Journal of Experimental Biology最新文献_第8页

Hummingbirds excel at maneuvering and flying through tight spaces. 蜂鸟擅长机动和在狭小空间中飞行。

IF 2.8 2区生物学

Journal of Experimental Biology Pub Date : 2025-06-01 Epub Date: 2025-06-02 DOI: 10.1242/jeb.250269

Zixuan M Zhang, Nicolai Konow, Andrew A Biewener

{"title":"Hummingbirds excel at maneuvering and flying through tight spaces.","authors":"Zixuan M Zhang, Nicolai Konow, Andrew A Biewener","doi":"10.1242/jeb.250269","DOIUrl":"10.1242/jeb.250269","url":null,"abstract":"Flying animals (birds, bats and insects) often negotiate cluttered environments, sometimes involving the need to safely transit through tight spaces between obstacles. Considering their remarkable flight capabilities, hummingbirds are suitable for gaining a better understanding of how flying animals transit tight passages. We studied wild ruby-throated hummingbirds (Archilochus colubris) transiting a chain-link fence with openings smaller than their wingspan to reach a feeder. We identified two distinct flight strategies, involving swept-wing versus sideways styles. Swept-wing transits were characterized by interrupted flapping and a retracted posture with a ballistic body trajectory and were faster than sideways transits, which involved continuous flapping with a reduced wingbeat amplitude, higher wingbeat frequencies and more uniform body pitch and yaw compared with the body movements dynamics used in swept-wing transits. Our novel data for free-flying hummingbirds voluntarily negotiating narrow openings to access food reinforce earlier findings of captive hummingbirds, demonstrating that some fliers can modulate their wing kinematics and body rotations sufficiently to safely navigate openings smaller than their wingspan, a finding that may reflect a more general strategy across fliers. This study contributes both to understanding biological flight dynamics in cluttered environments and potentially to informing the design of autonomous aerial vehicles.","PeriodicalId":15786,"journal":{"name":"Journal of Experimental Biology","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144027090","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Prior cueing affects the saccadic response to targets in the praying mantis Sphodromantis lineola. 先前的线索会影响螳螂对目标的扫视。

IF 2.8 2区生物学

Journal of Experimental Biology Pub Date : 2025-06-01 Epub Date: 2025-06-11 DOI: 10.1242/jeb.249296

Théo Robert, Yi Ting Tan, Dune Ganot, Yi Jie Loh, Vivek Nityananda

{"title":"Prior cueing affects the saccadic response to targets in the praying mantis Sphodromantis lineola.","authors":"Théo Robert, Yi Ting Tan, Dune Ganot, Yi Jie Loh, Vivek Nityananda","doi":"10.1242/jeb.249296","DOIUrl":"10.1242/jeb.249296","url":null,"abstract":"External cues bias human attention and the perception of subsequent targets. Little is known about how cue properties, such as depth, influence insect attention. One robust cue to depth is stereoscopic disparity, which is the difference in the position of an object in the views of the two eyes. Praying mantises are known to use disparity to judge the distance to prey and are therefore ideal insect models to investigate its role in attention. We investigated how three cue properties - position, duration and stereoscopic disparity - affect mantis selective attention towards subsequent targets. We fitted mantises with 3D glasses and presented them with a cue in 2D or 3D, followed by two 3D stimuli: a high-contrast target and a 'distractor' at different contrasts. Our results show that cue position and distractor contrast had the most influence on responses to targets, with no strong effect of disparity. Compared with the 'uncued' condition, cues in two of our disparity conditions reduced target responses if presented on the opposite side of the screen, when the distractor was absent. The cues affected subsequent selective attention even when they did not themselves elicit head saccades, suggesting covert but not overt attention to the cues. Our results show that the position of prior cues can affect mantis selective attention and add further evidence for the complexity of attention-like processes in insects.","PeriodicalId":15786,"journal":{"name":"Journal of Experimental Biology","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12188249/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144078383","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Trade-offs between behavioral plasticity and physiological adaptations in midday gerbils (Meriones meridianus) in response to extreme temperatures. 正午沙鼠（Meriones meridianus）对极端温度反应的行为可塑性和生理适应性之间的权衡。

