Mobile Nature Research Articles

Through-Thickness Electric Field Establishes Complex Molecular Architectures for Localized Liquid Secretion.

Localized liquid secretion, being an important process in nature such as the secretion of tears or mucus, has been an attractive point in developing biomimetic materials. However, precise localization remains challenging due to the cohesive and mobile nature of liquids. In this paper, light-induced localized liquid secretion is demonstrated on the scale of tens of micrometers by a liquid crystal polymer coating with an alternating homeotropic-planar alignment. The light responsiveness is achieved by the incorporation of azobenzene derivative. The localization is achieved by applying regional through-thickness electric fields to the monomeric liquid crystals before polymerization. The polymerized coating preserves both homeotropic and planar alignment. Upon actuation, the liquid can be locally secreted from the homeotropic region while suppressed in the planar area. This method allows precise control over various secretion patterns based on different pre-designed electrodes, which paves the way for the development of responsive devices in a multitude of fields, such as targeted drug delivery, tissue engineering, and microfluidic devices.

Exploring the Intricacies of Social Mobility Trajectories and Perceived Stress in Post-Reform China.

Among transitional societies, the impact of rapid and widespread intragenerational social mobilities on stress remains understudied. This empirical research explores the intricate relationship between various social mobility trajectories and perceived stress within the dynamic context of contemporary China. Drawing upon data from the China Health and Nutrition Survey spanning from 1991 to 2015, this study advances beyond conventional methodologies that typically categorise social mobility as either upward or downward. It employs the Growth Mixture Model to discern six latent mobility trajectories: 'Fall into Poverty', 'Rise from Rags', 'Middle Class', 'Fall from Grace', 'Upper Middle Class' and 'Elite.' The resulting findings then reveal the diverse impacts of these distinct mobility trajectories on perceived stress, emphasising gender-specific patterns. Among men, those categorised as 'Elite' and 'Fall from Grace' report lower perceived stress levels in comparison to the middle-class reference group, while individuals in the 'Fall into Poverty' category exhibit the highest stress levels. Conversely, for women, the 'Upper Middle Class' and 'Elite' categories are associated with lower stress levels, with 'Upper Middle Class' women experiencing the least stress. The findings unveiled in this study shed light on the multifaceted nature of social mobility and its consequences for stress within a rapidly changing society. These insights hold significant implications for public health interventions, underscoring the necessity of a more nuanced theoretical framework for understanding the stress experiences of Chinese residents amidst societal transformation.

Critical mobility in policy making for epidemic containment

When considering airborne epidemic spreading in social systems, a natural connection arises between mobility and epidemic contacts. As individuals travel, possibilities to encounter new people either at the final destination or during the transportation process appear. Such contacts can lead to new contagion events. In fact, mobility has been a crucial target for early non-pharmaceutical containment measures against the recent COVID-19 pandemic, with a degree of intensity ranging from public transportation line closures to regional, city or even home confinements. Nonetheless, quantitative knowledge on the relationship between mobility-contagions and, consequently, on the efficiency of containment measures remains elusive. Here we introduce an agent-based model with a simple interaction between mobility and contacts. Despite its simplicity, our model shows the emergence of a critical mobility level, inducing major outbreaks when surpassed. We explore the interplay between mobility restrictions and the infection in recent intervention policies seen across many countries, and how interventions in the form of closures triggered by incidence rates can guide the epidemic into an oscillatory regime with recurrent waves. We consider how the different interventions impact societal well-being, the economy and the population. Finally, we propose a mitigation framework based on the critical nature of mobility in an epidemic, able to suppress incidence and oscillations at will, preventing extreme incidence peaks with potential to saturate health care resources.

Transnational youth mobility through trajectories and temporalities

ABSTRACT The physical mobility of young people affected by their own or their parents’ international migration – whom we call ‘transnational youth’ – has been under-researched due to assumptions about young people’s sedentarism and the dominance of a nation-state perspective. This Special Issue brings together eight articles on transnational youth mobility studied through the lenses of trajectories and temporalities, including cases from Africa, Asia, the Americas, and Europe. The articles analyse various types of transnational youth mobility over time and space, by contextualising mobility experiences in young people’s broader life courses (trajectories) and focusing on the way in which young people experience time in relation to their mobility (temporalities). This introduction presents the five main conceptual and methodological advancements of these investigations: de-nationalising the study of youth mobility; embedding youth mobility in (infra)structures; viewing mobility as processual and non-linear; capturing the embodied and emotional nature of youth mobility; and experimenting with methodological innovations relating to visualisation methods, ‘following’ mobility, and youth-centricity. This introduction proposes a research agenda for conceptual, theoretical, and methodological developments that can shed greater light on the role that physical mobility plays in the lives of transnational youth in the Global South and North.

