Search Results (160)

S-adenosylmethionine (AdoMet) is a central metabolite required for methylation and sulfur metabolism, synthesized in Saccharomyces cerevisiae by the cytosolic enzymes Sam1 and Sam2. While transcriptional and metabolic regulation of AdoMet biosynthesis have been extensively studied, how metabolic state influences the spatial organization of AdoMet synthases remains incompletely understood. Herein, we show that Sam1 undergoes robust and reversible relocalization into cytosolic assemblies under low-glucose metabolic states. These assemblies are dynamic and dissolve rapidly upon glucose refeeding in a manner that requires metabolizable glucose, indicating regulation by metabolic flux. While Sam1 assemblies associate with stress granules during prolonged starvation, a substantial fraction form independently under acute low-glucose conditions, indicating that Sam1 relocalization is not fully coordinated with canonical stress granule formation. Untargeted metabolomic analysis indicates that AdoMet pools are broadly maintained, while a targeted fluorescence-based enzymatic assay detects a modest but reproducible reduction in AdoMet under low-glucose conditions. Together, these findings define a metabolically gated mechanism for reversible Sam1 sequestration and support a model in which spatial organization of metabolic enzymes is coupled to cellular metabolic state. Full article

Haze Pollution in China arises from the rapid enlargement of ultrafine particles into light-absorbing fine particulate matter through adsorption processes under atmospheric stagnation conditions. This study focuses on the sources of ultrafine particles (UFPs), the most critical component of haze pollutants during severe pollution periods in China. Utilizing methods including the spatial Durbin model and statistical data for the 28 cities (the “2 + 26” cities) within the Beijing–Tianjin–Hebei air pollution transmission channel—suffering the most severe haze pollution—it investigates the impact of pollution-intensive industries on haze pollution. This study reveals several key findings regarding China’s haze pollution. First, the principal source of ultrafine particles within China’s haze stems from the desulfurization, denitrification, and dust removal processes of pollution-intensive industries (the direct effect of these industries on haze is 0.028 * according to the SDM regression results). Crucially, the specific operational factors driving the abrupt increase in atmospheric UFPs during severe haze periods in China are identified as extensive management practices in desulfurization, the progressive tightening and annual escalation of denitrification emission standards, and the reliance on electrostatic precipitation which is ineffective against ultrafine particles. Second, haze pollution predominantly occurs in regions characterized by concentrations of pollution-intensive industries coupled with weak atmospheric environmental self-purification capacity (this carrying capacity for pollution-intensive industries exerts a significant negative impact on haze, demonstrated by a direct effect of −0.020 **; further analysis reveals that this is caused by regional differences in atmospheric self-purification capacity). Third, regional air transport acts as a contributing source, introducing UFPs from neighboring areas into local haze pollution, reflected by an indirect effect of pollution-intensive industries of 0.151 ** stemming from such spatial spillovers. Based on these conclusions, the study proposes a set of policy recommendations: relocate pollution-intensive industries using a gradient approach based on atmospheric self-purification capacity differences; systematically upgrade wet flue gas desulfurization technologies for industrial emissions; effectively promote technological innovation in denitrification processes; implement scientific controls on ammonia emissions; strengthen R&D in core technologies for UFP removal; innovate dust removal technologies to enhance overall system efficiency; reinforce regional coordinated governance; implement targeted training programs and select qualified management personnel; systematically enhance the environmental management capabilities of staff; and effectively mitigate the spillover effects of haze pollution. Full article

Remote sensing has become a key non-invasive tool in archaeological prospection, particularly in regions where logistical constraints limit sustained fieldwork. This study presents the results from Zar Tepe (1st–5th centuries AD), in the Surkhandarya province of southern Uzbekistan, within northwestern Bactria. The research aimed to document the site’s urban layout, accurately relocate Soviet-era excavation sectors within the present-day topography, and refine the interpretation of earlier interventions that were only partially documented and lacked precise georeferencing. A multiscale and multitemporal methodology was applied, integrating CORONA and WorldView-3 satellite imagery, UAV and terrestrial photogrammetry, GNSS Precise Point Positioning, magnetic prospection, and targeted archaeological verification. The workflow followed an iterative laboratory–field sequence, combining remote-sensing analysis, field checks, data refinement, and systematic ground-truth validation. Fieldwork was conducted during two contrasting phenological periods, in June 2024 and December 2025, to assess seasonal variability in surface and subsurface visibility. The integrated approach enabled the accurate spatial fitting of legacy excavation sectors and supported the cross-validation of optical and salt-efflorescence-related anomalies with geophysical evidence. These results provide a stronger basis for the cautious interpretation of buried architectural features and for refining hypotheses concerning Zar Tepe’s urban organization and occupational dynamics. Full article

