Transfer Of Elements Research Articles

METHOD OF DISCRETE SINGULARITIES FOR ACCOUNTING FOR CONVECTION WHEN MODELING DYNAMICS OF INFECTIOUS DISEASE UNDER DIFFUSION PERTURBATIONS AND CONCENTRATED INFLUENCES

A wide range of various mathematical models have been developed to predict the dynamics of an infectious disease. As a rule, such models do not take into account spatial effects, which are associated with both the uneven distribution of active factors and their convective transfer by the intercellular fluid. The paper proposes a variant of taking into account convection when modeling the process of an infectious disease under conditions of diffusion perturbations and concentrated influences. Based on the reduction of original singularly perturbed model problem with delay to a sequence of problems without delay, an effective step-by-step procedure for numerically asymptotically approximating the solution as a perturbation of the solution of the corresponding degenerate problems is synthesized. To find the velocity field, it is proposed to model the movement of fluid in the intercellular medium as a potential flow in the source-drain system. It is emphasized that this approach can be used for a wide range of configurations of model areas with sufficient variability of boundary conditions. The results of computer modeling are presented, which illustrate the influence of diffusion scattering and convection on the development of a viral disease under the conditions of injections of immunological drugs. It is shown that as a result of diffusion scattering and convective transfer of viral elements, their concentration in the epicenter of infection decreases over time, which leads to a corresponding decrease in the "severity" of the disease. It is also shown that with an uneven field of movement speed of the intercellular fluid, there will be zones with a less intense influx of both own and donor antibodies. As a result, the amount of antibodies available in these zones may be insufficient to neutralize antigens, which may lead to the emergence of new epicenters of infection here. The importance of taking such effects into account, in particular, when forming effective treatment programs, is indicated.

Improving the Accuracy of Silicon Transfer Prediction in Submerged Arc Welding: A Multi-Reaction-Zone Analysis

This study aims to predict and evaluate the transfer behavior of silicon employing SiO2-bearing fluxes during submerged arc welding. Unlike previous studies that only focused on chemical reactions in the weld pool zone, this research investigates the elemental behavior of silicon subjected to essential reaction zones in a submerged arc welding process. The proposed method is compared with the traditional thermodynamic equilibrium models, enhancing the understanding of silicon transfer behavior in the submerged arc welding process. It is demonstrated that relying solely on thermodynamics within the weld pool zone is inadequate for accurately predicting the extent of silicon transfer level since the loss of silicon during the droplet zone and the improvement in oxygen content in the molten droplet are not considered, resulting in an overestimation of the ΔSi level. Finally, the limitations of the traditional elemental transfer quantification method and corresponding corrective suggestions are proposed.

Floristic survey, trace element transfers between soil and vegetation and human health risk at an urban industrial wasteland

This study aimed to determine the trace element accumulation in the soil and plants in an industrial wasteland and to estimate the extent of transfer to humans to measure the effects on and risks to vegetation and human health and find bioindicator plants representative of the levels of the main contaminants. In areas with the highest extractable trace element levels, we observed decreases in plant biodiversity explained by the disappearance of several families, favouring the coverage of tolerant species, such as Urtica dioica and Hedera helix. Trace elements were also found in the leaves of several plants, especially in a dominant species that is poorly studied, Alliaria petiolata. Indeed, this species had the highest contents of Zn (1750 mg.kg-1 DW), Ni (13.1 mg.kg-1 DW), and Cd (18 mg.kg-1 DW) found at the site and is a potential Zn bioindicator since its leaf contents were also representative of the Zn extractable contents in soil (R² = 0.94). The hazard quotient and carcinogen risk revealed that most of the site had an identified or possible risk, mainly due to Pb and As. Native species, especially A. petiolata, could be used in phytoextraction to manage and limit these human and environmental risks.

