Marine aggregate extraction represents an opportunity to face the depletion of terrestrial aggregate resources. The environmental effects of this activity have been assessed in several studies, leading to the formulation of recommendations to mitigate its effects. This study investigates its environmental impacts in a coarse, high-current environment with low-intensity extraction, a unique scenario not extensively studied before. Employing multivariate analyses and a trophic group approach, it examines complex responses at both species and community levels. Results indicate a decline in biodiversity, promoting the establishment of r-selected species, particularly filter feeders. Although site restoration timelines remain uncertain, initial indications suggest rapid recovery (2-3 years) for this site. The study also discusses methodological challenges in sampling these low-intensity dredged sites and emphasizes the need for new indices tailored to this pressure and coarse sediments under strong hydrodynamics. These insights offer valuable directions for future research.

Owing to increasing anthropogenic impacts, wetlands have suffered a serious environmental decline in recent decades. The sustainable management of these natural resources is fundamental to maintain both the ecosystems and the economic activities. The Lake Massaciuccoli and nearby areas represent one of the largest residual coastal marshy areas in Tuscany (Italy). This wetland is characterized by large-scale and intensive agricultural use and affected by reclamation activities, with consequent problems of erosion, subsidence and lake eutrophication and siltation. In this context, an integrated study combining hydrochemical data (water levels, electrical conductivity, pH, turbidity, major ions, trace metals) and stable isotopes (H, O, S) has been performed in the southernmost part of the basin, to better disentangle processes and interactions between groundwater and surface water and to understand the origin of solutes and their evolution. Our results indicated that both groundwater and surface water have a meteoric origin and that geochemical composition of groundwater is mainly affected by local geological and biological processes. Moreover, surface water is affected by sea water mixing and evapotranspiration/precipitation processes. The impact of agricultural activity and the use of fertilizers on the water quality appears to be limited as regards nitrates, indicating that less intense agricultural practices implemented in recent years have been successful. As regards sulfates, Fe, and Mn, we cannot fully elucidate the mechanisms underlying human influence, but the oscillation of water level and degradation of peat enhanced by reclamation and agriculture activities likely played an important role in controlling the fate of these elements. Overall, these results underline the importance of integrated approaches to disentangle geochemical processes and will be useful in supporting policy implementation and environmental protection in this valuable area of Tuscany. Findings from this work suggest the need for policy-making authorities to take actions as soon as possible to mitigate risks. Closer co-operation is essential between authorities and farmers to reduce inputs of fertilizers and chemicals into the lake and the surrounding area. Also, additional policy measures should be enforced to reduce the mechanical soil tillage and limit erosion and runoff, such as the NBSs implemented within the Phusicos Project.

OBJECTIVE: Drug inhalation is generally accepted as the preferred administration method for treating respiratory diseases. To achieve effective inhaled drug delivery for an individual, it is necessary to use an interdisciplinary approach that can cope with inter-individual differences. The paper aims to present an individualised pulmonary drug deposition model based on Computational Fluid and Particle Dynamics simulations within a time frame acceptable for clinical use.
METHODS: We propose a model that can analyse the inhaled drug delivery efficiency based on the patient\'s airway geometry as well as breathing pattern, which has the potential to also serve as a tool for a sub-regional diagnosis of respiratory diseases. The particle properties and size distribution are taken for the case of drug inhalation by using nebulisers, as they are independent of the patient\'s breathing pattern. Finally, the inhaled drug doses that reach the deep airways of different lobe regions of the patient are studied.
RESULTS: The numerical accuracy of the proposed model is verified by comparison with experimental results. The difference in total drug deposition fractions between the simulation and experimental results is smaller than 4.44% and 1.43% for flow rates of 60 l/min and 15 l/min, respectively. A case study involving a COVID-19 patient is conducted to illustrate the potential clinical use of the model. The study analyses the drug deposition fractions in relation to the breathing pattern, aerosol size distribution, and different lobe regions.
CONCLUSIONS: The entire process of the proposed model can be completed within 48 h, allowing an evaluation of the deposition of the inhaled drug in an individual patient\'s lung within a time frame acceptable for clinical use. Achieving a 48-hour time window for a single evaluation of patient-specific drug delivery enables the physician to monitor the patient\'s changing conditions and potentially adjust the drug administration accordingly. Furthermore, we show that the proposed methodology also offers a possibility to be extended to a detection approach for some respiratory diseases.

