8,966 research outputs found

    The impact of cattle drinking points on aquatic macroinvertebrates in streams in south-east Ireland

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    peer-reviewedTeagasc PublicationMeasures that prevent cattle access to watercourses are commonly implemented through agri-environment schemes, in an effort to address the objectives of the Water Framework Directive. Despite the widespread implementation, few studies have assessed the impact of cattle access to streams on aquatic macroinvertebrates. This study assessed the local-scale impact of cattle drinking points on water quality parameters (i.e. macroinvertebrate and water chemistry metrics) on 39 intensively-managed grassland farms in the south-east of Ireland. The results indicate that sites that were more than or equal to good quality upstream of cattle drinking points, were more susceptible to cattle access impacts than sites where upstream water quality was less than good. The European Court of Auditors (2011) recommended that there should be a higher rate of EU contribution for measures with higher environmental potential, in this instance, for cattle exclusion measures targeted to sites where background quality is more than or equal to good. Appropriate efforts should thus be made to incentivise farmers in good to high status sites to adopt cattle exclusion measures

    Modeling the physical properties in the ISM of the low-metallicity galaxy NGC4214

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    We present a model for the interstellar medium of NGC4214 with the objective to probe the physical conditions in the two main star-forming regions and their connection with the star formation activity of the galaxy. We used the spectral synthesis code Cloudy to model an HII region and the associated photodissociation region (PDR) to reproduce the emission of mid- and far-infrared fine-structure cooling lines from the Spitzer and Herschel space telescopes for these two regions. Input parameters of the model, such as elemental abundances and star formation history, are guided by earlier studies of the galaxy, and we investigated the effect of the mode in which star formation takes place (bursty or continuous) on the line emission. Furthermore, we tested the effect of adding pressure support with magnetic fields and turbulence on the line predictions. We find that this model can satisfactorily predict (within a factor of ~2) all observed lines that originate from the ionized medium ([SIV] 10.5um, [NeIII] 15.6um, [SIII] 18.7um, [SIII] 33.5um, and [OIII] 88um), with the exception of [NeII] 12.8um and [NII] 122um, which may arise from a lower ionization medium. In the PDR, the [OI] 63um, [OI] 145um, and [CII] 157um lines are matched within a factor of ~5 and work better when weak pressure support is added to the thermal pressure or when the PDR clouds are placed farther away from the HII regions and have covering factors lower than unity. Our models of the HII region agree with different evolutionary stages found in previous studies, with a more evolved, diffuse central region, and a younger, more compact southern region. However, the local PDR conditions are averaged out on the 175 pc scales that we probe and do not reflect differences observed in the star formation properties of the two regions.Comment: accepted for publication in A&

    Applications of inertial navigation and modern control theory to the all weather landing problem

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    Inertial navigation and automatic landing control theory applied to instrument landing proble

    The construction of a reliable potential for GeO2 from first-principles

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    The construction of a reliable potential for GeO2, from first-principles, is described. The obtained potential, which includes dipole polarization effects, is able to reproduce all the studied properties (structural, dynamical and vibrational) to a high degree of precision with a single set of parameters. In particular, the infrared spectrum was obtained with the expression proposed for the dielectric function of polarizable ionic solutions by Weis et al. [J.M. Caillol, D. Levesque and J.J. Weis, J. Chem. Phys. 91, 5544 (1989)]. The agreement with the experimental spectrum is very good, with three main bands that are associated to tetrahedral modes of the GeO2 network. Finally, we give a comparison with a simpler pair-additive potential.Comment: 9 pages, 8 figure

    Genetic algorithms: a pragmatic, non-parametric approach to exploratory analysis of questionnaires in educational research

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    Data from a survey to determine student attitudes to their courses are used as an example to show how genetic algorithms can be used in the analysis of questionnaire data. Genetic algorithms provide a means of generating logical rules which predict one variable in a data set by relating it to others. This paper explains the principle underlying genetic algorithms and gives a non-mathematical description of the means by which rules are generated. A commercially available computer program is used to apply genetic algorithms to the survey data. The results are discussed

    Stephen Parrish, THE KNOWER AND THE KNOWN: PHYSICALISM, DUALISM, AND THE NATURE OF INTELLIGIBILITY

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    Evaluation of a Phosphate Management Protocol to Achieve Optimum Serum Phosphate Levels in Hemodialysis Patients

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    Original article can be found at: http://www.sciencedirect.com/science/journal/10512276 Copyright National Kidney Foundation, Inc. DOI: 10.1053/j.jrn.2008.05.003To evaluate the effectiveness of a protocol designed to optimize serum phosphate levels in patients undergoing regular hemodialysis (HD).Peer reviewe
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