Average Acceleration Research Articles

Inverse Cherenkov dielectric laser accelerator with alternating phase focusing for subrelativistic particles

In this paper, we propose a dielectric laser acceleration scheme based on the inverse Cherenkov effect, which uses the principle of alternating phase focusing to accelerate, confine, and bunch the subrelativistic electron beam over an extended distance. In this scheme, the reference electron is always synchronized with the acceleration wave and is thus continuously accelerated. Electrons around it are alternately subjected to focusing and defocusing forces by alternately jumping its phase. Optimizing the focusing period can achieve stable beam confinement. Simulations show that a 100 keV electron bunch can be coherently accelerated with the average acceleration gradient of 220.8 MV/m, and it can travel nearly 200 μm without loss in a channel only 500 nm wide. This approach is scalable, potentially enabling the development of millimeter-scale MeV particle accelerators for ground-breaking use in medical, scientific, and materials research. Published by the American Physical Society 2024

From hardware to software integration: A comparative study of usability and safety in vehicle interaction modes

The increasing advancement of human–machine interaction (HMI) technology has brought the modes of vehicle HMI into focus, as they are closely related to driver and passenger safety and directly affect the travel experiences. This study compared the usability and safety of three vehicle HMI modes: hardware interaction (HI), hardware and software interaction (HSI), and software interaction (SI). The evaluation comprised two dimensions: usability and safety. Sixty participants’ performance on these tasks was evaluated at two driving speeds (30 km/h and 60 km/h). The results of the nonparametric tests indicated significant differences between the three interaction modes: (1) HI was the highest safety-oriented interaction mode with participants had the highest average vehicle speed and maximum acceleration measured at 60 km/h and the lowest glance frequency at both speeds; (2) HSI was the most usable interaction mode. Participants had the shortest task-completion time measured at 60 km/h and the highest score on the NASA-TLX and SUS scales taken for both speeds; (3) SI was the lowest secure and usable in-vehicle interaction mode. Participants had the longest task-completion time at 60 km/h, the highest error frequency under 30 and 60 km/h and the highest glance frequency, the longest total glance duration and the longest average glance time. In conclusion, HI and HSI were more secure and usable in-vehicle interaction modes than SI. From a theoretical exploration perspective, this paper elaborates on some exploratory thoughts and innovative ideas for practical application to the screen HMI mode selection and design in intelligent vehicle cabins.

Accelerometer-measured physical activity pattern in older patients with frailty and heart failure

Abstract Background Physical activity (PA) assessed by accelerometers represents a novel method to understand the PA profile of older patients with heart failure (HF). We hypothesized that PA level and pattern vary in HF patients across the spectrum of frailty status. Aim To report the duration, intensity and volume of PA in older patients with HF according to frailty status. Methods We recruited 150 HF patients≥65 years from a hospital-based HF clinic between March and October 2023. Frailty was assessed using the Short Physical Performance Battery (SPPB); patients with SPPB 10-12, 7-9, 4-6 and ≤3 was classified as robust, mildly, moderately and severely frail respectively. To evaluate PA profile, all patients wore a wrist accelerometer on their non-dominant hand for 7 days (24 hours/ day). PA parameters including average acceleration over 24 hours (proxy of volume of activity); time spent in inactive, light, moderate and vigorous intensity activities; intensity gradient (more negative gradient equates to poorer intensity profile) and time of most active continuous bouts of PA, were compared amongst frailty groups. Results 146 participants with good quality accelerometer data were included in the analysis; median age 80 (range 65-94 years), 65% male. Thirty-eight percent had heart failure with reduced ejection fraction (HFrEF); 21% had NYHA class III/IV symptoms; median NT-proBNP was 2040 ng/L (IQR = 1110 - 4930). Frail patients were more likely to be older with more comorbidities; they also had more severe HF symptoms and higher NT-proBNP. Frail patients had lower volume of PA compared to robust patients, evidenced by lower average acceleration (milligravity-mg) over 24 hours [20.4 (robust); 16.0 (mildly frail); 13.5 (moderately frail); 13.2 (severely frail), p<0.001]. PA intensity profile was poorer in frail patients compared to robust patients [median intensity gradient: -2.72 (robust); -2.92 (mildly frail); -3.00 (moderately frail); -3.07 (severely frail), p<0.001]. (Table 1) Frail patients spent more time inactive compared to robust patients [median time spent inactive (minutes): 654 (robust); 689 (mildly frail); 780 (moderately frail); 720 (severely frail), p<0.001]. The median time (minutes) spent in light [225 (robust); 190 (mildly frail); 164 (moderately frail); 159 (severely frail)] and moderate to vigorous activity [62 (robust), 23 (mildly frail), 15 (moderately frail) and 13 (severely frail), p<0.001] were significantly shorter in frail compared to robust patients. (Figure 1) The most active continuous bout of PA of patients across the frailty spectrum appeared to between 10 AM to 2 PM. Conclusion The duration, volume and intensity of PA was generally low in older patients with HF. Worse frailty status was associated with longer duration of physical inactivity, shorter duration of light, moderate or vigorous activity, poorer PA intensity profile and lower volume of PA.

