Highly parallelizable path sampling with minimal rejections using asynchronous replica exchange and infinite swaps.

Capturing rare yet pivotal events poses a significant challenge for molecular simulations. Path sampling provides a unique approach to tackle this issue without altering the potential energy landscape or dynamics, enabling recovery of both thermodynamic and kinetic information. However, despite its exponential acceleration compared to standard molecular dynamics, generating numerous trajectories can still require a long time. By harnessing our recent algorithmic innovations-particularly subtrajectory moves with high acceptance, coupled with asynchronous replica exchange featuring infinite swaps-we establish a highly parallelizable and rapidly converging path sampling protocol, compatible with diverse high-performance computing architectures. We demonstrate our approach on the liquid-vapor phase transition in superheated water, the unfolding of the chignolin protein, and water dissociation. The latter, performed at the ab initio level, achieves comparable statistical accuracy within days, in contrast to a previous study requiring over a year.

Signatures of cross-modal alignment in children's early concepts.

Whether supervised or unsupervised, human and machine learning is usually characterized as event-based. However, learning may also proceed by systems alignment in which mappings are inferred between entire systems, such as visual and linguistic systems. Systems alignment is possible because items that share similar visual contexts, such as a car and a truck, will also tend to share similar linguistic contexts. Because of the mirrored similarity relationships across systems, the visual and linguistic systems can be aligned at some later time absent either input. In a series of simulation studies, we considered whether children's early concepts support systems alignment. We found that children's early concepts are close to optimal for inferring novel concepts through systems alignment, enabling agents to correctly infer more than 85% of visual-word mappings absent supervision. One possible explanation for why children's early concepts support systems alignment is that they are distinguished structurally by their dense semantic neighborhoods. Artificial agents using these structural features to select concepts proved highly effective, both in environments mirroring children's conceptual world and those that exclude the concepts that children commonly acquire. For children, systems alignment and event-based learning likely complement one another. Likewise, artificial systems can benefit from incorporating these developmental principles.

A cellular and molecular spatial atlas of dystrophic muscle.

Asynchronous skeletal muscle degeneration/regeneration is a hallmark feature of Duchenne muscular dystrophy (DMD); however, traditional -omics technologies that lack spatial context make it difficult to study the biological mechanisms of how asynchronous regeneration contributes to disease progression. Here, using the severely dystrophic D2-mdx mouse model, we generated a high-resolution cellular and molecular spatial atlas of dystrophic muscle by integrating spatial transcriptomics and single-cell RNAseq datasets. Unbiased clustering revealed nonuniform distribution of unique cell populations throughout D2-mdx muscle that were associated with multiple regenerative timepoints, demonstrating that this model faithfully recapitulates the asynchronous regeneration observed in human DMD muscle. By probing spatiotemporal gene expression signatures, we found that propagation of inflammatory and fibrotic signals from locally damaged areas contributes to widespread pathology and that querying expression signatures within discrete microenvironments can identify targetable pathways for DMD therapy. Overall, this spatial atlas of dystrophic muscle provides a valuable resource for studying DMD disease biology and therapeutic target discovery.

Recurrent Hippocampo-neocortical sleep-state divergence in humans.

Sleep is assumed to be a unitary, global state in humans and most other animals that is coordinated by executive centers in the brain stem, hypothalamus, and basal forebrain. However, the common observation of unihemispheric sleep in birds and marine mammals, as well as the recently discovered nonpathological regional sleep in rodents, calls into question whether the whole human brain might also typically exhibit different states between brain areas at the same time. We analyzed sleep states independently from simultaneously recorded hippocampal depth electrodes and cortical scalp electrodes in eight human subjects who were implanted with depth electrodes for pharmacologically intractable epilepsy evaluation. We found that the neocortex and hippocampus could be in nonsimultaneous states, on average, one-third of the night and that the hippocampus often led in asynchronous state transitions. Nonsimultaneous bout lengths varied from 30 s to over 30 min. These results call into question the conclusions of studies, across phylogeny, that measure only surface cortical state but seek to assess the functions and drivers of sleep states throughout the brain.

