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Coastal reservoirs (CRs) are important water resources worldwide, but environmental problems can arise due to limited material mixing caused by the blocked propagation of tidal waves. The Saemangeum Reservoir is a large brackish reservoir in South Korea; owing to its complex fluctuation characteristics, accurate reproduction of its three-dimensional (3D) circulation and material distribution characteristics remains a challenge. Here, we aimed to improve the reproducibility of the Delft3D model through long-term precision monitoring and analyze problems occurring in CRs. The model reproduced the hydraulic flow and stratification phenomena in CRs. The Richardson number ( $ {\textrm{R}_\textrm{i}} $ R i ) was higher than 100, and the Stratification Index ( $ \textrm{SI} $ SI ) was higher than 1 due to the density difference between the surface and bottom layers. The stratification strength of the Saemangeum Reservoir was, therefore, considered high. Moreover, a two-layer circulation occurred due to the strength of the eddy and the horizontal gradient of salinity. When the sluice gate was expanded, the area and number of days where hypoxia occurred decreased. It would also mitigate the retention of materials caused by the eddy and improve circulation. The findings of this study can be used as foundational data for solving and managing hydraulic problems within CRs. [ABSTRACT FROM AUTHOR]

Phytoplankton, as key primary producers, play a critical role in the dynamics of marine ecosystems. This study explores the variation in phytoplankton species appearance along the Jeju coast from spring to summer 2022, emphasizing the stratification and changes in nutrient dynamics. Through extensive field surveys at twelve points around Jeju Island, we measured a range of physical and chemical oceanographic parameters. Monthly average stratification indices displayed an abrupt increase from 22 in May to 3,196 in August, highlighting intense stratification, significantly influenced by the influx of Changjiang River Diluted Water during the summer months. Concurrently, nutrient concentrations exhibited a downward trend, with nitrate and nitrite levels decreasing from 6.7 µM in March to 1.3 µM in July, and phosphate levels declining from 0.31 µM to 0.02 µM during the same period, while silicate concentrations, ranging from 6.8 to 9.8 µM, remained consistently high throughout the study. Similarly, a reduction in monthly average phytoplankton biomass was observed, with concentrations peaking in the spring (April and May) at 406,053 to 409,139 cells L-1 and declining to 45,546 to 118,214 cells L-1 by summer (June to August). Diatoms (Chaetoceros spp. and Skeletonema spp.) dominated the phytoplankton community throughout the period; however, an increased proportion of dinoflagellates (Gyrodinium spp. and Heterocapsa spp.) was observed during the summer months, when stratification was most pronounced. This study confirms that variations in currents and water masses impacting the Jeju coast can significantly influence phytoplankton community dynamics, emphasizing the need for ongoing monitoring in this region. [ABSTRACT FROM AUTHOR]

Groundwater resources are typically affected by both global climate factors and anthropogenic activities. This influence is most apparent in arid and semi-arid climates of the Saharan desert. With rising temperatures and minimal precipitation, climate variability in these regions has a particularly significant and systemic impact on the chemical composition of shallow aquifer water. In this regard, our study aims to evaluate the climatic effects on groundwater in Saharan environments, using the Ouargla basin as a prime example. Water samples taken from 45 observation piezometers in our selected study area in February and June 2021 were used to assess the overall impact of inter-annual climate variations on salinity within this shallow groundwater basin. The obtained results show that groundwater located in the first three meters of shallow aquifer depth is directly influenced by surface climate. This pattern holds true for both observed seasonal periods. Stratification indices within the saturated zone were found to be positive, indicating an increase in groundwater salinity at lower depths and negative in shallower depths. This suggests a direct climate influence on this groundwater. These findings can be used to enhance sustainable development strategies in such environments, notably by quantifying salt accumulation and efficiently managing salinity exchange between saturated and vadose horizons.

