Search Results (123)

Background/Objectives: Course-based Undergraduate Research Experiences (CUREs) represent a form of student crowdsourcing in which individuals perform authentic discovery-based research in a class setting with interest to outside stakeholders. Here, the renowned Tiny Earth (TE) CURE is being utilized to teach microbiology and perform natural product discovery research by students in the course. Methods: In our TE CURE, students collect soil samples from their hometown and characterize bacteria that can inhibit plant and animal pathogens. This unique growing collection of isolates from across Ohio has provided opportunities to facilitate drug discovery and establish biotechnology collaborations. Results: In this study, we describe two outcomes using our environmental strain collection that initiated biotechnology collaborations and identified bacterial candidates for drug discovery. Results from one project led to a partnership with an aquaculture company. A novel biosynthetic gene cluster involved in antagonistic activity was identified, whose product inhibits Aeromonas pathogens, which cause disease in freshwater fish. The other project involves a collaboration with a global commercial cleaning and equipment company to identify lipase activity among Bacillus strains for its potential use in bioremediation. Conclusions: The unique strain collection generated by students in the CURE led to collaboration with biotechnology companies, which contributed to natural product discovery of an antimicrobial product and active enzymatic activity, all of which benefit education and scientific discovery. Full article

Lactobacillus species are widely used in various food products, including conventional food products, dairy products, and health food products. To achieve the desired functional properties, manufacturers commonly incorporate two or more distinct Lactobacillus species during production. In this study, a multiplex PCR detection method was developed for four Lactobacillus species commonly used in food based on TaqMan real-time fluorescent PCR technology, enabling the efficient and rapid identification of multiple Lactobacillus strains in food matrices. The research team selected and validated four representative species—Lactobacillus rhamnosus, Lactobacillus plantarum, Lactobacillus acidophilus, and Lactobacillus paracasei—as targets for the multiplex PCR assay, designing specific primer–probe combinations for each. The accuracy and reliability of the detection method were rigorously evaluated through a series of validation experiments, including the assessment of primer–probe specificity, optimization of fluorescent signal labeling chemistries, determination of the limits of detection for individual strains, evaluation of the method’s repeatability, and analysis of commercial food samples. The results demonstrated that the selected primer–probe sets exhibited no cross-reactivity in the multiplex system and specifically amplified their target Lactobacillus species, with no amplification observed for non-target strains. The established method achieved a minimum LOD for L. acidophilus of 10² CFU/g and showed high repeatability across replicates. Furthermore, the successful detection of labeled Lactobacillus strains in commercial products confirmed the method’s practical applicability. Therefore, the developed multiplex real-time PCR assay provides a reliable, sensitive, and high-throughput tool for the simultaneous detection of multiple Lactobacillus species in complex food products and holds potential for application in quality control, product authentication, and regulatory compliance monitoring. Full article

Conventional web analytics treats the human user as its fundamental unit of analysis, assuming stable preferences, identifiable intentions, and behavioral patterns that unfold over time. That assumption is under strain. Crawlers and traditional bots already account for a substantial fraction of online interactions, and autonomous AI agents are emerging as a further class of actors layered on top of this automated traffic. Unlike either, these agents do not possess persistent identities or psychologically grounded motivations. They are task-specific, dynamically instantiated processes whose behaviors are contingent and often orchestrated by external systems. Their presence weakens the interpretive value of core metrics, including sessions, engagement, conversion, and retention. A click may reflect an optimization routine, a proxy objective, or a recursive agent-to-agent exchange rather than meaningful human intent, and traditional inference frameworks cannot reliably distinguish among these possibilities. This is a position paper. It synthesizes literature across bot and agent detection, agent architecture, web measurement validity, governance of automated systems in adjacent sectors, and the epistemology of digital trace data, and it argues that web analytics should supplement, and in places replace, its human-centered model with an agent-aware model focused on interaction dynamics within hybrid ecosystems of human and non-human actors. The paper develops a working taxonomy of crawlers, traditional bots, AI agents, LLM-powered agents, and autonomous agents; identifies three properties of LLM agents (identity discontinuity by design, task-based instantiation, agent-to-agent loops) that distinguish the present challenge from prior bot-detection problems; examines opaque agent objectives, synthetic traffic loops, and the indistinguishability between human-originated and agent-mediated signals; and proposes five candidate measurement primitives (task chain, actor class, interaction provenance, objective alignment, signal authenticity) with explicit operational definitions. Governance machinery from energy systems and critical infrastructure offers a partial template, and we delimit which dimensions transfer and which do not. The contribution is conceptual and programmatic, presenting a vocabulary, set of candidate primitives, and research agenda for a field whose foundational unit of analysis is becoming unreliable. Full article

