Plant_SNP_TATA_Z-Tester: A Web Service That Unequivocally Estimates the Impact of Proximal Promoter Mutations on Plant Gene Expression

Synthetic targeted optimization of plant promoters is becoming a part of progress in mainstream postgenomic agriculture along with hybridization of cultivated plants with wild congeners, as well as marker-assisted breeding. Therefore, here, for the first time, we compiled all the experimental data—on mutational effects in plant proximal promoters on gene expression—that we could find in PubMed. Some of these datasets cast doubt on both the existence and the uniqueness of the sought solution, which could unequivocally estimate effects of proximal promoter mutation on gene expression when plants are grown under various environmental conditions during their development. This means that the inverse problem under study is ill-posed. Furthermore, we found experimental data on in vitro interchangeability of plant and human TATA-binding proteins allowing the application of Tikhonov’s regularization, making this problem well-posed. Within these frameworks, we created our Web service Plant_SNP_TATA_Z-tester and then determined the limits of its applicability using those data that cast doubt on both the existence and the uniqueness of the sought solution. We confirmed that the effects (of proximal promoter mutations on gene expression) predicted by Plant_SNP_TATA_Z-tester correlate statistically significantly with all the experimental data under study. Lastly, we exemplified an application of Plant_SNP_TATA_Z-tester to agriculturally valuable mutations in plant promoters.     

Cement composition and sulfate attack: Part I

Four cements were used to address the effect of tricalcium silicate content of cement on external sulfate attack in sodium sulfate solution. The selected cements had similar fineness and Bogue-calculated tricalcium aluminate content but variable tricalcium silicates. Durability was assessed using linear expansion and compressive strength. Phases associated with deterioration were examined using scanning electron microscopy and X-ray diffraction. Mineralogical phase content of the as-received cements was studied by X-ray diffraction using two methods: internal standard and Rietveld analysis.The results indicate that phase content of cements determined by X-ray mineralogical analysis correlates better with the mortar performance in sulfate environment than Bogue content. Additionally, it was found that in cements containing triclacium aluminate only in the cubic form, the observed deterioration is affected by tricalcium silicate content. Morphological similarities between hydration products of high tricalcium aluminate and high tricalcium silicate cements exposed to sodium sulfate environment were also observed.     

Ontogenesis of the thermogenic center in hornets

In the Oriental hornet, a thermogenic center is located in its prothorax. The present study attempted to elucidate the development of this organ with age, that is, by following the development of the thermogenic center in the hornet from its pupal stage until several days after eclosion of the imago. To this end, use was made of an infrared camera, with which pictures were taken of the prothorax in hornets at various ages, i.e., several days prior eclosion, 24 h after eclosion, and 48-h posteclosion. The photographic findings established that prior to 48-h posteclosion there was no thermally distinct region or spot in the prothorax, but at about 48 h, such a "hot spot," namely, a point whose temperature is greater than that of the rest of the prothorax, does appear, and its appearance coincides with certain specific nest activities like warming of the pupae. Next, an attempt was made to transplant by allograft the region in the prothorax housing the hot spot. Accordingly, several pupae at 2 days prior to eclosion were subjected to the following procedure; their future prothoracic thermogenic center was excised and so also an equally sized piece of cuticle from the dorsal region of their abdomen, and the two now allografted in exchange, i.e., the piece from the prothorax replacing the abdominal piece and vice versa. The result of this exchange-transplant was studied 48 h after eclosion of the operated hornets and showed disruption of heat formation in the prothoracic site coupled with nonappearance of a hot spot in the abdominal site. As for the functional, intact hot spot in the adult hornet, it is characterized by a high concentration of tracheae, with numerous mitochondria in between them that probably contribute to the heat generation.     

Synthesis and properties of magnetite nanoparticles with peroxide-containing polymer shell and nanocomposites based on them

Magnetite nanoparticles (Fe₃O₄ NPs) with peroxide-containing polymer shell have been synthesized using the method of coprecipitation from the mixture solutions of Fe (II) and Fe (III) salts in the presence of peroxide-containing copolymer (PCC). Polymer shell presence has been proved by elemental and complex thermal analysis. Synthesized Fe₃O₄ NPs possess superparamagnetic properties. Their specific saturation magnetization decreases gradually from 65 to 54 A·m²·kg⁻¹ with increasing PCC concentration owing to the surface spin pinning effect caused by a polymer shell. The average sizes of Fe₃O₄ NPs estimated from the data of XRD analysis and magnetic measurements are in the range of 9–12 nm. The NP sizes determined by the DLS method lie in the range of 150–270 nm; this result is significantly larger than the sizes estimated by the two aforementioned methods evidencing a tendency for Fe₃O₄ NPs toward self-association. Cross-linked composite films based on polyvinyl alcohol have been obtained via radical curing initiated by the PCC shell of nanoparticles. The resulting composite films are magnetically sensitive films with rather high physico-mechanical properties (tensile strength reaches 48–67 MPa and relative elongation – 4%–21% depending on cross-linking degree), a priori non-toxic and biocompatible, which makes them promising materials for various applications.     

