Impact of the California Lead Ammunition Ban on Reducing Lead Exposure in Golden Eagles and Turkey Vultures

Predatory and scavenging birds may be exposed to high levels of lead when they ingest shot or bullet fragments embedded in the tissues of animals injured or killed with lead ammunition. Lead poisoning was a contributing factor in the decline of the endangered California condor population in the 1980s, and remains one of the primary factors threatening species recovery. In response to this threat, a ban on the use of lead ammunition for most hunting activities in the range of the condor in California was implemented in 2008. Monitoring of lead exposure in predatory and scavenging birds is essential for assessing the effectiveness of the lead ammunition ban in reducing lead exposure in these species. In this study, we assessed the effectiveness of the regulation in decreasing blood lead concentration in two avian sentinels, golden eagles and turkey vultures, within the condor range in California. We compared blood lead concentration in golden eagles and turkey vultures prior to the lead ammunition ban and one year following implementation of the ban. Lead exposure in both golden eagles and turkey vultures declined significantly post-ban. Our findings provide evidence that hunter compliance with lead ammunition regulations was sufficient to reduce lead exposure in predatory and scavenging birds at our study sites

Copy rights: The politics of copying and creativity

This article analyses the politics of copyright and copying. Copyright is an increasingly important driver of the modern economy, but this does not exhaust its significance. It matters, we argue, not just for the distribution of rewards and resources in the creative industries, but as a site within which established political concerns – collective and individual interests and identities - are articulated and negotiated, and within which notions of ‘originality’, ‘creativity’ and ‘copying’ are politically constituted. Set against the background of the increasing economic value attributed to the creative industries, the impact of digitalization on them, and the European Union’s Digital Single Market strategy, the article reveals how copyright policy, and the underlying assumptions about ‘copying’ and ‘creativity’, express (often unexamined) political values and ideologies. Drawing on a close reading of policy statements, official reports, court cases, and interviews with stakeholders, we explore the multiple political aspects of copyright, showing how copyright policy operates to privilege particular interests and practices, and to acknowledge only specific forms of creative endeavour

Bone density and breaking strength in UK raptors to second generation anticoagulant rodenticides

Journal articleWe present methodologies for calculating the direct correlation function c(1,2), the cavity function y(1,2), and the bridge function b(1,2), for molecular liquids, from Monte Carlo simulations. As an example we present results for the isotropic hard spheroid fluid with elongatione=3. The simulation data are compared with the results from integral equation theory. In particular, we solve the Percus-Yevick and hypernetted chain equations. In addition, we calculate the first two terms in the virial expansion of the bridge function and incorporate this into the closure. At low densities, the bridge functions calculated by theory and from simulation are in good agreement, lending support to the correctness of our numerical procedures. At higher densities, the hypernetted chain results are brought into closer agreement with simulation by incorporating the approximate bridge function, but significant discrepancies remain.EPSRC grants GR/S77240 and GR/S7710

Measuring electromagnetic fields (EMF) around wind turbines in Canada: is there a human health concern?

Abstract Background The past five years has seen considerable expansion of wind power generation in Ontario, Canada. Most recently worries about exposure to electromagnetic fields (EMF) from wind turbines, and associated electrical transmission, has been raised at public meetings and legal proceedings. These fears have not been based on any actual measurements of EMF exposure surrounding existing projects but appear to follow from worries from internet sources and misunderstanding of the science. Methods The study was carried out at the Kingsbridge 1 Wind Farm located near Goderich, Ontario, Canada. Magnetic field measurements were collected in the proximity of 15 Vestas 1.8 MW wind turbines, two substations, various buried and overhead collector and transmission lines, and nearby homes. Data were collected during three operational scenarios to characterize potential EMF exposure: ‘high wind’ (generating power), ‘low wind’ (drawing power from the grid, but not generating power) and ‘shut off’ (neither drawing, nor generating power). Results Background levels of EMF (0.2 to 0.3 mG) were established by measuring magnetic fields around the wind turbines under the ‘shut off’ scenario. Magnetic field levels detected at the base of the turbines under both the ‘high wind’ and ‘low wind’ conditions were low (mean = 0.9 mG; n = 11) and rapidly diminished with distance, becoming indistinguishable from background within 2 m of the base. Magnetic fields measured 1 m above buried collector lines were also within background (≤ 0.3 mG). Beneath overhead 27.5 kV and 500 kV transmission lines, magnetic field levels of up to 16.5 and 46 mG, respectively, were recorded. These levels also diminished rapidly with distance. None of these sources appeared to influence magnetic field levels at nearby homes located as close as just over 500 m from turbines, where measurements immediately outside of the homes were ≤ 0.4 mG. Conclusions The results suggest that there is nothing unique to wind farms with respect to EMF exposure; in fact, magnetic field levels in the vicinity of wind turbines were lower than those produced by many common household electrical devices and were well below any existing regulatory guidelines with respect to human health

Mechanical properties of single supramolecular polymers from correlative AFM and fluorescence microscopy

We characterize the structure and mechanical properties of 1,3,5-benzenetricarboxamide (BTA) supramolecular polymers using correlative AFM and fluorescence imaging. AFM allows for nanoscale structural investigation but we found that statistical analysis is difficult because these structures are easily disrupted by the AFM tip. We therefore correlate AFM and fluorescence microscopy to couple nanoscale morphological information to far-field optical images. A fraction of the immobilized polymers are in a clustered or entangled state, which we identify based on diffraction limited fluorescence images. We find that clustered and entangled polymers exhibit a significantly longer persistence length that is broader distributed than single unentangled polymers. By comparison with numerical simulations we find significant heterogeneity in the persistence length of single unentangled polymers, which we attribute to polymer–substrate interactions and the presence of structural diversity within the polymer

Mechanical properties of single supramolecular polymers from correlative AFM and fluorescence microscopy

We characterize the structure and mechanical properties of 1,3,5-benzenetricarboxamide (BTA) supramolecular polymers using correlative AFM and fluorescence imaging. AFM allows for nanoscale structural investigation but we found that statistical analysis is difficult because these structures are easily disrupted by the AFM tip. We therefore correlate AFM and fluorescence microscopy to couple nanoscale morphological information to far-field optical images. A fraction of the immobilized polymers are in a clustered or entangled state, which we identify based on diffraction limited fluorescence images. We find that clustered and entangled polymers exhibit a significantly longer persistence length that is broader distributed than single unentangled polymers. By comparison with numerical simulations we find significant heterogeneity in the persistence length of single unentangled polymers, which we attribute to polymer–substrate interactions and the presence of structural diversity within the polymer