Acquisition Delays Research Articles

18 F-Fluorination of Nitroimidazolyl-Containing Sultone: A Direct Access to a Highly Hydrophilic Radiotracer for High-Performance Positron Emission Tomography Imaging of Hypoxia.

Hypoxia, characterized by nonphysiological levels of oxygen tension, is a key phenomenon common to the majority of malignant tumors with poor prognosis. Many efforts have been made to develop hypoxia imaging for diagnosis, staging, and monitoring of diseases, as well as for evaluating therapies. PET Imaging using 18F-fluoronitroimidazoles (i.e., [18F]FMISO as a lead radiotracer) has demonstrated potential for clinical investigations, but the poor contrast and prolonged acquisition times (>2.5 h) strongly limit its accuracy and routine developments. Here, we report an original [18F]fluoronitroimidazole bearing a sulfo group ([18F]FLUSONIM) that displays highly hydrophilic properties and rapid clearance, providing high-performance hypoxia specific PET imaging. We describe the synthesis and radiosynthesis of [18F]FLUSONIM, its in vivo preclinical evaluation by PET imaging in healthy rats and a rhabdomyosarcoma rat model, as well as its radiometabolization and histological studies. [18F]FLUSONIM was prepared in a single step by high yielding radiofluorination of a sultone precursor, highlighting the advantages of this new radiolabeling approach not yet explored for radiopharmaceutical development. PET imaging experiments were conducted by systematically comparing [18F]FLUSONIM to [18F]FMISO as a reference. The overall results unequivocally demonstrate that the developed radiopharmaceutical meets the criteria of an ideal candidate for hypoxia PET imaging-rapid and efficient radiosynthesis, total stability, exclusive urinary elimination, high specificity for hypoxic regions, unprecedented tumor/background ratios, short acquisition delays (<60 min), and promising potential for further preclinical and clinical applications.

Study of Dholera Special Investment Region

This study examines the issues faced by Gujarat, India's Dholera Special Investment Region (DSIR) as it transitions to an entrepreneurial urbanization paradigm. The main focus of the study challenge is to comprehend the development trajectory of DSIR, specifically with respect to industrial expansion and sustainable urbanization, while tackling problems like land acquisition disputes and delays in infrastructure. The study uses a mixed-method approach, drawing on secondary literature analysis, industry reports, and direct data from governmental sources. It looks at the beginnings of DSIR, its growth plan, its corporate directional approach, and the wider socioeconomic effects of its evolution. The primary conclusions point to a paradigm shift toward a "entrepreneurial urbanization" model that is driven by funding from the private sector and government assistance. However, obstacles like property disputes and delays in infrastructure provide serious obstacles to the advancement of DSIR.

Investigating construction delays in cold storage projects in the Philippines

Construction delays pose significant challenges affecting project timelines, budgets, and quality standards globally. This study focuses on bridging the knowledge between differences of construction between cold storage facility projects among other types of projects and identifying influential factors causing delays in cold storage construction projects in the Philippines. Through a questionnaire survey including 30 critical delay factors derived from comprehensive literature review and expert consultations, data was gathered from 100 stakeholders across diverse cold storage projects via simple random sampling. Analysis using the Relative Importance Index (RII) highlighted inadequate manpower, delays in the concrete slab construction, permit acquisition delays, quality-related rework, problems arising during testing and commissioning of the temperature-controlled room, and late procurement as the primary causes of construction delays in these projects. These findings underscore the critical need for improvements to pre-emptively manage risks leading to project overruns. The study recommends a concentrated effort by construction stakeholders targeting the top 10 critical delay factors identified, to mitigate future delays and ensure smoother project execution. This approach is very crucial for meeting the country’s reliance on timely completion of cold storage facilities which is vital for accommodating the increasing demands across diverse sectors including food, pharmaceuticals, and agriculture.

