2,230 research outputs found

    Human Time-Frequency Acuity Beats the Fourier Uncertainty Principle

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    The time-frequency uncertainty principle states that the product of the temporal and frequency extents of a signal cannot be smaller than 1/(4Ď€)1/(4\pi). We study human ability to simultaneously judge the frequency and the timing of a sound. Our subjects often exceeded the uncertainty limit, sometimes by more than tenfold, mostly through remarkable timing acuity. Our results establish a lower bound for the nonlinearity and complexity of the algorithms employed by our brains in parsing transient sounds, rule out simple "linear filter" models of early auditory processing, and highlight timing acuity as a central feature in auditory object processing.Comment: 4 pages, 2 figures; Accepted at PR

    Carbon based substrates for interfacing neurons: Comparing pristine with functionalized carbon nanotubes effects on cultured neuronal networks

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    Pristine (as prepared) carbon nanotube (CNT) based substrates have been widely used to grow and interface neurons in culture. Nerve cells normally differentiate on CNTs and the synaptic networks, newly formed at the interface with this material, usually show an improved robustness in signal transfer. However manipulation of pristine CNTs is often prevented by their low dispersibility and tendency to aggregate in most solvents. This issue can be at least partially solved by adding solubilizing groups to the surface of CNT, which also helps improving their biocompatibility. It becomes therefore of crucial importance to determine whether chemically manipulated CNTs may maintain their performance in improving nerve signaling. Here we study and compare the impact in vitro on neuronal signaling of two classes of chemically modified multiwalled CNTs in reference to pristine CNTs, which are known to be a substrate able to boost neuronal growth and communication. We found that the extent of functionalization and the nature of the functional groups on MWNT sidewalls affect the conductivity and the biological effects of the final derivatives. This information is important for the future design of biointegrated devices

    GADA titer-related risk for organ-specific autoimmunity in LADA subjects subdivided according to gender (NIRAD study 6).

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    CONTEXT: Latent autoimmune diabetes in adults (LADA) includes a heterogeneous population wherein, based on glutamic acid decarboxylase antibody (GADA) titer, different subgroups of subjects can be identified. OBJECTIVE: The aim of the present study was to evaluate GADA titer-related risk for β-cell and other organ-specific autoimmunity in LADA subjects. METHODS: Adult-onset autoimmune diabetes subjects (n=236) and type 2 diabetes (T2DM) subjects (n=450) were characterized for protein tyrosine phosphatase (IA-2IC and IA-2(256-760)), zinc transporter 8 (ZnT8), thyroid peroxidase, (TPO), steroid 21-hydroxylase (21-OH), tissue transglutaminase (tTG), and antiparietal cell (APC) antibodies. RESULTS: High GADA titer compared to low GADA titer showed a significantly higher prevalence of IA-2IC, IA-2(256-760), ZnT8, TPO, and APC antibodies (P≤0.04 for all comparison). 21-OH antibodies were detected in 3.4% of high GADA titer. A significant decreasing trend was observed from high GADA to low GADA and to T2DM subjects for IA-2(256-760), ZnT8, TPO, tTG, and APC antibodies (P for trend≤0.001). TPO was the only antibody showing a different prevalence between gender; low GADA titer and T2DM female patients had a higher frequency of TPO antibody compared to males (P=0.0004 and P=0.0006, respectively), where the presence of high GADA titer conferred an odds ratio of 8.6 for TPO compared to low GADA titer. After subdividing high and low GADA titer subjects according to the number of antibodies, we observed that 73.3% of high GADA titer subjects were positive for at least one or more antibodies, compared to 38.3% of low GADA titer (P<0.0001). CONCLUSIONS: In LADA subjects, high GADA titer was associated with a profile of more severe autoimmunity and, in male gender, specifically predisposed to thyroid autoimmunity. A regular screening for other antibodies is recommended in LADA patients according to GADA titer and gender

    Low-frequency internal friction in silica glass

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    Precise low-frequency internal friction measurements on vitreous silica, taken over a wide temperature (4 K160 K the loss angle develops a distinct step-like structure followed by a plateau, both independent of ν, thus signalling the onset of a competing relaxation mechanism with much higher an activation energy.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/58117/2/epl_80_5_50008.pd

    A First Comparison Between LIGO and Virgo Inspiral Search Pipelines

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    This article reports on a project that is the first step the LIGO Scientific Collaboration and the Virgo Collaboration have taken to prepare for the mutual search for inspiral signals. The project involved comparing the analysis pipelines of the two collaborations on data sets prepared by both sides, containing simulated noise and injected events. The ability of the pipelines to detect the injected events was checked, and a first comparison of how the parameters of the events were recovered has been completed.Comment: GWDAW-9 proceeding

    A first comparison of search methods for gravitational wave bursts using LIGO and Virgo simulated data

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    We present a comparative study of 6 search methods for gravitational wave bursts using simulated LIGO and Virgo noise data. The data's spectra were chosen to follow the design sensitivity of the two 4km LIGO interferometers and the 3km Virgo interferometer. The searches were applied on replicas of the data sets to which 8 different signals were injected. Three figures of merit were employed in this analysis: (a) Receiver Operator Characteristic curves, (b) necessary signal to noise ratios for the searches to achieve 50 percent and 90 percent efficiencies, and (c) variance and bias for the estimation of the arrival time of a gravitational wave burst.Comment: GWDAW9 proceeding

    Paraoxonase-1 (PON-1) Arylesterase Activity Levels in Patients with Coronary Artery Disease: A Meta-Analysis

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    Aim: To review and compare the PON-1 arylesterase activity between coronary artery disease (CAD) and non-CAD patients. Methods: Data were obtained by searching MEDLINE and Scopus for all investigations published between January 1, 2000 and March 1, 2021 comparing PON-1 arylesterase activity between CAD and controls. Results: Twenty studies, based on 5417 patients, met the inclusion criteria and were included in the analysis. A random effect model revealed that PON-1 arylesterase activity was significantly lower in the CAD group compared to controls (SMD = -0.587, 95%CI = -0.776 to -0.339, p &lt; 0.0001, I2 = 92.3%). In CAD patients, the PON-1 arylesterase activity was significantly higher among CAD patients without diabetes mellitus (DM) compared to those with diabetes (SMD: 0.235, 95% CI: 0.014 to 0.456, p = 0.03, I2 = 0%). Conclusions: PON-1 activity is significantly lower in CAD patients, and those without DM presented a significantly higher PON-1 arylesterase activity

    Confusion background from compact binaries

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    URL to conference site: http://www.amaldi8.org/index.htmlDouble neutron stars are one of the most promizing sources for terrestrial gravitational wave interferometers. For actual interferometers and their planned upgrades, the probability of having a signal present in the data is small, but as the sensitivity improves, the detection rate increases and the waveforms may start to overlap, creating a confusion background, ultimately limiting the capabilities of future detectors. The third generation Einstein Telescope, with an horizon of z > 1 and very low frequency "seismic wall" may be affected by such confusion noise. At a minimum, careful data analysis will be require to separate signals which will appear confused. This result should be borne in mind when designing highly advanced future instruments
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