Search Results (3,312)

There is limited information on the effects of irregular-spaced and clumped planting on forest production and structural diversity. We explored Tagetes patula L. development as a model system to demonstrate stand development under varying planting patterns, and conceptualized in the context of Pseudotsuga menziesii (Mirb.) Franco mesic production forests of the Pacific Northwestern USA. Two variable planting patterns, clumps of 24 plants and of four plants, were compared to square regular patterns in replicate growing boxes. Spatial patterns were compared post-planting and at maturation, along with stand-level metrics and final dry weights, and stand structural statistics were used to compare production and diversity. The clumped spatial structure of 24-plant clumps was maintained to maturity. Groups of four plants maintained clumping at small scales and regular patterns at larger scales. Initial Regular-Square spacing remained at 2 cm at maturity but became indistinguishable from random patterns at larger scales. There was (1) overall greater mean directional index for the Large-Clumped patterns and greater spatial complexity indices for both clumped patterns, (2) greater social class (size) mean mingling index for small clumps, and (3) higher mean dominance index and mean differentiation index and lower crown volume complexity and height-to-diameter ratios for Regular-Square spacing. The structural complexity was accompanied by limited differences in dried weights by plant tissue (total weight, stem, leaf, flower weight) or plant biometric parameters (stem straightness, crown ratio, crown volume, number of leaves and flowers). The results from irregular planted marigold stand development are discussed in the context of increasing forest stand complexity, potentially without compromising productivity. Full article

Tailings backfilling (TB) is widely recognized as an environmentally friendly and engineering safe technique to enhance mining efficiency. However, the heterogeneous particle distribution in TB slurry, also-named the segregation phenomenon, can significantly affect the mechanical strength of the backfill, especially under high goaf conditions. Therefore, elucidating the spatial distribution characteristics of particles during high-goaf filling has become a crucial research focus for improving the mechanical behavior of tailings backfill. A systematic experimental investigation was conducted in this study, incorporating the similarity principle, to analyze the migration behavior of backfill slurry particles and to clarify how the different backfill heights influence the spatial distribution of fine, medium, and coarse particles. The results indicate a clear vertical variation in PSD. Based on statistical analysis of samples collected from different backfill height experiments, coarse particle content increased progressively from the upper to lower layers (median: 16.2%, 23.6%, and 25.0%), while medium-sized particles remained relatively stable (37.0%, 37.3%, 37.0%). Fine particles dominated overall but decreased with layers (45.6%, 38.8%, 38.3%). Coarse particles tended to settle downward due to gravitational forces, whereas fine particles migrated upward. The distribution of medium-sized particles remained largely homogeneous. Fine and coarse particles were subjected to opposing driving forces. Meanwhile, particles maintained an approximately symmetrical distribution in the horizontal direction. Moreover, when the backfill height exceeded 800 mm, a notable intensification of stratification occurred, indicating a strong height-dependent transition in segregation behavior. In contrast, in the horizontal direction, the PSD showed no clear dependence on backfill height. These findings provide new insights into the mechanisms of particle segregation within backfill materials, offering a theoretical foundation and experimental support for optimizing PSD within the backfill body and elucidating the collapse mechanisms of high goafs. Full article

Background: Tendons adapt to mechanical loading by increasing cross-sectional area (CSA), stiffness, and matrix organization, with structural remodeling critical for both rehabilitation and performance. Collagen supplementation has been proposed to enhance this process by supplying key amino acids for collagen synthesis; however, inconsistent results across trials have limited its clinical and athletic application. Methods: A systematic review of randomized controlled trials evaluating collagen supplementation in humans was conducted. PubMed, EMBASE, CINAHL, and Web of Science were searched from database inception through May 2025. Risk of bias was assessed using the PEDro scale (≥6/10 classified as good-to-excellent quality). Due to substantial heterogeneity in supplementation protocols, training modalities, and outcome measures, results were synthesized narratively without meta-analysis. Data extraction included collagen type, dose, training modality, intervention duration, and outcome measures. Results: Of 887 unique citations, eight RCTs (n = 257; ages 18–52; 246 M:11 F) met the inclusion criteria. All studies incorporated resistance or plyometric training (3–15 weeks). Three of four studies reported significantly greater increases in tendon CSA in collagen groups versus placebo. Four studies investigated tendon stiffness and Young’s modulus; the two using higher doses (15–30 g/day) demonstrated significant between-group improvements favoring collagen, while lower-dose studies (~5 g) showed only within-group effects. Muscle strength improved with training in all trials, but no additive effects of collagen were observed. One study reported improvements in eccentric rate of force development and deceleration impulse with collagen, though gross explosive metrics (e.g., jump height) were unaffected. Conclusions: Collagen supplementation (15–30 g) with vitamin C (≥50 mg) may enhance tendon remodeling when combined with high-intensity resistance training (≥70% 1 RM). The current literature suggests strong evidence (GRADE A) for increases in tendon CSA and stiffness, strong evidence (GRADE A) against an effect on muscle strength, and conflicting evidence (GRADE C) for muscle cross-sectional area and physical performance. Limitations include small sample sizes, heterogeneous protocols, and short intervention durations. Full article

