Search Results (410)

Taraxacum kok-saghyz Rodin, an important rubber-producing plant, has emerged as a potential alternative crop for the natural rubber industry. Geranyl diphosphate synthase (GDS) catalyzes the condensation of dimethylallyl pyrophosphate and isopentenyl pyrophosphate into geranyl pyrophosphate in the mevalonate pathway in plants. However, its specific functions in natural rubber biosynthesis in T. kok-saghyz remain unclear. Methods: We conducted genome-wide analyses of TkGDS genes, followed by transient transformation assay, expression profiling, natural rubber quantification, and analysis of T. kok-saghyz photosynthesis. Results: Seven TkGDS genes are located on chromosomes A6 and A7 with an uneven distribution. All encoded TkGDS proteins contain FARM and SARM motifs. TkGDS1, TkGDS2, and TkGDS7 possess lspA domains, while TkGDS3, TkGDS4, TkGDS5, and TkGDS6 contain PLN02890 domains; both subgroups share similar domain architecture. TkGDS1, TkGDS2, and TkGDS7 exhibit interspecies collinearity with Arabidopsis thaliana; no intraspecies collinearity was detected. The putative cis-acting elements in promoter region of TkGDS genes mainly comprised abscisic acid responsiveness, anaerobic induction, light responsiveness, and MeJA responsiveness. Transient expression assays confirmed chloroplast localization of all TkGDS proteins. A strong positive correlation was observed between TkGDS1/TkGDS7 expression and natural rubber content, as confirmed by both transcriptome and qPCR analyses in T. kok-saghyz lines. Furthermore, overexpression of TkGDS1 and TkGDS7 improved photosynthetic efficiency and significantly increased natural rubber content (OE-TkGDS1: 6.08 ± 0.16%; OE-TkGDS7: 5.62 ± 0.32%; WT: 4.76 ± 0.28%). Conclusions: Our study elucidates the role of GDS1 and GDS7 in promoting growth and latex content, offering a genetic strategy for enhancing rubber accumulation in T. kok-saghyz. Full article

Differential privacy (DP) has become a cornerstone for privacy-preserving machine learning, yet its application to high-resolution satellite imagery remains underexplored. Existing DP algorithms, such as DP-SGD, often rely on static noise levels and global clipping thresholds, which lead to slow convergence and poor utility in deep neural networks. In this paper, we propose ADP-SIR, an Adaptive Differential Privacy framework for Satellite Image Recognition with provable convergence guarantees. ADP-SIR introduces two novel components: Convergence-Guided Noise Scaling (CGNS), which dynamically adjusts the noise multiplier based on training stability, and Layerwise Sensitivity Profiling (LSP), which enables fine-grained clipping at the layer level. We provide theoretical analysis showing that ADP-SIR achieves good convergence in non-convex settings under Rényi differential privacy. Empirically, we evaluate ADP-SIR on EuroSAT and RESISC45, demonstrating significant improvements over DP-SGD and AdaClip-DP in terms of accuracy, convergence speed, and per-class fairness. Our framework bridges the gap between practical performance and rigorous privacy for remote sensing applications. Full article

This study examines the pedagogical potential of LEGO^® SERIOUS PLAY^® (LSP) in optometric education, aiming to foster critical reflection on optics, sustainability, and professional identity. A qualitative interpretative phenomenological analysis was conducted with 48 students from Optics and Optometry and Renewable Energies programs at ISEC Lisboa. Participants took part in LSP sessions focused on optics and sustainability, using metaphorical models to express their reflections. Data were collected via observations, group discussions, and open-ended questionnaires, and analyzed with Grounded Theory. In the optics theme, models revealed both scientific and symbolic views, with visual correction (46.7%), professional roles (21.3%), and perception (14.7%) being most frequent. Statistically significant differences appeared by academic background (p < 0.001) and experience (p = 0.0018): optometry students emphasized clinical roles, while environmental students highlighted perception. For sustainability, main categories included sustainable practices (41.7%), polluting industries (15.3%), ecological footprint (13.9%), and social responsibility (12.5%). Actions proposed included recycling, reuse, and biodegradable materials. Age was linked to action-oriented responses (p = 0.038), with no differences by gender or nationality. LSP emerged as an effective tool for deep reflection, interdisciplinary learning, and ethical engagement, supporting integration of sustainability and identity in technical education. Further research should explore its long-term educational impact. Full article

