Symmetric Mean-field Langevin Dynamics for Distributional Minimax Problems

In this paper, we extend mean-field Langevin dynamics to minimax optimization over probability distributions for the first time with symmetric and provably convergent updates. We propose mean-field Langevin averaged gradient (MFL-AG), a single-loop algorithm that implements gradient descent ascent in the distribution spaces with a novel weighted averaging, and establish average-iterate convergence to the mixed Nash equilibrium. We also study both time and particle discretization regimes and prove a new uniform-in-time propagation of chaos result which accounts for the dependency of the particle interactions on all previous distributions. Furthermore, we propose mean-field Langevin anchored best response (MFL-ABR), a symmetric double-loop algorithm based on best response dynamics with linear last-iterate convergence. Finally, we study applications to zero-sum Markov games and conduct simulations demonstrating long-term optimality.Comment: ICLR 2024 spotligh

CHOROIDAL STRUCTURE IN RP

Purpose: To investigate the choroidal structures in the enhanced depth imaging optical coherence tomographic images in eyes with retinitis pigmentosa (RP) and to determine correlations between the choroidal structures and visual functions. Methods: The enhanced depth imaging optical coherence tomographic images of 100 eyes with typical RP and 60 age-, sex-, and axial length–matched normal eyes were binarized using ImageJ. The cross-sectional luminal and stromal areas of the inner and outer subfoveal choroid of 1,500-µm width were measured. The inner choroid included the choriocapillaris and medium vessel layer, and the outer choroid included the larger vessel layer. Results: In the inner choroid, the luminal area and the ratio of luminal/total choroidal area (L/C ratio) were significantly smaller in RP than in controls (P = 0.010, P < 0.001, respectively), whereas the stromal area was not significantly different (P = 0.114). The inner choroidal L/C ratio was significantly correlated with the best-corrected visual acuity, mean deviation, foveal sensitivity, width of the ellipsoid zone, and central foveal thickness in RP after adjusting for the axial length, age, and sex (all P < 0.005). Conclusion: The significant correlations between the inner choroidal structures and the visual functions and retinal structures indicate that the choroidal structures are altered in association with the progression of RP

Association of elevated plasma B-type natriuretic peptide levels with paroxysmal atrial fibrillation in patients with nonobstructive hypertrophic cardiomyopathy

Objectives: To investigate the relationship between the plasma B-type natriuretic peptide (BNP) level and the occurrence of atrial fibrillation (AF) in nonobstructive hypertrophic cardiomyopathy (HCM) patients. Methods: Patients (n=97) were classified into chronic AF (CAF; n=14), paroxysmal AF (PAF; n=18) and normal sinus rhythm (NSR; n=65) groups. The plasma BNP values were analyzed with logarithmic transformation. Results: The PAF group showed significantly higher plasma BNP levels than the NSR group [mean (range; -1 SD and +1 SD); 248.3 (143.5, 429.5) vs. 78.2 (27.9, 218.8 ng/L), p Conclusions: The present study indicated that plasma BNP level is clinically useful for identification of nonobstructive HCM patients who have a risk of PAF.</p

Üsküdar mesireleri

Taha Toros Arşivi, Dosya No: 63-Salacak-Üsküdarİstanbul Kalkınma Ajansı (TR10/14/YEN/0033) İstanbul Development Agency (TR10/14/YEN/0033

Characterization of a new rice glutelin gene GluD-1 expressed in the starchy endosperm

A new glutelin gene, designated GluD-1, has been discovered by comparing the seed storage proteins from 48 japonica and indica rice cultivars on SDS-PAGE gels. Evidence that GluD-1 is a member of the glutelin family was provided by Western blots using anti-glutelin antiserum and by mapping the gene to the chromosomal glutelin gene cluster. The limited GluD-1 size polymorphism among the rice varieties is due to amino acid substitutions rather than to post-transcriptional modification. GluD-1 is maximally expressed in the starchy endosperm starting at 5 d after flowering (DAF) and increasing through 30 DAF, a major difference from the other glutelins which are primarily expressed in the subaleurone from 10–16 DAF. Only about 0.2 kb of the GluD-1 promoter was sufficient to confer inner starchy endosperm-specific expression. The 0.2 kb truncated GluD-1 promoter contains a bifactorial endosperm box consisting of a truncated GCN4 motif (TGA(G/C)TCA) and AAAG Prolamin box (P box), and ACGT and AACA motifs as cis-regulatory elements. Gel retardation assays and trans-activation experiments indicated that the truncated GCN4 and P box are specifically recognized by RISBZ1 b-ZIP and RPBF Dof activators in vitro, respectively, and are synergistically transactivated, indicating that combinatorial interactions of these motifs are involved in essential endosperm-specific regulation. Furthermore, deviation from the cognate GCN4 motif alters tissue-specific expression in the inner starchy endosperm to include other endosperm tissues

