The Extent and Patterns of Usage of Agent Orange and Other Herbicides in Vietnam

Herbicides including Agent Orange were sprayed by United States forces for military purposes during the Vietnam War (1961–1971) at a rate more than an order of magnitude greater than for similar domestic weed control. In 1974, the US National Academy of Sciences published estimates of the extent and distribution of herbicides sprayed. Here we present revised estimates, developed using more-complete data. The spray inventory is expanded by more than seven million litres, in particular with heavily dioxin-contaminated herbicides. Estimates for the amount of dioxin sprayed are almost doubled. Hamlet census data reveal that millions of Vietnamese were likely to have been sprayed upon directly. Our identification of specific military herbicide targets has led to a more coherent understanding of spraying. Common errors in earlier interpretations of the spray data are also discussed

On the mechanisms governing gas penetration into a tokamak plasma during a massive gas injection

A new 1D radial fluid code, IMAGINE, is used to simulate the penetration of gas into a tokamak plasma during a massive gas injection (MGI). The main result is that the gas is in general strongly braked as it reaches the plasma, due to mechanisms related to charge exchange and (to a smaller extent) recombination. As a result, only a fraction of the gas penetrates into the plasma. Also, a shock wave is created in the gas which propagates away from the plasma, braking and compressing the incoming gas. Simulation results are quantitatively consistent, at least in terms of orders of magnitude, with experimental data for a D 2 MGI into a JET Ohmic plasma. Simulations of MGI into the background plasma surrounding a runaway electron beam show that if the background electron density is too high, the gas may not penetrate, suggesting a possible explanation for the recent results of Reux et al in JET (2015 Nucl. Fusion 55 093013)

Proton magnetic resonance spectroscopy of the frontal lobe in schizophrenics: a critical review of the methodology Espectroscopia de próton por ressonância magnética de lobo frontal em esquizofrênicos: revisão crítica da metodologia

Schizophrenic patients undergoing proton magnetic resonance spectroscopy show alterations in N-acetyl aspartate levels in several brain regions, indicating neuronal dysfunction. The present review focuses on the main proton magnetic resonance spectroscopy studies in the frontal lobe of schizophrenics. A MEDLINE search, from 1991 to March 2004, was carried out using the key-words spectroscopy and schizophrenia and proton and frontal. In addition, articles cited in the reference list of the studies obtained through MEDLINE were included. As a result, 27 articles were selected. The results were inconsistent, 19 papers reporting changes in the N-acetyl aspartate levels, while 8 reported no change. Methodological analysis led to the conclusion that the discrepancy may be due the following factors: (i) number of participants; (ii) variation in the clinical and demographic characteristics of the groups; (iii) little standardization of the acquisition parameters of spectroscopy. Overall, studies that fulfill strict methodological criteria show N-acetyl aspartate decrease in the frontal lobe of male schizophrenics.<br>Pacientes esquizofrênicos submetidos à espectroscopia de próton por ressonância magnética demonstram alterações nos níveis de N-acetilaspartato em diversas regiões cerebrais, suportando a hipótese de disfunção neuronal nestas áreas. Objetiva-se apresentar uma revisão da literatura, sobre os principais estudos de espectroscopia de próton por ressonância magnética na região frontal em esquizofrênicos. Utilizou-se o indexador MEDLINE, no período entre 1991 e março de 2004, com o cruzamento dos termos spectroscopy, schizophrenia, proton e frontal. Foram selecionados 27 artigos originais, cujos resultados mostram-se discordantes quanto à alteração nos valores de N-acetilaspartato (19 artigos apresentaram alterações nos níveis de N-acetilaspartato e oito estudos não apresentam alterações). A presente revisão sugere que esta diversidade de resultados pode ser atribuída aos seguintes fatores: 1-número de participantes; 2- variação nas características clínicas e demográficas dos grupos; 3- pouca padronização dos parâmetros de aquisição dos espectros. Os artigos que satisfazem os critérios metodológicos mais rígidos sugerem diminuição de NAA no lobo frontal de esquizofrênicos do sexo masculino

Epigenetic profiling of ADHD symptoms trajectories: a prospective, methylome-wide study.

Attention-deficit/hyperactivity disorder (ADHD) is a prevalent developmental disorder, associated with a range of long-term impairments. Variation in DNA methylation, an epigenetic mechanism, is implicated in both neurobiological functioning and psychiatric health. However, the potential role of DNA methylation in ADHD symptoms is currently unclear. In this study, we examined data from the Avon Longitudinal Study of Parents and Children (ALSPAC)-specifically the subsample forming the Accessible Resource for Integrated Epigenomics Studies (ARIES)-that includes (1) peripheral measures of DNA methylation (Illumina 450k) at birth (n=817, 49% male) and age 7 (n=892, 50% male) and (2) trajectories of ADHD symptoms (7-15 years). We first employed a genome-wide analysis to test whether DNA methylation at birth associates with later ADHD trajectories; and then followed up at age 7 to investigate the stability of associations across early childhood. We found that DNA methylation at birth differentiated ADHD trajectories across multiple genomic locations, including probes annotated to SKI (involved in neural tube development), ZNF544 (previously implicated in ADHD), ST3GAL3 (linked to intellectual disability) and PEX2 (related to perixosomal processes). None of these probes maintained an association with ADHD trajectories at age 7. Findings lend novel insights into the epigenetic landscape of ADHD symptoms, highlighting the potential importance of DNA methylation variation in genes related to neurodevelopmental and peroxisomal processes that play a key role in the maturation and stability of cortical circuits.This article is freely available via Open Access. Click on the Additional Link above to access the full tex