Frequency Variation Research Articles

Comparative Characteristics of Electrolyte Solutions Using Electrical Impedance Spectroscopy Method

Electrolyte solutions can conduct electric current and help maintain balance in the human body. This study compares the electrical impedance characteristics of various electrolyte solutions using the Electrical Impedance Spectroscopy (EIS) method. Three types of electrolyte solutions were tested: NaCl solution, Ringer’s Lactate (RL) solution, and Simulated Body Fluid (SBF) solution with concentration variations of 20%, 40%, 60%, 80%, and 100%. Measurements were conducted over a frequency range from 1 Hz to 1 MHz to compare electrolyte solutions using a frequency of 10 kHz with an electric current of 50 μA. At a frequency of 10 kHz, a comparison of the three types of electrolyte solutions with concentration variations from 20% to 100% was made. The measurement result showed that the NaCl solution had an impedance value of 200Ω to 900Ω at high frequencies. The Ringer’s Lactate (RL) solution exhibited impedance variations with impedance values ranging from 800Ω to 300Ω, which is more complex due to the other hand, the Simulated Body Fluid (SBF) solution demonstrated impedance stability at high frequencies with impedance values ranging from 400Ω to 200Ω, indicating its electrical properties suitability with human body conditions. Each electrolyte solution has its characteristics in impedance values at a frequency of 10 kHz, which allows for comparing the three types of electrolyte solutions. For further research, additional studies could include impedance characteristics of electrolyte solutions to broaden understanding of their electrical properties, considering variations in frequency and current conditions to optimise impedance characteristic measurements for various electrolyte solutions.

Time course and neural locus of the Flashed Face Distortion Effect

Viewing a rapid sequence of face images shown in the periphery can lead to large caricature-like distortions in the perceived images, a phenomenon known as the Flashed Face Distortion Effect (FFDE). The mechanisms underlying FFDE are poorly understood. Here we examined the timing and sites of the adaptation processes giving rise to the FFDE. To investigate the effects of presentation rate, we maintained consistent trial lengths while assessing how variations in the temporal frequencies of face presentation influenced the magnitude of face distortion and the averaging of facial expressions. Over a wide range of temporal frequencies (1.2–60 Hz) tested, we observed a decrease in FFDE strength as the presentation rate increased. To probe the neural sites of FFDE, we varied whether successive faces were presented to the same or different eyes using a dichoptic display. Distortion effects were comparable for monocular, binocular, and interocular conditions, yet much larger than a control condition where faces were presented with a temporal interval between successive images, suggesting a cortical locus for FFDE.

A Novel SERS Label-Free Sensing Strategy for DON and NIV: A DFT Study on the Interaction between DON/NIV and Ag/Au.

In this study, we propose a novel label-free detection strategy based on surface-enhanced Raman spectroscopy (SERS) for detecting deoxynivalenol (DON) and nivalenol (NIV), analyzing the interactions between these fungal toxins and Ag/Au substrates using density functional theory (DFT). The DFT calculation results indicate that the oxygen atoms in DON and NIV molecules exhibit high electronegativity, suggesting that they can serve as active sites in interaction with the metal surfaces in the SERS effect. By constructing DON/NIV-Ag6/Au6 complex models and evaluating their binding energies, we demonstrate the formation of stable complexes, showing characteristic frequency shifts, broadening, and selective enhancement in theoretical Raman spectra. The results indicate that the structural differences between DON and NIV lead to significant variations in the characteristic frequencies of their theoretical SERS spectra, providing a reproducible and interference-resistant method for the label-free detection of these fungal toxins. This work enhances the understanding of molecular-substrate interactions in SERS effects and provides a theoretical basis for the application of label-free SERS sensing strategies based on characteristic frequency shifts.

20 years of monitoring of a steel jacket offshore platform: variability of environmental and modal parameters

The fixed steel offshore platform VEGA-A has been operating in the Sicily channel since 1988. The platform, one of the largest in the Mediterranean Sea, is equipped with a monitoring system that collects environmental (by means of a current meter, a depth gauge, and a system for detecting wind speed and direction) and structural (by means of nine accelerometers) data. After a description of the recording system, this paper provides a statistical interpretation of the structural response of the platform over the last 20 years. The structural monitoring system is aimed at performing dynamic identification (i.e., evaluating main frequencies and mode shapes), and part of the acquired data is directly processed on the platform in order to constantly check their representativeness in relation to the structural control of the platform. The possible variation of main frequencies and mode shapes over time may be due to both changes in environmental loads/conditions and/or structural damage; in this respect, a data-driven approach capable of recognizing anomalies in the dynamic behavior was adopted here to assess the performances of the platform over the 20 years monitoring period.

