Living with voracious roommates: Factors that explain isotopic niche variation in a mixed colony of insectivorous bats.

Theory predicts that in resource-limited environments, coexisting species may overlap their niche dimensions but must differ in at least one to avoid competitive exclusion. Specifically, it has been suggested that the coexistence of competing species within a guild, could be sustained with mechanisms of resource partitioning, such as segregation along a trophic dimension. Among the most gregarious mammals are bats, which present diversification in their diet based on habitat choice and body size.

The effects of urban thermal heterogeneity and feather coloration on oxidative stress and metabolism of pigeons (Columba livia).

Urbanization stands out as a significant anthropogenic factor, exerting selective pressures on ecosystems and biotic components. A notable outcome of urbanization is thermal heterogeneity where the emergence of Urban Heat Islands is characterized by elevated air and surface temperatures compared to adjacent rural areas. Investigating the influence of thermal heterogeneity on urban animals could offer insights into how temperature variations can lead to phenotypic shifts.

Prenatal caloric restriction adjusts the energy homeostasis and behavior in response to acute and chronic variations in food availability in adulthood.

Fetal metabolic programming produced by unfavorable prenatal nutritional conditions leads to the development of a disorder called "thrifty phenotype", which is associated with pathologies such as diabetes and obesity in adulthood. However, from an ecophysiological approach, few studies have addressed the development of thrifty phenotypes in terms of energy. This might represent an adaptive advantage against caloric deficiency conditions extending into adulthood.

Hyperbaric oxygen treatment increases intestinal stem cell proliferation through the mTORC1/S6K1 signaling pathway in Mus musculus.

Background: Hyperbaric oxygen treatment (HBOT) has been reported to modulate the proliferation of neural and mesenchymal stem cell populations, but the molecular mechanisms underlying these effects are not completely understood. In this study, we aimed to assess HBOT somatic stem cell modulation by evaluating the role of the mTOR complex 1 (mTORC1), a key regulator of cell metabolism whose activity is modified depending on oxygen levels, as a potential mediator of HBOT in murine intestinal stem cells (ISCs).

Results: We discovered that acute HBOT synchronously increases the proliferation of ISCs without affecting the animal's oxidative metabolism through activation of the mTORC1/S6K1 axis.

Perinatal Food Deprivation Modifies the Caloric Restriction Response in Adult Mice Through Sirt1.

Variations in the availability of nutritional resources in animals can trigger reversible adjustments, which in the short term are manifested as behavioral and physiological changes. Several of these responses are mediated by Sirt1, which acts as an energy status sensor governing a global genetic program to cope with changes in nutritional status. Growing evidence suggests a key role of the response of the perinatal environment to caloric restriction in the setup of physiological responses in adulthood.

The Netrin-1-Neogenin-1 signaling axis controls neuroblastoma cell migration via integrin-β1 and focal adhesion kinase activation.

Neuroblastoma is a highly metastatic tumor that emerges from neural crest cell progenitors. Focal Adhesion Kinase (FAK) is a regulator of cell migration that binds to the receptor Neogenin-1 and is upregulated in neuroblastoma. Here, we show that Netrin-1 ligand binding to Neogenin-1 leads to FAK autophosphorylation and integrin β1 activation in a FAK dependent manner, thus promoting neuroblastoma cell migration.

Effect of salinity acclimation on osmoregulation, oxidative stress, and metabolic enzymes in the invasive Xenopus laevis.

Aquatic animals often display physiological adjustments to improve their biological performance and hydrosaline balance in saline environments. In addition to energetic costs associated with osmoregulation, oxidative stress, and the activation of the antioxidant system are common cellular responses to salt stress in many species, but the knowledge of osmoregulation-linked oxidative homeostasis in amphibians is scarce. Here we studied the biochemical responses and oxidative responses of Xenopus laevis females exposed for 40 days to two contrasting salinities: hypo-osmotic (150 mOsm·kg ·H O NaCl, HYPO group) and hyper-osmotic environments (340 mOsm·kg ·H O NaCl, HYPER group).

Costs of exploratory behavior: the energy trade-off hypothesis and the allocation model tested under caloric restriction.

In order to maintain the energy balance, animals often exhibit several physiological adjustments when subjected to a decrease in resource availability. Specifically, some rodents show increases in behavioral activity in response to food restriction; a response regarded as a paradox because it would imply an investment in locomotor activity, despite the lack of trophic resources. Here, we aim to explore the possible existence of trade-offs between metabolic variables and behavioral responses when rodents are faced to stochastic deprivation of food and caloric restriction.

