Search Results (53)

During the last few years, the requirements for highly efficient, sustainable, and versatile materials in modern biomedicine, aircraft and aerospace industries, automotive production, and electronic and electrical engineering applications have increased. This has led to the development of new and innovative methods for material modification and optimization. This can be achieved in many different ways, but one such approach is the application of surface thin films. They can be conductive (metallic), semi-conductive (metal-ceramic), or isolating (polymeric). Special emphasis is placed on applying semi-conductive thin films due to their unique properties, be it electrical, chemical, mechanical, or other. The particular thin films of interest are composite ones of the type of transition metal oxide (TMO) and transition metal nitride (TMN), due to their widespread configurations and applications. Regardless of the countless number of studies regarding the application of such films in the aforementioned industrial fields, some further possible investigations are necessary to find optimal solutions for modern problems in this topic. One such problem is the possibility of characterization of the applied thin films, not via textbook approaches, but through a simple, modern solution using their electrical properties. This can be achieved on the basis of measuring the films’ electrical impedance, since all different semi-conductive materials have different impedance values. However, this is a huge practical work that necessitates the collection of a large pool of data and needs to be based on well-established methods for both characterization and formation of the films. A thorough review on the topic of applying thin films using physical vapor deposition techniques (PVD) in the field of different modern applications, and the current results of such investigations are presented. Furthermore, current research regarding the possible methods for applying such films, and the specifics behind them, need to be summarized. Due to this, in the present work, the specifics of applying thin films using PVD methods and their expected structure and properties were evaluated. Special emphasis was paid to the electrical impedance spectroscopy (EIS) method, which is typically used for the investigation and characterization of electrical systems. This method has increased in popularity over the last few years, and its applicability in the characterization of electrical systems that include thin films formed using PVD methods was proven many times over. However, a still lingering question is the applicability of this method for backwards engineering of thin films. Currently, the EIS method is used in combination with traditional techniques such as X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray spectroscopy (EDX), and others. There is, however, a potential to predict the structure and properties of thin films using purely a combination of EIS measurements and complex theoretical models. The current progress in the development of the EIS measurement method was described in the present work, and the trend is such that new theoretical models and new practical testing knowledge was obtained that help implement the method in the field of thin films characterization. Regardless of this progress, much more future work was found to be necessary, in particular, practical measurements (real data) of a large variety of films, in order to build the composition–structure–properties relationship. Full article

The aim of this study was to test the Implicit Prosody Hypothesis using a reading corpus, i.e., a text without experimental manipulation labelled with eye-tracking parameters. For this purpose, a bilingual Croatian–English reading corpus was analysed. In prosodic terms, Croatian and English are at the opposite ends of the spectrum: English is considered a time-framed language, while Croatian is a syllable-framed language. This difference served as a kind of experimental control in this study on natural reading. The results show that readers’ eyes lingered more on stressed syllables than on the arrangement of stressed and unstressed syllables for both languages. This is especially pronounced for English, a language with greater differences in the duration of stressed and unstressed syllables. This study provides indirect evidence in favour of the Implicit Prosody Hypothesis, i.e., the idea that readers are guided by their inner voice with its suprasegmental features when reading silently. The differences between the languages can be traced back to the typological differences in stress in English and Croatian. Full article

A concise model, utilizing the threshold values of closed depressions, the convergence index, and the leaf area index (LAI) that play a significant role in modeling vegetation–atmosphere interactions and understanding the impact of vegetation on the hydrological cycle, was employed to pinpoint potential aquifer recharge centroids. The LAI index served as a geographic mask, linking centroid locations to soil vegetation cover. Analyzing a paired subsample of 500 centroids for each strata (true and false), we observed that maximum values of true centroids, indicating potential groundwater recharge, correlated with the presence of abundant vegetation (0.074 < LAI < 0.639). Conversely, lower LAI values were associated with sparse vegetation in false centroids (0.01 < LAI < 0.590). The study’s findings hold promising implications for aquifer management, biodiversity conservation, hydric planning, and land use protection, making a substantial contribution to the field. The recharge hypothesis is theoretically sound and empirically supported to propose that areas of high topographic convergence and closed depressions are potential water recharge zones, and these locations may exhibit permanent or denser vegetation, reflected as higher LAI values. This happens because water accumulates or lingers in these zones, soil moisture is maintained more consistently, and plant roots access water for longer periods, even during dry seasons. Vegetation becomes more resilient and persistent (possibly even forming phreatophytes—plants accessing groundwater). Additionally, there is potential for expanding the research by incorporating field observations, including tracking the routes of surface and subsurface runoff and determining arrival times to the aquifer. Such studies are increasingly vital for addressing contemporary environmental and water resource challenges. Full article

