scholarly journals Sometimes noise is beneficial: stream noise informs vocal communication in the little torrent frog

2016 ◽  
Author(s):  
Longhui Zhao ◽  
Jichao Wang ◽  
Steven E. Brauth ◽  
Yezhong Tang ◽  
Jianguo Cui
Keyword(s):  
Ambient Noise ◽  
Animal Species ◽  
Vocal Communication ◽  
Information Source ◽  
High Amplitude ◽  
Dominant Frequency ◽  
Noise Sources ◽  
Running Water ◽  
Sound Communication ◽  
Low Amplitude

Many animal species use acoustic signals for social communication including attracting mates, defending resources and assessing risks. Nevertheless, a variety of ambient noise sources often interfere with sound communication and efficient decision making. In the present study we identified an exception to this generalization in a streamside species, the little torrent frog (Amolops torrentis) which communicates in an environment in which stream noise is always present. To show that stream noise can act as a biological signal which reflects the character of the microhabitat of the sender, we performed female phonotaxis experiments using synthetic male advertisement calls. Calls with high dominant frequency exceeding the ambient stream noise band and calls with lower dominant frequency centered at the frequency range of best hearing were used. The signal-noise ratio was varied by adding noise to each kind of call. We found that females prefer calls with high amplitude stream noise added to those with low amplitude stream noise added for both the high and low dominant frequency stimulus pairs; however, the sound of running water had no attractiveness in the absence of calls. These results show that stream noise can function as an information source by enhancing the attractiveness of calls in the torrent frog. Stream noise associates closely with rocks, topographies and vegetation; thus the sound of running water may provide useful information to signal receivers about variations in microhabitats and thereby act on sexual selection under some circumstances. These data therefore contribute to our understanding of how the perception of mate attractiveness in heterogeneous ecological environments can evolve.

scholarly journals Sometimes noise is beneficial: stream noise informs vocal communication in the little torrent frog

2016 ◽  
Author(s):  
Longhui Zhao ◽  
Jichao Wang ◽  
Steven E. Brauth ◽  
Yezhong Tang ◽  
Jianguo Cui
Keyword(s):  
Ambient Noise ◽  
Animal Species ◽  
Vocal Communication ◽  
Information Source ◽  
High Amplitude ◽  
Dominant Frequency ◽  
Noise Sources ◽  
Running Water ◽  
Sound Communication ◽  
Low Amplitude

Many animal species use acoustic signals for social communication including attracting mates, defending resources and assessing risks. Nevertheless, a variety of ambient noise sources often interfere with sound communication and efficient decision making. In the present study we identified an exception to this generalization in a streamside species, the little torrent frog (Amolops torrentis) which communicates in an environment in which stream noise is always present. To show that stream noise can act as a biological signal which reflects the character of the microhabitat of the sender, we performed female phonotaxis experiments using synthetic male advertisement calls. Calls with high dominant frequency exceeding the ambient stream noise band and calls with lower dominant frequency centered at the frequency range of best hearing were used. The signal-noise ratio was varied by adding noise to each kind of call. We found that females prefer calls with high amplitude stream noise added to those with low amplitude stream noise added for both the high and low dominant frequency stimulus pairs; however, the sound of running water had no attractiveness in the absence of calls. These results show that stream noise can function as an information source by enhancing the attractiveness of calls in the torrent frog. Stream noise associates closely with rocks, topographies and vegetation; thus the sound of running water may provide useful information to signal receivers about variations in microhabitats and thereby act on sexual selection under some circumstances. These data therefore contribute to our understanding of how the perception of mate attractiveness in heterogeneous ecological environments can evolve.

scholarly journals Mechanistic Characteristics of Double Dominant Frequencies of Acoustic Emission Signals in the Entire Fracture Process of Fine Sandstone

Energies ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3959 ◽  
Author(s):  
Chuangye Wang ◽  
Xinke Chang ◽  
Yilin Liu ◽  
Shijiang Chen
Keyword(s):  
Frequency Band ◽  
High Frequency ◽  
Fracture Process ◽  
Low Frequency ◽  
High Amplitude ◽  
Dominant Frequency ◽  
Band Energy ◽  
Ae Signal ◽  
Low Amplitude ◽  
Frequency Band Energy

