factor for coronary artery disease, MRA lesion and MRI lesion.

CONCLUSIONS

Cervical and cerebral atherosclerosis and silent brain infarction are frequently observed in patients with multivessel coronary artery disease.

The influence of acoustic and perceptual factors on perceived hypernasality in the vowel

The purpose of this study was to examine the influence of acoustic and perceptual factors of speech on listeners' perceived hypernasality in the vowel [i]. The isolated syllable [pi] produced by 22 children with hypernasal speech and 6 noncleft children was rated by 10 listeners. These speech samples were then divided into two groups: (1) the samples (n = 14) that received inconsistent ratings from each listener or variable ratings among listeners (i.e., unreliable ratings) and (2) the samples (n = 14) that received consistent ratings from each listener and similar ratings among listeners (i.e., reliable ratings). These results suggest that the severity of hypernasality was easy to rate in some speech samples and not in others. Voice quality deviation and a particular type of spectral change that related to the severity of hypernasality could be factors that influence perceived hypernasality.

The relationship between spectral characteristics and perceived hypernasality in children

The purpose of this study was to quantify perceived hypernasality in children. One-third octave spectra of the isolated vowel [i] were obtained from 32 children with cleft palate and 5 children without cleft palate. Four experienced listeners rated the severity of hypernasality of the 37 speech samples using a 6-point equal-appearing interval scale. When the average 1/3-octave spectra from the hypernasal group and the normal resonance group were compared, spectral characteristics of hypernasality were identified as increased amplitudes between F1 and F2 and decreased amplitudes in the region of F2. Based on the findings of the children's speech, 36 speech samples with manipulated spectral characteristics were used to minimize the influences of voice source characteristics on perceived hypernasality. Multiple regression analysis revealed a high correlation (R = 0.84) between the amplitudes of 1/3-octave bands (1 k, 1.6 k, and 2.5 kHz) and the perceptual ratings. Increased amplitudes of bands between F1 and F2 (1 k, 1.6 kHz) and decreased amplitude of the band of F2 (2.5 kHz) was associated with an increasing perceived hypernasality. These results suggest that the amplitudes of the three 1/3-octave bands are appropriate acoustic parameters to quantify hypernasality in the isolated vowel [i].

Effect of celiprolol on cardiac hypertrophy in hypertension

The present study was undertaken to clarify whether celiprolol and atenolol, beta1-selective beta blockers with and without intrinsic sympathomimetic activity (ISA), respectively, might improve ischemic damage in the isolated perfused hearts of spontaneously hypertensive rats (SHR), and whether long-term treatment with celiprolol may reduce left ventricular hypertrophy (LVH) in patients with essential hypertension. Atenolol (50 mg/kg/day) or celiprolol (300 mg/kg/day) for 7 weeks significantly reduced the blood pressure in SHR to the same degree, and both drugs decreased the heart rate, but the magnitude of the fall in heart rate was significantly higher with atenolol treatment than with celiprolol treatment. Both treatments significantly reduced the ratio of LV weight to body weight in SHR and significantly improved the coronary reserve in SHR to the same extent. Both treatments significantly improved the extent of recovery of the pressure-rate product and the extent of percent recovery of the coronary flow after reperfusion following 30 min of ischemia in SHR. Celiprolol treatment in patients with essential hypertension for 12 months significantly decreased interventricular septal thickness (IVST)+LV posterior wall thickness (PWT) and LV mass index (LVMI), but there was no significant correlation between IVST+PWT or LVMI and blood pressure before and after treatment. IVST+PWT and LVMI were significantly decreased after 3 months of treatment and these LVH indices were significantly smaller after 6 and 12 months of treatment than after 3 months of treatment. In conclusion, both celiprolol and atenolol treatment reduced LVH and improved the ischemic damage in SHR. In essential hypertensive patients with LVH, celiprolol treatment effectively reduced blood pressure and achieved LVH regression.

Spectral characteristics of hypernasality in maxillectomy patients

To reveal the acoustic characteristics associated with hypernasality and to ascertain their correlation to the severity of hypernasality, 30 speech samples produced by 15 maxillectomy patients were acoustically analysed with and without an obturator prosthesis in place. The isolated, sustained Japanese vowel /i/ was used as the stimulus for acoustic measurement and perceptual judgment to evaluate the severity of hypernasality. Normalized 1/3-octave spectral analysis demonstrated the spectral characteristics of hypernasality as a rise in amplitude between the first and second formants around the 1 kHz region, and a reduction in amplitude of the frequencies higher than the second formant. High correlation was shown between the perceptual ratings and the predicted values derived from stepwise regression analysis.

Nasal coarticulation in normal speakers: a re-examination of the effects of gender

The purpose of this study was to re-examine the influence of gender on nasal coarticulation in normal speakers. Twenty adult speakers (10 men, 10 women) produced the vowel-nasal-vowel (VNV) sequence /ini/ within a carrier phrase using two stress patterns: (1) with equal stress placed on both syllables, and (2) with contrastive stress placed on the second syllable. A partitioned, circumferentially vented pneumotachograph mask and microphone were used to determine nasal airflow, ratios of nasal to oral-plus-nasal airflow, and sound pressure levels (SPLs) at the midpoints of the first and second vowels of the syllables. Volume ratios of nasal to oral-plus-nasal airflow that reflected the entire duration of the vowels were also obtained. Results indicated that all speakers except 1 woman exhibited nasal airflow at the midpoint of the first vowel when /ini/ was produced with equal stress; all speakers exhibited carryover nasal airflow during the second vowel. During contrastive stress, all speakers except 1 woman and 1 additional man exhibited anticipatory nasal airflow; all speakers exhibited carryover nasal airflow. Analysis of variance (ANOVA) procedures with repeated measures indicated significant main effects of syllable stress (p < 0.001) relative to nasal airflow and ratios of nasal to oral-plus-nasal airflow. Regardless of the gender of the speakers, syllable stress resulted in reduced anticipatory and carryover nasal airflow during the first and second vowels of /ini/, respectively. The results suggest that (a) both men and women adhere to similar patterns of velar articulation, and (b) velopharyngeal closure during the vowel /i/ may be enhanced during stressed syllables. Implications relative to aspects of speech production and clinical practice are discussed.