Impact of spilanthol supplementation with balance training on neuromuscular performance

Abstract Background Age-related reductions in muscle mass, muscle contraction power, force, and coordination contribute to an elevated risk of falls and associated consequences. Research suggests that the enhancement of neuromuscular function is attainable through a regimen of targeted exercises and the strategic inclusion of certain supplements like spilanthol. This randomized controlled trial investigated the effect of resistance exercise with either spilanthol plus coordination/ balance training (BAL) or BAL-alone on neuromuscular function (countermovement jump, multiple one-leg hopping, and sit-to-stand test). Materials and methods In the course of this study, a cohort of 68 healthy male participants, aged 40 to 50 years, completed a rigorous 6-month intervention, from the initial 75 recruits. In the spilanthol-plus-BAL group, participants engaged in 30 minutes of resistance exercise sessions four times a week, complemented by daily supplementation of 17.5 mg of spilanthol. Results The analysis of the results showed significant improvements in the spilanthol-plus-BAL group, particularly evident in the peak countermovement power (p < 0.01). The mean effect size for this parameter was a + 1.5[0.9 to 2.1] W/kg greater change in spilanthol-plus-BAL group than BAL-alone group after six months. Moreover, multiple one-leg hopping performance showed significant enhancement in the spilanthol-plus-BAL group post-intervention. The parameters of sit-to-stand duration (1.04 s vs. 1.95 s; p = 0.03) and average acceleration (1.54 g vs. 1.06 g; p = 0.04) both exhibited substantial improvements in the spilanthol-plus-BAL group compared to the BAL-alone group. Conclusions The findings of this investigation contribute empirical evidence supporting the proposition that spilanthol supplementation, when integrated with BAL training, can exert a more pronounced impact on select facets of neuromuscular function. Key messages • Spilanthol supplementation with balance training can exert a pronounced impact on neuromuscular function. • Spilanthol supplementation with balance training demonstrates potential in mitigating sarcopenia and other degenerative conditions.

Smartphone Technology to Facilitate Remote Postural Balance Assessment in Acute Concussion Management: Pilot Study.

Impaired balance is a key symptom following acute concussion. Unfortunately, the recommended clinical balance assessment lacks sensitivity and discriminative ability, relying on the experience of the clinician for interpretation. The aim of this pilot study is to explore smartphone technology to remotely assess balance impairment in people with acute concussion. A smartphone app was developed to allow the clinician to connect remotely using their personal web browser to the participant's smartphone and collect motion data while instructing the participant to perform the following balance tests: standing on firm and foam surface with eyes opened and closed (FIRMEO, FIRMEC, FOAMEO, and FOAMEC). Outcome measures were processed from the raw acceleration to calculate the average acceleration magnitude from the mean and the root-mean square, with greater values indicating more sway. Eleven healthy controls (HCs) and 11 people with concussion (CON) participated. In all sway measurements, the CON group had significantly (p < 0.05) greater values when standing on a firm surface. In the FOAMEC condition, the CON group had significantly (p < 0.05) greater sway measures only in the AP direction, while significantly greater sway in all directions were found in the CON group in the FOAMEO condition. This study shows that remote balance assessment using a smartphone can discriminate between healthy controls and people with acute concussion. This technology could play an important role in concussion management to assist with determining recovery from concussions and the optimal timing for return to sport.

