ABSTRACT
Introduction
Existing normal value references for pediatric nerve conduction studies (NCS) are based on limited sample sizes with uncertain reliability, suggesting a need for better ...normative data.
Methods
Electronic medical records were reviewed for pediatric patients (0 to <18 years) with normal findings on electromyography and NCS during the period from January 1, 1997 through September 20, 2017. Electrodiagnostic and demographic data were collected. Gaussian and descriptive statistics were used to establish normal values by age group.
Results
In this study we analyzed 1,918 normal NCS on 1,849 unique pediatric patients. Patients were stratified by age: 0 to <1 month; 1 to <6 months; 6 to <12 months; 12 to <24 months; 2 to <3 years; 3 to <4 years; 4 to <5 years; 5 to <10 years; 10 to <15 years; and 15 to <18 years. Normal reference ranges for amplitude, conduction velocity, and distal latency were established for each age group for 4 motor and 4 sensory nerves.
Discussion
The large sample size of this study provides reliable reference values for interpreting pediatric NCS. Muscle Nerve 60: 155–160, 2019
This work investigates the potential for using Grammatical Evolution (GE) to generate an initial seed for the construction of a pseudo-random number generator (PRNG) and cryptographically secure (CS) ...PRNG. We demonstrate the suitability of GE as an entropy source and show that the initial seeds exhibit an average entropy value of 7.940560934 for 8-bit entropy, which is close to the ideal value of 8. We then construct two random number generators, GE-PRNG and GE-CSPRNG, both of which employ these initial seeds. We use Monte Carlo simulations to establish the efficacy of the GE-PRNG using an experimental setup designed to estimate the value for pi, in which 100,000,000 random numbers were generated by our system. This returned the value of pi of 3.146564000, which is precise up to six decimal digits for the actual value of pi. We propose a new approach called control_flow_incrementor to generate cryptographically secure random numbers. The random numbers generated with CSPRNG meet the prescribed National Institute of Standards and Technology SP800-22 and the Diehard statistical test requirements. We also present a computational performance analysis of GE-CSPRNG demonstrating its potential to be used in industrial applications.
Microwave Photonic Direction-Finding Spectrometer Beardell, William L.; Ryan, Conor J.; Schneider, Garrett J. ...
Journal of lightwave technology,
05/2023, Letnik:
41, Številka:
10
Journal Article
Recenzirano
Odprti dostop
In this paper, we propose an architecture wherein the radio-frequency (RF) field at the antenna array is up-converted to an optical carrier and passed through an array of optical fibers, after which ...an analog Fourier transform is taken in a free-space optical processor. Through the use of multiple temporal dispersion projections, implemented through varied-length optical fiber segments, the locations of RF sources in three-dimensional space spanning angle-of-arrival (AoA) and instantaneous frequency may be determined on a millisecond time scale using commercial computing hardware after detection by a charge-coupled device (CCD) camera. We present a mathematical formulation of the problem, followed by simulated and experimental results showing three-dimensional spatial-spectral localization through the solution to a system of equations brought forth through the use of Fourier optics to process the RF field.
This work studies enhancing the capabilities of compact laser spectroscopes integrated into space-exploration rovers by adding 3D topography measurement techniques. Laser spectroscopy enables the in ...situ analysis of sample composition, aiding in the understanding of the geological history of extraterrestrial bodies. To complement spectroscopic data, the inclusion of 3D imaging is proposed to provide unprecedented contextual information. The morphological information aids material characterization and hence the constraining of rock and mineral histories. Assigning height information to lateral pixels creates topographies, which offer a more complete spatial dataset than contextual 2D imaging. To aid the integration of 3D measurement into future proposals for rover-based laser spectrometers, the relevant scientific, rover, and sample constraints are outlined. The candidate 3D technologies are discussed, and estimates of performance, weight, and power consumptions guide the down-selection process in three application examples. Technology choice is discussed from different perspectives. Inline microscopic fringe-projection profilometry, incoherent digital holography, and multiwavelength digital holography are found to be promising candidates for further development.
