Just Noticeable Difference Research Articles

Remote Sensing Monitoring of Pine Wilt Disease Based on Time-Series Remote Sensing Index

Under the strong influence of climate change and human activities, the frequency and intensity of disturbance events in the forest ecosystem both show significant increasing trends. Pine wood nematode (Bursapherenchus xylophilus, PWN) is one of the major alien invasive species in China, which has rapidly infected the forest and spread. In recent years, its tendency has been to spread from south to north, causing serious losses to Pinus and non-Pinus coniferous forests. It is urgent to carry out remote sensing monitoring and prediction of pine wilt disease (PWD). Taking Anhui Province as the study area, we applied ground survey, satellite-borne optical remote sensing imagery and environmental factor statistics, relying on the Google Earth Engine (GEE) platform to build a new vegetation index NDFI based on time-series Landsat images to extract coniferous forest information and used a random forest classification algorithm to build a monitoring model of the PWD infection stage. The results show that the proposed NDFI differentiation threshold classification method can accurately extract the coniferous forest range, with the overall accuracy of 87.75%. The overall accuracy of the PWD monitoring model based on random forest classification reaches 81.67%, and the kappa coefficient is 0.622. High temperature and low humidity are conducive to the survival of PWN, which aggravates the occurrence of PWD. Under the background of global warming, the degree of PWD in Anhui Province has gradually increased, and has transferred from the southwest and south to the middle and northeast. Our results show that PWD monitoring and prediction at a regional scale can be realized by using long time-series multi-source remote sensing data, NDFI index can accurately extract coniferous forest information and grasp disease information in a timely manner, which is crucial for effective monitoring and control of PWD.

Studies on the Effectiveness of High-luminance Monitors in Mammography Softcopy Interpretation

Recently, monitors with maximum luminance exceeding 2000 cd/m2 (high-luminance monitor) have been used for diagnostic mammography. In this study, we examined the visibility of high-luminance monitors by converting luminance meter measurements into the just noticeable difference (JND) Index. The ambient light was also examined at the same time. The high-luminance monitor is a 21.3-inch IPS monochrome monitor with a maximum luminance of 3000 cd/m2. Experiments were conducted with a minimum luminance of 0.6 cd/m2 and a maximum luminance of 500, 850, and 1200 cd/m2. The luminance ratio was set to 1 : 2000 and the maximum luminance was changed to 500, 1000, and 2000 cd/m2. The ambient light was varied to 8.7, 36.1, 61.3, and 129.6 lx. The Japan Radiological Society recommended luminance values for each stage of phantom and Grayscale Standard Display Function curves were measured. The JND increased as the maximum luminance was increased for both the case with the same minimum luminance and the case with the same luminance ratio, and visibility was improved. In both the case of the same minimum luminance and the case of the same luminance ratio, the JND was found to increase as the maximum luminance was increased. The results suggest that high-luminance monitors may improve visibility and allow for higher ambient light settings. Furthermore, the degree of eye fatigue needs to be verified.

A Review on Just Noticeable Difference(JND) Quality Metric towards its Drawbacks and Limitations

A Review on Just Noticeable Difference(JND) Quality Metric towards its Drawbacks and Limitations

Encoded Feature Enhancement in Watermarking Network for Distortion in Real Scenes

