USIM-DAL: Uncertainty-aware Statistical Image Modeling-based Dense Active Learning for Super-resolution

Dense regression is a widely used approach in computer vision for tasks such as image super-resolution, enhancement, depth estimation, etc. However, the high cost of annotation and labeling makes it challenging to achieve accurate results. We propose incorporating active learning into dense regression models to address this problem. Active learning allows models to select the most informative samples for labeling, reducing the overall annotation cost while improving performance. Despite its potential, active learning has not been widely explored in high-dimensional computer vision regression tasks like super-resolution. We address this research gap and propose a new framework called USIM-DAL that leverages the statistical properties of colour images to learn informative priors using probabilistic deep neural networks that model the heteroscedastic predictive distribution allowing uncertainty quantification. Moreover, the aleatoric uncertainty from the network serves as a proxy for error that is used for active learning. Our experiments on a wide variety of datasets spanning applications in natural images (visual genome, BSD100), medical imaging (histopathology slides), and remote sensing (satellite images) demonstrate the efficacy of the newly proposed USIM-DAL and superiority over several dense regression active learning methods.Comment: Accepted at UAI 202

Exploring the Potential Role of Herbal Ayurveda Formulation Vasadi Kashaya in Chronic Obstructive Pulmonary Disease - A Review

Chronic obstructive pulmonary disease (COPD) is a disease of respiratory system having chronic nature which is characterised by airway inflammation and airflow obstruction that is not fully reversible. It includes two clinical conditions, chronic bronchitis and emphysema which generally overlap in patients. It is a preventable and treatable disease that is caused by significant exposure to harmful gases or organic matter. The common clinical symptoms include dyspnoea, cough, sputum production, chest tightness. According to the global burden of disease study reports published in 2018, COPD is the second leading cause of death due to non-communicable diseases in India. COPD in Ayurveda is can be dealt in Ayurvedic clinical practice using treatment principles of Shwasa and Kasa. Vasadi Kashaya, a herbal Ayurveda medicine is commonly used in the treatment of respiratory disorders by Ayurveda practitioners. Aim: In this article, possible mode of action of Vasadi Kashaya in the treatment of COPD have been explored based on available Ayurvedic and scientific literature. Methodology: Information from Ayurveda text books and available full text articles on different medical online sources was collected using relevant keywords and are summarised in this article. Conclusion: Available scientific evidence supports the anti-inflammatory, bronchodilator, anti-allergic, anti-oxidant and immune-modulator properties of Vasadi Kashaya making it a potential herbal formulation for Ayurvedic management of COPD

Molecular characterization of methanogenic N(5)-methyl-tetrahydromethanopterin : coenzyme M methyltransferase

Methanogenic archaea share one ion gradient forming reaction in their energy metabolism catalyzed by the membrane-spanning multisubunit complex N5-methyl-tetrahydromethanopterin: coenzyme M methyltransferase (MtrABCDEFGH or simply Mtr). In this reaction the methyl group transfer from methyl-tetrahydromethanopterin to coenzyme M mediated by cobalamin is coupled with the vectorial translocation of Na+ across the cytoplasmic membrane. No detailed structural and mechanistic data are reported about this process. In the present work we describe a procedure to provide a highly pure and homogenous Mtr complex on the basis of a selective removal of the only soluble subunit MtrH with the membrane perturbing agent dimethyl maleic anhydride and a subsequent two-step chromatographic purification. A molecular mass determination of the Mtr complex by laser induced liquid bead ion desorption mass spectrometry (LILBID-MS) and size exclusion chromatography coupled with multi-angle light scattering (SEC-MALS) resulted in a (MtrABCDEFG)3 heterotrimeric complex of ca. 430 kDa with both techniques. Taking into account that the membrane protein complex contains various firmly bound small molecules, predominantly detergent molecules, the stoichiometry of the subunits is most likely 1:1. A schematic model for the subunit arrangement within the MtrABCDEFG protomer was deduced from the mass of Mtr subcomplexes obtained by harsh IR-laser LILBID-MS

High-Resolution Cryoelectron Microscopy Structure of the Cyclic Nucleotide-Modulated Potassium Channel MloK1 in a Lipid Bilayer

