Improving spring-mass parameter estimation in running using nonlinear regression methods [RESEARCH ARTICLE]
We present a method to model runners as spring–mass systems using nonlinear regression (NLR) and the full vertical ground reaction force (vGRF) time series without additional inputs and fewer traditional parameter assumptions. We derived and validated a time-dependent vGRF function characterized by four spring–mass parameters – stiffness, touchdown angle, leg length and contact time – using a sinusoidal approximation. Next, we compared the NLR-estimated spring–mass parameters with traditional calculations in runners. The mixed-effect NLR method (ME NLR) modeled the observed vGRF best (RMSE:155...
Source: Journal of Experimental Biology - March 18, 2021 Category: Biology Authors: Burns, G. T., Gonzalez, R., Zernicke, R. F. Tags: RESEARCH ARTICLE Source Type: research
Physiological adjustments to high foraging effort negatively affect fecundity but not final reproductive output in captive zebra finches [RESEARCH ARTICLE]
Kang Nian Yap, Donald R. Powers, Melissa L. Vermette, Olivia Hsin-I Tsai, and Tony D. Williams Foraging at elevated rates to provision offspring is thought to be an energetically costly activity and it has been suggested that there are potentially physiological costs associated with the high workload involved. However, for the most part evidence for costs of increased foraging and/or reproductive effort is weak. Furthermore, despite some experimental evidence demonstrating negative effects of increased foraging and parental effort, the physiological mechanisms underlying costs associated with high workload remain poorly un...
Source: Journal of Experimental Biology - March 18, 2021 Category: Biology Authors: Yap, K. N., Powers, D. R., Vermette, M. L., Tsai, O. H.-I., Williams, T. D. Tags: RESEARCH ARTICLE Source Type: research
Genome size influences adaptive plasticity of water loss, but not metabolic rates in lungless salamanders [RESEARCH ARTICLE]
Benjamin B. Johnson, Jeremy B. Searle, and Jed P. Sparks Many expressions of phenotype, such as physiological performance, integrate multiple underlying traits to function. Linking component traits to adaptive physiology thus gives insight into mechanisms of selection acting on performance. Genome size (C-value) is a trait that influences physiology in multiple taxa by exerting a nucleotypic effect, constraining cell size and cellular physiology such that whole-organism mass-specific metabolism is reduced with increasing C-value. We tested for this mechanism of C-value function acting in lungless salamanders, plus an unexp...
Source: Journal of Experimental Biology - March 18, 2021 Category: Biology Authors: Johnson, B. B., Searle, J. B., Sparks, J. P. Tags: RESEARCH ARTICLE Source Type: research
Mantis shrimp identify an object by its shape rather than its color during visual recognition [SHORT COMMUNICATION]
Rickesh N. Patel, Veniamin Khil, Laylo Abdurahmonova, Holland Driscoll, Sarina Patel, Olivia Pettyjohn-Robin, Ahmad Shah, Tamar Goldwasser, Benjamin Sparklin, and Thomas W. Cronin Mantis shrimp commonly inhabit seafloor environments with an abundance of visual features including conspecifics, predators, prey, and landmarks used for navigation. While these animals are capable of discriminating color and polarization, it is unknown what specific attributes of a visual object are important during recognition. Here we show that mantis shrimp of the species Neogonodactylus oerstedii are able to learn the shape of a trained targ...
Source: Journal of Experimental Biology - March 18, 2021 Category: Biology Authors: Patel, R. N., Khil, V., Abdurahmonova, L., Driscoll, H., Patel, S., Pettyjohn-Robin, O., Shah, A., Goldwasser, T., Sparklin, B., Cronin, T. W. Tags: SHORT COMMUNICATION Source Type: research
How extraordinary periwinkles withstand extreme heat [INSIDE JEB]
Kathryn Knight (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - March 15, 2021 Category: Biology Authors: Knight, K. Tags: INSIDE JEB Source Type: research
Aversive operant conditioning alters the phototactic orientation of the marbled crayfish [RESEARCH ARTICLE]
Shione Okada, Natsumi Hirano, Toshiki Abe, and Toshiki Nagayama
Aversive learning was applied to affect the phototactic behaviour of the marbled crayfish. Animals initially showed negative phototaxis to white light and positive taxis to blue light. Using an aversive learning paradigm, we investigated the plasticity of innate behaviour following operant conditioning. The initial rate of choosing a blue-lit exit was analysed by a dual choice experiment between blue-lit and white-lit exits in pre-test conditions. During training, electrical shocks were applied to the animals when they oriented to the blue-lit exit. Memory te...