While numerous bioactive polysaccharides have been identified from mushrooms, their mechanisms of action, particularly through the induction of oxidative stress in tumor cells, remain underexplored. This study isolates a novel polysaccharide, LSPS2, derived from Laetiporus sulphureus, followed by the elucidation of its distinctive structural features and specific antitumor activity in A549 lung carcinoma cells. LSPS2 was composed primarily of glucose (88.1%) and minor amounts of mannose (8.0%) and galactose (3.9%). Methylation and one-dimensional/two-dimensional nuclear magnetic resonance (1D/2D NMR) analysis results indicated that LSPS2 was composed of (1→3)-linked-D-β-glucopyran residues and (1→4)-linked-D-α-glucopyran residues as the main chain. The side chains were connected to O-6 and O-3 of glucopyranose (Glcp) residues with terminal Glcp. It differs from previous reports on L. sulphureus polysaccharides. Functionally, LSPS2 markedly suppressed A549 cell viability in a manner that depended on both exposure duration and concentration. LSPS2 upregulated malondialdehyde (MDA) and downregulated reduced glutathione (GSH), demonstrating that LSPS2 induces oxidative stress in A549 cells. The results of superoxide dismutase (SOD) activity assays further indicated that LSPS2 downregulates SOD activity, which may be the mechanism by which LSPS2 induces oxidative stress and, consequently, apoptosis in A549 cells. This targeted downregulation of a key antioxidant enzyme highlights a potential pathway for polysaccharide-induced tumor cell death. Our findings not only identify LSPS2 as a structurally distinct biopolymer but also elucidate its mode of action, underscoring its prospective application in tumor therapy and functional foods, warranting further investigation. Full article

Background: Industry 4.0 (I4.0) has gained significant attention in recent years, with the term Logistics 4.0 (L4.0) emerging in the logistics industry. However, L4.0 remains vague and lacks a unified definition or classification of related technologies. Existing studies defining L4.0 are mainly conceptual and speculative, rather than grounded in empirical research. To address this gap, this study contributes to defining L4.0 through the sub-area of Warehouse 4.0 (W4.0), focusing on the challenges of adopting I4.0 technologies in warehouses. Methods: Through the I4.0 and L4.0 literature, an initial classification of W4.0 technologies in third-party logistics (3PL) was developed. This was refined using a case study of a global logistics service provider (LSP) in the 3PL industry, through semi-structured interviews with stakeholders. Results: The empirical findings identify new application areas for I4.0 technology in 3PL warehouses, including horizontal and vertical system integration, big data, and cybersecurity, technologies that can enhance 3PL competitiveness. Conclusions: This study offers a structured classification of W4.0 technologies and insights into the application areas of W4.0 in 3PLs. It contributes practical insights into which I4.0 technologies are relevant for the 3PL warehouse industry and their potential application areas. Full article

To accurately assess the residual stress distribution on the superficial layer of the weld for a pure copper butt-welded joint after laser shock peening (LSP), a coupled model was established by integrating experimental measurements with numerical simulations. This model simulates both the tungsten inert gas (TIG) welding process of pure copper and the subsequent LSP treatment applied to the weld. On this basis, the effects of the spot overlapping rate, number of impact layers, and pulse width on the weld residual stress profile were evaluated via multi-point LSP simulations. The findings imply that LSP converts the weld’s superficial residual stress from tensile to compressive, which verifies the accuracy of the simulations through the experimental data. Multi-point LSP numerical simulations demonstrate that elevating the spot overlapping rate and number of impact layers enhances the amplitude and affected depth of the surface compressive residual stress (CRS). A slight decrease in the CRS on the superficial layer of the weld was observed with an increase in pulse width. Compared with increasing the overlapping rate and pulse width, increasing the number of impact layers has a more significant strengthening effect. When the impact layer reached 3 times, the surface CRS reached −219.4 MPa, and the influence depth was 1.3 mm. Full article