Objective: This study investigated gait and cognitive dual-task costs under a dual-task paradigm that was more challenging than the traditional tasks used in research. Methods: A total of 43 18–25-year-old male and female student athletes were recruited (20 asymptomatic concussed athletes who suffered at least one concussion 2.79–7.92 months before testing, 23 never concussed). Athletes performed a complex rapid decision-making and executive function computerized task while walking continuously and maintaining a predetermined speed on a non-motorized treadmill (6.5 km/h). The outcome measures were gait and cognitive dual-task costs. Results: Repeated-measures ANOVAs were conducted to evaluate group differences. Pearson correlations were conducted to evaluate the association between dual-task costs and concussion injury variables. The results showed that both groups experienced greater difficulty with dual-task performance related to gait, whereas only the concussion group exhibited poorer cognitive performance under the dual-task condition (both not significant). The significant correlation between time since injury and gait dual-task cost (r = −0.72, p < 0.001) indicated that athletes with a more recent concussion increased their gait speed whilst athletes with an older concussion reduced their gait speed during the dual-task. Moreover, the cognitive dual-task cost was significantly correlated to symptom recovery (r = 0.461, p = 0.047), suggesting that a longer recovery time from concussion is associated with an increased dual-task cost. Conclusions: While dual-task gait alterations were common to both groups, only individuals with a history of concussion showed specific cognitive impairments under dual-task conditions. The observed associations between dual-task costs and both time since injury and symptom recovery underscore the potential of complex dual-task assessments to provide nuanced insights into post-concussion recovery trajectories and to detect subtle, lingering deficits. Full article

The G5 geomagnetic storm of May 2024 provided a significant opportunity to investigate global ionospheric disturbances using vertical total electron content (VTEC) data derived from 422 GNSS-IGS stations and GIM. This study presents a comprehensive spatio-temporal analysis of VTEC modulation before, during, and after the storm, focusing on hemispheric asymmetries and longitudinal variations. The primary objective of this study is to analyze the spatial and temporal modulation of VTEC under extreme geomagnetic conditions, assess the hemispheric asymmetry and longitudinal disruptions, and evaluate the influence of geomagnetic indices on storm-time ionospheric variability. The indices examined reveal intense geomagnetic activity, with the dst index plunging to −412 nT, the Kp index reaching 9, and significant fluctuations in the auroral electrojet indices (AE, AL, AU), all indicative of severe space weather conditions. The results highlight storm-induced hemispheric asymmetries, with positive storm effects (VTEC enhancement) in the Northern Hemisphere and negative storm effects (VTEC depletion) in the Southern Hemisphere. These anomalies are primarily attributed to penetration electric fields, neutral wind effects, and composition changes in the ionosphere. The storm’s peak impact on DoY 132 exhibited maximum disturbances at ±90° and ±180° longitudes, emphasizing the role of geomagnetic forces in plasma redistribution. Longitudinal gradients were strongly amplified, disrupting the usual equatorial ionization anomaly structure. Post-storm recovery on DoY 136 demonstrated a gradual return to equilibrium, although lingering effects persisted at mid- and high latitudes. These findings are crucial for understanding space weather-induced ionospheric perturbations, directly impacting GNSS-based navigation, communication systems, and space weather forecasting. Full article

