Search Results (40)

The adoption of predictive maintenance in public transportation has gained increasing attention in the context of Industry 4.0. However, many urban bus fleets remain in early digital transformation stages, with limited historical data and fragmented infrastructures that hinder the implementation of data-driven strategies. This study proposes a reproducible Machine Learning pipeline tailored to such data-scarce conditions, integrating domain-informed feature engineering, lightweight and interpretable models (Linear Regression, Ridge Regression, Decision Trees, KNN), SMOGN for imbalance handling, and Leave-One-Out Cross-Validation for robust evaluation. A scheduled batch retraining strategy is incorporated to adapt the model as new data becomes available. The pipeline is validated using real-world data from hybrid diesel buses, focusing on the prediction of time spent in critical soot accumulation zones of the Diesel Particulate Filter (DPF). In Zone 4, the model continued to outperform the baseline during the production test, indicating its validity for an additional operational period. In contrast, model performance in Zone 3 deteriorated over time, triggering retraining. These results confirm the pipeline’s ability to detect performance drift and support predictive maintenance decisions under evolving operational constraints. The proposed framework offers a scalable solution for digitally emerging fleets. Full article

Algae-based supplements are gaining attention for their potential metabolic, antioxidant, and anti-inflammatory properties in sports nutrition. Methods: A 30-day pilot randomized controlled trial was conducted in 70 healthy male athletes (mean age 25.4 ± 4.9 years) from competitive soccer and handball teams. Participants were randomly assigned to a supplementation group (6 g/day of Ulva-derived algae powder) or a control group. Both groups followed identical training routines and adhered to standardized nutritional recommendations, including macronutrient distribution and permitted supplements (e.g., isotonic drinks, protein shakes). Biochemical markers analyzed at baseline and post-intervention included HbA1c, lipid profile, malondialdehyde (MDA), catalase, myeloperoxidase (MPO), erythrocyte sedimentation rate (ESR), and cortisol. Genetic polymorphisms related to metabolic traits were also assessed. Results: Significant group × time interactions (p < 0.001) were observed for HbA1c, LDL, triglycerides, MDA, MPO, ESR, and cortisol, all of which improved in the algae-supplemented group. Correlation analysis revealed associations between HbA1c and LDL/TG as well as between cortisol and MPO. No significant genetic modulation of responses was detected, although a trend was noted for cortisol variation and insulin resistance risk. Conclusions: Algae-based supplementation led to favorable metabolic, oxidative, and inflammatory changes. These findings suggest its potential utility as a nutritional strategy to support recovery in athletes during periods of high training load or competition. Full article

This study presents an artificial intelligence-based approach for the pose detection of passengers’ skeletons when boarding and alighting from an urban bus in Valparaíso, Chile. Using the AlphaPose pose estimator and an activity recognition model based on Random Forest, video data were processed to analyze the poses and activities of passengers. The results obtained allow for an evaluation of safety and ergonomics in public transportation, providing valuable information for improving design and accessibility in buses. This approach not only enhances understanding of passenger behavior but also contributes to the optimization of bus systems to accommodate diverse needs, ensuring a safer and more comfortable environment for all users. AlphaPose accurately estimates the posture of passengers, offering insights into their movements when interacting with the bus. In addition, the Random Forest model recognizes a variety of activities, from walking to sitting, helping to analyze how passengers interact with the space. The analysis helps identify areas where improvements can be made in terms of accessibility, comfort, and safety, contributing to the overall design of public transport systems. This study opens up new possibilities for AI-driven urban transportation analysis and can serve as a foundation for future improvements in transportation planning. Full article

This study explores the passengers’ accessibility dilemma in Valparaíso, Chile, through field observations and laboratory experiments. The aim is to investigate the accessibility in metro stations based on the users’ emotional experience. Perceptions were reported through the emotions of passengers according to a circumplex psychological model and an accessibility ranking. Passengers reported their emotions (e.g., stress, sadness, relaxation, and happiness) during different trip moments. Results indicate that rearranging train seats parallel to movement creates a more spacious aisle, enhancing mobility and evoking positive emotions such as happiness. However, an unexpected rise in sadness suggests that social dynamics may influence emotional responses, warranting further investigation. Overcrowding increases stress and sadness, emphasizing the need for capacity management to improve passengers’ emotional experiences. Field observations reveal that early journey stages, such as walking to the station or waiting on the platform, are associated with unpleasant experiences due to poor infrastructure and accessibility barriers. In contrast, train rides foster more positive emotions, credited to better accessibility onboard. Passenger dissatisfaction arises from issues such as elevator malfunctions, inconsistent train schedules, and inadequate station accessibility. This study could help to understand passenger behavior when the accessibility conditions of metro stations and their surroundings are changed. Further studies will expand the concept of emotions by considering social and psychological factors and explore different types of stations and their surroundings considering a larger sample size in laboratory experiments and field studies. Full article