Correlation models for next-generation amplitude and cumulative intensity measures using artificial neural networks

Various next-generation intensity measures (IMs) have emerged in recent years. For instance, filtered incremental velocity, FIV3, was shown to be efficient in predicting the collapse of structures, or average spectral acceleration, Saavg, shown to be well-correlated with a wide range of response, from initiation of structural damage yielding to structural collapse. Different ground motion models (GMMs) are available to predict the probabilistic distribution of these IMs, given a set of seismological parameters. Nonetheless, a few key correlation models are still missing in the literature, which are elemental for a more holistic approach to ground motion record selection. These models are vital when performing seismic hazard analysis and ground motion record selection using state-of-the-art approaches like the conditional spectrum or generalized conditional intensity measure (GCIM) methods. This study uses a single machine-learning-based generalized ground motion model (GGMM) to estimate all the IMs. The model is based on the Next-Generation Attenuation (NGA)-West2 database and was utilized to quantify the correlations between the residuals. Correlations were calculated for intra- and inter-event residuals, but only those for total residuals are presented here, given their utility. Since the calculation of residuals comes from the same GMM and the same database of ground motions, this produces more consistent correlation coefficients between all IMs. To facilitate the usage of these correlation coefficients, predictive models of the empirical data were developed using machine-learning-based techniques, namely artificial neural networks (ANNs). It was found that FIV3 is strongly correlated with Sa(~1 s) and itself across all periods and has a weak negative correlation with duration at short periods and near-zero correlation for longer periods. Also, a stronger negative correlation between Sa and significant duration was found, compared with other prominent existing models. Direct correlation models between Sa and Saavg are also proposed.

Directionality of average spectral acceleration, SaAvg, in the 2023 Kahramanmaras, Türkiye earthquake sequence

Directionality of average spectral acceleration, SaAvg, in the 2023 Kahramanmaras, Türkiye earthquake sequence

A Super Vibration Drag Reduction System Based on Drilling Robot

Summary For directional or horizontal wells, friction between the drillstring and the borehole wall has become a significant factor in reducing the rate of penetration, leading to a decrease in weight on bit (WOB) and inefficient rock breaking. Generally, a larger amplitude yields a better oscillation effect. Conventional hydraulic oscillators rely on their inherent inertia to produce oscillating loads. However, the mass of the oscillating load provided by hydraulic oscillators is relatively small compared with the entire pipe string, resulting in limited oscillation amplitude that fails to effectively reduce friction and drag. To enhance the vibration effect and strength of the pipe string, in this article we propose the development of a novel hydraulic oscillation device that utilizes drilling robots for support. The relevant structure of the drilling robot has been designed, and a simulation wellbore experiment platform, based on the drilling robot, has been constructed. The simulation wellbore experiment based on different supporting conditions was completed. Through analysis of the collected experimental data, it has been observed that the axial and radial vibrations generated by the drilling robot are influenced by its supporting condition. The average acceleration amplitude and frequency of axial vibration without support are measured to be 0.37 m/s² and 8.2 Hz, respectively. In contrast, with supporting conditions, the average axial vibration acceleration amplitude increases to 0.63 m/s², and the frequency reaches 12.8 Hz. Consequently, the axial vibration intensity of the drilling robot is significantly higher when the drilling robot is supported. The average acceleration amplitude and frequency of radial vibration without support are 0.83 m/s² and 20.4 Hz, respectively. However, with supporting conditions, the average radial vibration acceleration amplitude drops to 0.43 m/s², and the frequency decreases to 12.2 Hz. The average axial vibration displacement amplitude of the supported drilling robot measures 50.2 mm, which is much greater than that of a typical hydraulic oscillator. Moreover, the WOB of the drilling robot with support is considerably higher compared with the unsupported drilling robot. By employing supporting conditions, the drilling robot can improve the transmission efficiency of drilling pressure and minimize the damage caused by radial vibration to downhole tools.

