Neighboring Segments Research Articles

Independent Contributions Of Segments IS6 And IIS6 To Activation Gating Of CaV1.2

Voltage dependence and kinetics of activation of CaV1.2 channels are affected by structural changes in pore lining S6 segments of the α1-subunit. Significant effects on channel activation are induced by either proline or threonine substitutions in the lower third of segment IIS6 (‘bundle crossing region’). Here we report that S435P in IS6 results in a large shift of the activation (−26mV) curve and slowed current kinetics. Threonine substitutions in positions Leu429 and Leu434 induced a similar kinetic phenotype with shifted activation curves.Double mutations in segments IS6 and IIS6 induced additive shifts of the activation curves, e.g.: L429T/I781T (-44.0±1.0), L434T/I781T (-50.3±0.8), L429T/L779T (-22.5±0.8) and L434T/L779T (-32.3±0.8). If the gating sensitive residues in the two neighboring segments IS6 and IIS6 do not interact then the change in free energy (ΔGdouble) of the double mutant is equal to the sum of the changes in free energy of the two single mutations (ΔGmut IS6 and ΔGmut IIS6 see scheme, see also Horovitz 1996). Double mutant cycle analysis revealed that the studied IS6 and IIS6 mutations are energetically independent and thus have independent impacts on activation gating.Supported by FWF-Project P19614-B11.View Large Image | View Hi-Res Image | Download PowerPoint Slide

Construction of Disarmed Ti Plasmids Transferable between Escherichia coli and Agrobacterium Species

Agrobacterium-mediated plant transformation has been used widely, but there are plants that are recalcitrant to this type of transformation. This transformation method uses bacterial strains harboring a modified tumor-inducing (Ti) plasmid that lacks the transfer DNA (T-DNA) region (disarmed Ti plasmid). It is desirable to develop strains that can broaden the host range. A large number of Agrobacterium strains have not been tested yet to determine whether they can be used in transformation. In order to improve the disarming method and to obtain strains disarmed and ready for the plant transformation test, we developed a simple scheme to make certain Ti plasmids disarmed and simultaneously maintainable in Escherichia coli and mobilizable between E. coli and Agrobacterium. To establish the scheme in nopaline-type Ti plasmids, a neighboring segment to the left of the left border sequence, a neighboring segment to the right of the right border sequence of pTi-SAKURA, a cassette harboring the pSC101 replication gene between these two segments, the broad-host-range IncP-type oriT, and the gentamicin resistance gene were inserted into a suicide-type sacB-containing vector. Replacement of T-DNA with the cassette in pTiC58 and pTi-SAKURA occurred at a high frequency and with high accuracy when the tool plasmid was used. We confirmed that there was stable maintenance of the modified Ti plasmids in E. coli strain S17-1lambdapir and conjugal transfer from E. coli to Ti-less Agrobacterium strains and that the reconstituted Agrobacterium strains were competent to transfer DNA into plant cells. As the modified plasmid delivery system was simple and efficient, conversion of strains to the disarmed type was easy and should be applicable in studies to screen for useful strains.

フィリピン海プレート沈み込みに伴う西南日本のスロー地震群の発見

New types of slow earthquakes have been revealed associated with the subduction of the Philippine Sea plate in southwest Japan based on the development of the dense seismic observation network. At the transition zone, which lies at the deeper extension of the seismogenic zone, deep low-frequency tremors, deep very-low-frequency earthquakes, and short-term slow slip events occur along the slab strike. The short-term slow slip event is the main phenomenon as a stick-slip on the plate interface and other seismic phenomena might be triggered events reflecting the source size. Considering the area of migration and activity of the deep low-frequency tremors, which indicate a transient slip, we can divide the deep slow earthquake belt into segments, each of which has a regular recurrence interval of 6 or 3 months. In each episode, the tremor activity migrates according to the propagation of the transient slip within the segment. Sometimes the migration reaches to the neighboring segment, and a connecting fault rupture occurs. These migrating phenomena are very similar to the rupture process of mega-thrust earthquakes. On the other hand, shallow very-low-frequency earthquakes have been detected in the accretionary prism near the Nankai trough. These events are considered seismic slow slip events at the reverse fault system reflecting the deformation of the accretionary prism. Watching these slow earthquakes is important for the monitoring of the plate motion.