After a brief review of Carnot’s everlasting contributions to the foundations of thermodynamics, we critically examine the consequences of the Carnot theorem, which leaves behind some lingering questions and confusion that persist even today. What is the one significant aspect of the Carnot cycle that leads to this theorem? When does the working substance play an important role for an engine and what is its correlation with the protocol of operational details? Do all reversible engines working between the same two temperatures have the same maximum efficiency of the Carnot engine as Fermi has suggested? Are all heat engines equivalent to a Carnot engine in disguise? Our new perspective allows for the clarification of these questions with a positive answer for the last question. Recognizing that Carnot eventually abandoned the caloric theory, we use a result by Carnot and simple dimensional analysis to show how the first law, the concept of entropy, and the efficiency of the Carnot engine could have been germinated by Carnot in his time. This then demonstrates that Carnot had good understanding of entropy before its invention by Clausius. We suggest that both should be credited with inventing entropy by calling it Carnot–Clausius entropy. We also clarify some fundamental misconceptions plaguing reversible regenerators and their irreversible replacement by heat exchangers in the field. Full article

The intensity of wildfires has increased dramatically in recent decades; thus, better understanding the impact of land-management efforts in biodiversity conservation on post-wildfire recovery could highlight the value of these interventions. Field assessments are often costly; therefore, monitoring the effectiveness of applied conservation practices using remote sensing tools is critical. The main goal of this study is to develop and apply a remote sensing framework to assess the impact of conservation practices on post-fire recovery. We focused on a study area in northern California and southern Oregon, a region with diverse conservation practices and increased wildfire activity in the past decade. The proposed framework uses the MODIS dataset to identify fire burn events and Landsat to analyze the time series of an area-aggregated vegetation index, the Normalized Burn Ratio (NBR). Using the remote sensing framework, we confirmed our hypothesis that in areas lacking conservation protection practices, post-fire recovery is slower and more lingering. The median 5-year dNBR recovery for unprotected burn events was around 27%, compared to 37% across all other burn areas. Along with our primary goal of recovery analysis, we also examined fire severity across different conservation practices to identify moderate-to-severe fire events and to capture differences in fire characteristics for the areas under different conversation practices. This analysis revealed that unprotected areas experienced more severe fire events. We also investigated the impact of conservation practices across three dominant forest types in our study area: Dry-Mesic Conifer, Mesic Conifer, and Evergreen Forests. The disparity in post-wildfire recovery between protected and non-protected areas was most pronounced in burn areas dominated by Evergreen Forests. Using the proposed aggregated remote sensing framework, this study highlights the importance of conservation practices in wildfire recovery. This approach could provide a cost-efficient tool for assessing the effectiveness of land-management practices on wildfire recovery across the globe. Full article

With the continual mutations of new variants in recent years, COVID-19 has adapted to coexist with humanity for decades to come. However, our understanding of the extent and longevity of the pandemic remains vague. Although the immediate repercussions of the pandemic on various sectors of the global economy still linger and could even last longer than was anticipated, four years into the pandemic provides an opportune time to examine key trends in research and strategies crucial to combating the effect in the long term. To that end, this study critically provides timely reflections on COVID-19’s impact on the tourism and agriculture industries highlighting their interdependence. It further examines key advancements, challenges, and prospects that have come to light during the pandemic era while reflecting on pre-, during-, and post-pandemic developments. Specifically, the review delves into the various dimensions and facets of these impacts, exploring how the pandemic affects the changing landscape in tourism and agriculture in the post-pandemic era, as well as the efficacy of the coping strategies. We proposed key novel strategies for ensuring the robustness of tourism and agriculture industries, integrating lessons from past crises into short-term, medium-term, and long-term solutions. It is worth noticing that the research outcomes align with the Sustainable Development Goals on sustainable production and consumption. The proposed strategies provide a solid foundation to fortify other industries in the face of subsequent crises of a similar kind. This review concludes by offering insightful perspectives on potential areas of investigation and recommendations during emergency crises. Full article

This study aims to quantify and graphically illustrate the negative lingering effect that the COVID-19 pandemic had on the sales in South African Rands (ZAR) of the food and beverage sector using the time series seasonal autoregressive integrated moving average with exogenous components (SARIMAX) intervention model. The SARIMAX$\left(2,1,0\right){\left(0,1,2\right)}_{12}$ intervention model provided the best fit, supported by the lowest values of the model selection and error metrics (Akaike’s information criterion, Bayesian information criterion, and root mean square error). The total estimated loss of sales in the 52 months during the intervention period (March 2020 to June 2024) amounts to ZAR 130,579 million. The most affected months were April 2020 and May 2020 with estimated losses of ZAR 7719 million and ZAR 7633 million, respectively. The findings of this study align with the Statistics South Africa^® statistical report based on empirical estimation without any model fitting, thus highlighting the effectiveness of the SARIMAX intervention model in quantifying the effects of the pandemic. The lingering negative impact of the COVID-19 pandemic still continues to threaten the sustainability of the South African food and beverage sector, violating the United Nations’ Sustainable Development Goal, Number 2, which is to end hunger, achieve food security, improve nutrition, and promote sustainable agriculture. Full article