OBJECTIVE: Tortuosity of the internal carotid artery (ICA) is associated with intracranial aneurysms (IAs). The siphon is the most curved segment of the ICA, but its morphology has controversial effects on IAs. This study aimed to explore the morphometric features of the siphon and the potential hemodynamic mechanisms that may affect C7 aneurysm formation.
METHODS: In this study 32 patients with C7 aneurysms diagnosed at Xiangya Hospital between 2019 and 2021 and 32 control subjects were enrolled after propensity score matching. Computed tomography angiography (CTA) images were acquired to measure morphologic features, and then, by combining clinical data, simplified carotid siphon models were constructed, and computational fluid dynamics (CFD) analysis was performed.
RESULTS: The presence of C7 aneurysms was associated with the height of the C4-C6 curved arteries (odds ratio [OR] 0.028, 95% confidence interval [CI] 0.003-0.201; P < 0.001). The heights of the C4-C6 curved arteries in the aneurysm group were significantly shorter than those in the control group. The CFD analysis revealed that shorter C4-C6 bends led to greater blood velocity and pressure in the C7 segment arteries.
CONCLUSIONS: A shorter C4-C6 bend was associated with distal C7 aneurysm formation, and an elaborate hemodynamic mechanism may underlie this association.

Deep learning techniques have offered innovative and efficient tools for accurate and automated detection of sewer defects by leveraging large-scale sewer data and advanced feature learning algorithms. However, there has been a lack of thorough characterization of the geometric properties of segmented defects, let alone systematically calculate the severity level of sewer defects and quantitatively evaluate their impacts on flood conditions in hydrodynamic models. This study proposed a comprehensive framework and related metrics to accurately and automatically detect, segment, characterize, and evaluate the impacts of sewer defects on flooded nodes and volumes by integrating a DeepLabv3+-based segmentation technique, an automated geometric characterization and severity quantification module, and a GIS and SWMM-based hydrodynamic modeling. The results clearly showed in details where and how much the urban flooding was affected by the different defect types. The segmentation model achieved satisfactory detection performance, with mean pixel accuracy (MPA), mean intersection over union (MIoU), and frequency weighted intersection over union (FWIoU) of 0.99, 0.74 and 0.95, respectively. In terms of severity level quantification, there were 98%, 90%, 90% and 83% of predictions consistent with real conditions for falling off, obstacle, disjoint and leakage. It was shown that the number of surcharging manholes and total flood volume (TFV) were greatly affected by sewer defects, with over 16% increase in TFVs under all investigated rainfall events. The results addressed the impacts of sewer defects on urban flooding and demonstrated the powerful tools provided by the proposed framework for decision-making on sewer defect detection and management.

The construction of fish passage facilities can mitigate the negative effects of dams and other water engineering construction on river connectivity and have a significant positive effect on the conservation of local fish diversity. To attract target fishes into fish passage facilities effectively, the optimal flow velocity range to attract fish must be determined. Three local endemic species of the Mishi Reservoir were considered as the protection targets. However, their swimming abilities remain unclear. Therefore, the induced swimming speed (Uind), critical swimming speed (Ucrit) and burst swimming speed (Uburst) of three fish species were tested. Based on these results, we identified the optimal flow velocity to attract fish, which falls within the range of 0.15-0.51 m/s. A validated three-dimensional hydrodynamic model was used to simulate different schemes. By comparing the flow field simulation results of different schemes, we obtained the optimal measure to restore the flow field, namely, a multiple engineering measure combining increased the fish attraction flow in the fish collection pond and the construction of a spur dike. This study offers a solution for the specific case and enhances the database of swimming characteristics of endemic fish in the upstream reaches of the Yangtze River. It also provides a valuable reference for designing fish-attracting flows and potential measures for restoring flow fields in similar future projects.

Hemodynamic mechanisms of the formation and growth of intracranial aneurysms (IA) in monozygotic twins (MTs) are still under-reported. To partially fill such knowledge gap, this study employed an experimentally validated numerical model to compare hemodynamics in 3 anatomical and 5 ablation study neurovascular models from a rare pair of MTs in terms of 7 critical hemodynamic parameters. Numerical results showed significant differences in hemodynamics between the MTs, although they share the same genes, indicating that genetic mutation and environmental factors might affect neurovascular morphologies and cause hemodynamic changes. After virtual removals of IAs in the ablation study, the locations where the aneurysmal sac/bleb generated in bifurcated anterior cerebral arteries (ACAs) register a locally high instantaneous wall shear stress (IWSS) of 52.9 and 70.1 Pa at the systolic peak in twin A and twin B, respectively. Same scenario can be observed in the distribution of instantaneous wall shear stress gradient (IWSSG), with 571.1 Pa/mm for twin A and 301.3 Pa/mm for twin B due to aggressive blood impingements, leading to IA generation. The fenestrated complex approaching ACA bifurcations in twin A may assist IA growth and rupture, via. Causing abnormal IWSS of 116.3 Pa, IWSSG of 832.5 Pa/mm, and oscillatory shear index (OSI) of 0.49. The bleb in twin B has high risks of progression and possible rupture as the IA suffers relatively low IWSS and high OSI. Additionally, IA generation can change blood flow rates in each connected artery, then affecting blood supplies to associated tissues and organs.

