Delta Machine Learning for Predicting Dielectric Properties and Raman Spectra

We propose a machine learning method for predicting polarizabilities with the goal of providing Raman spectra from molecular dynamics trajectories at reduced computational cost. A linear-response model is used as a first step and symmetry-adapted machine learning is employed for the higher-order contributions as a second step. We investigate the performance of the approach for several systems including molecules and extended solids. The method can reduce training set sizes required for accurate dielectric properties and Raman spectra in comparison to a single-step machine learning approach

Hybrid localized graph kernel for machine learning energy-related properties of molecules and solids

Nowadays, the coupling of electronic structure and machine learning techniques serves as a powerful tool to predict chemical and physical properties of a broad range of systems. With the aim of improving the accuracy of predictions, a large number of representations for molecules and solids for machine learning applications has been developed. In this work we propose a novel descriptor based on the notion of molecular graph. While graphs are largely employed in classification problems in cheminformatics or bioinformatics, they are not often used in regression problem, especially of energy-related properties. Our method is based on a local decomposition of atomic environments and on the hybridization of two kernel functions: a graph kernel contribution that describes the chemical pattern and a Coulomb label contribution that 1encodes finer details of the local geometry. The accuracy of this new kernel method in energy predictions of molecular and condensed phase systems is demonstrated by considering the popular QM7 and BA10 datasets. These examples show that the hybrid localized graph kernel outperforms traditional approaches such as, for example, the smooth overlap of atomic positions (SOAP) and the Coulomb matrices

Prevalence of gastrointestinal parasites of red deer from Protected Landscape Area Štiavnické vrchy

Count of red deer in some areas of Slovak republic exceeds standard count. To these areas belongs as well Protected Landscape Area Štiavnické vrchy (N48°24'42'' E18°52'21''). High count of is a risk for spread of viral, bacterial as well as parasitic diseases. The aim of this study was to determined and evaluated prevalence of gastrointestinal parasites of red deer (Cervus elaphus) from Protected Landscape Area Štiavnické vrchy in year 2016. Monitoring was realized through cooperation between Department of Veterinary Sciences at Slovak University of Agriculture in Nitra and District Veterinary and Food Administration in Zvolen as well as with Hunting Associations acting in area of Štiavnické vrchy. Total 120 faecal samples (10 from each month of the year 2016) was analysed using flotation method and eggs and oocysts were identified. Highest prevalence was detected by Trichostrongylus axei, Eimeria spp. and Spiculopteragia boehmi. Prevalence of endoparasites is affected by age structure of red deer and then by using antiparasitics, climatic condition. Result of these was, that prevalence of total gastrointestinal parasites was lowest during months January to March, when Hunting Associations realised regular worming. The highest prevalence of total gastrointestinal parasites was in months July to December, when the relative humidity is higher and to red deer population belongs as well new offspring, which has high predisposition to gastrointestinal parasites

Polyelectrolyte Complex Beads by Novel Two-Step Process for Improved Performance of Viable Whole-Cell Baeyer-Villiger Monoxygenase by Immobilization.

A novel immobilization matrix for the entrapment of viable whole-cell Baeyer–Villiger monooxygenase was developed. Viable recombinant Escherichia coli cells overexpressing cyclohexanone monooxygenase were entrapped in polyelectrolyte complex beads prepared by a two-step reaction of oppositely-charged polymers including highly defined cellulose sulphate. Immobilized cells exhibited higher operational stability than free cells during 10 repeated cycles of Baeyer–Villiger biooxidations of rac-bicyclo[3.2.0]hept-2-en-6-one to the corresponding lactones (1R,5S)-3-oxabicyclo-[3.3.0]oct-6-en-3-one and (1S,5R)-2-oxabicyclo-[3.3.0]oct-6-en-3-one. The morphology of polyelectrolyte complex beads was characterised by environmental scanning electron microscopy; the spatial distribution of polymers in the beads and cell viability were examined using confocal laser scanning microscopy, and the texture was characterised by the mechanical resistance measurements

Ab Initio Calculations of Free Energy of Activation at Multiple Electronic Structure Levels Made Affordable: An Effective Combination of Perturbation Theory and Machine Learning

International audienc