172 research outputs found

    Backpack-mounted satellite transmitters do not affect reproductive performance in a migratory bustard

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    Backpack-mounted satellite transmitters (PTTs) are used extensively in the study of avian habitat use and of the movements and demography of medium- to large-bodied species, but can affect individualsā€™ performance and fitness. Transparent assessment of potential transmitter effects is important for both ethical accountability and confidence in, or adjustment to, life history parameter estimates. We assessed the influence of transmitters on seven reproductive parameters in Asian houbara Chlamydotis macqueenii, comparing 114 nests of 38 females carrying PTTs to 184 nests of untagged birds (non-PTT) over seven breeding seasons (2012ā€’2018) in Uzbekistan. There was no evidence of any influence of PTTs on: lay date (non-PTT xĢ… = 91.7 Julian day Ā± 12.3 SD; PTT xĢ… = 95.1 Julian day Ā± 15.7 SD); clutch size (non-PTT xĢ… = 3.30 Ā± 0.68 SD; PTT xĢ… = 3.25 Ā± 0.65 SD); mean egg weight at laying (non-PTT xĢ… = 66.1g Ā± 5.4 SD; PTT xĢ… = 66.4g Ā± 5.4 SD); nest success (non-PTT xĢ… = 57.08% Ā± 4.3 SE; PTT xĢ… = 58.24% Ā± 4.5 SE for nests started 2 April); egg hatchability (non-PTT xĢ… = 88.3% Ā± 2.2 SE; PTT xĢ… = 88.3% Ā± 2.6 SE); or chick survival to fledging from broods that had at least one surviving chick (non-PTT xĢ… = 63.4% Ā± 4.2 SE; PTT xĢ…= 64.4% Ā± 4.7 SE). High nesting propensity (97.3% year-1 Ā± 1.9% SE) of tagged birds indicated minimal PTT effect on breeding probability. These findings show harness-mounted transmitters can give unbiased measures of demographic parameters of this species, and are relevant to other large-bodied, cursorial, ground-nesting birds of open habitats, particularly other bustards

    Intranasal administration of acetylcholinesterase inhibitors

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    This short review outlines the rationale, challenges, and opportunities for intranasal acetylcholinesterases, in particular galantamine. An in vitro screening model facilitated the development of a therapeutically viable formulation. In vivo testing confirmed achievement of therapeutically relevant drug levels that matched or exceeded those for oral dosing, with a dramatic reduction in undesired emetic responses. Intranasal drug delivery is an effective option for the treatment of Alzheimer's disease and other central nervous system disorders

    Effects of body size on estimation of mammalian area requirements

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    Accurately quantifying speciesā€™ area requirements is a prerequisite for effective areaā€based conservation. This typically involves collecting tracking data on species of interest and then conducting homeā€range analyses. Problematically, autocorrelation in tracking data can result in space needs being severely underestimated. Based on previous work, we hypothesized the magnitude of underestimation varies with body mass, a relationship that could have serious conservation implications. To evaluate this hypothesis for terrestrial mammals, we estimated homeā€range areas with GPS locations from 757 individuals across 61 globally distributed mammalian species with body masses ranging from 0.4 to 4,000 kg. We then applied block crossā€validation to quantify bias in empirical homeā€range estimates. Area requirements of mammals 1, meaning the scaling of the relationship changed substantially at the upper end of the mass spectrum
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