Transport Patterns Research Articles

Paradoxes in magnesium transport in type 1 Bartter's syndrome and Gitelman's syndrome: a modeling analysis.

Type 1 Bartter's syndrome and Gitelman's syndrome are characterized by mutations in two key renal Na+ transporters, Na-K-2Cl cotransporter (NKCC2) and Na-Cl cotransporter (NCC). Since these two transporters play an important role in regulating magnesium (Mg2+) and calcium (Ca2+) transport in the kidney, significant alterations in the transport of these two electrolytes are observed in type 1 Bartter's syndrome and Gitelman's syndrome. In this study, we used our sex-specific computational models of renal electrolyte transport in rats to understand the complex compensatory mechanisms, in terms of alterations in tubular dimensions and ion transporter activities, that lead to Mg2+ and Ca2+ preservation or wasting in these two genetic disorders. Given the sexual dimorphism in renal transporter patterns, we also assessed how the magnitude of these alterations may differ between males and females. Model simulations showed that in type 1 Bartter's syndrome, nephron adaptations prevent salt wasting and favor Mg2+ preservation but not Ca2+, whereas in Gitelman's syndrome, those adaptations favor Ca2+ preservation over Mg2+. In addition, our models predicted that the compensatory alterations in tubular dimensions and ion transporter activities are stronger in females than in males.NEW & NOTEWORTHY Although changes in Ca2+ excretion in type 1 Bartter's syndrome and Gitelman's syndrome are well understood, Mg2+ excretion displays an interesting paradox. This computational modeling study provides insights into how renal adaptations in these two disorders impact Ca2+ and Mg2+ transport along different nephron segments. Model simulations showed that nephron adaptations favor Mg2+ preservation over Ca2+ in Bartter's syndrome and Ca2+ preservation over Mg2+ in Gitelman's syndrome and are stronger in females than in males.

Good for the planet… and for you too? Comparing five travel and health-related outcomes among active, motorized, and public transport commuters

Aligned with sustainable development goals, the promotion of active and public transport commuting has gained ground in the last decade. However, literature empirically addressing the individual outcomes of different commuting modes remains scarce. AimThe core aim of this research was to assess and compare a literature-based set of travel, health, and welfare-related outcomes among three different groups of urban daily commuters: private motorized, public transport, and active commuters. MethodsThis cross-sectional study used a nationwide sample of n= 2370 urban daily commuters from all 17 regions of Spain. Participants, aged between 18 and 70, with an average of M= 33 years, were drawn from all 17 regions of Spain, and responded to an electronic survey on commuting issues. ResultsAs hypothesized, different groups of commuters had different psychosocial trip- and welfare-related outcomes. Indeed, most indicators, except for travel satisfaction, showed a favorable association with the sustainability value attributed to each commuting means. Particularly, active travelers had significantly lower commuting stress and Body Mass Index (BMI) values, and higher rates of life satisfaction and pro-environmental behavior in areas beyond transport, in stark contrast to private motorized users. Public transport users, although ‘in the middle’ in most aspects, report the highest commuter stress rates. ConclusionThe results of this research endorse the assumption that the commuting mode matters, but the relationship between transport sustainability and user outcomes cannot be understood as ‘totally linear’. These insights can be valuable for initiatives aimed at promoting shifts towards more sustainable –and active– transportation patterns among commuters, who constitute an interest group in current mobility planning and decision-making.

Integrated Modeling of Flow, Soil Erosion, and Nutrient Dynamics in a Regional Watershed: Assessing Natural and Human‐Induced Impacts

