Summary: When given an oxidative challenge, copepods deprived of carotenoids show higher oxidative damage and mortality than carotenoid-restored copepods.
Splitting of circulating red blood cells as an in vivo mechanism of erythrocyte maturation in developing zebrafish, chick and mouse embryos
Summary: Splitting of circulating nucleated red blood cells occurs in fish, chick and mouse embryos, often by tangling at vascular pillars, and promotes either cell division (fish, mouse) or maturation (chick).
Highlighted Article: Faster embryonic growth rate, manipulated using incubation temperature, results in shorter telomere length at hatching in a wild bird species, the common tern.
Summary: Fast, voluntary changes to human walking patterns do not affect the motor memory formed through simultaneous adaptive learning.
Woodpecker drumming behavior is linked to the elevated expression of genes that encode calcium handling proteins in the neck musculature
Highlighted Article: Drumming behavior in woodpeckers is linked to the increased expression of genes that encode proteins related to calcium trafficking, specifically in the birds' neck musculature.
Exploring nature's natural knockouts: in vivo cardiorespiratory performance of Antarctic fishes during acute warming
Summary: Routine cardiac output in the haemoglobinless icefish Chaenocephalus aceratus is lower than previously reported; they have a large cardiorespiratory scope during acute warming and activity, and show the same cardiac breakpoint temperature as the red-blooded Antarctic fish Notothenia coriiceps.
Cardiac mitochondrial metabolism may contribute to differences in thermal tolerance of red- and white-blooded Antarctic notothenioid fishes
Summary: Hearts of icefishes have a lower capacity to maintain ATP levels through aerobic metabolic pathways compared with those of red-blooded species, which may constrain cardiac performance and lower thermal tolerance.
Summary: Selection has resulted in domestic turkeys that are three times more massive than wild birds, leading to decreased locomotor speeds, an altered center of mass position and a shuffling gait.
Weakly electric fish distinguish between envelope stimuli arising from different behavioral contexts
Summary: Weakly electric fish can experience stimuli arising from different behavioral contexts; we provide the first evidence that they can distinguish envelopes arising from movement from those that occur during social interactions.
Repeated freezing induces a trade-off between cryoprotection and egg production in the goldenrod gall fly, Eurosta solidaginis
Highlighted Article: In response to repeated freezing events, gall flies produce additional cryoprotectants at the expense of reproductive potential, suggesting that changes in thermal variability over winter will exacerbate the ecological impacts of climate change.
Summary: Big brown bats (Eptesicus fuscus) presented with active jamming signals alter their echolocation to decrease the effects of interference.
Cardiac plasticity influences aerobic performance and thermal tolerance in a tropical, freshwater fish at elevated temperatures
Summary: Elevated temperature induces cardiac remodeling in Nile perch, establishing mechanistic links between cardiac plasticity, metabolic performance and thermal tolerance in a fish faced with climate-change-related stressors.
Summary: The slack test does not assess the true maximal shortening velocity of muscle fascicles in humans and does not appear appropriate for in vivo measurements.
Highlighted Article: Daily torpor in energetically challenged mice is transiently inhibited by feeding while the circadian clock gates the expression of torpor, thereby restricting torpor from occurring during the early subjective night.
Comparative feeding strategies and kinematics in phocid seals: suction without specialized skull morphology
Summary: Behavioral and kinematic differences exist between suction feeding and biting in seals. Suction feeding is common in seals and can occur without specialized skull morphology.
Short- and long-term effects of altered point of ground reaction force application on human running energetics
Summary: The authors describe two interventions that successfully decreased the cost coefficient and the counterbalancing effect of the rate of force generation. Furthermore, they report how stability can affect the economy of running.
Changes in hemolymph total CO2 content during the water-to-air respiratory transition of amphibiotic dragonflies
Editor's Choice: Measurements of hemolymph total CO2 (TCO2) and partial pressure of CO2 (PCO2) indicate that water-breathing dragonfly nymphs have unexpectedly high CO2 content compared with other water breathers.
Summary: Caenorhabditis elegans exhibits a behavioural response to vibration that is distinct from its responses to touch.
Update and extension of the ‘equivalent slope’ of speed-changing level locomotion in humans: a computational model for shuttle running
Summary: A revision/update of the ‘equivalent slope’ concept to estimate the metabolic cost of level locomotion at unsteady speed, and its application via a computational model to shuttle running.
Summary: Muscle fascicles bulge transversely during contraction; the transverse deformation of fascicles is asymmetrical in pennate muscles, supporting the idea that the stress distribution is also asymmetric.