Unique Structure and Dynamics of Poly(ethylene oxide) in Layered Silicate Nanocomposites: Accelerated Segmental Mobility Revealed by Simulating ESR Spectra of Spin-Labels, XRD, FTIR, and DSC

The structure and dynamics of poly(ethylene oxide) (PEO) intercalated in the galleries of a fluoromica inorganic clay were studied by spin-label electron spin resonance (ESR), XRD, FTIR, and DSC. The polymer was end-labeled by attachment of a nitroxide radical. Basic structural information was determined by XRD, while DSC and FTIR revealed that the crystallization of the PEO was inhibited in the clay galleries. The temperature variation of the ESR spectra from the spin-label was simulated based on the “macroscopic order with microscopic disorder” (MOMD) model. For PEO intercalated in the narrow (0.33 nm) clay galleries, the ESR spectra indicated a very low segmental mobility even at high temperature, 410 K, which was attributed to the strong polymer interaction with the charged mica platelets. In wider (0.83 nm) galleries, however, the parameters used to simulate the ESR spectra of the nitroxide labels reflected a lowering of the PEO segmental density: In this sample, the ESR spectrum consisted of two distinct contributions from slow- and fast-motional components, and the relative intensity of the fast component increased with an increase in temperature. The two spectral components were attributed to segments located close to, and away from, the polar solid walls in the gallery, respectively. Interestingly, the fast-motional component had higher mobility compared to that of PEO chains adsorbed on the fluoromica surface. In addition, the activation energy of the segmental motion in the fast-motional component was lower compared to that of bulk PEO. The low segmental density and reduced cooperative motion with neighboring segments are considered the main factors leading to the fast PEO chain motion with low activation energy.

Chain helicity of a poly(phenylacetylene) with chiral centers between backbone and mesogenic groups on side chains

An optically active poly(phenylacetylene), poly{2-(R)-methyl-2-[4′-(tetradecyloxy)biphenyl-4-yloxy]propyl 4-ethynylbenzoate} (P1) is synthesized in a high yield with a high molecular weight (1.3×106g/mol) by [Rh(nbd)Cl]2 catalyst. The chemical structure of the polymer is characterized by IR and NMR spectroscopies with satisfactory analysis data. The polymer is soluble in many common organic solvents. It shows circular dichroism (CD) band in the absorption region of the polyacetylene backbone, indicating that P1 is chiroptical owing to the formation of helical conformation with an excess screw sense. Combining the results of CD and light scattering experiments, we find that addition of poor solvent can induce the neighboring helical segments within a single polymer strand to become closer, resulting in exciton coupling prior to polymer precipitation. The exciton coupling can be kept in the solid state after solvent evaporation.

Micromagnetic study of domain wall dynamics in bit-patterned nanodots

Domain wall dynamics in magnetic nanodots is critical to the understanding of the magnetization reversal mechanisms in bit-patterned arrays, the issues of writeablility, data rate maximization, and bit stability. In this work, micromagnetic simulations were carried out to investigate the dynamics of domain walls in disk-shaped nanostructures with large built-in perpendicular anisotropy. Due to the strong demagnetizing effect, the domain wall motion falls into the supercritical regime. A 90 degrees phase shift of the wall velocity is developed due to the finite thicknesses. The mean value of the wall velocity increases as the domain wall propagates away from the center. This induced asymmetry causes the frequency of the wall oscillations to be halved. At large diameters, the wall acceleration deceases and the periodicity is lost. The in-plane magnetization configuration shows that multiple spin wave modes are present. The absence of the coherency in the magnetization orientations causes phase canceling. The out-of-phase motion of neighboring segments reduces the wall acceleration.

1D-based defect detection in patterned TFT-LCD panels using characteristic fractal dimension and correlations

Thin film transistor-liquid crystal display (TFT-LCD) is a major technology for flat panel display used in a wide range of electronic devices. As the TFT-LCD panel becomes dense, small defects can only be observed at an extremely high resolution. For fast imaging of a large-sized TFT-LCD panel at a high resolution, a one-dimensional (1D) line scan system is demanded. A TFT-LCD panel image at a fine resolution presents very complicated repetitive patterns, which increases the difficulty of the defect detection task. In this paper, we propose a 1D self-comparison defect detection scheme that directly works on the 1D line images of a TFT-LCD panel. The proposed method first uses the fractal transformation to enhance the periodicity and regularity of a 1D gray-level line image, and then divides the resulting fractal signal into small segments, each of the length of the repeated period. By calculating each divided segment’s normalized cross correlation with its neighboring segments and comparing the resulting correlation value with a predetermined threshold, the segments containing a defect can be effectively identified. Since the proposed method does not require a reference template, it is invariant to changes in illumination and image translation. Experimental results on a number of microdefects in patterned TFT-LCD panel surfaces show that the proposed method can well detect various ill-defined defects and is computationally very efficient.

