Search Results (129)

The quality of the soundscape in historical districts is receiving increasing attention from urban governments due to its significant potential to highlight historical characteristics and enhance the acoustic environment of urban areas. However, there is still a lack of research on the relationship between natural and cultural soundscapes as they interact in historic areas. Using the historical area of Wuhou Shrine Museum in Chengdu as a case study, this study analyzed the differences in sound levels, sound source recognition, and subjective perception between two distinct spatial types: the historical street and adjacent urban forest. Additionally, structural equation modeling (SEM) was employed to explore the impact of sound source recognition and sound levels on subjective perception. The results reveal the following: (1) The soundscape interaction between the historical street and the adjacent urban forest exhibits a conflicting relationship, with cultural and natural soundscapes struggling to coexist harmoniously. (2) Within the historical region, L₁₀ has the strongest effect on subjective evaluation, while L₉₀ has the weakest. (3) Quietness is not always positively correlated with comfort and pleasure, indicating that a tranquil environment does not necessarily enhance pleasantness. These findings provide differentiated soundscape optimization strategies tailored to historical areas. Full article

Incomplete spinal cord injury (iSCI) results in impaired postural control and walking ability. Visual over-reliance may occur in iSCI individuals to maintain postural control. This can challenge their postural stability in various contexts of daily life activities. The present study assessed the feasibility, acceptability, and preliminary outcomes of balance training with intermittent visual deprivation using stroboscopic glasses on postural control and visual reliance during quiet standing in iSCI individuals. Training impact on walking performance was also evaluated. Seven chronic iSCI individuals participated in a 6-week home-based balance training program, three times weekly, using stroboscopic glasses. Postural and walking abilities were assessed pre- and post-training using a bipedal stance test (BST) and 10 m walking test (10 MWT). BST was performed, with open-eyes (OE) and closed-eyes (CE), on a force plate for three 30 s trials. The center of pressure (CoP) variables included were CoP area (A-CoP) and CoP mean velocity (MV-CoP). Romberg ratios (CE/OE) for two CoP variables were calculated. Duration and speed were measured in 10 MWT. Intervention feasibility was assessed using the feasibility and acceptability questionnaire. Data from able-bodied individuals were recorded and used as references of physiological performance. iSCI individuals were significantly less stable and showed visual over-reliance for postural steadiness compared to controls. Also, their walking ability was impaired. All iSCI individuals completed the training (adherence rate: 84%) and rated it highly feasible. A-CoP and MV-CoP significantly reduced after training in CE condition (p = 0.018, respectively) but not in OE condition (p > 0.05). The Romberg ratio of A-CoP was significantly lower (p = 0.018), but the Romberg ratio of MV-CoP was not (p > 0.05). A significant reduction in duration and increase in speed (p = 0.018, respectively) in performing the 10 MWT were observed. Preliminary findings from this explorative study indicated that 6-week home-based balance training with intermittent visual deprivation was feasible, acceptable, and had promising potential benefits in improving postural control with a reduction in visual over-reliance in iSCI individuals. The training enhanced also their walking performance. Full article

This research examines in detail the behavior of the Equatorial Ionization Anomaly (EIA) during a severe geomagnetic storm that occurred on 10–11 October 2024. The global data of Total Electron Content (TEC) represented by relative deviation, giving information about the variations compared to quiet conditions, were used. The main attention is paid to the appearance of an additional “fountain effect” under the action of disturbed dynamo currents and the vertical drift of the ionospheric plasma caused by them. The results show that the area in which a positive response (increase) of TEC is observed occurs in an area corresponding to local time around 18–20 h (longitude around 60 °W) at magnetic latitudes ±30° and during the storm shifts westward to around 180 °W. The westward drift of the storm-induced “fountain effect” is moving at a speed much slower than the Earth’s rotation speed. As a result, the area of positive TEC response (vertical upward drift) and the area of negative response (vertical downward drift) are localized in both nighttime and daytime conditions. In this investigation, an example of a very similar geomagnetic storm registered on 25 September 1998 is given for comparison, in which a similar stationing of the storm-induced EIA was observed at longitudes around 180 °E. Full article

