Scoping a public health impact assessment of aquaculture with particular reference to tilapia in the UK

Background. The paper explores shaping public health impact assessment tools for tilapia, a novel emergent aquaculture sector in the UK. This Research Council’s UK Rural Economy and Land Use project embraces technical, public health, and marketing perspectives scoping tools to assess possible impacts of the activity. Globally, aquaculture produced over 65 million tonnes of food in 2008 and will grow significantly requiring apposite global public health impact assessment tools.<p></p> Methods. Quantitative and qualitative methods incorporated data from a tridisciplinary literature. Holistic tools scoped tilapia farming impact assessments. Laboratory-based tilapia production generated data on impacts in UK and Thailand along with 11 UK focus groups involving 90 consumers, 30 interviews and site visits, 9 visits to UK tilapia growers and 2 in The Netherlands.<p></p> Results. The feasibility, challenges, strengths, and weaknesses of creating a tilapia Public Health Impact Assessment are analysed. Occupational and environmental health benefits and risks attached to tilapia production were identified.<p></p> Conclusions. Scoping public health impacts of tilapia production is possible at different levels and forms for producers, retailers, consumers, civil society and governmental bodies that may contribute to complex and interrelated public health assessments of aquaculture projects. Our assessment framework constitutes an innovatory perspective in the field

A comparison of coyote ecology after 25 years: 1978 versus 2003

Most ecological studies of coyotes are of short duration and studies are generally never repeated, thus the opportunity to compare changes in coyote (Canis latrans Say, 1823) ecology over time is rare. We compared coyote home ranges, activity patterns, age, and diet at the Welder Wildlife Refuge in south Texas between 1978-1979 and 2003-2004 (25 years later). The Minta index of overlap between 1978 and 2003 home ranges was 51.7 ± 7.0 (n = 7), much greater than the Minta index value based on randomized tests (28.7 ± 8.6), indicating similar spatial patterns between time periods. The Minta index was 12.3 ± 6.2 (n = 7) for core areas, whereas the Minta index value based on randomized tests was 4.0 ± 3.0. Although overall diets were similar between 1978 and 2003, we detected some differences in prey species consumed. Activity patterns were similar between the two study periods, with peaks in movement occurring around sunrise and sunset. There was no difference in the mean age between the two populations (P = 0.44, n = 68, t [66] = 2.00). Our findings suggest that population features, such as home-range position and age structure, are similar between extended time periods, while individual-level patterns, such as the prey species consumed and distribution of locations within a home range, are dynamic and may reflect changes in the local environment

A comparison of coyote ecology after 25 years: 1978 versus 2003

Most ecological studies of coyotes are of short duration and studies are generally never repeated, thus the opportunity to compare changes in coyote (Canis latrans Say, 1823) ecology over time is rare. We compared coyote home ranges, activity patterns, age, and diet at the Welder Wildlife Refuge in south Texas between 1978-1979 and 2003-2004 (25 years later). The Minta index of overlap between 1978 and 2003 home ranges was 51.7 ± 7.0 (n = 7), much greater than the Minta index value based on randomized tests (28.7 ± 8.6), indicating similar spatial patterns between time periods. The Minta index was 12.3 ± 6.2 (n = 7) for core areas, whereas the Minta index value based on randomized tests was 4.0 ± 3.0. Although overall diets were similar between 1978 and 2003, we detected some differences in prey species consumed. Activity patterns were similar between the two study periods, with peaks in movement occurring around sunrise and sunset. There was no difference in the mean age between the two populations (P = 0.44, n = 68, t [66] = 2.00). Our findings suggest that population features, such as home-range position and age structure, are similar between extended time periods, while individual-level patterns, such as the prey species consumed and distribution of locations within a home range, are dynamic and may reflect changes in the local environment

Structure and dynamics of the interface between a binary hard-sphere crystal of NaCl type and its coexisting binary fluid

Molecular dynamics simulations are performed to study the [100] and [111] orientations of the crystal-melt interface between an ordered two-component hard sphere with a NaCl structure and its coexisting binary hard-sphere fluid. The diameter ratio of the two types of hard spheres making up the mixture is taken to be 0.414. This work complements our earlier interface simulations [J. Chem. Phys.116, 3410] for the same diameter ratio at lower pressures where the smaller component is immiscible in the solid and the fluid mixture coexists with a pure FCC crystal of large particles. Density profiles and diffusion coefficient profiles are presented for the AB interfacial system. We find that for this system, the transition from crystal-like to fluid-like behavior of both the density and diffusion constant profiles occurs over a narrower region than that seen in our previous studies [J. Chem. Phys. 116, 3410] of the FCC/binary fluid system. But similar to what was found in the FCC/binary fluid interface the transition region for the large particle diffusion constant is shifted about the size of the large particles toward the fluid phase relative to that for the small particles.Comment: 8 page

The Effect of Pravastatin on Intima Media Thickness of the Carotid Artery in Patients with Normal Cholesterol

