Search Results (238)

The search for sustainable, economically viable, and effective plant protection strategies against pathogenic bacteria, fungi, and viruses is a major challenge in modern agricultural practices. Chitosan (CS) is an abundant cationic natural biopolymer known for its biocompatibility, low toxicity, and antimicrobial properties. Its potential use in agriculture for pathogen control is a promising alternative to traditional chemical fertilisers and pesticides, which raise concerns regarding public health, environmental protection, and pesticide resistance. This study focused on the preparation of chitosan nanoparticles (CS-NPs) through cross-linking with organic molecules, such as tannic acid (TA). Various formulations were explored for the development of stable nanoscale particles having encapsulation capabilities towards low compounds of varying polarity and with potential agricultural applications relevant to plant health and growth. The solution properties of the NPs were assessed using dynamic and electrophoretic light scattering (DLS and ELS); their morphology was observed through atomic force microscopy (AFM), while analytical ultracentrifugation (AUC) measurements provided insights into their molar mass. Their properties proved to be primarily influenced by the concentration of CS, which significantly affected its intrinsic conformation. Additional structural insights were obtained via infrared and UV–Vis spectroscopic measurements, while detailed fluorescence analysis with the use of three different probes, as model cargo molecules, provided information regarding the hydrophobic and hydrophilic microdomains within the particles. Full article

The quality of Crocus sativus L. flowers, beyond their stigmas, is influenced by the presence of bioactive metabolites also in their floral bio-residues. Given the effect of climatic and soil variables on these bioactive compounds, the aim of this research was to develop an agroecological zoning of saffron crop areas within the Protected Designation of Origin (PDO) La Mancha region (Castilla-La Mancha, Spain) by integrating the floral metabolite content with climatic and soil variables. To achieve this, a total of 173 samples were collected during the 2022 and 2023 harvests and analyzed via RP-HPLC-DAD to determine crocins, picrocrocin, kaempferols, and anthocyanins. Two new indices, Cropi (crocins + picrocrocin) and Kaeman (kaempferols + anthocyanins), were defined to classify flowers into four quality categories (A–D). High-quality classifications (A and B) were consistently associated with plots grouped in the meteorological stations of Ontur, El Sanchón, and Bolaños, indicating favorable edaphoclimatic conditions and climatic parameters, such as moderate temperatures and reduced humidity, for metabolite biosynthesis. In contrast, plots included in the meteorological stations of Tarazona and Pedernoso were mostly assigned to lower categories (C and D). Spatial analysis using thematic maps revealed that areas with an intermediate carbonate content, less calcareous soils, and higher organic matter levels were linked to higher flower quality. These findings highlight the influence of soil characteristics and climate, with distinct seasonal contrasts, that positively influence metabolite synthesis and flower quality. Full article

Fresh water is vital for human activities; however, an increase in the contamination of water bodies has been observed, so it is necessary to monitor the degree of contamination and take measures to preserve it. In Altamira, Tamaulipas, the Guayalejo-Tamesí River basin has three estuaries and seven lagoons, including Laguna El Conejo, of which the National Water Commission only monitors one. The objective of this research is to determine water quality on the basis of the parameters COD, BOD₅, T, pH, and sediment characteristics. The open reflux method was used according to NMX-AA-030-SCFI-2012 for COD, BOD Track II, HACH equipment for BOD₅, and the granulometric characterization recommended by the Unified Soil Classification System ASTM D-2487-17. The water was found to be uniformly contaminated throughout its length in the range of 117.3–200 mg/L COD, and BOD₅ ranged from 15.8–112.75 mg/L throughout the study period, with sediments dominated by poorly graded soil and fine clay. Comprehensive management is needed because the BOD₅/COD ratio varies between 0.11and 0.56, indicating that it contains recalcitrant organic matter, which is difficult to biodegrade. Full article