Fire history in northern Sierra Nevada mixed conifer forests across a distinct gradient in productivity

BackgroundUnderstanding the role of fire in forested landscapes is fundamental to fire reintroduction efforts, yet few studies have examined how fire dynamics vary in response to interactions between local conditions, such as soil productivity, and more broadscale changes in climate. In this study, we examined historical fire frequency, seasonality, and spatial patterning in mixed conifer forests across a distinct gradient of soil productivity in the northern Sierra Nevada. We cross-dated 46 different wood samples containing 377 fire scars from 6 paired sites, located on and off of ultramafic serpentine soils. Forests on serpentine-derived soils have slower growth rates, lower biomass accumulation, and patchier vegetation than adjacent, non-serpentine sites. Due to these differences, we hypothesized that historical fire frequency and spatial extent would be reduced in mixed conifer forests growing on serpentine soils.ResultsFire scars revealed a history of frequent fire at all of our sites (median composite interval: 6–22.5 years) despite clear differences in soil productivity. Fire frequency was slightly shorter in more productive non-serpentine sites, but this difference was not consistently significant within our sample pairs. While fires were frequent, both on and off of serpentine, they were also highly asynchronous, and this was largely driven by differing climate–fire relationships. Fires in more productive sites were strongly associated with drought conditions in the year of the fire, while fires in less productive serpentine sites appeared to be more dependent on a cycle of wet and dry conditions in the years preceding the fire. Widespread fires that crossed the boundary between serpentine and non-serpentine were associated with drier than normal years.ConclusionsIn our study, fine-scale variation in historical fire regime attributes was linked to both bottom-up and top-down controls. Understanding how these factors interact to create variation in fire frequency, timing, and spatial extent can help managers more effectively define desired conditions, develop management objectives, and identify management strategies for fire reintroduction and forest restoration projects.

Coordinated frequency control strategy for modern power system considering engagement willingness

The large scale integration of renewable energy sources (RES) is posing unprecedented challenges to the frequency stability of modern power systems, with system inertia being the primary concern. Under such a landscape, this paper introduces a coordinated control strategy aiming at enhancing frequency stability by swiftly adjusting the power output of flexible resources to mitigate power imbalances and further dampen frequency fluctuations. Firstly, a communication-free center of inertia (COI) frequency estimation method is proposed. An equivalent inertia estimation method tailored for modern power systems is then developed by exploiting the correlation between synchronous inertia and active power fluctuations. By integrating the COI frequency variation rate with the estimated equivalent inertia, the imbalance power is calculated and compensated through the proposed coordinated control strategy. In this work, two typical flexible resources including photovoltaic (PV) generation and electric vehicles (EVs) are modeled and integrated into the testing system in PSCAD/EMTDC. Considering the contradiction between maximizing generation profit and reducing power output to mitigate frequency variation, the Corporate Social Responsibility (CSR) of renewable Generation Companies (GENCOs) is modeled to sketch their willingness of engaging into frequency support. Moreover, the frequency modulation potential of EVs in both commercial and residential areas are quantified for practical implementation. The simulations results successfully validate the effectiveness of the proposed control strategy.

A Highly Linear Ultra-Low-Area-and-Power CMOS Voltage-Controlled Oscillator for Autonomous Microsystems.

Voltage-controlled oscillators (VCOs) can be an excellent means of converting a magnitude into a readable value. However, their design becomes a real challenge for power-and-area-constrained applications, especially when a linear response is required. This paper presents a VCO for smart dust systems fabricated by 65 nm technology. It is designed to minimize leakage, limit high peak currents and provide an output whose frequency variation is linear with the input voltage, while allowing rail-to-rail input range swing. The oscillator occupies 592 μm2, operates in a frequency range from 43 to 53 Hz and consumes a maximum average power of 210 pW at a supply voltage of 1 V and 4 pW at 0.3 V. In addition, the proposed VCO exhibits a quasi-linear response of frequency vs. supply voltage and temperature, allowing easy temperature compensation with complementary to absolute temperature (CTAT) voltage.

