THE CORRELATIONS BETWEEN DYNAMIC WALKING STABILITY AND PERCEPTION-MOTOR ABILITIES OF HUMANS

External perturbations can challenge a person’s walking stability, and people will autonomously make a series of responses to regain the balance of walking, which includes two periods: perturbation-perception (reaction time, RT) and posture-adjustment (motion time, MT). The purpose of this paper was to investigate the correlations between the dynamic walking stability and perception-motor abilities. During the 30 level walking trials preformed by sixteen healthy participants, perturbations were applied at random. The fall probability (FP) during the walking with perturbations was calculated to evaluate the dynamic walking stability of each participant. Furthermore, the ground reaction force (GRF) of each participant during walking with perturbations was recorded and analyzed. The experimental results show that the RT had a significant positive-correlation with FP, while MT had no correlation with FP

Ticagrelor vs Clopidogrel in CYP2C19 loss-of-function carriers with Stroke or TIA

BACKGROUNDComparisons between ticagrelor- aspirin and clopidogrel-aspirin in CYP2C19 loss-of-function carriers have not been well studied for secondary stroke prevention.METHODSWe conducted a randomized, double-blind, placebo-controlled trial of 6,412 patients with a minor ischemic stroke or TIA who carried CYP2C19 LOF alleles determined by point-of-care testing. Patients were randomly assigned within 24 hours after symptom onset, in a 1:1 ratio to receive ticagrelor (180 mg loading dose on day 1 followed by 90 mg twice daily for days 2 through 90) or clopidogrel (300 mg loading dose on day 1 followed by 75 mg per day for days 2 through 90), plus aspirin (75-300 mg loading dose followed by 75 mg daily for 21 days). The primary efficacy outcome was stroke and the primary safety outcome was severe or moderate bleeding, both within 90 days. RESULTSStroke occurred within 90 days in 191 (6.0%) versus 243 (7.6%), respectively (hazard ratio, 0.77; 95% confidence interval, 0.64 to 0.94; P=0.008). Moderate or severe bleeding occurred in 9 patients (0.3%) in the ticagrelor-aspirin group and in 11 patients (0.3%) in the clopidogrel-aspirin group; any bleeding event occurred in 170 patients (5.3%) vs 80 (2.5%), respectively. CONCLUSIONSAmong Chinese patients with minor ischemic stroke or TIA within 24 hours after symptoms onset who were carriers of CYP2C19 loss-of-function alleles, ticagrelor- aspirin was modestly better than clopidogrel-aspirin for reducing the risk of stroke but was associated with more total bleeding events at 90 days. (CHANCE-2 ClinicalTrials.gov number, NCT04078737.

Subwavelength imaging designed with meander-line anisotropic epsilon-near-zero (AENZ) metamaterial structures

Subwavelength imaging is designed and demonstrated utilizing practical meander-line metamaterial structures in this work. By carefully designing the composite structure, desirable anisotropic epsilon-near-zero (AENZ) index is obtained. To verify the imaging performance, a 3D model is constructed which is composed of period meander-line elements in numerical validation. Imaging in super resolution is observed. We remark that in the model, both of natural material loss and finite element size effect are considered mimicking practical scenarios. The demonstration results are convincing and helpful to provide practical insights for future applications of subwavelength imaging in microwave frequency range

A Long-Term Wind Speed Ensemble Forecasting System with Weather Adapted Correction

Wind forecasting is critical in the wind power industry, yet forecasting errors often exist. In order to effectively correct the forecasting error, this study develops a weather adapted bias correction scheme on the basis of an average bias-correction method, which considers the deviation of estimated biases associated with the difference in weather type within each unit of the statistical sample. This method is tested by an ensemble forecasting system based on the Weather Research and Forecasting (WRF) model. This system provides high resolution wind speed deterministic forecasts using 40 members generated by initial perturbations and multi-physical schemes. The forecasting system outputs 28–52 h predictions with a temporal resolution of 15 min, and is evaluated against collocated anemometer towers observations at six wind fields located on the east coast of China. Results show that the information contained in weather types produces an improvement in the forecast bias correction

Effects of a Detached Eddy Simulation-Curvature Correction (DES-CC) Turbulence Model on the Unsteady Flows of Side Channel Pumps

