Space and Time: Wind in an Investment Planning Model

Investment planning models inform investment decisions and government policies. Current models do not capture the intermittent nature of renewable energy sources, restricting the applicability of the models for high penetrations of renewables. We provide a methodology to capture spatial variation in wind output in combination with transmission constraints. The representation of wind distributions with stochastic approaches or an extensive historic data set would exceed computational constraints for real world application. Hence we restrict the amount of input data, and use boot-strapping to illustrate the robustness of the results. For the UK power system we model wind deployment and the value of transmission capacity

Assessing the vulnerability of the marine bird community in the western North Sea to climate change and other anthropogenic impacts

Ocean warming and anthropogenic activities such as fishing, shipping and marine renewable developments are affecting marine top predators. Research has focussed on the impacts of single stressors on single species, yet understanding cumulative effects of multiple stressors on communities is vital for effective conservation management. We studied a marine bird community (45 species; 11 families) that used the Forth and Tay region of the North Sea for breeding, overwintering or migration between 1980 and 2011. Local sea surface temperature (SST) increased significantly over this period, with concomitant changes in lower trophic levels. Simultaneously, the region has been subject to fishing pressure and shipping disturbance and is a priority area for renewable energy developments. We used colony-based and at-sea data to quantitatively assess relationships between SST and counts, productivity and survival of 25 species for which sufficient data were available for analysis. For the remaining species, we applied a qualitative approach using published population trends, published climate relationships and foraging sensitivity. In total, 53% of species showed negative relationships with SST. Trends in counts and demography were combined with climate vulnerability to give an index of population concern to future climate warming, and 44% of species were classified as high or very high concern, notably cormorants, grebes, skuas, shearwaters, terns and auks, as well as species breeding in the region. Qualitative assessments of vulnerability to fisheries, pollutants, disturbance (including introduced predators), marine renewables and climate found that 93% of species were vulnerable to ≥2 threats, and 58% to ≥4. Our results indicate that the majority of birds in this region of the North Sea face an uncertain future, potentially threatening the resilience of this important marine bird community

Deformation of an Elastic Beam on a Winkler Foundation

We present a simple model for geophysical systems involving sources of deformation, such as magmatic intrusions, supraglacial lakes, and the subsurface storage of CO 2 . We consider the idealised system of a uniform elastic layer overlying a localised region of constant pressure that is surrounded by a Winkler foundation composed of springs. We investigate the effect of source depth and foundation stiffness on the resulting displacement profiles at both the surface and the level of the source. The system is characterised by three key features: the maximum uplift, the maximum subsidence, and the distance to the point of zero displacement. For each of these we determine asymptotic scaling behaviour in the limits of a thin/thick layer and a soft/stiff foundation and form composite curves that allow specific parameter values to be determined from field data. Both two-dimensional and axisymmetric pressure patches are considered, and in the thin-layer limit we derive analytical solutions

Validating accelerometry estimates of energy expenditure across behaviours using heart rate data in a free-living seabird

Two main techniques have dominated the field of ecological energetics, the heart-rate and doubly labelled water methods. Although well established, they are not without their weaknesses, namely expense, intrusiveness and lack of temporal resolution. A new technique has been developed using accelerometers; it uses the Overall Dynamic Body Acceleration (ODBA) of an animal as a calibrated proxy for energy expenditure. This method provides high resolution data without the need for surgery. Significant relationships exist between rate of oxygen consumption (V̇o2) and ODBA in controlled conditions across a number of taxa; however, it is not known whether ODBA represents a robust proxy for energy expenditure consistently in all natural behaviours and there have been specific questions over its validity during diving, in diving endotherms. Here we simultaneously deployed accelerometers and heart rate loggers in a wild population of European shags (Phalacrocorax aristotelis). Existing calibration relationships were then used to make behaviour-specific estimates of energy expenditure for each of these two techniques. Compared against heart rate derived estimates the ODBA method predicts energy expenditure well during flight and diving behaviour, but overestimates the cost of resting behaviour. We then combine these two datasets to generate a new calibration relationship between ODBA and V̇o2 that accounts for this by being informed by heart rate derived estimates. Across behaviours we find a good relationship between ODBA and V̇o2. Within individual behaviours we find useable relationships between ODBA and V̇o2 for flight and resting, and a poor relationship during diving. The error associated with these new calibration relationships mostly originates from the previous heart rate calibration rather than the error associated with the ODBA method. The equations provide tools for understanding how energy constrains ecology across the complex behaviour of free-living diving birds

Sublethal effects of natural parasitism act through maternal, but not paternal; reproductive success in a wild population

Parasites are a major component of all animal populations. Males and females often differ in their levels of parasite prevalence, potentially leading to sex differences in the impact of parasitism on fitness, with important implications for the evolution of parasite and host traits including resistance, tolerance, and virulence. However, quantitative measures of the impact of parasitism under free‐living conditions are extremely rare, as they require detailed host demographic data with measures of parasite burden over time. Here, we use endoscopy for direct quantification of natural‐parasite burdens and relate these to reproductive success over 7 yr in a wild population of seabirds. Contrary to predictions, only female burdens were associated with negative impacts of parasitism on breeding success, despite males having significantly higher burdens. Female reproductive success declined by 30% across the range of natural parasite burdens. These effects persisted when accounting for interannual population differences in breeding success. Our results provide quantitative estimates of profound sub‐lethal effects of parasitism on the population. Importantly, they highlight how parasites act unpredictably to shape ecological and evolutionary processes in different components of the same population, with implications for demography and selection on host and parasite traits

