Pentaquark baryon production at the Relativistic Heavy Ion Collider

Production of pentaquark $\Theta^+$ baryons in central relativistic heavy ion collisions is studied in a kinetic model. Assuming that a quark-gluon plasma is produced in the collisions, we first determine the number of $\Theta^+$ produced from the quark-gluon plasma using a parton coalescence model, and then take into consideration its production and absorption in subsequent hadronic matter via the reactions $KN\leftrightarrow\Theta$, $KN\leftrightarrow\pi\Theta$, and \piN\leftrightarrow\bar K\Theta. We find that although the final $\Theta^+$ number is affected by hadronic interactions, it remains sensitive to the initial number of $\Theta^+$ produced from the quark-gluon plasma, particularly in the case of a small $\Theta^+$ width as imposed by the $K^+N$ and $K^+d$ scattering data. Because of small baryon chemical potential in the hot dense matter produced in these collisions, the number of produced anti-$\Theta$ is only slightly smaller than that of $\Theta^+$.Comment: 6 pages, 2 figures, revised version, to appear in PL

Long-term Observation of Osteomalacia Caused by Adefovir-Induced Fanconi’s Syndrome

A 64-year-old man suffering polyarthralgia and bone pain was referred to our hospital. Renal dysfunction, hypophosphatemia and increased levels of bone alkaline phosphatase were found. The patientʼs serum creatinine level had gradually increased after the initiation of adefovir dipivoxil administration for hepatitis B. In agreement with multifocal uptakes of bone scintigraphy, iliac bone biopsy revealed an abnormal increase in osteoid tissues. Reducing the dose of adefovir and initiating the administration of eldecalcitol were effective for reducing proteinuria and glucosuria, and for ameliorating bone pain with an increase in serum phosphate level. This case first showed a clinical course of hypophosphatemic osteomalacia caused by secondary Fanconiʼs syndrome for 8 years after adefovir administration. Early diagnosis is important for the reversibility of bone damage and for a better renal prognosis

Determining Pentaquark Quantum Numbers from Strong Decays

Assuming that the recently observed $\Theta^+$ and $\Xi^{--}$ are members of an anti-decuplet of SU(3), decays to ground state baryons and mesons are calculated using an effective Lagrangian which incorporates chiral and SU(3) symmetry. We consider the possible quantum number assignments $J^\Pi ={1/2}^\pm,{3/2}^\pm$ and calculate ratios of partial widths. The branching ratios of exotic cascades can be used to discriminate between even and odd parity pentaquarks.Comment: 9 pages, references added, accepted for publication in PL

Kinetic modeling of particle acceleration in a solar null point reconnection region

The primary focus of this paper is on the particle acceleration mechanism in solar coronal three-dimensional reconnection null-point regions. Starting from a potential field extrapolation of a Solar and Heliospheric Observatory (SOHO) magnetogram taken on 2002 November 16, we first performed magnetohydrodynamics (MHD) simulations with horizontal motions observed by SOHO applied to the photospheric boundary of the computational box. After a build-up of electric current in the fan-plane of the null-point, a sub-section of the evolved MHD data was used as initial and boundary conditions for a kinetic particle-in-cell model of the plasma. We find that sub-relativistic electron acceleration is mainly driven by a systematic electric field in the current sheet. A non-thermal population of electrons with a power-law distribution in energy forms in the simulated pre-flare phase, featuring a power-law index of about -1.78. This work provides a first step towards bridging the gap between macroscopic scales on the order of hundreds of Mm and kinetic scales on the order of cm in the solar corona, and explains how to achieve such a cross-scale coupling by utilizing either physical modifications or (equivalent) modifications of the constants of nature. With their exceptionally high resolution - up to 135 billion particles and 3.5 billion grid cells of size 17.5 km - these simulations offer a new opportunity to study particle acceleration in solar-like settings.Comment: 18 pages, 12 figure

The Pilot Study for Health Check-Ups System at Elementary School in Cambodia

Background: In Cambodia, there is no national health check-ups system for the schoolchildren and the general population. This pilot study aimed to promote a school health check-ups system in collaboration with the government of Cambodia. Method: From 2016 to 2017, we conducted a survey in an elementary school in Siem Reap province, Cambodia. Two hundred and ninety-two students were eligible for data analysis. Physical examination, questionnaire and urinalysis were conducted using the Japanese school health check-ups model. Anthropometry was measured using the World Health Organization’s growth reference data for school-age children. Results: Among 292 schoolchildren, 88.7% were diagnosed as healthy. Based on the evaluation criteria of health examination in the study, two (0.7%) students with rale, one (0.3%) student with abnormal urinalysis, and another 27 students complaining of cardiopulmonary symptoms were recommended for further consultation at hospital. The prevalence of overweight (15.1%) was higher than that of underweight (8.6%). According to parents’ questionnaires responses, the coverage rate of the National Immunization Program varied from 41.8% to 79.8% depending on each particular vaccine. Conclusion: In this pilot study, we showed the prevalence of healthy among Cambodian schoolchildren and detected the students having possibility of health problem through this health check-ups and then recommended for further hospital visit. Based on the results, we assume that health check-ups system in elementary school as a whole Cambodia will be effective to assess the current health status in ordinary time and possibility of early detection of disease

