Impact of Fatigue on Ergonomic Risk Scores and Foot Kinetics: A Field Study Employing Inertial and In-Shoe Plantar Pressure Measurement Devices.

(1) Background: Occupational fatigue is a primary factor leading to work-related musculoskeletal disorders (WRMSDs). Kinematic and kinetic experimental studies have been able to identify indicators of WRMSD, but research addressing real-world workplace scenarios is lacking. Hence, the authors of this study aimed to assess the influence of physical strain on the Borg CR-10 body map, ergonomic risk scores, and foot pressure in a real-world setting. (2) Methods: Twenty-four participants (seventeen men and seven women) were included in this field study. Inertial measurement units (IMUs) (n = 24) and in-shoe plantar pressure measurements (n = 18) captured the workload of production and office workers at the beginning of their work shift and three hours later, working without any break. In addition to the two 12 min motion capture processes, a Borg CR-10 body map and fatigue visual analog scale (VAS) were applied twice. Kinematic and kinetic data were processed using MATLAB and SPSS software, resulting in scores representing the relative distribution of the Rapid Upper Limb Assessment (RULA) and Computer-Assisted Recording and Long-Term Analysis of Musculoskeletal Load (CUELA), and in-shoe plantar pressure. (3) Results: Significant differences were observed between the two measurement times of physical exertion and fatigue, but not for ergonomic risk scores. Contrary to the hypothesis of the authors, there were no significant differences between the in-shoe plantar pressures. Significant differences were observed between the dominant and non-dominant sides for all kinetic variables. (4) Conclusions: The posture scores of RULA and CUELA and in-shoe plantar pressure side differences were a valuable basis for adapting one-sided requirements in the work process of the workers. Traditional observational methods must be adapted more sensitively to detect kinematic deviations at work. The results of this field study enhance our knowledge about the use and benefits of sensors for ergonomic risk assessments and interventions.

[4D electromagnetic navigation bronchoscopy for the diagnosis of peripheral pulmonary nodules - An overview and preliminary clinical results]. / 4D-Elektromagnetische Navigationsbronchoskopie zur Diagnostik peripherer Rundherde.

BACKGROUND: The diagnostic of peripheral pulmonary nodules (PPN) is a particular challenge in interventional bronchology, which is why navigation systems such as electromagnetic navigation (ENB) are increasingly being used. The 4D-ENB represents the most current development of the ENB. It utilizes inspiratory and expiratory CT scans for mapping and thus helps compensate for respiratory movements-induced CT-to-body divergence. The aim of this work was to present the first clinical data and experiences using the 4D-ENB method for diagnosis of PPNs. METHODS: We retrospectively describe the results of the first nine consecutive patient cases diagnosed at Klinikum Braunschweig using 4D-ENB in a unimodal diagnostic procedure. RESULTS: Of the first 9 PPNs examined by 4D-ENB, navigation and puncture of the lesion was successful in 8 patients (89%). Diagnostic biopsy was could be carried out in six out of nine patients (67%). There were no significant procedure-related complications. CONCLUSION: Our preliminary data suggest that 4D-ENB is a promising new alternative for the diagnosis of PPNs. To further improve diagnostic yield, 4D-END, which lacks real-time visualization, should be embedded in a multimodal diagnostic procedure with rEBUS and/or fluoroscopy.

Correlation between the sacral tilt measured with an inclinometer and the pelvic tilt as a tool for assessing the pelvic position.

[Purpose] The aim of this study was to examine whether the forward tilt of the sacrum, which can be measured using an inclinometer, correlates with pelvic tilt and is therefore suitable for therapeutic use as part of a postural assessment for treatment planning or for preventive screening. [Participants and Methods] In 121 athletes (22 females, 99 males), we measured the forward tilt of the sacrum in habitual stance using a digital inclinometer attached to the skin at the level of the posterior superior spinae. At the same time, the forward tilt of the pelvis was determined using videography. For this purpose, we determined the angle between two marker spheres placed on the posterior and anterior superior spinae and the horizontal using sagittal posture photographs. [Results] Taking age as a control variable, we found a significant correlation of moderate strength between pelvic tilt and sacral tilt in men. In women, there was a significant correlation with a strong effect. [Conclusion] The measurement of sacral tilt using an inclinometer positioned on the skin between the posterior superior spinae correlates statistically significantly with pelvic tilt and is therefore suitable as an easy-to-use diagnostic tool for therapeutic use in treatment planning and evaluation.

