Search Results (288)

Recently, how to improve the aquaculture efficiency of sea cucumber Apostichopus japonicus and promote the sustainable development of its artificial cultivation has become an increasingly important issue. The pond water environment plays important roles in the survival rate and growth of A. japonicus seedlings. This study investigated the changes in water quality and plankton from June to November in A. japonicus ponds. The seawater temperature, pH, dissolved oxygen, salinity, nitrogen, and active phosphate contents were measured, and the planktonic species were detected and identified. The results showed that the seawater temperature ranged from 11.2 to 29.9 °C, and the highest temperature did not exceed the tolerance survival limits of A. japonicus. The changes in pH, dissolved oxygen, and salinity were also suitable for growth. A total of six phyla and 14 species of planktonic algae were detected, among which diatoms were dominant, and the dominant species changed over time. In the early stage, it was Chroomonas acuta, then, after it was Nitzschia sp., and then it returned to C. acuta again later. The biomass and density of algae peaked in week 5 (p < 0.05), but decreased to their lowest in week 18. The changes in chlorophyll-a content were consistent with the biomass of algae. Both the chlorophyll-a and pheophytin contents peaked in weeks 5 and 10 (p < 0.05). The changes in suspended particulate matter (SPM) and particulate organic matter (POM) were synchronized, and they peaked in weeks 5 and 12. These results suggested that the planktonic algae have the functions of a food supply and an environmental indication, and changes in chlorophyll-a, pheophytin, SPM, and POM support the food source reserve for A. japonicus. This study provides important information for the artificial cultivation of sea cucumber seedlings in a pond, and it is useful to promote the sustainable development of the sea cucumber industry. Full article

Phosphorus is a key nutrient regulating algal growth and eutrophication in aquatic systems, yet its isolated effect on microalgae-based wastewater treatment remains underexplored. This study evaluated how varying phosphorus loads drive microalgal community structure and purification performance in controlled photobioreactors fed synthetic wastewater. The synthetic wastewater was formulated with constant carbon and nitrogen but graded phosphorus at C/N/P ratios of 100/5/1, 100/5/10, and 100/5/20 under 6000 lux, a 14 h photoperiod, and 24 ± 2 °C with a 15-day hydraulic retention time. Monitoring of chlorophyll a, pH, total and volatile suspended solids, and algal composition showed that phosphorus enrichment significantly increased chlorophyll a (up to 43.9 µg/L at 20 mg P/L) and particulate biomass (TSS and VSS), while pH remained near neutral to slightly alkaline, with no significant differences among the three bioreactors. Although the same core taxa—Chlorella spp., Scenedesmus spp., Navicula spp., and filamentous algae were present across all bioreactors, their relative abundances shifted significantly with phosphorus concentration. A two-way ANOVA confirmed a highly significant interaction between bioreactor (P level) and genus (p < 0.001), demonstrating phosphorus-driven changes in the microalgal community. Notably, filamentous cyanobacteria (Anabaena spp.) were undetectable in the low- and medium-phosphorus treatments but emerged prominently only at the highest phosphorus level (20 mg/L). Nutrient removal efficiencies peaked in this high-phosphorus bioreactor (C), achieving 85% for bCOD, 78% for nitrogen, and >70% for phosphorus. These results show that phosphorus loading drives predictable shifts in microalgal community composition toward fast-growing algae and cyanobacteria and that these shifts likely contribute to enhanced nutrient removal. The findings support optimization of phosphorus supply and hydraulic residence time in low-cost, sunlight-driven systems to improve polishing performance for small settlements in arid regions. Full article