Zearalenone (ZEN) is an estrogenic mycotoxin produced by Fusarium spp. and commonly found in cereals and feed materials. This study evaluated the ability of Metschnikowia pulcherrima KKP 1368 biomass to reduce extractable ZEN under controlled buffered pH conditions (pH 3.50 and 7.00) selected as simplified conditions relevant to the porcine gastrointestinal environment. ZEN was quantified by LC-MS/MS, whereas LC-MS-QTOF was used as a qualitative/semi-quantitative screening approach for tentatively assigned transformation-related features. In the presence of yeast biomass, extractable ZEN was already lower than in the corresponding controls at the first sampling point, indicating a rapid biomass-associated effect. After 12 h, reductions relative to the corresponding controls reached 63.0% at pH 3.50 (p < 0.0001) and 51.6% at pH 7.00 (p = 0.0001). ZEN remained stable in control samples, and the strain remained viable under both pH conditions throughout incubation. LC-MS-QTOF detected several tentatively assigned features consistent with zearalanone, zearalenone-14-glucuronide, and zearalenol O-glucoside; these assignments require confirmation with authentic standards. Overall, M. pulcherrima KKP 1368 reduced extractable ZEN in a simplified buffered in vitro system, probably through rapid adsorption/reduced extractability and possible biotransformation. Further studies using biomass fractions or inactivated biomass, mass-balance experiments, authentic standards, and toxicological assays are needed to clarify the relative contribution of adsorption and transformation and to assess the practical relevance of this approach. Full article

The integration of salt removal and structural consolidation remains a major challenge in heritage brick conservation. This research proposes a preliminary experimental setup for a dual-function microbial strategy using a single bacterium, Stutzerimonas stutzeri D1, capable of sequential denitrification (biocleaning) and ureolysis-driven microbially induced calcium carbonate precipitation (biocementation). After the pre-check assessment, which compared standalone, simultaneous, and sequential metabolic configurations, sequential denitrification followed by ureolysis (A→B) optimized functional compatibility, achieving 90.1% nitrate removal within 48 h and the highest precipitation rate during the biocementation phase. Application on authentic demolition waste (solid fired-clay brick specimens) demonstrated highly efficient nitrate reduction, alkalization (from pH value of 6.4 to 9.12), surface mineral deposition confirmed by visual inspection, SEM imaging, and XRD analysis. Furthermore, reduced water absorption (by 30%) and improved compressive strength (by 25%) for only 72 h of this dual treatment indicate a promising and holistic approach in the field of construction biotechnology of heritage brick conservation. These pioneer findings demonstrate that metabolic sequencing governs compatibility in dual-function bacterial systems and validate a sustainable, single-strain platform for combined biocleaning and biocementation of historic brick masonry structures. Full article

The load characteristics of the helicopter tail rotor system are critical to flight safety and handling performance, and flight testing remains the most direct and reliable means to obtain authentic load data. In this paper, the well-established Wheatstone bridge strain measurement method is adopted to carry out accurate load testing on the helicopter tail rotor system. The tail rotor assembly mainly consists of the tail rotor shaft, pitch link, and tail rotor blades, which undertake different load transfer tasks during flight. Under actual operating conditions, the tail rotor shaft bears significant axial tension as well as combined lateral and vertical bending moments; the pitch link is primarily subjected to alternating axial tension and compression; and the tail rotor blades withstand complex loads including flapping bending, lagwise bending, and torsional moments. According to the distinct stress characteristics and force transmission paths of each component, targeted flight test maneuvers are reasonably designed. These maneuvers include steady-level flight at low, medium, and high speeds, zigzag climbing flight, near-ground side-rear flight, as well as deceleration-to-sprint and obstacle slope maneuvers specified in ADS-33E. Key flight parameters are selected for in-depth analysis to reveal the load distribution and dynamic variation patterns of the tail rotor under typical operating conditions. On this basis, a helicopter load risk test point matrix is established to identify high-risk working conditions and key monitoring positions. This study provides a solid theoretical and data foundation for subsequent flight test monitoring and structural strength verification. It effectively reduces flight test risks, improves monitoring efficiency and accuracy, and helps cut down the human, material, and financial costs associated with flight test monitoring. The research results can also provide important references for the design optimization and safety evaluation of helicopter tail rotor systems. Full article

