mteb/BrightProPsychologyRetrieval huggingface dataset:
Polarized light microscopy  33  ,  34  ,  35  ,  36  ,  37
.") was used to
measure the birefringence of fine structures in the BM to obtain detailed
analyses of changes in the anisotropy of the BM during its development
(Supplementary Fig.  1  ).
Birefringence imaging was performed on thin optical sections in 0.5 μm
increments of acutely isolated, unfixed BM, which avoided artifacts associated
with fixation and dehydration (Supplementary Fig.  2
 ). The technique examines the
anisotropy of the refractive index in birefringent materials using polarized
of light. The collagen fibers of the BM are intrinsically birefringent  38  ,
39  ,  40  ,  41 .") and constitute its dominant birefringent component. The fiber
orientation in the thin optical sections is revealed by the axis of high
refractive index, also called slow axis   33
.") ,  38 , 305–310
\(2006\).") . The slow axis or fiber orientation is shown in pseudocolor
images with a color wheel that associates a specific hue with an orientation
(Fig.  1  G). Our data confirm that the
collagen networks of the BM are positive birefringent materials (Fig.  1
 B,D) where the extraordinary refractive
index is greater than the ordinary index and the slow optic axis is oriented
along the axis of the fiber, consistent with previous reports (Fig.  1
 C,E;   38
, 305–310
\(2006\).") ,  40 .") ). To study structural
differences in the developing BM architecture, images were collected at
various stages of development along the tonotopic axis. Example of images
collected from the basal end of immature (P10) and mature (P20) BM in Figs. 
1  C and E show developmental differences
in the arrangement and orientation of fibers as reflected in the greater
uniformity in color of the mature BM.
1. ** ^  **  "Definition of FREQUENCY"  . Retrieved  3 October  2016  .
2. ** ^  **  "Definition of PERIOD"  . Retrieved  3 October  2016  .
3. ** ^  ** Serway & Faughn 1989  , p. 346.
4. ^  _**a** _ _**b** _ Serway & Faughn 1989  , p. 354.
5. ** ^  **  "Resolution 12 of the 11th CGPM (1960)"  . BIPM (International Bureau of Weights and Measures). Archived from  the original  on 8 April 2020  . Retrieved  21 January  2021  .
6. ** ^  **  "Special Publication 811: NIST Guide to the SI, Chapter 8"  . _NIST_ . 28 January 2016  . Retrieved  2022-11-08  .
7. ** ^  ** Davies 1997  , p. 275.
8. ** ^  ** Young 1999  , p. 7.
9. ** ^  ** Boreman, Glenn D.  "Spatial Frequency"  .  SPIE  . Retrieved  22 January  2021  .
10. ** ^  ** Bakshi, K.A.; A.V. Bakshi; U.A. Bakshi (2008).  _Electronic Measurement Systems_  . US: Technical Publications. pp. 4–14.  ISBN  "ISBN \(identifier\)")  978-81-8431-206-5   .  [ _ permanent dead link   _ ]
11. ** ^  **  "Definition of SOUND"  . Retrieved  3 October  2016  .
12. ** ^  ** Pilhofer, Michael (2007).  _Music Theory for Dummies_  . For Dummies. p. 97.  ISBN  "ISBN \(identifier\)")  978-0-470-16794-6   .
13. ** ^  ** Condon, Tim (2003). Elert, Glenn (ed.).  "Frequency range of dog hearing"  . _The Physics Factbook_ . Retrieved  2008-10-22  .
14. ** ^  ** Lombardi, Michael A. (2007). "Fundamentals of Time and Frequency". In Bishop, Robert H. (ed.). _Mechatronic Systems, Sensors, and Actuators: Fundamentals and Modeling_ . Austin: CRC Press.  ISBN  "ISBN \(identifier\)")  9781420009002   .
15. ** ^  ** Newell, David B; Tiesinga, Eite (2019).  The international system of units (SI)  (PDF)  (Report). Gaithersburg, MD: National Institute of Standards and Technology.  doi  "Doi \(identifier\)") :  10.6028/nist.sp.330-2019  .  sub§2.3.4, Table 4.
