Changes In Relative Frequency Research Articles

Damage identification in concrete using impact non-linear reverberation spectroscopy

High amplitude non-linear acoustic methods have shown potential for the identification of micro damage in brittle materials such as concrete. Commonly, these methods evaluate a non-linearity parameter from the relative change in frequency and attenuation with strain amplitude. Here, a novel attenuation model is introduced to describe the free reverberation from a standard impact resonance frequency test, together with an algorithm for estimating the unknown model coefficients. The non-linear variation can hereby by analyzed over a wider dynamic range as compared to conventional methods. The experimental measurement is simple and fully compatible with the standardized free-free linear impact frequency test.

A pooled shRNA screen for regulators of primary mammary stem and progenitor cells identifies roles for Asap1 and Prox1.

BackgroundThe molecular regulators that orchestrate stem cell renewal, proliferation and differentiation along the mammary epithelial hierarchy remain poorly understood. Here we have performed a large-scale pooled RNAi screen in primary mouse mammary stem cell (MaSC)-enriched basal cells using 1295 shRNAs against genes principally involved in transcriptional regulation.MethodsMaSC-enriched basal cells transduced with lentivirus pools carrying shRNAs were maintained as non-adherent mammospheres, a system known to support stem and progenitor cells. Integrated shRNAs that altered culture kinetics were identified by next generation sequencing as relative frequency changes over time. RNA-seq-based expression profiling coupled with in vitro progenitor and in vivo transplantation assays was used to confirm a role for candidate genes in mammary stem and/or progenitor cells.ResultsUtilizing a mammosphere-based assay, the screen identified several candidate regulators. Although some genes had been previously implicated in mammary gland development, the vast majority of genes uncovered have no known function within the mammary gland. RNA-seq analysis of freshly purified primary mammary epithelial populations and short-term cultured mammospheres was used to confirm the expression of candidate regulators. Two genes, Asap1 and Prox1, respectively implicated in breast cancer metastasis and progenitor cell function in other systems, were selected for further analysis as their roles in the normal mammary gland were unknown. Both Prox1 and Asap1 were shown to act as negative regulators of progenitor activity in vitro, and Asap1 knock-down led to a marked increase in repopulating activity in vivo, implying a role in stem cell activity.ConclusionsThis study has revealed a number of novel genes that influence the activity or survival of mammary stem and/or progenitor cells. Amongst these, we demonstrate that Prox1 and Asap1 behave as negative regulators of mammary stem/progenitor function. Both of these genes have also been implicated in oncogenesis. Our findings provide proof of principle for the use of short-term cultured primary MaSC/basal cells in functional RNAi screens.Electronic supplementary materialThe online version of this article (doi:10.1186/s12885-015-1187-z) contains supplementary material, which is available to authorized users.

Synoptic Climatology of the Southern Beaufort Sea Troposphere with Comparisons to Surface Winds

Synoptic-scale atmospheric circulation patterns drive wind forcing of dynamic and thermodynamic processes in Arctic sea ice. Synoptic typing and compositing are common techniques used to identify a limited number of prevailing weather classifications that govern a region's climate. This work investigates atmospheric circulation patterns (surface to 250 hPa) for the southern Beaufort Sea and corresponding surface wind regimes within each synoptic type. Significant changes (p < 0.05) in relative frequencies of a number of synoptic types were attributed to declining summer sea ice. Corresponding upper-level circulation anomalies show increasingly meridional atmospheric circulation. Synoptic Types 9 and 11 were identified as key October-November-December circulation features that represent deepening of the Aleutian low with concomitant strengthening of pressure gradients over the southern Beaufort Sea. Classification of coastal-based wind observations shows a shift towards increased easterly wind forcing. A case study of surface wind data from the CCGS Amundsen (2009–2011) provided a direct example of the surface wind regime within the marginal ice zone within each synoptic type during a period of reduced Arctic sea-ice cover.