Urban expansion in cold semi-arid regions poses significant threats to river ecosystems through land use changes and impervious surface proliferation. This study examined the Selbe River in Ulaanbaatar, Mongolia, integrating Landsat satellite imagery (2000–2020) with long-term water quality monitoring data (2012–2023) to assess land use change impacts on river water quality. Land use classification revealed that built-up areas expanded 3.5-fold from 16.20 km² (2000) to 57.9 km² (2020), driven primarily by informal Ger residential areas and high-rise residential zones. Over the same period, barren land decreased from 149.5 km² to 64.80 km², while green areas increased from 156.89 km² to 200.11 km², which was insufficient to offset ecological stress from impervious surfaces. Water quality analysis of five sampling sites along the river showed progressive deterioration, with the Water Quality Index (WQI) increasing from 1.08 (2012) to 7.24 (2023), classifying the river as “dirty”, the most severe pollution category in Mongolia’s national classification system. Downstream sites adjacent to high-rise residential and Ger districts exhibited elevated concentrations of NH₄⁺, NO₂⁻, NO₃⁻, PO₄³⁻, and suspended solids, frequently exceeding permissible limits established by MNS 4586-98. These findings underscore the cumulative impact of unregulated urban growth on aquatic ecosystems and emphasize the urgent necessity for integrated land use regulation and watershed-based planning to safeguard urban water resources in cold semi-arid environments. The study provides a replicable framework for assessing land use impacts on water quality in rapidly urbanizing regions. Full article

This article proposes a conceptual reformulation of the phenomenon of boredom by carefully distinguishing ordinary situational or psychologically driven boredom from what is here termed existential boredom: a specific mode of disconnection in which the subject’s capacity to inhabit a meaningful horizon of possibilities becomes temporarily suspended. Rather than interpreting boredom as a mere lack of stimulation, momentary dissatisfaction, or simple emotional discomfort, the study argues that certain forms of boredom reveal a phenomenological contraction of possibility, involving disturbances in lived temporality, value orientation, imaginative projection, and embodied intentionality. Through a critical analysis of key thinkers, the article clarifies the tensions and limitations within classical accounts and delineates the proposed concept of existential boredom from adjacent phenomena such as Unheimlichkeit, Frankl’s “existential vacuum”, clinical apathy, and everyday boredom. It is argued that existential boredom functions as a phenomenological indicator of existential disconnection, not as an ontological diagnosis of meaninglessness but as a liminal experience that renders visible the temporary suspension of the structures that normally sustain meaningful world-disclosure. This conceptualisation also illuminates the contemporary prevalence of this affective state within contexts of hyper-stimulation, attentional fragmentation, and the erosion of meaning frameworks. By offering an integrated analytical framework, the article contributes to a more rigorous understanding of boredom as an existential phenomenon, with implications for philosophy, contemporary psychology, and the study of human experience in modern life. This approach not only expands our understanding of boredom but also invites us on a journey of self-discovery and personal growth. Full article

The accelerating pace of global population growth, urbanization, and industrialization is exerting considerable pressure on freshwater resources. In developing countries, where infrastructure constraints often hinder the adoption of advanced treatment technologies, cost-effective and efficient wastewater solutions are essential. Algal–bacterial bioremediation represents a promising, eco-friendly method for removing organic pollutants through biological processes. This study evaluates a hybrid treatment system composed of three ponds: a covered anaerobic pond for organic matter digestion, a microalgal pond equipped with rotating biological contactors (RBCs) that facilitate interactions between heterotrophic bacteria and diatoms, and a final settling pond. Granular activated carbon embedded within the RBC enhances biofilm formation by attracting heterotrophic bacteria, thereby increasing treatment efficiency. Under optimal conditions—10 g of activated carbon and 1.7 d hydraulic retention time—the system achieved removal efficiencies of 95.8% for total suspended solids (TSS), 96.3% for turbidity, 85% for biological oxygen demand (BOD), and 99.9% for Escherichia coli. Bacteriological analysis showed complete removal of fecal coliform and total coliform. The characteristics of the outflow treated wastewater are 3 mg/L, 0.9 NTU, and 3.2 mg/L for TSS, turbidity, and BOD, respectively, while E. coli detection is under detection limit. The treated effluent complies with Category A for the reuse of treated wastewater in the Egyptian code for the reuse of treated municipal wastewater for agricultural purposes, offering a scalable and sustainable solution for wastewater management in resource-constrained regions. Full article

