Search Results (465)

The “athlete’s heart” phenotype, featuring resting bradycardia, has traditionally been viewed as a benign adaptation. However, emerging evidence associates prolonged, high-intensity endurance training with an increased risk of clinical sinoatrial node dysfunction. This systematic review synthesizes evidence on exercise-induced intrinsic Sinoatrial Node (SAN) electrophysiological remodelling and evaluates its dual nature along the adaptation–pathology continuum. Following PRISMA guidelines, a systematic search of PubMed, Web of Science, and Google Scholar (2000–2025) identified 17 eligible studies. Analysis revealed that in humans, rodents, and rabbits, exercise induces intrinsic SAN electrophysiological remodelling—a “membrane clock” reset characterized by coordinated downregulation of pacemaker currents, notably Hyperpolarization-activated cyclic nucleotide-gated cation channel (I_f), via the Nkx2.5-miR-423-5p transcription factor pathway. Evidence for “calcium clock” involvement remains inconsistent. In contrast, large animal models (e.g., dogs, horses) show only parasympathetic-mediated bradycardia without intrinsic remodelling. Training loads may induce structural changes (e.g., fibrosis), providing an anatomical substrate for pathology. Moderating factors such as training type and ageing contribute to a phenotype of “acquired SAN reserve reduction. Exercise-induced intrinsic SAN remodelling is a physiological adaptation mechanism that, under certain conditions, can cross a threshold to become a pathological cause of clinical dysfunction. Recognizing this continuum is essential for risk stratification and future therapeutic innovation. Full article

Satellite clock bias exhibits complex, time-varying periodic characteristics due to environmental disturbances. Accurate modeling and prediction of periodic terms play a crucial role in improving the precision and stability of short-term predictions. Traditional models such as spectral analysis model (SAM) estimate the frequency, amplitude, and phase of periodic terms through global fitting, which limits their ability to adapt to abrupt changes at the prediction boundary. To address this limitation, this paper proposes an improved spectral analysis model (IM-SAM) based on the inaction method (IM). The model employs IM to extract the instantaneous frequency, amplitude, and phase parameters of periodic terms precisely at the data endpoint, and utilizes the parameters of periodic terms at the data endpoint for prediction, effectively suppressing periodic fluctuations in prediction errors. Experimental results based on real GPS clock bias data demonstrate that the root mean square (RMS) of IM-SAM prediction errors is reduced by 19.14%, 14.39%, and 10.48% for 3 h, 6 h, and 12 h prediction tasks, respectively, compared with SAM. Furthermore, a kinematic precise point positioning experiment was performed using IM-SAM-predicted clock products and compared with the predicted half of IGS ultra-rapid clock products. The RMS of position error was reduced by 14.3%, 12.6%, and 7.9% in the east, north, and up directions, respectively. These results demonstrate the practical effectiveness and accuracy of IM-SAM in real-time clock prediction and GPS positioning applications. Full article

Disruptions in the circadian clock and their link with cancer constitute a growing area of research, as evidenced by the steadily increasing number of articles on the topic. While the genes associated with circadian rhythms are relatively well characterized, the complexity of their regulation remains an important direction for study. It has been demonstrated that the interplay between genes, their expression products and external factors, such as environmental pollutants and human behavioral patterns, can lead to pathological changes, including metabolic diseases and cancer. Investigation of circadian cycle deregulations can not only provide a better understanding of carcinogenicity mechanisms and risk assessment but also create possibilities to identify new chemotherapeutics targeted at neoplastic cells. REV-ERBs and RORs are two groups of circadian clock-related nuclear factors that are examined regarding their interactions with small-molecule modulators of the circadian clock. These can act as either receptor agonists or inverse agonists, depending on the specific characteristics of a particular cancer. This review therefore summarizes and systematizes existing knowledge regarding the effectiveness of circadian modulators as chemotherapy agents, with the aim of indicating further directions for research in the field. Full article

