Search Results (1,354)

Selective separation of gold-bearing pyrite from gold-free pyrite through flotation to improve the gold-to-sulfur ratio in the feed can significantly enhance the throughput of autoclaves, thus achieving efficient and clean processing of refractory pyritic gold ores. To achieve this expectation, this study examined the surface physicochemical differences between gold-bearing and gold-free pyrite under flotation conditions using cyclic voltammetry, polarization curve testing, electrochemical impedance spectroscopy (EIS), X-ray photoelectron spectroscopy (XPS), and density functional theory (DFT) simulations. Electrochemical tests showed higher reactivity in gold-bearing pyrite, with reactivity positively correlated to gold content. XPS results indicated more oxidation products on gold-bearing pyrite surfaces under identical conditions. DFT simulations revealed that the presence of gold reduced the oxygen adsorption energy on the pyrite surface while enhancing interactions between oxygen atoms and sulfur and iron atoms. Based on these findings, the selective separation of gold-bearing and gold-free pyrite in the flotation process can be explored through pulp aeration pre-oxidation combined with collectors demonstrating selectivity toward barren pyrite (e.g., dithiocarbamate collectors). This study provides theoretical foundations for the efficient exploitation and utilization of refractory gold-bearing pyrite resources. Full article

Plasticized polyvinyl chloride (PVC-P) geomembranes (GMBs) are applied as anti-seepage materials in membrane-faced rockfill dams and pumped storage power stations. Assessing their lifetime to ensure durability during operation is crucial. This study conducted accelerated aging tests on three PVC-P GMBs immersed in water, along with axial tensile tests to investigate the degradation of mechanical properties. The degradation model was constructed using the Arrhenius equation, and the time to nominal failure (TNF) was predicted based on this model and failure criterion. The prediction model’s accuracy was verified using test data collected over 180 days at 20 °C. The results demonstrate that the TNF of PVC-P GMBs is influenced by water temperature, plasticizer content, and thickness of GMBs. Elevated temperatures accelerate the loss rate of plasticizers. Specifically, at 20 °C in a water environment, the estimated TNFs of Materials A and B with identical thicknesses were 49.05 and 153.76 years, respectively. This suggests that increasing the initial plasticizer content and enhancing its structural stability can significantly extend the TNF. Furthermore, Material C, which has a composition similar to Material B but with increased thickness, exhibited a predicted TNF of 181.30 years, indicating that greater thickness can effectively reduce the migration rate of plasticizers. The findings provide a theoretical basis for evaluating the TNF of PVC-P GMBs in reservoir bottom and below dead water level applications during operation. Full article

Group A rotaviruses (RVAs) are a major cause of acute dehydrating diarrhea in infants and young animals worldwide. In rabbits, RVAs are associated with enteric disease, likely in combination with other pathogens. We report the identification and characterization of a lapine RVA strain in an Italian rabbit breeding farm. Increased mortality rates associated with enteric symptoms were reported in the facility in post-weaning rabbits around 40 days of age. By quantitative RT-PCR, an RVA strain was identified in the intestinal contents of deceased rabbits. A PCR-based enrichment protocol coupled with Nanopore sequencing allowed the reconstruction of the nearly complete genome of a rabbit RVA strain, Rabbit-wt/ITA/36-9/2022/G3P[14], with a genotype constellation (G3-P[14]-I2-R2-C2-M3-A9-N2-T6-E5-H3) conserved among lapine RVAs. Each of the 11 gene segments displayed high nucleotide identity and phylogenetic clustering with lapine rotavirus strains, as well as two Belgian human G3P[14] strains, which had been shown to have a zoonotic (lapine) origin. However, the NSP2 gene of strain 36-9 clustered closer with a group of rare human G3P[9] strains, suggesting a common path during their evolution. Gathering sequence data on animal RVAs is pivotal to reconstructing the history of homologous and heterologous RVAs in various mammals, including humans. Full article

The strain A-9^T, isolated from Oncorhynchus mykiss (rainbow trout) in a Turkish aquaculture facility, was characterized through integrated phenotypic, phylogenetic, and genomic analyses. Whole-genome sequencing revealed a 5.21 Mb circular chromosome (GC content: 58.16%) and three plasmids encoding proteins for mobilization and toxin–antitoxin systems. Multilocus phylogenetic analysis (MLPA) using seven housekeeping genes supported the distinct lineage of A-9^T. Digital DNA–DNA hybridization (77.6–78.6%) and average nucleotide identity values (96.59–97.58%) confirmed taxonomic divergence from all currently recognized A. salmonicida subspecies. Comparative proteomic and pangenomic analyses identified 328 strain-specific genes, including virulence factors, secretion system components (Type II and Type VI), and efflux-related proteins. Although genes encoding Type III secretion systems and biofilm formation were absent, A-9^T harbored a broad virulence gene repertoire and resistance determinants, including OXA-956, cphA5, and FOX-20, supporting a multidrug-resistant phenotype. Based on its genomic, phenotypic, and functional distinctiveness, we propose the novel taxon Aeromonas salmonicida subsp. oncorhynchi subsp. nov. (type strain A-9^T = LMG 33538^T = DSM 117494^T), expanding the taxonomic landscape of the A. salmonicida complex and offering insights into fish-associated bacterial evolution. Full article

