Capture Data Research Articles

Lower limb joint loading during high-impact activities: implication for bone health.

Osteoporosis results in low-trauma fractures affecting millions globally, in particular elderly populations. Despite the inclusion of physical activity in fracture prevention strategies, the optimal bone-strengthening exercises remain uncertain, highlighting the need for a deeper understanding of lower limb joint loading dynamics across various exercise types and levels. This study examines lower limb joint loading during high-impact exercises across different intensities. A total of 40 healthy, active participants were recruited (mean ± SD: age of 40.3 ± 13.1yr; height 1.71 ± 0.08m; and mass 68.44 ± 11.67kg). Motion capture data and ground reaction forces of 6 different exercises: a self-selected level of walking, running, countermovement jump, squat jump, unilateral hopping, and bilateral hopping were collected for each participant. Joint reaction forces were estimated using lower body musculoskeletal models developed in OpenSim. Running and hopping increased joint forces compared to walking, notably at the hip (83% and 21%), knee (134% and 94%), and ankle (94% and 77%), while jump exercises reduced hip and ankle loading compared to walking (36% and 19%). Joint loading varied with exercise type and intensity, with running faster increasing forces on all joints, particularly at the hip. Sprinting increased forces at the hip but lowered knee and ankle forces. Higher jumps intensified forces on all joints, while faster hopping reduced forces. The wide variation of lower limb joint loading observed across the exercises tested in this study underscores the importance of implementing diverse exercise routines to optimize overall bone health and strengthen the musculoskeletal structure. Practitioners must therefore ensure that exercise programs include movements that are specifically suitable for their intended purpose.

DNA Replication and Polymer Chain Duplication Reshape the Genome in Space and Time

In eukaryotes, DNA replication constitutes a complex process whereby multiple origins are stochastically fired, and from which the replication machinery proceeds along chromosomes to achieve the faithful synthesis of two identical copies of the genome during the S phase of the cell cycle. Experimental evidence shows a functional correlation between the dynamics of replication and the spatial organization of the genome inside cell nuclei, suggesting that the process of replicating DNA may impact chromosome folding. However, the theoretical and mechanistic bases of such a hypothesis remain elusive. To address that question, we propose a quantitative, minimal framework that integrates the dynamics of replication along a polymer chain by accounting explicitly for the progression of the replication machinery and the resulting formation of sister chromatids. By systematically characterizing the 3D structural consequences of replication, and of possible interactions between active replication machineries, we show that the formation of transient loops may potentially impact chromosome organization across multiple temporal and spatial scales, from the level of individual origins to that of the global polymer chain. Comparison with available microscopy and chromosome conformation capture data in yeast suggests that a replication-dependent loop extrusion process may be acting , and may shape chromosomes as loose polymer bottle brushes during the S phase. Lastly, we explore the postreplication relative organization of sister chromatids and demonstrate the emergence of catenations and intertwined structures, which are regulated by the density of fired origins. Published by the American Physical Society 2024

PneumoBrowse 2: an integrated visual platform for curated genome annotation and multiomics data analysis of Streptococcus pneumoniae.

Streptococcus pneumoniae is an opportunistic human pathogen responsible for high morbidity and mortality rates. Extensive genome sequencing revealed its large pangenome, serotype diversity, and provided insight into genome dynamics. However, functional genome analysis has lagged behind, as that requires detailed and time-consuming manual curation of genome annotations and integration of genomic and phenotypic data. To remedy this, PneumoBrowse was presented in 2018, a user-friendly interactive online platform, which provided the detailed annotation of the S. pneumoniae D39V genome, alongside transcriptomic data. Since 2018, many new studies on S. pneumoniae genome biology and protein functioning have been performed. Here, we present PneumoBrowse 2 (https://veeninglab.com/pneumobrowse), fully rebuilt in JBrowse 2. We updated annotations for transcribed and transcriptional regulatory features in the D39V genome. We added genome-wide data tracks for high-resolution chromosome conformation capture (Hi-C) data, chromatin immunoprecipitation coupled to high-throughput sequencing (ChIP-Seq), ribosome profiling, CRISPRi-seq gene essentiality data and more. Additionally, we included 18 phylogenetically diverse S. pneumoniae genomes and their annotations. By providing easy access to diverse high-quality genome annotations and links to other databases (including UniProt and AlphaFold), PneumoBrowse 2 will further accelerate research and development into preventive and treatment strategies, through increased understanding of the pneumococcal genome.

