Search Results (82)

The agglomeration characteristics of innovation spaces reflect the intrinsic mechanisms of regional resource integration and collaborative innovation. Investigating the contributions of influencing factors to innovation space agglomeration and their spatial differentiation has significant implications for improving urban innovation quality. Taking the Nanjing central urban area as a case study, this research applied gradient boosting regression trees (GBRT) and multiscale geographically weighted regression (MGWR) models to explore the contributions of influencing factors to innovation space agglomeration and its spatial differentiation. Findings demonstrated that (1) Innovation platforms and patents emerged as the most significant driving factors, collectively accounting for 54.8% of the relative contributions; (2) The contributions of influencing factors to innovation space agglomeration exhibited marked nonlinear characteristics, specifically categorized into five distinct patterns: Sustained Growth Pattern, Growth-Stabilization Pattern, Growth-Decline Pattern, Global Stabilization Pattern, and Global Decline Pattern. The inflection thresholds of marginal effects across factors ranged from approximately 12% to 55% (e.g., 40% for metro stations, 13% for integrated commercial hubs); (3) Each influence factor’s contribution mechanism showed pronounced spatial heterogeneity across different regions. Based on these discoveries, governments should optimize innovation resource allocation according to regional characteristics and enhance spatial quality to promote efficient resource integration and transformation. This research provides a novel perspective for understanding innovation space agglomeration mechanisms and offers actionable references for urban policymakers to implement context-specific innovation economic development strategies. Full article

Underground metro stations are integral to urban transit infrastructure, and ensuring their safety during fire emergencies is crucial. This study proposes a novel evacuation strategy for underground metro stations wherein a segment of evacuees descends to the platform level via train, while the remaining individuals evacuate upward to the ground level through station exits. A novel safety assessment methodology is established to evaluate fire evacuation efficacy, incorporating the cumulative effects of smoke, elevated temperatures, carbon dioxide, and reduced oxygen levels. Employing an actual underground metro station in Guangzhou, China, as a case study, fire and evacuation models were developed to compare the traditional upward evacuation method with the proposed partial downward evacuation strategy. The analysis reveals that both evacuation strategies are effective under the assessed fire scenario. However, the partial downward evacuation is completed more swiftly—in 385.5 s compared to 494.8 s for upward evacuation—thereby mitigating smoke inhalation risks, as the smoke height remains above the critical threshold of 1.8 m for a longer duration than observed in the upward evacuation scenario. Simulations further indicate that neither high temperatures nor carbon monoxide concentrations reach hazardous levels in either evacuation mode, ensuring evacuee safety. The study concludes that, with appropriate training arrangements and under specific fire and evacuation conditions, the partial downward evacuation strategy is safer and more efficient than upward evacuation. Full article

Earthquakes can trigger emergency braking in urban rail systems, yet the combined effect of braking and ground motion on train–bridge safety remains poorly quantified. Using the Wuxi Metro Line S1 (160 km/h initial speed) on a ten-span simply supported bridge as a case study, we build a multi-body dynamic subway model coupled to a finite element track–bridge model with non-linear Hertz wheel–rail contact. Under the design-basis earthquake (PGA ≈ 0.10 g), the train’s derailment coefficient and lateral car body acceleration rise by 37% and 45%, while the bridge’s lateral and vertical accelerations increase by 62% and 30%, respectively. Introducing a constant emergency brake deceleration of 1.2 m/s² cuts those train-side peaks by 20–25% and lowers the bridge’s lateral acceleration by 18%. The results show that timely braking not only protects passengers but also mitigates seismic demand on the structure, offering quantitative guidance for urban rail emergency protocols in earthquake-prone regions. Full article

Prefabricated structures have gained wider application. However, there is little research on the vibration response of prefabricated frame structures in subway environments. Prolonged metro-induced vibrations may severely degrade human comfort levels for nearby residents, interfere with the operation of precision instruments, and accelerate structural fatigue damage. Consequently, it is imperative to investigate the vibration response patterns of prefabricated frame structures under metro operational conditions. Structural vibration responses demonstrated greater sensitivity to column sections and slab thickness than beam dimensions when using semirigid connections, though marginal effects emerged with parameter increases. Enhanced vibration thresholds require supplementary vibration reduction measures. Increasing total spans proved more effective in vibration reduction than adding stories, with vibration transmission exhibiting notable edge effects. Related research can provide reference for the structural design of prefabricated frame structures around the subway. Full article

