155 research outputs found
Long-term reproductive costs of snare injuries in a keystone terrestrial by-catch species
Extensive bushmeat hunting is a major threat to wildlife conservation worldwide, particularly when unselective methods such as wire snares kill target and non-target species (by-catch). Animals that escape from snares have injuries of varying severity, with effects on performance that are largely unknown, as most studies typically focus on immediate mortality caused by snaring. Here, we assessed the life-history costs of debilitating snare injuries in individually known female spotted hyenas Crocuta crocuta in three clans in the Serengeti National Park, Tanzania. This keystone predator is a regular by-catch of illegal bushmeat hunting of herbivores in the Serengeti ecosystem. We monitored individuals which escaped from snares between May 1987 and March 2020 and survived long enough to return to their clan territories from commuting trips in the park and surrounding protected areas. Snares that inflicted debilitating injuries on females did not reduce longevity but did delay age at first reproduction and reduced both litter size and offspring survival to the age of 1 year. This long-term decrease in reproductive performance likely resulted from increased inflammatory and immune responses to the snare injury and/or a decreased ability to travel the long distances necessary to feed on migratory herbivores. While our results are based on a relatively small sample of females with debilitating injuries, they suggest that the total population-level costs of wire snares in terrestrial by-catch species may be underestimated and that future studies may need to account for the potential reproductive costs of sublethal snare injuries
Testing growth rate dependence in cosmological perturbation theory using scale-free models
We generalize previously derived analytic results for the one-loop power
spectrum (PS) in scale-free models (with linear PS ) to a
broader class of such models in which part of the matter-like component driving
the Einstein de Sitter expansion does not cluster. These models can be
conveniently parametrized by , the constant logarithmic linear growth
rate of fluctuations (with in the usual case). For , where
the one-loop PS is both infrared and ultraviolet convergent and thus explicitly
self-similar, it is characterized conveniently by a single numerical
coefficient . We compare the analytical predictions for with results from a suite of -body simulations with performed with an appropriately modified version of the Gadget code.
Although the simulations are of small () boxes, the constraint of
self-similarity allows the identification of the converged PS at a level of
accuracy sufficient to test the analytical predictions for the
dependence of the evolved PS. Good agreement for the predicted dependence on
of the PS is found. To treat the UV sensitivity of results which grows
as one approaches , we derive exact results incorporating a
regularisation and obtain expressions for . Assuming
that this regularisation is compatible with self-similarity allows us to infer
a predicted functional form of the PS equivalent to that derived in effective
field theory (EFT). The coefficient of the leading EFT correction at one loop
has a strong dependence on , with a change in sign at , providing a potentially stringent test of EFT.Comment: 14 pages, 6 figures, 3 table
Early-life adversity predicts performance and fitness in a wild social carnivore
1. Studies on humans indicate that encountering multiple sources of adversity in childhood increases the risk of poor long-term health and premature death. Far less is known about cumulative effects of adversity during early life in wildlife.
2. Focusing on the spotted hyena Crocuta crocuta, a social mammal with small litters, extensive maternal care, slow development and access to resources determined by social rank, we determined the contribution of ecological, maternal, social and demographic factors during early life on performance and fitness, and tested whether the impact of early-life adversity is cumulative.
3. Using longitudinal data from 666 female hyenas in the Serengeti National Park, we determined the early growth rate, survival to adulthood, age at first reproduction (AFR), lifetime reproductive success (LRS) and longevity. We fitted multivariate models in which we tested the effects of environmental factors on these performance measures. We then constructed a cumulative adversity index and fitted models to test the effect of this index on each performance measure. Finally, the value of cumulative adversity models was tested by comparing them to multivariate and single-effect models in which the effect of each environmental factor was considered separately.
4. High maternal rank decreased the AFR of daughters. Singleton and dominant cubs had higher growth rate than subordinate cubs, and singletons also had a higher survival chance to adulthood than subordinates. Daughters of prime age mothers had a higher growth rate, longevity and LRS. Little and heavy rainfall decreased survival to adulthood. Increasing numbers of lactating female clan members decreased growth rate, survival to adulthood and LRS. Cumulative adversity negatively affected short-term performance and LRS. Multivariate models outperformed cumulative adversity and single-effect models for all measures except for AFR and longevity, for which single-effect models performed better.
