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Physiological and Biochemical Zoology: PBZ

Kirstin Bilham, Chris Newman, Christina D Buesching, Michael J Noonan, Amy Boyd, Adrian L Smith, David W Macdonald
Wild-living animals are subject to weather variability that may cause the generation of reactive oxygen species, resulting in oxidative stress and tissue damage, potentially driving demographic responses. Our 3-yr field study investigated the effects of seasonal weather conditions on biomarkers for oxidative stress, oxidative damage, and antioxidant defense in the European badger (Meles meles). We found age class effects: cubs were more susceptible to oxidative stress and oxidative damage than adults, especially very young cubs in the spring, when they also exhibited lower antioxidant biomarkers than adults...
July 2018: Physiological and Biochemical Zoology: PBZ
Ana T Silva, Jonathan D Midwood, Kim Aarestrup, Tom G Pottinger, Steffen S Madsen, Steven J Cooke
Migration of adult European eels (Anguilla anguilla) from freshwater feeding grounds to oceanic spawning grounds is an energetically demanding process and is accompanied by dramatic physiological and behavioral changes. Humans have altered the aquatic environment (e.g., dams) and made an inherently challenging migration even more difficult; human activity is regarded as the primary driver of the collapse in eel populations. The neuroendocrine stress response is central in coping with these challenging conditions, yet little is known about how various biotic factors such as sex, parasites, and ontogeny influence (singly and via interactions) the stress response of eels...
July 2018: Physiological and Biochemical Zoology: PBZ
Scott Jarvie, Tim Jowett, Michael B Thompson, Philip J Seddon, Alison Cree
The thermal sensitivity of physiological rates is a key characteristic of organisms. For tuatara (Sphenodon punctatus), the last surviving member of the reptilian order Rhynchocephalia and an unusually cold-tolerant reptile, we aimed to clarify responses in indices of metabolic rate (oxygen consumption [[Formula: see text]] and carbon dioxide production [[Formula: see text]]) as well as rates of total evaporative water loss (TEWL) to temperatures at the warmer end of the known tolerated range; currently, patterns for metabolic rate are unclear above 25°C, and TEWL has not been measured above 25°C...
July 2018: Physiological and Biochemical Zoology: PBZ
Tim S Jessop, Meagan Lane, Robbie S Wilson, Edward J Narayan
Phenotypic plasticity, broadly defined as the capacity of one genotype to produce more than one phenotype, is a key mechanism for how animals adapt to environmental (including thermal) variation. Vertebrate glucocorticoid hormones exert broad-scale regulation of physiological, behavioral, and morphological traits that influence fitness under many life-history or environmental contexts. Yet the capacity for vertebrates to demonstrate different types of thermal plasticity, including rapid compensation or longer acclimation in glucocorticoid hormone function, when subject to different environmental temperature regimes remains poorly addressed...
July 2018: Physiological and Biochemical Zoology: PBZ
Jessica L Malisch, Daniel J Bennett, Brad A Davidson, Elizabeth E Wenker, Renee N Suzich, Erin E Johnson
Organisms experience stressors, and the physiological response to these stressors is highly conserved. Acute stress activates both the sympathetic nervous system and the hypothalamic-pituitary-adrenal axis, increasing epinephrine, norepinephrine, and glucocorticoids, collectively promoting glucose mobilization. While this is well characterized in mammals, the hyperglycemic response to stress in avian and nonavian reptiles has received less attention. A number of factors, ranging from time of day to blood loss, are reported to influence the extent to which acute stress leads to hyperglycemia in birds...
July 2018: Physiological and Biochemical Zoology: PBZ
Neil Hammerschlag, Rachel A Skubel, James Sulikowski, Duncan J Irschick, Austin J Gallagher
To fuel the high energetic demands of reproduction, vertebrates employ different tactics of resource use. Large sharks exhibit long gestation periods and have relatively few well-developed young, which likely incurs high energetic costs. However, information on the relationship between the reproductive and energetic states for most shark species is lacking. In the present study, we used a noninvasive approach to assess relationships among reproductive stage, plasma triglyceride levels, body condition, and circulating reproductive hormones in free-ranging female tiger sharks (Galeocerdo cuvier)...
