Estimation of Local Site Conditions in Kushiro City Based on Array Observation of Microtremors

Possible use of short-period microtremors is explored for estimating the effects of subsurface soil conditions on the ground motion characteristics. For this purpose, microtremor measurements are conducted using arrays of sensors at two strong motion stations (Kushiro Japan Meteorological Agency and Kushiro Harbor, Hokkaido, Japan), which are located nearby but on different soils. Based on the F-k spectrum analysis of microtremors, dispersion curves of Rayleigh waves for the sites are determined. The inverse analysis of these dispersion curves results in shear wave velocity profiles down to a depth of 300 m. With these profiles, the spectrum ratio of ground surface motions between the two sites is computed, and compared with that of the observed records. The computed and observed spectrum ratios show a fairly good agreement, indicating that the array observation of microtremors is an economical and yet reliable means of estimating local site conditions

Characteristic time of transition from write error to retention error in voltage-controlled magnetoresistive random-access memory

Voltage controlled magnetoresistive random access memory (VC MRAM) is a promising candidate for a future low-power high-density memory. The main causes of bit errors in VC MRAM are write error and retention error. As the size of the memory cell decreases, the data retention time decreases, which causes a transition from the write-error-dominant region to the retention-error-dominant region at a certain operating time. Here we introduce the characteristic time of the transition from the write-error-dominant region to the retention-error-dominant region and analyze how the characteristic time depends on the effective anisotropy constant, $K_{0}$. The characteristic time is approximately expressed as $t_{\rm c} = 2\, w\, \tau$, where $w$ is the write error rate, and $\tau$ is the relaxation time derived by Kalmkov [J. Appl. Phys. 96, (2004) 1138-1145]. We show that for large $K_{0}$, $t_{\rm c}$ increases with increase of $K_{0}$ similar to $\tau$. The characteristic time is a key parameter for designing the VC MRAM for the variety of applications such as machine learning and artificial intelligence.Comment: 6 pages, 5 figure

Efficacy and Safety of Once-daily Oxybutynin Patch in Patients with Overactive Bladder Who had Experienced Adverse Reactions Caused by Oral Antimuscarinic Drugs

Objectives：To evaluate the efficacy and safety of once-daily oxybutynin patch for overactive bladder (OAB) patients not tolerating oral antimuscarinic drugs. Methods：We prospectively investigated 43 OAB patients treated with once-daily oxybutynin patches for dry mouth and constipation due to oral antimuscarinic drugs. Results：Oxybutynin patch treatment for 8 weeks significantly improved the visual analogue scale scores for dry mouth and constipation；total score and subscore (mean number of urgency episodes and daily micturitions) for OAB symptoms；and King’s Health Questionnaire scores for social limitations, emotions and sleep/energy (P＝0.016 and 0.001；0.008, 0.041 and 0.015；and 0.007, 0.003 and 0.026, respectively). The 3-day frequency volume chart showed significant improvement in hours of undisturbed sleep（P＝0.011）. Eight patients had adverse reactions at the application site and withdrew from the study, while others only developed mild erythema and pruritus. Conclusions：Oxybutynin patch reduces adverse reactions caused by oral antimuscarinic drugs

Efficacy of Tadalafil Add-on Treatment for Men with Lower Urinary Tract Symptoms Refractory to Alpha-1 Adrenoceptor Blockers

Introduction：To evaluate the efficacy and safety of once daily phosphodiesterase type 5 inhibitor(PDE5i) tadalafil as an add-on treatment for men with lower urinary tract symptoms suggestive of benign prostatic hyperplasia（BPH/LUTS）refractory to an alpha 1-blocker（a1-blocker）. Materials and Methods：This study enrolled men aged ＞50 years with BPH/LUTS and erectile dysfunction(ED) that were refractory to ＞3 months of a1-blocker. We defined “refractory” as an international prostate symptoms score (IPSS) of ＞8 and a maximum flow rate (Qmax) ＜15 despite in no space take of an a1-blocker. Patients with contraindications to phosphodiesterase-5 inhibitors；those with symptoms of other diseases that were difficult to differentiate from BPH/LUTS；and those with postvoid residual of ＞100 ml were excluded. Eligible patients received added-on treatment with tadalafil 5 mg/day for 12 weeks. Results：Tadalafil add-on treatment significantly improved the IPSS parameters in terms of total score（P＜0.001）, subscore for storage（P＝0.001）, subscore for voiding（P＜0.001）, and quality of life（P＝0.002）. The 3-day frequency volume chart showed significant improvements in mean number of daily nocturnal micturations（P＝0.002）, nocturnal polyuria index（P＝0.001）, and hours of undisturbed sleep（P＝0.006）. Five patients dropped out because of an adverse event：two with a headache, two with dizziness and one with dyspepsia. There were no serious adverse events. Conclusion：Tadalafil add-on treatment was effective for patients with BPH/LUTS and ED that were resistant to a1-blockers

Experimental petrology of ancient lunar mare basalt Asuka-881757: Spinel crystallization as a petrologic indicator

The paucity of titanian chromites in lunar-meteorite basalt Asuka (A)-881757 is unusual compared to the general occurrence of co-existing chromites and ulvospinels in the Apollo and Luna mare basalts. The unique spinel crystallization of A-881757 is expected to hold a key to elucidate the crystallization and cooling episodes of the basalt. In this study, we investigated the possible reason for the missing chromite by conducting isothermal and cooling experiments on the bulk-rock composition of A-881757 and discuss the petrogenesis of the ancient low-Ti mare basalt in light of spinel crystallization. A series of isothermal experiments showed the A-881757 basalt magma is not saturated with chromite under the expected lunar oxygen fugacity condition (IW～IW-1). A peritectic reaction among chromite, melt, and pyroxene is present for A-881757 basalt magma under the more oxidized condition which is one or two log unit higher than the lunar condition. The cooling experiment successfully reproduced the chromian ulvospinels with similar compositions to those in A-881757. The result of the cooling experiments further implies that ulvospinels solely crystallized from highly-fractionated interstitial melts in the late crystallization stage. The disparity in the crystallization of the liquidus chromite between the low-Ti and very low-Ti basalts might reflect the difference of bulk Cr_2O_3 concentration. The low liquidus temperature and the paucity of the liquidus olivine in A-881757 infer that the A-881757 basalt represents a liquid derived from near-surface fractionation processes. Chromites might possibly have been present during that near-surface fractionation episode prior to the eruption of the magma