Search Results (19,622)

Evapotranspiration (ET) estimation in desert-oasis ecotones remains challenging due to sparse meteorological observations and the coarse spatial resolution of satellite remote sensing, which limit the ability to resolve highly heterogeneous surface conditions. To address this issue, this study develops a high-resolution ET estimation framework by integrating unmanned aerial vehicle (UAV)-based thermal infrared remote sensing with a three-temperature (3T) model in the Hexi Corridor. UAV-derived land surface temperature (LST) at meter-scale resolution, together with meteorological and vegetation data, was used to drive the model and generate high-resolution ET maps. The model’s performance was validated spatially against the Surface Energy Balance Algorithm for Land (SEBAL) model and at the point-scale against a two-source model. The results show that: (1) The 3T model effectively captured the spatial gradient of decreasing ET from cropland (3–10.69 mm d⁻¹), through shelterbelts (3–6 mm d⁻¹), to desert areas (<3 mm d⁻¹). (2) Spatial validation against the SEBAL model was conducted using stratified pixel-wise comparisons across four land-cover types over 14 UAV transects, showing strong agreement (R² = 0.90–0.95; RMSE = 0.22–0.43 mm d⁻¹). The model achieved highest accuracy in cropland (R² = 0.92; RMSE = 0.24 mm d⁻¹), with slight overestimation in shelterbelts. (3) Point-scale validation against the two-source model yielded an MAE of 0.38 mm d⁻¹. This study demonstrates the effectiveness of combining UAV thermal infrared data with the 3T model for high-resolution ET simulation in complex ecological transition zones, offering a promising technical approach for ecohydrological monitoring and water resource assessment in arid regions. Full article

Precipitation is central to the global hydrological cycle, and its accurate monitoring is vital for preventing meteorological disasters. Traditional satellite retrieval methods fail to model nonlinear relationships and adapt to regional heterogeneity. Using China’s new-generation geostationary satellite FY-4B/AGRI, this study develops a two-step machine learning model—separating precipitation identification from intensity estimation—for the complex terrain of Anhui Province and further conducts experiments in the Huaibei Plain, Jianghuai Hills, and Jiangnan mountainous areas. This design separately addresses precipitation occurrence and rainfall intensity, which represent distinct classification and regression tasks. The model takes 37 features as input, including multispectral brightness temperatures, brightness temperature differences, spatiotemporal cloud-top temperature dynamics, secondary cloud parameters, and terrain. For identification, XGBoost at a 1:4 precipitation/non-precipitation ratio performed best, with POD, FAR, CSI, and ETS of 0.6961, 0.3676, 0.4956, and 0.4422, outperforming the FY-4B QPE product (0.5876, 0.5703, 0.3301, 0.2607). Subregional modeling further improved CSI to 0.4716, 0.5186, and 0.5210 for the three areas. For rainfall estimation, XGBoost trained with the original precipitation class ratio was optimal in all subregions, markedly surpassing the QPE product. Spatial aggregation of the three regional models yielded a correlation coefficient of 0.5304 and RMSE of 0.6274 mm, outperforming the unified model and QPE during the study period. This study provides a useful machine learning approach for precipitation retrieval, and the results demonstrate the efficacy of incorporating regional heterogeneity into machine-learning-based precipitation retrieval, leading to enhanced precipitation estimation during the June–July 2024 Meiyu period over Anhui Province. Full article

Nili-Ravi buffalo is a core dairy breed for China’s genetic improvement, yet its assisted reproductive technologies are restricted by low ovum pick-up (OPU) efficiency and unstable embryo transfer (ET) pregnant rates. This study established statistically optimized key parameters for OPU procedures in Nili-Ravi buffalo, and evaluated the effects of multiple ET-related protocols. For OPU, 50–55 mmHg vacuum pressure balanced oocyte recovery and usable rate best (p < 0.05). Young and adult buffalo performed significantly better than prepubertal heifers (p < 0.05). Four consecutive weekly consecutive OPU sessions did not significantly reduce oocyte yield (p > 0.05). FSH treatment markedly enhanced oocyte quantity, quality and recovery efficiency (p < 0.05), with no significant difference between two FSH protocols (p > 0.05). For ET, three estrus synchronization protocols showed no significant effects on estrus, ovulation, transferable recipient and pregnant rates in breeding or non-breeding seasons (p > 0.05), though optimized protocols showed a numerical improvement. Combinations of CL grade and embryo quality, as well as post-transfer treatments with vitamin ADE, hCG and progesterone, did not significantly affect pregnancy or early abortion rates (p > 0.05). This study built a practical reference framework for OPU-ET procedures in Nili-Ravi buffalo, with key OPU parameters statistically optimized and ET protocols showing numerical improvements that require further validation with larger sample sizes. Full article