###  Stroboscope
Other units
###  Light
For cyclical phenomena such as  oscillations  ,  waves  , or for examples of  simple
harmonic motion  , the
term _frequency_ is defined as the number of cycles or repetitions per unit of
time. The conventional symbol for frequency is _f_ or _ν_ (the Greek letter 
nu  "Nu \(letter\)") ) is also used.  [3]  The _period_
_T_ is the time taken to complete one cycle of an oscillation or rotation. The
frequency and the period are related by the equation  [4]
*   Physics
* cycle per second (cps)
*  revolution per minute  (rpm or r/min)
Emilin2 was recently reported to be responsible for providing the mature BM
with elasticity and mechanical frequency resolution   18
.") . We,
therefore, investigated the developmental role of emilin2 in BM maturation.
The BMs of mice that do not express emilin2 (emilin2  −/−  ) appear to display
an immature phenotype throughout life (Fig.  4
 A), resulting in reported functional
consequences (Russell et al., 2020). Within a given emilin2  +/+  preparation,
the image color was constant for > P10, indicating uniform alignment of
collagenous fibers within the preparation, (Fig.  4
 A top row). In contrast, in emilin2  −/−
mice, this uniformity was disturbed, as indicated by the varied colors of
fibers within a preparation throughout development and maturation (Fig.  4
 A bottom row). The thickness and spacing
of fibers and bundles of fibers also showed increases in emilin2  −/−
compared to emilin2  +/+  preparations, consistent with the disorder of these
structures (Fig.  4  B–E).
Above the range of frequency counters, frequencies of electromagnetic signals
are often measured indirectly utilizing  heterodyning  (  frequency conversion  ). A reference signal of a known frequency near the unknown
frequency is mixed with the unknown frequency in a nonlinear mixing device
such as a  diode  . This creates a  heterodyne
 or "beat" signal at the difference between
the two frequencies. If the two signals are close together in frequency the
heterodyne is low enough to be measured by a frequency counter. This process
only measures the difference between the unknown frequency and the reference
frequency. To reach higher frequencies, several stages of heterodyning can be
used. Current research is extending this method to infrared and light
frequencies (  optical heterodyne detection
 ).
When  monochromatic waves  travel from one  medium  "Medium
\(optics\)") to another, their frequency remains the same—only their
wavelength and  speed  change.
Retrieved from " 
https://en.wikipedia.org/w/index.php?title=Frequency&oldid=1213386947
 "
**Figure 1**
* 4  Citations
In addition to providing an anatomical basis for tonotopic maps and frequency
tuning, the BM may interact with the cellular responses of the OC sensory and
supporting cells, with which it in close contact, thereby further influencing
cochlear responses beyond alterations in the tonotopicity of the BM   66
.") ,  67
.") . Macrophages located
within the BM activate in response to sensory cell damage during acute stress
(e.g. NIHL) and chronic stress (e.g. presbycusis). Macrophages are the major
innate immune cells in the cochlea, and important drivers of inflammatory and
tissue repair responses after cochlear injury  68  ,  69  ,  70
.") . However, it is not clear if the
sensory cells become damaged first and then initiate a macrophage immune
response, or if perhaps there is dysregulation of cochlear immune responses
within the BM which cause damage to the sensory epithelium   71
.") .
Either way, this is one example which illustrates the possibility that
structural elements of the BM interact with their environment, including the
sensory epithelium. This also suggests that the BM is capable of adaptation to
changes in the local sensory epithelium environment influenced by sensory cell
status. Moreover, the changes in BM responses and passive mechanics were
reported in cochlear connexin30 A88V mutants   72
.") . Connexin 30 is one of two
most prevalent gap junctional proteins localized in the cochlear supporting
cells which are located on top of the BM. This creates a possibility for a
structural remodeling of the BM, due to signaling alterations in supporting
cells, which is yet to be investigated   73
.") .
