Belief inference for hierarchical hidden states in spatial navigation

Uncertainty abounds in the real world, and in environments with multiple layers of unobservable hidden states, decision-making requires resolving uncertainties based on mutual inference. Focusing on a spatial navigation problem, we develop a Tiger maze task that involved simultaneously inferring the local hidden state and the global hidden state from probabilistically uncertain observation. We adopt a Bayesian computational approach by proposing a hierarchical inference model. Applying this to human task behaviour, alongside functional magnetic resonance brain imaging, allows us to separate the neural correlates associated with reinforcement and reassessment of belief in hidden states. The imaging results also suggest that different layers of uncertainty differentially involve the basal ganglia and dorsomedial prefrontal cortex, and that the regions responsible are organised along the rostral axis of these areas according to the type of inference and the level of abstraction of the hidden state, i.e. higher-order state inference involves more anterior parts

Turbulence on open string worldsheets under non-integrable boundary conditions

We demonstrate the turbulent dynamics of the Nambu-Goto open string in the AdS3 spacetime. While the motion of a classical closed string in AdS is known to be integrable, the integrability of an open string motion depends on the boundary conditions at the string endpoints. We numerically solve the equations of motion of the open string under the boundary conditions where the endpoints are i) fixed to a finite radial coordinate in AdS, and ii) free. For i), we find turbulence on the string, that shows a cascade in the energy and angular momentum spectra. This result indicates the non-integrability of the open string with this type of boundary conditions. For ii), we find no turbulence. This is consistent with the integrability of the open string with the free boundary conditions.Comment: 21 pages, 10 figure

Integrated analysis of cell shape and movement in moving frame

形を変えながら動く3次元物体の解析手法の提唱 --動くから形が変わるのか、形を変えることで動くのか--. 京都大学プレスリリース. 2021-03-31.The cell's movement and morphological change are two interrelated cellular processes. An integrated analysis is needed to explore the relationship between them. However, it has been challenging to investigate them as a whole. The cell's trajectory can be described by its speed, curvature, and torsion. On the other hand, the three-dimensional (3D) cell shape can be studied by using a shape descriptor such as spherical harmonic (SH) descriptor, which is an extension of a Fourier transform in 3D space. We propose a novel method using parallel-transport (PT) to integrate these shape-movement data by using moving frames as the 3D-shape coordinate system. This moving frame is purely determined by the velocity vector. On this moving frame, the movement change will influence the coordinate system for shape analysis. By analyzing the change of the SH coefficients over time in the moving frame, we can observe the relationship between shape and movement. We illustrate the application of our approach using simulated and real datasets in this paper

The absence of SOX2 in the anterior foregut alters the esophagus into trachea and bronchi in both epithelial and mesenchymal components

In the anterior foregut (AFG) of mouse embryos, the transcription factor SOX2 is expressed in the epithelia of the esophagus and proximal branches of respiratory organs comprising the trachea and bronchi, whereas NKX2.1 is expressed only in the epithelia of respiratory organs. Previous studies using hypomorphic Sox2 alleles have indicated that reduced SOX2 expression causes the esophageal epithelium to display some respiratory organ characteristics. In the present study, we produced mouse embryos with AFG-specific SOX2 deficiency. In the absence of SOX2 expression, a single NKX2.1-expressing epithelial tube connected the pharynx and the stomach, and a pair of bronchi developed in the middle of the tube. Expression patterns of NKX2.1 and SOX9 revealed that the anterior and posterior halves of SOX2-deficient AFG epithelial tubes assumed the characteristics of the trachea and bronchus, respectively. In addition, we found that mesenchymal tissues surrounding the SOX2-deficient NKX2.1-expressing epithelial tube changed to those surrounding the trachea and bronchi in the anterior and posterior halves, as indicated by the arrangement of smooth muscle cells and SOX9-expressing cells and by the expression of Wnt4 (esophagus specific), Tbx4 (respiratory organ specific), and Hoxb6 (distal bronchus specific). The impact of mesenchyme-derived signaling on the early stage of AFG epithelial specification has been indicated. Our study demonstrated an opposite trend where epithelial tissue specification causes concordant changes in mesenchymal tissues, indicating a reciprocity of epithelial-mesenchymal interactions

Diagnostic value of computed high b-value whole-body diffusion-weighted imaging for primary prostate cancer

