Publications by authors named "Speirs D"

Thousands of offshore oil and gas platforms have been installed throughout the world's oceans and more structures are being installed as part of the transition to renewable energy. These structures increase the availability of ecological niches by providing hard substrate in midwater and complex 3D habitat on the seafloor. This can lead to 'hotspots' of biodiversity, or increased densities of flora and fauna, which potentially spill over into the local area.

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Objective: To determine if framing the etiology of obesity as a disease, food addiction, or caloric imbalance would increase or decrease anti-fat attitudes (AFA) and challenge the belief that obesity is caused by a lack of personal responsibility or willpower.

Methods: Two hundred and forty-nine fitness practitioners (M = 37.49 years) were randomly assigned to one of four experimental conditions and asked to read a short article describing obesity as either: (a) food addiction, (b) disease, or (c) caloric imbalance, while a control group read an unrelated article.

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The changing Arctic environment is affecting zooplankton that support its abundant wildlife. We examined how these changes are influencing a key zooplankton species, Calanus finmarchicus, principally found in the North Atlantic but expatriated to the Arctic. Close to the ice-edge in the Fram Strait, we identified areas that, since the 1980s, are increasingly favourable to C.

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Stimulated Brillouin scattering experiments in the ionospheric plasma using a single electromagnetic pump wave have previously been observed to generate an electromagnetic sideband wave, emitted by the plasma, together with an ion- acoustic wave. Here we report results of a controlled, pump and probe beat-wave driven Brillouin scattering experiment, in which an ion-acoustic wave generated by the beating of electromagnetic pump and probe waves, results in electromagnetic sideband waves that are recorded on the ground. The experiment used the EISCAT facility in northern Norway, which has several high power electromagnetic wave transmitters and receivers in the radio frequency range.

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Article Synopsis
  • Projecting the effects of climate change on Arctic marine food webs and fisheries is complex because of the close ties between biology and ice conditions.
  • A food web model called StrathE2EPolar was used to simulate how climate change impacts fisheries in the Barents Sea, based on predictions from the NEMO-MEDUSA climate model.
  • By the 2040s, the Barents Sea is expected to be over 95% ice-free year-round and about 2°C warmer, leading to increased productivity for demersal fish like cod and haddock, but decreased reference points for planktivorous fish, creating challenges for ecosystems and fisheries management.
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Phenotypic plasticity plays an important role in the survival of individuals. In microbial host-virus systems, previous studies have shown the stabilizing effect that host plasticity has on the coexistence of the system. By contrast, it remains uncertain how the dependence of the virus on the metabolism of the host (i.

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We examine long-term trends in the average growth rates and maturation schedules of herring and sprat populations using survey data collected from the North Sea and west of Scotland since the 1960s and 1980s respectively. Otolith age data and maturity data are used to calculate time series of mean lengths at age, von Bertalanffy growth parameters, and probabilistic maturation reaction norms. As the growth and maturation of fish is known to be influenced by temperature and stock abundances, we account for these variables using Generalised Additive Models.

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There is an urgent need for a better understanding of animal migratory ecology under the influence of climate change. Most current analyses require long-term monitoring of populations on the move, and shorter-term approaches are needed. Here, we analysed the ecological drivers of seabird migration within the framework of the energyscape concept, which we defined as the variations in the energy requirements of an organism across geographical space as a function of environmental conditions.

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Diapause plays a key role in the life cycle of high latitude zooplankton. During diapause, animals avoid starving in winter by living in deep waters where metabolism is lower and met by lipid reserves. Global warming is therefore expected to shorten the maximum potential diapause duration by increasing metabolic rates and by reducing body size and lipid reserves.

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The purpose of this study was to investigate the effects of a 5-week lower-limb unilateral or bilateral strength program on measures of strength, sprinting, and change of direction speed. Eighteen academy rugby players (18.1 ± 0.

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In this Letter, we present theory and particle-in-cell simulations describing cyclotron radio emission from Earth's auroral region and similar phenomena in other astrophysical environments. In particular, we find that the radiation, generated by a down-going electron horseshoe distribution is due to a backward-wave cyclotron-maser emission process. The backward wave nature of the radiation contributes to upward refraction of the radiation that is also enhanced by a density inhomogeneity.

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Discarding by fisheries is perceived as contrary to responsible harvesting. Legislation seeking to end the practice is being introduced in many jurisdictions. However, discarded fish are food for a range of scavenging species; so, ending discarding may have ecological consequences.

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Climate fluctuations and human exploitation are causing global changes in nutrient enrichment of terrestrial and aquatic ecosystems and declining abundances of apex predators. The resulting trophic cascades have had profound effects on food webs, leading to significant economic and societal consequences. However, the strength of cascades-that is the extent to which a disturbance is diminished as it propagates through a food web-varies widely between ecosystems, and there is no formal theory as to why this should be so.

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Atlantic salmon exhibit a partially heritable polymorphism in which the morphs are distinguished by the duration and location of the sea-phase of their life-cycle. These morphs co-occur, albeit in characteristically different proportions, in most Scottish rivers and in both the spring and autumn spawner runs; early running fish being generally associated with upland spawning locations while late running fish are associated with lowland spawning. Thus, differences in riverine and marine environment appear to be linked to differences in the relative abundance of the morphs, rather than to the specific morph which is optimally adapted.

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Following the repeal in 1962 of a long-standing ban on trawling, yields of demersal fish from the Firth of Clyde, southwest Scotland, increased to a maximum in 1973 and then declined until the directed fishery effectively ceased in the early 2000s. Since then, the only landings of demersal fish from the Firth have been by-catch in the Norway lobster fishery. We analysed changes in biomass density, species diversity and length structure of the demersal fish community between 1927 and 2009 from scientific trawl surveys, and related these to the fishery harvesting rate.

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This paper is concerned with characterizing the quasistatic mechanical behaviour of arterial tissue undergoing finite deformation through hyperelastic constitutive functions. Commonly the parameters of constitutive functions are established by a process of optimization based on experimental data. Instead we construct a finite element model of a representative volume element of the material and compute its homogenized response to a range of deformations.

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This paper will describe the application of a finite element (FE) code to design a test cell, in which a single transducer is used to generate acoustic cavitation. The FE model comprises a 2-D slice through the centre of the test cell and was used to evaluate the generated pressure fields as a function of frequency. Importantly, the pressure fields predicted by FE modelling are used to indicate the position of pressure peaks, or 'hot-spots', and nulls enabling the systems design engineer to visualise both the potential cavitation areas, corresponding to the 'hot-spots', and areas of low acoustic pressure.

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The aims of the research were to: (1) establish a profile of 'special recyclers', i.e. those who make special trips by car to recycle their household waste; and (2) establish whether the environmental burden resulting from their activities presents a significant environmental problem than needs pro-active management.

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Common shrews (Sorex araneus L.) were presented with two prey types at various densities in a depleting environment. Observed diet choice was compared to predictions of the classical optimal diet model and of "shrew-specific" simulations incorporating patch depletion.

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The ability of insect parasitoids to discriminate between parasitized and unparasitized hosts is well documented. Despite this, hosts that have been parasitized more than once are frequently found, an occurrence known as superparasitism. Since superparasitism results in interlarval competition, it was generally assumed to be caused by discriminatory 'mistakes'.

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The importance of the interpersonal meanings of symptomatology, especially as they relate to issues of control in therapy, is explored across a wide variety of treatment approaches. It is concluded that the often destructive behavior of distrubed adolescents may be viewed not simply as pathology to be altered, but as potential strength to be channeled. Implications for therapeutic technique are discussed, and examples are offered.

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