Geographic body size variation in ectotherms: effects of seasonality on an anuran from the southern temperate forest

Indexación: Web of Science; Scopus.Background: Body size variation has played a central role in biogeographical research, however, most studies have aimed to describe trends rather than search for underlying mechanisms. In order to provide a more comprehensive understanding of the causes of intra-specific body size variation in ectotherms, we evaluated eight hypotheses proposed in the literature to account for geographical body size variation using the Darwin's frog (Rhinoderma darwinii), an anuran species widely distributed in the temperate forests of South America. Each of the evaluated hypotheses predicted a specific relationship between body size and environmental variables. The level of support for each of these hypotheses was assessed using an information-theoretic approach and based on data from 1015 adult frogs obtained from 14 sites across the entire distributional range of the species. Results: There was strong evidence favouring a single model comprising temperature seasonality as the predictor variable. Larger body sizes were found in areas of greater seasonality, giving support to the "starvation resistance" hypothesis. Considering the known role of temperature on ectothermic metabolism, however, we formulated a new, non-exclusive hypothesis, termed "hibernation hypothesis": greater seasonality is expected to drive larger body size, since metabolic rate is reduced further and longer during colder, longer winters, leading to decreased energy depletion during hibernation, improved survival and increased longevity (and hence growth). Supporting this, a higher post-hibernation body condition in animals from areas of greater seasonality was found. Conclusions: Despite largely recognized effects of temperature on metabolic rate in ectotherms, its importance in determining body size in a gradient of seasonality has been largely overlooked so far. Based on our results, we present and discuss an alternative mechanism, the "hibernation hypothesis", underlying geographical body size variation, which can be helpful to improve our understanding of biogeographical patterns in ectotherms.https://frontiersinzoology.biomedcentral.com/articles/10.1186/s12983-015-0132-

Public health risks from illegally imported African bushmeat and smoked fish

Large-scale importation of bushmeat from West and Central Africa into Europe was reported in 2010. We sampled 18 illegal African bushmeat consignments seized at Charles de Gaulle airport, Paris, France and tested for the presence of bacteria. Additionally, five smuggled smoked fish were analysed for polycyclic aromatic hydrocarbons, which are known carcinogens. All bushmeat samples had viable counts of aerobic bacteria above levels considered safe for human consumption. We also identified zoonotic bacterial pathogens in bushmeat and unsafe levels of carcinogens in fish. The illegal importation of meat is a potential risk for the introduction of pathogens

One Health for a changing world: new perspectives from Africa

The concept of One Health, which aims to drive improvements in human, animal and ecological health through an holistic approach, has been gaining increasing support and attention in recent years. While this concept has much appeal, there are few examples where it has been successfully put into practice. This Special Issue explores the challenges in African contexts, with papers looking at the complex interactions between ecosystems, diseases and poverty dynamics; at underlying social and political dimensions; at the potentials for integrative modelling; and at the changes in policy and practice required to realise a One Health approach. This introductory paper offers an overview of the 11 papers, coming from diverse disciplinary perspectives, that each explore how a One Health approach can work in a world of social, economic and environmental change

Citizen science and wildlife disease surveillance

Achieving effective wildlife disease surveillance is challenging. The incorporation of citizen science (CS) in wildlife health surveillance can be beneficial, particularly where resources are limited and cost-effectiveness is paramount. Reports of wildlife morbidity and mortality from the public facilitate large-scale surveillance, both in time and space, which would otherwise be financially infeasible, and raise awareness of incidents occurring on privately-owned land. CS wildlife disease surveillance schemes benefit scientists, the participating public and wildlife alike. CS has been employed for targeted, scanning and syndromic surveillance of wildlife disease. Whilst opportunistic surveillance is most common, systematic observations enable the standardization of observer effort and, combined with wildlife population monitoring schemes, can allow evaluation of disease impacts at the population level. Near-universal access to digital media has revolutionized reporting modalities and facilitated rapid and economical means of sharing feedback with participants. Here we review CS schemes for wildlife disease surveillance and highlight their scope, benefits, logistical considerations, financial implications and potential limitations. The need to adopt a collaborative and multidisciplinary approach to wildlife health surveillance is increasingly recognized and the general public can make a significant contribution through CS

A call to prioritise prevention: Action is needed to reduce the risk of zoonotic disease emergence

Anthropogenic changes to the environment are facilitating the spread of animal pathogens into human populations. A global focus on detecting and containing emerging infectious diseases has deflected from the need for upstream prevention measures to reduce the risk of pathogen emergence. The drivers of infectious disease emergence have predominantly been considered as environmental and conservation issues and not as risks to human health. There is an opportunity for the UK to take a leadership position on this complex issue. This will require the establishment and maintenance of effective governance and policy mandates. Novel ways of policymaking are needed urgently to achieve three key aims: coordination and collaboration across sectors and government departments, the inclusion of diverse expertise, and the prioritisation of measures directed at prevention

