Biologically active polymeric materials based on water polyurethane dispersions as the agent for increase of agricultural plants productivity

Biologically active polymeric materials (BAPM) with prolonged activity have been created on the basis of ecologically safe, economically expedient water xanthan (XA)- and castor (CO)/xanthan-comprising ionomer polyurethanes (IPU) which are aggregatively stable, capable of water dilution, with the size of micelles 250-270 nm and water absorption up to 220%. IPUs of amorphous-crystalline structure (Xa- and CO/Xa-comprising) are characterized by increased degradability as compared to amorphous (CO- comprising) IPUs. After the 12 months of incubation the weight loss of IPU / CO12 / Xa20 due to the synergistic effect of the components is 71%, while the additive contribution of the components and their total content are equaled 43.6%, 32.0%, respectively. Changing the polyether nature and/or introduction of Xa into the IPU structure allow to reduce of adhesive effects from 1.43 to 0.20 MPa, sufficient for "sticking" of BAPM on the plant surface and to reduce the surface tension, and for formation of a non-monolithic film on plant surface, and, thus, will not interfere with the activity of the plant photosynthetic apparatus. 170 BAPM with prolonged action was obtained by chemical and physical immobilization into the IPU macrochain of the domestic polyfunctional biological product Averkom-N. After pre-sowing treatment of seeds of grain and vegetable crops with BAPM, their growth-stimulating activity was established: an increase in biomass up to 60% compared to 40% after treatment with Averkom-N; an increase of: tomatoes productivity (24%), average weight of fruits (30%), and a decrease of: plants’ damage by diseases in 5-8 times and the level of nitrates in comparison with Averkom-N. BAPM increase the productivity of agrophytocenoses, the resistibility of agricultural crops to abiotic and biotic stresses, yield, improve the quality of products, and improve the ecological state of the environment.

Multi-species relationships in legume roots: From pairwise legume-symbiont interactions to the plant – microbiome - soil continuum

Mutualistic relationships of legume plants with, either bacteria (like rhizobia) or fungi (like arbuscular mycorrhizal fungi), have been investigated intensively, usually as bi-partite interactions. However, diverse symbiotic interactions take place simultaneously or sequentially under field conditions. Their collective, but not additive, contribution to plant growth and performance remains hard to predict, and appears to be furthermore affected by crop species and genotype, non-symbiotic microbial interactions and environmental variables. The challenge is: (1) to unravel the complex overlapping mechanisms that operate between the microbial symbionts as well as between them, their hosts and the rhizosphere (2) to understand the dynamics of the respective mechanisms in evolutionary and ecological terms. The target for agriculture, food security and the environment, is to use this insight as a solid basis for developing new integrated technologies, practices and strategies for the efficient use of beneficial microbes in legumes and other plants. We review recent advances in our understanding of the symbiotic interactions in legumes roots brought about with the aid of molecular and bioinformatics tools. We go through single symbiont-host interactions, proceed to tripartite symbiont-host interactions, appraise interactions of symbiotic and associative microbiomes with plants in the root-rhizoplane-soil continuum of habitats and end up by examining attempts to validate community ecology principles in the legume-microbe-soil biosystem.

Erroneous or Arrhenius: A Degradation Rate-Based Model for EPDM during Homogeneous Ageing

To improve the predictive capability of long-term stress relaxation of elastomers during thermo-oxidative ageing, a method to separate reversible and irreversible processes was adopted. The separation is performed through the analysis of compression set after tempering. On the basis of this separation, a numerical model for long-term stress relaxation during homogeneous ageing is proposed. The model consists of an additive contribution of physical and chemical relaxation. Computer simulations of compression stress relaxation were performed for long ageing times and the results were validated with the Arrhenius treatment, the kinetic study and the time-temperature superposition technique based on experimental data. For chemical relaxation, two decay functions are introduced each with an activation energy and a degradative process. The first process with the lower activation energy dominates at lower ageing times, while the second one with the higher activation energy at longer ageing times. A degradation-rate based model for the evolution of each process and its contribution to the total system during homogeneous ageing is proposed. The main advantage of the model is the possibility to quickly validate the interpolation at lower temperatures within the range of slower chemical processes without forcing a straight-line extrapolation.

7q35 Microdeletion and 15q13.3 and Xp22.33 Microduplications in a Patient with Severe Myoclonic Epilepsy, Microcephaly, Dysmorphisms, Severe Psychomotor Delay and Intellectual Disability

Copy number variations (CNVs) play a key role in the pathogenesis of several diseases, including a wide range of neurodevelopmental disorders. Here, we describe the detection of three CNVs simultaneously in a female patient with evidence of severe myoclonic epilepsy, microcephaly, hypertelorism, dimorphisms as well as severe psychomotor delay and intellectual disability. Array-CGH analysis revealed a ~240 kb microdeletion at the 7q35 inherited from her father, a ∼538 kb microduplication at the 15q13.3 region and a ∼178 kb microduplication at Xp22.33 region, both transmitted from her mother. The microdeletion in 7q35 was included within an intragenic region of the contactin associated protein-like 2 (CNTNAP2) gene, whereas the microduplications at 15q13.3 and Xp22.33 involved the cholinergic receptor nicotinic α 7 subunit (CHRNA7) and the cytokine receptor-like factor 2 (CRLF2) genes, respectively. Here, we describe a female patient harbouring three CNVs whose additive contribution could be responsible for her clinical phenotypes.

GWEHS: A Genome-Wide Effect Sizes and Heritability Screener

During the last decade, there has been a huge development of Genome-Wide Association Studies (GWAS), and thousands of loci associated to complex traits have been detected. These efforts have led to the creation of public databases of GWAS results, making a huge source of information available on the genetic background of many diverse traits. Here we present GWEHS (Genome-Wide Effect size and Heritability Screener), an open-source online application to screen loci associated to human complex traits and diseases from the NHGRI-EBI GWAS Catalog. This application provides a way to explore the distribution of effect sizes of loci affecting these traits, as well as their contribution to heritability. Furthermore, it allows for making predictions on the change in the expected mean effect size, as well as in the heritability as new loci are found. The application enables inferences on whether the additive contribution of loci expected to be discovered in the future will be able to explain the estimates of familial heritability for the different traits. We illustrate the use of this tool, compare some of the results obtained with those from a previous meta-analysis, and discuss its uses and limitations.

Inferring the Nature of Missing Heritability in Human Traits Using Data from the GWAS Catalog

Thousands of genes responsible for many diseases and other common traits in humans have been detected by Genome Wide Association Studies (GWAS) in the last decade. However, candidate causal variants found so far usually explain only a small fraction of the heritability estimated by family data. The most common explanation for this observation is that the missing heritability corresponds to variants, either rare or common, with very small effect, which pass undetected due to a lack of statistical power. We carried out a meta-analysis using data from the NHGRI-EBI GWAS Catalog in order to explore the observed distribution of locus effects for a set of 42 complex traits and to quantify their contribution to narrow-sense heritability. With the data at hand, we were able to predict the expected distribution of locus effects for 16 traits and diseases, their expected contribution to heritability, and the missing number of loci yet to be discovered to fully explain the familial heritability estimates. Our results indicate that, for 6 out of the 16 traits, the additive contribution of a great number of loci is unable to explain the familial (broad-sense) heritability, suggesting that the gap between GWAS and familial estimates of heritability may not ever be closed for these traits. In contrast, for the other 10 traits, the additive contribution of hundreds or thousands of loci yet to be found could potentially explain the familial heritability estimates, if this were the case. Computer simulations are used to illustrate the possible contribution from nonadditive genetic effects to the gap between GWAS and familial estimates of heritability.