Spatial-photonic Boltzmann machines: low-rank combinatorial optimization and statistical learning by spatial light modulation

The spatial-photonic Ising machine (SPIM) [D. Pierangeli et al., Phys. Rev. Lett. 122, 213902 (2019)] is a promising optical architecture utilizing spatial light modulation for solving large-scale combinatorial optimization problems efficiently. However, the SPIM can accommodate Ising problems with only rank-one interaction matrices, which limits its applicability to various real-world problems. In this Letter, we propose a new computing model for the SPIM that can accommodate any Ising problem without changing its optical implementation. The proposed model is particularly efficient for Ising problems with low-rank interaction matrices, such as knapsack problems. Moreover, the model acquires learning ability and can thus be termed a spatial-photonic Boltzmann machine (SPBM). We demonstrate that learning, classification, and sampling of the MNIST handwritten digit images are achieved efficiently using SPBMs with low-rank interactions. Thus, the proposed SPBM model exhibits higher practical applicability to various problems of combinatorial optimization and statistical learning, without losing the scalability inherent in the SPIM architecture.Comment: 7 pages, 5 figures (with a 3-page supplemental

Spatial-photonic Ising machine by space-division multiplexing with physically tunable coefficients of a multi-component model

This paper proposes a space-division multiplexed spatial-photonic Ising machine (SDM-SPIM) that physically calculates the weighted sum of the Ising Hamiltonians for individual components in a multi-component model. Space-division multiplexing enables tuning a set of weight coefficients as an optical parameter and obtaining the desired Ising Hamiltonian at a time. We solved knapsack problems to verify the system's validity, demonstrating that optical parameters impact the search property. We also investigated a new dynamic coefficient search algorithm to enhance search performance. The SDM-SPIM would physically calculate the Hamiltonian and a part of the optimization with an electronics process.Comment: 12 pages, 5 figure

ALS mutations in the TIA-1 prion-like domain trigger highly condensed pathogenic structures

筋萎縮性側索硬化症（ALS）の発症機構の一端を解明 --タンパク質の高密度な凝縮構造が鍵--. 京都大学プレスリリース. 2022-09-13.T cell intracellular antigen-1 (TIA-1) plays a central role in stress granule (SG) formation by self-assembly via the prion-like domain (PLD). In the TIA-1 PLD, amino acid mutations associated with neurodegenerative diseases, such as amyotrophic lateral sclerosis (ALS) or Welander distal myopathy (WDM), have been identified. However, how these mutations affect PLD self-assembly properties has remained elusive. In this study, we uncovered the implicit pathogenic structures caused by the mutations. NMR analysis indicated that the dynamic structures of the PLD are synergistically determined by the physicochemical properties of amino acids in units of five residues. Molecular dynamics simulations and three-dimensional electron crystallography, together with biochemical assays, revealed that the WDM mutation E384K attenuated the sticky properties, whereas the ALS mutations P362L and A381T enhanced the self-assembly by inducing β-sheet interactions and highly condensed assembly, respectively. These results suggest that the P362L and A381T mutations increase the likelihood of irreversible amyloid fibrillization after phase-separated droplet formation, and this process may lead to pathogenicity

Topographic variability of the left atrium and pulmonary veins assessed by 3D-CT predicts the recurrence of atrial fibrillation after catheter ablation

AbstractBackgroundCatheter ablation (CA) is an established therapy for atrial fibrillation (AF). However, the assessment of anatomical information and predictors of AF recurrence remain unclear. We investigated the relationship between anatomical information on the left atrium (LA) and pulmonary veins (PVs) from three-dimensional computed tomography images and the recurrence of AF after CA.MethodsSixty-seven consecutive AF patients (mean age: 62±10 years, median AF history: 42 (12; 60) months, mean LA size: 41±7mm, paroxysmal: 56%) underwent CA and were followed for 19±10 months. The segmented surface areas (antral, posterior, septal, and lateral) and dimensions (between the anterior and posterior walls, the right inferior PV and mitral annulus [MA], the right superior PV and MA, the left superior PV and MA, and the mitral isthmus) of the LA were evaluated three dimensionally using the NavX system. The cross-sectional areas of the PVs were also evaluated.ResultsAfter the follow-up period, 49 patients (73%) remained free from AF. A multivariate analysis showed that the diameter of the mitral isthmus and cross-sectional area of the right upper PV were associated with AF recurrence (odds ratio: 1.070, CI: 1.02–1.12, p=0.001; odds ratio: 0.41, CI: 0.21–0.77, p=0.006).ConclusionEnlargement of the mitral isthmus and a smaller right superior PV cross-sectional area were associated with AF recurrence