A moon jellyfish (Aurelia aurita) is a representative of the phylum Cnidaria, commonly found in the northern seas of the globe. The regenerative abilities of cnidarians have recently been associated with extracellular vesicles (EVs) secreted by these organisms. In this study, a method for the isolation of EVs from the oral arms of A. aurita is presented. The methodology includes differential centrifugation, size-exclusion chromatography, and ultrafiltration. The isolates were characterized with tunable resistive pulse sensing, cryogenic transmission electron microscopy, capillary electrophoresis (CE), and electrophoretic light scattering (ELS). Small (<150 nm in diameter) EVs were abundant in the isolates. The EVs were found to carry nucleic acids, indicating their role in signaling. Additionally, the difference in zeta potential values measured with ELS and CE indicates high glycation in the vesicles analyzed. Although the method developed was effective in isolating EVs from small sample volumes (0.5 mL), the EV yield was insufficient for omics analysis. Thus, the scaling up of the isolation process is required for comprehensive biochemical analysis and biological activity assessment in A. aurita-derived EVs. Full article

The analysis of activity patterns is a valuable tool for understanding the temporal organization of mammal communities, which is determined by biological requirements, resource availability, and competitive pressures both within and between species. Research on this ecological aspect can contribute to the development of effective conservation strategies. Cloud forest is an ecosystem of high biological relevance, as this provides habitat for a wide diversity of species in Mexico, including endemic, emblematic, and threatened taxa. Our main objectives were to analyze mammalian activity patterns and predator–prey relationships in the cloud forest of the El Cielo Biosphere Reserve, Tamaulipas, Mexico. From 2018 to 2020, twenty camera trap stations were installed, and independent photographic records were obtained, divided into 24 one-hour intervals, and subsequently classified as diurnal, nocturnal, crepuscular, or cathemeral. Temporal activity was estimated using circular statistics in RStudio v4.3.1, and activity overlap between major carnivores and their prey was assessed using the ‘overlap’ package in R. A total of 18 medium- and large-sized mammal species were recorded in this study. The activity of four species was seasonally influenced, with a predominantly nocturnal pattern observed during the dry season. The activity overlap analysis revealed potential temporal similarity between predators and their prey. For example, Panthera onca exhibited a high overlap with Mazama temama (Δ = 0.83), Puma concolor with Nasua narica (Δ = 0.91), and Ursus americanus with M. temama (Δ = 0.77). These findings suggest that the activity patterns of certain species can be influenced by seasonality and that large predators may favor specific prey whose activity overlaps with their own. Full article

Globally, arid and semi-arid agricultural land is characterized by low soil organic carbon (SOC) content. This impacts on the abundance and diversity of soil microorganisms in such environments. We therefore examined SOC and bacterial community structure dynamics in the single plots of the conventional (PC), improved fertilization (PA) and unimproved control (PT) at El Hmadna experimental station (Northwest Algeria) during five-time intervals T(0), T(15), T(70), T(104) and T(147 days). The SOC content was determined using the modified Walkley and Black method. The 16S rRNA genes were isolated from soils and sequenced using the Illumina sequencing platform. Over time, OC levels increased by more than 15%, especially in the improved plot. The highest OC stock was observed for the unmanaged control plot (47 Mg ha⁻¹), also associated with higher bacterial biomass. However, taxonomic analysis revealed that bacterial diversity was higher in PA and PC, with Actinobacteria (42%) and Firmicutes (15%) dominating. Soil salinity did negatively influence SOC but the imposed management practices such as organic amendments did improve both carbon retention and bacterial diversity. The results underline the importance of imposing sustainable agricultural practices to improve carbon sequestration and soil health in semi-arid regions. Full article

