Temporal and Spatial Analyses of Spectral Indices of Nonthermal Emissions Derived from Hard X-Rays and Microwaves

We studied electron spectral indices of nonthermal emissions seen in hard X-rays (HXRs) and in microwaves. We analyzed 12 flares observed by the Hard X-ray Telescope aboard {\it Yohkoh}, Nobeyama Radio Polarimeters (NoRP), and the Nobeyama Radioheliograph (NoRH), and compared the spectral indices derived from total fluxes of hard X-rays and microwaves. Except for four events, which have very soft HXR spectra suffering from the thermal component, these flares show a gap $\Delta\delta$ between the electron spectral indices derived from hard X-rays $\delta_{X}$ and those from microwaves $\delta_{\mu}$ ($\Delta\delta = \delta_{X} - \delta_{\mu}$) of about 1.6. Furthermore, from the start to the peak times of the HXR bursts, the time profiles of the HXR spectral index $\delta_{X}$ evolve synchronously with those of the microwave spectral index $\delta_{\mu}$, keeping the constant gap. We also examined the spatially resolved distribution of the microwave spectral index by using NoRH data. The microwave spectral index $\delta_{\mu}$ tends to be larger, which means a softer spectrum, at HXR footpoint sources with stronger magnetic field than that at the loop tops. These results suggest that the electron spectra are bent at around several hundreds of keV, and become harder at the higher energy range that contributes the microwave gyrosynchrotron emission.Comment: 24 pages, 6 figures, accepted for publication in Ap

Control of the ZZZZ coupling between Kerr-cat qubits via transmon couplers

Kerr-cat qubits are a promising candidate for fault-tolerant quantum computers owing to the biased nature of errors. The $ZZ$ coupling between the qubits can be utilized for a two-qubit entangling gate, but the residual coupling causes unnecessary always-on gates and crosstalk. In order to resolve this problem, we propose a tunable $ZZ$-coupling scheme using two transmon couplers. By setting the detunings of the two couplers at opposite values, the residual $ZZ$ couplings via the two couplers cancel each other out. We also apply our scheme to the $R_{zz}(\Theta)$ gate ($ZZ$ rotation with angle $\Theta$), one of the two-qubit entangling gates. We numerically show that the fidelity of the $R_{zz}(-\pi/2)$ gate is higher than 99.9% in a case of 16 ns gate time and without decoherence.Comment: 8 pages, 5 figure

Postoperative clinical outcomes of unicompartmental knee arthroplasty in patients with isolated medial compartmental osteoarthritis following medial meniscus posterior root tear

Background: Cartilage degradation progresses rapidly following medial meniscus posterior root tear (MMPRT). Unicompartmental knee arthroplasty (UKA) has been performed for medial compartmental osteoarthritis following MMPRT. We evaluated the clinical and radiographic outcomes of UKA for medial compartmental osteoarthritis after an untreated MMPRT. Methods: Twenty-one patients who underwent UKA for isolated medial compartment osteoarthritis following MMPRT were retrospectively investigated. Clinical outcomes were assessed using the Knee Injury and Osteoarthritis Outcome Score and knee range of motion. The posterior tibial slope and tibial component inclination were evaluated using plain radiographs. Results: The mean follow-up periods were 25.5 +/- 13.8 months. Clinical outcomes improved significantly postoperatively. The mean postoperative knee extension angle was-1.1 degrees +/- 2.1 degrees, and the knee flexion angle was 134.3 degrees +/- 4.9 degrees. The posterior tibial slope angle decreased from 9.0 degrees +/- 2.0 degrees preoperatively to 5.4 degrees +/- 1.8 degrees postoperatively, and postoperative tibial component inclination at the final follow-up was 2.9 degrees +/- 1.1 degrees varus. No aseptic loosening or deep infections were observed. Conclusion: UKA significantly improved clinical outcomes and could be a viable surgical option for treating isolated medial compartmental osteoarthritis accompanied by untreated MMPRT

Combining pullout suture and retrograde screw fixation for anterior cruciate ligament tibial eminence avulsion fractures: A case report

This report describes a novel arthroscopic technique for the treatment of anterior cruciate ligament (ACL) tibial eminence avulsion fractures. A 16-year-old boy who was diagnosed with a left ACL tibial eminence avulsion fracture was treated by arthroscopic fixation. Two bone tunnels were created from the anterior tibial cortex into the fracture bed, and a strong suture passed through the ACL just above its insertion was pulled out through them for reduction and fixation. A retrograde cannulated screw fixation was added for stronger fixation. Weight-bearing and range of motion exercises were started immediately after surgery. Radiographically, bone union was obtained 6 months postoperatively. During second-look arthroscopy (24 months postoperatively), there was no loss of reduction and no subsequent meniscal or cartilage injuries. At that point, the Lysholm score was 95, and the International Knee Documentation Committee score was 96

