Dynamo action in the ABC flows using symmetries

This is an Accepted Manuscript of an article published by Taylor & Francis in Geophysical and Astrophysical Fluid Dynamics, Volume 108, Issue 1, 2014 available online 25 Sep 2013: http://wwww.tandfonline.com/10.1080/03091929.2013.832762.This paper concerns kinematic dynamo action by the 1:1:1 ABC flow, in the highly conducting limit of large magnetic Reynolds number Rm. The flow possesses 24 symmetries, with a symmetry group isomorphic to the group O24 of orientation preserving transformations of a cube. This can be exploited to break up the linear eigenvalue problem into five distinct symmetry classes, or irreducible representations, which we label I–V. The paper discusses how to reduce the scale of the numerical problem to a subset of Fourier modes for a magnetic field in each representation, which then may be solved independently to obtain distinct branches of eigenvalues and magnetic field eigenfunctions. Two numerical methods are employed: the first is to time step a magnetic field in a given symmetry class and obtain the growth rate and frequency by measuring the magnetic energy as a function of time. The second method involves a more direct determination of the eigenvalue using the eigenvalue solver ARPACK for sparse matrix systems, which employs an implicitly restarted Arnoldi method. The two methods are checked against each other, and compared for efficiency and reliability. Eigenvalue branches for each symmetry class are obtained for magnetic Reynolds numbers Rm up to 104 together with spectra and magnetic field visualisations. A sequence of branches emerges as Rm increases and the magnetic field structures in the different branches are discussed and compared. In a parallel development,results are presented for the corresponding fluid stability problem as a function of the Reynolds number Re.Leverhulme Trus

In Memoriam: Keith R. Briffa, 1952–2017

Keith R. Briffa was one of the most influential palaeoclimatologists of the last 30 years. His primary research interests lay in Late-Holocene climate change with a geographical emphasis on northern Eurasia. His greatest impact was in the field of dendroclimatology, a field that he helped to shape. His contributions have been seminal to the development of sound methods for tree-ring analysis and in their proper application to allow the interpretation of climate variability from tree rings. This led to the development of many important records that allow us to understand natural climate variability on timescales from years to millennia and to set recent climatic trends in their historical context

IUPHAR-DB: An Expert-Curated, Peer-Reviewed Database of Receptors and Ion Channels

The International Union of Basic and Clinical Pharmacology database (IUPHAR-DB) integrates peer-reviewed pharmacological, chemical, genetic, functional and anatomical information on the 354 non-sensory G protein-coupled receptors (GPCRs), 71 ligand-gated ion channel subunits and 141 voltage-gated ion channel subunits encoded by the human, rat and mouse genomes. These genes represent the targets of about a third of currently approved drugs and are a major focus of drug discovery and development programs in the pharmaceutical industry. Individual gene pages provide a comprehensive description of the genes and their functions, with information on protein structure, ligands, expression patterns, signaling mechanisms, functional assays and biologically important receptor variants (e.g. single nucleotide polymorphisms and splice variants). The phenotypes resulting from altered gene expression (e.g. in genetically altered animals) and genetic mutations are described. Links are provided to bioinformatics resources such as NCBI RefSeq, OMIM, PubChem, human, rat and mouse genome databases. Recent developments include the addition of ligand-centered pages summarising information about unique ligand molecules in IUPHAR-DB. IUPHAR-DB represents a novel approach to biocuration because most data are provided through manual curation of published literature by a network of over 60 expert subcommittees coordinated by NC-IUPHAR. Data are referenced to the primary literature and linked to PubMed. The data are checked to ensure accuracy and consistency by the curators, added to the production server using custom-built submission tools and peer-reviewed by NC-IUPHAR, before being transferred to the public database. Data are reviewed and updated regularly (at least biennially). Other website features include comprehensive database search tools, online and downloadable gene lists and links to recent publications of interest to the field, such as reports on receptor-ligand pairings. The database is freely available at "http://www.iuphar-db.org":http://www.iuphar-db.org. Curators can be reached at curators [at] iuphar-db.org. We thank British Pharmacological Society, UNESCO (through the ICSU Grants Programme), Incyte, GlaxoSmithKline, Novartis, Servier and Wyeth for their support