Multi-Agent Deep Reinforcement Learning for content caching within the Internet of Vehicles

In the Internet of Vehicles (IoV), multiple applications and multimedia services are deployed to enhance the quality of traveling experienced by passengers. These software components ingest heterogeneous multimedia content (e.g., streams, safety information, etc.) acquired through the Internet. However, the high mobility constraints and time-variant dynamics of the IoV may delay the acquisition process. Caching lowers acquisition delays of the content by storing requested content in the vicinity of its consumers.We propose a Multi-Agent Deep Reinforcement Learning (MADRL) based framework to design an optimal caching strategy for IoVs. The framework objective is to incentivize sharing caching resources while minimizing errors in estimating content needs. Extensive simulation results with different system parameters demonstrate the efficiency of the proposed solution.

Evaluation of optimal acquisition delays of DECT iodine maps in pancreatic adenocarcinoma: A potential alternative to the Patlak model of CT perfusion

IntroductionBy using bolus tracking with an appropriate acquisition delay dual-energy computed tomography (DECT) iodine maps might serve as a replacement of CT perfusion maps at reduced radiation exposure. This study aimed to evaluate the optimal acquisition delays of DECT for the replacement of parameter maps calculated with the Patlak model in pancreatic adenocarcinoma by corresponding iodine maps. Materials and methodsDual-source dynamic DECT acquisitions at 80 kVp/Sn140 kVp of 14 patients with pancreatic carcinoma were used to calculate CT perfusion maps of blood volume and permeability with the Patlak model. DECT iodine maps were generated from individual DECT acquisitions, matching acquisition times relative to prior bolus-triggered three-phase CT acquisitions for investigating different acquisition delays. Correlation between perfusion parameters and iodine concentrations was determined for acquisition delays between −6 s and 33 s. ResultsCorrelation between iodine concentrations and perfusion parameters ranged from −0.05 to 0.63 for blood volume and from −0.05 to 0.71 for permeability, depending on potential trigger delay. The correlation was significant for potential acquisition delays above 1.5 s for blood volume and above 9.0 s for permeability (both p < 0.05). Maximum correlation occurred at an acquisition delay of 15.0 s for blood volume (r = 0.63) and at 25.5 s for permeability (r = 0.71), with significantly lower iodine concentrations in carcinoma (15.0 s: 1.3 ± 0.5 mg/ml; 22.5 s: 1.4 ± 0.7 mg/ml) than in non-neoplastic pancreatic parenchyma (15.0 s: 2.3 ± 0.8 mg/ml; 22.5 s: 2.4 ± 0.6 mg/ml; p < 0.05). DiscussionIn the future, well-timed DECT iodine maps acquired with bolus tracking could provide an alternative to permeability and blood volume maps calculated with the Patlak model.

System requirements to improve adaptive 4-dimensional computed tomography (4D CT) imaging

Four-Dimensional Computed Tomography (4D CT) is of increasing importance in stereotactic body radiotherapy (SBRT) treatments affected by respiratory motion. However, 4D CT images are commonly impacted by irregular breathing, causing image artifacts that can propagate through to treatment, negatively effecting local control. REspiratory Adaptive CT (REACT) is a real-time gating method demonstrated to reduce motion artifacts by avoiding imaging during irregular respiration. Despite artifact reduction seen through in silico and clinical phantom-based studies, REACT has not been able to remove all artifacts. Here, we explore several hardware and software latencies (gantry rotation time, couch shifts, acquisition delays and phase calculation method) inherently linked to REACT and 4D CT in general and investigate their contribution to artifacts beyond those caused by irregular breathing. Imaging was simulated using the digital extended cardiac-torso (XCAT) phantom for fifty patient-measured respiratory traces. Imaging protocols included conventional cine 4D CT and five REACT scans with systematically varied parameters to test the effect of different latencies on artifacts. Artifacts were quantified by comparing the image normalized cross correlation across couch transition points and determining the volume error compared to a static phantom ground truth both as a total error and individually across pixel rows in the main plane of motion. Artifacts were determined for each lung, the whole heart and lung tumour and were compared back to conventional 4D CT and REACT with standard clinical scanning parameters. The gantry rotation time and acquisition delay were found to have the largest impact on reducing image artifacts and should be the focus of future development. The phase calculation method was also found to influence motion artifacts and should potentially be assessed on a patient-to-patient basis. Finally, the correlation between an increase in artifacts and baseline drift suggests that longer scan times allowing drift to occur may impact image quality.