During a severe earthquake, the violent shaking causes freestanding non-structural elements to sway and overturn, potentially injuring occupants or causing the elements themselves to break apart. This study investigates how freestanding contents (FSCs) in buildings respond to various earthquake intensities, detailing their movement through extensive analysis of dynamic performance. The stability of the FSCs on each floor varies depending on the earthquake’s intensity, the building’s structural mode shape, the FSCs’ geometry, and the chosen performance assessment method. A series of multi-level seismic excitation assessments of FSCs were conducted using 30 earthquake records, classified into 50%, 10%, and 2% probabilities of exceedance in 50 years. The floor’s responses, including absolute peak floor acceleration and relative peak floor velocity from both elastic and inelastic analyses, provided the seismic demand. The Ishiyama criterion made it difficult to evaluate FSCs’ seismic capacity because of the ambiguous distinction between rocking and overturning movements. A new criterion, specifically developed to differentiate between rocking and overturning of FSCs, has been proposed to address this issue. The results translate into practical guidance for design and protection: because the demand-to-capacity ratios for overturning are governed by the floor level, content slenderness, and the elastic-versus-inelastic modeling assumption, the proposed criterion identifies which floors and which content geometries are genuinely at risk, allowing anchorage, restraint, or relocation measures to be targeted where they are most needed rather than applied uniformly. This supports more reliable and economical seismic protection of non-structural building contents. Full article

China has achieved rapid industrial development, but at the same time, the problems of tightening energy supply and environmental degradation have become increasingly prominent. Improving green total factor productivity (GTFP) has become a central task in China’s industrial transformation. Using industrial input–output data for 30 Chinese provinces from 2008 to 2020, this paper innovatively extends the Hsieh–Klenow framework by introducing land, energy and environmental pollution as input factors, and combines it with a spatial Durbin model to quantify industrial GTFP losses caused by energy misallocation and factor price distortions and to examine their spatial spillover effects. The results show that resource misallocation has generated significant inter-provincial industrial GTFP losses, with loss rates ranging from 13.96% to 32.57%, among which energy misallocation is the most important source. By comparing effective GTFP under a scenario without energy distortions with the observed GTFP, it can be found that eliminating energy misallocation would increase the average level of China’s inter-provincial industrial GTFP by about 40% during the sample period. Spatially, GTFP losses exhibit significant clustering, mainly concentrated in the northwest region, particularly in the Yellow River Basin, while lower losses are observed in the Yangtze River Basin and the southeastern coastal regions. In addition, industrial GTFP losses show significant spatial correlation and spillover effects. Environmental regulation can reduce local GTFP losses, but it may increase losses in neighboring regions through mechanisms such as industrial relocation or pollution spillovers. To support the sustainable development of China’s industry, these findings indicate the need for more efficient energy allocation, faster technological upgrading and talent investment, as well as stricter and more targeted environmental regulation. Full article

Background: The rise in global throughput has created major challenges for container terminals and depots, especially in managing limited storage space and unsynchronized truck pickup schedules from different companies. These conditions complicate the organization, retrieval, and relocation of containers, especially when target containers are located in the middle of stacks. This study aims to develop an integrated optimization model that combines Truck Appointment Scheduling (TAS) and Restricted Block Relocation Problem (RBRP) to minimize container relocations, coordinate pickup schedules, and improve operational efficiency. Methods: An integer programming model is formulated to integrate relocation and scheduling decisions by considering practical operational constraints, including maximum stack capacity, queue length, crane movement capacity, relocation validity, prevention of redundant movements, and efficient slot utilization. Two solution schemes are evaluated, simultaneous RPRP-TAS approaches and sequential TAS-then-RBRP approaches, to minimize relocations. Results: The results show that the simultaneous approach produces fewer relocation and more stable than the sequential approach. Sensitivity analysis also confirms that the simultaneous scheme is more robust to variations in the number of containers and crane movement capacity, while maintaining comparable pickup time-shift performance. Conclusions: The simultaneous integration of RBRP and TAS provides coordinated, practical, and efficient decision support for depot and terminal operations. Full article