The energetic cost of parasitism in a wild population

Parasites have profound fitness effects on their hosts, yet these are often sub-lethal, making them difficult to understand and quantify. A principal sub-lethal mechanism that reduces fitness is parasite-induced increase in energetic costs of specific behaviours, potentially resulting in changes to time and energy budgets. However, quantifying the influence of parasites on these costs has not been undertaken in free-living animals. We used accelerometers to estimate energy expenditure on flying, diving and resting, in relation to a natural gradient of endo-parasite loads in a wild population of European shags Phalacrocorax aristotelis. We found that flight costs were 10% higher in adult females with higher parasite loads and these individuals spent 44% less time flying than females with lower parasite loads. There was no evidence for an effect of parasite load on daily energy expenditure, suggesting the existence of an energy ceiling, with the increase in cost of flight compensated for by a reduction in flight duration. These behaviour specific costs of parasitism will have knock-on effects on reproductive success, if constraints on foraging behaviour detrimentally affect provisioning of young. The findings emphasize the importance of natural parasite loads in shaping the ecology and life-history of their hosts, which can have significant population level consequences

Public values for energy futures: Framing, indeterminacy and policy making

PublishedJournal ArticleCopyright © 2015 Elsevier. NOTICE: this is the author’s version of a work that was accepted for publication in Energy Policy. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Energy Policy (2015), DOI: 10.1016/j.enpol.2015.01.035© 2015 Elsevier Ltd. In the UK there are strong policy imperatives to transition toward low carbon energy systems but how and in what ways such transitional processes might be realised remains highly uncertain. One key area of uncertainty pertains to public attitudes and acceptability. Though there is wide-ranging research relevant to public acceptability, very little work has unpacked the multiple questions concerning how policy-makers can grapple with and mitigate related uncertainties in efforts to enact energy systems change. In this paper, public acceptability is identified as an indeterminate form of uncertainty that presents particular challenges for policy making. We build on our existing research into public values for energy system change to explore how the outcomes of the project can be applied in thinking through the uncertainties associated with public acceptability. Notably, we illustrate how the public values identified through our research bring into view alternative and quite different problem and solution framings to those currently evident within UK policy. We argue that engagement with a wide range of different framings can offer a basis for better understanding and anticipating public responses to energy system change, ultimately aiding in managing the complex set of uncertainties associated with public acceptability.Natural Environment Research CouncilLeverhulme Trus

CLINICAL AND BIOMECHANICAL COMPARISONS BETWEEN YOUTH PITCHERS WITH AND WITHOUT A HISTORY OF THROWING ARM PAIN OR INJUR

This study aimed to determine if there are clinical and kinematic differences in youth pitchers with a self-reported history of throwing arm pain or injury (PI) to those without (NPI). Forty male baseball pitchers ages 9 to 14 years old were divided into a PI group (n=20) and a NPI group (n=20). Injury history, pitching exposure, subject demographics, range of motion, and strength measurements were collected, along with throwing arm kinematics via a motion capture system. When comparing PI and NPI, significant physical differences were observed, with a greater presence of axillary hair, increased forearm length and decreased shoulder internal rotation strength in PI. No significant differences of upper limb motion during pitching were reported. When considering youth pitchers, evidence of physical maturity, arm length, and strength could be important factors in developing pain or injury

Among-year and within-population variation in foraging distribution of European shags Phalacrocorax aristotelis over two decades: implications for marine spatial planning

Marine spatial planning aims to deliver sustainable use of marine resources by minimizing environmental impacts of human activities and designating Marine Protected Areas. This poses a challenge where species’ distributions show spatio-temporal heterogeneity. However, due to logistic constraints and challenging timescales many studies of distribution are undertaken over few years or on a restricted subset of the population. Long-term studies can help identify the degree of uncertainty in those less comprehensive in space and time. We quantify inter-annual and sub-colony variation in the summer foraging distribution of a population of European shags Phalacrocorax aristotelis, using a tracking data set comprising 320 individuals and 1106 foraging trips in 15 years from 1987 to 2010. Foraging distribution over the study period was concentrated in three areas. Data from one and two years captured an average of 54% and 64% of this distribution, respectively, but it required 8 years’ data to capture over 90% of the distribution. Foraging range increased with population size when breeding success was low, suggesting interplay between extrinsic and intrinsic effects. Furthermore, females had foraging ranges on average 36% greater than males. Finally, sub-colony segregation occurred in foraging areas up to 4 km from the colony and in the most distant locations (>10 km), whilst there was considerable overlap at intermediate distances (6–10 km). Our study highlights important considerations for marine spatial planning in particular, and species conservation in general, notably the proportion of the population distribution identified, the prevailing conditions experienced and the need for balanced sampling across the population

Isotopic Composition of the Ogallala-high Plains Aquifer Andvadose Zone

AbstractThe Ogallala-High Plains aquifer is an important resource for irrigated agriculture in a semi-arid region of the United States. Steep declines in groundwater levels are putting increasing strain on the viability of the aquifer for irrigation, necessitating improved estimates of recharge rates and sources to the aquifer. This study uses a combined approach to obtain high resolution geochemical and isotopic composition of the vadose zone and aquifer pore fluids to better understand recharge dynamics to the aquifer. Significant differences between the shallow, intermediate and deep vadose zone and shallow and deep aquifer indicate modern precipitation is not providing a significant source of recharge to the aquifer across a large area (diffuse recharge). Rather, recharge to the aquifer is a result of either focused recharge or long-term, delayed drainage from the portion of the vadose zone which was saturated before irrigation development