Hugo Robotham

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The effects of capsaicin on the function and structure of muscularis mucosa of opossum esophagus were studied. In this tissue there are numerous nerves containing a substance P-like immunoreactive substance (SPLS), and electrical field stimulation (EFS) leads to a phasic response that appears to be due to release of acetylcholine, followed by a tonic(More)
Close intraarterial injections of motilin to the small intestine of the anaesthetized dog produce prolonged phasic contractions. Tetrodotoxin infused intraarterially blocked field stimulated contractions and abolished the response to motilin as did treatment with a combination of hexamethonium and atropine. Atropine alone increased the dose of motilin(More)
The quiescent canine gastrointestinal tract responsed to close intraarterial acetylcholine with an atropine-sensitive, hexamethonium, and tetrodotoxin-insensitive contraction, thus suggesting acetylcholine interacts with a muscarinic receptor located on the muscle. When the gut is actively contracting (spontaneously, in response to field stimulation or to(More)
A regional survey of Jamaican surface soils has been conducted in which more than 200 samples were collected at a sample density of 1 per 64 km(2) across the island and analysed for total concentrations of 31 elements by instrumental neutron activation analysis (INAA), energy dispersive X-ray fluorescence (EDXRF) analysis and atomic absorption(More)
The peat of the Negril Morass in Western Jamaica was sampled at depths down to 7 m in directions parallel and perpendicular to the seashore, and the samples were analysed for Al, As, B, Br, Ca, Ce, Cl, Co, Cr, Cs, Dy, Eu, Fe, Hf, I, La, Mg, Mn, Na, Sb, Sc, Sm, Sr, Ti, U and V by instrumental neutron activation analysis and by spectrophotometry. The peat is(More)
In this work we apply multi-class support vector machines (SVMs) and a multi-class stochastic SVM formulation to the classification of fish schools of three species: anchovy, common sardine, and Jack Mackerel, and we compare their performance. The data used come from acoustic measurements in southerncentral Chile. These classifications were carried out by(More)
The purpose of this study was to compare the results of the classification of the pelagic fish species, the common sardine, anchovy, and jack mackerel with classification trees (CART), Support Vector Machine (SVM) and artificial neural network (multilayer perceptron, MLP), using mono-frequency acoustic data in southern-central Chile. The classifiers had(More)
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