840 research outputs found

    Planning Ability in Schizophrenia

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    This publication-based thesis investigates planning ability in psychiatric patients with schizophrenia, combining a problem solving perspective with a psychometric approach to assessing executive functions. The manuscripts presented address four research questions: (1) Is the newly developed Plan-a-Day test a reliable and valid measure of planning ability in schizophrenia? (2) Is planning ability – in particular as measured by the Plan-a-Day test – predictive of functional outcome? (3) Is a planning and problem solving training based on the Plan-a-Day concept effective in cognitive remediation? (4) How specific is a planning deficit in schizophrenia

    Three dimensional generalization of the J1J_1-J2J_2 Heisenberg model on a square lattice and role of the interlayer coupling JcJ_c

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    A possibility to describe magnetism in the iron pnictide parent compounds in terms of the two-dimensional frustrated Heisenberg J1J_1-J2J_2 model has been actively discussed recently. However, recent neutron scattering data has shown that the pnictides have a relatively large spin wave dispersion in the direction perpendicular to the planes. This indicates that the third dimension is very important. Motivated by this observation we study the J1J_1-J2J_2-JcJ_c model that is the three dimensional generalization of the J1J_1-J2J_2 Heisenberg model for S=1/2S = 1/2 and S = 1. Using self-consistent spin wave theory we present a detailed description of the staggered magnetization and magnetic excitations in the collinear state. We find that the introduction of the interlayer coupling JcJ_c suppresses the quantum fluctuations and strengthens the long range ordering. In the J1J_1-J2J_2-JcJ_c model, we find two qualitatively distinct scenarios for how the collinear phase becomes unstable upon increasing J1J_1. Either the magnetization or one of the spin wave velocities vanishes. For S=1/2S = 1/2 renormalization due to quantum fluctuations is significantly stronger than for S=1, in particular close to the quantum phase transition. Our findings for the J1J_1-J2J_2-JcJ_c model are of general theoretical interest, however, the results show that it is unlikely that the model is relevant to undoped pnictides.Comment: 11 pages, 10 figures. Updated version, several references adde

    The Plan-a-Day Approach to Measuring Planning Ability in Patients with Schizophrenia

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    Deficits in executive functioning are closely related to the level of everyday functioning in patients with schizophrenia. However, many existing neuropsychological measures are limited in their ability to predict functional outcome. To contribute towards closing this gap, we developed a computer-based test of planning ability ("Plan-a-Day”) that requires participants to create daily activity schedules in a simulated work setting. Eighty patients diagnosed with schizophrenia were tested with Plan-a-Day and a battery of cognitive ability tests. Plan-a-Day showed satisfactory psychometric properties in terms of consistency, reliability, and construct validity. Compared to other neuropsychological tests used in this study, it also demonstrated incremental validity with regard to the Global Assessment of Functioning. The Plan-a-Day approach, therefore, seems to represent a valid alternative for measuring planning ability in patients with executive function deficits, occupying a middle ground between traditional neuropsychological tests and real-life assessments. (JINS, 2011, 17, 327-335

    Evolution of structural and optical properties of ion-beam synthesized GaAsN nanostructures

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    We have investigated the evolution of structural and optical properties of GaAsN nanostructures synthesized by N ion implantation into epitaxial GaAs, followed by rapid thermal annealing. Transmission electron microscopy and x-ray diffraction indicate the formation of nanometer-sized crystallites with lattice parameters close to those of pure zincblende GaN. The average crystallite size increases with annealing temperature while the size distribution is self-similar and the volume fraction remains constant, suggesting a coarsening process governed by Ostwald ripening. These GaAsN nanostructures exhibit significant photoluminescence in the near infrared range. The apparent lowering of the fundamental band gap is likely due to the incorporation of a small amount of As in GaN. © 2002 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70225/2/JAPIAU-92-7-4012-1.pd

    The Douglas-Fir Genome Sequence Reveals Specialization of the Photosynthetic Apparatus in Pinaceae.

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    A reference genome sequence for Pseudotsuga menziesii var. menziesii (Mirb.) Franco (Coastal Douglas-fir) is reported, thus providing a reference sequence for a third genus of the family Pinaceae. The contiguity and quality of the genome assembly far exceeds that of other conifer reference genome sequences (contig N50 = 44,136 bp and scaffold N50 = 340,704 bp). Incremental improvements in sequencing and assembly technologies are in part responsible for the higher quality reference genome, but it may also be due to a slightly lower exact repeat content in Douglas-fir vs. pine and spruce. Comparative genome annotation with angiosperm species reveals gene-family expansion and contraction in Douglas-fir and other conifers which may account for some of the major morphological and physiological differences between the two major plant groups. Notable differences in the size of the NDH-complex gene family and genes underlying the functional basis of shade tolerance/intolerance were observed. This reference genome sequence not only provides an important resource for Douglas-fir breeders and geneticists but also sheds additional light on the evolutionary processes that have led to the divergence of modern angiosperms from the more ancient gymnosperms

    Deep learning at the edge enables real-time streaming ptychographic imaging

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    Coherent microscopy techniques provide an unparalleled multi-scale view of materials across scientific and technological fields, from structural materials to quantum devices, from integrated circuits to biological cells. Driven by the construction of brighter sources and high-rate detectors, coherent X-ray microscopy methods like ptychography are poised to revolutionize nanoscale materials characterization. However, associated significant increases in data and compute needs mean that conventional approaches no longer suffice for recovering sample images in real-time from high-speed coherent imaging experiments. Here, we demonstrate a workflow that leverages artificial intelligence at the edge and high-performance computing to enable real-time inversion on X-ray ptychography data streamed directly from a detector at up to 2 kHz. The proposed AI-enabled workflow eliminates the sampling constraints imposed by traditional ptychography, allowing low dose imaging using orders of magnitude less data than required by traditional methods

    Predictors for Improvement of Problem-Solving during Cognitive Remediation for Patients with Schizophrenia

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    Cognitive remediation is a promising pathway for ameliorating cognitive impairment of patients with schizophrenia. Here, we investigate predictors of improvement in problem-solving ability for two different types of cognitive remediation - specific problem-solving training and training of basic cognition. For this purpose we conducted a re-analysis of a randomized controlled trial comparing these two training approaches. The main outcome measure was improvement in problem-solving performance. Correlational analyses were used to assess the contribution of clinical, cognitive and training-related predictors. In the problem-solving training group, impaired pre-training planning ability was associated with stronger improvement. In contrast, in the basic cognition training group antipsychotic medication dose emerged as a negative predictor. These results demonstrate that predictors for successful cognitive remediation depend on the specific intervention. Furthermore, our results suggest that at least in the planning domain patients with impaired performance benefit particularly from a specific intervention. (JINS, 2014, 20, 1-6

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    journal homepage: www.elsevier.com/locate/schres Planning impairments in schizophrenia: Specificity, task independence an

    Scaling of the F_2 structure function in nuclei and quark distributions at x>1

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    We present new data on electron scattering from a range of nuclei taken in Hall C at Jefferson Lab. For heavy nuclei, we observe a rapid falloff in the cross section for x>1x>1, which is sensitive to short range contributions to the nuclear wave-function, and in deep inelastic scattering corresponds to probing extremely high momentum quarks. This result agrees with higher energy muon scattering measurements, but is in sharp contrast to neutrino scattering measurements which suggested a dramatic enhancement in the distribution of the `super-fast' quarks probed at x>1. The falloff at x>1 is noticeably stronger in ^2H and ^3He, but nearly identical for all heavier nuclei.Comment: 5 pages, 4 figures, to be submitted to physical revie
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