Cells and ionic conductances contributing to spontaneous activity in bladder and urethral smooth muscle.

Smooth muscle organs of the lower urinary tract comprise the bladder detrusor and urethral wall, which have a reciprocal contractile relationship during urine storage and micturition. As the bladder fills with urine, detrusor smooth muscle cells (DSMCs) remain relaxed to accommodate increases in intravesical pressure while urethral smooth muscle cells (USMCs) sustain tone to occlude the urethral orifice, preventing leakage. While neither organ displays coordinated regular contractions as occurs in small intestine, lymphatics or renal pelvis, they do exhibit patterns of rhythmicity at cellular and tissue levels. In rabbit and guinea-pig urethra, electrical slow waves are recorded from USMCs. This activity is linked to cells expressing vimentin, c-kit and Ca2+-activated Cl- channels, like interstitial cells of Cajal in the gastrointestinal tract. In mouse, USMCs are rhythmically active (firing propagating Ca2+ waves linked to contraction), and this cellular rhythmicity is asynchronous across tissues and summates to form tone. Experiments in mice have failed to demonstrate a voltage-dependent mechanism for regulating this rhythmicity or contractions in vitro, suggesting that urethral tone results from an intrinsic ability of USMCs to 'pace' their own Ca2+ mobilization pathways required for contraction. DSMCs exhibit spontaneous transient contractions, increases in intracellular Ca2+ and action potentials. Consistent across numerous species, including humans, this activity relies on voltage-dependent Ca2+ influx in DSMCs. While interstitial cells are present in the bladder, they do not 'pace' the organ in an excitatory manner. Instead, specialized cells (PDGFRα+ interstitial cells) may 'negatively pace' DSMCs to prevent bladder overexcitability.

Dynamically driven correlations in elastic net models reveal sequence of events and causality in proteins.

An explicit analytic solution is given for the Langevin equation applied to the Gaussian Network Model of a protein subjected to both a random and a deterministic periodic force. Synchronous and asynchronous components of time correlation functions are derived and an expression for phase differences in the time correlations of residue pairs is obtained. The synchronous component enables the determination of dynamic communities within the protein structure. The asynchronous component reveals causality, where the time correlation function between residues i and j differs depending on whether i is observed before j or vice versa, resulting in directional information flow. Driver and driven residues in the allosteric process of cyclophilin A and human NAD-dependent isocitrate dehydrogenase are determined by a perturbation-scanning technique. Factors affecting phase differences between fluctuations of residues, such as network topology, connectivity, and residue centrality, are identified. Within the constraints of the isotropic Gaussian Network Model, our results show that asynchronicity increases with viscosity and distance between residues, decreases with increasing connectivity, and decreases with increasing levels of eigenvector centrality.

Monomeric Fe(III)-Hydroxo and Fe(III)-Aqua Complexes Display Oxidative Asynchronous Hydrogen Atom Abstraction Reactivity.

This paper presents the synthesis and characterization of a series of novel monomeric aqua-ligated iron(III) complexes, [FeIII(L5R)(OH2)]2+ (R=OMe, H, Cl, NO2), supported by an amide-containing pentadentate N5 donor ligand, L5R [HL5R=2-(((1-methyl-1H-imidazol-2-yl)methyl)(pyridin-2-yl-methyl)amino)-N-(5-R-quinolin-8-yl)acetamide]. The complexes were characterized by various spectroscopic and analytical techniques, including electrochemistry and magnetic measurements. The Fe(III)-hydroxo complexes, [FeIII(L5R)(OH)]1+, were generated in situ by deprotonating the corresponding aqua complexes in a pH ~7 aqueous medium. In another way, adding one equivalent of a base to a methanolic solution of the Fe(III)-aqua complexes also produced the Fe(III)-hydroxo complexes. The study uses linoleic fatty acid as a substrate to explore the hydrogen atom abstraction (HAA) reactivity of both hydroxo and aqua complexes. The investigation highlights the substitution effect of the L5R ligand on reactivity, revealing a higher rate when an electron-withdrawing group is present. Hammett analyses and(or) determination of the asynchronicity factor (η) suggest an oxidative asynchronous concerted proton-electron transfer (CPET) pathway for the HAA reactions. Aqua complexes exhibited a higher asynchronicity in CPET, resulting in higher reaction rates than their hydroxo analogs. Overall, the work provides insights into the beneficial role of a higher imbalance in electron-transfer-proton-transfer (ET-PT) contributions in HAA reactivity.