Background: Accurate differentiation of Parkinson’s disease (PD) from healthy aging is crucial for timely intervention and effective management. Postural sway abnormalities are prominent motor features of PD. Quantitative stabilometry and machine learning (ML) offer a promising avenue for developing objective markers to support the diagnostic process. This study aimed to develop and validate high-performance ML models to classify individuals with PD and age-matched healthy older adults (HOAs) using a comprehensive set of stabilometric parameters. Methods: Thirty-seven HOAs (mean age 70 ± 6.8 years) and 26 individuals with idiopathic PD (Hoehn and Yahr stages 2–3, on medication; mean age 66 years ± 2.9 years), all aged 60–80 years, participated. Stabilometric data were collected using a force platform during quiet stance under eyes-open (EO) and eyes-closed (EC) conditions, from which 34 parameters reflecting the time- and frequency-domain characteristics of center-of-pressure (COP) sway were extracted. After data preprocessing, including mean imputation for missing values and feature scaling, three ML classifiers (Random Forest, Gradient Boosting, and Support Vector Machine) were hyperparameter-tuned using GridSearchCV with three-fold cross-validation. An ensemble voting classifier (soft voting) was constructed from these tuned models. Model performance was rigorously evaluated using 15 iterations of stratified train–test splits (70% train and 30% test) and an additional bootstrap procedure of 1000 iterations to derive reliable 95% confidence intervals (CIs). Results: Our optimized ensemble voting classifier achieved excellent discriminative power, distinguishing PD from HOAs with a mean accuracy of 0.91 (95% CI: 0.81–1.00) and a mean Area Under the ROC Curve (AUC ROC) of 0.97 (95% CI: 0.92–1.00). Importantly, feature analysis revealed that anteroposterior sway velocity with eyes open (V-AP) and total sway path with eyes closed (TOD_EC, calculated using COP displacement vectors from its mean position) are the most robust and non-invasive biomarkers for differentiating the groups. Conclusions: An ensemble ML approach leveraging stabilometric features provides a highly accurate, non-invasive method to distinguish PD from healthy aging and may augment clinical assessment and monitoring. Full article

The subject of this paper is how certain electrode array parameters affect the operating characteristics of electrohydrodynamic (EHD) propulsion systems. The focus is on how changes in the shapes and arrangements of electrodes, such as the diameter of the coronating conductor, effective electrode length and the spacing between electrodes, influence the formation and behaviour of the corona discharge and the resulting ion-induced airflow. A modular experimental setup was created to allow for a systematic study of each parameter in controlled atmospheric conditions using a high-voltage DC power supply. The study includes both the theoretical background and experimental methods, in order to explore the connections between the electric field distribution, ion mobility and propulsion force generation. By measuring the current, voltage and flow velocity, the impacts of design changes on the propulsion behaviour are examined. The findings help to improve the understanding of EHD propulsion mechanics and lay the groundwork for optimising electrode designs in future applications. This research supports the ongoing work to create compact, quiet and efficient propulsion technologies for use in lightweight aerial vehicles, precise fluid control and other engineering areas, where solid-state thrust systems have clear benefits over traditional methods. Full article