A novel microwave microfluidic sensor for purity detection of Medicines’ raw materials

A novel microwave microfluidic sensor is offered for purity detection of medicine’s raw materials which is composed of two radial components and a PDMS microfluidic holder to apply the test samples. The basis of the sensing method is the shift in the resonance frequency and quality factor of the resonator in the presence of liquids with different complex permittivity. To investigate the performance of the proposed sensor, various solvents, binary mixtures of ethanol–water, and raw materials of 3 different medicines have been checked and a 980 MHz variation of resonance frequency, which provided a very high sensitivity equal to 0.53, was achieved for a complex permittivity range of 1–78.4. The proposed sensor has a small size, simple design, easy fabrication process, and very high sensitivity while it is fabricated on an FR4 substrate which decreases the total cost significantly.

A novel multi-scale gated convolutional neural network based on informer for predicting the remaining useful life of rotating machinery

Abstract Recently, neural networks based on deep learning techniques have been employed for Remaining Useful Life (RUL) prediction of rotating machinery. However, there are some limitations: 1) CNNs primarily use local receptive fields to extract features, which leads to a relative weakness in modeling long-term dependencies on a global scale; 2) Transformers face difficulties when dealing with uncertainties such as anomalies in input sequences, missing data, or variations in sampling frequency. This paper introduces a informer-based multi-scale gated convolutional network (MSGCN-Informer). Initially, a multi-scale gated convolution module is constructed to effectively extract features across various levels, adeptly capturing temporal patterns and long-term dependencies within the dataset. Subsequently, the derived multi-scale degradation features are utilized in predicting the RUL through an informer network, thereby enhancing the efficiency of parallel computing. To validate the effectiveness and superiority of this method, comparative experiments were conducted using two publicly available bearing datasets and various model approaches.

Closed‐form optimal solution of two‐degree‐of‐freedom system with Inerter based on equal modal damping with potential application in non‐structural elevator for seismic control

AbstractTargeting the great demand for adding non‐structural elevators to old residential buildings, this article proposes an updated configuration of tuned mass damper inerter (U‐TMDI) applied in external non‐structural elevators. An analog 2‐DOF system is established to describe the residential building controlled by an inerter elevator. Then, three closed‐form optimal solutions for designing the U‐TMDI are derived via the fixed‐point method, equal modal damping criterion, and the infinity damping assumption. Subsequently, these optimal solutions are compared and discussed involving the expressions of tuning frequency ratio and the optimal damping parameters, root locus diagram and supplemental damping ratios, transfer function, and robustness to frequency variation, respectively. Finally, a residential building example is adopted to validate the feasibility of the proposed retrofitting strategy and the closed‐form optimal design solutions. It is demonstrated that the optimal tuning frequency ratios derived by the fixed‐point method and equal modal damping criterion are different for U‐TMDI due to the influence of elevator stiffness ratio , while its degradation forms for tuned mass damper (TMD) are identical, recognizing the importance of the elevator stiffness. Moreover, the proposed retrofitting strategy of using an inerter elevator can significantly mitigate the main structure displacement by about 18%∼23% for both far‐field and near‐fault earthquakes.

How Do Schumann Resonance Frequency Changes in the Vertical Electric Field Component Reflect Global Lightning Dynamics at Different Time Scales?

AbstractThe electromagnetic waves in the Schumann resonance (SR) frequency range (<100 Hz) radiated by natural “lightning antennas” excite the Earth‐ionosphere cavity confined between the Earth's surface and the lower ionosphere. The peak frequencies of SR are known to vary with source‐observer distance (SOD), while the daily frequency range (DFR: fmax − fmin) is also indicative of the average size of thunderstorm regions. This paper provides observational evidence for these relationships based on SR frequency observations of the vertical electric (EZ) field component at Nagycenk (NCK), Hungary in Central Europe from the period 1994–2015. Variations of the peak frequencies are considered on the annual, seasonal and diurnal time scales as well as during a specific event when squall‐line formation of lightning activity in South America moves toward NCK. DFR is studied in relation to the El Niño Southern Oscillation (ENSO). Increasing area of lightning activity in mid‐high Northern hemisphere latitudes has been identified by DFR variations during the transition from warm to cold episodes of the ENSO in 1998 and 2010. The extension of the lightning area is considered as a consequence of energy released in the tropics and exported to higher latitudes with some months of delay from the end of the El Niño episodes. The frequency variations are interpreted via model calculations and supported with satellite‐based optical lightning observations (Optical Transient Detector, Geostationary Lightning Mapper). The described variations of SR peak frequencies and DFR yield information on the global/regional lightning dynamics and on this basis they have important application to climate issues as well.