Tracing nickel smelter emissions using European honey bees

This study investigated trace element contamination in honey bees inhabiting urban areas around the South Pacific's largest and longest operating nickel smelter in Nouméa, New Caledonia. There remains a paucity of research on the environmental impact of nickel smelting, and to date, there has been no assessment of its effects on the popular practice of beekeeping, or whether honey bees are a suitable tracer for nickel smelting emissions. Honey bees and honey were sampled from 15 hives across Nouméa to ascertain linkages between nickel smelter emissions, environmental contamination, and trace element uptake by bees. Comparison of washed and unwashed bees revealed no significant difference in trace element concentrations, indicating trace elements bioaccumulate within the internal tissues of bees over time. Accordingly, trace element concentrations were higher in dead bees than those that were sampled live, with smelter related elements chromium, cobalt and nickel being significantly different at p < 0.05. Except for boron, trace element concentrations were consistently higher in bees than in honey, suggesting that the transfer of trace elements from bees during honey production is negligible. Elevated concentrations of potentially toxic trace elements including cobalt, chromium and nickel in bees declined with distance from smelting operations (Spearman's Rho, p < 0.05), indicating the relationship between environmental contamination and the uptake of trace elements by bees. The findings of this study emphasise potential environmental and human health risks associated with trace element contamination from nickel smelting operations and affirm the use of honey bees as a biomonitor of potentially harmful nickel smelting emissions.

Plot Positioning and Media Planning

The major structural formation that will be offered with the aid of the services system that is being created are stream analysis and competitive resolution. In the Present scenario different tools are used for analyzing different social media. In this application the analysis over different social media is done by a single tool. The system offers high volume flexibility, numerous types of element transfer and statistic aggregation. The platform interactions and positioned crafting activities are both protected by authenticated processed security, which increases the system’s flexibility and security.

Distribution, bioaccumulation, and trace element transfer among trophic levels in the southeastern Gulf of California

Our understanding of the trophic transfer of pollutants in marine subtropical ecosystems remains limited due to the complexity of their food webs. Thus, we aimed to evaluate Cd, Cu, Mn, Pb, and Zn sources, incorporation, and trophodynamics throughout the food web of the southeastern Gulf of California by stomach content analysis, stable isotope analysis, isotope mixing models, and trace element analysis in biological and environmental matrices. The food web comprised three main trophic guilds (TG1, TG2, and TG3). The bioaccumulation of Cd and Zn from seawater was efficient (> 1000) in TG2 and TG3. Bioaccumulation factor from sediment (BSAF >1) evidenced of Cd in all trophic guilds. In addition, non-trophic Cd relationships were identified in the food web. Based on the trophic magnification factor (TMF), Mn and Pb showed biodilution (TMFMn = 0.38; TMFPb = 0.16), while Cu and Zn exhibited biomagnification (TMFCu = 2.08; TMFZn = 3.31).

Role of colloids in the transfer and dispersion of trace elements into river waters through a former mining district

Characterizing the different chemical forms of trace elements in surface inland waters of mining regions is very important to understand the mechanisms underlying metal(loid) transport, their accumulation and toxicity, especially when waste storage areas are closely linked to the hydrographic network. This study focuses on the oldmining district of Salsigne in the Orbiel Valley (France), which was at one time the largest gold mine in Europe and the world’s largest arsenic mine. Our objective was to better understand the factors governing the transport of As and to investigate the role of colloidal matter as vector of major (Al, Ca, Fe, Mg) and trace (As, Pb, REE) elements in waters.A field sampling campaign was carried out during high water season to collect samples from the Orbiel River and its tributaries. In situ (ultra)filtrations at different cut-off thresholds (0.22 μm, 0.025 μm, 100 kDa and 3 kDa) were performed and physicochemical parameters (conductivity, pH, alkalinity, Dissolved Organic Carbon: DOC, anions, major cations, and metal(loid)s concentrations) of river water were assessed in all fractions.Results showed decreasing concentrations of DOC, Fe, Al and REE in the conventionally dissolved fraction (< 0.22 μm) from upstream to downstream. Arsenic concentration increased from upstream to downstream, especially at the exit of the old mining zone, and was mainly present in the truly dissolved fraction. However, arsenic in the colloid fraction was about 40% upstream and showed a clear decrease when going downstream. Upstream, Fe and Al were mostly present in the colloidal fraction (around 90%, but decreased to 30% downstream for Al). REE patterns suggested that colloidal organic matter played a significant role in metal transport. This was also inferred from the greater enrichment in middle REE as compared to light and heavy REE; this difference in enrichment progressively disappeared with decreasing cut-off filter size. The concentration variations along the length of the river were found to be a combined effect of the changes in lithology and input of contaminants from storage areas or alluvial table.