IF 2.8 2区生物学

Journal of Experimental Biology Pub Date : 2025-06-01 Epub Date: 2025-06-02 DOI: 10.1242/jeb.250423

Yang-Yang Guo, Fangyan Liu, Honglei Chang, Songzhao Du, De-Hua Wang

{"title":"Trade-offs between behavioral plasticity and physiological adaptations in midday gerbils (Meriones meridianus) in response to extreme temperatures.","authors":"Yang-Yang Guo, Fangyan Liu, Honglei Chang, Songzhao Du, De-Hua Wang","doi":"10.1242/jeb.250423","DOIUrl":"10.1242/jeb.250423","url":null,"abstract":"Climate change is reshaping the thermal environment of Meriones meridianus habitats in the Mu Us Desert in China. However, the trade-off between behavioral plasticity and physiological adaptations in this species when coping with extreme temperatures across seasons remains poorly understood. Here, we measured activity patterns and serum and brown adipose tissue (BAT) metabolite levels in this rodent during summer and autumn, and analyzed their relationships with microhabitat temperatures. Behaviorally, 87.9% of extra-burrow summer activity occurred between 22:00 h and 01:00 h, while autumn activity showed a bimodal distribution: 40.9% concentrated during 18:00-20:00 h and 18.9% during 03:00-06:00 h. This temporal niche shifting effectively minimizes direct heat exposure in summer but provides incomplete protection against autumn cold exposure. Physiologically, serum metabolite concentrations exhibited significant seasonal variation. Specifically, metabolites associated with glycolysis, the tricarboxylic acid (TCA) cycle, oxidative phosphorylation and pathways contributing to acetyl-CoA or TCA cycle intermediates production were downregulated in autumn. Conversely, glycolysis, pyruvate oxidation, the TCA cycle and oxidative phosphorylation pathways in BAT were significantly enhanced in autumn. Notably, adenosine 5'-triphosphate (ATP) levels in BAT showed no significant seasonal differences. This physiological linkage suggests chronic cold activation of BAT in autumn. Our results show a trade-off where behavioral thermoregulation sufficiently counteracts summer heat through temporal niche shifting but fails to mitigate chronic cold exposure in autumn, necessitating physiological adaptations.","PeriodicalId":15786,"journal":{"name":"Journal of Experimental Biology","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143983218","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Temperature and precipitation explain variation in metabolic rate but not frequency of gas exchange in Fijian bees. 温度和降水解释了斐济蜜蜂代谢率的变化，但不能解释气体交换的频率。

IF 2.8 2区生物学

Journal of Experimental Biology Pub Date : 2025-05-15 Epub Date: 2025-05-23 DOI: 10.1242/jeb.249948

Carmen R B da Silva, Julian E Beaman, Marika Tuiwawa, Mark I Stevens, Michael P Schwarz, Rosalyn Gloag, Vanessa Kellermann, Lesley A Alton