The investigation aimed to determine if live feedback of team- and player-specific global positioning system (GPS) running performance data between bouts of hurling small-sided games (SSGs) altered the physical and physiological responses during subsequent bouts of SSGs during a 6-week hurling pre-season period. Twenty-four (n = 24) hurling players (age 25.5 ± 3.2 years; height 177.9 ± 3.2 cm; body mass 83.5 ± 4.5 kg) received either feedback or no feedback during hurling-specific SSGs across a 6-week pre-season period. Teams were assigned to two specific groups, a) GPS live feedback or b) no GPS live feedback (control) for each session, with feedback provided during the SSG rest interval. Running performance (10-Hz, STATSports, Apex, Northern Ireland), heart rate (Polar T31 coded, Polar Electro, Finland), and rating of perceived exertion (RPE) were measured. Data was analyzed using linear mixed-effect models with the effect size (Cohen’s d) used to determine the size of the effect between feedback and non-feedback conditions. Trivial-o-small differences at all time points were observed in heart rate and RPE measures during SSGs, respectively. Trivial-to-moderate effects were observed between feedback and non-feedback conditions for total distance (p = 0.04; ES = 0.25; small) high-speed running (p = 0.043; ES = 0.59; moderate), maximal speed (p = 0.345; ES = 0.11; trivial) and accelerations (p = 0.03; ES = 0.55; moderate). The current data suggests that coaches and applied practitioners may use live GPS feedback to alter the running and physiological performance within hurling-specific SSGs during a pre-season period. Full article

Wheeled multifunctional motorized crossing frames represent a new type of crossing equipment for high-voltage transmission line construction. The initial design is too conservative, having a large safety margin and high material redundancy. Therefore, it is necessary to study a lightweight design version. However, as the structure constitutes an assembly consisting of multiple components, it also exhibits relatively high complexity. In a lightweight design, optimizing multi-component and multi-size parameters can lead to structural interference and separation, seriously affecting the smooth progress of design optimization. Therefore, an optimization design method of a multi-parameter complex assembly structure is proposed to solve this problem. Firstly, the typical stress conditions of the wheeled multifunctional motorized crossing frame were analyzed using its structural model. Then, a finite element model of the beam was established in ANSYS 2021 R1 Workbench, and the mechanical characteristics were analyzed. The results show that the arm support is the key load-bearing component and has significant optimization potential. Subsequently, functional mapping relationships were established among the 14 dimension parameters of the arm support, reducing the number of design variables to six and successfully avoiding component separation or interference during optimization. Through global sensitivity analysis, the height, thickness, and length of the arm body were screened out as the core optimization parameters from six initial design variables. Then, 29 groups of sample points were generated via central composite design (CCD), and a response surface model reflecting the relationships among the arm body’s dimensional parameters, total mass, maximum stress, and maximum deformation was established using the Kriging method. Leave-one-out cross-validation (LOOCV) was performed, and the coefficients of determination (R²) for model fitting were all higher than 0.995, indicating extremely high prediction accuracy. Taking mass and deformation minimization as the optimization objectives, the MOGA algorithm was adopted to perform multi-objective optimization and determine the optimal engineering parameters. Simulation verification was conducted on the optimized arm support, and an eigenvalue buckling analysis was performed simultaneously to verify structural stability. Finally, the proposed optimization method was experimentally verified through mechanical performance tests of the full-scale prototype under symmetric and eccentric loads. The results show that the mass of the optimized arm support is reduced from 217.73 kg to 189.8 kg, with a weight reduction rate of 12.8%. Under an eccentric load of 70,000 N, the maximum deformation of the arm support is 8.9763 mm, the maximum equivalent stress is 314.86 MPa, and the buckling load factor is 6.08, all of which meet the requirements for structural stiffness, strength, and buckling stability. The maximum error between the experimental and finite element results is only 4.64%, verifying the accuracy and reliability of the proposed method. The proposed optimization methodology, validated on a wheeled multifunctional motorized crossing frame, serves as a transferable paradigm for the lightweight design of complex assemblies with coupled dimensional constraints, thereby offering a general reference for the structural optimization of multi-component transmission line equipment, construction machinery, and other multi-component engineering systems. Full article