Background: In Uganda, COVID-19-related disruptions increased the number of children who missed scheduled routine vaccination (defaulters). Identifying and following up with defaulter children is important for improving vaccination coverage. This paper describes Uganda’s experience in revitalizing community-led defaulter tracking to improve vaccination coverage post-COVID-19 in four purposefully selected districts. Methods: During two 6-month periods in 2022 and 2024, healthcare workers (HCWs) worked with village health teams (VHTs) to review health facility-based immunization registers, identify and track defaulters aged 0 to 59 months. VHTs visited identified defaulters’ homes, reviewed vaccination histories and reminded caregivers to bring defaulters to immunization sites for catch-up vaccination. Results: Overall, 20,922 defaulters were identified by health register review; VHTs located 15,749 (75.3%) through household visits, of whom 3688 (23.4%) were verified as previously vaccinated based on their home-based vaccination records, leaving 12,061 as true defaulters. Among the true defaulters, 9662 (80.1%) received at least one catch-up vaccination after follow-up by the VHT. The most frequently administered catch-up vaccines were measles–rubella first dose (MR1) at 55.4%, followed by diphtheria–tetanus–pertussis third dose (DTP3) at 48.3% and Bacillus Calmette–Guérin (BCG) at 47.4%. Among the 2399 children who remained unvaccinated after follow-up, the most common reasons were relocation outside the original catchment area (49.5%) and caregiver intention to vaccinate later (16.3%). Conclusion: Community-led defaulter tracking was feasible and improved vaccination uptake in post-COVID-19 Uganda. Strengthening the quality and availability of health facility immunization data, along with targeted community engagement, caregiver reminders and integrated vaccination services would improve identification and follow-up of defaulters, reducing population immunity gaps. Full article

The squint synthetic aperture radar (SAR) offers flexible beam pointing control and a wider range of applications compared to the side-looking SAR. Unlike the latter, ground moving targets exhibit shifts in both along-track and cross-track directions in squint SAR systems. To address this issue, a two-dimensional relocation method for moving targets is proposed in this paper. Firstly, the shift characteristics of moving targets in squint SAR systems are analyzed, revealing that the two-dimensional location shifts are correlated with both the target’s radial velocity and its imaging location. The proposed algorithm initially performs clutter suppression on the SAR imagery and estimates the radial velocity of the moving target. The two-dimensional location information is then derived by solving a set of joint equations. Finally, some numerical experiments are provided to demonstrate the effectiveness of the proposed method in the squint SAR system. Full article

Siamese tracking is widely used in object tracking due to its efficient dual-branch symmetric structure, deep feature matching mechanism, and flexible template strategy. Existing mainstream Siamese tracking algorithms typically employ static template matching or linear combination-based template updating to localize the target in the next frame. However, these mechanisms often struggle to ensure template accuracy in complex environments involving changes in target appearance, scale, occlusion, and motion blur, thereby compromising robustness and stability. To address these issues, this paper proposes a confidence-guided adaptive template update with a re-detection (CATUR) network. CATUR constructs a tracking confidence assessment module that uses average peak-to-correlation energy (APCE) and a dynamic threshold mechanism to determine the current tracking state, providing a basis for template updates and target re-detection. It also designs an adaptive template update network that effectively combines the initial, historical, and current-frame templates, enhancing adaptation to target appearance variations. By integrating a global search module and a re-detection module, CATUR achieves precise target re-localization, rapid template updating, and tracking recovery. Extensive experiments and ablation studies on LaSOT and TrackingNet demonstrate that CATUR improves AUC, PNorm, and P by 4.0%, 4.0%, and 3.2%, respectively, significantly enhancing tracking accuracy and robustness in complex environments. Full article