Learning to Play Guitar with Robotic Hands

AbstractPlaying the guitar is a dexterous human skill that poses significant challenges in computer graphics and robotics due to the precision required in finger positioning and coordination between hands. Current methods often rely on motion capture data to replicate specific guitar playing segments, which restricts the range of performances and demands intricate post‐processing. In this paper, we introduce a novel reinforcement learning model that can play the guitar using robotic hands, without the need for motion capture datasets, from input tablatures. To achieve this, we divide the simulation task for playing guitar into three stages. (a): for an input tablature, we first generate corresponding fingerings that align with human habits. (b): based on the generated fingerings as the guidance, we train a neural network for controlling the fingers of the left hand using deep reinforcement learning, and (c): we generate plucking movements for the right hand based on inverse kinematics according to the tablature. We evaluate our method by employing precision, recall, and F1 scores as quantitative metrics to thoroughly assess its performance in playing musical notes. In addition, we conduct qualitative analysis through user studies to evaluate the visual and auditory effects of guitar performance. The results demonstrate that our model excels in playing most moderately difficult and easier musical pieces, accurately playing nearly all notes.

Viscoelasticity estimation of sports prosthesis by energy-minimizing inverse kinematics and its validation by forward dynamics

In this study, we present a method for estimating the viscoelasticity of a leaf-spring sports prosthesis using advanced energy minimizing inverse kinematics based on the Piece-wise Constant Strain (PCS) model to reconstruct the three-dimensional dynamic behavior. Dynamic motion analysis of the athlete and prosthesis is important to clarify the effect of prosthesis characteristics on foot function. However, three-dimensional deformation calculations of the prosthesis and viscoelasticity have rarely been investigated. In this letter, we apply the PCS model to a prosthesis deformation, which can calculate flexible deformation with low computational cost and handle kinematics and dynamics. In addition, we propose an inverse kinematics calculation method that is consistent with the material properties of the prosthesis by considering the minimization of elastic energy. Furthermore, we propose a method to estimate the viscoelasticity by solving a quadratic programming based on the measured motion capture data. The calculated strains are more reasonable than the results obtained by conventional inverse kinematics calculation. From the result of the viscoelasticity estimation, we simulate the prosthetic motion by forward dynamics calculation and confirm that this result corresponds to the measured motion. These results indicate that our approach adequately models the dynamic phenomena, including the viscoelasticity of the prosthesis.

CP decomposition-based algorithms for completion problem of motion capture data

Motion capture (MoCap) technology is an essential tool for recording and analyzing movements of objects or humans. However, MoCap systems frequently encounter the challenge of missing data, stemming from mismatched markers, occlusion, or equipment limitations. Recovery of these missing data is imperative to maintain the reliability and integrity of MoCap recordings. This paper introduces a novel application of the tensor framework for MoCap data completion. We propose three completion algorithms based on the canonical polyadic (CP) decomposition of tensors. The first algorithm utilizes CP decomposition to capture the low-rank structure of the tensor. However, relying only on low-rank assumptions may be insufficient to deal with complex motion data. Thus, we propose two modified CP decompositions that incorporate additional information, SmoothCP and SparseCP decompositions. SmoothCP integrates piecewise smoothness prior, while SparseCP incorporates sparsity prior, each aiming to improve the accuracy and robustness of MoCap data recovery. To compare and evaluate the merit of the proposed algorithms over other tensor completion methods in terms of several evaluation metrics, we conduct numerical experiments with different MoCap sequences from the CMU motion capture dataset.

Chromosome-level genome assembly of American sweetgum (Liquidambar styraciflua, Altingiaceae)

The deciduous American sweetgum (Liquidambar styraciflua, Altingiaceae) is a popular ornamental and economically valuable tree renowned for its sweet-smelling bark resin, abundant volatile substances, and spectacular fall leaf color. However, the absence of a reference genome hinders thorough investigations into the mechanisms underlying phenotypic variation, secondary metabolite synthesis and adaptation, both in this species and other Liquidambar members. In this study, we sequenced and constructed a chromosome-level assembly of the L. styraciflua genome, covering 662.48 Mb with a scaffold N50 of 39.54 Mb, by integrating PacBio, Illumina and chromosome conformation capture data. We identified 58.83% of the genome sequences as repetitive elements and 25,713 protein-coding genes, 97.28% of which were functionally annotated. The genome sequencing reads, assembly and annotation data have been deposited in publicly available repositories. This high-quality genome assembly provides valuable resources for further evolutionary and functional genomic studies in American sweetgum and other Liquidambar species.

