7,438 research outputs found
Demographics of cattle movements in the United Kingdom
Background: The United Kingdom (UK) government has been recording the births, deaths, and movements of
cattle for the last decade. Despite reservations about the accuracy of these data, they represent a large and
valuable body of information about the demographics of the UK cattle herd and its contact structure. In this
article, a range of demographic data about UK cattle, and particularly their movements, are presented, as well as
yearly trends in the patterns of movements.
Results: A clear seasonal pattern is evident in the number of movements of cattle, as are the reductions in
movement volume due to foot and mouth disease outbreaks in 2001 and 2007. The distribution of ages of cattle at
their time of death is multimodal, and the impact of the over thirty months rule is marked. Most movements occur
between agricultural holdings, markets, and slaughterhouses, and there is a non-random pattern to the types of
holdings movements occur between. Most animals move only a short distance and a few times in their life. Most
movements between any given pair of holdings only occurred once in the last 10 years, but about a third occurred
between 2 and 10 times in that period. There is no clear trend to movement patterns in the UK since 2002.
Conclusions: Despite a substantial number of regulatory interventions during the last decade, movement patterns
show no clear trend since 2002. The observed patterns in the repeatability of movements, the types of holdings
involved in movements, the distances and frequencies of cattle movements, and the batch sizes involved give an
insight into the structure of the UK cattle industry, and could act as the basis for a predictive model of livestock
movements in the UK
Scottish social survey data, past present and future:Does Scotland need its own data strategy?
The UK now has a National Data Strategy. In this paper we explore whether or not in addition Scotland needs its own specific data strategy. This paper is intended to be a ‘think piece’ or critical essay, the motivation being to encourage debate about Scottish social survey data. Post-devolution, with the emergence of new forms of governance and new institutional arrangements, the political desire to research Scotland in the 21st Century has been brought into sharper resolution. Social and economic life in Scotland shares both similarities and differences with life south of the border. It is important that these characteristics are correctly identified with empirical data rather than simply being assumed. Scotland is a small territory with a good social science tradition and a healthy research sector. There is an increasing amount of survey data collecting measures relating to social and economic life in Scotland. These include both United Kingdom or Great Britain based surveys with a Scottish component, and Scotland focussed surveys. In this paper we outline a number of key issues relating to Scottish social science data resources. We provide a number of critical recommendations for social science data collection in Scotland. Finally, we examine the potential benefits of a comprehensive data strategy
Representing the UK's cattle herd as static and dynamic networks
Network models are increasingly being used to understand the spread of diseases through sparsely connected populations, with particular interest in the impact of animal movements upon the dynamics of infectious diseases. Detailed data collected by the UK government on the movement of cattle may be represented as a network, where animal holdings are nodes, and an edge is drawn between nodes where a movement of animals has occurred. These network representations may vary from a simple static representation, to a more complex, fully dynamic one where daily movements are explicitly captured. Using stochastic disease simulations, a wide range of network representations of the UK cattle herd are compared. We find that the simpler static network representations are often deficient when compared with a fully dynamic representation, and should therefore be used only with caution in epidemiological modelling. In particular, due to temporal structures within the dynamic network, static networks consistently fail to capture the predicted epidemic behaviour associated with dynamic networks even when parameterized to match early growth rates
THE BAYESIAN DECISION MODEL WITH MORE THAN ONE PREDICTOR--AN APPLICATION TO THE STOCKING RATE PROBLEM
Research Methods/ Statistical Methods,
Tunnel junctions for InP-on-Si solar cells
Growing, by metalorganic chemical vapor deposition, a tunnel junction is described, which makes possible and ohmic back contact in an n-on-p InP solar cell on a silicon substrate. The junction between heavily doped layers of p-type InGaAs and n-type InP shows resistance low enough not to affect the performance of these cells. InP solar cells made on n-type Si substrates with this structure were measured with an efficiency of 9.9 percent. Controls using p-type GaAs substrates showed no significant difference in cell performance, indicating that the resistance associated with the tunnel junction is less than about 0.1 ohm/sq cm
