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This study aims to develop an in vitro barrier effect test over biomimetic membrane, which is useful to establish the film forming ability of a substance-based medical device (SB-MD). The method contemplates a multiparametric approach including: i) the measurement of the transmembrane passage of a molecular-like marker over a lipid-impregnated biomimetic membrane (simulating the skin and gastro-intestinal and buccal tissues) by using a static diffusion cell apparatus (Franz cell); and ii) the evaluation of the integrity of the membrane (colorimetric test). In the first step, a series of lipid-impregnated biomimetic membranes (simulating gastro-intestinal, buccal, and skin tissues) were implemented and their permeability performance validated using model drugs (caffeine and acyclovir) by referring to literature data. As a result, the apparent permeability (Papp) of caffeine over the biomimetic gastro-intestinal membrane (Papp = 30.5E-6 cm/s) was roughly comparable to the literature values obtained with Caco-2 cell line membrane (Papp = 30.8E-6 cm/s) and with the Franz cell method (Papp = 36.2E-6 cm/s). Acyclovir was shown to be a poorly permeable substance both in the literature and experimental data. Following this step, the permeability study was extended to both biomimetic buccal and skin (STRAT-M®) membranes: for caffeine, biomimetic gastro-intestinal membrane was the most permeable (Papp = 30.5E-6 cm/s), followed by the buccal (Papp = 18.2E-6 cm/s) then the skin (Papp = 0.5E-6 cm/s) biomimetic membranes. In a second part of the work, the barrier effect test was developed following a similar permeability-like approach. The protocol was designed with the idea of assessing the capacity of a certain product to prevent the passage of caffeine across the biomimetic membrane with respect to a negative and positive control. The untreated membrane was the negative control, while membrane covered with a Vaseline film was the positive. As a last step, the developed barrier effect protocol was applied to an experimental gel-like SB-MD under development for the treatment of aphthae (Aphthae gel, an invented trade name), herein used as a case study. Regarding the results, Aphthae gel reduced the caffeine passage by 60.3%, thus highlighting its effectiveness to form a protective film. Overall, these results provide important knowledge and may pave the way for the use—including for industrial applications—of these simple but effective biomimetic membranes for carrying out high throughput screening necessary to design safe and effective SB-MDs before proceeding further with clinical trials, as requested by the regulations. [ABSTRACT FROM AUTHOR]

The article discusses how endangered Black-faced Spoonbills alter their migration patterns across the Yellow Sea due to the presence of offshore wind farms. The study highlights two cases of GPS-tracked Spoonbills changing their routes after encountering wind farms, leading to delays and altered behaviors. The research emphasizes the potential impact of offshore wind farms on migratory bird species and calls for further studies to assess cumulative effects and behavioral responses. [Extracted from the article]

Electrochemical impedance spectroscopy (EIS) is a modern and efficient method for the evaluation of the protective abilities of coatings. However, the interpretation of the experimental data is a difficult task. This paper aims to investigate the effect of the addition of a nano clay, Cloesite 30B®, on the barrier properties of an epoxy-based system through electrochemical impedance spectroscopy in an aerated sodium chloride solution. The EIS spectra of the samples analysed showed different evolutions over time. The subsequent processing of spectra using equivalent electrical circuits is an excellent analytical tool and allows the protective capacity of coatings to be assessed. By using this analysis, it was possible to define and comprehend the impact of adding nano clay in different concentrations to the epoxy resin coating. The work has shown the effectiveness of increasing the barrier effect of the coating with this type of nano clay. However, the improvement is linked to obtaining a correct dispersion of nanoparticles. Otherwise, there is the formation of macro-clusters of particles inside the coating. Their appearance can cause a deterioration in coating performance. [ABSTRACT FROM AUTHOR]

Building and ground settlement due to construction dewatering is a well-studied topic. However, most previous investigations have not considered the barrier effect of an adjacent underground structure on the drawdowns and resulting settlements. In this study, the barrier effect and its influence during construction dewatering for a metro station foundation pit is investigated. There are five aquifers at the foundation pit site, and a row of buildings supported on pile foundations, which act as an underground barrier to flow, is present on one side of the pit. On the other sides, there are no deep underground structures to impede groundwater flow. Field monitoring of the groundwater level drawdown, diaphragm wall movement, and ground and building settlements on both sides of the pit was carried out during dewatering. The results indicate that on the side with the pile foundations, the groundwater level drawdown, ground settlement, differential settlement, and angular distortion of building incurred by dewatering were relatively greater, but the diaphragm wall movements were relatively smaller. The effect of preexisting barriers should be considered in the assessment of construction dewatering-induced drawdowns, soil settlements, and building movements. [ABSTRACT FROM AUTHOR]

Copyright of China Plastics / Zhongguo Suliao is the property of Journal Office of CHINA PLASTICS and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

TAMIXAM® is a novel technology that combines hyaluronic acid and tamarind seed extract in its formulation. It is designed to protect the esophageal mucosa by creating a barrier through its filmogenic properties. The aim of this study is to evaluate the safety and efficacy of this technology through mucoadhesion tests, a cell viability assay, TEER measurements, and morphological analysis on reconstructed esophageal mucosa exposed to 10% hydrochloric acid before and after treatment. The mucoadhesion test highlighted the synergistic bioadhesive effect of the technology’s components. Cell viability assays revealed the substantial mucoprotective and barrier effects of the technology, preserving tissue viability when applied before exposure to acid insult. A morphological analysis illustrated TAMIXAM®’s efficacy in countering acid-induced damage, reducing erosion, necrosis, and tissue degeneration compared to the positive control, both pre- and post-acid insult. An evaluation of epithelial integrity through TEER measurements indicated a minimal reduction in tissues treated with the invention before acid exposure, demonstrating its ability to maintain epithelial integrity in the presence of an acid insult. However, this effect was less pronounced in tissues treated with the technology after the acid insult, implying a potential partial recovery of epithelial integrity. Furthermore, comprehensive in vitro and in vivo studies supported the safety profile of the invention. In conclusion, TAMIXAM® emerged as a compelling solution, providing enhanced mechanical action to maintain epithelial balance and shield the esophageal mucosa from acid-induced damage.

