Multiscale relevance of natural images.

We use an agnostic information-theoretic approach to investigate the statistical properties of natural images. We introduce the Multiscale Relevance (MSR) measure to assess the robustness of images to compression at all scales. Starting in a controlled environment, we characterize the MSR of synthetic random textures as function of image roughness [Formula: see text] and other relevant parameters.

Free energy decompositions illuminate synergistic effects in interfacial binding thermodynamics of mixed surfactant systems.

Recent vibrational sum frequency generation spectroscopic experiments [Sengupta et al., J. Phys.

Environmental fluctuations explain the universal decay of species-abundance correlations with phylogenetic distance.

Multiple ecological forces act together to shape the composition of microbial communities. Phyloecology approaches-which combine phylogenetic relationships between species with community ecology-have the potential to disentangle such forces but are often hard to connect with quantitative predictions from theoretical models. On the other hand, macroecology, which focuses on statistical patterns of abundance and diversity, provides natural connections with theoretical models but often neglects interspecific correlations and interactions.

Diverging conformations guide dipeptide self-assembly into crystals or hydrogels.

The prediction of dipeptide assembly into crystals or gels is challenging. This work reveals the diverging conformational landscape that guides self-organization towards different outcomes. and experimental data enabled deciphering of the electronic circular dichroism (ECD) spectra of self-assembling dipeptides to reveal folded or extended conformers as key players.

Stable cooperation emerges in stochastic multiplicative growth.

Understanding the evolutionary stability of cooperation is a central problem in biology, sociology, and economics. There exist only a few known mechanisms that guarantee the existence of cooperation and its robustness to cheating. Here, we introduce a mechanism for the emergence of cooperation in the presence of fluctuations.

Examining the origins of observed terahertz modes from an optically pumped atomistic model protein in aqueous solution.

The microscopic origins of terahertz (THz) vibrational modes in biological systems are an active and open area of current research. Recent experiments [Phys Rev X. , 031061 (2018)] have revealed the presence of a pronounced mode at ∼0.

Solvation thermodynamics from cavity shapes of amino acids.

According to common physical chemistry wisdom, the solvent cavities hosting a solute are tightly sewn around it, practically coinciding with its van der Waals surface. Solvation entropy is primarily determined by the surface and the volume of the cavity while enthalpy is determined by the solute-solvent interaction. In this work, we challenge this picture, demonstrating by molecular dynamics simulations that the cavities surrounding the 20 amino acids deviate significantly from the molecular surface.

Improved Hot Dark Matter Bound on the QCD Axion.

We obtain a reliable cosmological bound on the axion mass m_{a} by (1) deriving the production rate directly from pion-pion scattering data, which overcomes the breakdown of chiral perturbation theory and results in ∼30% differences from previous estimates; (2) including momentum dependence in the Boltzmann equations for axion-pion scatterings, which enhances the relic abundance by ∼40%. Using present cosmological datasets we obtain m_{a}≤0.24  eV, at 95% C.

Matrix factorization with neural networks.

Matrix factorization is an important mathematical problem encountered in the context of dictionary learning, recommendation systems, and machine learning. We introduce a decimation scheme that maps it to neural network models of associative memory and provide a detailed theoretical analysis of its performance, showing that decimation is able to factorize extensive-rank matrices and to denoise them efficiently. In the case of binary prior on the signal components, we introduce a decimation algorithm based on a ground-state search of the neural network, which shows performances that match the theoretical prediction.

Fundamental limits in structured principal component analysis and how to reach them.

How do statistical dependencies in measurement noise influence high-dimensional inference? To answer this, we study the paradigmatic spiked matrix model of principal components analysis (PCA), where a rank-one matrix is corrupted by additive noise. We go beyond the usual independence assumption on the noise entries, by drawing the noise from a low-order polynomial orthogonal matrix ensemble. The resulting noise correlations make the setting relevant for applications but analytically challenging.

High-Throughput Screening of Promising Redox-Active Molecules with MolGAT.

Redox flow batteries (RFBs) have emerged as a promising option for large-scale energy storage, owing to their high energy density, low cost, and environmental benefits. However, the identification of organic compounds with high redox activity, aqueous solubility, stability, and fast redox kinetics is a crucial and challenging step in developing an RFB technology. Density functional theory-based computational materials prediction and screening is a time-consuming and computationally expensive technique, yet it has a high success rate.

The Oxygen Evolution Reaction at MoS Edge Sites: The Role of a Solvent Environment in DFT-Based Molecular Simulations.

Density functional theory (DFT) calculations are employed to study the oxygen evolution reaction (OER) on the edges of stripes of monolayer molybdenum disulfide. Experimentally, this material has been shown to evolve oxygen, albeit with low efficiency. Previous DFT studies have traced this low catalytic performance to the unfavourable adsorption energies of some reaction intermediates on the MoS edge sites.

Klobuchar, NeQuickG, BDGIM, GLONASS, IRI-2016, IRI-2012, IRI-Plas, NeQuick2, and GEMTEC Ionospheric Models: A Comparison in Total Electron Content and Positioning Domains.

Global navigation satellite systems (GNSS) provide a great data source about the ionosphere state. These data can be used for testing ionosphere models. We studied the performance of nine ionospheric models (Klobuchar, NeQuickG, BDGIM, GLONASS, IRI-2016, IRI-2012, IRI-Plas, NeQuick2, and GEMTEC) both in the total electron content (TEC) domain-i.