Temporal evolution of neural activity underlying auditory discrimination of frequency increase and decrease.

Discriminating a direction of frequency change is an important ability of the human auditory system, although temporal dynamics of neural activity underlying this discrimination remains unclear. In the present study, we recorded auditory-evoked potentials when human subjects explicitly judged a direction of a relative frequency change between two successive tones. A comparison of two types of trials with ascending and descending tone pairs revealed that neural activity discriminating a direction of frequency changes appeared as early as the P1 component of auditory-evoked potentials (latency 50ms). Those differences between the ascending and descending trials were also observed in subsequent electroencephalographic components such as the N1 (100ms) and P2 (200ms). Furthermore, amplitudes of the P2 were significantly modulated by behavioral responses (upward/downward judgments) of subjects in the direction discrimination task, while those of the P1 were not. Those results indicate that, while the neural responses encoding a direction of frequency changes can be observed in an early component of electroencephalographic responses (50ms after the change), the activity associated (correlated) with behavioral judgments evolves over time, being shaped in a later time period (around 200ms) of the auditory processing.

Usage Guides and Usage Trends in Australian and British English

This paper presents a mini-diachronic investigation into the question of whether usage guides (prescriptive or descriptive) affect the evolution of standard written English, using the notions of codification, standardization and hyperstandardization. It examines the commentaries on three variable usage items (-ise/-ize spellings, alright v. all right, and data in singular/plural agreement) in dictionaries, style manuals and usage guides published in Australia and Britain from 1966 to 1995. The treatment of each usage item in terms of prescription/proscription or acceptance is then compared with quantitative evidence of actual usage, using (a) a set of standard corpora (Australian and British) from 1966 to 1995, and (b) twenty-first century data from the internet (Google searches of Australian and UK sites). Changes in relative frequencies of the variants for each pair are then analysed as reflections of the standardization process and/or the putative hyperstandardizing influence of usage commentaries. Despite markedly different treatments in Australian and British references, the trends for the three variable usage items in twenty-first century English are found to be much the same. Hyperstandardization may be seen where prescribed spellings replace the alternatives previously available; but the outcomes for the other variable items suggest they are rationalized by common usage sooner or later, whether the local usage commentary is prescriptive or descriptive.

Assessment of plasma impedance probe for measuring electron density and collision frequency in a plasma with spatial and temporal gradients

Numerical simulations and experimental measurements were combined to determine the ability of a plasma impedance probe (PIP) to measure plasma density and electron collision frequency in a plasma containing spatial gradients as well as time-varying oscillations in the plasma density. A PIP is sensitive to collision frequency through the width of the parallel resonance in the Re[Z]-vs.-frequency characteristic, while also being sensitive to electron density through the zero-crossing of the Im[Z]-vs.-frequency characteristic at parallel resonance. Simulations of the probe characteristic in a linear plasma gradient indicated that the broadening of Re[Z] due to the spatial gradient obscured the broadening due to electron collision frequency, preventing a quantitative measurement of the absolute collision frequency for gradients considered in this study. Simulation results also showed that the PIP is sensitive to relative changes in electron collision frequency in a spatial density gradient, but a second broadening effect due to time-varying oscillations made collision frequency measurements impossible. The time-varying oscillations had the effect of causing multiple zero-crossings in Im[Z] at parallel resonance. Results of experiments and simulations indicated that the lowest-frequency zero-crossing represented the lowest plasma density in the oscillations and the highest-frequency zero-crossing represented the highest plasma density in the oscillations, thus the PIP probe was found to be an effective tool to measure both the average plasma density as well as the maximum and minimum densities due to temporal oscillations.

