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1.
Pediatrics ; 153(Suppl 2)2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38300010

RESUMO

Using multiple metrics, the diversity of the pediatric population in the United States is increasing. However, recent data suggest significant disparities in both the prevalence and management of child health conditions cared for by pediatric subspecialists. These inequities occur across multiple dimensions of diversity, including race and ethnicity, country of origin, socioeconomic status, sex and gender, and disability. Research also suggests that attending to diversity, equity, and inclusion in the medical workforce may positively affect health outcomes. High-quality pediatric subspecialty care thus requires knowledge of these data, attention to the effects of social drivers, including racism and discrimination, on health and wellbeing, and interventions to improve pediatric health equity through educational, practice, policy, and research innovations. In this article, we review data on the diversity of the pediatric population and pediatric subspecialty workforce, suggest potential strengths, weaknesses, opportunities, and threats of current diversity, equity, and inclusion initiatives in academic pediatrics, and provide recommendations across 4 domains: education and training, practice, policy, and future research. The ultimate goal of pediatrics is to improve health equity for all infants, children, adolescents, and young adults cared for in the United States by pediatric subspecialists.


Assuntos
Saúde da Criança , Diversidade, Equidade, Inclusão , Adolescente , Lactente , Feminino , Masculino , Adulto Jovem , Humanos , Criança , Escolaridade , Benchmarking , Recursos Humanos
2.
Transfusion ; 64(1): 104-115, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-38098310

RESUMO

BACKGROUND AND OBJECTIVES: We evaluated the operational and safety impact of implementing anaerobic culture screening of apheresis and pooled platelets at the American Red Cross on the already established use of the aerobic culture screening of each donation performed no sooner than 24 h following collection. MATERIALS AND METHODS: Platelets were screened for bacterial contamination with the BACT/ALERT 3D® (bioMérieux, Durham, NC) microbial detection testing system. The addition of anaerobic culture to the already existing aerobic culture resulted in sampling an additional 8-10 mL from each donation. RESULTS: Implementation of anaerobic testing resulted in an approximate 3.5-fold increased rate of False Positive BACT/ALERT alarms. There was a modest increase in the rate of True Positive alarms of 1.4-fold with increased detection of Klebsiella and Propionibacterium species, including Cutibacterium acnes. In addition, there was an approximate 3.5-fold increase rate of False Positives and a 13.5-fold increase rate of Indeterminates, the majority (~57%) were due to Cutibacterium acnes. The combined costs and lost revenue associated with adding anaerobic screening increased by ~$1,000,000/year due to testing cost and product discards. CONCLUSION: The addition of anaerobic culture to aerobic culture to the original donation (without the introduction of sampling delay) resulted in a significant increase in the rate of alerts. The 40% increased rate of True Positive alarms may have modestly improved platelet safety. However, there was a disproportionate increase in the rate of False Positive and Indeterminate bacterial culture alarms, which added substantial cost and overall loss of platelet products.


Assuntos
Remoção de Componentes Sanguíneos , Plaquetas , Humanos , Anaerobiose , Plaquetas/microbiologia , Bactérias , Contaminação de Medicamentos , Técnicas Bacteriológicas
3.
Opt Express ; 31(21): 35131-35142, 2023 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-37859251

RESUMO

Hyper-entanglement between two or more photonic degrees of freedom (DOF) can enhance and enable new quantum protocols by allowing each DOF to perform the task it is optimally suited for. Here we demonstrate the generation of photon pairs hyper-entangled between pulse modes and frequency bins. The pulse modes are generated via parametric downconversion in a domain-engineered crystal and subsequently entangled to two frequency bins via a spectral mapping technique. The resulting hyper-entangled state is characterized and verified via measurement of its joint spectral intensity and non-classical two-photon interference patterns from which we infer its spectral phase. The protocol combines the robustness to loss, intrinsic high dimensionality and compatibility with standard fiber-optic networks of the energy-time DOF with the ability of hyper-entanglement to increase the capacity and efficiency of the quantum channel, already exploited in recent experimental applications in both quantum information and quantum computation.