Revealing Elasmobranch Distributions in Turbid Coastal Waters: Insights From Environmental DNA and Particle Tracking.

Many sharks, rays and skates are highly threatened and vulnerable to overexploitation, as such reliable monitoring of elasmobranchs is key to effective management and conservation. The mobile and elusive nature of these species makes monitoring challenging, particularly in temperate waters with low visibility. Environmental DNA (eDNA) methods present an opportunity to study these species in the absence of visual identification or invasive techniques. However, eDNA data alone can be difficult to interpret for species monitoring, particularly in a marine setting where its distribution can be influenced by water currents. In this study, we investigated the spatial and temporal distribution of elasmobranch species in two Special Areas for Conservation (SAC) off the coast of Wales. We took monthly eDNA samples for 1 year (starting September 2020 and March 2022 for the northern and southern SACs, respectively), and used metabarcoding to reveal the presence of elasmobranch species. We combined these data with hydrodynamic modelling and particle tracking methods to simulate the potential origins of the detected eDNA. We detected 11 elasmobranch species, including the critically endangered angelshark (Squatina squatina) and tope (Galeorhinus galeus). Most detections were in the spring and the fewest in the autumn. The particle tracking simulations predicted that eDNA was shed, on average, approximately 7 km and 15 km (in the northern and southern SACs, respectively) from the sampling stations at which it was detected. These results show that the two SACs represent important areas for elasmobranchs in the United Kingdom and demonstrate that eDNA methods combined with particle tracking simulations can represent a new frontier for monitoring marine species.

Multifunctional Quasi‐Homogeneous Catalysts as a New Catalytic Strategy to Boost the Performance of Li‐O2 Batteries

AbstractLi‐O2 batteries have been considered as a kind of prospective next‐generation batteries due to their ultrahigh energy densities. However, limited capacities, high charge overpotentials, and short lifetime are troubling obstacles for realizing their real‐world implementation. Common strategies, including introducing solid‐state catalysts (SSCs) and redox mediators (RMs), are insufficient to solve these issues. Herein, Ru‐loaded amino‐phenanthroline‐based carbonized polymer dots (RuApCPDs) integrating the catalytic activity of SSCs with the mobility of RMs have been designed to behave as quasi‐homogeneous catalysts in the electrolyte. Their mobile nature can ensure the avoidance of complete coverage of active sites, and the catalytic ability decreases the charge overpotential through co‐deposition with the discharge products. Additionally, the RuApCPDs can also adjust the Li+ solvation structure and well protect the Li metal anodes with high stability. As a result, the introduction of RuApCPDs leads to a fivefold increase in discharge capacity, a low charge voltage of 3.75 V, and a running life of 168 cycles (79 cycles without RuApCPDs). The multifunctional quasi‐homogeneous catalyst developed here demonstrates its advantageous potential as a new catalytic strategy for bringing Li‐O2 batteries to become a viable technology.

Bio-Inspired Algorithms for Efficient Clustering and Routing in Flying Ad Hoc Networks.

The high mobility and dynamic nature of unmanned aerial vehicles (UAVs) pose significant challenges to clustering and routing in flying ad hoc networks (FANETs). Traditional methods often fail to achieve stable networks with efficient resource utilization and low latency. To address these issues, we propose a hybrid bio-inspired algorithm, HMAO, combining the mountain gazelle optimizer (MGO) and the aquila optimizer (AO). HMAO improves cluster stability and enhances data delivery reliability in FANETs. The algorithm uses MGO for efficient cluster head (CH) selection, considering UAV energy levels, mobility patterns, intra-cluster distance, and one-hop neighbor density, thereby reducing re-clustering frequency and ensuring coordinated operations. For cluster maintenance, a congestion-based approach redistributes UAVs in overloaded or imbalanced clusters. The AO-based routing algorithm ensures reliable data transmission from CHs to the base station by leveraging predictive mobility data, load balancing, fault tolerance, and global insights from ferry nodes. According to the simulations conducted on the network simulator (NS-3.35), the HMAO technique exhibits improved cluster stability, packet delivery ratio, low delay, overhead, and reduced energy consumption compared to the existing methods.