BACKGROUND: Hedgerows represent an agroecological lever for pest management. To date, few studies have shown that they can be used as a lever for the control of aerial fungal diseases, especially as a barrier to dispersal. On banana production, the main disease is black leaf streak disease (BLSD), which is a fungal disease caused by Pseudocercospora fijiensis. This pathogen disperses through two types of spores: ascospore and conidia. The aim of this study was to observe and to quantify the effect of hedgerows on BLSD dispersal. Trap plants were placed at the same distance to an artificial source of inoculum with a hedgerow on one side. Lesions were counted to establish the daily lesion density of each trap plant. The combination of hedgerow characteristics such as height, width, and optical porosity were used to evaluate its potential capacity to intercept spores. RESULTS: When ascospores were used as a source of inoculum, the lesion density on traps plant decreased up to 50% between the hedgerow with the lowest interception capacities and the one with the highest interception capacities. For conidia, hedgerow height and side of the trap plants (with or without hedgerow between them and the source) were not significant, but low porosity of the hedgerow reduced the lesion density. On the contrary, for ascospore, the hedgerow effect was anisotropic; the trap plants on hedgerow side had less lesions. CONCLUSION: Our study is the first experimental proof of the effect of hedgerows on P. fijiensis dispersion, both on conidia and ascospore. We showed that hedgerow characteristics impact the capacity of interception of the hedgerow. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

TAMIXAM® is a novel technology that combines hyaluronic acid and tamarind seed extract in its formulation. It is designed to protect the esophageal mucosa by creating a barrier through its filmogenic properties. The aim of this study is to evaluate the safety and efficacy of this technology through mucoadhesion tests, a cell viability assay, TEER measurements, and morphological analysis on reconstructed esophageal mucosa exposed to 10% hydrochloric acid before and after treatment. The mucoadhesion test highlighted the synergistic bioadhesive effect of the technology's components. Cell viability assays revealed the substantial mucoprotective and barrier effects of the technology, preserving tissue viability when applied before exposure to acid insult. A morphological analysis illustrated TAMIXAM®'s efficacy in countering acid-induced damage, reducing erosion, necrosis, and tissue degeneration compared to the positive control, both pre- and post-acid insult. An evaluation of epithelial integrity through TEER measurements indicated a minimal reduction in tissues treated with the invention before acid exposure, demonstrating its ability to maintain epithelial integrity in the presence of an acid insult. However, this effect was less pronounced in tissues treated with the technology after the acid insult, implying a potential partial recovery of epithelial integrity. Furthermore, comprehensive in vitro and in vivo studies supported the safety profile of the invention. In conclusion, TAMIXAM® emerged as a compelling solution, providing enhanced mechanical action to maintain epithelial balance and shield the esophageal mucosa from acid-induced damage. [ABSTRACT FROM AUTHOR]

Otolaryngological disorders encompass a broad spectrum of conditions that affect the ear, nose, and throat. These conditions often lead to significant discomfort, a reduced quality of life, and the necessity for effective and well-tolerated therapeutic interventions. This article aims to provide an efficacy and safety assessment of VIARINOX®, a patented technology designed to remove mucus residue from nasal passages in both children and adults, targeting nasal congestion. The study focused on evaluating the antioxidant and anti-inflammatory capacities and the barrier effect of the patented technology. This evaluation involved chemical assays centered on free radical inhibition and assays conducted on reconstructed respiratory epithelium inserts, where damage was induced using LPS. The results obtained indicate that, owing to the presence of sodium hyaluronate, methylsulfonylmethane, and N-acetyl cysteine, this technology could serve as a pharmacological tool for treating otolaryngological disorders and as a preventive measure against the risk of microbial contamination. [ABSTRACT FROM AUTHOR]

Animal movement throughout the landscape is a key concept for population viability. Human footprint can reduce animal movement through barrier effects such as habitat change and fragmentation, or through enhanced resources. Artificial light at night (ALAN) can affect the movement of nocturnal animals such as bats that are highly mobile in the landscape. Very few studies have explicitly quantified the choices that moving bats make when they encounter a light source on their flight routes. We assessed whether ALAN of different colours (green, red and white) compared to control conditions affected the use of ecological corridors, considering (i) activity and (ii) movement along the corridor, for open, edge (i.e. light‐opportunistic) and narrow‐space (i.e. light‐averse) foraging bats. We modelled the effects of 28 independent lampposts at four experimental sites on bat activity and movement (i.e. the number of trajectories towards the lamppost and the probability of lamppost crossing). Each lamppost was sampled two to three times over eight complete nights using paired passive acoustic stereo recorders to record bat activity and reconstruct bat trajectories. Narrow‐space foragers were much less active in presence of any light source, and fewer flew towards any lit lampposts. Open and edge‐space foragers were more active close to white and green lights, and to a lesser extent red light, compared to unlit control sites. Edge‐space foragers overall flew more towards white and green lampposts, but had a lower probability of fully crossing a white and red‐lighted site. The study shows that ALAN can strongly alter bat movements along landscape structures, for light‐averse but also light‐opportunistic species. Such changes in flight behaviour may involve bypasses or detours, which may force bats to fly longer distances at night which could ultimately affect fitness. Our findings suggest that avoiding artificial lighting close to flight routes will benefit bats. [ABSTRACT FROM AUTHOR]

Copyright of GeSec: Revista de Gestao e Secretariado is the property of Sindicato das Secretarias e Secretarios do Estado de Sao Paulo (SINSESP) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Species with wide‐range distributions usually display high genetic variation. This variation can be partly explained by historical lineages that were temporally isolated from each other and are back into secondary reproductive contact, and partly by local adaptations. The smooth newt (Lissotriton vulgaris) is one of the most widely distributed amphibians species across Eurasia and forms a species complex with a partially overlapping distribution and morphology. In the present study, we explored the population genomic structure of smooth newt lineages in the Carpathian Basin (CB) relying on single‐nucleotide polymorphisms. Our dataset included new and previously published data to study the secondary contact zone between lineages in the CB and also tested for the barrier effect of rivers to gene flow between these lineages. We confirmed the presence of the South L. v. vulgaris Lineage distributed in Transdanubia and we provided new distribution records of L. v. ampelensis inhabiting the eastern territories of the CB. High genetic diversity of smooth newts was observed, especially in the North Hungarian Mountains and at the interfluves of the main rivers in the South with four distinct lineages of L. v. vulgaris and one lineage of L. v. ampelensis showing a low level of admixture with the spatially closest L. v. vulgaris lineage. Moreover, admixture detected at the interfluve of the main rivers (i.e. Danube and Tisza) suggested a secondary contact zone in the area. Finally, we found that the river Danube has a very weak effect on population divergence, while the river Tisza is a geographical barrier limiting gene flow between smooth newt lineages. As the range boundaries of L. v. vulgaris and L. v. ampelensis in the CB coincide with the river Tisza, our study underpins the influence of rivers in lineage diversification. [ABSTRACT FROM AUTHOR]

