Net ecosystem exchange and energy fluxes measured with the eddy covariance technique in a western Siberian bog

Very few studies of ecosystem-atmosphere exchange involving eddy covariance data have been conducted in Siberia, with none in the western Siberian middle taiga. This work provides the first estimates of carbon dioxide (CO2) and energy budgets in a typical bog of the western Siberian middle taiga based on May-August measurements in 2015. The footprint of measured fluxes consisted of a homogeneous mixture of tree-covered ridges and hollows with the vegetation represented by typical sedges and shrubs. Generally, the surface exchange rates resembled those of pinecovered bogs elsewhere. The surface energy balance closure approached 100 %. Net CO2 uptake was comparatively high, summing up to CO2 gCm(-2) for the four measurement months, while the Bowen ratio was seasonally stable at 28 %. The ecosystem turned into a net CO2 source during several front passage events in June and July. The periods of heavy rain helped keep the water table at a sustainably high level, preventing a usual drawdown in summer. However, because of the cloudy and rainy weather, the observed fluxes might rather represent the special weather conditions of 2015 than their typical magnitudes.Peer reviewe

A survey of multi-task learning methods in chemoinformatics

Despite the increasing volume of available data, the proportion of experimentally measured data remains small compared to the virtual chemical space of possible chemical structures. Therefore, there is a strong interest in simultaneously predicting different ADMET and biological properties of molecules, which are frequently strongly correlated with one another. Such joint data analyses can increase the accuracy of models by exploiting their common representation and identifying common features between individual properties. In this work we review the recent developments in multi-learning approaches as well as cover the freely available tools and packages that can be used to perform such studies

Simulation models and research algorithms of thin shell structures deformation Part I. Shell deformation models

In the article the development of thin shell construction theory is considered according to the contribution of researchers, chronology, including the most accurate and simplified solutions. The review part of the article consists only of those publications which are related to the development of shell theory. The statement is based on the works of famous Russian researchers (V. V. Novozhilov, A. I. Lurie, A. L. Goldenweiser, H. M. Mushtari, V. Z. Vlasov), who developed the specified theory the most. The paper also mentions the researchers who improved the theory, calculation methods in aspects of strength, sustainability and vibrations of thin elastic shell constructions. Separately the application of the models for ribbed shells constructions is shown. It is reporting the basic principles of nonlinear thin shell construction theory development, including the nonlinear relations for deformations. In the article it is shown that if median surface of the shell is referred to the orthogonal coordinate system, then the expressions for deformations, obtained by different authors, practically correspond. The case in which the median surface of the shell is referred to an oblique-angled coordinate system was developed by A. L. Goldenweiser. For static problem, the functional of the total potential energy of deformation, representing the difference between the potential energy and the work of external forces, is used. The equilibrium equations and natural boundary conditions are derived from the minimum condition of this functional. In case of dynamic problem, the functional of the total deformation energy of the shell is described in which it is necessary to consider the kinetic energy of shell deformation. It is necessary to underline that the condition for minimum of the specified functional lets to derive the movement equations and natural boundary and initial conditions. Also, in the article the results of contemporary research of thin shell theory are presented

Quantitative analysis of cementitious materials by X-ray ptychographic nanotomography

