6,494 research outputs found

    Control of common scab without the use of water

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    The most effective way to control common scab is by irrigating a potato crop at tuber initiation. With the introduction of legislation such as the Water Framework Directive this will become increasingly difficult. In this field experiment, we assessed the potential of a number of non-water measures for controlling this disease. Common scab on daughter tubers at harvest was reduced by applying rapeseed meal at 1 t ha-1 to the beds and then incorporating it into the soil, and adding a mixture of Trichoderma viride isolates into the furrow at planting. None of these treatments was as effective as using water

    IN MEMORIAM: S B JACKSON 8 December 1946 – 26 May 2012

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    Steven Brian Jackson was born in Belfast, Northern Ireland, and was educated at Campbell College in the same city. In his teens he was diagnosed with ankylosing spondylitis and, after experiencing acute heart failure in his thirties, lived with a complex combination of chronic illnesses for the rest of his life. Despite this, or perhaps because of it, he made the most of his earthly existence and followed the lives of others with empathy.1 He chose to lead an academic career and obtained a BA Honours degree in Classics from the University of Ulster in 1971 after which he taught Classics at the Royal Belfast Academical Institution from 1971-1985

    EMERALDS AND EMBASSIES IN THE ETHIOPIAN STORY OF HELIODORUS

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    In The Ethiopian story of Heliodorus reference is made to a disputebetween the Persians and the Ethiopians over control of the emeraldmines to the south of Egypt. This disagreement leads to war betweenthese two nations and sets the action of the plot of the novel inmotion. When taken together with the similar manner in whichprecious stones are viewed in The Ethiopian story and in the pseudo-Orphic Lithica — a poem about the magical properties of stonesdated to the fourth century of our era — the argument overpossession of the mines can convincingly be placed in the context ofthe political and religious changes taking place at this time inEthiopia, as documented by Epiphanius of Cyprus in his sermonOn the gems. Under Constantine and his successor Constantius IIembassies were exchanged with the Ethiopians, specifically with thepeople of Axum (who appear to have displaced the people of Meroefrom power at about 350), the Blemmyes, and the Indians. The factthat embassies involving these peoples feature prominently in TheEthiopian story also provides yet more circumstantial evidence tosuggest that the novel belongs to a similar fourth-century milieu toother texts from the same period, especially the anonymous Lithicaand the Περὶ Καταρχῶν (On Beginnings) of Maximus of Ephesus

    Mass and density of B-type asteroid (702) Alauda

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    Observations with the adaptive optics system on the Very Large Telescope reveal that outer main belt asteroid (702) Alauda has a small satellite with primary to secondary diameter ratio of \sim56. The secondary revolves around the primary in 4.9143 ±\pm 0.007 days at a distance of 1227 ±\pm 24 km, yielding a total system mass of (6.057 ±\pm 0.36) ×\times 1018^{18} kg. Combined with an IRAS size measurement, our data yield a bulk density for this B-type asteroid of 1570 ±\pm 500 kg~m3^{-3}.Comment: In press, ApJ 2011. 6 pages, 4 figure

    RESEARCH STUDIES IN HIGHER EDUCATION: EDUCATING MULTICULTURAL COLLEGE STUDENTS-Ch 3

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    Book Chapte

    Geological respiration of a mountain belt revealed by the trace element rhenium

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    Oxidation of rock-derived, petrogenic, organic carbon (OCpetro) during weathering of sedimentary rocks is a major source of carbon dioxide (CO2) to the atmosphere. This geological respiration is thought to be enhanced by physical erosion, suggesting that mountain belts could release large amounts of CO2 to counter the CO2 sequestration achieved by the erosion, riverine transfer and oceanic burial of organic carbon from the terrestrial biosphere. However, OCpetro oxidation rates in mountain belts have not been quantified. Here we use rhenium (Re) as a proxy to track OCpetro oxidation in mountain river catchments of Taiwan, where existing measurements of physical erosion rate allow the controls on OCpetro oxidation to be assessed. Re has been shown to be closely associated with OCpetro in rocks and following oxidation during chemical weathering forms a soluble oxyanion (View the MathML source) which contributes to the dissolved load of rivers. Soils on meta-sedimentary rocks in Taiwan show that Re loss is coupled to OCpetro loss during weathering, confirming previous observations from soil profiles on sedimentary rocks elsewhere. In Taiwan rivers, dissolved Re flux increases with the catchment-average sediment yield, suggesting that physical erosion rate is a major control on OCpetro oxidation. Based on our current understanding of Re mobility during weathering, the dissolved Re flux can be used to quantify an upper bound on the OCpetro oxidation rate and the associated CO2 transfer. The estimated CO2 release from this mountain belt by OCpetro oxidation does not negate estimates of CO2 sequestration by burial of biospheric OC offshore. The findings are compared to OC transfers estimated for the Himalaya, where OCpetro oxidation in the mountain belt remains unconstrained. Together, these cases suggest that mountain building in the tropics can result in a net sink of OC which sequesters atmospheric CO2

    Spin injection from perpendicular magnetized ferromagnetic δ\delta-MnGa into (Al,Ga)As heterostructures

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    Electrical spin injection from ferromagnetic δ\delta-MnGa into an (Al,Ga)As p-i-n light emitting diode (LED) is demonstrated. The δ\delta-MnGa layers show strong perpendicular magnetocrystalline anisotropy, enabling detection of spin injection at remanence without an applied magnetic field. The bias and temperature dependence of the spin injection are found to be qualitatively similar to Fe-based spin LED devices. A Hanle effect is observed and demonstrates complete depolarization of spins in the semiconductor in a transverse magnetic field.Comment: 4 pages, 3 figure

    Noise measurement evaluations of various takeoff-climbout profiles of a four-engine turbojet transport airplane

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    Noise measurement evaluations of various takeoff-climbout profiles of four engine turbojet transport airplan
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