The ability to both spatially and spectrally demultiplex wireless transmitters enables communication networks with higher spectral and energy efficiency. In practice, demultiplexing requires ...sub-millisecond latency to map the dynamics of the user space in real-time. Here, we present a system architecture, referred to as
k-space imaging
, which channelizes the radio frequency signals both spatially and spectrally through optical beamforming, where the latency is limited only by the speed of light traversing the optical components of the receiver. In this architecture, a phased antenna array samples radio signals, which are then coupled into electro-optic modulators (EOM) that coherently up-convert these signals to the optical domain, preserving their relative phases. The received signals, now optical sidebands, are transmitted in optical fibers of varying path lengths, which act as true time delays that yield frequency-dependent optical phases. The output facets of the optical fibers form a two-dimensional optical phased array in an arrangement preserving the phases generated by the angle of arrival (AoA) and the time-delay phases. Directing the beams emanating from the fibers through an optical lens produces a two-dimensional Fourier transform of the optical field at the fiber array. Accordingly, the optical beam formed at the back focal plane of the lens is steered based upon the phases, providing the angle of arrival and instantaneous frequency measurement (IFM), with latency determined by the speed of light over the optical path length. We present a numerical evaluation and experimental demonstration of this passive AoA- and frequency-detection capability.
Photo‐catalysis by small‐molecules is often limited by catalyst degradation and low electron‐transfer efficiency. Herein we report a stable N‐phenyl‐phenothiazine (PTH)‐derived porous coordination ...cage (PCC) as a highly efficient photocatalyst. By the incorporation of the photocatalytic PTH moiety into a PCC, aggregation‐induced quenching (AIQ) was shown to be reduced. An improvement in catalyst stability was discovered, ascribed to the synergistic effects of the PTH moieties. The catalyst, operating through a photolytic single‐electron transfer, was utilized for photo‐catalyzed dehalogenation and borylation. Evaluation of the catalytic mechanism in the borylation reaction showed that the improved performance results from the more efficient formation of the electron donor‐acceptor (EDA) complex with the cage. This discovery provides a potential strategy to improve the photophysical properties and stabilities of small‐molecule organic photocatalysts via supramolecular chemistry.
Porous coordination cages (PCCs) are known for their strong intermolecular interaction and high stability for homogeneous catalysis. In this work, a photo‐active molecule, PTH, was assembled into PCC‐40, which showed excellent photocatalytic performance in dehalogenation and photo‐borylation. The synergistic effect of multi catalytic centers was studied. The results may provide future directions for improvement of a large group of photocatalysts.
The hereditary spastic paraplegias (HSPs) are a heterogeneous group of disorders characterized by degeneration of the corticospinal and spinocerebellar tracts leading to progressive spasticity. One ...subtype, spastic paraplegia type 47 (SPG47 or HSP‐AP4B1), is due to bi‐allelic loss‐of‐function mutations in the AP4B1 gene. AP4B1 is a subunit of the adapter protein complex 4 (AP‐4), a heterotetrameric protein complex that regulates the transport of membrane proteins. Since 2011, 11 individuals from six families with AP4B1 mutations have been reported, nine of whom had homozygous mutations and were from consanguineous families. Here we report eight patients with AP4B1‐associated SPG47, the majority born to non‐consanguineous parents and carrying compound heterozygous mutations. Core clinical features in this cohort and previously published patients include neonatal hypotonia that progresses to spasticity, early onset developmental delay with prominent motor delay and severely impaired or absent speech development, episodes of stereotypic laughter, seizures including frequent febrile seizures, thinning of the corpus callosum, and delayed myelination/white matter loss. Given that some of the features of AP‐4 deficiency overlap with those of cerebral palsy, and the discovery of the disorder in non‐consanguineous populations, we believe that AP‐4 deficiency may be more common than previously appreciated.
