Tunnel resilience models unveiled to aid post-earthquake recovery

Higher Education Press

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Resilience models for post-hazard recovery of tunnels.

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Credit: Zhong-Kai Huang, Nian-Chen Zeng, Dong-Mei Zhang, Sotirios Argyroudis, and Stergios-Aristoteles Mitoulis

A new study published in Engineering presents novel resilience models for assessing and quantifying the recovery of tunnels after earthquakes. The research, conducted by a team from Tongji University, Brunel University of London, and University College London, offers a probabilistic approach to predict tunnel recovery, providing valuable insights for infrastructure operators and city planners.

 

Tunnels are critical components of urban infrastructure, continuously exposed to various hazards, including earthquakes, fires, floods, and aging-related disturbances. Events such as the magnitude-7.8 earthquake in southeastern Türkiye in 2023 and the Chi-Chi earthquake in Taiwan of China have caused significant damage to tunnels, highlighting the vulnerability of these structures and the need for robust resilience assessment tools. Previous research has extensively explored the vulnerability and fragility of tunnels, but studies focusing on restoration to quantify resilience have been limited. This gap has hindered proactive and reactive adaptation measures to ensure seamless tunnel functionality.

 

To address this issue, the study introduces a damage-level-dependent probabilistic approach for quantifying tunnel recovery. The research team conducted a global expert survey to gather input on restoration tasks, their duration, sequencing, and cost. The survey focused primarily on damage induced by seismic events, incorporating idle times and traffic capacity gains over time. The results were used to generate deterministic and probabilistic reinstatement and restoration models, with the probabilistic models accounting for epistemic uncertainties.

 

The study proposes a framework for assessing tunnel resilience, which includes hazard characterization, vulnerability assessment, and the development of restoration models. The framework is based on defining structural damage levels and using fragility functions to determine the probability of damage at a given hazard intensity. The restoration models are tailored to tunnel resilience assessments, incorporating expert knowledge on required restoration tasks and their prioritization. The models help quantify resilience and optimize the repair process for tunnels with various levels of damage.

 

The research highlights that the most time-consuming restoration tasks typically involve replacing tunnel structural components or reinforcing tunnel structures and soil. The study also finds that idle time and cost ratios increase significantly with greater damage severity. For example, the mean idle time for tunnels with minor, moderate, extensive, and complete damage levels were found to be 6.52, 12.09, 24.02, and 50.57 days, respectively. The cost ratio, which represents the restoration cost relative to the total construction cost, also rises with increasing damage severity, ranging from 7.73% for minor damage to 74.05% for complete damage.

 

The study’s findings are demonstrated through a case study of a typical tunnel, showing how the newly developed restoration models can be applied to assess tunnel resilience. The results indicate that the resilience index of the tunnel decreases as seismic intensity increases, with more severe damage levels corresponding to longer restoration times and higher uncertainty in the resilience index.

 

The research underscores the importance of incorporating resilience models into post-earthquake restoration workflows, guiding practitioners in optimal decision-making. The models provide a scientific basis for estimating downtime and losses due to tunnel disruptions, facilitating proactive tunnel adaptation and resource allocation. Future research is suggested to enhance the reliability and generalizability of the restoration models by collecting more expert responses and incorporating parameters tailored to specific tunnel designs and conditions.

The paper “Resilience Models for Tunnel Recovery After Earthquakes,” is authored by Zhong-Kai Huang, Nian-Chen Zeng, Dong-Mei Zhang, Sotirios Argyroudis, and Stergios-Aristoteles Mitoulis. Full text of the open access paper: https://doi.org/10.1016/j.eng.2025.06.028. For more information about Engineering, visit the website at https://www.sciencedirect.com/journal/engineering.

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Journal

Engineering

DOI

10.1016/j.eng.2025.06.028 

Article Title

Resilience Models for Tunnel Recovery After Earthquakes

 

URI researchers uncover molecular mechanisms behind speciation in corals

Findings shed light on the origins of species on coral reefs driven by eye related genes

University of Rhode Island

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Matías Gómez-Corrales, a recent biological sciences Ph.D. graduate from the University of Rhode Island, and his advisor, Associate Professor Carlos Prada, have published a paper in Nature Communications, revealing key mechanisms in speciation in corals and proposing a new hypothesis on the origin of species in the ocean. 