Chemotherapy-induced metabolic reprogramming of glioblastoma multiforme (GBM) cells increases intracellular levels of reductive and energetic carriers, thereby fueling drug-relocation and retention systems and enhancing GBM drug-resistance. We have previously shown the role of this process in the adaptation of poly(morpho)nuclear “giant” cells (PGCs) in T98G populations to doxorubicin (DOX)-induced stress. Here, we addressed the role of a “resistance triad”, which coordinates metabolic T98G reprogramming with the activation of the drug-relocation and drug-retention axis, in the recovery of GBM populations from chemotherapeutic stress. A combination of proteomic analyses with metabolic and phenotypic profiling of pulse DOX-treated T98G cells revealed the significance of mitochondrial dynamics for the efficiency of the T98G “resistance triad”. DOX-induced mobilization of ATP-generating systems and ATP-dependent anabolic pathways was accompanied by the formation of DOX-negative, “mosaic” mitochondrial networks and the upregulation of mitofusin-2 (MFN2) in T98G PGCs. Transient MFN2 down-regulation correlated with the respiratory capacity of T98G cells, while impairing cell welfare in the absence and presence of DOX. However, minute fractions of PGCs, which withstood combined MFN2 down-regulation and pulse DOX treatment, retained mitochondrial networks and displayed efficient ABC transporter-/V-type channel-dependent lysosomal DOX retention. Collectively, a “triad” of mitochondrial activation, ABC transporter-dependent perinuclear redistribution and V-type channel-mediated lysosomal DOX compartmentalization determines DOX resistance of T98G cells. Whereas MFN2-dependent mitochondrial rearrangements may contribute to these processes, complementary adaptative mechanisms can compensate MFN2 dysfunction, limiting its potential as a therapeutic target. Full article

Mobility-aware digital twin (DT) migration is increasingly used in edge computing to sustain low-latency service as physical entities and service demand move across domains. However, stateful DT migration across administrative domains requires more than placement adaptation; it also requires target-side legitimacy verification, protected-state transfer, continuity-preserving traffic transition, and invalidation of stale source-side instances. This paper presents a secure cross-domain authentication and service continuity mechanism for mobility-aware DT migration in edge computing. The proposed design formulates migration as a six-phase ordered control procedure comprising migration triggering, target-side authorization, protected-state transfer, continuity-aware traffic transition, post-migration activation, and revocation-aware completion. Security analysis examines authorization soundness, migration-state confidentiality and integrity, transition safety, and post-migration uniqueness. Performance evaluation shows that the full mechanism introduces only a bounded increase in migration-related cost while reducing service interruption at 500 MB from approximately 1.79 s without continuity-aware transition control to 285 ms in the full mechanism. The results indicate that the proposed mechanism preserves the operational benefit of mobility-aware DT migration while strengthening migration authorization, state transfer protection, and service continuity under cross-domain relocation. Full article

Background: University students’ mental health represents an increasing public health concern, particularly in STEM contexts characterized by high academic demands. Students living away from home, including international students, may face additional stressors related to relocation, social integration, and adaptation. This study examined how narrated academic experiences are associated with psychological and academic functioning among relocated STEM students. Methods: A cross-sectional convergent parallel mixed-methods study was conducted at an Italian STEM university (May–June 2024). An online survey was distributed to the entire accessible student population (33,336 invitations; 12,538 accesses; response rate = 37.6%). Analyses focused on relocated students who completed all relevant sections (N = 776; M age = 22.96). Quantitative measures assessed academic self-efficacy, burnout (Emotional Exhaustion; Cynicism), engagement (Vigor; Dedication), study program satisfaction, and perceived academic goal attainment. Open-ended responses underwent thematic analysis with a codebook approach and transformed into category count variables. Hierarchical regression models examined associations controlling for age, gender, and academic level. Results: Organizational and learning-related difficulties were the most frequent categories. Content categories explained additional variance across outcomes (ΔR² = 0.054–0.107). Teaching-related narratives were associated with higher burnout and lower engagement and satisfaction, whereas Positive narratives showed the opposite pattern. Conclusions: Institutional and pedagogical experiences are systematically associated with student well-being among relocated STEM students, highlighting modifiable targets for university-level mental health promotion strategies. Full article