Tissue-Specific Knockdown of Genes of the Argonaute Family Modulates Lifespan and Radioresistance in Drosophila melanogaster

Small RNAs are essential to coordinate many cellular processes, including the regulation of gene expression patterns, the prevention of genomic instability, and the suppression of the mutagenic transposon activity. These processes determine the aging, longevity, and sensitivity of cells and an organism to stress factors (particularly, ionizing radiation). The biogenesis and activity of small RNAs are provided by proteins of the Argonaute family. These proteins participate in the processing of small RNA precursors and the formation of an RNA-induced silencing complex. However, the role of Argonaute proteins in regulating lifespan and radioresistance remains poorly explored. We studied the effect of knockdown of Argonaute genes (AGO1, AGO2, AGO3, piwi) in various tissues on the Drosophila melanogaster lifespan and survival after the γ-irradiation at a dose of 700 Gy. In most cases, these parameters are reduced or did not change significantly in flies with tissue-specific RNA interference. Surprisingly, piwi knockdown in both the fat body and the nervous system causes a lifespan increase. But changes in radioresistance depend on the tissue in which the gene was knocked out. In addition, analysis of changes in retrotransposon levels and expression of stress response genes allow us to determine associated molecular mechanisms.     

Changes in the Number of Double-Strand DNA Breaks in Chinese Hamster V79 Cells Exposed to γ-Radiation with Different Dose Rates

A comparative investigation of the induction of double-strand DNA breaks (DSBs) in the Chinese hamster V79 cells by γ-radiation at dose rates of 1, 10 and 400 mGy/min (doses ranged from 0.36 to 4.32 Gy) was performed. The acute radiation exposure at a dose rate of 400 mGy/min resulted in the linear dose-dependent increase of the γ-H2AX foci formation. The dose-response curve for the acute exposure was well described by a linear function y = 1.22 + 19.7x, where “y” is an average number of γ-H2AX foci per a cell and “x” is the absorbed dose (Gy). The dose rate reduction down to 10 mGy/min lead to a decreased number of γ-H2AX foci, as well as to a change of the dose-response relationship. Thus, the foci number up to 1.44 Gy increased and reached the “plateau” area between 1.44 and 4.32 Gy. There was only a slight increase of the γ-H2AX foci number (up to 7) in cells after the protracted exposure (up to 72 h) to ionizing radiation at a dose rate of 1 mGy/min. Similar effects of the varying dose rates were obtained when DNA damage was assessed using the comet assay. In general, our results show that the reduction of the radiation dose rate resulted in a significant decrease of DSBs per cell per an absorbed dose.     

Expertise Recognition and Influence in Intercultural Groups: Differences Between Face-to-Face and Computer-Mediated Communication

Expertise recognition is challenging in teamwork, particularly in intercultural collaboration. This research seeks to investigate how cultural differences in communication styles may affect expertise recognition and influence in face-to-face (FtF) versus text-based computer-mediated communication (CMC). Using experimental intercultural groups, we found that in FtF groups East Asian experts had a lower participation rate, and were perceived as less competent, less confident, and less influential than experts from Western culture. No such differences occurred in CMC. The results support mediated moderation effect of perceived confidence on expert influence such that changes in perceptions of Chinese and American experts' confidence accounted for their different levels of influence in CMC versus FtF. No such effect was found with participation rate.     

Management of the Quality of Corrosion Protection of Structural Steel Based on Corrosion Risk Level

The paper deals with the theoretical and practical aspects of improving regulatory and technical framework for assuring the quality and safety of metal structures and their protective coatings under the exposure of corrosive environment. Methodological approach has been developed to managing technological safety, assessing the risks of corrosion failures, and extension of an industrial facility＇s life based on company standards taking into account the requirements for safe operation of buildings and installations. Basic provisions of the method of limit states design have been analyzed to determine： design characteristics of corrosion impacts, computational models and design cases for affirming compliance of corrosion resistance, and durability and maintainability of structures and their protective coatings. Presented are practical examples of justifying the choice of means of primary and secondary protection, taking into account classification of the established levels of facility corrosion hazard. On the basis of limit state design principles, logistical control- and decision-making system is generated for reliability assurance of steel structures and protective coatings. Assessment criteria are specified for the risks with the use of the materials and technologies of primary and secondary corrosion protection.     

The aliphatic isothiocyanates erucin and sulforaphane do not effectively up‐regulate NAD(P)H:quinone oxidoreductase (NQO1) in human liver compared with rat

Isothiocyanate up‐regulation of hepatic NAD(P)H:quinone oxidoreductase (NQO1) and glutathione S‐transferases (GSTs) is an integral mechanism of their chemoprevention. In this paper, for the first time, the potential of the isothiocyanates erucin and sulforaphane to modulate these enzymes was investigated in two human livers and compared to rat liver. Precision‐cut liver slices were incubated with erucin or sulforaphane (1–50 μM). Both isothiocyanates elevated NQO1 activity in rat slices that was paralleled by a fourfold rise in protein levels. No change in activity was noted in human slices, and only a weak rise in protein levels, < 10% of that in rat, was observed in only one of the human livers, whereas the other was refractive. GST activity, assessed with three substrates, was elevated in rat slices treated with either isothiocyanate, and was accompanied by a rise in GSTα and GSTμ, but not GSTπ, protein levels. A rise in activity and in GSTα and GSTμ protein levels was also noted in one of the human livers. It appears that erucin and sulforaphane elevate GST expression in isoform‐specific manner in both rat and human liver, whereas NQO1 is inducible by these compounds only in rat liver and very poorly in human liver.