Background and Objectives: Eustachian tube (ET) dysfunction links adenoidal disease to persistent middle ear dysfunction in children, yet the independent contribution of ET orifice obstruction grade to audiological outcomes and health-related quality of life remains unquantified after adjustment for anatomical and inflammatory confounders. Because conventional anatomical grading (e.g., the Cassano classification) does not directly characterize the degree of ET orifice compromise, it may underestimate the functional threat to middle ear ventilation; this study is the first to quantify the independent predictive value of endoscopic ET obstruction grade. This study aimed to evaluate ET obstruction grade as an independent determinant of hearing thresholds, middle ear pressure, and quality-of-life impairment in children with chronic adenoiditis and otitis media with effusion. Materials and Methods: A retrospective cohort of 236 children (aged 3–12 years) was analyzed. ET orifice obstruction was graded endoscopically as none, partial, or complete. Primary outcomes included pure tone average (PTA), middle ear pressure (MEP), and OSA-18 total score. Multivariate linear and logistic regression models were fitted, adjusting for age, sex, Cassano grade, neutrophil-to-lymphocyte ratio (NLR), allergic status, and acute otitis media frequency. The modifying role of mucosal appearance (edematous versus fibrotic/remodeling) on quality-of-life outcomes was also assessed. Results: ET obstruction was absent in 42 (17.8%), partial in 114 (48.3%), and complete in 80 (33.9%) children. PTA increased progressively across groups (22.2 ± 5.5 to 36.2 ± 6.7 dB; p < 0.001), as did OSA-18 scores (44.9 ± 7.9 to 80.4 ± 10.3; p < 0.001). In adjusted analysis, each obstruction increment independently predicted a 5.57 dB PTA increase (95% CI 4.37–6.77; p < 0.001), a 14.89-point OSA-18 increase (95% CI 12.87–16.92; p < 0.001), and 5.12-fold higher odds of PTA > 30 dB (95% CI 2.84–9.24; p < 0.001). Persistent middle ear dysfunction at six months occurred in 7.1%, 26.3%, and 61.3% across obstruction grades. Among children with complete obstruction, fibrotic mucosa was associated with higher OSA-18 scores than edematous mucosa (82.3 vs. 76.8; p = 0.02). Conclusions: ET obstruction grade independently determines audiological and quality-of-life outcomes in pediatric chronic adenoiditis. Mucosal remodeling further amplifies quality-of-life burden in complete obstruction. These findings support routine ET endoscopic grading in pediatric otorhinolaryngology risk stratification. Full article

The study evaluated the conventional extraction (CE), microwave-assisted extraction (MAE), ultrasound-assisted extraction (UAE), and pulsed electric fields-assisted extraction (PEFAE) of bioactive compounds from orange peel waste. The effect of extraction time (0–120 min), ethanol concentration (0, 50 & 80%), and temperature (25–70 °C) were investigated, while response surface methodology (RSM) was applied for each process optimization. MAE achieved the highest total phenolic content (TPC) (6.36 mg/g w.m.) under optimized conditions (50 kJ microwave energy, 50% ethanol, 60 min), representing approximately 12% higher recovery compared to CE (TPC: 5.29 mg/g w.m.; 50 °C, 55% EtOH, 80 min). UAE (90% amplitude, 66.4 W/kg) resulted in the highest flavonoid recovery (0.48 mg/g w.m.) using 50% ethanol at 50 °C for 90 min, while PEFAE (4 kV/cm, 1000 pulses) for 75 min extraction time exhibited the same TPC yield as CE and the highest antioxidant activity (1.12 mg/g w.m.) using only water at room temperature. RSM analysis confirmed that ethanol concentration and extraction time significantly affected extraction performance. These findings demonstrate the potential of green extraction technologies for sustainable valorization of citrus processing waste and recovery of high added-value compounds. Full article

Young forests are recognized as important contributors to climate change mitigation due to their high productivity. However, their structural simplicity and transitional nature render them ecologically vulnerable to long-term climatic stress. We explored the long-term responses of young forests to climate change by applying the LANDIS-II forest landscape model coupled with a PnET-based physiological model to simulate 200 years of forest succession and carbon dynamics. Simulations were conducted under three climate scenarios (BAU, RCP45, and RCP85) to evaluate changes in aboveground biomass (AGB), carbon storage, and carbon absorption across elevation gradients. The results revealed that climate change significantly altered successional pathways and carbon capacity, with effects varying with elevation and initial species composition. Predominant species such as Quercus mongolica maintained dominance under the RCP45 and RCP85 scenarios across all elevations, whereas shade-tolerant mid and understory species showed suppressed growth. Sub-alpine species showed prominent declines in AGB, particularly in the RCP85 scenario. These divergent responses increased the spatial heterogeneity of forest productivity and reduced the predictability of forest carbon dynamics over time. Our findings emphasize the uncertainty of predicting forest development and carbon sequestration in young forests under future climatic conditions. They highlight the urgent need to plan forest management strategies incorporating site-specific ecological characteristics, promote successional advancement, and maintain functional stability for effective climate adaptation and mitigation. Full article