Model-based determination of the synchronization delay between MRI and trajectory data.

Real-time monitoring of dynamic magnetic fields has recently become a commercially available option for measuring MRI k-space trajectories and magnetic fields induced by eddy currents in real time. However, for accurate image reconstructions, sub-microsecond synchronization between the MRI data and field dynamics (ie, k-space trajectory plus other spatially varying fields) is required. In this work, we introduce a new model-based algorithm to automatically perform this synchronization using only the MRI data and field dynamics. The algorithm works by enforcing consistency among the MRI data, field dynamics, and receiver sensitivity profiles by iteratively alternating between convex optimizations for (a) the image and (b) the synchronization delay. A healthy human subject was scanned at 7 T using a transmit-receive coil with integrated field probes using both single-shot spiral and EPI, and reconstructions with various synchronization delays were compared with the result of the proposed algorithm. The accuracy of the algorithm was also investigated using simulations, in which the acquisition delays for simulated acquisitions were determined using the proposed algorithm and compared with the known ground truth. In the in vivo scans, the proposed algorithm minimized artifacts related to synchronization delay for both spiral and EPI acquisitions, and the computation time required was less than 30 s. The simulations demonstrated accuracy to within tens of nanoseconds. The proposed algorithm can automatically determine synchronization delays between MRI data and field dynamics measured using a field probe system.

Scientific Workflow Makespan Minimization in Edge Multiple Service Providers Environment

The edge computing model offers an ultimate platform to support scientific and real-time workflow-based applications over the edge of the network. However, scientific workflow scheduling and execution still facing challenges such as response time management and latency time. This leads to deal with the acquisition delay of servers, deployed at the edge of a network and reduces the overall completion time of workflow. Previous studies show that existing scheduling methods consider the static performance of the server and ignore the impact of resource acquisition delay when scheduling workflow tasks. Our proposed method presented a meta-heuristic algorithm to schedule the scientific workflow and minimize the overall completion time by properly managing the acquisition and transmission delays. We carry out extensive experiments and evaluations based on commercial clouds and various scientific workflow templates. The proposed method has approximately 7.7% better performance than the baseline algorithms, particularly in overall deadline constraint that gives a success rate.

Delays in the Reticulospinal System Are Associated With a Reduced Capacity to Learn a Simulated Feeding Task in Older Adults.

Learning declines with age. Recent evidence indicates that the brainstem may play an important role in learning and motor skill acquisition. Our objective was to determine if delays in the reticular formation, measured via the startle reflex, correspond to age-related deficits in learning and retention. We hypothesized that delays in the startle reflex would be linearly correlated to learning and retention deficits in older adults. To determine if associations were unique to the reticulospinal system, we also evaluated corticospinal contributions with transcranial magnetic stimulation. Our results showed a linear relationship between startle onset latency and percent learning and retention but no relationship between active or passive motor-evoked potential onsets or peak-to-peak amplitude. These results lay the foundation for further study to evaluate if (1) the reticular formation is a subcortical facilitator of skill acquisition and (2) processing delays in the reticular formation contribute to age-related learning deficits.

Enfants handicapés abandonnés : quel profil dans une pouponnière en Côte d’Ivoire ?

The admission of children with disabilities to a dedicated nursery in Côte d’Ivoire has made it possible to respond to the fight against infanticide or neglect without care. The aim of this work was to define the profile of disabled children abandoned and admitted to the Dabou nursery in Côte d’Ivoire. Material and methodsDescriptive cross-sectional study carried out over a 9-month period in the Dabou nursery in Côte d’Ivoire and including 74 children and adolescents with disabilities. The epidemiological, clinical and functional data and the treatment needs of infants were described. ResultsChildren aged 0 to 3 and 6 to 10 years were the most numerous (45% of cases) with a predominance of males (sex ratio=1.31). They came mainly from the capital of the country. The infants’ clinical aspects were polymorphic, sometimes associated with limb malformations (68.9%), various motor impairments, neuro-orthopaedic deformities (59.46%), and psychomotor acquisition delays. The therapeutic needs expressed were varied and superimposed on the clinical aspects of the children and were broken down into rehabilitation activities, orthopaedic devices and care. ConclusionThe implementation of an adapted rehabilitation care strategy is necessary to support disabled children who have been abandoned and admitted to a dedicated nursery.