Chapter  
Google Scholar
Psychoacoustics  |
###   Neuronal dynamics direct cerebrospinal fluid perfusion and brain
clearance
###   Supplementary Information 1.
*  Frequency
As a matter of convenience, longer and slower waves, such as  ocean surface
waves  , are more typically
described by wave period rather than frequency.  [8]  Short and fast waves,
like  audio  and radio, are usually described by their
frequency. Some commonly used conversions are listed below:
###  Experimental methods
###   A single-cell time-lapse of mouse prenatal development from gastrula to
birth
* Article
*  Open access 
* Published:  07 April 2021
119 languages
Article  28 February 2024
Article   CAS
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d  θ  d  t  =  ω  =  2  π  f  .  {\displaystyle {\frac {\mathrm {d} \theta
}{\mathrm {d} t}}=\omega =2\mathrm {\pi } f.}
To characterize the BM structural signature in more detail, optical sections
at 0.5 μm intervals were collected to track the distribution and arrangement
of fibers throughout the depth of the BM structure (Supplementary Fig.  2
 ) and the axis of orientation was
measured to quantify the arrangement of collagenous elements within the
preparation (Fig.  3  ). The histograms
were taken at 10-degree intervals, ranging from 0 to 180 degrees and the
standard deviation (SD) of the measurements was used to indicate the
disorganization of the collagenous elements (Methods- statistical analysis,
and Fig.  3  A,B). There were
statistically significant differences in fiber orientation at all stages of
development compared to P20, taken as the adult form, the age of onset of
hearing in mice. The broader distribution of fiber orientations in the younger
and aging animals is reflected in the larger SD measured (Table  1
 ).
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*  संस्कृतम्   "आवर्तनम् \(Frequency\) – Sanskrit")
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*  Slovenčina   "Frekvencia \(fyzika\) – Slovak")
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*  Wolof  
*  吴语  
*  ייִדיש  
*  粵語  
*  Žemaitėška  
*  中文
###  Frequency counter
1.  nature  
2.  scientific reports  
3.  articles  
4. article
Complete spectrum of 
electromagnetic radiation  with the visible portion highlighted
Currently, it is unknown if these developmental changes in the structure of
the cochlear partition occur independently of each other or are
interdependent. As a first step to understanding the basis for developmental
changes in the stiffness of the cochlear partition and their possible
interdependence, we exploited polarized light microscopy techniques using
acutely isolated BM in wild type (emilin2  +/+  ) and _Emilin-2_ _-/-_
(emilin2  -/-  ) mice. Polarized light microscopy provides a label free, non-
invasive, sensitive tool to analyze the alignment of fine structural
signatures in cells or tissues   32 .") . All tissues, cells, and organelles that include
extensive membranous structures—such as cochlear ECMs can exhibit
birefringence (refractive index anisotropy) that are characteristic of their
molecular architecture (such as collagen fibrils, stress fibers made of
filamentous actin and myosin, and microtubules (Supplementary Fig.  1
 ). New polarized light microscopy
techniques (LC-PolScope and Polychromatic PolScope  33  ,  34  ,  35
.") ) can represent the optical axis of birefringence and map
the measured orientation. Thus, quantitative information available in PolScope
images allowed for unique insights into the architectural dynamics of the BM.
Common symbols
Article   PubMed

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* Published  :  07 April 2021
Visible light is an  electromagnetic wave  , consisting of oscillating  electric
 and  magnetic fields
 traveling through space. The
frequency of the wave determines its color: 400 THz (  4  ×  10  14  Hz) is
red light, 800 THz (  8  ×  10  14  Hz  ) is violet light, and between these
(in the range 400–800 THz) are all the other colors of the  visible spectrum
 . An electromagnetic wave with a
frequency less than  4  ×  10  14  Hz  will be invisible to the human eye;
such waves are called  infrared  (IR) radiation.
At even lower frequency, the wave is called a  microwave  , and at still lower frequencies it is called a  radio wave
 . Likewise, an electromagnetic wave with a
frequency higher than  8  ×  10  14  Hz  will also be invisible to the human
eye; such waves are called  ultraviolet 
(UV) radiation. Even higher-frequency waves are called  X-rays  , and higher still are  gamma rays  .
