1,961 research outputs found

    An Account of the Loss of the Country Ship Forbes and Frazer Sinclair, Her Late Commander

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    This paper reports on the life of the English Country trader Captain Frazer Sinclair leading up to and following the loss of the Forbes in the Karimata Strait in 1806. It examines the adventure and tenuous times of trading around the Indonesian archipelago after the fall of the VOC and subsequent transfer to the British. Included are the details of Captain Sinclair\u27s trading history, multiple prizes as a privateer, and shipwrecks

    Contribution of exposure and genetics to the development of beryllium sensitization and chronic beryllium disease

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    Department Head: Jac A. Nickoloff.2010 Spring.Includes bibliographical references.To view the abstract, please see the full text of the document

    Stratigraphy and Paleoecology of Quaternary Sediments Along Pasley River, Boothia Peninsula, Central Canadian Arctic

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    Quaternary sediments exposed along Pasley River consist of a lower marine deltaic sand overlain in succession by complexly interbedded tills and glaciomarine sediments (the lower glacigenic assemblage), by a mid-section fluvial gravel, by an upper marine deltaic sand, and by glaciomarine sediment and till (the upper glacigenic assemblage). The midsection fluvial gravels contain plant and insect fossils indicating a climate as warm as and perhaps warmer than present. The top of the gravel is more than 55 000 years old ; the unit is probably of Sangamonian age (>75 000 ka) and separates Wisconsinan from lllinoian glacial deposits. The deltaic sands that underlie both glacigenic assemblages indicate substantial crustal depression during glacial buildup episodes prior to arrival of ice at the site. This implies that the process of buildup was slow and involved glacier expansion into major marine basins. Glaciomarine beds of the lower glacigenic assemblage locally contain abundant detrital terrestrial organic material as well as marine molluscs. The terrestrial organic detritus, an unusual constituent of glaciomarine sediment, is thought to have been released into the sea from glacier ice. These terrestrial fossil asemblages exhibit compositional differences which vary with the sediment faciès and probably reflect taphonomic factors such as differential buoyancy of the fossils. The upper marine deltaic sands contain some "old " rebedded plant detritus and amber indicating a nearby source of Tertiary sediment, possibly equivalent in age to the Beaufort Formation. Other rebedded fossils from the upper deltaic unit may be the same age as the mid-section fluvial gravels.Les berges de la rivière Pasley montrent des séquences de sédiments quaternaires qui comprennent de la base vers le sommet : un sable marin d'origine deltaïque, un ensemble complexe de couches de till interstratifiées avec des sédiments glaciomarins (assemblage inférieure de sédiments glacigéniques), un gravier fluviatile vers le milieu, un sable deltaïque marin supérieur et, au sommet, des sédiments glaciomarins et du till (assemblage supérieur de sédiments glacigéniques). Le gravier fluviatile dont la partie supérieure a été datée à plus de 55 000 ans contient des fossiles de plantes et d'insectes indicateurs d'un climat aussi chaud ou plus chaud que celui d'aujourd'hui. Cette unité date probablement du Sangamonien (> 75 000 BP) et sépare les dépôts glaciaires du Wisconsinien de ceux de !'Illinois. Les sables deltaïques à la base des deux assemblages glacigéniques signalent qu'un affaissement important de la croûte terrestres, lié à un épisode de croissance glaciaire, s'est produit avant l'arrivée du glacier. Les couches des dépôts glaciomarins de l'assemblage glacigénique inférieur renferment parfois d'abondants débris organiques d'origine terrestre et des mollusques marins. Le matériel d'origine terrestre, une composante inhabituelle des sédiments glaciomarins, représente probablement un apport direct du glacier à la mer. Les différentes compositions de ces assemblages de fossiles terrestres sont liées au changement de faciès des sédiments et sont le reflet de facteurs taphonomiques comme la différence d'apesanteur entre les fossiles. Le sable marin deltaïque supérieur contient d'anciens débris de plantes et de l'ambre restratifiés, un indice d'une source proche de sédiments tertiaires, probablement d'un âge comparable à celui de la Formation de Beaufort.Die entlang dem PasIey-FluB freiliegenden Quartàr-Sedimente bestehen aus einer unteren marinen Delta-Sandschicht, ùberlagert von einer Folge von komplex geschichteten Tills und glaziomarinen Sedimenten (die untere glazigenen Ablagerung), aus einer mittleren FluBKies-Schicht, einer hôheren marinen Delta-Sandschicht und einem glaziomarinen Sediment und Till (die obère glazigene Ablagerung). Der FluBkies der mittleren Schicht enthâlt Pflanzen- und Insektenfossile, welche auf ein ebenso warmes oder vielleicht sogar wârmeres Klima als gegenwârtig hinweisen. Der obère Teil der Kiesschicht ist mehr als 55000 Jahre ait, dièse Schicht stammt môglicherweise aus dem Sangamon (alter als 75 000 ka) und trennt Ablagerungen aus dem Wisconsin von den glazialen Ablagerungen des Illinois. Der Delta-Sand, der unter beiden glazigenen Schichtungen liegt, IaBt auf bedeutende Krustensenkungen wàhrend der glazialen Aufbauphase schlieBen, vor dem Auftreten von Eis an dieser Stelle. Das bedeutet, daB der ProzeB des Aufbaus langsam war und mit Gletscher-Ausdehnung in grôBere marine Becken verbunden war. Die glaziomarinen Betten der unteren glazigenen Schichtung enthalten ôrtlich umfangreiches organisches Erdgerôllmaterial sowie marine Weichtiere. Das organische Erdgerôll, ein ungewôhnlicher Bestandteil glaziomariner Sedimente, soil vom Gletscher-Eis in das Meer geschoben worden sein. Dièse Erdfossilschichtungen zeigen Unterschiede in der Zusammensetzung, von einer zur anderen Sediment-Fazies und spiegeln môglicherweise taphonomische Faktoren, wie unterschiede in der Tragfàhigkeit der Fossile. Der obère marine Delta-Sand enthâlt einige "alte" neugeschichtete Pflanzenpartikel und Bernstein, was auf eine nahegelegene Quelle tertiâren Sediments hinweist, die vermutlich ebenso alt ist wie die Beaufort-Formation