SIMULATING SEDIMENT TRANSPORT ON RIVER NETWORKS

The simulation of the variation of the erosion or sedimentation and the sediment-carrying capability of the water on the river segments, as it changes from the lower-water season to the higher-water season, is performed by a dynamical model of the sediment transport on a river network. The model is constructed by considering that the sediment-carrying capability of the water in one segment is modulated by the undergone state of it and that of its neighbor segments. The calculated results can simulate the relative variations occuring in the natural river when the water seasons alternate.

Global Circumferential Strain by 2-Dimensional Speckle Tracking Method for the Evaluation of the Left Ventricular Function

Background and Objectives: The speckle tracking method using 2-dimensional (2D) echocardiography is not affected by the tethering of neighboring segments and angulation. Global circumferential strain (GCS) of the left ventricle (LV) has been suggested as a systolic index and correlated with LV contractility. The purpose of this study was to investigate whether acute changes in preload affect global circumferential strain and to evaluate the usefulness of GCS by the speckle tracking method. Subjects and Methods: 2D echocardiography was performed in 69 patients with end-stage renal disease before and after hemodialysis to measure the LV end-diastolic volume and LV ejection fraction. 2D images were acquired from the short-axis view of the mid-LV for the evaluation of GCS. Results: Mean LV end-diastolic volume significantly decreased from 91.2±33.3 mL to 72.3±32.0 mL (p< 0.05), and LV ejection fraction decreased from 63.6±13.1% to 60.0±11.2% (p=0.006) after hemodialysis. However, mean GCS showed no significant change after hemodialysis (17.2±5.3% vs. 16.6±4.7%, p=0.13). GCS was found to be well correlated with LV ejection fraction (r=0.54, p<0.05) and peak systolic mitral annular velocity (r=0.46, p=0.000), but not with LV preload (r=0.06, p=0.622). Conclusion: GCS using the speckle tracking method is a useful index for the evaluation of LV systolic function because it is not affected by acute preload change and is correlated with LV ejection fraction and peak systolic mitral annular velocity. (Korean Circ J 2008;38:379-386)

Mechanisms of Postsystolic Thickening in Ischemic Myocardium: Mathematical Modelling and Comparison With Experimental Ischemic Substrates

In the setting of regional ischemia, the “at-risk” myocardium exhibits a flow-related reduction in systolic thickening with a concomitant development of abnormal thickening after aortic valve closure (postsystolic thickening [PST]). With the introduction of high time–resolution ultrasonic-based strain/strain-rate imaging, this short lived phenomenon can be measured accurately in the clinical setting. The mechanisms underlying this ischemia-related PST are poorly understood and both active and passive etiologies have been proposed. This study aims at elucidating the potential mechanisms behind PST in the intact heart. A theoretical model, describing active force development, elasticity and segment interaction has been developed to simulate radial deformation during systole and iso-volumetric relaxation. Simulation results have been compared with experimental deformation curves obtained from postero-basal segments of a pig model undergoing varying controlled ischemic challenges. Three forms of regional ischemia could be simulated by varying the model parameters of the ischemic segments: (i) chronic regional hypo-perfusion (reduced and prolonged active force development; preserved elasticity); (ii) acute short-lived ischemia—temporary vessel occlusion (no active force development; preserved elasticity); and (iii) chronic myocardial infarction (no active force development; decreased elasticity). For all ischemic substrates, the simulated curves closely correlate to the deformation measured in the corresponding porcine models without the need for active force development during the occurrence of PST. This suggests that segment interaction is the key determinant in the development of PST. Thus, in all instances, at the time of its manifestation, ischemia-related PST could be explained in a unified way as a passive phenomenon that was the result of elastic segment interaction. Its occurrence originates from the end-systolic inhomogeneous state where neighboring segments have a different wall thickness. The occurrence of these differences at end-systole depends on the presence of regional differences within the ventricle in the magnitude and duration of the developed contraction force during the first part of systole, the elasticity of the ischemic segment and the left-ventricular pressure. (E-mail: Piet.Claus@med.kuleuven.be)

ADATOM INCORPORATION AND STEP CROSSING AT THE EDGES OF 2D NANOISLANDS

Adatom incorporation into the "faceted" steps bordering the 2D nanoislands is analyzed. The step permeability and incorporation coefficients are derived for some typical growth situations. It is shown that the step consisting of equivalent straight segments can be permeable even in the case of fast edge migration if there exist factors delaying creation of new kinks. The step consisting of alternating rough and straight segments may be permeable if there is no adatom transport between neighboring segments through the corner diffusion.

