1,287 research outputs found

    Physiology, environmental change, and anuran conservation

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    This paper reviews diverse ways in which the emerging discipline of conservation physiology may contribute to the conservation of anuran amphibians. We first present a summary of the goals of conservation physiology. Then, we review five specific sources of environmental change that are known to affect anurans: introduced pathogens (highlighting the case of chytridiomycosis) and exotic species, pollutants, habitat fragmentation, and global climate change. We discuss these types of environmental change in the context of how and why altered environments may become stressing to anurans and cause population declines. We also discuss synergism among variables that may worsen the effect of environmental alterations, and emphasize the importance of conservation physiology for Brazilian anurans

    Desiccation Risk Drives the Spatial Ecology of an Invasive Anuran (Rhinella marina) in the Australian Semi-Desert

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    Some invasive species flourish in places that impose challenges very different from those faced in their native geographic ranges. Cane toads (Rhinella marina) are native to tropical and subtropical habitats of South and Central America, but have colonised extremely arid regions over the course of their Australian invasion. We radio-tracked 44 adult cane toads at a semi-arid invasion front to investigate how this invasive anuran has managed to expand its geographic range into arid areas that lie outside of its native climatic niche. As predicted from their low physiological control over rates of evaporative water loss, toads selected diurnal shelter sites that were consistently cooler and damper (and thus, conferred lower water loss rates) than nearby random sites. Desiccation risk also had a profound influence on rates of daily movement. Under wet conditions, toads that were far from water moved further between shelter sites than did conspecifics that remained close to water, presumably in an attempt to reach permanent water sources. However, this relationship was reversed under dry conditions, such that only toads that were close to permanent water bodies made substantial daily movements. Toads that were far from water bodies also travelled along straighter paths than did conspecifics that generally remained close to water. Thus, behavioural flexibility—in particular, an ability to exploit spatial and temporal heterogeneity in the availability of moist conditions—has allowed this invasive anuran to successfully colonize arid habitats in Australia. This finding illustrates that risk assessment protocols need to recognise that under some circumstances an introduced species may be able to thrive in conditions far removed from any that it experiences in its native range

    Editorial: Efeitos das mudanças ambientais globais e regionais sobre a fauna

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    Territory quality and male dominance in Tropidurus torquatus (Squamata, Tropiduridae)

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    In territorial species, females are often attracted by high-quality territories, which are expected to be owned by males that successfully won competition with other males. Because morphological and behavioral traits frequently influence males' combat success, these parameters may be used by females to assess the male (and associated territory) quality. In the present study, we tested the hypothesis that organismal traits in dominant males of the lizard Tropidurus torquatus are associated with the quality of the territory owned. After characterizing the territories occupied, we used a discriminant analysis to test if morphological and behavioral traits of the dominant male predict the quality of the territory owned. High-quality territories were characterized by a larger number of refuges, shorter distances among shelters and a well-defined harem, in comparison with low-quality territories. Organismal traits predicted with 100% accuracy the type of the territory owned: high-quality territories were associated with larger males that had longer heads, while males occupying low-quality territories exhibited more head displays, traveled larger distances and ran slightly slower than those associated with high-quality territories. We discuss possible implications of territory quality and male traits for reproductive success in Tropidurus torquatus

    Se extinções associadas a mudanças climáticas são eventos naturais, por que devemos nos preocupar com o cenário atual?

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    The climate of Earth is changing in parallel to an accelerated biodiversity lost. Massive extinctions associated with climate change happened already along the history of life in the Earth. So, are we witnessing one more event of natural mass extinction? This assay aims to discuss this question.O clima da Terra está mudando e, simultaneamente, presenciamos uma acelerada perda da biodiversidade. Grandes extinções derivadas de mudanças climáticas já aconteceram na vida na Terra. Estamos, então, presenciando mais um evento natural de extinção em massa? Este ensaio visa discutir essa pergunta