Over the course of industrialization in the 20th century, vast emissions of air pollutants have occurred. The exhaust gasses contain sulfur and nitrogen oxides, which are converted to sulfuric acid and nitric acid in the atmosphere. This causes acid rain to enter aquatic and terrestrial ecosystems, the most serious consequence of which is large-scale forest dieback across Europe and North America. However, through various political measures, the exhaust gasses have been reduced and, thus, acid rain and forest dieback were stopped. Nevertheless, the lingering effects of this pollution are still present today and are reflected in hydrochemistry. More recently, fluctuating precipitation regimes are causing additional stress to ecosystems in Central Europe. Climatic extremes are becoming more pronounced with climate change. Substantial differences between drought years and years with regular precipitation are directly altering the discharge of springs. Now, two overlapping and interacting syndromes of environmental pressures can be studied in these small catchments at a landscape scale: (1) acidification and (2) climate change. In this long-term study, the waters of 102 forest springs, located in two neighboring forest landscapes in north-eastern Bavaria, Germany (Frankenwald and Fichtelgebirge), were investigated over 24 years (1996 to 2020). By linking changes in pH values with changes in precipitation and spring discharge, we found that pH increases with decreasing discharge and decreasing precipitation. This effect was strongest in the Frankenwald compared to the Fichtelgebirge. We hypothesize that this temporal pattern reflects the longer residence time and, in consequence, the increased buffering of acidic interflow in small catchments during periods of drought. However, this should not be misinterpreted as rapid recovery from acidification because this effect fades in times of enhanced precipitation. We recommend that fluctuations in weather regimes be considered when investigating biogeochemical patterns throughout forest landscapes. Full article

Background: Data on the health-related quality of life (HRQoL) for invasive meningococcal disease (IMD) survivors, particularly among adolescents and young adults (AYAs), are limited. This study aimed to investigate the in-depth experiences and impacts of IMD on AYAs. Methods: Participants were recruited from two Australian states, Victoria and South Australia. We conducted qualitative, semi-structured interviews with 30 patients diagnosed with IMD between 2016 and 2021. The interview transcripts were analyzed thematically. Results: Of the participants, 53% were aged 15–19 years old, and 47% were aged 20–24. The majority (70%) were female. Seven themes relating to the participants’ experience of IMD were identified: (1) underestimation of the initial symptoms and then rapid escalation of symptoms; (2) reliance on social support for emergency care access; (3) the symptoms prompting seeking medical care varied, with some key symptoms missed; (4) challenges in early medical diagnosis; (5) traumatic and life-changing experience; (6) a lingering impact on HRQoL; and (7) gaps in the continuity of care post-discharge. Conclusion: The themes raised by AYA IMD survivors identify multiple areas that can be addressed during their acute illness and recovery. Increasing awareness of meningococcal symptoms for AYAs may help reduce the time between the first symptoms and the first antibiotic dose, although this remains a challenging area for improvement. After the acute illness, conducting HRQoL assessments and providing multidisciplinary support will assist those who require more intensive and ongoing assistance during their recovery. Full article

This study introduces a methodology for the real-time detection of human movement based on two legs using ultra-wideband (UWB) sensors. Movements were primarily categorized into four states: stopped, walking, lingering, and the transition between sitting and standing. To classify these movements, UWB sensors were used to measure the distance between the designated point and a specific point on the two legs in the human body. By analyzing the measured distance values, a movement state classification model was constructed. In comparison to conventional vision/laser/LiDAR-based research, this approach requires fewer computational resources and provides distinguished real-time human movement detection within a CPU environment. Consequently, this research presents a novel strategy to effectively recognize human movements during human–robot interactions. The proposed model effectively discerned four distinct movement states with classification accuracy of around 95%, demonstrating the novel strategy’s efficacy. Full article