4.
Cureus ; 15(9): e45100, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37842373

RESUMO

Sarcoidosis is a systemic disorder characterized by the aberrant development of granulomatous inflammation within various organs in the body. In over 90% of cases, sarcoidosis typically manifests initially in the intra-thoracic region, characterized by pulmonary involvement or mediastinal lymphadenopathy. It is rare for sarcoidosis to manifest exclusively as extra-thoracic involvement and even more rarely for hypercalcemia to be the only initial sign. We present a case of a 70-year-old female with hypercalcemia and elevated 1,25-dihydroxyvitamin D3 (1,25(OH)2 D) which raised the suspicion of a granulomatous disease. Granulomatous diseases increase levels of 1,25(OH)2 D via the abnormal expression of 1 alpha-hydroxylase enzyme; therefore, these conditions should be considered in the differential diagnosis when encountered with hypercalcemia. PET-CT showed increased FDG uptake in the reticuloendothelial system. An easily accessible inguinal lymph node biopsy was performed which revealed non-necrotizing granulomatous inflammation. Other causes of non-necrotizing granulomatous diseases, cancer, and lymphoma were ruled out, leading to sarcoidosis being considered as a possible diagnosis. When diagnosing sarcoidosis, other potential causes of granulomatous inflammation need to be ruled out definitively via laboratory findings, imaging, and tissue histopathology before initiation of treatment with steroids. Treatment with glucocorticoids remains the mainstay therapy of 1,25(OH)2 D-mediated hypercalcemia associated with sarcoidosis. The patient was accordingly treated with prednisone which led to the normalization of calcium and 1,25(OH)2 D levels within three weeks. Here, we discuss the clinical features and investigations of extra-pulmonary sarcoidosis for early diagnosis and management.

5.
Biology (Basel) ; 12(3)2023 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-36979053

RESUMO

Loss of hollow-bearing trees threatens many hollow-dependent wildlife. To mitigate this process, artificial chainsaw-carved hollows (CHs) are often created in dead trees, yet little is known about their thermal profiles. We measured temperatures inside 13 natural hollows (8 live and 5 dead trees) and 45 CHs (5 live and 40 dead trees) in the central west of NSW, Australia, over the course of 2 summers. Maximum temperatures and daily temperature ranges within natural hollows and artificial hollows were similar in 2017-2018. Hollow temperatures were lower in thicker-walled hollows than in thinner-walled hollows. During the January 2019 heatwave, temperatures inside CHs in dead trees exceeded 4-35 °C higher than the upper limit of the thermal neutral zone of sugar gliders-for 6.2 consecutive days (range 0-9 days). CHs in dead trees provided little buffering from thermal extremes; when air temperatures peaked at 44.6 °C, CHs in dead trees were on average 2.4 °C cooler than ambient (range: 5.5 °C cooler to 1.0 °C hotter than ambient). These results show that CHs created in dead trees may not provide suitable thermal conditions for hollow-dependent marsupials during summer heatwaves. Retention of large live trees, coupled with revegetation, is crucial for conserving hollow-dependent fauna in agricultural landscapes.

6.
Biology (Basel) ; 11(9)2022 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-36138760

RESUMO

Most lizards lay eggs inside nests where embryos experience daily fluctuations in temperature. As embryos are sensitive to exposure to high temperatures, increases in nest temperatures may pose a risk to lizards. In the velvet gecko Amalosia lesueurii, nest temperatures are positively correlated with air temperatures, so nests may get hotter in future. However, maternal variation in oviposition site choice might buffer populations from future warming. To evaluate the consequences of oviposition site choice, we incubated eggs under two fluctuating temperature regimes that mimicked temperatures experienced inside sun-exposed ("warm": mean = 25.4 °C; range = 16.5-35.5 °C) and shaded ("cold": mean = 23.3 °C; 17.5-30.5 °C) communal nests. We measured the phenotypic traits of hatchlings, released them to the wild, and monitored their survival over 6 months. Warm-incubated hatchlings hatched 15 days earlier, on average, and were smaller than their cold-incubated clutch mates. Incubation treatment did not influence the apparent survival of hatchlings. Hence, even if air temperatures increase by 2 °C in future, thermal regimes inside some currently used shaded nests will be suitable for embryo development. Maternal variation in nest site choice may therefore allow southern populations of the velvet gecko to persist in changing environments.