Dispersal traits determine passive restoration trajectory of a Nigerian montane forest

Passive restoration methods offer great promise for tropical regions where resources are limited but the success of such efforts can be variable. Using trait-based theory, we investigated the likely trajectories of passive restoration efforts in a degraded Nigerian montane forest system recently protected from burning and cattle grazing. We quantified the density, species richness, and functional trait dispersion of dispersed seeds and seedling communities at increasing distances from the forest edge. We then determined which plant traits are responsible for colonisation by quantifying changes in functional-trait dispersion and relative frequencies of dispersal-linked traits with increasing distance from the forest. We found a rapid decrease in density and species richness, and significant species turnover in both seeds and seedlings just beyond the forest edge. This was mirrored by a significant decline in functional-trait dispersion and a shift in the relative frequencies of dispersal-linked traits. These findings suggest that the reassembly of plant communities adjacent to remnant forest is dependent on functional traits present in these remnant source populations, providing support for the incorporation of trait-based theory in restoration management.

The Effect of Rate Reduction on Signaling Prosodic Contrasts in Dysarthria

Background/Aims: To understand how reducing speaking rate alters prosodic contrasts in speakers with dysarthria (DYS) and healthy controls (HC). Methods: Seven male speakers with DYS (mean age = 34.9) and 7 age- and sex-matched HC (mean age = 36.9) produced identical phrases with affirmative (A), contrastive stress (CS) or question (Q) intonation at habitual and slow rate within a naturalistic game. Relative (word-to-word) changes in peak fundamental frequency (F0), intensity, and duration were compared across conditions, groups, and rates. Results: For some contrasts, rate reduction differentially affected the speaking groups, with HC exaggerating and speakers with DYS dampening some prosodic cues. Rate reduction diminished the Q contrast for both groups, with reduced peak F0 differences for HC and reduced word duration differences for HC and with DYS speakers. Slow rate also resulted in decreased lengthening of the final word for all three contrasts, thereby diminishing the Q contrast while exaggerating the CS and A contrasts. Conclusion: Although slow rate may improve segmental intelligibility, it may inadvertently dampen prosodic contrasts for some DYS speakers, thereby impacting communication effectiveness and naturalness. Implications for designing interventions that balance trade-offs between prosodic modulation and segmental clarity are discussed.

Inkjet Printed All-Polymer Flexural Plate Wave Sensors

We discuss the fabrication and performance of an all-polymer, flexural plate wave gravimetric sensor using flexible, piezoelectric Polyvinylidene fluoride as the substrate and an inkjet-printed interdigital transducer (IDT) employing conductive poly(3, 4-ethylenedioxythiophene) poly(styrenesulfonate) to excite Lamb waves within the film. Lamb waves are measured both electronically, using a second IDT, and mapped directly using a scanning laser Doppler vibrometer. Pulsed wave excitation is utilized to isolate the weak acoustic signal from the electromagnetic crosstalk, enabling the measurement of relative changes in the resonant frequency, Δf/f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> , in response to added mass, Δm, to the sensing area. A gravimetric mass sensitivity equivalent to Δf/(f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> Δm)=-153 cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> /g is measured by mass loading the sensor with printed polymer layers. It is found that the low stiffness of the substrate contributes significantly to the response of the sensor, yielding a measured overall sensitivity of Δf/(f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> Δm)=-83 cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> /g.

Methods for extending resonance frequency tuning ranges of frequency-selective surfaces using varactors

Methods for tuning resonance frequencies of elements of frequency-selective surfaces with the help of varactors are considered. The varactors are placed both in breaks of the conductor inside elements and in gaps between elements. Results of the approximate calculation and measurement of resonance frequencies of elements of frequency-selective surfaces of various shapes (butterfly, loop, and snake) with different-type varactors are presented. The measurement is based on the waveguide method. It is shown that, when varactors are placed in an element, the maximum relative resonance frequency change (37%) is reached with an element having a large self-capacitance (butterfly shape) and a small-capacitance varactor (MA46H120). The efficiency of the method for extending the resonance frequency tuning range of the element by means of the inductive shunting of the varactor circuit is estimated.