In-situ elemental quantitative imaging in plant leaves by LA-ICP-MS with matrix-matching external calibration

Due to the enormous interest in plants related to bioscience, environmental and toxicological research, analytical methods are expected with the ability of getting information on elemental transfer, distribution and contents in plants. In this work, a mixture of gelatin (GA) and hydroxypropyl methyl cellulose (HPMC) was prepared to simulate plant matrix, a method based on laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) with matrix-matching external calibration was proposed for direct quantification of multiple elements in plants. The composition of GA&HPMC substrate was optimized, such as the concentration of spiked nitric acid, the mass fraction of both GA and HPMC in the substrate and the mass ratio of GA: HPMC. After spiking elemental solution, coating the mixture onto a glass slide and drying overnight at room temperature, GA&HPMC substrate was obtained. The substrate obtained with GA: HPMC of 8: 2 was used to fabricate the standard series, which exhibited good elemental homogeneity and similar elemental signal intensities in LA-ICP-MS detection to that obtained for plant Certified Reference Material (CRM). CRMs of different plants including Citrus leaf (GBW10019), Tea (GBW07605), Beans (GBW10021) and Scallions (GBW10049) were further pressed into pellets and subjected to the proposed method, and the quantification accuracy was demonstrated. The limits of detections of this method were found to be 0.003 (Ce)-104 (Ca) μg g−1, with a wide linear range (0.01–10000 μg g−1) for 17 target elements. The application potential of the method was further demonstrated by performing elemental imaging in Trigonotis peduncularis leaves. Rapid in-situ quantitative imaging of Zn, Cu, Sr and Mn was achieved, and the elemental quantitative distributions were discussed. The constructed substrate helped direct elemental quantification in plants. It provided a powerful and efficient tool for the investigation of the distribution and transfer of elements in plants, favoring further exploration of elemental bioavailability, transport and toxicity mechanisms.

Horizontal transfer of probable chicken-pathogenicity chromosomal islands between Staphylococcus aureus and Staphylococcus agnetis.

Staphylococcus agnetis is an emerging pathogen in chickens but has been most commonly isolated from sub-clinical mastitis in bovines. Previous whole-genome analyses for known virulence genes failed to identify determinants for the switch from mild ductal infections in cattle to severe infections in poultry. We now report identification of a family of 15 kbp, 17-19 gene mobile genetic elements (MGEs) specific to chicken osteomyelitis and dermatitis isolates of S. agnetis. These MGEs can be present in multiple copies per genome. The MGE has been vectored on a Staphylococcus phage that separately lysogenized two S. agnetis osteomyelitis strains. The S. agnetis genome from a broiler breeder case of ulcerative dermatitis contains 2 orthologs of this MGE, not associated with a prophage. BLASTn and phylogenetic analyses show that there are closely related intact MGEs found in genomes of S. aureus. The genome from a 1980s isolate from chickens in Ireland contains 3 copies of this MGE. More recent chicken isolates descended from that genome (Poland 2009, Oklahoma 2010, and Arkansas 2018) contain 2 to 4 related copies. Many of the genes of this MGE can be identified in disparate regions of the genomes of other chicken isolates of S. aureus. BLAST searches of the NCBI databases detect no similar MGEs outside of S. aureus and S. agnetis. These MGEs encode no proteins related to those produced by Staphylococcus aureus Pathogenicity Islands, which have been associated with the transition of S. aureus from human to chicken hosts. Other than mobilization functions, most of the genes in these new MGEs annotate as hypothetical proteins. The MGEs we describe appear to represent a new family of Chromosomal Islands (CIs) shared amongst S. agnetis and S. aureus. Further work is needed to understand the role of these CIs/MGEs in pathogenesis. Analysis of horizontal transfer of genetic elements between isolates and species of Staphylococci provides clues to evolution of host-pathogen interactions as well as revealing critical determinants for animal welfare and human diseases.

Effect of the S008-sgaCD operon on IncC plasmid stability in the presence of SGI1-K or absence of an SGI1 variant

