Weighing the evidence for using vascular conductance, not resistance, in comparative cardiovascular physiology
Summary: Vascular conductance and resistance are reciprocal variables, but are not interchangeable terms. We argue that when blood flow changes by a greater relative magnitude than blood pressure, conductance yields a more faithful representation of cardiovascular status.
METHODS & TECHNIQUES
Summary: Development of a surgical technique that allows for controlled activation of individual muscles in an agonistic group and provides the first-ever information on the contribution of individual muscles to joint biomechanics.
Different incubation patterns affect selective antimicrobial properties of the egg interior: experimental evidence from eggs of precocial and altricial birds
Summary: Experimental manipulation of eggs of two typical precocial and altricial birds demonstrates how different incubation patterns may affect selective antimicrobial potential of the egg interior against invading pathogenic and beneficial probiotic microorganisms.
Summary: Colonial siphonophores produce high-speed jets and generate forward thrust during refill using a flexible velum to achieve effective propulsion.
Adult diet does not compensate for impact of a poor larval diet on stress resistance in a tephritid fruit fly
Summary: Nutrition may enhance stress resistance in insects. Low protein larval diets improved desiccation and starvation resistance in Ceratitis cosyra and adult feeding did not compensate for deficiencies in a larval diet.
Mechanical properties of the venomous spines of Pterois volitans and morphology among lionfish species
Summary: Mechanical properties vary among fin region and length along the venomous spines of Pterois volitans. Cross-sectional shape of the dorsal spines differs among lionfish species.
Summary: Patterns of energy management in animals inferred from slope estimates from linear regressions of energy expenditure can be affected by regression dilution unless r2 is very high, influencing the accuracy and interpretation of these estimates.
Early-life adversity programs long-term cytokine and microglia expression within the HPA axis in female Japanese quail
Summary: Developmental exposure to a non-pathogenic stressor can cause long-term changes in inflammatory and anti-inflammatory cytokine gene expression and microglia abundance in different brain regions involved in stress response regulation.
A tale of two genes: divergent evolutionary fate of haptoglobin and hemopexin in hemoglobinless Antarctic icefishes
Summary: The contrasting fates of the hemoglobin scavenger haptoglobin and the heme scavenger hemopexin contribute to the understanding of gene fate under relaxed selection in the hemoglobinless Antarctic icefishes.
Moving in complex environments: a biomechanical analysis of locomotion on inclined and narrow substrates
Summary: An organism's performance provides insight to its survival. To understand significant population declines in the northern quoll, we quantified biomechanical performance as they ran up narrow and wide substrates.
Editors' Choice: Newts deploy a derived processing mechanism where prey items are rasped rhythmically against the dentition on the mouth roof, driven by a loop motion of the tongue.
Summary: Flying bats respond to both optic and echo-acoustic flow and rely on a weighted integration of the two cues for manoeuvring in light and dark environments.
Summary: Lizards can run at high-speed on complex terrains, relying on leg movements that adjust to substrate variations, while enhancing the stability of the head and centre of mass.
Highlighted Article: The total energy expended by migratory bats during daytime roosting at stopovers is independent of ambient temperature as a result of facultative adjustment of torpor.
Summary: Within 6 h, starfish respond to injury via a change in the proteomic composition of coelomic fluid, revealing both novel, uncharacterized soluble factors and those sharing similarity with vertebrate proteins.
Summary: In the hearts of freshwater turtles, contraction of smooth muscle in the atria limits cardiac filling thereby decreasing cardiac output.
Summary: In quail, plasma levels of oxidative damage and biliverdin concentration are negatively correlated, consistent with a localized antioxidant function of biliverdin.
Summary: Characterization of a prior residence effect in marbled crayfish by a behavioural neurobiological approach reveals a dependence on both perception of shelter quality and fighting motivation.
Testing the resource trade-off hypothesis for carotenoid-based signal honesty using genetic variants of the domestic canary
Summary: Contrary to resource trade-off predictions, white canaries with mutations that disable the absorption or deposition of carotenoids show no significant increase in oxidative stress or any loss of immune system function.
Variable vision in variable environments: the visual system of an invasive cichlid (Cichla monoculus) in Lake Gatun, Panama
Summary: Examination of the visual system plasticity of the peacock bass, Cichla monoculus, shows that this species adapts to a changing environment by alternating the use of chromophores A1 and A2, and through differential gene expression in the retina.
Mitochondrial plasticity in the cerebellum of two anoxia-tolerant sharks: contrasting responses to anoxia/re-oxygenation
Highlighted Article: The brain mitochondria of reef sharks reveal some adaptations that parallel their contrasted physiological strategies to cope with environmental oxygen deprivation.
Summary: Larger forward and smaller vertical COM displacements were observed in runners with a high versus a low duty factor, with the two duty factor groups demonstrating comparable running economy values.
Environmental temperature alters the overall digestive energetics and differentially affects dietary protein and lipid use in a lizard
Summary: Temperature alters the class of nutrients oxidized and assimilated, and the amount of energy spent for processing a meal in an ectotherm.
An intra-population heterothermy continuum: notable repeatability of body temperature variation in food-deprived yellow-necked mice
Summary: Intra-specific analysis of the heterothermic response in a wild mammal supports a novel specialist–generalist theoretical model for endothermic thermoregulation.