Water Self-Dissociation is Insensitive to Nanoscale Environments.

Nanoconfinement effects on water dissociation and reactivity remain controversial, despite their importance to understand the aqueous chemistry at interfaces, pores, or aerosols. The pKw in confined environments has been assessed from experiments and simulations in a few specific cases, leading to dissimilar conclusions. Here, with the use of carefully designed ab initio simulations, we demonstrate that the energetics of bulk water dissociation is conserved intact to unexpectedly small length-scales, down to aggregates of only a dozen molecules or pores of widths below 2 nm.

Bacteria-phage coevolution with a seed bank.

Dormancy is an adaptation to living in fluctuating environments. It allows individuals to enter a reversible state of reduced metabolic activity when challenged by unfavorable conditions. Dormancy can also influence species interactions by providing organisms with a refuge from predators and parasites.

The phase range extension and accuracy improvement in Fresnel biprism-based digital holography microscopy.

We report a highly stable and affordable dual-wavelength digital holographic microscopy system based on common-path geometry. A Fresnel biprism is used to create an off-axis geometry, and two diode laser sources with different wavelengths λ1 = 532 nm and λ2 = 650 nm generate the dual-wavelength compound hologram. In order to extend the measurement range, the phase distribution is obtained using a synthetic wavelength Λ1 = 2930.

Structure-Based Design and Pharmacophore-Based Virtual Screening of Combinatorial Library of Triclosan Analogues Active against Enoyl-Acyl Carrier Protein Reductase of with Favourable ADME Profiles.

Cost-effective therapy of neglected and tropical diseases such as malaria requires everlasting drug discovery efforts due to the rapidly emerging drug resistance of the plasmodium parasite. We have carried out computational design of new inhibitors of the enoyl-acyl carrier protein reductase (ENR) of (ENR) using computer-aided combinatorial and pharmacophore-based molecular design. The Molecular Mechanics Poisson-Boltzmann Surface Area (MM-PBSA) complexation QSAR model was developed for triclosan-based inhibitors (TCL) and a significant correlation was established between the calculated relative Gibbs free energies of complex formation (∆∆Gcom) between ENR and TCL and the observed inhibitory potencies of the enzyme (IC50exp) for a training set of 20 known TCL analogues.

Prevalence of Human and Animal Fasciolosis in Butajira and Gilgel Gibe Health Demographic Surveillance System Sites in Ethiopia.

Fasciolosis is regarded as a major challenge to livestock productivity worldwide, but the burden of disease in humans has only started to receive some attention in the past three decades. The aim of this study was to determine the prevalence of human and animal fasciolosis and its determinant factors in the Gilgel Gibe and Butajira Health and Demographic Surveillance System (HDSS) sites in Ethiopia. A study was undertaken among 389 households across the two sites.

Impact of patient's habitus on image quality and quantitative metrics in 18F-FDG PET/CT images.

Purpose: To study how the quantitative parameters of 18F-FDG PET imaging change with the emission scan duration (ESD) and the body-mass-index (BMI) in phantom and patients on a time-of-flight (TOF)-PET/CT system.

Methods: The image-quality phantom with (b-NEMA-IQ, BMI = 29.2 kg/m) and without (NEMA-IEC, BMI = 21.

Effects of Land-Use and Environmental Factors on Snail Distribution and Trematode Infection in Ethiopia.

Freshwater snails are intermediate hosts for several snail-borne diseases affecting humans and animals. Understanding the distribution of snail intermediate hosts and their infection status is very important to plan and implement effective disease prevention and control interventions. In this study, we determined the abundance, distribution, and trematode infection status of freshwater snails in two agro-ecological zones of Ethiopia.

The Interaction of Amines with Gold Nanoparticles.

Understanding the interactions between amines and the surface of gold nanoparticles is important because of their role in the stabilization of the nanosystems, in the formation of the protein corona, and in the preparation of semisynthetic nanozymes. By using fluorescence spectroscopy, electrochemistry, X-ray photoelectron spectroscopy, high-resolution transmission electron microscopy, and molecular simulation, a detailed picture of these interactions is obtained. Herein, it is shown that amines interact with surface Au(0) atoms of the nanoparticles with their lone electron pair with a strength linearly correlating with their basicity corrected for steric hindrance.

Nonreciprocal forces enable cold-to-hot heat transfer between nanoparticles.

We study the heat transfer between two nanoparticles held at different temperatures that interact through nonreciprocal forces, by combining molecular dynamics simulations with stochastic thermodynamics. Our simulations reveal that it is possible to construct nano refrigerators that generate a net heat transfer from a cold to a hot reservoir at the expense of power exerted by the nonreciprocal forces. Applying concepts from stochastic thermodynamics to a minimal underdamped Langevin model, we derive exact analytical expressions predictions for the fluctuations of work, heat, and efficiency, which reproduce thermodynamic quantities extracted from the molecular dynamics simulations.

Molecular dynamics study of collective water vibrations in a DNA hydration shell.

The structure of DNA double helix is stabilized by water molecules and metal counterions that form the ion-hydration shell around the macromolecule. Understanding the role of the ion-hydration shell in the physical mechanisms of the biological functioning of DNA requires detailed studies of its structure and dynamics at the atomistic level. In the present work, the study of collective vibrations of water molecules around the DNA double helix was performed within the framework of classical all-atom molecular dynamics methods.