An IncC or IncA plasmid is needed to enable transfer of SGI1 type integrative mobilisable elements but an IncC plasmid does not stably co-exist with SGI1. However, the plasmid is stably maintained with SGI1-K, a natural SGI1 deletion variant that lacks the sgaDC genes (S007 and S006) and the upstream open reading frame (S008) found in the SGI1 backbone. Here, the effect of the sgaDC genes and S008 on the stability of an IncC plasmid in an Escherichia coli strain with or without SGI1-K was examined. Co-transcription of the S008 open reading frame with the downstream sgaDC genes was established. When a strain containing SGI1-K complemented with a pK18 plasmid that included S008-sgaDC or sgaDC expressed from the constitutive pUC promoter was grown without antibiotic selection, the resident IncC plasmid was rapidly lost but loss was slower when S008 was present. In contrast, SGI1-K and the S008-sgaDC or sgaDC plasmid were quite stably maintained for >100 generations. However, the high copy number plasmids carrying the SGI1-derived S008-sgaDC or sgaDC genes constitutively expressed could not be introduced into an E. coli strain carrying the IncC plasmid but without SGI1-K. Using equivalent plasmids with S008-sgaDC or sgaDC genes controlled by an arabinose-inducible promoter, under inducing conditions the IncC plasmid was stable but the plasmid containing the SGI1-derived genes was rapidly lost. This unexpected observation indicates that there are multiple interactions between the IncC plasmid and SGI1 in which the transcriptional activator genes sgaDC play a role. These interactions will require further investigation.

Рекурсивное сравнение как основа поиска трансляционных эквивалентов в агглютинативных и флективных языках

The study offers a developed algorithm, aimed to observe cognitive-communicative syntactic specifiers based on recursive comparison in the process of computer-aided translation of statements in agglutinating languages. The key method that enables fast and adequate search for translation equivalent in the languages with different structures is the multilevel recursive comparison of interim forms with dictionary equivalents, as well with contextual matches within the frameworks of prospective modelling in the course of an invariant thesaurus development according to dynamic complicated codes. The combination of cognitive-semantic and semantemic-morphological parallel comparison with spiral references will make it possible to create not only an equivalent version of the target text that meets the requirements of lexico-morphological correctness, but also to ensure the transfer of cognitive and consituational elements of the original utterance. The inclusion of cognitive-communicative syntactic samples in the recursive comparison algorithm during automatic processing of the utterance, as the final stage of generating the target utterance, is designed to solve the problem of polysemic, synonymous and homonymous barriers that arise at the stage of generating the target text. The described automated analysis algorithm is demonstrated on the utterances in languages with different structures (Turkish, Russian and English). The article also provides examples of the interaction of the invariant thesaurus of commonly used constructions with variant correspondences while connecting recursive comparison with elements of cognitive-communicative syntax.

Влияние биогумуса на основе отходов птицеводства на физико-химические свойства дерново-подзолистых почв и выращиваемых растений

Introduction. The current phase of mass production in the poultry products sector creates large volumes of waste in the form of chicken manure. This waste contributes to the negative environmental impact on the neighboring territories. To address the issue of storing chicken manure, several methods have been developed, of which incomplete combustion and composting with gradual decay are two major ones. The application of both technologies results in the production of fertilizers such as mineral biochar and organic humus. The role of these fertilizers is particularly important for regions that face the challenge of insufficient fertility of the zonal soil type, a concern that is common in some mountainous regions. The goal of the study is to develop a method and analyze the results of its application to successfully solve the problem of excess chicken manure by producing a substance that improves the physicochemical properties of sod-podzolic soils and increases their biological efficiency. Materials and methods. The laboratory facilities of the Ecosystem Research Center at St. Petersburg Mining University were used in this study. The physicochemical properties of soils and plants were analyzed based on a standard method for determining the organic content of soils using gravimetric, thermogravimetric, and optical emission spectrometry methods. Results and discussion. Given the relatively low fertility of sod-podzolic soils, which are common in mixed forest regions, the article proposes a modified version of composting as a priority for processing poultry manure. This method accelerates the biochemical processes of manure decay by using a specially bred subspecies of the earthworm Eisenia fetida. The article provides a detailed description of this method for processing poultry manure, which results in the production of an organic fertilizer. To evaluate the effect of the biofertilizer produced by the proposed method on the physicochemical properties of sod-podzolic soils and the plants grown on them, we conducted an experiment involving the addition of the biofertilizer to the soil, followed by sowing ryegrass and spring onion seeds, followed by an analysis of soil and plant samples. The results of the experiment showed that the presence of the biofertilizer in the soil increases its moisture content, improves moisture retention, and reduces ash content. The addition of the biofertilizer significantly increases the contents of humus, organic carbon, total nitrogen, phosphorus, and potassium, also promoting the removal of heavy metals. The use of the proposed biofertilizer enhances the uptake of carbon, nitrogen, and potassium into plants. The proposed method is adapted to residential area conditions and can be used by agricultural companies in various regions of Russia. A future line of research includes experiments to find the rational biofertilizer application rates for growing more common vegetable and grain crops in soils of different types. Conclusions. The study has developed a comprehensive method for investigating the processes of transfer of organic matter and chemical elements from the proposed biofertilizer into soils and plants. This method includes laboratory tests of the physicochemical properties of soils before and after the experiment and those of fertilizers and plants after the experiment. The results demonstrate that the presence of the biofertilizer in dry sod-podzolic soils increases their fertility and improves the physicochemical properties of both the soils and the plants. Resume. The proposed method is adapted to residential area conditions and can be used by agricultural companies in various regions of Russia. A future line of research includes experiments to find the rational biofertilizer application rates for growing more common vegetable and grain crops in soils of different types.