Gut Microbiota Patterns Associated with Colonization of Different Clostridium difficile Ribotypes

C. difficile infection is associated with disturbed gut microbiota and changes in relative frequencies and abundance of individual bacterial taxons have been described. In this study we have analysed bacterial, fungal and archaeal microbiota by denaturing high pressure liquid chromatography (DHPLC) and with machine learning methods in 208 faecal samples from healthy volunteers and in routine samples with requested C. difficile testing. The latter were further divided according to stool consistency, C. difficile presence or absence and C. difficile ribotype (027 or non-027). Lower microbiota diversity was a common trait of all routine samples and not necessarily connected only to C. difficile colonisation. Differences between the healthy donors and C. difficile positive routine samples were detected in bacterial, fungal and archaeal components. Bifidobacterium longum was the single most important species associated with C. difficile negative samples. However, by machine learning approaches we have identified patterns of microbiota composition predictive for C. difficile colonization. Those patterns also differed between samples with C. difficile ribotype 027 and other C. difficile ribotypes. The results indicate that not only the presence of a single species/group is important but that certain combinations of gut microbes are associated with C. difficile carriage and that some ribotypes (027) might be associated with more disturbed microbiota than the others.

Abstract WP228: Measurement Of Oxygen Extraction Fraction (OEF) By A Novel MRI Technique

We report a novel application of an MRI technique called Parameter Assessment by Retrieval from Signal Encoding (PARSE) to measure OEF. OEF is of crucial importance, providing information about the stage of neurovascular impairment in a patient and the risk of stroke in such a patient. In this study, we test the hypothesis that PARSE can be used to measure oxygen extraction in the brain. This method uses a more accurate MR signal model, employs a non-Cartesian Rosette trajectory to encode multiple parameters and can simultaneously estimate M 0 , R 2 *, and local frequency in a single, non-invasive 5 second acquisition. Of particular interest here, is the feasibility to directly measure susceptibility related frequency changes from local frequency estimates. Since OEF abnormalities are focal, contralateral measurements were used to estimate the relative frequency change. We acquired data on 5 human subjects. In the series of 5 normal volunteers (M/F 3/2, &lt;age&gt; = 26 +/-10 years) we acquired a single slice, 5.0 mm thick, 220 mm x 220 mm FOV, 64 x 64 matrix, image resolution = 3 x 3 x 5.0 mm 3 ) 2D PARSE images. The total sequence time was 5 seconds. One arterio-venous malformation (AVM) patient was also tested with the PARSE-OEF sequence. The parameters were identical to the volunteer scans. For the 5 volunteers, the average frequency change (δω) across the brain image slice was 15.49 Hz ±2.77 Hz. This corresponded to an average whole brain-slice OEF of 37.23 ± 6.60%. This is in agreement with gold-standard Positron Emission Tomography (PET) OEF studies of normative values from Carpenter (35±7%), Yamauchi (42±5%), Diringer (41±6%) and Raichle (40±9%). Our current values are in excellent agreement with PET literature values. Upon further validation, this technique may be a viable clinical alternative to PET-OEF.

Stimulus change detection in phasic auditory units in the frog midbrain: frequency and ear specific adaptation

Neural adaptation, a reduction in the response to a maintained stimulus, is an important mechanism for detecting stimulus change. Contributing to change detection is the fact that adaptation is often stimulus specific: adaptation to a particular stimulus reduces excitability to a specific subset of stimuli, while the ability to respond to other stimuli is unaffected. Phasic cells (e.g., cells responding to stimulus onset) are good candidates for detecting the most rapid changes in natural auditory scenes, as they exhibit fast and complete adaptation to an initial stimulus presentation. We made recordings of single phasic auditory units in the frog midbrain to determine if adaptation was specific to stimulus frequency and ear of input. In response to an instantaneous frequency step in a tone, 28% of phasic cells exhibited frequency specific adaptation based on a relative frequency change (delta-f=±16%). Frequency specific adaptation was not limited to frequency steps, however, as adaptation was also overcome during continuous frequency modulated stimuli and in response to spectral transients interrupting tones. The results suggest that adaptation is separated for peripheral (e.g., frequency) channels. This was tested directly using dichotic stimuli. In 45% of binaural phasic units, adaptation was ear specific: adaptation to stimulation of one ear did not affect responses to stimulation of the other ear. Thus, adaptation exhibited specificity for stimulus frequency and lateralization at the level of the midbrain. This mechanism could be employed to detect rapid stimulus change within and between sound sources in complex acoustic environments.