Emotional labor is inherently intensive in preschool teaching, and it is often conceptualized as resource loss, which may heighten burnout and hinder early childhood education quality-improvement initiatives. Accordingly, this study shifts attention to the resource-enhancing potential of authentic emotional displays and examines the mechanisms linking authentic displays to preschool teachers’ burnout, with psychological capital and family–work conflict as key mediators. Using cross-sectional survey data from 234 preschool teachers in Jiangxi Province, China, and structural equation modeling, we observed that authentic emotional displays were associated with lower burnout primarily through psychological capital, with an additional sequential association via psychological capital and family–work conflict, whereas the pathway through family–work conflict alone was not supported. These findings suggest a potential role of authentic emotional displays in relation to psychological resources and family-to-work spillover, extending emotional labor research and providing insights for interventions aimed at reducing preschool teacher burnout. The study challenges the prevailing resource loss perspective of emotional labor, clarifies psychological capital as a central mechanism linking authenticity to cross-domain strain and teacher well-being, and emphasizes the importance of interventions that strengthen psychological resources and boundary management. Full article

Background: Parents of school-age children with neurodevelopmental and conduct difficulties face elevated stress, reduced self-efficacy and relational strain, yet evidence for scalable, school-embedded support remains limited. Drawing on mentalization theory—which emphasises parents’ capacity to understand behaviour in terms of underlying mental states—this mixed-methods study evaluated a weekly parent learning group integrating psychoeducation, mentalization-based practice and peer support, delivered within an alternative provision school. Methods: A group of twelve parents who attended at least six sessions completed retrospective pretest–posttest questionnaires assessing parental reflective functioning (PRFQ) and parenting self-efficacy (PSOC). Semi-structured interviews explored parents’ subjective experiences and perceived changes in parent–child interactions and parent–school relationships. Quantitative outcomes were analysed using paired t-tests and effect sizes; qualitative data underwent reflexive thematic analysis. Results: Quantitative analyses revealed statistically significant improvements in parental reflective functioning and self-efficacy. Pre-mentalizing scores decreased substantially (d = 1.34), indicating reductions in non-mentalizing, while interest and curiosity about children’s mental states increased markedly (d = 1.83). Parenting self-efficacy improved significantly (d = 1.61). Although a reduction in excessive certainty about mental states approached significance (d = 0.63, p = 0.053), trends suggested greater epistemic balance. Qualitative analysis identified six themes elucidating mechanisms of change, including enhanced mentalizing capacity, reduced parental stress, transformed parent–child interactions and facilitation style as a critical active ingredient. Integration of findings suggests that psychoeducational content provided conceptual grounding for understanding behaviour, facilitator modelling scaffolded reflective practice, and relational safety within the group enabled authentic engagement with challenging experiences. Conclusions: These preliminary findings indicate that a school-based parent learning group combining psychoeducation, mentalization-based practice and peer support is feasible and associated with meaningful improvements in parental reflective functioning and self-efficacy. Parent narratives of transformed relational practices and shifts from reactive to reflective engagement echo broader literature demonstrating that group-delivered mentalization-oriented programmes can enhance reflective capacities and caregiving quality in diverse family contexts. The school setting may extend the reach of such interventions to families not engaged with clinical services and support collaborative parent–school partnerships. Future research should employ larger, controlled designs, incorporate observational and child outcome measures, and explore scalability across educational contexts. Full article

This article explores the perceived benefits and barriers associated with employing former prisoners as street outreach workers, based on the perspectives of social welfare and prison system professionals. The study aims to contribute to discussions on collaborative approaches to social reintegration and community-based support for socially excluded populations. A qualitative study was conducted between January and March 2025 using in-depth individual interviews. The sample consisted of 30 participants, including 15 social welfare workers and 15 prison officers with professional experience in working with individuals leaving prison. The findings indicate that employing former prisoners as street outreach workers is perceived as offering potential benefits, such as increased credibility, authenticity, and improved engagement with hard-to-reach groups, alongside significant concerns related to emotional stability, institutional readiness, and the risk of role strain. The results suggest that this model may represent an innovative form of support for social reintegration when embedded within appropriate structures of preparation, supervision, and inter-institutional cooperation. The study contributes to ongoing debates on peer-based support and post-prison employment by highlighting professional perceptions of both opportunities and limitations associated with this approach. Full article