Under the backdrop of urban renewal, harmonizing transit-oriented development (TOD) with urban renewal to maximize rail value has emerged as a critical focus in contemporary planning. Based on this, this paper proposes the node–place–revenue (NPR) model, which constructs evaluation indexes from the three dimensions of the node, place, and revenue. It determines the weights of each index by using expert scoring and the Analytic Hierarchy Process (AHP). Taking Shenyang Metro Line 1 as an example, the study first used the model to measure the node value, place value, and revenue value of each sample TOD station area. Secondly, K-means clustering analysis was used to form a spatial classification of five station areas. Finally, this paper proposes one differentiated urban renewal strategy for each type of station area. It is found that (1) the NPR model classifies stations into five categories: stress and high revenue, balanced, unbalanced node, unbalanced place, and dependence and low revenue and (2) the differentiated urban renewal strategies for each type of station area can be explored in terms of precise decongestion, node upgrading, function expansion, endogenous optimization, and infill quality improvement. This paper examines the economic driving effect of Shenyang Metro Line 1 stations on the renewal of the surrounding areas from the perspective of the economic balance of payments, providing a new reference for Shenyang-rail-transit-guided urban renewal work. Full article

Background/Objectives: The COVID-19 pandemic, caused by severe acute respiratory syndrome coronavirus type-2 (SARS-CoV-2), has resulted in 777 million cases worldwide. Various vaccines have been approved to control the spread of COVID-19, with mRNA vaccines (Pfizer and Moderna) being widely used in the USA. We conducted a prospective longitudinal study to analyze the immune response elicited by two/three and four doses of monovalent mRNA vaccines in both vaccinated individuals and those who experienced breakthrough infections. Participants were stratified into different age groups: 18–40, 41–60, and over 60 years. Methods: We assessed cross-variant neutralization responses in two cohorts—Cohort I: n = 167 (serum), Cohort II: n = 92 (serum and nasal swab) samples—using infectious virus microneutralization assay (MN) and antibody (IgG or IgA) binding ELISA titers to the spike protein receptor binding domain (RBD). Samples were collected from the Louisville Metro–Jefferson County Co-Immunity Project, a federally funded, population-based study for the surveillance of SARS-CoV-2 in Jefferson County, Kentucky during 2020–2022, involving both health care workers and a local community. Results: Individuals who received two doses of the mRNA vaccine exhibited reduced neutralization against Beta, Delta, and Omicron BA.1 variants compared to wildtype Wuhan, with further decline observed six months post-booster vaccination. However, individuals who experienced natural COVID-19 infection (breakthrough) after receiving two vaccine doses showed enhanced neutralization and antibody responses, particularly against Omicron BA.1. Following the 3rd dose, antibodies and neutralization responses were restored. Among triple-vaccinated individuals, reduced neutralization was observed against Omicron variants BA.1, BA.5, and BA.2 compared to Wuhan. Neutralization responses were better against BA.2 variant compared to BA.1 and BA.5. However, individuals who received three doses of vaccine and experienced a breakthrough infection (n = 45) elicited significantly higher neutralizing antibodies responses against all Omicron subvariants compared to vaccinated individuals. Interestingly, nasal swab samples collected from volunteers with breakthrough infection showed significantly elevated spike-reactive mucosal IgA antibodies and enhanced cross neutralization against BA.1, BA.2, and BA.5 compared to individuals who received only three vaccine doses. Conclusions: mRNA vaccination elicits a strong systemic immune response by boosting serum neutralizing antibodies (NAb), although this protection wanes over time, allowing new variants to escape neutralization. Breakthrough individuals have extra enrichment in nasal NAb offering protection against emerging variants. This longitudinal immune profiling underscores the strengthening of pandemic preparedness and supports the development of durable mucosal vaccines against respiratory infectious disease. Full article

