Diffuse neutrino background from past core-collapse supernovae

Core-collapse supernovae are among the most powerful explosions in the universe, emitting thermal neutrinos that carry away the majority of the gravitational binding energy released. These neutrinos create a diffuse supernova neutrino background (DSNB), one of the largest energy budgets among all radiation backgrounds. Detecting the DSNB is a crucial goal of modern high-energy astrophysics and particle physics, providing valuable insights in both core-collapse modeling, neutrino physics, and cosmic supernova rate history. In this review, we discuss the key ingredients of DSNB calculation and what we can learn from future detections, including black-hole formation and non-standard neutrino interactions. Additionally, we provide an overview of the latest updates in neutrino experiments, which could lead to the detection of the DSNB in the next decade. With the promise of this breakthrough discovery on the horizon, the study of DSNB holds enormous potential for advancing our understanding of the Universe.Comment: 21 pages, 8 figures. Invited review article submitted to Proceedings of the Japan Academy, Series B. Figures are made using the numerical codes that accompany this paper; see https://github.com/shinichiroando/PyDSNB/tree/mai

Water transport model during CAPD: Determination of parameters

Water transport model during CAPD: Determination of parameters. To minimize the total amount of glucose required for removing the same volume of water as a bolus, a continuous infusion of glucose during CAPD was proposed and studied. Both a computer simulation of water transport through the peritoneal membrane and in vivo assessment with rats were carried out to evaluate the feasibility of the newly proposed mathematical model in which lymphatic drainage of dialysate from the peritoneal cavity to lymphatic system was considered in addition to conventional water transport. Mass transport area coefficients (KA) of 0.041 to 0.063 ml/min/100 g body wt and 0.045 to 0.066 ml/min/100 g body wt were measured for glucose and urea during CAPD with male Wistar rats. Hydraulic conductivity of peritoneal membrane (Lc) was 7.9 × 10-5 to 1.5 × 10-4 ml/min/mm Hg/100 g body wt, which was calculated by a linear relationship between volume and osmotic pressure. Simulated water transport model using determined parameters indicated that the ratio of lymphatic transport to convective transport would be changeable in CAPD with glucose infusion at varying infusion rates, while up to 16% of the glucose uptake could be reduced compared with that of the common CAPD at the same dwell time

Effect of substrate and thickness on the photoconductivity of nanoparticle titanium dioxide thin film vacuum ultraviolet photoconductive detector

Vacuum ultraviolet radiation (VUV, from 100 nm to 200 nm wavelength) is indispensable in many applications, but its detection is still challenging. We report the development of a VUV photoconductive detector, based on titanium dioxide (TiO2 ) nanoparticle thin films. The effect of crystallinity, optical quality, and crystallite size due to film thickness (80 nm, 500 nm, 1000 nm) and type of substrate (silicon Si, quartz SiO2, soda lime glass SLG) was investigated to explore ways of enhancing the photoconductivity of the detector. The TiO2 film deposited on SiO2 substrate with a film thickness of 80 nm exhibited the best photoconductivity, with a photocurrent of 5.35 milli-Amperes and a photosensitivity of 99.99% for a bias voltage of 70 V. The wavelength response of the detector can be adjusted by changing the thickness of the film as the cut-off shifts to a longer wavelength, as the film becomes thicker. The response time of the TiO2 detector is about 5.8 µs and is comparable to the 5.4 µs response time of a diamond UV sensor. The development of the TiO2 nanoparticle thin film detector is expected to contribute to the enhancement of the use of VUV radiation in an increasing number of important technological and scientific applications.Cadatal-Raduban M., Kato T., Horiuchi Y., et al. Effect of substrate and thickness on the photoconductivity of nanoparticle titanium dioxide thin film vacuum ultraviolet photoconductive detector. Nanomaterials 12, 10 (2022); https://doi.org/10.3390/nano12010010

