Search Results (603)

The ongoing effects of climate change have led to a rise in global temperature, significantly reducing snow cover and resulting in the abandonment of numerous ski areas across Switzerland. As a result, many ski lifts have been decommissioned and left to deteriorate due to lenient local regulations. To address this issue, this paper presents a case study approach to repurposing steel trusses from abandoned ski lifts for a new structural application within the building industry. The design, sourcing, and construction of a new load-supporting column are described, focusing on reusing the ski lift steel trusses as a whole, without dismantling them into their components. After collection, these elements are adapted to comply with current building standards. By pouring out the hollow structure with the recently developed building material Cleancrete ©, a new load-bearing structure is developed. A comprehensive life cycle assessment (LCA) demonstrates the environmental performance of the steel–Cleancrete hybrid construction, which achieves a global warming potential (GWP) of 536.58 kg CO₂-eq. In comparison, alternative designs using wood and concrete exhibited GWP values of 679.45 kg CO₂-eq, +26.6%, and 1593.72 kg CO₂-eq, +197.02%, respectively. These findings suggest that repurposing abandoned ski lift structures can significantly contribute to sustainable building practices, waste reduction, and the promotion of circular economy principles. The process outlined in this paper holds potential for future applications, particularly in the reuse of other steel components, ensuring continued circularity even as the supply of ski lift structures may dwindle. Full article

The aim of this current work is to identify three different gears of cross-country skiing utilizing embedded inertial measurement units and a suitable deep learning model. The cross-country style studied was the skating style during the uphill, which involved three different gears: symmetric gear pushing with poles on both sides (G3) and two asymmetric gears pushing with poles on the right side (G2R) or to the left side (G2L). To monitor the technique, inertial measurement units (IMUs) were affixed to the skis, recording acceleration and Euler angle data during the uphill tests performed by two experienced skiers using the gears under study. The initiation and termination points of the tests were controlled via Bluetooth by a smartphone using a custom application developed with Android Studio. Data were collected on the smartphone and stored on the SD memory cards included in each IMU. Convolutional neural networks combined with long short-term memory were utilized to classify and extract spatio-temporal features. The performance of the model in cross-user evaluations demonstrated an overall accuracy of 90%, and it achieved an accuracy of 98% in the cross-scene evaluations for individual users. These results indicate a promising performance of the developed system in distinguishing between different ski gears within skating styles, providing a valuable tool to enhance ski training and analysis. Full article

Climate change is a major challenge for the global tourism sector, affecting destinations worldwide. Greece, known for its scenery and abundant cultural history, is particularly vulnerable to these impacts. Tourism is a key driver of Greece’s economy, yet climate change threatens both natural environments and cultural sites. To evaluate the impacts of climate change on different types of Greek tourism (beach, sightseeing, winter tourism in mountainous areas), the widely used Holiday Climate Index (beach and urban versions) alongside three additional climatic indices customized for Greek climatic conditions, namely the Urban Climate Comfort Index, the Beach Utility Index, and the Mountainous Winter Climate Index were utilized for top tourist destinations of Greece. The results indicate that urban tourism may face challenges during peak summer months due to rising temperatures, but the shoulder seasons (April–May and September–October) will offer improved conditions, potentially extending the tourist season. For beach tourism, favorable conditions are expected to increase from April to October, with significant gains in June and September. Winter tourism in mountainous areas, especially snow-dependent activities like skiing, is at risk due to the declining snow availability. Overall, the study highlights both the challenges and opportunities posed by climate change for Greece’s tourism sector. It emphasizes the importance of adaptation strategies, including infrastructural improvements and promoting alternative activities, to minimize negative impacts and enhance the future attractiveness of Greek tourism. Full article

Near-surface air temperature (T_a) estimation by geostationary meteorological satellites is mainly carried out under clear-sky conditions. In this study, we propose an all-weather T_a estimation method utilizing FY-4A Advanced Geostationary Radiation Imager (AGRI) and the Global Forecast System (GFS), along with additional auxiliary data. The method includes two neural-network-based T_a estimation models for clear and cloudy skies, respectively. For clear skies, AGRI LST was utilized to estimate the T_a (T_a,clear), whereas cloud top temperature and cloud top height were employed to estimate the T_a for cloudy skies (T_a,cloudy). The estimated T_a was validated using the 2020 data from 1211 stations in China, and the RMSE values of the T_a,clear and T_a,cloudy were 1.80 °C and 1.72 °C, while the correlation coefficients were 0.99 and 0.986, respectively. The performance of the all-weather T_a estimation model showed clear temporal and spatial variation characteristics, with higher accuracy in summer (RMSE = 1.53 °C) and lower accuracy in winter (RMSE = 1.88 °C). The accuracy in southeastern China was substantially better than in western and northern China. In addition, the dependence of the accuracy of the T_a estimation model for LST, CTT, CTH, elevation, and air temperature were analyzed. The global sensitivity analysis shows that AGRI and GFS data are the most important factors for accurate T_a estimation. The AGRI-estimated T_a showed higher accuracy compared to the ERA5-Land data. The proposed models demonstrated potential for T_a estimation under all-weather conditions and are adaptable to other geostationary satellites. Full article

