132 research outputs found
Optionality in semantic-pragmatic interface of bilingualism? Bare numeral constructions in Tibetan and Chinese bilinguals’ grammar
Bare numeral constructions (BNCs) can be anaphoric in Chinese but not Tibetan. Since the interpretation of BNCs requires a specific context, we consider it to involve a semantic-pragmatic interface, which has been argued to be vulnerable to crosslinguistic transfer for bilinguals (e.g., Sorace 2005, 2011). This study conducted a controlled sentence-picture matching truth value judgment task to examine whether Tibetan-Chinese bilinguals show crosslinguistic influence when interpreting BNCs in both languages. The data suggests that crosslinguistic effects did occur among some bilinguals. However, there were more bilinguals who successfully differentiated the two languages regarding the interpretation of BNCs. Our findings imply that early bilinguals may not necessarily show optionality in interface phenomena
Varying magnetism in the lattice distorted Y2NiIrO6 and La2NiIrO6
We investigate the electronic and magnetic properties of the newly
synthesized double perovskites YNiIrO and LaNiIrO,
using density functional calculations, crystal field theory, superexchange
pictures, and Monte Carlo simulations. We find that both systems are
antiferromagnetic (AFM) Mott insulators, with the high-spin Ni
() and the low-spin Ir
() configurations. We address that their lattice distortion induces
- orbital mixing and thus enables the normal Ni-Ir
charge excitation with the electron hopping from the Ir `' to Ni
`' orbitals, which promotes the AFM Ni-Ir coupling.
Therefore, the increasing - mixing accounts for the enhanced
from the less distorted LaNiIrO to the more distorted
YNiIrO. Moreover, our test calculations find that in the otherwise
ideally cubic YNiIrO, the Ni-Ir charge excitation is
forbidden, and only the abnormal Ni-Ir excitation gives a weakly
ferromagnetic (FM) behavior. Furthermore, we find that owing to the crystal
field splitting, Hund exchange, and broad band formation in the highly
coordinated fcc sublattice, Ir ions are not in the
state but in the state carrying a finite orbital moment by spin-orbit
coupling (SOC). This work clarifies the varying magnetism in YNiIrO
and LaNiIrO associated with the lattice distortions.Comment: 7 pages, 7 figures, 1 tabl
Asymptomatic foot and ankle structural injuries: a 3D imaging and finite element analysis of elite fencers
Background: Fencing is a highly asymmetrical combat sport, that imposes high mechanical demands over repeated exposures on the musculoskeletal structures, a primary cause of injuries in fencers. However, there are limited epidemiological studies on the structural injuries of the foot and ankle in fencers. This study aimed to investigate foot and ankle structural injuries and explore how metatarsophalangeal joint structural changes may affect the mechanisms of foot and ankle injuries in asymptomatic fencers.
Methods: 3D images of foot and ankle morphology using computed tomography were obtained from ten elite fencers. We then constructed finite element models of the first metatarsophalangeal joint in the foot of their trail legs. The validated models were used to simulate stress distribution changes from different ankle joint angles during lunging.
Results: The findings showed that stress distribution changes at the medial and lateral sesamoid may have caused sesamoid fractures, and that habitual and concentrated stress on the metatarsal bones might have flattened the sesamoid groove. This process may damage the integrity of the first metatarsophalangeal joint, and consequently affect the efficiency of the windlass mechanism in fencers. During lunging, different ankle joint angles of the trail foot influenced the lunging quality and its stability.
Conclusions: Our findings revealed that the asymmetric nature of fencing might have caused asymptomatic foot and ankle structural injuries, and finite element analysis results indicated that this might increase the incidence of the serious injuries if unattended. Regular computed tomography examination should be introduced to monitor elite fencers’ lower limb alterations, permitting unique angle adjustments in the trail foot without sacrificing technical or physiologic properties based on the exam results and reduce the lower limb injury risk
A data-driven approach design for carbon emission prediction of machining
The issue of carbon emission reduction for manufacturing industry attracts increasing attention. As a major contributor in the manufacturing industry, machining has generated large amounts of carbon emissions through the resource consumption, energy consumption, and waste disposal. The carbon emission prediction of machining is a priori technology for its reduction, and has been established as one of the most crucial research targets. The purpose of this study is to design a carbon emission prediction model of machining through a data-driven approach. First of all, the multiple sources and impact factors of carbon emissions in machining are studied, and the relationship between these factors is also studied to describe the carbon emissions. Then, a data-driven approach is designed to predict the carbon emission of machining, which consists of data collection and preprocessing, feature extraction, prediction model establishment and model validation. The ridge regression, BP neural network based on Genetic Algorithm (GA-BP), root means square error (RMSE) and mean relative percentage error (MPAE) are respectively employed to fulfill the above tasks in the design approach. Finally, an experimental study of a real turning machining is proposed to verify the feasibility and merits of the designed approach
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Monitoring of the central blood pressure waveform via a conformal ultrasonic device.