筋発揮張力維持法実施における筋への触圧覚刺激の変化が血中乳酸値に与える影響

研究報告Original Articles　目的；理学療法において，筋力増強を目的とするプログラムは頻繁に処方されている．しかし，筋力増強運動は強度の違いなど効果は様々な報告が発表されている．本研究の目的は，効率よく筋収縮を促すための手段（運動条件の設定）を明らかにすることである．筋発揮張力維持法は，比較的低強度運動と言われていることから触圧覚刺激と融合し，血中乳酸値を測定することで生体反応から筋機能へ影響を及ぼす要因を検討した．方法；対象は整形外科的疾患の既往がない健常成人男性15 名とした．筋発揮張力維持法は推奨されている運動方法で施行した．圧刺激（0, 30, 40, 50, 60mmHg）には水銀血圧計を用い，下腿最大膨隆部にカフを巻いた．安静5 分終了後と各条件間の運動直後に血中乳酸値を測定した．結果；血中乳酸値は圧迫の上昇に伴い変化量も増加がみられた．0mmHg と60mmHg の間では有意差が認められた（p<0.05）．考察；乳酸は筋肉に対してエネルギー源の元と言われている．本研究の結果からも，代謝産物である乳酸の蓄積は筋力増強には欠かせないことが推測された．　Purpose: In physiotherapy, muscle-strengthening is frequently prescribed. However, to carry it out efficiently understanding how to achieve an adequate vital response is required. Therefore we combined high intensity training, low-intensity resistance exercise with slow movement andtonic force generation, and tactile pressure stimulation, to study the effects on muscle functionand strength by measuring blood lactate levels. Method: Fifteen healthy adult men, without a history of orthopedic disease, were studied. A low-intensity resistance exercise with slow movement and tonic force generation was performed, and the average value was compared to a representative one. A cuff around the most bulbous part of the lower thigh was used for pressure stimulation at 0, 30, 40, 50, and 60 mmHg, using a mercury sphygmomanometer. Theblood lactate levels were measured immediately after training, at the end of five minutes’ rest,and during each stimulation condition. Results: Blood lactate levels increased with an increasein pressure, with a significant difference between 0 mmHg and 60 mmHg (p < 0.05). Discussion:Lactic acid is the energy source in muscles. Our results suggest that the accumulation of lacticacid, which is a metabolic product, is indispensable to muscle-strength

Prescription trend and lactic acidosis in patients prescribed metformin before and after the revision of package insert for allowing metformin administration to patients with moderately decreased kidney function based on real-world data from MID-NET® in Japan

IntroductionThis study was conducted to understand the impact of package insert (PI) revision in Japan on 18 June 2019 to allow metformin use for patients with moderately decreased kidney function (30 ≤ estimated glomerular filtration rate (eGFR) &lt; 60 mL/min/1.73 m2).MethodsA new user cohort design was employed to examine the prescription trend and the occurrence of lactic acidosis in patients prescribed metformin before and after PI revision using the Medical Information Database Network (MID-NET®).ResultsFrom 12 May 2016 to 31 March 2020, 5,874 patients (before, n = 4,702; after, n = 1,172) were identified as new metformin users, including 1,145 patients (before, n = 914; after, n = 231) with moderately decreased kidney function. Although no marked changes in metformin prescription were observed before and after PI revision, the daily metformin dose at the first prescription decreased after PI revision. For both before and after PI revision, less than 10 cases of lactic acidosis occurred in all patients prescribed metformin, and no lactic acidosis was observed in patients with moderately decreased kidney function.ConclusionThe results of this study are useful for understanding the safety of metformin use in patients with decreased kidney function and suggest no worse impacts of PI revision in Japan, indicating no further safety concerns on metformin use in patients with moderately decreased kidney function under the situation with careful use and safety monitoring of metformin

