2,760 research outputs found
Exploring the role of voluntary disease schemes on UK farmer bio-security behaviours: Findings from the Norfolk-Suffolk Bovine Viral Diarrhoea control scheme
The article describes the influence of a disease control scheme (the Norfolk-Suffolk Bovine Viral Diarrhoea Disease (BVD) Eradication scheme) on farmers' bio-security attitudes and behaviours. In 2010, a survey of 100 cattle farmers (53 scheme members vs. 47 out of scheme farmers) was undertaken among cattle farmers residing in Norfolk and Suffolk counties in the UK. A cross-sectional independent measures design was employed. The main analytical tool was content analysis. The following variables at the farmer-level were explored: the specific BVD control measures adopted, livestock disease priorities, motivation for scheme membership, wider knowledge acquisition, biosecurity behaviours employed and training course attendance. The findings suggest that participation in the BVD scheme improved farmers' perception of the scheme benefits and participation in training courses. However, no association was found between the taking part in the BVD scheme and livestock disease priorities or motivation for scheme participation, or knowledge about BVD bio-security measures employed. Equally importantly, scheme membership did appear to influence the importance accorded specific bio-security measures. Yet such ranking did not appear to reflect the actual behaviours undertaken. As such, disease control efforts alone while necessary, are insufficient. Rather, to enhance farmer bio-security behaviours significant effort must be made to address underlying attitudes to the specific disease threat involved
Nanodiamond arrays on glass for quantification and fluorescence characterisation
Quantifying the variation in emission properties of fluorescent nanodiamonds
is important for developing their wide-ranging applicability. Directed
self-assembly techniques show promise for positioning nanodiamonds precisely
enabling such quantification. Here we show an approach for depositing
nanodiamonds in pre-determined arrays which are used to gather statistical
information about fluorescent lifetimes. The arrays were created via a layer of
photoresist patterned with grids of apertures using electron beam lithography
and then drop-cast with nanodiamonds. Electron microscopy revealed a 90%
average deposition yield across 3,376 populated array sites, with an average of
20 nanodiamonds per site. Confocal microscopy, optimised for nitrogen vacancy
fluorescence collection, revealed a broad distribution of fluorescent lifetimes
in agreement with literature. This method for statistically quantifying
fluorescent nanoparticles provides a step towards fabrication of hybrid
photonic devices for applications from quantum cryptography to sensing
A multiple-access satellite relay system for low data rate users
Multiple access satellite relay system for low data rate user
Discovery and Assessment of New Target Sites for Anti-HIV Therapies
Human immunodeficiency virus (HIV) infects cells by endocytosis and takes over parts of the cell’s reaction pathways in order to reproduce itself and spread the infection. One such pathway taken over by HIV becomes the inflammatory pathway which uses Nuclear Factor κB (NF-κB) as the principal transcription factor. Therefore, knocking out the NF-κB pathway would prevent HIV from reproducing itself. In this report, our goal is to produce a simple model for this pathway with which we can identify potential targets for anti-HIV therapies and test out various hypotheses. We present a very simple model with four coupled first-order ODEs and see what happens if we treat IκK concentration as a parameter that can be controlled (by some unspecified means). In Section 3, we augment this model to account for activation and deactivation of IκK, which is controlled (again, by some unspecified means) by TNF
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Respiration of aged soil carbon during fall in permafrost peatlands enhanced by active layer deepening following wildfire but limited following thermokarst
Permafrost peatlands store globally significant amounts of soil organic carbon (SOC) that may be vulnerable to climate change. Permafrost thaw exposes deeper, older SOC to microbial activity, but SOC vulnerability to mineralization and release as carbon dioxide is likely influenced by the soil environmental conditions that follow thaw. Permafrost thaw in peat plateaus, the dominant type of permafrost peatlands in North America, occurs both through deepening of the active layer and through thermokarst. Active layer deepening exposes aged SOC to predominately oxic conditions, while thermokarst is associated with complete permafrost thaw which leads to ground subsidence, inundation and soil anoxic conditions. Thermokarst often follows active layer deepening, and wildfire is an important trigger of this sequence. We compared the mineralization rate of aged SOC at an intact peat plateau (∼70 cm oxic active layer), a burned peat plateau (∼120 cm oxic active layer), and a thermokarst bog (∼550 cm anoxic peat profile) by measuring respired 14C-CO2. Measurements were done in fall when surface temperatures were near-freezing while deeper soil temperatures were still close to their seasonal maxima. Aged SOC (1600 yrs BP) contributed 22.1 ± 11.3% and 3.5 ± 3.1% to soil respiration in the burned and intact peat plateau, respectively, indicating a fivefold higher rate of aged SOC mineralization in the burned than intact peat plateau (0.15 ± 0.07 versus 0.03 ± 0.03 g CO2-C m−2 d−1). None or minimal contribution of aged SOC to soil respiration was detected within the thermokarst bog, regardless of whether thaw had occurred decades or centuries ago. While more data from other sites and seasons are required, our study provides strong evidence of substantially increased respiration of aged SOC from burned peat plateaus with deepened active layer, while also suggesting inhibition of aged SOC respiration under anoxic conditions in thermokarst bogs
