173 research outputs found

    Markers of cognitive function in individuals with metabolic disease: Morquio Syndrome and Tyrosinemia Type III

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    We characterized cognitive function in two metabolic diseases. MPS–IVa (mucopolysaccharidosis IVa, Morquio) and tyrosinemia type III individuals were assessed using tasks of attention, language and oculomotor function. MPS–IVa individuals were slower in visual search, but the display size effects were normal, and slowing was not due to long reaction times (ruling out slow item processing or distraction). Maintaining gaze in an oculomotor task was difficult. Results implicated sustained attention and task initiation or response processing. Shifting attention, accumulating evidence and selecting targets were unaffected. Visual search was also slowed in tyrosinemia type III, and patterns in visual search and fixation tasks pointed to sustained attention impairments, although there were differences from MPS–IVa. Language was impaired in tyrosinemia type III but not MPS–IVa. Metabolic diseases produced selective cognitive effects. Our results, incorporating new methods for developmental data and model selection, illustrate how cognitive data can contribute to understanding function in biochemical brain systems

    Top EW couplings at Linear Colliders

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    In this talk, we present the latest study of e+e− → tÂŻt, based on a detailed simulation of the ILD detector concept, which assumes a centre-of-mass energy of √s = 500 GeV and a luminosity of L = 500fb−1, equality shared between the incoming beam polarisations of P e−,e+ = (±0.8,∓0.3). The study comprises the cross sections, the forward-backward asymmetry and the slope of the helicity angle asymmetry. The vector and axial vector couplings are separately determined for the photon and the Z component. The tensorial CP-conserving coupling can be also extracted by assuming the other couplings to be the SM values. We show that the sensitivity to new physics would be dramatically improved with respect to what is expected from LHC for electroweak couplings

    A precise characterisation of the top quark electro-weak vertices at the ILC

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    Top quark production in the process e+e−→ttˉe^+e^- \to t\bar{t} at a future linear electron positron collider with polarised beams is a powerful tool to determine indirectly the scale of new physics. The presented study, based on a detailed simulation of the ILD detector concept, assumes a centre-of-mass energy of s=500 \sqrt{s}=500\,GeV and a luminosity of L=500 fb−1\mathcal{L}=500\,{\rm fb}^{-1} equally shared between the incoming beam polarisations of Pe−,Pe+=±0.8,∓0.3\mathcal{P}_{e^-}, \mathcal{P}_{e^+} =\pm0.8,\mp0.3. Events are selected in which the top pair decays semi-leptonically and the cross sections and the forward-backward asymmetries are determined. Based on these results, the vector, axial vector and tensorial CPCP conserving couplings are extracted separately for the photon and the Z0Z^0 component. With the expected precision, a large number of models in which the top quark acts as a messenger to new physics can be distinguished with many standard deviations. This will dramatically improve expectations from e.g. the LHC for electro-weak couplings of the top quark.Comment: This work is an update of arXiv:1307.8102, minor changes w.r.t. v1 (typos, wrong grammar, incomplete sentences etc.

    Processing words and Short Message Service shortcuts in sentential contexts::An eye movement study

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    The present study investigated whether Short Message Service shortcuts are more difficult to process in sentence context than the spelled-out word equivalent and, if so, how any additional processing difficulty arises. Twenty-four student participants read 37 Short Message Service shortcuts and word equivalents embedded in semantically plausible and implausible contexts (e.g., He left/drank u/you a note) while their eye movements were recorded. There were effects of plausibility and spelling on early measures of processing difficulty (first fixation durations, gaze durations, skipping, and first-pass regression rates for the targets), but there were no interactions of plausibility and spelling. Late measures of processing difficulty (second run gaze duration and total fixation duration) were only affected by plausibility but not by spelling. These results suggest that shortcuts are harder to recognize, but that, once recognized, they are integrated into the sentence context as easily as ordinary words

    Oculomotor abnormalities in children with Niemann-Pick type C

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    Niemann-Pick type C (NP-C) is a rare recessive disorder associated with progressive supranuclear gaze palsy. Degeneration occurs initially for vertical saccades and later for horizontal saccades. There are studies of oculomotor degeneration in adult NP-C patients [1, 2] but no comparable studies in children. We used high-resolution video-based eye tracking to record monocular vertical and horizontal eye movements in 2 neurological NP-C patients (children with clinically observable oculomotor abnormalities) and 3 pre-neurological NP-C patients (children without clinically observable oculomotor abnormalities). Saccade onset latency, saccade peak velocity and saccade curvature were compared to healthy controls (N = 77). NP-C patients had selective impairments of vertical saccade peak velocity and vertical saccade curvature, with slower peak velocities and greater curvature. Changes were more pronounced in neurological than pre-neurological patients, showing that these measures are sensitive to disease progress, but abnormal curvature and slowed downward saccades were present in both groups, showing that eye-tracking can register disease-related changes before these are evident in a clinical exam. Both slowing, curvature and the detailed characteristics of the curvature we observed are predicted by the detailed characteristics of RIMLF population codes. Onset latencies were not different from healthy controls. High-resolution video-based eye tracking is a promising sensitive and objective method to measure NP-C disease severity and neurological onset. It may also help evaluate responses to therapeutic interventions