AbstractCurrent integrated modeling frameworks for simulating nutrient sources and dynamics are inadequate for large regional watersheds dominated by groundwater‐surface water interactions due to their simplistic representations of groundwater. In this study, we develop a coupled model that integrates comprehensive surface water, 3‐D groundwater, soil erosion, and nutrient processes. The model is intended to enhance the understanding of nutrient dynamics and sources in the Pearl River Basin (PRB). The model exhibits satisfactory performance in simulating streamflow and sediment transport patterns, capturing essential seasonal variations in water quality indicators. Hydrological budget assessments from 2002 to 2020 in the PRB reveal that 54% of precipitation drains into the South China Sea as surface water, while groundwater discharge as baseflow accounts for 18% of the streamflow. The nutrient budget for the PRB indicates that non‐point sources are the dominant contributors to both nitrogen (N) and phosphorus (P), ranging between 64% and 90%. Improved sewage collection and treatment have reduced point source nutrient contributions over the evaluation period. Groundwater remains a significant and consistent source of N, contributing between 11% and 19%. Natural disturbances and fertilization have led to an upward trend in river N inputs, while afforestation and sewage reduction efforts have resulted in a downward trend in river P inputs. Increased fertilization emerges as a central concern for the PRB, suggesting cost‐effective mitigation of fertilizer usage a pragmatic solution. The coupled simulation model developed in this study offers a novel systems approach for basin‐wide nutrient analysis and pollution control strategies, considering both natural and human‐induced disturbances.

Occurrence and risks of PPCPs of a typical mountainous region: Implications for sustainable urban water systems

Urban wastewater treatment plants (WWTPs) and drinking water treatment plants (DWTPs) play vital roles in the urban water cycle, ensuring access to safe drinking water and maintaining aquatic ecosystems. This study comprehensively assessed the occurrence and risks of pharmaceuticals and personal care products (PPCPs) in urban WWTPs and DWTPs. Our findings revealed widespread PPCPs presence, with concentrations ranging from <1 ng/L to several thousand ng/L. Significant regional disparities in occurrence and composition were observed linked to population types and economic structures. Furthermore, strong correlations were observed between DWTPs and WWTPs indicating consistent transport and transformation patterns of PPCPs within the urban water cycle. Approximately two-thirds of PPCPs were degraded post-WWTP treatment, with about one-tenth persisting in drinking water following surface water dilution and purification processes. Thus, we suggested that controlling the total concentration of the five priority PPCPs in the effluent from the WWTP to <1100 ng/L have potential to reduce the environmental and health risk of PPCPs. Additionally, this research identified influential water quality parameters, such as pH, dissolved oxygen, and temperature, through redundancy analysis. This research underscores the importance of establishing emission standards to mitigate PPCP-related risks and supports sustainable urban water system advancement.

Cascading consequences of structural interventions in a tropical wandering gravel‐bed river

AbstractRiverscapes are often modified and managed through ‘command and control’ structural engineering approaches. These structures not only alter flow and sediment transport patterns but also negatively affect riverscape biodiversity. These impacts are particularly acute for rivers that are characterised by high mobility and wide flow distribution during extreme events. We used hydrodynamic and geomorphological change assessment to appraise the impacts of existing flood structures and their potential for removal in a tropical wandering gravel‐bed river in the Philippines. Our approach informs a systematic decision‐making process to screen opportunities for channel reconnection. Two‐dimensional hydraulic modelling showed flood structures confine flood water within the active channel for more frequent flood events, but banks are overtopped during larger magnitude events (&gt;50‐year recurrence interval). Incorporating modelling results, a multi‐criteria analysis was developed to appraise opportunities for river reconnection based on structure purpose, functionality, and local land‐use. We differentiate among four actions for each structure: removal, redesign, set back, or retention. One structure is recommended for removal because it cuts off an anabranch, reduces channel capacity, and increases main anabranch bed shear stress. Increased potential for bed and bank erosion due to the structure's presence had a cascading effect, resulting in further interventions downstream and on the opposite bank. We show how the use of system‐scale two‐dimensional hydraulic modelling alongside high‐resolution topographic mapping can support management of interventions to reconnect a river to its wider anabranch‐bar morphology. Such actions form part of proactive, adaptive, and nature‐based flood management plans with local and non‐local benefits.