Asterid Phylogenomics/Phylotranscriptomics Uncover Morphological Evolutionary Histories and Support Phylogenetic Placement for Numerous Whole-Genome Duplications.

Asterids are one of the most successful angiosperm lineages, exhibiting extensive morphological diversity and including a number of important crops. Despite their biological prominence and value to humans, the deep asterid phylogeny has not been fully resolved, and the evolutionary landscape underlying their radiation remains unknown. To resolve the asterid phylogeny, we sequenced 213 transcriptomes/genomes and combined them with other data sets, representing all accepted orders and nearly all families of asterids. We show fully supported monophyly of asterids, Berberidopsidales as sister to asterids, monophyly of all orders except Icacinales, Aquifoliales, and Bruniales, and monophyly of all families except Icacinaceae and Ehretiaceae. Novel taxon placements benefited from the expanded sampling with living collections from botanical gardens, resolving hitherto uncertain relationships. The remaining ambiguous placements here are likely due to limited sampling and could be addressed in the future with relevant additional taxa. Using our well-resolved phylogeny as reference, divergence time estimates support an Aptian (Early Cretaceous) origin of asterids and the origin of all orders before the Cretaceous-Paleogene boundary. Ancestral state reconstruction at the family level suggests that the asterid ancestor was a woody terrestrial plant with simple leaves, bisexual, and actinomorphic flowers with free petals and free anthers, a superior ovary with a style, and drupaceous fruits. Whole-genome duplication (WGD) analyses provide strong evidence for 33 WGDs in asterids and one in Berberidopsidales, including four suprafamilial and seven familial/subfamilial WGDs. Our results advance the understanding of asterid phylogeny and provide numerous novel evolutionary insights into their diversification and morphological evolution.

Classification and Automated Interpretation of Spinal Posture Data Using a Pathology-Independent Classifier and Explainable Artificial Intelligence (XAI).

Clinical classification models are mostly pathology-dependent and, thus, are only able to detect pathologies they have been trained for. Research is needed regarding pathology-independent classifiers and their interpretation. Hence, our aim is to develop a pathology-independent classifier that provides prediction probabilities and explanations of the classification decisions. Spinal posture data of healthy subjects and various pathologies (back pain, spinal fusion, osteoarthritis), as well as synthetic data, were used for modeling. A one-class support vector machine was used as a pathology-independent classifier. The outputs were transformed into a probability distribution according to Platt's method. Interpretation was performed using the explainable artificial intelligence tool Local Interpretable Model-Agnostic Explanations. The results were compared with those obtained by commonly used binary classification approaches. The best classification results were obtained for subjects with a spinal fusion. Subjects with back pain were especially challenging to distinguish from the healthy reference group. The proposed method proved useful for the interpretation of the predictions. No clear inferiority of the proposed approach compared to commonly used binary classifiers was demonstrated. The application of dynamic spinal data seems important for future works. The proposed approach could be useful to provide an objective orientation and to individually adapt and monitor therapy measures pre- and post-operatively.

Interpretability of Input Representations for Gait Classification in Patients after Total Hip Arthroplasty.

Many machine learning models show black box characteristics and, therefore, a lack of transparency, interpretability, and trustworthiness. This strongly limits their practical application in clinical contexts. For overcoming these limitations, Explainable Artificial Intelligence (XAI) has shown promising results. The current study examined the influence of different input representations on a trained model's accuracy, interpretability, as well as clinical relevancy using XAI methods. The gait of 27 healthy subjects and 20 subjects after total hip arthroplasty (THA) was recorded with an inertial measurement unit (IMU)-based system. Three different input representations were used for classification. Local Interpretable Model-Agnostic Explanations (LIME) was used for model interpretation. The best accuracy was achieved with automatically extracted features (mean accuracy Macc = 100%), followed by features based on simple descriptive statistics (Macc = 97.38%) and waveform data (Macc = 95.88%). Globally seen, sagittal movement of the hip, knee, and pelvis as well as transversal movement of the ankle were especially important for this specific classification task. The current work shows that the type of input representation crucially determines interpretability as well as clinical relevance. A combined approach using different forms of representations seems advantageous. The results might assist physicians and therapists finding and addressing individual pathologic gait patterns.