Changes in BM structure at different stages of development. ( **A** ) Examples
of LC-PolScope images of collagenous fibers in unfixed BM preparations at P2,
P7, P10, P15, P20 and P60 from apical turns of the cochlea corresponding to
the ~ 7 kHz region, corresponding to location about 90% of BM length, with
base being 0% and apex 100%   42 .") . Sample size shown is 10 × 10 μm. ( **B** ) Examples of LC-
PolScope images of collagenous fibers in unfixed BM preparations at P2, P7,
P10, P15, P20 and P60 from basal turns of the cochlea corresponding to the ~
60 kHz region, corresponding to location about 10% of BM length, with base
being 0% and apex 100%   42 .") . Sample size shown 10 × 10 μm. ( **C** ) Fiber thickness in
apical, midturn and basal regions of BM all increase significantly (as
indicated by asterisks, see below) in size with age to P20 (as indicated by
different column hatchings, see key for postnatal ages P1 to P60), but not
significantly between P15 and P20 in cochlear basal turn. Fiber thickness
continues to increase with age to P60 in mid and basal turns and decreases in
apical turns. ( **D** ) Fiber spacing decreases with postnatal age to P20 in
the BM apical, midturn and basal regions and increases significantly between
P20 and P60 in the mid and basal turns. ( **E** ) Bundle thickness increases
with age to P20 in the BM midturn and basal regions. Bundles were not observed
in apical turns. Bundle thickness decreases significantly between P20 and P60
in the basal turn. ( **F** ) Bundle spacing in the BM midturn and basal
regions decreases with age to P20 and increases from P20 to P60. ( **G** )
Color wheel shows a visual vectorial representation of orientations. A color
wheel correlates the pseudo colors and the optical axis orientation. The
reference (zero degrees) is the longitudinal axis of basilar membrane or X
axis when you align the images of fibers along Y axis. Similar fiber colors
indicate uniform alignment; color variations indicate nonuniformity in
alignment. The measurements used for ( **C** )–( **F** ) were derived from
measuring 200 samples for each age and location, using BM samples from six
cochleae (3 mice) per age group, means ± SD. , * _p_ < 0.001 and ** _p_ <
0.0001, two-tailed unpaired _t_ test comparing measurements taken at different
ages with P20.
Article  Open access  15 March 2024
The basilar membrane (BM), of the mammalian cochlea serves as the anatomical
substrate for frequency selectivity, fundamental function of hearing, whereby
incoming sounds are decomposed into specific frequencies. The width of the BM
decreases, while its thickness and stiffness increase from the apex to base of
the cochlea   1 .") . Together these
spatially varying characteristics of the BM confer frequency-to-place
(tonotopic) organization to the cochlea, with the base tuned to high frequency
and the apex to low-frequency sounds. This passive, mechanical, tonotopic
frequency map provides a basis for neural encoding of frequency information to
higher auditory processing centers   1 .") ,  2
.") , a process enhanced by the non-linear cochlear amplifier
 3 .") .
The ability for sound to be encoded correctly with fine frequency resolution
is essential for auditory perception, which guides appropriate behavioral
responses, including the ability to understand speech   4
.") ,  5
.") .
Dimension  |
T  −  1  {\displaystyle {\mathsf {T}}^{-1}}
* _f_ = 1 / _T_
##  Measurement
*  Research articles 
*  News & Comment 
*  Collections 
*  Subjects
If the number of counts is not very large, it is more accurate to measure the
time interval for a predetermined number of occurrences, rather than the
number of occurrences within a specified time.  [10]  The latter method
introduces a  random error  into the
count of between zero and one count, so on  average  half a count. This is called _gating error_ and causes an average
error in the calculated frequency of  Δ  f  =  1  2  T  m  {\textstyle \Delta
f={\frac {1}{2T_{\text{m}}}}}  
, or a fractional error of  Δ  f  f  =  1  2  f  T  m  {\textstyle {\frac
{\Delta f}{f}}={\frac {1}{2fT_{\text{m}}}}}  
where  T  m  {\displaystyle T_{\text{m}}}  
is the timing interval and  f  {\displaystyle f}  
is the measured frequency. This error decreases with frequency, so it is
generally a problem at low frequencies where the number of counts _N_ is
small.
*  Echo  "Echo \(phenomenon\)")
*  Infrasound 
*  Sound 
*  Ultrasound 
*  Musical acoustics 
*  Piano 
*  Violin
##  Related quantities
* 1744  Accesses
_Birefringence imaging_ : LC-PolScope and Polychromatic PolScope were used to
measure magnitude (retardance) and orientation (slow optical axis) of BM
birefringence   18 .") Fiber
orientations were determined using a color wheel. Images were analyzed using
OpenPolScope software (  www.openpolscope.org 
), which included Micro-Manager version 1.4.22 and OpenPolScope version 3.2,
with further analysis using Fiji (ImageJ), Photoshop (Adobe), and Origin
software (MicroCal LLC,  www.originlab.com  ).
Samples were imaged blind, without knowledge of genotypes, which were
confirmed later.