A Human Reaching Movement Model for Myoelectric Prosthesis Control

This paper proposes a reaching movement model for the generation of desired trajectories within a myoelectric prosthesis training system. First, an experiment was performed to observe reaching movements with a non-impaired subject and a myoelectric prosthesis user. Reaching movements made by the prosthesis user were then adopted to construct a model based on a logistic function. The proposed model can be used to generate three trajectory types with a bell-shaped speed profile with the adjustment of only a few parameters.This work was partially supported by a Grant-in-Aid for Young Scientists B Number 26730111

Imaging Spectroscopy on Preflare Coronal Nonthermal Sources Associated with the 2002 July 23 Flare

We present a detailed examination on the coronal nonthermal emissions during the preflare phase of the X4.8 flare that occurred on 2002 July 23. The microwave (17 GHz and 34 GHz) data obtained with Nobeyama Radioheliograph, at Nobeyama Solar Radio Observatory and the hard X-ray (HXR) data taken with {\it Reuven Ramaty High Energy Solar Spectroscopic Imager} obviously showed nonthermal sources that are located above the flare loops during the preflare phase. We performed imaging spectroscopic analyses on the nonthermal emission sources both in microwaves and in HXRs, and confirmed that electrons are accelerated from several tens of keV to more than 1 MeV even in this phase. If we assume the thin-target model for the HXR emission source, the derived electron spectral indices ($\sim 4.7$) is the same value as that from microwaves ($\sim 4.7$) within the observational uncertainties, which implies that the distribution of the accelerated electrons follows a single power-law. The number density of the microwave-emitting electrons is, however, larger than that of the HXR-emitting electrons, unless we assume low ambient plasma density of about $1.0 \times 10^9$ cm$^{-3}$ for the HXR-emitting region. If we adopt the thick-target model for the HXR emission source, on the other hand, the electron spectral index ($\sim 6.7$) is much different, while the gap of the number density of the accelerated electrons is somewhat reduced.Comment: 21 pages, 6 figures, ApJ accepte

A virtual myoelectric prosthesis training system capable of providing instructions on hand operations

This article proposes a virtual hand and a virtual training system for controlling the MyoBock—the most commonly used myoelectric prosthetic hand worldwide. As the virtual hand is controlled using the method also adopted for the MyoBock hand, the proposed system provides upper-limb amputees with operation sensibilities similar to those experienced in MyoBock control. It can also display an additional virtual hand for the provision of instructions on hand operation, such as the recommended posture for object grasping and the trajectory desirable to reach a target. In virtual hand control experiments conducted with an amputee to evaluate the proposed virtual hand’s operability, the subject successfully performed stable opening and closing with high discrimination rates (89.3±6.65%), thanks to the virtual hand’s incorporation of the MyoBock’s operational characteristics. A training experiment using the proposed system was also conducted with eight healthy participants over a period of 5 days. The participants were asked to perform the box and block test using the MyoBock hand in a real environment on the first and final days. The results showed that the number of blocks transported in 1 min significantly increased and that the participants using the instruction virtual hand changed the orientation of the hand approaching blocks from vertical to lateral. The outcomes of the experiment indicate that the proposed system can be used to improve MyoBock hand control operation both quantitatively and qualitatively.This work was partially supported by a Grant-in-Aid for Young Scientists B Number 26730111 and a Grant-in-Aid for Scientific Research C Number 26462242

Glycolate is a Novel Marker of Vitamin B2 Deficiency Involved in Gut Microbe Metabolism in Mice

Microbes in the human gut play a role in the production of bioactive compounds, including some vitamins. Although several studies attempted to identify definitive markers for certain vitamin deficiencies, the role of gut microbiota in these deficiencies is unclear. To investigate the role of gut microbiota in deficiencies of four vitamins, B2, B6, folate, and B12, we conducted a comprehensive analysis of metabolites in mice treated and untreated with antibiotics. We identified glycolate (GA) as a novel marker of vitamin B2 (VB2) deficiency, and show that gut microbiota sense dietary VB2 deficiency and accumulate GA in response. The plasma GA concentration responded to reduced VB2 supply from both the gut microbiota and the diet. These results suggest that GA is a novel marker that can be used to assess whether or not the net supply of VB2 from dietary sources and gut microbiota is sufficient. We also found that gut microbiota can provide short-term compensation for host VB2 deficiency when dietary VB2 is withheld