This study explores how small family wineries in the Croatian Split-Dalmatia County integrate social media into their marketing and business strategies, focusing on the interplay between tradition, family identity, and digital innovation. Utilising a qualitative methodology, semi-structured interviews were conducted with winery owners to explore their use of social media platforms, their sales and distribution strategies, and their perceptions of Croatia’s EU membership. The results show that social media, particularly Facebook and Instagram, serve as highly personalised, low-cost marketing tools, predominantly managed by younger family members and used to convey authenticity, family heritage, and local identity. Despite limited resources and professional marketing expertise, these wineries take an intuitive, do-it-yourself approach and rely on direct customer relationships, storytelling, and experiential offerings to drive loyalty. While EU membership is generally seen as beneficial for tourism and funding opportunities, bureaucratic complexity remains a significant obstacle. This study highlights the importance of leveraging cultural heritage for digital content and emphasises the need for targeted policy support to improve digital competencies and reduce administrative barriers. These findings contribute to a deeper understanding of how family-run SMEs can gain and sustain competitive advantage by blending tradition with digital marketing practices in a rapidly evolving business environment. Full article

Mediterranean wood pastures are the result of traditional silvo-pastoral uses that shaped these ecosystems into a mosaic of trees and open grassland. This ecosystem structure is generally associated with increased soil fertility under tree canopies. However, the response of herbaceous plant functional types (PFTs)—grasses, legumes, and non-legume forbs—to these heterogeneous microenvironments (under the canopy vs. open grassland) remains largely unknown, particularly regarding carbon (C) and nitrogen (N) acquisition and use. Even less is known about how different tree species and environmental conditions influence these responses. In this study, we aim to assess how tree canopies influence carbon and nitrogen cycling by comparing the effects of traditional oak stands and pine plantations on herbaceous PFTs and soil dynamics. For that we use C and N content and natural isotopic abundances (δ¹³C and δ¹⁵N) as proxies for biogeochemical cycling. Our results show that ecosystem C and N patterns depend not only on herbaceous PFTs and the presence or absence of tree canopies but also on tree species identity and environmental conditions, including climate. In particular, pine-dominated plantations exhibited lower nitrogen availability compared to those dominated by oak, suggesting that oak stands may contribute more effectively to enhance soil fertility in Mediterranean wood pastures. Furthermore, the canopy effect was more pronounced under harsher environmental conditions, highlighting the role of trees in buffering environmental stress, particularly in arid regions. This suggests that changes in tree cover and tree species may drive complex changes in ecosystem C and N storage and cycling. Full article

Image smoothing is a low-level image processing task mainly aimed at homogenizing an image, mitigating noise, or improving the visibility of certain image areas. There exist two main strategies for image smoothing. The first strategy is content-unaware image smoothing. This strategy replicates identical smoothing behavior at every region in the image, hence ignoring any local or semi-local properties of the image. The second strategy is content-aware image smoothing, which takes into account the local properties of the image in order to adapt the smoothing behavior. Such adaptation to local image conditions is intended to avoid the blurring of relevant structures (such as ridges, edges, and blobs) in the image. While the former strategy was ubiquitous in the early years of image processing, the last 20 years have seen an ever-increasing use of the latter, fueled by a combination of greater computational capability and more refined mathematical models. In this work, we propose a novel content-aware image smoothing method based on soft (fuzzy) clustering. Our proposal capitalizes on the strengths of soft clustering to produce content-aware smoothing and allows for the direct configuration of the most relevant parameters for the task: the number of distinctive regions in the image and the relative relevance of spatial and tonal information in the smoothing. The proposed method is put to the test on both artificial and real-world images, combining both qualitative and quantitative analyses. We also propose the use of a local homogeneity measure for the quantitative analysis of image smoothing results. We show that the proposed method is not sensitive to centroid initialization and can be used for both artificial and real-world images. Full article