Minimum cost scheduling of stored video in dynamic bandwidth allocation networks

In this paper, a minimum cost scheduling algorithm is proposed for high-quality video streaming in dynamic bandwidth allocation networks. It targets the problem of service cost minimization in optimal smoothing algorithms. Based on the bandwidth usage and the number of bandwidth renegotiations, service cost functions are defined for each transmission segment and a group of segments. The relative cost flags are also defined for each segment, which indicate the direction in which the segment is merged with less service cost. By inspecting the relative cost flags on the boundaries of segments, it is determined whether neighboring segments should be merged, until there is no reduction in the overall service cost. From the simulation results, the proposed algorithm is shown to merge neighboring segments in the direction minimizing the service cost. Compared with the optimal smoothing algorithm, the overall service cost is greatly reduced with a similar level of network resource usage and less transmission rate variability, especially for larger renegotiation cost parameters.

A synthetic seismicity model for the Xianshuihe fault, southwestern China: simulation using a rate- and state-dependent friction law

SUMMARY We performed a numerical simulation of seismic activity along the Xianshuihe fault, a highly active strike-slip fault approximately 350 km long, located along the eastern margin area of the Tibetan plateau, southwestern China. Historical earthquake data over the last 300 yr indicate repeated periods of seismic activity, and migration of large earthquakes along the fault during active seismic periods. To understand the characteristics of historical seismicity and to obtain insight into seismic potential, we performed a numerical simulation of slip behaviour along the fault using a 2-D elastic plate model. The friction on the model fault obeys a laboratory-derived rate- and state-dependent friction law, while the long-term slip rates along the fault are assumed to be consistent with geologically and geodetically estimated slip rates. To simulate segmented rupture behaviour we introduced non-uniformity into friction parameters along the fault. The simulation results indicate that seismic rupture is arrested in regions with frictional properties that are highly velocity-strengthening or large values of characteristic slip distance over which frictional stress evolves. In the regions where seismic rupture is arrested, post-seismic sliding occurs, causing time-dependent stress transfer along the fault. Post-seismic slip histories in highly velocity-strengthening regions are well approximated by logarithmic time functions, while those in regions with large characteristic slip distances increase more rapidly in the initial stages of post-seismic sliding. This difference in post-seismic sliding produces the difference in time-dependent stress transfer and, in consequence, the statistical characteristics of earthquake recurrence. Fault interactions near a fault branch point produce complexity in the simulated earthquake sequence. Simulated rupture commonly triggers additional rupture in a neighbouring segment with a time delay of several years. The simulated seismic activity shows good agreement with observational data with respect to the following statistical features: (1) successive seismically active periods are separated by periods of relative quiescence of 100‐ 200 yr duration (2) and the duration of active period is a few tens of years. Strictly speaking, neither the time- nor slip-predictable models are able to describe the simulated local slip history for each fault segment. The ratio of the standard deviation to the average value of the recurrence intervals of simulated earthquakes ranges from 0.05 to 0.22, depending on the fault segment. The cumulative distribution function of the recurrence intervals of simulated earthquakes at each segment approximately obeys a Brownian passage time distribution or a lognormal distribution, which is commonly used in the statistical evaluation of earthquake occurrence.

Follow-up study on the motion range after treatment of degenerative disc disease with the Bryan cervical disc prosthesis