316L stainless steel offers attractive characteristics for hydrogen applications, including low hydrogen diffusivity and high hydrogen solubility. However, its use is limited by relatively low strength and resistance to hydrogen embrittlement (HE) under prolonged hydrogen exposure. Laser-directed energy deposition (L-DED) can not only increase the strength of 316L, but also induce significant tensile residual stresses that promote HE. In this study, 316L stainless steel samples produced by L-DED were post-processed by laser shock peening (LSP) to release the tensile residual stresses and refine the near-surface microstructure. LSP-treated samples showed refined grains, higher hardness, and the introduction of compressive residual stress, which led to improved tensile performance in hydrogen. Notably, after seven passes of LSP, the HE index (reduction in elongation due to hydrogen) was 12.5%, compared with 36.1% for the unpeened material. These results demonstrate that LSP is an effective approach to simultaneously increase strength and significantly improve HE resistance in additively manufactured 316L stainless steel. Full article

As global e-commerce expands, efficient cross-border logistics services have become essential. To support the evaluation of logistics service providers (LSPs), we propose HD-CBDTOPSIS (Technique for Order Preference by Similarity to Ideal Solution with heterogeneous data and cloud Bhattacharyya distance), a hybrid multi-criteria group decision-making (MCGDM) model designed to handle complex, uncertain data. Our criteria system integrates traditional supplier evaluation with cross-border e-commerce characteristics, using heterogeneous data types—including exact numbers, intervals, digital datasets, multi-granularity linguistic terms, and linguistic expressions. These are unified using normal cloud models (NCMs), ensuring uncertainty is consistently represented. A novel algorithm, improved multi-step backward cloud transformation with sampling replacement (IMBCT-SR), is developed for converting dataset-type indicators into cloud models. We also introduce a new similarity measure, the Cloud Bhattacharyya Distance (CBD), which shows superior discrimination ability compared to traditional distances. Using the coefficient of variation (CV) based on CBD, we objectively determine criteria weights. A cloud-based TOPSIS approach is then applied to rank alternative LSPs, with all variables modeled using NCMs to ensure consistent uncertainty representation. An application case and comparative experiments demonstrate that HD-CBDTOPSIS is an effective, flexible, and robust tool for evaluating cross-border LSPs under uncertain and multi-dimensional conditions. Full article

This study investigated the effect of laser shock peening (LSP) treatment on the fatigue performance of Q355D steel butt-welded joints. The results demonstrate that LSP sig-nificantly enhances joint fatigue resistance through gradient hardening in surface lay-ers, introduction of high-magnitude residual compressive stress fields, and micro-structural refinement. Specifically, microhardness increased across all joint zones with gradient attenuation of strengthening effects within an approximately 700 μm depth. LSP effectively suppressed residual tensile stress concentration in regions beyond 4 mm on both sides of the weld. Fatigue tests confirmed that LSP substantially extended joint fatigue life: by 113–165% in the high-stress region (250–270 MPa) and 46–63% in the medium-low-stress region (230–240 MPa). Fractographic analysis further revealed reduced fatigue striation spacing and lower microcrack density in LSP-treated speci-mens, reflecting the synergistic effect of residual compressive stress fields and micro-structural refinement in retarding crack propagation. This work substantiates LSP as an effective method for enhancing fatigue resistance in Q355D steel welded joints. Full article