Background: Chronic kidney disease (CKD) continues to place immense strain on health systems globally, with nurses at the centre of care delivery physically, emotionally, and relationally. In dialysis units, nurses form long-term therapeutic relationships with patients who depend on life-sustaining treatment several times a week. Objective: This study explored the lived experiences of professional nurses caring for patients with CKD in a dialysis unit, using Watson’s Theory of Human Caring as a guiding framework. Methods: A qualitative, exploratory, descriptive design was employed. Data were collected through in-depth face-to-face interviews with twelve professional nurses and analyzed using thematic analysis. Trustworthiness was ensured through credibility, dependability, confirmability, transferability, and authenticity. Ethical approval and informed consent were obtained. Results: Three themes emerged: (1) emotional and professional experiences, (2) systemic resource constraints, and (3) recommendations for practice improvement. These findings highlight the tension between caring ideals and systemic limitations. Conclusions: The study concludes that dialysis nursing is profoundly meaningful yet emotionally demanding. Strengthened emotional support, improved leadership visibility, consistent resource allocation, and enhanced nephrology nursing education are critical to sustaining compassionate care. The findings offer important insights for policy, workforce development, and quality improvement efforts in CKD care. Full article

Background: The SARS-CoV-2 3CLpro is essential for viral replication and an attractive target for antiviral intervention. While most strategies target the catalytic site, recent studies suggest that the dimerization interface and cryptic allosteric pockets offer alternative mechanisms for inhibition. Objective: This study investigated lipid metabolites from the marine sediment-derived Streptomyces sp. DSD454^T as potential multi-site 3CLpro inhibitors. Methods: Metabolites were extracted from cultured biomass and characterized using LCMS-QTOF, MS/MS (LCMS-TQ), and ¹H NMR, with identities confirmed against authentic standards. 3CLpro inhibition was assessed using a FRET-based assay, and ligand–protein interactions were evaluated through molecular docking and MM/GBSA calculations. Lipid content and comparative lipidomic signatures were examined across bioactive Streptomyces strains through LCMS-TQ and BODIPY^TM 493/503 staining. Results: Palmitoleic and linoleic acids were identified as major constituents and inhibited SARS-CoV-2 3CLpro with IC₅₀ values of 1.59 µg/mL (6.25 µM) and 5.29 µg/mL (18.88 µM). Molecular docking predicted that both fatty acids bind not only to the catalytic site but also to the dimerization interface and cryptic allosteric pocket. Additional lipids, including 9-heptadecenoic acid, linolenic acid, 9-HODE, and monoacylglycerols such as aggrecerides A–C and glyceryl-based lipids, showed similarly favorable multi-site binding profiles. Streptomyces sp. DSD454^T also exhibited substantial lipid accumulation (~63% of crude extract). Across bioactive Streptomyces strains, a conserved lipid signature correlated strongly with 3CLpro inhibition. Conclusions: This study highlights the potential of microbial lipids as promising scaffolds for developing catalytic and allosteric SARS-CoV-2 3CLpro inhibitors and underscore marine Streptomyces as a valuable source of structurally simple yet mechanistically versatile antiviral metabolites. Full article

Probiotics are live microorganisms that provide health benefits when administered in adequate amounts. Due to the increasing popularity of probiotic supplements, concerns have arisen regarding their quality, microbial composition, and safety. This study aimed to evaluate the quantitative and qualitative characteristics of the selected probiotics available on the Polish market, including both dietary supplements and foods for special medical purposes, and to compare the obtained results with the information provided on the product labels. Fifteen commercial probiotic products were analysed. Viable microorganism counts were determined using the traditional culture-based plate count method and by flow cytometry for selected products. Species identification was performed using MALDI-TOF MS and qPCR, whereas microbiological purity testing was conducted to confirm the absence of pathogenic bacteria. Significant differences were observed between the declared and experimentally determined numbers of viable microorganisms. Only a few products maintained bacterial counts consistent with label claims, while most contained considerably low viable cells. Flow cytometry revealed higher viable cell counts than plate counting, indicating the presence of viable but non-culturable bacteria. The declared species composition of the strains was mostly confirmed, although in several cases, undeclared probiotic microorganisms were identified. All tested products were free from pathogens. The study indicates significant discrepancies in the quality of probiotic supplements available on the Polish market. From a consumer perspective, these findings highlight the importance of verifying probiotic quality and suggest that not all commercial products may guarantee the full range of claimed health benefits. The implementation of standardised analytical procedures and enhanced quality control measures is therefore essential to ensure the product safety, strain authenticity, and reliability of health-related claims. Full article

