Mechanisms of proton-proton inelastic cross-section growth in multi-peripheral model within the framework of perturbation theory. Part 2

We demonstrate a new technique for calculating proton-proton inelastic cross-section, which allows one by application of the Laplace' method replace the integrand in the integral for the scattering amplitude in the vicinity of the maximum point by expression of Gaussian type. This in turn, allows one to overcome the computational difficulties for the calculation of the integrals expressing the cross section to sufficiently large numbers of particles. We have managed to overcome these problems in calculating the proton-proton inelastic cross-section for production (n \le 8) number of secondary particles in within the framework of \phi^3 model. As the result the obtained dependence of inelastic cross-section and total scattering cross-section on the energy \sqrt{s} are qualitative agrees with the experimental data. Such description of total cross-section behavior differs considerably from existing now description, where reggeons exchange with the intercept greater than unity is considered.Comment: 11 pages, 10 figures (v3: some inaccuracies corrected

Effect of Soil Moisture Status and Animal Treading on N\u3csub\u3e2\u3c/sub\u3eO Emissions and the Effectiveness of a Nitrification Inhibitor Mitigation Technology

Nitrous oxide (N2O) is a potent greenhouse gas with a long-term global warming potential about 298 times that of carbon dioxide (CO2). In grazed grassland, most of the N2O is emitted from nitrogen (N) excreted by the grazing animal, particularly in the animal urine. When the soil is wet, such as that in winter grazing conditions, animal grazing can cause soil structural damage, leading to soil compaction. The combination of a wet soil plus soil compaction is particularly conducive for N2O production. A nitrification inhibitor technology using dicyandiamide (DCD) has been developed to reduce N2O emissions from grazed grassland (Di and Cameron 2002; 2003). However, the efficacy of this technology under wet and compact soil conditions has not been well studied. The objectives of this study were to determine: (1) The impact of soil moisture content on the abundance of ammonia oxidizers and N2O emissions; (2) the impact of animal treading on N2O emissions; and (3) The effectiveness of the nitrification inhibitor DCD in reducing N2O emissions, as affected by soil moisture status and animal treading

SCRIPDB: a portal for easy access to syntheses, chemicals and reactions in patents

The patent literature is a rich catalog of biologically relevant chemicals; many public and commercial molecular databases contain the structures disclosed in patent claims. However, patents are an equally rich source of metadata about bioactive molecules, including mechanism of action, disease class, homologous experimental series, structural alternatives, or the synthetic pathways used to produce molecules of interest. Unfortunately, this metadata is discarded when chemical structures are deposited separately in databases. SCRIPDB is a chemical structure database designed to make this metadata accessible. SCRIPDB provides the full original patent text, reactions and relationships described within any individual patent, in addition to the molecular files common to structural databases. We discuss how such information is valuable in medical text mining, chemical image analysis, reaction extraction and in silico pharmaceutical lead optimization. SCRIPDB may be searched by exact chemical structure, substructure or molecular similarity and the results may be restricted to patents describing synthetic routes. SCRIPDB is available at http://dcv.uhnres.utoronto.ca/SCRIPDB

Soil nitrogen treatment alters microbiome networks across farm niches

Agriculture is fundamental for food production, and microbiomes support agriculture through multiple essential ecosystem services. Despite the importance of individual (i.e., niche specific) agricultural microbiomes, microbiome interactions across niches are not well-understood. To observe the linkages between nearby agricultural microbiomes, multiple approaches (16S, 18S, and ITS) were used to inspect a broad coverage of niche microbiomes. Here we examined agricultural microbiome responses to 3 different nitrogen treatments (0, 150, and 300 kg/ha/yr) in soil and tracked linked responses in other neighbouring farm niches (rumen, faecal, white clover leaf, white clover root, rye grass leaf, and rye grass root). Nitrogen treatment had little impact on microbiome structure or composition across niches, but drastically reduced the microbiome network connectivity in soil. Networks of 16S microbiomes were the most sensitive to nitrogen treatment across amplicons, where ITS microbiome networks were the least responsive. Nitrogen enrichment in soil altered soil and the neighbouring microbiome networks, supporting our hypotheses that nitrogen treatment in soil altered microbiomes in soil and in nearby niches. This suggested that agricultural microbiomes across farm niches are ecologically interactive. Therefore, knock-on effects on neighbouring niches should be considered when management is applied to a single agricultural niche