Background/Objectives: The COVID-19 pandemic highlighted the limitations of pulse oximetry in detecting occult hypoxemia. The superiority of the alveolar gas monitor (AGM) compared to pulse oximetry (SpO₂) in predicting respiratory deterioration among COVID-19-positive individuals has previously been demonstrated. Here, we combine COVID-19 and non-COVID-19 individuals as a combined cohort of participants to determine if the AGM has similar utility across a larger, more generalizable cohort. Methods: Adult patients (n = 75) at risk of respiratory deterioration in the emergency department (ED) underwent prospective assessments of their oxygen deficit (OD) and SpO₂, simultaneously measured during quiet breathing on the AGM. The OD and SpO₂ were then compared for their ability to predict the dichotomous outcome of the need for supplemental oxygen. The administration of supplemental oxygen was ordered by the clinical care team with no knowledge of the patients’ enrollment in this study. Results: In the logistic regression analysis, both SpO₂ and OD significantly predicted the need for supplemental oxygen among COVID-19-negative individuals. However, in the multivariable regression, only OD (p < 0.001) significantly predicted the need for supplemental oxygen, while SpO₂ (p = 0.05) did not in the combined cohort of COVID-19-negative and -positive individuals. Receiver operating characteristic (ROC) curve analysis demonstrated the superior discriminative ability of OD (area under ROC curve = 0.937) relative to SpO₂ (area under ROC curve = 0.888) to predict the need for supplemental oxygen. Conclusions: The noninvasive AGM, which combines the measurement of exhaled partial pressures of gas with SpO₂, outperforms SpO₂ alone in predicting the need for supplemental oxygen among individuals in the ED at risk of respiratory deterioration regardless of the etiology for their symptoms (COVID-19-positive or -negative). Full article

Objectives: We assessed the difference between quiet stance and gait in the spatial distribution and intensity of foot plantar pressures and whether it is possible to estimate the distribution during gait from data obtained during stance. Methods: A total of 60 healthy subjects with a mean age of 31.0 ± 9.4 years performed two trials for quiet stance and four trials for gait on a baropodometric walkway with their eyes open. Foot plantar pressures were recorded from 10 areas of the foot sole. Results: During quiet stance, the highest plantar pressure occurred at metatarsal heads (M2 to M4) and the medial (MH) and lateral halves of the heel (LH). During gait, the profile of plantar pressure values was like that during stance, but significantly higher. The differences concentrated at the big toe (T1), M2 to M4, MH, and LH, whilst toes (T2,3,4,5) and midfoot (MF) showed the smallest difference. A significant positive correlation was found between the corresponding areas of foot pressure during gait and stance. Conclusions: During quiet stance and gait, the overall profile of plantar pressure distribution was similar. During quiet stance, the subjects loaded more on the heels, in keeping with the known position of the center of pressure just in front of the ankles. During gait, higher pressures on the metatarsal areas are related to the forward propulsion of the center of mass. The correlation between the corresponding areas of foot pressure during gait and stance suggests that the pressure distribution during gait can partly be estimated from that during stance. This finding might be useful in most clinical settings when a single sensorized platform rather than a complete walkway is available. Full article

Multiple Sclerosis (MS) is a chronic neurological disorder affecting the central nervous system that significantly impairs postural control and functional abilities. Robotic-assisted gait training mitigates this functional deterioration. This preliminary study aims to investigate the effects of a four-week gait training with the ExoAtlet II exoskeleton on static balance control and functional mobility in five individuals with MS (Expanded Disability Status Scale ≤ 2.5). Before and after the training, they were assessed in quiet standing under Eyes Open (EO) and Eyes Closed (EC) conditions and with the Timed Up and Go (TUG) test. Center of Pressure (CoP) Sway Area, Antero–Posterior (AP) and Medio–Lateral (ML) CoP displacement, Stay Time, and Total Instability Duration were computed. TUG test Total Duration, sit-to-stand, stand-to-sit, and linear walking phase duration were analyzed. To establish target reference values for rehabilitation advancement, the same evaluations were performed on a matched healthy cohort. After the training, an improvement in static balance with EO was observed towards HS values (reduced Sway Area, AP and ML CoP displacement, and Total Instability Duration and increased Stay Time). Enhancements under EC condition were less marked. TUG test performance improved, particularly in the stand-to-sit phase. These preliminary findings suggest functional benefits of exoskeleton gait training for individuals with MS. Full article