This study examined effect of a new intervertebral cervical disc prosthesis in relieving the neurological symptoms and signs, improving the patients' ability to perform daily activities, reducing pain, and maintaining the stability and segmental motion. From December 2003 to October 2004, 12 patients, who had received 14 replacements of cervical artificial discs, were followed-up for 2 to 8 months (with a mean of 5.2 months). Of them 5 had cervical spondylotic myelopathy and 7 had cervical disc herniation. The patients included 7 males and 5 females, with their age ranging from 35 to 62 y and a mean of 50.3 y. Single-level replacements were performed in 10 cases and 2 cases received two-level replacement. Operation time of the single-level surgery averaged 130+/-50 min and the time of two-level surgery was 165+/-53 min on average (from skin incision to skin suturing). Neurological or vascular complications during or after surgery was not observed. Japanese Orthopedic Association scores (JOA scores) increased from 8.6 to 15.8 on average. There was no prothesis subsidence or excursion. Replaced segments were stable and the range of motion was partially restored, being 4.68 degrees (3.6 degrees -6.1 degrees ) in flexion and extension position and 3.51 degrees (2.5 degrees -4.6 degrees ), 3.42 degrees (2.6 degrees -4.3 degrees ) in left and right bending position. No obvious loss of physiological curvature was noted. CT or MRI follow-up showed that excursion was less than 1.5 mm) in 2 of 14 levels and between 1.5 mm and 3 mm) in 1 of 14 levels. No ossification in the replaced levels was observed. It is concluded that satisfactory short-term results were achieved in the 12 cases of artificial disc replacements. Different from anterior cervical discectomy and fusion, the replacement could achieve quick functional recovery and did not lead to the movement limitation of cervical vertebrae. At least a 5-years follow-up was needed to assess the long-term effect of the prosthesis on its neighboring segments.

Diffusion model of internal friction in nanocrystalline materials

The stress normal and tangenital components arise in grain-boundary segments differently oriented with respect to an external periodic load, causing the fluxes of vacancies and impurity atoms between neighboring segments. By solving the diffusion problem, one can find the velocity of mutual displacement of grains, the stress distribution in the segments with allowance for stress adjustment, and the amount of internal friction. The frequency dependence of the internal friction shows peaks associated with the redistribution of impurity atoms over the segments, grain sliding, and a high-temperature background.

Freeway traffic estimation within particle filtering framework

This paper formulates the problem of real-time estimation of traffic state in freeway networks by means of the particle filtering framework. A particle filter (PF) is developed based on a recently proposed speed-extended cell-transmission model of freeway traffic. The freeway is considered as a network of components representing different freeway stretches called segments. The evolution of the traffic in a segment is modelled as a dynamic stochastic system, influenced by states of neighbour segments. Measurements are received only at boundaries between some segments and averaged within possibly irregular time intervals. This limits the measurement update in the PF to only these time instants when a new measurement arrives, while in between measurement updates any simulation model can be used to describe the evolution of the particles. The PF performance is validated and evaluated using synthetic and real traffic data from a Belgian freeway. An unscented Kalman filter is also presented. A comparison of the PF with the unscented Kalman filter is performed with respect to accuracy and complexity.

Interaction between a railway track and uniformly moving tandem wheels

Interaction among loaded wheels via railway track is studied. The vertical parametric oscillations of an infinite row of identical equally spaced wheels, bearing constant load and uniformly moving over a railway track, are calculated by means of Fourier series technique. If the distance between two consecutive wheels is big enough, then one can disregard their interaction via the railway track and consider every wheel as a single one. In this case, however, the Fourier series technique represents an appropriate computation time-saving approximation to a Fourier integral transformation technique that describes the oscillations of a single moving wheel. Two schemes are considered. In the first scheme, every wheel bears the same load. In the second one, consecutive wheels bear contrarily directed loads of the same magnitude. The second scheme leads to simpler calculations and so is recommended to model the wheel–track interaction. The railway track periodicity due to sleeper spacing is taken into account. Each period is the track segment between two adjacent sleepers. A partial differential equation with constant coefficients governs the vertical oscillations of each segment. Boundary conditions bind the oscillations of two neighbour segments and provide periodicity to the track. The shear deformation in the rail cross-section strongly influences the parametric oscillations. It also causes discontinuity of the rail centre-line slope at any point, where a concentrated transverse force is applied. Therefore, Timoshenko beam properties with respect to the topic of this paper are discussed. Interaction between a railway track and a bogie moving at moderate speed is studied. The study points to influence of the bogie frame oscillations on variation in the wheel–rail contact force over the sleeper span. The simplified bogie model considered includes only the primary suspension. A static load applied to the bogie frame centre presents the vehicle body.