Can A Superimposed Whole-Body Electromyostimulation Intervention Enhance the Effects of a 10-Week Athletic Strength Training in Youth Elite Soccer Players?

Strength training in youth soccer has both a preventive and a sports-specific component. Whole-body electromyostimulation (WB-EMS) could represent an interesting time-saving add-on to classical strength exercises in performance-oriented soccer. The objective of this study was to find out whether a 10-week superimposed WB-EMS training might have a more positive impact on strength parameters in male youth elite soccer players than regular athletic strength exercises alone. A total of 30 male youth soccer players from a youth academy aged 15 to 17 years participated in the study. Before and after the intervention, the isometric extension and flexion forces of trunk and knee, and the hip abduction and adduction forces were tested. Twelve players (control group) absolved a conventional 20-minute strength training once a week for a period of ten weeks. Eighteen players absolved the same exercises but with superimposed WB-EMS. Blood creatine kinase concentration was measured for training control. ANOVAs, Friedman tests and post hoc t-tests were calculated (p = 0.05) to examine the strength development during the training period between the groups. While we could not find significant strength increases in the leg, hip and trunk muscles in the control group (<4%), the strength of the WB-EMS group improved significantly in 4 of the 6 muscle groups tested. In this group, the strength of knee flexors increased significantly by 20.68 ± 21.55%, knee extensors by 31.43 ± 37.02%, hip adductors by 21.70 ± 12.86% and trunk flexors by 33.72 ± 27.43%. The rates of strength increase are partly in line with other studies, partly clearly higher, which might be explained by the athletically active target group. A 10-week superimposed WB-EMS training improves the strength of certain leg, hip and trunk muscles in male adolescent elite soccer players to a greater extent than a pure athletic strength training of the same duration.

Effects of an Impulse Frequency Dependent 10-Week Whole-body Electromyostimulation Training Program on Specific Sport Performance Parameters.

The difference in the efficacy of altered stimulation parameters in whole-body-electromyostimulation (WB-EMS) training remains largely unexplored. However, higher impulse frequencies (>50 Hz) might be most adequate for strength gain. The aim of this study was to analyze potential differences in sports-related performance parameters after a 10-week WB-EMS training with different frequencies. A total of 51 untrained participants (24.9 ± 3.9 years, 174 ± 9 cm, 72.4 ± 16.4 kg, BMI 23.8 ± 4.1, body fat 24.7 ± 8.1 %) was randomly divided into three groups: one inactive control group (CON) and two training groups. They completed a 10-week WB-EMS program of 1.5 sessions/week, equal content but different stimulation frequencies (training with 20 Hz (T20) vs. training with 85 Hz (T85)). Before and after intervention, all participants completed jumping (Counter Movement Jump (CMJ), Squat Jump (SJ), Drop Jump (DJ)), sprinting (5m, 10m, 30m), and strength tests (isometric trunk flexion/extension). One-way ANOVA was applied to calculate parameter changes. Post-hoc least significant difference tests were performed to identify group differences. Significant differences were identified for CMJ (p = 0.007), SJ (p = 0.022), trunk flexion (p = 0.020) and extension (p=.013) with significant group differences between both training groups and CON (not between the two training groups T20 and T85). A 10-week WB-EMS training leads to significant improvements of jump and strength parameters in untrained participants. No differences could be detected between the frequencies. Therefore, both stimulation frequencies can be regarded as adequate for increasing specific sport performance parameters. Further aspects as regeneration or long term effects by the use of different frequencies still need to be clarified.

Whole-body electromyostimulation in physical therapy: do gender, skinfold thickness or body composition influence maximum intensity tolerance?