Some parameters of attitudes towards health and stress in the workplace with a mobile nature of work in Arctic conditions

Objective. To determine associations of stress at work and some parameters of attitudes towards health among people engaged in mobile work at industrial enterprises of the oil and gas production complex of the Arctic, depending on their work experience. Materials and methods. The object of the study was a “random” representative sample of male workers engaged in mobile labor in the Arctic latitudes of the Russian Federation. The sample included 750 men aged 25-54 years, the response rate was 82.4%. Determination of stress at work and attitude towards one's health was carried out through analysis of the standard WHO MONICA-MOPSY questionnaire. Results. In the presence of stress in the workplace and a long period of work as an expeditionary shift worker in the Arctic, a tendency has been established towards a decrease in self-esteem of health and the lowest level of responsibility for one’s health. With less than ten years of experience as an expeditionary shift worker and the presence of stress in the workplace, a lesser desire for disease prevention and care for one’s health was determined. Conclusion. Thus, the results of determining the associations of stress in the workplace with the parameters of attitude towards health, its self-esteem among workers of the oil and gas production complex engaged in mobile work, depending on the length of work on an expeditionary rotational basis, must be used as a significant part of a comprehensive preventive program at industrial enterprises in the Arctic. Keywords:

Who bears the tax burden? The withholding tax policy and persistent informality in artisanal small-scale mining in Ghana

ABSTRACT This article examines the withholding tax policy and the challenges of taxing ASM activities in Ghana. Based on qualitative interviews with operators and stakeholders, the article reveals that the mobile and uncertain nature of operations makes it difficult for state institutions to govern and generate domestic revenue from the sector. Assessment of the withholding tax policy reveals how taxation without ‘actual’ formalization indirectly legitimizes illegal activities. Formalization efforts must prioritize the livelihood security of operators over revenue generation concerns. State accountability and a working social contract are critical to domestic revenue mobilization in developing countries.

Real-Time Elemental and Isotopic Measurements of Molten Salt Systems through Laser-Induced Breakdown Spectroscopy.

Molten salt reactors are an emerging advanced nuclear reactor concept in which the fuel is dissolved into the working fluid in the form of a high-temperature molten salt. The complex, mobile, and corrosive nature of this fluid presents a fundamental challenge for analytical measurements. Tracking species throughout the reactor is important for ensuring proper operation. This article presents laser-induced breakdown spectroscopy (LIBS) used to monitor the elemental composition of a molten salt and corresponding hydrogen isotopic shifts in real-time. A NaNO3-KNO3 eutectic salt was saturated with protium and deuterium gases, then the effluent aerosol stream formed using an argon sparging vessel was monitored with LIBS. This modular LIBS system permitted several spectrometers to be used simultaneously to capture high-resolution isotopic shifts and provide broadband elemental coverage. The results exhibit how LIBS can be used to understand salt-gas chemical and physical interactions such as diffusion. Furthermore, LIBS' broad elemental coverage can provide greater insight into the chemical reactions within the salt vessel such as the formation of water vapor by monitoring hydrogen and oxygen signatures simultaneously. Ultimately, this study demonstrates the analytical possibilities of LIBS for real-time monitoring of isotopes and elemental composition in molten salt systems.

Mobility, infrastructure, and peacebuilding: (Im-)mobilising Morocco's waters in the early French Protectorate, 1912–1925

The Administration of the French Protectorate in Morocco sought to build water infrastructure to redirect water resources into the colonial economy. Moroccan water users resisted this process intensely, forcing the Administration to adjust its aims. This article examines this historical conflict through a mobility lens. It argues that the mobile nature of water was a formative element in shaping Moroccan resistance because of the potential of water mobilisation to evoke an emotive response. Perceiving this response as an element of mobility allows a more profound analysis of “active violent infrastructure”, as it explores the need of colonial elites to navigate this emotive response while planning marginalising and deleterious infrastructural designs.