Model-based tool wear detection and fault diagnosis for end mill in various cutting conditions

In recent developments in the field of manufacturing systems, there has been a growing emphasis on optimizing cutting conditions. These optimizations are primarily based on intricate parameters, such as the material removal rate (MRR), surface roughness, and position accuracy. Simultaneously, there’s an increasing focus on enhancing manufacturing efficiency through equipment maintenance strategies that consider parameters, such as corrosion, pressure, temperature, vibration, and other environmental factors. Wear is inevitable during processing, which affects productivity. It is generated in various forms, such as flank, crater, and edge wear, which reduce the tool lifespan and impact machining quality, especially by increasing the cutting forces. Various studies have been conducted to address this issue. Direct measurements using microscopes have high accuracy but require interruption during the process, which adversely affects efficiency and productivity. As a solution, the modern era has witnessed an increase in indirect methods. These methods are often sensor-based, capture data during the machining process, and employ various models, including emerging artificial intelligence techniques, for predicting tool wear. However, these methods have problems with environmental susceptibility, reduced reliability, limitations of application, and excessive costs. This paper suggests a tool wear integrated cutting load prediction model, tool wear detection, and fault diagnosis mechanism. The tool-wear-integrated cutting-load prediction model was constructed by combining the cutting-load prediction and tool-wear models. The coefficients of the model were derived from the actual cutting data extracted by the spindle load. Tool wear detection was implemented by dividing regions based on the tendency of the coefficient of the constructed tool wear integrated cutting load prediction model and the errors between the predicted and actual values. The proposed model demonstrated a performance comparable to that of the existing models in a single-cutting-condition path. However, it excelled in extracting the tool wear coefficients in paths with a mixture of various cutting conditions, which was not achievable with conventional models. Based on these coefficients, the cutting force was predicted with a maximum error of 3.3 %. Also, an accurate determination of the tool-wear regions was possible. Furthermore, the performance of the tool fault diagnosis method was validated using images of tools identified as being at risk of damage.

Effect of Exercise Intensity on Biathlon Standing Shooting Performance and Rifle Movement during Outdoor Roller Skiing.

To investigate the effect of exercise intensity on standing shooting performance and related technical variables in elite biathletes performing roller skiing and live shooting outdoors. Nineteen male biathletes performed two 5-shot series in the following order of exercise intensity: rest, low (%heart rate max 73 ± 4; blood lactate 1.5 ± 0.3 mmol·L-1), moderate (84 ± 3; 2.4 ± 0.6), 'race-pace' (90 ± 2; 4.5 ± 0.8), and 'final-lap' (i.e., near-maximal effort: 93 ± 3; 8.7 ± 1.4). Except for rest, each shooting series was preceded by 1 km roller ski skating on a competition track. Rifle movements and triggering were determined from marker-based motion capture and accelerometer data. The primary variables were shooting outcome (hit/miss) and distance from center (dC), determined from an electronic target, and barrel velocity. Mediation analyses for shooting outcome and dC were conducted with barrel velocity (mean over last 0.25 s before triggering) as mediator and intensity as predictor. Exercise intensity increased the likelihood of miss at 'race' (odds ratio (OR) 2.2, 95% CI 1.0-4.7) and 'final-lap' (OR 2.8, 95% CI 1.4-5.8) intensities compared to rest, with no meaningful differences between rest, low, and moderate intensities. Further, intensity affected dC (~32 ± 15 mm at rest, low, and moderate, 36 ± 20 mm at 'race', and 40 ± 23 mm at 'final-lap'; p < 0.001). Barrel velocity was a partial mediator of both shooting outcome and dC, explaining some, but not all, of the effect of intensity. Exercise intensity seems to have a clear negative effect on standing shooting performance in biathlon, which is partially explained by an increase in barrel velocity. Deteriorating effects were mainly seen at the two highest (race-like) intensities. Accordingly, for specificity reasons, more shooting practice should perhaps be performed at higher, competition-like exercise intensities than what is currently the norm.