[Purpose] Whole-body electromyostimulation (WB-EMS) is an extension of the EMS application known in physical therapy. In WB-EMS, body composition and skinfold thickness seem to play a decisive role in influencing the Ohmic resistance and therefore the maximum intensity tolerance. That is why the therapeutic success of (WB-)EMS may depend on individual anatomical parameters. The aim of the study was to find out whether gender, skinfold thickness and parameters of body composition have an influence on the maximum intensity tolerance in WB-EMS. [Participants and Methods] Fifty-two participants were included in the study. Body composition (body impedance, body fat, fat mass, fat-free mass) and skinfold thicknesses were measured and set into relation to the maximum intensity tolerance. [Results] No relationship between the different anthropometric parameters and the maximum intensity tolerance was detected for both genders. Considering the individual muscle groups, no similarities were found in the results. [Conclusion] Body composition or skinfold thickness do not seem to have any influence on the maximum intensity tolerance in WB-EMS training. For the application in physiotherapy this means that a dosage of the electrical voltage within the scope of a (WB-) EMS application is only possible via the subjective feedback (BORG Scale).

Towards an Inertial Sensor-Based Wearable Feedback System for Patients after Total Hip Arthroplasty: Validity and Applicability for Gait Classification with Gait Kinematics-Based Features.

Patients after total hip arthroplasty (THA) suffer from lingering musculoskeletal restrictions. Three-dimensional (3D) gait analysis in combination with machine-learning approaches is used to detect these impairments. In this work, features from the 3D gait kinematics, spatio temporal parameters (Set 1) and joint angles (Set 2), of an inertial sensor (IMU) system are proposed as an input for a support vector machine (SVM) model, to differentiate impaired and non-impaired gait. The features were divided into two subsets. The IMU-based features were validated against an optical motion capture (OMC) system by means of 20 patients after THA and a healthy control group of 24 subjects. Then the SVM model was trained on both subsets. The validation of the IMU system-based kinematic features revealed root mean squared errors in the joint kinematics from 0.24° to 1.25°. The validity of the spatio-temporal gait parameters (STP) revealed a similarly high accuracy. The SVM models based on IMU data showed an accuracy of 87.2% (Set 1) and 97.0% (Set 2). The current work presents valid IMU-based features, employed in an SVM model for the classification of the gait of patients after THA and a healthy control. The study reveals that the features of Set 2 are more significant concerning the classification problem. The present IMU system proves its potential to provide accurate features for the incorporation in a mobile gait-feedback system for patients after THA.

Effects of a 6-Week Strength Training of the Neck Flexors and Extensors on the Head Acceleration during Headers in Soccer.

The importance of well trained and stable neck flexors and extensors as well as trunk muscles for intentional headers in soccer is increasingly discussed. The neck flexors and extensors should ensure a coupling of trunk and head at the time of ball contact to increase the physical mass hitting the ball and reduce head acceleration. The aim of the study was to analyze the influence of a 6-week strength training program (neck flexors, neck extensors) on the acceleration of the head during standing, jumping and running headers as well as after fatigue of the trunk muscles on a pendulum header. A total of 33 active male soccer players (20.3 ± 3.6 years, 1.81 ± 0.07 m, 75.5 ± 8.3 kg) participated and formed two training intervention groups (IG1: independent adult team, IG2: independent youth team) and one control group (CG: players from different teams). The training intervention consisted of three exercises for the neck flexors and extensors. The training effects were verified by means of the isometric maximum voluntary contraction (IMVC) measured by a telemetric Noraxon DTS force sensor. The head acceleration during ball contact was determined using a telemetric Noraxon DTS 3D accelerometer. There was no significant change of the IMVC over time between the groups (F=2.265, p=.121). Head acceleration was not reduced significantly for standing (IG1 0.4 ± 2.0, IG2 0.1 ± 1.4, CG -0.4 ± 1.2; F = 0.796, p = 0.460), jumping (IG1-0.7 ± 1.4, IG2-0.2 ± 0.9, CG 0.1 ± 1.2; F = 1.272, p = 0.295) and running (IG1-1.0 ± 1.9, IG2-0.2 ± 1.4, CG -0.1 ± 1.6; F = 1.050, p = 0.362) headers as well as after fatigue of the trunk musculature for post-jumping (IG1-0.2 ± 2.1, IG2-0.6 ± 1.4; CG -0.6 ± 1.3; F = 0.184, p = 0.833) and post-running (IG1-0.3 ± 1.6, IG2-0.7 ± 1.2, CG 0.0 ± 1.4; F = 0.695, p = 0.507) headers over time between IG1, IG2 and CG. A 6-week strength training of the neck flexors and neck extensors could not show the presumed preventive benefit. Both the effects of a training intervention and the consequences of an effective intervention for the acceleration of the head while heading seem to be more complex than previously assumed and presumably only come into effect in case of strong impacts.