Source: Journal of Experimental Biology - March 15, 2021 Category: Biology Authors: Okada, S., Hirano, N., Abe, T., Nagayama, T. Tags: RESEARCH ARTICLE Source Type: research
Temperature adaptations of the thermophilic snail Echinolittorina malaccana: insights from metabolomic analysis [RESEARCH ARTICLE]
Ya-qi Chen, Jie Wang, Ming-ling Liao, Xiao-xu Li, and Yun-wei Dong
The periwinkle snail Echinolittorina malaccana, for which the upper lethal temperature is near 55°C, is one of the most heat-tolerant eukaryotes known. We conducted a multi-level investigation – including cardiac physiology, enzyme activity, and targeted and untargeted metabolomic analyses – that elucidated a spectrum of adaptations to extreme heat in this organism. All systems examined showed heat intensity-dependent responses. Under moderate heat stress (37–45°C), the snail depressed cardiac activity and entered a state of metab...
Source: Journal of Experimental Biology - March 15, 2021 Category: Biology Authors: Chen, Y.-q., Wang, J., Liao, M.-l., Li, X.-x., Dong, Y.-w. Tags: RESEARCH ARTICLE Source Type: research
Parallel evolution of placental calcium transfer in the lizard Mabuya and eutherian mammals [RESEARCH ARTICLE]
Nathaly Hernandez-Diaz, Francisca Leal, and Martha Patricia Ramirez-Pinilla
An exceptional case of parallel evolution between lizards and eutherian mammals occurs in the evolution of viviparity. In the lizard genus Mabuya, viviparity provided the environment for the evolution of yolk-reduced eggs and obligate placentotrophy. One major event that favored the evolution of placentation was the reduction of the eggshell. As with all oviparous reptiles, lizard embryos obtain calcium from both the eggshell and egg yolk. Therefore, the loss of the eggshell likely imposes a constraint for the conservation of the egg yolk, which c...
Source: Journal of Experimental Biology - March 15, 2021 Category: Biology Authors: Hernandez-Diaz, N., Leal, F., Ramirez-Pinilla, M. P. Tags: RESEARCH ARTICLE Source Type: research
Neuroethology of number sense across the animal kingdom [REVIEW]
Andreas Nieder
Many species from diverse and often distantly related animal groups (e.g. monkeys, crows, fish and bees) have a sense of number. This means that they can assess the number of items in a set – its ‘numerosity’. The brains of these phylogenetically distant species are markedly diverse. This Review examines the fundamentally different types of brains and neural mechanisms that give rise to numerical competence across the animal tree of life. Neural correlates of the number sense so far exist only for specific vertebrate species: the richest data concerning explicit and abstract number represe...
Source: Journal of Experimental Biology - March 15, 2021 Category: Biology Authors: Nieder, A. Tags: Neuroethology REVIEW Source Type: research
Effect of density and species preferences on collective choices: an experimental study on maggot aggregation behaviours [RESEARCH ARTICLE]
This study was designed to (1) assess the collective behaviours of blow fly larvae (Diptera: Calliphoridae) in groups varying in density and species composition, and (2) relate them to the costs and benefits of aggregating on fresh or decomposed food. First, experiments testing conspecific groups of Lucilia sericata and Calliphora vicina larvae, two species feeding at the same time on fresh carcasses, demonstrated decreases in growth and survival on rotten beef liver compared with fresh liver. However, mixing species together reduced this adverse impact of decomposition by increasing the mass of emerged adults. Second, lar...
Source: Journal of Experimental Biology - March 12, 2021 Category: Biology Authors: Fouche, Q., Hedouin, V., Charabidze, D. Tags: RESEARCH ARTICLE Source Type: research
Visual stimulus-specific habituation of innate defensive behaviour in mice [RESEARCH ARTICLE]
Azadeh Tafreshiha, Sven A. van der Burg, Kato Smits, Laila A. Blömer, and J. Alexander Heimel
Innate defensive responses such as freezing or escape are essential for animal survival. Mice show defensive behaviour to stimuli sweeping overhead, like a bird cruising the sky. Here, we tested this in young male mice and found that mice reduced their defensive freezing after sessions with a stimulus passing overhead repeatedly. This habituation is stimulus specific, as mice freeze again to a novel shape. Habituation occurs regardless of the visual field location of the repeated stimulus. The mice generalized over a rang...
