Efficient and Scalable Architecture for Multiple-chip Implementation of Simulated Bifurcation Machines

Ising machines are specialized computers for finding the lowest energy states of Ising spin models, onto which many practical combinatorial optimization problems can be mapped. Simulated bifurcation (SB) is a quantum-inspired parallelizable algorithm for Ising problems that enables scalable multi-chip implementations of Ising machines. However, the computational performance of a previously proposed multi-chip architecture tends to saturate as the number of chips increases for a given problem size because both computation and communication are exclusive in the time domain. In this paper, we propose a streaming architecture for multi-chip implementations of SB-based Ising machines with full spin-to-spin connectivity. The data flow in in-chip computation is harmonized with the data flow in inter-chip communication, enabling the computation and communication to overlap and the communication time to be hidden. Systematic experiments demonstrate linear strong scaling of performance up to the vicinity of the ideal communication limit determined only by the latency of chip-to-chip communication. Our eight-FPGA (field-programmable gate array) cluster can compute a 32,768-spin problem with a high pipeline efficiency of 97.9%. The performance of a 79-FPGA cluster for a 100,000-spin problem, projected using a theoretical performance model validated on smaller experimental clusters, is comparable to that of a state-of-the-art 100,000-spin optical Ising machine.Comment: 20 pages, 8 figure

The Significance of Age and Causative Bacterial Morphology in the Choice of an Antimicrobial Agent to Treat Acute Uncomplicated Cystitis

Differentiating patients by age and causative bacterial morphology might aid in making the appropriate choice of antimicrobial agent when treating acute uncomplicated cystitis. In this retrospective analysis, the non-susceptibility rates of the causative bacteria to cefcapene-pivoxil (CFPN-PI) and levofloxacin (LVFX) were determined after dividing patients with acute uncomplicated cystitis by age group (15-54 and 55-74 years old) and by bacterial morphology: gram-positive cocci (GPC) or gram-negative rod (GNR). The overall non-susceptibility rates for CFPN-PI and LVFX were 19.4% and 15.3%, respectively. When the subjects were divided by age, only the non-susceptibility rate for LVFX in the younger group significantly decreased (to 8.7%). When the groups were divided by both age and bacterial morphology, the younger GNR group had non-susceptibility rates of 6.9% to CFPN-PI and 7.8% to LVFX, whereas the younger GPC group showed 10.2% non-susceptibility to LVFX. The older GNR group showed 9.8% non-susceptibility to CFPN-PI, while the older GPC group showed 7.2% non-susceptibility to LVFX. All the non-susceptibility rates were lower than 10.2% in the sub-divided groups. Differentiating patients by age and the morphology of causative bacteria can aid in making the appropriate choice of antimicrobial agent and may improve treatment outcomes in patients with acute uncomplicated cystitis

Real-time Trading System based on Selections of Potentially Profitable, Uncorrelated, and Balanced Stocks by NP-hard Combinatorial Optimization

Financial portfolio construction problems are often formulated as quadratic and discrete (combinatorial) optimization that belong to the nondeterministic polynomial time (NP)-hard class in computational complexity theory. Ising machines are hardware devices that work in quantum-mechanical/quantum-inspired principles for quickly solving NP-hard optimization problems, which potentially enable making trading decisions based on NP-hard optimization in the time constraints for high-speed trading strategies. Here we report a real-time stock trading system that determines long(buying)/short(selling) positions through NP-hard portfolio optimization for improving the Sharpe ratio using an embedded Ising machine based on a quantum-inspired algorithm called simulated bifurcation. The Ising machine selects a balanced (delta-neutral) group of stocks from an $N$-stock universe according to an objective function involving maximizing instantaneous expected returns defined as deviations from volume-weighted average prices and minimizing the summation of statistical correlation factors (for diversification). It has been demonstrated in the Tokyo Stock Exchange that the trading strategy based on NP-hard portfolio optimization for $N$=128 is executable with the FPGA (field-programmable gate array)-based trading system with a response latency of 164 $\mu$s.Comment: 12 pages, 5 figures. arXiv admin note: text overlap with arXiv:2307.0592

The Efficacy of Mirabegron for the Relief of Ureteral Stent-Related Symptoms

To investigate the efficacy of mirabegron for lower urinary tract symptoms in patients with an indwelling ureteral stent after ureterorenoscopic lithotripsy. This was a prospective follow-up study of 76 patients with stent-related symptoms (SRSs). Patients with upper urinary calculi who were pre-stented for > 2 weeks before lithotripsy were examined for the presence of SRSs by tests including the International Prostate Symptom Score (IPSS), OAB Symptom Score (OABSS), and urinary bother and pain measured by a Visual Analogue Scale (VAS) before lithotripsy. Mirabegron (50 mg/day) was prescribed post-lithotripsy for 2 weeks. SRSs were assessed at the time of stent removal. The IPSS scores improved significantly from 16.2 to 14.3 (p<0.001) and the IPSS-QoL scores decreased significantly from 5.0 to 4.6 (p=0.012). The OABSS scores improved significantly from 7.7 to 6.8 (p=0.006), and the urinary urgency scores (OABSS-Q3) decreased significantly from 3.24 to 2.68 (p<0.001). The number of nocturia episodes decreased significantly from 2.5 to 2.2 (p=0.045). Urinary bother and pain assessed by the VAS declined from 4.2 and 3.1 to 3.8 (p=0.15) and 2.5 (p=0.075), respectively. Mirabegron significantly improved SRSs and the number of nocturia episodes due to a ureteral stent