7.
J Therm Biol ; 102: 103121, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34863484

RESUMO

In many oviparous reptiles, thermal conditions inside nests influence phenotypic traits of hatchlings that are linked to survival. Maternal nest-site selection can therefore have long-term implications for offspring and maternal fitness. We studied nest-site selection in a nocturnal lizard (Amalosia lesueurii) from south eastern Australia. Females of this species lay their eggs communally inside rock crevices, and previous studies have shown that maximum daily nest temperatures are positively correlated with maximum daily air temperatures. The incubation period extends for up to 100 d, so during hot summers, embryos may be exposed to stressful thermal conditions. Potentially, mothers could buffer their eggs from thermal extremes via careful selection of nest sites. To evaluate this, we studied nest site selection in a southern population (Morton) and a northern population (Yengo) that experience mild and hot summers respectively. In the field, we measured the physical characteristics, orientation, canopy cover and incident radiation load, and thermal regimes of nest sites and randomly available crevices during one of the hottest Australian summers on record (2018-2019). We found strong inter population differences in the degree of canopy cover and solar radiation loads above nest sites. Nest sites from Morton were more open, and received higher radiation loads, than nest sites from Yengo. Mean nest temperatures were similar in Morton and Yengo, but nests from Yengo experienced higher daily temperatures than those from Morton. During heatwaves, temperatures in some nests exceeded the species critical thermal maximum (39.9 °C) for several hours each day. Our results show that females can adjust nest-site choice to match local environments, but future research is necessary to clarify whether exposure to high temperatures influences hatching success or offspring phenotypes in this species.


Assuntos
Ecossistema , Temperatura Alta , Lagartos , Comportamento de Nidação , Animais , Feminino , New South Wales
8.
Sci Rep ; 11(1): 18035, 2021 09 10.
Artigo em Inglês | MEDLINE | ID: mdl-34508110

RESUMO

Tooling is associated with complex cognitive abilities, occurring most regularly in large-brained mammals and birds. Among birds, self-care tooling is seemingly rare in the wild, despite several anecdotal reports of this behaviour in captive parrots. Here, we show that Bruce, a disabled parrot lacking his top mandible, deliberately uses pebbles to preen himself. Evidence for this behaviour comes from five lines of evidence: (i) in over 90% of instances where Bruce picked up a pebble, he then used it to preen; (ii) in 95% of instances where Bruce dropped a pebble, he retrieved this pebble, or replaced it, in order to resume preening; (iii) Bruce selected pebbles of a specific size for preening rather than randomly sampling available pebbles in his environment; (iv) no other kea in his environment used pebbles for preening; and (v) when other individuals did interact with stones, they used stones of different sizes to those Bruce preened with. Our study provides novel and empirical evidence for deliberate self-care tooling in a bird species where tooling is not a species-specific behaviour. It also supports claims that tooling can be innovated based on ecological necessity by species with sufficiently domain-general cognition.


Assuntos
Comportamento Animal , Papagaios/fisiologia , Autocuidado , Animais , Animais Selvagens , Nova Zelândia , Autocuidado/instrumentação , Autocuidado/métodos
9.
Ecology ; 102(7): e03363, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33830501