Visible light communication in aircraft cabins: challenges and opportunities in power, coverage, and handover management

Abstract Visible light communication (VLC) presents a compelling solution for enhancing in-flight connectivity within commercial aircraft cabins. This study investigates the power distribution, coverage area, and handover performance of VLC systems inside aircraft based on line-of-sight (LoS) and first reflection signal. Results indicate that received power levels at different receiver positions are significantly affected with varying half-power semi-angles. Analysis of first reflection signal power distribution reveals maximum reflected power is achieved at semi-angle equal to 45°. Simulated coverage areas demonstrate the importance of half-power semi-angle size in determining signal confinement and separability. Handover simulations highlight the dynamic nature of passenger mobility and its impact on handover frequency, with smaller semi-angles resulting in higher handover counts. While directional transmission offers benefits such as interference mitigation and spatial reuse, it also introduces challenges related to handover frequency and coverage area. These findings underscore the need for careful optimization of VLC system designs and handover algorithms to ensure seamless connectivity and optimal performance in diverse aircraft environments.

Deep Reinforcement Learning for Dynamic Task Scheduling in Edge-Cloud Environments

With The advent of the Internet of Things (IoT) and its use cases there is a necessity for improved latency which has led to edgecomputing technologies. IoT applications need a cloud environment and appropriate scheduling based on the underlying requirements of a given workload. Due to the mobility nature of IoT devices and resource constraints and resource heterogeneity, IoT application tasks need more efficient scheduling which is a challenging problem. The existing conventional and deep learning scheduling techniques have limitations such as lack of adaptability, issues with synchronous nature and inability to deal with temporal patterns in the workloads. To address these issues, we proposed a learning-based framework known as the Deep Reinforcement Learning Framework (DRLF). This is designed in such a way that it exploits Deep Reinforcement Learning (DRL) with underlying mechanisms and enhanced deep network architecture based on Recurrent Neural Network (RNN). We also proposed an algorithm named Reinforcement Learning Dynamic Scheduling (RLbDS) which exploits different hyperparameters and DRL-based decision-making for efficient scheduling. Real-time traces of edge-cloud infrastructure are used for empirical study. We implemented our framework by defining new classes for CloudSim and iFogSim simulation frameworks. Our empirical study has revealed that RLbDS out performs many existing scheduling methods.

Development of a simple test to quantify the consolidation properties of liquefied granular materials

AbstractLiquefaction can have devastating consequences by causing increased mobility of debris flows, tailings dam breaches, and settlement following seismic shaking. Observations on the consolidation behaviour of liquefied soils in 1-g or centrifuge shake table tests have permitted significant advancements in analytical and numerical methods to predict the rate and magnitude of consolidation settlement. However, advanced consolidation models introduce material parameters which are currently difficult to define quickly and at low cost. The objective of this paper is to demonstrate the development of a simple, low-cost test that can be used to quickly estimate the spatially and temporally varying coefficient of consolidation, which controls post-liquefaction settlements. Using the proposed simple setup, experiments were conducted on four uniformly graded sands of varying grain size and on one well-graded mixture. A range of analytical and numerical approaches from literature were assessed for their ability to back-analyse the observed pore pressure dissipation and settlement. Estimated values for the coefficient of consolidation were comparable between models and estimates of surface settlement matched well the experimental results. The simplicity of the proposed test combined with its low-cost and mobile nature, raise significant possibilities for quick estimations of the evolution of the coefficient of consolidation post-liquefaction.

Cooperative Use of N-Heterocyclic Carbenes and Thiols on a Silver Surface: A Synergetic Approach to Surface Modification.

Surface modification through the formation of a self-assembled monolayer (SAM) can effectively engineer the physicochemical properties of the surface/material. However, the precise design of multifunctional SAMs at the molecular level is still a major challenge. Here, we jointly use N-heterocyclic carbenes (NHCs) and thiols to form multifunctional hetero-SAM systems that demonstrate excellent chemical stability, electrical conductivity, and, in silico, catalytic activity. This synergistic effect is facilitated by the high surface mobility and electron-rich nature of NHCs, combined with the strong binding strength of thiols. Scanning tunneling microscopy, electrical conductivity, and scanning electron microscope measurements, as well as density functional theory calculations, were employed to explore the synergistic interactions in the supramolecular SAMs. The van der Waals integration of ballbot-type NHCs and thiols enables the SAMs to exhibit both superior surface anticorrosion properties (attributing to the shift in the d-band center) and low surface resistance originating from the band alignment. Moreover, we find that the deposition sequence of flat-lying NHCs and thiols results in SAMs with different configurations, which can further tune the mechanistic pathway in silico in the acetylene hydrogenation process. Our results provide essential molecular insights into the local electronic control of the new SAM/metal interface and the high stability of the emergent multifunctionality (NHC/thiol)-SAMs forming self-assembled lamellae structures in the nanometer regime.