INTERLINGUAL PLAY OF WORDS AND ITS REPRODUCTION IN TRANSLATION

Objective. The objective of the article is to study the influence of interlingual word play on fiction translation, to provide practical recommendations and strategies for this stylistic device rendering in he process of translation; to expand the understanding of the complexities and peculiarities of language game elements transfer, which will help preserve the original meaning and emotional impact of the text. Methods. The main scientific results are obtained with the help of such methods as the analysis and generalization of scientific and educational and methodological literature on the problems of functioning and translation of stylistic means of an literary work, interlingual play of words in particular; system analysis; combination of cultural and linguistic methods in research; separation of subsystems of complex objects and their systematic analysis, an integral approach to the study of linguistic phenomena. Results. Interlingual wordplay plays an important role in fiction translation, adding elements of humour, suspense, and cultural depth to the text. It can cause different emotional reactions and influence readers’ perception and interpretation of the work of art. However, the translation of wordplay creates certain difficulties related to lexical, semantic, cultural and stylistic limitations. The translator needs to balance skillfully between preserving the original effect and adapting the wordplay to the target language and culture. Analysis of recent studies demonstrates the importance of understanding and accounting for cultural features, context, stylistic features, and semantic fields during the translation of interlingual wordplay. Various methods and strategies, such as adaptation, substitution, use of equivalent word games, are applied to convey cultural information and emotional effect in translation. The authors consider the meaning and effect of puns in literary texts, analyze their semantic and contextual complexity, translation problems, and consider different methods and strategies used to convey puns. The study emphasizes the importance of cultural and linguistic competence of the translator, as well as a deep understanding and consideration of the context, semantic field, stylistics and emotional component of the original text when translating interlingual wordplay. Only by taking into account all these factors one can achieve an accurate and adequate translation that preserves the author's style.

THE COMPARISON OF PHONEME PRONUNCIATION PHONOLOGICAL INTERFERENCE OF ق [Q] IN SUNDANESE AND JAVANESE SPEAKERS

The study analyses the phonological interference of phoneme pronunciation [q] by Sundanese and Javanese speakers compared with Arabic speakers. The researchers used a descriptive comparative qualitative method. The researchers listened, took notes, and documented the voice recordings of male students from the Sundanese and Javanese ethnic groups when reading the Qur'an to collect research data and analyse it using Praat software version 6.2.13. From the results of the recordings, Sundanese-speaking students and Javanese speakers would then be compared with reference speakers, namely Syekh Sa'ad Al-ghamidi, who has the capability of reciting verses from the Qur'an. The research results indicated phonological interference in the phoneme [q] when Sundanese and Javanese male students read the Qur'an. The factor contributing to the occurrence of pronunciation errors in the phoneme [q] was the transfer of SL and JL elements when using AL. Errors occurred due to deviations from the proper language rules. The research is expected to have positive implications, minimizing interference and increasing fluency in reading the Qur'an.