The new region demarcation framework for implementing the joint prevention and control of groundwater pollution: A case study in western of Bohai Bay, China

The joint groundwater pollution prevention and control (GPPC) strategy has been extensively implemented to address the coastal region groundwater pollution challenges in China. However, regional groundwater pollution control and treatment efficiency cannot achieve the expected results due to the lack of regional priority control orders and accurate restoration levels. Thus, this study developed a new region demarcation framework method for delineating GPPC zones, in tandem with a comprehensive pollution index method, the DRASTIC model, source apportionment. To validate the new methodological framework, a case study of groundwater pollution in Qinhuangdao, the western of Bohai Bay, China, was implemented to calculate pollution prevention and control zoning. In total, 340 groundwater samples from shallow aquifers with 9 target pollutants (NO3-, NO2-, NH4+, As, Cd, Cr, Cu, Pb, and Ni) were selected as the dataset for GPPC regionalization. The results showed that GPPC zoning further clarified the direction of groundwater pollution protection and management in Qinhuangdao. Compared to the traditional method, the new GPPC zoning better reflects groundwater mobility characteristics and pollution transport and enrichment patterns in terms of groundwater functional integrity and delineation. This new regional demarcation framework method contributes to providing support for the fine division of groundwater pollution zoning and precise pollution control for groundwater resource management in China.

Interpretation of Soil Characteristics and Preferential Water Flow in Different Forest Covers of Karst Areas of China

Soil hydrology seriously affects the prevention of desertification in karst areas. However, water infiltration in the different soil layers of secondary forests and artificial forests in karst areas remains uncertain. This lack of clarity is also the factor that constrains local vegetation restoration. Therefore, monitoring and simulating the priority transport of soil moisture will help us understand the shallow soil moisture transport patterns after artificial vegetation restoration in the local area, providing a reference for more scientific restoration of the ecological environment and enhancement of carbon storage in karst areas. The integration of soil physical property assessments, computed tomography (CT) scanning, dye tracing studies, and HYDRUS-2D modeling was utilized to evaluate and contrast the attributes of soil macropores and the phenomenon of preferential flow across various forestland categories. This approach allowed for a comprehensive analysis of how the soil structure and water movement are influenced by different forest ecosystems and infiltration head simulations (5 mm, 15 mm, 35 mm, and 55 mm) to elucidate the dynamics of water movement across diverse soil types within karst regions, to identify the causes of water leakage due to preferential flow in secondary forests, and to understand the mechanisms of water conservation and reduction in artificial forests adopting a multifaceted approach. This study demonstrated that (1) the soil hydrological capacity of a plantation forest was 20% higher than a natural forest, which may be promoted by the clay content and distribution. (2) Afforestation-enhanced soils in karst regions demonstrate a significant capacity to mitigate the loss of clay particles during episodes of preferential flow and then improve the soil erosion resistance by about 5 times, which can effectively control desertification in karst area. (3) The uniform distribution of macropores in plantation forest soil was conducive to prevent water leakage more effectively than the secondary forest but was incapable of hindering the occurrence of preferential flow. The secondary forest had a very developed preferential flow phenomenon, and soil clay deposition occurred with an increase in depth. (4) Moreover, the results for preferential flow showed that the matrix flow depth did not increase with the increase in water quantity. Short-term and high-intensity heavy rainfall events facilitated the occurrence of preferential flow. Infiltration along the horizontal and vertical directions occurred simultaneously. These results could facilitate a further understanding of the contribution of the plantation to soil amelioration and the prevention of desertification in karst areas, and provide some suggestions for the sustainable development of forestry in karst areas where plantation restoration is an important ingredient.

Beyond Large-Shaped Tools: Technological Innovations and Continuities at the Late Early Pleistocene Assemblage of El Barranc de la Boella (Tarragona, Spain)