A side channel pump is a pump with a high head and a small flow that is widely used in various industrial fields. Many scientists have studied the hydraulic performance, pressure fluctuation characteristics, and gas-liquid mixed transport characteristics of this type of pump. However, these studies mainly focused on the single-stage impeller of the side channel pump, without considering the inter-stage connection channel and the multistage timing effect. These characteristics affect the hydraulic performance and pressure-pulsation characteristics of the side channel pump. Therefore, we carried out a numerical simulation and an experimental comparison on the multistage side channel pump to explore its flow characteristics during the stages. This study focused on the influence of different turbulence models on the numerical simulation of multistage side channel pumps. Shear stress transport (SST), detached eddy simulation (DES), and detached eddy simulation-curvature correction (DES-CC) turbulence models were selected for consideration. By studying the pressure and velocity streamline distribution, the turbulent kinetic energy, and the shape and volume of the vortex core area simulated by the three models, we concluded that the DES-CC model, when compared to the other models, can more fully reflect the vortex characteristics and the simulation results that are closer to the experimental data. The results of this study can be used as the basis for future research on multistage side channel pumps

Characterization of the complete chloroplast genome of a Chinese endangered species Cymbidium mannii

Cymbidium mannii is an endangered species belonging to the first ranking in protection category in China with important ornamental value and breeding value. This study used Illumina high-throughput sequencing technologies to sequence and analyze the complete chloroplast genome of C. mannii. The genome features of C. mannii and the phylogenetic relationships among Orchidaceae species were reported and established. The complete chloroplast genome is 152,544 bp in length, consisting of a pair of inverse duplication regions 25,357 bp, a large single-copy region 86,014 bp and a small single-copy region 15,816 bp. The entire genome contains 74 mRNA genes, 30 tRNA genes and 4 rRNA genes. The phylogenetic tree of 23 Orchidaceae species revealed C. mannii is more closely related to Cymbidium aloifolium

Genetic characterisation and forensic importance of 20 Y-STRs in Han population from Anshan, Northeast of China

Background With a population of over 1.4 billion and 56 ethnic groups, China is the largest country in the world in terms of population. Han is the main ethnic group of China (93%). Aim To provide genetic data of Y chromosomal STRs from Anshan City, Northeast of China, for the first time, which will serve as a reference database for forensic and population studies. Subjects and methods We report data of 20 Y-chromosomal short tandem repeats (YSTRs) genotyped with the Goldeneye® 20Y kit in 270 Han individuals residing in Anshan City of China. Results A total of 170 alleles were observed on 20 Y-STRs. The gene diversities varied from 0.3460 (DYS391) to 0.9692 (DYS385). Overall haplotype diversity was almost 1 with 261 unique haplotypes, while the discrimination capacity (DC) was 0.9814. Pairwise Rst and Fst genetic analyses, MDS plot, N-J tree and PCA showed the genetic structure of Anshan Han population was significantly different from other minority groups like Tibetans and Kazakhs. Conclusions Results of this study showed that Goldeneye® 20Y system loci have strong discriminatory power in the Anshan Han population of China which makes this kit suitable for forensic applications in this ethnic group

Investigations on vortex evolution and wake dynamics of bio-inspired pitching hydrofoils

Recently, lots of oscillating targets inspired from motions of some insects and birds have been applied extensively to many engineering applications. The aim of this work is to reveal the performance and detailed flow structures over the pitching corrugated hydrofoils under various working conditions, using the SST [Formula: see text] transition model. First of all, the lift coefficients of a smooth oscillating airfoil at different reduced frequency and pitching angles show a good agreement with the experiments, characterized by the accurate prediction of the light and deep stall. For the pitching corrugated hydrofoils, it shows that the mean lift coefficient increases with the pitching magnitude, but it has an obvious drop at high reduced frequency for the case with large pitching amplitude, which is mainly induced by the pressure modification on the surface with smooth curvature, depending on the oscillation significantly. In addition, the mean drag coefficient also indicates that the drag turns into the thrust at high reduced frequency when the pitching amplitude exceeds to the value of 10°. Increasing the reduced frequency delays the flow structure and leads to the deflection of the wake vortical flow. The Reynolds number also has an impact on the hydrofoil performance and wake morphology. Furthermore, regarding the shape effect, it seems that hydrofoil A (consisting of two protrusions and hollows and the aft part with smooth curvature) achieves the higher lift than hydrofoil B (comprising several protrusions and hollows along the surface), specially at high reduced frequency. Although the frequency collected from two hydrofoils remains nearly the same near the leading edge and in the wake region, the high sub-frequency is evidently reduced for hydrofoil B in second and third hollows, due to the relatively stable trapped vortices. Then, the wake transition from the thrust-indicative to drag-indicative profile for hydrofoil B is also slower compared with hydrofoil A. Finally, it is observed that with the increase of the thickness, the lift/drag ratio decreases and the slow wake transition is detected for the thin hydrofoil, which is associated with the relatively low drag coefficient