H2-H2O immiscibility in Earth’s upper mantle

Immiscibility between water and hydrogen-rich fluids may be responsible for the formation of super-reduced mineral assemblages and for the early oxidation of Earth´s upper mantle. In the current study, we present new data on the critical curve in the H2-H2O system to 1400 ℃ and 4 GPa. We utilized a synthetic fluid inclusion method to trap fluids at high P–T conditions within quartz and olivine crystals. Experiments were performed in a piston-cylinder type apparatus, employing a double-capsule technique. The inner capsule contained the crystal and fluids of interest, while the outer served as oxygen fugacity buffer, maintaining f(O2) at the iron-wüstite (Fe-FeO) equilibrium. Our results suggest that below ~ 2.5 GPa, the critical curve has a mostly linear slope of 200 ℃/GPa, while at more elevated pressure it becomes significantly steeper (400 ℃/GPa). This implies that in most of the modern, reduced upper mantle, water and hydrogen are immiscible, while localized heating events, such as rising plumes, may close the miscibility gap. The steep increase of the critical curve at high pressure observed in this study implies that even for very hot geotherms in the early Archean or the late Hadean, H2-H2O immiscibility likely occurred in the deeper parts of the upper mantle, thus making a plausible case for rapid H2 loss as a mechanism of early mantle oxidation. To constrain the geochemical fingerprint of this process, we performed a series of element partitioning experiments to unravel how the H2-H2O unmixing may affect element transfer. Noble gases such as Xe as well as methane are preferentially incorporated in the hydrogen-rich phase, with a XeH2O/XeH2 ratio of ~ 8. This partitioning pattern may, for example, explain the underabundance of Xe isotopes produced by fission of Pu in the mantle. These Xe isotopes may have been removed by a primordial H2-H2O unmixing event during the early stages of planetary evolution.

Characterization of a prophage and a defective integrative conjugative element carrying the optrA gene in linezolid-resistant Streptococcus dysgalactiae subsp. equisimilis isolates from pigs, Italy.

To investigate the optrA-carrying genetic elements and their transferability in two linezolid-resistant Streptococcus dysgalactiae subsp. equisimilis (SDSE) strains of swine origin. SDSE strains (V220 and V1524) were phenotypically and genotypically characterized. Transferability of oxazolidinone resistance genes (filter mating), genetic elements and relatedness between isolates (WGS) were analysed. Excision of the genetic elements was assayed by inverse PCR. SDSE isolates were resistant to chloramphenicol, florfenicol and linezolid, but susceptible to tedizolid and both carried the optrA gene.In SDSE V220 optrA was located on a 72.9-kb ICESdyV220 inserted in the 3' end of the chromosomal rum gene. It was 94%-96% identical (coverage, from 31% to 61%) to other optrA-carrying ICEs. In-depth ICESdyV220 sequence analysis revealed that optrA was carried by an IMESdyV220 (17.9 kb), also containing the tet(O/W/32/O) gene. Inverse PCR assays excluded the ICESdyV220 mobility. In SDSE V1524, optrA was carried by the ΦSdyV1524 prophage, integrated near the 5' end of the chromosomal had gene, showing a genetic organization similar to that of other streptococcal phage. Conjugation and transduction assays failed to demonstrate the optrA transferability to streptococcal recipients. V220 and V1524 belonged to two novel sequence types (ST704 and ST634, respectively). To the best of our knowledge, this is the first identification of the optrA gene on a prophage and an ICE in SDSE isolates from swine brain.These findings are consistent with the current belief in the key role of bacteriophages and ICEs in the streptococcal evolution and adaptation.

DUF2285 is a novel helix-turn-helix domain variant that orchestrates both activation and antiactivation of conjugative element transfer in proteobacteria.

Horizontal gene transfer is tightly regulated in bacteria. Often only a fraction of cells become donors even when regulation of horizontal transfer is coordinated at the cell population level by quorum sensing. Here, we reveal the widespread 'domain of unknown function' DUF2285 represents an 'extended-turn' variant of the helix-turn-helix domain that participates in both transcriptional activation and antiactivation to initiate or inhibit horizontal gene transfer. Transfer of the integrative and conjugative element ICEMlSymR7A is controlled by the DUF2285-containing transcriptional activator FseA. One side of the DUF2285 domain of FseA has a positively charged surface which is required for DNA binding, while the opposite side makes critical interdomain contacts with the N-terminal FseA DUF6499 domain. The QseM protein is an antiactivator of FseA and is composed of a DUF2285 domain with a negative surface charge. While QseM lacks the DUF6499 domain, it can bind the FseA DUF6499 domain and prevent transcriptional activation by FseA. DUF2285-domain proteins are encoded on mobile elements throughout the proteobacteria, suggesting regulation of gene transfer by DUF2285 domains is a widespread phenomenon. These findings provide a striking example of how antagonistic domain paralogues have evolved to provide robust molecular control over the initiation of horizontal gene transfer.

A Mechanism Study of Redox Reactions of the Ruthenium-oxo-polypyridyl Complex.