Unmanned Aerial Vehicle (UAV) fertilization is important for precision agriculture. However, multi-rotor UAVs show a lot of inconsistencies in homogeneity and unclear deposition patterns when they spread granular fertilizer in different operational situations. This study utilized the DJI T40 UAV to measure discharge rates and create a correlation model. An orthogonal design combined DEM simulation with field experiments to look at how flight height and disc speed affected spreading uniformity and effective swath for single and overlapping flight paths. The discharge rate has a strong linear relationship with control parameters (R² > 0.94), which means that it is very easy to predict for all particle sizes. Single-pass deposition shows an “M-shaped” bimodal profile with particles of different sizes arranged in a radial pattern. The best values for H and n were found to be 7 m and 1200 rpm, respectively, and gave a 10 m effective swath width and a coefficient of variation (CV) of 13.79%. Deposition patterns change nonlinearly with flight height and disc speed. Particle size consistency is critical for distribution stability, with flight height being the key quality determinant and particle size variation the primary source of instability. Full article

Feed handling activities in cattle feedlots—such as feed leveling, reconditioning, and the removal of feed refusals along the trough—remain largely manual in many developing countries, resulting in high labor demand and inconsistent feed availability. This study aimed to design, develop, and evaluate an integrated machine capable of leveling feed, conditioning refused feed, and collecting feed refusals. The machine was developed using trough-geometry data (550–650 mm) and feed-residue properties (particle size, bulk density, terminal velocity), integrating a shovel–dual-brush unit with pneumatic suction. A prototype was subsequently fabricated and tested under practical feedlot conditions using various trough widths and operating speeds. Performance evaluation included feed-pile geometry, distribution uniformity, suction efficiency, suction capacity, and fuel consumption. The leveling mechanism significantly improved feed distribution uniformity, reducing the coefficient of variation for feed-pile height and feed mass by up to 67% and 73%, respectively. During conditioning, the machine increased feed-pile height by 8–10 cm and reduced pile width by 6–13 cm. The suction system maintained high efficiency (94–97%) with an average capacity of 14.1 ± 0.8 kg·min⁻¹. Fuel consumption ranged from 0.54 L·h⁻¹ during leveling to 1.30 L·h⁻¹ during suction. Overall, the machine offers a practical solution for improving feed shaping, uniformity, and residue removal. Full article

Background/Objectives: Biventricular volume (BVV) can be measured from non-contrast-enhanced CT images in patients undergoing coronary artery calcium (CAC) scoring. BVV correlates with left ventricular mass and may predict mortality risk in type 2 diabetes mellitus patients. This study examines the relationships among body size, age, and BVV using the Standard Human Index (SHI), which combines height and bodyprint (BP = k × height − body surface area, h-BSA; k = 1 for females, 1.1 for males). We hypothesize that this novel indexing method enhances the discrimination of increased BVV in overweight and obese patients and assesses the relevance of age in interpreting BVV changes. Methods: We analyzed CT data from 2466 patients (1606 women, 860 men; mean age 64 ± 11 years) referred for CAC scoring. Fatless BVV was measured semi-automatically, and we compared raw BVV values and BVV normalized for height, body surface area (BSA), and the SHI across sex, age, and body mass index (BMI) categories. Results: BVV was significantly higher in males (414 ± 97 mL) than females (297 ± 66 mL) (p < 0.001). BVV decreased non-linearly with age, stabilizing in older patients. Normal-weight males had higher BVV than females (p < 0.001). Normalization for height, BSA, and the SHI indicated that BSA did not effectively distinguish BVV changes in overweight and obese patients. Conclusions: The proposed index effectively diagnosed BVV increases in overweight individuals, while BSA indexing may be misleading. The age dependence of BVV challenges the validity of standards based on younger populations for detecting ventricular enlargement in older adults. Full article