(1) Background: COVID-19 was responsible for the latest pandemic, shaking and reshaping healthcare systems worldwide. Its late clinical manifestations make it linger in medical memory as a debilitating illness over extended periods. (2) Methods: the recent literature was systematically analyzed to categorize and examine the symptomatology and pathophysiology of Long COVID across various bodily systems, including pulmonary, cardiovascular, gastrointestinal, neuropsychiatric, dermatological, renal, hematological, and endocrinological aspects. (3) Results: The review outlines the diverse clinical manifestations of Long COVID across multiple systems, emphasizing its complexity and challenges in diagnosis and treatment. Factors such as pre-existing conditions, initial COVID-19 severity, vaccination status, gender, and age were identified as influential in the manifestation and persistence of Long COVID symptoms. This condition is highlighted as a debilitating disease capable of enduring over an extended period and presenting new symptoms over time. (4) Conclusions: Long COVID emerges as a condition with intricate multi-systemic involvement, complicating its diagnosis and treatment. The findings underscore the necessity for a nuanced understanding of its diverse manifestations to effectively manage and address the evolving nature of this condition over time. Full article

The COVID-19 pandemic caused by SARS-CoV-2 has posed unparalleled challenges due to its rapid transmission, ability to mutate, high mortality and morbidity, and enduring health complications. Vaccines have exhibited effectiveness, but their efficacy diminishes over time while new variants continue to emerge. Antiviral medications offer a viable alternative, but their success has been inconsistent. Therefore, there remains an ongoing need to identify innovative antiviral drugs for treating COVID-19 and its post-infection complications. The ORF3a (open reading frame 3a) protein found in SARS-CoV-2, represents a promising target for antiviral treatment due to its multifaceted role in viral pathogenesis, cytokine storms, disease severity, and mortality. ORF3a contributes significantly to viral pathogenesis by facilitating viral assembly and release, essential processes in the viral life cycle, while also suppressing the body’s antiviral responses, thus aiding viral replication. ORF3a also has been implicated in triggering excessive inflammation, characterized by NF-κB-mediated cytokine production, ultimately leading to apoptotic cell death and tissue damage in the lungs, kidneys, and the central nervous system. Additionally, ORF3a triggers the activation of the NLRP3 inflammasome, inciting a cytokine storm, which is a major contributor to the severity of the disease and subsequent mortality. As with the spike protein, ORF3a also undergoes mutations, and certain mutant variants correlate with heightened disease severity in COVID-19. These mutations may influence viral replication and host cellular inflammatory responses. While establishing a direct link between ORF3a and mortality is difficult, its involvement in promoting inflammation and exacerbating disease severity likely contributes to higher mortality rates in severe COVID-19 cases. This review offers a comprehensive and detailed exploration of ORF3a’s potential as an innovative antiviral drug target. Additionally, we outline potential strategies for discovering and developing ORF3a inhibitor drugs to counteract its harmful effects, alleviate tissue damage, and reduce the severity of COVID-19 and its lingering complications. Full article

Microcystin can be present in variable concentrations, phases (dissolved and particulate), and structural forms (congeners), all which impact the toxicity and persistence of the algal metabolite. Conducting incubation experiments with six bloom assemblages collected from the Chowan River, North Carolina, we assessed microcystin dynamics during active growth and biomass degradation. Upon collection, average particulate and dissolved microcystin ranged between 0.2 and 993 µg L⁻¹ and 0.5 and 3.6 µg L⁻¹, respectively. The presence of congeners MC-LA, -LR, -RR, and -YR was confirmed with MC-RR and MC-LR being the most prevalent. Congener composition shifted over time and varied between dissolved and particulate phases. Particulate microcystin exponentially declined in five of six incubations with an average half-life of 10.2 ± 3.7 days, while dissolved microcystin remained detectable until the end of the incubation trials (up to 100 days). Our findings suggest that concerns about food-web transfer via intracellular toxins seem most warranted within the first few weeks of the bloom peak, while dissolved toxins linger for several months in the aftermath of the event. Also, it was indicated there were differences in congener profiles linked to the sampling method. We believe this study can inform monitoring strategies and aid microcystin-exposure risk assessments for cyanobacterial blooms. Full article