Groundwater resources are typically affected by both global climate factors and anthropogenic activities. This influence is most apparent in arid and semi-arid climates of the Saharan desert. With rising temperatures and minimal precipitation, climate variability in these regions has a particularly significant and systemic impact on the chemical composition of shallow aquifer water. In this regard, our study aims to evaluate the climatic effects on groundwater in Saharan environments, using the Ouargla basin as a prime example. Water samples taken from 45 observation piezometers in our selected study area in February and June 2021 were used to assess the overall impact of inter-annual climate variations on salinity within this shallow groundwater basin. The obtained results show that groundwater located in the first three meters of shallow aquifer depth is directly influenced by surface climate. This pattern holds true for both observed seasonal periods. Stratification indices within the saturated zone were found to be positive, indicating an increase in groundwater salinity at lower depths and negative in shallower depths. This suggests a direct climate influence on this groundwater. These findings can be used to enhance sustainable development strategies in such environments, notably by quantifying salt accumulation and efficiently managing salinity exchange between saturated and vadose horizons. [ABSTRACT FROM AUTHOR]

Background: Adjuvant chemotherapy has been shown to produce a favorable prognosis for patients with resectable mucosal melanoma (MM), resulting in the need for stratification to optimally select patients to benefit from adjuvant therapy. This study analyzed Ki67 as a potential stratification index for adjuvant chemotherapy in resectable MM. Methods: Patients with resected MM who received subsequent adjuvant therapy in Beijing Cancer Hospital between 2010 and 2018 were retrospectively enrolled and analyzed. Relapse-free survival (RFS) and melanoma-specific survival (MSS) curves were used to perform the survival comparisons across different subgroups. Results: From Jan 2010 to Dec 2018, 1106 MM patients were screened from a database of 4706 patients and 175 of these patients were finally enrolled. A total of 100 patients received temozolomide (TMZ)-based adjuvant chemotherapy and 75 patients received high-dose interferon-α2b (HDI) adjuvant therapy. Compared with HDI, patients who received TMZ-based adjuvant chemotherapy had significantly superior RFS (21.0 vs. 9.6 months, P = 0.002). For patients with low Ki67 expression (<30%), the two regimens showed no significant difference for impact on RFS (33.9 vs. 22.7 months, P = 0.329). However, for patients with high Ki67 expression (≥30%), TMZ-based adjuvant chemotherapy achieved favorable RFS compared with HDI (18.0 vs. 6.7 months, P < 0.001) and tended to improve MSS compared to HDI (41.4 vs. 25.1 months, P = 0.067). Conclusion: Compared with HDI, adjuvant chemotherapy may be more relevant for patients with Ki67 ≥ 30%. Ki67 may serve as a potential index to distinguish populations benefiting from adjuvant chemotherapy in resectable MM, and may provide a basis for stratification in the selection of adjuvant regimens. [ABSTRACT FROM AUTHOR]

Objective: Coronavirus disease 2019 (COVID-19) is a disease with a high rate of progression to critical illness. However, the stratification of patients at risk of mortality is not well defined. In this study, we aimed to define a mortality risk index to allocate patients to the appropriate intensity of care.Methods: This is a 12 months observational longitudinal study designed to develop and validate a pragmatic mortality risk score to stratify COVID-19 patients aged ≥18 years and admitted to hospital between March 2020 and March 2021. Main outcome was in-hospital mortality.Results: 244 patients were included in the study (mortality rate 29.9%). The Covid-19 Assessment for Survival at Admission (CASA) index included seven variables readily available at admission: respiratory rate, troponin, albumin, CKD-EPI, white blood cell count, D-dimer, Pa02/Fi02. The CASA index showed high discrimination for mortality with an AUC of 0.91 (sensitivity 98.6%; specificity 69%) and a better performance compared to SOFA (AUC = 0.76), age (AUC = 0.76) and 4C mortality (AUC = 0.82). The cut-off identified (11.994) for CASA index showed a negative predictive value of 99.16% and a positive predictive value of 57.58%.Conclusions: A quick and readily available index has been identified to help clinicians stratify COVID-19 patients according to the appropriate intensity of care and minimize hospital admission to patients at high risk of mortality.