Optical Sensing Method for Screening Disease in Melon Seeds by Using Optical Coherence Tomography

We report a noble optical sensing method to diagnose seed abnormalities using optical coherence tomography (OCT). Melon seeds infected with Cucumber green mottle mosaic virus (CGMMV) were scanned by OCT. The cross-sectional sensed area of the abnormal seeds showed an additional subsurface layer under the surface which is not found in normal seeds. The presence of CGMMV in the sample was examined by a blind test (n = 140) and compared by the reverse transcription-polymerase chain reaction. The abnormal layers (n = 40) were quantitatively investigated using A-scan sensing analysis and statistical method. By utilizing 3D OCT image reconstruction, we confirmed the distinctive layers on the whole seeds. These results show that OCT with the proposed data processing method can systemically pick up morphological modification induced by viral infection in seeds, and, furthermore, OCT can play an important role in automatic screening of viral infections in seeds

Long-lived neutral-kaon flux measurement for the KOTO experiment

The KOTO ($K^0$ at Tokai) experiment aims to observe the CP-violating rare decay $K_L \rightarrow \pi^0 \nu \bar{\nu}$ by using a long-lived neutral-kaon beam produced by the 30 GeV proton beam at the Japan Proton Accelerator Research Complex. The $K_L$ flux is an essential parameter for the measurement of the branching fraction. Three $K_L$ neutral decay modes, $K_L \rightarrow 3\pi^0$, $K_L \rightarrow 2\pi^0$, and $K_L \rightarrow 2\gamma$ were used to measure the $K_L$ flux in the beam line in the 2013 KOTO engineering run. A Monte Carlo simulation was used to estimate the detector acceptance for these decays. Agreement was found between the simulation model and the experimental data, and the remaining systematic uncertainty was estimated at the 1.4\% level. The $K_L$ flux was measured as $(4.183 \pm 0.017_{\mathrm{stat.}} \pm 0.059_{\mathrm{sys.}}) \times 10^7$ $K_L$ per $2\times 10^{14}$ protons on a 66-mm-long Au target.Comment: 27 pages, 16 figures. To be appeared in Progress of Theoretical and Experimental Physic

Immunomodulation by Mesenchymal Stem Cells : A Potential Therapeutic Strategy for Type 1 Diabetes

Mesenchymal stem cells (MSCs) are pluripotent stromal cells that have the potential to give rise to cells of diverse lineages. Interestingly, MSCs can be found in virtually all postnatal tissues. The main criteria currently used to characterize and identify these cells are the capacity for self-renewal and differentiation into tissues of mesodermal origin, combined with a lack in expression of certain hematopoietic molecules. Because of their developmental plasticity, the notion of MSC-based therapeutic intervention has become an emerging strategy for the replacement of injured tissues. MSCs have also been noted to possess the ability to impart profound immunomodulatory effects in vivo. Indeed, some of the initial observations regarding MSC protection from tissue injury once thought mediated by tissue regeneration may, in reality, result from immunomodulation. Whereas the exact mechanisms underlying the immunomodulatory functions of MSC remain largely unknown, these cells have been exploited in a variety of clinical trials aimed at reducing the burden of immune-mediated disease. This article focuses on recent advances that have broadened our understanding of the immunomodulatory properties of MSC and provides insight as to their potential for clinical use as a cell-based therapy for immune-mediated disorders and, in particular, type 1 diabetes

Reflectivity of Venus’s Dayside Disk During the 2020 Observation Campaign: Outcomes and Future Perspectives

We performed a unique Venus observation campaign to measure the disk brightness of Venus over a broad range of wavelengths in 2020 August and September. The primary goal of the campaign was to investigate the absorption properties of the unknown absorber in the clouds. The secondary goal was to extract a disk mean SO2 gas abundance, whose absorption spectral feature is entangled with that of the unknown absorber at ultraviolet wavelengths. A total of three spacecraft and six ground-based telescopes participated in this campaign, covering the 52–1700 nm wavelength range. After careful evaluation of the observational data, we focused on the data sets acquired by four facilities. We accomplished our primary goal by analyzing the reflectivity spectrum of the Venus disk over the 283–800 nm wavelengths. Considerable absorption is present in the 350–450 nm range, for which we retrieved the corresponding optical depth of the unknown absorber. The result shows the consistent wavelength dependence of the relative optical depth with that at low latitudes, during the Venus flyby by MESSENGER in 2007, which was expected because the overall disk reflectivity is dominated by low latitudes. Last, we summarize the experience that we obtained during this first campaign, which should enable us to accomplish our second goal in future campaigns