Purpose: To investigate the utility of post-acquisition computed diffusion-weighted imaging (cDWI) for primary prostate cancer (PCa) evaluation in biparametric whole-body MRI (bpWB-MRI). Methods: Patients who underwent pelvic MRI for PCa screening and subsequent bpWB-MRI for staging were included. Two radiologists assessed the diagnostic performance of the following datasets for clinically significant PCa diagnosis (grade group >= 2 according to the Prostate Imaging-Reporting and Data System, version 2.1): bpMRI(2000) (axial DWI scans with a b-value of 2,000 s/mm(2) + axial T2WI scans from pre-biopsy pelvic MRI), computed bpWB-MRI2000 (computed WB-DWI scans with a b-value of 2,000 s/mm(2) + axial WB-T2WI scans), and native bpWB-MRI1000 (native axial WB-DWI scans with a b-value of 1,000 s/mm(2) + axial WB-T2WI scans). Systemic biopsy was used as reference standard. Results: Fifty-one patients with PCa were included. The areas under the curve (AUCs) of bpMRI(2000) (0.89 for reader 1 and 0.86 for reader 2) and computed bpWB-MRI2000 (0.86 for reader 1 and 0.83 for reader 2) were significantly higher (p < 0.001) than those of native bpWB-MRI1000 (0.67 for both readers). No significant difference was observed between the AUCs of bpMRI(2000) and computed bpWB-MRI2000 (p = 0.10 for reader 1 and p = 0.25 for reader 2). Conclusions: The diagnostic performance of computed bpWB-MRI2000 was similar to that of dedicated pelvic bpMRI(2000) for primary PCa evaluation. cDWI can be recommended for implementation in standard WB-MRI protocols to facilitate a one-step evaluation for concurrent detection of primary and metastatic PCa

Clinical utility of the Bosniak classification version 2019:Diagnostic value of adding magnetic resonance imaging to computed tomography examination

Purpose: To assess the impact of the updated Bosniak classification (BC2019) for cystic renal masses (CRMs) on interobserver agreement between radiologists and urologists and the diagnostic value of adding MRI to CT examination (combined CT/MRI). Method: This study included 103 CRMs from 83 consecutive patients assessed using contrast-enhanced CT and MRI between 2010 and 2016. Nine readers in three groups (three radiologists, three radiology residents, and three urologists) reviewed CT alone and the combined CT/MRI using BC2019. Bosniak category was determined by consensus in each group for diagnosing malignancy, with a cut-off category of ?>= III. Interobserver agreement was assessed using Fleiss' kappa values. The effect of CT or combined CT/MRI on the diagnosis of malignancy was assessed using McNemar's test. Results: Interobserver agreement of BC2019 for CT alone was substantial for radiologists and residents, moderate for urologists (0.77, 0.63, and 0.58, respectively). Interobserver agreement of BC2019 for combined CT/MRI was substantial for all three groups (radiologists: 0.78; residents: 0.65; and urologists: 0.61). Among residents, the sensitivity/specificity/accuracy rates of combined CT/MRI vs. CT alone were 82.1/74.7/76.7% vs. 75.0/66.7/68.9%, and specificity and accuracy were significantly higher for combined CT/MRI than that for CT alone (p = 0.03 and 0.008, respectively). Similarly, sensitivity/specificity/accuracy values were significantly higher for combined CT/MRI among urologists (78.6/73.3/74.8% vs. 64.3/64.0/64.1%, p = 0.04/0.04/0.008). However, sensitivity/specificity/accuracy did not significantly differ between the two among radiologists (89.3/74.7/78.6% vs. 85.7/73.3/76.7%, p = 0.32/0.56/0.32). Conclusions: Combined CT/MRI is useful for diagnosing malignancy in patients with CRMs using BC2019, especially for non-expert readers

Comparison of Efficacy and Safety between Mosapride and Acotiamide for Japanese patients with Functional Dyspepsia

　Background: 5-HT4 agonists (mosapride) and acetylcholine esterase inhibitor (acotiamide) are prokinetics used to treat functional dyspepsia (FD). However, to date, there has been no direct comparative study between them. The aim of this study was to compare the drugs’ efficacy and safety and to determine their predictive biomarkers.　Methods: The present study was a prospective, randomized, open-labeled, and crossover trial in Japanese FD patients. FD was diagnosed using Rome IV. We performed upper gastrointestinal (GI) endoscopy, GI symptom rating scale, and 8-item Short-Form Health Survey to evaluate the presence of GI disorders, GI symptoms, and quality of life (QOL), respectively. Responders were defined when reporting at least a 40% improvement of the GSRS scores from their baseline.　Results: In total, 60 Japanese FD patients were randomly assigned to the acotiamide preceding group (n = 30) or mosapride preceding group (n = 30), and 51 patients were finally analyzed. Following treatment with both mosapride and acotiamide, GI symptoms and QOL scores improved significantly. The responder rates of mosapride and acotiamide were 37% and 33%, respectively. No severe adverse clinical event developed. The prevalence of H. pylori eradication history was significantly lower in the mosapride responder group than in the nonresponder group (45.9% vs. 14.2%, p = 0.03).　Discussion: Mosapride and acotiamide had similar effects on GI symptoms in FD patients in the absence of severe adverse events. H. pylori infection might impact in the pathogenesis of functional dyspepsia. Further investigation is needed to clarify the difference between mosapride and acotiamide