Linear infrastructures like roads, pipelines, and electrical networks are among the main causes of habitat fragmentation and diversity loss in animal species. We evaluated the effects of 20-30mwide deforested corridors above underground oil pipelines on the movements of the long-furred woolly mouse opossum Marmosa paraguayana, an arboreal marsupial ubiquitous in the Brazilian Atlantic Forest. Using capture, mark, and recapture protocols along four transects, two on either side of the deforested corridor, one within the forest, and one along the forest edge, we compared movements within the forest with those across the deforested corridor. This experimental design was repeated in six locations within two protected areas in the state of Rio de Janeiro, Brazil. Pipeline crossings were rare, performed by few individuals, and significantly less frequent than movements inside the forest fragment, indicating that the deforested pipeline corridors act as a partial barrier to the movements of M. paraguayana. All crossings were restricted to the mating season. Both sexes crossed the pipeline strips and males travelled longer distances than females. Also, individuals used the forest interior more frequently and avoided edges, decreasing the likelihood of crossing the unforested corridors. This study revealed an underestimated effect of a narrow-deforested matrix like the ones created by underground pipelines on forest connectivity and the need for the development of measures to mitigate these impacts. [ABSTRACT FROM AUTHOR]

Long‐distance dispersal is a key factor explaining the success of invasive alien species, particularly across oceanic islands. However, it is often not feasible to reliably measure long‐distance seed dispersal (LDD) over many kilometers in the field. Here, we used a three‐dimensional kinematic trajectory model (Computing Atmospheric Trajectory tool [CAT]) initiated on the basis of regional wind field data to assess the potential for LDD of a wind‐dispersed invasive tree, Spathodea campanulata (African tulip tree), across the Society Islands (French Polynesia, South Pacific Ocean) following its initial planting and spread on the island of Tahiti. The main objective of our study was to determine whether S. campanulata could be expected to spread naturally among islands. Atmospheric dynamics, seed terminal velocity, precipitation, and temperature of air masses were considered to assess the potential for LDD between oceanic islands, with the island of Tahiti serving as the island source for multiple, geographically distant invasions. Aerial trajectories of modeled S. campanulata seeds indicated that wind‐dispersed seeds originating from trees on the island of Tahiti could reach most of the Society Islands and disperse as far as 1364 km. This result suggests that Spathodea can be expected to spread naturally among the Society Islands. When rainfall events were modeled as causal agents of seed settlement, fewer seeds reached distant islands, but more seeds settled on the closest island (20 km away). Including effects of island topography ("barrier effects") also resulted in more seeds settling on the closest island and fewer seeds reaching the most distant islands. Overall, our findings suggest that recent atmospheric models can provide valuable insights into LDD and invasion patterns of wind‐dispersed invasive species. [ABSTRACT FROM AUTHOR]

Copyright of Acta Silvae et Ligni is the property of Biotechnical Faculty, Slovenian Forestry Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Regional and local habitat factors affecting the distribution and abundance of Japanese eel (Anguilla japonica) were systematically analysed in 123 reaches of 21 stream systems in south‐western Japan, with particular attention paid to human habitat modification, such as artificial barriers and concrete revetment.The density of Japanese eel decreased upstream, and they were absent from the upper reaches of each stream system. The upper limits of their distribution were explained by the distance from the sea and the channel gradient, rather than barriers. However, the number of barriers had the highest explanatory capacity for the upstream decline in abundance of small eels (<40 cm in total length).Analyses of the relative importance of regional and local habitat factors showed that the number of barriers (regional factor) was more important than local habitat factors in determining small eel abundance, whereas regional and local habitat factors (e.g. concrete revetment or cover habitat) were similarly important for large eel abundance.These results suggest that: (i) barriers are not a major factor limiting the distribution (presence/absence) of the Japanese eel in the streams studied; (ii) barriers can substantially decrease the abundance of young eels; and (iii) as eels grow older and larger, local habitat factors, such as bank conditions and cover, become more important in determining their abundance.The results for the relative importance of regional and local habitat factors suggest that in habitat restoration for the Japanese eel, priority should be given to mitigating barrier effects. The improvement of longitudinal connectivity to facilitate colonization by young eels is primarily needed for a more efficient use of the existing carrying capacity of streams. The improvement of local habitat conditions to increase the carrying capacity should be conducted in stream reaches free from barrier effects. [ABSTRACT FROM AUTHOR]

Abstract Species with wide‐range distributions usually display high genetic variation. This variation can be partly explained by historical lineages that were temporally isolated from each other and are back into secondary reproductive contact, and partly by local adaptations. The smooth newt (Lissotriton vulgaris) is one of the most widely distributed amphibians species across Eurasia and forms a species complex with a partially overlapping distribution and morphology. In the present study, we explored the population genomic structure of smooth newt lineages in the Carpathian Basin (CB) relying on single‐nucleotide polymorphisms. Our dataset included new and previously published data to study the secondary contact zone between lineages in the CB and also tested for the barrier effect of rivers to gene flow between these lineages. We confirmed the presence of the South L. v. vulgaris Lineage distributed in Transdanubia and we provided new distribution records of L. v. ampelensis inhabiting the eastern territories of the CB. High genetic diversity of smooth newts was observed, especially in the North Hungarian Mountains and at the interfluves of the main rivers in the South with four distinct lineages of L. v. vulgaris and one lineage of L. v. ampelensis showing a low level of admixture with the spatially closest L. v. vulgaris lineage. Moreover, admixture detected at the interfluve of the main rivers (i.e. Danube and Tisza) suggested a secondary contact zone in the area. Finally, we found that the river Danube has a very weak effect on population divergence, while the river Tisza is a geographical barrier limiting gene flow between smooth newt lineages. As the range boundaries of L. v. vulgaris and L. v. ampelensis in the CB coincide with the river Tisza, our study underpins the influence of rivers in lineage diversification.

