55 research outputs found

    Towards Reliability and Performance-Aware Wireless Network-on-Chip Design

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    Recently, an improved surface wave-enabled communication fabric has been proposed to solve the reliability issues of emerging hybrid wired-wireless Network-on-Chip (WiNoC) architectures. Thus, providing a promising solution to the performance and scalability demands of the fast-paced technological growth towards exascale and Big-Data processing on future System-on-Chip (SoC) design. However, WiNoCs tradeoff optimized performance for cost by restricting the number of area and power hungry wireless nodes. Consequently, in this paper, we propose a low-latency adaptive router with a low-complexity single-cycle bypassing mechanism to alleviate the performance degradation due to the slow wired routers in such emerging hyhbrid NoCs. The proposed router is able to redistribute traffic in the network to alleviate average packet latency at both low and high traffic conditions. As a second contribution the paper presents an experimental evaluation of a practically implemented surface wave communication fabric. By reducing the latency between the wired nodes and wireless nodes the proposed router can improve performance efficiency in terms of average packet delay by an average of 50% in WiNoC

    Multi-modal MRI investigation of volumetric and microstructural changes in the hippocampus and its subfields in mild cognitive impairment, Alzheimer's disease, and dementia with Lewy bodies

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    BACKGROUND\textbf{BACKGROUND}: Volumetric atrophy and microstructural alterations in diffusion tensor imaging (DTI) measures of the hippocampus have been reported in people with Alzheimer's disease (AD) and mild cognitive impairment (MCI). However, no study to date has jointly investigated concomitant microstructural and volumetric changes of the hippocampus in dementia with Lewy bodies (DLB). METHODS\textbf{METHODS}: A total of 84 subjects (23 MCI, 17 DLB, 14 AD, and 30 healthy controls) were recruited for a multi-modal imaging (3T MRI and DTI) study that included neuropsychological evaluation. Freesurfer was used to segment the total hippocampus and delineate its subfields. The hippocampal segmentations were co-registered to the mean diffusivity (MD) and fractional anisotropy (FA) maps obtained from the DTI images. RESULTS\textbf{RESULTS}: Both AD and MCI groups showed significantly smaller hippocampal volumes compared to DLB and controls, predominantly in the CA1 and subiculum subfields. Compared to controls, hippocampal MD was elevated in AD, but not in MCI. DLB was characterized by both volumetric and microstructural preservation of the hippocampus. In MCI, higher hippocampal MD was associated with greater atrophy of the hippocampus and CA1 region. Hippocampal volume was a stronger predictor of memory scores compared to MD within the MCI group. CONCLUSIONS\textbf{CONCLUSIONS}: Through a multi-modal integration, we report novel evidence that the hippocampus in DLB is characterized by both macrostructural and microstructural preservation. Contrary to recent suggestions, our findings do not support the view that DTI measurements of the hippocampus are superior to volumetric changes in characterizing group differences, particularly between MCI and controls.This study is funded by the UK National Institute of Health Research Cambridge Biomedical Research Centre and Biomedical Research Unit in Dementia. JBR is supported by the Wellcome Trust (103838). JPC is supported by the UK National Institute of Health Research Biomedical Research Centre at Cambridge. PVR is supported by the PSP Association. EM is in receipt of a Gates Cambridge scholarship and an Alzheimer's Research UK Research Grant

    Planck 2015 results I. Overview of products and scientific results

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    The European Space Agency's Planck satellite, which is dedicated to studying the early Universe and its subsequent evolution, was launched on 14 May 2009. It scanned the microwave and submillimetre sky continuously between 12 August 2009 and 23 October 2013. In February 2015, ESA and the Planck Collaboration released the second set of cosmology products based on data from the entire Planck mission, including both temperature and polarization, along with a set of scientific and technical papers and a web-based explanatory supplement. This paper gives an overview of the main characteristics of the data and the data products in the release, as well as the associated cosmological and astrophysical science results and papers. The data products include maps of the cosmic microwave background (CMB), the thermal Sunyaev-Zeldovich effect, diffuse foregrounds in temperature and polarization, catalogues of compact Galactic and extragalactic sources (including separate catalogues of Sunyaev-Zeldovich clusters and Galactic cold clumps), and extensive simulations of signals and noise used in assessing uncertainties and the performance of the analysis methods. The likelihood code used to assess cosmological models against the Planck data is described, along with a CMB lensing likelihood. Scientific results include cosmological parameters derived from CMB power spectra, gravitational lensing, and cluster counts, as well as constraints on inflation, non-Gaussianity, primordial magnetic fields, dark energy, and modified gravity, and new results on low-frequency Galactic foregrounds

    A brief cognitive-behavioral stress management program for secondary school teachers

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    Objective: This study aimed to assess the efficacy of a brief cognitivebehavioral program that was designed to reduce the work-related stress levels of secondary school teachers. Methods: A quasi-experimental design was used to compare the intervention groups with the wait-list control groups. Seventy teachers from the intervention groups and 54 from the control groups completed a set of validated scales at the baseline and 3-4 wk later. The scales included the Depression Anxiety Stress Scale, the Dysfunctional Attitude Scale-Form A, the Health-Promoting Lifestyle Profile II, and the Occupational Stress Inventory Revised Edition. Results: After controlling for the baseline measures, the intervention groups had significantly lower role stress, personal strain and overall work-related stress 3-4 wk after the baseline measurements. The intervention groups also had significantly higher stress management behaviors, and less general stress and dysfunctional thoughts than the control groups (all p≤0.05). The levels of dysfunctional thoughts and stress management behaviors significantly predicted general stress after intervention and personal resource deficits. The level of dysfunctional thoughts also predicted the personal strain of work-related stresses (all p<0.05). Conclusions: The brief program reported in this study was efficacious in reducing the work-related stress of secondary teachers. Teachers experienced less work-related stress after the program, and they reported reduced dysfunctional thoughts and enhanced stress management behaviors. This program may be considered as an initial strategy for teachers to develop skills to cope with their work-related stress in the short term and could be incorporated with other strategies to achieve longer-term effects.link_to_OA_fulltex
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