July 2018: Physiological and Biochemical Zoology: PBZ
Julita Sadowska, Andrzej K Gębczyński, Marek Konarzewski
The majority of studies show that metabolic rates are usually repeatable at the individual level, although their repeatabilities tend to decline with time and to be strongly affected by physiological changes. Changes in individual repeatabilities may therefore affect putative differences between experimental groups or populations. This problem is particularly relevant to artificial selection experiments that apply the selection protocol at early life stages, running the risk of a poor correlation of the trait with itself throughout the life cycle of individuals...
July 2018: Physiological and Biochemical Zoology: PBZ
Alistair Dawson
Photoperiodic control of reproduction in birds is based on two processes, a positive effect leading to gonadal maturation and an inhibitory effect subsequently inducing regression. Nonphotoperiodic cues can modulate photoperiodic control, particularly the inhibitory process. In previous studies of common starlings (Sturnus vulgaris), (1) restriction of food availability to 8 h after dawn had little effect on testicular maturation but dramatically delayed subsequent regression and (2) lower ambient temperature also had little effect during maturation but delayed regression...
July 2018: Physiological and Biochemical Zoology: PBZ
Suvi Ruuskanen, Bin-Yan Hsu
Maternal effects are currently acknowledged as important causes of transgenerational phenotypic variation and a potential mechanism to adapt offspring to predicted environments, thus having a pivotal role in ecology and evolution. Research in hormonal mechanism underlying maternal effects has focused heavily on steroid hormones. Other hormones, such as thyroid hormones (THs; thyroxine and triiodothyronine), have been largely ignored in ecological research until recently. We summarize the recent findings, identify knowledge gaps, and provide future research directions investigating the role of TH-mediated maternal effects in ecological context across taxa...
May 2018: Physiological and Biochemical Zoology: PBZ
Collin J Horn, Monika K Mierzejewski, Lien T Luong
Host bioenergetics and energy fluxes can be applied to measure the ecological and physiological effects of parasitism. By measuring changes in host metabolic rate, one can estimate the physiological costs of infection. Additionally, metabolic rate dictates the rate of resource conversion within a host and, by extension, the resources available to a parasite. We hypothesize that parasites are selected to respond to cues that indicate high resource availability, that is, host metabolic state. We investigated whether an ectoparasite mite (Macrocheles subbadius) can differentiate between potential hosts (Drosophilia nigrospiracula) on the basis of relative carbon dioxide output as measured by respirometry...
May 2018: Physiological and Biochemical Zoology: PBZ
Konstantinos Feidantsis, Hans O Pörtner, Elisavet Vlachonikola, Efthimia Antonopoulou, Basile Michaelidis
Seasonal temperature changes may take organisms to the upper and lower limit of their thermal range, with respective variations in their biochemical and metabolic profile. To elucidate these traits, we investigated metabolic and antioxidant patterns in tissues of sea bream Sparus aurata during seasonal acclimatization for 1 yr in the field. Metabolic patterns were assessed by determining lactate dehydrogenase, citrate synthase, and β-hydroxyacyl CoA dehydrogenase activities, their kinetic properties and plasma levels of glucose, lactate, and triglycerides and tissue succinate levels...
May 2018: Physiological and Biochemical Zoology: PBZ
Jimena López-Arrabé, Pat Monaghan, Alejandro Cantarero, Winnie Boner, Lorenzo Pérez-Rodríguez, Juan Moreno
Oxidative stress can contribute to an acceleration of telomere erosion, leading to cellular senescence and aging. Increased investment in reproduction is known to accelerate senescence, generally resulting in reduced future reproductive potential and survival. To better understand the role played by oxidative status and telomere dynamics in the conflict between maintenance and reproduction, it is important to determine how these factors are related in parents and their offspring. We investigated the relationship between oxidative status and telomere measurements in pied flycatchers (Ficedula hypoleuca)...
May 2018: Physiological and Biochemical Zoology: PBZ
Catherine M Ivy, Julia M York, Sabine L Lague, Beverly A Chua, Luis Alza, Kevin G McCracken, William K Milsom, Graham R Scott
Hypoxia at high altitudes constrains O2 supply to support metabolism, thermoregulation in the cold, and exercise. High-altitude natives that somehow overcome this challenge-who live, reproduce, and sometimes perform impressive feats of exercise at high altitudes-are a powerful group in which to study the evolution of physiological systems underlying hypoxia resistance. Here, we sought to determine whether a common pulse oximetry system for rodents (MouseOx Plus) can be used reliably in studies of high-altitude birds by examining the hypoxia responses of the Andean goose...
