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Search Results: 1 - 10 of 117869 matches for " T. Goulding "
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Strategies for farmers and policy makers to control nitrogen losses whilst maintaining crop production
Keith W. T. Goulding
Science China Life Sciences , 2005, DOI: 10.1007/BF03187111
Abstract: The nitrogen (N) cycle is essentially ‘leaky’. The losses of small amounts of nitrate to waters and of ammonia and nitrous oxide to the atmosphere are a part of the global biogeochemical N cycle. However, intensive agricultural production, industry and vehicle use have more than doubled the amount of ‘reactive’ N in the environment, resulting in eutrophication, ecosystem change and health concerns. Research has identified agricultural practices that cause large losses of N and, in some cases, developed solutions. This paper discusses the problems of maintaining productivity while reducing N losses, compares conventional with low input (integrated) and organic farming systems, and discusses wider options. It also looks at the need to integrate studies on N with other environmental impacts, set in the context of the whole farm system, to provide truly sustainable agricultural systems.
SNS Front End Diagnostics
L. Doolittle,T. Goulding,D. Oshatz,A. Ratti,J. Staples
Physics , 2000,
Abstract: The Front End of the Spallation Neutron Source (SNS) extends from the Ion Source (IS), through a 65 keV LEBT, a 402.5 MHz RFQ, a 2.5 MeV MEBT, ending at the entrance to the DTL. The diagnostics suite in this space includes stripline beam position and phase monitors (BPM), toroid beam current monitors (BCM), and an emittance scanner. Provision is included for beam profile measurement, either gas fluorescence, laser-based photodissociation, or a crawling wire. Mechanical and electrical design and prototyping of BPM and BCM subsystems are proceeding. Significant effort has been devoted to packaging the diagnostic devices in minimal space. Close ties are maintained to the rest of the SNS effort, to ensure long term compatibility of interfaces and in fact share some design work and construction. The data acquisition, digital processing, and control system interface needs for the BPM, BCM, and LEBT diagnostic are similar, and we are committed to using an architecture common with the rest of the SNS collaboration.
Patrick Hamilton’s Hangover Square and the Landscapes of Fascism
E-rea : Revue électronique d’études sur le Monde Anglophone , 2006, DOI: 10.4000/erea.252
Abstract: If Patrick Hamilton’s name is recognised at all these days, then it is for his stage thrillers Rope (1929) and Gaslight (1938). Still played in repertory, these may be his best-known works but are hardly typical of his output. Hamilton had been a published writer since his early twenties and Hangover Square (1941) was his eighth novel. Like the preceding novels, it covers much of the same thematic and topographic territory. It is a world of boarding houses in unfashionable parts of London, pu...
Computer Programming: An Activity as Compelling as Game Play
Tom Goulding
Journal of Systemics, Cybernetics and Informatics , 2010,
Abstract: Game motif programming exercises (GM-Games) were developed to help novices develop complex client server game systems within their freshman year. GM-Games foster a strong work ethic in as much as they reproduce the challenges and excitement associated with game play; yet their purpose is the development of advanced programming skills. We have found that young people are just as interested in mastering programming skills as they are in mastering the shooting, racing or strategy skills required in many entertainment games. We describe in this paper how GM-Games imitate many of the aspects of game play.
Nitrous oxide emission from a range of land uses across Europe
S. E. Machefert,N. B. Dise,K. W. T. Goulding,P.G. Whitehead
Hydrology and Earth System Sciences (HESS) & Discussions (HESSD) , 2002,
Abstract: The results of a literature study examining quantitative estimates of N2O emission rates are presented for a range of land-uses across Europe. The analysis shows that the highest N2O emission rates are for agricultural lands compared to forests and grasslands. The main factors regulating these rates are available mineral nitrogen, soil temperature, soil water content and the available labile organic compounds. These controls operate across different time-scales, all must exceed a certain threshold for N2O emission to occur. The results support the need for an emission factor function of land-use and climate within models describing nitrogen dynamics in catchments. This would allow the assessment of the net N2O emission within catchments in terms of current levels and potential changes associated with climate variability, climate change and land use change. Keywords: nitrous oxide, soil water content, inorganic N, soil temperature, ecosystems, land-use management, soil type
Periodic variability of spotted M dwarfs in WTS
Goulding N.T.,Barnes J.R.,Pinfield D.J.,del Burgo C.
EPJ Web of Conferences , 2013, DOI: 10.1051/epjconf/20134701006
Abstract: We present an analysis of the photometric variability of M dwarfs in the WFCAM Transit Survey, selected from spectral types inferred by their WTS and SDSS colours, with periods detected using a Lomb-Scargle Periodogram Analisys. We estimate population membership of these objects from their tangential velocities and photometric parralaxes. Examples of M dwarfs with variable light curve morphologuies are found. We discuss possible causes for this and make use of models of spotted stars in our interpretation of the results.
Nutrient Management in Support of Environmental and Agricultural Sustainability
Andrew P. Whitmore,Keith W. T. Goulding,Margaret J. Glendining,A. Gordon Dailey,Kevin Coleman,David S. Powlson
Sustainability , 2012, DOI: 10.3390/su4102513
Abstract: Given that we must farm land in order to eat, the total environmental burden imposed by farming a crop, such as winter wheat in the UK, appears to be close to the minimum given current production techniques. The value of the services other than food production, such as flood water buffering, pollination, carbon storage and so on, that land can provide is relatively large compared with the value in reducing environmental burdens from pesticide use, nutrient pollution and greenhouse gas emissions that might arise by farming less intensively. More land will need to be brought into cultivation in order to provide the same amount of food if the intensity of farming is reduced and the resultant loss of ecosystem services (ES) outweighs the reduction in other burdens. Nevertheless, losses of nutrients, especially nitrogen (N), from agriculture are a serious concern and the current cost of the environmental footprint of agriculture is significant compared with the value of the food it produces. This article examines nutrient burdens and analyses the means by which the total environmental burden might be reduced relative to productivity. These include increasing the efficiency of farming, removing constraints to yield, and establishing multiple uses for land at the same time as farming. It concludes that agronomic measures which improve nutrient capture and which obtain more yield per unit area are valuable means to avoid degradation of environmental quality because both nutrient pollution and land consumption can be avoided.