Novel ADNP Syndrome Mice Reveal Dramatic Sex-Specific Peripheral Gene Expression With Brain Synaptic and Tau Pathologies

BackgroundADNP is essential for embryonic development. As such, de novo ADNP mutations lead to an intractable autism/intellectual disability syndrome requiring investigation. MethodsMimicking humans, CRISPR (clustered regularly interspaced short palindromic repeats)–Cas9 editing produced mice carrying heterozygous Adnp p.Tyr718∗ (Tyr), a paralog of the most common ADNP syndrome mutation. Phenotypic rescue was validated by treatment with the microtubule/autophagy-protective ADNP fragment NAPVSIPQ (NAP). ResultsRNA sequencing of spleens, representing a peripheral biomarker source, revealed Tyr-specific sex differences (e.g., cell cycle), accentuated in females (with significant effects on antigen processing and cellular senescence) and corrected by NAP. Differentially expressed, NAP-correctable transcripts, including the autophagy and microbiome resilience–linked FOXO3, were also deregulated in human patient-derived ADNP-mutated lymphoblastoid cells. There were also Tyr sex-specific microbiota signatures. Phenotypically, Tyr mice, similar to patients with ADNP syndrome, exhibited delayed development coupled with sex-dependent gait defects. Speech acquisition delays paralleled sex-specific mouse syntax abnormalities. Anatomically, dendritic spine densities/morphologies were decreased with NAP amelioration. These findings were replicated in the Adnp+/− mouse, including Foxo3 deregulation, required for dendritic spine formation. Grooming duration and nociception threshold (autistic traits) were significantly affected only in males. Early-onset tauopathy was accentuated in males (hippocampus and visual cortex), mimicking humans, and was paralleled by impaired visual evoked potentials and correction by acute NAP treatment. ConclusionsTyr mice model ADNP syndrome pathology. The newly discovered ADNP/NAP target FOXO3 controls the autophagy initiator LC3 (microtubule-associated protein 1 light chain 3), with known ADNP binding to LC3 augmented by NAP, protecting against tauopathy. NAP amelioration attests to specificity, with potential for drug development targeting accessible biomarkers.

Atomic emission dual-spectrum thermometry for laser-induced Cu plasma temperature

Atomic emission double-spectrum temperature measurement method was developed, and a photoelectric temperature detector based on silicon photomultiplier tube was designed. The structure and principle of the temperature measurement of the photoelectric temperature detector were introduced. The spectral radiation signal of the copper sheet excited by the laser was transmitted to the photoelectric thermometer, and Cu I 510.5 nm and Cu I 521.8 nm were used as the temperature scale spectral lines during the temperature measurement. In different acquisition delays, the ratio of the intensity of the two Cu plasma spectral lines was obtained through the LIBS system. At the same time, the ratio of the maximum voltage value of the two channels was measured using a photoelectric thermometer. At the time of 6us, and the maximum temperature of Cu plasma excited by different laser energy was calculated to be 12745 K. The results show that the atomic emission dual-spectrum temperature measurement method has the characteristics of the higher temperature measurement limit and faster response speed.