May 2018: Physiological and Biochemical Zoology: PBZ
Chiara Morosinotto, Miia Rainio, Suvi Ruuskanen, Erkki Korpimäki
Prolonged physiological stress response may lead to an excessive production of reactive oxygen species (ROS) and ultimately to oxidative stress and severe fitness costs. We investigated whether natural variation in predation risk, induced by pygmy owls (Glaucidium passerinum), modifies the oxidative status of two free-living food-supplemented passerine bird species-the great tit (Parus major) and the willow tit (Poecile montanus)-in March 2012 and 2013. Predation risk significantly affected antioxidant enzyme activities of willow tits...
May 2018: Physiological and Biochemical Zoology: PBZ
Yufeng Zhang, Kang Nian Yap, Tony D Williams, David L Swanson
Skeletal muscle remodeling is an important component of phenotypic flexibility in birds and impacts organismal metabolism and performance, which could potentially influence fitness. One regulator of skeletal muscle remodeling is myostatin, an autocrine/paracrine muscle growth inhibitor that may be down-regulated under conditions promoting heavier muscle masses. In this study, we employed protocols requiring hovering while foraging to increase foraging costs and modify phenotypes of zebra finches (Taeniopygia guttata)...
May 2018: Physiological and Biochemical Zoology: PBZ
Raymond B Huey, C Richard Tracy
No abstract text is available yet for this article.
March 2018: Physiological and Biochemical Zoology: PBZ
Jonathan P Velotta, Stephen D McCormick, Andrew W Jones, Eric T Schultz
Whole-organism performance tasks are accomplished by the integration of morphological traits and physiological functions. Understanding how evolutionary change in morphology and physiology influences whole-organism performance will yield insight into the factors that shape its own evolution. We demonstrate that nonmigratory populations of alewife (Alosa pseudoharengus) have evolved reduced swimming performance in parallel, compared with their migratory ancestor. In contrast to theoretically and empirically based predictions, poor swimming among nonmigratory populations is unrelated to the evolution of osmoregulation and occurs despite the fact that nonmigratory alewives have a more fusiform (torpedo-like) body shape than their ancestor...
March 2018: Physiological and Biochemical Zoology: PBZ
Rebecca Rimbach, Jörg Jäger, Neville Pillay, Carsten Schradin
Resting metabolic rate (RMR) influences energy allocation to survival, growth, and reproduction, and significant seasonal changes in RMR have been reported. According to one hypothesis, seasonal changes in RMR are mainly attributable to seasonal changes in ambient temperature (Ta ) and food availability. Studies on species from the temperate zone indicated that food availability is the main driver. However, whether this is generally true is unknown, because studies from the tropics and subtropics, where most species live, are rare...
March 2018: Physiological and Biochemical Zoology: PBZ
Paul H Yancey, Ben Speers-Roesch, Sheila Atchinson, James D Reist, Andrew R Majewski, Jason R Treberg
Accumulation of trimethylamine N-oxide (TMAO) by deep-sea animals is proposed to protect proteins against the destabilizing effects of high hydrostatic pressure (the piezolyte hypothesis). Chondrichthyan fishes (sharks, rays, and chimaeras) provide a unique test of this hypothesis because shallow-living species have elevated TMAO levels to counteract the destabilizing effects of high urea levels accumulated for osmoregulation. Limited interspecific studies of chondrichthyans reveal that increasing depth correlates with decreased urea and increased TMAO levels, suggesting a dynamic balance between destabilizing forces on proteins (high urea, hydrostatic pressure) and TMAO to counteract these forces...
March 2018: Physiological and Biochemical Zoology: PBZ
Kim Frisch, Aage Kristian Olsen Alstrup
In recent decades, our knowledge of bile salts has undergone a vast development, and bile salts are now known not only for their detergent properties that aid in the absorption of dietary lipids but also for their interaction with specific nuclear and membrane receptors. In particular, it has been realized that the response of the farnesoid X receptor (FXR) to bile acids provides a signal bridge between the liver and small intestine, controlling the intracellular levels, biosynthesis, and enterohepatic circulation of bile acids...
March 2018: Physiological and Biochemical Zoology: PBZ
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