RESUMO

The arrival of novel predators can trigger trophic cascades driven by shifts in prey numbers. Predators also elicit behavioral change in prey populations, via phenotypic plasticity and/or rapid evolution, and such changes may also contribute to trophic cascades. Here, we document rapid demographic and behavioral changes in populations of a prey species (grassland melomys Melomys burtoni, a granivorous rodent) following the introduction of a novel marsupial predator (northern quoll Dasyurus hallucatus). Within months of quolls appearing, populations of melomys exhibited reduced survival and population declines relative to control populations. Quoll-invaded populations were also significantly shyer than nearby, quoll-free populations of conspecifics. This rapid but generalized response to a novel threat was replaced over the following 2 yr with more threat-specific antipredator behaviors (i.e., predator-scent aversion). Predator-exposed populations, however, remained more neophobic than predator-free populations throughout the study. These behavioral responses manifested rapidly in changed rates of seed predation by melomys across treatments. Quoll-invaded melomys populations exhibited lower per-capita seed take rates, and rapidly developed an avoidance of seeds associated with quoll scent, with discrimination playing out over a spatial scale of tens of meters. Presumably the significant and novel predation pressure induced by quolls drove melomys populations to fine-tune behavioral responses to be more predator specific through time. These behavioral shifts could reflect individual plasticity (phenotypic flexibility) in behavior or may be adaptive shifts from natural selection imposed by quoll predation. Our study provides a rare insight into the rapid ecological and behavioral shifts enacted by prey to mitigate the impacts of a novel predator and shows that trophic cascades can be strongly influenced by behavioral as well as numerical responses.


Assuntos
Marsupiais , Comportamento Predatório , Animais , Odorantes , Seleção Genética
10.
Sci Rep ; 11(1): 5380, 2021 03 08.
Artigo em Inglês | MEDLINE | ID: mdl-33686113

RESUMO

Global wildlife trade is a multibillion-dollar industry and a significant driver of vertebrate extinction risk. Yet, few studies have quantified the impact of wild harvesting for the illicit pet trade on populations. Long-lived species, by virtue of their slow life history characteristics, may be unable to sustain even low levels of collecting. Here, we assessed the impact of illegal collecting on populations of endangered broad-headed snakes (Hoplocephalus bungaroides) at gated (protected) and ungated (unprotected) sites. Because broad-headed snakes are long-lived, grow slowly and reproduce infrequently, populations are likely vulnerable to increases in adult mortality. Long-term data revealed that annual survival rates of snakes were significantly lower in the ungated population than the gated population, consistent with the hypothesis of human removal of snakes for the pet trade. Population viability analysis showed that the ungated population has a strongly negative population growth rate and is only prevented from ultimate extinction by dispersal of small numbers of individuals from the gated population. Sensitivity analyses showed that the removal of a small number of adult females was sufficient to impose negative population growth and suggests that threatened species with slow life histories are likely to be especially vulnerable to illegal collecting.


Assuntos
Conservação dos Recursos Naturais , Elapidae/fisiologia , Espécies em Perigo de Extinção , Animais , Humanos
11.
Conserv Biol ; 35(4): 1245-1255, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33502048

RESUMO

Cultural adaptation is one means by which conservationists may help populations adapt to threats. A learned behavior may protect an individual from a threat, and the behavior can be transmitted horizontally (within generations) and vertically (between generations), rapidly conferring population-level protection. Although possible in theory, it remains unclear whether such manipulations work in a conservation setting; what conditions are required for them to work; and how they might affect the evolutionary process. We examined models in which a population can adapt through both genetic and cultural mechanisms. Our work was motivated by the invasion of highly toxic cane toads (Rhinella marina) across northern Australia and the resultant declines of endangered northern quolls (Dasyurus hallucatus), which attack and are fatally poisoned by the toxic toads. We examined whether a novel management strategy in which wild quolls are trained to avoid toads can reduce extinction probability. We used a simulation model tailored to quoll life history. Within simulations, individuals were trained and a continuous evolving trait determined innate tendency to attack toads. We applied this model in a population viability setting. The strategy reduced extinction probability only when heritability of innate aversion was low (<20%) and when trained mothers trained >70% of their young to avoid toads. When these conditions were met, genetic adaptation was slower, but rapid cultural adaptation kept the population extant while genetic adaptation was completed. To gain insight into the evolutionary dynamics (in which we saw a transitory peak in cultural adaptation over time), we also developed a simple analytical model of evolutionary dynamics. This model showed that the strength of natural selection declined as the cultural transmission rate increased and that adaptation proceeded only when the rate of cultural transmission was below a critical value determined by the relative levels of protection conferred by genetic versus cultural mechanisms. Together, our models showed that cultural adaptation can play a powerful role in preventing extinction, but that rates of cultural transmission need to be high for this to occur.