Abstract Background Anthropogenic linear features change the behavior and selection patterns of species, which must adapt to these ever-increasing features on the landscape. Roads are a well-studied linear feature that alter the survival, movement, and distribution of animals. Less understood are the effects of fences on wildlife, though they tend to be more ubiquitous across the landscape than roads. Even less understood are potential indirect effects when fences are found in tandem with roads along transportation corridors. Methods We assessed how the spatial configuration of fences and roads effect the movement (crossing effect) and distribution (proximity effect) of a partially migratory pronghorn population (Antilocapra americana) on the grasslands of southern Alberta, Canada. We used data from 55 collared pronghorn within a step-selection function framework to assess the influence of 4 linear features: (1) pasture fences, (2) roads not fenced, (3) roads fenced on one side, and (4) roads fenced on both sides on the selection pattern of migratory and resident animals. We examined whether steps along a movement pathway (i.e., crossing effect) were influenced by the type of linear feature animals attempted to cross and, whether these features affected the distribution of pronghorn (i.e., proximity effect) across the landscape. Results The top model for crossing effect for both movement tactics contained all 4 linear features and land cover. Regression coefficients were negative for all linear features, indicating that individuals were less likely to chose steps that crossed linear features. For the proximity effect, migrant animals avoided all linear features except roads fenced on both sides, where they selected areas closer to this feature. Resident animals, on the other hand, were found closer to pasture fences but further from roads without fences. Conclusions Our results indicate that both fences and roads are indirectly affecting pronghorn resource use spatially and behaviorally, whether each linear feature is found separately or in tandem. Modifying existing fences and roads to account for responses to these distinct linear features could facilitate more successful crossing opportunities and/or shifts in distribution. Allowing pronghorn to freely move across the landscape will maintain functional connectivity to ensure population persistence of this endemic ungulate.

For more than six decades, the European Union (EU) has promoted, one way or the other, systematic European territorial integration, understood as the process of reducing many kinds of cross-border barriers. This article debates the role of the EU b-solutions initiative in facilitating cross-border commuting in Europe via its contribution to a body of knowledge, which, in its practical application, has the potential to act as a resource to be drawn on in the mitigation of a wide range of legal-administrative barriers. A theoretical framework for relating cross-border commuting and cross-border barriers is set out, and existing cases from the b-solutions initiative are mapped against it. The authors demonstrate the framework's value as a tool for determining the relevance of cross-border obstacles and solution factors for the issue of cross-border commuting. The paper concludes that the EU b-solutions contributed with concrete policy actions as well as a body of knowledge and solution-orientated planning towards reducing a range of legal-administrative cross-border barriers in Europe, and therefore represents a set of lebenswelt interventions contributing to the potential for increasing cross-border commuting flows. [ABSTRACT FROM AUTHOR]

Odour emissions from digestate applied on 21 October 2020 in a 2.4 ha field in the Po Valley (Casalino, 28060, Novara, Italy) were measured using dynamic olfactometry and a six-specialist odour panel, and two application techniques were compared. The measured odour emissions were 3024 and 1286 ou m−2 h−1, corresponding to the digestate application with surface spreading and direct injection, respectively. The odour dispersion for the different emission values was modeled to a distance of approx. 500 m from the center of the field and 15 m from the ground using a Lagrangian puff model (SCICHEM) in different meteorological conditions. The meteorological variables were measured at the closest station during the whole month in which the digestate application took place, mimicking a "worst-case scenario" characterized by the frequent applications along the considered period. The maximum odour concentrations within one square km area from the center of the field occurred in calm wind and stable atmospheric conditions. This study also evaluated the effect of a barrier downwind from the source. In the worst-case scenario (spreading technique with maximum emissions, no barriers), the average and maximum estimated odour concentrations were 3.2 and 18.9 ou m−3, respectively. The calculated probabilities of exceeding the threshold value of 1 ou m−3 were 36% and 47% for the whole period and the episodes of calm winds, respectively, and 14% on average for the episode of maximum wind gust. In the best emission scenario (direct injection), the average and maximum odour concentrations were 1.5 and 8.6 ou m−3, respectively, while the probabilities of exceeding 1 ou m−3 were 26% and 36% for the whole period and the episodes of calm winds, respectively, and 0.016% for the maximum wind gust episode. In the presence of a solid barrier downwind from the source and for the wind gust episode, the peak values of the concentrations and exceedance probabilities at the sampling height were found to be reduced by a factor close to 2.5 and 5 × 105, respectively. The study also evaluated the concentration field's vertical distribution, showing that the odour plume's vertical and horizontal dispersion slightly increased with the barrier. This is not a cause of concern unless the emitted substances causing odour nuisance are also atmospheric pollutants with potential harm to far-field ecosystems and human settlements at low concentration levels. [ABSTRACT FROM AUTHOR]

The pile foundations of adjacent buildings can have an impact on the precipitation process in subway stations. In this paper, surface settlement monitoring is carried out by precipitation of horizontal wells in subway stations, and the law of surface settlement change with and without neighboring pile foundations is studied. The influence law of surface settlement in subway stations under different pile depth, different pile spacing and different distance between piles and station boundary is obtained through numerical simulation. Three models of groundwater infiltration in the adjacent pile foundation were established, the principle of pile-soil permeability coefficient equivalence was proposed, and the function relationship between the equivalent soil permeability discount factor and pile parameters was derived. The research results show that the surface settlement is smaller when there are piles in the measured precipitation process than when there are no piles. The greater the pile depth, the smaller the pile spacing and the smaller the pile-station boundary, the stronger the barrier effect and the smaller the final settlement of the ground surface. The accuracy of the formula is also analyzed to show that changing the pile parameters also changes the permeability coefficient of the piles and the soil between the piles. The station surface settlement law is related to the pile parameters, and the study can provide an important theoretical reference for the construction of precipitation with adjacent pile foundations. [ABSTRACT FROM AUTHOR]

