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)

One thousand plant transcriptomes and the phylogenomics of green plants

Abstract: Green plants (Viridiplantae) include around 450,000–500,000 species1, 2 of great diversity and have important roles in terrestrial and aquatic ecosystems. Here, as part of the One Thousand Plant Transcriptomes Initiative, we sequenced the vegetative transcriptomes of 1,124 species that span the diversity of plants in a broad sense (Archaeplastida), including green plants (Viridiplantae), glaucophytes (Glaucophyta) and red algae (Rhodophyta). Our analysis provides a robust phylogenomic framework for examining the evolution of green plants. Most inferred species relationships are well supported across multiple species tree and supermatrix analyses, but discordance among plastid and nuclear gene trees at a few important nodes highlights the complexity of plant genome evolution, including polyploidy, periods of rapid speciation, and extinction. Incomplete sorting of ancestral variation, polyploidization and massive expansions of gene families punctuate the evolutionary history of green plants. Notably, we find that large expansions of gene families preceded the origins of green plants, land plants and vascular plants, whereas whole-genome duplications are inferred to have occurred repeatedly throughout the evolution of flowering plants and ferns. The increasing availability of high-quality plant genome sequences and advances in functional genomics are enabling research on genome evolution across the green tree of life

Variabilidade genética entre e dentro de procedências de pinheiros tropicais.

Este trabalho teve como objetivo estimar parametros geneticos e avaliar as caracteristicas de crescimento e forma do tronco de procedencias de tres especies de pinheiros tropicais Pinus tecunumanii (Schw.) Eguiluz & Perry, Pinus caribaea var. hondurensis Barret & Golfari e Pinus oocarpa Schiede, na regiao do Cerrado, por meio das seguintes caracteristicas: volume solido sem casca, forma do tronco, bifurcacao e foxtail ou rabo-de-raposa. O delineamento experimental utilizado foi o de blocos casualizados, com cinco repeticoes, com informacao dentro da parcela. Os resultados das analises de variancia indicaram a existencia de diferencas significativas (P<0,01 e P<0,005) e nao-significativas entre as procedencias quanto aos caracteres avaliados. As estimativas de herdabilidade calculadas com os dados da media de procedencia no bloco foram sempre maiores que as estimativas calculadas com os valores dos individuos dentro da procedencia, no bloco e no experimento. O P. tecunumanii apresentou melhor desempenho silvicultural que o P. caribaea var. hondurensis e o P. oocarpa.199

Anticorpos contra Toxoplasma gondii em estudantes de medicina veterinária de Campo Grande, MS, Brasil Antibodies to Toxoplasma Gondii in veterinary medicine students of Campo Grande, MS, Brazil

Amostras de soro obtidas de estudantes do curso de Medicina Veteriná ria da Universidade para o Desenvolvimento do Estado e da Região do Pantanal, Campo Grande, MS, Brasil, foram examinadas para a presença de anticorpos contra Toxoplasma gondii. Dos 145 soros testados, 44 (30,34%) foram positivos na hemaglutinação, com título igual ou superior a 1:16. Não foram observadas associações entre as caracterí sticas epidemiológicas examinadas, tais como hábitos alimentares (ingestão de carne bovina crua ou malpassada, vegetais crus/não lavados, produtos lácteos não pasteurizados) ou contato constante com cães e a presença de anticorpos contra T. gondii, exceto pelo percentual significativamente maior de estudantes soropositivos que relataram ter contato freqüente com gatos (P=0,03).<br>Serum samples obtained from students of the School of Veterinary Medicine, Universidade para o Desenvolvimento do Estado e da Região do Pantanal, Campo Grande, MS, Brazil, were examined for Toxoplasma gondii gondii antibodies. Serum samples from 44 (30.34%) of the 145 veterinary students examined were positive on the hemagglutination test, yielding a titer of 1:16 or greater. There were no relations between the epidemiological characteristics examined, such as food habits (eating of raw or rare-cooked cattle meat, raw/uncleaned vegetables, unpasteurized dairy products), frequent contact with dogs and the presence of T. gondii antibodies, except for a significantly higher percentual of seropositive students that reported frequent contact with cats (P=0.03)