Given the current degradation problems that Mediterranean soils endure, the implementation of alley cropping in olive orchards has been suggested as a sustainable strategy to increase agricultural productivity and improve carbon storage and soil fertility. Therefore, the objective of this study was to evaluate in the short term (3 years) the effect of alley cropping with minimum tillage versus conventional tillage in a traditional rainfed olive grove on soil organic carbon, total nitrogen concentrations, and stocks. Changes in soil quality through a stratification index, and the success of the 4‰ strategy in these soils with this type of management were also evaluated. Three intercropping strategies were tested: Crocus sativus (D-S), Vicia sativa and Avena sativa in rotation (D-O), and Lavandula x intermedia (D-L), all with minimum tillage versus olive with conventional tillage without intercropping, which was used as a control. Intercropping increased soil organic carbon in topsoil (0–10 cm) by 41.1, 28.5, and 30.5% for D-S, D-O, and D-L, respectively, compared to conventional tillage. At a depth of 10–30 cm, the soil organic carbon and the soil organic carbon stock increased slightly, although significant differences were found only in D-L. In the diversified plots, total nitrogen did not vary. However, total nitrogen increased in olive with conventional tillage due to fertilisation. Concerning soil quality, no significant differences were observed when evaluating the soil carbon and nitrogen stratification index in any of the treatments. However, the implementation of intercropping reached the objectives set by the 4‰ initiative in these soils with an increase in soil carbon per hectare and per year of 80, 87.4, and 86.4% for D-S, D-O, and D-L, respectively. Therefore, based on these results, in the short term, intercropping treatment enhances carbon storage in these soils, effectively achieving the objectives of the 4‰ initiative. [Display omitted] • Soil organic carbon increased due to the effect of intercropping. • N concentration and stock only increase in control plot due to fertilization. • Diversifications did not cause variations in soil quality indexes. • Intercropping affected the achievement of Initiative 4‰ carbon storage targets. • The adoption of intercropping favored the soil's capacity to store carbon. [ABSTRACT FROM AUTHOR]

Literature exhibit a great number of soil quality indices, many of them based on organic carbon and its fractions, for a wide variety of natural and cultivated soils. In four sites located in the argentine Pampa region, the effect of the sequence and intensity of crop rotations on different organic carbon fractions in no-tilled soils, and the sensitivity of some quality indices to management practices were evaluated. At each site, three treatments were identified: two different agricultural scenarios in terms of crop rotation, fertilizers and use of agrochemicals (diversified intensive and regional representative managements, MID and MRR, respectively) and an undisturbed environment, natural (ASD) adjacent to agricultural sites as control treatment. Agricultural management with a high frequency or soybean monoculture caused COT decreases of about 30% in 0-10 cm depth. These decreases mainly affected labile fractions (particulate CO 105-2000 μm and particulate CO 53-105 μm) which decreased by 50% and 40% with respect an ASD field. These situations present the worst values in the most indices including labile fractions. However, the magnitude of the observed changes in these indices were lower in relation to those associated with the COT. The COT stratification index (0-5:5-20 cm) showed differences between treatments, which ranged from 2.0 (ASD) to 1.5 (MRR). The differential carbon input to the soil between treatments was reflected in the carbon pool index (IRC), considering a simple index to measure and sensitive to detect differences between agricultural managements. The results highlight the importance of the COT as universal indicator and the need to take into account local issues either management and/or seasonal, for the interpretation of the indices associated with the most labile fractions. [ABSTRACT FROM AUTHOR]