Narrating ‘Home’ in Early Christian Biography: Athanasius’ Life of Antony and Its Literary Predecessors

In this paper, I provide a close examination of early Christian biographical sources through the heuristic lens of “home studies”, tracing a thread from the New Testament Gospels to martyrdom texts, the apocryphal Acts literature, Eusebius’ biography of Origen in his Church History, and finally, Athanasius’ Life of Antony. I demonstrate that the lens of home allows us to see that in each of these discrete groups of texts, Christ’s call to discipleship is understood to redefine and reconstitute the meaning of home and relatedly, family: to be “home” required a great deal of displacement and mobility as one forsook one’s biological family and household for the sake of obedience to the call of Christ. I argue that three topics, typically examined separately, are fruitfully brought together through the lens of home: (1) the shaping of ancient Christian identity formation, as expressed by the characters’ use of familial language to identify other members of the early Christian movement; (2) the mobile nature of the person who joins the movement, providing insights about the mobility and travel of many of its members; and (3) ancient Christian eschatological thought concerning the final dwelling of Christ-believers in some form of otherworldly home after death.

«Spanish Noir»: towards a Literary Understanding of Genre (on the Example of the Novel «Todo esto te daré» by D. Redondo)

The theoretical orientation of the article pursues a practical purpose: to embed a sample of contemporary Spanish crime literature in the genre framework and to be able to apply the results obtained in this type of works. The issue of genre attribution in crime literature has not yet been resolved due to the different starting points of numerous approaches: genre genesis, national specifics, gender perspective, stylistics, etc. Our hypothesis consists in the possibility of attributing any sample of modern criminal literature to a certain genre on the basis of unified literary parameters regardless of the national origin of the work. The artistic analysis of Dolores Redondo’s novel «Todo esto te daré» (2016) on the basis of the genre-typological method – is preceded by theoretical sections. In the introduction, the expediency of this study in the light of the influence of publishing practices on the literary component itself is substantiated. The issue of genre determination is often distorted for the sake of commercial success, depriving researchers of the possibility of scientific analysis using unified terms. Turning directly to the subject of the study, we offer a short excursion into the history of Spanish crime literature and into the environment of scholarly reflection on the so-called «noir» – frequent, but lacking terminological nomination. The methodology proposed by N.N. Kirilenko and O.V. Fedunina becomes the main tool for analyzing the text. The consistent «filtering» of the novel through the constant structural features (type of hero, subject structure, chronotope, and compositional forms of speech) allows it to be attributed to the genre of “victim investigation” with some features of a police novel. The search for the genre of a work in a synchronic context is convenient and universal, therefore, firstly, it is applicable to almost all samples of modern criminal literature, and secondly, it can be complementarily combined with other research purposes. So, you can focus on the genesis of the genre or various factors influencing it in the past and present. In any case, for all the mobility and hybrid nature of contemporary crime literature, its samples can be classified according to uniform criteria, which significantly enriches the toolkit for further research.

The Petrogenesis of the Lower Critical Zone and Lower Group Chromitites, Eastern Bushveld Complex: Incremental Development of Igneous Layering and Injection of Chromite Slurries