Their new study examines how coral species form and contributes to long-standing questions in evolutionary biology about how marine biodiversity originates. The work builds on decades of ecological, reproductive, and evolutionary studies led by national academy member Nancy Knowlton and pioneering researchers and co-authors Don Levitan and Mónica Medina — a legacy that Gómez-Corrales and Prada are continuing to develop.

A closer look at corals

One of the most iconic examples of mutualism is the relationship between reef-building corals and micro (dinoflagellate) algae. These symbionts harvest light and provide corals with more than 90% of their energy through photosynthesis. As a result, both corals and algae adjust their physiology and morphology to enhance performance across different light environments, such as those found along depth gradients.

While corals and their close relatives lack eyes, they are able to perceive light and do so using the same light-sensitive protein receptors (rhodopsin) on cones or rods in human eyes. 

Prada says their recent research revealed a new twist, uncovering the molecular mechanisms behind speciation in the ocean: “We discovered that opsin genes, the same genes responsible for vision in human eyes, play a key role in driving this process.”

The role of rhodopsin is well-established in fish adapted to different wavelengths across multiple species and geographic locales. For instance, a single amino acid substitution in an opsin gene in the Baltic herring has evolved more than 20 times independently in other species adapted to red-shifted light environments.

Traditionally, marine speciation has been attributed to rapid evolution of sperm-egg interaction proteins. This study presents a complementary view, showing that species can diverge through habitat-specific adaptation to light cues that regulate spawning, with rhodopsins mediating these cues and driving reproductive isolation in corals. This was the first time rhodopsin’s role in coral divergence was found.

Such a pattern of parallel divergence could occur independently in corals as they colonize waters with different optical properties, favoring rhodopsin divergence that fuels speciation.

This mechanism would allow corals to evolve reproductive isolation via genes involved in phototransduction signals that cue reproduction.

Speciation study

The Nature Communications study builds on earlier work by Prada, who proposed that speciation in corals occurs as a result of adaptation to live at different depths with different light environments (ecological speciation), a mechanism that has gained traction in the last two decades with examples ranging from plants to vertebrates. Unveiling the mechanisms behind reproduction isolation is central to understanding this process.

Gómez-Corrales and Prada investigated a recent divergence within a common Caribbean reef builder (Orbicella faveolata), where lineages diverged approximately 212,000 years ago across a narrow depth range in the water, less than 20 meters. The team showed that depth-related distributions are common among sister lineages of corals within the upper, sunlight-filled zone of the ocean. They focused on the Orbicella species, looking at the drivers of adaptive divergence and how corals display environmental sensing, studying coral colonies from Puerto Rico, Panama, Mexico, and Florida. Their analysis indicates divergence across depths through adaptation across different environments, highlighting avenues to increase biodiversity in the sea.

Coral’s reproductive processes are triggered by the interaction of differential light wavelengths, such as moonlight, neuropeptides (including dopamine), and temperature variation, which excite light receptors on the coral. By comparing genomes of deep and shallow lineages, Gómez-Corrales’ team demonstrated that the genes associated with environmental sensing in corals evolve under strong natural selection.

Genome differentiation between shallow and deep lineages occurs primarily in proteins responding to environmental sensing, affecting signaling pathways linked to coral reproductive cycles. This pattern is echoed at macroevolutionary scales across other aquatic species, such as jellyfish and sea anemones, in which neuropeptides, light, and temperature variations regulate reproductive physiology.

Notably, they found that corals use the same environmental cues tied to natural cycles to time reproduction. Coral species alter their reproductive timing under light and temperature manipulation experiments, hinting at a common mechanism for fine-tuning reproductive activity via environmental sensing.

Given the significant body of evidence supporting light as the primary sensory cue for coral spawning, Gómez-Corrales and Prada propose that differential timing of spawning driven by different light perceptions across depths is fine-tuned by expression changes in rhodopsin-like genes, causing corals exposed to different light environments to perceive spawning cues differently due to light. This process occurs across the coral tree of life and in all ocean basins across the world.

Understanding this research fills a key gap in understanding how reef species form, showing how speciation, light interactions, and ecology shape ocean biodiversity and inform predictions of marine ecosystems under climate change.