Decoherence of superconducting qubits caused by quasiparticle tunneling

In superconducting qubits, the interaction of the qubit degree of freedom with quasiparticles defines a fundamental limitation for the qubit coherence. We develop a theory of the pure dephasing rate \Gamma_{\phi} caused by quasiparticles tunneling through a Josephson junction and of the inhomogeneous broadening due to changes in the occupations of Andreev states in the junction. To estimate \Gamma_{\phi}, we derive a master equation for the qubit dynamics. The tunneling rate of free quasiparticles is enhanced by their large density of states at energies close to the superconducting gap. Nevertheless, we find that \Gamma_{\phi} is small compared to the rates determined by extrinsic factors in most of the current qubit designs (phase and flux qubits, transmon, fluxonium). The split transmon, in which a single junction is replaced by a SQUID loop, represents an exception that could make possible the measurement of \Gamma_{\phi}. Fluctuations of the qubit frequency leading to inhomogeneous broadening may be caused by the fluctuations in the occupation numbers of the Andreev states associated with a phase-biased Josephson junction. This mechanism may be revealed in qubits with small-area junctions, since the smallest relative change in frequency it causes is of the order of the inverse number of transmission channels in the junction.

Impaired emotion processing from vocal and facial cues in frontotemporal dementia compared to right hemisphere stroke

To advance our understanding about the emotional and cognitive deficits of patients with frontotemporal dementia with behavioral variant (bvFTD), the current study examined comprehension and expression of emotions from prosodic and facial cues in a 66-year-old woman. The patient diagnosed with bvFTD is compared to six patients with acute right hemisphere stroke. Recognition of emotion from prosodic cues was assessed using an identification task in four conditions with decreasing verbal demands (neutral sentences, language-like pseudo sentences, monosyllables, and asyllabic vowel sounds). Repetition of utterances with emotional connotations and self-generated conversations were analyzed to measure relative changes in mean fundamental frequency (f0), f0 variance, speech rate, and intensity along with the facial musculature pattern. The patient showed a marked deficit in identifying emotions in all four prosody conditions; and she did not show much variation in modulating mean f0, f0 variance, speech rate and intensity for all emotion categories when compared to neutral utterances. In addition, this patient demonstrated little to no facial expressions during emotionally provoking tasks, but demonstrated no difficulty recognizing emotions from facial expressions or verbal scenarios. Results show that the patient seems to have selective impairment in recognition of emotions from prosody and expression of emotions using both prosodic and facial features. Impaired processing of emotional prosody and facial expressions could be important for detecting bvFTD with greater right hemisphere atrophy.

Deliquescence Phase Transition Measurements by Quartz Crystal Microbalance Frequency Shifts