Sociolinguistic monitoring and L2 speakers of English

Abstract This study contributes to a growing body of research on the social meanings of linguistic variation with particular interest in the cognitive processes governing their emergence. Our research follows in the tradition of Labov et al.’s (2011) work on the sociolinguistic monitor, a cognitive mechanism hypothesized to track quantitative linguistic variation and prompt social evaluations (Labov et al. 2011. Properties of the sociolinguistic monitor. Journal of Sociolinguistics 15(4). 431–463). Previous research shows that L1 English listeners are sensitive to frequency variation, but it is unclear whether this also applies to L2 listeners. This study thus replicates Labov et al.’s (2011) original experiment in a context where English is primarily acquired through L2 instruction. To test the generality of sociolinguistic monitoring, we investigate L2 listeners’ sensitivity to quantitative differences in sociolinguistic variation (ing) as well as proficiency-based variation. Since participants were L1 speakers of (Austrian) German, we tested evaluations of varying realizations of /θ/ ([θ]/[s]), /d/ ([d]/[t]), and /w/ ([w]/[v]). Experiments included 135 participants, who rated several versions of newscaster test passages regarding professionalism. Our data shows that both sociolinguistic and proficiency-based variation are monitored and evaluated by L2 listeners, albeit to different extents. This supports the assumption that the focus of the monitoring process is socially meaningful variation that includes L1 sociolinguistic but also L2 proficiency-based features.

Robust model-based control and stability analysis of PMSM drive with DC-link voltage and parameter variations

To ensure a stable operation of Permanent Magnet Synchronous Motor (PMSM) drive under both DC link voltage and parameter variations, a robust control technique based on a new dynamic model that includes both drive’s and motor’s specifications is proposed in this paper. In the proposed controller, the first component of the drive’s control law consists of the d-component error of the stator current, and the second one is shaped based on the error in the square value of q-component of the stator current. To further deal with the dynamic alterations of the drive system, compensators are designed to reduce the adverse effects of rotor angular frequency variations and the difference between electrical and load torque errors. Another compensator based on the drive’s output power error is also placed at the q-component of the proposed control law. Moreover, a general operation curve (GOC) for the stator current is introduced to further assess the operation of the PMSM. In the next step, a comprehensive stability analysis verifying the stable operation of both d- and q-components of the stator current is performed using two closed-loop descriptions of the proposed control strategy. Several simulation results in MATLAB/SIMULINK environment are provided to verify the validity of the proposed control technique under various dynamic scenarios. It is worth mentioning that comparative results show that the proposed control technique compared to conventional PI controller has enabled the PMSM speed and torque to reach its 50% and 95% of their desirable values with respectively 42.9% and 28.6% less time. Also, the PMSM speed and torque responses due to proposed control technique have 75% less undershoot compared to conventional PI controller.

Updated Static Influential Factor Analysis for Unidirectional Carbon-Based Composites.

The orientation of carbon fibers significantly affects the dynamic properties of unidirectional carbon-based composites (UCBCs), with variations under different static loads. A previous study analyzed changes in the modal parameters of UCBC structures by using the static load influential factor (SLIF). This study introduces a revised SLIF, derived from a simplified formulation that accounts for shifts in resonance frequency and the in-phase relationship between static load and modal response. The revised SLIF is theoretically linked to the modal participation factor in UCBC structures. The dynamic behavior of UCBCs was studied across six modes-four bending and two torsional-using specimens with five carbon fiber orientations, from 0 to 90 degrees. The revised SLIF showed significant effects in two robust specimens, #1 and #2, and an isotropic SUS304 specimen subjected to uniaxial pre-static load, with resonance frequency variations under 0.16%. In contrast, the original SLIF gave negligible results in the fifth mode due to a damping term, which, when multiplied by the resonance frequency, led to an undetectable indicator. Therefore, the revised SLIF more effectively captures the static load's impact on UCBC dynamic behavior compared with the original method.