Implementation of Direct-to-Patient Mobile Teledermatology in VA.

BACKGROUND: Innovative technology can enhance patient access to healthcare but must be successfully implemented to be effective. OBJECTIVE: We evaluated Department of Veterans Affairs' (VA's) implementation of My VA Images, a direct-to-patient asynchronous teledermatology mobile application enabling established dermatology patients to receive follow-up care remotely instead of in-person. DESIGN /PARTICIPANTS/APPROACH: Following pilot testing at 3 facilities, the app was introduced to 28 facilities (4 groups of 7) every 3 months using a stepped-wedge cluster-randomized design. Using the Organizational Theory of Implementation Effectiveness, we examined the app's implementation using qualitative and quantitative data consisting of encounter data from VA's corporate data warehouse; app usage from VA's Mobile Health database; bi-monthly reports from facility representatives; phone interviews with clinicians; and documented communications between the operational partner and facility staff. KEY RESULTS: Implementation policies and practices included VA's vision to expand home telehealth and marketing/communication strategies. The COVID-19 pandemic dominated the implementation climate by stressing staffing, introducing competing demands, and influencing stakeholder attitudes to the app, including its fit to their values. These factors were associated with mixed implementation effectiveness, defined as high quality consistent use. Nineteen of 31 exposed facilities prepared to use the app; 10 facilities used it for actual patient care, 7 as originally intended. Residents, nurse practitioners, and physician assistants were more likely than attendings to use the app. Facilities exposed to the app pre-pandemic were more likely to use and sustain the new process. CONCLUSIONS: Considerable heterogeneity existed in implementing mobile teledermatology, despite VA's common mission, integrated healthcare system, and stakeholders' broad interest. Identifying opportunities to target favorable facilities and user groups (such as teaching facilities and physician extenders, respectively) while addressing internal implementation barriers including incomplete integration with the electronic health record as well as inadequate staffing may help optimize the initial impact of direct-to-patient telehealth. The COVID pandemic was a notable extrinsic barrier. CLINICAL TRIALS REGISTRATION: NCT03241589.

Long-Term Reproducibility of BMD-Measurements with Clinical QCT Using Simultaneous and Asynchronous Calibration Methods and Different Measurement and Reconstruction Protocols.

Osteoporosis is underdiagnosed and undertreated. To improve timely fracture risk assessment optimized densitometry methods are required such as opportunistic spinal quantitative computed tomography (QCT). However, it is unclear how to best calibrate these scans and correct for potential scanner drift of QCT when used for monitoring bone mineral density (BMD) changes. We compared gold standard simultaneous calibration with asynchronous calibration methods, assessing mid-term (12 weeks) and long-term (1.5 years) reproducibility of BMD measurements. Cortical and trabecular compartments of the European Spine Phantom were studied with ten different protocols including low dose and high resolution (HR)-modes. Based on weekly phantom data, we compared simultaneous calibration to asynchronous single (termed global) or monthly calibration. The accuracy was better for trabecular measurements than for cortical measurements for all calibration methods. Reproducibility was excellent for all methods and slightly better for asynchronous than for simultaneous calibration both for trabecular and cortical bone. For HR protocols, reproducibility was better than for low dose measurements. In trabecular compartments averaged HR-BMD remained stable for global (- 0.1%/year, ns) but not for simultaneous calibration (- 1.5%/year, p < 0.001). No significant drifts could be detected for averaged low dose BMD (- 0.9 to + 0.8%/year) for either calibration method. Our data suggest that with regard to precision and accuracy measurements with asynchronous calibration are suitable for vertebral BMD assessment (no contrast agents) in clinical practice. Regular (e.g., monthly) stability tests using a calibration phantom could assure long term stability of at least 1 year.