{"title":"Temperature and precipitation explain variation in metabolic rate but not frequency of gas exchange in Fijian bees.","authors":"Carmen R B da Silva, Julian E Beaman, Marika Tuiwawa, Mark I Stevens, Michael P Schwarz, Rosalyn Gloag, Vanessa Kellermann, Lesley A Alton","doi":"10.1242/jeb.249948","DOIUrl":"10.1242/jeb.249948","url":null,"abstract":"Temperature and water availability are hypothesised to be important drivers of the evolution of metabolic rate and gas exchange patterns, respectively. Specifically, the metabolic cold adaptation (MCA) hypothesis predicts that cold environments select for faster temperature-specific metabolic rates to counter the thermodynamics of biochemical reactions, while the hygric hypothesis predicts that dry environments select for discontinuous gas exchange to reduce water loss. Although these two hypotheses consider different physiological traits and how they vary along different abiotic gradients, metabolic rate drives the frequency of gas exchange in insects meaning these two traits are inherently linked. Despite this link, the MCA and hygric hypotheses are rarely considered together and the extent to which metabolic rates and frequency of gas exchange vary and co-vary across climatic gradients remains unclear. We tested the MCA and hygric hypotheses within a species of endemic Fijian bee, Homalictus fijiensis, and among four Fijian bee species across an altitudinal gradient of 1100 m (highlands are colder and wetter than lowlands). We found an MCA-like pattern within H. fijiensis and among Fijian bee species, where bees from colder environments had higher metabolic rates than bees from warmer environments when measured at 25°C, but precipitation also explained variation in metabolic rate. However, we did not find support for the hygric hypothesis within H. fijiensis or among species (frequency of gas exchange was not negatively correlated with precipitation). The relationship between metabolic rate and frequency of gas exchange was steeper for species that occupied lower elevations on average, suggesting it is possible that these two traits can evolve independently of each other despite being positively correlated.","PeriodicalId":15786,"journal":{"name":"Journal of Experimental Biology","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12148022/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143995651","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Gait compliance alters ground reaction forces in human walking: implications for the evolution of bipedalism. 步态顺应性改变了人类行走中的地面反作用力：对两足动物进化的影响。

IF 2.8 2区生物学

Journal of Experimental Biology Pub Date : 2025-05-15 Epub Date: 2025-05-27 DOI: 10.1242/jeb.250219

Sarah E Little-Letsinger, Rebecca W Cook, Demi Wilson, Kennedy Truitt, Daniel Schmitt

{"title":"Gait compliance alters ground reaction forces in human walking: implications for the evolution of bipedalism.","authors":"Sarah E Little-Letsinger, Rebecca W Cook, Demi Wilson, Kennedy Truitt, Daniel Schmitt","doi":"10.1242/jeb.250219","DOIUrl":"10.1242/jeb.250219","url":null,"abstract":"Despite decades of inquiry, the evolution of bipedalism remains a mystery. Some have argued that a compliant walking gait, with deep hip and knee flexion to moderate ground reaction forces, was used by early human ancestors, marking our relatively stiff modern gait as a recently acquired feature of our genus. Building on previous compliant walking studies, we test the hypothesis that vertical ground reaction forces are attenuated in compliant walking through increases in contact time. Twenty-four adults walked on an instrumented runway using a normal and a compliant gait at a self-selected pace. Vertical, mediolateral and fore-aft ground reaction forces were assessed using both standard discrete and novel continuous methods. We report mixed evidence for the effect of contact time on peak vertical force in the first third of stance during compliant walking. Our data show greater vertical forces at midstance and reduced vertical forces in the last third of stance during compliant walking. Vertical impulse did not differ between gaits. Compliant walking minimized medial and fore-directed forces and increased lateral and aft-directed forces compared with stiff walking. We identified robust increases in lateral and aft impulses. In addition to discrete analysis of force trace peaks, we employed continuous waveform analysis of force traces that confirmed and further illuminated these patterns. Our data clearly demonstrate that compliant walking has lower vertical forces in late stance, with lower medial and fore forces and higher lateral and aft forces across the gait cycle. These results point toward key changes in leg and foot mechanics and advance our understanding of advantages and challenges associated with the evolution of bipedalism.","PeriodicalId":15786,"journal":{"name":"Journal of Experimental Biology","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144012434","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A multi-scaling approach showing a transient metabolic mismatch in a freshwater fish (Zingel asper) during an acute heat stress. 一种多尺度方法显示了淡水鱼在急性热应激期间的短暂代谢不匹配。

IF 2.8 2区生物学

Journal of Experimental Biology Pub Date : 2025-05-15 Epub Date: 2025-05-29 DOI: 10.1242/jeb.250202