Effects of changes in the waveform and frequency of radio frequency energy on tissue ablation range

This study reports the effects of changes in the waveform and frequency of radio frequency (RF) energy on the tissue ablation range. We developed a 70-watt RFA generator that provides sine and square waves and allows frequency control between 10 Hz and 500 kHz. The changes in the ablation range according to the waveform and frequency were observed using the developed generator. In the waveform variation test, the distance between the electrodes and the electrode type were changed for both waveforms with the frequency set to 500 kHz. In the frequency variation test, the waveform and electrode type were changed with the frequency set to 10, 100, and 500 kHz, while the distance between the electrodes was set to 20 mm. A fixed 45 voltage was applied using the bipolar method. RF energy was applied for 90 s in vitro. The temperature was regulated to not exceed 70°C. The ablation range was calculated using ImageJ software. The analysis results showed that the ablation range was larger with the square wave than with the sine wave and at 10 kHz than at 500 kHz. The developed generator can advance research on ablation area and depth in RF ablation.

Characterizing m6A modification factors and their interactions in colorectal cancer: implications for tumor subtypes and clinical outcomes

BackgroundThe study aims to comprehensively combine colorectal cancer data cohorts in order to analyze the effects of various DNA methylation-coding genes on colorectal cancer patients. The annual incidence and mortality of colorectal cancer are very high, and there are no effective treatments for advanced colorectal cancer. DNA methylation is a method widely used to regulate epigenetics in the molecular mechanism study of tumors.MethodThree single-cell cohorts GSE166555, GSE146771, and EMTAB8107, and five transcriptome cohorts GSE17536, GSE39582, GSE72970, and TCGA-CRC (TCGA-COAD and TCGA-READ) were applied in this study. 2 erasers (ALKBH5 and FTO), There are 7 writers (METTL3, METTL14, WTAP, VIRMA, RBM15, RBM15B, and ZC3H13) and 11 readers (YTHDC1, IGF2BP1, IGF2BP2, IGF2BP3, YTHDF1, YTHDF3, YTHDC2, and HNRNPA2B1, YTHDF2, HNRNPC and RBMX), a total of 20 M6A regulators, were used as the basis of the dataset in this study and were applied to the construction of molecular typing and prognostic models. Drugs that are differentially sensitive in methylation-regulated gene-related prognostic models were identified using the ConsensusClusterPlus package, which was also used to identify distinct methylation regulatory expression patterns in colorectal cancer and to model the relationship between tissue gene expression profiles and drug IC50 values. Finally, TISCH2 assessed which immune cells were significantly expressed with M6A scores. The immunosuppression of M6A methylation is spatially explained.ResultsThis study used data from 583 CRC patients in the TCGA-CRC cohort. Firstly, the mutation frequency and CNV variation frequency of 20 m6A modification-related factors were analyzed, and the corresponding histogram and heat map were drawn. The study next analyzed the expression variations between mutant and wild forms of the VIRMA gene and explored differences in the expression of these variables in tumor and normal tissues. In addition, the samples were divided into different subgroups by molecular clustering method based on m6A modification, and each subgroup’s expression and clinicopathological characteristics were analyzed. Finally, we compared prognostic differences, tumor microenvironment (TME) characteristics, immune cell infiltration, and gene function enrichment among different subpopulations. We also developed a colorectal cancer m6A-associated gene signature and validated its prognostic effects across multiple cohorts. Finally, using single-cell RNA sequencing data, we confirmed that tumor cells show elevated expression of m6A-related gene signatures.DiscussionThis study explored the mutation frequency, expression differences, interactions, molecular clustering, prognostic effect, and association with tumor characteristics of m6A modification-related factors in CRC and validated them at the single-cell level. These results clarify the association between m6A alteration and colorectal cancer (CRC) and offer important insights into the molecular recognition and management of cancer.

Epidemiology and Regional Variation in Additional Surgical Interventions for Children with Congenital Diaphragmatic Hernia: A Multi-institutional Analysis.

