Parallel Tracks Research Articles

On the Flux Density Spectral Property of High Linearly Polarized Signal from Pulsar J0332+5434

The polarization position angles (PPA) of time samples with high linear polarization often show two parallel tracks across the pulsar profile that follow the rotating vector model (RVM). This feature supports coherent curvature radiation (CCR) as the underlying mechanism of radio emission from pulsars, where the parallel tracks of the PPA represent the orthogonal extraordinary (X) and ordinary (O) eigenmodes of strongly magnetized pair plasma. However, the frequency evolution of these high linearly polarized signals remains unexplored. In this work, we explore the flux density spectral nature of high linearly polarized signals by studying the emission from PSR J0332+5434 over a frequency range between 300 and 750 MHz, using the Giant Metrewave Radio Telescope. The pulsar average profile comprises a central core and a pair of conal components. We find the high linearly polarized time samples to be broadband in nature, and in many cases, they resemble a narrow spiky feature in the conal regions. These spiky features are localized within a narrow pulse longitude over the entire frequency range, and their spectral shapes sometimes resemble an inverted parabolic shape. In all such cases, the PPA is exclusively along one of the orthogonal RVM tracks, likely corresponding to the X-mode. The inverted spectral shape can, in principle, be explained if the high linearly polarized emission in these time samples is formed due to the incoherent addition of CCR from a large number of charged solitons (charge bunches) exciting the X-mode.

Individual bacterial cells can use spatial sensing of chemical gradients to direct chemotaxis on surfaces

Swimming bacteria navigate chemical gradients using temporal sensing to detect changes in concentration over time. Here we show that surface-attached bacteria use a fundamentally different mode of sensing during chemotaxis. We combined microfluidic experiments, massively parallel cell tracking and fluorescent reporters to study how Pseudomonas aeruginosa senses chemical gradients during pili-based ‘twitching’ chemotaxis on surfaces. Unlike swimming cells, we found that temporal changes in concentration did not induce motility changes in twitching cells. We then quantified the chemotactic behaviour of stationary cells by following changes in the sub-cellular localization of fluorescent proteins as cells are exposed to a gradient that alternates direction. These experiments revealed that P. aeruginosa cells can directly sense differences in concentration across the lengths of their bodies, even in the presence of strong temporal fluctuations. Our work thus overturns the widely held notion that bacterial cells are too small to directly sense chemical gradients in space.

Research on key technologies of railway station codification digital twin

According to the requirements of railway transportation, to ensure that locomotives can receive frequency-shifted signal information through the track within the station, the track circuits must be codified. Due to the increased speed of train operations, braking has become more challenging, increasing the possibility of running a red signal compared to the present. Therefore, it is imperative to implement pre-overlay codification technology and equipment suitable for use in speed-enhanced sections. As the pre-overlay coding method must be adopted, it requires the isolation components in the interface equipment to have "fault-safe" performance. When the isolation component fails, the current or voltage introduced into the parallel track relay must not cause malfunction. Therefore, ensuring that the current and voltage of each component in the codified track meet the requirements is crucial. This research aims to establish a circuit simulation model based on MATLAB Simulink to achieve dynamic simulation of the pre-overlay ZPW-2000 codification circuit diagram of the 25Hz phase-sensitive track circuit in the electrified section. Through this model, the electrical characteristic indicators such as current, voltage, and waveform of each component on the circuit can be observed in real-time. This helps optimize the design and maintenance of the railway signal system, improving the safety and efficiency of train operations and contributing to the establishment of a digital twin model for the entire railway system's signal system.

Interactive visualization of nanopore sequencing signal data with Squigualiser.