Geochemical characteristics of back-arc basin lower crust and upper mantle at final spreading stage of Shikoku Basin: an example of Mado Megamullion

AbstractThis paper explores the evolutional process of back-arc basin (BAB) magma system at final spreading stage of extinct BAB, Shikoku Basin (Philippine Sea) and assesses its tectonic evolution using a newly discovered oceanic core complex, the Mado Megamullion. Bulk and in-situ chemical compositions together with in-situ Pb isotope composition of dolerite, oxide gabbro, gabbro, olivine gabbro, dunite, and peridotite are presented. Compositional ranges and trends of the igneous and peridotitic rocks from the Mado Megamullion are similar to those from the slow- to ultraslow-spreading mid-ocean ridges (MOR). Since the timing of the Mado Megamullion exhumation corresponds to the very end of the Shikoku Basin opening, the magma supply was subdued and highly episodic, leading to extreme magma differentiation to form ferrobasaltic, hydrous magmas. In-situ Pb isotope composition of magmatic brown amphibole in the oxide gabbro is identical to that of depleted source mantle for mid-ocean ridge basalt (MORB). In the context of hydrous BAB magma genesis, the magmatic water was derived solely from the MORB source mantle. The distance from the back-arc spreading center to the arc front increased away through maturing of the Shikoku Basin to cause MORB-like magmatism. After the exhumation of Mado Megamullion along detachment faults, dolerite dikes intruded as a post-spreading magmatism. The final magmatism along with post-spreading Kinan Seamount Chain volcanism were introduced around the extinct back-arc spreading center after the opening of Shikoku Basin by residual mantle upwelling

Diphenhydramine against cisplatin nephrotoxicity

Cisplatin is widely used as an anti-tumor drug for the treatment of solid tumors. Unfortunately, it causes nephrotoxicity as a critical side effect, limiting its use, given that no preventive drug against cisplatin-induced nephrotoxicity is currently available. This study identified that a previously developed drug, diphenhydramine, may provide a novel treatment for cisplatin-induced nephrotoxicity based on the results of the analysis of medical big data. We evaluated the actual efficacy of diphenhydramine via in vitro and in vivo experiments in a mouse model. Diphenhydramine inhibited cisplatin-induced cell death in renal proximal tubular cells. Mice administered cisplatin developed kidney injury with renal dysfunction (plasma creatinine: 0.43 ± 0.04 mg/dl vs 0.15 ± 0.01 mg/dl, p<0.01) and showed augmented oxidative stress, increased apoptosis, elevated inflammatory cytokines, and mitogen-activated protein kinases activation; however, most of these symptoms were suppressed by treatment with diphenhydramine. Further, the renal concentration of cisplatin was attenuated in diphenhydramine-treated mice (platinum content: 70.0 ± 3.3 µg/g dry kidney weight vs 53.4 ± 3.6 µg/g dry kidney weight, p<0.05). Importantly, diphenhydramine did not influence or interfere with the anti-tumor effect of cisplatin in any of the in vitro or in vivo experiments. Moreover, a retrospective clinical study of 1467 cancer patients treated with cisplatin showed that patients who had used diphenhydramine exhibited less acute kidney injury than patients who had not used diphenhydramine (6.1 % vs 22.4 %, p<0.05). Thus, diphenhydramine demonstrated efficacy as a novel preventive medicine against cisplatin-induced nephrotoxicity

A variant Philadelphia chromosome (Ph1) positive chronic myelocytic leukemia.

A rare case of variant Philadelphia (Ph1) chromosome positive [46, XX, t (9; 22) (q34; q11), inv (9) (9q22; 22q13)] chronic myelocytic leukemia (CML) was described. The patient, 73 years old female, was hospitalized to our hospital because of leukocytosis. Hematological findings corresponded to those of CMLs. However, this case lacked hepatosplenomegaly. Southern blot analysis using a 3 breakpoint cluster region (bcr) probe revealed a bcr rearrangement. The patient has been in the chronic phase for sixteen months without treatment. Clinical and chromosomal changes are under observation in order to get accumulate data for a pathophysiological analysis of variant Ph1 positive CMLs.</p