Validity, Test-Retest Reliability and Long-Term Stability of Magnetometer Free Inertial Sensor Based 3D Joint Kinematics.

The present study investigates an algorithm for the calculation of 3D joint angles based on inertial measurement units (IMUs), omitting magnetometer data. Validity, test-retest reliability, and long-term stability are evaluated in reference to an optical motion capture (OMC) system. Twenty-eight healthy subjects performed a 6 min walk test. Three-dimensional joint kinematics of the lower extremity was recorded simultaneously by means of seven IMUs and an OptiTrack OMC system. To evaluate the performance, the root mean squared error (RMSE), mean range of motion error (ROME), coefficient of multiple correlations (CMC), Bland-Altman (BA) analysis, and intraclass correlation coefficient (ICC) were calculated. For all joints, the RMSE was lower than 2.40°, and the ROME was lower than 1.60°. The CMC revealed good to excellent waveform similarity. Reliability was moderate to excellent with ICC values of 0.52⁻0.99 for all joints. Error measures did not increase over time. When considering soft tissue artefacts, RMSE and ROME increased by an average of 2.2° ± 1.5° and 2.9° ± 1.7°. This study revealed an excellent correspondence of a magnetometer-free IMU system with an OMC system when excluding soft tissue artefacts.

Towards Inertial Sensor Based Mobile Gait Analysis: Event-Detection and Spatio-Temporal Parameters.

The aim of this study was to assess the validity and test-retest reliability of an inertial measurement unit (IMU) system for gait analysis. Twenty-four healthy subjects conducted a 6-min walking test and were instrumented with seven IMUs and retroreflective markers. A kinematic approach was used to estimate the initial and terminal contact events in real-time. Based on these events twelve spatio-temporal parameters (STP) were calculated. A marker based optical motion capture (OMC) system provided the reference. Event-detection rate was about 99%. Detection offset was below 0.017 s. Relative root mean square error (RMSE) ranged from 0.90% to 4.40% for most parameters. However, the parameters that require spatial information of both feet showed higher errors. Step length showed a relative RMSE of 6.69%. Step width and swing width revealed the highest relative RMSE (34.34% and 35.20%). Test-retest results ranged from 0.67 to 0.92, except for the step width (0.25). Summarizing, it appears that the parameters describing the lateral distance between the feet need further improvement. However, the results of the validity and reliability of the IMU system encourage its validation in clinical settings as well as further research.

A link between LEAFY and B-gene homologues in Welwitschia mirabilis sheds light on ancestral mechanisms prefiguring floral development.

Flowering plants evolved from an unidentified gymnosperm ancestor. Comparison of the mechanisms controlling development in angiosperm flowers and gymnosperm cones may help to elucidate the mysterious origin of the flower. We combined gene expression studies with protein behaviour characterization in Welwitschia mirabilis to test whether the known regulatory links between LEAFY and its MADS-box gene targets, central to flower development, might also contribute to gymnosperm reproductive development. We found that WelLFY, one of two LEAFY-like genes in Welwitschia, could be an upstream regulator of the MADS-box genes APETALA3/PISTILLATA-like (B-genes). We demonstrated that, even though their DNA-binding domains are extremely similar, WelLFY and its paralogue WelNDLY exhibit distinct DNA-binding specificities, and that, unlike WelNDLY, WelLFY shares with its angiosperm orthologue the capacity to bind promoters of Welwitschia B-genes. Finally, we identified several cis-elements mediating these interactions in Welwitschia and obtained evidence that the link between LFY homologues and B-genes is also conserved in two other gymnosperms, Pinus and Picea. Although functional approaches to investigate cone development in gymnosperms are limited, our state-of-the-art biophysical techniques, coupled with expression studies, provide evidence that crucial links, central to the control of floral development, may already have existed before the appearance of flowers.

Characterization of Apoptosis Signaling Cascades During the Differentiation Process of Human Neural ReNcell VM Progenitor Cells In Vitro.