The emergence of the mode 2 technocomplex, traditionally characterized by the development of large cutting tools (LCTs) or standardized large-shaped tools, has also implied a range of new technological behaviours. These include enhanced raw material management, more sophisticated knapping strategies, and transport patterns, among other innovations. Unit II of the localities of La Mina, El Forn, and Pit 1 in El Barranc de la Boella (Tarragona, Spain) — dating back to between 0.99–0.78 million years ago — contains the oldest mode 2 assemblages in the European subcontinent and represents an exceptional opportunity to examine the technological features associated with the appearance of LCTs in Europe and to provide clues to shed light to different hypotheses about their appearance. The presence of functionally diverse but environmentally similar localities enables a study of behavioural flexibility and technological variation, marking a critical contribution to understanding early human technological evolution. Our research focuses on the technological behaviours of hominins in unit II of Pit 1, La Mina, and El Forn at Barranc de la Boella, examining five keys technological aspects such as (1) raw material management, (2) core reduction sequences, (3) reduction intensity, (4) large flake production, and (5) the spatiotemporal integrity of reduction sequences. We compare these behaviours with those observed in mode 1 (~ 1.8–0.9 Ma) and early Middle Pleistocene (~ 0.78–0.6 Ma) assemblages across western Europe. Our findings reveal significant advancements and anticipatory behaviours at El Barranc de la Boella, such as the use of procedural templates for core reduction strategies and the production of large-shaped tools governed by principles of gestural economy, and also the existence of different reduction sequences in different raw materials according to specific purposes. The technological behaviours observed at El Barranc de la Boella seem to be more indicative of population dispersals rather than local evolutionary developments from mode 1 technologies. The non-linear evolution of core knapping strategies, along with the variability in large-shaped tool types, suggests multiple waves of hominin dispersals into Europe during this crucial period. We propose that El Barranc de la Boella may represent an early dispersal of the Acheulean from Africa around 1.4 million years ago, potentially connected to assemblages such as ‘Ubeidiya. This study underscores the complexity of lithic technology during this period and contributes significantly to our understanding of the complex emergence and adoption of new technological behaviours in European early mode 2 assemblages, extending beyond the mere appearance of LCTs.

Influence of cascade reservoirs on the distribution, transport, and retention patterns of biogenic elements in the Jinsha River

Cascade reservoirs construction can greatly alter flow regime and sediment transport of rivers, further affecting migration and transformation processes of biogenic elements. The Jinsha River (JSR) is the China's largest hydropower base and the main runoff, sediment suspension, and nutrient source areas of the Yangtze River. However, the distribution, transport, and retention patterns of biogenic elements in the JSR are still unclear under the influence of cascade reservoirs. Therefore, monthly concentration monitoring work was conducted from November 2021 to October 2023 for various forms of carbon (C), nitrogen (N), phosphorus (P), and silicon (Si). Results showed that the concentrations and fluxes of total phosphorus (TP) and particulate phosphorus (PP) exhibited continuous decreasing trends along the reservoirs cascade, whereas N exhibited contrasting trends. The concentrations of dissolved total carbon (DTC), dissolved inorganic carbon (DIC), and total silicon also showed decreasing trends from upstream to downstream, whereas their fluxes were primarily influenced by runoff and exhibited upward fluctuations. Compared with other biogenic elements, there was a more pronounced retention effect on TP and PP by reservoirs, with average retention rates of 8.29 % and 16.01 %, respectively. Longer hydraulic retention time (HRT) can retain more TP and PP. Meanwhile, the retention rates of DTC, DIC, and particulate silicon were positively correlated with HRT, while the retention rate of dissolved silicon (DSi) showed a positive correlation with reservoir age. Moreover, the higher ratios of dissolved inorganic nitrogen to dissolved inorganic phosphorus (DIP) and DSi to DIP have occurred, resulting in apparent P limitation, particularly during the non-flood season due to lower DIP concentration. Overall, cascade reservoirs construction exists great influences on the spatial allocation, fluxes transport, and biogeochemical cycles of biogenic elements, potentially affecting the stability of rivers ecosystem along the food chain network.