To determine the intrinsic relationship between the acoustic emission (AE) phenomenon and the fracture pattern pertaining to the entire fracture process of rock, the present paper proposed a multi-dimensional spectral analysis of the AE signal released during the entire process. Some uniaxial compression AE tests were carried out on the fine sandstone specimens, and the axial compression stress–strain curves and AE signal released during the entire fracture process were obtained. In order to deal with tens of thousands of AE data efficiently, a subroutine was programmed in MATLAB. All AE waveforms of the tests were denoised by wavelet threshold firstly. The fast Fourier transform (FFT) and wavelet packet transform (WPT) were applied to the denoised waveforms to obtain the dominant frequency, amplitude, fractal, and frequency band energy ratio distribution. The results showed that the AE signal in the entire fracture process of fine sandstone had a double dominant frequency band of the low and high-frequency bands, which can be subdivided into low-frequency low-amplitude, high-frequency low-amplitude, high-frequency high-amplitude, and low-frequency high-amplitude signals, according to the magnitude. The low-frequency amplitude relevant fractal dimension and the high-frequency amplitude relevant fractal dimension each had turning points that corresponded to significant decreases in the middle and end stages of loading, respectively. The frequency band energy was mainly concentrated in the range of 0–187.5 kHz, and the energy ratios of some bands had different turning points, which appeared before the complete failure of the rock. It is suggested that the multi-dimensional spectral analysis may understand the failure mechanism of rock better.

scholarly journals Vocal plasticity in a reptile

2017 ◽  
Vol 284 (1855) ◽  
pp. 20170451 ◽  
Author(s):  
Henrik Brumm ◽  
Sue Anne Zollinger
Keyword(s):  
Signal Detection ◽  
Communication Systems ◽  
Vocal Communication ◽  
Animal Communication ◽  
High Amplitude ◽  
Vocal Plasticity ◽  
Lombard Effect ◽  
Gekko Gecko ◽  
High Degree ◽  
Signalling Systems

Sophisticated vocal communication systems of birds and mammals, including human speech, are characterized by a high degree of plasticity in which signals are individually adjusted in response to changes in the environment. Here, we present, to our knowledge, the first evidence for vocal plasticity in a reptile. Like birds and mammals, tokay geckos ( Gekko gecko ) increased the duration of brief call notes in the presence of broadcast noise compared to quiet conditions, a behaviour that facilitates signal detection by receivers. By contrast, they did not adjust the amplitudes of their call syllables in noise (the Lombard effect), which is in line with the hypothesis that the Lombard effect has evolved independently in birds and mammals. However, the geckos used a different strategy to increase signal-to-noise ratios: instead of increasing the amplitude of a given call type when exposed to noise, the subjects produced more high-amplitude syllable types from their repertoire. Our findings demonstrate that reptile vocalizations are much more flexible than previously thought, including elaborate vocal plasticity that is also important for the complex signalling systems of birds and mammals. We suggest that signal detection constraints are one of the major forces driving the evolution of animal communication systems across different taxa.

Frequency Response Analysis of Piecewise Nonlinear Vibration Isolator

2005 ◽  
Author(s):  
Patrick Stahl ◽  
G. Nakhaie Jazar
Keyword(s):  
Low Frequency ◽  
High Amplitude ◽  
Relative Displacement ◽  
Response Analysis ◽  
Frequency Response Analysis ◽  
State Behavior ◽  
Vibration Isolators ◽  
Short Period ◽  
Secondary Suspension ◽  
Low Amplitude

Non-smooth piecewise functional isolators are smart passive vibration isolators that can provide effective isolation for high frequency/low amplitude excitation by introducing a soft primary suspension, and by preventing a high relative displacement in low frequency/high amplitude excitation by introducing a relatively damped secondary suspension. In this investigation a linear secondary suspension is attached to a nonlinear primary suspension. The primary is assumed to be nonlinear to model the inherent nonlinearities involved in real suspensions. However, the secondary suspension comes into action only during a short period of time, and in mall domain around resonance. Therefore, a linear assumption for the secondary suspension is reasonable. The dynamic behavior of the system subject to a harmonic base excitation has been analyzed utilizing the analytic results derived by applying the averaging method. The analytic results match very well in the transition between the two suspensions. A sensitivity analysis has shown the effect of varying dynamic parameters in the steady state behavior of the system.

