9,470 research outputs found
UK Foot and Mouth disease: a systemic risk assessment of existing controls
This article details a systemic analysis of the controls in place and possible interventions available to further reduce the risk of a foot and mouth disease (FMD) outbreak in the United Kingdom. Using a research-based network analysis tool, we identify vulnerabilities within the multibarrier control system and their corresponding critical control points (CCPs). CCPs represent opportunities for active intervention that produce the greatest improvement to United Kingdom's resilience to future FMD outbreaks. Using an adapted ‘features, events, and processes’ (FEPs) methodology and network analysis, our results suggest that movements of animals and goods associated with legal activities significantly influence the system's behavior due to their higher frequency and ability to combine and create scenarios of exposure similar in origin to the U.K. FMD outbreaks of 1967/8 and 2001. The systemic risk assessment highlights areas outside of disease control that are relevant to disease spread. Further, it proves to be a powerful tool for demonstrating the need for implementing disease controls that have not previously been part of the system
Non-Zhang-Rice singlet character of the first ionization state of T-CuO
We argue that tetragonal CuO (T-CuO) has the potential to finally settle
long-standing modelling issues for cuprate physics. We compare the one-hole
quasiparticle (qp) dispersion of T-CuO to that of cuprates, in the framework of
the strongly-correlated () limit of the three-band
Emery model. Unlike in CuO, magnetic frustration in T-CuO breaks the
rotational symmetry and leads to strong deviations from the Zhang-Rice singlet
picture in parts of the reciprocal space. Our results are consistent with
angle-resolved photoemission spectroscopy data but in sharp contradiction to
those of a one-band model previously suggested for them. These differences
identify T-CuO as an ideal material to test a variety of scenarios proposed for
explaining cuprate phenomenology.Comment: 4 pages, 2 figure
Scientific commentary: Strategic analysis of environmental policy risks-heat maps, risk futures and the character of environmental harm
We summarise our recent efforts on the policy level risk appraisal of environmental risks. These have necessitated working closely with policy teams and a requirement to maintain crisp and accessible messages for policy audiences. Our comparative analysis uses heat maps, supplemented with risk narratives, and employs the multidimensional character of risks to inform debates on the management of current residual risk and future threats. The policy research and ensuing analysis raises core issues about how comparative risk analyses are used by policy audiences, their validation and future developments that are discussed in the commentary below
The Species Concordance Method of Tide Prediction in Estuaries
The harmonic method of tide prediction is developed to its fullest extent, so that it can deal with tide curves which are so distorted that they have gradient discontinuities. It is better, however, to use a new two-step method known as the method of species concordance. This method is applied to the Gironde, and then to the Loire, where the variation in fresh-water level is important
Recommended from our members
Characterising the dynamics of placental glycogen stores in the mouse.
INTRODUCTION: The placenta performs a range of functions to support fetal growth. In addition to facilitating nutrient transport, the placenta also stores glucose as glycogen, which is thought to maintain fetal glucose supply during late gestation. However, evidence to support such a role is currently lacking. Similarly, our understanding of the dynamics of placental glycogen metabolism in normal mouse pregnancy is limited. METHODS: We quantified the placental glycogen content of wild type C57BL/6JOlaHsd mouse placentas from mid (E12.5) to late (E18.5) gestation, alongside characterising the temporal expression pattern of genes encoding glycogenesis and glycogenolysis pathway enzymes. To assess the potential of the placenta to produce glucose, we investigated the spatiotemporal expression of glucose 6-phosphatase by qPCR and in situ hybridisation. Separate analyses were undertaken for placentas of male and female conceptuses to account for potential sexual dimorphism. RESULTS: Placental glycogen stores peak at E15.5, having increased over 5-fold from E12.5, before declining by a similar extent by E18.5. Glycogen stores were 17% higher in male placentas than in females at E15.5. Expression of glycogen branching enzyme (Gbe1) was reduced ~40% towards term. Expression of the glucose 6-phosphatase isoform G6pc3 was enriched in glycogen trophoblast cells and increased towards term. DISCUSSION: Reduced expression of Gbe1 suggests a decline in glycogen branching towards term. Expression of G6pc3 by glycogen trophoblasts is consistent with an ability to produce and release glucose from glycogen stores. However, the ultimate destination of the glucose generated from placental glycogen remains to be elucidated.Centre for Trophoblast Researc
Fuzzy Robot Controller Tuning with Biogeography-Based Optimization
Biogeography-based optimization (BBO) is an evolutionary algorithm (EA) based upon the models of biogeography, which describe the relationship between habitat suitability and the migration of species across habitats. In this work, we apply BBO to the problem of tuning the fuzzy tracking controller of mobile robots. This is an extension of previous work, in which we used BBO to tune a proportional-derivative (PD) controller for these robots. We show that BBO can successfully tune the shape of membership functions for a fuzzy controller with both simulation and real world experimental results
Report by the ESA-ESO Working Group on Fundamental Cosmology
ESO and ESA agreed to establish a number of Working Groups to explore
possible synergies between these two major European astronomical institutions.
This Working Group's mandate was to concentrate on fundamental questions in
cosmology, and the scope for tackling these in Europe over the next ~15 years.
One major resulting recommendation concerns the provision of new generations of
imaging survey, where the image quality and near-IR sensitivity that can be
attained only in space are naturally matched by ground-based imaging and
spectroscopy to yield massive datasets with well-understood photometric
redshifts (photo-z's). Such information is essential for a range of new
cosmological tests using gravitational lensing, large-scale structure, clusters
of galaxies, and supernovae. Great scope in future cosmology also exists for
ELT studies of the intergalactic medium and space-based studies of the CMB and
gravitational waves; here the synergy is less direct, but these areas will
remain of the highest mutual interest to the agencies. All these recommended
facilities will produce vast datasets of general applicability, which will have
a tremendous impact on broad areas of astronomy.Comment: ESA-ESO Working Groups Report No. 3, 125 pages, 28 figures. A PDF
version including the cover is available from
http://www.stecf.org/coordination/esa_eso/cosmology/report_cover.pdf and a
printed version (A5 booklet) is available in limited numbers from the Space
Telescope-European Coordinating Facility (ST-ECF): [email protected]
Biogeography-Based Optimization of a Variable Camshaft Timing System
Automotive simulations often prohibit the use of traditional optimization techniques because these simulations are complex and computationally expensive. These two qualities motivate the use of evolutionary algorithms and meta-modeling techniques respectively. In this work, we apply biogeography-based optimization (BBO) to optimize radial basis function (RBF)-based lookup table controls of a variable camshaft timing system for fuel economy. Also, we reduce computational search effort by finding an effective parameterization of the problem, optimizing the parameters of the BBO algorithm for the problem, and estimating the cost of a portion of the candidate solutions in BBO with design and analysis of computer experiments (DACE). We find that we can improve fuel economy by 1.7% over the original control parameters, and we find a tradeoff in population size, and an optimal value for mutation rate. Finally, we find that we can use a small number of samples to construct DACE models, and we can use these models to estimate a significant portion of the candidate solutions each generation to reduce computation effort and still obtain good BBO solutions
Anyon Wave Function for the Fractional Quantum Hall Effect
An anyon wave function (characterized by the statistical factor )
projected onto the lowest Landau level is derived for the fractional quantum
Hall effect states at filling factor ( and are
integers). We study the properties of the anyon wave function by using detailed
Monte Carlo simulations in disk geometry and show that the anyon ground-state
energy is a lower bound to the composite fermion one.Comment: Reference adde
- …