Cement manufacturing is responsible for ~7% of the anthropogenic CO2 emissions and hence, decreasing the CO2 footprint, in a sustainable, safe, and cost-effective way, is a top priority. It is also key to develop more durable binders as the estimated world concrete stock is 315 Gt which currently results in ~0.3 Gt/yr of concrete demolition waste (CDW). Moreover, models under development predict a skyrocketing increase of CDW to 20–40 Gt/yr by 2100. This amount could not be easily reprocessed as aggregates for new concretes as such volumes would be more than two times the predicted need. Furthermore, concretes have very complex hierarchical microstructures. The largest components are coarse aggregates with dimensions bigger than a few centimetres and the smallest ones are amorphous components and the calcium silicate hydrate gel with nanoparticle sizes smaller than a few nanometres. To fully understand the properties of current and new cement binders and to optimize their performances, a sound description of their spatially-resolved contents is compulsory. However, there is not a tomographic technique that can cover the spatial range of heterogeneity and features of concretes and mortars. This can only be attained within a multitechnique approach overlapping the spatial scales in order to build an accurate picture of the different microstructural features. Here, we have employed far-field and near-field synchrotron X-ray ptychographic nanotomographies to gain a deeper insight into the submicrometer microstructures of Portland cement binders. With these techniques, the available fields of view range from 40 to 300 um with a true spatial resolution evolving between ~50to~300 nm. It is explicitly acknowledged here that other techniques like X-ray synchrotron microtomography are necessary to develop the whole picture accessing to larger fields of view albeit with poorer spatial resolution and without the quantitativeness in the reconstructed electron densities

Prokineticin Receptor-1 Signaling Inhibits Dose- and Time-Dependent Anthracycline-Induced Cardiovascular Toxicity Via Myocardial and Vascular Protection

Abstract Background High prevalence of heart failure during and following cancer treatments remains a subject of intense research and therapeutic interest. Objectives This study investigated how different concentrations of doxorubicin (DOX) can affect the function of the cardiac cells. This study also examined whether activation of prokineticin receptor-1 (PKR1) by a nonpeptide agonist, IS20, prevents DOX-induced cardiovascular toxicity in mouse models. Methods We used cultured cardiomyocytes, endothelial cells (ECs), and epicardium-derived progenitor cells (EPDCs) for in vitro, assays and tumor-bearing and acute and chronic toxicity mouse models for in vivo assays. Results Brief exposure to cardiomyocytes with high-dose DOX increases the accumulation of reactive oxygen species (ROS) by inhibiting a detoxification mechanism via stabilization of cytoplasmic NRF2. Prolonged exposure to medium-dose DOX induces apoptosis in cardiomyocytes, ECs, and EPDCs. However, low-dose DOX promotes functional defects without inducing apoptosis in EPDCs and ECs. IS20 alleviates detrimental effects of DOX in cardiac cells via activating AKT or mitogen-activated protein kinase pathways. Genetic or pharmacological inactivation of PKR1 subdues these effects of IS20. In a chronic mouse model of DOX cardiotoxicity, IS20 normalizes an elevated serum marker of cardiotoxicity and vascular and EPDC deficits, attenuates apoptosis and fibrosis, and improves the survival rate and cardiac function. IS20 does not interfere with the cytotoxicity or antitumor effects of DOX in breast cancer lines or in a mouse model of breast cancer but attenuates the decreases in LV diastolic volume induced by acute DOX treatment. Conclusions This study identifies the molecular and cellular signature of dose-dependent DOX-mediated cardiotoxicity and provides evidence that PKR1 is a promising target to combat cardiotoxicity of cancer treatments

Weak selection and stability of localized distributions in Ostwald ripening

We support and generalize a weak selection rule predicted recently for the self-similar asymptotics of the distribution function (DF) in the zero-volume-fraction limit of Ostwald ripening (OR). An asymptotic perturbation theory is developed that, when combined with an exact invariance property of the system, yields the selection rule, predicts a power-law convergence towards the selected self-similar DF and agrees well with our numerical simulations for the interface- and diffusion-controlled OR.Comment: 4 pages, 2 figures, submitted to PR

Active Learning for Image Recognition Using a Visualization-Based User Interface

Limberg C, Krieger K, Wersing H, Ritter H. Active Learning for Image Recognition Using a Visualization-Based User Interface. In: Tetko IV, Kůrková V, Karpov P, Theis F, eds. Artificial Neural Networks and Machine Learning – ICANN 2019: Deep Learning. Lecture Notes in Computer Science. Vol 11728. Cham: Springer; 2019: 495-506