Prada says studies such as this highlight why it’s so important to better understand coral responses to ocean warming and ways that coral can adapt and acclimate to their environments, to highlight challenges and opportunities for conservation and restoration effort in the future.

“My passion for studying speciation stems from the gap between the vast biodiversity on coral reefs and our poor understanding of the mechanisms that generate and maintain this diversity,” adds Gómez-Corrales. “Uncovering the evolutionary processes shaping their diversification gives us important tools to help preserve them in the future.”

In addition to support from URI and the College of the Environment and Life Sciences, this project was supported by the International Coral Reef Society, the American Museum of Natural History, the National Science Foundation, the National Oceanic and Atmospheric Administration, and the Global Marine Initiative Student Research Award Program (The Nature Conservancy and URI).

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Journal

Nature Communications

DOI

10.1038/s41467-025-65226-9 

Method of Research

Observational study

Subject of Research

Animals

Article Title

Speciation across depth gradients in reef corals

 

Viruses on plastic pollution may quietly accelerate the spread of antibiotic resistance

Biochar Editorial Office, Shenyang Agricultural University

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Plastisphere viruses: hidden drivers of antibiotic resistance dissemination

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Credit: Xue-Peng Chen, Di Wu & Dong Zhu

Plastic pollution does more than litter landscapes and oceans. According to a new perspective article published in Biocontaminant, viruses living on plastic surfaces may play an underrecognized role in spreading antibiotic resistance, raising concerns for environmental and public health worldwide.

When plastics enter natural environments, they quickly become coated with microbial biofilms known as the plastisphere. These plastic associated communities are already known hotspots for antibiotic resistance genes. The new study highlights that viruses, the most abundant biological entities on Earth, could be key players in moving these resistance genes between microbes.

“Most research has focused on bacteria in the plastisphere, but viruses are everywhere in these communities and interact closely with their hosts,” said corresponding author Dong Zhu of the Chinese Academy of Sciences. “Our work suggests that plastisphere viruses may act as hidden drivers of antibiotic resistance dissemination.”

Viruses can transfer genetic material between bacteria through a process called horizontal gene transfer. In plastisphere biofilms, where microbes are densely packed, viruses may more easily shuttle resistance genes across species, including to potential pathogens. Some viruses also carry auxiliary metabolic genes that can boost bacterial survival under stressful conditions, such as exposure to antibiotics or pollutants, indirectly favoring resistant microbes.

The authors point out that viral behavior appears to differ between environments. In aquatic plastispheres, viruses are more likely to adopt life strategies that promote gene transfer, potentially increasing resistance risks. In soils, viruses may instead limit resistant bacteria by killing their hosts. These contrasting roles highlight the need to consider environmental context when assessing the risks of plastic pollution.

“This perspective emphasizes that antibiotic resistance linked to plastics cannot be fully understood without including viral ecology,” said lead author Xue Peng Chen. “Incorporating viruses into a One Health framework will help us better evaluate the long term consequences of plastic pollution.”

The authors call for future studies to directly measure gene exchange between viruses and bacteria on plastics and to refine methods for detecting virus encoded resistance genes. Such insights could inform environmental monitoring and plastic waste management strategies aimed at reducing antibiotic resistance risks.

 

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Journal reference: Chen XP, Wu D, Zhu D. 2025. Plastisphere viruses: hidden drivers of antibiotic resistance dissemination. Biocontaminant 1: e018  

https://www.maxapress.com/article/doi/10.48130/biocontam-0025-0020  

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About Biocontaminant:
Biocontaminant is a multidisciplinary platform dedicated to advancing fundamental and applied research on biological contaminants across diverse environments and systems. The journal serves as an innovative, efficient, and professional forum for global researchers to disseminate findings in this rapidly evolving field.

Follow us on Facebook, X, and Bluesky. 

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DOI

10.48130/biocontam-0025-0020 

Method of Research

News article

Subject of Research

Not applicable

Article Title

Plastisphere viruses: hidden drivers of antibiotic resistance dissemination

Article Publication Date

11-Dec-2025

Tracing hidden sources of nitrate pollution in rapidly changing rural urban landscapes

Biochar Editorial Office, Shenyang Agricultural University

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Tracing the nitrate source and process in rural-urban ecotone: integrated multi-tracer approach

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Credit: Zihan Zhao, Jiayu Zhao, Sidi Chen, Letian Ning, Zucong Cai & Yanhua Wang

Nitrate pollution has become one of the most widespread water quality challenges in intensively farmed regions around the world, threatening drinking water safety, aquatic ecosystems, and downstream lakes. A new study published in Nitrogen Cycling reveals how human activities in rural urban transition zones are reshaping the nitrogen cycle, allowing nitrate to move through rivers and groundwater and ultimately reach large freshwater lakes.