The imperative for sustainable water management strategies is driven by challenges, such as limited water availability, economic development, population growth, and escalating environmental concerns. A viable strategy involves water collection and reuse. This study assessed the quality of wastewater produced by paint manufacturing companies, which is characterised by high chemical oxygen demand and turbidity, as well as the presence of organic materials, suspended particles, and heavy metals. Such wastewater requires treatment prior to environmental discharge. After analysing the current methods of wastewater treatment in the paint industry, this study seeks to establish a conceptual framework for developing a methodology for the collection of wastewater from rinsing machines and containers within the paint manufacturing sector while identifying optimal practices in raw wastewater management. It examines various strategies for minimising the waste generated in the paint manufacturing industry, drawing upon the waste management practices of a specific plant. Utilising data from 190 samples, the quality of the generated wastewater was estimated using probabilistic methods, including the Monte Carlo simulations, distribution fitting, and Student’s t-test. Based on the results, a wastewater management strategy was formulated for the company. By implementing water treatment and recycling systems, paint manufacturers can reduce their reliance on freshwater resources, lower the costs associated with wastewater disposal, and mitigate their environmental impact. Effective management in this domain can significantly enhance the treatment of industrial wastewater and facilitate the development of strategies for the reuse of rinse wastewater, thereby supporting the principles of a circular economy. Full article

The growing interest in the commercial exploitation of the bioactive components of Dictyota species, including Dictyota kunthii due to its antifungal activity and use in the development of innovative bioproducts, depends on the availability of biomass. In this context, the cultivation of this species emerges as a promising alternative. This study examined thallus fragmentation and ligulae development as methods to produce D. kunthii. Accordingly, thalli were divided into apical, middle, and basal sections to generate the respective tissue fragments, which were cultured under controlled conditions. On the other hand, ligulae development was studied under different conditions of photon flux density (10, 35 and 65 µmol m⁻²s⁻¹); temperature (10, 17 °C); photoperiod (8:16, 12:12, 16:08 h [Light:Dark]), and seawater enrichment:Basfoliar^®, Compo Expert, Krefeld, Germany and von Stosch solutions. The results show that fragmented thalli were non-viable, exhibiting neither wound healing nor regeneration at the cut sites. Furthermore, no buds or new branches were formed. In contrast, ligulae developed under all tested conditions, with nutrients, light, temperature, and photon flux enhancing apical cell formation and branching. We conclude that ligulae can effectively be used as propagules to cultivate fast-growing, branched D. kunthii plantlets. Accordingly, we recommend using a suspended culture system at 17 °C with a 12:12 (Light:Dark) photoperiod and 65 µmol m⁻² s⁻¹ light intensity, as well as adding nutrients (Basfoliar^® at 0.1 mL L⁻¹). Under these conditions, growth rates equal to or exceeding 10% d⁻¹ can be achieved, supporting the feasibility of scaling up to larger volumes for biomass production. Full article

The present study used a syngeneic mouse model of malignant melanoma to evaluate the inhibitory efficacy of continuous xylitol administration via a subcutaneous osmotic minipump. The B16F10 syngeneic model for malignant melanoma consisted of 6–8-week-old C57BL/6 male mice subcutaneously injected with 5 × 10⁵ B16F10 cells suspended in 100 μL PBS in the right flank. The mice were randomly assigned to two groups: Group 1 was the treatment group, which received 10% w/v xylitol in saline-loaded pumps (n = 10), while Group 2 was the control group, which received saline-loaded pumps (n = 10). ALZET 2004 minipumps were implanted subcutaneously in the left flank of B16F10-injected mice once more than 50% of all mice developed palpable tumors. After pump implantation surgery, the mice were monitored daily and weighed 2–3× times per week. Tumor sizes were measured with calipers 2–3× per week, and all mice were euthanized when their tumors became too large (20 mm on any axis or 2000 mm³). The tumor size growth was reduced by approximately 35% by volume in the xylitol-treated group which was not statistically significant. The xylitol group had a longer survival time, but this was not statistically significant (Kaplan–Meier), as was the case with the survival analysis by the Cox proportional hazards model. The metabolomic analysis suggests that xylitol significantly alters the tumor’s metabolism, potentially affecting the host immune response. Full article