Deep-learning based watermarking framework has be extensively studied recently. The main structure of such framework is an encoder, a noise layer and a decoder. By training with different distortion sets in the noise layer, the whole network can realize different robustness. However, such framework has a huge drawback that is the noise layer must be differentiable, otherwise it cannot be trained end-to-end. But for practical use, much distortions are non-differentiable, so such framework cannot be applied. To address such limitations, this paper propose a triple-phase watermarking framework for practical distortions. The proposed framework consists of three phases including a noise-free initial phase, a mask-guided frequency enhancement phase and an adversarial-training phase. Phase 1 aims to initialize an encoder to embed watermark with high visual quality and a decoder to extract the watermark. In order to generate high quality watermarked image, we design the just noticeable difference (JND)-mask image loss in phase 1 to guide the encoder. At phase 2, based on the investigation of the encoded features and distortions, we propose a mask-guided frequency enhancement algorithm to enhance the encoded feature which ensures the survival of such features after distortion, so that there will be enough features to be learned in phase 3. And phase 3 aims to train a stronger decoder to extract the watermark from the image after practical distortions. The combination of these 3 phases can well handle the non-differentiable problems and make the whole network trainable. Various experiments indicate the superior performance of the proposed scheme in the view of traditional differentiable image processing distortion robustness and practical non-differentiable distortion robustness.

Edge detection of remote sensing image based on Grünwald-Letnikov fractional difference and Otsu threshold

<abstract><p>With the development of remote sensing technology, the resolution of remote sensing images is improving, and the presentation of geomorphic information is becoming more and more abundant, the difficulty of identifying and extracting edge information is also increasing. This paper demonstrates an algorithm to detect the edges of remote sensing images based on Grünwald–Letnikov fractional difference and Otsu threshold. First, a convolution difference mask with two parameters in four directions is constructed by using the definition of the Grünwald–Letnikov fractional derivative. Then, the mask is convolved with the gray image of the remote sensing image, and the edge detection image is obtained by binarization with Otsu threshold. Finally, the influence of two parameters and threshold values on detection results is discussed. Compared with the results of other detectors on the NWPU VHR-10 dataset, it is found that the algorithm not only has good visual effect but also shows good performance in quantitative evaluation indicators (binary graph similarity and edge pixel ratio).</p></abstract>

Sensory Perception of Varied Shoe Masses in Running.

Studies on the sensory perception of mass mostly focus on the hands rather than the feet. The aim of our study is to measure how accurately runners can perceive additional shoe mass in comparison to a control shoe (CS) while running, and moreover, whether there is a learning effect in the perception of mass. Indoor running shoes were categorized as a CS (283 g) and shoes with four additional masses: shoe 2 (+50 g), shoe 3 (+150 g), shoe 4 (+250 g), and shoe 5 (+315 g). There were 22 participants in the experiment, which was divided into two sessions. In session 1, participants ran on a treadmill for 2 min with the CS and then put on one set of weighted shoes and ran for another 2 min at a preferred velocity. A binary question was used after the pair test. This process was repeated for all the shoes to compare them with the CS. Based on our statistical analysis (mixed effect logistic regression), the independent variable (ie, mass) did have a significant effect on perceived mass (F4,193 = 10.66, P < .0001), whereas repeating the task did not show a significant learning effect (F1,193 = 1.06, P = .30). An increase of 150 g is the just-noticeable difference among other weighted shoes and the Weber fraction is equal to 0.53 (150:283 g). Learning effect did not improve by repeating the task in two sessions in the same day. This study facilitates our understanding about sense of force and enhances multibody simulation in running.

Perception of Line Attributes for Visualization.

Line attributes such as width and dashing are commonly used to encode information. However, many questions on the perception of line attributes remain, such as how many levels of attribute variation can be distinguished or which line attributes are the preferred choices for which tasks. We conducted three studies to develop guidelines for using stylized lines to encode scalar data. In our first study, participants drew stylized lines to encode uncertainty information. Uncertainty is usually visualized alongside other data. Therefore, alternative visual channels are important for the visualization of uncertainty. Additionally, uncertainty-e.g., in weather forecasts-is a familiar topic to most people. Thus, we picked it for our visualization scenarios in study 1. We used the results of our study to determine the most common line attributes for drawing uncertainty: Dashing, luminance, wave amplitude, and width. While those line attributes were especially common for drawing uncertainty, they are also commonly used in other areas. In studies 2 and 3, we investigated the discriminability of the line attributes determined in study 1. Studies 2 and 3 did not require specific application areas; thus, their results apply to visualizing any scalar data in line attributes. We evaluated the just-noticeable differences (JND) and derived recommendations for perceptually distinct line levels. We found that participants could discriminate considerably more levels for the line attribute width than for wave amplitude, dashing, or luminance.

