Search Results (132)

Modern manufacturing demands real-time, scalable coordination that legacy manufacturing management systems cannot provide. Digital transformation encompasses the entire manufacturing infrastructure, which can be represented by digital twins for facilitating efficient monitoring, prediction, and optimization of factory operations. A Federated Digital Twin (FDT) emerges by combining heterogeneous digital twins, enabling real-time collaboration, data sharing, and collective decision-making. However, deploying FDTs introduces new concurrency control challenges, such as priority inversion and synchronization failures, which can potentially cause process delays, missed deadlines, and reduced customer satisfaction. Traditional concurrency control approaches in the computing domain, due to their reliance on static priority assignments and centralized control, are inadequate for managing dynamic, real-time conflicts effectively in real production lines. To address these challenges, this study proposes a novel concurrency control framework combining Deep Reinforcement Learning with the Priority Ceiling Protocol. Using SimPy-based discrete-event simulations, which accurately model the asynchronous nature of FDT interactions, the proposed approach adaptively optimizes resource allocation and effectively mitigates priority inversion. The results demonstrate that against the rule-based PCP controller, our hybrid DRLCC enhances completion time maximum of 24.27% to a minimum of 1.51%, urgent-job delay maximum of 6.65% and a minimum of 2.18%, while preserving lower-priority inversions. Full article

Abandoned smelting sites in karst terrain pose a serious environmental problem due to the complex relationship between specific hydrogeological elements and heavy metal contamination. This review combines work from across the globe to consider how karst-specific features (i.e., rapid underground drainage, high permeability, and carbonate mineralogy) influence the mobility, speciation, and bioavailability of “metallic” pollutants, such as Pb, Cd, Zn, and As. In some areas, such as Guizhou (China), the Cd content in the surface soil is as high as 23.36 mg/kg, indicating a regional risk. Molecular-scale analysis, such as synchrotron-based XAS, can elucidate the speciation forms that underlie toxicity and remediation potential. Additionally, we emphasize discrepancies between karst in Asia, Europe, and North America and synthesize cross-regional contamination events. The risk evaluation is complicated, particularly when dynamic flow systems and spatial heterogeneity are permanent, and deep models like DI-NCPI are required as a matter of course. The remediation is still dependent on the site; however, some technologies, such as phytoremediation, biosorption, and bioremediation, are promising if suitable geochemical and microbial conditions are present. This review presents a framework for integrating molecular data and hydrogeological concepts to inform the management of risk and sustainable remediation of legacy metal pollution in karst. Full article

The forest ecosystems of large Mediterranean islands are critical hubs of evolutionary diversity with unique floristic composition and distinctive vegetation patterns reflecting long-term population dynamics and ecological legacies. Mediterranean islands provide invaluable natural archives, preserving crucial insights into the resilience of past forest ecosystems and their responses to climate variability. In this paper, we provide a comprehensive overview of the Holocene vegetation history of major western Mediterranean islands, with the twofold aim of examining the timing, extent, and rates of vegetation changes over the last few thousand years, and evaluating the influence of Rapid Climate Changes (RCCs) on forest ecosystems. The rate of change analysis allowed the identification of a distinct pattern of rapid shifts in forest composition, corresponding to periods of climate instability. These shifts align with the periodicity of Bond events, suggesting synchronicity between changes in forest ecosystems and centennial-scale climatic oscillations at a supra-regional scale. A REDFIT spectral analysis applied to palynological proxies of forest cover changes identified prominent periodicities suggesting a direct influence of solar activity and/or a relation with complex ocean–atmosphere circulation mechanisms triggered by global climate forcings. Full article

Among the diverse challenges to the sustainability of China’s rich tangible cultural heritage, climate change, associated with increased temperatures, altered precipitation regimes, and the augmented frequency and magnitude of extreme events, is regarded as one of the most prominent. However, there is a diverse range of rapidly emerging environmental and socio-economic hazards that threaten cultural heritage in the country but have thus far received scant attention in this context. Without adequate attention and intervention, the sustainability of the country’s historic urban heritage is highly vulnerable. Anthropocene threats to this important legacy include climate change, sea level rise, land subsidence, water and air pollution, rampant urbanization, and tourism. Suzhou, situated in the low-elevation Yangtze River delta within one or two meters of current sea level, lies in the heart of one of the fastest socio-economically developing and urbanizing regions in the world and is especially vulnerable to the range of threats. As one of the jewels in the crown of China’s architectural heritage, Suzhou represents a model case in which to consider the conflicting interests of socio-economic development and environmental and cultural conservation in the context of rapidly changing environmental conditions. In this review, we consider the diverse risks to the sustainability of Suzhou’s cultural heritage posed by these circumstances, highlight key problems, and prioritize the most urgent issues requiring attention. In recognizing the spatial and temporal nature of these multiple challenges, we highlight the need for integrated approaches to safeguard the sustainability of such valuable resources. Moreover, considering the imperative of accelerating progress towards the UN Sustainable Development Goals and reflecting on current theories of sustainable management of urban cultural heritage, we outline the potential policy and practice implications for the conservation of Suzhou’s historic buildings, canals, and gardens. Full article