Molecular Basis for the Cu 2+ Binding-Induced Destabilization of β2-Microglobulin Revealed by Molecular Dynamics Simulation

According to experimental data, binding of the Cu 2+ ions destabilizes the native state of β2-microglobulin ( β2m). The partial unfolding of the protein was generally considered an early step toward fibril formation in dialysis-related amyloidosis. Recent NMR studies have suggested that the destabilization of the protein might be achieved through increased flexibility upon Cu 2+ binding. However, the molecular mechanism of destabilization due to Cu 2+, its role in amyloid formation, and the relative contributions of different potential copper-binding sites remain unclear. To elucidate the effect of ion ligation at atomic detail, a series of molecular dynamics simulations were carried out on apo- and Cu 2+- β2m systems in explicit aqueous solutions, with varying numbers of bound ions. Simulations at elevated temperatures (360 K) provide detailed pictures for the process of Cu 2+-binding-induced destabilization of the native structure at the nanosecond timescale, which are in agreement with experiments. Conformational transitions toward partially unfolded states were observed in protein solutions containing bound copper ions at His-31 and His-51, which is marked by an increase in the protein vibrational entropy, with TΔS(vibr) ranging from 30 to 69 kcal/mol. The binding of Cu 2+ perturbs the secondary structure and the hydrogen bonding pattern disrupts the native hydrophobic contacts in the neighboring segments, which include the β-strand D2 and part of the β-strand E, B, and C and results in greater exposure of the D-E loop and the B-C loop to the water environment. Analysis of the MD trajectories suggests that the changes in the hydrophobic environment near the copper-binding sites lower the barrier of conformational transition and stabilize the more disordered conformation. The results also indicate that the binding of Cu 2+ at His-13 has little effect on the conformational stability, whereas the copper-binding site His-31, and to a lesser extent His-51, are primarily responsible for the observed changes in the protein conformation and dynamics.

Sequential contrast and assimilation in the perception of neighboring vowels and consonants

Sequential contrast exaggerates perceptual differences between neighboring segments. Our experiments measure this effect in consonant-vowel-stop and stop-vowel-consonant strings. Listeners identify and discriminate vowels from a front-to-back continuum in next-to-coronal versus labial stops, or stops from a coronal-to-labial continuum in next-to-front versus back vowels. If these intervals contrast sequentially, a vowel midway between front and back should sound backer next to a coronal than a labial stop because a coronal concentrates energy high in the spectrum. Similarly, a stop midway between coronal and labial should sound more labial next to a front vowel, because it too concentrates energy high in the spectrum. Exaggeration of spectral differences would also make a front vowel + labial stop versus a back vowel + coronal stop more discriminable than a front vowel + coronal stop versus a back vowel + labial stop. The strings’ lexical status is manipulated orthogonally via the other consonant to test whether sequential contrast effects are independent of lexical biases. Both identification and discrimination results show independent sequential contrast effects in stop judgments after front versus back vowels, but assimilation in vowel judgments before labial versus coronal stops. The stop-vowel-consonant strings test whether this difference reflects segment order or a consonants-vowel difference. [Work supported by NIH.]

Contextual effects on the perception of duration

English speakers perceive silent intervals with the same duration as longer when preceded by shorter vocalic intervals [Kluender et al. ‘‘Vowel length differences before voiced and voiceless consonants: An auditory explanation,’’ J. of Phonetics, 16, 153–169 (1988)]. This may be due to sequential contrast effects which exaggerate perceptual differences between neighboring segments. In Japanese, vowels are longer before geminates than before singletons [Han ‘‘Acoustic manifestations of more timing in Japanese,’’ J. Acoust. Soc. Am. 96, 73–82 (1994)]. Reflecting this correlation, Japanese speakers perceive silent intervals with the same duration as longer (as more ‘‘geminatelike’’) when preceded by longer vowels. The same pattern holds when non-speech analogs are used in place of speech stimuli: silent intervals are judged as longer when preceded by longer anharmonic buzzes. These results suggest that the perception of silent duration by Japanese speakers follows the pattern predicted from the acoustic properties of Japanese, but goes in the opposite direction from that predicted if durational contrast determines judgments, as it did for Kluender et al.’s (1988) listeners. This suggests that the segmental properties of the listener’s native language may influence nonspeech temporal judgments [cf. Moreton and Kusumoto ‘‘Native language determines parsing of nonlinguistic rythmic stimuli,’’ J. Acoust. Soc. Am. 102, 3204 (1997)]. English speakers will be tested on the same tasks to determine whether the perception of the temporal properties of nonspeech signals are generally determined by those of the listeners’ native language. [Work supported by NIH.]