Cell Lineage of the Ilyanassa Embryo: Evolutionary Acceleration of Regional Differentiation during Early Development
Morgan Q. Goulding
PLOS ONE , 2009, DOI: 10.1371/journal.pone.0005506
Abstract: Cell lineage studies in mollusk embryos have documented numerous variations on the lophotrochozoan theme of spiral cleavage. In the experimentally tractable embryo of the mud snail Ilyanassa, cell lineage has previously been described only up to the 29-cell stage. Here I provide a chronology of cell divisions in Ilyanassa to the stage of 84 cells (about 16 hours after first cleavage at 23°C), and show spatial arrangements of identified nuclei at stages ranging from 27 to 84 cells. During this period the spiral cleavage pattern gives way to a bilaterally symmetric, dorsoventrally polarized pattern of mitotic timing and geometry. At the same time, the mesentoblast cell 4d rapidly proliferates to form twelve cells lying deep to the dorsal ectoderm. The onset of epiboly coincides with a period of mitotic quiescence throughout the ectoderm. As in other gastropod embryos, cell cycle lengths vary widely and predictably according to cell identity, and many of the longest cell cycles occur in small daughters of highly asymmetric divisions. While Ilyanassa shares many features of embryonic cell lineage with two other caenogastropod genera, Crepidula and Bithynia, it is distinguished by a general tendency toward earlier and more pronounced diversification of cell division pattern along axes of later differential growth.
Towards a Complete Census of AGNs in Nearby Galaxies: A Large Population of Optically Unidentified AGNs
Andy Goulding,Dave Alexander
Physics , 2009, DOI: 10.1111/j.1365-2966.2009.15194.x
Abstract: Using Spitzer-IRS spectroscopy, we investigate the ubiquity of Active Galactic Nuclei (AGN) in a complete (~94%), volume-limited sample of the most bolometrically-luminous galaxies (L_IR > (0.3-20) x 10^10 L_sun) to D < 15 Mpc. Our analyses are based on the detection of the high-excitation emission line [NeV](\lambda 14.32 um; 97.1 eV) to unambiguously identify AGN activity. We find that 17 of the 64 IR-bright galaxies in our sample host AGN activity (~27^{+8}_{-6}%), >50% of which are not identified as AGNs using optical spectroscopy. The large AGN fraction indicates a tighter connection between AGN activity and IR luminosity for galaxies in the local Universe than previously found, potentially indicating a close association between AGN activity and star formation. The optically unidentified AGNs span a wide range of galaxy type (S0-Ir) and are typically starburst-dominated systems hosting modest-luminosity AGN activity (L_[NeV] ~ 10^37 - 10^39 erg s^-1). The non-identification of optical AGN signatures in the majority of these galaxies appears to be due to extinction towards the AGN, rather than intrinsically low-luminosity AGN activity. Examination of optical images shows that the optically unidentified AGNs with evidence for extinction are hosted in either highly inclined galaxies or galaxies with dust lanes, indicating that obscuration of the AGN is not necessarily due to an obscuring torus. We therefore conclude that optical spectroscopic surveys miss approximately half of the AGN population simply due to extinction through the host galaxy.
Connecting Dark Matter Halos with the Galaxy Center and the Supermassive Black Hole
Akos Bogdan,Andy D. Goulding
Physics , 2015, DOI: 10.1088/0004-637X/800/2/124
Abstract: Observational studies of nearby galaxies have demonstrated correlations between the mass of the central supermassive black holes (BHs) and properties of the host galaxies, notably the stellar bulge mass or central stellar velocity dispersion. Motivated by these correlations, the theoretical paradigm has emerged, in which BHs and bulges co-evolve. However, this picture was challenged by observational and theoretical studies, which hinted that the fundamental connection may be between BHs and dark matter halos, and not necessarily with their host galaxies. Based on a study of 3130 elliptical galaxies $-$ selected from the Sloan Digital and ROSAT All Sky Surveys $-$ we demonstrate that the central stellar velocity dispersion exhibits a significantly tighter correlation with the total gravitating mass, traced by the X-ray luminosity of the hot gas, than with the stellar mass. This hints that the central stellar velocity dispersion, and hence the central gravitational potential, may be the fundamental property of elliptical galaxies that is most tightly connected to the larger-scale dark matter halo. Furthermore, using the central stellar velocity dispersion as a surrogate for the BH mass, we find that in elliptical galaxies the inferred BH mass and inferred total gravitating mass within the virial radius (or within five effective radii) can be expressed as $M_{\rm{BH}} \propto M_{\rm tot}^{1.6^{+0.6}_{-0.4}} $ (or $M_{\rm{BH}} \propto M_{\rm{5r_{eff}}}^{1.8^{+0.7}_{-0.6}}$). These results are consistent with a picture in which the BH mass is directly set by the central stellar velocity dispersion, which, in turn, is determined by the total gravitating mass of the system.
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