1,350 research outputs found

    Seeing beneath the ground using geophysics at the former ecclesiastical site of Clonard, Co. Meath

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    The geophysical investigation undertaken in this project has uncovered many features, which may be related to the ecclesiastical settlement at Clonard. A 300m long palaeochannel dominates the magnetic data and four areas of concentrated magnetic anomalies, up to 50m in extent, probably indicate the presence of extended anthropogenic activity. A sub-square 60m across enclosure is also evident. In addition, there are four distinct zones which have large concentrations of high resistance values suggesting that buildings were located in these areas. Resistivity and ground penetrating radar depth slices show that one of these zones has characteristics which indicate the presence of an east-west aligned building approximately 7m wide in a north-south direction and about 15m long in an east-west direction. This structure may represent a small church

    Magnetic Characteristics of the Cuilcagh Dyke, Co. Fermanagh, Northern Ireland

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    The Cuilcagh Dyke in Co. Fermanagh forms part of the NW-SE trending Donegal-Kingscourt dyke swarm. Dykes in this swarm, along with others in the Irish Tertiary Igneous Province, are associated with negative magnetic anomalies. Segments of the Cuilcagh Dyke have these negative magnetic anomalies but some parts have been found to be associated with positive magnetic anomalies. Susceptibility measurements also show significant variations along the dyke. Palaeo-magnetic investigations suggest that parts of the dyke formed during a period of reverse polarity, similar to the rest of the Irish Tertiary Igneous Province, and parts formed during normal polarity conditions. The Cuilcagh Dyke in unique in Ireland in that it is the only known dyke to possess both normal (positive) and reverse (negative) polarity magnetic characteristics

    Consumption of dissolved organic carbon by Caribbean reef sponges

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    Sponges are conspicuous and abundant within the benthic fauna on Caribbean reefs. The ability of these organisms to efficiently capture carbon from particulate sources is well known and the importance of dissolved organic carbon (DOC) uptake has been recognized for several species. We surveyed DOC ingestion by seven sponge species common to Florida Keys reefs using nondisruptive sampling methods on undisturbed individuals. Three of the seven species exhibited significant DOC removal ranging from 13% to 24% of ambient concentrations. The tested species that removed DOC host large microbial consortia within their tissues, while the converse was observed for those that did not. This divergent behavior may suggest an important role for sponge associated microbes in the utilization of DOC by these species. The feeding behaviors of individuals of Xestospongia muta were then monitored over time to investigate its respiratory consumption of particulate and DOC. The uptake rates of dissolved oxygen (DO) and organic carbon by two undisturbed individuals revealed that DOC represented 96% of removed C, and that the tested individuals removed approximately equal quantities of C and DO. This demonstrates that X. muta largely satisfies its respiration demands through DOC consumption, and that DOC likely represents the dominant C source for biomass production and cell overturn in this species. These results further illustrate the metabolic importance of DOC to sponges, and suggest that these organisms are an important pathway for remineralizing organic matter on Caribbean reefs

    The influence of Prenatal DHA supplementation on individual domains of behavioral functioning in school‐aged children: Follow‐up of a randomized controlled trial

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    Docosahexaenoic acid (DHA) accumulates in the fetal brain during pregnancy and is thought to have a role in supporting neurodevelopment. We conducted a multicenter, double-blind, randomized controlled trial in women with a singleton pregnancy who were <21 weeks’ gestation at trial entry. Women were provided with 800 mg DHA/day or a placebo supplement from trial entry until birth. When children reached seven years of age, we invited parents to complete the Strengths and Difficulties Questionnaire (SDQ), the Behavior Rating Inventory of Executive Function (BRIEF), and the Conners 3rd Edition Attention-Deficit Hyperactivity Disorder (ADHD) Index to assess child behavior and behavioral manifestations of executive dysfunction. There were 543 parent–child pairs (85% of those eligible) that participated in the follow-up. Scores were worse in the DHA group than the placebo group for the BRIEF Global Executive, Behavioral Regulation and Metacognition Indexes, and the Shift, Inhibit, Monitor, Working Memory, and Organization of Materials scales, as well as for the Conners 3 ADHD index, and the SDQ Total Difficulties score, Hyperactivity/Inattention score, and Peer Relationship Problems score. In this healthy, largely term-born sample of children, prenatal DHA supplementation conferred no advantage to childhood behavior, and instead appeared to have an adverse effect on behavioral functioning, as assessed by standardized parental report scales.Jacqueline F. Gould, Peter J. Anderson, Lisa N. Yelland, Robert A. Gibson, and Maria Makride

    Astronaut ophthalmic syndrome

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    During and after missions on the International Space Station, some astronauts experience ophthalmic changes, including choroidal folds, optic disc edema, cotton-wool spots, globe flattening, and refraction changes. Astronauts with ophthalmic issues had significantly higher plasma concentrations of metabolites that are associated with the 1-carbon metabolic pathway than those without ophthalmic issues. We hypothesized that genetic differences might explain the metabolite differences. Indeed, genetics and B vitamin status were significant predictors of ophthalmic issues. We now have developed a hypothesis regarding the mechanisms that link 1-carbon pathway genetics and the condition that we suggest calling, “astronaut ophthalmic syndrome.” We maintain that this condition is genetically predisposed and is associated with endothelial dysfunction that is induced by oxidative stress. Subsequent edema can hinder cerebrospinal fluid efflux and can lead to locally increased pressures in the subarachnoid space within the orbit, which impinges on the optic nerve and/or eye in affected individuals. Confirming this hypothesis will help characterize the genetics of 1-carbon pathway metabolism, homocysteine, oxidative stress, endothelial dysfunction, and cardiovascular and potentially other diseases

    Influence of OATP1B1 Function on the Disposition of Sorafenib-β-D-Glucuronide

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    The oral multikinase inhibitor sorafenib undergoes extensive UGT1A9-mediated formation of sorafenib-β-D-glucuronide (SG). Using transporter-deficient mouse models, it was previously established that SG can be extruded into bile by ABCC2 or follow a liver-to-blood shuttling loop via ABCC3-mediated efflux into the systemic circulation, and subsequent uptake in neighboring hepatocytes by OATP1B-type transporters. Here we evaluated the possibility that this unusual process, called hepatocyte hopping, is also operational in humans and can be modulated through pharmacological inhibition. We found that SG transport by OATP1B1 or murine Oatp1b2 was effectively inhibited by rifampin, and that this agent can significantly increase plasma levels of SG in wildtype mice, but not in Oatp1b2-deficient animals. In human subjects receiving sorafenib, rifampin acutely increased the systemic exposure to SG. Our study emphasizes the need to consider hepatic handling of xenobiotic glucuronides in the design of drug-drug interaction studies of agents that undergo extensive phase II conjugation

    The Modeling of Anisotropic Fuselage Lining Material

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    In this paper a theoretical model that can account for the effect of lining anisotropy on sound transmission through fuselage structures is developed. The model allows for anisotropic flow resistivity, tortuosity and elastic moduli. Implicit to the theory is a characteristic dispersion relation of sixth order that yields the allowed wave numbers for wave propagation in anisotropic elastic porous media. In addition, explicit expressions for field variables such as displacements and stresses appropriate for anisotropic foams are derived. Predictions of random incidence sound transmission loss for double panels with anisotropic linings have been performed. To verify the prediction, the theoretical results have been compared with random incidence transmission loss measurements
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