Phase field thermal shock analysis of rotating porous cracked pretwisted FGM microblade using exact shear correction factor

The present work is an attempt to develop a simple and accurate finite element formulation for the thermal shock analysis of the rotating porous cracked pretwisted functionally graded material (FGM) microblade using modified coupled stress theory in conjunction with phase-field and first-order shear deformation theory (FSDT). The physical neural surface is taken as the reference plane and the exact value of the shear correction factor is calculated from the shear stiffness. The elastic properties are assumed to be temperature-dependent and the upper ceramic layer is subjected to a high thermal shock whereas the bottom metallic layer is maintained at room temperature or is thermally insulated. The governing differential equation for the present analysis is derived using Hamilton’s principle and Newmark average acceleration method is used to obtain the transient response of the rotating porous cracked pretwisted FGM microblade subjected to thermal shock. The results obtained from the present finite element formulation are first validated with several benchmark examples available in the literature. New results are presented investigating the effect of crack depth, crack location, crack angle, rotational velocity and material scale ratio on the transient response of the cracked rotating porous pretwisted FGM microblade subjected to thermal shock. It is shown here that the parameters like crack depth, crack location and crack angle have a significant influence on the transient response of the rotating porous cracked pretwisted FGM microblade.

A comparative analysis of 24-hour movement behaviors features using different accelerometer metrics in adults: Implications for guideline compliance and associations with cardiometabolic health.

Movement behavior features such as time use estimates, average acceleration and intensity gradient are crucial in understanding associations with cardiometabolic health. The aim of this study was to 1) compare movement behavior features processed by commonly used accelerometer metrics among adults (i.e. Euclidian Norm Minus One (ENMO), Mean Amplitude Deviation (MAD) and counts per minute (CPM)), 2) investigate the impact of accelerometer metrics on compliance with movement behavior guidelines, and 3) explore potential variations in the association between movement behavior features and cardiometabolic variables depending on the chosen metric. This cross-sectional study collected movement behavior features (Actigraph GT3X+) and cardiometabolic variables. Accelerometer data were analyzed by four metrics, i.e. ENMO, MAD, and CPM vertical axis and CPM vector magnitude (GGIR). Intraclass correlations and Bland‒Altman plots identified metric differences for time use in single movement behaviors (physical activity, sedentary behavior), average acceleration and intensity gradient. Regression models across the four metrics were used to explore differences in 24-hour movement behaviors (24h-MBs; compositional variable) as for exploration of associations with cardiometabolic variables. Movement behavior data from 213 Belgian adults (mean age 45.8±10.8 years, 68.5% female) differed according to the metric used, with ENMO representing the most sedentary movement behavior profile and CPM vector magnitude representing the most active profile. Compliance rates for meeting integrated 24h-MBs guidelines varied from 0-25% depending on the metric used. Furthermore, the strength and direction of associations between movement behavior features and cardiometabolic variables (body mass index, waist circumference, fat% and HbA1c) differed by the choice of metric. The metric used during data processing markedly influenced cut-point dependent time use estimates and cut-point independent average acceleration and intensity gradient, impacting guideline compliance and associations with cardiometabolic variables. Consideration is necessary when comparing findings from accelerometry studies to inform public health guidelines.

Daily physical activity and prognostic implications in patients with heart failure: an accelerometer study.

Physical activity (PA) measured by accelerometry is proposed as a novel trial endpoint for heart failure (HF). However, standardised methods and associations with established markers are lacking. This study aimed to examine PA measurements and accelerometer repeatability in patients with HF and age- and sex-matched controls, and study correlations with established prognostic HF markers, body composition, and quality of life (QoL). Accelerometry was performed in 105 patients with HF with left ventricular ejection fraction (LVEF) ≤ 40% and in 46 controls. Participants also underwent dual X-ray absorptiometry, cardiopulmonary exercise testing, a six-minute walking test (6MWT), echocardiography, and NT-proBNP measurement, and completed a QoL questionnaire. Average acceleration was markedly reduced in patients with HF compared with healthy controls (16.1 ± 4.8mg vs 27.2 ± 8.5mg, p < 0.001). Healthy controls spent a median daily 56min (IQR 41-96min) in moderate-to-vigorous PA (MVPA), whereas HF patients spent only 12min (IQR 6-24) in MVPA. In HF patients, average acceleration correlated moderately with 6MWT (R = 0.41, p < 0.001) and maximal oxygen uptake (peak VO2) (R = 0.36, p < 0.001) but not with NT-proBNP, LVEF, or QoL. Patients in NYHA class II showed a higher average acceleration than patients in NYHA III (16.6 ± 4.9mg vs 14.0 ± 3.6mg, p = 0.01). Daily PA was severely reduced in patients with HF compared with healthy controls. In HF patients, we found moderate correlations of accelerometer measurements with markers of physical capacity but not with LVEF or NT-proBNP. NCT05063955. Registered 01 June 2021-retrospectively registered.