The popular perception of Matilda of Canossa (1046–1115) is one which is typically filtered through the events of the Investiture Controversy and the famed 1077 meeting at Canossa and is thus prismatically reflected through the legacy of two men, Emperor Henry IV (1050–1106) and Pope Gregory VII (1020–1085). Though not an atypical journey through time for any female figure of history, it is a historiographical transformation which has altogether subverted studies of Matilda’s agency and authority. This has obfuscated studies of Matilda’s own agency and authority, where her oft contentious attitude toward and relationship to the regnum has typically been classified as a side effect of her extreme devotion to the papacy, rather than its own effort. This paper will begin to unwind the evidence of Matilda’s personal rebellion from the king by examining the biography produced at the end of her lifetime, the Vita Mathildis (Vatican City, Bibliotheca Apostolica Vaticana, MS. Vat. Lat. 4922). The examination of both the text and illuminations of the manuscript makes clear that Matilda’s rejection of the regnum was not merely a side effect of lifelong loyalty to the papacy but was also part of a conscious rejection of imperial authority, evidence of which can be found through vigorous textual and visual analyses. Full article

This study addresses the challenge of capturing both short-run volatility and long-run dependencies in global stock markets by introducing fractional transfer entropy (FTE), a new framework that embeds fractional calculus into transfer entropy. FTE allows analysts to tune memory parameters and thus observe how different temporal emphases reshape the network of directional information flows among major financial indices. Empirical evidence reveals that when short-memory effects dominate, markets swiftly incorporate recent news, creating networks that adapt quickly but remain vulnerable to transient shocks. In contrast, balanced memory parameters yield a more stable equilibrium, blending immediate reactions with persistent structural ties. Under long-memory configurations, historically entrenched relationships prevail, enabling established market leaders to remain central despite ongoing fluctuations. These findings demonstrate that FTE uncovers nuanced dynamics overlooked by methods focusing solely on either current events or deep-rooted patterns. Although the method relies on price returns and does not differentiate specific shock types, it offers a versatile tool for investors, policymakers, and researchers to gauge financial stability, evaluate contagion risk, and better understand how ephemeral signals and historical legacies jointly govern global market connectivity. Full article

Climate change has led to an increasing frequency of droughts, potentially undermining soil stability. In such a changing environment, the shallow reinforcement effect of plant roots often fails to meet expectations. This study aims to explore whether this is associated with the alteration of plant traits as a response to environmental change. Focusing on Amorpha fruticosa, a species known for its robust root system that plays a crucial role in soil consolidation and slope stabilization, thereby reducing soil and water erosion, we simulated a drought-rewetting event to assess the legacy effects of drought on the soil shear strength and the mechanical and hydrological traits associated with the reinforcement provided by A. fruticosa. The results show that the legacy effect of drought significantly diminishes the soil shear strength. Pretreated with drought, plant roots undergo morphological alterations such as deeper growth, yet the underground root biomass and diameter decline, thereby influencing mechanical reinforcement. Chemical composition analysis indicates that the plant’s adaptation to drought modifies the intrinsic properties of the roots, with varying impacts on different root types and overall reinforcement. Concurrently, the stomatal conductance and transpiration rate of leaves decrease, weakening the capacity to augment soil matric suction through transpiration and potentially reducing hydrological reinforcement. Although rewetting treatments aid in recovery, drought legacy effects persist and impact plant functional attributes. This study emphasizes that, beyond soil matric suction, plant adaptive mechanisms in response to environmental changes may also contribute significantly to reduced soil shear strength. Consequently, ecological restoration strategies should consider plant trait adaptations to drought, enhancing root systems for soil conservation and climate resilience. Full article