A Robotic Device for Measuring Human Ankle Motion Sense.

Proprioceptive signals about ankle motion are essential for the control of balance and gait. However, objective, accurate methods for testing ankle motion sense in clinical settings are not established. This study presents a fast and accurate method to assess human ankle motion sense acuity. A one degree-of-freedom (DOF) robotic device was used to passively rotate the ankle under controlled conditions and applied a psychophysical forced-choice paradigm. Twenty healthy participants were recruited for study participation. Within a trial, participants experienced one of three reference velocities (10°/s, 15°/s, and 20°/s), and a smaller comparison velocity. Subsequently, they verbally indicated which of the two movements was faster. As outcome measures, a just-noticeable-difference (JND) threshold and interval of uncertainty (IU) were derived from the psychometric stimulus-response difference function for each participant. Our data show that mean JND threshold increased almost linearly from 0.53°/s at the 10°/s reference to 1.6°/s at 20°/s ( ). Perceptual uncertainty increased similarly (median IU = 0.33°/s at 10°/s and 0.97°/s at 20°/s; ). Both measures were strongly correlated ( r s = 0.70). This implies that the bias of the human ankle motion sense is approximately 5 - 8% of the experienced movement velocity. We demonstrate that this robot-aided test produces quantitative data on human ankle motion sense acuity. It provides a useful addition to the current measures of ankle proprioceptive function.

Violation of the conformity between the induction current and the emission current during the pyroelectric effect in a single crystal of lithium tantalate under vacuum conditions

A comparison of the induction current and the emission current during the pyroelectric effect under vacuum conditions with periodic variation in the temperature of a single crystal of lithium tantalate is presented. An increase in the variation frequency leads to suppression of the emission current, which prevents observing the effect of the optimal frequency with the maximum amplitude as in the case of the induction current. The conformity of both current forms is shown, except for the region of 2 mHz and less where an additional current wave is observed. It is established that this additional wave is initiated above a certain threshold of potential difference and leads to its stabilization. Keywords: pyroelectric effect, ferroelectric electron emission, pyroelectric accelerator, lithium tantalate.

Нарушение соответствия тока индукции и тока эмиссии при пироэлектрическом эффекте в монокристалле танталата лития в условиях вакуума

A comparison of the induction current and the emission current during the pyroelectric effect in vacuum conditions with periodic variation in the temperature of a single crystal of lithium tantalate is presented. An increase in the variation frequency leads to suppression of the emission current, which does not allow one to observe the effect of the optimal frequency with the maximum amplitude, as for the induction current. The conformity of both current forms is shown, except for the region of 2 mHz or less, where an additional current wave is observed. It is established that this additional wave is initiated above a certain threshold of potential difference and leads to its stabilization.

Partial versus total knee arthroplasty for isolated antero-medial osteoarthritis – An analysis of PROMs and satisfaction