Circadian clock precision, health, and longevity

2021 ◽  
Vol 23 (1) ◽  
pp. 3-15
Author(s):  
D. G. Gubin ◽  
◽  
S. N. Kolomeichuk ◽  
D. Weinert ◽  
◽  
...  
Keyword(s):  
Health Status ◽  
Circadian Rhythms ◽  
Life Expectancy ◽  
Circadian Clock ◽  
Animal Species ◽  
Genetic Factors ◽  
High Amplitude ◽  
Phenotypic Trait ◽  
Precision Health ◽  
Lower Morbidity

An accurate circadian clock, associated with the precise intrinsic period, tau, can be linked with a definite chronotype and health status. Exemplified by different animal species, and, as we argue herein, may as well be in humans, endogenous tau close enough to 24 hours is associated with higher life expectancy, lower morbidity, and is possibly adhered to moderate morning chronotype. Accurate circadian tau facilitates maintaining a high amplitude of circadian rhythms, a phenotypic trait that is related to health and longevity. Some genetic factors that coordinate tau and ensure circadian clock precision is considered.

scholarly journals Duetting Patterns of Titi Monkeys (Primates, Pitheciidae: Callicebinae) and Relationships with Phylogeny

Animals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 178 ◽  
Author(s):  
Patrice Adret ◽  
Kimberly Dingess ◽  
Christini Caselli ◽  
Jan Vermeer ◽  
Jesus Martínez ◽  
...  
Keyword(s):  
Vocal Communication ◽  
Power Spectral Analysis ◽  
Dominant Frequency ◽  
Sensu Stricto ◽  
Potential Contribution ◽  
Linear Discriminant ◽  
Loud Calls ◽  
Titi Monkeys ◽  
Socially Monogamous ◽  
Habitat Acoustics

Long-range vocal communication in socially monogamous titi monkeys is mediated by the production of loud, advertising calls in the form of solos, duets, and choruses. We conducted a power spectral analysis of duets and choruses (simply “duets” hereafter) followed by linear discriminant analysis using three acoustic parameters—dominant frequency of the combined signal, duet sequence duration, and pant call rate—comparing the coordinated vocalizations recorded from 36 family groups at 18 sites in Bolivia, Peru and Ecuador. Our analysis identified four distinct duetting patterns: (1) a donacophilus pattern, sensu stricto, characteristic of P. donacophilus, P. pallescens, P. olallae, and P. modestus; (2) a moloch pattern comprising P. discolor, P. toppini, P. aureipalatii, and P. urubambensis; (3) a torquatus pattern exemplified by the duet of Cheracebus lucifer; and (4) the distinctive duet of P. oenanthe, a putative member of the donacophilus group, which is characterized by a mix of broadband and narrowband syllables, many of which are unique to this species. We also document a sex-related difference in the bellow-pant phrase combination among the three taxa sampled from the moloch lineage. Our data reveal a presumptive taxonomic incoherence illustrated by the distinctive loud calls of both P. urubambensis and P. oenanthe within the donacophilus lineage, sensu largo. The results are discussed in light of recent reassessments of the callicebine phylogeny, based on a suite of genetic studies, and the potential contribution of environmental influences, including habitat acoustics and social learning. A better knowledge of callicebine loud calls may also impact the conservation of critically endangered populations, such as the vocally distinctive Peruvian endemic, the San Martin titi, P. oenanthe.

Application of instantaneous rotations to S‐wave vertical seismic profiling

Geophysics ◽  
1997 ◽  
Vol 62 (5) ◽  
pp. 1365-1368
Author(s):  
M. Boulfoul ◽  
Doyle R. Watts
Keyword(s):  
High Amplitude ◽  
Seismic Profile ◽  
P Wave ◽  
Petroleum Exploration ◽  
S Wave ◽  
Amplitude Variation With Offset ◽  
Seismic Profiling ◽  
Vertical Seismic Profiling ◽  
Seismic Models ◽  
Low Amplitude

The petroleum exploration industry uses S‐wave vertical seismic profiling (VSP) to determine S‐wave velocities from downgoing direct arrivals, and S‐wave reflectivities from upgoing waves. Seismic models for quantitative calibration of amplitude variation with offset (AVO) data require S‐wave velocity profiles (Castagna et al., 1993). Vertical summations (Hardage, 1983) of the upgoing waves produce S‐wave composite traces and enable interpretation of S‐wave seismic profile sections. In the simplest application of amplitude anomalies, the coincidence of high amplitude P‐wave reflectivity and low amplitude S‐wave reflectivity is potentially a direct indicator of the presence of natural gas.