The construction of subways exacerbates the non-uniformity of surface deformation, which in turn poses a potential threat to the safe construction and stable operation of urban rail transit systems. Beijing, the city with the most extensive subway network in China, has long been affected by land subsidence. Utilizing data from Envisat ASAR, Radarsat-2, and Sentinel-1 satellites, this study employs PS-InSAR technology to monitor and analyze land subsidence within a 2 km buffer zone along Beijing Metro Line 22 over a span of 20 years (from January 2004 to November 2024). The results indicate that land subsidence at Guanzhuang Station and Yanjiao Station along Metro Line 22 is particularly pronounced, forming two distinct subsidence zones. After 2016, the overall rate of subsidence along the subway line began to stabilize, with noticeable ground rebound emerging around 2020. This study further reveals a strong correlation between land subsidence and confined groundwater levels, while geological structures and building construction also exert a significant influence on subsidence development. These findings provide a crucial scientific foundation for the formulation of effective prevention and mitigation strategies for land subsidence along urban rail transit lines. Full article

Adolescents living with HIV (ALHIV) (10–19 years) make up approximately 4.2% (320,000) of people living with HIV in South Africa. Adolescence is a developmental period characterized by pervasive biological, social and psychological changes, which challenges adherence and retention in care for ALHIV on antiretroviral therapy (ART). Further, as ALHIV grow “older”, they are expected to transition to the adult HIV treatment programme, where they should assume greater responsibility for managing their chronic condition and healthcare pathway. Whereas it is imperative that ALHIV are transitioned when they are ready, little is known about the challenges and experiences of ALHIV before and during transition. The aim of this paper was to report on the experiences and challenges of transition for ALHIV who received ART at an adolescent-friendly service that is adjunct to a public primary healthcare facility in the Western Cape province of South Africa. Methods: Photovoice methods were employed to explore the transition experiences of ALHIV on ART at a “supportive transition” public health facility in the Cape Town Metro in South Africa. Participants took pictures that depict their experience pre- and during transition to adult care and discussed these in groups with peers. Audio data were digitally recorded and transcribed verbatim and subjected to thematic analysis using Atlas.Ti version 24. Results: The emergent themes described their apprehension to transitioning to adult care; self-management; challenges to adherence; the need for psychosocial support; and how adolescent-friendly services were filling the gap. Conclusions: We illuminate the “I-We-I” configuration, to reflect (the first “I”) individual ALHIV experiences as isolated before being transferred to the supportive facility; how they experience a sense of belonging and family (“we”) in the supportive facility; but face apprehension about transitioning to adult care in the local clinic, where they have to self-manage (final “I”). Full article

The span of pile foundations beneath metro depots typically ranges from 10 to 20 m, exhibiting a notably large span. This structural characteristic results in the pile foundations bearing a more concentrated upper load, while the interstitial soil between the piles bears minimal force. Concurrently, global climate change and enhanced urban greening initiatives have led to a significant increase in rainfall in northwest China, a region traditionally characterized by arid and semi-arid conditions. This climatic shift has precipitated a continuous rise in groundwater levels. Furthermore, the extensive distribution of collapsible loess in this region exacerbates the situation, as the rising groundwater levels induce loess collapse, thereby adversely affecting the mechanical behavior of the pile foundations. In light of these factors, this study utilized the pile foundations of a metro depot in Xi’an as a prototype to conduct static load model tests under conditions of rising groundwater levels. The experimental results reveal that the load–settlement curve of the pile foundations in the absence of groundwater exhibited a steep decline with distinct three-stage characteristics, and the ultimate bearing capacity was determined to be 5 kN. When the groundwater level is situated below the loess stratum, the settlement of both the pile foundations and the foundation soil, as well as the axial force, skin friction, and pile tip force, remains relatively stable. However, when the groundwater level rises to the loess stratum, there is a significant increase in the settlement of the pile foundations and foundation soil. Negative skin friction emerges along the pile shaft, and the bearing type of the pile foundation transitions gradually from a friction pile to an end-bearing pile. The influence range of the pile foundation on the settlement of the foundation soil is approximately three times the pile diameter. Full article

Ethnic segregation, a global phenomenon shaping social dynamics, urban development, and political behavior, is typically studied between distinct racial or national groups. This study provides insights into internal divisions within seemingly unified populations by investigating intra-group segregation within Israel’s ultra-Orthodox (Haredi) Jewish communities. By analyzing Knesset voting patterns as a proxy for residential distribution, I quantify segregation between two major ethnic groups within the Haredi community and identify significant segregation across Haredi-majority cities and clusters. Dissimilarity indices reveal distinct voluntary segregation patterns, with the city of Ashdod emerging as a unique case study due to its dynamic segregation trends and an unexplained sharp decline in dissimilarity in 2021. A comparison with Black–White segregation in U.S. metro areas highlights differing drivers of segregation: cultural and religious dynamics in Haredi communities versus structural inequalities in the U.S. Despite relatively lower dissimilarity scores, cultural and institutional factors reinforce residential separation. This research underscores the need for continued exploration of segregation’s underlying drivers and its implications for fostering more cohesive societies. Full article