Microplastic pollution in the ocean is a growing problem. It affects the entire ecosystem and, therefore, the species that inhabit it. Plastics can be filtered or ingested by organisms, entering and negatively affecting individuals. Among the populations affected are crustaceans. In previous studies, fibers have been found mainly in the stomach contents of these animals, although other types, such as pellets, have also been found. This study examines the presence of microplastics in Cronius ruber, an invasive crab species in the Canary Islands, and investigates their potential links to nearby wastewater discharges. A total of 63 crabs were sampled from four beaches in Gran Canaria in 2021, and their stomach contents were analyzed through alkaline digestion, filtration, and micro-Fourier transform infrared spectroscopy (micro-FTIR). Microplastics were detected in 52% of individuals; the particles averaged 0.7 ± 0.5 mm in length, with an average of 1.73 ± 1.02 particles per crab. Fibers constituted 89% of the microplastics, with blue and black being the predominant colors. Rayon, commonly used in textiles, was the most frequently identified polymer (52%), highlighting the role of wastewater from laundry processes as a significant pollution source. Beaches close to unauthorized wastewater discharges, such as Anfi del Mar (n = 3) and El Puertillo (n = 32), showed the highest contamination levels, with a frequency of occurrence (FO) of microplastic particles of 67% and 58%, respectively. Playa de Las Nieves was the one with the lowest contamination level (n = 22), with a frequency of occurrence of microplastic particles of 41%. This is the first study to document microplastic ingestion in C. ruber, raising concerns about its ecological presence and the potential bioaccumulation of contaminants in marine ecosystems. Further research is essential to understand the long-term consequences of microplastic exposure on invasive species and their possible roles in pollutant transfer through food webs. Full article

The wastewater treatment involves various techniques at different technological levels. Treatment takes place in several stages, of which coagulation and flocculation are the most important. Most suspended solids are indeed eliminated during this stage by the addition of a coagulant. In this research, bio-coagulant was extracted from pumpkin seed (PS) waste after extraction of the essential oils, and used with ferric chloride to treat wastewater from the plant of Chalghoum El Aid-Oued El Athmania Mila. In this study, the Box–Behnken design (BBD) with three factors was used to investigate the effect of pH, organic coagulant dosage Pumpkin seed extract (PSE), and chemical coagulant dosage (FeCl₃) on coagulation–flocculation performance in relation to turbidity, chemical oxygen demand (COD), aromatic organic matter (UV 254), and phosphate. The main characteristics of the raw water were turbidity (250 NTU), COD (640 mg/L), UV 254 (0.893 cm⁻¹), and phosphate (0.115 mg/L). The results obtained were very significant. All the statistical estimators (R² ≥ 97% and p ≤ 0.05) reveal that the models developed are statistically validated for simulating the coagulation–flocculation process. It should be noted that the residual values of turbidity, COD, UV 254, and phosphate after treatment by this process were 0.754 NTU; 190.88 mg/L; 0.0028 cm⁻¹; and 0.0149 mg/L, respectively. In this case, the pH, bio-coagulant dosage, and chemical coagulant dosage values were 4; 17.81 mL/L; and 10 mL/L, respectively. In this study, Fourier-transform infrared spectrometer (FTIR) and scanning electron microscope (SEM) characterization of the bio-coagulant proved the presence of the active functional groups responsible for coagulation, namely carboxyl group. Full article

Paraliobacillus zengyii CGMCC1.16464 (P. zengyii) is a novel antiviral probiotic candidate strain. To ensure its safety as a potential probiotic, a safety evaluation was conducted in this study. The safety and functional potential of P. zengyii were systematically assessed through genomic bioinformatics analysis, in vitro experiments, and acute oral toxicity tests in mice. Genomic analysis revealed that P. zengyii is rich in genes related to carbohydrate and amino acid metabolisms and carries genes encoding antimicrobial and antiviral agents (such as ectoine, type III polyketide synthase, and lasso peptides). It also expresses gastrointestinal tolerance-related proteins (ClpC, GroEL, and ClpP). Its resistance to polymyxins is an inherent trait with no risk of plasmid-mediated transfer. In vitro experiments confirmed that P. zengyii is somewhat tolerant to bile salts and acidic environments and does not exhibit hemolytic or gelatinase activity. Importantly, an acute oral toxicity test in mice revealed that after intervention with high, medium, or low doses, no significant abnormalities in the body weight, organ index, or tissue morphology of the mice were observed. In conclusion, P. zengyii exhibited good safety and probiotic potential in terms of genomic safety, metabolic function, and in vitro and in vivo toxicities, providing a theoretical basis for the development of novel functional probiotics. Full article