Audio podcast and procedural video use in anaesthesiology and intensive care: A nationwide survey of Swedish anaesthetists.

BACKGROUND: Digital modalities which enable asynchronous learning, such as audio podcasts and videos demonstrating procedures, may benefit acquisition and retention of knowledge and clinical skills. The main objective of this nationwide cross-sectional survey study was to evaluate key aspects and factors related to usage of audio podcasts and procedural videos in anaesthesiology and intensive care. METHODS: A 20-item multiple-choice-question online survey was created through a consensus process including pilot testing among residents and consultants. Data were collected over a 3-month period, September-November 2023. RESULTS: The survey was completed by 466 anaesthetists. More than a third reported using procedural videos ≥1 time per week, whereas fewer than one in four participants used audio podcasts at least once per week. Multivariable logistic regression analysis showed that working at a university hospital, male sex, and younger age were independently associated with podcast use ≥1 time per week, with the highest odds ratio (OR) for younger age (<40 years vs. ≥40 years old; OR 5.86 (95% confidence interval 3.55-9.67), p < .001). Younger age was also significantly associated with higher frequency of video use (OR 1.71 (1.13-2.58), p = .011), while working predominantly in intensive care was associated with a lower frequency of video use. Podcasts were often used during commuting (42.3%), household work (30.7%), and exercise (24.9%), indicating a role in multi-tasking. Approximately half of respondents expressed that audio podcast-based learning has a moderate to very large positive impact on acquisition of theoretical knowledge, as well as practical skills. A vast majority, 85.2%, reported that procedural videos have a moderate to very large impact on development of clinical skills. CONCLUSION: Audio podcasts and procedural videos are appreciated tools with potential to supplement more traditional didactic techniques in anaesthesiology and intensive care. Procedural video use is common, with perceived large effects on development of clinical skills. Further data are needed to fully understand learning outcomes, quality of peer-review processes, and potential sex-differences.

Evaluation of an Online Training Course for Childcare Providers Participating in the CACFP Infant Feeding Program.

INTRODUCTION: The Child and Adult Care Food Program (CACFP) provides reimbursement for meals and snacks offered in participating centers and issues nutrition standards, including guidelines for feeding infants in childcare settings. Offering training to childcare providers participating in the CACFP is necessary to ensure compliance with nutrition standards in childcare settings. METHODS: A State Department of Education and University Extension system collaborated to develop an online nutrition training course for childcare providers. Providers (n = 57) participated in the course on CACFP nutrition standards related to feeding infants (0-12 months of age). Thirty-two of 57 participants completed both pre- and post-training surveys that were used to assess changes in knowledge and confidence concerning infant feeding standards. Paired t-tests and Wilcoxon signed-rank tests were conducted to assess differences in survey responses before and after the course. RESULTS: Self-confidence and knowledge of providers related to infant feeding were significantly increased after completion of the training course (p < 0.001). More participants reported their sites were likely to respond to infants showing they were hungry or full than before the course (44.4% vs. 75.7%, respectively). Participant feedback indicated the online asynchronous course was convenient, useful, and topics were relevant to training needs. DISCUSSION: The online course was feasible and effective for providing training on CACFP guidelines for childcare providers. Feedback from participants can be adapted and used for future training programs to further improve the course and delivery methods and efficiently reach a broad audience of childcare providers.

Implementation of a Web-Based Outpatient Asynchronous Consultation Service: Mixed Methods Study.