Nanopore sequencing current signal data can be 'basecalled' into sequence information or analysed directly, with the capacity to identify diverse molecular features, such as DNA/RNA base modifications and secondary structures. However, raw signal data is large and complex, and there is a need for improved visualization strategies to facilitate signal analysis, exploration and tool development. Squigualiser (Squiggle visualiser) is a toolkit for intuitive, interactive visualization of sequence-aligned signal data, which currently supports both DNA and RNA sequencing data from Oxford Nanopore Technologies instruments. Squigualiser is compatible with a wide range of alternative signal-alignment software packages and enables visualization of both signal-to-read and signal-to-reference aligned data at single-base resolution. Squigualiser generates an interactive signal browser view (HTML file), in which the user can navigate across a genome/transcriptome region and customize the display. Multiple independent reads are integrated into a 'signal pileup' format and different datasets can be displayed as parallel tracks. Although other methods exist, Squigualiser provides the community with a software package purpose-built for raw signal data visualization, incorporating a range of new and existing features into a unified platform. Squigualiser is an open-source package under an MIT licence: https://github.com/hiruna72/squigualiser. The software was developed using Python 3.8 and can be installed with pip or bioconda or executed directly using prebuilt binaries provided with each release.

Les reconnaissances en maladie professionnelle lors du suivi de la cohorte ARDCO

Questions concerning under-reporting of occupational diseases (OD) linked to asbestos exposure are regularly voiced in France. Monitoring of the French multicenter Asbestos-Related Disease Cohort (ARDCO), which ensures post-occupational medical surveillance of subjects having been exposed to asbestos, provides information on (1) the medico-legal steps taken following screening by computed tomography (CT) for benign thoracic diseases, and (2) recognition of OD as a causal factor in malignant diseases. OD recognition -and possible compensation- was analyzed in July 2021 among 13,289 volunteers in the cohort recruited between 2003 and 2005. Fifteen percent of the subjects in the cohort were found to have at least one recognized asbestos-related OD (78.2% benign pleural disease, 10.3% asbestosis, 14.2% lung cancer, and 6.0% mesothelioma). Only 58% of pleural plaques reported by the radiologist who performed the CT resulted in their recognition as ODs. On a parallel track, 88.7% of the mesotheliomas identified based on French National health insurance data and 46.9% of lung cancers were recognized as ODs. This study confirms the feasibility of a system designed to facilitate recognition, leading to possible compensation, of asbestos-related occupational diseases. The system could be improved by better training of the medical actors involved.

Anomalous Interlayer Exciton Diffusion in WS2/WSe2 Moiré Heterostructure.

Stacking van der Waals crystals allows for the on-demand creation of a periodic potential landscape to tailor the transport of quasiparticle excitations. We investigate the diffusion of photoexcited electron-hole pairs, or excitons, at the interface of WS2/WSe2 van der Waals heterostructure over a wide range of temperatures. We observe the appearance of distinct interlayer excitons for parallel and antiparallel stacking and track their diffusion through spatially and temporally resolved photoluminescence spectroscopy from 30 to 250 K. While the measured exciton diffusivity decreases with temperature, it surprisingly plateaus below 90 K. Our observations cannot be explained by classical models like hopping in the moiré potential. A combination of ab initio theory and molecular dynamics simulations suggests that low-energy phonons arising from the mismatched lattices of moiré heterostructures, also known as phasons, play a key role in describing and understanding this anomalous behavior of exciton diffusion. Our observations indicate that the moiré potential landscape is dynamic down to very low temperatures and that the phason modes can enable efficient transport of energy in the form of excitons.

Improving efficiency and quality of operational industrial production assets information management in customer–vendor interaction

Industrial assets management has a key role in ensuring continuity of industrial production via purchasing, warehousing and maintenance of devices and spare parts used in manufacturing, but it suffers from data and information accessibility, completeness, consistency, interoperability, and timeliness challenges in the customer - equipment vendors interaction and information sharing. Current practices in devices and spare parts purchasing, warehousing and maintenance include a lot of manual information search, validation and update work done at the manufacturing companies to maintain high quality master data records for the production assets management. This article addresses the challenge of improving efficiency and quality of operational production assets information management in industry customer company interaction with their production equipment vendors, with a design science research approach. The research was executed in collaboration between research organizations, forest industry companies, industrial production equipment vendors and information technology (IT) companies on two parallel and complementary research tracks, which are described with their key research results. The contributions are an ex-ante evaluated digital marketplace concept with preliminary requirements, and an ex-post evaluated semi-automated master data harmonization tool, as artefacts for improving efficiency and quality of production assets information management in industrial customer–vendors interaction. As theoretical contribution, the article provides a synthesis of the research results in the framework of information systems (IS) design theory as a nascent and novel design theory on designing IS artifacts for improving efficiency and quality of production assets information management, both in single industrial customer company and ecosystem settings. The contributions provide a starting point for further research and development of a digital marketplace for improving production assets information management in industrial customers – vendors interaction, potentially also applicable for similar ecosystems in other continuous production process -based manufacturing industries.