This study aimed to compare the patient-reported functional outcomes and patient satisfaction after medial Unicompartmental Knee Arthroplasty (UKA) versus Total Knee Arthroplasty (TKA), performed for anteromedial osteoarthritis (AMOA) of the knee in patients from an Indian population, at a minimum 3-year follow-up. This is a prospective matched cohort study (1:2 ratio). One hundred and one UKA cases were matched to 206 TKA cases by propensity score matching for age, body mass index (BMI), gender distribution, and the Charlson Comorbidity Index (CCI). The primary outcome (Oxford knee score, OKS) was assessed at a 3-year follow-up, along with secondary outcomes (Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC] Score, Forgotten Joint Score (FJS), Anterior Knee Pain (Kujala) score, patient satisfaction, and revision rate at the final follow-up). The UKA group was superior to the TKA group in patient-reported functional outcomes based on the OKS (p=0.004). Using the FJS score, UKA was more likely to be a forgotten joint compared to TKA (p<0.001). However, differences in the OKS and FJS did not meet the reported minimal clinically important difference (MCID) thresholds. Quality of life (EuroQol-5D VAS scale) was found to be significantly higher in the UKA group (p<0.001). Patients in the UKA group were more likely to be very satisfied (75.2%) versus the TKA group (62.1%, p=0.023). For AMOA, UKA was associated with improved patient satisfaction compared to TKA. Although patient-reported outcome measures were statistically in favour of UKA over TKA, the differences were not clinically significant. Multicenter and randomized studies comparing the two procedures are warranted. Level-II Therapeutic.

Locating robust patterns based on invariant of LTP-based features

• A novel concept of robust patterns (called RLTP) is introduced by considering the invariance of LTP-based features. • A crucial derivative of CLTP (called RCLTP) is proposed to be in accordance with RLTP. • An efficient application is presented to take into account RCLTP for local DT representation. • Local optical-flow-based features are taken into account DT motions for boosting the discrimination. • Just addressing the robust patterns, our RCLTP descriptor obtains very good performance compared to state of the art. Efficiently representing Dynamic Textures (DTs) based on salient features is one of the considerable challenges in computer vision. Locating these features can be obstructed due to the impact of encoding factors. In this article, a novel concept of Robust Local Ternary Patterns (RLTP) is introduced in consideration of the invariance of Local Ternary Patterns (LTP) subject to the deviation of thresholds. Our locating process is able to simultaneously encapsulate the discrimination of local features, and deal with the noise sensibility caused by a small gray-scale change of local neighbors. RLTP is then adapted to the completed LTP model to form an efficient operator for capturing completely properties of RLTP. Finally, RLTP is taken into account for the DT description, where the robust patterns of spatial-temporal features and optical-flow-based motions are exploited to improve the performance. Experiments have clearly corroborated the efficacy of our proposed approach.

Measuring interaction forces in surgical telemanipulation using conventional instruments

AbstractMinimally invasive surgery (MIS) has been an essential tool in the surgical sector for many years due to its crucial advantages compared to open surgery. To overcome remaining limitations, teleoperated MIS experienced a strong emergence. However, the widespread usage of such systems is hindered by the enormous financial hurdle. The use of standard components and conventional tools for teleoperated MIS can facilitate integration into existing hospital workflows and can be a cost-efficient and versatile approach for research purposes. To compensate for the lack of haptic feedback, some teleoperation setups inherit a sensor system allowing them to record interaction forces and display them at the user interface. In research and in commercially available systems, different positions for the sensor can be found. In this paper, mechanical interfaces for the guidance and actuation of non-wristed and wristed standard instruments are presented. Furthermore, a method for the extracorporeal measurement of interaction forces is presented, characterized, and discussed. The overall mean relative error of the magnitude of the interaction force is 9.4%, while the overall mean absolute error of the force vector is 14.4 $^{\circ }$ , both below the respective human differential perception threshold. The presented measurement method is a simple, yet sufficiently accurate approach to measure interaction forces in surgical telemanipulation.

Damaged Area Mapping and Ground Displacement Estimation using Sentinel-1 Synthetic Aperture Radar (SAR) Interferometry: January 12, 2020, Taal Volcano Eruption Case Study, Philippines