Neural networks have revolutionised the way we approach problem solving across multiple domains; however, their effective design and efficient use of computational resources is still a challenging ...task. One of the most important factors influencing this process is model hyperparameters which vary significantly with models and datasets. Recently, there has been an increased focus on automatically tuning these hyperparameters to reduce complexity and to optimise resource utilisation. From traditional human-intuitive tuning methods to random search, grid search, Bayesian optimisation, and evolutionary algorithms, significant advancements have been made in this direction that promise improved performance while using fewer resources. In this article, we propose HyperGE, a two-stage model for automatically tuning hyperparameters driven by grammatical evolution (GE), a bioinspired population-based machine learning algorithm. GE provides an advantage in that it allows users to define their own grammar for generating solutions, making it ideal for defining search spaces across datasets and models. We test HyperGE to fine-tune VGG-19 and ResNet-50 pre-trained networks using three benchmark datasets. We demonstrate that the search space is significantly reduced by a factor of ~90% in Stage 2 with fewer number of trials. HyperGE could become an invaluable tool within the deep learning community, allowing practitioners greater freedom when exploring complex problem domains for hyperparameter fine-tuning.
Introduction
Myokymic discharges are classically associated with nerve injury from prior radiation but may occur in other neuromuscular disorders. Using quantitative analysis we aimed to identify the ...spectrum of conditions in which myokymic discharges are present and determine if there are electrophysiological features that distinguish postradiation from nonradiation causes of myokymia.
Methods
We reviewed the clinical history of all patients examined in our electromyography labs with myokymic discharges recorded from June 2017 to February 2020. Quantitative analysis of each myokymic discharge was performed using a custom MATLAB script, assessing features such as burst frequency, spikes per burst, and burst regularity.
Results
Eighty‐eight distinct myokymic discharges (70 patients) were analyzed: 51 postradiation recordings from 35 patients and 37 recordings from 35 nonradiation patients. The diagnostic spectrum of nonradiation cases was diverse, with common causes being median neuropathy (n = 8), cervical (n = 7), and lumbar (n = 5) radiculopathy, and motor neuron disease (n = 5). On quantitative analysis, postradiation myokymia had an increased burst‐to‐silence ratio (median, 0.29; nonradiation, 0.08) and greater peak number (median, 15; nonradiation, 7). Except for one patient with hereditary peripheral nerve hyperexcitability, all patients who had two or more muscles demonstrating myokymic discharges belonged to postradiation group.
Conclusions
Myokymic discharges can be seen in diverse neuromuscular conditions; most common in our cohort was chronic median neuropathy. Postradiation myokymia appears to have distinguishing morphological features when quantitatively analyzed compared with nonradiation cases.
Graphene oxide (GO) is a graphene derivative that emits fluorescence, which makes GO an attractive material for optoelectronics and biotechnology. In this work, we utilize ozone treatment to ...controllably tune the band gap of GO, which can significantly enhance its applications. Ozone treatment in aqueous GO suspensions yields the addition/rearrangement of oxygen-containing functional groups suggested by the increase in vibrational transitions of C-O and C=O moieties. Concomitantly it leads to an initial increase in GO fluorescence intensity and significant (100 nm) blue shifts in emission maxima. Based on the model of GO fluorescence originating from sp
graphitic islands confined by oxygenated addends, we propose that ozone-induced functionalization decreases the size of graphitic islands affecting the GO band gap and emission energies. TEM analyses of GO flakes confirm the size decrease of ordered sp
domains with ozone treatment, whereas semi-empirical PM3 calculations on model addend-confined graphitic clusters predict the inverse dependence of the band gap energies on sp
cluster size. This model explains ozone-induced increase in emission energies yielding fluorescence blue shifts and helps develop an understanding of the origins of GO fluorescence emission. Furthermore, ozone treatment provides a versatile approach to controllably alter GO band gap for optoelectronics and bio-sensing applications.
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