La adaptación cultural es un medio mediante el cual los conservacionistas pueden ayudar a las poblaciones a adaptarse a las amenazas. Un comportamiento aprendido puede proteger a un individuo de las amenazas y este comportamiento puede transmitirse horizontalmente (dentro de las generaciones) y verticalmente (entre generaciones), lo que otorga rápidamente una protección a nivel poblacional. Aunque esto es posible en teoría, aún no está claro si dichas manipulaciones funcionan dentro de un escenario de conservación; cuáles son las condiciones requeridas para que funcionen las manipulaciones; y cómo pueden afectar el proceso evolutivo. Examinamos modelos en los cuales una población puede adaptarse tanto con mecanismos genéticos como culturales. Nuestro trabajo estuvo motivado por la invasión de sapos altamente tóxicos (Rhinella marina) en todo el norte de Australia y las declinaciones resultantes de cuoles norteños (Dasyurus hallucatus), los cuales atacan y mueren envenenados por los sapos tóxicos. Analizamos si una estrategia de manejo novedoso en la cual los cuoles silvestres son entrenados para evitar a los sapos puede reducir la probabilidad de extinción. Usamos un modelo de simulación diseñado alrededor de la historia de vida de los cuoles. Dentro de las simulaciones, se entrenó a cuoles individuales y una característica en continua evolución determinó la tendencia innata para atacar a los sapos. Aplicamos este modelo en un escenario de viabilidad poblacional. La estrategia redujo la probabilidad de extinción sólo cuando la heredabilidad de la aversión innata fue baja (<20%) y cuando las madres entrenadas entrenaron a más del 70% de sus crías para evitar a los sapos. Cuando ambas condiciones fueron cumplidas, la adaptación genética fue más lenta pero la adaptación cultural rápida mantuvo a la población vigente mientras se completaba la adaptación genética. Para ganar conocimiento sobre las dinámicas evolutivas (en las cuales vimos un pico transitorio en la adaptación cultural a lo largo del tiempo) también desarrollamos un modelo analítico simple de las dinámicas evolutivas. Este modelo mostró que la fuerza de la selección natural declinó conforme incrementó la tasa de transmisión cultural y que la adaptación procedió solamente cuando la tasa de transmisión cultural estuvo por debajo de un valor crítico determinado por los niveles relativos de protección otorgados por los mecanismos genéticos contra los mecanismos evolutivos. En conjunto, nuestros modelos mostraron que la adaptación cultural puede jugar un papel importante en la prevención de la extinción, pero las tasas de transmisión cultural necesitan ser altas para que esto ocurra.


Assuntos
Conservação dos Recursos Naturais , Marsupiais , Animais , Evolução Biológica , Bufo marinus , Humanos , Fenótipo
12.
J Therm Biol ; 93: 102728, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33077139

RESUMO

The locomotor performance of reptiles is profoundly influenced by temperature, but little is known about how the time of day when the animal is usually active may influence performance. Time of day may be particularly relevant for studies on nocturnal reptiles that thermoregulate by day, but are active at night when ambient temperatures are cooler. If selection favours individuals that match their performance to activity times, then nocturnal species should perform better during the night, when they are normally active, than during the day. To test this hypothesis, we investigated how the time of day and body temperature affected the locomotor performance of adult females of the velvet gecko (Amalosia lesueurii). We measured the sprint speeds, running speeds and number of stops of 43 adult females at four different body temperatures (20, 25, 30 and 35 °C) during the day and at night. At night, sprint speeds were higher at 20 and 35 °C but sprint speeds were similar at 25 and 30 °C. By day, sprint speed increased with body temperature, peaking at 30 °C, before declining at 35 °C. However, gecko speeds over 1 m was higher at night at all four test temperatures than by day. Number of stops showed broadly similar patterns and females stopped almost twice as often on the racetrack during the day than they did at night. Furthermore, the thermal breadth of performance differed depending on when geckos were tested. Our results demonstrate that both body temperature and the time of day affects the behaviour and locomotor performance of female velvet geckos, with geckos running faster at night, the time of day when they are usually active. This study adds to evidence that both body temperature and the time of day are crucial for estimating the performance of ectotherms and evaluations and predictions of their vulnerability to climate warming should consider the context of laboratory experimental design.


