3,189 research outputs found
The continuum of personalized cardiovascular medicine: a position paper of the European Society of Cardiology.
Restricting detergent protease action to surface of protein fibres by chemical modification
Due to their excellent properties, such as
thermostability, activity over a broad range of pH and
efficient stain removal, proteases from Bacillus sp. are
commonly used in the textile industry including industrial
processes and laundry and represent one of the most
important groups of enzymes. However, due to the action
of proteases, severe damage on natural protein fibres such
as silk and wool result after washing with detergents
containing proteases. To include the benefits of proteases in
a wool fibre friendly detergent formulation, the soluble
polymer polyethylene glycol (PEG) was covalently
attached to a protease from Bacillus licheniformis. In
contrast to activation of PEG with cyanuric chloride (50%)
activation with 1,1′-carbonyldiimidazole (CDI) lead to
activity recovery above 90%. With these modified
enzymes, hydrolytic attack on wool fibres could be
successfully prevented up to 95% compared to the native
enzymes. Colour difference (ΔE) measured in the three dimensional colour space showed good stain removal
properties for the modified enzymes. Furthermore, half-life
of the modified enzymes in buffers and commercial
detergents solutions was nearly twice as high as those of
the non-modified enzymes with values of up to 63 min. Out
of the different modified proteases especially the B.
licheniformis protease with the 2.0-kDa polymer attached
both retained stain removal properties and did not
hydrolyse/damage wool fibres
Alpha-band rhythms in visual task performance: phase-locking by rhythmic sensory stimulation
Oscillations are an important aspect of neuronal activity. Interestingly, oscillatory patterns are also observed in behaviour, such as in visual performance measures after the presentation of a brief sensory event in the visual or another modality. These oscillations in visual performance cycle at the typical frequencies of brain rhythms, suggesting that perception may be closely linked to brain oscillations. We here investigated this link for a prominent rhythm of the visual system (the alpha-rhythm, 8-12 Hz) by applying rhythmic visual stimulation at alpha-frequency (10.6 Hz), known to lead to a resonance response in visual areas, and testing its effects on subsequent visual target discrimination. Our data show that rhythmic visual stimulation at 10.6 Hz: 1) has specific behavioral consequences, relative to stimulation at control frequencies (3.9 Hz, 7.1 Hz, 14.2 Hz), and 2) leads to alpha-band oscillations in visual performance measures, that 3) correlate in precise frequency across individuals with resting alpha-rhythms recorded over parieto-occipital areas. The most parsimonious explanation for these three findings is entrainment (phase-locking) of ongoing perceptually relevant alpha-band brain oscillations by rhythmic sensory events. These findings are in line with occipital alpha-oscillations underlying periodicity in visual performance, and suggest that rhythmic stimulation at frequencies of intrinsic brain-rhythms can be used to reveal influences of these rhythms on task performance to study their functional roles
Front-end technologies for robust ASR in reverberant environments—spectral enhancement-based dereverberation and auditory modulation filterbank features
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Output from VIP cells of the mammalian central clock regulates daily physiological rhythms
The suprachiasmatic nucleus (SCN) circadian clock is critical for optimising daily cycles in mammalian physiology and behaviour. The roles of the various SCN cell types in communicating timing information to downstream physiological systems remain incompletely understood, however. In particular, while vasoactive intestinal polypeptide (VIP) signalling is essential for SCN function and whole animal circadian rhythmicity, the specific contributions of VIP cell output to physiological control remains uncertain. Here we reveal a key role for SCN VIP cells in central clock output. Using multielectrode recording and optogenetic manipulations, we show that VIP neurons provide coordinated daily waves of GABAergic input to target cells across the paraventricular hypothalamus and ventral thalamus, supressing their activity during the mid to late day. Using chemogenetic manipulation, we further demonstrate specific roles for this circuitry in the daily control of heart rate and corticosterone secretion, collectively establishing SCN VIP cells as influential regulators of physiological timing
An acoustic data transmission system based on audio data hiding: method and performance evaluation
Implementation and Characterization of Vibrotactile Interfaces
While a standard approach is more or less established for rendering basic vibratory cues in consumer electronics, the implementation of advanced vibrotactile feedback still requires designers and engineers to solve a number of technical issues. Several off-the-shelf vibration actuators are currently available, having different characteristics and limitations that should be considered in the design process. We suggest an iterative approach to design in which vibrotactile interfaces are validated by testing their accuracy in rendering vibratory cues and in measuring input gestures. Several examples of prototype interfaces yielding audio-haptic feedback are described, ranging from open-ended devices to musical interfaces, addressing their design and the characterization of their vibratory output
Metadiffusers : deep-subwavelength sound diffusers
We present deep-subwavelength diffusing surfaces based on acoustic metamaterials, namely metadiffusers. These sound diffusers are rigidly backed slotted panels, with each slit being loaded by an array of Helmholtz resonators. Strong dispersion is produced in the slits and slow sound conditions are induced. Thus, the effective thickness of the panel is lengthened introducing its quarter wavelength resonance in the deep-subwavelength regime. By tuning the geometry of the metamaterial, the reflection coefficient of the panel can be tailored to obtain either a custom reflection phase, moderate or even perfect absorption. Using these concepts, we present ultra-thin diffusers where the geometry of the metadiffuser has been tuned to obtain surfaces with spatially dependent reflection coefficients having uniform magnitude Fourier transforms. Various designs are presented where, quadratic residue, primitive root and ternary sequence diffusers are mimicked by metadiffusers whose thickness are 1/46 to 1/20 times the design wavelength, i.e., between about a twentieth and a tenth of the thickness of traditional designs. Finally, a broadband metadiffuser panel of 3 cm thick was designed using optimization methods for frequencies ranging from 250 Hz to 2 kHz
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