This study examines the integration of digital fabrication technologies into the design and production of mycelium-based components, addressing the growing demand for sustainable and innovative interior design solutions. Using a parametric design approach, modular and customized suspended ceiling elements were developed for a specific interior setting to explore a material-specific design approach for mycelium-based components. Three-dimensional printing was employed to produce molds, which were subsequently tested with plaster, silicone, and mycelium across three different scales. Experimental observations focused on the overall form, surface details, growth behavior and dimensional accuracy, systematically capturing volumetric deviations arising from the living nature of the material. In parallel, acoustic performance was evaluated through simulations using the Sabine method. The untreated condition demonstrated the longest reverberation times, whereas conventional panels achieved reductions consistent with typical comfort standards. Prototypes produced with mycelium yielded measurable decreases in reverberation time compared to the untreated condition, particularly within the speech frequency range, and approached the performance of standard acoustic panels. These findings suggest that mycelium-based components, when further optimized in terms of density and geometry, hold the potential to contribute both aesthetic and acoustic value within sustainable interior environments. Full article

Cell transplantation is often performed with ultrasonographic guidance for accurate delivery through injection. In such procedures, using ultrasonographic contrast greatly improves target delivery. However, accumulating evidence suggests that exposure to such contrast agents may have negative effects on transplanted cells. No study so far has researched this issue. Stabilized sulfur hexafluoride (SF6) microbubbles are a widely used sonographic contrast agent. Skin hCD55 porcine transgenic fibroblasts and mesenchymal stem cells from human bone marrow (hMSCs) were exposed in vitro to SF6 in concentrations ranging from 1.54 µM to 308 µM. The effects on viability and cell growth were registered using an impedance-based label-free Real-Time Cell Analyzer (RTCA). Data was recorded every 15 min for 50 h of total study time. Both cell lines behave distinctly when exposed to SF6. Porcine fibroblast growth showed relevant alterations only when exposed to higher concentrations. In contrast, hMSCs showed progressive growth decrease in relation to SF6 concentration. Taken together, while SF6-based contrast agents pose no threat to patient safety, our results indicate that exposure of suspended stem cells to the contrast agent could affect the effective dose administered in cell therapy procedures. This prompts specific cell lineage testing, adjusting methods and properly compensating for cell loss, with a potential impact on procedural cost and success rates. Full article

Water deficit is a limitation to maize (Zea mays L.) productivity, and seed physiological conditioning (priming) is a strategy to mitigate its effects. Niobium (Nb), an abundant element in the Earth’s crust and crucial for emerging technologies, is primarily produced and exported by Brazil, particularly in the state of Minas Gerais. However, its behavior in soil and effects on plants remain poorly understood. This study evaluated the impact of maize seed hydropriming with different solutions, including ammonium niobate (V) oxalate (C₄H₄NNbO₉), on germination, seedling physiological performance under water deficit, and recovery after rehydration. The experiment was conducted in a greenhouse using a randomized block design with eight treatments and five replications. The germination speed index (GSI) was recorded over a period of seven days. Water deficit was imposed on day eight by suspending irrigation for seven days, followed by rehydration until day 21. Morphological, biochemical, and physiological traits were evaluated, including biomass, pigments, oxidative stress, antioxidant activity, starch, and osmolytes, with photosynthetic parameters measured during rehydration. Hydropriming with Nb-enhanced seed germination but also induced oxidative stress and reduced biomass accumulation. Nb seed priming affected photosynthetic performance in a treatment-dependent manner, leading to phototoxic effects. Overall, although Nb shows biostimulant potential by improving maize germination, its use under water-deficit conditions may trigger toxic responses associated with increased oxidative stress and growth inhibition. These findings highlight the need for further studies to define safe and effective Nb concentrations for improving drought tolerance. Full article

Neopestalotiopsis zimbabwana is an emerging phytopathogen with multiple hosts. Considering the environmental, toxicological, and resistance issues linked to synthetic fungicides, Origanum vulgare L. essential oil (OEO) was evaluated through in vitro, in vivo, and in silico approaches. The pathogen, isolated from Watsonia borbonica L., was molecularly identified. Gas chromatography–mass spectrometry (GC–MS) analysis showed hexadecanoic acid (15.98%), dodecanoic acid (15.74%), terpinen-4-ol (11.61%), and thymol (7.65%) as the main components. In vitro assays determined a minimum inhibitory concentration (MIC) of 30% OEO and a minimal fungicidal concentration (MFC) of 60% OEO. Growth chamber trials demonstrated that preventive sprays maintained 0% foliar damage—similar to Captan^®—while controls reached ≈98%; suspending applications after week 4 resulted in ≈45% damage by week 8. These results confirm that OEO lacks systemic residual activity, acting only as a protectant within preventive integrated pest management (IPM) schemes. Docking to cytochrome b (protein data bank, PDB: 5TL8) indicated strong binding of α-farnesene (−7.638 kcal·mol⁻¹), isoterpinolene (−6.944), and α-terpineol (−6.918), suggesting disruption of mitochondrial respiration via Complex III. OEO represents a promising eco-friendly alternative for managing N. zimbabwana under controlled conditions and reducing reliance on synthetic fungicides. Full article

