-
Nature Jun 2023Quantum computing promises to offer substantial speed-ups over its classical counterpart for certain problems. However, the greatest impediment to realizing its full...
Quantum computing promises to offer substantial speed-ups over its classical counterpart for certain problems. However, the greatest impediment to realizing its full potential is noise that is inherent to these systems. The widely accepted solution to this challenge is the implementation of fault-tolerant quantum circuits, which is out of reach for current processors. Here we report experiments on a noisy 127-qubit processor and demonstrate the measurement of accurate expectation values for circuit volumes at a scale beyond brute-force classical computation. We argue that this represents evidence for the utility of quantum computing in a pre-fault-tolerant era. These experimental results are enabled by advances in the coherence and calibration of a superconducting processor at this scale and the ability to characterize and controllably manipulate noise across such a large device. We establish the accuracy of the measured expectation values by comparing them with the output of exactly verifiable circuits. In the regime of strong entanglement, the quantum computer provides correct results for which leading classical approximations such as pure-state-based 1D (matrix product states, MPS) and 2D (isometric tensor network states, isoTNS) tensor network methods break down. These experiments demonstrate a foundational tool for the realization of near-term quantum applications.
PubMed: 37316724
DOI: 10.1038/s41586-023-06096-3 -
Molecular Ecology Resources Oct 2021Software tools for linkage disequilibrium (LD) analyses are designed to calculate LD among all genetic variants in a single region. Since compute and memory requirements...
Software tools for linkage disequilibrium (LD) analyses are designed to calculate LD among all genetic variants in a single region. Since compute and memory requirements grow quadratically with the distance between variants, using these tools for long-range LD calculations leads to long execution times and increased allocation of memory resources. Furthermore, widely used tools do not fully utilize the computational resources of modern processors and/or graphics processing cards, limiting future large-scale analyses on thousands of samples. We present quickLD, a stand-alone and open-source software that computes several LD-related statistics, including the commonly used r . quickLD calculates pairwise LD between genetic variants in a single region or in arbitrarily distant regions with negligible memory requirements. Moreover, quickLD achieves up to 95% and 97% of the theoretical peak performance of a CPU and a GPU, respectively, enabling 21.5× faster processing than current state-of-the-art software on a multicore processor and 49.5× faster processing when the aggregate processing power of a multicore CPU and a GPU is harnessed. quickLD can also be used in studies of selection, recombination, genetic drift, inbreeding and gene flow. The software is available at https://github.com/pephco/quickLD.
Topics: Algorithms; Genetic Linkage; Linkage Disequilibrium; Software
PubMed: 34062051
DOI: 10.1111/1755-0998.13438 -
Musculoskeletal Science & Practice Jun 2022Magnetic resonance imaging (MRI) is the standard to quantify size and structure of lumbar muscles. Three-dimensional volumetric measures are expected to be more closely...
INTRODUCTION
Magnetic resonance imaging (MRI) is the standard to quantify size and structure of lumbar muscles. Three-dimensional volumetric measures are expected to be more closely related to muscle function than two-dimensional measures such as cross-sectional area. Reliability and agreement of a standardized method should be established to enable the use of MRI to assess lumbar muscle characteristics.
OBJECTIVES
This study investigates the intra- and inter-processor reliability for the quantification of (1) muscle volume and (2) fat fraction based on chemical shift MRI images using axial 3D-volume measurements of the lumbar multifidus in patients with low back pain.
METHODS
Two processors manually segmented the lumbar multifidus on the MRI scans of 18 patients with low back pain using Mevislab software following a well-defined method. Fat fraction of the segmented volume was calculated. Reliability and agreement were determined using intra-class correlation coefficients (ICC), Bland-Altman plots and calculation of the standard error of measurement (SEM) and minimal detectable change (MDC).
RESULTS
Excellent ICCs were found for both intra-processor and inter-processor analysis of lumbar multifidus volume measurement, with slightly better results for the intra-processor reliability. The SEMs for volume were lower than 4.1 cm³. Excellent reliability and agreement were also found for fat fraction measures, with ICCs of 0.985-0.998 and SEMs below 0.946%.