Continuous monitoring of the central-blood-pressure waveform from deeply embedded vessels, such as the carotid artery and jugular vein, has clinical value for the prediction of all-cause cardiovascular mortality. However, existing non-invasive approaches, including photoplethysmography and tonometry, only enable access to the superficial peripheral vasculature. Although current ultrasonic technologies allow non-invasive deep-tissue observation, unstable coupling with the tissue surface resulting from the bulkiness and rigidity of conventional ultrasound probes introduces usability constraints. Here, we describe the design and operation of an ultrasonic device that is conformal to the skin and capable of capturing blood-pressure waveforms at deeply embedded arterial and venous sites. The wearable device is ultrathin (240 μm) and stretchable (with strains up to 60%), and enables the non-invasive, continuous and accurate monitoring of cardiovascular events from multiple body locations, which should facilitate its use in a variety of clinical environments
An improved model using convolutional sliding window-attention network for motor imagery EEG classification
IntroductionThe classification model of motor imagery-based electroencephalogram (MI-EEG) is a new human-computer interface pattern and a new neural rehabilitation assessment method for diseases such as Parkinson's and stroke. However, existing MI-EEG models often suffer from insufficient richness of spatiotemporal feature extraction, learning ability, and dynamic selection ability.MethodsTo solve these problems, this work proposed a convolutional sliding window-attention network (CSANet) model composed of novel spatiotemporal convolution, sliding window, and two-stage attention blocks.ResultsThe model outperformed existing state-of-the-art (SOTA) models in within- and between-individual classification tasks on commonly used MI-EEG datasets BCI-2a and Physionet MI-EEG, with classification accuracies improved by 4.22 and 2.02%, respectively.DiscussionThe experimental results also demonstrated that the proposed type token, sliding window, and local and global multi-head self-attention mechanisms can significantly improve the model's ability to construct, learn, and adaptively select multi-scale spatiotemporal features in MI-EEG signals, and accurately identify electroencephalogram signals in the unilateral motor area. This work provided a novel and accurate classification model for MI-EEG brain-computer interface tasks and proposed a feasible neural rehabilitation assessment scheme based on the model, which could promote the further development and application of MI-EEG methods in neural rehabilitation
Crystal Structure of the Caenorhabditis elegans Apoptosome Reveals an Octameric Assembly of CED-4
SummaryThe CED-4 homo-oligomer or apoptosome is required for initiation of programmed cell death in Caenorhabditis elegans by facilitating autocatalytic activation of the CED-3 caspase zymogen. How the CED-4 apoptosome assembles and activates CED-3 remains enigmatic. Here we report the crystal structure of the complete CED-4 apoptosome and show that it consists of eight CED-4 molecules, organized as a tetramer of an asymmetric dimer via a previously unreported interface among AAA+ ATPases. These eight CED-4 molecules form a funnel-shaped structure. The mature CED-3 protease is monomeric in solution and forms an active holoenzyme with the CED-4 apoptosome, within which the protease activity of CED-3 is markedly stimulated. Unexpectedly, the octameric CED-4 apoptosome appears to bind only two, not eight, molecules of mature CED-3. The structure of the CED-4 apoptosome reveals shared principles for the NB-ARC family of AAA+ ATPases and suggests a mechanism for the activation of CED-3
Gaussian Boson Sampling with Pseudo-Photon-Number Resolving Detectors and Quantum Computational Advantage
We report new Gaussian boson sampling experiments with
pseudo-photon-number-resolving detection, which register up to 255 photon-click
events. We consider partial photon distinguishability and develop a more
complete model for characterization of the noisy Gaussian boson sampling. In
the quantum computational advantage regime, we use Bayesian tests and
correlation function analysis to validate the samples against all current
classical mockups. Estimating with the best classical algorithms to date,
generating a single ideal sample from the same distribution on the
supercomputer Frontier would take ~ 600 years using exact methods, whereas our
quantum computer, Jiuzhang 3.0, takes only 1.27 us to produce a sample.
Generating the hardest sample from the experiment using an exact algorithm
would take Frontier ~ 3.1*10^10 years.Comment: submitted on 10 Apri
Gaussian Boson Sampling with Pseudo-Photon-Number-Resolving Detectors and Quantum Computational Advantage
We report new Gaussian boson sampling experiments with pseudo-photon-number-resolving detection, which register up to 255 photon-click events. We consider partial photon distinguishability and develop a more complete model for the characterization of the noisy Gaussian boson sampling. In the quantum computational advantage regime, we use Bayesian tests and correlation function analysis to validate the samples against all current classical spoofing mockups. Estimating with the best classical algorithms to date, generating a single ideal sample from the same distribution on the supercomputer Frontier would take ∼600 yr using exact methods, whereas our quantum computer, Jizhāng 3.0, takes only 1.27 μs to produce a sample. Generating the hardest sample from the experiment using an exact algorithm would take Frontier∼3.1×1010 yr.</p
Occupational exposure to formaldehyde, hematotoxicity and leukemia-specific chromosome changes in cultured myeloid progenitor cells - Response
There are concerns about the health effects of formaldehyde exposure, including carcinogenicity, in light of elevated indoor air levels in new homes and occupational exposures experienced by workers in health care, embalming, manufacturing and other industries. Epidemiological studies suggest that formaldehyde exposure is associated with an increased risk of leukemia. However, the biological plausibility of these findings has been questioned because limited information is available on formaldehyde’s ability to disrupt hematopoietic function. Our objective was to determine if formaldehyde exposure disrupts hematopoietic function and produces leukemia-related chromosome changes in exposed humans. We examined the ability of formaldehyde to disrupt hematopoiesis in a study of 94 workers in China (43 exposed to formaldehyde and 51 frequency-matched controls) by measuring complete blood counts and peripheral stem/progenitor cell colony formation. Further, myeloid progenitor cells, the target for leukemogenesis, were cultured from the workers to quantify the level of leukemia-specific chromosome changes, including monosomy 7 and trisomy 8, in metaphase spreads of these cells. Among exposed workers, peripheral blood cell counts were significantly lowered in a manner consistent with toxic effects on the bone marrow and leukemia-specific chromosome changes were significantly elevated in myeloid blood progenitor cells. These findings suggest that formaldehyde exposure can have an adverse impact on the hematopoietic system and that leukemia induction by formaldehyde is biologically plausible, which heightens concerns about its leukemogenic potential from occupational and environmental exposures
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