Background: Patients suffering from a new variant of endemic pemphigus foliaceus in El Bagre, Colombia, South America (El Bagre-EPF) produce autoantibodies (Abs) to different proteins in the skin (frustre form), as well as to those in other organs (Senear–Usher-like and systemic forms). Here, we hypothesize whether patients’ autoantibodies play a role in triggering epicardium and pericardium autoimmunity and pathogenicity. We based this hypothesis on knowing that these patients frequently show clinical symptoms of the chest and heart, and we hypothesize that the autoantibodies of this disease are the main contributors to the base of the pericardial conditions of these patients. Materials and Methods: A case-control study for testing the sera of patients affected by El Bagre-EPF (n = 45) and matched controls from the endemic area (n = 45) was conducted to evaluate reactivity with the pericardial tissue. Patients’ necropsies were tested by immunohistochemistry (IHC), in El Bagre-EPF patients (n = 7) and matched controls. Results: The sera from most El Bagre-EPF patients displayed polyclonal autoreactivity with both layers of the pericardium, i.e., fibrous pericardium and serous pericardium (mainly to cell junctions and sensory nerve formations), as well as with the neurovascular cell junction branches. Controls were negative (p < 0.1). These reactivities were detected by IIF, CM, and IHC using secondary Abs against total IgG, IgM, Kappa and lambda, C3C of the complement, fibrinogen, and albumin. Furthermore, Abs against MIZAP, ARVCF, desmoplakin I-II, and p0071 colocalized with the Abs of El Bagre-EPF (p < 0.1). Conclusions: Patients affected by El Bagre-EPF produce autoantibodies directed against molecules present in the cell junctions of the pericardium and adnexal structures. Further studies will focus on the clinical significance of these findings. Full article

The pursuit of effective climate change mitigation strategies is driving research into geological carbon dioxide (CO₂) storage. The present work explores the interaction of CO₂ with carbonate rocks from the El Abra formation in the Tampico-Misantla basin, focusing on the comparative influence of organic matter (OM) content on mineralization processes, hypothesizing that variations in OM content significantly modulate the mineralization process affecting both the rate and type of carbonate formation. Expanding on a previous study, CO₂ is studied and injected under high-pressure (1350-2350 PSI) and high-temperature (60–110 °C) conditions into two contrasting samples: one with high OM content and another with low OM content. Structural, morphological, and physical adsorption changes were evaluated through Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and Brunauer–Emmett–Teller (BET) analyses. The findings indicate that the mineralogy of El Abra promotes secondary carbonate precipitation, with rock–fluid interactions significantly enhanced by brine presence. Samples with high OM exhibited a dramatic reduction in average particle size from 13 μm to 2 μm, along with the formation of metastable phases, such as vaterite—evidenced by XRD peak shifting and modifications in the FT-IR spectrum of carbonate bands. Meanwhile, low-OM samples showed an increase in particle size from 1.6 μm to between 3.26 and 4.12 μm, indicating predominant recrystallization. BET analysis confirmed a significant porosity enhancement in high-OM samples (up to 2.918 m²/g). Therefore, OM content plays a critical role in modulating both the rate and type of mineralization, potentially enhancing physical storage capacity in low-OM samples. These integrated findings demonstrate that OM critically governs calcite dissolution, secondary carbonate formation, and microstructural evolution, providing key insights for optimizing CO₂ storage in complex carbonate reservoirs. Full article

Food waste remains a critical global concern, with approximately one third of all food produced being ultimately discarded. Therefore, it is urgent to develop new techniques for the effective repurpose of waste. Aqueous two-phase systems (ATPSs) stand out as a simple and biocompatible liquid–liquid extraction technique for the recovery of bioactive substances from food waste. In ATPSs, the target species partition between two liquid phases, according to affinity, which facilitates its extraction. This work aimed at extracting three polyphenols—chlorogenic acid (CA), ferulic acid (FA), and resveratrol (RV)—through the application of eco-friendly ATPSs composed of water, ethyl lactate (EL), and organic salts, namely disodium succinate (Na₂Succinate) and disodium tartrate (Na₂Tartrate), for future application in the valorisation of food waste. All partitions presented successful results, with values of partition coefficients (K) higher than 1 and extraction efficiencies (E) higher than 50%, indicating a preferential migration of the polyphenols to the top phase. The extraction of FA using the ATPS based on Na₂Tartrate presented the most promising results, with K = 19 ± 6 and E = (94.2 ± 0.9)% for the longest tie-line. Additionally, a comparison with previous works of the research group was drawn, with the extraction of RV exhibiting outstanding performance across all studied ATPSs. Therefore, the assessed ATPSs were shown to hold immense potential for the recovery of polyphenols. Full article