The efficiency of a metro station is determined by the transfer capacity it has on the platform. This is the critical area and the primary motivation for this research. This study analyzed the impact of platform typology on the efficiency and capacity of metro stations. Through the study, the simulation of different typologies, the design logic of the station was analyzed from the ground up, examining each of its components from both a physical and operational perspective. To evaluate the efficiency and capacity of a platform configuration, Fruin’s level of service or LOS is used to compare the efficiency across different platform typologies, allowing for the quantification of constraints within the platform configuration. The platform configuration, access points, and connectors impact the station’s transfer capacity. This configuration must align with the environmental conditions and the station’s role within the system as a whole. The mixed-platform station configuration is twice as efficient as a central platform station and slightly more efficient than a side-platform station, with variations depending on station usage, environment, and position within the network. Under symmetric flow conditions, the side platform is more efficient, reaching a LOS D (density between 1.54 and 3.57 passengers/m²). Under asymmetric flow conditions, the central platform is more efficient, reaching a LOS D. However, under both symmetric and asymmetric flow conditions, the mixed platform is more efficient than the two previous configurations, and this design is proposed as the most suitable for transfer station designs, reaching a LOS D. A modular station design is proposed, where a mixed station is built with the capacity to expand based on increased passenger demand. This means constructing a central-platform station initially, and when the capacity is reached (LOS = E or density of 5.26 passengers/m²), the second phase is built, adding lateral platforms, thus converting it into a mixed station and doubling its capacity. Full article

Crowd management at turnstiles in metro stations is a critical task for ensuring safety, efficiency, and comfort for passengers. A methodology based on observation and microsimulation provides an advanced understanding and optimization of crowd flow through these turnstiles. The aim is to optimize crowd management and prevent overcrowding and delays at metro turnstiles through innovative solutions. The methodology is based on simulating passenger movements through turnstiles to observe and optimize crowd behavior. The results show that passenger decisions (e.g., choosing which turnstile to use, adjusting pace) are based on perceived crowd density, level of service, and usage of space. For instance, the number of turnstiles, their location, and the layout are important variables to be considered in the decision-making sequence. These decisions can be influenced by parameters like turnstile availability, walking paths, and real-time data (e.g., density of passengers). The methodology can help metro operators decide where to place additional turnstiles or adjust operational schedules. By simulating crowd behavior, operators can make informed decisions to reduce congestion and improve the efficiency of turnstile usage. This methodology could be implemented in various metro systems to optimize operations during different crowd conditions and peak times, ensuring smooth, safe, and efficient passenger flow. Full article

Cities are growing larger, and congestion is becoming a major issue. Walking is increasingly becoming an important mode of transport in developing cities. One of the reasons for the high death toll is the lack of pedestrian facilities at transport infrastructures such as signalized intersections, where a conflict arises between vehicles turning right and pedestrians crossing at different speeds. This conflict, known as the vehicle–pedestrian conflict (in right-driving jurisdictions), occurs when the green light for vehicles is shared with the green pedestrian light. Additionally, if the intersection is congested due to high pedestrian flow, vehicles will turn right only during the yellow light, trying to find a gap in the pedestrian flow. As a result, delays increase for both pedestrians and vehicles, reducing the intersection’s capacity. To reduce the vehicle–pedestrian conflict, various pedestrian facilities can be implemented, such as Shibuya-type crossings, which include an exclusive pedestrian phase and diagonal crossing. When applying this type of solution, vehicle delays are reduced up to 81% on average, increasing the efficiency and safety of the space used at the intersection. However, pedestrian delays might increase up to 5 times, due to the need to wait for the third exclusive phase for them to cross the intersection in all directions. The method is applied in a case of study in Valparaiso, Chile, and therefore can be expanded in further research to other developing cities in Chile and specifically Latin America. Full article