Postal survey of contacts between cattle farms on the Isle of Lewis
The British Cattle Movement Service (BCMS) database contains an unprecedented quantity of data on the movement of cattle within the UK. These data may be used to construct models of the contact structure of the UK cattle herd, for epidemiological purposes. There are two significant potential sources of inaccuracy within such models: movements that are not reported or are reported inaccurately to the BCMS, and contacts between farms that might transmit infection, but are not animal movements. This field study addressed these issues. Cattle farmers on the Isle of Lewis were recruited with the assistance of the local veterinary surgeon, and asked to record a range of potential risk behaviours for a one-month period. They were also asked questions about husbandry practices on their farm. Comparison of the BCMS contact data with that reported by Lewis' farmers highlighted use of common grazing land as a significant source of contact, and potential disease transmission, between cattle that currently goes unreported; around half of responding holdings on Lewis use common grazing land at some point during the year, and these movements are not reported to the BCMS
Higgs-Pair Production and Measurement of the Triscalar Coupling at LHC(8,14)
We simulate the measurement of the triscalar Higgs coupling at LHC(8,14) via
pair production of h(125 GeV). We find that the most promising hh final state
is bb gamma gamma. We account for deviations of the triscalar coupling from its
SM value and study the effects of this coupling on the hh cross-section and
distributions with cut-based and multivariate methods. Our fit to the hh
production matrix element at LHC(14) with 3 ab^-1 yields a 40% uncertainty on
this coupling in the SM and a range of 25-80% uncertainties for non-SM values.Comment: 4 pages, 7 page
Event-related brain potential correlates of human auditory sensory memory-trace formation
The event-related potential (ERP) component mismatch negativity (MMN) is a neural marker of human echoic memory. MMN is elicited by deviant sounds embedded in a stream of frequent standards, reflecting the deviation from an inferred memory trace of the standard stimulus. The strength of this memory trace is thought to be proportional to the number of repetitions of the standard tone, visible as the progressive enhancement of MMN with number of repetitions (MMN memory-trace effect). However, no direct ERP correlates of the formation of echoic memory traces are currently known. This study set out to investigate changes in ERPs to different numbers of repetitions of standards, delivered in a roving-stimulus paradigm in which the frequency of the standard stimulus changed randomly between stimulus trains. Normal healthy volunteers (n = 40) were engaged in two experimental conditions: during passive listening and while actively discriminating changes in tone frequency. As predicted, MMN increased with increasing number of standards. However, this MMN memory-trace effect was caused mainly by enhancement with stimulus repetition of a slow positive wave from 50 to 250 ms poststimulus in the standard ERP, which is termed here "repetition positivity" (RP). This RP was recorded from frontocentral electrodes when participants were passively listening to or actively discriminating changes in tone frequency. RP may represent a human ERP correlate of rapid and stimulus-specific adaptation, a candidate neuronal mechanism underlying sensory memory formation in the auditory cortex
Assessment of the environmental toxicity and carcinogenicity of tungsten-based shot.
The toxicity of elemental tungsten released from discharged shot was assessed against previous studies that established a 1% toxic threshold for soil organisms. Extremely heavy theoretical shot loadings of 69,000 shot/ha were used to generate estimated environmental concentrations (EEC) for two brands of tungsten-based shot containing 51% and 95% tungsten. The corresponding tungsten EEC values were 6.5–13.5 mg W/kg soil, far below the 1% toxic threshold. The same shot loading in water produced tungsten EEC values of 2.1–4.4 mg W/L, levels that are not toxic under experimental conditions. Pure tungsten has not been shown to exhibit carcinogenic properties when ingested or embedded in animal tissues, but nickel, with which it is often alloyed, has known carcinogenicity. Given the large number of waterfowl that carry shot embedded in their body, it is advisable to screen lead shot substitutes for their carcinogenic potential through intra-muscular implantation
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