    Word frequency in fast priming: Evidence for immediate cognitive control of eye movements during reading

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    Numerous studies have demonstrated effects of word frequency on eye movements during reading, but the precise timing of this influence has remained unclear. The fast priming paradigm (Sereno & Rayner, 1992) was previously used to study influences of related versus unrelated primes on the target word. Here, we used this procedure to investigate whether the frequency of the prime word has a direct influence on eye movements during reading when the prime-target relation is not manipulated. We found that with average prime intervals of 32 ms readers made longer single fixation durations on the target word in the low than in the high frequency prime condition. Distributional analyses demonstrated that the effect of prime frequency on single fixation durations occurred very early, supporting theories of immediate cognitive control of eye movements. Finding prime frequency effects only 207 ms after visibility of the prime and for prime durations of 32 ms yields new time constraints for cognitive processes controlling eye movements during reading. Our variant of the fast priming paradigm provides a new approach to test early influences of word processing on eye movement control during reading

    Rational design of biosafe crop resistance to a range of nematodes using RNA interference

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    Double stranded RNA (dsRNA) molecules targeting two genes have been identified that suppress economically important parasitic nematode species of banana. Proteasomal Alpha Subunit 4 (pas-4) and Actin-4 (act-4) were identified from a survey of sequence databases and cloned sequences for genes conserved across four pests of banana, Radopholus similis, Pratylenchus coffeae, Meloidogyne incognita and Helicotylenchus multicinctus. These four species were targeted with dsRNAs containing exact 21 nucleotide matches to the conserved regions. Potential off-target effects were limited by comparison to Caenorhabditis, Drosophila, rat, rice and Arabidopsis genomes. In vitro act-4 dsRNA treatment of R. similis suppressed target gene expression by 2.3 fold, nematode locomotion by 66 ± 4% and nematode multiplication on carrot discs by 49 ± 5%. The best transgenic carrot hairy root lines expressing act-4 or pas-4 dsRNA reduced transcript message abundance of target genes in R. similis by 7.9 fold and 4 fold and nematode multiplication by 94 ± 2% and 69 ± 3%, respectively. The same act-4 and pas-4 lines reduced P. coffeae target transcripts by 1.7 and 2 fold and multiplication by 50 ± 6% and 73 ± 8%. Multiplication of M. incognita on the pas-4 lines was reduced by 97 ± 1% and 99 ± 1% while target transcript abundance was suppressed 4.9 and 5.6 fold. There was no detectable RNAi effect on non-target nematodes exposed to dsRNAs targeting parasitic nematodes. This work defines a framework for development of a range of non-protein defences to provide broad resistance to pests and pathogens of crops

    HapBead: on-skin microfluidic haptic interface using tunable bead

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    On-skin haptic interfaces using soft elastomers which are thin and flexible have significantly improved in recent years. Many are focused on vibrotactile feedback that requires complicated parameter tuning. Another approach is based on mechanical forces created via piezoelectric devices and other methods for non-vibratory haptic sensations like stretching, twisting. These are often bulky with electronic components and associated drivers are complicated with limited control of timing and precision. This paper proposes HapBead, a new on-skin haptic interface that is capable of rendering vibration like tactile feedback using microfluidics. HapBead leverages a microfluidic channel to precisely and agilely oscillate a small bead via liquid flow, which then generates various motion patterns in channel that creates highly tunable haptic sensations on skin. We developed a proof-of-concept design to implement thin, flexible and easily affordable HapBead platform, and verified its haptic rendering capabilities via attaching it to users’ fingertips. A study was carried out and confirmed that participants could accurately tell six different haptic patterns rendered by HapBead. HapBead enables new wearable display applications with multiple integrated functionalities such as on-skin haptic doodles, mixed reality haptics and visual-haptic displays

    The Time Structure of Hadronic Showers in highly granular Calorimeters with Tungsten and Steel Absorbers

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    The intrinsic time structure of hadronic showers influences the timing capability and the required integration time of hadronic calorimeters in particle physics experiments, and depends on the active medium and on the absorber of the calorimeter. With the CALICE T3B experiment, a setup of 15 small plastic scintillator tiles read out with Silicon Photomultipliers, the time structure of showers is measured on a statistical basis with high spatial and temporal resolution in sampling calorimeters with tungsten and steel absorbers. The results are compared to GEANT4 (version 9.4 patch 03) simulations with different hadronic physics models. These comparisons demonstrate the importance of using high precision treatment of low-energy neutrons for tungsten absorbers, while an overall good agreement between data and simulations for all considered models is observed for steel.Comment: 24 pages including author list, 9 figures, published in JINS

    Performance of the first prototype of the CALICE scintillator strip electromagnetic calorimeter

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    A first prototype of a scintillator strip-based electromagnetic calorimeter was built, consisting of 26 layers of tungsten absorber plates interleaved with planes of 45x10x3 mm3 plastic scintillator strips. Data were collected using a positron test beam at DESY with momenta between 1 and 6 GeV/c. The prototype's performance is presented in terms of the linearity and resolution of the energy measurement. These results represent an important milestone in the development of highly granular calorimeters using scintillator strip technology. This technology is being developed for a future linear collider experiment, aiming at the precise measurement of jet energies using particle flow techniques
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