Over the years, RuIV(bpy)2(py)(O)2+([RuIVO]2+) has garnered considerable interest owing to its extensive use as a polypyridine mono-oxygen complex. However, as the active-site Ru=O bond changes during the oxidation process, [RuIVO]2+ can be used to simulate the reactions of various high-priced metallic oxides. In order to elucidate the hydrogen element transfer process between the Ruthenium-oxo-polypyridyl complex and organic hydride donor, the current study reports on the synthesis of [RuIVO]2+, a polypyridine mono-oxygen complex, in addition to 1H and 3H (organic hydride compounds) and 1H derivative: 2. Through 1H-NMR analysis and thermodynamics- and kinetics-based assessments, we collected data on [RuIVO]2+ and two organic hydride donors and their corresponding intermediates and established a thermodynamic platform. It was confirmed that a one-step hydride transfer reaction between [RuIVO]2+ and these organic hydride donors occurs, and here, the advantages and nature of the new mechanism approach are revealed. Accordingly, these findings can considerably contribute to the better application of the compound in theoretical research and organic synthesis.

Effects of Arbuscular Mycorrhizal Fungi on the Physiology and Saponin Synthesis of Paris polyphylla var. yunnanensis at Different Nitrogen Levels

Arbuscular mycorrhizal fungi (AMF) are important members of the plant microbiome and affect the uptake and transfer of mineral elements by forming a symbiotic relationship with plant roots. Nitrogen (N), as an important mineral element, can directly affect plant growth and development at different N levels. It has been confirmed that inoculation with AMF can improve the efficiency of N utilization by plants. However, there are still fewer reports on the dynamic relationship between arbuscular mycorrhizal and plant secondary metabolites at different nitrogen levels. In this experiment, the physiological indexes and genes related to saponin synthesis were determined by applying different concentration gradients of nitrogen to the medicinal plant P. polyphylla var. yunnanensis infested by AMF as the test material. It was found that nitrogen addition increased the biomass, chlorophyll content, and nutrient content of above- and below-ground plant parts and increased the content of saponin content of P. polyphylla var. yunnanensis to some extent, but AMF inoculation increased the saponin content of P. polyphylla var. yunnanensis more significantly. AMF inoculation also promoted the expression of genes related to the saponin synthesis pathway, including 3-hydroxy-3-methylglutaryl coenzyme A synthase (HMGS), squalene epoxidase 1 (SE1), and cycloartenol synthase (CAS), which is in according with the accumulation of saponin in plants. It also may increase the saponin content of AMF plants by altering the expression of P450s and UGTs related to saponin synthesis.

Static and dynamic source identification of trace elements in river and soil environments under anthropogenic activities in the Haraz plain, Northern Iran

Unsustainable human activities have disrupted the natural cycle of trace elements, causing the accumulation of chemical pollutants and making it challenging to determine their sources due to interwoven natural and human-induced processes. A novel approach was introduced for identifying the sources and for quantifying the contribution of trace elements discharge from rivers to soils. We integrated fingerprinting techniques, soil and sediment geochemical data, geographically weighted regression model (GWR) and soil quality indices. The FingerPro package and the state-of-the-art tracer selection techniques including the conservative index (CI) and consensus ranking (CR) were used to quantify the relative contribution of different upland sub-watersheds in trace element discharge soil. Our analysis revealed that off-site sources (upland watersheds) and in-site sources (land use) both play an important role in transferring trace elements to the Haraz plain (northern Iran). The unmixing model's results suggest that the Haraz sub-watersheds exhibit a higher contribution to trace elements transfer in the Haraz plain, and therefore, require greater attention in terms of implementing soil and water conservation strategies. However, it is noteworthy that the Babolroud (adjacent to Haraz) exhibited a better performance of the model. A spatial correlation between certain heavy metals, such as As and Cu, and rice cultivation existed. Additionally, we found a significant spatial correlation between Pb and residential areas, particularly in the Amol region. Our result highlights the importance of using advanced spatial statistical techniques, such as GWR, to identify subtle but critical associations between environmental variables and sources of pollution. The methodology used comprehensively identifies dynamic trace element sourcing at the watershed scale, allowing for pollutant source identification and practical strategies for soil and water quality control. Tracer selection techniques (CI and CR) based on conservatives and consensus improve unmixing model accuracy and flexibility for precise fingerprinting.