scholarly journals Estimating the frequency dependent behavior of marine sediment sound speeds using low frequency aircraft sound

2008 ◽  
Vol 123 (5) ◽  
pp. 3349-3349
Author(s):  
Alireza Amiri‐Simkooei ◽  
Mirjam Snellen ◽  
Dick G. Simons ◽  
Michael Buckingham
Keyword(s):  
Marine Sediment ◽  
Low Frequency ◽  
Frequency Dependent ◽  
Sound Speeds ◽  
Dependent Behavior

scholarly journals A TEST FOR RARE MALE MATING ADVANTAGE WITH DROSOPHILA PSEUDOOBSCURA KARYOTYPES

Genetics ◽  
1984 ◽  
Vol 107 (4) ◽  
pp. 577-589
Author(s):  
Wyatt W Anderson ◽  
Celeste J Brown
Keyword(s):  
Mating Success ◽  
Low Frequency ◽  
Behavioral Observation ◽  
Drosophila Pseudoobscura ◽  
Male Mating ◽  
Frequency Dependent ◽  
Mating Advantage ◽  
Large Numbers ◽  
Laboratory Populations ◽  
Statistical Artifact

ABSTRACT Recent work has called into question the reality of the rare male mating advantage, pointing out that it could be a statistical artifact of marking flies for behavioral observation or of experimental bias in collecting males. We designed an experiment to test for rare male mating advantage that avoids these sources of bias. Large numbers of males of three Drosophila pseudoobscura karyotypes were allowed to mate with females of one karyotype in population cages. The females were then isolated before multiple mating occurred and their progeny used to diagnose the males that mated them. Populations were studied at five sets of male karyotypic frequencies. The mating success of the male homokaryotypes ST/ST and CH/CH, relative to that of the heterokaryotype ST/CH, was frequency dependent. Both ST/ST and CH/CH males displayed a statistically significant mating advantage at low frequency by comparision with their mating success in the midrange of karyotypic frequencies. Both male homokaryotypes also showed a significantly greater mating success at high homokaryotypic frequency than at intermediate frequencies, which is the same as saying that the heterokaryotype not only failed to show a rare male advantage but actually suffered a mating disadvantage at low frequency. We conclude that rare male mating advantage is not always an experimental or methodological artifact but does occur in laboratory populations of D. pseudoobscura. It may occur for some genotypes and not for others, however, and it may be only one of several forms of frequency-dependent mating behavior operating in a population.

scholarly journals Reproducibility of frequency-dependent low frequency fluctuations in reaction time over time and across tasks

PLoS ONE ◽  
2017 ◽  
Vol 12 (9) ◽  
pp. e0184476 ◽  
Author(s):  
Zan-Zan Liu ◽  
Hui-Jie Qu ◽  
Zhuo-Ling Tian ◽  
Meng-Jian Han ◽  
Yi Fan ◽  
...  
Keyword(s):  
Reaction Time ◽  
Low Frequency ◽  
Frequency Dependent ◽  
Frequency Fluctuations ◽  
Over Time

Mapping of induced polarization using natural fields

Geophysics ◽  
2001 ◽  
Vol 66 (1) ◽  
pp. 137-147 ◽  
Author(s):  
Erika Gasperikova ◽  
H. Frank Morrison
Keyword(s):  
Electric Field ◽  
Surrounding Medium ◽  
Low Frequency ◽  
Induced Polarization ◽  
The Body ◽  
Electromagnetic Response ◽  
Frequency Dependent ◽  
Finite Body ◽  
Electric Field Profile ◽  
Measured Response

The observed electromagnetic response of a finite body is caused by induction and polarization currents in the body and by the distortion of the induction currents in the surrounding medium. At a sufficiently low frequency, there is negligible induction and the measured response is that of the body distorting the background currents just as it would distort a direct current (dc). Because this dc response is not inherently frequency dependent, any observed change in response of the body for frequencies low enough to be in this dc limit must result from frequency‐dependent conductivity. Profiles of low‐frequency natural electric (telluric) fields have spatial anomalies over finite bodies of fixed conductivity that are independent of frequency and have no associated phase anomaly. If the body is polarizable, the electric field profile over the body becomes frequency dependent and phase shifted with respect to a reference field. The technique was tested on data acquired in a standard continuous profiling magnetotelluric (MT) survey over a strong induced polarization (IP) anomaly previously mapped with a conventional pole‐dipole IP survey. The extracted IP response appears in both the apparent resistivity and the normalized electric field profiles.

Low-frequency layer-induced kinematic parameters in transversely isotropic media and orthorhombic media

2019 ◽  
Vol 220 (2) ◽  
pp. 839-855
Author(s):  
Da Shuai ◽  
Alexey Stovas
Keyword(s):  
Volume Fraction ◽  
Velocity Ratio ◽  
Symmetry Plane ◽  
Low Frequency ◽  
Transversely Isotropic ◽  
Kinematic Parameters ◽  
Frequency Dependent ◽  
Cross Term ◽  
Transversely Isotropic Media ◽  
Isotropic Media

SUMMARY We develop a method to compute frequency-dependent kinematic parameters for an effective orthorhombic (ORT) medium. In order to investigate the influence of fracture weaknesses on the kinematic parameters, the effective ORT medium is composed based on the linear slip theory and derived by applying the limited Baker–Campbell–Hausdorff series. The frequency-dependent kinematic parameters including vertical velocity, two normal moveout velocities defined in vertical symmetry planes, and three anelliptic parameters (two of them are defined in vertical symmetry plane and one parameter is the cross-term one). We also investigate the influence of volume fraction, frequency, velocity ratio and fracture weaknesses on the effective kinematic parameters.

scholarly journals A Parametric Study on the Immunomodulatory Effects of Electroacupuncture in DNP-KLH Immunized Mice

2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
Sun Kwang Kim ◽  
Youngseop Lee ◽  
Hyunjoo Cho ◽  
Sungtae Koo ◽  
Sun Mi Choi ◽  
...  
Keyword(s):  
Parametric Study ◽  
High Frequency ◽  
Low Frequency ◽  
Specific Ige ◽  
Th2 Cytokines ◽  
Immunomodulatory Effects ◽  
Frequency Dependent ◽  
Total Ige ◽  
The Difference

This study was conducted to compare the effects of low frequency electroacupuncture (EA) and high frequency EA at acupoint ST36 on the production of IgE and Th1/Th2 cytokines in BALB/c mice that had been immunized with 2,4-dinitrophenylated keyhole limpet protein (DNP-KLH), as well as to investigate the difference in the immunomodulatory effects exerted by EA stimulations at acupoint ST36 and at a non-acupoint (tail). Female BALB/c mice were divided into seven groups: normal (no treatments), IM (immunization only), ST36-PA (IM + plain acupuncture at ST36), ST36-LEA (IM + low frequency (1 Hz) EA at ST36), ST36-HEA (IM + high frequency (120 Hz) EA at ST36), NA-LEA (IM + low frequency (1 Hz) EA at non-acupoint) and NA-HEA (IM + high frequency (120 Hz) EA at non-acupoint). EA stimulation was performed daily for two weeks, and total IgE, DNP-KLH specific IgE, IL-4 and IFN-γlevels were measured at the end of the experiment. The results of this study showed that the IgE and IL-4 levels were significantly suppressed in the ST36-LEA and ST36-HEA groups, but not in the NA-LEA and NA-HEA groups. However, there was little difference in the immunomodulatory effects observed in the ST36-LEA and ST36-HEA groups. Taken together, these results suggest that EA stimulation-induced immunomodulation is not frequency dependent, but that it is acupoint specific.

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