Many Records of Hermatypic Scleractinian Corals that Grew on Molluscan Shells

Forty cases of hermatypic scleractinian corals colonizing molluscan shells were recorded. Forty-five colonies of the corals belonging to eight genera in six families grew on 40 shells belonging to 15 genera in 12 families. Forty colonies were found in Tanabe Bay and its vicinity, southwestern Kii Peninsula, Japan, and 10 colonies in coral reef regions in Okinawa, Palau and probably the Banda Sea and/or the Arafura Sea. Usually one colony, rarely two to four colonies of at least two species of corals, grew on a shell of three families of gastropods and nine families of bivalves. Although the shell surface is a suitable substratum for planula larvae to settle down, coral colonies can not grow to large sizes on the shells. In most cases, shells may not be stable and sufficient substrata for continuous growth of corals. However, the corals on the shells may conduct the sexual reproduction to some extent. Unstability of molluscan shells as footholds may be one of the reasons why the association is not remarkable on the reefs

Simultaneous Measurement of Amino Acid Enantiomers in Aged Mouse Brain Samples by LC/MS/MS Combined with Derivatization Using Nα-(5-Fluoro-2,4-dinitrophenyl)-l-leucinamide (l-FDLA)

d-amino acids have distinct roles from their l-enantiomer. In particular, some d-amino acids function as agonists or antagonists of neuronal receptors and are involved in higher brain functions. Thus, it is important to precisely measure the levels of these amino acid enantiomers in cells and tissues. Various quantification methods have been developed for measurements of chiral amino acids. However, each method has advantages and disadvantages. Additionally, measuring the amino acid enantiomers in crude biological samples requires a higher selectivity. In this study, we developed a quantification method for amino acid enantiomers using derivatization with N&alpha;-(5-Fluoro-2,4-dinitrophenyl)-l-leucinamide (l-FDLA) followed by liquid chromatography&ndash;tandem mass spectrometry (LC/MS/MS) with a conventional reversed-phase column. We simultaneously identified 10 chiral amino acids. Furthermore, we applied this method to investigate murine tissue samples and examined the effect of aging on the amino acid levels in aged brain regions. We found that aging decreased the levels of both d-serine and d-aspartate in the hippocampus. In addition, d-Phenylalanine in the thalamus significantly increased with age. In conclusion, our method is suitable for the quantification of the d-amino acids in crude biological samples and may contribute to elucidating the biological roles of chiral amino acids

Calcium response in single osteocytes to locally applied mechanical stimulus: Differences in cell process and cell body

It is proposed that osteocytes embedded in the bone matrix have the ability to sense deformation and/or damage to the matrix and to feed these mechanical signals back to the adaptive bone remodeling process. When osteoblasts differentiate into osteocytes during the bone formation process, they change their morphology to a stellate form with many slender processes. This characteristic cell shape may underlie the differences in mechanosensitivity between the cell processes and cell body. To elucidate the mechanism of cellular response to mechanical stimulus in osteocytes, we investigated the site-dependent response to quantitatively controlled local mechanical stimulus in single osteocytes isolated from chick embryos, using the technique of calcium imaging. A mechanical stimulus was applied to a single osteocyte using a glass microneedle targeting a microparticle adhered to the cell membrane by modification with a monoclonal antibody OB7.3. Application of the local deformation induced calcium transients in the vicinity of the stimulated point and caused diffusive wave propagation of the calcium transient to the entire intracellular region. The rate of cell response to the stimulus was higher when applied to the cell processes than when applied to the cell body. In addition, a large deformation was necessary at the cell body to induce calcium transients, whereas a relatively small deformation was sufficient at the cell processes, suggesting that the mechanosensitivity of the cell processes was higher than that of the cell body. These results suggest that the cell shape with slender processes contributes to the site-dependent mechanosensitivity in osteocytes

Computer simulation of orthodontic tooth movement using CT image-based voxel finite element models with the level set method

Orthodontic tooth movement (OTM) is an adaptive biomechanical response of dentoalveolar components to orthodontic forces, in which remodeling of the alveolar bone occurs in response to changes in the surrounding mechanical environment. In this study, we developed a framework for OTM simulation by combining an image-based voxel finite element method, with a surface-tracking level set method using three-dimensional computer models. For a case study to demonstrate its capability of expressing clinical tooth movement, we observed displacement and rotation of the tooth under three types of force conditions. The simulation results demonstrate that the proposed simulation method has the potential to predict clinical OTM