Uranium mining for the production of nuclear technologies has left visible scars across the United States and perpetuated legacies of extraction that extend beyond material consumption to the exploitation of people and the environment. Influenced by important ongoing conversations in the environmental and energy humanities, posthumanism, and decolonial studies, I analyze how uranium extraction has been conceived of as an “event” within a colonial temporal framework. A critical examination of how religious worldviews have informed the ways that time is conceptualized and understood shifts thinking about extraction away from colonial temporalities and helps reimagine extraction through a decolonial perspective as temporally distributed, enmeshed, and complex. This reframing is imperative to foster an understanding that the radioactive byproducts of uranium created through the nuclear production process are globally dispersed, will persist across generations, and will have transgenerational implications for human and non-human organisms and the health and viability of ecologic systems. Full article

The desire of Gukurahundi survivors for cultural platforms that enable them to discuss, mourn, and commemorate their loved ones is now very loud in Zimbabwe’s Matabeleland and Midlands provinces. While community-based organisations have provided platforms for Gukurahundi survivors, the children of survivors, and academics to interface and interact, the government’s gatekeeping processes remain a challenge for the community-wide memorialisation and documentation of the genocide. In this conceptual paper, I frame Gukurahundi as a meteorological event within a general Zimbabwean cultural context, foregrounding the desecration of the Ndebele people’s cultural practices, rituals, and ceremonies. Drawing from the documented legacies of this cultural violence within Matabeleland and south-western parts of the Midlands, through videos and the literature, I argue that this cultural violence resulted in the silencing of the remembrance of Gukurahundi, which remains critical to the resolution of the stand-off between the ZANU-PF government and the communities. In this paper, I further argue that this ecological symbolism provided a justification and legitimated direct brutal violence on presumed ZAPU and ex-ZPRA veterans who were largely Ndebele-speaking or of ethnic descent. Finally, I argue that it is not that the absence of alternative narratives but the sociopolitical and cultural environment that constrains these from being available and implemented. Full article

Throughout the twentieth century, U.S. American evangelicals engaged in an ongoing series of definitional debates over the contours and limits of a distinctly evangelical approach to theology. Developed as an explicit counter to theological liberalism—and often signaled by strict adherence to biblical inerrancy—American evangelical theology might conceivably have made common cause with Karl Barth, whose infamous rebellion against his liberal teachers became one of the founding events in the story of twentieth-century Christian theology. Despite Barth’s putative anti-liberalism, evangelical theologians never fully embraced Barthian theology, consistently vilifying it as un-evangelical and beyond the pale. In this essay, I recover the history of U.S. American evangelical theologians wrestling with Karl Barth and his legacy, highlighting how an enduring aversion to Barthianism became a key feature of evangelical theology. Full article

This research builds on previous mega event research that found that policymakers must understand citizens’ perceptions of mega events and the long-term effects it has on their community to create positive and sustainable legacies. The present study provides new insights and understanding of the social impact of the 2002 Salt Lake City Winter Olympics on Heber Valley. Using the well-established systemic model of community and quantitative survey data from 1999 until 2003, as well as waves from 2007, 2012, and 2018 data, we investigate, first, if community attachment, satisfaction, and desirability changed over time and, second, how enduring feelings about the Olympics affected community sentiment. Our research finds that there were some changes in residents’ community experience over time; community attachment decreased during 2018, community satisfaction decreased in 2001, 2007, and 2018, and community desirability increased slightly in 2002. We also found that the legacies of the 2002 Winter Olympics do influence how residents feel about their community. Full article

For decades, GNSS code measurements were much noisier than phase ones, limiting their applicability to ionospheric total electron content (TEC) studies. Ultra-wideband AltBOC signals changed the situation. This study revisits the Galileo E5 and BeiDou B2 AltBOC signals and their potential applications in TEC estimation. We found that TEC noises are comparable for the single-frequency AltBOC phase-code combination and those of the dual-frequency legacy BPSK/QPSK phase combination, while single-frequency BPSK/QPSK TEC noises are much higher. A two-week high-rate measurement campaign at the ACRG receiver revealed a mean 100 sec TEC RMS (used as the noise proxy) of 0.26 TECU, 0.15 TECU, and 0.09 TECU for the BeiDou B2(a+b) AltBOC signal and satellite elevations 0–30°, 30–60°, and 60–90°, correspondingly, and 0.22 TECU, 0.14 TECU, and 0.09 TECU for the legacy B1/B3 dual-frequency phase combination. The Galileo E5(a+b) AltBOC signal corresponding values were 0.25 TECU, 0.14 TECU, and 0.09 TECU; for the legacy signals’ phase combination, the values were 0.19 TECU, 0.13 TECU, and 0.08 TECU. The AltBOC (for both BeiDou and Galileo) SNR exceeds those of BPSK/QPSK by 7.5 dB-Hz in undisturbed conditions. Radio frequency interference (the 28 August 2022 and 9 May 2024 Solar Radio Burst events in our study) decreased the AltBOC SNR 5 dB-Hz more against QPSK SNR, but, due to the higher initial SNR, the threshold for the loss of the lock was never broken. Today, we have enough BeiDou and Galileo satellites that transmit AltBOC signals for a reliable single-frequency vTEC estimation. This study provides new insights and evidence for using Galileo and BeiDou AltBOC signals in high-precision ionospheric monitoring. Full article

