993 resultados para Smith, John
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Encholirium Lutzii is distinguished from the majority of species by its branched inflorescence. Only E. horridum L. B. Smith and rarely E. spectabile Martius exhibit this character, but have much larger flowers than E. Lutzii and stout floral axes. Also the wing of the seed in E. horridum is very long-caudate. We feel that it is particularly appropriate to dedicate this new species to Dr. Adolpho Lutz because of his great discoveries in the biological relationships of the Bromeliaceae.
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A large fraction of genome variation between individuals is comprised of submicroscopic copy number variation of genomic DNA segments. We assessed the relative contribution of structural changes and gene dosage alterations on phenotypic outcomes with mouse models of Smith-Magenis and Potocki-Lupski syndromes. We phenotyped mice with 1n (Deletion/+), 2n (+/+), 3n (Duplication/+), and balanced 2n compound heterozygous (Deletion/Duplication) copies of the same region. Parallel to the observations made in humans, such variation in gene copy number was sufficient to generate phenotypic consequences: in a number of cases diametrically opposing phenotypes were associated with gain versus loss of gene content. Surprisingly, some neurobehavioral traits were not rescued by restoration of the normal gene copy number. Transcriptome profiling showed that a highly significant propensity of transcriptional changes map to the engineered interval in the five assessed tissues. A statistically significant overrepresentation of the genes mapping to the entire length of the engineered chromosome was also found in the top-ranked differentially expressed genes in the mice containing rearranged chromosomes, regardless of the nature of the rearrangement, an observation robust across different cell lineages of the central nervous system. Our data indicate that a structural change at a given position of the human genome may affect not only locus and adjacent gene expression but also "genome regulation." Furthermore, structural change can cause the same perturbation in particular pathways regardless of gene dosage. Thus, the presence of a genomic structural change, as well as gene dosage imbalance, contributes to the ultimate phenotype.
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Gas chromatography (GC) is an analytical tool very useful to investigate the composition of gaseous mixtures. The different gases are separated by specific columns but, if hydrogen (H2 ) is present in the sample, its detection can be performed by a thermal conductivity detector or a helium ionization detector. Indeed, coupled to GC, no other detector can perform this detection except the expensive atomic emission detector. Based on the detection and analysis of H2 isotopes by low-pressure chemical ionization mass spectrometry (MS), a new method for H2 detection by GC coupled to MS with an electron ionization ion source and a quadrupole analyser is presented. The presence of H2 in a gaseous mixture could easily be put in evidence by the monitoring of the molecular ion of the protonated carrier gas. Copyright © 2013 John Wiley & Sons, Ltd.
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This paper discusses the development of Marx’s thought over a period of something like fifteen months, between the spring of 1843 and the autumn of 1844. The focus of the paper is Marx’s first encounter with classical political economy as he found it in the Wealth of Nations. The outcome of this encounter was presented by Marx in his Economic and Philosophical Manuscripts of 1844. It is argued here that in the classical theory, with which he had hitherto been largely unfamiliar, Marx found all the elements he needed to synthesise the philosophical standpoint he had developed in the preceding months with political economy. The Manuscripts represent the first crucial stage in the development of this synthesis. This first encounter of Marx with classical political economy, and his first steps in the development of his synthesis, have received hardly any attention in the literature. The present paper seeks to fill this gap.
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This paper discusses the development of Marx’s thought over a period of something like fifteen months, between the spring of 1843 and the autumn of 1844. The focus of the paper is Marx’s first encounter with classical political economy as he found it in the Wealth of Nations. The outcome of this encounter was presented by Marx in his Economic and Philosophical Manuscripts of 1844. It is argued here that in the classical theory, with which he had hitherto been largely unfamiliar, Marx found all the elements he needed to synthesise the philosophical standpoint he had developed in the preceding months with political economy. The Manuscripts represent the first crucial stage in the development of this synthesis. This first encounter of Marx with classical political economy, and his first steps in the development of his synthesis, have received hardly any attention in the literature. The present paper seeks to fill this gap.