The integration of diel vertical migration and hydrodynamic process influences the transport of swimming crab zoea (Portunus trituberculatus)

AbstractVertical migration and dispersal processes during the marine crab larval stage markedly affect transport, habitat selection, population connectivity, and resource replenishment success rates. However, not much is known of the reproductive ecology of swimming crabs in the nearshore waters of the northwest Pacific shelf. Here, we investigated the diel vertical migration (DVM) characteristics and transport patterns of the swimming crab zoea (Portunus trituberculatus) in this area. A Lagrangian particle‐tracking algorithm coupled with a hydrodynamic model, incorporating a DVM pattern of zoeae based on observations from a field survey of the diurnal distribution of swimming crab zoea, was used to simulate the transport of zoeae, and the impact of zoeal transport on population connectivity was explored. The results revealed that particles were predominantly transported in a nearshore direction from the particle release point, with short dispersal distances during the zoeal stages. In nearshore waters on the continental shelf, the swimming crab zoeae are exposed to shoreward‐moving currents with the aid of prolonged daytime locations in the lower water column, whereas larvae migrate upward to the middle and upper layers of the water column at night rather than the most superficial layer, potentially avoiding surface offshore‐moving currents that may be responsible for the retention and shoreward transport of larvae. Most zoeae are transported to shallow waters, and the contribution of transport to population connectivity during the zoeal stages is relatively limited. The findings here have considerable implications for understanding the mechanisms governing the early recruitment dynamics of this species, as well as for fisheries management and conservation of marine biodiversity.

EMS Bypass to Endovascular Stroke Centers is Associated with Shorter Time to Thrombolysis and Thrombectomy for LVO Stroke

Objectives Large vessel occlusion (LVO) strokes may be eligible for treatment with intravenous thrombolysis (IVT) and endovascular therapy (EVT). Patients selected for treatment have better neurologic outcomes with EVT, and delays in this therapy lead to worse outcomes. However, EVT is offered at a limited number of hospitals, referred to as endovascular stroke centers (ESC). This poses a difficult decision for EMS: to take potential stroke patients to the closest primary stroke center (PSC) or longer transport time to a more distant ESC. We hypothesized that patients with LVO stroke undergoing EVT transported directly to an ESC would have more favorable outcomes as measured by the modified Rankin scale (mRS) at 90 days, compared to transport to a PSC followed by transfer to an ESC. Methods The OPUS-REACH consortium examined transportation patterns and outcomes in patients with LVO stroke who received endovascular treatment. This cohort includes 2400 patients with LVO stroke throughout eight endovascular centers in the Northeast U.S. from 2015 to 2020. All patients enrolled in the OPUS-REACH database were eligible for inclusion. Patients were excluded if they were missing the pickup address, had an in-hospital stroke, or arrived via mobile stroke unit. The remaining patients were separated into two groups: the bypass group, with transportation by EMS to an ESC by bypassing PSC, and the non-bypass group, with initial transport to PSC and interfacility transport to an ESC. The primary outcome was the modified Rankin scale (mRS) at 90 days, where 0–2 was defined as “good”. Results The primary outcome did not reach significance with 40% of the bypass group as compared with the 33.1% of the non-bypass group having a “good” outcome. However, the bypass group underwent shorter times from last-known-well to both thrombolysis (120.9 vs 153.3 min, p < 0.001) and thrombectomy (356.1 vs 454.8 min, p = 0.001). Conclusions In patients with LVO stroke who undergo thrombectomy, EMS transport directly to an ESC results in shorter time thrombectomy, although we did not observe a difference in 90-day functional outcomes. Additionally, bypass to reach a more capable endovascular stroke center does not delay administration of IVT from time of LKW.

Scaling traffic variables from sensors sample to the entire city at high spatiotemporal resolution with machine learning: applications to the Paris megacity

Abstract Road transportation accounts for up to 35% of carbon dioxide and 49% of nitrogen oxides emissions in the Paris region. However, estimates of city traffic patterns are often incomplete and of coarse spatio-temporal resolution, even where extensive networks of sensors exist. This study uses a machine learning approach to analyze data from 2086 magnetic road sensors across Paris, generating a detailed dataset of hourly traffic flow and road occupancy covering 6846 road segments from 2018 to 2022. Our model captures flow and occupancy with a Symmetric Mean Absolute Percentage Error of 37% and 54% respectively, providing high-resolution insights into traffic patterns. These insights allow for the creation of a comprehensive map of hourly transportation patterns in Paris, offering a robust framework for assessing traffic variables for each significant road link in the city. The model's ability to incorporate an emission factor based on the mean speed of the vehicle fleet, derived from flow and occupancy data, holds promise for developing a detailed CO2 and pollutant inventory. This methodology is not limited to Paris; it can be applied to other urban centers with similar data availability, highlighting its potential as a versatile tool for sustainable urban monitoring.