Assuntos
Ciclos de Atividade , Lagartos/fisiologia , Fotoperíodo , Temperatura Cutânea , Animais , Movimento
13.
J Therm Biol ; 91: 102625, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32716874

RESUMO

Despite its tropical origin, the Asian house gecko (Hemidactylus frenatus) is currently invading higher latitudes around the world. In this study, we investigated whether the introduced geckos in the subtropical/temperate region of southeastern Australia have shifted their thermal biology to cope with colder temperatures. In the lab, we measured the body temperatures of geckos from Thailand and Australia in a cost-free thermal gradient. Native H. frenatus from Thailand displayed a diel pattern of thermoregulation. Geckos maintained higher body temperatures during mid-afternoon and at dusk but selected cooler temperatures during the night. Introduced geckos showed a similar pattern of thermoregulation, but selected lower body temperatures in summer (mean = 28.9 °C) and winter (mean = 25.5 °C) than native geckos (mean = 31.5 °C). While the Asian house geckos from Thailand did not alter their body temperatures after feeding, their conspecifics from southeastern Australia selected body temperatures that were 1.6-3.1 °C higher after feeding. In conclusion, our study shows that invasive house geckos in Australia have shifted their preferred body temperatures downwards relative to their native conspecifics in Thailand, presumably as a result of plasticity or natural selection. Our findings suggest that these tropical geckos have adapted to colder regions, and thus, they may spread much further than expected for a tropical ectotherm.


Assuntos
Aclimatação , Temperatura Corporal , Espécies Introduzidas , Lagartos/fisiologia , Distribuição Animal , Animais
14.
Anim Cogn ; 23(4): 613-620, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32130559

RESUMO

Stressful environments in utero can have a profound influence on cognitive functions and learning ability. In lizards, thermal environments experienced by embryos can shape a range of traits, including sex, body size, and locomotor performance, which may influence fitness. Recent studies suggest that incubation temperatures may also influence brain development and learning ability of some lizard species. Therefore, predicted increases in nest temperatures of lizards may not only affect hatchling morphology and performance, but could also affect their learning ability. To investigate how incubation temperatures influence cognitive abilities of hatchlings, we incubated eggs of the velvet gecko, Amalosia lesueurii, under two fluctuating temperature regimes. The warm treatment mimicked the thermal profiles of currently used partly shaded communal nests (mean = 24.3 °C, range 18.4-31.1 °C), and the hot treatment simulated thermal profiles that could be experienced in sun-exposed nests in 2050 (mean = 28.9 °C, range 19.1-38.1 °C). At age three to four weeks, we measured the ability of hatchlings to locate an open shelter in a Y-maze choice test. Both hot and warm-incubated hatchlings successfully learned the task, but hatchlings from the warm-temperature treatment learned the task faster, and made fewer mistakes in the first five trials than hot-incubated hatchlings. These patterns were consistent for hatchlings from two geographic locations, suggesting that thermally stressful conditions in utero may alter the learning abilities of hatchling lizards. Because learning ability can affect the survival of hatchling velvet geckos, future increase in nest temperatures may have wide reaching impacts on populations.