Based on an actual excavation of a metro station in Tianjin, China, a fluid–solid coupling numerical model was developed to study the characteristics of groundwater flow and strata movement induced by dewatering and excavation considering the barrier effect of pre-existing adjacent underground structures. Two parameters were selected for the model: the distance between the excavation and the existing underground structure (D), and the buried depth of the adjacent structure (H). By comparing the distribution of groundwater drawdown and deformation modes of the retaining structure and the strata under different working conditions, the influence mechanism of adjacent structures on the movement of groundwater and strata was revealed. The results show that the pile foundations have different effects on the groundwater flow and excavation deformation. Generally, the maximum groundwater drawdown could be enlarged by considering the adjacent underground structure, while the retaining structure deflection would be reduced and the ground settlement could be either enlarged or reduced. Additionally, as D decreases and H increases, a much greater groundwater drawdown and a much smaller retaining structure deflection would appear, which together affect the ground behavior. On the one hand, greater groundwater drawdown would lead to greater ground settlement by soil consolidation, while on the other hand, a smaller retaining structure deflection would lead to smaller ground settlement. Thus, a complex development of ground settlement would appear, and a specific analysis should be performed to assess this in practice, based on a specific H and D. [ABSTRACT FROM AUTHOR]

Historically, public policies in Brazil and many developing countries have prioritized individual motorized modes of transport. The urban space of Brazilian cities has been repeatedly remodeled, often to meet the demands of vehicle flow, to the detriment of spaces for pedestrian use. Part of the transport infrastructure, particularly the highways, are obstacles to the population's mobility, constituting the barrier effect and expanding the physical separation of the communities that reside or transit between the adjacent neighborhoods. Based on the proposed mobility and accessibility indicators extracted from the Origin and Destination Survey databases, this article aims to analyze pedestrian mobility and access to cross the Celso Mello Azevedo Ring Road, located in Belo Horizonte/Brazil. The results indicate that, over the period analyzed, the flows of foot crossings were significantly reduced, even in areas where population growth was recorded. The evidence also shows the prevalence of crossings by motorized modes, whose mobility and access are characterized by a tangible inequality in spatial distribution, linked to the occupation pattern of the surroundings, one consequence of which is the expressive volume of accidents involving pedestrians on the highway. [ABSTRACT FROM AUTHOR]

Mitigation planning for road projects in Colombia has been largely based on actions aimed at reducing wildlife roadkills. Nonetheless, the efficiency of these actions is compromised because of the absence of robust empirical studies supporting their implementation. In this work, I used the Road Permeability Index (RPI) in conjunction with expert knowledge information to estimate the strength of the barrier effect imposed by an under-construction road (Yuma road, Santander department, Colombia) on nine functional groups of medium and large-sized mammals. The influence of 12 landscape variables on the permeability of each functional group was assessed at 30 locations along the road. The RPI was calculated for each functional group, and the whole studied mammal assemblage at each location. The relative influence of each variable on overall permeability was also estimated. I found that functional groups including terrestrial and semiarboreal species present higher contribution values to overall road permeability, indicating that they represent priority targets for mitigation actions. The RPI identified six highly permeable locations for animal movement—where higher roadkill rates are expected—which are key for implementing mitigation strategies aimed at reducing wildlife road mortality. Forest cover had the strongest influence on road permeability, therefore is crucial for landscape conectivity. Overall, the results of this work show that RPI constitutes a reliable and easily adaptable alternative for identi-fying priority species, or faunal groups, and locations for road mitigation planning.

The permeability of line barriers in the landscape is often a prerequisite for the survival of the wide spectrum of native species. The aim of this study is to create a methodology for assessing the attractiveness of wildlife underpasses used by animals during migrations, translocations or as a habitat. Understanding the relationship between the parameters of underpasses in the broader landscape-ecological context and their attractiveness for animals is a key aspect in spatial planning and the construction of new linear transport structures, which will significantly help mitigate the barrier effect and isolation of animal populations. The attractiveness assessment is based on the evaluation of the underpass individual parameters and its surroundings through the 8 sub-indexes (openness, substrate, anthropogenic, vegetation, landscape structure elements, ecological networks, potential and real migration/habitat).

Otolaryngological disorders encompass a broad spectrum of conditions that affect the ear, nose, and throat. These conditions often lead to significant discomfort, a reduced quality of life, and the necessity for effective and well-tolerated therapeutic interventions. This article aims to provide an efficacy and safety assessment of VIARINOX®, a patented technology designed to remove mucus residue from nasal passages in both children and adults, targeting nasal congestion. The study focused on evaluating the antioxidant and anti-inflammatory capacities and the barrier effect of the patented technology. This evaluation involved chemical assays centered on free radical inhibition and assays conducted on reconstructed respiratory epithelium inserts, where damage was induced using LPS. The results obtained indicate that, owing to the presence of sodium hyaluronate, methylsulfonylmethane, and N-acetyl cysteine, this technology could serve as a pharmacological tool for treating otolaryngological disorders and as a preventive measure against the risk of microbial contamination.

This study aims to develop an in vitro barrier effect test over biomimetic membrane, which is useful to establish the film forming ability of a substance-based medical device (SB-MD). The method contemplates a multiparametric approach including: i) the measurement of the transmembrane passage of a molecular-like marker over a lipid-impregnated biomimetic membrane (simulating the skin and gastro-intestinal and buccal tissues) by using a static diffusion cell apparatus (Franz cell); and ii) the evaluation of the integrity of the membrane (colorimetric test). In the first step, a series of lipid-impregnated biomimetic membranes (simulating gastro-intestinal, buccal, and skin tissues) were implemented and their permeability performance validated using model drugs (caffeine and acyclovir) by referring to literature data. As a result, the apparent permeability (Papp) of caffeine over the biomimetic gastro-intestinal membrane (Papp = 30.5E-6 cm/s) was roughly comparable to the literature values obtained with Caco-2 cell line membrane (Papp = 30.8E-6 cm/s) and with the Franz cell method (Papp = 36.2E-6 cm/s). Acyclovir was shown to be a poorly permeable substance both in the literature and experimental data. Following this step, the permeability study was extended to both biomimetic buccal and skin (STRAT-M®) membranes: for caffeine, biomimetic gastro-intestinal membrane was the most permeable (Papp = 30.5E-6 cm/s), followed by the buccal (Papp = 18.2E-6 cm/s) then the skin (Papp = 0.5E-6 cm/s) biomimetic membranes. In a second part of the work, the barrier effect test was developed following a similar permeability-like approach. The protocol was designed with the idea of assessing the capacity of a certain product to prevent the passage of caffeine across the biomimetic membrane with respect to a negative and positive control. The untreated membrane was the negative control, while membrane covered with a Vaseline film was the positive. As a last step, the developed barrier effect protocol was applied to an experimental gel-like SB-MD under development for the treatment of aphthae (Aphthae gel, an invented trade name), herein used as a case study. Regarding the results, Aphthae gel reduced the caffeine passage by 60.3%, thus highlighting its effectiveness to form a protective film. Overall, these results provide important knowledge and may pave the way for the use—including for industrial applications—of these simple but effective biomimetic membranes for carrying out high throughput screening necessary to design safe and effective SB-MDs before proceeding further with clinical trials, as requested by the regulations.