Apoptosis is an essential physiological process accompanying the development of the central nervous system and human neurogenesis. However, the time scale and the underlying molecular mechanisms are yet poorly understood. Due to this fact, we investigated the functionality and general inducibility of apoptosis in the human neural ReNcell VM progenitor cell line during differentiation and also after exposure to staurosporine (STS) and ultraviolet B (UVB) irradiation. Transmission light microscopy, flow cytometry, and Western-/Immunoblot analysis were performed to compare proliferating and differentiating, in addition to STS- and UVB-treated cells. In particular, from 24 to 72 h post-initiation of differentiation, G0/G1 cell cycle arrest, increased loss of apoptotic cells, activation of pro-apoptotic BAX, Caspase-3, and cleavage of its substrate PARP were observed during cell differentiation and, to a higher extent, after treatment with STS and UVB. We conclude that redundant or defective cells are eliminated by apoptosis, while otherwise fully differentiated cells were less responsive to apoptosis induction by STS than proliferating cells, likely as a result of reduced APAF-1 expression, and increased levels of BCL-2. These data provide the evidence that apoptotic mechanisms in the neural ReNcell VM progenitor cell line are not only functional, but also inducible by external stimuli like growth factor withdrawal or treatment with STS and UVB, which marks this cell line as a suitable model to investigate apoptosis signaling pathways in respect to the differentiation processes of human neural progenitor cells in vitro.

Strength training adaptations after cold-water immersion.

Several studies analyzed the effectiveness of cold-water immersion (CWI) to support recovery after strenuous exercise, but the overall results seem to be conflicting. Most of these studies analyzed only short-term recovery effects, whereas the adaptational aspect has been widely neglected. Therefore, we analyzed the effects of repeated cooling after training sessions (CWI) on adaptations to strength training. Seventeen trained male students volunteered the study. After a 2-week familiarization period, a pretest (T1) of 1 repetition maximum (RM) and 12RM was conducted followed by the 5-week strength training period (within-subject design). After the posttest (T2) and a 2-week detraining period, a retention test (T3) was carried out. Directly after each training session, CWI was applied for 1 randomly assigned leg. Cooling consisted of 3 4-minute intervals with a 30-second rest period. The other leg was not cooled. A significant increase in 1RM and 12RM from baseline to T2 and T3 (p < 0.001), respectively, and a further significant increase in 12RM from T2 to T3 (p ≤ 0.05) were observed. In addition, a tendency for a large leg effect with higher values for the "control leg" in both parameters (p = 0.08 each) and a moderate time × leg interaction in favor of the control leg was found (1RM: p = 0.11; 12RM: p = 0.09). The percentage change differences between both conditions were 1.6% for the increase in 1RM from T1 to T2 and 2.0% from T1 to T3 in favor of the control leg. Long-term strength training adaptations in trained subjects can be negatively affected by CWI. However, effects were small, and the practical relevance relative to possible recovery effects needs to be considered in a sports practical setting.

Muscular Strategies for Correcting the Pelvic Position to Improve Posture-An Exploratory Study.

The correction of postural weaknesses through the better positioning of the pelvis is an important approach in sports therapy and physiotherapy. The pelvic position in the sagittal plane is largely dependent on the muscular balance of the ventral and dorsal muscle groups. The aim of this exploratory study was to examine whether healthy persons use similar muscular activation patterns to correct their pelvic position or whether there are different motor strategies. The following muscles were recorded in 41 persons using surface electromyography (EMG): M. trapezius pars ascendens, M. erector spinae pars lumbalis, M. gluteus maximus, M. biceps femoris, M. rectus abdominis, and M. obliquus externus. The participants performed 10 voluntary pelvic movements (retroversion of the pelvis). The anterior pelvic tilt was measured videographically via marker points on the anterior and posterior superior iliac spine. The EMG data were further processed and normalized to the maximum voluntary contraction. A linear regression analysis was conducted to assess the relationship between changes in the pelvic tilt and muscle activities. Subsequently, a Ward clustering analysis was applied to detect potential muscle activation patterns. The differences between the clusters and the pelvic tilt were examined using ANOVA. Cluster analysis revealed the presence of four clusters with different muscle activation patterns in which the abdominal muscles and dorsal muscle groups were differently involved. However, the gluteus maximus muscle was involved in every activation pattern. It also had the strongest correlation with the changes in pelvic tilt. Different individual muscle patterns are used by different persons to correct pelvic posture, with the gluteus maximus muscle apparently playing the most important role. This can be important for therapy, as different muscle strategies should be trained depending on the individually preferred motor patterns.