This study explores the potential of using eye-tracking technology as a marketing tool to enhance domestic tourism. By examining the visual preferences of users, this research aims to improve the informational resources and visual components of advertising campaigns for tourism destinations. An experiment was conducted to determine which of three image categories—architecture (Ia), nature (In), and people (Ip)—captures more user attention. Participants’ eye movements were tracked to collect data on fixation time, first glance, and the order of image exploration. The findings indicate that images of people (Ip) attract more attention than images of architecture or nature, irrespective of pose, angle, or clothing. Within the Ip category, dynamic images of people in authentic clothing (Ip3–Ip5) held viewers’ attention longer, averaging 3.3 s compared to 1.3 s for static portrait photos (Ip6–Ip8). This study concludes that eye-tracking technology can effectively identify visual elements that interest potential tourists, facilitating the creation of compelling advertising content. This approach can support the development of a cohesive and engaging visual identity for tourism destinations, thereby enhancing marketing strategies and promoting sustainable tourism. Full article

The accumulation of polyolefin waste, particularly high-density polyethylene (HDPE), presents a growing environmental challenge due to limited recycling options and poor end-of-life recovery. This study explores a strategy to convert HDPE into mesophase pitch (MP), a valuable carbon precursor, by integrating polyolefin recycling with the mild solvolysis liquefaction (MSL) of low-rank coals. HDPE was first hydrogenolyzed into a hydrogen-rich aromatic liquid (HDPE-liquid), which was then used as the liquefaction solvent. Under identical conditions (400 °C, 60 min), Utah Sufco coal co-liquefied with HDPE-liquid produced tar that formed mesophase pitch with a higher mesophase content (84.5% vs. 78.6%) and a lower softening point (~302 °C vs. >350 °C) compared to pitch from conventional tetralin (THN). The approach was extended to Illinois #6 and Powder River Basin coals, increasing the mesophase content from 12.4% to 32.6% and 17.8% to 62.1%, respectively. These improvements are attributed to differences in tar composition: HDPE-derived tars had lower terminal methyl (Hγ) contents, reducing cross-linking during thermal upgrading. This work demonstrates that HDPE-derived liquids can act as functional solvents for coal liquefaction, enabling an effective route to recycle polyolefin waste into durable carbon products, while also reducing reliance on fossil-based solvents for mesophase pitch production. Full article

This article deals with teachers’ professional development, focusing specifically on their competencies to assess learning. Research in this field has shown a lack of instruments for measuring such competencies in practicing teachers. In this context, we present the validation process of such an instrument, called Classroom Evaluative Judgment, which is designed to assess teachers’ competencies in evaluating their students’ school work. We adopt a quantitative approach, with a non-experimental and sequential design. First, the instrument was subjected to content validation through expert judgment. Subsequently, a pilot test was carried out with an unintentional sample, applying statistical reliability analysis and confirmatory factor analysis to ensure the internal consistency of the instrument with respect to its theoretical basis. Finally, we validated the instrument with 266 participants, obtaining high levels of internal consistency and statistical reliability. The results support the soundness of the proposed model and its usefulness for measuring professional teaching competencies in the field of learning assessment. Its application in real contexts of professional practice could open new lines of research on the evaluative judgment of teachers and the strengthening of their evaluative identity. Full article

In an increasingly competitive global tourism context, territorial branding plays a key role in enhancing the visibility, identity, and resilience of regions. This study focuses on the Algarve, a region in southern Portugal, and investigates how innovation and competitiveness are reflected in its digital communication strategy. Using a mixed-methods approach, this research combines the quantitative analysis of 689 social media posts published in 2024 on Facebook, Instagram, and YouTube with the qualitative content analysis of 38 documents and the official website of Algarve. The findings reveal a coherent and visually appealing brand narrative centred on the coastal identity of the Algarve, complemented by content related to nature, gastronomy, and cultural heritage. Instagram stands out as the most engaging platform, particularly when posts adopt a participatory tone, emotional storytelling, and references to specific locations. However, only 6.4% of the content surpassed the 1% engagement threshold, suggesting limited audience connection. The website presents a broader thematic range but under-represents intangible heritage and local products.The Algarve brand successfully projects an aspirational image based on landscape and leisure but would benefit from greater content diversification, enhanced stakeholder integration, and expanded narrative strategies to strengthen digital engagement and destination competitiveness. Full article