Greater squat stance width alters three-dimensional hip moment demands

Barbell squat exercise may be performed with different stance widths, which will influence lower limb kinematics and joint reaction forces. Consequently, three-dimensional hip moments may vary with stance width, influencing muscle loading, and the muscles trained when performing squat exercise. To examine how squat stance width affects hip moments, males (n = 11) and females (n = 13) performed barbell squats at narrow, medium, and wide stance widths. Motion capture and force platform data were used to calculate three-dimensional hip net joint moments (NJM) as indicators of the muscular moments required. Hip extensor NJM was greater for wide than medium (P < 0.001) and narrow (P < 0.001) stance squats. Hip adductor NJM was not different between squat stance widths (P = 0.414). Hip lateral rotator NJM was greater in medium versus narrow squats (P < 0.001), and in wide versus medium (P < 0.001) and narrow (P < 0.001) squats. Taken together, the rotational demands at the hip increase as stance width increases, due to higher hip extensor and lateral rotator NJM. In contrast hip adductor NJM is invariant. These data provide insight into the three-dimensional requirements that muscles must meet at the hip when squat exercise is performed at different stance widths.

Joint reaction and simulated muscle forces during squatting and walking in persons with hemophilia

BackgroundPersons with hemophilia experience joint bleeding that can lead to debilitating arthropathy, most commonly seen in ankles, knees, and elbows. Arthropathy can hinder participation in daily and athletic activities. We explored how hemophilic arthropathy impacts movement patterns in walking and bilateral squatting tasks in persons with hemophilia compared to healthy controls. MethodsPersons with hemophilia and healthy controls completed walking and squatting tasks while kinematic and kinetic motion capture data were collected. The Hemophilia Joint Health Score exam was performed to measure hemophiliac arthropathy. OpenSim was used to model muscle and joint reaction forces and calculate moments and angles. Peak values were compared using Cohen's d to estimate effect sizes of hemophilia on movement parameters. FindingsNine persons with hemophilia and eight age-matched controls were analyzed. Temporal-spatial metrics were similar between hemophilia and control groups in both tasks. In walking, persons with hemophilia had higher peak ankle dorsiflexion angles, vertical ground reaction force weight acceptance peaks, and hip extension and flexion moments compared to controls. In squatting, persons with hemophilia had lower knee extension moments, ankle joint reaction force, and knee extensor forces, but had higher hip extension moments. InterpretationTemporal-spatial metric similarity between hemophilia and controls suggests that kinetic and kinematic analyses are needed to identify movement pattern differences. These data identify potential compensatory strategies at the hip that may be used by persons with hemophilia to mitigate impact on the knee and ankle. Future work will confirm these data in a larger sample size and be used to develop physical therapy strategies.

Modeling movements improves capture–recapture estimates for mobile species with sparse data: Polar bears (Ursus maritimus) in Viscount Melville sound

AbstractWildlife management requires estimates of demographic parameters that are difficult to obtain for mobile species at low densities. Biased parameter estimates often result from capture–recapture (CR) studies due to small sample sizes and unequal recapture probabilities, the latter of which can be caused by animal movements with respect to the sampling area. We developed a multistate CR model designed to minimize biases by including multiple data types (capture, harvest, natural mortality, and telemetry) and accounting for temporary emigration. We applied the model to data collected intensively from 2012 to 2014, and intermittently since the 1970s, for the Viscount Melville (VM) subpopulation of polar bears (Ursus maritimus) in the Canadian Arctic. The number of bears within the VM subpopulation boundary likely increased from an average of 145 (Bayesian 95% credible interval [CRI] [109, 221]) in 1989–1992 to 235 (95% CRI [148, 569]) in 2012–2014. Survival probability increased for all sex and age classes except adult females, for which estimates declined due to unknown reasons. Polar bear movements exhibited Markovian dependence with approximately 28% of the subpopulation located outside of the sampling area each spring. This contributed to inaccurate parameter estimates when using a simpler, single‐state CR model that only included capture data. Although the interpretation of demographic status was complicated by statistical uncertainty and changes in study design, our findings suggest that—as of 2014—the VM polar bear subpopulation had likely recovered from an earlier period of overharvest, was stable, and had not exhibited detectable negative effects of climate warming.

