433 research outputs found

    Quantifying fenbendazole and its metabolites in self-medicating wild red grouse Lagopus lagopus scoticus using an HPLC–MS–MS approach

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    On red grouse estates in the UK the nematode parasite Trichostrongylus tenuis is often controlled by application of grit medicated with the anthelmintic fenbendazole (FBZ). To date, assessment of the efficacy has been inhibited by the inability to quantify uptake of FBZ by the birds. We have developed a simple and sensitive HPLC–MS–MS method for detecting and quantifying FBZ and its metabolites from a 300 mg sample of red grouse liver. This method could be used to improve the efficacy of medicated grit treatment by allowing the identification of conditions and application methods that optimize the uptake of FBZ. With the necessary modifications, our method will also be applicable to other wildlife species where self-medication is used for parasite control

    Urban agriculture: a global analysis of the space constraint to meet urban vegetable demand

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    Urban agriculture (UA) has been drawing a lot of attention recently for several reasons: the majority of the world population has shifted from living in rural to urban areas; the environmental impact of agriculture is a matter of rising concern; and food insecurity, especially the accessibility of food, remains a major challenge. UA has often been proposed as a solution to some of these issues, for example by producing food in places where population density is highest, reducing transportation costs, connecting people directly to food systems and using urban areas efficiently. However, to date no study has examined how much food could actually be produced in urban areas at the global scale. Here we use a simple approach, based on different global-scale datasets, to assess to what extent UA is constrained by the existing amount of urban space. Our results suggest that UA would require roughly one third of the total global urban area to meet the global vegetable consumption of urban dwellers. This estimate does not consider how much urban area may actually be suitable and available for UA, which likely varies substantially around the world and according to the type of UA performed. Further, this global average value masks variations of more than two orders of magnitude among individual countries. The variations in the space required across countries derive mostly from variations in urban population density, and much less from variations in yields or per capita consumption. Overall, the space required is regrettably the highest where UA is most needed, i.e., in more food insecure countries. We also show that smaller urban clusters (i.e., <100 km2 each) together represent about two thirds of the global urban extent; thus UA discourse and policies should not focus on large cities exclusively, but should also target smaller urban areas that offer the greatest potential in terms of physical space

    Positive interactions between vulnerable species in agrarian pseudo-steppes: habitat use by pin-tailed sandgrouse depends on its association with the little bustard

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    Abstract Positive interactions between species can have important conservation implications, especially when the species associating are both vulnerable. We studied the habitat use of pin-tailed sandgrouses Pterocles alchata and their association with another vulnerable species, the little bustard Tetrax tetrax in agrarian pseudosteppes of central Spain using radio-tracking. The occurrence of mixed-species flocks varied seasonally, being more frequent in winter (65% of pin-tailed sandgrouse flocks). In this season, pin-tailed sandgrouses preferred stubble fields and fallows. Moreover, we found that habitat selection of pin-tailed sandgrouse depended on the association with little bustards in mixed-species flocks. When in mixed-species groups, sandgrouses changed their agrarian substrate preferences, and used stubble fields significantly more often than when in sandgrouse-only flocks. We also provide evidence that pin-tailed sandgrouse benefited from the anti-predator vigilance of little bustards, allowing sandgrouse to exploit new feeding grounds (stubble fields) that would otherwise be too risky to exploit. Our results indicate a close positive association between these two species, which are both declining in Europe, and we discuss implications for their management and conservation. We also recommend taking into account inter-specific positive interactions when designing conservation strategies for threatened species

    Investigating the loss of recruitment potential in red grouse (Lagopus lagopus scoticus) : the relative importance of hen mortality, food supply, tick infestation and louping-ill

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    Ticks and their pathogens cause significant disease and economic loss in many animal populations. Despite this, experiments that test the impact of ticks and tickborne diseases on wild animal populations are rare. Here, we report on an experiment assessing the effect of ticks on red grouse productivity and chick growth in relation to other causes of poor recruitment at two sites in the Scottish uplands during 2005. Treated hens received two leg bands impregnated with the acaricide permethrin, while controls hens were untreated. Chicks were captured at c.2 weeks of age and fitted with a metal patagial tag, and chicks from treated hens also received a permethrinimpregnated strip. Mean tick burdens in treated chicks were close to zero compared with a mean of around 12 in the control group. Although treatment reduced tick infestations, it did not increase brood size. Growth rates in chicks from control and treated hens were similar during the first 10 days and comparable with chicks fed an ad-lib invertebrate-based diet. These results suggest that in this case, neither ticks (and the tick transmitted louping-ill virus) nor food shortages was the main cause of chick mortality. However, mortality in the adult hens was around 35 %, and predation accounted for 62 % of these losses before broods fledged. Our results indicate that on our study sites, predation may have a more important impact on grouse population dynamics than ticks and tick-borne disease. We suggest that it may be more cost effective to determine the causes of poor grouse population performance before implementing popular but expensive tick control measures such as the culling of alternative hosts and running acaracide treated sheep ‘tick-mop’ flocks.http://link.springer.com/journal/10344hb201

    Nuclear structure and reaction studies at SPIRAL

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    The SPIRAL facility at GANIL, operational since 2001, is described briefly. The diverse physics program using the re-accelerated (1.2 to 25 MeV/u) beams ranging from He to Kr and the instrumentation specially developed for their exploitation are presented. Results of these studies, using both direct and compound processes, addressing various questions related to the existence of exotic states of nuclear matter, evolution of new "magic numbers", tunnelling of exotic nuclei, neutron correlations, exotic pathways in astrophysical sites and characterization of the continuum are discussed. The future prospects for the facility and the path towards SPIRAL2, a next generation ISOL facility, are also briefly presented.Comment: 48 pages, 27 figures. Accepted for publication in Journal of Physics

    Shell Gap Reduction In Exotic N = 17 Nuclei

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    An experimental spectroscopic investigation of some neutron rich Mg and Al isotopes around the shell closure N=20 has been performed. The delayed neutron and γ\gamma spectra, following the β\beta-decay of 33^{33}Mg and 35^{35}Al have been measured using the delayed neutron detector array TONNERRE coupled with high efficiency EXOGAM clover detectors, a LEPS detector and eight low-energy neutron detectors. A detailed analysis of such spectra allows one to construct the level schemes of their daughters, ^{32,33)Al and 34,35^{34,35}Si. The resulting spectroscopic information will provide stringent tests of large scale shell model calculations including np - nh excitations aimed at the understanding of the structural effects occurring in this region
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