Deepfake technology uses artificial intelligence to create highly realistic but fake audio, video, or images, often making it difficult to distinguish from real content. Due to its potential use for misinformation, fraud, and identity theft, deepfake technology has gained a bad reputation in the digital world. Recently, many works have reported on the detection of deepfake videos/images. However, few studies have concentrated on developing robust deepfake voice detection systems. Among most existing studies in this field, a deepfake voice detection system commonly requires a large amount of training data and a robust backbone to detect real and logistic attack audio. For acoustic feature extractions, Mel-frequency Filter Bank (MFB)-based approaches are more suitable for extracting speech signals than applying the raw spectrum as input. Recurrent Neural Networks (RNNs) have been successfully applied to Natural Language Processing (NLP), but these backbones suffer from gradient vanishing or explosion while processing long-term sequences. In addition, the cross-dataset evaluation of most deepfake voice recognition systems has weak performance, leading to a system robustness issue. To address these issues, we propose an acoustic feature-fusion method to combine Mel-spectrum and pitch representation based on cross-attention mechanisms. Then, we combine a Transformer encoder with a convolutional neural network block to extract global and local features as a front end. Finally, we connect the back end with one linear layer for classification. We summarized several deepfake voice detectors’ performances on the silence-segment processed ASVspoof 2019 dataset. Our proposed method can achieve an Equal Error Rate (EER) of 26.41%, while most of the existing methods result in EER higher than 30%. We also tested our proposed method on the ASVspoof 2021 dataset, and found that it can achieve an EER as low as 28.52%, while the EER values for existing methods are all higher than 28.9%. Full article

Biomphalaria pfeifferi is a key intermediate host for Schistosoma mansoni transmission in Sudan. In total, 27 complete mitochondrial genomes from seven B. pfeifferi populations in Gezira State, Sudan, were sequenced for the first time to investigate their population structure and phylogenetic relationships. This involved comparing the nucleotide composition, codon usage, rRNAs, and tRNAs of the East Gezira (EG), South Gezira (SG), Hasahisa (HA), Greater Wad Medani (GW), Managil (MA), and North Umelgura (NU1, NU3) populations. All 27 mitogenomes (13,688–13,696 bp) contained 37 genes with conserved AT/GC content (76.7/23.4%). Phylogenetic analysis revealed that although samples clustered within the same clade, B. pfeifferi from EG, SG, NU1, and NU3 grouped closely with B. pfeifferi from Kenya, whereas HA and GW samples formed distinct ancestral lineages. The MA population exhibited unique genetic characteristics, supported by phylogenetic trees and nucleotide/amino acid identity, suggesting the potential presence of a distinct B. pfeifferi subspecies that warrants further investigation. All protein-coding genes evolved under negative selection, with the amino acids of nad1 and nad6 being highly conserved, while nad3 exhibited some variation. Further research on the mitogenomic diversity of B. pfeifferi and other Biomphalaria species in Sudan and across Africa is needed in order to better understand the population structure and evolutionary history of Biomphalaria. Full article

The variation in organic acids during malolactic fermentation (MLF) affects the wine’s quality, presenting a challenge for the wine industry. This study aimed to investigate the kinetics of organic acids during MLF using two Oenococcus oeni strains under different barrel conditions. The study examined the variation in pH, total and volatile acidity, and concentration of tartaric, malic, lactic, and citric acid during MLF in the identical initial wine. In addition, the aromatic profile of the final wines was evaluated. The fermentation occurred in new and used French oak barrels. Two strains of O. oeni were used: (a) citrate-negative O. oeni (CINE) and (b) O. oeni, commonly used in the wine industry. The experimental data obtained were fitted to the logistic model for each monitored parameter. The degree of fitting R2 was higher than 92.79%, indicating good predictive accuracy for substrate consumption (malic and citric acid), as well as product formation (lactic and acetic acid). The mean values of O. oeni and O. oeni CINE differ in acetic (0.29 and 0.15 g/L) and citric acid (0.13 and 0.18 g/L), respectively. The logistic model effectively predicted the change in acid content during fermentation, describing the changes in organic acid levels during the MLF conducted in barrels. Modeling can be useful in forecasting industrial-scale production. Full article

The issue of improving the effectiveness of international climate policy, one of the main goals of which is to reduce greenhouse gas (GHG) emissions, poses a critical and acute challenge for the global economic system. At every COP conference and in every IPCC report, it is evident that current measures fall short. To address this gap, this study examines the structure and trends of global climate policy development through content analysis, PRISMA methodology, and correlation and regression analysis using censored Bayesian Tobit regression. The obtained results are supplemented with the LMDI (Logarithmic Mean Divisia Index) decomposition of the Kaya identity. The research covers 198 countries and 4241 documents spanning 1950 to 2023 that shape global climate policy. The results showed that (1) the success of climate goals varies depending on policy instruments, institutional conditions, and the time frame of analysis; (2) the greatest success in achieving climate targets was often observed in countries that adopted moderate, realistic, and institutionally supported targets; (3) in some cases, an overachievement of targets and GHG emissions reduction was a temporal observation or the result of economic decline; (4) in countries without officially declared targets, emissions also continued under similar growth trends, calling into question the effectiveness of current methods of setting up CO₂ emissions reduction targets. These findings provide a deeper understanding of the factors determining the effectiveness of climate policy. They highlight key barriers to achieving too ambitious emission reduction targets, which can lead to economic shocks and a subsequent increase in environmental impact. Ultimately, this research can contribute to the development of more realistic and effective decarbonization strategies. Full article