BACKGROUND: Asynchronous outpatient patient-to-provider communication is expanding in UK health care, requiring evaluation. During the pandemic, Aberdeen Royal Infirmary in Scotland expanded its outpatient asynchronous consultation service from dermatology (deployed in May 2020) to gastroenterology and pain management clinics. OBJECTIVE: We conducted a mixed methods study using staff, patient, and public perspectives and National Health Service (NHS) numerical data to obtain a rounded picture of innovation as it happened. METHODS: Focus groups (3 web-based and 1 face-to-face; n=22) assessed public readiness for this service, and 14 interviews with staff focused on service design and delivery. The service's effects were examined using NHS Grampian service use data, a patient satisfaction survey (n=66), and 6 follow-up patient interviews. Survey responses were descriptively analyzed. Demographics, acceptability, nonattendance rates, and appointment outcomes of users were compared across levels of area deprivation in which they live and medical specialties. Interviews and focus groups underwent theory-informed thematic analysis. RESULTS: Staff anticipated a simple technical system transfer from dermatology to other receptive medical specialties, but despite a favorable setting and organizational assistance, it was complicated. Key implementation difficulties included pandemic-induced technical integration delays, misalignment with existing administrative processes, and discontinuity in project management. The pain management clinic began asynchronous consultations (digital appointments) in December 2021, followed by the gastroenterology clinic in February 2022. Staff quickly learned how to explain and use this service. It was thought to function better for pain management as it fitted preexisting practices. From May to September 2022, the dermatology (adult and pediatric), gastroenterology, and pain management clinics offered 1709 appointments to a range of patients (n=1417). Digital appointments reduced travel by an estimated 44,712 miles (~71,956.81 km) compared to the face-to-face mode. The deprivation profile of people who chose to use this service closely mirrored that of NHS Grampian's population overall. There was no evidence that deprivation impacted whether digital appointment users subsequently received treatment. Only 18% (12/66) of survey respondents were unhappy or very unhappy with being offered a digital appointment. The benefits mentioned included better access, convenience, decreased travel and waiting time, information sharing, and clinical flexibility. Overall, patients, the public, and staff recognized its potential as an NHS service but highlighted informed choice and flexibility. Better communication-including the use of the term assessment instead of appointment-may increase patient acceptance. CONCLUSIONS: Asynchronous pain management and gastroenterology consultations are viable and acceptable. Implementing this service is easiest when existing administrative processes face minimal disruption, although continuous support is needed. This study can inform practical strategies for supporting staff in adopting asynchronous consultations (eg, preparing for nonlinearity and addressing task issues). Patients need clear explanations and access to technical support, along with varied consultation options, to ensure digital inclusion.

A Quarter-Century of Online Informatics Education: Learners Served and Lessons Learned.

The value and methods of online learning have changed tremendously over the last 25 years. The goal of this paper is to review a quarter-century of experience with online learning by the author in the field of biomedical and health informatics, describing the learners served and the lessons learned. The author details the history of the decision to pursue online education in informatics, describing the approaches taken as educational technology evolved over time. A large number of learners have been served, and the online learning approach has been well-received, with many lessons learned to optimize the educational experience. Online education in biomedical and health informatics has provided a scalable and exemplary approach to learning in this field.

Implementing Telemedicine into Clinical Training Through Pre-recorded Video Consultations.

Although the contribution of real patient encounters to medical education is well known, challenges such as a lack of suitable cases, patients not consenting to student involvement, physical space limitations that prevent every student from participating, the inability to replicate the same patient encounter, and reduced patient admissions to healthcare facilities during extraordinary periods are common obstacles that need to be addressed in clinical education. To overcome these challenges, video consultation (VC) recordings, which were made with the consent of patients having a telemedicine consultation, were collected as an archive of medical interview recordings covering a wide spectrum of pulmonary diseases. These recordings were watched by students in a classroom setting during clinical clerkships, with case discussions interspersed. This article, which also discusses the results of clinical clerkship evaluations, indicates that the use of pre-recorded VC sessions can be an effective tool for teaching good clinical practices through the ideal method of medical interviews, diagnostic approaches, evaluation of test results, communication skills with patients and their relatives, and addressing the socio-psychological aspects and social impacts of diseases. As an innovative attempt, sharing this process at an early stage of development may inspire enthusiasm for implementing this approach and open the field for further development.

Assigned group work is associated with increased student motivation and perceptions of belonging in an asynchronous online physiology laboratory course.