Physiotherapy aims to improve postural dysfunction, often using balance exercises. The effects of rehabilitation-based balance exercises on postural control in dogs remains understudied. This study aimed to assess the impact of specific balancing exercises and blindfolding on center of pressure parameters in healthy dogs. Thirteen healthy adult dogs participated in the study. Center of pressure parameters were measured using a pressure platform during quiet standing, external perturbation, head turn, and blindfolded trials. External perturbation significantly increased the area of the elliptical sway, cranio-caudal excursion, and right–left excursion. Head turning led to large effect sizes, but no significant differences compared to quiet standing. Blindfolding led to medium to large effect sizes, though no significant differences were observed. The study confirmed that external perturbation challenges postural stability, resulting in increased sway. Head turning induces sway but may require further training or different methodologies for reliable outcomes. Blindfolding increased sway but was not statistically different. These findings underscore the potential use of perturbation-based exercises in canine rehabilitation to improve balance, while also highlighting the need for further studies to standardize balance challenges and explore the effects in dogs with orthopedic or neurological conditions. Full article

The current level of civilization development results in the widespread presence of devices that generate sound waves. Even in the so-called quiet zones, infrasound can be recorded, which, despite the lack of audibility, causes undesirable physiological reactions or affects the environment. Research on noise pollution and its effects on human health and the environment is increasingly prevalent. Thus, the problem of noise should be considered an important and increasingly real problem. In the presented article, an advanced review of the literature on the noise was carried out in order to systematize the issues, diagnose trends, and identify research gaps. The literature review included 1952 articles present in the Scopus database. After selecting the material, 112 documents were qualified for full analysis. Publications were grouped based on selected categories, cross-analyzed for statistical correlations, and described on the basis of content. The findings indicate the dominant areas of research interest in noise and its sources and reveal the most widespread methodological trends such as increased interest in the area of engineering (66.67% increase) and air transport (19.04% increase); an increased frequency of use of the experimental method (28.12% increase); and the rising interest of noise annoyance in China (150% increase). On the other hand, the largest drops of interest occur in Earth and planetary sciences (decrease of 50%), in road transportation (21.87%), in conceptual papers (decrease of 16.21%), and a reduced number of affiliations of authors from Germany (decrease of 45.45%). Outcomes indicate a proposal for future research to fill the identified gaps in the literature. Full article

This study presents a comprehensive analysis of the impact of Storm Laura, which was observed over Europe and the Baltic Sea on 12 March 2020, on the thermosphere–ionosphere system. The investigation of ionospheric disturbances caused by the meteorological storm was carried out using a combined modeling approach, incorporating the regional AtmoSym and the global GSM TIP models. This allowed for the consideration of acoustic and internal gravity waves (AWs and IGWs) generated by tropospheric convective sources and the investigation of wave-induced effects in both the neutral atmosphere and ionosphere. The simulation results show that, three hours after the activation of the additional heat source, an area of increased temperature exceeding 100 K above the background level formed over the meteorological storm region. This temperature change had a significant impact on the meridional component of the thermospheric wind and total electron content (TEC) variations. For example, meridional wind changes reached 80 m/s compared a the meteorologically quiet day, while TEC variations reached 1 TECu. Good agreement was obtained with experimental TEC maps from CODE (Center for Orbit Determination in Europe), MOSGIM (Moscow Global Ionospheric Map), and WD IZMIRAN (West Department of Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation Russian Academy of Sciences), which revealed a negative TEC value effect over the meteorological storm region. Full article

Urban regions represent complex acoustic environments with few respites from noise other than small or remote patches of green infrastructure (GI). Recent noise action planning in the German Ruhr region indicates that urban expansion is fueling encroachment upon GI and subsequently the loss of quiet areas. A systematic exploration of this loss in Germany is needed. An explorative systematic review on Scopus with snowballing supports the synthesis of a conceptual framework linking acoustically relevant ecosystem services with GI. Our review identifies natural quietness, abatement, connection to nature, positive soundscape perception, fidelity, and bird sound presence as sound-related ecosystem functions or services. Empirical case studies justify the need to better understand the link between GI, ecosystem services, and the acoustic environment. Guidance for quiet area assessments in the EU to address this research gap in noise action planning is an emerging topic and needs further study. To address the knowledge gap and provide quiet area assessment guidance, we present a stratified habitat-based acoustic study design for a multi-community area in the middle of the German Ruhr region. A multi-tier sample of 120 locations across eleven habitat and land use strata in the Ruhr is presented, pointing out the scarcity of protected biotopes and large biotope complexes in the study area. This work is a contribution towards a conceptual and methodological basis for quiet area assessment, especially in German and EU noise action planning. Full article