CONCLUSION
The proposed method to quantify muscle volume and fat fraction of the lumbar multifidus on MRI was highly reliable, and can be used in further research on lumbar multifidus structure.
Topics: Humans; Low Back Pain; Lumbosacral Region; Magnetic Resonance Imaging; Paraspinal Muscles; Reproducibility of Results
PubMed: 35245881
DOI: 10.1016/j.msksp.2022.102532 -
International Journal of Food Science 2022Baobab fruit demand has been on the rise in the recent past, and in an attempt to match the demand, farmers and middlemen are forced to harvest immature fruits which are...
Baobab fruit demand has been on the rise in the recent past, and in an attempt to match the demand, farmers and middlemen are forced to harvest immature fruits which are not fully dried. To ensure an acceptable moisture content, baobab fruits are subjected to solar drying, which is a slow process and often carried out in open and unhygienic conditions raising safety concerns. This study was conducted to investigate the microbial and aflatoxin contamination levels in ready-to-eat baobab products from selected formal and informal processors in specific counties of Kenya. Selected processed baobab products were sampled randomly from formal and informal processors and analyzed for the total aerobic count, Enterobacteriaceae, yeast and molds, ergosterol, aflatoxins, moisture, and water activity. The moisture and water activity of baobab pulp and candies from formal processors ranged between 7.73% and 15.06% and 0.532 and 0.740 compared to those from informal processors which ranged from 10.50% to 23.47% and 0.532 to 0.751, respectively. In this study, baobab pulp from formal processors had significantly ( = 0.0008, 0.0006) lower Enterobacteriaceae and yeast and molds loads (0.7 ± 0.29 and 3.1 ± 0.38 log 10 CFU/g, respectively) than pulp from informal processors (3.1 ± 0.70 and 5.3 ± 0.11 log 10 CFU/g, respectively). Similarly, the Enterobacteriaceae counts of candies from formal processors (nondetectable) were considerably lower ( = 0.015) than those from informal processors (1.8 ± 0.56 log 10 CFU/g). The ergosterol content in these baobab product samples ranged between 0.46 and 1.92 mg/100 g while the aflatoxin content ranged between 3.93 and 11.09 × 103 g/kg, respectively. Fungal and aflatoxin contamination was detected in 25% and 5% of pulp from formal and informal processors, respectively, and in 5% of candies from informal processors. Microbial contamination in processed baobab products shows an unhygienic processing environment while the fungal and aflatoxin contamination may indicate poor postharvest handling, transport, and storage conditions of baobab fruits along the baobab value chain.
PubMed: 35252436
DOI: 10.1155/2022/2577222 -
Cochlear Implants International Jul 2023Cochlear implant reimplantation (CIR) for external processor upgrade or device failure is becoming increasingly common as the population of cochlear implant recipients...
INTRODUCTION
Cochlear implant reimplantation (CIR) for external processor upgrade or device failure is becoming increasingly common as the population of cochlear implant recipients ages. Patients with Advanced Bionics (AB) Clarion 1.2 cochlear implants may undergo CIR for device age/failure or desired technology upgrade so that they may use newer external processors that have improved connectivity features. The objective of this study was to evaluate audiologic outcomes for patients who were initially implanted with an AB Clarion 1.2 internal device and underwent CIR for technology upgrade or device failure.
METHODS
Retrospective chart review was performed at a single academic medical center for patients (pediatric and adult) with an AB Clarion 1.2 internal device who underwent CIR to a later generation AB internal device and had available audiologic data.
RESULTS
Forty-eight individuals with a Clarion 1.2 implant underwent CIR. Pre- and post-CIR speech understanding did not change for AzBio (p-value = 0.11, mean change = 12.1%, 95% CI = -2.9-27.2%), CNCw (p-value = 0.74, mean change = -1%, 95% CI = -10.4-12.4%), or HINT (p-value = 0.12, mean change = 19.9%, 95% CI = -2.6-42.4%) scores. Pure-tone averages improved following CIR (p-value < 0.01, mean change = 4.3 dB, 95% CI = 1.5-7.1 dB).