Source: Journal of Experimental Biology - March 12, 2021 Category: Biology Authors: Tafreshiha, A., van der Burg, S. A., Smits, K., Blömer, L. A., Heimel, J. A. Tags: RESEARCH ARTICLE Source Type: research
Continuous body 3-D reconstruction of limbless animals [METHODS [amp ] TECHNIQUES]
Qiyuan Fu, Thomas W. Mitchel, Jin Seob Kim, Gregory S. Chirikjian, and Chen Li
Limbless animals such as snakes, limbless lizards, worms, eels and lampreys move their slender, long bodies in three dimensions to traverse diverse environments. Accurately quantifying their continuous body's 3-D shape and motion is important for understanding body–environment interactions in complex terrain, but this is difficult to achieve (especially for local orientation and rotation). Here, we describe an interpolation method to quantify continuous body 3-D position and orientation. We simplify the body as an elastic rod and apply a ...
Source: Journal of Experimental Biology - March 12, 2021 Category: Biology Authors: Fu, Q., Mitchel, T. W., Kim, J. S., Chirikjian, G. S., Li, C. Tags: Comparative biomechanics of movement METHODS [amp ] TECHNIQUES Source Type: research
Plasticity in parental effects confers rapid larval thermal tolerance in the estuarine anemone Nematostella vectensis [RESEARCH ARTICLE]
Hanny E. Rivera, Cheng-Yi Chen, Matthew C. Gibson, and Ann M. Tarrant
Parental effects can prepare offspring for different environments and facilitate survival across generations. We exposed parental populations of the estuarine anemone, Nematostella vectensis, from Massachusetts to elevated temperatures and quantified larval mortality across a temperature gradient. We found that parental exposure to elevated temperatures resulted in a consistent increase in larval thermal tolerance, as measured by the temperature at which 50% of larvae die (LT50), with a mean increase in LT50 of 0.3°C. Larvae from subsequent spawns r...
Source: Journal of Experimental Biology - March 11, 2021 Category: Biology Authors: Rivera, H. E., Chen, C.-Y., Gibson, M. C., Tarrant, A. M. Tags: RESEARCH ARTICLE Source Type: research
Comparative cranial biomechanics in two lizard species: impact of variation in cranial design [RESEARCH ARTICLE]
Hugo Dutel, Flora Gröning, Alana C. Sharp, Peter J. Watson, Anthony Herrel, Callum F. Ross, Marc E. H. Jones, Susan E. Evans, and Michael J. Fagan
Cranial morphology in lepidosaurs is highly disparate and characterised by the frequent loss or reduction of bony elements. In varanids and geckos, the loss of the postorbital bar is associated with changes in skull shape, but the mechanical principles underlying this variation remain poorly understood. Here, we sought to determine how the overall cranial architecture and the presence of the postorbital bar relate to the loading and deformation of the cranial bones duri...
Source: Journal of Experimental Biology - March 11, 2021 Category: Biology Authors: Dutel, H., Gröning, F., Sharp, A. C., Watson, P. J., Herrel, A., Ross, C. F., Jones, M. E. H., Evans, S. E., Fagan, M. J. Tags: RESEARCH ARTICLE Source Type: research
Pendulum-based measurements reveal impact dynamics at the scale of a trap-jaw ant [RESEARCH ARTICLE]
Justin F. Jorge, Sarah Bergbreiter, and S. N. Patek
Small organisms can produce powerful, sub-millisecond impacts by moving tiny structures at high accelerations. We developed and validated a pendulum device to measure the impact energetics of microgram-sized trap-jaw ant mandibles accelerated against targets at 105 m s–2. Trap-jaw ants (Odontomachus brunneus; 19 individuals, 212 strikes) were suspended on one pendulum and struck swappable targets that were either attached to an opposing pendulum or fixed in place. Mean post-impact kinetic energy (energy from a strike converted to pendulum motion) was high...
Source: Journal of Experimental Biology - March 11, 2021 Category: Biology Authors: Jorge, J. F., Bergbreiter, S., Patek, S. N. Tags: RESEARCH ARTICLE Source Type: research