(1) Background/Objectives: Cardiovascular diseases (CVD) are the leading cause of morbidity and mortality globally, necessitating effective risk prediction strategies. This study was aimed at developing and validating a multivariate predictive model integrating body composition and lipid profile to assess cardiovascular risk in an adult population. (2) Methods: A cross-sectional analysis of 90 participants from the general Spanish population was conducted. Participants were classified into cardiovascular risk groups (low, medium, high) based on systolic blood pressure. (3) Results: Descriptive and multinomial logistic regression analyses revealed significant associations between cardiovascular risk and specific parameters, such as visceral fat, glucose levels, and waist-to-hip ratio. Visceral adiposity emerged as a strong predictor of high cardiovascular risk, highlighting its critical role in cardiovascular health. Glucose levels were also significantly associated with increased risk, underscoring the importance of metabolic health in cardiovascular outcomes. Contrary to expectations, lipid markers like cholesterol and triglycerides did not show significant variations across risk categories, suggesting that traditional lipid profiles may not fully capture cardiovascular risk in the study group. Waist-to-hip ratio showed significant associations with cardiovascular risk transitions, particularly between low and medium risk, emphasizing the importance of fat distribution patterns. (4) Conclusions: These findings suggest that body composition, particularly visceral fat, is a crucial determinant of cardiovascular risk, necessitating more personalized risk assessment approaches that move beyond traditional lipid markers. Full article

Metro stations are essential for daily commuting, but overcrowding due to increased demand can severely impact infrastructure quality and passenger experience. The Level of Service (LOS), a key indicator of congestion, is influenced by factors such as density, flow, and speed, and poor LOS leads to issues like longer boarding times, overcrowded platforms, and reduced accessibility, especially for vulnerable populations. To address these challenges, the study explores innovative solutions to improve platform design infrastructure for better accessibility and LOS, aligning sustainable development goals to create safer, more inclusive transport systems. This study presents two strategies designed to reduce passenger congestion at Francia station on the Valparaíso metro platform infrastructures. The strategies, tested in experimental scenarios, showed minimal differences in boarding and alighting times, with less than a one-second average variation between the two. However, survey results revealed that passengers preferred the strategy “let passengers alight before boarding the train”, as it provided greater comfort and accessibility, reducing the number of passengers per door and improving the LOS from level C to B. Despite the minimal intervention in the experiments, the results suggest potential operational improvements. Future research will focus on measuring passengers’ emotional responses using psychophysiological data to further evaluate the suitability of the proposed strategies. Full article

The need to assess whether accessibility in urban mobility meets the required standards to provide a satisfactory experience for users is emphasized. The general objective of this research is to evaluate pedestrian accessibility in urban mobility, taking as a case study different access points such as the sidewalks and crossings between the trolleybus system and the EFE metro system in Valparaíso. Specific objectives have been set, including identifying the area to study and the elements to evaluate, designing an evaluation system, and applying descriptive and numerical methods for the assessment. The methodology used includes two approaches: the descriptive, which provides a detailed view of accessibility conditions in each evaluated area, highlighting aspects such as physical condition and compliance with regulations, and the numerical, which assigns quantitative values to the elements being assessed to establish a classification of accessibility levels. Additionally, a survey was conducted to obtain a subjective view of pedestrian preferences. Based on the above, evaluating pedestrian accessibility in urban mobility in Valparaíso allowed for identifying aspects that require improvement to ensure a satisfactory experience for users. Furthermore, it promotes the use of both transportation systems and provides recommendations for future research. Full article

Microplastics are plastic particles ranging in size from 1 μm to 5 mm, emitted at the source or resulting from the degradation of larger objects. Today, their global distribution is one of the major environmental problems recognized by the United Nations Sustainable Development Goals, polluting aquatic, terrestrial and atmospheric systems and requiring avant-garde solutions. Solid–liquid filtration is widely used in both industrial and biological systems, where some aquatic species are examined using very specialized filter-feeding apparatus, and when applied to industrial processes, microparticles can be separated from the water while minimizing maintenance costs, as they require less backwashing or additional energy consumption. The REMOURE project uses the Mediterranean species Mobula mobular (Bonnaterre, 1788) as a reference for the testing and optimization of low-cost microplastic filters applied to wastewater. For this purpose, a hydrodynamic test rig was designed and constructed by considering the hydraulic feeding conditions of the marine species, with a scale factor of 6. This paper presents the design conditions and the evaluation of the test results for the combination of three different variables: (1) flap disposition (two different models were considered); (2) inclination with respect to the flow direction; and (3) flow velocity. The models were printed in polyamide and videos were recorded to evaluate the behaviour of dye injection through the lobes. The videos were processed, and the results were statistically treated and used to calibrate a CFD model to optimize the filter design to be studied in a prototype wastewater treatment plant. Full article

