1,071 research outputs found

    Does Perceptual Learning Suffer from Retrograde Interference?

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    In motor learning, training a task B can disrupt improvements of performance of a previously learned task A, indicating that learning needs consolidation. An influential study suggested that this is the case also for visual perceptual learning [1]. Using the same paradigm, we failed to reproduce these results. Further experiments with bisection stimuli also showed no retrograde disruption from task B on task A. Hence, for the tasks tested here, perceptual learning does not suffer from retrograde interference

    Diagnosis of the neuronal ceroid lipofuscinoses: An update

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    AbstractFor the majority of families affected by one of the neuronal ceroid lipofuscinoses (NCLs), a biochemical and/or genetic diagnosis can be achieved. In an individual case this information not only increases understanding of the condition but also may influence treatment choices and options. The presenting clinical features prompt initial investigation and also guide clinical care. The clinical labels “infantile NCL”, “late infantile NCL” and “juvenile NCL”, therefore remain useful in practice. In unusual or atypical cases ultra-structural analysis of white blood cells or other tissue samples enables planning and prioritisation of biochemical and genetic tests.This review describes current methods available to achieve clinical, pathological, biochemical and genetic diagnosis in children presenting with symptoms suggestive of one of the NCLs

    Tests and applications of self-consistent cranking in the interacting boson model

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    The self-consistent cranking method is tested by comparing the cranking calculations in the interacting boson model with the exact results obtained from the SU(3) and O(6) dynamical symmetries and from numerical diagonalization. The method is used to study the spin dependence of shape variables in the sdsd and sdgsdg boson models. When realistic sets of parameters are used, both models lead to similar results: axial shape is retained with increasing cranking frequency while fluctuations in the shape variable γ\gamma are slightly reduced.Comment: 9 pages, 3 ps figures, Revte

    A measure of majorisation emerging from single-shot statistical mechanics

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    The use of the von Neumann entropy in formulating the laws of thermodynamics has recently been challenged. It is associated with the average work whereas the work guaranteed to be extracted in any single run of an experiment is the more interesting quantity in general. We show that an expression that quantifies majorisation determines the optimal guaranteed work. We argue it should therefore be the central quantity of statistical mechanics, rather than the von Neumann entropy. In the limit of many identical and independent subsystems (asymptotic i.i.d) the von Neumann entropy expressions are recovered but in the non-equilbrium regime the optimal guaranteed work can be radically different to the optimal average. Moreover our measure of majorisation governs which evolutions can be realized via thermal interactions, whereas the nondecrease of the von Neumann entropy is not sufficiently restrictive. Our results are inspired by single-shot information theory.Comment: 54 pages (15+39), 9 figures. Changed title / changed presentation, same main results / added minor result on pure bipartite state entanglement (appendix G) / near to published versio

    Calculation of the photoionization with de-excitation cross sections of He and helium-like ions

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    We discuss the results of the calculation of the photoionization with de-excitation of excited He and helium-like ions Li+^{+} and B3+^{3+} at high but non-relativistic photon energies ω\omega . Several lower 1S^{1}S and 3S^{3}S states are considered. We present and analyze the ratios Rd+R_{d}^{+\ast} of the cross sections of photoionization with de-excitation, σ(d)+(ω)\sigma_{(d)}^{+\ast}(\omega), and of the photo-ionization with excitation, σ+(ω)\sigma ^{+\ast}(\omega). The dependence of Rd+R_{d}^{+\ast} on the excitation of the target object and the charge of its nucleus is presented. Apart to theoretical interest, results obtained can be verified using such long living excited state as 23S2^{3}S of He.Comment: 10 pages, 6 table

    Design and Integration of Electrical Bio-Impedance Sensing in a Bipolar Forceps for Soft Tissue Identification: A Feasibility Study

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    This paper presents the integration of electrical bio-impedance sensing technology into a bipolar surgical forceps for soft tissue identification during a robotic assisted procedure. The EBI sensing is done by pressing the forceps on the target tissue with a controlled pressing depth and a controlled jaw opening distance. The impact of these 2 parameters are characterized by finite element simulation. Subsequently, an experiment is conducted with 4 types of ex-vivo tissues including liver, kidney, lung and muscle. The experimental results demonstrate that the proposed EBI sensing method can identify these 4 tissue types with an accuracy higher than 92.82%

    Circulating granulocyte colony-stimulating factor and functional outcome after ischemic stroke: an observational study

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    Objectives: While granulocyte colony-stimulating factor (G-CSF) has shown beneficial effects in experimental ischemic stroke (IS), these effects have not been reproduced clinically. Small-to-medium-sized observational studies have reported varying associations for G-CSF with stroke severity and post-stroke functional outcome, prompting their investigation in a larger study. Methods: Endogenous serum G-CSF (S-GCSF) was measured in the acute phase and after 3 months in patients with IS (N = 435; 36% females; mean age, 57 years) from the Sahlgrenska Academy Study on Ischemic Stroke (SAHLSIS). Stroke severity was scored according to the National Institutes of Health Stroke Scale (NIHSS), and the modified Rankin Scale (mRS) assessed functional outcomes at 3-month and 2-year post-stroke. Correlation and logistic regression analyses with confounder adjustments assessed the relationships. Results: The acute S-GCSF level was 23% higher than at 3-month post-stroke (p < 0.001). Acute G-CSF correlated weakly with stroke severity quintiles (r = 0.12, p = 0.013) and with high-sensitivity C-reactive protein (r = 0.29, p < 0.001). The association between S-GCSF (as quintiles, q) and poor functional outcome at 3 months (mRS 3–6; S-GCSF-q5 vs. S-GCSF-q1, age- and sex-adjusted odds ratio: 4.27, 95% confidence interval: 1.82–9.99; p = 0.001) withstood adjustment for cardiovascular risk factors and stroke subtype, but not additional correction for stroke severity. Post-stroke changes in S-GSCF and absolute 3-month S-GCSF were not associated with 3-month or 2-year functional outcomes. Discussion: Early post-stroke S-GCSF is increased in severe IS and associated with 3-month poor functional outcomes. The change in S-GCSF and the 3-month S-GCSF appear to be less-important, and S-GCSF likely reflects inflammation in large infarctions

    Quasiclassical double photoionization from the 2^{1,3}S excited states of helium including shakeoff

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    We account for the different symmetries of the 2^{1,3}S helium excited states in a quasiclassical description of the knockout mechanism augmented by a quantum shakeoff contribution. We are thus able to formulate the separate contribution of the knockout and shakeoff mechanisms for double photoionization for any excess energy from the 2^{1,3}S states. Photoionization ratios and singly differential cross sections calculated for the 2^{1,3}S excited states of helium are found to be in very good agreement with recent theoretical results.Comment: 9 pages, 5 figure
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