Assuntos
Lagartos , Animais , Fenótipo , Temperatura
15.
Glob Chang Biol ; 26(5): 2829-2840, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32034982

RESUMO

Invasive vertebrates are frequently reported to have catastrophic effects on the populations of species which they directly impact. It follows then, that if invaders exert strong suppressive effects on some species then other species will indirectly benefit due to ecological release from interactions with directly impacted species. However, evidence that invasive vertebrates trigger such trophic cascades and alter community structure in terrestrial ecosystems remains rare. Here, we ask how the cane toad, a vertebrate invader that is toxic to many of Australia's vertebrate predators, influences lizard assemblages in a semi-arid rangeland. In our study area, the density of cane toads is influenced by the availability of water accessible to toads. We compared an index of the abundance of sand goannas, a large predatory lizard that is susceptible to poisoning by cane toads and the abundances of four lizard families preyed upon by goannas (skinks, pygopods, agamid lizards and geckos) in areas where cane toads were common or rare. Consistent with the idea that suppression of sand goannas by cane toads initiates a trophic cascade, goanna activity was lower and small lizards were more abundant where toads were common. The hypothesis that suppression of sand goannas by cane toads triggers a trophic cascade was further supported by our findings that small terrestrial lizards that are frequently preyed upon by goannas were more affected by toad abundance than arboreal geckos, which are rarely consumed by goannas. Furthermore, the abundance of at least one genus of terrestrial skinks benefitted from allogenic ecosystem engineering by goannas where toads were rare. Overall, our study provides evidence that the invasion of ecosystems by non-native species can have important effects on the structure and integrity of native communities extending beyond their often most obvious and frequently documented direct ecological effects.


Assuntos
Ecossistema , Lagartos , Animais , Austrália , Bufo marinus , Espécies Introduzidas
16.
Animals (Basel) ; 10(1)2020 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-31963758

RESUMO

Recognising stress is an important component in maintaining the welfare of captive animal populations, and behavioural observation provides a rapid and non-invasive method to do this. Despite substantial testing in zoo elephants, there has been relatively little interest in the application of behavioural assessments to the much larger working populations of Asian elephants across Southeast Asia, which are managed by workers possessing a broad range of behavioural knowledge. Here, we developed a new ethogram of potential stress- and work-related behaviour for a semi-captive population of Asian elephants. We then used this to collect observations from video footage of over 100 elephants and evaluated the reliability of behavioural welfare assessments carried out by non-specialist observers. From observations carried out by different raters with no prior experience of elephant research or management, we tested the reliability of observations between-observers, to assess the general inter-observer agreement, and within-observers, to assess the consistency in behaviour identification. The majority of ethogram behaviours were highly reliable both between- and within-observers, suggesting that overall, behaviour was highly objective and could represent easily recognisable markers for behavioural assessments. Finally, we analysed the repeatability of individual elephant behaviour across behavioural contexts, demonstrating the importance of incorporating a personality element in welfare assessments. Our findings highlight the potential of non-expert observers to contribute to the reliable monitoring of Asian elephant welfare across large captive working populations, which may help to both improve elephant wellbeing and safeguard human workers.

17.
Curr Zool ; 66(6): 693-694, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33391369
18.
Biol Open ; 8(4)2019 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-31000681