    Urban Physiology: City Ants Possess High Heat Tolerance

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    Urbanization has caused regional increases in temperature that exceed those measured on a global scale, leading to urban heat islands as much as 12°C hotter than their surroundings. Optimality models predict ectotherms in urban areas should tolerate heat better and cold worse than ectotherms in rural areas. We tested these predications by measuring heat and cold tolerances of leaf-cutter ants from South America's largest city (São Paulo, Brazil). Specifically, we compared thermal tolerances of ants from inside and outside of the city. Knock-down resistance and chill-coma recovery were used as indicators of heat and cold tolerances, respectively. Ants from within the city took 20% longer to lose mobility at 42°C than ants from outside the city. Interestingly, greater heat tolerance came at no obvious expense of cold tolerance; hence, our observations only partially support current theory. Our results indicate that thermal tolerances of some organisms can respond to rapid changes in climate. Predictive models should account for acclimatory and evolutionary responses during climate change

    Commercially available endoscopy facemasks to prevent aerosolizing spread of droplets during COVID-19 outbreak

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    We read with great interest the ESGE and ESGENA Position Statement [1] on gastrointestinal endoscopy and the COVID-19 pandemic. We share the concerns listed in the suggested research agenda, particularly about enhancing procedural protection in the endoscopy unit to reduce risk of COVID-19 dissemination. We would like to bring attention to commercially available endoscopy masks that can be used to avoid aerosolizing spread of droplets during upper endoscopic procedures. These products seem to improve intra-procedure risk management and can serve as an alternative to a modified ventilation mask reported for this purpose by Marchese et al [2]

    Interdisciplinary discussions on palliative care among university students in Spain: giving voice to the social debate

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    Background: University students are the future professionals who will influence society. It is thus essential to improve students' understanding of palliative care (PC), especially those in the non-health field, to generate and encourage propitious opinions about PC. This study describes the perceptions of PC among university students from different disciplines. Method: Qualitative exploratory study using virtual focus groups (FGs) and design thinking (DT) approach. An intentional sample of students from various disciplines, universities and cities from Spain were selected. Numerous researchers from different fields were involved in the discussion of the final thematic analysis. Results: Four themes and seven subthemes were found: i) Students have an ambiguous understanding about PC; ii) PC is not a common issue for non-health students; ii) Students see PC as an important and necessary field; iii) Students build counter-narratives against PC myths, demonstrating PC brings key benefits into people's lives; iv) PC is a synonym of death. Conclusion: Despite the fact that students do not know much about PC, the topic easily arouses reflection and positive discussion. Through the conversations they find positive values and arguments against misunderstand- ing. Students from different disciplines could be the target of innovative educational initia- tives and the social debate on PC

    Sticking under wet conditions: the remarkable attachment abilities of the torrent frog, staurois guttatus

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    Tree frogs climb smooth surfaces utilising capillary forces arising from an air-fluid interface around their toe pads, whereas torrent frogs are able to climb in wet environments near waterfalls where the integrity of the meniscus is at risk. This study compares the adhesive capabilities of a torrent frog to a tree frog, investigating possible adaptations for adhesion under wet conditions. We challenged both frog species to cling to a platform which could be tilted from the horizontal to an upside-down orientation, testing the frogs on different levels of roughness and water flow. On dry, smooth surfaces, both frog species stayed attached to overhanging slopes equally well. In contrast, under both low and high flow rate conditions, the torrent frogs performed significantly better, even adhering under conditions where their toe pads were submerged in water, abolishing the meniscus that underlies capillarity. Using a transparent platform where areas of contact are illuminated, we measured the contact area of frogs during platform rotation under dry conditions. Both frog species not only used the contact area of their pads to adhere, but also large parts of their belly and thigh skin. In the tree frogs, the belly and thighs often detached on steeper slopes, whereas the torrent frogs increased the use of these areas as the slope angle increased. Probing small areas of the different skin parts with a force transducer revealed that forces declined significantly in wet conditions, with only minor differences between the frog species. The superior abilities of the torrent frogs were thus due to the large contact area they used on steep, overhanging surfaces. SEM images revealed slightly elongated cells in the periphery of the toe pads in the torrent frogs, with straightened channels in between them which could facilitate drainage of excess fluid underneath the pad
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