Background: Body mass index (BMI) is commonly used to assess obesity but does not differentiate between fat and lean mass, limiting its effectiveness to assess cardiometabolic risk. Measurements of central adiposity, such as waist circumference (WC), waist-hip ratio (WHR) and waist-to-height ratio (WHtR), are better predictors of metabolic dysfunction, especially with respect to visceral fat. Aim: To examine BMI trends and assess the association between BMI and waist-related anthropometric indicators WC, WHR, and WHtR, among university students in South Africa. Methods: A cross-sectional study involving 842 university students was conducted. Anthropometric measurements were taken according to ISAK standards. Quantile regression models supplemented by ROC curves were used to assess the predictive effects of WC, WHR, and WHtR on BMI across its distribution. Results: A total of 842 participants (63.8% female) were included, with a mean age of 21.8 ± 4.0 years. Significant differences were observed across BMI categories for all demographic and anthropometric characteristics (p < 0.001). Quantile regression analyses showed that WHtR and WC were strong and consistent predictors of BMI in all quantiles, with effect sizes increasing at higher levels of BMI. The WHR showed weaker associations overall, but these became significant in the upper BMI quantiles. Collectively, waist-related indicators, particularly WHtR and WC, exhibited robust predictive values for elevated BMI. Conclusions: Waist-related indicators, especially WHtR and WC are robust predictors of elevated BMI among university students, particularly in higher BMI ranges. These findings highlighted the value of incorporating central adiposity measures alongside BMI for more accurate health risk assessments in young adult populations. Full article

This study investigates the core optimization of a Prismatic Solid Molten-Salt Reactor (PSMSR) to meet key objectives of compactness, high power density, and extended operational life. With graphite irradiation resistance being a paramount concern in high-flux environments, the analysis focuses on the influence of core height-to-diameter ratio, active zone size, and reflector thickness on the graphite displacement per atom (DPA) distribution and burnup performance. The results indicate an optimal active core configuration characterized by a 1:1 height-to-diameter ratio, a 175 cm active zone radius, and a 55 cm reflector. Building on these findings, reactivity-control strategies were refined. An evaluation of burnable-poison addition against fuel-loading optimization revealed that the latter, by adjusting the TRISO (TRi-structural ISOtropic) packing factor and control-rod dimensions, can meet the safety shutdown margin requirements and substantially improve the fuel utilization efficiency, ultimately achieving a burnup depth of 50.3 MWd/kgU and a 10-year operation lifetime without refueling at a 500 MWt power level. This research provides an effective technical solution for the modular deployment of solid-state molten-salt reactors in remote areas and in special application scenarios. This research offers a viable technical pathway for implementing solid-fueled molten-salt reactors in remote and specialized scenarios, enabling their modular deployment. Full article

Amazonian large trees act as central elements of forest ecosystems, storing a disproportionate fraction of aboveground biomass. However, these trees are not randomly distributed across the landscape, and it is expected that edaphic attributes influence floristic composition, forest structure, and vegetation biomass. In this study, we investigated how variation in soil chemical and physical properties affects the diversity and biomass of large trees. Forest inventories were conducted at five sites within protected areas in the states of Pará and Amapá. Aboveground biomass was estimated using allometric equations, while soil samples were analyzed for their physical and chemical properties. Diversity indices, rarefaction, Redundancy Analysis, and Generalized Additive Models were applied. Edaphic variables such as soil pH, organic matter, phosphorus, and aluminum were associated with floristic composition and the biomass of these individuals. Trees with a diameter at breast height greater than or equal to 70 cm accounted for up to 80% of total biomass, revealing a pattern of biomass hyperdominance. The results indicate that the occurrence of large trees is related to edaphic and structural attributes, such as tree density and size distribution, suggesting that these individuals are not randomly distributed along soil gradients. Understanding these patterns is essential for improving ecological models, biomass extrapolations, and management strategies aimed at conserving the Amazon rainforest. Full article

To address the feasible issues in water treatment facilities such as low particle removal and overuse of chemical in flocculation–sedimentation treatment of complex sediment-laden particles in snowmelt and high-intensity rainfall water, this research presents a new multi-layered separation tank. Combining a multi-layer structural design and a synergistic enhancement mechanism flocculation–centrifugation, it is possible to engineer the tank to achieve improvement in the coexistence of the sediment and water. This study methodically examines the impact of the agitator speed, agitator height, and the number of blades on the flow field qualities and the effectiveness of the agitator in removing particles in the multi-layer separation tank. Computational fluid dynamics (CFD) simulation validation in comparison with hydro-calculations and laboratory experiments are used in a combined method. The findings show that there is strong agreement between numerical representation and experimental values in determining the optimal conditions of operation and the exact rate of dosage of polyaluminum chloride (PAC) and polyacrylamide (PAM). At these optimized conditions, the system achieves at a 75.25 percent removal rate of particles whose size ranges are 20–50 μm and turbidity of the effluent decreases to 10.6 NTU in 30 min of settling time. The proposed technology is more efficient than conventional coagulation processes in that effluent turbidity is reduced by 22.1% with same dosages of chemical additive indicating a higher performance of the proposed technology. Full article