Thermal-diffusivity measurements by the converging-thermal-wave technique

1986 ◽  
Vol 64 (9) ◽  
pp. 1172-1177 ◽  
Author(s):  
P. Cielo ◽  
L. A. Utracki ◽  
M. Lamontagne
Keyword(s):  
Thermal Diffusivity ◽  
Thermal Wave ◽  
Infrared Detector ◽  
Thermal Flux ◽  
Thin Sheet ◽  
High Amplitude ◽  
Practical Implementation ◽  
Noise Sources ◽  
Wave Technique ◽  
Effect Of Surface

A converging-thermal-wave technique is described for the measurement of thermal diffusivity in bulk or thin-sheet materials. An annular-shaped area is heated by a pulsed laser beam focused on the material's surface through a combination of spherical and conical lenses, and the surface temperature is monitored by an infrared detector focused on the center of the annulus. The converging action of the thermal flux results in a high amplitude of the detected signal with little overheating of the irradiated material. An analysis of such a technique is presented, as well as some experimental results obtained on heterogeneous materials. Several aspects relevant to the practical implementation of such a technique in an industrial environment, such as the effect of surface losses and different noise sources, are discussed.

A Method for Noise Source Levels Inversion with Underwater Ambient Noise Generated by Typhoon in Deep Ocean

2018 ◽  
Vol 26 (02) ◽  
pp. 1850007 ◽  
Author(s):  
Qiulong Yang ◽  
Kunde Yang ◽  
Shunli Duan
Keyword(s):  
Ambient Noise ◽  
Noise Source ◽  
Surface Wind ◽  
Deep Ocean ◽  
Noise Sources ◽  
Noise Field ◽  
Sea Surface Wind ◽  
Source Level ◽  
The Western Pacific ◽  
Good Agreement

Sea-surface wind agitation can be considered the dominant noise sources whose intensity relies on local wind speed during typhoon period. Noise source levels in previous researches may be unappreciated for all oceanic regions and should be corrected for modeling typhoon-generated ambient noise fields in deep ocean. This work describes the inversion of wind-driven noise source level based on a noise field model and experimental measurements, and the verification of the inverted noise source levels with experimental results during typhoon period. A method based on ray approach is presented for modeling underwater ambient noise fields generated by typhoons in deep ocean. Besides, acoustic field reciprocity is utilized to decrease the calculation amount in modeling ambient noise field. What is more, the depth dependence and the vertical directionality of noise field based on the modeling method and the Holland typhoon model are evaluated and analyzed in deep ocean. Furthermore, typhoons named “Soulik” in 2013 and “Nida” in 2016 passed by the receivers deployed in the western Pacific (WP) and the South China Sea (SCS). Variations in sound speed profile, bathymetry, and the related oceanic meteorological parameters are analyzed and taken into consideration for modeling noise field. Boundary constraint simulated annealing (SA) method is utilized to invert the three parameters of noise source levels and to minimize the objective function value. The prediction results with the inverted noise source levels exhibit good agreement with the measured experiment data and are compared with predicted results with other noise sources levels derived in previous researches.

Variability of the dynamics of somatometric parameters in schoolchildren with different nutritional status (longitudinal study)

2020 ◽  
Vol 15 (5) ◽  
pp. 68-72
Author(s):  
V.L. Gritsinskaya ◽  
◽  
V.P. Novikova ◽  
A.I. Khavkin ◽  
◽  
...  
Keyword(s):  
Nutritional Status ◽  
High Amplitude ◽  
Physical Development ◽  
Growth Spurt ◽  
Pubertal Growth Spurt ◽  
Pubertal Growth ◽  
Normal Limits ◽  
Study Participants ◽  
Two Peaks ◽  
Low Amplitude

Objective. To identify specific features of pubertal growth spurt in adolescents depending on their nutritional status in prepuberty. Patients and methods. We analyzed the dynamics of height and weight in 645 children (331 boys and 314 girls) aged between 8 and 16 years. All study participants were divided into three groups depending on whether their weight and height at the age of 8 years were within the normal limits given in the ‘WHO Growth Reference 2007’: children with physical development; underweight children; and overweight children. Results. The dynamics of somatometric parameters during pubertal growth spurt varied between children with different nutritional status. Underweight boys demonstrated prolonged and low-amplitude pubertal growth pattern; in boys with normal physical development, the growth spurt was usually shorter and had high amplitude. In overweight boys, the pubertal growth spurt started with higher annual increase in height, had a more pronounced amplitude, and was shorter than in peers (р < 0.001 ÷ р < 0.05). Both underweight girls and girls with normal physical development demonstrated low-amplitude pubertal growth spurt lasting for two years. Overweight girls had two peaks of pubertal growth spurt, which usually started earlier than in other girls (р < 0.001 ÷ р < 0.01). Conclusion. Our findings can be used as a guide for predicting pubertal spurt in children during medical examinations, determining adequate physical activity in physical education classes at school and in sports sections. Key words: children, nutritional status, pubertal growth spurt

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