CONCLUSIONS
Revision of AB Clarion 1.2 cochlear implants does not significantly worsen audiologic outcomes and may improve hearing in some individuals, but individual patient-level outcomes are variable.
Topics: Adult; Humans; Child; Cochlear Implants; Cochlear Implantation; Retrospective Studies; Bionics; Reoperation; Speech Perception
PubMed: 37095648
DOI: 10.1080/14670100.2023.2198789 -
Reports on Progress in Physics.... Sep 2022Quantum annealing (QA) is a heuristic quantum optimization algorithm that can be used to solve combinatorial optimization problems. In recent years, advances in quantum... (Review)
Review
Quantum annealing (QA) is a heuristic quantum optimization algorithm that can be used to solve combinatorial optimization problems. In recent years, advances in quantum technologies have enabled the development of small- and intermediate-scale quantum processors that implement the QA algorithm for programmable use. Specifically, QA processors produced by D-Wave systems have been studied and tested extensively in both research and industrial settings across different disciplines. In this paper we provide a literature review of the theoretical motivations for QA as a heuristic quantum optimization algorithm, the software and hardware that is required to use such quantum processors, and the state-of-the-art applications and proofs-of-concepts that have been demonstrated using them. The goal of our review is to provide a centralized and condensed source regarding applications of QA technology. We identify the advantages, limitations, and potential of QA for both researchers and practitioners from various fields.
PubMed: 36001953
DOI: 10.1088/1361-6633/ac8c54 -
International Journal of Environmental... Mar 2023fish can be an affordable and accessible animal-source food in many Low- and Middle-Income Countries (LMIC).
INTRODUCTION
fish can be an affordable and accessible animal-source food in many Low- and Middle-Income Countries (LMIC).
BACKGROUND
Traditional fish processing methods pose a risk of exposing fish to various contaminants that may reduce their nutritional benefit. In addition, a lack of literacy may increase women fish processors' vulnerability to malnutrition and foodborne diseases.
OBJECTIVE
The overall aim of the project was to educate women and youth fish processors in Delta State, Nigeria about the benefit of fish in the human diet and to develop low literacy tools to help them better market their products. The objective of this study was to describe the development and validation of a low-literacy flipbook designed to teach women fish processors about nutrition and food safety.
METHOD
developing and validating instructional material requires understanding the population, high-quality and relevant graphics, and the involvement of relevant experts to conduct the content validation using the Content Validity Index (CVI) and the index value translated with the Modified Kappa Index ().
RESULT
The Item-level Content Validity Index (I-CVI) value of all domains evaluated at the initial stage was 0.83 and the Scale-level Content Validity Index (S-CVI) was 0.90. At the final stage, the material was validated with CVI 0.983 by four experts and satisfied the expected minimum CVI value for this study (CVI ≥ 0.83, -value = 0.05). The overall evaluation of the newly developed and validated flipbook was "excellent".
CONCLUSIONS
the developed material was found to be appropriate for training fish processors in Nigeria in nutrition and food safety and could be modified for a population of fish processors in other LMICs.
Topics: Humans; Female; Adolescent; Surveys and Questionnaires; Nigeria; Nutritional Status; Diet; Food Safety; Reproducibility of Results
PubMed: 36981799
DOI: 10.3390/ijerph20064891 -
IEEE Transactions on Biomedical... Jan 2023This paper presents an ultra-low power electrocardiogram (ECG) processor that can detect QRS-waves in real time as the data streams in. The processor performs...
This paper presents an ultra-low power electrocardiogram (ECG) processor that can detect QRS-waves in real time as the data streams in. The processor performs out-of-band noise suppression via a linear filter, and in-band noise suppression via a nonlinear filter. The nonlinear filter also enhances the QRS-waves by facilitating stochastic resonance. The processor identifies the QRS-waves on noise-suppressed and enhanced recordings using a constant threshold detector. For energy-efficiency and compactness, the processor exploits current-mode analog signal processing techniques, which significantly reduces the design complexity when implementing the second-order dynamics of the nonlinear filter. The processor is designed and implemented in TSMC 65 nm CMOS technology. In terms of detection performance, the processor achieves an average F1 = 99.88% over the MIT-BIH Arrhythmia database and outperforms all previous ultra-low power ECG processors. The processor is the first that is validated against noisy ECG recordings of MIT-BIH NST and TELE databases, where it achieves better detection performances than most digital algorithms run on digital platforms. The design has a footprint of 0.08 mm and dissipates 2.2 nW when supplied by a single 1V supply, making it the first ultra-low power and real-time processor that facilitates stochastic resonance.