A comparative study of the hydrogen-bonding patterns and prototropism in solid 2-thiocytosine (potential antileukemic agent) and cytosine, as studied by 1H-14N NQDR and QTAIM/ DFT

A potential antileukemic and anticancer agent, 2-thiocytosine (2-TC), has been studied experimentally in the solid state by 1H-14N NMR-NQR double resonance (NQDR) and theoretically by the quantum theory of atoms in molecules (QTAIM)/density functional theory (DFT). Eighteen resonance frequencies on 14N were detected at 180 K and assigned to particular nitrogen sites (−NH2, –N=, and –NH–) in 2-thiocytosine. Factors such as the nonequivalence of molecules (connected to the duplication of sites) and possible prototropic tautomerism (capable of modifying the type of site due to proton transfer) were taken into account during frequency assignment. The result of replacing oxygen with sulfur, which leads to changes in the intermolecular interaction pattern and molecular aggregation, is discussed. This study demonstrates the advantages of combining NQDR and DFT to extract detailed information on the H-bonding properties of crystals with complex H-bonding networks. Solid-state properties were found to have a profound impact on the stabilities and reactivities of both compounds

Soil microbial sensitivity to temperature remains unchanged despite community compositional shifts along geothermal gradients.

Climate warming may be exacerbated if rising temperatures stimulate losses of soil carbon to the atmosphere. The direction and magnitude of this carbon-climate feedback are uncertain, largely due to lack of knowledge of the thermal adaptation of the physiology and composition of soil microbial communities. Here, we applied the macromolecular rate theory (MMRT) to describe the temperature response of the microbial decomposition of soil organic matter (SOM) in a natural long-term warming experiment in a geothermally active area in New Zealand. Our objective was to test whether microbial communities adapt to long-term warming with a shift in their composition and their temperature response that are consistent with evolutionary theory of trade-offs between enzyme structure and function. We characterized the microbial community composition (using metabarcoding) and the temperature response of microbial decomposition of SOM (using MMRT) of soils sampled along transects of increasing distance from a geothermally active zone comprising two biomes (a shrubland and a grassland) and sampled at two depths (0?50 and 50?100 mm), such that ambient soil temperature and soil carbon concentration varied widely and independently. We found that the different environments were hosting microbial communities with distinct compositions, with thermophile and thermotolerant genera increasing in relative abundance with increasing ambient temperature. However, the ambient temperature had no detectable influence on the MMRT parameters or the relative temperature sensitivity of decomposition (Q10). MMRT parameters were, however, strongly correlated with soil carbon concentration and carbon:nitrogen ratio. Our findings suggest that, while long-term warming selects for warm-adapted taxa, substrate quality and quantity exert a stronger influence than temperature in selecting for distinct thermal traits. The results have major implications for our understanding of the role of soil microbial processes in the long-term effects of climate warming on soil carbon dynamics and will help increase confidence in carbon-climate feedback projections

IVSPlat 1.0: an integrated virtual screening platform with a molecular graphical interface

<p>Abstract</p> <p>Background</p> <p>The virtual screening (VS) of lead compounds using molecular docking and pharmacophore detection is now an important tool in drug discovery. VS tasks typically require a combination of several software tools and a molecular graphics system. Thus, the integration of all the requisite tools in a single operating environment could reduce the complexity of running VS experiments. However, only a few freely available integrated software platforms have been developed.</p> <p>Results</p> <p>A free open-source platform, IVSPlat 1.0, was developed in this study for the management and automation of VS tasks. We integrated several VS-related programs into a molecular graphics system to provide a comprehensive platform for the solution of VS tasks based on molecular docking, pharmacophore detection, and a combination of both methods. This tool can be used to visualize intermediate and final results of the VS execution, while also providing a clustering tool for the analysis of VS results. A case study was conducted to demonstrate the applicability of this platform.</p> <p>Conclusions</p> <p>IVSPlat 1.0 provides a plug-in-based solution for the management, automation, and visualization of VS tasks. IVSPlat 1.0 is an open framework that allows the integration of extra software to extend its functionality and modified versions can be freely distributed. The open source code and documentation are available at <url>http://kyc.nenu.edu.cn/IVSPlat/.</url></p