Investigation into the Ratio of Operating and Support Costs to Life-Cycle Costs for DoD Weapon Systems

Recent legislation, such as the Weapon Systems Acquisition Reform Act of 2009, requires a renewed emphasis on understanding Operating and Support (O&S) costs. Conventional wisdom within the acquisition community suggests a 70:30 cost ratio with respect to O&S and acquisition of an average weapon system. Using 37 Air Force and Navy programs, the authors estimate the mean overall ratio of O&S costs to acquisition costs to be closer to 55:45, although many weapon systems displayed significant deviation from this 55 percent average. Contributing factors such as life expectancy and acquisition strategy (i.e., new system or modification) affect this variance. Their research advises against using a single “one-size-fits-all” O&S/ acquisition cost ratio for all major DoD weapon systems

Combining Slaughterhouse Surveillance Data with Cattle Tracing Scheme and Environmental Data to Quantify Environmental Risk Factors for Liver Fluke in Cattle.

Liver fluke infection causes serious disease (fasciolosis) in cattle and sheep in many regions of the world, resulting in production losses and additional economic consequences due to condemnation of the liver at slaughter. Liver fluke depends on mud snails as an intermediate host and infect livestock when ingested through grazing. Therefore, environmental factors play important roles in infection risk and climate change is likely to modify this. Here, we demonstrate how slaughterhouse data can be integrated with other data, including animal movement and climate variables to identify environmental risk factors for liver fluke in cattle in Scotland. We fitted a generalized linear mixed model to the data, with exposure-weighted random and fixed effects, an approach which takes into account the amount of time cattle spent at different locations, exposed to different levels of risk. This enabled us to identify an increased risk of liver fluke with increased animal age, rainfall, and temperature and for farms located further to the West, in excess of the risk associated with a warmer, wetter climate. This model explained 45% of the variability in liver fluke between farms, suggesting that the unexplained 55% was due to factors not included in the model, such as differences in on-farm management and presence of wet habitats. This approach demonstrates the value of statistically integrating routinely recorded slaughterhouse data with other pre-existing data, creating a powerful approach to quantify disease risks in production animals. Furthermore, this approach can be used to better quantify the impact of projected climate change on liver fluke risk for future studies

Surface and Subsurface Attenuation of Trenbolone Acetate Metabolites and Manure-Derived Constituents in Irrigation Runoff on Agro-Ecosystems

Although studies have evaluated the ecotoxicity and fate of trenbolone acetate (TBA) metabolites, namely 17α-trenbolone (17α-TBOH), 17β-trenbolone (17β-TBOH), and trendione (TBO), their environmental transport processes remain poorly characterized with little information available to guide agricultural runoff management. Therefore, we evaluated TBA metabolite transport in representative agricultural systems with concurrent assessment of other manure-derived constituents. Leachate generated using manure from TBA-implanted cattle was applied to a subsurface infiltration plot (4 m) and surface vegetative filter strips (VFSs; 3, 4, and 5 m). In the subsurface experiment, 17α-TBOH leachate concentrations were 36 ng L−1 but decreased to 12 ng L−1 in initial subsurface discharge. Over 75 minutes, concentrations linearly increased to 23 ng L−1 (C/Co = 0.32–0.64). In surface experiments (n = 4), 17α-TBOH leachate concentrations ranged from 11–150 ng L−1, remained nearly constant with time, but were attenuated by ∼70–90% after VFS treatment with no statistical dependence on the VFS length. While attenuation clearly occurred, the observations of a highly mobile fraction of all constituents in both surface runoff and subsurface discharge suggest that these treatment strategies may not always be capable of achieving threshold discharge concentrations. To attain no observed adverse effect levels (NOAELs) in receiving waters, concurrent assessment of leachate concentrations and available dilution capacities can be used to guide target treatment performance levels for runoff management. Dilution is usually necessary to achieve NOAELs, and receiving waters with less than 70–100 fold dilution capacity are at the highest risk for steroidal endocrine disruption

A Quasi Experimental Evaluation of Thinking for a Change: A Real-World Application

