3,596 research outputs found
EOS MLS observations of dehydration in the 2004-2005 polar winters
We prove various estimates for the first eigenvalue of the magnetic Dirichlet
Laplacian on a bounded domain in two dimensions. When the magnetic field is
constant, we give lower and upper bounds in terms of geometric quantities of
the domain. We furthermore prove a lower bound for the first magnetic Neumann
eigenvalue in the case of constant field.Comment: 19 page
The integration of single case designs in coaching contexts: A commentary for applied sport psychologists
From personal experiences of working with coaches toward the modification of behaviors and psychological constructs that include motivation, enjoyment, and self-confidence, this commentary highlights how the integration of single case designs can enhance the services of sport psychology practitioners. Interventions within golf, soccer, and tennis are outlined, targeting factors pertinent to the coaches, their players or team members, and the development of relationships with parents. Single case designs are posited as enabling the implementation of personal, evidence-based interventions that yield perceptible differences in cognitive, affective, and behavioral responses within athletic populations; factors that enhance and underpin the practitioner-coach relationship
Macrophage activation by lipopolysaccharide, interferon-γ and interleukin-4: effect of fatty acid metabolism
The aim of this study was to investigate the effects of interferon-γ and -β (IFN-γ, -β), interleukin-4 and -10 (IL-4, -10) and Hpopolysaccharide (LPS) on the metabolism and composition of phospholipid fatty acids in macrophages. Murine J774.2 macrophages were incubated with radiolabelled fatty acids and the appropriate stimulus and the incorporation and composition of the phospholipid classes was determined. IFN-γ and IL-4 specifically stimulated enhanced incorporation of [14C]-linoleic acid into the phosphatidytethanolamine fraction. IL-4 (in contrast to IFN-γ and LPS) reduced incorporation of [14C]- arachidonic acid into phosphatidylinositol. Incubation of J774.2 cells with linoleic acid significantly increased TNFα and nitric oxide production; arachidonic acid enhanced TNFα production but reduced nitric oxide production. It is concluded that IFN-γ, IL-4 and IL-10 may differentially regulate macrophage activation via effects on the metabolism of polyunsaturated fatty acids
Predicted rocket and shuttle effects on stratospheric ozone
The major chemical effluents of either solid- or liquid-fueled rockets that can potentially perturb stratospheric ozone include chlorine compounds (HCl), nitrogen compounds (NO(x)), and hydrogen compounds (H2 and H2O). Radicals (Cl, ClO, H, OH, HO2, NO, and NO2) formed directly or indirectly from rocket exhaust can cause the catalytic destruction of ozone. Other exhaust compounds that could presumably lead to ozone destruction either by direct reaction with ozone or by providing a surface for heterogeneous processes include the particulates Al2O3, ice, and soot. These topics are discussed in terms of the possible effects of rocket exhausts on stratospheric ozone
Search and modelling of remnant radio galaxies in the LOFAR Lockman Hole field
Accepted for publication in Astronomy & Astrophysics. Reproduced with permission from Astronomy & Astrophysics, © 2017 ESO.The phase of radio galaxy evolution after the jets have switched off, often referred to as the remnant phase, is poorly understood and very few sources in this phase are known. In this work we present an extensive search for remnant radio galaxies in the Lockman Hole, a well-studied extragalactic field. We create mock catalogues of low-power radio galaxies based on Monte Carlo simulations to derive first-order predictions of the fraction of remnants in radio flux limited samples for comparison with our Lockman-Hole sample. We have combined LOFAR observations at 150 MHz with public surveys at higher frequencies to perform a complete selection and have used, for the first time, a combination of spectral criteria (e.g. the classical ultra-steep spectral index and high spectral curvature) as well as morphological criteria (e.g. low radio core prominence and relaxed shapes). Mock catalogues of radio galaxies are created based on existing spectral and dynamical evolution models combined with observed source properties. We have identified 23 candidate remnant radio galaxies which cover a variety of morphologies and spectral characteristics. We suggest that these different properties are related to different stages of the remnant evolution. We find that ultra-steep spectrum remnants represent only a fraction of our remnant sample suggesting a very rapid luminosity evolution of the radio plasma. Results from mock catalogues demonstrate the importance of dynamical evolution in the remnant phase of low-power radio galaxies to obtain fractions of remnant sources consistent with our observations. Moreover, these results confirm that ultra-steep spectrum remnants represent only a subset of the entire population (50%) when frequencies higher than 1400 MHz are not included in the selection process, and that they are biased towards old ages.Peer reviewe
Designing a methodology for surveying fish populations in freshwater lakes
This report was commissioned to review available fish survey methods and the limitations and constraints presented by the lakes within the SSSI series, to design a standardised, practical, and representative method for fish survey which could be reasonably applied throughout the SSSI lakes to achieve comparable results.
The report then goes on to design a study which applies this fish survey design to a selection of SSSI lakes to ascertain whether fish are likely to be contributing to their unfavourable condition.
This report has been used to inform a follow up study which seeks to apply the fish survey techniques to a range of SSSI lakes to ascertain information about their fish populations and their likely impact on SSSI condition.
The report also includes a comprehensive review of fish survey methods and concludes with a recommended standardised fish survey method which can be applied consistently across different SSSIs to provide comparable quantitative results. It is expected that this methodology can be applied in subsequent fish surveys commissioned on SSSI lakes, to provide more robust and repeatable results
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