Sturgeon stock enhancement is one of the key approaches for the conservation of sturgeon species and the restoration of aquatic biological resources. In Kazakhstan, these activities are mainly concentrated in the Caspian and Irtysh river basins, where broodstocks are formed from natural populations for artificial reproduction and annual replenishment of natural stocks. Such programs also provide an opportunity to assess the biological status of populations and evaluate the level of differentiation between sterlet populations inhabiting the Irtysh and Caspian basins. This study analyzed morphological similarities and differences between sterlet (Acipenser ruthenus) populations from the Irtysh and Zhayik rivers. Morphometric analysis revealed clear morphological differentiation between the studied populations. The most pronounced differences were observed in head width parameters (HC and BC), as well as in the SO and R indices, whereas measurements related to total body length showed minimal variation between samples (about 1%). Statistically significant differences (t-test, p ≤ 0.05) were identified for several morphometric indices, including the length-to-height ratio (L/H), head size index (C/L), and relative body height index (H/L). Considering these differences is important when planning stocking activities to ensure successful adaptation, maintain genetic diversity, and minimize the risk of degradation of local sterlet populations. Full article

Yield-related traits of rice (Oryza sativa L.) are pivotal to safeguarding global food security. As a powerful and efficient strategy, genome-wide association study (GWAS) has identified numerous genes for yield-related traits in rice over recent decades, providing critical resources for germplasm improvement. Most yield-related traits are complex quantitative traits controlled by multiple genes with diverse effect sizes, and traditional GWAS approaches have limited power to detect small-effect loci. In this study, we employed Fast3VmrMLM, a compressed mixed linear model integrating genome-wide scanning and machine learning, to perform GWAS for 10 key yield-related traits using a panel of 529 rice accessions and 4,945,006 single-nucleotide polymorphisms (SNPs). The traits included heading date, plant height, panicle number, effective panicle number, yield per plant, spikelet length, grain length, grain width, grain weight, and grain thickness. We detected 141 significant quantitative trait nucleotides (QTNs) associated with target traits and identified 92 previously validated genes located near these QTNs. As a key environmental regulator, photoperiod directly controls flowering and indirectly modulates yield-related traits, and we further identified 182 photoperiod-responsive candidate genes via differential expression and Gene Ontology (GO) enrichment analysis. Through tissue-specific expression analysis, homology analysis with Arabidopsis genes, and haplotype-phenotype differential analysis, six pleiotropic candidate genes were confirmed; notably, LOC_Os02g02210 appears to contribute substantially to grain width and yield-related traits. In conclusion, Fast3VmrMLM proved effective for dissecting the genetic basis of yield-related traits, especially in detecting small-effect loci. These results not only establish a potential genetic link between photoperiod regulation and rice yield formation but also provide high-confidence candidate genes and loci that will accelerate functional genomic studies and precision molecular breeding for high-yield rice. Full article

Intraspecific phenotypic diversity in clonally propagated crops is frequently constrained by narrow domestication histories and the widespread use of a limited number of elite cultivars. In Stevia rebaudiana, commercial production has largely centred on cv. ‘Morita II’, raising concerns about reduced diversity and adaptive potential. This study characterised and structured phenotypic diversity within a segregating population derived from ‘Morita II’ under tropical field conditions. Eighty-six progeny-derived genotypes (clonally propagated) plus the commercial control (87 genotypes total) were evaluated using 25 agromorphological descriptors (qualitative and quantitative). Quantitative traits showed broad variation, including plant height (28.26–119.50 cm) and dry yield rate (0.94–28.55 g plant⁻¹). Multivariate analyses of mixed descriptors (PCA and hierarchical clustering based on Gower distance) identified plant architecture, vegetative growth, and phenology as the main sources of differentiation. The first two principal components explained 19.65% and 12.58% of total phenotypic variance, respectively (32.23% cumulative). Hierarchical clustering (UPGMA; dissimilarity cut-off = 0.25) resolved four phenotypic groups (GI–GIV) with sizes n = 3, 1, 66, and 17, respectively, enabling the definition of contrasting ideotype candidates based on recurrent trait combinations. These results provide a quantitative baseline for phenotypic structuring, prioritization of materials for further evaluation, and management of clonal stevia collections in tropical production systems. These ideotype candidates should be considered preliminary until validated across environments and linked to chemical quality traits. Full article