264 research outputs found

    Intestinal parasites from public and private latrines and the harbour canal in Roman Period Ephesus, Turkey (1st c. BCE to 6th c. CE)

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    To improve our knowledge of the parasite species affecting the inhabitants of Roman period Asia Minor, we analysed faecal material from Ephesus, Turkey. Mineralised material from the drain from a private house latrine (3rd c. CE), sediment samples from the sewer drain of a public communal latrine (6th c. CE), and sediment from the harbour canal (ca. 1st c. BCE to ca. 6th c. CE) were studied for the presence of intestinal parasites. Samples were viewed by light microscopy for helminth eggs, and commercial enzyme-linked immunosorbent assay (ELISA) kits were used to test for protozoal parasites that cause dysentery. Eggs of roundworm were found in the public latrine, whipworm in the house latrine, and both whipworm and roundworm in the harbour canal. Sequential sampling of the harbour core suggests that whipworm was by far the most common parasite throughout the Roman period, and there was no clear evidence for change in parasite species over the centuries. Whipworm and roundworm are both spread by the contamination of food and drink by human faeces. Despite the large number of travellers to Ephesus, as the capital of its province and a major port city in the Roman Empire, there was a surprising lack of diversity in parasite species found. This is especially apparent when we consider that ten species of intestinal parasite have been found across the Roman Empire. This is the first Roman site to be directly assessed for differences between infection in individuals using private latrines, public latrines, and mixed town effluent (in the harbour) at the same site.This research was supported by a doctoral award from the Social Sciences and Humanities Research Council of Canada [752-2016-2085] and a Tidmarsh Cambridge Scholarship from the Cambridge Commonwealth, European and International Trust and Trinity Hall Colleg

    Trace elements in magnetite from massive iron oxide-apatite deposits indicate a combined formation by igneous and magmatic-hydrothermal processes

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    Iron oxide-apatite (IOA) deposits are an important source of iron and other elements (e.g., REE, P, U, Ag and Co) vital to modern society. However, their formation, including the namesake Kiruna-type IOA deposit (Sweden), remains controversial. Working hypotheses include a purely magmatic origin involving separation of an Fe-, P-rich, volatile-rich oxide melt from a Si-rich silicate melt, and precipitation of magnetite from an aqueous ore fluid, which is either of magmatic-hydrothermal or non-magmatic surface or metamorphic origin. In this study, we focus on the geochemistry of magnetite from the Cretaceous Kiruna-type Los Colorados IOA deposit (~350. Mt Fe) located in the northern Chilean Iron Belt. Los Colorados has experienced minimal hydrothermal alteration that commonly obscures primary features in IOA deposits. Laser ablation-inductively coupled plasma-mass spectroscopy (LA-ICP-MS) transects and electron probe micro-analyzer (EPMA) wavelength-dispersive X-ray (WDX) spectrometry mapping demonstrate distinct chemical zoning in magnetite grains, wherein cores are enriched in Ti, Al, Mn and Mg. The concentrations of these trace elements in magnetite cores are consistent with igneous magnetite crystallized from a silicate melt, whereas magnetite rims show a pronounced depletion in these elements, consistent with magnetite grown from an Fe-rich magmatic-hydrothermal aqueous fluid. Further, magnetite grains contain polycrystalline inclusions that re-homogenize at magmatic temperatures (>850. °C). Smaller inclusions (500. ppm) concentrations

    Intrinsic solidification behaviour of basaltic to rhyolitic melts: a cooling rate experimental study