The availability of damage assessment maps and ground displacement information is essential in the Philippines, which experiences various types of climate-induced and naturally-driven geohazards. The emergence of freely accessible space-borne synthetic aperture radar (SAR) data has led to interferometric SAR (InSAR) applications in the Philippines. However, most InSAR studies only focused on ground displacement detection, monitoring, and modeling and not on damages resulting from geohazards. This work used pre- and co-eruption Sentinel-1 interferometric pair datasets and the SeNtinel-1 Application Platform tool to create a pixel-based damage proxy map (DPM) for the 2020 Taal Volcano eruption in the Philippines, employing a coherence difference analysis. The pre-eruption coherence difference data stack mean and standard deviation were exploited to achieve a coherence difference threshold that reasonably created the DPM that delineated damaged areas, which included buildings and roads. The DPM was qualitatively evaluated through comparison with the field investigation and reports obtained from the Philippine Institute of Volcanology and Seismology (PHIVOLCS) and showed significant agreement with 89% overall accuracy. The decomposition of the line-of-sight displacement field map revealed the dynamic geological activities due to the phreatomagmatic eruption. The vertical displacements from InSAR and in-situ measurements obtained from field inspection and PHIVOLCS reports showed excellent agreement with root-mean-squared less than 2 cm and coefficient of determination (R2) close to unity. Overall, the application of InSAR to Sentinel-1 SAR images successfully mapped damaged areas and estimated ground displacements associated with the Taal Volcano phreatomagmatic eruption on January 12, 2020.

Empirical validation of QUEST+ in PSE and JND estimations in visual discrimination tasks

One of the most precise methods to establish psychometric functions and estimate threshold and slope parameters is the constant stimuli procedure. The large distribution of predetermined stimulus values presented to observers enables the psychometric functions to be fully developed, but makes this procedure time-consuming. Adaptive procedures enable reliable threshold estimation while reducing the number of trials by concentrating stimulus presentations around observers’ supposed threshold. Here, the stimulus value for the next trial depends on observer’s responses to the previous trials. One recent improvement of these procedures is to also estimate the slope (related to discrimination sensitivity). The Bayesian QUEST+ procedure (Watson Journal of Vision, 17(3), 10, 2017), a generalization and extension of the QUEST procedure, includes this refinement. Surprisingly, this procedure is barely used. Our goal was to empirically assess its precision to evaluate size, orientation, or temporal perception, in three yes/no discrimination tasks that increase in demands. In 72 adult participants in total, we compared points of subjective equivalence (PSEs) or simultaneity (PSSs) as well as discrimination sensitivity obtained with the QUEST+, constant stimuli, and simple up-down staircase procedures. While PSEs did not differ between procedures, sensitivity estimates obtained with the 64-trials QUEST+ procedure were overestimated (i.e., just-noticeable differences, or JNDs, were underestimated). Overall, agreement between procedures was good, and was at its best for the easiest tasks. This study empirically confirmed that the QUEST+ procedure can be considered as a method of choice to accelerate PSE estimation, while keeping in mind that sensitivity estimation should be handled with caution.

Cross-scale feature fusion-based JND estimation for robust image watermarking in quaternion DWT domain

Owing to the rapid development of just-noticeable difference (JND) and the high robustness of discrete wavelet transform (DWT) based watermarking, robust watermarking methods based on JND models have been extensively adopted in the area of image copyright protection. In general, in existing JND model-based methods, transform domain-based features play an important role during the quantization strength measurement. However, most existing methods only use the subband-specific features from the final multi-scale wavelet transform domain, ignoring the feature relevance among subband-specific features with different scales among RGB channels. To address this issue, in this study, we put forward a JND estimation based on cross-scale feature fusion (CFJnd) mechanism in quaternionic DWT domain for robust image watermarking. For the proposed CFJnd, we first design different quaternionic wavelet scales for the JND modeling, which can be used to measure the minimum distortion level of the embedding-specific subband relevance. Furthermore, the cross-scale features among different subbands are adopted to jointly generate the pattern, texture and color measurement, making the final perceptual masking more representative. In addition, we further develop a CFJnd-based robust image watermarking, and the watermark is embedded by quantifying the candidate quaternionic DWT coefficients of the embedding-specific subband on a level which is adaptively defined according to the proposed CFJnd. Experimental results based on the publicly available image database show that the proposed method can produce reliable and promising results, compared to other state-of-the-art image watermarking methods.