White-spotted charr (Salvelinus leucomaenis subspp.) and masu salmon (Oncorhynchus masou subspp.) are representative stream salmonids in the Japanese Archipelago. Although white-spotted charr is not naturally distributed in Shikoku and Kyushu Islands, its introduced populations have been found there. In this study, we describe a range expansion of non-native white-spotted charr in headwater tributaries of a Shikoku river by comparing data in 1998 with that in 2013–2014, and examined its effect on the abundance of native red-spotted masu salmon (Oncorhynchus masou ishikawae). In 1998, the distribution of non-native white-spotted charr had been limited to a part of one tributary, but white-spotted charr in 2013–2014 was widely distributed throughout the study area (three tributaries and the river mainstem), except stream reaches above a sediment-control dam or a waterfall. Relative abundance of white-spotted charr (percentage in the total density of the two species combined) showed a pattern of upstream increase, being consistent with the well-known longitudinal distribution pattern of the two species in their native ranges (i.e., numerical dominance of white-spotted charr and red-spotted masu salmon in the upper and downstream reaches, respectively). Generalized linear models predicting the abundance of each species indicated that the distribution of white-spotted charr was limited by the barriers (dam, waterfall), while the abundance of red-spotted masu salmon was negatively affected by white-spotted charr. Overall, it is likely that non-native white-spotted charr had decreased the abundance of native red-spotted masu salmon during spreading, having created the common longitudinal distribution pattern of the two species in the white-spotted charr's non-native region. Our results suggest that interspecific interactions play an important role in shaping the complementary distribution of white-spotted charr and red-spotted masu salmon along longitudinal gradients. [ABSTRACT FROM AUTHOR]

Copyright of Caldasia is the property of Universidad Nacional de Colombia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Being the heart of every human settlement, the road network constitutes a significant component of the built environment that serves the accessibility and mobility needs and supports economic activities. Despite its positive role, the road network, in some cases, due to increased geometric and functional characteristics, can act as a barrier to the movement of vulnerable road users, thus fragmenting the urban space and creating the phenomenon of the "barrier effect". The barrier effect is considered detrimental to the mobility of vulnerable users, causing delays or even cancellation of trips, increasing collision risk, limiting access to services, posing negative impacts on public health, and loosening social ties. In this context, the current paper focuses on a settlement in Greece (Dispilio) developed along two national roads and comprehensively evaluates the barrier effect. More specifically, the presented methodological approach attempts to investigate the actual and the perceived dimension of this phenomenon by applying well-established metrics and landscape indicators, such as the effective mesh size, and conducting a questionnaire survey, respectively. The overall research results highlighted interesting findings regarding the intensity of the barrier effect in the examined area and outlined some critical interventions that could be implemented in similar cases. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of High Pressure Physics is the property of Chinese Journal of High Pressure Physics Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The positive influence of chloride adsorption on the enhanced protection effect was always emphasized in the published literature. The concrete contribution of chloride adsorption and physical barrier effect of LDH in coatings still remains unclear at present. This work was aimed at exploring the significance of the chloride adsorption role of LDH in the corrosion protection of epoxy coatings. The synthesized LDH samples were characterized by scanning electronic microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) to show the influence of different parameters on its morphology, structure and composition, respectively. The corrosion-electrochemical behavior was investigated using electrochemical impedance spectroscopy (EIS) and salt spray test. It was found that although CaAl-LDH presented a lower chloride adsorption ability in comparison with other samples; it showed effective corrosion protection due to the higher physical barrier effect of CaAl-LDH with typically hexagonal and plate-like morphology due to good compatibility with the epoxy coatings. The results indicated that the corrosion protection effect of the incorporated LDH was more closely related to its physical barrier role rather than the role of the chloride adsorption, which was misunderstood in the previous publications. This work clarified the contribution comparison of the chloride adsorption and physical barrier of LDH in epoxy coating corrosion protection for the first time. [ABSTRACT FROM AUTHOR]

Skin infections are currently a worldwide emergency as antibiotic-resistant bacteria are spreading, leading to the ineffectiveness of most antibiotics and antibacterial strategies. Consequently, there is an urgency of developing and testing innovative antibacterial therapies. As traditional 2D cell culture and planktonic bacteria culture can be obsolete due to their incapability of resembling the complex infection environment, 3D in vitro skin models can be a powerful tool to test and validate therapies. In this article, a 3D in vitro epidermis-dermis skin model has been developed and biofabricated to be broadly available, reaching a balance between the simplicity and reproducibility of the model and its complexity in terms of wound, infection, and treatment response. The results are really promising, as the skin model developed a comprehensive physical barrier. To further investigate the skin model, controlled wounding, infection, and antibiotic treatments were performed. The results were remarkable: Not only was the unwounded epidermal barrier able to partially stop the bacterial proliferation, but the entire system reacted to both wound and infection in a complex and complete way. Extracellular matrix deposition and remodeling, inflammatory response, antimicrobial peptide production, and change in cellular behaviors, from epithelial to mesenchymal and from fibroblasts to myofibroblasts, were witnessed, with different extents depending on the bacterial strain. In addition, the inflammatory response to the antibiotic administration was opposite for the two bacterial infections, probably revealing the release of inflammatory endotoxins during Escherichia coli death. In conclusion, the presented 3D in vitro skin model has all the characteristics to be a future landmark as a platform for antibacterial strategy therapy testing.