A machine translation mechanism of Brazilian Portuguese to Libras with syntactic-semantic adequacy

AbstractDeaf people communicate naturally using visual-spatial languages, called sign languages (SL). Although SLs are recognized as a language in many countries, the problems faced by Deaf people for accessing information remain. As a result, they have difficulties exercising their citizenship and access information in SLs, which usually leads to linguistic and knowledge acquisition delays. Some scientific works have been developed to address these problems related to the machine translation of spoken languages to sign languages. However, the existing machine translation platforms have some limitations, especially in syntactic and lexical nature. Thus, this work aims to develop a mechanism for machine translation to Libras, the Brazilian Sign Language, with syntactic-semantic adequacy. It consists of an automatic translation component for Libras based on syntactic-semantic translation rules and a formal syntactic-semantic rule description language. As proof of concept of the proposed approach, we created a specific grammar for Libras translation exploring these aspects and integrating these elements into VLibras Suite, a service for machine translation of digital content in Brazilian Portuguese (BP) to Libras. We performed several tests using this modified version of VLibras to measure the level of comprehension of the output generated by the new translator mechanism. In the computational experiments, as well as in the actual tests with Deaf and hearing users, the proposed approach was able to improve the results of the current VLibras version.

Robust visual servoing control for quadrotors landing on a moving target

In this paper, a robust visual servoing control approach is proposed to address the landing problem for quadrotors on a moving platform. A vision system is implemented to estimate the position and velocity of the quadrotor. A robust cascade controller is proposed by following backstepping-like fundamentals and robust compensating theory. The effects of time-varying uncertainties, including parameter uncertainties and external disturbances, and time-varying delays resulted from image acquisition, image processing, and sensor measurement delays can be restrained. Experimental results using a quadrotor to land on a ground moving target illustrate the effectiveness of the proposed approach.

An anomaly detection method based on feature mining for wireless sensor networks

To overcome the problems of large errors in data feature acquisition and long detection delays in traditional detection methods, this paper proposes an anomaly detection method based on feature mining for wireless sensor networks (WSNs). In our method, dimensionality reduction is performed on the data, all wireless sensor nodes are classified by a hybrid immune method, and data features are mined through vector set recognition. Moreover, the confidence interval is set by a time series, and the effective detection of abnormal data is conducted by comparison. The experimental results show that the maximum error of anomaly data collection is only 1.9%, the maximum time cost of anomaly detection is 8.4 s, and the P-R value is high, indicating that the proposed method is effective.

Prevalence of Sensorineural Hearing Loss in Children with Palliated or Repaired Congenital Heart Disease.

BackgroundChildren with congenital heart disease (CHD) are at increased risk of neurodevelopmental deficits, and the presence of sensorineural hearing loss (SNHL) may further lead to poor language skills acquisition and speech delays. Prevalence of SNHL in the general pediatric population is estimated to be 0.2% at birth to 0.35% during adolescence. Very few studies have attempted to estimate SNHL prevalence in children who have undergone congenital heart surgery.MethodsThis retrospective study aimed to estimate SNHL prevalence in children who underwent congenital heart surgery in our institution and were followed up in our high-risk pediatric cardiology clinics for four years from 2009 to 2013. Data were collected on demographics, preoperative variables, surgical variables, and post-operative variables.ResultsSNHL prevalence in asymptomatic, palliated/repaired CHD patients followed in our high-risk clinics and undergoing routine surveillance was 11.6% (20 of 172 patients with hearing impairment). SNHL prevalence was not statistically higher in single-ventricle patients (17.2%) compared to biventricular patients (14.7%). Inotropic score in the first 24 hours of postoperative period (p=0.05), lowest arterial PaO2 (p=0.003), duration of Lasix drip (p=0), and bolus dose in days (p=0.03) were all found to be statistically significant in the hearing-impaired group. However, using logistic regression, we identified no statistically significant predictors for hearing loss.ConclusionThe results suggest the need for routine audiology screening of all patients with complex CHD, especially those who have undergone neonatal cardiac repair/palliation at less than one year of age, irrespective of risk factors.

A Novel Completion-Time-Minimization Scheduling Approach of Scientific Workflows Over Heterogeneous Cloud Computing Systems

The cloud computing paradigm provides an ideal platform for supporting large-scale scientific-workflow-based applications over the internet. However, the scheduling and execution of scientific workflows still face various challenges such as cost and response time management, which aim at handling acquisition delays of physical servers and minimizing the overall completion time of workflows. A careful investigation into existing methods shows that most existing approaches consider static performance of physical machines (PMs) and ignore the impact of resource acquisition delays in their scheduling models. In this article, the authors present a meta-heuristic-based method to scheduling scientific workflows aiming at reducing workflow completion time through appropriately managing acquisition and transmission delays required for inter-PM communications. The authors carry out extensive case studies as well based on real-world commercial cloud sand multiple workflow templates. Experimental results clearly show that the proposed method outperforms the state-of-art ones such as ICPCP, CEGA, and JIT-C in terms of workflow completion time.