As embedded and IoT systems demand secure and compact encryption, developing cryptographic solutions that are both lightweight and efficient remains a major challenge. Many existing AES implementations either lack flexibility or consume excessive hardware resources. This paper presents an area-efficient and flexible AES-128 implementation based on a hardware/software (HW/SW) co-design, specifically optimized for platforms with limited hardware resources, resulting in reduced power consumption. In this approach, key expansion is performed in software on a lightweight MicroBlaze processor, while encryption and decryption are accelerated by dedicated hardware IP cores optimized at the Look-up Table (LuT) level. The design is implemented on a Xilinx XC5VLX50T Virtex-5 FPGA, synthesized using Xilinx ISE 14.7, and tested at a 100 MHz system clock. It achieves a throughput of 13.3 Gbps and an area efficiency of 5.44 Gbps per slice, requiring only 2303 logic slices and 7 BRAMs on a Xilinx FPGA. It is particularly well-suited for resource-constrained applications such as IoT nodes, secure mobile devices, and smart cards. Since key expansion is executed only once per session, the runtime is dominated by AES core operations, enabling efficient processing of large data volumes. Although the present implementation targets AES-128, the HW/SW partitioning allows straightforward extension to AES-192 and AES-256 by modifying only the software Key expansion module, ensuring practical scalability with no hardware changes. Moreover, the architecture offers a balanced trade-off between performance, flexibility and resource utilization without relying on complex pipelining. Experimental results demonstrate the effectiveness and flexibility of the proposed lightweight design. Full article

The inverter is the key element that converts the intermittent DC power of the PV array into a quality AC flow to the grid and simultaneously performs functions such as power factor control, reactive services, and grid code compliance. Therefore, the detailed operating profile of the inverter, how the power, dynamics, power quality, and efficiency evolve over time, is critical for both the scientific understanding of the system and the daily operation (O&M). Monitoring only aggregated energy indicators or single KPIs (e.g., PR) is often insufficient: it does not distinguish weather-related variations from technical limitations (clipping, curtailment), does not show dynamic loads (ramp rate), and does not provide confidence in the quality of the injected energy (PF, P–Q behavior). These deficiencies motivate research that simultaneously covers the physical side of the conversion, the operational dynamics, and the climatic reference of the resource. The analysis covers the window of 25 January–15 April 2025 (winter→spring). Due to the pronounced seasonality of the solar resource and temperature regime, all quantitative results and conclusions regarding efficiency, dynamics, clipping, and degradation are valid only for this window; generalizations to other seasons require additional data. In the next stage, we will add ≥12 months of data and perform a comparable seasonal analysis. Full specifications of the measuring equipment (DC/AC current/voltage, clock synchronization, separate high-frequency $PQ$-logger) and quantitative uncertainty estimates, including distribution to key indicators ($\eta$, $PR$, $THD$, $I_{DC}$), are presented. The PVGIS per-kWp climate reference is anchored to the nameplate DC peak and cross-checked against percentile scaling; $a\pm \epsilon$ scale error shifts $PR$ by $\epsilon$ and changes $\Delta E$ proportionally only on hours with $\widehat{P}>P$. The capacity for the climate reference (PVGIS per-kWp) is calibrated to the tabulated DC peak power $C_{cert}$ and is cross-validated using a percentile scale ($Q_{0.99}$). Full article