This systematic literature review (SLR) focuses on indoor environmental quality (IEQ) in passenger transport vehicles within tropical and subtropical regions. It specifically examines indoor air quality (IAQ), thermal comfort (TC), acoustic comfort (AC), and visual comfort (VC) of passenger vehicle cabins (PVCs) in auto rickshaws, sedans, trucks, bus rapid transits (BRTs), buses, trains, trams, metro systems, aircraft and ferries of tropical and subtropical regions. The SLR used the PRISMA approach to identify and review scientific studies between 2000 and 2024 on the IEQ of PVCs in the tropics. Studies reviewed were found in SCOPUS, Web of Science, Science Direct, and EBSCO databases including relevant citation references. Findings reveal a significant geographical imbalance in research, with most studies concentrated in tropical Asia (78.2%), while sub-Saharan Africa (8.2%), South America (11.8%), and Oceania (1.8%) are considerably underrepresented. In 113 studies, most addressed IAQ and TC but limited attention to AC and VC. Moreover, fewer studies have jointly addressed all the IEQ parameters, highlighting the need for a more comprehensive approach to IEQ for tropical PVCs. Several studies alluded to in-cabin commuter risk linked to PM_2.5, PM₁₀, carbon monoxide (CO), and volatile organic compounds (VOCs). These risks are exacerbated by traffic hotspots, poor ventilation, ambient pollution, overcrowding, and poor vehicle conditions. Additionally, thermal discomfort is compounded by extreme heat loads, inefficient HVAC systems, and high vehicle occupancy. Common gaps include a paucity of IEQ studies and inadequate IEQ regulations or adapted standards in developing tropics. Infrastructural and regulatory deficiencies have been identified, along with strategies for mitigation. Recommendations are for more holistic IEQ studies in the tropics, including exposure studies for emerging gaps in new indoor pollutants, integration of AI and IoT for sustainable ventilation strategies, and development of effective regulatory frameworks considering region-specific conditions. Finally, Policymakers are encouraged to establish localized IEQ standards, enforce regulations, and prioritize upgrades to transport infrastructure. The SLR findings emphasize the urgent need for targeted interventions in developing tropical regions to address disparities in IEQ, ensuring healthier and more sustainable transport environments that could be replicated across transport systems worldwide. Full article

Bike-sharing has emerged as an innovative green transportation mode, showing promising potential in addressing the ‘last-mile’ transportation challenge in an eco-friendly manner. However, shared bikes around metro stations often face supply–demand imbalance problems during peak hours, causing bike shortages or congestion that compromise user experience and bike utilization. Accurate prediction enables operators to develop rational dispatch strategies, improve bike turnover rate, and promote synergistic metro–bike integration. However, state-of-the-art research predominantly focuses on improving complex deep-learning models while overlooking their inherent drawbacks, such as overfitting and poor interpretability. This study proposes a model–data dual-driven approach that integrates the classical statistical regression model as a model-driven component and the advanced deep-learning model as a data-driven component. The model-driven component uses the Seasonal Autoregressive Integrated Moving Average (SARIMA) model to extract periodic patterns and seasonal variations of historical data, while the data-driven component employs an Extended Long Short-Term Memory (xLSTM) neural network to process nonlinear relationships and unexpected variations. The fusion model achieved R-squared values of 0.9928 and 0.9770 for morning access and evening egress flows, respectively, and reached 0.9535 and 0.9560 for morning egress and evening access flows. The xLSTM model demonstrates an 8% improvement in R² compared to the conventional LSTM model in the morning egress flow scenario. For the morning egress and evening access flows, which exhibit relatively high variability, classical statistical models show limited effectiveness (SARIMA’s R² values are 0.8847 and 0.9333, respectively). Even in scenarios like morning access and evening egress, where classical statistical models perform well, our proposed fusion model still demonstrates enhanced performance. Therefore, the proposed data–model dual-driven architecture provides a reliable data foundation for shared bike rebalancing and shows potential for addressing the challenges of limited robustness in statistical regression models and the susceptibility of deep-learning models to overfitting, ultimately enhancing transportation ecosystem sustainability. Full article