We investigated the influence of gold deposition on the magnetic behavior, biocompatibility, and bioactivity of CoFe₂O₄ (MCF) nanomaterials (NMs) functionalized with sodium citrate (Cit) or glycine (Gly). The resulting multifunctional plasmonic nanostructured materials (MCF-Au-L, where L is Cit, Gly) exhibit superparamagnetic behavior with magnetic saturation of 59 emu/g, 55 emu/g, and 60 emu/g, and blocking temperatures of 259 K, 311 K, and 322 K for pristine MCF, MCF-Au-Gly, and MCF-Au-Cit, respectively. The MCF NMs exhibit a small uniform size (with a mean size of 7.1 nm) and an atomic ratio of Fe:Co (2:1). The gold nanoparticles (AuNPs) show high heterogeneity as determined by high-resolution transmission electron microscopy (HR-TEM) and energy-dispersive X-ray spectroscopy (EDX). The UV-Vis spectroscopy of the composites reveals two localized surface plasmons (LSPs) at 530 nm and 705 nm, while Fourier Transformed-Infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA) confirm the presence of Cit and Gly on their surface. Subsequent biocompatibility tests confirm that MCF-Au-L NMs do not exert hemolytic activity (hemolysis < 5%). In addition, the CCK-8 viability assay tests indicate the higher sensitivity of cancerous cells (A549) to the photoactivity of MCF-Au compared to healthy Detroit 548 (D548) cell lines. We use advanced microscopy techniques, namely atomic force, fluorescence, and holotomography microscopies (AFM, FM, and HTM, respectively) to provide further insights into the nature of the observed photoactivity of MCF-Au-L NMs. In addition, in situ radiation, using a modified HTM microscope with an IR laser accessory, demonstrates the photoactivity of the MCF-Au NMs and their suitability for destroying cancerous cells through photodynamic therapy. The combined imaging capabilities demonstrate clear morphological changes, NMs internalization, and oxidative damage. Our results confirm that the fabricated multifunctional NMs exhibit high stability in aqueous solution, chemical solidity, superparamagnetic behavior, and effective IR responses, making them promising precursors for hybrid cancer therapy. Full article

Polyploidisation is a very common phenomenon in the plant kingdom and plays a key role in plant evolution and breeding. It promotes speciation and the extension of biodiversity. It is estimated that approximately 47% of flowering plant species are polyploids, derived from two or more diploid ancestral species. In natural populations, the predominant methods of whole-genome multiplication are somatic cell polyploidisation, meiotic cell polyploidisation, or endoreduplication. The formation and maintenance of polyploidy is accompanied by a series of epigenetic and gene expression changes, leading to alterations in the structural, physiological, and biochemical characteristics of polyploids relative to diploids. This article provides information on the mechanisms of formation of natural and synthetic polyploids. It presents a number of examples of the effects of polyploidisation on the composition and content of secondary metabolites of polyploids, providing evidence of the importance of the phenomenon in plant adaptation to the environment, improvement of wild species, and crops. It aims to gather and systematise knowledge on the effects of polyploidisation on plant physiological traits, including stomatal conductance (Gs), transpiration rate (Tr), light saturation point (LSP), as well as the most important photosynthetic parameters determining biomass accumulation. The text also presents the latest findings on the adaptation of polyploids to biotic and abiotic stresses and explains the basic mechanisms of epigenetic changes determining resistance to selected stress factors. Full article

The discrete element method (DEM), based on particle dynamics, is used to simulate the technological process of soil tillage using agricultural machinery. A key aspect of the DEM for obtaining accurate agrotechnical and energy indicators of soil cultivation is the formulation of particle contact rules, determined by normal and tangential interactions as well as cohesion forces. This study presents a comprehensive analysis of discrete element method (DEM) contact models used to simulate soil cultivation processes. This study addresses a key issue—the absence of a systematic approach to selecting adequate contact models, which limits the accuracy of predicting soil behavior during interaction with agricultural machinery. A detailed classification of 17 combinations of contact models implemented in the commercial software Rocky DEM was performed, grouped into three categories: normal force models (Linear Spring [LSP], Hysteresis [HLS], Hertzian [HSD]), tangential force models (Coulomb, linear spring limit [linear], Mindlin–Deresiewicz), and cohesive force models (linear cohesion [linear], constant force [constant], Johnson–Kendall–Roberts [JKR]). Experimental validation was conducted by analyzing the angle of repose for various soil types (sandy loam, light loam, medium loam, and heavy clay) with moisture contents ranging from 11 to 31%. This analysis identified the nine most effective combinations of contact models to describe normal, tangential, and cohesive forces (LSP–Coulomb–linear, HLS–linear–linear, HLS–Coulomb–linear, HSD–linear–linear, HSD–linear–JKR, HSD–Coulomb–linear, HSD–Coulomb–JKR, HSD–Mindlin–Deresiewicz–linear, HSD–Mindlin–Deresiewicz–JKR), which showed reliable agreement with experimental angle of repose measurements at approximately 85% accuracy. This study significantly contributes to advancing computer modeling methods in agriculture by providing a scientifically grounded approach for selecting DEM contact models. Full article

