952 resultados para single channel algorithm
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This paper presents a novel moving target indicator which is selective with respect to a direction of interest. Preliminary results indicate that the obtained selectivity may have high interest in civil traffic monitoring using single channel SAR data.
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Non-resonant light interacting with diatomics via the polarizability anisotropy couples different rotational states and may lead to strong hybridization of the motion. The modification of shape resonances and low-energy scattering states due to this interaction can be fully captured by an asymptotic model, based on the long-range properties of the scattering (Crubellier et al 2015 New J. Phys. 17 045020). Remarkably, the properties of the field-dressed shape resonances in this asymptotic multi-channel description are found to be approximately linear in the field intensity up to fairly large intensity. This suggests a perturbative single-channel approach to be sufficient to study the control of such resonances by the non-resonant field. The multi-channel results furthermore indicate the dependence on field intensity to present, at least approximately, universal characteristics. Here we combine the nodal line technique to solve the asymptotic Schrödinger equation with perturbation theory. Comparing our single channel results to those obtained with the full interaction potential, we find nodal lines depending only on the field-free scattering length of the diatom to yield an approximate but universal description of the field-dressed molecule, confirming universal behavior.
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This paper reviews a study to compare two commercially available single-channel tactile aids for the deaf.
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This paper presents observations on the effects of a single-channel cochlear implant on a seven year-old hearing impaired child.
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This paper examines the results of testing five severely hearing impaired children using a special binaural system with s single amplification channel and two attenuators, allowing presentation of the stimulus materials monaurally or at different relative levels to the two ears.
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BACKGROUND: Increased activity of single ventricular L-type Ca(2+)-channels (L-VDCC) is a hallmark in human heart failure. Recent findings suggest differential modulation by several auxiliary beta-subunits as a possible explanation. METHODS AND RESULTS: By molecular and functional analyses of human and murine ventricles, we find that enhanced L-VDCC activity is accompanied by altered expression pattern of auxiliary L-VDCC beta-subunit gene products. In HEK293-cells we show differential modulation of single L-VDCC activity by coexpression of several human cardiac beta-subunits: Unlike beta(1) or beta(3) isoforms, beta(2a) and beta(2b) induce a high-activity channel behavior typical of failing myocytes. In accordance, beta(2)-subunit mRNA and protein are up-regulated in failing human myocardium. In a model of heart failure we find that mice overexpressing the human cardiac Ca(V)1.2 also reveal increased single-channel activity and sarcolemmal beta(2) expression when entering into the maladaptive stage of heart failure. Interestingly, these animals, when still young and non-failing ("Adaptive Phase"), reveal the opposite phenotype, viz: reduced single-channel activity accompanied by lowered beta(2) expression. Additional evidence for the cause-effect relationship between beta(2)-subunit expression and single L-VDCC activity is provided by newly engineered, double-transgenic mice bearing both constitutive Ca(V)1.2 and inducible beta(2) cardiac overexpression. Here in non-failing hearts induction of beta(2)-subunit overexpression mimicked the increase of single L-VDCC activity observed in murine and human chronic heart failure. CONCLUSIONS: Our study presents evidence of the pathobiochemical relevance of beta(2)-subunits for the electrophysiological phenotype of cardiac L-VDCC and thus provides an explanation for the single L-VDCC gating observed in human and murine heart failure.
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Human embryonic kidney cells 293 (HEK293) are widely used as cellular heterologous expression systems to study transfected ion channels. This work characterizes the endogenous expression of TRPM4 channels in HEK293 cells. TRPM4 is an intracellular Ca(2+)-activated non-selective cationic channel expressed in many cell types. Western blot analyses have revealed the endogenous expression of TRPM4. Single channel 22pS conductance with a linear current-voltage relationship was observed using the inside-out patch clamp configuration in the presence of intracellular Ca(2+). The channels were permeable to the monovalent cations Na(+) and K(+), but not to Ca(2+). The open probability was voltage-dependent, being higher at positive potentials. Using the whole-cell patch clamp "ruptured patch" configuration, the amplitude of the intracellular Ca(2+)-activated macroscopic current was dependent on time after patch rupture. Initial transient activation followed by a steady-increase reaching a plateau phase was observed. Biophysical analyses of the macroscopic current showed common properties with those from HEK293 cells stably transfected with human TRPM4b, with the exception of current time course and Ca(2+) sensitivity. The endogenous macroscopic current reached the plateau faster and required 61.9±3.5μM Ca(2+) to be half-maximally activated versus 84.2±1.5μM for the transfected current. The pharmacological properties, however, were similar in both conditions. One hundred μM of flufenamic acid and 9-phenanthrol strongly inhibited the endogenous current. Altogether, the data demonstrate the expression of endogenous TRMP4 channels in HEK293 cells. This observation should be taken into account when using this cell line to study TRPM4 or other types of Ca(2+)-activated channels.
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Slow nonselective cation conductances play a central role in determining the excitability of many neurons, but heretofore this channel type has not been analyzed at the single-channel level. Neurotensin (NT) excites cultured dopaminergic neurons from the ventral tegmental area primarily by increasing such a cation conductance. Using the outside–out configuration of the patch clamp, we elicited single-channel activity of this NT-induced cation channel. Channel activity was blocked by the nonpeptide NT antagonist SR48692, indicating that the response was mediated by NT receptors. The channel opened in both solitary form and in bursts. The reversal potential was −4.2 ± 1.7 mV, and the elementary conductance was 31 pS at −67 mV with [Na+]o = 140 mM, [Cs+]o = 5 mM, [Na+]i = 88 mM, and [Cs+]i = 74 mM. Thus, the channel was permeable to both Na+ and Cs+. From these characteristics, it is likely that this channel is responsible for the whole-cell current we studied previously. In guanosine 5′-[γ-thio]triphosphate-loaded cells, NT irreversibly activated about half of the channel activity, suggesting that at least part of the response was mediated by a G protein. Similar channel activity could be induced occasionally in the cell-attached configuration by applying NT outside the patch region.
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"U.S. Atomic Energy Commission Contract AT(29-1)-1106."
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The latency variation of the P100M from minute to minute, between morning and afternoon and from day to day was investigated in an unshielded environment using two single channel magnetometers. Latency variation was greatest from minute to minute with relatively little longer term variation. The two magnetometers differed both in mean latency and in the degree of variation. This may be attributed to variation in the performance of the filters which were set a narrow bandwidth for recording in an unshielded environment.
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Error free propagation of a single polarisation optical time division multiplexed 40 Gbit/s dispersion managed pulsed data stream over dispersion (non-shifted) fibre. This distance is twice the previous record at this data rate.
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Error free propagation of a single polarisation optical time division multiplexed 40Gbit/s dispersion managed pulse data stream over 509km has been achieved in standard (non-dispersion shifted) fibre. Dispersion compensating fibre was used after each amplifier to reduce the high local dispersion of the standard fibre. © IEE 1999.
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Error-free transmission of a single polarization optical time division multiplexed 40 Gbit/s dispersion managed pulse data stream over 1009 km has been achieved in dispersion-compensated standard (non-dispersion shifted) fibre. This distance is twice the previous record at this data rate.