A comprehensive analysis of cross-country skiing races is a pivotal step in establishing effective training objectives and tactical strategies. This study aimed to develop a method of classifying sub-techniques and analyzing skiing characteristics during cross-country skiing skating style timed races on snow using high-precision kinematic GNSS devices. The study involved attaching GNSS devices to the heads of two athletes during skating style timed races on cross-country ski courses. These devices provided precise positional data and recorded vertical and horizontal head movements and velocity over ground (VOG). Based on these data, sub-techniques were classified by defining waveform patterns for G2, G3, G4, and G6P (G6 with poling action). The validity of the classification was verified by comparing the GNSS data with video analysis, a process that yielded classification accuracies ranging from 95.0% to 98.8% for G2, G3, G4, and G6P. Notably, G4 emerged as the fastest technique, with sub-technique selection varying among skiers and being influenced by skiing velocity and course inclination. The study’s findings have practical implications for athletes and coaches as they demonstrate that high-precision kinematic GNSS devices can accurately classify sub-techniques and detect skiing characteristics during skating style cross-country skiing races, thereby providing valuable insights for training and strategy development. Full article

CMTM6 is a membrane protein that acts as a regulator of PD-L1, maintaining its expression on the cell surface, and can prevent its lysosome-mediated degradation. It is unknown if CMTM6 is present in the plasma of patients with cervical cancer, and if it has non-canonical subcellular localizations in cell lines derived from cervical cancer. Our objective was to determine whether CMTM6 is found in plasma derived from cervical cancer patients and its subcellular localization in cell lines. Patient plasma was separated into exosome-enriched, exosome-free, and total plasma fractions. The levels of CMTM6 in each fraction were determined using ELISA and Western blot. Finally, for the cellular model, HeLa, SiHa, CaSki, and HaCaT were used; the subcellular locations of CMTM6 were determined using immunofluorescence and flow cytometry. Soluble CMTM6 was found to be elevated in plasma from patients with cervical cancer, with a nearly three-fold increase in patients (966.27 pg/mL in patients vs. 363.54 pg/mL in controls). CMTM6 was preferentially, but not exclusively, found in the exosome-enriched plasma fraction, and was positively correlated with exosomal PD-L1; CMTM6 was identified in the membrane, intracellular compartments, and culture supernatant of the cell lines. These results highlight that CMTM6, in its various presentations, may play an important role in the biology of tumor cells and in immune system evasion. Full article

This article draws on the stimulus–organism–response (SOR) model to understand the role of negative emotions in the anti-brand behaviors of online users who consume snow sports brands. To this end, both the online social influence and the mediating effect of symbolic incongruence (stimulus) on the generation of negative emotions (anger, stress, frustration, fear, boredom and sadness) (organism), and how these influence the formation of negative customer brand engagement (nCBE) (response), are analyzed. The study also analyses the moderating effects of “level of expertise”, this makes it possible to capture differences in behaviors based on the profile of the users in each of the proposed relationships. Questionnaire responses of 400 ski and snowboard users over 18 years of age were analyzed using a quantitative methodology. The results obtained have important theoretical and practical implications, since they confirm that online social influences have both a direct and indirect (mediating) effect on negative emotions, which positively affects the nCBE of online users of snow sports brands. Significant differences in behavior based on experience level (moderation effect) were also found. The study proposes useful practical recommendations applicable in online environments that the extreme sports industry could use to neutralize/avoid highly detrimental consequences. Full article