With the development of the city, people pay more attention to the ecological construction of the city. The objective of this work was to study the effect of artificial lakes on hydrodynamic conditions in urban drainage systems. With Arcgis and the advantage of SWMM in analyzing the impact of the rainfall process on urban runoff, the urban flooding model of \"pipe network + river network + artificial lake\" was established in the study area. Two scenarios were set up with and without the presence of artificial lakes, and comparative analyses were conducted under the different intensities of rainfall (0.5a, 1a, 2a, 5a, 10a, 20a). The results show that under certain rainfall conditions, the presence of the artificial lake increases the peak flow and rate of upstream streams and decreases the flow and rate of downstream streams in the regional drainage system. The duration of the peak flow rate in the upstream channel increases, and the flow rate curve becomes flat during the confluence; the flow rate in the downstream section decreases, and the magnitude of the peak flow rate change decreases, and a more obvious horizontal section appears. The time of peak occurrence in the downstream river is earlier. The hydrodynamic impact on the downstream channel is more significant. The improvement of hydrodynamic conditions of the drainage system by the artificial lake helps to optimize the layout of low impact development (LID) measures in the study area and also guides ecological construction in other cities.

Tailings are one of the largest pollutant sources in the world. The wind and water leaching were often considered the main distribution tool of their pollutants. However, the carbonate crust precipitation has negated the trace toxic element (TTE) release. To identify the release mode of Pb, Zn, and Cd from mine wastes, the hydrodynamic evolution of waste piles was considered. The macroscopic and microscopic observation, the grain sizes, cohesion particles, density, hydraulic conductivity, and Pb, Zn, and Cd concentrations performed from eight drill cores of the two waste dumps and the principal component and the hierarchical cluster analysis showed that the physical properties of waste piles closely controlled the TTE mobility and migration from the tailings. The obtained data also showed that the upper carbonate layers were first eroded by wind and rainfall. Then, the formation of an impermeable carbonate crust limited the Pb, Zn, and Cd releases. However, the hydrodynamic evolution of the underneath layers was different. As the high pile waste sediments\' weight meaning the lithostatic pressure (Pl), the geostatic ratios (λ = Pf/Pl) were in DII and DIII dumps superior to 0.29 and 0.26, respectively. Therefore, the overpressured fluids increased the mineral dissolution, including the sulfides and carbonates of metals, and hydraulic fracturing that raised the percentages of the mobile TTE and migration indexes. By the secondary pore and fracture volumes, the polluted fluids were progressively channeled towards the underpressured marge (dumps edge) by repetitive (polyphase) fluid pulsations.

Glacier-associated hazards are becoming a common and serious challenge to the high mountainous regions of the world. Glacial lake outburst floods (GLOFs) are one of the most serious unanticipated glacier hazards, with the potential to release a huge amount of water and debris in a short span of time, resulting in the loss of lives, property, and severe damage to downstream valleys. The present study used multi-temporal Landsat and Google earth imageries to analyze the spatio-temporal dynamism of the selected glacial lake (moraine-dammed) in the Satluj basin of Western Himalayas. Furthermore, GLOF susceptibility of the lake was assessed using a multi-criteria decision-based method. The results show that the lake area has increased from 0.11 to 0.26 km2 over the past 28 years from 1990 to 2018. The susceptibility index value for the lake was calculated as 0.75, which indicates that the lake is highly susceptible to the GLOF. The depth and volume of the lake were estimated to be 16 m and 57 × 105 m3, respectively, using an empirical formula. HEC-RAS, HECGeo-RAS, and Arc-GIS software were utilized in this study to perform unsteady flow analysis and to determine the GLOF impact on the downstream area. The worst-case GLOF scenario (breach width of 75 m) was revealed during an overtopping failure of the moraine dam, resulted in a peak discharge of 4060 m3/s and releasing a total water volume of 57 × 105 m3. The breach hydrograph has been routed to calculate the spatial and temporal distribution of peak flood, inundation depth, velocity, water surface elevation, and flood peak arrival time along the river channel. The analysis further reveals that the routed flood waves reach the nearest settlement, i.e., Rajpur town, situated at a distance of 102 km in the downstream valley of the lake at 6 h after the beginning of the lake breach event with a peak discharge/flood of 1757 m3/s and maximum flow velocity of 1.5 m/s. With the ongoing climate warming and glacier retreat, moraine-dammed lakes are becoming more hazardous and thus increasing the total threat. Therefore, it is mandatory to monitor and assess such lakes at regular intervals of time to lessen the disastrous impacts of GLOFs on the livelihood and infrastructure in the downstream valleys. The findings of this study will aid in the creation of risk management plans, preparatory tactics, and risk reduction techniques for GLOF hazards in the region.