This study analyses the potential carrying of bicycles inside a train carriage. To this end, an experimental methodology based on observation and experimentation is implemented. The survey is conducted on the metro system in Valparaíso, Chile, highlighting the importance of intermodality between bicycles and trains. It identifies that the current capacity of the carriages is not adequate to ensure safety and efficiency during boarding and alighting. As a result of the survey, a solution is tested to reduce the number of seats in the carriage and create a designated special waiting area for cyclists. This test is conducted experimentally in a laboratory, using a full-scale model of a metro carriage and its corresponding platform. The experiments show that the designated special waiting area for bicycles reduces boarding time and results in a better distribution of passengers inside the carriage, offering a solution that improves both safety and efficiency. This study could contribute to the development of incentive policies for intermodality, which is a key aspect in achieving sustainability in railway transportation systems. Future research will aim to expand this study by including other carriage configurations and a wider variation of demand levels. Full article

The Escherichia coli Keio mutant collection has been a tool for assessing the role of specific genes and determining their role in E. coli physiology and uncovering novel functions. In this work, specific mutants in the DNA repair pathways and oxidative stress response were evaluated to identify the primary targets of silver nanoparticles (NPs) and their mechanism of action. The results presented in this work suggest that NPs mainly target DNA via double-strand breaks and base modifications since the recA, uvrC, mutL, and nfo mutants rendered the most susceptible phenotype, rather than involving the oxidative stress response. Concomitantly, during the establishment of the control conditions for each mutant, the katG and sodA mutants showed a hypersensitive phenotype to mitomycin C, an alkylating agent. Thus, we propose that KatG catalase plays a key role as a cellular chaperone, as reported previously for the filamentous fungus Neurospora crassa, a large subunit catalase. The Keio collection mutants may also be a key tool for assessing the resistance mechanism to metallic NPs by using their potential to identify novel pathways involved in the resistance to NPs. Full article

This study explored the crucial relationship between base fluids and polyamide, a prevalent polymer in electric vehicle (EV) components, with the aim of enhancing the longevity and performance of EVs in the context of thermal management by immersion cooling. Focusing on polyalphaolefin and polyol ester as base fluids, an immersion test was conducted to assess their interaction with polyamide 6 using adapted ASTM standards. The results revealed the significant influences of both fluids on the physical properties and chemical structure of polyamide. Polyol ester demonstrated a lesser impact on the chemical and mechanical properties of polyamide 6. Full article

Bivalves accumulate toxins produced by microalgae, thus becoming harmful for humans. However, little information is available about their toxicity to the bivalve itself. In the present work, the physiological stress and damage after the ingestion of toxic dinoflagellate species (Gymnodinium catenatum) and a diatom species (Skeletonema marinoi, which is non-toxic to humans but may be to grazers) in the oyster Magallana angulata are evaluated against a control treatment fed with the chlorophyte Tetraselmis sp. Oysters were exposed for two hours to a concentration of 4 × 10⁴ cells/L of G. catenatum and 2 × 10⁷ cells/L of S. marinoi. The biomarkers superoxide dismutase (SOD), catalase (CAT), glutathione S-Transferase, total Ubiquitin (Ubi) and Acetylcholinesterase (AchE) were assessed. The exposure of M. angulata to G. catenatum lead to a reduction in SOD and AchE activity and ubiquitin concentrations when compared to the control treatment. Moreover, it increased CAT activity in the adductor muscle, and maintained its activity in the other tissues tested. This may be related to the combination of reduced metabolism with the deployment of detoxification processes. S. marinoi also lead to a decrease in all biomarkers tested in the gills and digestive glands. Therefore, both species tested caused physiological alterations in M. angulata after two hours of exposure. Full article