Ghana, being blessed with abundant solar resources, has strategically invested in solar photovoltaic (PV) technologies to diversify its energy mix and reduce the environmental impacts of traditional energy technologies. The 50 MW solar PV installation by the Bui Power Authority (BPA) exemplifies the nation’s dedication to utilizing clean energy for sustainable growth. This study seeks to close the knowledge gap by providing a detailed analysis of the system’s performance under different weather conditions, particularly on days with abundant sunshine and those with cloudy skies. The research consists of one year’s worth of monitoring data for the climatic conditions at the facility and AC energy output fed into the grid. These data were used to analyze PV performance on each month’s sunniest and cloudiest days. The goal is to aid in predicting the system’s output over the next 365 days based on the system design and weather forecast and identify opportunities for system optimization to improve grid dependability. The results show that the total amount of AC energy output fed into the grid each month on the sunniest day varies between 229.3 MWh in December and 278.0 MWh in November, while the total amount of AC energy output fed into the grid each month on the cloudiest day varies between 16.1 MWh in August and 192.8 MWh in February. Also, the percentage variation in energy produced between the sunniest and cloudiest days within a month ranges from 16.9% (December) to 94.1% (August). The reference and system yield analyses showed that the PV plant has a high conversion efficiency of 91.3%; however, only the sunniest and overcast days had an efficiency of 38% and 92%, respectively. The BPA plant’s performance can be enhanced by using this analysis to identify erratic power generation on sunny days and schedule timely maintenance to keep the plant’s performance from deteriorating. Optimizing a solar PV system’s design, installation, and operation can significantly improve its AC energy output, performance ratio, and capacity factor on sunny and cloudy days. The study reveals the necessity of hydropower backup during cloudy days, enabling BPA to calculate the required hydropower for a consistent grid supply. Being able to predict the daily output of the system allows BPA to optimize dispatch strategies and determine the most efficient mix of solar and hydropower. It also assists BPA in identifying areas of the solar facility that require optimization to improve grid reliability. Full article

This study aimed to analyze the aerodynamic characteristics of Chinese Nordic combined athletes during the ski jump take-off process, comparing them with elite athletes from the 2009 Nordic World Ski Championships using computational fluid dynamics (CFD) methods. Methods: Using 3D model analysis and continuous relative phase analysis, CFD methods were utilized to assess the mechanical characteristics of athletes during the take-off phase. Results: The analysis revealed that Chinese athletes displayed a lower dominance of the knee joint during the take-off phase, leading to increased air drag. Conclusion: Reduced knee joint dominance and an excessive ankle angle at the initiation of the ski jump take-off contribute to higher air drag. The lean angle of the body and the ankle angle post-take-off significantly affect the resultant lift and drag forces. Full article

In cross-country skiing, ski poles play a crucial role in technique, propulsion, and overall performance. The kinematic parameters of ski poles can provide valuable information about the skier’s technique, which is of great significance for coaches and athletes seeking to improve their skiing performance. In this work, a new smart ski pole is proposed, which combines the uniaxial load cell and the inertial measurement unit (IMU), aiming to provide comprehensive data measurement functions more easily and to play an auxiliary role in training. The ski pole can collect data directly related to skiing technical actions, such as the skier’s pole force, pole angle, inertia data, etc., and the system’s design, based on wireless transmission, makes the system more convenient to provide comprehensive data acquisition functions, in order to achieve a more simple and efficient use experience. In this experiment, the characteristic data obtained from the ski poles during the Double Poling of three skiers were extracted and the sample t-test was conducted. The results showed that the three skiers had significant differences in pole force, pole angle, and pole time. Spearman correlation analysis was used to analyze the sports data of the people with good performance, and the results showed that the pole force and speed (r = 0.71) and pole support angle (r = 0.76) were significantly correlated. In addition, this study adopted the commonly used inertial sensor data for action recognition, combined with the load cell data as the input of the ski technical action recognition algorithm, and the recognition accuracy of five kinds of cross-country skiing technical actions (Diagonal Stride (DS), Double Poling (DP), Kick Double Poling (KDP), Two-stroke Glide (G2) and Five-stroke Glide (G5)) reached 99.5%, and the accuracy was significantly improved compared with similar recognition systems. Therefore, the equipment is expected to be a valuable training tool for coaches and athletes, helping them to better understand and improve their ski maneuver technique. Full article

Due to the material properties of current ski face masks for adolescents, moisture in exhaled air can become trapped within the material fibers and freeze, leading to potential issues such as breathing difficulties and increased risk of facial frostbite after prolonged skiing. This paper proposes a research approach combining computational fluid dynamics (CFD) and ergonomics to address these issues and enhance the comfort of adolescent skiers. We developed head and face mask models based on the head dimensions of 15–17-year-old males. For enclosed cavities, ensuring the smooth expulsion of exhaled air to prevent re-inhalation is the primary challenge. Through fluid simulation of airflow characteristics within the cavity, we evaluated three different inlet configurations. The results indicate that the location of the air inlets significantly affects the airflow characteristics within the cavity. The side inlet design (type II) showed an average face temperature of 35.35 °C, a 38.5% reduction in average CO₂ concentration within the cavity, and a smaller vortex area compared to the other two inlet configurations. Although the difference in airflow velocity within the cavity among the three configurations was minimal, the average exit velocity differed by up to 0.11 m/s. Thus, we conclude that the side inlet configuration offers minimal obstruction to airflow circulation and better thermal insulation when used in the design of fully enclosed helmets. This enhances the safety and comfort of adolescent wearers during physical activities in cold environments. Through this study, we aim to further promote the development of skiing education, enhance the overall quality of adolescents’ skiing, and thus provide them with more opportunities for the future. Full article