Julia Watson, Chloé Souques, François-Xavier Dechaume-Moncharmont, Damien Roussel, Julie Le Guyader, Rémy Lassus, Ludovic Guillard, Angeline Clair, Laétitia Averty, Candice Bastianini, Lilian Redon, Anne Morales-Montaron, Yann Voituron, Martin Daufresne, Elisa Thoral, Loïc Teulier

{"title":"A multi-scaling approach showing a transient metabolic mismatch in a freshwater fish (Zingel asper) during an acute heat stress.","authors":"Julia Watson, Chloé Souques, François-Xavier Dechaume-Moncharmont, Damien Roussel, Julie Le Guyader, Rémy Lassus, Ludovic Guillard, Angeline Clair, Laétitia Averty, Candice Bastianini, Lilian Redon, Anne Morales-Montaron, Yann Voituron, Martin Daufresne, Elisa Thoral, Loïc Teulier","doi":"10.1242/jeb.250202","DOIUrl":"10.1242/jeb.250202","url":null,"abstract":"Heat stress events will be more frequent and intense in the future. These events will challenge the capacity of organisms to exhibit sufficient metabolic flexibility to adapt to such variations. To better understand the acclimation processes implemented in response to acute warming, with an integrative approach we examined in vivo metabolic rate and cardiac mitochondrial respiration in the Rhône streber, during and after a heat stress on a precise time line. The temperature was raised from 13°C to 18°C (+1°C per hour) and maintained at 18°C for 5 days, before returning to 13°C at the same rate. We repeatedly measured, during the heat stress and 5 days after the end of the event, in vivo metabolic rate in the same individuals and cardiac mitochondrial respiration from different individuals. At the organismal level, oxygen consumption increased in line with warming, and was followed by a return to pre-acclimated levels just after the end of the heat stress. Conversely, cardiac mitochondrial respiration decreased during the heat stress, especially 24 h in, and recovered at the end of the event. Our results suggest that the heat stress was responsible for a metabolic mismatch in the strebers. Indeed, we observed (i) a strong thermodynamic effect without any acclimation process, suggesting that the range of temperatures chosen was not stressful for the fish, and (ii) the establishment of a transitory energy saving process. Our results underline the need for more integrative studies to understand how organisms will adapt to climate change.","PeriodicalId":15786,"journal":{"name":"Journal of Experimental Biology","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143999648","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Behavioural evidence of a humidistat: a temperature-compensating mechanism of hydroregulation in spotted salamanders. 湿润器的行为证据：水文调节的温度补偿机制。

IF 2.8 2区生物学

Journal of Experimental Biology Pub Date : 2025-05-15 Epub Date: 2025-05-23 DOI: 10.1242/jeb.250297

Danilo Giacometti, Glenn J Tattersall

{"title":"Behavioural evidence of a humidistat: a temperature-compensating mechanism of hydroregulation in spotted salamanders.","authors":"Danilo Giacometti, Glenn J Tattersall","doi":"10.1242/jeb.250297","DOIUrl":"10.1242/jeb.250297","url":null,"abstract":"The ability to control hydration state is essential for terrestrial species, especially amphibians, which are highly susceptible to dehydration. Here, we examined how temperature (17°C versus 22°C) influenced behavioural hydroregulation in spotted salamanders (Ambystoma maculatum) using a laboratory humidity gradient. Salamanders defended a constant vapour pressure deficit (VPD) between temperatures by targeting higher relative humidity at 22°C than at 17°C, possibly to compensate for increased evaporative demand at warmer temperatures. Individuals selecting higher VPDs experienced greater evaporative water loss (EWL), with larger salamanders losing more water than smaller ones after accounting for temperature. Together, these results highlight a trade-off among body size, humidity preference and desiccation tolerance. Salamanders also rehydrated faster at 22°C than 17°C, highlighting temperature-dependent water uptake rates. Our finding that salamanders regulated a constant driving force of evaporation between temperatures suggests they are able to detect rates of EWL. Local evaporative cooling of the skin is a plausible mechanism: if moist-skinned ectotherms show local evaporative cooling on exposed surfaces but not on those in contact with the substrate, then the temperature gradient between dorsal and ventral skin could act as an effective cue to detect the drive for EWL. Ultimately, our study underscores the complexity of amphibian hydroregulation and emphasises the role of behaviour in maintaining hydration state.","PeriodicalId":15786,"journal":{"name":"Journal of Experimental Biology","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12148020/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143968976","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