Effect of different weight initialization strategies on transfer learning for plant disease detection

AbstractThe weight initialization technique for transfer learning refers to the practice of using pretrained models that can be modified to solve new problems, instead of starting the training process from scratch. In this study, six different transfer learning weight initialization strategies were proposed for plant disease detection: scratch (i.e., random initialization), pretrained model on cross‐domain (ImageNet), model trained on related domain (ISIC 2019), model trained on related domain (ISIC 2019) with cross‐domain (ImageNet) weights, model trained on same domain (PlantVillage), and model trained on same domain (PlantVillage) with cross‐domain weights (ImageNet). Weights from each strategy were transferred to a target dataset (Plant Pathology 2021). These strategies were implemented using eight deep learning architectures. It was observed that transferring from any strategy led to an average acceleration of convergence ranging from 33.88% to 73.16% in mean loss and an improvement of 8.72%–42.12% in mean F1‐score compared to the scratch strategy. Moreover, although smaller and less comprehensive than ImageNet, transferring information from the same domain or related domain proved to be competitive compared to transferring from ImageNet. This indicates that ImageNet, which is widely favoured in the literature, may not necessarily represent the most optimal transfer source for the given context. In addition, to identify which strategies have significant differences, a post hoc analysis using Tukey's HSD test was conducted. Finally, the classifications made by the proposed models were visualized using Grad‐CAM to provide a qualitative understanding of how different weight initialization strategies affect the focus areas of the models.

A Detailed Analysis of a Magnetic Island Observed by WISPR on Parker Solar Probe

We present the identification and physical analysis of a possible magnetic island feature seen in white-light images observed by the Wide-field Imager for Solar Probe (WISPR) on board the Parker Solar Probe. The island is imaged by WISPR during Parker's second solar encounter on 2019 April 6, when Parker was ∼38 R ⊙ from the Sun's center. We report that the average velocity and acceleration of the feature are approximately 334 km s−1 and −0.64 m s−2. The kinematics of the island feature, coupled with its direction of propagation, indicate that the island is likely entrained in the slow solar wind. The island is elliptical in shape with a density deficit in its center, suggesting the presence of a magnetic guide field. We argue that this feature is consistent with the formation of this island via reconnection in the current sheet of the streamer. The feature's aspect ratio (calculated as the ratio of its minor to major axis) evolves from an elliptical to a more circular shape that approximately doubles during its propagation through WISPR’s field of view. The island is not distinct in other white-light observations from the Solar and Heliospheric Observatory and the Solar Terrestrial Relations Observatory coronagraphs, suggesting that this is a comparatively faint heliospheric feature and that viewing perspective and WISPR’s enhanced sensitivity are key to observing the magnetic island.

Tibial acceleration alone is not a valid surrogate measure of tibial load in response to stride length manipulation

PurposeThis study aimed to evaluate the relationship between peak tibial acceleration and peak ankle joint contact forces in response to stride length manipulation during level-ground running. MethodsTwenty-seven physically active participants ran 10 trials at preferred speed in each of 5 stride length conditions: preferred, ±5 %, and ±10 % of preferred stride length. Motion capture, force platform, and tibial acceleration data were directly measured, and ankle joint contact forces were estimated using an inverse-dynamics-based static optimization routine. ResultsIn general, peak axial tibial accelerations (p < 0.001) as well as axial (p < 0.001) and resultant (p < 0.001) ankle joint contact forces increased with stride length. When averaged within the 10 strides of each stride condition, moderate positive correlations were observed between peak axial acceleration and joint contact force (r = 0.49) as well as peak resultant acceleration and joint contact force (r = 0.51). However, 37% of participants illustrated either no relationship or negative correlations. Only weak correlations across participants existed between peak axial acceleration and joint contact force (r = 0.12) as well as peak resultant acceleration and ankle joint contact force (r = 0.18) when examined on a step-by-step basis. ConclusionThese results suggest that tibial acceleration should not be used as a surrogate for ankle joint contact force on a step-by-step basis in response to stride length manipulations during level-ground running. A 10-step averaged tibial acceleration metric may be useful for some runners, but an initial laboratory assessment would be required to identify these individuals.