The weak interlayer, as a problematic geological body during tunnel construction, greatly influences the propagation of the blasting stress wave, the blasting excavation qualities, and the explosion efficiency. A series of numerical models were established to study the changes in the propagation process of blasting stress waves and the failure morphology of the surrounding rock mass, aiming to reveal the weak interlayer's influence mechanism. The result indicates that the weak interlayer's existence reduces the propagation velocity and stress peak of the stress wave at barred zones but strengthens the peak stress at reflection zones, which leads to an asymmetrical distribution of rock damage. Furthermore, the type and distribution of the weak interlayer were classified and generalized into four types. The tunnel blasting outlines under different types of weak interlayers are derived through numerical modeling for designing references. A strategy to resist tunnel overbreak and underbreak was proposed combined with previous work. The actual blasting solution is compared to the designed blasting solution with optimised blasting parameters. [ABSTRACT FROM AUTHOR]

Polylactic acid (PLA) is a highly promising bio-based polymer that can replace petroleum-based materials. The PLA-modified membrane has been found to effectively block soil odours in laboratory experiments, but its barrier effect at the excavated soil interfaces of actual pesticide sites requires further evaluation. This study investigates the barrier effect of the PLA-modified membrane on odours at the excavated soil interface of a pesticide-contaminated site in Guangdong Province, China. The membrane's barrier effect on odours was comprehensively evaluated using the static chamber technique with three indicators: diffusion flux, odour concentration, and a health risk index. The results showed that the initial diffusion fluxes of six main odour substances: m- and p-xylene, o-xylene, toluene, ethylbenzene, n-propylbenzene, and cumene were 1.95 × 100, 2.88 × 10−1, 7.27 × 10−3, 1.49 × 100, 2.97 × 10−3, and 3.89 × 10−3 mg/(m2·s) based on the contribution rate. After laying the PLA-modified membrane, the flux reduction rate of all six odour substances was generally >90%. The background odour concentration in the test area was 109.56, and the odour concentration after laying the membrane was <1.12. The initial non-carcinogenic and carcinogenic risk indices of the test area were 3.03 and 1.62 × 10−4, respectively. After laying the membrane, these indices were <0.05 and <3.78 × 10−7, respectively, indicating no health risk. Overall, the PLA-modified membrane had a good barrier effect on odours in the on-site application, effectively reducing the diffusion and nuisances of odours, as well as their health risks. [ABSTRACT FROM AUTHOR]

Background: Anthropogenic linear features change the behavior and selection patterns of species, which must adapt to these ever-increasing features on the landscape. Roads are a well-studied linear feature that alter the survival, movement, and distribution of animals. Less understood are the effects of fences on wildlife, though they tend to be more ubiquitous across the landscape than roads. Even less understood are potential indirect effects when fences are found in tandem with roads along transportation corridors. Methods: We assessed how the spatial configuration of fences and roads effect the movement (crossing effect) and distribution (proximity effect) of a partially migratory pronghorn population (Antilocapra americana) on the grasslands of southern Alberta, Canada. We used data from 55 collared pronghorn within a step-selection function framework to assess the influence of 4 linear features: (1) pasture fences, (2) roads not fenced, (3) roads fenced on one side, and (4) roads fenced on both sides on the selection pattern of migratory and resident animals. We examined whether steps along a movement pathway (i.e., crossing effect) were influenced by the type of linear feature animals attempted to cross and, whether these features affected the distribution of pronghorn (i.e., proximity effect) across the landscape. Results: The top model for crossing effect for both movement tactics contained all 4 linear features and land cover. Regression coefficients were negative for all linear features, indicating that individuals were less likely to chose steps that crossed linear features. For the proximity effect, migrant animals avoided all linear features except roads fenced on both sides, where they selected areas closer to this feature. Resident animals, on the other hand, were found closer to pasture fences but further from roads without fences. Conclusions: Our results indicate that both fences and roads are indirectly affecting pronghorn resource use spatially and behaviorally, whether each linear feature is found separately or in tandem. Modifying existing fences and roads to account for responses to these distinct linear features could facilitate more successful crossing opportunities and/or shifts in distribution. Allowing pronghorn to freely move across the landscape will maintain functional connectivity to ensure population persistence of this endemic ungulate. [ABSTRACT FROM AUTHOR]

Insulation barriers are an effective way to improve the insulation strength of the resistive-type superconducting fault current limiters (R-SFCLs). The objective of this article is to obtain the dc discharge characteristics of composite insulation systems including two liquid nitrogen (LN2) gaps in series, but separated by a solid insulation barrier mixed with vapor bubbles. The needle–needle–plane stainless steel electrodes with the insulation barrier and bubbles generation systems are used to simulate the electric strength under quenching conditions of the R-SFCLs. The results show that the composite systems’ breakdown characteristic switched from insulation barrier breakdown to surface flashover with the insulation barrier approaches the needle electrodes side. The breakdown voltage of the composite systems decreased due to the thermal induced bubbles. The presence of the bubbles increases the probability of the surface flashover of the insulation barrier. The results have guiding significance for the design of the high-voltage R-SFCLs. [ABSTRACT FROM AUTHOR]

Two strategic documents issued by the Chinese Central Government projected that, by the mid-21st century, the linear transport infrastructure (LTI) network of China will rank at the forefront of ecological and sustainable transport networks globally. With this goal, it is urgent to summarize existing research, benchmark international research levels, and propose development directions and strategies for terrestrial vertebrate species protection around LTI in China. In this study, we searched for peer-reviewed papers before 2020 in both Chinese and international databases. A total of 170 academic articles were collected. Most focused on roads, but some focused on railways, of which the Qinghai-Tibet Railway occupied half. The most researched taxa were mammals, including the Tibetan antelope (Pantholops hodgsonii), Siberian tiger (Panthera tigris), and Asian elephant (Elephas maximus), the number of bird research papers was less than half that of mammal research papers, and fewer amphibian and reptile studies. The impact of LTI on wildlife was classified to habitat effects, roadkill, behavioral influences, and barrier effects. Wildlife preservation efforts included wildlife and habitat surveys, route selection, subgrade and pavement design, and the design and monitoring of wildlife crossing structures. Studies were concentrated in five zoogeographical regions, i.e., the Qinghai-Tibet, South China, Central China, Northeast China, and Southwest China regions. Conservation suggestions, knowledge gaps, and future research directions for China were identified through comparisons with the state of international research. These focal priorities will help guide the development of road ecology in China. Multi-disciplinary, cross-departmental, and national level research is necessary. Based on this review, a national data integration platform should be established and efforts to cooperate with international research teams to mitigate the adverse effects of LTI should be made.