Floating photovoltaic arrays on ponds may alter thermal and optical conditions that are relevant to aquaculture performance. This study compared 0% and 40% surface shading in two outdoor earthen-pond trials, one with Asian sea bass (Lates calcarifer) and one with Japanese sea bass (Lateolabrax japonicus). Temperature was logged hourly and summarized as daily means; water quality was sampled biweekly; fish were measured repeatedly, with endpoint growth compared within species. The result shows that shading lowered pond temperature and the diurnal temperature range and reduced the number of days above species benchmark temperatures. Indicators associated with phytoplankton, including suspended solids and chlorophyll a, were lower under shading, whereas dissolved inorganic nutrients were higher. In the Japanese sea bass trial, dissolved oxygen was higher without shading. Final body weight did not differ between treatments within either trial, but survival was higher with 40% shading. Principal component analysis and permutational multivariate analysis of variance indicated a treatment signal in multivariate water quality. Because the trials occurred in different years with one pond per treatment, inference was restricted to contrasts within each species. Overall, moderate surface shading cooled ponds and altered water quality without reducing growth. Full article

This study aims to identify the key factors contributing to time and cost deviations in educational infrastructure projects in Colombia, using a data-driven approach based on open government datasets. By examining 175 procurement records from Colombia’s public data platform, the research seeks to uncover patterns and variables that influence project performance, offering a transparent alternative to traditional expert-based assessments. The results show an average time deviation of 77.73% and a cost deviation of 22.17%, with a significant correlation between both metrics. Project type, contract value, and process type were significant for both deviations. Additional cost-related factors included initial duration, award growth, and number of bidders, while time deviations were influenced by project intensity and time suspended. These findings highlight the need for integrated planning and procurement strategies to improve efficiency in public infrastructure delivery. Although the methodology ensures robustness, limitations include the focus on finalized educational projects and the exclusion of qualitative factors such as stakeholder behavior and site-specific challenges. The insights are valuable for policymakers, public sector managers, and researchers seeking to enhance infrastructure outcomes through evidence-based decision-making and better resource allocation. Full article

Exploring microbial resources from coastal environments is crucial for enhancing food security; however, current knowledge remains limited. This study aimed to isolate and molecularly characterize bacteria associated with maize and groundnut, and to evaluate their potential as plant growth-promoting (PGP) agents. Rhizobacteria were isolated from rhizospheric soil, and endophytic bacteria were obtained from surface-sterilized and macerated plant roots. One gram of each sample was suspended in sterile distilled water in test tubes, serially diluted, and plated on nutrient agar. After incubation, distinct colonies were sub-cultured to obtain pure cultures for biochemical tests, screening for PGP traits, assessment of pH and salt tolerance, optimal growth conditions, bioinoculation potential, and molecular analysis. Out of sixty isolated bacteria, five potent strains, BS1-BS5, were identified. BS3 showed the highest mannanase activity, with a 2.3 cm zone of clearance, while BS2 exhibited high indole-3-acetic acid (IAA) and phosphate solubilization activities of 10.92 µg/mL and 10.78 mg/L. BS1 and BS4 demonstrated high drought tolerance, 0.94 and 0.98 at 10% PEG, with BS1 also showing maximum salt tolerance of 0.76. At 6.0 g and 2.0 g supplementation, BS1 and BS2 utilized 100% lactose and fructose. BS3 exhibited the highest percentage of antifungal activity, with a 30.12% inhibition rate. BS4 and BS5 promoted shoot lengths of 55.00 cm and 49.80 cm, respectively. Although the bacterial species isolated are generally considered pathogenic, their positive effects contributed significantly to maize growth. Full article