1,355,705 research outputs found
Guillain-Barré syndrome: What have we learnt during one century? A personal historical perspective
No full textWe are approaching the centenary of the first description of Guillain-Barré syndrome. The past 30 years had witnessed an amazing progress in the understanding of the immunological and pathological mechanisms of this disorder. We now recognize that Guillain-Barré syndrome is remarkably heterogeneous and under this umbrella term are several variants and subtypes with distinct clinical, electrophysiological and immunopathological features. This review is a historical journey, through a personal perspective, following the milestones that led to the current substantial knowledge of Guillain-Barré syndrom
Figure 11. Mesochaetopterus xerecus. A, Dorsalmost uncini from neuropodia B1. B, Ventralmost uncini from neuropodia B1. C, Uncini from notopodia B2. D, Uncini from neuropodia B2. E, Uncini from notopodia B3. F, Uncini from neuropodia B3. G in Description of a new species of Mesochaetopterus (Annelida, Polychaeta, Chaetopteridae), with redescription of Mesochaetopterus xerecus and an approach to the phylogeny of the family
No full textFigure 11. Mesochaetopterus xerecus. A, Dorsalmost uncini from neuropodia B1. B, Ventralmost uncini from neuropodia B1. C, Uncini from notopodia B2. D, Uncini from neuropodia B2. E, Uncini from notopodia B3. F, Uncini from neuropodia B3. G, Uncini from the anterior region of notopodia C2. H, Uncini from the posterior region of notopodia C2. I, Uncini from the anterior region of neuropodia C2. J, Uncini from the posterior region of neuropodia C2. K, Uncini from notopodia C30. L, Uncini from neuropodia C30. Scale bars are in Mm.Published as part of Martin, Daniel, Gil, João, Carreras-Carbonell, Josep & Bhaud, Michel, 2008, Description of a new species of Mesochaetopterus (Annelida, Polychaeta, Chaetopteridae), with redescription of Mesochaetopterus xerecus and an approach to the phylogeny of the family, pp. 201-225 in Zoological Journal of the Linnean Society 152 (2) on page 218, DOI: 10.1111/j.1096-3642.2007.00342.x, http://zenodo.org/record/468762
Fisher syndrome with tetraparesis and antibody to GQ1b: Evidence for motor nerve terminal block
No full textA Fisher syndrome (FS) patient with antibody to tetrasyaloganglioside GQ1b (GQ1b) developed late limb weakness. Serial motor conduction velocities (MCVs) showed a marked reduction of distal compound muscle action potential (CMAP) amplitudes, worse at 2-3 weeks, followed by a dramatic increase in week 5. Motor conduction velocities were always in the normal range, distal motor latencies changed only slightly, and conduction block in intermediate nerve segments was absent. These electrophysiological data might suggest an axonal neuropathy or a distal demyelinating conduction block. However, the dramatic increase of distal CMAP amplitudes over a short time without significant changes of distal motor latencies, CMAP duration, and morphology indicate that weakness in this FS patient might be due to a block of acetylcholine release from motor terminals, possibly mediated by anti-GQ1b antibodies
Neuropatie disimmuni: La terapia
No full textDisamina delle diverse caratteristiche delle neuropatie disimmuni e delle associazioni con specifici autoanticorp
Adaptive room acoustic response simulation: a virtual 3D application
No full textIn this paper we propose a method to simulate a 3D acoustical environment in which sound sources are positioned in well defined sides. Our method is real-time applications oriented, due to the low computational cost of the implemented operations. The spatial position that the human brain assigns to a sound is influenced mainly by the differences between the sound signals that reach the listener's ears, related to the sound source angulation with respect to the listener's head. The reverberation effect, on the other side, depends on the type of environment. All this elements have to be simulated in order to give the illusion that a sound comes from a particular position in a particular environment. To obtain this result, we perform a suitable sound processing, that can be separated in two main tasks: reverberation and spatialization. The first one is mainly related to the environment itself: it depends on the shape of the environment and on the absorption coefficients of the walls. This is the most computational intensive component, if we want to reproduce it accurately, so we approximate it by an adaptive IIR filter. By the spatialization, the listener hears the sound as coming from a particular direction. This task, carried out by using the head related transfer functions (HRTFs), has to be applied to every sound source differently
Real-time room acoustic response simulation by IIR adaptive filter
No full textA new IIR adaptive filter for real-time, room acoustic response simulation is proposed, the structure of which derives from Jot's model of an artificial reverberator. The simultaneous perturbation stochastic approximation (SPSA) algorithm is used to set parameter values. Results show good similarity between the desired and artificial response
Subbands Neural Networks Prediction for On-line Audio Signal Recovery
No full textIn this paper, a subbands multirate architecture is presented for audio signal recovery. Audio signal recovery is a common problem in digital music signal restoration field, because of corrupted samples that must be replaced. The subband approach allows for the reconstruction of a long audio data sequence from forward-backward predicted samples. In order to improve prediction performances, neural networks with spline flexible activation function are used as narrow subband nonlinear forward-backward predictors. Previous neural-networks approaches involved a long training process. Due to the small networks needed for each subband and to the spline adaptive activation functions that speed-up the convergence time and improve the generalization performances, the proposed signal recovery scheme works in online (or in continuous learning) mode as a simple nonlinear adaptive filter. Experimental results show the mean square reconstruction error and maximum error obtained with increasing gap length, from 200 to 5000 samples for different musical genres. A subjective performances analysis is also reported. The method gives good results for the reconstruction of over 100 ms of audio signal with low audible effects in overall quality and outperforms the previous approaches
SUBBANDS AUDIO SIGNAL RECOVERING USING NEURAL NONLINEAR PREDICTION
No full textAudio signal recovery is a common problem in the digital audio restoration field, because of corrupted samples that must be replaced. In this paper a subband architecture is presented for audio signal recovery, using neural nonlinear prediction based on adaptive spline neural networks. The experimental results show the mean square reconstruction error, and maximum error obtained with increasing gap length, from 200 to 5000 samples. The method gives good results allowing the reconstruction of over 100 ms of signal with low audible effects in overall quality
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