With the rise of online instruction, a better understanding of the factors that contribute to belonging and motivation in these contexts is essential to creating optimal learning environments. Although group work is known to be beneficial to student success, few studies have investigated its role in the context of asynchronous online courses. The present study addresses this gap through a survey of 146 undergraduate students in an asynchronous online physiology lab over two semesters, one with required group work and one without group work. Students were surveyed to evaluate the influence of group work on their motivation and sense of belonging, as well as their perceptions of inclusive and exclusive features of the course. Students assigned to groups had a higher sense of belonging (P = 0.006) and beliefs about their competence (P = 0.002) and perceived lower effort and psychological costs associated with the course (P = 0.04 and 0.04, respectively) compared to students not assigned to groups. Students assigned to groups reported that peer interactions made them feel included in the course (70% of coded responses) while those not assigned to groups valued instructor interactions (51% of coded responses) as inclusive. Negative peer interactions were commonly reported as exclusive by students assigned to groups (28% of coded responses) while a lack of peer interactions (23% of coded responses) made students not assigned to groups feel excluded. These data indicate that assigning groups in asynchronous online courses is an effective way to increase student motivation and perceptions of belonging.NEW & NOTEWORTHY This study explores the effect of assigned group work in an asynchronous online physiology laboratory course on student motivation and belonging. Students' perceptions of belonging and competence-related beliefs were higher, and effort and psychological costs were lower, when assigned to groups compared to students not assigned to groups. Students assigned to groups noted peer interactions as the most inclusive aspect of the course, whereas instructor interactions were noted as inclusive by those not assigned group work.

Asynchronous lecture participation negatively predicts exam scores for females and students of color in an introductory physiology course during COVID-19.

In response to COVID-19, educators rapidly pivoted to new and innovative ways of delivering lecture material. The ability to host synchronous lectures on platforms like Zoom gave students continued access to classroom material in the face of an ongoing pandemic. The purpose of this study was to investigate the differences in exam scores between students attending a physiology class (PHSL3051) synchronously via Zoom or asynchronously by viewing recorded lectures posted after class. Students in PHSL3051 were evaluated with four unit exams and one cumulative final exam. Although pooled analysis of all students showed that synchronous lecture viewing positively predicted exam scores, this positive association was even larger when the data were analyzed by gender and ethnicity. For female-identified students and students of color (SOC), attending lectures synchronously was associated with average scores on every unit exam that were higher by 2.7-7.4 percentage points. Moreover, the greater a student's synchronous participation in the course throughout the semester, the better that student's performance on the cumulative final exam was likely to be. These data highlight the need to better understand how different groups of undergraduate students select and respond to different assessment methods used in the same course, which may have long-term effects on their overall performance at 4-year institutions.NEW & NOTEWORTHY This study examined the relationship between lecture attendance (synchronous or asynchronous) and exam scores throughout the semester. Although everyone in the course benefited from synchronous lecture attendance, our data indicated that students of color (SOC) and female-identified students benefited most. SOC and female-identified students who participated synchronously had even higher mean scores on all exams within the course compared with SOC and female-identified students who participated asynchronously by watching recordings of the same lectures.

Didactic program in dietetics (DPD) students' experiences with pandemic learning and expectations for their future education: a descriptive study through a systems lens.

BACKGROUND: The systems approach has been used to evaluate higher education and explores inputs, transformation process, and outputs of a system that is also influenced by environmental factors such as COVID-19. The COVID-19 pandemic shifted many college students to different learning modes, changing their university experience. This study evaluated dietetics students' education experiences and characteristics in the latter period (spring 2022) of the COVID-19 pandemic using the systems approach. METHODS: Researchers developed and distributed an electronic survey to all 215 US-based Didactic Program in Dietetics (DPD) directors during March to May 2022 to forward to their students. Researchers calculated descriptive statistics for variables related to inputs, transformation process, and outputs in the systems approach. RESULTS: Respondents (n = 341) represented 51 DPDs in 31 states in the United States. Overall, DPD students (88.5%) were mostly or very satisfied with their choice of majoring in dietetics. Most (84.0%) planned to earn the RDN credential. Nearly half (46.9%) of DPD students were somewhat or extremely concerned about their readiness to continue their dietetics education path due to the pandemic-related learning conditions. Most students (43.6%) reported dissatisfaction with asynchronous remote instruction in laboratory courses. DPD students' GPAs remained consistent within the range of 3.75-4.0 from Fall 2019 (43.2%) to Spring 2022 (44.5%). The most important expectations of professors moving forward were to communicate effectively (97.3%), employ cultural humility (93.8%), eliminate discrimination in the classroom (93.6%), provide lecture slides (89.7%), and be flexible and accommodating (88.7%). CONCLUSIONS: DPD students emerged from COVID-19 with new perspectives and expectations for their university learning experience. Future research should explore the perspectives of DI directors, preceptors, and employers of COVID-19 era DPD graduates.