In this paper, the different effects of laser shock peening (LSP) and laser shock peening without coating (LSPwC) on the morphology, microhardness and fretting-wear behavior of DD6 Ni-based single-crystal superalloy are investigated. The results show that the surface roughness of DD6 decreases slightly after LSP, while it increases after LSPwC due to surface remelting. Shock wave strengthening during LSP and LSPwC results in plastic deformation of the surface layer of DD6 samples. However, besides work hardening from shock wave, dispersion strengthening of oxide particles also occurs during LSPwC. Therefore, after LSPwC, the microhardness of the DD6 surface layer increases by 38.8%, higher than the increase of 27.7% after LSP. The fretting wear resistance of DD6 increases by about 42.8% and 58% after LSP and LSPwC, respectively. The surface roughness only affects the friction coefficient at the initial stage of fretting wear. The hardness increase caused by work hardening and the dispersion strengthening of surface oxides after laser strengthening is the key to the improvement of fretting wear resistance. The main wear mechanisms of untreated and LSP sample are oxidation wear, abrasive wear and adhesive wear, while the main wear mechanisms of LSPwC sample are oxidation wear and adhesive wear. Full article

To accurately assess the effect of different plate thicknesses on the residual stress field of laser shock peened GH3039 superalloy, residual stress measurements were performed on GH3039 alloy plates with thicknesses of 2 mm and 5 mm after laser shock peening (LSP) treatment. Both quasi-static and high strain rate mechanical tests of GH3039 were conducted, and the Johnson-Cook (J-C) constitutive equation for GH3039 alloy at specific strain rates was fitted based on the experimental results. To obtain the parameter C in the J-C constitutive equation of GH3039 alloy under ultra-high strain rates, a modified method was proposed based on LSP experiment and finite element simulation results. Using the modified GH3039 alloy J-C constitutive equation, numerical simulations and comparative analyses of the residual stress field of GH3039 alloy plates of different thicknesses under LSP were carried out using ABAQUS software. The simulated residual stress fields of laser-shocked GH3039 alloy plates of different thicknesses were in good agreement with the experimental measurements, indicating that the modified GH3039 alloy J-C constitutive equation can accurately predict the mechanical behavior of GH3039 alloy under ultra-high strain rates. Based on the modified GH3039 alloy J-C constitutive equation, the effect of different plate thicknesses on the residual stress distribution of laser-shocked GH3039 alloy was studied, along with the underlying mechanisms. The unique distribution characteristics of residual stresses in laser-shocked GH3039 plates with varying thicknesses are primarily attributed to differences in plate bending stiffness and the detrimental coupling effects of reflected tensile waves. Full article

The high-precision and long-duration photometry provided by the $Kepler$ mission has greatly advanced frequency analyses of a large number of pulsating stars, a fundamental step in asteroseismology. For $\delta$ Scuti stars, analyses are typically confined to frequencies below the Nyquist frequency. However, signals above this limit can be reflected into the sub-Nyquist range, especially in long-cadence data, where they may overlap with genuine pulsation modes and lead to misinterpretation. To address this issue, a recently proposed method—the sliding Lomb–Scargle periodogram (sLSP)—can effectively distinguish real frequencies from aliased ones. In this study, we compiled a sample of 68 $\delta$ Scuti stars whose frequency analyses were based on the $Kepler$ photometry. Using the sLSP method, we systematically examined the 1406 reported frequencies in the literature. As a result, we identified six previously unrecognized reflected super-Nyquist frequencies in four stars: KIC 3440495, KIC 5709664, KIC 7368103, and KIC 9204718. We have once again demonstrated the ability of the sLSP method to detect and correct such artifacts. This technique improves the reliability of frequency selection, thereby enhancing the accuracy of asteroseismic interpretation and stellar modeling for pulsating stars. Full article