Eukaryotic cyclic nucleotide-modulated channels perform their diverse physiological roles by opening and closing their pores to ions in response to cyclic nucleotide binding. We here present a structural model for the cyclic nucleotide-modulated potassium channel homolog from Mesorhizobium loti, MloK1, determined from 2D crystals in the presence of lipids. Even though crystals diffract electrons to only ∼10 Å, using cryoelectron microscopy (cryo-EM) and recently developed computational methods, we have determined a 3D map of full-length MloK1 in the presence of cyclic AMP (cAMP) at ∼4.5 Å isotropic 3D resolution. The structure provides a clear picture of the arrangement of the cyclic nucleotide-binding domains with respect to both the pore and the putative voltage sensor domains when cAMP is bound, and reveals a potential gating mechanism in the context of the lipid-embedded channel

Structure and Catalytic Mechanism of <i>N</i>⁵,<i>N</i>¹⁰-Methenyl-tetrahydromethanopterin Cyclohydrolase

Methenyltetrahydromethanopterin (methenyl-H₄MPT⁺) cyclohydrolase (Mch) catalyzes the interconversion of methenyl-H₄MPT⁺ and formyl-H₄MPT in the one-carbon energy metabolism of methanogenic, methanotrophic, and sulfate-reducing archaea and of methylotrophic bacteria. To understand the catalytic mechanism of this reaction, we kinetically characterized site-specific variants of Mch from <i>Archaeoglobus fulgidus</i> (aMch) and determined the X-ray structures of the substrate-free aMch­(E186Q), the aMch:H₄MPT complex, and the aMch­(E186Q):formyl-H₄MPT complex. (Formyl-)­H₄MPT is embedded inside a largely preformed, interdomain pocket of the homotrimeric enzyme with the pterin and benzyl rings being oriented nearly perpendicular to each other. The active site is primarily built up by the segment 93:95, Arg183 and Glu186 that either interact with the catalytic water attacking methenyl-H₄MPT⁺ or with the formyl oxygen of formyl-H₄MPT. The catalytic function of the strictly conserved Arg183 and Glu186 was substantiated by the low enzymatic activities of the E186A, E186D, E186N, E186Q, R183A, R183Q, R183E, R183K, and R183E-E186Q variants. Glu186 most likely acts as a general base. Arg183 decisively influences the p<i>K</i>_a value of Glu186 and the proposed catalytic water mainly by its positive charge. In addition, Glu186 appears to be also responsible for product specificity by donating a proton to the directly neighbored <i>N</i>¹⁰ tertiary amine of H₄MPT. Thus, <i>N</i>¹⁰ becomes a better leaving group than <i>N</i>⁵ which implies the generation of <i>N</i>⁵-formyl-H₄MPT. For comparison, methenyltetrahydrofolate (H₄F) cyclohydrolase produces <i>N</i>¹⁰-formyl-H₄F in an analogous reaction. An enzymatic mechanism of Mch is postulated and compared with that of other cyclohydrolases

Bed Diameter Effect on the Hydrodynamics of Gas-Solid Fluidized Beds Via Radioactive Particle Tracking (RPT) Technique

The hydrodynamics observed in large-scale gas-solid fluidized bed reactors are different from those observed in smaller scale beds. In this study, the effect of bed diameter on the hydrodynamics of gas-solid fluidized bed reactors has been investigated in two bubbling fluidized beds of 44 cm and 14 cm in diameter using an advanced non-invasive radioactive particle tracking (RPT) technique. Compressed air at room temperature was used as the gas phase, and the solid was glass beads with a particle size of 210 μm (Geldart-B) and density of 2.5 g · cm-3. Particle velocity field, Reynolds stresses, normal stresses, turbulent kinetic energy, and axial and radial eddy diffusivities were measured in two beds at gas velocities of 1.5 Umf, 2 Umf, and 3 Umf. Experimental results showed that the bed scales have a significant effect on some of these hydrodynamic parameters where the magnitude of solids velocity is much higher in the larger bed and the solids mixing and diffusion of particles are increased by increasing the column diameter