Enhancing biomechanical machine learning with limited data: generating realistic synthetic posture data using generative artificial intelligence.

Objective: Biomechanical Machine Learning (ML) models, particularly deep-learning models, demonstrate the best performance when trained using extensive datasets. However, biomechanical data are frequently limited due to diverse challenges. Effective methods for augmenting data in developing ML models, specifically in the human posture domain, are scarce. Therefore, this study explored the feasibility of leveraging generative artificial intelligence (AI) to produce realistic synthetic posture data by utilizing three-dimensional posture data. Methods: Data were collected from 338 subjects through surface topography. A Variational Autoencoder (VAE) architecture was employed to generate and evaluate synthetic posture data, examining its distinguishability from real data by domain experts, ML classifiers, and Statistical Parametric Mapping (SPM). The benefits of incorporating augmented posture data into the learning process were exemplified by a deep autoencoder (AE) for automated feature representation. Results: Our findings highlight the challenge of differentiating synthetic data from real data for both experts and ML classifiers, underscoring the quality of synthetic data. This observation was also confirmed by SPM. By integrating synthetic data into AE training, the reconstruction error can be reduced compared to using only real data samples. Moreover, this study demonstrates the potential for reduced latent dimensions, while maintaining a reconstruction accuracy comparable to AEs trained exclusively on real data samples. Conclusion: This study emphasizes the prospects of harnessing generative AI to enhance ML tasks in the biomechanics domain.

'Living stones' reveal alternative petal identity programs within the core eudicots.

Petals, defined as the showy laminar floral organs in the second floral whorl, have been shown to be under similar genetic control in distantly related core eudicot model organisms. On the basis of these findings, it is commonly assumed that the petal identity program regulated by B-class MADS-box gene homologs is invariant across the core eudicot clade. However, the core eudicots, which comprise >70% of angiosperm species, exhibit numerous instances of petal and sepal loss, transference of petal function between floral whorls, and recurrent petal evolution. In the face of these complex patterns of perianth evolution, the concept of a core eudicot petal identity program has not been tested. We therefore examined the petal identity program in the Caryophyllales, a core eudicot clade in which perianth differentiation into sepals and petals has evolved multiple times. Specifically, we analyzed the expression patterns of B- and C-class MADS-box homologs for evidence of a conserved petal identity program between sepal-derived and stamen-derived petaloid organs in the 'living stone' family Aizoaceae. We found that neither sepal-derived nor stamen-derived petaloid organs exhibit gene expression patterns consistent with the core eudicot petal identity program. B-class gene homologs are not expressed during the development of sepal-derived petals and are not implicated in petal identity in stamen-derived petals, as their transient expression coincides with early expression of the C-class homolog. We therefore provide evidence for petal development that is independent of B-class genes and suggest that different genetic control of petal identity has evolved within this lineage of core eudicots. These findings call for a more comprehensive understanding of perianth variation and its genetic causes within the core eudicots--an endeavor that will have broader implications for the interpretation of perianth evolution across angiosperms.

After a dozen years of progress the origin of angiosperms is still a great mystery.

Here we discuss recent advances surrounding the origin of angiosperms. Putatively primitive characters are now much better understood because of a vastly improved understanding of angiosperm phylogenetics, and recent discoveries of fossil flowers have provided an increasingly detailed picture of early diversity in the angiosperms. The 'anthophyte theory', the dominant concept of the 1980s and 1990s, has been eclipsed; Gnetales, previously thought to be closest to the angiosperms, are related instead to other extant gymnosperms, probably most closely to conifers. Finally, new theories of flower origins have been proposed based on gene function, duplication and loss, as well as on morphology. Further studies of genetic mechanisms that control reproductive development in seed plants provide a most promising avenue for further research, including tests of these recent theories. Identification of fossils with morphologies that convincingly place them close to angiosperms could still revolutionize understanding of angiosperm origins.