AbstractObjectiveCarotid intima media thickness (IMT) is a good indicator of the severity of atherosclerotic disease. Statins have been found to reduce carotid IMT in patients with hypercholesterolaemia. The aim of this study was to investigate if pravastatin is effective in reducing IMT in normocholesterolaemic patients with carotid artery disease.MethodsPatients with carotid artery stenosis and normal cholesterol levels who were not on a statin, were recruited. Patients were randomised to receive pravastatin or placebo daily. Serum concentration of cholesterol and IMT of common carotid arteries were measured before randomisation and at 3 monthly intervals thereafter, for 9 months. IMT was analysed to give the mean of a standardised 2cm of the common carotid artery (CCA). Results are expressed as median (IQR) and comparison made using the Wilcoxon signed ranks test.ResultsFifty-four patients were examined. Twenty-eight patients were randomised to active treatment. There was no difference in demographic details and co-morbid states between the two groups. A significant reduction in cholesterol concentration was observed from 3 months in patients randomised to the pravastatin group [5.14(4.72–5.88) vs. 4.11(3.44–5.33), p<0.05], while there was also a significant decrease in combined IMT form 6 months [1.53(1.36–1.87) vs. 1.41 (1.33–1.78), p<0.05].ConclusionsThe results demonstrate that pravastatin reduces intima media thickness of the common carotid artery in normocholesterolaemic patients with moderate carotid stenosis

The two-dimensional random-bond Ising model, free fermions and the network model

We develop a recently-proposed mapping of the two-dimensional Ising model with random exchange (RBIM), via the transfer matrix, to a network model for a disordered system of non-interacting fermions. The RBIM transforms in this way to a localisation problem belonging to one of a set of non-standard symmetry classes, known as class D; the transition between paramagnet and ferromagnet is equivalent to a delocalisation transition between an insulator and a quantum Hall conductor. We establish the mapping as an exact and efficient tool for numerical analysis: using it, the computational effort required to study a system of width $M$ is proportional to $M^{3}$, and not exponential in $M$ as with conventional algorithms. We show how the approach may be used to calculate for the RBIM: the free energy; typical correlation lengths in quasi-one dimension for both the spin and the disorder operators; even powers of spin-spin correlation functions and their disorder-averages. We examine in detail the square-lattice, nearest-neighbour $\pm J$ RBIM, in which bonds are independently antiferromagnetic with probability $p$, and ferromagnetic with probability $1-p$. Studying temperatures $T\geq 0.4J$, we obtain precise coordinates in the $p-T$ plane for points on the phase boundary between ferromagnet and paramagnet, and for the multicritical (Nishimori) point. We demonstrate scaling flow towards the pure Ising fixed point at small $p$, and determine critical exponents at the multicritical point.Comment: 20 pages, 25 figures, figures correcte

Nonlocal charges of T-dual strings

We obtain sets of infinite number of conserved nonlocal charges of strings in a flat space and pp-wave backgrounds, and compare them before and after T-duality transformation. In the flat background the set of nonlocal charges is the same before and after the T-duality transformation with interchanging odd and even-order charges. In the IIB pp-wave background an infinite number of nonlocal charges are independent, contrast to that in a flat background only the zero-th and first order charges are independent. In the IIA pp-wave background, which is the T-dualized compactified IIB pp-wave background, the zero-th order charges are included as a part of the set of nonlocal charges in the IIB background. To make this correspondence complete a variable conjugate to the winding number is introduced as a Lagrange multiplier in the IIB action a la Buscher's transformation.Comment: 23 pages, 1 figur

Thin-Film Metamaterials called Sculptured Thin Films

Morphology and performance are conjointed attributes of metamaterials, of which sculptured thin films (STFs) are examples. STFs are assemblies of nanowires that can be fabricated from many different materials, typically via physical vapor deposition onto rotating substrates. The curvilinear--nanowire morphology of STFs is determined by the substrate motions during fabrication. The optical properties, especially, can be tailored by varying the morphology of STFs. In many cases prototype devices have been fabricated for various optical, thermal, chemical, and biological applications.Comment: to be published in Proc. ICTP School on Metamaterials (Augsut 2009, Sibiu, Romania

Basal topographic controls on rapid retreat of Humboldt Glacier, northern Greenland

Discharge from marine-terminating outlet glaciers accounts for up to half the recent mass loss from the Greenland ice sheet, yet the causal factors are not fully understood. Here we assess the factors controlling the behaviour of Humboldt Glacier (HG), allowing us to evaluate the influence of basal topography on outlet glacier response to external forcing since part of HG’s terminus occupies a large overdeepening. HG’s retreat accelerated dramatically after 1999, coinciding with summer atmospheric warming of up to 0.19°C a–1 and sea-ice decline. Retreat was an order of magnitude greater in the northern section of the terminus, underlain by a major basal trough, than in the southern section, where the bedrock is comparatively shallow. Velocity change following retreat was spatially non-uniform, potentially due to a pinning point near HG’s northern lateral margin. Consistent with observations, numerical modelling demonstrates an order-of-magnitude greater sensitivity to sea-ice buttressing and crevasse depth (used as a proxy for atmospheric warming) in the northern section. The trough extends up to 72 km inland, so it is likely to facilitate sustained retreat and ice loss from HG during the 21st century

Liquid antiferromagnets in two dimensions

It is shown that, for proper symmetry of the parent lattice, antiferromagnetic order can survive in two-dimensional liquid crystals and even isotropic liquids of point-like particles, in contradiction to what common sense might suggest. We discuss the requirements for antiferromagnetic order in the absence of translational and/or orientational lattice order. One example is the honeycomb lattice, which upon melting can form a liquid crystal with quasi-long-range orientational and antiferromagnetic order but short-range translational order. The critical properties of such systems are discussed. Finally, we draw conjectures for the three-dimensional case.Comment: 4 pages RevTeX, 4 figures include