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    Dynamic cooling-induced solidification experiments were run using six silicate glasses along the basalt - rhyolite join (B100= 100 wt % of basalt, R100= 100 wt % of rhyolite), i.e. B100, B80R20, B60R40, B40R60, B20R80 and R100; the glasses directly quenched from 1300 °C after a dwell of 120 minutes (experiment E0) contain 50-400 ppm H2O, << 1 area% μm-sized bubble, and Fe2+/Fetot between 0.34 and 0.46. Experiments were performed in Pt capsules at room pressure and fO2 of air, between 1300 and 800 °C using three different cooling rates of 0.0167, 3 and 30 °C/min; these cooling rates were run two times: E1-E2 experiments at 0.0167°C/min, S1-E3 at 3 °C/min, and E4-E5 at 30 °C/min. In experiments E1 to E5, samples were annealed for 120 minutes at 1300 °C, whereas in the experiment S1 the samples were firstly heated for 30 minutes at 1400 °C followed by a dwell time of 2400 minutes at 1300°C before cooling. In the experiments a preferential crystallization was not observed at the melt/gas interface. B100, B80R20 and B60R40 run-products have a low tendency to preferentially crystallize on Pt walls, while B40R60, B20R80 and R100 are not affected by the presence of Pt substrata. All run-products show very homogeneous textures, except for B60R40 and B40R60 at 0.0167°C/min in the E1 experiment. The duplicates of B40R60 and B60R40 at 0.0167°C/min and B100 at 30 °C/min show relatively large differences in crystal content (> 4 and < 14 area%). B40R60 and B60R40 duplicated run-products have the same amount of earlycrystallized clinopyroxene and spinel, but different contents in lately-formed plagioclase. The run-products with the same starting composition from E3-S1 (3 °C/min) show a high reproducibility in terms of crystal shape, size, and amount (< 4 area%). This demonstrates that the crystallization path is not affected by the different heat treatment above the liquidus temperature, i.e. the time scale of structural re-equilibration (relaxation) and chemical rehomogenization are shorter than our experimental time scale. Possible chemicalheterogeneities on a length scale of several micrometers for R100 and several hundreds of micrometers for B100 can be removed at 1300 °C within 120 minutes. A heat treatment at 1300 °C for 120 minutes significantly reduces the amount of μm-sized bubbles, potentially responsible for the onset of nucleation and unreveals the intrinsic solidification of silicate melts. The experimental reproducibility is low when the cooling path intersects the tip of the time-temperature-transformation (TTT) curves, i.e. when the nucleation rate is near its maximum (Imax). In that case, even small thermal variations in cooling rate and local composition can have large effects on phase abundance and crystal size. Dynamic crystallization experiments can be properly interpreted and compared only if they are texturally homogeneous and the physico-chemical state of the superheated silicate liquid is known. The solidification conditions used in this study mirror those of aphyric lavas and dikes emplaced at shallower crustal levels

    Non-allergic rhinitis: a case report and review

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    Rhinitis is characterized by rhinorrhea, sneezing, nasal congestion, nasal itch and/or postnasal drip. Often the first step in arriving at a diagnosis is to exclude or diagnose sensitivity to inhalant allergens. Non-allergic rhinitis (NAR) comprises multiple distinct conditions that may even co-exist with allergic rhinitis (AR). They may differ in their presentation and treatment. As well, the pathogenesis of NAR is not clearly elucidated and likely varied. There are many conditions that can have similar presentations to NAR or AR, including nasal polyps, anatomical/mechanical factors, autoimmune diseases, metabolic conditions, genetic conditions and immunodeficiency. Here we present a case of a rare condition initially diagnosed and treated as typical allergic rhinitis vs. vasomotor rhinitis, but found to be something much more serious. This case illustrates the importance of maintaining an appropriate differential diagnosis for a complaint routinely seen as mundane. The case presentation is followed by a review of the potential causes and pathogenesis of NAR

    Examination of Late Palaeolithic archaeological sites in northern Europe for the preservation of cryptotephra layers

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    We report the first major study of cryptotephra (non-visible volcanic ash layers) on Late Palaeolithic archaeological sites in northern Europe. Examination of 34 sites dating from the Last Termination reveals seven with identifiable cryptotephra layers. Preservation is observed in minerogenic and organic deposits, although tephra is more common in organic sediments. Cryptotephra layers normally occur stratigraphically above or below the archaeology. Nearby off-site palaeoclimate archives (peat bogs and lakes &lt;0.3 km distant) were better locations for detecting tephra. However in most cases the archaeology can only be correlated indirectly with such cryptotephras. Patterns affecting the presence/absence of cryptotephra include geographic position of sites relative to the emitting volcanic centre; the influence of past atmospherics on the quantity, direction and patterns of cryptotephra transport; the nature and timing of local site sedimentation; sampling considerations and subsequent taphonomic processes. Overall, while tephrostratigraphy has the potential to improve significantly the chronology of such sites many limiting factors currently impacts the successful application

    The French Didactic Tradition in Mathematics

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    This chapter presents the French didactic tradition. It first describes theemergence and development of this tradition according to four key features (role ofmathematics and mathematicians, role of theories, role of design of teaching andlearning environments, and role of empirical research), and illustrates it through two case studies respectively devoted to research carried out within this traditionon algebra and on line symmetry-reflection. It then questions the influence of thistradition through the contributions of four researchers from Germany, Italy, Mexicoand Tunisia, before ending with a short epilogue