The spread of panic can swiftly trigger group behaviors, leading to public security incidents and significant social hazards. Increasing attention is being paid to the impact of human psychology and behavior on the evolution and management of emergencies. Drawing on the Weber–Fechner Law, we proposed an emotional contagion model to explore the dynamics of crowd panic during metro emergencies, focusing on the interplay of emotional levels and stimuli. Key influencing factors such as crowd density, personality traits, official interventions, and evacuation rates are analyzed. Additionally, a case study is conducted to validate the model’s effectiveness in quantifying emotions and characterizing the emotional contagion of crowd panic. Numerical results reveal that the initial intensity of panic stimuli significantly impacts peak panic levels, while contagion duration plays a minor role. Panic intensifies with increased crowd density, with sensitive individuals being more susceptible to extreme emotions, escalating negative contagion. Official intervention proves crucial in mitigating panic, though its effect is transient in enclosed environments. Evacuation rate minimally affects emotional contagion during the train’s motion but becomes pivotal post-arrival. Highly panicked passengers evacuate quickly, necessitating timely interventions to prevent secondary panic on platforms. This highlights the importance of immediate, effective control measures to manage panic dynamics and ensure public safety. Full article

Utilizing the intermediate air shaft for smoke exhaust is one of the crucial emergency ventilation methods in metro tunnel fires. To study the impact of metro tunnel slope on smoke exhaust performance of intermediate air shaft, this paper employs numerical simulation to conduct research from the following aspects: the longitudinal distribution of ceiling smoke temperature, visibility distribution, smoke layer height, and the smoke exhaust efficiency of intermediate air shaft. The results demonstrate that as the tunnel slope increases, the maximum ceiling temperature decreases, and the visibility at dangerous height increases. The smoke layer height on the downhill side of a sloped tunnel is higher than that of a horizontal tunnel, while the smoke layer height on the uphill side is lower. Under single-side smoke exhaust mode, the smoke exhaust efficiency of the 2# intermediate air shaft rises as the tunnel slope increases. However, under air supply plus smoke exhaust mode, the smoke exhaust efficiency of the 2# intermediate air shaft decreases with the growing tunnel slope. Full article

Background/Objectives: In the postpartum period, approximately 12% of patients seek care in the emergency department (ED), with a higher representation of Black patients. Hypertension is a common reason for ED visits during this period, often leading to dangerously delayed diagnosis and treatment. Objective: This study aims to assess the time to diagnosis and treatment of hypertensive disorders in the postpartum period in the ED, focusing on potential disparities in care, to identify areas for quality improvement. Design: Retrospective cohort study. Setting: A multi-centered large medical institution in the metro Detroit area. Methods: Postpartum patients (day 2 through day 28) presenting to the ED from November 2015 to December 2022. Exposures: none. Main Outcome Measures: Primary analysis assessed the time elapsed between severe-range blood pressure readings (greater than/equal to 160 systolic and/or 110 diastolic) and the administration of antihypertensives. Secondary analyses assessed the presence of essential laboratory workups such as complete blood counts, complete metabolic panels, and urine protein and creatinine. Results: Among the 430 women who presented to the ED during the postpartum period with hypertension, 372 (86.5%) exhibited severe-range blood pressure (greater than/equal to 160 systolic and/or 110 diastolic). Patients presented on average on postpartum day 6. Of the patients with severe hypertension, only 72% received a complete blood count, 66% underwent evaluation of creatinine and liver profile, and 4% had a urine protein and creatinine test ordered. The average time from severe-range blood pressure reading to antihypertensive administration was 189 min for Black patients and 370 min for White patients. There were no statistically significant differences in the time of the first blood pressure reading, laboratory evaluation, or treatment of severe-range blood pressure between racial groups. Conclusions: This study identifies the most significant area for improvement in the timely administration of antihypertensive medication following severe-range blood pressure readings. Additional areas for improvement were observed in ordering essential laboratory tests to assess the severity of preeclampsia. The institution demonstrated delayed yet equitable care for White and Black patients, contrary to the existing literature indicating potential racial disparities. A targeted quality improvement plan has been implemented to improve the identified areas of concern to adhere to the ACOG’s treatment recommendations for hypertensive disorders of pregnancy. The impact on patient care will be reassessed at the 1-year mark. Full article