Measurements of the hygroscopic properties of aerosols are needed to better understand the role of aerosols as cloud condensation nuclei. Several techniques have been used to measure deliquescence (solid to liquid) phase transitions in particular. In this study, we have measured the deliquescence relative humidity (DRH) of organic and inorganic salts, organic acids (glutaric and succinic acid), and mixtures of organic acids with ammonium sulfate using a quartz crystal microbalance (QCM). The QCM allows for measurement of the deliquescence phase transition due to inherent measurement differences between solids and liquids in the oscillation frequency of a quartz crystal. The relative humidity dependent frequency measurements can be used to identify compounds that adsorb monolayer amounts of water or form hydrates prior to deliquescence (e.g., lithium chloride, potassium and sodium acetate). Although the amount of water uptake by a deliquescing material cannot be quantified with this technique, deliquescence measurements of mixtures of hygroscopic and nonhygroscopic components (e.g., ammonium sulfate and succinic acid (DRH > 95%)) show that the mass fraction of the deliquescing portion of the sample can be quantitatively determined from the relative change in oscillation frequency at deliquescence. The results demonstrate the use of this technique as an alternative method for phase transition measurements and as a direct measurement of the mass fraction of a sample that undergoes deliquescence. Further, deliquescence measurements by the QCM may provide improved understanding of discrepancies in atmospheric particle mass measurements between filter samples and the tapered element oscillating microbalance given the similar measurement principle employed by the QCM.

The influence of changes in synoptic regimes on north Australian wet season rainfall trends

Precipitation over the north of Australia mainly falls during the wet season and is associated with the Australian monsoon. Recent studies have shown that precipitation in the north and northwest of Australia during the wet season has increased over the past 50 years. In previous work, daily radiosonde data at a single site (Darwin) were used to identify five distinct wet season regimes, each associated with a characteristic synoptic circulation pattern and rainfall probability distribution. Here the five regimes are used to decompose the 50‐year precipitation trend at Darwin from 1957/1958–2007/2008 into two contributions; that due to changes in the regime relative frequency of occurrence, and that due to changes in the within‐regime precipitation. Over the entire wet season from September to April, the within‐regime precipitation does not change significantly for any of the regimes. However, the relative frequency of occurrence decreases significantly for the driest regimes, and increases significantly for one of the wettest regimes, suggesting that changes in the large‐scale circulation are a more important contributor to the precipitation trends than are thermodynamic changes. During December to March, the largest contributions to the total precipitation trend come from changes in all three of the wettest regimes. During November and April, when the average precipitation is lower, there is a large relative contribution to the precipitation trend from the increase in frequency of a wet regime and a decrease in frequency of the dry regimes. This contributes to the significant lengthening of the north Australian wet season.

Piezoelectric Impedance Based Elastic Modulus Monitoring for Concrete during Curing

This paper presented an experimental study on piezoelectric impedance based elastic modulus monitoring for concrete during curing. The piezoceramic (PZT) patch was attached on the concrete specimen to collect the monitoring signal. The electro-mechanical impedance (EMI) spectra of surface bonded PZT patch were collected using an impedance analyzer by sweeping the frequency. A regression analysis is conducted to establish the empirical relationship between the relative elastic modulus of concrete and the monitored relative resonant frequency change of the EMI spectra. The established empirical formula is used for concrete elastic modulus monitoring via EMI spectra. The experimental results tell that the EMI technique is a practical and reliable nondestructive test method for concrete elastic modulus monitoring.

Temporal variations in endophytic fungal assemblages of Ginkgo biloba L.

We isolated endophytic fungi from living healthy leaves, petioles, and current-year twigs of Ginkgo biloba L. from April to November 2004 with the objective of identifying the dominant endophytic fungal taxa, and monitoring their occurrence and frequency. A total of 9 fungal taxa were identified to the genus level. Diversity measures inferred from the Shannon–Wiener, Morisita–Horn, and Sørensen indices indicated that leaves and petioles harbored more diverse endophytic fungal assemblages than twigs, and that fungal taxa involved in twigs shared less with those in leaves and petioles. Among the organs, the occurrence pattern of overall endophytic fungi differed significantly, and two taxa, Phomopsis sp. and Phyllosticta sp., were the most frequently isolated and thus regarded as the dominant endophytic fungi. Phomopsis sp. was isolated frequently from twigs (84.8%) but rather few from leaves (16.1%) and petioles (24.3%). Phyllosticta sp. was isolated frequently from leaves (72.9%) and petioles (65.7%) but was never isolated from twigs. Temporal changes in relative frequency of total endophytic fungi tended to differ among sampling dates for all three organs. The occurrence of Phyllosticta sp. in both leaves and petioles was first detected in August and peaked in October. Phomopsis sp. was detected in twigs throughout the growing season. These results suggest that the distribution of the two dominant endophytic fungi was organ-specific and differed within seasons.