Due to the popularity of cognitive behavioral interventions, programs that follow this model are often assumed to be effective. Yet evaluations of specific programs have been slow in coming. The current investigation seeks to bridge this gap by evaluating the effectiveness of Thinking for a Change (TFAC), a widely used cognitive behavioral curriculum for offenders. Furthermore, this evaluation provides a “real-world” test of TFAC, because it was implemented by line staff in a community corrections agency as opposed to being a pilot project implemented by program developers. The results of the analyses indicate that offenders participating in the TFAC program had a significantly lower recidivism rate than similar offenders that were not exposed to the program

Connections: A Journal of Public Education Advocacy - Fall 2003, Vol. 10, No. 1

President's Message - As the 50th anniversary of Brown v. Board of Education approaches, and state budget shortfalls continue, Wendy D. Puriefoy calls for "no child left behind" to become a sacred national commitment.Senator Kennedy on the Vision of Public Education - Sen. Edward M. Kennedy argues that the funding made available for school reform must be aligned with the goals set by NCLB.Making It Happen - Legal Defense Fund President Elaine R. Jones says courts must advance the cause of equity in schools to banish remnants of segregation that linger long after Brown.Viewpoint - Jack Jennings, director of the Center on Education Policy, played a role in implementing the Elementary and Secondary Education Act in the 1960s. Today he examines the policy and funding parallels between the original act and NCLB.Conversations - Peter McWalters, president-elect of the Council of Chief State School Officers; Angela Z. Monson, Oklahoma state senator; and Ted Sanders, president of the Education Commission of the States, discuss the many challenges states face in meeting NCLB requirements.End Notes - Richard Navarro, UNICEF's education chief, encourages international support to help Afghanistan rebuild its education system

970–6 In Vivo Studies of Aortic Stenosis: Role of Inertial and Viscous Forces in Doppler/Catheter Discrepancies

In previous studies in vitro we have used a Reynolds number approach to analyze second order effects on pressure recovery distal to stenosis. It was shown that two fundamentally different effects, viscous losses and turbulent dissipation, can control the basic overestimation due to pressure recovery at both ends of the Reynolds number scale. Having quantified this effect in vitro, this study attempted to reconcile Doppler and catheter gradients across aortic stenosis in vivo.MethodsIn 4 sheep with surgically created aortic stenosis, 30 hemodynamic states were studied (4–11 per sheep) using Millar transducers in the LV and Aorta (peak PG ranged 3–150mmHg). A Vingmed 775 interfaced to a computer was used to measure CVV velocities simultaneously with catheter recordings.ResultsInstantaneous Doppler peak gradient correlated with catheter instantaneous gradient throughout the range of baseline and stenotic conditions (r=0.973, SEE=8.7mmHg). but Doppler overestimated cath gradient (up to 70%) for all stenotic valve conditions by an average of 17%. Plotting overestimation versus Reynolds number revealed a second order profile of the shape derived in vitro. Correction of Doppler gradients using this parabolic factor reduced average overestimation from 17% to 1.5%.ConclusionsOverestimation due to pressure recovery is basic to aortic stenosis, but this overestimation can be partially canceled by two apparently unrelated effects: viscous effects and turbulent dissipation. The former is deleted from the simplified Bernoulli equation, but more importantly, the latter is not characterized by any form of the Bernoulli equation. A Reynolds number based approach characterizes the relative importance of these effects and could lead to reconciliation of Doppler and catheter gradients in the clinical setting

Extruded Monofilament and Multifilament Thermoplastic Stitching Yarns

Carbon fibre reinforced polymer composites offer significant improvement in overall material strength to weight, when compared with metals traditionally used in engineering. As a result, they are replacing metals where overall weight is a significant consideration, such as in the aerospace and automotive industries. However, due to their laminate structure, delamination is a prime concern. Through-thickness stitching has been shown to be a relatively simple method of improving resistance to delamination. In this paper, monofilament and multifilament fibres of a similar overall diameter were characterised and their properties compared for their suitability as stitching yarns. Dissimilar to other published works which rely on commercially available materials, such as polyparaphenylene terephthalamide, criteria were produced on the required properties and two potentially promising polymers were selected for extrusion. It was found that although the multifilament fibres had a greater ultimate tensile strength, they began to yield at a lower force than their monofilament equivalent