On asymmetric failure in additively manufactured continuous carbon fiber reinforced composites

Due to a filament-by-filament and layer-by-layer structure produced by an additive manufacturing (or namely 3D printing) technique, mechanical properties of 3D printed materials diverge considerably from those of carbon fiber reinforced polymer (CFRP) composites made by traditional processes. This study aims to experimentally characterize their mechanical properties through the off-axis tensile, compressive and V-notch shear tests. Advanced imaging techniques, such as digital image correlation (DIC), scanning electron microscopy (SEM) and computed tomography (CT), are used to investigate anisotropic nature of materials and failure mechanisms of the 3D printed CFRP composites. The applicability of conventional failure criteria to the 3D printed CFRP composites, including Tsai-Wu, Tsai-Hill, Hoffman, Maximum Stress, Hashin, Puck and LaRC05, is assessed systematically. The experimental results divulge that the filament-by-filament and layer-by-layer features intrinsic to 3D printed CFRP composites lead to an uneven yet organized distribution of voids. This characteristic contributes on the development of claw mark strain patterns, parallel track inter-fiber failure patterns, and distinct compression failure modes such as delamination and interlayer crack under loading perpendicular to the fiber direction. The voids in the 3D printed CFRP materials are partially responsible for the significant asymmetry when off-axis angle increases. Notably, the conventional failure criteria exhibit limited capability for predicting the off-axis tensile strength accurately. This phenomenon can be attributed to the redistribution of inherent fiber waviness as the fiber encounters tensile loads. Based on the experimental results, the inter-fiber failure as per the LaRC05 is modified to obtain an enhanced failure criterion for predicting the off-axis tensile strength. This study is expected to provide fundamental understanding of structural characteristics and mechanical properties for 3D printed CFRP composites.

“RAIL BIOPSY” A Novel and Useful Technique for Hysteroscopic Endometrial Target Biopsy

Endometrial biopsy (EB) is one of the most common gynecologic procedures. Office-based EB has replaced procedures involving general/loco-regional anesthesia and cervical dilatation performed in the operating room [1-3]. The Grasp Biopsy seems to be the most appropriate EB technique for reproductive-aged women [1,2,4]. Recently, the Visual D&C performed with hysteroscopic tissue removal devices has shown to be a valid alternative [5]. However, it is often difficult to obtain an adequate specimens in peri/post-menopausal women with hypo/atrophic endometrium [2]. Our aim is to show a novel hysteroscopic EB technique called "Rail Biopsy" which requires widespread and cheap instruments. A step-by-step explanation of surgical techinque with narrated video footage. Tertiary Level Academic Hospital "IRCCS Azienda Ospedaliero-Universitaria di Bologna" Bologna, Italy. We performed the "Rail Biopsy" technique with a 5.0 mm Continuous Flow Operative Hysteroscope with a 30° Lens and a 5Fr operative channel. We identify the endometrial target area (ETA), and we create a first track cutting through the endometrium in a caudo-cranial direction using cold scissors. We repeat the procedure, creating a second parallel track, thus completing our "rail" and isolating a wide ETA. Then, in the caudo-cranial direction, we cut through the stromal layer beneath the ETA. With a 5Fr cold grasping forceps, we clench the cranial edge of the ETA, and we remove it from the uterine cavity. A high-quality specimen, even in the case of hypo/atrophic endometrium or focal sessile lesions, can be obtained with this technique. The crucial aspect of the "Rail Biopsy" indeed is cutting through the stromal tissue while the endometrium is minimally touched, avoiding thermal damage deriving from electrosurgery. The instruments required are widespread and cheap. Moreover, this technique can be performed on any wall of the uterus, under vision, and, in the majority of patients, in an office-setting without cervical dilatation or general/loco-regional anesthesia, making it an attractive alternative to hysteroscopy performed in the operating room setting. Further studies comparing "Rail Biopsy" to other EB techniques are needed. We showed a novel approach for hysteroscopic EB that may be particularly useful in patients with hypo/atrophic endometrium, easy to learn and with low costs. VIDEO ABSTRACT.