Adaptation in phasic auditory units of the frog midbrain is sensitive to changes in stimulus frequency and ear of input

Event Abstract Back to Event Adaptation in phasic auditory units of the frog midbrain is sensitive to changes in stimulus frequency and ear of input Abhilash Ponnath1, Kim Hoke2 and Hamilton Farris1* 1 Louisiana St. University Health Sciences Center, Neuroscience, United States 2 Colorado State University, Biology, United States Neural adaptation, a reduction in response to a constant or maintained stimulus, is an important mechanism for detecting stimulus change. Contributing to stimulus change detection is the fact that neural adaptation is often stimulus specific: adaptation to a particular stimulus reduces excitability to only a subset of stimuli, while the ability to respond to other stimuli is unaffected. Phasic cells (e.g., responding to stimulus onset), with their fast adaptation, are considered good candidates for detecting the most rapid changes in natural auditory scenes, as they adapt quickly to the initial presentation of a stimulus and do not require adaptation buildup from many repeated stimulus presentations. Our study uses in vivo, single unit recordings to show that the fast and complete adaptation of phasic auditory units in the frog torus semicircularis is specific to stimulus frequency and ear of input. In response to an instantaneous frequency step in a 200 ms tone, 28% of cells exhibit frequency specific adaptation (FSA) based on relative frequency change (delta-f = +/-16%). FSA is not limited to frequency steps, however, as adaptation is also overcome during continuous frequency modulated stimuli. When temporal gaps in tones produce frequency transients, FSA cells outperform non-FSA cells in gap detection. When gaps in noise produce only temporal cues, however, gap detection is identical in the two cell classes. The results suggest that adaptation is separated for peripheral (e.g., frequency) channels, which we tested directly using dichotic stimuli. In 45% of binaural phasic units, adaptation was ear specific: adaptation to stimulation of one ear does not affect responses to stimulation of the other ear. Thus, adaptation exhibits specificity during processing of frequency and lateralization at the level of the midbrain. This mechanism could be employed to detect stimulus change within and between acoustic sources in rapidly changing complex acoustic environments. Acknowledgements KLH and HEF were supported in part by a Grass Faculty Fellowship at the Marine Biological Laboratory, Woods Hole, MA (2009). AP and HEF were supported by NIH grant P20RR016816 (to N. Bazan). Keywords: adaptation, auditory scene, chorus, critical band Conference: Tenth International Congress of Neuroethology, College Park. Maryland USA, United States, 5 Aug - 10 Aug, 2012. Presentation Type: Poster Presentation (see alternatives below as well) Topic: Sensory: Audition Citation: Ponnath A, Hoke K and Farris H (2012). Adaptation in phasic auditory units of the frog midbrain is sensitive to changes in stimulus frequency and ear of input. Conference Abstract: Tenth International Congress of Neuroethology. doi: 10.3389/conf.fnbeh.2012.27.00157 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 27 Apr 2012; Published Online: 07 Jul 2012. * Correspondence: Dr. Hamilton Farris, Louisiana St. University Health Sciences Center, Neuroscience, New Orleans, Louisiana, 70112, United States, hfarri@lsuhsc.edu Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Abhilash Ponnath Kim Hoke Hamilton Farris Google Abhilash Ponnath Kim Hoke Hamilton Farris Google Scholar Abhilash Ponnath Kim Hoke Hamilton Farris PubMed Abhilash Ponnath Kim Hoke Hamilton Farris Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.