The research focuses on the rural urban ecotone of the Yangtze River Delta in eastern China, an area where agriculture, aquaculture, and residential development coexist. Using an integrated multi tracer approach, the research team traced nitrate sources and transformation processes across surface water and groundwater systems, offering one of the most detailed pictures to date of how nitrogen pollution travels through complex landscapes.

“Nitrate pollution does not come from a single source, and it does not stay in one place,” said corresponding author Yanhua Wang. “Our goal was to understand not only where nitrate originates, but also how it moves, transforms, and accumulates as water flows from farmland and villages toward major lakes.”

The team combined water chemistry measurements, dual stable isotope analysis, Bayesian mixing models, and a county scale nitrogen cascade model. This approach allowed them to distinguish nitrate derived from manure, chemical fertilizers, aquaculture effluent, soil leaching, and atmospheric deposition. Field samples were collected across multiple seasons from rivers, canals, and groundwater wells in two contrasting river networks upstream of Taihu Lake, one of China’s largest freshwater lakes.

The results show that nitrate contamination was widespread in both surface water and groundwater, often exceeding regional water quality thresholds. In traditional agricultural areas, manure was identified as the dominant source of nitrate, contributing nearly 70 percent of surface water nitrate and about 60 percent of groundwater nitrate across seasons. In more industrialized and aquaculture intensive zones, aquaculture effluent emerged as the main nitrate source during dry and wet seasons, highlighting a pollution pathway that is often underestimated.

“Our findings show that manure and aquaculture are major drivers of nitrate pollution, yet they are frequently overlooked compared to chemical fertilizers,” said Wang. “This has important implications for how we design pollution control strategies.”

The study also revealed clear differences in nitrogen transformation processes. Nitrification dominated in agricultural surface waters, especially during dry periods, while denitrification was more pronounced in groundwater, where low oxygen conditions allow microbes to convert nitrate into other nitrogen forms. These underground processes can reduce nitrate concentrations locally, but they may also produce greenhouse gases such as nitrous oxide.

By integrating isotopic evidence with a nitrogen cascade model, the researchers linked observed water pollution to long term changes in land use and agricultural practices. Rapid expansion of aquaculture and commercial crop production has significantly increased nitrogen losses to aquatic systems in some counties, while reductions in cropland area and livestock restructuring have altered nitrogen pathways in others.

“Surface water and groundwater are not separate systems,” Wang explained. “They act together as major transport pathways that deliver nitrogen from land to lakes. Effective water protection must consider both.”

The study underscores the need for coordinated watershed management strategies that address manure application, pond aquaculture, and fragmented cropland management. According to the authors, reducing nitrate pollution in large lakes like Taihu will require integrated solutions that balance agricultural productivity with environmental protection, especially in rapidly urbanizing regions.

This multi tracer framework provides a powerful tool for policymakers and scientists seeking to untangle complex pollution sources and design targeted strategies to protect water resources in agricultural landscapes worldwide.

 

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Journal Reference: Zhao Z, Zhao J, Chen S, Ning L, Cai Z, et al. 2025. Tracing the nitrate source and process in rural-urban ecotone: integrated multi-tracer approach. Nitrogen Cycling 1: e011  

https://www.maxapress.com/article/doi/10.48130/nc-0025-0011  

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About Nitrogen Cycling:
Nitrogen Cycling is a multidisciplinary platform for communicating advances in fundamental and applied research on the nitrogen cycle. It is dedicated to serving as an innovative, efficient, and professional platform for researchers in the field of nitrogen cycling worldwide to deliver findings from this rapidly expanding field of science.

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DOI

10.48130/nc-0025-0011 

Method of Research

Experimental study

Subject of Research

Not applicable

Article Title

Tracing the nitrate source and process in rural-urban ecotone: integrated multi-tracer approach

Article Publication Date

30-Dec-2025