Predicting parking lot availability by graph-to-sequence model: a case study with SmartSantander

Nowadays, so as to improve services and urban area livability, multiple smart city initiatives are being carried out throughout the world. SmartSantander is a smart city project in Santander, Spain, which has relied on wireless sensor network technologies to deploy heterogeneous sensors within the city to measure multiple parameters, including outdoor parking information. In this paper, we study the prediction of parking lot availability using historical data from more than 300 outdoor parking sensors with SmartSantander. We design a graph-to-sequence model to capture the periodical fluctuation and geographical proximity of parking lots. For developing and evaluating our model, we use a 3-year dataset of parking lot availability in the city of Santander. Our model achieves a high accuracy compared with existing sequence-to-sequence models, which is accurate enough to provide a parking information service in the city. We apply our model to a smartphone application to be widely used by citizens and tourists.This research is partially supported by the Grant-in-Aid for Scientific Research JP20H00584 and JP22H03700. We thank to SmartSantander developer group

IgA-enhancing effects of membrane vesicles derived from Lactobacillus sakei subsp. sakei NBRC15893

Immunoglobulin (Ig) A in the mucus of the intestinal tract plays an important role in preventing the invasion of pathogenic microorganisms and regulating the composition of the gut microbiota. Several strains of probiotic lactic acid bacteria (LAB) are known to promote intestinal IgA production. Bacteria are also known to naturally release spherical membrane vesicles (MVs) that are involved in various biological functions such as quorum sensing, pathogenesis, and host immunomodulation. However, the production of MVs by LAB and their effects on host immunity remain poorly understood. In this study, we investigated the MV production by Lactobacillus sakei subsp. sakei NBRC15893 isolated from kimoto, the traditional seed mash used for brewing sake. MVs were separated from the culture broth of L. sakei NBRC15893 through filtration and density gradient ultracentrifugation and were observed by transmission electron microscopy. The MVs showed a spherical morphology, with a diameter of 30–400 nm, and contained proteins and nucleic acids. In addition, both the LAB cells and purified MVs promoted IgA production by murine Peyer’s patch cells. This MV- and cell-induced IgA production was suppressed by neutralization of Toll-like receptor (TLR) 2, which recognizes cell wall components of gram-positive bacteria, using an anti-TLR2 antibody. Collectively, our results indicate that MVs released from L. sakei NBRC15893 enhance IgA production by activating host TLR2 signaling through its cell wall components. Thus, it is important to consider novel interactions between gut microbiota and hosts via MVs, and MVs derived from probiotic bacteria could have promising applications as safe adjuvants.Japan Society for the Promotion of Science (JSPS) KAKENHI grant (Nos. 16K18302 and 18K04857 [to S.Y.Y]; 15H05790, 16H01373, 17H04134, and 26293111 [to J.K.]

Thoracoscopic Surgery in a Patient with Multiple Esophageal Carcinomas after Surgery for Esophageal Achalasia

We present a case in which we used a thoracoscopic approach for resection of multiple esophageal carcinomas diagnosed 33 years after surgery for esophageal achalasia. A 68-year-old Japanese man had been diagnosed with esophageal achalasia and underwent surgical treatment 33 years earlier. He was examined at our hospital for annual routine checkup in which upper gastrointestinal endoscopy showed a “0-IIb+IIa” lesion in the middle esophagus. Iodine staining revealed multiple irregularly shaped iodine-unstained areas, the diagnosis of which was esophageal carcinoma. Thoracoscopic subtotal esophagectomy was performed. Esophageal carcinoma may occur many years after surgery for esophageal achalasia, even if the passage symptoms have improved. So, long-term periodic follow-up is necessary for detection of carcinoma at an earlier stage

Splenic Infarction in Acute Cytomegalovirus and Human Parvovirus Concomitant Infection

We present a case report of a 35-year-old woman who had splenic infarction. She had persistent high fever, systemic joint pain, and abnormal liver function. She was diagnosed with cytomegalovirus and human parvovirus B19 concomitant infection. Her coagulopathy test revealed no abnormal results. She was treated with intravenous ganciclovir for 13 days; consequently, her splenic infarction improved after 7 weeks. As per our knowledge, this is the first case of cytomegalovirus and parvovirus B19 coinfection complicated by splenic infarction. Cytomegalovirus and parvovirus B19 may induce a hypercoagulation state during the acute phase