Assessing readiness: the impact of an experiential learning entrustable professional activity-based residency preparatory course

ABSTRACT As medical schools move to integrate the Core Entrustable Professional Activities for Entering Residency (EPAs) into curricula and address the transition from student to resident, residency preparatory courses have become more prevalent. The authors developed an experiential learning EPA-based capstone course for assessment to determine impact on learner self-assessed ratings of readiness for residency and acquisition of medical knowledge. All fourth-year students from the classes of 2018–2020 completed a required course in the spring for assessment of multiple EPAs, including managing core complaints, performing basic procedures, obtaining informed consent, and providing patient handoffs. Learners selected between three specialty-based parallel tracks – adult medicine, surgery, or pediatrics. Students completed a retrospective pre-post questionnaire to provide self-assessed ratings of residency preparedness and comfort in performing EPAs. Finally, the authors studied the impact of the course on knowledge acquisition by comparing student performance in the adult medicine track on multiple choice pre- and post-tests. Four hundred and eighty-one students were eligible for the study and 452 (94%) completed the questionnaire. For all three tracks, there was a statistically significant change in learner self-assessed ratings of preparedness for residency from pre- to post-course (moderately or very prepared: adult medicine 61.4% to 88.6% [p-value < 0.001]; surgery 56.8% to 81.1% [p-value < 0.001]; pediatrics 32.6% to 83.7% [p-value 0.02]). A similar change was noted in all tracks in learner self-assessed ratings of comfort from pre- to post-course for all studied EPAs. Of the 203 students who participated in the adult medicine track from 2019–2020, 200 (99%) completed both the pre- and post-test knowledge assessments. The mean performance improved from 65.0% to 77.5% (p-value < 0.001). An experiential capstone course for the assessment of EPAs can be effective to improve learner self-assessed ratings of readiness for residency training and acquisition of medical knowledge.

Parallel Parking Path Planning and Tracking Control Based on Simulated Annealing Algorithm

Parallel Parking Path Planning and Tracking Control Based on Simulated Annealing Algorithm

Full-Length Single Protein Molecules Tracking and Counting in Thin Silicon Channels.

Emerging single-molecule protein sensing techniques are ushering in a transformative era in biomedical research. Nevertheless, challenges persist in realizing ultra-fast full-length protein sensing, including loss of molecular integrity due to protein fragmentation, biases introduced by antibodies affinity, identification of proteoforms, and low throughputs. Here, a single-molecule method for parallel protein separation and tracking is introduced, yielding multi-dimensional molecular properties used for their identification. Proteins are tagged by chemo-selective dual amino-acid specific labels and are electrophoretically separated by their mass/charge in custom-designed thin silicon channel with subwavelength height. This approach allows analysis of thousands of individual proteins within a few minutes by tracking their motion during the migration. The power of the method is demonstrated by quantifying a cytokine panel for host-response discrimination between viral and bacterial infections. Moreover, it is shown that two clinically-relevant splice isoforms of Vascular endothelial growth factor (VEGF) can be accurately quantified from human serum samples. Being non-destructive and compatible with full-length intact proteins, this method opens up ways for antibody-free single-protein molecule quantification.

Location- and Object-Based Representational Mechanisms Account for Bilateral Field Advantage in Multiple-Object Tracking.

Keeping track of multiple visually identical and independently moving objects is a remarkable feature of the human visual system. Theoretical accounts for this ability focus on resource-based models that describe parametric decreases of performance with increasing demands during the task (i.e., more relevant items, closer distances, higher speed). Additionally, the presence of two central tracking resources, one within each hemisphere, has been proposed, allowing for an independent maintenance of moving targets within each visual hemifield. Behavioral evidence in favor of such a model shows that human subjects are able to track almost twice as many targets across both hemifields compared with within one hemifield. A number of recent publications argue for two separate and parallel tracking mechanisms during standard object tracking tasks that allow for the maintenance of the relevant information in a location-based and object-based manner. Unique electrophysiological correlates for each of those processes have been identified. The current study shows that these electrophysiological components are differentially present during tracking within either the left or right hemifield. The present results suggest that targets are mostly maintained as an object-based representation during left hemifield tracking, while location-based resources are preferentially engaged during right hemifield tracking. Interestingly, the manner of representation does not seem to have an impact on behavioral performance within the subjects, while the electrophysiological component indicating object-based tracking does correlate with performance between subjects. We propose that hemifield independence during multiple-object tracking may be an indication of the underlying hemispheric bias for parallel location-based and object-based tracking mechanisms.