A telomere-to-telomere Eucalyptus regnans genome: unveiling haplotype variance in structure and genes within one of the world’s tallest trees

BackgroundEucalyptus regnans (Mountain Ash) is an Australian native giant tree species which form forests that are among the highest known carbon-dense biomasses in the world. To enhance genomic studies in this ecologically important species, we assembled a high-quality, mostly telomere-to-telomere complete, chromosome-level, haplotype-resolved reference genome. We sampled a single tree, the Centurion, which is currently a contender for the world’s tallest flowering plant.ResultsUsing long-read sequencing data (PacBio HiFi, Oxford Nanopore ultra-long reads) and chromosome conformation capture data (Hi-C), we assembled the most contiguous and complete Eucalyptus reference genome to date. For each haplotype, we observed contig N50s exceeding 36 Mbp, scaffold N50s exceeding 43 Mbp, and genome BUSCO completeness exceeding 99%. The assembled genome revealed extensive structural variations between the two haplotypes, consisting mostly of insertions, deletions, duplications and translocations. Analysis of gene content revealed haplotype-specific genes, which were enriched in functional categories related to transcription, energy production and conservation. Additionally, many genes reside within structurally rearranged regions, particularly duplications, suggesting that haplotype-specific variation may contribute to environmental adaptation in the species.ConclusionsOur study provides a foundation for future research into E. regnans environmental adaptation, and the high-quality genome will be a powerful resource for conservation of carbon-dense giant tree forests.

Analysis of a global wheat panel reveals a highly diverse introgression landscape and provides evidence for inter-homoeologue chromosomal recombination

Key messageThis study highlights the agronomic potential of rare introgressions, as demonstrated by a major QTL for powdery mildew resistance on chromosome 7D. It further shows evidence for inter-homoeologue recombination in wheat.Agriculturally important genes are often introgressed into crops from closely related donor species or landraces. The gene pool of hexaploid bread wheat (Triticum aestivum) is known to contain numerous such “alien” introgressions. Recently established high-quality reference genome sequences allow prediction of the size, frequency and identity of introgressed chromosome regions. Here, we characterise chromosomal introgressions in bread wheat using exome capture data from the WHEALBI collection. We identified 24,981 putative introgression segments of at least 2 Mb across 434 wheat accessions. Detailed study of the most frequent introgressions identified T. timopheevii or its close relatives as a frequent donor species. Importantly, 118 introgressions of at least 10 Mb were exclusive to single wheat accessions, revealing that large populations need to be studied to assess the total diversity of the wheat pangenome. In one case, a 14 Mb introgression in chromosome 7D, exclusive to cultivar Pamukale, was shown by QTL mapping to harbour a recessive powdery mildew resistance gene. We identified multiple events where distal chromosomal segments of one subgenome were duplicated in the genome and replaced the homoeologous segment in another subgenome. We propose that these examples are the results of inter-homoeologue recombination. Our study produced an extensive catalogue of the wheat introgression landscape, providing a resource for wheat breeding. Of note, the finding that the wheat gene pool contains numerous rare, but potentially important introgressions and chromosomal rearrangements has implications for future breeding.

Tall and Fall Versus Drop and Drive Strategy in College Baseball Pitchers for Velocity and Elbow Valgus Torque

Background: Depending on anthropometrics and coaching style, pitchers are taught to pitch with a stride strategy that are traditionally classified as “tall and fall” or “drop and drive” for the purpose of maximizing pitch velocity. Purpose/Hypothesis: The purpose of this study was to determine the effects of stride strategy (tall and fall vs drop and drive) in college baseball pitching on pitch velocity and elbow valgus torque. It was hypothesized that pitch velocity and elbow valgus torque would increase as pitchers aligned more with the tall and fall technique. Study Design: Controlled laboratory study. Methods: Markerless motion capture data were recorded on 64 collegiate pitchers (height, 1.89 ± 0.06 m; weight, 93.06 ± 9.44 kg) during game play at the host institution during the 2023 season. Peak magnitudes of body center of mass (COM) vertical displacement were determined using a straight-line trajectory between peak knee height and lead foot contact and used as a continuous variable. Pitchers were required to throw ≥4 fastballs during their outing to be included in the analysis. Multilevel modeling was used to determine associations between peak magnitudes of positive and negative vertical displacement of COM on pitch velocity and elbow valgus torque. Every fastball throughout the season with biomechanics data for each pitcher was included in the multilevel model. Results: Fastball velocity was mean ± SD 90.68 ± 2.90 mph (40.54 ± 1.29 m/s). Mean maximal negative vertical COM displacement was −0.91 ± 0.47 inches (−0.023 ± 0.012 m), which occurred 18.1% ± 5.75% of the way between peak knee height and stride foot contact. Mean maximal positive vertical COM displacement was 1.73 ± 1.14 inches (0.044 ± 0.029 m), which occurred 65.7% ± 7.8% of the time from peak knee height to stride foot contact. Positive COM displacement (β = 0.54; P < .001) and timing of peak positive COM displacement (β = 1.82; P = .023) reduced interpitcher variance by 9.9% and improved the ability of our model to predict fastball velocity. Negative COM displacement improved the ability of our model to predict ball velocity (β = −0.45; P = .021). Vertical COM displacement did not influence elbow valgus torque. Conclusion: Increasing vertical COM displacement in either the positive or the negative direction resulted in increased fastball velocity but did not result in greater elbow valgus torque. This indicates that the stride method may be used for performance enhancement but is unlikely to influence ulnar collateral ligament injury risk in college baseball pitchers. Clinical Relevance: Clinicians should not use stride mechanics as an injury risk indicator or diagnostic factor in injury etiology for college baseball pitchers.