Riverine systems in tropical deltaic environments are increasingly exposed to hydrological variability driven by climate change, sea level rise, and extreme precipitation. In Nigeria’s Niger Delta, recurrent flooding and environmental degradation are intensifying pressures on freshwater ecosystems and dependent communities. This study examines hydrological stressors in riverine settlements of Bayelsa State and explores associated socio-ecological responses. Using an exploratory qualitative design, data were collected from 51 women residing in highly vulnerable riverine communities through 24 in-depth interviews and three focus group discussions. Thematic analysis identified prolonged flooding, riverbank erosion, salinity intrusion, water quality deterioration, and oil pollution, as key drivers of declining fisheries, reduced agricultural productivity, and household water insecurity. These stressors have prompted relocation, livelihood diversification, and reliance on indigenous adaptation practices. The study recommends: (1) installation of community-based flood early warning systems; (2) routine monitoring of surface water quality and salinity; (3) enforcement of oil spill remediation and pollution control measures; (4) rehabilitation of wetlands and natural drainage channels; and (5) targeted support for climate-resilient livelihoods such as aquaculture and elevated farming systems. These measures are critical for sustaining freshwater ecosystems and strengthening resilience in vulnerable deltaic communities. Full article

Rural settlements serve as the core spatial carriers of rural living space, and their spatial evolution and functional transformation reflect the dynamic restructuring of human–land relationships. In karst mountainous areas, complex topography, fragmented land resources, and uneven distribution of public facilities significantly influence settlement patterns and residents’ living spaces. This study aims to quantify the relationship between settlement clustering characteristics and living-space demand and to construct a spatially explicit framework for rural settlement restructuring from a living-space perspective. Taking the Qixingguan District of Bijie City, Guizhou Province—a representative karst mountainous area in Southwest China—as a case study, we develop an integrated analytical framework encompassing spatial identification, demand measurement, and zoning optimization. Settlement clusters were identified using the Nearest Neighbor Index and Kernel Density Analysis, while accessibility to essential services—including education, healthcare, and shopping—was quantified via a Gaussian-based two-step floating catchment area method. Living-space demand was further assessed by integrating accessibility gradients with residential conditions, and restructuring types were classified based on the Living Space Index and the distance from settlements to town centers. The results indicate that (1) rural settlements in Qixingguan District exhibit significant clustering, with high-density zones concentrated around urban peripheries and along transportation corridors; (2) accessibility to living services follows a distance-decay pattern modulated by transportation networks, forming hotspots in suburban and town-center areas and cold spots in peripheral karst mountainous areas; and (3) based on the comprehensive assessment, settlements are categorized into four types—urbanizing villages, central villages, preserved villages, and relocation villages—with corresponding targeted spatial restructuring strategies proposed. This study advances the geographical understanding of rural settlement restructuring in karst mountainous areas and provides empirical evidence for optimizing human–land relationships and promoting more equitable and sustainable spatial development in mountainous regions. Full article

Mixed Reality (MR) teleoperation offers an intuitive interface for Human-Robot Collaboration (HRC), yet it often faces the “Embodiment Gap”—a physical and kinematic mismatch between human operators and robotic platforms. Existing MR systems primarily rely on a “direct mapping” approach, where user movements are transferred directly to the robot. This forces operators to manually adapt to robotic constraints, such as singularities and joint limits, making task performance heavily dependent on individual skill. This study proposes Mixed reality Adaptive Spatial and Kinematic support (MASK), an adaptive shared-control framework designed to bridge the “Gulf of Execution” and “Gulf of Evaluation” by separating target selection from reachability and kinematic feasibility. The MASK system integrates three core modules: (1) Target Object Identification (TOI) based on body motion features to identify the intended manipulation target; (2) a Base Relocation Module (BRI) utilizing Inverse Reachability Maps to optimize the robot’s spatial configuration; and (3) a Kinematic Correction Module (KCM) that autonomously resolves kinematic constraints through pose blending and null-space optimization. Initial experimental results suggest that MASK reduces the operator’s cognitive and physical load by shifting the burden of kinematic resolution from the human to the system. This approach enables high-precision manipulation through an intuitive interface, potentially reducing the performance gap between different levels of operator proficiency. Full article