Death at the water hole: Opportunistic hunting and scavenging events in the upper sequence of Middle Paleolithic Nesher Ramla, Israel

Distinguishing between selective and opportunistic hunting is a major challenge in Paleolithic archaeology, requiring the comparison of the human hunting record to the usually unknown natural prey abundance. Open-air hunting camps are ubiquitous in the Eurasian Middle Paleolithic (MP) record, alongside cave sites, and are often dominated by large-bodied species. In the Levant, MP faunal records differ between caves and open-air sites: Caves are dominated by mountain gazelle and fallow deer, while open-air sites are more aurochs-dominated. This discrepancy can be explained by transport patterns, but whether the abundance of aurochs in open-air sites is due to deliberate targeting or natural abundance in the landscape is unclear. The Nesher Ramla open-air site is a natural sinkhole in central Israel with an 8-m-deep MP sequence. Detailed zooarchaeological, dental wear, and isotope analyses of the upper sequence fauna found a highly diverse assemblage dominated by medium-sized ungulates in the uppermost phases (Units I and IIa). Results concerning ungulate dietary niches and isotopic signatures demonstrate that animals from different biomes and topographies congregated at the site. Evidence of human butchery is infrequent and fewer than carnivore modifications. Several articulated vertebral columns attest to in situ preservation. Our results demonstrate that the Nesher Ramla's uppermost sequence formed primarily under natural conditions, suggesting that it was a site of opportunistic hunting by humans and carnivores, probably targeting ungulates that came to the sinkhole to drink. Therefore, we consider this assemblage representative of the site's “natural” environment and use it as a benchmark for comparing assemblages and hunting strategies. Thus, we observe a clear difference between our case study and those recovered from the site's lower layers (Unit IIB and below) and other open-air sites. For the first time, we can show that the abundance of large bovines in MP open-air sites is not necessarily due to their abundance in the environment but to deliberate human planning and selective hunting.

Morpho-hydrodynamic processes impacted by the 2022-extreme La Niña event and high river discharge conditions in the southern coastal area of West Java, Indonesia

ABSTRACT The significance of sediment-laden river discharges is strongly related to climate change and rainfall intensity, resulting in severe erosion of the catchment areas and riverbanks. The combination of tides and waves considerably influence the sediment transport and distribution patterns of an estuary, inducing the sedimentary processes of the coastal area. This study aims to analyze the impacts of the La Niña event in 2022 and high river discharges in the Bojong Salawe Beach, Pangandaran. This area has a large estuary with several tributaries, with a high potential for erosion and sedimentation. Furthermore, its location directly faces the Indian Ocean, posing the risk of wind-induced high waves. The methods used in this research are descriptive analysis (using dataset ERA-5 taken from the Copernicus Climate Change Service) and numerical models (using Mike21) with an identification of erosion and accretion processes. The results show that the boreal autumn 2022 significantly impacted the study area, compared to the boreal winter 2022. Higher precipitation levels during boreal autumn substantially increased the river discharges, transferring the total load of sediment of about 1.48 × 10−3 m3/s/m. Moreover, shoreline change analysis using digital shoreline analysis system confirmed that Bojong Salawe Beach was indicated to experience high erosion, particularly around the mouth of the estuary.

