Cardiorespiratory reflexes in white sturgeon (Acipenser transmontanus): Lack of cardiac baroreflex response to blood pressure manipulation?

Arterial pressure (Pa) regulation is essential to adequately distribute nutrients to metabolizing tissues, remove wastes and avoid lesions associated with hypertension. In vertebrates, short-term Pa regulation is achieved through the baroreflex, which elicits inversely proportional changes in heart rate (f) and vascular resistance to restore Pa. The cardiac limb of this reflex has been reported in all vertebrate groups studied to date: teleosts, amphibians, snakes, lizards, crocodiles, birds and mammals - which led to the suggestion that the baroreflex is an ancient trait present in all vertebrate species.

Hydrothermal impacts of water release on early life stages of white sturgeon in the Nechako river, B.C. Canada.

Water temperature plays a crucial role in the physiology of aquatic species, particularly in their survival and development. Thus, resource programs are commonly used to manage water quality conditions for endemic species. In a river system like the Nechako River system, central British Columbia, a water management program was established in the 1980s to alter water release in the summer months to prevent water temperatures from exceeding a 20 °C threshold downstream during the spawning season of Sockeye salmon (Oncorhynchus nerka).

Genomic determination of breeding systems and trans-specific evolution of HD MAT genes in suilloid fungi.

Studying the signatures of evolution can help to understand genetic processes. Here, we demonstrate how the existence of balancing selection can be used to identify the breeding systems of fungi from genomic data. The breeding systems of fungi are controlled by self-incompatibility loci that determine mating types between potential mating partners, resulting in strong balancing selection at the loci.

The role of salinity in recovery of white sturgeon () from stimulated angling stress.

White sturgeon () in the Lower Fraser River are the focus of a catch-and-release angling fishery in British Columbia, Canada. However, the lower region of the catch area includes areas where tidal waters invade, and the consequence of salinity levels on recovery from an angling challenge are not characterized in sturgeon, despite theoretical implications of its import. We acclimated white sturgeon to various salinities (0, 10 and 20‰ (parts per thousand)) to investigate the effects of acclimation on recovery from stimulated angling stress that was induced through manual chasing.

The current state of carnivore cognition.

The field of animal cognition has advanced rapidly in the last 25 years. Through careful and creative studies of animals in captivity and in the wild, we have gained critical insights into the evolution of intelligence, the cognitive capacities of a diverse array of taxa, and the importance of ecological and social environments, as well as individual variation, in the expression of cognitive abilities. The field of animal cognition, however, is still being influenced by some historical tendencies.

Fish feeds supplemented with calcium-based buffering minerals decrease stomach acidity, increase the blood alkaline tide and cost more to digest.

Predatory fish in the wild consume whole prey including hard skeletal parts like shell and bone. Shell and bone are made up of the buffering minerals calcium carbonate (CaCO) and calcium phosphate (Ca(PO)). These minerals resist changes in pH, meaning they could have physiological consequences for gastric acidity, digestion and metabolism in fish.

Rapid cardiac thermal acclimation in wild anadromous Arctic char (Salvelinus alpinus).

Migratory fishes commonly encounter large and rapid thermal variation, which has the potential to disrupt essential physiological functions. Thus, we acclimated wild, migratory Arctic char to 13°C (∼7°C above a summer average) for an ecologically relevant period (3 days) and measured maximum heart rate (ƒH,max) during acute warming to determine their ability to rapidly improve cardiac function at high temperatures. Arctic char exhibited rapid compensatory cardiac plasticity similar to past observations following prolonged warm acclimation: they reduced ƒH,max over intermediate temperatures (-8%), improved their ability to increase ƒH,max during warming (+10%), and increased (+1.

Application of transport-based metric for continuous interpolation between cryo-EM density maps.

Cryogenic electron microscopy (cryo-EM) has become widely used for the past few years in structural biology, to collect single images of macromolecules "frozen in time". As this technique facilitates the identification of multiple conformational states adopted by the same molecule, a direct product of it is a set of 3D volumes, also called EM maps. To gain more insights on the possible mechanisms that govern transitions between different states, and hence the mode of action of a molecule, we recently introduced a bioinformatic tool that interpolates and generates morphing trajectories joining two given EM maps.

Links between personality traits and problem-solving performance in zebra finches ().

Consistent individual differences in behaviour across time or contexts (i.e. personality types) have been found in many species and have implications for fitness.

Local adaptation in fungi.

In this review, I explore the pervasive but underappreciated role of local adaptation in fungi. It has been difficult historically to study local adaptation in fungi because of the limited understanding of fungal species and their traits, but new hope has been offered with technological advances in sequencing. The filamentous nature of fungi invalidates some assumptions made in evolution because of their ability to exist as multinucleate entities with genetically different nuclei sharing the same cytoplasm.

Sensory mechanisms for the shift from phytophagy to haematophagy in mosquitoes.

The Culicomorpha are an infraorder of several families of blood-feeding flies, including mosquitoes (Diptera: Culicidae). Here we discuss the evolutionary origins of blood-feeding within the Culicomorpha and review literature that suggests this behaviour may have evolved from ancestral plant-feeding or a combination of plant-feeding and insect-feeding. Sialomic and life-history evidence suggest that plant-feeding, concurrent or not with insect-feeding, is parsimonious as an ancestral diet for Culicomorpha.

Changes in CO sensitivity during entrance into, and arousal from hibernation in Ictidomys tridecemlineatus.