Investigating the Effect of Motion Capture Suits on the Test–Retest Reliability of Gait Parameters

When collecting marker-based motion capture data from clinical populations, speed of collection and comfort for the participant is a priority. This could be achieved by attaching markers to motion capture Velcro suits, as opposed to the skin. This study aimed to ascertain the reliability of sagittal-plane gait parameters estimated using Plug-in Gait (PiG) and Conventional Gait Model 2 (CGM2) marker sets from data collected in Suited and Non-suited (markers placed onto skin) conditions. For ten participants, markers were placed based on PiG and CGM2 models and data captured during a 2-min treadmill walk. Trials were repeated in suited and non-suited conditions. PiG ankle flexion/extension measurements had poor/moderate reliability (Non-suited ICC = 0.531, Suited ICC = 0.435). CGM2 ankle flexion/extension measurements had good/excellent reliability (Non-suited ICC = 0.916, Suited ICC = 0.900). There were significant differences in minimal detectable change (MDC) between conditions at the ankle for PiG (Non-suited MDC = 2.32°, Suited MDC = 18.90°), but not for CGM2 (Non-suited MDC = 0.63°, Suited MDC = 0.95°). When using CGM2, knee (Non-suited ICC = 0.878, Suited ICC = 0.855) and hip (Non-suited ICC = 0.897, Suited ICC = 0.948) showed good/excellent reliability in both conditions. A motion capture suit is not a reliable solution when collecting joint angle data using the PiG model but is reliable enough to consider when using the CGM2 model.

Detecting bias in abundance estimates of spawning fish from closed‐capture models using remote and physical capture data

AbstractObjectiveMixed‐data models incorporating remote antenna detections from PIT‐tagged fish together with physical capture data (mixed data) can improve precision of mark–recapture abundance estimates, particularly for spawning fish. However, if the entire population is not available for physical capture during the mark–recapture sampling period, abundance estimates will be biased low. Our objectives were to examine bias and precision of two modeling approaches and develop a simple diagnostic to determine whether the entire population was sampled.MethodsWe use a simulation modeling approach to compare specified abundances with abundance estimates from closed‐capture models using mixed data (the mixed‐data approach) and using only marked (e.g., PIT‐tagged) individuals divided by the proportion of individuals that are marked (proportional approach). We use the difference in bias between the two models as our diagnostic of whether a population was randomly sampled. We then applied our diagnostic to two case studies: a spawning population of adfluvial June Sucker Chasmistes liorus in Utah Lake, Utah, 2008–2020, and a spawning population of Bull Trout Salvelinus confluentus in the Imnaha River, a tributary of the Snake River, Oregon, 2013–2020.ResultSimulation experiments revealed that the mixed‐data approach became increasingly negatively biased as the proportion of the population that was unavailable for physical capture increased, yet the proportional approach remained unbiased. Abundance estimates from the proportional approach averaged approximately 6× greater for June Sucker and 2× greater for Bull Trout compared to the mixed‐data approach, suggesting a proportion of the population was not available for physical capture in both case studies.ConclusionUnderstanding the magnitude of bias in abundance estimates is particularly important for the management of imperiled species that are subject to recovery plans. Comparing estimates using the unbiased proportional approach that we described here with those from a mixed‐data approach when PIT tag detection data are used to estimate abundance is a straightforward method to evaluate bias in these estimates.

