39 research outputs found

    Paraoxonase 1 Polymorphism and Prenatal Pesticide Exposure Associated with Adverse Cardiovascular Risk Profiles at School Age

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    Background: Prenatal environmental factors might influence the risk of developing cardiovascular disease later in life. The HDL-associated enzyme paraoxonase 1 (PON1) has anti-oxidative functions that may protect against atherosclerosis. It also hydrolyzes many substrates, including organophosphate pesticides. A common polymorphism, PON1 Q192R, affects both properties, but a potential interaction between PON1 genotype and pesticide exposure on cardiovascular risk factors has not been investigated. We explored if the PON1 Q192R genotype affects cardiovascular risk factors in school-age children prenatally exposed to pesticides. Methods: Pregnant greenhouse-workers were categorized as high, medium, or not exposed to pesticides. Their children underwent a standardized examination at age 6-to-11 years, where blood pressure, skin folds, and other anthropometric parameters were measured. PON1-genotype was determined for 141 children (88 pesticide exposed and 53 unexposed). Serum was analyzed for insulin-like growth factor I (IGF-I), insulin-like growth factor binding protein 3 (IGFBP3), insulin and leptin. Body fat percentage was calculated from skin fold thicknesses. BMI results were converted to age and sex specific Z-scores. Results: Prenatally pesticide exposed children carrying the PON1 192R-allele had higher abdominal circumference, body fat content, BMI Z-scores, blood pressure, and serum concentrations of leptin and IGF-I at school age than unexposed children. The effects were related to the prenatal exposure level. For children with the PON1 192QQ genotype, none of the variables was affected by prenatal pesticide exposure. Conclusion: Our results indicate a gene-environment interaction between prenatal pesticide exposure and the PON1 gene. Only exposed children with the R-allele developed adverse cardiovascular risk profiles thought to be associated with the R-allele

    Tungsten isotope evidence that mantle plumes contain no contribution from the Earth's core

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    Osmium isotope ratios provide important constraints on the sources of ocean-island basalts, but two very different models have been put forward to explain such data. One model interprets Os-187-enrichments in terms of a component of recycled oceanic crust within the source material(1,2). The other model infers that interaction of the mantle with the Earth's outer core produces the isotope anomalies and, as a result of coupled Os-186-Os-187 anomalies, put time constraints on inner-core formation(3-5). Like osmium, tungsten is a siderophile ('iron-loving') element that preferentially partitioned into the Earth's core during core formation but is also 'incompatible' during mantle melting (it preferentially enters the melt phase), which makes it further depleted in the mantle. Tungsten should therefore be a sensitive tracer of core contributions in the source of mantle melts. Here we present high-precision tungsten isotope data from the same set of Hawaiian rocks used to establish the previously interpreted Os-186-Os-187 anomalies and on selected South African rocks, which have also been proposed to contain a core contribution(6). None of the samples that we have analysed have a negative tungsten isotope value, as predicted from the core-contribution model. This rules out a simple core-mantle mixing scenario and suggests that the radiogenic osmium in ocean-island basalts can better be explained by the source of such basalts containing a component of recycled crust.</p

    Controlling the near-field oscillations of loaded plasmonic nanoantennas

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    Optical and infrared antennas enable a variety of cutting-edge applications ranging from nanoscale photodetectors to highly sensitive biosensors. All these applications critically rely on the optical near-field interaction between the antenna and its ‘load’ (biomolecules or semiconductors). However, it is largely unexplored how antenna loading affects the near-field response. Here, we use scattering-type near-field microscopy to monitor the evolution of the near-field oscillations of infrared gap antennas progressively loaded with metallic bridges of varying size. Our results provide direct experimental evidence that the local near-field amplitude and phase can be controlled by antenna loading, in excellent agreement with numerical calculations. By modelling the antenna loads as nanocapacitors and nanoinductors, we show that the change of near-field patterns induced by the load can be understood within the framework of circuit theory. Targeted antenna loading provides an excellent means of engineering complex antenna configurations in coherent control applications, adaptive nano-optics and metamaterials.This research was supported by the Etortek program of the Department of Industry of the Basque Government and the Basque Foundation for Science (Ikerbasque). J.A. acknowledges CSIC special intramural project PIE 2008601039.Peer reviewe
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