Ventral temporal and posteromedial sulcal morphology in autism spectrum disorder

Two parallel research tracks link the morphology of small and shallow indentations, or sulci, of the cerebral cortex with functional features of the cortex and human cognition, respectively. The first track identified a relationship between the mid-fusiform sulcus (MFS) in ventral temporal cortex (VTC) and cognition in individuals with Autism Spectrum Disorder (ASD). The second track identified a new sulcus, the inframarginal sulcus (IFRMS), that serves as a tripartite landmark within the posteromedial cortex (PMC). As VTC and PMC are structurally and functionally different in ASD, here, we integrated these two tracks and tested if there are morphological differences in VTC and PMC sulci in a sample of young (5–17 years old) male participants (50 participants with ASD and 50 neurotypical controls). Our approach replicates and extends recent findings in four ways. First, regarding replication, the standard deviation (STD) of MFS cortical thickness (CT) was increased in ASD. Second, MFS length was shorter in ASD. Third, the CT STD effect extended to other VTC and to PMC sulci. Fourth, additional morphological features of VTC sulci (depth, surface area, gray matter volume) and PMC sulci (mean CT) were decreased in ASD, including putative tertiary sulci, which emerge last in gestation and continue to develop after birth. To our knowledge, this study is the most extensive comparison of the sulcal landscape (including putative tertiary sulci) in multiple cortical expanses between individuals with ASD and NTs based on manually defined sulci at the level of individual hemispheres, providing novel targets for future studies of neurodevelopmental disorders more broadly.

Optimization of the Tracking Beam Sequence in Harmonic Motion Imaging.

Harmonic motion imaging (HMI) is an ultrasound elastography technique that estimates the viscoelastic properties of tissues by inducing localized oscillatory motion using focused ultrasound (FUS). The resulting displacement, assumed to be inversely proportional to the tissue local stiffness, is estimated using an imaging array based on RF speckle tracking. In conventional HMI, this is accomplished with plane-wave (PW) imaging, which inherently suffers from low lateral resolution. Coherent PW compounding (PWC) leverages spatial and temporal resolution using synthetic focusing in transmit. In this study, we introduced focused imaging with parallel tracking in HMI and compared parallel tracking of various transmit F-numbers (F/2.6, 3, 4, and 5) qualitatively and quantitatively with PW and PWC imaging at various compounded angle ranges (6°, 12°, and 18°). An in silico model of a 56-kPa spherical inclusion (diameter: 3.6 mm) embedded in a 5.3-kPa background and a 5.3-kPa elastic phantom with cylindrical inclusions (Young's moduli: 22-56 kPa, diameters: 2.0-8.6 mm) were imaged to assess different tracking beam sequences. Speckle biasing in displacement estimation associated with parallel tracking was also investigated and concluded to be negligible in HMI. Parallel tracking in receive (Rx) resulted in 2%-7% and 8%-12% increase compared to PW imaging ( ) in HMI contrast and contrast-to-noise ratio in silico and phantoms. Focused imaging with parallel tracking in Rx was concluded to be most robust among PW and PWC imaging for displacement estimation, and its preclinical feasibility was demonstrated in postsurgical human cancerous breast tissue specimens and in vivo murine models of breast cancer.

Rehabilitation of rail track facing cross-level issues using polymeric geocell

One of the issues with the existing rail network is the cross-level issue, where the two parallel tracks have unwanted elevation differences, risking train derailment. The speed of trains is typically reduced in those identified areas but still, the geometric irregularity causes train body vibrations reduces the riding comfort. Once that elevation difference exceeds a design limit operation ceases for safety. Conventional solutions to this are jacking up the track by re-filling material inside and injecting expandable foam. None of those temporary techniques have a significant contribution to eliminating the root cause; rather invite additional risks with unpredictable differential stiffness. An enduring solution is rebuilding the embankment with the use of strong geocell reinforcement. The threedimensional confinement along with the high tensile strength of reinforcing polymeric geocell introduces a stiffer layer. Through this paper, a design approach utilizing the tensile strength, stiffness, and geometric properties of the geocell has been established to provide a dependable solution. Three projects have been discussed where a high-strength novel polymeric alloy geocell with the established design method was successfully used. The effective theoretical reduction of bearing pressure was from 38% to 55%. Observation over a year indicated the effectiveness of the design methodology.