5. Our results suggest that in some wildlife populations the combination of specific conditions in early life may matter more than the accumulation of adverse conditions as such
Climate change does not decouple interactions between a central-place-foraging predator and its migratory prey
Little is known about potential cascading effects of climate change on the ability of predators to exploit mobile aggregations of prey with a spatiotemporal distribution largely determined by climatic conditions. If predators employ central-place foraging when rearing offspring, the ability of parents to locate sufficient prey could be reduced by climate change. In the Serengeti National Park, Tanzania, migratory species dominate mammalian herbivore biomass. These migratory herds exploit nutrient-rich vegetation on the southern plains in the rainy season and surface water in the northwest in the dry season. Female spotted hyenas Crocuta crocuta breed throughout the year and use long-distance central-place-foraging “commuting trips” to migratory herds to fuel lactation for ≥12 months. Changes in rainfall patterns that alter prey movements may decrease the ability of mothers to locate profitable foraging areas and thus increase their overall commuting effort, particularly for high-ranking females that have priority of access to food resources within their clan territory and thus less commuting experience. In hyena clan territories, this may be reflected by a decrease in migratory herd presence and a decrease in the presence of lactating females, as maternal den presence represents the opposite of commuting effort. We investigated the strength of the relationship between rainfall volume, migratory herd presence in three hyena clan territories, and the responses of lactating females to this climate/prey relationship in terms of maternal den presence, using an observation-based dataset spanning three decades. The probability of migratory herd presence in hyena clan territories increased with the amount of rainfall 2 months earlier, and maternal den presence increased with migratory herd presence. Rainfall volume substantially increased over 30 years, whereas the presence of migratory herds in hyena clans and the strength of the relationship between rainfall and migratory herd presence decreased. Hyenas thus adjusted well to the climate change-induced decreased the presence of migratory herds in their territories, since maternal den presence did not decrease over 30 years and still matched periods of high prey abundance, irrespective of female social status. These results suggest a high plasticity in the response of this keystone predator to environmental variability
11-2001 Newsletter
Minnesota State University, Mankato, Library Services Newsletter for November 2001
Interés de la hipnosis médica en cirugía
The purpose of this article is to report the application of medical hypnosis as a complement to our field of work. From its first incarnation, known as animal magnetism thanks to the works of Mesmer in the 18th century, its name, its practice and its indications have changed. Historically, hypnosis has evolved with ups and downs, until finally coming to occupy hospital services worldwide, thanks to the work of Milton Erickson.
Within the context of hospital structures, hypnosis has been applied as a therapy by psychotherapists. Other health professionals can now practise medical hypnosis within their speciality, after they have had complementary training.
The use of hypnosis as a complement to our anaesthesia practice is not novel, although it is not a widespread practice in Spain, unlike in northern Europe.
Rigorous studies in neurosciences have investigated the brain modifications under hypnosis to explain the patient’s experience.
There are various applications of hypnosis in anaesthesia: hypnosedation as a complement to anaesthetic techniques, management of stress, anxiety, pain, labour and delivery, complementary imaging studies, etc. The benefits and efficacy obtained not only result in improved comfort and communication for the patient, but also for the rest of the surgical team.El propósito de este artículo es dar a conocer la aplicación de la hipnosis médica como complemento a nuestro ámbito de trabajo. Desde su primer avatar conocido como magnetismo animal gracias a los trabajos de Mesmer en el siglo XVIII, ha cambiado su nombre su práctica y sus indicaciones. Históricamente la hipnosis ha evolucionado con altibajos, hasta finalmente ocupar los servicios hospitalarios en el mundo entero, gracias a los trabajos de Milton Erickson.
La hipnosis dentro del contexto de las estructuras hospitalarias ha sido aplicada como terapia por psicoterapeutas. Actualmente otros profesionales de la salud pueden ejercer la hipnosis médica dentro de su especialidad, desde que tengan dicha formación complementaria.
El empleo de la hipnosis como complemento a nuestra práctica anestésica, no es una novedad aunque en España no es una práctica difundida a diferencia del norte de Europa.
Rigurosos estudios en neurociencias han investigado las modificaciones cerebrales bajo hipnosis a fin de explicar la vivencia del paciente.
Las aplicaciones de la hipnosis en anestesia son múltiples; hipnosedación como complemento en técnicas anestésicas, gestión del stress, ansiedad, dolor, trabajo de parto y parto, estudios complementares de imagen etc. El beneficio y la eficacia que conseguimos no solo repercuten en mejorar el confort y la comunicación en el paciente sino también en el resto del equipo quirúrgico
Landscape Structures Affect Risk of Canine Distemper in Urban Wildlife
Urbanization rapidly changes landscape structure worldwide, thereby enlarging the human-wildlife interface. The emerging urban structures should have a key influence on the spread and distribution of wildlife diseases such as canine distemper, by shaping density, distribution and movements of wildlife. However, little is known about the role of urban structures as proxies for disease prevalence. To guide management, especially in densely populated cities, assessing the role of landscape structures in hampering or promoting disease prevalence is thus of paramount importance. Between 2008 and 2013, two epidemic waves of canine distemper hit the urban red fox (Vulpes vulpes) population of Berlin, Germany. The directly transmitted canine distemper virus (CDV) causes a virulent disease infecting a range of mammals with high host mortality, particularly in juveniles. We extracted information about CDV serological state (seropositive or seronegative), sex and age for 778 urban fox carcasses collected by the state laboratory Berlin Brandenburg. To assess the impact of urban landscape structure heterogeneity (e.g., richness) and shares of green and gray infrastructures at different spatial resolutions (areal of 28 ha, 78 ha, 314 ha) on seroprevalence we used Generalized Linear Mixed-Effects Models with binomial distributions. Our results indicated that predictors derived at a 28 ha resolution were most informative for describing landscape structure effects (AUC = 0.92). The probability to be seropositive decreased by 66% (0.6 to 0.2) with an increasing share of gray infrastructure (40 to 80%), suggesting that urbanization might hamper CDV spread in urban areas, owing to a decrease in host density (e.g., less foxes or raccoons) or an absence of wildlife movement corridors in strongly urbanized areas. However, less strongly transformed patches such as close-to-nature areas in direct proximity to water bodies were identified as high risk areas for CDV transmission. Therefore, surveillance and disease control actions targeting urban wildlife or human-wildlife interactions should focus on such areas. The possible underlying mechanisms explaining the prevalence distribution may be increased isolation, the absence of alternative hosts or an abiotic environment, all impairing the ability of CDV to persist without a host
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