Oxidative status and metabolic profile in a long-lived bird preparing for extreme endurance migration.

The high metabolic activity associated with endurance flights and intense fuelling of migrant birds may produce large quantities of reactive oxygen species, which cause oxidative damage. Yet it remains unknown how long-lived birds prepare for oxidative challenges prior to extreme flights. We combined blood measurements of oxidative status and enzyme and fat metabolism in Hudsonian godwits (Limosa haemastica, a long-lived shorebird) before they embarked on non-stop flights longer than 10,000 km during their northbound migrations.

The interplay between ambient temperature and salt intake affects oxidative status and immune responses in a ubiquitous Neotropical passerine, the rufous-collared sparrow.

Physiological traits associated with maintenance, growth, and reproduction demand a large amount of energy and thus directly influence an animal's energy budget, which is also regulated by environmental conditions. In this study, we evaluated the interplay between ambient temperature and salinity of drinking water on energy budgets and physiological responses in adult Rufous-collared sparrow (Zonotrichia capensis), an omnivorous passerine that is ubiquitous in Chile and inhabits a wide range of environments. We acclimated birds to 30 days at two ambient temperatures (27 °C and 17 °C) and drinking water salinity (200 mM NaCl and fresh water) conditions.

Adaptive Physiological and Morphological Adjustments Mediated by Intestinal Stem Cells in Response to Food Availability in Mice.

Several studies have evaluated plastic changes in the morphology of the digestive tract in rodents subjected to caloric restriction or restricted availability. Nevertheless, studies that link these morphological responses to physiological consequences are scarce. In order to investigate short-term plastic responses in the intestine, we acclimated adult (BALB/c) males for 20 days to four distinctive treatments: two caloric regimens ( and 60% of calorie ingestion) and two levels of periodicity of the regimens (continuous and stochastic treatment).

Hyperbaric Oxygen Increases Stem Cell Proliferation, Angiogenesis and Wound-Healing Ability of WJ-MSCs in Diabetic Mice.

Hyperbaric oxygen therapy (HBOT) is effective for the medical treatment of diverse diseases, infections, and tissue injury. In fact, in recent years there is growing evidence on the beneficial effect of HBOT on non-healing ischemic wounds. However, there is still yet discussion on how this treatment could benefit from combination with regenerative medicine strategies.

Coping with Salt Water Habitats: Metabolic and Oxidative Responses to Salt Intake in the Rufous-Collared Sparrow.

Many physiological adjustments occur in response to salt intake in several marine taxa, which manifest at different scales from changes in the concentration of individual molecules to physical traits of whole organisms. Little is known about the influence of salinity on the distribution, physiological performance, and ecology of passerines; specifically, the impact of drinking water salinity on the oxidative status of birds has been largely ignored. In this study, we evaluated whether experimental variations in the salt intake of a widely-distributed passerine () could generate differences in basal (BMR) and maximum metabolic rates (M), as well as affect metabolic enzyme activity and oxidative status.

Energetic Effects of Pre-hatch Albumen Removal on Embryonic Development and Early Ontogeny in .

Studies on the yolk and albumen content in bird eggs, and the effects of variations in their relative loads in the phenotype of the birds, have revealed multiple consequences at different levels of biological organization, from biochemical traits to behavior. However, little is known about the effect of albumen variation on energetics performance during development and early ontogeny, despite the fact that variation in energy expenditure may have consequences in terms of fitness for both feral and domestic species. In this work, we evaluated experimentally whether variations in the content of albumen of eggs could generate differences in metabolic rates during embryonic development.

Metabolic cost of osmoregulation in a hypertonic environment in the invasive African clawed frog Xenopus laevis.

Studies of aquatic invertebrates reveal that salinity affects feeding and growth rates, reproduction, survival, and diversity. Little is known, however, about how salinity impacts the energy budget of vertebrates and amphibians in particular. The few studies focused on this topic in vertebrates suggest that the ingestion of salts and the resulting osmoregulatory activity is energetically expensive.

Osmoregulatory and metabolic costs of salt excretion in the Rufous-collared sparrow Zonotrichia capensis.

Recent experiments on shorebirds have demonstrated that maintaining an active osmoregulatory machinery is energetically expensive. This may, in part, explain diet and habitat selection in birds with salt glands. However little is known about the osmoregulatory costs in birds lacking functional salt glands.