CRISPR/Cas9-mediated myostatin disruption elevates the expression of genes associated with myofiber composition and growth in Exopalaemon carinicauda. CRISPR/ cas9介导的肌生长抑制素破坏可提高外腭肌纤维组成和生长相关基因的表达。

IF 2.8 2区生物学

Journal of Experimental Biology Pub Date : 2025-05-15 Epub Date: 2025-05-23 DOI: 10.1242/jeb.250148

Yuke Bu, Rongxiao Wang, Yujie Liu, Kefan Xing, Xue Zhang, Yuying Sun, Jiquan Zhang

{"title":"CRISPR/Cas9-mediated myostatin disruption elevates the expression of genes associated with myofiber composition and growth in Exopalaemon carinicauda.","authors":"Yuke Bu, Rongxiao Wang, Yujie Liu, Kefan Xing, Xue Zhang, Yuying Sun, Jiquan Zhang","doi":"10.1242/jeb.250148","DOIUrl":"10.1242/jeb.250148","url":null,"abstract":"Myostatin (MSTN) is a negative regulator of skeletal muscle development and growth in vertebrates, but its role in crustaceans remains debated. To explore the functional role of MSTN in Exopalaemon carinicauda (EcMSTN) and to facilitate the development of new strains with enhanced growth rates, we investigated the molecular characteristics, expression patterns and functional implications of EcMSTN. We employed CRISPR/Cas9-mediated gene editing technology to generate EcMSTN knockout (EcMSTN-KO) prawns and subsequently monitored their hatching rate, survival rate and growth performance. The findings revealed that the hatching rate in the EcMSTN-KO group was only 11%, significantly lower than the 50% in the control group (P<0.05). In comparison to their wild-type (WT) siblings (1.212±0.114 cm), the EcMSTN-KO prawns (1.481±0.192) demonstrated a markedly enhanced body length (P<0.001). The expression of genes associated with myofiber composition and growth, including myosin heavy chain 2 (EcMHC2) and myosin light chain 1 (EcMLC1), exhibited a highly significant increase (P<0.001) in EcMSTN-KO prawns. Additionally, the expression of ecdysone receptor (EcEcR), a molt-related gene, was significantly elevated (P<0.001), while the expression of retinoid X receptor (EcRXR) showed no significant difference (P>0.05). The above studies indicate that EcMSTN functions as a negative regulator of muscle growth in E. carinicauda. Moreover, EcMSTN may play a role in molting. These results underscore the significant potential of MSTN as a genetic target for improving crustacean aquaculture, particularly through gene editing technologies aimed at enhancing growth traits.","PeriodicalId":15786,"journal":{"name":"Journal of Experimental Biology","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143988140","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Dive-by-dive variation in the diving respiratory air volume of southern elephant seals (Mirounga leonina). 南象海豹（miounga leonina）潜水呼吸气量随潜水的变化。

IF 2.8 2区生物学

Journal of Experimental Biology Pub Date : 2025-05-15 Epub Date: 2025-05-23 DOI: 10.1242/jeb.249659