Infectious disease threats to amphibian conservation

The unexplained decline of amphibian populations across the world was first recognised in the late 20th century. When investigated, most of these “enigmatic” declines have been shown to be due to one of two types of infectious disease: ranavirosis caused by infection with FV3-like ranavirus or with common midwife toad virus, or chytridiomycosis caused by infection with Batrachochytrium dendrobatidis or B. salamandrivorans. In all cases examined, infection has been via the humanmediated introduction of the pathogen to a species or population in which it has not naturally coevolved. While ranaviruses and B. salamandrivorans have caused regionally localised amphibian population declines in Europe, the chytrid fungus, B. dendrobatidis, has caused catastrophic multi-species amphibian population declines and species extinctions globally. These diseases have already caused the loss of amphibian biodiversity, and over 40% of known amphibian species are threatened with extinction. If this biodiversity loss is to be halted, it is imperative that regulations are put in place – and enforced – to prevent the spread of known and yet-to-be discovered amphibian pathogens. Also, it is incumbent on those who keep or study amphibians to take measures to minimise the risk of disease spread, including from captive animals to those in the wild

Disease driven extinction in the wild of the Kihansi spray toad, Nectophrynoides asperginis

The Kihansi spray toad, Nectophrynoides asperginis, became extinct in the wild despite population monitoring and conservation management of its habitat in the Kihansi gorge, Tanzania. Previous investigations have indicated human induced habitat modification, predators, pesticides and disease as possible causes of a rapid population decline and the species extirpation. Here, we systematically investigate the role of disease in the extinction event of the wild toad population. The amphibian chytrid fungus, Batrachochytrium dendrobatidis, was detected in spray toads that died during the extinction event and subsequently in other amphibian species in Kihansi Gorge and the adjacent Udagaji Gorge, but not in any toads collected prior to this. Following the population decline, the remaining spray toad population gradually disappeared over a nine-month period. We demonstrate how demographic (rare, low fecundity, high elevation species) and behavioural (congregate in high densities) attributes predisposed the spray toads to chytridiomycosis, as a result of B. dendrobatidis infections, and how epidemic disease could have been exacerbated by altered environmental conditions in the spray wetlands. Our results show that chytridiomycosis was the proximate cause of extinction in the wild of N. asperginis. This represents the first known case of extinction by disease of an amphibian species in Africa. Captive breeding programs, in both the US and Tanzania, have been introduced in order to ensure the survival of the species and a reintroduction program is underway. However, we caution that chytridiomycosis remains an existing threat, which requires a comprehensive mitigation strategy before the desired conservation outcome of an established population of repatriated toads can be achieved

Mortality associated with avian reovirus infection in a free-living magpie (Pica pica) in Great Britain

Avian reoviruses (ARVs) cause a range of disease presentations in domestic, captive and free-living bird species. ARVs have been reported as a cause of significant disease and mortality in free-living corvid species in North America and continental Europe. Until this report, there have been no confirmed cases of ARV-associated disease in British wild birds

The Supernumerary Robotic 3rd Thumb for Skilled Music Tasks

Wearable robotics bring the opportunity to augment human capability and performance, be it through prosthetics, exoskeletons, or supernumerary robotic limbs. The latter concept allows enhancing human performance and assisting them in daily tasks. An important research question is, however, whether the use of such devices can lead to their eventual cognitive embodiment, allowing the user to adapt to them and use them seamlessly as any other limb of their own. This paper describes the creation of a platform to investigate this. Our supernumerary robotic 3rd thumb was created to augment piano playing, allowing a pianist to press piano keys beyond their natural hand-span; thus leading to functional augmentation of their skills and the technical feasibility to play with 11 fingers. The robotic finger employs sensors, motors, and a human interfacing algorithm to control its movement in real-time. A proof of concept validation experiment has been conducted to show the effectiveness of the robotic finger in playing musical pieces on a grand piano, showing that naive users were able to use it for 11 finger play within a few hours

Facility-based surveillance for emerging infectious diseases; diagnostic practices in rural West African hospital settings: observations from Ghana

The aim of this study was to better understand the effectiveness of Integrated Disease Surveillance and Response (IDSR) facility-based surveillance in detecting newly emerging infectious diseases (EIDs) in rural West African settings. A six-month ethnographic study was undertaken in 2012 in the Techiman Municipality of the Brong-Ahafo Region of Ghana, aimed at documenting the trajectories of febrile illness cases of unknown origin occurring within four rural communities. Particular attention was paid to where these trajectories involved the use of formal healthcare facilities and the diagnostic practices that occurred there. Seventy-six participants were enrolled in the study, and 24 complete episodes of illness were documented. While participants routinely used hospital treatment when confronted with enduring or severe illness, the diagnostic process within clinical settings meant that an unusual diagnosis, such as an EID, was unlikely to be considered. Facility-based surveillance is unlikely to be effective in detecting EIDs due to a combination of clinical care practices and the time constraints associated with individual episodes of illness, particularly in the resource-limited settings of rural West Africa, where febrile illness due to malaria is common and specific diagnostic assays are largely unavailable. The success of the ‘One Health' approach to EIDs in West Africa is predicated on characterization of accurately diagnosed disease burdens. To this end, we must address inefficiencies in the dominant approaches to EID surveillance and the weaknesses of health systems in the region generally.The authors are supported by the European Union FP7 project ANTIGONE (contract number 278976) and A.A.C. and J.L.N.W. were also supported by the Dynamic Drivers of Disease in Africa Consortium, NERC project no. NE-J001570-1, funded with support from the Ecosystem Services for Poverty Alleviation (ESPA) programme. J.L.N.W. and A.A.C. also benefit from the support of the small mammal disease working group, funded by the Research and Policy for Infectious Disease Dynamics (RAPIDD) programme of the Science and Technology Directorate, Department of Homeland Security and Fogarty International Center, USA. A.A.C. is supported by a Royal Society Wolfson Research Merit Award. J.L.N.W. is supported by the Alborada Trust