Accelerated motion and the self-force in Schwarzschild spacetime
We provide expansions of the Detweiler-Whiting singular field for motion
along arbitrary, planar accelerated trajectories in Schwarzschild spacetime. We
transcribe these results into mode-sum regularization parameters, computing
previously unknown terms that increase the convergence rate of the mode-sum. We
test our results by computing the self-force along a variety of accelerated
trajectories. For non-uniformly accelerated circular orbits we present results
from a new 1+1D discontinuous Galerkin time-domain code which employs an
effective-source. We also present results for uniformly accelerated circular
orbits and accelerated bound eccentric orbits computed within a
frequency-domain treatment. Our regularization results will be useful for
computing self-consistent self-force inspirals where the particle's worldline
is accelerated with respect to the background spacetime.Comment: 19 pages, 6 figures (accepted CQG special issue article version
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A comparison of policies to reduce the methane emission intensity of smallholder dairy production in India
Within the dairy sector, the effects of climate change are particularly diverse as cows are affected by, and a
significant contributor to climate change. With a burgeoning body of work indicating the importance of livestock’s
contribution to climate change (via Greenhouse Gas (GHG) emissions), the dairy sector will increasingly
be targeted for emission reduction. Yet, gaps in knowledge remain as to the effectiveness of interventions in
achieving emission reductions. The investigation examines two high-profile Indian policies to evaluate their
effectiveness in reducing the methane emission intensity of milk production in Odisha, India. Selected policies
included the installation of smallscale anaerobic digesters and the control of Foot and Mouth Disease (FMD). The
interventions were evaluated at the cow level informed by data collected from 115 smallholder dairy producers
in Puri (n =31) and Khurda (n =84) districts in Odisha, India. The installation of an anaerobic digester was
found to increase methane emission intensity by 4.41–5.01%. Control of FMD reduced methane emission intensity
by 3.68–12.95% depending on the infection scenario considered. The findings highlight the importance
of contextually relevant and multi-sectoral approaches to mitigation as the increase in methane emission intensity
following anaerobic digester installation represents movement of emissions from the energy sector into
the dairy sector where mitigation is inherently more complex. Thus, the long-term usefulness of anaerobic
digester installation as a mitigation strategy is limited
Relation between Exercise Central Hemodynamic Load and Resting Cardiac Structure and Function in Young Men
Please view abstract in the attached PDF file
Lexicographically-ordered constraint satisfaction problems
We describe a simple CSP formalism for handling multi-attribute preference problems with hard constraints, one that combines hard constraints and preferences so the two are easily distinguished conceptually and for purposes of problem solving. Preferences are represented as a lexicographic order over complete assignments based on variable importance and rankings of values in each domain. Feasibility constraints are treated in the usual manner. Since the preference representation is ordinal in character, these problems can be solved with algorithms that do not require evaluations to be represented explicitly. This includes ordinary CSP algorithms, although these cannot stop searching until all solutions have been checked, with the important exception of heuristics that follow the preference order (lexical variable and value ordering). We describe relations between lexicographic CSPs and more general soft constraint formalisms and show how a full lexicographic ordering can be expressed in the latter. We discuss relations with (T)CP-nets, highlighting the advantages of the present formulation, and we discuss the use of lexicographic ordering in multiobjective optimisation. We also consider strengths and limitations of this form of representation with respect to expressiveness and usability. We then show how the simple structure of lexicographic CSPs can support specialised algorithms: a branch and bound algorithm with an implicit cost function, and an iterative algorithm that obtains optimal values for successive variables in the importance ordering, both of which can be combined with appropriate variable ordering heuristics to improve performance. We show experimentally that with these procedures a variety of problems can be solved efficiently, including some for which the basic lexically ordered search is infeasible in practice
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