To elucidate the micromechanical origins of the macroscopic anisotropic behavior of granular materials, this study develops a micromechanically based elastoplastic constitutive model for sand. First, anchored in the static equilibrium hypothesis and granular micromechanics theory, a true stress tensor is introduced to characterize the authentic inter-particle contact forces. Serving as a coupled variable of the macroscopic stress and the microscopic fabric tensor, this formulation not only quantifies the directional distribution of the contact network but also enables the mapping of anisotropic yielding and deformation analyses into an equivalent isotropic true stress space. Subsequently, a comprehensive constitutive framework is established by integrating critical state theory, an anisotropic fabric evolution law, and an energy-based stress–dilatancy relationship that explicitly accounts for the evolution mechanism of the microscopic coordination number. The physical interpretation, calibration procedure, and sensitivity analysis of the model parameters are also presented. The predictive capability of the model is rigorously validated against conventional triaxial tests on Ottawa sand, true triaxial numerical simulations, and experimental data for Toyoura sand with inherent anisotropy. The comparisons demonstrate that the model accurately captures not only the stress–strain response and volumetric deformation under conventional loading but also the strength dependency on loading direction and mechanical characteristics under complex stress paths, substantiating the validity and universality of the proposed micromechanical approach. Full article

The cheese microbiome is a complex ecosystem strongly influenced by both technological practices and the processing environment. Moving beyond traditional cultured-based methods, the integration of shotgun metagenomics into cheese microbiology has enabled in-depth resolution of microbial communities at the species and strain levels. The aim of the present study was to review recent applications of shotgun metagenomics in cheese research, underscoring its role in tracking microbial dynamics during production and in discovering genes of technological importance. In addition, the review highlights how shotgun metagenomics enables the identification of key metabolic pathways, including amino acid catabolism, lipid metabolism, and citrate degradation, among others, which are central to flavor formation and ripening. Results of the discussed literature demonstrate how microbial composition, functional traits, and overall quality of cheese are determined by factors such as raw materials, the cheesemaking environment, and artisanal practices. Moreover, it highlights the analytical potentials of shotgun metagenomics, including metagenome-assembled genomes (MAGs) reconstruction, characterization of various genes contributing to flavor-related biosynthetic pathways, bacteriocin production, antimicrobial resistance, and virulence, as well as the identification of phages and CRISPR-Cas systems. These insights obtained are crucial for ensuring product’s authenticity, enabling traceability, and improving the assessment of safety and quality. Despite shotgun metagenomics’ advantages, there are still analytical restrictions concerning data handling and interpretation, which need to be addressed by importing standardization steps and moving towards integrating multi-omics approaches. Such strategies will lead to more accurate and reproducible results across studies and improved resolution of active ecosystems. Ultimately, shotgun metagenomics has shifted the field from descriptive surveys to a more detailed understanding of the underlying mechanisms shaping the overall quality and safety of cheese, thus bringing innovation in modern dairy microbiology. Full article

The molecular fatty acid (FA) profiles of seven certified thermophilic Lactobacillus strains, including the influence of an extracellular source of oleic acid (as Tween 80^TM), were characterised using advanced chromatographic and spectrometric methods. Cyclic and conjugated fatty acids were identified by GC-MS using co-injections with authentic standards, ECL, and diagnostic EI ions, with a secondary confirmation using literature data. Additionally, the molecular-level characterisation of fatty acid profiles of bacterial cells was summarised using the latest analytical approaches, highlighting inconsistencies and differences reported in previous studies. Six saturated fatty acids, two single-branched fatty acids with iso and anteiso structures, one hydroxy fatty acid, nine unsaturated fatty acids with one double bond, two fatty acids with unsaturated double bonds, six fatty acids with conjugated bonds, and three fatty acids with a cyclic part in the carbon chain were identified. Within these fatty acids, we also demonstrated the limitations of molecular chromatographic resolution and structural discrimination, which impacted the effective identification of fatty acids in our research. We confirmed the significant differences in terms of the identification of C18:1,cis-9 and C18:1,cis-11 acids, as well as cycC19:0,cis-10,11, and cycC19:0,cis-9,10 acids. The observations at the molecular–physiological interface related to the lack of growth of L. acidophilus strains and the visibly reduced growth of L. delbrueckii subsp. lactis ATCC 4797 in the MRS without the addition of Tween 80^TM allowed us to confirm that the exclusion of this medium is useful in differentiating the lactobacilli. Full article