Background: White adipose tissue (WAT) exhibits diurnal oscillations regulated by clock genes, which autonomously control its functionality. These rhythms are modulated by the central clock and external factors, such as light exposure and diet. Flavanols, phenolic compounds known for their beneficial metabolic effects, have been shown to modulate the expression of clock genes. This study explored the impact of flavanols on clock gene expression in WAT explants from lean and obese rats under changes in light/dark cycles. Methods: WAT explants were obtained from 24 Fischer rats fed a standard diet (STD) or cafeteria diet (CAF) for seven weeks. During the final week, rats were changed to short (6 h of light, L6) or long (18 h of light, L18) photoperiods. CAF-fed rats were also administered a grape seed (poly)phenol-rich extract (GSPE) (25 mg/kg) or vehicle (VH). After sacrifice, WAT explants were collected every 6 h starting at 8 a.m. the following day (CT0, CT6, CT12, CT18, and CT24). Results: The results showed that under L18 conditions, STD-fed rats displayed oscillations in Bmal1, Cry1, Per1, and Rev-erbα clock gene expression, whereas many of these rhythms were disrupted under L6 conditions. Moreover, the administration of the CAF diet also resulted in the loss of clock gene circadian oscillations in the WAT explants. GSPE administration restored the oscillation of these clock genes under L18 and L6 conditions. Conclusions: These findings highlight the potential zeitgeber role of flavanols in modulating WAT peripheral clocks and their capacity to improve metabolic and circadian regulation under conditions of diet- and photoperiod-induced disruption. Full article

The spotted seal (Phoca largha), the only pinniped species capable of natural breeding in Chinese waters, serves as a flagship species for the Bohai Sea and the Yellow Sea marine ecosystems. Changes in its population numbers are an important indicator of the status of the marine ecological environment. However, when using traditional monitoring methods, such as telescope inspections and routine unmanned aerial vehicle (UAV) photography, it is difficult to accurately grasp the changes in spotted seal populations. Here, we document the use of infrared imaging with a UAV to facilitate round-the-clock monitoring of spotted seal numbers in a protected area. This approach revealed that late night and early morning (22:00–05:00) were peak times for their haul-out activity, with a maximum count of 166. This provides a new idea for the investigation and monitoring of marine mammals and the protection of marine ecosystems. Full article

This paper proposes and implements a method to efficiently parallelize constraint solving in rigid body simulation using GPUs. Rigid body simulation is widely used in robot development, computer games, movies, and other fields, and there is a growing need for faster computation. As current computers are reaching their limits in terms of scale-up, such as clock frequency improvements, performance improvements are being sought through scale-out, which increases parallelism. However, rigid body simulation is difficult to parallelize efficiently due to its characteristics. This is because, unlike fluid or molecular physics simulations, where each particle or lattice can be independently extracted and processed, rigid bodies can interact with a large number of distant objects depending on the instance. This characteristic causes significant load imbalance, making it difficult to evenly distribute computational resources using simple methods such as spatial partitioning. Therefore, this paper proposes and implements a computational method that enables high-speed computation of large-scale scenes by hierarchically clustering rigid bodies based on their number and associating the hierarchy with the hardware structure of GPUs. In addition, to effectively utilize parallel computing resources, we considered a more relaxed parallelization condition for the conventional Gauss–Seidel block parallelization method and demonstrated that convergence is guaranteed. We investigated how speed and convergence performance change depending on how much computational cost is allocated to each hierarchy and discussed the desirable parameter settings. By conducting experiments comparing our method with several widely used software packages, we demonstrated that our approach enables calculations at speeds previously unattainable with existing techniques, while leveraging GPU computational resources to handle multiple rigid bodies simultaneously without significantly compromising accuracy. Full article

Brown croaker (Miichthys miiuy) is an economically, ecologically, and culturally important species in the East China Sea (ECS); however, populations of M. miiuy have declined in recent years due to climate change and high fishing intensity. Our limited understanding of wild M. miiuy’s migratory life history hampers effective population conservation. To meet this need, and to elucidate the migratory life history of wild M. miiuy, we quantified the elemental composition of otolith samples using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). This approach, combined with analysis of otolith microstructure, was used to evaluate the feasibility of using the Mg:Ca of otoliths chemical clock for M. miiuy. Using cluster analysis alongside bivariate time series analysis, we identified natal sources and reconstructed migratory histories. The results showed that consistent, periodic fluctuation of Mg:Ca ratios in otolith profiles can be used as a chemical index to indicate the age and life history stage of M. miiuy. Natal sources of M. miiuy originated from three distinct water environments: estuary (14.2%), coastal mixed waters (57.3%), and coastal reef waters (28.5%). A diverse migratory life history of M. miiuy was observed based on Sr:Ba thresholds, and ultimately, we identified four migratory life histories of the species, including an estuary–coastal migratory type, a coastal resident type, a coastal–offshore migratory type and an estuary–coastal–offshore migratory type. This study provides a scientific basis for the protection of key habitats and seasonal management of M. miiuy in the ECS. Full article