(1) Woody plant species selection for urban forests is one of the key factors in reducing traffic noise in urban areas, and the ability of sound wave attenuation by leaves is one of the foundations for species selection. However, less references regarding the relationships between leaf morphological traits and noise reduction have been reported, especially the relationships between leaf texture (LT), leaf surface roughness (LSR), and noise reduction. (2) Eighteen arbors and shrubs were selected based on leaf texture and surface roughness characteristics, and noise reduction was measured using white noise sources in a self-designed device in a quiet laboratory at night. Then, the changes in noise reduction with LT and LSR were analyzed. (3) The noise reduction was significantly affected by LT, LSR, and their interaction (p < 0.05). The coriaceous leaf was usually more efficient in noise reduction than the chartaceous leaf, and LSR had an auxiliary effect on noise reduction. The effects of noise reduction were mainly influenced by leaf texture through physical blocking and by leaf surface roughness through interference. (4) The findings demonstrate that leaf texture and leaf surface roughness are the suitable predictors for selecting highly efficient woody plants for establishing and improving noise-reduction-oriented forests. Full article

Technological innovation toward electrification and digitalization is revolutionizing aviation, paving the way for new aeronautical paradigms and novel modes to transport goods and people in urban and regional environments. Advanced Air Mobility (AAM) leverages vertical and digital mobility, driven by safe, quiet, sustainable, and cost-effective electric vertical takeoff and landing (VTOL) aircraft. A key enabler of this transformation is the development of vertiports—dedicated infrastructure designed for VTOL operations. Vertiports are pivotal in integrating AAM into multimodal transport networks, ensuring seamless connectivity with existing urban and regional transportation systems. Their design, placement, and operational framework are central to the success of AAM, influencing urban accessibility, safety, and public acceptance. These facilities should accommodate passenger and cargo operations, incorporating charging stations, takeoff and landing areas, and optimized traffic management systems. Public and private sectors are investing in vertiports, shaping the regulatory and technological landscape for widespread adoption. As cities prepare for the future of aerial mobility, vertiports will be the cornerstone of sustainable, efficient, and scalable air transportation. Full article

Background: Motor impairments following stroke contribute to deficits in functional mobility. Traditionally, these impairments are quantified by mean-level motor performance. However, this mean-level approach neglects the well-established fact that motor performance becomes highly variable in aging and disease. Increased intra-individual variability (IIV) in behavior predicts functional decline in neurological disorders. Despite this, the impact of stroke on IIV in motor performance and its influence on functional mobility has not been investigated. This study aimed to (1) quantify the impact of stroke on IIV in motor performance, and (2) determine the contribution of IIV and mean motor performance to functional mobility. Methods: Twenty stroke survivors and 20 age-matched controls performed a goal-directed ankle movement task over 30 trials. We measured average accuracy (mean endpoint error) and IIV (within-person SD of endpoint error). Functional mobility was assessed with postural control (sway area during quiet standing) and braking response time in a driving simulator. Results: Stroke participants showed a higher mean (p = 0.04) and greater IIV (p = 0.016) in endpoint error than controls. Sway area did not differ between groups (p = 0.24), but stroke survivors had increased braking response time (p = 0.016). In stroke survivors, IIV significantly predicted sway area (R² = 0.33, p = 0.008) and braking response time (R² = 0.27, p = 0.02), and mean error did not account for any additional variance. Conclusions: Stroke reduces the trial-to-trial consistency of executing motor tasks with precision. IIV in motor performance predicts postural balance and braking response time and can potentially serve as an indicator of increased vulnerability and an important target for stroke rehabilitation. Full article