97 research outputs found

    Stimulant Medication and Reading Performance

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    The study examined the sustained effects of methylphenidate on reading performance in a sample of 42 boys, ages 8 to 11, with attention deficit-hyperactivity disorder (ADHD). Two subgroups were formed based on the presence or absence of co-occurring conduct disorders. Subjects were selected on the basis of their positive response to methylphenidate as determined in a series of original medication trials (Forness, Cantwell, Swanson, Hanna, & Youpa, 1991). For the purpose of this study, subjects were placed on their optimal dose of medication for a 6-week period and then tested on measures of oral reading and reading comprehension equivalent to those used in the original trials, retested after a week without medication (placebo), then tested again the following week after return to medication. Only the subgroup with conduct disorders responded, and this response was limited to reading comprehension improvement in only those subjects who also demonstrated improvement in oral reading on original trials. No response differences were found between subjects with or without learning disabilities.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68569/2/10.1177_002221949202500205.pd

    Tectonic controls on post-subduction granite genesis and emplacement : the late Caledonian suite of Britain and Ireland

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    Rates of magma emplacement commonly vary as a function of tectonic setting. The late Caledonian granites of Britain and Ireland are associated with closure of the Iapetus Ocean and were emplaced into a varying regime of transpression and transtension throughout the Silurian and into the early Devonian. Here we evaluate a new approach for examining how magma volumes vary as a function of tectonic setting. Available radiometric ages from the late Caledonian granites are used to calculate probability density functions (age spectra), with each pluton weighted by outcrop area as a proxy for its volume. These spectra confirm an absence of magmatic activity during Iapetus subduction between c. 455 Ma and 425 Ma and a dominance of post-subduction magmas between c. 425 Ma and 380 Ma. We review possible reasons why, despite the widespread outcrop of the late Caledonian granites, magmatism appears absent during Iapetus subduction. These include shallow angle subduction or extensive erosion and tectonic removal of the arc. In contrast to previous work we find no strong difference in the age or major element chemistry of post-subduction granites across all terranes. We propose a common causal mechanism in which the down-going Iapetus oceanic slab peeled back and detached beneath the suture following final Iapetus closure. The lithospheric mantle was delaminated beneath the suture and for about 100 km back beneath the Avalonian margin. While magma generation is largely a function of gravitationally driven lithosphere delamination, strike-slip dominated kinematics in the overlying continental crust is what modulated granitic magma emplacement. Early Devonian (419–404 Ma) transtension permitted large volumes of granite emplacement, whereas the subsequent Acadian (late Early Devonian, 404–394 Ma) transpression reduced and eventually suppressed magma emplacement

    Community-led comparative genomic and phenotypic analysis of the aquaculture pathogen Pseudomonas baetica a390T sequenced by Ion semiconductor and Nanopore technologies

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    Pseudomonas baetica strain a390T is the type strain of this recently described species and here we present its high-contiguity draft genome. To celebrate the 16th International Conference on Pseudomonas, the genome of P. baetica strain a390T was sequenced using a unique combination of Ion Torrent semiconductor and Oxford Nanopore methods as part of a collaborative community-led project. The use of high-quality Ion Torrent sequences with long Nanopore reads gave rapid, high-contiguity and -quality, 16-contig genome sequence. Whole genome phylogenetic analysis places P. baetica within the P. koreensis Glade of the P. fluorescens group. Comparison of the main genomic features of P. baetica with a variety of other Pseudomonas spp. suggests that it is a highly adaptable organism, typical of the genus. This strain was originally isolated from the liver of a diseased wedge sole fish, and genotypic and phenotypic analyses show that it is tolerant to osmotic stress and to oxytetracycline.Microbial Biotechnolog
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