Plants possess several molecular mechanisms that enable them to adapt their development to environmental changes. Many plant biological processes depend on the circadian rhythm and are regulated by the internal biological clock. Predictable environmental changes, such as variations in photoperiod, can modulate circadian rhythms, allowing organisms to synchronize their biological processes with seasonal conditions. Plant tissue culture is a valuable tool for investigating and monitoring plant plasticity in response to environmental fluctuations, as well as for elucidating the biological changes that occur under these conditions. This review highlights the importance of in vitro culture as a tool to study the physiological plasticity triggered by photoperiod and its interaction with the plant biological clock. To achieve this, a descriptive analysis was conducted through a literature search in the Scopus database, followed by a bibliometric analysis to demonstrate the progress in the application of in vitro culture to studies on photoperiod and circadian regulation in plants. Full article

Background: Postoperative delirium is frequent among elderly patients and often presents after major surgery or intervention. Validated screening tools should be routinely used to recognise this psychopathological syndrome. Delirium might be associated with systematic changes in brain network organisation, including reduced EEG connectivity. Methods: This observational single-centre pilot study aimed to evaluate the agreement between DeltaScan^® (Prolira BV, Utrecht, The Netherlands) and CAM-ICU screening in detecting postoperative delirium in patients undergoing cardiac surgery or cardiac intervention. Results: 1. Patients showing delirium have DeltaScan^® scores ≥ 3. 2. Patients scoring ≥ 3 in the DeltaScan^® examination do not necessarily show signs of delirium in CAM-ICU testing. 3. All patients showing delirium in CAM-ICU testing have pathological clock-drawing results. Conclusions: DeltaScan^® reliably detects delta wave abnormalities associated with delirium, though some patients with increased delta activity did not exhibit clinically manifest delirium. Full article

Background: β-casomorphin-10 (CM-10), a peptide fragment derived from milk casein with the sequence YPFPGPIPNS, has demonstrated notable anxiolytic activity in BALB/c mice. Yet, its cellular responses and mechanistic pathways remain largely uncharacterized. Methods: We performed RNA-seq analysis to profile gene expression changes in δ-opioid receptor-expressing HEK293 cells (DOR-HEK), comparing CM-10-treated and untreated conditions. Results: CM-10 exposure led to differential expression of 1714 genes in DOR-HEK cells, with 34 upregulated (>1.4-fold) (1.9%) and 1680 downregulated (<0.71-fold) (98.1%), based on a predicted p-value threshold of <0.05. Notably, we identified 10 clusters that were associated with reduced cyclic AMP (cAMP) in DOR-HEK cells following CM-10 treatment. These clusters particularly involved genes related to regulatory subunits of cAMP-dependent protein kinases, such as PRKAR2A, cAMP-responsive element-binding pathway, circadian rhythms, such as CLOCK, ARNT1, CRY2, PER1, and PER2, and anxiety and depression, such as NOTCH1, NOTCH2 and ANK2. A network with these selected genes was confirmed by STRING analysis. Conclusions: These findings indicate that CM-10 may activate DOR-mediated signaling by suppressing cAMP levels, implicating a distinct molecular cascade in HEK293 cells. Full article