Cumulative Dose of Macrocyclic Gadolinium-Based Contrast Agent Improves Detection of Enhancing Lesions in Patients with Multiple Sclerosis.

Gadolinium-enhanced MR imaging is currently the reference standard for detecting active inflammatory lesions in patients with multiple sclerosis. The sensitivity of MR imaging for this purpose may vary according to the physicochemical characteristics of the contrast agent used and the acquisition strategy. The purpose of this study was to compare detection of gadolinium-enhancing lesions or active disease following a single or cumulative dose of a macrocyclic gadolinium-based contrast agent with different image acquisition delays in patients with clinically isolated syndrome or relapsing multiple sclerosis. All patients received a first dose (0.1 mmol/kg) of gadobutrol and, 20 minutes later, a second dose (0.1 mmol/kg), with a cumulative dose of 0.2 mmol/kg. Two contrast-enhanced T1-weighted sequences were performed at 5 and 15 minutes after the first contrast administration, and 2 additional T1-weighted sequences at 5 and 15 minutes after the second contrast administration with a 3T magnet. One hundred fifteen patients were considered evaluable. A significantly larger number of lesions were detected in scans obtained at 5 and 15 minutes after the second contrast injection compared with scans obtained at 5 and 15 minutes after the first injection (P < .001). The number of patients with active lesions on MR imaging was significantly higher after the second dose administration (52.0%, first dose versus 59.2%, second dose; P < .001). Cumulative dosing of a macrocyclic gadolinium-based contrast agent increases detection of enhancing lesions and patients with active lesions. These data could be considered in the design of MR imaging protocols aimed at detecting active multiple sclerosis lesions.

Vocalization Rate and Consonant Production in Toddlers at High and Low Risk for Autism.

Previous work has documented lower vocalization rate and consonant acquisition delays in toddlers with autism spectrum disorder (ASD). We investigated differences in these variables at 12, 18, and 24 months in toddlers at high and low risk for ASD. Vocalization rate and number of different consonants were obtained from speech samples from a prospective study of infant siblings of children with ASD. Three groups were compared: 18 toddlers at low risk for ASD (low-risk control), 18 high-risk siblings without ASD (HRA-), and 10 high-risk siblings with ASD (HRA+). All groups' mean language scores were within the normal range. HRA+ toddlers showed consistently lower vocalization rate; vocalization rate did not predict number of different consonants at 12 months for HRA+. HRA-, not HRA+, toddlers had the smallest number of different consonants and produced significantly fewer different consonants than predicted by their vocalization rate at 12 months. Consonant-acquisition trajectories differed between groups, with HRA- showing the greatest increase from 12 to 18 months. Lower vocalization rate was not associated with reduced number of different consonants in these toddlers. Between-groups differences in developmental trajectories are discussed in the context of the social feedback loop and differential ability to benefit from adult feedback between groups.

Estimator of the Rotor Temperature of Induction Machine Based on Terminal Voltages and Currents

Monitoring of the rotor temperature is very important for both control and protection of induction machines. Temperature sensors are usually avoided due to additional wiring. Although the best precision is achieved by test-signal-based methods, they are rarely used due to a high-torque ripple. The ripple is negligible in cases where inherent pulse width modulation (PWM) voltage component is used as the test signal. In this paper, a novel temperature estimation method is devised, robust against the PWM delays, signal acquisition delays, and phase errors in high-frequency voltage and current components. Opposed to previous solutions where temperature is calculated based on the real part of the impedance, the presented method is based on the absolute value of the impedance at the PWM frequencies. The temperature is calculated from the change of the input impedance. Proposed method for temperature estimation was tested on an experimental setup which uses an inverter with sine modulated output voltages and an induction servo motor.