RESUMO

Heatwaves are a regular occurrence in Australia, and are predicted to increase in intensity and duration in the future. These changes may elevate temperatures inside lizard nests, shortening the incubation period, so that hatchlings are more likely to emerge during heatwaves. Potentially, developmental plasticity or heat hardening could buffer hatchings from future warming. For example, higher incubation temperatures could shift critical thermal maxima upwards, enabling lizards to withstand higher temperatures. To investigate whether developmental plasticity affects hatchling thermal tolerance, we incubated eggs of the velvet gecko Amalosia lesueurii under two fluctuating incubation treatments to mimic current (mean=24.3°C, range 18.4-31.1°C) and future 'hot' (mean=28.9°C, range 19.1-38.1°C) nest temperatures. We maintained the hatchlings under identical conditions, and measured their thermal tolerance (CTmax) aged 14 days and 42 days. We then released hatchlings at field sites, and recaptured individually marked lizards aged 6 months, to determine whether incubation induced shifts in thermal tolerance were transitory or long-lasting. We found that at age 14 days, hatchlings from hot-temperature incubation had higher CTmax [mean=39.96±0.25°C (s.d.)] than hatchlings from current-temperature incubation [mean=39.70±0.36°C (s.d.)]. Hatchlings from the current-incubation treatment also had significantly higher heat hardening capacity [mean=0.79±0.37°C (s.d.)] than hatchlings from hot-temperature incubation treatment [mean=0.47±0.17°C (s.d. )]. However, both of these incubation-induced effects did not persist into later life. By contrast, incubation treatment had significant and long-lasting effects on the cold tolerance of hatchlings. At age 14 days, current-incubated hatchlings tolerated colder temperatures [CTmin=11.24±0.41°C (s.d.)] better than hot-incubated hatchlings [CTmin=14.11±0.25°C (s.d.)]. This significant difference in cold tolerance persisted into the juvenile life stage, and was present in 6-month-old lizards that we recaptured from field sites. This finding indicates that upward shifts in cold tolerance caused by higher incubation temperatures might affect overwinter survival of lizards, but field studies linking fitness to thermal tolerance are necessary to test this idea. Overall, our results suggest that developmental plasticity for heat tolerance is unlikely to buffer lizard populations from higher temperatures.

19.
J Exp Biol ; 221(Pt 24)2018 12 12.
Artigo em Inglês | MEDLINE | ID: mdl-30352824

RESUMO

Animals use irruptive movement to avoid exposure to stochastic and pervasive environmental stressors that impact fitness. Beneficial irruptive movements transfer individuals from high-stress areas (conferring low fitness) to alternative localities that may improve survival or reproduction. However, being stochastic, environmental stressors can limit an animal's preparatory capacity to enhance irruptive movement performance. Thus individuals must rely on pre-existing, or rapidly induced, physiological and behavioural responses. Rapid elevation of glucocorticoid hormones in response to environmental stressors are widely implicated in adjusting physiological and behaviour processes that could influence irruptive movement capacity. However, there remains little direct evidence demonstrating that corticosterone-regulated movement performance or interaction with pervasiveness of environmental stress, confers adaptive movement outcomes. Here, we compared how movement-related survival of cane toads (Rhinella marina) varied with three different experimental corticosterone phenotypes across four increments of increasing environmental stressor pervasiveness (i.e. distance from water in a semi-arid landscape). Our results indicated that toads with phenotypically increased corticosterone levels attained higher movement-related survival compared with individuals with control or lowered corticosterone phenotypes. However, the effects of corticosterone phenotypes on movement-related survival to some extent co-varied with stressor pervasiveness. Thus, our study demonstrates how the interplay between an individual's corticosterone phenotype and movement capacity alongside the arising costs of movement and the pervasiveness of the environmental stressor can affect survival outcomes.


Assuntos
Migração Animal/fisiologia , Bufo marinus/fisiologia , Corticosterona/metabolismo , Longevidade/fisiologia , Estresse Fisiológico , Distribuição Animal/fisiologia , Animais , Northern Territory , Fenótipo
20.
Microorganisms ; 6(3)2018 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-30002322

RESUMO

The Australian northern quoll is an important predatory marsupial carnivore that is currently endangered due to inappropriate fire regimes, predation, and the spread of invasive cane toads. The microbiota of Australian marsupials has not been extensively studied, but is thought to play a role in their health. This study provides an initial characterization of the cloacal microbiota of the northern quoll, as well as other marsupials including possums and kangaroos which were opportunistically sampled. The northern quoll cloaca microbiota was dominated by Enterococcus and Lactobacillus and had a relatively high proportion of members of the Proteobacteria phylum, which has been observed in other carnivorous marsupials. The diversity and structure of the microbiota was not influenced by presence of Chlamydiales which are intracellular bacteria and potential pathogens. The microbiota of the other marsupials was quite varied, which may be related to their health status. Characterization of the northern quoll microbiota will help to better understand the biology of this endangered animal.

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