PubMed: 37018643
DOI: 10.1109/TBCAS.2023.3235786 -
Journal of Human Lactation : Official... May 2022The retention of human milk nutrients in gastric tubes used to feed premature infants is a challenge to be overcome.
BACKGROUND
The retention of human milk nutrients in gastric tubes used to feed premature infants is a challenge to be overcome.
RESEARCH AIMS
To evaluate (1) the performance of six homogenizers (mixing processor, piston valve, ultrasonic bath, ultraturrax, stirring mixer, and ultrasound probe) for the fat retention reduction in gastric tubes; (2) the influence of the best homogenization conditions on the fatty acid and protein profiles of human milk; and (3) the cost/benefit ratio for the inclusion of homogenization as a new step in human milk processing.
METHODS
The influence of different levels and times of homogenization on reducing fat retention of human milk in probes was evaluated in this comparative prospective cross-sectional study. After homogenization, human milk flowed through a gavage and infusion pump apparatus used for feeding. Fat content was quantified before and after feeding. The techniques that reduced fat globule sizes and/or promoted a lower percentage of fat holding were evaluated for efficiency, variations in the fatty acid and protein profiles, and energy density and operating costs.
RESULTS
Homogenization led to a reduction in fat retention in feeding probes. The mixer processor and the ultrasound probe reduced fat retention by 99.23% (SD = 0.07) and 99.95% (SD = 0.02), respectively, and did not negatively influence fatty acid and protein profiles. The mixer processor demonstrated low energy density and low cost for human milk processing.
CONCLUSION
Homogenization promoted reduced fat retention in the feed probe and could help maintain fat nutrients of human milk during enteral feeding.
Topics: Breast Feeding; Cross-Sectional Studies; Fatty Acids; Female; Humans; Infant; Milk, Human; Prospective Studies
PubMed: 34308701
DOI: 10.1177/08903344211031456 -
IEEE Transactions on Biomedical... Jun 2023Versatile and energy-efficient neural signal processors are in high demand in brain-machine interfaces and closed-loop neuromodulation applications. In this paper, we...
Versatile and energy-efficient neural signal processors are in high demand in brain-machine interfaces and closed-loop neuromodulation applications. In this paper, we propose an energy-efficient processor for neural signal analyses. The proposed processor utilizes three key techniques to efficiently improve versatility and energy efficiency. 1) Hybrid neural network design: The processor supports artificial neural network (ANN)- and spiking neural network (SNN)-based neuromorphic processing where ANN is used to support the processing of ExG signals and SNN is used for handling neural spike signals. 2) Event-driven processing: The processor can perform always-on binary neural network (BNN)-based event detection with low-energy consumption, and it only switches to the high-accuracy convolutional neural network (CNN)-based recognition mode when events are detected. 3) Reconfigurable architecture: By exploiting the computational similarity of different neural networks, the processor supports critical BNN, CNN, and SNN operations with the same processing elements, achieving significant area reduction and energy efficiency improvement over those of a naive implementation. It achieves 90.05% accuracy and 4.38 uJ/class in a center-out reaching task with an SNN and 99.4% sensitivity, 98.6% specificity, and 1.93 uJ/class in an EEG-based seizure prediction task with dual neural network-based event-driven processing. Moreover, it achieves a classification accuracy of 99.92%, 99.38%, and 86.39% and energy consumption of 1.73, 0.99, and 1.31 uJ/class for EEG-based epileptic seizure detection, ECG-based arrhythmia detection, and EMG-based gesture recognition, respectively.
Topics: Neural Networks, Computer; Brain-Computer Interfaces; Humans
PubMed: 37074883
DOI: 10.1109/TBCAS.2023.3268502