    The United States' next generation of atmospheric composition and coastal ecosystem measurements : NASA's Geostationary Coastal and Air Pollution Events (GEO-CAPE) Mission

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    Author Posting. © American Meteorological Society, 2012. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Bulletin of the American Meteorological Society 93 (2012): 1547–1566, doi:10.1175/BAMS-D-11-00201.1.The Geostationary Coastal and Air Pollution Events (GEO-CAPE) mission was recommended by the National Research Council's (NRC's) Earth Science Decadal Survey to measure tropospheric trace gases and aerosols and coastal ocean phytoplankton, water quality, and biogeochemistry from geostationary orbit, providing continuous observations within the field of view. To fulfill the mandate and address the challenge put forth by the NRC, two GEO-CAPE Science Working Groups (SWGs), representing the atmospheric composition and ocean color disciplines, have developed realistic science objectives using input drawn from several community workshops. The GEO-CAPE mission will take advantage of this revolutionary advance in temporal frequency for both of these disciplines. Multiple observations per day are required to explore the physical, chemical, and dynamical processes that determine tropospheric composition and air quality over spatial scales ranging from urban to continental, and over temporal scales ranging from diurnal to seasonal. Likewise, high-frequency satellite observations are critical to studying and quantifying biological, chemical, and physical processes within the coastal ocean. These observations are to be achieved from a vantage point near 95°–100°W, providing a complete view of North America as well as the adjacent oceans. The SWGs have also endorsed the concept of phased implementation using commercial satellites to reduce mission risk and cost. GEO-CAPE will join the global constellation of geostationary atmospheric chemistry and coastal ocean color sensors planned to be in orbit in the 2020 time frame.Funding for GEO-CAPE definition activities is provided by the Earth Science Division of the National Aeronautics and Space Administration.2013-04-0

    The RESET project: constructing a European tephra lattice for refined synchronisation of environmental and archaeological events during the last c. 100 ka

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    This paper introduces the aims and scope of the RESET project (. RESponse of humans to abrupt Environmental Transitions), a programme of research funded by the Natural Environment Research Council (UK) between 2008 and 2013; it also provides the context and rationale for papers included in a special volume of Quaternary Science Reviews that report some of the project's findings. RESET examined the chronological and correlation methods employed to establish causal links between the timing of abrupt environmental transitions (AETs) on the one hand, and of human dispersal and development on the other, with a focus on the Middle and Upper Palaeolithic periods. The period of interest is the Last Glacial cycle and the early Holocene (c. 100-8 ka), during which time a number of pronounced AETs occurred. A long-running topic of debate is the degree to which human history in Europe and the Mediterranean region during the Palaeolithic was shaped by these AETs, but this has proved difficult to assess because of poor dating control. In an attempt to move the science forward, RESET examined the potential that tephra isochrons, and in particular non-visible ash layers (cryptotephras), might offer for synchronising palaeo-records with a greater degree of finesse. New tephrostratigraphical data generated by the project augment previously-established tephra frameworks for the region, and underpin a more evolved tephra 'lattice' that links palaeo-records between Greenland, the European mainland, sub-marine sequences in the Mediterranean and North Africa. The paper also outlines the significance of other contributions to this special volume: collectively, these illustrate how the lattice was constructed, how it links with cognate tephra research in Europe and elsewhere, and how the evidence of tephra isochrons is beginning to challenge long-held views about the impacts of environmental change on humans during the Palaeolithic. © 2015 Elsevier Ltd.RESET was funded through Consortium Grants awarded by the Natural Environment Research Council, UK, to a collaborating team drawn from four institutions: Royal Holloway University of London (grant reference NE/E015905/1), the Natural History Museum, London (NE/E015913/1), Oxford University (NE/E015670/1) and the University of Southampton, including the National Oceanography Centre (NE/01531X/1). The authors also wish to record their deep gratitude to four members of the scientific community who formed a consultative advisory panel during the lifetime of the RESET project: Professor Barbara Wohlfarth (Stockholm University), Professor Jørgen Peder Steffensen (Niels Bohr Institute, Copenhagen), Dr. Martin Street (Romisch-Germanisches Zentralmuseum, Neuwied) and Professor Clive Oppenheimer (Cambridge University). They provided excellent advice at key stages of the work, which we greatly valued. We also thank Jenny Kynaston (Geography Department, Royal Holloway) for construction of several of the figures in this paper, and Debbie Barrett (Elsevier) and Colin Murray Wallace (Editor-in-Chief, QSR) for their considerable assistance in the production of this special volume.Peer Reviewe
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