Preliminary Design Study of the TMT Telescope Structure System: Overview

We present an overview of the preliminary design of the Telescope Structure System (STR) of Thirty Meter Telescope (TMT). NAOJ was given responsibility for the TMT STR in early 2012 and engaged Mitsubishi Electric Corporation (MELCO) to take over the preliminary design work. MELCO performed a comprehensive preliminary design study in 2012 and 2013 and the design successfully passed its Preliminary Design Review (PDR) in November 2013 and April 2014. Design optimizations were pursued to better meet the design requirements and improvements were made in the designs of many of the telescope subsystems as follows: 1. 6-legged Top End configuration to support secondary mirror (M2) in order to reduce deformation of the Top End and to keep the same 4% blockage of the full aperture as the previous STR design. 2. “Double Lower Tube” of the elevation (EL) structure to reduce the required stroke of the primary mirror (M1) actuators to compensate the primary mirror cell (M1 Cell) deformation caused during the EL angle change in accordance with the requirements. 3. M1 Segment Handling System (SHS) to be able to make removing and installing 10 Mirror Segment Assemblies per day safely and with ease over M1 area where access of personnel is extremely difficult. This requires semi-automatic sequence operation and a robotic Segment Lifting Fixture (SLF) designed based on the Compliance Control System, developed for controlling industrial robots, with a mechanism to enable precise control within the six degrees of freedom of position control. 4. CO2 snow cleaning system to clean M1 every few weeks that is similar to the mechanical system that has been used at Subaru Telescope. 5. Seismic isolation and restraint systems with respect to safety; the maximum acceleration allowed for M1, M2, tertiary mirror (M3), LGSF, and science instruments in 1,000 year return period earthquakes are defined in the requirements. The Seismic requirements apply to any EL angle, regardless of the operational status of Hydro Static Bearing (HSB) system and stow lock pins. In order to find a practical solution, design optimization study for seismic risk mitigation was carried out extensively, including the performing of dynamic response analyses of the STR system under the time dependent acceleration profile of seven major earthquakes. The work is now moving to the final design phase from April 2014 for two years

Multicolor and multi-spot observations of Starlink's Visorsat

This study provides the results of simultaneous multicolor observations for the first Visorsat (STARLINK-1436) and the ordinary Starlink satellite, STARLINK-1113 in the $U$, $B$, $V$, $g'$, $r$, $i$, $R_{\rm C}$, $I_{\rm C}$, $z$, $J$, $H$, and $K_s$ bands to quantitatively investigate the extent to which Visorsat reduces its reflected light. Our results are as follows: (1) in most cases, Virorsat is fainter than STARLINK-1113, and the sunshade on Visorsat, therefore, contributes to the reduction of the reflected sunlight; (2) the magnitude at 550 km altitude (normalized magnitude) of both satellites often reaches the naked-eye limiting magnitude ($<$ 6.0); (3) from a blackbody radiation model of the reflected flux, the peak of the reflected components of both satellites is around the $z$ band; and (4) the albedo of the near infrared range is larger than that of the optical range. Under the assumption that Visorsat and STARLINK-1113 have the same reflectivity, we estimate the covering factor, $C_{\rm f}$, of the sunshade on Visorsat, using the blackbody radiation model: the covering factor ranges from $0.18 \leq C_{\rm f} \leq 0.92$. From the multivariable analysis of the solar phase angle (Sun-target-observer), the normalized magnitude, and the covering factor, the phase angle versus covering factor distribution presents a moderate anti-correlation between them, suggesting that the magnitudes of Visorsat depend not only on the phase angle but also on the orientation of the sunshade along our line of sight. However, the impact on astronomical observations from Visorsat-designed satellites remains serious. Thus, new countermeasures are necessary for the Starlink satellites to further reduce reflected sunlight.Comment: 31 pages, 9 figures, published in PAS

Measurements of cosmogenic radionuclides during geomagnetic excursions in ice core

第2回極域科学シンポジウム　氷床コアセッション 11月16日（水） 国立極地研究所 2階大会議

Cosmogenic beryllium 10 in ice cores and cosmic-ray stratigraphy

第2回極域科学シンポジウム　氷床コアセッション 11月16日（水） 国立極地研究所 2階大会議