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Land use shapes riverine nutrient and sediment concentrations on Moorea, French Polynesia
Abstract Human activities drive changes in freshwater ecosystems by altering biogeochemical cycles. Freshwater networks provide important ecosystem services to human societies by purifying water and serving as an intermediary between terrestrial and marine systems. On high volcanic tropical islands, human activities are compartmentalized by steep terrain that delineates watershed boundaries. Patterns of land use affect adjacent stream ecosystems through runoff of sediment and nutrients, which fluctuates in the tropics as a result of seasonal rainfall. Here, we sought to reveal human impacts on nutrient and sediment regimes of tropical rivers by tracking patterns of river chemistry across a series of watersheds on Moorea, French Polynesia, between 2018 and 2019. Repeated sampling of rivers across a gradient of human activities revealed that water chemistry varied seasonally and with respect to rainfall and land use. In particular, dissolved inorganic nitrogen was more concentrated in rivers of watersheds with higher amounts of land clearing during the rainy season, and total suspended solids and phosphate were higher when recent rainfall was high. Importantly, the water quality of the rivers on Moorea repeatedly exceeded safe water quality standards established for similar high tropical islands in the Pacific. Our results show that differential land use across the landscape can have a substantial impact on the amounts of nutrients and sediment that tropical rivers transport, which on tropical islands could facilitate movement of materials from land to sea as precipitation increases with intensifying climate change.
Quantum correlations of spontaneous two-photon emission from a quantum dot
Allosteric modulation and biased signalling at free fatty acid receptor 2
Overburden failure characteristics and fracture evolution rule under repeated mining with multiple key strata control
A successive framework for brain tumor interpretation using Yolo variants
Abstract Accurate identification and segmentation of brain tumors in Magnetic Resonance Imaging (MRI) images are critical for timely diagnosis and treatment. MRI is frequently used to diagnose these disorders; however medical professionals find it challenging to manually evaluate MRI pictures because of time restrictions and unpredictability. Computerized methods such as R-CNN, attention models and earlier YOLO variants face limitations due to high computational demands and suboptimal segmentation performance. To overcome these limitations, this study proposes a successive framework that evaluates YOLOv9, YOLOv10, and YOLOv11 for tumor detection and segmentation using the Figshare Brain Tumor dataset (2100 images) and BraTS2020 dataset (3170 MRI slices). Preprocessing involves log transformation for intensity normalization, histogram equalization for contrast enhancement, and edge-based ROI extraction. The models were trained on 80% of the combined dataset and evaluated on the remaining 20%. YOLOv11 demonstrated superior performance, achieving 96.22% classification accuracy on BraTS2020 and 96.41% on Figshare, with an F1-score of 0.990, recall of 0.984, mAP@0.5 of 0.993, and mAP@ [0.5:0.95] of 0.801 during testing. With a fast inference time of 5.3 ms and a balanced precision–recall profile, YOLOv11 proves to be a robust, real-time solution for brain tumor detection in clinical applications.
Effects of a warm-up program on jump-landing pattern and lumbopelvic function in female basketball players with dynamic knee valgus
Abstract Dynamic knee valgus (DKV), commonly observed during functional movements, is recognized as a key biomechanical factor contributing to the risk of anterior cruciate ligament (ACL) injury. Given its importance in injury prevention, this study aimed to investigate the effects of a warm-up program on jump-landing pattern and lumbopelvic function in female basketball players exhibiting dynamic knee valgus. The present study employed a quasi-experimental design. Thirty female basketball players with DKV were screened using the single-leg landing (SLL) test and subsequently randomized into control (n = 15) and experimental (n = 15) groups. The jump-landing test was utilized to assess the jump-landing pattern, whereas the forward step-down (FSD) test was implemented to evaluate lumbopelvic function. The experimental group participated in the STOP-X warm-up program over 8 weeks, whereas the control group continued with their traditional warm-up routine. Data were analyzed using a 2 × 2 repeated measures ANOVA, followed by Bonferroni post hoc tests, with statistical significance set at P < 0.05. All analyses were conducted using SPSS version 26. The results revealed significant differences in maximum flexion (F = 20.73; P = 0.001; effect size (ES) = 0.42, percentage change (PC) = ↑4.48%), initial valgus (F = 90.12; P = 0.001; ES = 0.76, PC = ↓32.56%), maximum valgus (F = 151.6; P = 0.001; ES = 0.84, PC = ↓52.86%), and FSD (F = 22.82; P = 0.001; ES = 0.44, PC = ↓51.45%) in the experimental group compared to the control group after following the STOP-X warm-up program. However, no significant impact was observed for the initial flexion (P = 0.49, ES = 0.01) variable. Implementing the warm-up injury prevention program significantly improves jump-landing pattern and optimizes lumbopelvic function. Therefore, it is recommended that coaches incorporate this program in place of traditional basketball warm-up routines. Such an approach may enhance athletic performance while reducing the risk of knee injuries associated with improper landing techniques. Trial registration No: IRCT20231230060574N1, (date of registration on 04/01/2024) registered in the Iranian Registry of Clinical Trials.
Effect of doped wax on the rheological properties and chemical structure of ultraviolet aged bitumen
Development of porous COP–ceramic composites for application as low-relative-permittivity, low-dielectric-loss substrates in next-generation communication systems
3D-printed setup for ocular drug delivery evaluation on ex vivo porcine whole eye
Abstract Reaching the back of the eye without invasive intraocular injections is still nowadays challenging. Luckily, the nanotechnology can help in improving the effectiveness and the patient compliance and, ultimately, the therapeutic success rate. The development and characterization of ophthalmic (nano)formulations benefit from the implementation of ex vivo models, that allow to disclose the formulation behaviour once in contact with biological tissues and consequently its optimization. Ex vivo ocular models help to minimize the number of promising formulations deserving to be investigated in in vivo animal models, in compliance with the 3Rs principle, and therefore their availability is of paramount importance. In this research work, we present a 3D-printed reusable device designed to be used in a whole porcine eye bulbs setup comparing it with the Franz-cell. The device, produced by a Masked Stereolithography Apparatus, consists of two components, the Ocudonor, acting as a donor chamber for the formulation, and the Ocutainer, which simultaneously contains up to three ocular bulbs. The porcine eye setup was validated using a dexamethasone-loaded nanostructured lipid carriers for periocular administration and intended for the treatment of the posterior segment of the eye. The porcine whole eye model proved capable of preserving eye structure integrity for at least 18 hours and, unlike the Franz-cell, enabled the evaluation of the drug’s lateral diffusion along the eye bulb.