Visual Navigation of Caged Chicken Coop Inspection Robot Based on Road Features.

The speed and accuracy of navigation road extraction and driving stability affect the inspection accuracy of cage chicken coop inspection robots. In this paper, a new grayscale factor (4B-3R-2G) was proposed to achieve fast and accurate road extraction, and a navigation line fitting algorithm based on the road boundary features was proposed to improve the stability of the algorithm. The proposed grayscale factor achieved 92.918% segmentation accuracy, and the speed was six times faster than the deep learning model. The experimental results showed that at the speed of 0.348 m/s, the maximum deviation of the visual navigation was 4 cm, the average deviation was 1.561 cm, the maximum acceleration was 1.122 m/s2, and the average acceleration was 0.292 m/s2, with the detection number and accuracy increased by 21.125% and 1.228%, respectively. Compared with inertial navigation, visual navigation can significantly improve the navigation accuracy and stability of the inspection robot and lead to better inspection effects. The visual navigation system proposed in this paper has better driving stability, higher inspection efficiency, better inspection effect, and lower operating costs, which is of great significance to promote the automation process of large-scale cage chicken breeding and realize rapid and accurate monitoring.

An Improved Average Acceleration Approach of Modelling Earth Gravity Field Based on K-Band Range-Rate Observations

The conventional average acceleration approach relies on K-band range observation, containing an unknown bias, which leads to possible degradation of the precision of Earth’s gravity field modelling. It also suffers from correlated errors caused by three-point numerical differentiation. In this study, an improved approach is proposed that makes use of K-band range-rate observations instead and overcoming the influence of correlated errors by introducing a whitening filter. GRACE-Follow On data spanning the period from January 2019 to December 2022 were processed by the proposed approach and a series of time-varying gravity field models was derived, referred to as SSM-AAA-GFO in this paper. This model series is compared comprehensively with three official model series. Results demonstrate that all model series are highly coincident below degree 30 and reflect similar time-varying gravity field signals in both large and small basins. After filtering, SSM-AAA-GFO shows uncertainty, in the form of equivalent water height below 2.5 cm, which is comparable with three official model series. The comparison results confirm the effectiveness of the proposed approach for precisely modelling a time-varying gravity field based on K-band range-rate observations.

Interplay between physical activity volume and intensity with modeled life expectancy in women and men: A prospective cohort analysis

BackgroundThere is a lack of research examining the interplay between objectively measured physical activity volume and intensity with life expectancy. MethodsIndividuals from UK Biobank with wrist-worn accelerometer data were included. The average acceleration and intensity gradient were extracted to describe the physical activity volume and intensity profile. Mortality data were obtained from national registries. Adjusted life expectancies were estimated using parametric flexible survival models. Results40,953 (57.1%) women (median age = 61.9 years) and 30,820 (42.9%) men (63.1 years) were included. Over a median follow-up of 6.9 years, there were 1719 (2.4%) deaths (733 in women; 986 in men). At 60 years, life expectancy was progressively longer for higher physical activity volume and intensity profiles, reaching 95.6 years in women and 94.5 years in men at the 90th centile for both volume and intensity, corresponding to 3.4 (95% confidence interval (95%CI): 2.4–4.4) additional years in women and 4.6 (95%CI: 3.6–5.6) additional years in men compared to those at the 10th centiles. An additional 10-min or 30-min daily brisk walk was associated with 0.9 (95%CI: 0.5–1.3) and 1.4 (95%CI: 0.9–1.9) years longer life expectancy, respectively, in inactive women; and 1.4 (95%CI: 1.0–1.8) and 2.5 (95%CI: 1.9–3.1) years in inactive men. ConclusionHigher physical activity volumes were associated with longer life expectancy, with a higher physical activity intensity profile further adding to a longer life. Adding as little as a 10-min brisk walk to daily activity patterns may result in a meaningful benefit to life expectancy.

Rapid Response of Daphnia magna Motor Behavior to Mercury Chloride Toxicity Based on Target Tracking.