To determine practice variation in surgical management of co-morbidities in pediatric patients with Congenital Diaphragmatic Hernia (CDH). A higher percentage of CDH patients are surviving to discharge, accompanied by an increase in morbidity requiring surgical interventions such as tracheostomy and gastrostomy tube insertion. The frequency, trends, and regional variations in operative management of these co-morbidities in this population are unclear. Neonates who underwent CDH repair between 2012-2022 in the United States Pediatric Health Information System database were identified. Multivariable regression identified predictive factors for additional surgical morbidity after CDH repair, defined by an additional surgical intervention during index hospitalization or within one year after discharge. To narrow the spectrum of severity of disease, only patients with an intensive care unit admission on index hospitalization were included. Secondary analysis compared frequency of operations and hospital resource utilization by region. 4003 patients underwent CDH repair and were discharged from their index hospitalization. 1939 (48%) underwent at least one additional surgical procedure after the index CDH repair. Most performed surgeries were gastrostomy tube (28%), fundoplication (13%), and tracheostomy (5%). Covariates associated with additional surgical morbidity included: prematurity (OR 1.38; 95% CI: 1.20-1.59), cardiac co-morbidity (OR 1.31; 95% CI: 1.14-1.49), and chromosomal anomalies (OR 1.76, 95% CI: 1.30-2.40). Northeast (OR: 2.43; CI 1.42-3.52), Midwest (OR 2.11; 95% CI: 1.45-3.07), and South (OR 1.45, 95% CI 1.02-2.12) regions were associated with additional surgical morbidity. Patients who required additional surgical procedures had longer initial inpatient length of stays (71 versus 31d) and higher associated costs ($357,000 versus $161,000). Surgical morbidity exists in CDH patients after initial CDH repair. Counseling families on these outcomes is important in establishing expectations for management. Establishing guidelines for optimal surgical management will require continued reporting from multi-institutional studies.

What is airflow vibrato?

Vocal vibrato has a number of manifestations. Typically vibrato is first thought of as a variation in fundamental frequency (fo), and secondarily as a variation in intensity and sound quality. Other variations that accompany these three types of vibrato include movement of throat structures (changes in larynx height, alterations in arytenoid adduction, pharyngeal wall movement, tongue movement, etc.), and especially muscle contraction variations that accompany all mentioned vibrato types.

Impact of Atmospheric Turbulence on Dynamic Wind Loads on Heliostats

This study analyses the turbulent wind properties in the lower 10 m of the atmospheric surface layer close to the ground where heliostats are located. Power spectral densities of streamwise and vertical components of wind are analysed, and the frequencies associated with the peak of the spectra are determined using field data collected at two open-country terrains in addition to spectral models of ESDU85020. Variations of the peak frequencies with height from the ground, terrain type and average wind speed are discussed and the impact on heliostat wind loads are described. It is found that while the peak frequency of the streamwise turbulence is between 0.01–0.1 Hz, the peak of the vertical turbulence occurs at frequencies in the range of 0.1–1 Hz. It is shown that smaller heliostats that are located closer to the ground are exposed to turbulent wind fluctuations at a higher frequency and are thus expected to experience wind loads with a higher dominant frequency compared to larger heliostats located higher above the ground. These frequencies need to be considered in design of heliostat drives and structural components

Assessing the impact of engine and non-engine urban noises on the calls of urban frogs: a natural experiment

Urban noise can potentially disturb the acoustic signals of animals inhabiting urban areas. Although a wide variety of noises from different sources is common in cities, the impact of non-engine noise on animal calls is less studied. In a natural experiment, we evaluated the effect of different urban noises on the advertisement calls of urban frogs (Eleutherodactylus nitidus) in the metropolitan area of Puebla, Mexico. We recorded and analyzed 672 advertisement calls from 28 male frogs and the corresponding environmental noises from three distinct localities. Our analysis focused on four acoustic properties of the calls: inter-call interval, call duration, dominant frequency, and call amplitude. To standardize the amplitude measurements of sound pressure levels produced by noise and frog calls, we employed a practical approach using a reference signal for calibration. We treated the longitudinal data of different noises occurring before, during, and after advertisement calls as repeated measures within the urban locations. During our samplings, frogs called amidst spontaneous urban noises, including dog barking, fireworks, and vehicle engine sounds. Our results indicate that vehicle engine sounds and dog barking do not cause significant distortions in the calls of these urban frogs. However, we observed slight variations in the dominant frequency of calls, decreasing by 11 Hz, during and after fireworks. Given the observed plasticity of E. nitidus in response to noise, urban noises may not pose a severe problem for this urban frog.