Search results for " locali"
showing 10 items of 539 documents
Source localization of event-related potentials to pitch change mapped onto age-appropriate MRIs at 6 months-of-age
2010
Auditory event-related potentials (ERPs) have been used to understand how the brain processes auditory input, and to track developmental change in sensory systems. Localizing ERP generators can provide invaluable insights into how and where auditory information is processed. However, age-appropriate infant brain templates have not been available to aid such developmental mapping. In this study, auditory change detection responses of brain ERPs were examined in 6-month-old infants using discrete and distributed source localization methods mapped onto age-appropriate magnetic resonance images. Infants received a passive oddball paradigm using fast-rate non-linguistic auditory stimuli (tone do…
Cumulative-Sum-Based Localization of Sound Events in Low-Cost Wireless Acoustic Sensor Networks
2014
Wireless acoustic sensor networks (WASNs) are known for their potential applications in multiple areas, such as audio-based surveillance, binaural hearing aids or advanced acoustic monitoring. The knowledge of the spatial position of a source of interest is usually a requirement for many of these applications. Therefore, source localization is an important problem to be addressed in WASNs. Unfortunately, most localization algorithms need costly signal processing stages that prevent them from being implemented in low-cost sensor networks, requiring additional modules for signal acquisition and processing. This paper presents a low-complexity method for acoustic event detection and localizati…
Effect of Rotating Auditory Scene on Postural Control in Normal Subjects, Patients With Bilateral Vestibulopathy, Unilateral, or Bilateral Cochlear I…
2018
International audience; Objective: The aim of this study was to investigate the impact of a rotating sound stimulation on the postural performances in normal subjects, patients with bilateral vestibulopathy (BVP), unilateral (UCI), and bilateral (BCD cochlear implantees.Materials and Methods: Sixty-nine adults were included (32 women and 37 men) in a multicenter prospective study. The group included 37 healthy subjects, 10 BVP, 15 UCI, and 7 BCI patients. The average of age was 47 +/- 2.0 (range: 23-82). In addition to a complete audiovestibular work up, a dynamic posturography (Multitest Framiral, Grasse) was conducted in silence and with a rotating cocktail party sound delivered by headph…
Microphones’ Directivity for the Localization of Sound Sources
2011
In a recent paper [P. Rizzo, G. Bordoni, A. Marzani, and J. Vipperman, "Localization of Sound Sources by Means of Unidirectional Microphones, Meas. Sci. Tech., 20, 055202 (12pp), 2009] the proof-of-concept of an approach for the localization of acoustic sources was presented. The method relies on the use of unidirectional microphones and amplitude-based signals' features to extract information about the direction of the incoming sound. By intersecting the directions identified by a pair of microphones, the position of the emitting source can be identified. In this paper we expand the work presented previously by assessing the effectiveness of the approach for the localization of an acoustic…
Occurrence of a sibling species complex within neotropical lymnaeids, snail intermediate hosts of fascioliasis.
2002
The delimitation of cryptic species within the genus Lymnaea, which are the main vectors of fascioliasis, remains a topic of controversy. An analysis of genetic variability based on 12 enzyme loci revealed different fixed alleles at 9 loci between two sympatric samples of Lymnaea viatrix at the type locality in Lima, Peru. The absence of heterozygotes within this locality indicates the presence of isolated populations or cryptic species within L. viatrix. Significant genetic differences were also found between these two L. viatrix samples from Lima and other populations of L. viatrix in South America and in addition to species such as L. truncatula, L. cubensis and L. columella. Moreover, t…
Following the Phoenician example: western Mediterranean colonization by <em>Spirobranchus</em> cf. <em>tetraceros</em> (Annel…
2020
A newly established population of the fouling polychaete Spirobranchus cf. tetraceros is reported from the western Mediterranean (Valencia Port). Despite previous intensive surveys, this is the first record for the taxon in the Iberian Peninsula. Molecular analyses revealed that S. cf. tetraceros from Valencia are genetically identical to specimens from Heraklion, Crete, but different from those collected in the Red Sea and S. tetraceros sensu stricto from the type locality in Australia. Mediterranean and Red Sea S. cf. tetraceros form a well-supported monophyletic clade but are clearly distinct from New South Wales specimens of S. tetraceros. Our new molecular evidence supports the hypothe…
GFP immunogold staining, from light to electron microscopy, in mammalian cells.
2012
GFP has emerged as an important reporter for monitoring gene expression, protein localization, cell transformation and cell lineage. The development of GFP as a marker in many different biological systems has emphasized the need to image GFP at high resolution. GFP immunogold labeling with colloidal gold particles becomes essential for electron microscopy (EM) ultrastructural detection. Because of the small size, colloidal gold particles require silver enhancement, a procedure to increase the size of the particle as well as gold toning to stabilize the silver layer. GFP preembedding immunogold staining enables high quality cellular-ultrastructural EM analysis mainly for two reasons, on one …
Random walk approach to the analytic solution of random systems with multiplicative noise—The Anderson localization problem
2006
We discuss here in detail a new analytical random walk approach to calculating the phase-diagram for spatially extended systems with multiplicative noise. We use the Anderson localization problem as an example. The transition from delocalized to localized states is treated as a generalized diffusion with a noise-induced first-order phase transition. The generalized diffusion manifests itself in the divergence of averages of wavefunctions (correlators). This divergence is controlled by the Lyapunov exponent $\gamma$, which is the inverse of the localization length, $\xi=1/\gamma$. The appearance of the generalized diffusion arises due to the instability of a fundamental mode corresponding to…
Anderson localization problem: An exact solution for 2-D anisotropic systems
2007
Our previous results [J.Phys.: Condens. Matter 14 (2002) 13777] dealing with the analytical solution of the two-dimensional (2-D) Anderson localization problem due to disorder is generalized for anisotropic systems (two different hopping matrix elements in transverse directions). We discuss the mathematical nature of the metal-insulator phase transition which occurs in the 2-D case, in contrast to the 1-D case, where such a phase transition does not occur. In anisotropic systems two localization lengths arise instead of one length only.
Electron correlation in metal clusters, quantum dots and quantum rings
2009
This short review presents a few case studies of finite electron systems for which strong correlations play a dominant role. In simple metal clusters, the valence electrons determine stability and shape of the clusters. The ionic skeleton of alkali metals is soft, and cluster geometries are often solely determined by electron correlations. In quantum dots and rings, the electrons may be confined by an external electrostatic potential, formed by a gated heterostructure. In the low density limit, the electrons may form so-called Wigner molecules, for which the many-body quantum spectra reveal the classical vibration modes. High rotational states increase the tendency for the electrons to loca…