Assessing lower extremity stiffness in countermovement jumps: a critical analysis of the differences between calculation methods

ABSTRACT Introduction: Stiffness (k) describes a material’s resistance to deformation and is useful for understanding neuromuscular function, performance, and injury risk. The aim of this study is to compare the lower limb stiffness method (k LLS ), which uses only force plate data, with methods combining force plate and motion capture data to calculate stiffness during the eccentric phase of a countermovement. Material and Methods: Twelve resistance-trained males: age 24.9 (4.4) years, height 1.81 (0.05) m, weight 88.2 (14) kg) performed three maximal effort countermovement jumps (CMJ). Data were collected synchronously using three-dimensional (3D) kinematic and kinetic data (dual force plate setup). Lower limb stiffness (z), joint stiffness (x, y, and z), and leg stiffness (linear, sagittal plane, and 3D) were calculated for the eccentric phase of all CMs. Results: k LLS showed high concurrent validity with strong correlations to kinetic-kinematic methods (r = 0.90-0.97, p < 0.05). A linear mixed model revealed no significant differences in k-values between k LLS and leg stiffness, indicating high concurrent validity. Discussion: k LLS offers valid and valuable information affecting performance, injury risk, and return-to-sport decisions. Conclusion: The findings suggest that k LLS is a valid method for calculating stiffness in CMJs and equal to 3D leg stiffness.

Phylogenomic Analysis of Target Enrichment and Transcriptome Data Uncovers Rapid Radiation and Extensive Hybridization in Slipper Orchid Genus Cypripedium L.

Cypripedium is the most widespread and morphologically diverse genus of slipper orchids. Despite several published phylogenies, the topology and monophyly of its infrageneric taxa remained uncertain. Here, we aimed to reconstruct a robust section-level phylogeny of Cypripedium and explore its evolutionary history using target capture data for the first time. We used the orchid-specific bait set Orchidaceae963 in combination with transcriptomic data to reconstruct the phylogeny of Cypripedium based on 913 nuclear loci, covering all 13 sections. Subsequently, we investigated discordance among nuclear and chloroplast trees, estimated divergence times and ancestral ranges, searched for anomaly zones, polytomies, and diversification rate shifts, and identified potential gene (genome) duplication and hybridization events. All sections were recovered as monophyletic, contrary to the two subsections within sect. Cypripedium. The two subclades within this section did not correspond to its subsections but matched the geographic distribution of their species. Additionally, we discovered high levels of discordance in the short backbone branches of the genus and within sect. Cypripedium, which can be attributed to hybridization events detected based on phylogenetic network analyses, and incomplete lineage sorting caused by rapid radiation. Our biogeographic analysis suggested a Neotropical origin of the genus during the Oligocene (~30 Ma), with a lineage of potentially hybrid origin spreading to the Old World in the Early Miocene (~22 Ma). The rapid radiation at the backbone likely occurred in Southeast Asia around the Middle Miocene Climatic Transition (~15-13 Ma), followed by several independent dispersals back to the New World. Moreover, the Pliocene-Quaternary glacial cycles may have contributed to further speciation and reticulate evolution within Cypripedium. Our study provided novel insights into the evolutionary history of Cypripedium based on high-throughput molecular data, shedding light on the dynamics of its distribution and diversity patterns from its origin to the present.

Multi-Sensing Inspection System for Thermally Induced Micro-Instability in Metal-Based Selective Laser Melting.

Additive manufacturing (AM) excels in engineering intricate shapes, pioneering functional components, and lightweight structures. Nevertheless, components fabricated through AM often manifest elevated residual stresses and a myriad of thermally induced micro-instabilities, including cracking, incomplete fusion, crazing, porosity, spheroidization, and inclusions. In response, this study proposed a sophisticated multi-sensing inspection system specifically tailored for the inspection of thermally induced micro-instabilities at the micro-nano scale. Simulation results substantiate that the modulation transfer function (MTF) values for each field of view in both visible and infrared optical channels surpass the benchmark of 0.3, ensuring imaging fidelity conducive to meticulous examination. Furthermore, the innovative system can discern and accurately capture data pertaining to thermally induced micro-instabilities across visible and infrared spectra, seamlessly integrating this information into a backend image processing system within operational parameters of a 380-450 mm distance and a 20-70 °C temperature range. Notably, the system's design is harmoniously aligned with the requisites of processing and assembly, heralding a significant advancement in bolstering the inspection effect of thermally induced micro-instabilities for the AM component.