The effectiveness of high-frequency, high-intensity ultrasound in accelerating mixing phenomena in liquid storage tanks of varying physical dimensions and aspect ratios is experimentally investigated. The accelerated mixing of hot water and cold water in a FRP (Fiber Reinforced Plastic) cylinder was studied for different ultrasonic frequencies (58/192 KHz, 172/192 KHz, 58 KHz and 132 KHz) with 200–500 W power input. To study the kinetics of sono-mixing, the storage tank containing the warm layers of water over the cold water was placed in an ultrasonic tank filled with water. The temperature distribution of the water in the FRP tank was measured using thermocouples. The temperature data collected by the data acquisition system were transmitted to a personal computer which recorded the instantaneous reading. Ultrasonically-enhanced mixing was thus studied. Dual frequency operation, which combines one high-frequency mode with one low-frequency mode, is found to be optimal in enhancing mixing. Mixing efficiency increases with cavitation intensity and the introduction of acoustic streaming augments it further. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this prospective study is to establish the frequency and the type (neoplastic and nonneoplastic) lesions defined endoscopically as flat elevated lesion (FEL) in the colon and rectum, as well as to compare flat adenomas (FAs) to polypoid lesions of the same size with morphometric and immunohistochemical analysis. One hundred nineteen patients were studied through fibrocolonoscopy with chromoscopy (indigo carmine spray). All detected lesions (total of 195) were removed, and FELs measuring 10 mm or smaller were also selected. Using histopathologic criteria, they were divided in neoplastic (adenomas and carcinomas) and nonneoplastic ones. In neoplastic lesions, the following parameters were evaluated to compare FAs with polypoid lesions: morphometric studies with Index of Structural Atypia (ISA) and Stratification Index (SI), evaluation of cellular proliferation with label index of Ki-67, and expression of p53 protein. Of 195 lesions resected, only 33 (17%) met the endoscopic requirements for FELs. Twelve (36.4%) were neoplastic and 21 (63.6%) considered nonneoplastic. Among the FAs, there were a percentage of high-grade (severe dysplasia) significantly more frequent than observed in polypoid lesions (16.7% vs 2.6%). In addition, the SI, Ki-67 label index and p53 positivity were significantly higher in FAs. The ISA also reached significant differences between both groups of adenomas. Non-neoplastic FELs included different entities such as hyperplasic polyps, focuses of colitis, normal mucosa, and scars. The endoscopic elements analyzed were shared between nonneoplastic FELs and FAs. A central depression, when air was properly insufflated, considered typical in neoplastic lesions, was frequently observed in nonneoplastic lesions. Following the endoscopic criteria of FELs, nonneoplastic lesions predominated over the adenomatous lesions, demonstrating that FELs and FAs are not homologous terms. The frequency of high-grade dysplasia was significantly more elevated in the adenomatous FELs than in polypoid adenomas. The ISA, SI, p53 expression, and Ki-67 label index were helpful in differentiating adenomatous FELs from polypoid lesions. Flat elevated lesions selected by endoscopic criteria are, in fact, a heterogeneous population of lesions. [Copyright &y& Elsevier]

Simpson's stratification index φ is widely used in oceanography as an index of vertical stratification. However, the use of φ can be problematic when the tidal amplitude is significant compared to the water depth, since φ fluctuates periodically with the external tide even if the vertical density structure does not change. The stratification potential-energy anomaly V is proportional to the square of the water column thickness D ; therefore, V ∗ = (H / D) 2 V (where H is the mean water depth) is an appropriate standardized stratification index for estuaries and regions of freshwater influence. The usefulness of this index is demonstrated using time series f k = H / D k V k = 0 , 1 , 2 , 3 (f 0 = V , f 1 = H φ , f 2 = V *) and their power spectra as obtained from tower B3 in Isahaya Bay in Japan. Tidal cycle fluctuation is removed most effectively for f 2 (= V ∗). • A new stratification index that does not depend on the tidal level is proposed. • This index is the standardized potential-energy anomaly with respect to water column thickness. • This index is useful in areas where the tidal amplitude is not negligible. [ABSTRACT FROM AUTHOR]

Thermal energy storage systems help to couple thermal energy generation and process demand in cogeneration facilities. One single deposit with two design temperatures and one main temperature step in sensible thermal energy storage define the thermocline systems. Performance of one high size real thermocline thermal energy storage system is analysed. Starting from temperature and mass flow rate data registered by the plant control system, one advanced thermodynamic analysis is performed. The quality of heat storage is analysed in terms of evaluation of the stratification in the thermocline zone. The temperature data registered at 21 positions is extended by displacement analysis generating detailed profiles. Fraction of recoverable heat, thermocline width, stratification indices based on energy and exergy analysis, and mean temperature gradients in the thermocline region are calculated. These parameters are monitored under real operation conditions of the plant. The calculated parameters are studied to check their distribution and correlation. First and Second Law indices show parallel behaviour and two values are found that delimit situations of high and low values of mean temperature gradients. It was observed that buoyancy generates uniform forced movement with the right water temperature entering the diffusers, but good control strategies are essential to avoid mixing. The system demonstrated great stability in this use. [ABSTRACT FROM AUTHOR]