Quantifying Surgeon Intuition Using a Judgment Analysis Model: Surgeon Accuracy of Predicting Patient-Reported Outcomes in Patients Undergoing Hip Arthroscopy for Femoroacetabular Impingement Is Moderate at Best

To quantify surgeon intuition, determine whether a surgeon's prediction of outcomes after hip arthroscopy correlates with actual patient-reported outcomes (PRO), and identify differences in clinical judgment between expert and novice examiners. This prospective, longitudinal study was conducted at an academic medical center on adults undergoing primary hip arthroscopy for treatment of femoroacetabular impingement. A Surgeon Intuition and Prediction (SIP) score was completed preoperatively by an attending surgeon (expert) and physician assistant (novice). Baseline and postoperative outcome measures included legacy hip scores (e.g., Modified Harris Hip score) and Patient-Reported Outcomes Information System tools. Mean differences were assessed using t-tests. Generalized estimating equations assessed longitudinal changes. Pearson correlation coefficients (r) evaluated associations between SIP score and PRO scores. Data from 98 patients (mean age 36 years, 67% female) with complete data sets at 12-month follow-up were analyzed. Weak-to-moderate strength correlations were seen between SIP score and PRO scores (r= 0.36 to r= 0.53) for pain, activity and physical function. Significant improvements were seen in all primary outcome measures at 6 and 12 months postoperatively when compared to baseline scores (P < .05), with about 50% to 80% of patients achieving the minimum clinically important difference and patient acceptable symptomatic state thresholds postoperatively. An experienced, high-volume hip arthroscopist had only weak-to-moderate ability to intuitively predict PRO. Surgical intuition and judgment were not superior in an expert examiner compared to a novice. Level III, retrospective comparative prognostic trial.

Oxidative stress protection and growth promotion activity of Pseudomonas mercuritolerans sp. nov., in forage plants under mercury abiotic stress conditions.

SAICEUPSMT strain was isolated from soils in the mining district of Almadén (Ciudad Real, Spain), subjected to a high concentration of mercury. Using the plant model of lupinus, the strain was inoculated into the rhizosphere of the plant in a soil characterized by a high concentration of mercury (1,710 ppm) from an abandoned dump in the mining district of Almadén (Ciudad Real, Spain). As a control, a soil with a minimum natural concentration of mercury, from a surrounding area, was used. Under greenhouse conditions, the effect that the inoculum of the SAICEUPSMT strain had on the antioxidant capacity of the plant was studied, through the quantification of the enzymatic activity catalase (CAT), ascorbate peroxidase (APX), superoxide dismutase (SOD), and glutathione reductase (GR). Likewise, the capacity of the plant to bioaccumulate mercury in the presence of the inoculum was studied, as well as the effect on the biometric parameters total weight (g), shoot weight (g), root weight (g), shoot length (cm), root length (cm), total number of leaves (N), and total number of secondary roots (No). Finally, in view of the results, the SAICEUPSMT strain was identified from the phenotypic and genotypic point of view (housekeeping genes and complete genome sequencing). The inoculum with the SAICEUPSMT strain in the presence of mercury produced a significant reduction in the enzymatic response to oxidative stress (CAT, APX, and SOD). It can be considered that the strain exerts a phytoprotective effect on the plant. This led to a significant increase in the biometric parameters total plant weight, root weight and the number of leaves under mercury stress, compared to the control without abiotic stress. When analyzing the mercury content of the plant with and without bacterial inoculum, it was found that the incorporation of the SAICEUPSMT strain significantly reduced the uptake of mercury by the plant, while favoring its development in terms of biomass. Given the positive impact of the SAICEUPSMT strain on the integral development of the plant, it was identified, proving to be a Gram negative bacillus, in vitro producer of siderophores, auxins and molecules that inhibit stress precursors. The most represented fatty acids were C16:0 (33.29%), characteristic aggregate 3 (22.80%) comprising C16:1 ω7c and C16: 1ω6c, characteristic aggregate 8 (13.66%) comprising C18:1 ω7c, and C18: 1 cycle ω6c and C 17:0 (11.42%). From the genotypic point of view, the initial identification of the strain based on the 16S rRNA gene sequence classified it as Pseudomonas iranensis. However, genome-wide analysis showed that average nucleotide identity (ANI, 95.47%), DNA-DNA in silico hybridization (dDDH, 61.9%), average amino acid identity (AAI, 97.13%), TETRA (0.99%) and intergenic distance (0.04) values were below the established thresholds for differentiation. The results of the genomic analysis together with the differences in the phenotypic characteristics and the phylogenetic and chemotaxonomic analysis support the proposal of the SAICEUPSMT strain as the type strain of a new species for which the name Pseudomonas mercuritolerans sp. is proposed. No virulence genes or transmissible resistance mechanisms have been identified, which reveals its safety for agronomic uses, under mercury stress conditions.