Evolution and deposition patterns of turbidity currents under complex vegetation canopies

Understanding the flow-vegetation-sediment feedback mechanism is critical for ecological restoration of gently sloped landscapes. Numerous simulation or laboratory experiments on turbidity currents over vegetation have revealed the important roles of vegetation canopy morphology and structure in this feedback mechanism. However, there is still a lack of analysis on the related physical processes. This study investigated the evolutionary characteristics and sediment transport and deposition patterns of turbidity currents with different sediment size distribution in vegetation patches of different canopy morphologies through lock-exchange experiments. The roles of vegetation leaf morphology and canopy structure were explored by varying the leaf morphology and vegetation density with turbidity currents prepared using sediment samples configured with different particle sizes, which are more compatible with natural conditions. The kinetic characteristics and sediment distribution of the turbidity currents over vegetation were simultaneously analyzed, providing a new perspective for updating the methodology in laboratory experiments. The major findings of this study can be summarized as follows: 1) the general spatiotemporal evolution law of turbidity currents is applicable to complex vegetation canopy morphology; 2) canopy structure dominated by leaf morphology is an important influencing factor that needs to be taken into account in the research on vegetation resistance; and 3) the correlation between turbidity current momentum and suspended sediment transport decreases under complex conditions, and coarse-grained suspended sediment tend to limit the movement of turbidity currents and major deposition distance of the sediment. These findings can provide theoretical support for conservation of floodplain soil and water and restoration of watershed ecology.

Seasonal dynamics of airborne biomolecules influence the size distribution of Arctic aerosols

Organic matter is crucial in aerosol–climate interactions, yet the physicochemical properties and origins of organic aerosols remain poorly understood. Here we show the seasonal characteristics of submicron organic aerosols in Arctic Svalbard during spring and summer, emphasizing their connection to transport patterns and particle size distribution. Microbial-derived organic matter (MOM) and terrestrial-derived organic matter (TOM) accounted for over 90% of the total organic mass in Arctic aerosols during these seasons, comprising carbohydrate/protein-like and lignin/tannin-like compounds, respectively. In spring, aerosols showed high TOM and low MOM intensities due to biomass-burning influx in the central Arctic. In contrast, summer exhibited elevated MOM intensity, attributed to the shift in predominant atmospheric transport from the central Arctic to the biologically active Greenland Sea. MOM and TOM were associated with Aitken mode particles (<100 nm diameter) and accumulation mode particles (>100 nm diameter), respectively. This association is linked to the molecular size of biomolecules, impacting the number concentrations of corresponding aerosol classes. These findings highlight the importance of considering seasonal atmospheric transport patterns and organic source-dependent particle size distributions in assessing aerosol properties in the changing Arctic.

Assessment of Multiple Trace Metal Fluxes in a Semi-Arid Watershed Containing Mine Tailing, Using a Multiple Tool Approach (Zaida Mine, Upper Moulouya Watershed, Morocco)

Few studies have quantified the complex flux of trace metals from mine tailings to rivers through water erosion, especially in the semi-arid region of North Morocco (Zaida mine) where soil erosion is a severe issue. This study applies (i) methods to understand and estimate the complex flux of trace metals from mine tailings to rivers, using the RUSLE model combined with the concentration of trace metals in the soil and additionally (ii) pollution indices and statistical analyses to assess the sediment contamination by Cd, Cu, Pb, and Zn. Our study revealed that the basin has a low erosion rate, with an average of 9.1 t/ha/yr. Moreover, the soil contamination is particularly high at the north of the mine tailings, as prevailing winds disperse particles across the basin. The assessment of the sediments indicated that Pb is the main contaminant, with concentrations exceeding 200 mg/kg specifically downstream of the tailings. This study also identified high a concentration of trace elements 14 km away from the tailings alongside the Moulouya river, due to the specific hydrological transport patterns in the area. This research contributes to a better understanding of the transport and fate of the trace metals in mining areas. It proposes a replicable method that can be applied in other regions to assess the contamination flows and thereby assist water resource management.

Sediment distribution and transport pattern in the nearshore region, southeast coast of India