The middle–upper Eocene successions of northwest Fayum, Egypt, provide a crucial archive for reconstructing paleoenvironmental conditions and paleobiogeographical patterns of the southern Tethys realm. Stratigraphically, the investigated section is subdivided into three rock units: the Gehannam Formation (Bartonian-Priabonian), the Birket Qarun Formation, and the Qasr El Sagha Formation (Priabonian). A total of 101 benthic foraminiferal taxa, representing 31 genera, 23 families, 13 superfamilies, and four suborders, were identified. The middle–late Eocene age is primarily determined by the co-occurrence of index spinose planktonic foraminifera (Acarinina spp., Morozovelloides spp., and Globigerinatheka semiinvoluta) and benthic foraminiferal assemblages, further supported by the presence of the nannofossil marker Chiasmolithus oamaruensis. Four local benthic biozones are identified and correlated with coeval zones in nearby areas. Quantitative analyses of benthic foraminiferal individuals, diversity indices, ecological parameters, and the benthic foraminiferal oxygen index (BFOI) reveal distinct environmental shifts. The rock unit occupied by the late middle Eocene assemblages is diversified and dominated by calcareous infaunal taxa (e.g., Bolivina spp., Fursenkoina spp., and Nonionella spp.), indicative of low-oxygen outer neritic conditions associated with elevated organic influx. In contrast, the late Eocene Birket Qarun and Qasr El Sagha showed an increase in epifaunal forms and reduced diversity, suggesting a transition to dysoxic-oxic conditions. Paleobiogeographical analysis indicates a strong affinity with the Tethyan realm, with potential faunal exchange through the Trans-Saharan Seaway. These findings enhance our understanding of Paleogene marine connections between the Tethyan and Indo-Pacific realms, contributing to broader discussions on Eocene paleobiogeography and depositional dynamics in North Africa. Full article

This study evaluated the efficiency of catalytic ozonation with magnetite (Fe₃O₄) in degrading recalcitrant organic compounds in leachates from two sanitary landfills in Colombia. The optimum treatment conditions were also analyzed by means of a response surface design, resulting in 6 g O₃/h, 2.5 g/L Fe₃O₄, and pH 9, which resulted in COD removal rates of 85.3% in El Guayabal and 75.8% in La Madera. Moreover, the BOD₅/COD ratio increased from 0.26 to 0.38 and from 0.23 to 0.32, respectively, suggesting increased effluent biodegradability. The most efficient ozone consumption (2.7 g O₃ per gram of COD removed) was obtained under alkaline conditions with a high catalyst concentration. Magnetite demonstrated structural stability, although its catalytic efficiency progressively decreased after three cycles of use, with COD removal decreasing from 85.3% to 73.6%. These findings validate catalytic ozonation with magnetite as an efficient alternative for advanced leachate treatment, with the potential to optimize contaminant removal in industrial effluents and strengthen environmental remediation strategies. Full article

This study explores the relationship between emotional labor and burnout, focusing on the moderating role of conflict management strategies. A total of 233 employees from diverse sectors in Portugal participated in this cross-sectional investigation. We employed the Emotional Labor Scale (ELS) and the Oldenburg Burnout Inventory (OLBI) to quantitatively assess emotional labor and burnout levels. Additionally, the study examined conflict management practices in the workplace using the Conflict Management Strategies Assessment Scale (ROCI-2). The findings reveal that participants reported high emotional labor and burnout levels and a positive correlation between these constructs. As expected, conflict management strategies were found to moderate this relationship. Additionally, participants reported employing collaborative approaches as the most frequent conflict management strategy. These results underscore the urgent need for organizations to implement targeted conflict management training programs and psychological and emotional support initiatives to alleviate the adverse effects of emotional labor on burnout. By fostering healthier workplace environments, organizations can enhance employee well-being and productivity. Full article