A rapid and timely response to the impacts of mercury chloride, which is indispensable to the chemical industry, on aquatic organisms is of great significance. Here, we investigated whether the YOLOX (improvements to the YOLO series, forming a new high-performance detector) observation system can be used for the rapid detection of the response of Daphnia magna targets to mercury chloride stress. Thus, we used this system for the real-time tracking and observation of the multidimensional motional behavior of D. magna. The results obtained showed that the average velocity (v¯), average acceleration (a¯), and cumulative travel (L) values of D. magna exposed to mercury chloride stress changed significantly under different exposure times and concentrations. Further, we observed that v¯, a¯ and L values of D. magna could be used as indexes of toxicity response. Analysis also showed evident D. magna inhibition at exposure concentrations of 0.08 and 0.02 mg/L after exposure for 10 and 25 min, respectively. However, under 0.06 and 0.04 mg/L toxic stress, v¯ and L showed faster toxic response than a¯, and overall, v¯ was identified as the most sensitive index for the rapid detection of D. magna response to toxicity stress. Therefore, we provide a strategy for tracking the motile behavior of D. magna in response to toxic stress and lay the foundations for the comprehensive screening of toxicity in water based on motile behavior.

Exploring the genetic causal relationship between physical activity and migraine in European population based on Mendelian randomization analysis.

Previous studies have shown a connection between physical activity and migraines, but they don't prove a cause-and-effect relationship due to potential biases in observational methods. Utilizing accelerometer-measured physical activity data from a cohort of 377,234 participants in the UK Biobank and information from 599,356 European migraine patients (including 48,975 cases and 550,381 controls) obtained from 24 cohorts, we performed a bidirectional Mendelian randomization analysis to investigate the genetic bidirectional causal relationship between accelerometer-measured physical activity and migraines. Research findings indicated a slight negative genetic correlation between "average acceleration" physical activity (rg = -0.091, p = 0.011), overall physical activity (rg = -0.081, p = 0.017), and migraine. Nevertheless, no shared genetic components were observed between migraine and "fraction of accelerations > 425 mg" of physical activity (rg = -0.124, p = 0.076). The study results also demonstrated a lack of genetic bidirectional causality between accelerometer-measured physical activity and migraine ("average acceleration", OR = 1.002, 95% CI 0.975-1.031, p = 0.855, "fraction of accelerations > 425 mg", OR = 1.127, 95% CI 0.802-1.583, p = 0.488, overall physical activity, OR = 0.961, 95% CI 0.713-1.296, p = 0.799), and vice versa. Additionally, this lack of causal association persists even after adjusting for obesity (OR = 1.005, p = 0.578), education (OR = 1.019, p = 0.143), and depression (OR = 1.005, p = 0.847), either separately or simultaneously. The Mendelian randomization results based on genetic data do not provide support for a causal association between physical activity and migraine.

The relationship between accelerometer-based physical activity, sedentary behavior, and seven common geriatric syndromes: a two-sample Mendelian randomization study.

To investigate the causal associations between accelerometer-based physical activity (PA), sedentary behavior (SB), and seven common geriatric syndromes (GSs) (frailty, falls, delirium, urinary incontinence, dysphagia, hearing loss, and visual impairment) by Mendelian randomization (MR) analysis. Instrumental variables from a genome-wide association study were used for MR analysis. The exposure factors were three PA phenotypes (average acceleration, overall activity, and moderate-intensity activity) and one SB phenotype (SB). The outcome variables were seven common GSs. The inverse variance weighted (IVW) method was utilized for the primary MR analysis. Additionally, sensitivity, pleiotropy, and heterogeneity analyses were subsequently conducted to assess the robustness of the present study's findings. According to the primary MR results obtained using the IVW method, genetically predicted PA (average acceleration) decreased the risk of two GSs (frailty, p = 0.01; dysphagia, p = 0.03). Similarly, overall activity decreased the risk of two GSs (frailty, p = 0.01; delirium, p = 0.03), and moderate-intensity activity reduced the risk of three GSs (urinary incontinence, p = 0.04; hearing loss, p = 0.02; visual impairment, p = 0.01). Furthermore, SB was causally correlated with a greater risk for three GSs (frailty, p = 0.03; fall, p = 0.01; dysphagia, p = 0.04). This study provided evidence that accelerometer-based PA may be causally associated with a lower risk of GSs, while SB may increase the risk of GSs.