The present paper aimed to assess the sediment distribution pattern, mode of transport, and its interaction with hydrodynamic and topographic conditions at different depths and regions along the east coast of India. About 900 surficial sediment samples were collected and analysed on a monthly basis for the Chennai coastal region at 32 stations from 2013 to 2015. The study region is classified into four types, such as beach, inlet, 5 m, and 10 m depth. Sediment textural and grain size trend analyses were conducted to achieve the objectives. Sediment characteristics for the region were recorded as sandy, equally dominated by unimodal and bimodal at the beach, while unimodal at shallow depths (5 and 15 m). The sediments were medium sand to coarse sand at the beach, mostly fine followed by medium at 5 and 15 m depths. The sediment sorting is dominated by moderately well-sorted sediments; the skewness of beach sediments was negative, while nearshore sediments were found positive; average kurtosis values of sediments were noticed to be mesokurtic. The CM plot depicts that the sediments were mostly derived by tractive current, and the modes of transport are “bottom suspension and rolling” and “graded suspension no rolling” at beach locations and shallow water depths, respectively. The GSTA analysis reveals the annual average sediment transport pattern is northerly. The numerical hydrodynamic study confirms the GSTA and CM plot analysis. The study reveals a stable sedimentary environment south of the Chennai port and instability in the northern part. The study includes large spatiotemporal nearshore sediment data with hydrodynamic conditions, immensely helpful to coastal stakeholders and researchers.

Dynamic Flow Algorithm with Intermediate Storage for Emergency Evacuation Allowing Lane Reversal based on Incomplete Intuitionistic Fuzzy Preference Relation

Background Evacuation in case of disasters is of the greatest importance because of significant occurrences of natural and artificial disasters worldwide, which is why a reliable evacuation plan is always needed. However, evacuation models are difficult to develop due to various uncertain aspects that need to be considered, multiple and often conflicting criteria for evaluation and as lack of expertise regarding a specific preference of alternatives. Objective This study aims to transport the maximum number of evacuees in a dynamic network with lane reversal by a safe pattern of transportation, i.e., allowing storage at intermediate nodes. The optimal order of shelters and intermediate nodes for a reliable evacuation plan will be defined by incomplete intuitionistic fuzzy preference relation. Methods The illustrated method incorporates multiple and often conflicting criteria into a process of emergency decision-making. When evaluating evacuation alternatives, a decision-maker may hesitate and be unsure which alternative is better or not have sufficient expertise to evaluate a pair of alternatives. To model uncertainty and hesitation, intuitionistic fuzzy values are used to describe alternatives in more detail. This study relies on flow models and graph theory to simulate the movement of evacuees to safe destinations. Furthermore, fuzzy methods and their recent modifications are applied to determine the effective priority order of shelters. A case study which simulates the evacuation of aggrieved to safe destinations is presented. Results A method of evaluating the shelters and intermediate nodes for evacuation based on incomplete intuitionistic fuzzy preference relation is proposed. The method allows the missed values of experts’ assessments to be filled in regarding the evacuation alternatives and deals with intuitionistic fuzzy values, which describe experts’ hesitation. The dynamic character of flow distribution enables transit arc capacities and time factors to be processed. The contraflow technique, which is a powerful tool to decrease traffic jams and congestion on roads by reversing the movement along the unused segments, is applied to maximize the number of survivors. Conclusion The results of the method were compared to those of existing methods, and their consistency was proved. In the future, we intend to apply interval-valued intuitionistic preference relations and iterative algorithms to improve the consistency of intuitionistic preference relations to the tasks of transporting the maximum possible number of aggrieved to safe locations.

Research on prepositioned air distribution and dust control devices for continuous mining faces

This study, based on the construction of a wind flow-dust two-phase coupled diffusion model, develops a novel method using a prepositioned air distributor to create an air curtain for dust control. This research involved the analysis of wind flow transportation patterns and dust diffusion mechanisms with varying structural parameters, and the verification of simulation results through field tests. The findings indicate that with the increase of the axial horizontal opening angle of the prepositioned air distributor, the wind speed of the air curtain decreases, while the size of the vortex field in the heading face area expands. Increasing the axial vertical opening angle enhances the strength of the vortex, leading to improved dust control abilities. The dust concentration at the rear of the tunnel initially decreases and then rises. Additionally, as the turning angle increases, the speed at which the wind flow diffuses towards the rear of the tunnel also rises. Compared with traditional ventilation methods, the dust reduction efficiency at the respiratory zone height is improved to over 94.0 %. The concentration of dust within the tunnel is significantly reduced, with approximately 98.9 % of the dust confined within a 10.0 m range from the heading face.