Event-Triggered Distributed Fusion Estimator for Asynchronous Markov Jump Systems with Correlated Noises and Fading Measurements.

In this study, we investigate event-triggered distributed fusion estimation for asynchronous Markov jump systems subject to correlated noises and fading measurements. The measurement noises are interrelated, and they are simultaneously coupled with the system noise. The sensor samples measurements uniformly, and the sampling rates of the sensors are different. First, the asynchronous system is synchronized at state update points; then, the local filter is obtained. Furthermore, a variance-based event-triggered strategy is introduced between the local estimator and the fusion center to decrease the energy consumption of network communication. Then, a distributed fusion estimation algorithm is proposed using a matrix-weighted fusion criterion. Finally, the effectiveness of the algorithm is verified using computer simulations.

Anomaly Detection for Asynchronous Multivariate Time Series of Nuclear Power Plants Using a Temporal-Spatial Transformer.

Industrial process monitoring is a critical application of multivariate time-series (MTS) anomaly detection, especially crucial for safety-critical systems such as nuclear power plants (NPPs). However, some current data-driven process monitoring approaches may not fully capitalize on the temporal-spatial correlations inherent in operational MTS data. Particularly, asynchronous time-lagged correlations may exist among variables in actual NPPs, which further complicates this challenge. In this work, a reconstruction-based MTS anomaly detection approach based on a temporal-spatial transformer is proposed. It employs a two-stage temporal-spatial attention mechanism combined with a multi-scale strategy to learn the dependencies within normal operational data at various scales, thereby facilitating the extraction of temporal-spatial correlations from asynchronous MTS. Experiments on simulated datasets and real NPP datasets demonstrate that the proposed model possesses stronger feature learning capabilities, as evidenced by its improved performance in signal reconstruction and anomaly detection for asynchronous MTS data. Moreover, the proposed TS-Trans model enables earlier detection of anomalous events, which holds significant importance for enhancing operational safety and reducing potential losses in NPPs.

Asynchronous Code Division Multiplexing-Based Visible Light Positioning and Communication Network Using Successive Interference Cancellation Decoding.

In the evolving landscape of sixth-generation wireless communication, the integration of visible light communication (VLC) and visible light positioning (VLP), known as visible light positioning and communication (VLPC), emerges as a pivotal technology. This study addresses the challenges of asynchronous code division multiplexing (ACDM) in VLPC networks, focusing on the enhancement of data transmission quality and positioning accuracy. Firstly, we propose an orthogonal pseudo-random code (OPRC) for ACDM-based VLP systems. Leveraging its excellent correlation properties, VLP signals preserve orthogonality even amidst asynchronous transmissions, achieving sub-centimeter average positioning errors. Next, by combining OPRC with successive interference cancellation decoding (SICD), we propose an enhanced ACDM-based VLPC system that utilizes OPRC for improved signal orthogonality and SICD for progressive elimination of multiple access interference (MAI) among VLPC signals. The results show substantial improvements in bit-error rate (BER) and positioning error (PE), approaching the performance levels observed in synchronized VLPC systems. Specifically, the SICD-OPRC scheme reduces average BER to 4.3 × 10-4 and average PE to 2.7 cm, demonstrating its robustness and superiority in complex asynchronous scenarios.