At the onset of entrance into hibernation in many mammals, there is a reduction in the respiratory exchange ratio (RER) thought to result in a retention of CO that contributes to the ensuing metabolic suppression. In steady-state hibernation, the relative hypercapnic ventilatory response (HCVR; the % change in ventilation to CO exposure) is elevated. These two observations, paradoxically, suggest a transient decrease in CO sensitivity at the onset of entrance into hibernation, allowing the retention of CO, then a subsequent increase in CO sensitivity giving rise to the elevated HCVR in steady-state hibernation.

Sterile males and females can synergistically suppress wild pests targeted by sterile insect technique.

The sterile insect technique (SIT) involves periodically releasing artificially sterilized insects to inhibit normal mating between wild insect pests, ultimately resulting in the eradication of wild pest populations. It has often been discussed whether releasing either one sex, mainly males, of sterile insects (i.e.

Kelp-associated Microbiota are Structured by Host Anatomy.

Seaweed-associated microbiota are essential for the health and resilience of nearshore ecosystems, marine biogeochemical cycling, and host health. Yet much remains unknown about the ecology of seaweed-microbe symbioses. In this study, we quantified fine-scale patterns of microbial community structure across distinct anatomical regions of the kelp Laminaria setchellii.

Is Carriage of Leptospira interrogans by Rats Influenced by the Urban Environment or Population Density?

Leptospira interrogans is one of the most important zoonotic pathogens globally. In urban settings, Norway rats (Rattus norvegicus) are important reservoirs of L. interrogans, but it is unclear how this bacterium is transmitted among rats.

Ketogenic regimens for acute neurotraumatic events.

Dietary modification would be the most translatable, cost-efficient, and, likely, the safest approach available that can reduce the reliance on pharmaceutical treatments for treating acute or chronic neurological disorders. A wide variety of evidence suggests that the ketogenic diet (KD) could have beneficial effects in acute traumatic events, such as spinal cord injury and traumatic brain injury. Review of existing human and animal studies revealed that KD can improve motor neuro-recovery, gray matter sparing, pain thresholds, and neuroinflammation and decrease depression.

Resilience in Greenland intertidal Mytilus: The hidden stress defense.

The Arctic is experiencing particularly rapid rates of warming, consequently invasive boreal species are now able to survive the less extreme Arctic winter temperatures. Whilst persistence of intertidal and terrestrial species in the Arctic is primarily determined by their ability to tolerate the freezing winters, air temperatures in the Arctic summer can reach 36 °C in the intertidal, which is beyond the upper thermal limits of many marine species. This is normally lethal for the conspicuous ecosystem engineer Mytilus edulis.

Individual variation and the biomechanics of maneuvering flight in hummingbirds.

An animal's maneuverability will determine the outcome of many of its most important interactions. A common approach to studying maneuverability is to force the animal to perform a specific maneuver or to try to elicit maximal performance. Recently, the availability of wider-field tracking technology has allowed for high-throughput measurements of voluntary behavior, an approach that produces large volumes of data.

On the Effect of Asymmetrical Trait Inheritance on Models of Trait Evolution.

Current phylogenetic comparative methods modeling quantitative trait evolution generally assume that, during speciation, phenotypes are inherited identically between the two daughter species. This, however, neglects the fact that species consist of a set of individuals, each bearing its own trait value. Indeed, because descendent populations after speciation are samples of a parent population, we can expect their mean phenotypes to randomly differ from one another potentially generating a "jump" of mean phenotypes due to asymmetrical trait inheritance at cladogenesis.

A potential role for hyperpolarization-activated cyclic nucleotide-gated sodium/potassium channels (HCNs) in teleost acid-base and ammonia regulation.

Increasing evidence suggests the involvement of hyperpolarization-activated cyclic nucleotide-gated sodium/potassium channels (HCNs) not only in cardiac and neural function, but also in more general physiological processes including acid-base and ammonia regulation. We have identified four different HCN paralogs/isoforms in the goldfish Carassius auratus (CaHCN1, CaHCN2b, CaHCN4a and CaHCN4b) as likely candidates to contribute to renal, branchial and intestinal acid-base and ammonia regulation in this teleost. Quantitative real-time PCR showed not only high mRNA abundance of all isoforms in heart and brain, but also detectable levels (particularly of CaHCN2b and CaHCN4b) in non-excitable tissues, including gills and kidneys.

The thermal limits of cardiorespiratory performance in anadromous Arctic char (): a field-based investigation using a remote mobile laboratory.

Despite immense concern over amplified warming in the Arctic, physiological research to address related conservation issues for valuable cold-adapted fish, such as the Arctic char (), is lacking. This crucial knowledge gap is largely attributable to the practical and logistical challenges of conducting sensitive physiological investigations in remote field settings. Here, we used an innovative, mobile aquatic-research laboratory to assess the effects of temperature on aerobic metabolism and maximum heart rate ( ) of upriver migrating Arctic char in the Kitikmeot region of Nunavut in the central Canadian Arctic.

Demography of snowshoe hare population cycles.

Cyclic fluctuations in abundance exhibited by some mammalian populations in northern habitats ("population cycles") are key processes in the functioning of many boreal and tundra ecosystems. Understanding population cycles, essentially demographic processes, necessitates discerning the demographic mechanisms that underlie numerical changes. Using mark-recapture data spanning five population cycles (1977-2017), we examined demographic mechanisms underlying the 9-10-yr cycles exhibited by snowshoe hares (Lepus americanus Erxleben) in southwestern Yukon, Canada.

Local cold adaption increases the thermal window of temperate mussels in the Arctic.

Species expand towards higher latitudes in response to climate warming, but the pace of this expansion is related to the physiological capacity to resist cold stress. However, few studies exist that have quantified the level of inter-population local adaptation in marine species freeze tolerance, especially in the Arctic. We investigated the importance of cold adaptation and thermal window width towards high latitudes from the temperate to the Arctic region.