Abstract The petrogenesis of the mafic-ultramafic layered rocks of the Bushveld Complex, South Africa, remains uncertain despite more than a century of intensive research. There is little evidence for the existence of a shallow crustal magma chamber, a principle entrenched in the scientific literature for many years, and we prefer an alternative hypothesis in which igneous layering developed from successive intrusive events. Geochemical discontinuities are explained by radical switches in the composition of intruding parental magmas. Here we investigate the origin of the Lower Critical zone, a sequence of five pyroxenitic and two peridotitic units containing the Lower Group (LG) of chromitites, of which LG6 is a major resource for chromium ore in the eastern limb. The pyroxenitic and peridotitic units are not part of magmatic cycles. Two discrete lineages of parental magma are recognized: a pyroxenitic magma sourced from deep crustal staging chambers, and a mantle-derived peridotitic magma. The pyroxenitic units reveal an absence of modal layering (with the exception of the 0.1- to 1-m-thick layers of chromitite) and limited height-related fractionation trends (enstatite: En86–811). Magma was fed as thin laminae. Intrusion rates were insufficient to create a magma reservoir because the supply of magma matched the rate of batch crystallization. There is little evidence of a fractionated residue having been removed. The recognition of minor geochemical trends of Mg- and Fe-enrichment in the pyroxenitic units reflects minor oscillations in the composition of the parental magma. The composition of the orthopyroxene and of the Cr spinel was primarily established at depth. The anomalous concentrations of chromite are explained by the introduction of pyroxenitic magmas containing crystals of Cr spinel, sufficiently abundant in some cases as to have created crystal slurries. The Cr spinel was entrained at depth, in the staging chambers. Each layer of chromitite is related to injection of a crystal slurry. The tiny size of the rounded xenocrysts of Cr spinel facilitated the mobile and dynamic nature of slurries. Coarse-grained mosaics of Cr spinel developed in the compacted layers of chromitite from prolonged periods of annealing. The irregular spacing of the chromitites, and occurrence of variable concentrations of disseminated Cr spinel in the pyroxenites, is explained by fluctuations in the proportion of entrained xenocrysts, rather than changes in the composition of the melt fraction of the magma. The peridotitic units are interpreted as sills, the chromitite layers having been inherited from the earlier formed pyroxenitic stratigraphy. The most primitive layers of dunite and harzburgite (olivine: Fo90-85 in which Fo = forsterite) accumulated in the center of sills, where a high magma flux facilitated growth of pegmatitic oikocrysts.

Resource selection by a megaomnivore in a marine foraging habitat

AbstractHabitat‐based approaches to animal conservation are bolstered by an understanding of resource selection, that is, use of resources (i.e., habitat features) relative to their availability in the environment. Quantifying resource selection is especially valuable when data characterizing animal space use are limited, as is often the case with mobile and/or cryptic species. Documenting associations with habitat features can better inform management in space in time, while also revealing key insight into movement ecology and behavior. Here, we evaluate resource selection by a megaomnivore whose highly mobile nature within marine habitats has resulted in an incomplete understanding of drivers of space use. We used satellite telemetry to track 29 green turtles (Chelonia mydas) from an eastern Pacific foraging aggregation in San Diego Bay, California, USA during 2013–2023. Tracking produced 5023 Fastloc‐GPS points which we used to model selection for local environmental resources relative to their availability. We employed logistic models to evaluate associations with seagrass, bathymetry, and water temperatures, implementing a framework that additionally allowed us to explore the roles of season, diel period, and turtle body size. Our methods demonstrate an approach for down‐weighting observations according to assumed telemetry error and autocorrelation. Results from fine‐scale resource selection models provide evidence that green turtles in San Diego Bay select for eelgrass meadows (Zostera marina), particularly during the warmest months of the year, but the strength of this selection changes from day to night. We additionally found day–night shifts in depth and temperature selection that changed with turtle body size and season. We discuss these findings in the context of diel patterns in resting and foraging behavior in addition to seasonal changes in thermally sensitive metabolic rates. Our study documents resource associations and provides quantitative information for the management of sea turtle foraging populations and their habitats. We offer key insight into habitat use by green turtles in the eastern Pacific at a pivotal time when multiple indicators point to population growth and expansion within the region.

Perceiving Low Social Mobility Induces Zero-Sum Beliefs About Social Hierarchies.

Individuals may consider socioeconomic status (SES) change from an absolute or relative standpoint. Across five studies and supplementary analyses of secondary data, we found that individuals who perceive SES as being unlikely to change (i.e., low perceived social mobility) tend to consider SES change from a relative standpoint-i.e., one person's gain in SES occurs at the expense of another's loss in SES-reflecting that they harbor zero-sum beliefs regarding social hierarchies. In other words, the extent to which individuals believe that society is mobile predicts how they consider the nature of social mobility. This relationship is mediated by a scarcity mindset and further predicts the tendency for aggression. The findings held when we controlled for variables such as perceived economic inequality, income, and education.