Measuring human perception of environmental safety and quantifying the street view elements that affect human perception of environmental safety are of great significance for improving the urban environment and residents’ safety perception. However, domestic large-scale quantitative research on the safety perception of Chinese local cities needs to be deepened. Therefore, this paper chooses Chaoyang District in Beijing as the research area. Firstly, the network safety perception distribution of Chaoyang District is calculated and presented through the CNN model trained based on the perception dataset constructed by Chinese local cities. Then, the street view elements are extracted from the street view images using image semantic segmentation and target detection technology. Finally, the street view elements that affect the road safety perception are identified and analyzed based on LightGBM and SHAP interpretation framework. The results show the following: (1) the overall safety perception level of Chaoyang District in Beijing is high; (2) the number of motor vehicles and the proportion of the area of roads, skies, and sidewalks are the four factors that have the greatest impact on environmental safety perception; (3) there is an interaction between different street view elements on safety perception, and the proportion and number of street view elements have interaction on safety perception; (4) in the sections with the lowest, moderate, and highest levels of safety perception, the influence of street view elements on safety perception is inconsistent. Finally, this paper summarizes the results and points out the shortcomings of the research. Full article

In Japan, a country prone to earthquakes, numerous damaging earthquakes have been recorded throughout history, often accompanied by descriptions of mysterious earthquake lights (EQL), which may involve various mechanisms. In this article, the possible mechanisms for different types of EQL in 11 cases are reviewed among 21 selected earthquakes. These involve preseismic physicochemical variations in the geological structure of the fault in the lithosphere, which contains deep Earth gases such as radon, methane, and others, as a primary factor for EQL generation. Additionally, various seismic, atmospheric, hydrospheric, and ionospheric variations interact with each other, resulting in the visualization of characteristic anomalous phenomena, such as glowing or shining ground, mountains, offshore areas, and skies of various colors. These phenomena appear momentarily but can sometimes last for extended periods. Because EQL often appear just before an earthquake, their study might be significant for earthquake prediction. Additionally, EQL involving methane flames in the ground is an important research topic as it relates to public safety. Was what they witnessed paranormal? Full article

This study investigates the performance of isotropic and anisotropic diffuse models to estimate the total solar energy received on flat-plate collectors fixed on dual-axis trackers. These estimations are applied at twelve sites selected in both hemispheres with different terrain and environmental conditions. The diffuse (or transposition) models used in this study are the isotropic Liu-Jordan (L&J), Koronakis (KOR), Badescu (BAD), and Tian (TIA), and the anisotropic Hay (HAY), Reindl (REI), Klucher (KLU), Skartveit and Olseth (S&O), and Steven and Unsworth (S&U). These models were chosen because of their simplicity in the calculations and minimum number of input values. The results show that a single transposition model is not efficient for all sites; therefore, the most appropriate models are selected for each site under all, clear, intermediate, and overcast conditions in skies. On the other hand, an increase in the ground albedo in the vicinity of the solar installation can increase the annual inclined solar availability on a two-axis tracker by at least 9% on average. Further, a linear dependence of the annual inclined solar energy on the variation of the ground albedo was found. Also, a linear relationship exists between the annual diffuse-fraction and cloud-modification factor values at the 12 sites. Full article

Cervical cancer ranks as the fourth most prevalent form of cancer and is a significant contributor to female mortality on a global scale. Pitavastatin is an anti-hyperlipidemic medication and has been demonstrated to exert anticancer and anti-inflammatory effects. Thus, the purpose of this study was to evaluate the anticancer effect of pitavastatin on cervical cancer and the underlying molecular mechanisms involved. The results showed that pitavastatin significantly inhibited cell viability by targeting cell-cycle arrest and apoptosis in Ca Ski, HeLa and C-33 A cells. Pitavastatin caused sub-G1- and G0/G1-phase arrest in Ca Ski and HeLa cells and sub-G1- and G2/M-phase arrest in C-33 A cells. Moreover, pitavastatin induced apoptosis via the activation of poly-ADP-ribose polymerase (PARP), Bax and cleaved caspase 3; inactivated the expression of Bcl-2; and increased mitochondrial membrane depolarization. Furthermore, pitavastatin induced apoptosis and slowed the migration of all three cervical cell lines, mediated by the PI3K/AKT and MAPK (JNK, p38 and ERK1/2) pathways. Pitavastatin markedly inhibited tumor growth in vivo in a cancer cell-originated xenograft mouse model. Overall, our results identified pitavastatin as an anticancer agent for cervical cancer, which might be expanded to clinical use in the future. Full article