The removal of endocrine disrupting compounds (EDCs) from water/wastewater is of significant importance. However, current nanofiltration (NF) membranes exhibit limited water permeance and hydrophobic EDCs rejection rates. Herein, we fabricated a novel NF membrane intercalated with the 3,4-dihydroxyphenylalanine-vanadium (DOPA-V) complex barrier layer. The DOPA-V intercalated NF membrane possessed a notable water permeance of ~38 L·m−2·h−1·bar−1, thanks to the formation of a thin and loosely structured PA layer in comparison to the control, as well as the gutter effect optimizing the pathway of water molecule transport induced by the DOPA-V layer. The rejections of methylparaben, nonylphenol, bisphenol AF, propiconazole, dioctyl phthalate, and heptachlorobiphenyl by the DOPA-V intercalated NF membrane were both enhanced compared with those of the control. The enhanced rejection of hydrophobic EDCs by the DOPA-V intercalated NF membrane was primarily dominated by the barrier role of DOPA-V layer. According to the resistance-in-series model, DOPA-V predominated the membrane resistance to hydrophobic EDCs, resulting in a reduction of 68.8 %, 76.5 %, 58.0 %, 58.1 %, 63.0 %, and 72.0 %, respectively, in the diffusion rates of those hydrophobic EDCs compared to the control. This research offers a novel strategy on customizing NF membranes to effectively remove specific trace organic contaminants from water/wastewater. [Display omitted] • DOPA-V intercalated NF membrane shows superior hydrophobic EDC rejection. • Enhanced water permeance achieved with DOPA-V NF membrane. • DOPA-V layer significantly reduces hydrophobic EDC diffusion rates. • DOPA-V NF membrane demonstrates stability and reliability in long-term use. [ABSTRACT FROM AUTHOR]

A comprehensive study is undertaken to investigate the evolution of microscopic deformation under in-situ uniaxial tensile testing of the Directed Energy Deposited (DED) Ti-6Al-4V alloy. The study uncovered a synergistic influence of the (α + β) lamellar microstructural features at different length scales, leading to distinct deformation mechanisms and barrier effects. At the smallest length scale, the deformation mechanisms are lattice slipping and phase boundary sliding (PBS), with a characteristic length scale comparable to the dimensions of α platelets and colonies. The slipping and PBS encountered complex barrier effects at β interlayers. At the intermediate length scale, a mechanism of strain localization manifests as shear bands along a 45° orientation to the uniaxial loading direction. The strain localization involves the activation of multiple slipping events and exhibits a propensity to choose large unobstructed phase-boundary pathways for its realization. At the highest length scale, grain boundaries introduce another barrier effect to both slipping and strain localization through intergranular deformation compatibility. The synergistic interplay between these three mechanisms constitutes a hierarchical response, enabling the material to effectively accommodate large plastic deformation. Moreover, the synergistic interplay influences the anisotropy of the material. [Display omitted] [ABSTRACT FROM AUTHOR]

The precise cause of PM2.5 (fine particular matter with a diameter smaller than 2.5 μm) explosive growth and the contribution of intermittent turbulence to the dispersion of PM2.5 are uncertain. Thus, the impact of boundary-layer structure and turbulence on the variations of surface PM2.5 during fog–haze episodes, especially during explosive growth and dispersion episodes, are investigated using turbulence data collected at a 255-m high meteorological tower in Tianjin from 2016 to 2018. Results suggest that the explosive growth of surface PM2.5 during fog–haze episodes is closely related to weak turbulent mixing, nocturnal inversions, or anomalous inversions, and the barrier effect of strong turbulent intermittency. Turbulent intermittency acts as a lid for hindering pollutant dispersion and is favourable for the fast accumulation of surface PM2.5. Apart from the potential causes mentioned above, the persistent moderate south-westerly flow is also a contributing factor for the explosive growth of surface PM2.5 during fog–haze episodes associated with regional transport. In addition, we demonstrate a possible mechanism of how intermittent turbulence affects the dispersion of PM2.5. Results verify that intermittent turbulence induced by the nocturnal low-level jet (LLJ) indeed plays an important role in the dispersion of PM2.5. However, the contribution of intermittent turbulence generated by the nocturnal LLJ to the dispersion of PM2.5 strongly relies on the intensity of the nocturnal LLJ. [ABSTRACT FROM AUTHOR]

This study aims to examine if an urban road with intense motorized traffic in a medium-sized Brazilian city constitutes a barrier for walking trips. A questionnaire was conducted with 103 individuals in an area up to 800 m from the road selected for the study to obtain information about personal characteristics (age, income, etc.), social interactions in the neighborhood, and travel and mobility characteristics. We used the dataset to explore the potential of Decision Tree and Random Forest classification models to predict the users' perception of the barrier effect, which was characterized by the dependent variables speed and volume (of motorized traffic). For 36.9% and 47.6% of respondents, traffic speed and traffic volume, respectively, represent a barrier to walking. The results also show that the following variables considerably affect the perception of the barrier effect of the respondents: distance from their residence to the studied road, time living at the address and in the study area, social connections in the neighborhood, and the street reported as the busiest one in the neighborhood. Identifying the variables with the largest influence on the perception of the barrier effect may be very useful for planning and policy initiatives. [ABSTRACT FROM AUTHOR]

Widespread tunnel settlement has been observed in the Yangtze River Delta region of China, but its formation mechanism remains unknown. In this study, a settlement trough and its development processes over nearly 7 years were monitored in detail. Notably, this representative case covers the majority of factors that can contribute to tunnel settlement. Records of acting processes of these factors are so comprehensive that factor decomposition was conducted to analyze the quantitative contributions. Specifically, potential factors were classified into internal and external factors, where internal factors (self-consolidation induced by tunnel construction and cyclic loading from traffic) account for 12% of the maximum observed tunnel settlement. Among the external factors, adjacent pile construction and diaphragm wall construction, ground buildings surcharge, adjacent pit excavation, and basement construction accounted for 5%, no more than 10%, no more than 22%, and less than 1% of the maximum observed tunnel settlement, respectively. Adjacent dewatering activities, which accounts for 46 to 67% of settling, were determined to be the dominant factor. Additionally, it was further found that the impact of adjacent dewatering activities on tunnels cannot be reduced by specially designed cutoff diaphragm walls. Wall leakage and the “pit dewatering with adjacent barriers effect” were proved to be potential causing factors. In particular, this effect can be a factor causing significant water head drawdown and subsequent tunnel settlement along metro lines, where high-density buildings tend to develop. These findings were extended to the entire metro line to discuss the mechanism of widespread metro tunnel settlement in this region. [ABSTRACT FROM AUTHOR]