Electrophysiological and Psychophysical Measures of Temporal Pitch Sensitivity in Normal-hearing Listeners

To obtain combined behavioural and electrophysiological measures of pitch perception, we presented harmonic complexes, bandpass filtered to contain only high-numbered harmonics, to normal-hearing listeners. These stimuli resemble bandlimited pulse trains and convey pitch using a purely temporal code. A core set of conditions consisted of six stimuli with baseline pulse rates of 94, 188 and 280 pps, filtered into a HIGH (3365–4755 Hz) or VHIGH (7800–10,800 Hz) region, alternating with a 36% higher pulse rate. Brainstem and cortical processing were measured using the frequency following response (FFR) and auditory change complex (ACC), respectively. Behavioural rate change difference limens (DLs) were measured by requiring participants to discriminate between a stimulus that changed rate twice (up-down or down-up) during its 750-ms presentation from a constant-rate pulse train. FFRs revealed robust brainstem phase locking whose amplitude decreased with increasing rate. Moderate-sized but reliable ACCs were obtained in response to changes in purely temporal pitch and, like the psychophysical DLs, did not depend consistently on the direction of rate change or on the pulse rate for baseline rates between 94 and 280 pps. ACCs were larger and DLs lower for stimuli in the HIGH than in the VHGH region. We argue that the ACC may be a useful surrogate for behavioural measures of rate discrimination, both for normal-hearing listeners and for cochlear-implant users. We also showed that rate DLs increased markedly when the baseline rate was reduced to 48 pps, and compared the behavioural and electrophysiological findings to recent cat data obtained with similar stimuli and methods.

Early enforcement of cell identity by a functional component of the terminally differentiated state.

How progenitor cells can attain a distinct differentiated cell identity is a challenging problem given the fluctuating signaling environment in which cells exist and that critical transcription factors are often not unique to a differentiation process. Here, we test the hypothesis that a unique differentiated cell identity can result from a core component of the differentiated state doubling up as a signaling protein that also drives differentiation. Using live single-cell imaging in the adipocyte differentiation system, we show that progenitor fat cells (preadipocytes) can only commit to terminally differentiate after up-regulating FABP4, a lipid buffer that is highly enriched in mature adipocytes. Upon induction of adipogenesis in mouse preadipocyte cells, we show that after a long delay, cells first abruptly start to engage a positive feedback between CEBPA and PPARG before then engaging, after a second delay, a positive feedback between FABP4 and PPARG. These sequential positive feedbacks both need to engage in order to drive PPARG levels past the threshold for irreversible differentiation. In the last step before commitment, PPARG transcriptionally increases FABP4 expression while fatty acid-loaded FABP4 increases PPARG activity. Together, our study suggests a control principle for robust cell identity whereby a core component of the differentiated state also promotes differentiation from its own progenitor state.