Implementing and evaluating integrated care models for non-communicable diseases in fragile and humanitarian settings

In this commentary, we advocate for the wider implementation of integrated care models for NCDs within humanitarian preparedness, response, and resilience efforts. Since experience and evidence on integrated NCD care in humanitarian settings is limited, we discuss potential benefits, key lessons learned from other settings, and lessons from the integration of other conditions that may be useful for stakeholders considering an integrated model of NCD care. We also introduce our ongoing project in North Lebanon as a case example currently undergoing parallel tracks of program implementation and process evaluation that aims to strengthen the evidence base on implementing an integrated NCD care model in a crisis setting.

Robust Optimal Parallel Tracking Control Based on Adaptive Dynamic Programming.

This article focuses on a novel robust optimal parallel tracking control method for continuous-time (CT) nonlinear systems subject to uncertainties. First, the designed virtual controller facilitates the transformation of the original nonlinear system into an affine system with an augmented state vector, which promotes the introduction of the optimal parallel tracking control problem. Then, this article generates fresh insight into counteracting the effects of uncertainty by developing a novel parallel control system that invokes the formulated virtual control law and an auxiliary variable obtained from the relationship between the solutions of the optimal control problems for the uncertain system and the nominal one. Next, critic neural networks (NNs) approximate the Hamilton-Jacobi-Bellman (HJB) equations' solution to implement the proposed robust optimal control method via adaptive dynamic programming (ADP). Finally, simulation experiments demonstrate the proposed method's remarkable effectiveness.

Serial attentional resource allocation during parallel feature value tracking.

The visual system has evolved the ability to track features like color and orientation in parallel. This property aligns with the specialization of processing these feature dimensions in the visual cortex. But what if we ask to track changing feature-values within the same feature dimension? Parallel tracking would then have to share the same cortical representation, which would set strong limitations on tracking performance. We address this question by measuring the precision of color representations when human observers track the color of two superimposed dot clouds that simultaneously change color along independent trajectories in color-space. We find that tracking precision is highly imbalanced between streams and that tracking precision changes over time by alternating between streams at a rate of ~1 Hz. These observations suggest that, while parallel color tracking is possible, it is highly limited, essentially allowing for only one color-stream to be tracked with precision at a given time.

Typification of Projects for Development of High-Speed Rail

The emerging demand for improving consumer parameters of rail passenger transport leads to the need to build a dedicated railway infrastructure for passenger trains with speeds exceeding in some sections 250 km/h. The high capital intensity of dedicated infrastructure development projects imposes significant restrictions on their scope and financial feasibility. The geographically determined location of urban agglomerations in European and Asian countries has led to formation of many approaches to the routing of lines for high-speed passenger transportation.The projects for development of dedicated high-speed railways being developed in various countries differ in their technical, technological, and operational characteristics. The use of different approaches has led to different efficiency of the passenger traffic, expressed in the demand of passengers for transportation.A structural analysis of existing high-speed transportation projects allowed revealing general patterns of their development. By the number of operational tasks arising with regard to movement of trains, the phases of traffic development were divided into linear, tree­like and network stages. Thus, when moving from the linear structure of a high-speed rail, an additional problem arises of trains passing from the main track to the secondary one. The transition to the network stage can result in emergence of parallel passages rail tracks between urban agglomerations.To generalise the experience of operating high-speed systems in the world, the article describes the developed method that allows comparing different projects for organising high-speed rail with each other. The comparison is made according to the main characteristics of traffic: travel time between separation points, the traffic speed, the total length of the railway line. Identification of the patterns inherent in various projects for development of high-speed rail will make it possible to compare their technological parameters, to identify the scope of rational use of high-speed lines and areas of competition with other core types of transport.