Circadian rhythms are endogenous ~24 h oscillations that regulate diverse biochemical processes. Although stress responses can exhibit circadian modulation, evidence for rhythmic regulation of stress granules (SGs)—cytoplasmic RNA–protein condensates formed under stress—remains limited. We investigated sodium arsenite-induced SG dynamics in NIH/3T3 cultures. SG number, eIF3 signal intensity—an established SG marker—and area oscillated with a period of ~24 h. These rhythms persisted in Bmal1^−/− mouse embryonic fibroblasts (MEFs), despite lacking a transcription–translation feedback loop (TTFL) that constitutes the canonical circadian clock, but with altered amplitude and phase, indicating partial dependence on the molecular clock. Several SG-associated RNA-binding proteins (TIA-1, BRF1, hnRNP Q, and LARK) exhibited time-dependent changes at the mRNA and/or protein level, suggesting potential mechanisms for rhythmic SG modulation. Unlike previous in vivo reports linking SG variation to eIF2α phosphorylation, no temporal changes in phosphorylated eIF2α were observed, highlighting differences between isolated cells and tissues. Our results show that SG rhythmicity can persist without BMAL1, supporting alternative oscillatory mechanisms that contribute to the temporal organization of stress responses. Given their role in cell survival and the association of SG dysfunction with disease, these rhythms provide insight into how cellular stress responses are temporally regulated. Full article

Plants, as sessile organisms, rely on sophisticated gene regulatory networks (GRNs) to adapt to dynamic environmental conditions. Among the central components of these networks are the interconnected pathways of light signaling and circadian rhythms, which together optimize growth, development, and stress resilience. While light and circadian pathways have been extensively investigated independently, their integrative coordination in mediating climate change adaptation responses remains a critical knowledge gap. Light perception via photoreceptors initiates transcriptional reprogramming, while the circadian clock generates endogenous rhythms that anticipate daily and seasonal changes. This review explores the molecular integration of light and circadian signaling, emphasizing how their crosstalk fine-tunes GRNs to balance resource allocation, photomorphogenesis, and stress adaptation. We highlight recent advances in systems biology tools, e.g., single-cell omics, CRISPR screens that unravel spatiotemporal regulation of shared hubs like phytochrome-interacting factors (PIFs), ELONGATED HYPOCOTYL 5 (HY5), and CIRCADIAN CLOCK ASSOCIATED 1 (CCA1). Here, we synthesize mechanistic insights across model and crop species to bridge fundamental molecular crosstalk with actionable strategies for enhancing cropresilience. Moreover, we have tried to discuss agricultural implications in engineering light–clock interactions for the enhancement in crop productivity under climate change scenarios. Through synthesizing mechanistic insights and translational applications, this work will help underscore the potential for manipulating light–circadian networks to promote sustainability in agriculture. Full article

Augmented Reality (AR) continues to generate interest as a pedagogical tool in contexts where English is a Foreign Language (EFL). However, its role in developing higher-order cognitive skills, such as inferencing, remains underexplored. This exploratory, mixed-methods study investigates whether AR can scaffold inference-making in advanced EFL learners. Forty-seven university students in XX were assigned to either a control group (CG) or an experimental group (EG). Both groups read Edgar Allan Poe’s “The Tell-Tale Heart” in digital format. The CG received a conventional inference-based comprehension lesson, while the EG engaged with two interactive AR scenes developed using the Onirix Studio platform. Pre- and post-tests assessed inferential comprehension, and qualitative data were gathered through open-ended responses. While the CG demonstrated modest post-test gains and the EG showed a slight decline, neither change reached statistical significance. Notably, qualitative findings revealed that a salient AR element—a ticking clock—likely prompted misinterpretation in the EG, disrupting symbolic reasoning and contributing to schema misalignment. However, some learners exhibited metacognitive insight suggestive of productive struggle. These results suggest that AR may hold untapped potential for developing metacognitive reflection and critical literacy. Directions for future research are outlined. Full article