    Dynamics of a deformable body in a fast flowing soap film

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    We study the behavior of an elastic loop embedded in a flowing soap film. This deformable loop is wetted into the film and is held fixed at a single point against the oncoming flow. We interpret this system as a two-dimensional flexible body interacting in a two-dimensional flow. This coupled fluid-structure system shows bistability, with both stationary and oscillatory states. In its stationary state, the loop remains essentially motionless and its wake is a von K\'arm\'an vortex street. In its oscillatory state, the loop sheds two vortex dipoles, or more complicated vortical structures, within each oscillation period. We find that the oscillation frequency of the loop is linearly proportional to the flow velocity, and that the measured Strouhal numbers can be separated based on wake structure

    Effective treatment with a tetrandrine/chloroquine combination for chloroquine-resistant falciparum malaria in Aotus monkeys

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    Background In vitro evidence indicates that tetrandrine (TT) can potentiate the action of chloroquine 40-fold against choloquine-resistant Plasmodium falciparum. The key question emanating from that study is “would tetrandine and chloroquine be highly effective in a live Aotus monkey model with chloroquine-resistant parasites”. This study was designed to closely mimic the pharmacological/anti-malarial activity in man. Methods The Vietnam Smith/RE strain of P. falciparum, which is chloroquine-resistant was used in this study. Previous experimental procedures were followed. Panamanian owl monkeys (Aotus) were inoculated with 5×106 erythrocytes parasitized with the CQ-resistant strain of P. falciparum. Oral drug treatment was with CQ (20 mg/kg) and/or tetrandrine at 15 mg/Kg, 30 mg/Kg or 60 mg/Kg or 25 mg/Kg depending on experimental conditions. Results and Discussion Parasitaemia was cleared rapidly with CQ and TT while CQ treatment alone was ineffective. Recrudescence of malaria occurred after seven days post-infection. However, four animals were treated orally with TT and CQ parasites were cleared. It is likely that monkeys were cured via a combination of both drug and host immune responses. A single Aotus monkey infected with P. falciparum and untreated with drugs, died. No side effects were observed with these drug treatments. Conclusions This combination of chloroquine and tetrandrine forms the basis of a new attack on chloroquine-resistant malaria - one based upon inhibition of the basis of chloroquine resistance, the multiple drug resistance pump. Previous studies demonstrated that the parasite MDR pump was found on parasite membranes using 3H azidopine photoaffinity labelling. Since MDR-based choloroquine resistance is induced by chloroquine, the basis of the action of tetrandrine is the following: 1) tetrandrine inhibits the MDR pump by stimulating MDR ATPase which limits the energy of the pump by depletion of parasite ATP, 2) tetrandrine blocks the genetic factor which controls the induction of the pump. Therefore, it appears that the parasite cannot outsmart these mechanisms and produce a new mode of resistance. Only time will tell if this is correct

    Fast-slow asymptotic for semi-analytical ignition criteria in FitzHugh-Nagumo system

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    We study the problem of initiation of excitation waves in the FitzHugh-Nagumo model. Our approach follows earlier works and is based on the idea of approximating the boundary between basins of attraction of propagating waves and of the resting state as the stable manifold of a critical solution. Here, we obtain analytical expressions for the essential ingredients of the theory by singular perturbation using two small parameters, the separation of time scales of the activator and inhibitor, and the threshold in the activator's kinetics. This results in a closed analytical expression for the strength-duration curve.Comment: 10 pages, 5 figures, as accepted to Chaos on 2017/06/2

    Final Calibration of the Berkeley Extreme and Far-Ultraviolet Spectrometer on the ORFEUS-SPAS I and II Missions

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    The Berkeley Extreme and Far-Ultraviolet Spectrometer (BEFS) flew as part of the ORFEUS telescope on the ORFEUS-SPAS I and II space-shuttle missions in 1993 and 1996, respectively. The data obtained by this instrument have now entered the public domain. To facilitate their use by the astronomical community, we have re-extracted and re-calibrated both data sets, converted them into a standard (FITS) format, and placed them in the Multimission Archive at Space Telescope (MAST). Our final calibration yields improved wavelength scales and effective-area curves for both data sets.Comment: To appear in the January 2002 issue of the PASP. 17 pages with 9 embedded postscript figures; uses emulateapj5.st

    The effect of date of planting on the yield of potatoes

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    RESP-354

    Forum: Nothing new under the greenhouse - A historial turn around the carbon cycle

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