This study explores the role of populist leaders as gatekeepers on social media, seeking to understand how André Ventura, president of Chega!, uses news to legitimize his political discourse. The methodology involved collecting 90 tweets containing legacy media news features, posted by Ventura on the social media platform X. These tweets cover key political events such as the resignation of Portugal’s Prime Minister, the dissolution of the Portuguese Parliament, and European elections. Quantitative analysis using Voyant Tools identified key terms related to Ventura’s ideological stance, while Critical Discourse Analysis (CDA) examined how these terms support his political narrative. The findings reveal a strategic use of news to promote themes like nationalism, immigration control, corruption and social dichotomy between “us” and “them”. Ventura’s tweets leverage news headlines to enhance his persuasive appeal, acting as heuristic shortcuts to reinforce his political messages. This study highlights the relevance of understanding social media’s role in promoting populism and suggests avenues for future research, including comparative analyses of other populist leaders and the impact of these narratives on voter behavior and perceptions. Full article

This research offers valuable insights into both the historical analysis and future management of water distribution network behavior. By examining the impacts of materials and identifying temporal patterns, the study presents a comprehensive viewpoint essential for informed decision-making in water network management. The findings emphasize the relationship between pressure dynamics and burst occurrences, leading to opportunities for further investigation and the development of more precise prediction and mitigation strategies for water distribution systems. The results indicate a consistent pattern of higher real positive percentages compared to random detection rates across the years tested. This suggests a significant correlation between burst events and pressure anomalies, with the detection system performing better than random chance. Full article

Despite decreasing anthropogenic mercury (Hg) emissions in Europe and the banning and restriction of many persistent organic pollutants (POPs) under the Stockholm Convention, Mediterranean marine mammals still have one of the highest body burdens of persistent pollutants in the world. Moreover, the Mediterranean basin is one of the most sensitive to climate change, with likely changes in the biogeochemical cycle and bioavailability of Hg, primary productivity, and the length and composition of pelagic food webs. The availability of food resources for marine mammals is also affected by widespread overfishing and the increasing number of alien species colonizing the basin. After reporting the most recent findings on the biogeochemical cycle of Hg in the Mediterranean Sea and the physico-chemical and bio-ecological factors determining its exceptional bioaccumulation in odontocetes, this review discusses possible future changes in the bioavailability of the metal. Recent ocean–atmosphere–land models predict that in mid-latitude seas, water warming (which in the Mediterranean is 20% faster than the global average) is likely to decrease the solubility of Hg and favor the escape of the metal to the atmosphere. However, the basin has been affected for thousands of years by natural and anthropogenic inputs of metals and climate change with sea level rise (3.6 ± 0.3 mm year⁻¹ in the last two decades), and the frequency of extreme weather events will likely remobilize a large amount of legacy Hg from soils, riverine, and coastal sediments. Moreover, possible changes in pelagic food webs and food availability could determine dietary shifts and lower growth rates in Mediterranean cetaceans, increasing their Hg body burden. Although, in adulthood, many marine mammals have evolved the ability to detoxify monomethylmercury (MMHg) and store the metal in the liver and other organs as insoluble HgSe crystals, in Mediterranean populations more exposed to the metal, this process can deplete the biological pool of Se, increasing their susceptibility to infectious diseases and autoimmune disorders. Mediterranean mammals are also among the most exposed in the world to legacy POPs, micro- and nanoplastics, and contaminants of emerging interest. Concomitant exposure to these synthetic chemicals may pose a much more serious threat than the Se depletion. Unfortunately, as shown by the literature data summarized in this review, the most exposed populations are those living in the NW basin, the main feeding and reproductive area for most Mediterranean cetaceans, declared a sanctuary for their protection since 2002. Thus, while emphasizing the adoption of all available approaches to mitigate anthropogenic pressure with fishing and maritime traffic, it is recommended to direct future research efforts towards the assessment of possible biological effects, at the individual and population levels, of chronic and simultaneous exposure to Hg, legacy POPs, contaminants of emerging interest, and microplastics. Full article