George Sato, Taiki Adachi, Christophe Guinet, Patrick Miller

{"title":"Dive-by-dive variation in the diving respiratory air volume of southern elephant seals (Mirounga leonina).","authors":"George Sato, Taiki Adachi, Christophe Guinet, Patrick Miller","doi":"10.1242/jeb.249659","DOIUrl":"10.1242/jeb.249659","url":null,"abstract":"The role of diving respiratory air volume (DRAV) in deep-diving phocid seals remains poorly understood, largely because of the lack of methods for measuring DRAV in free-ranging divers that exhale before diving. We developed a method to estimate DRAV using a hydrodynamic glide model applied to descent glides recorded using multi-sensor data loggers. We estimated dive-by-dive DRAV for six negatively buoyant female southern elephant seals (Mirounga leonina). During shallow descent glides, rapid compression of DRAV influenced net buoyancy and gliding speed, making this phase suitable for estimating DRAV. Our results revealed dive-by-dive variation in DRAV, which was positively correlated with root mean square (RMS) sway acceleration (a proxy for per-stroke effort) and the depth at which gliding began during the initial descent. DRAV increased with both tissue density and maximum dive depth, suggesting that seals adjusted their DRAV to stay closer to neutral buoyancy through their dives. However, the observed level of adjustment did not result in neutral buoyancy at half of the maximum dive depth, as predicted to minimise round-trip locomotion costs. Instead, the seals typically adjusted DRAV to reach neutral buoyancy at ∼30 m depth, <10% of their mean maximum dive depth. This indicates that strong negative tissue density imposes transit costs that cannot be fully compensated for by DRAV adjustment alone. Future work should explore whether other breath-hold divers show similar patterns of DRAV adjustment and quantify the associated physiological and ecological benefits.","PeriodicalId":15786,"journal":{"name":"Journal of Experimental Biology","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12148017/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144010654","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Detecting artificially impaired balance in human locomotion: metrics, perturbation effects and detection thresholds. 检测人体运动中人为受损的平衡：度量、扰动效应和检测阈值。

IF 2.8 2区生物学

Journal of Experimental Biology Pub Date : 2025-05-15 Epub Date: 2025-05-22 DOI: 10.1242/jeb.249339

Jiaen Wu, Michael Raitor, Guan Rong Tan, Kristan L Staudenmayer, Scott L Delp, C Karen Liu, Steven H Collins

{"title":"Detecting artificially impaired balance in human locomotion: metrics, perturbation effects and detection thresholds.","authors":"Jiaen Wu, Michael Raitor, Guan Rong Tan, Kristan L Staudenmayer, Scott L Delp, C Karen Liu, Steven H Collins","doi":"10.1242/jeb.249339","DOIUrl":"10.1242/jeb.249339","url":null,"abstract":"Measuring balance is important for detecting impairments and developing interventions to prevent falls, but there is no consensus on which method is most effective. Many balance metrics derived from steady-state walking data have been proposed, such as step-width variability, step-time variability, foot placement predictability, maximum Lyapunov exponent and margin of stability. Recently, perturbation-based metrics such as center of mass displacement have also been explored. Perturbations typically involve unexpected disturbances applied to the subject. In this study we collected walking data from 10 healthy human subjects while walking normally and while impairing balance with ankle braces, eye-blocking masks and pneumatic jets on their legs. In some walking trials we also applied mechanical perturbations to the pelvis. We obtained a comprehensive biomechanics dataset and compared the ability of various metrics to detect impaired balance using steady-state walking and perturbation recovery data. We also compared metric performance using thresholds informed by data from multiple subjects versus subject-specific thresholds. We found that step-width variability, step-time variability and foot placement predictability, using steady-state data and subject-specific thresholds, detected impaired balance with the highest accuracy (≥86%), whereas other metrics were less effective (≤68%). Incorporating perturbation data did not improve accuracy of these metrics, although this comparison was limited by the small amount of perturbation data included and analyzed. Subject-specific baseline measurements improved the detection of changes in balance ability. Thus, in clinical practice, taking baseline measurements might improve the detection of impairment due to aging or disease progression.","PeriodicalId":15786,"journal":{"name":"Journal of Experimental Biology","volume":"228 10","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12148027/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144127882","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0