57 research outputs found

    Choline transporter gene variation is associated with attention-deficit hyperactivity disorder

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    The neurotransmitter acetylcholine (ACh) plays a critical role in brain circuits mediating motor control, attention, learning and memory. Cholinergic dysfunction is associated with multiple brain disorders including Alzheimer’s Disease, addiction, schizophrenia and Attention-Deficit Hyperactivity Disorder (ADHD). The presynaptic choline transporter (CHT, SLC5A7) is the major, rate-limiting determinant of ACh production in the brain and periphery and is consequently upregulated during tasks that require sustained attention. Given the contribution of central cholinergic circuits to the control of movement and attention, we hypothesized that functional CHT gene variants might impact risk for ADHD. We performed a case-control study, followed by family-based association tests on a separate cohort, of two purportedly functional CHT polymorphisms (coding variant Ile89Val (rs1013940) and a genomic SNP 3’ of the CHT gene (rs333229), affording both a replication sample and opportunities to reduce potential population stratification biases. Initial genotyping of pediatric ADHD subjects for two purportedly functional CHT alleles revealed a 2–3 fold elevation of the Val89 allele (n = 100; P = 0.02) relative to healthy controls, as well as a significant decrease of the 3’SNP minor allele in Caucasian male subjects (n = 60; P = 0.004). In family based association tests, we found significant overtransmission of the Val89 variant to children with a Combined subtype diagnosis (OR = 3.16; P = 0.01), with an increased Odds Ratio for a haplotype comprising both minor alleles. These studies show evidence of cholinergic deficits in ADHD, particularly for subjects with the Combined subtype, and, if replicated, may encourage further consideration of cholinergic agonist therapy in the disorder

    Seawater-dominated, tectonically controlled and volcanic related geothermal systems: the case of the geothermal area in the northwest of the island of Euboea (Evia), Greece

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    The northwest of the island of Euboea is located in a back-arc geological position, at the western extremity of the North Anatolian Fault. In that area, several hot springs occur in three locations (Ilia, Gialtra, Aedipsos; including newly found offshore-springs) with temperatures up to 84 °C, depositing ore-grade thermogenic travertine. The geothermal system is seawater-dominated and under pressure, using the local fault systems and is related to the Plio-Pleistocene Lichades volcanic centre. The whole area could be characterized as the lateral tips of a major fault segment, with the presence of complex networks of additional fault systems leading to fault intersections. That conclusion is also supported by the travitonic data. The geothermal fluids are near neutral pH, sodium-chloride and their chemistry is controlled by: (i) high seawater participation, (ii) a deep magmatic source and (iii) chemical composition of the bedrocks. Based on all the available data, including drilling and temperature logging data, the bedrock hosting the upflow circulation of the geothermal fluid is not in hydraulic connection with cold aquifers or permeable geological formations of the area. The local metamorphic rock formations are impermeable and work as a geothermal cap. Also, Aedipsos’ vast deposit of thermogenic travertine probably acts as a second geothermal cap formation. However, at the same time, it presents serious thermal anomalies, since major geothermal fluid circulation has been identified inside its fractures. According to chemical geothermometers, the temperature of the geothermal reservoir is 140–164 °C. The typical geothermal gradients in the area are from 7.8 °C/100 m to 18.7 °C/100 m. In one case, an anomalous high geothermal gradient (53.9 °C/100 m) was found, most probably due to spatial shape diversity of the geothermal reservoir, a suggestion also supported by the estimated circulation depth of the geothermal fluid, which varies from area to area (~ 300–1800 m) and the fluid residence time (by 226Ra–222Rn method), which is around 80–100 years. © 2020, Geologische Vereinigung e.V. (GV)

    Household Air Pollution from Biomass Fuel for Cooking and Adverse Fetal Growth Outcomes in Rural Sri Lanka

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    The aim of this study was to investigate the impact of biomass fuel for cooking on adverse fetal growth outcomes in Sri Lanka. A cross-sectional study of mothers recruited at maternity clinics in rural communities in Sri Lanka's Central Province was undertaken. Data pertaining to household air pollution and fetal growth parameters were collected using an interviewer-administered questionnaire. Logistic regression models, adjusted for potential confounders, were used to evaluate the impact of biomass fuel for cooking on low birth weight (LBW) and small for gestational age (SGA) parameters. Findings showed that exposure to biomass cooking fuels during pregnancy was associated with an increased risk of LBW adjusted odds ratio (aOR) 2.74 (95% CI 1.08-6.96) and SGA (aOR: 1.87, 95% CI 1.03-3.41) compared with the use of clean energy. The risk of LBW was highest for traditional biomass stoves compared to improved biomass stoves (aOR: 3.23, 95% 1.17-8.89) and biomass use in kitchens without a chimney compared to kitchens with a chimney (aOR: 4.63, 95% 1.54-13.93). Similar trends were observed for SGA
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