5. Snezana Levic
*  Beat  "Beat \(acoustics\)")
*  Formant 
*  Fundamental frequency 
*  Frequency spectrum 
*  harmonic spectrum 
*  Harmonic 
*  Series  "Harmonic series \(music\)")
*  Inharmonicity 
*  Missing fundamental 
*  Combination tone 
*  Mersenne's laws 
*  Overtone 
*  Resonance 
*  Standing wave 
*  Node  "Node \(physics\)")
*  Subharmonic
* Received  :  30 December 2020
Article   CAS   PubMed

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Acousticians  |
*  Auditory system 
*  Development of the nervous system 
*  Developmental biology 
*  Diseases of the nervous system 
*  Imaging 
*  Neuroscience 
*  Sensory processing
Look up _** frequency  ** _ or _** often
 ** _ in Wiktionary,
the free dictionary.
High: 10kHz
* Davies, A. (1997).  _Handbook of Condition Monitoring: Techniques and Methodology_  . New York: Springer.  ISBN  "ISBN \(identifier\)")  978-0-412-61320-3   .
* Serway, Raymond A.; Faughn, Jerry S. (1989).   _College Physics_  . London: Thomson/Brooks-Cole.  ISBN  "ISBN \(identifier\)")  978-05344-0-814-5   .
* Young, Ian R. (1999).  _Wind Generated Ocean Waves_  . Elsevere Ocean Engineering. Vol. 2. Oxford: Elsevier.  ISBN  "ISBN \(identifier\)")  978-0-08-043317-2   .
Higher frequencies are usually measured with a  frequency counter
 . This is an  electronic
instrument 
which measures the frequency of an applied repetitive electronic  signal
 "Signal \(electronics\)") and displays the
result in hertz on a  digital display  . It uses  digital logic  to
count the number of cycles during a time interval established by a precision 
quartz  time base. Cyclic processes that
are not electrical, such as the rotation rate of a shaft, mechanical
vibrations, or  sound waves  , can be
converted to a repetitive electronic signal by  transducers
 and the signal applied to a frequency
counter. As of 2018, frequency counters can cover the range up to about 100
GHz. This represents the limit of direct counting methods; frequencies above
this must be measured by indirect methods.
Maki Koike-Tani
The current findings provide evidence for structural changes in the BM with
age, consistent with the reports indicating developmental changes in BM
collagen expression   12 .") . We are confident that the fibers observed are
collagen, based on the published immunohistochemistry and biochemical evidence
 56 .") . Namely, the most abundant constituent of the basilar membrane
are collagen fibers which are also regarded as a main source of basilar
membrane stiffness, thereby playing a critical role in establishing its tuned
resonant frequency map   9 . Z. Zellforsch. Mikrosk. Anat. 56, 40–96 \(1962\).") ,  57
.") ,  58 .") .
They are also highly birefringent as shown in other studies  38  ,  39  ,  40
.") ,  59 .") .
Thus coupled together, we feel confident to presume that the fibers being
examined are indeed collagen fibers, as no other structural element is known
to meet the above criteria. However, it is not excluded that we were imaging
some other biochemically unidentified elements, although if they were so
abundant in the BM, one would expect that they would have been identified
readily so far. Compared to mature BM at P20, collagenous fibers arrangement
may undergo further changes in aging animals (Fig.  2
 ,   60
.") ) Thus, it is likely
that the BM is a dynamic structure which changes throughout the life span of
the animal, which is consistent with reported age-related changes in human BM
 61 .") .
The importance of BM structural contribution to normal hearing is highlighted
in human patients with mutations in BM structural collagen proteins. For
example, Stickler syndrome, resulting in variants in coding Collagen II or IX,
 62 
\(University of Washington, Seattle, 2000\).") ; or Alport syndrome, resulting
in pathogenic variants in Collagen IV   63
.") can lead to sensorineural hearing loss in
humans. Therefore, it is conceivable that BM structure may reflect the
underlying changes in hearing, such as in noise induced hearing loss (NIHL) or
age-related hearing loss (presbycusis). While structural changes associated
with NIHL or presbycusis are yet to be reported, there is other evidence to
suggest BM involvement in pathological states   64
.") . For instance, cochlear implantation induced
collagen deposition, resulting in BM stiffening in the basal turn of the
guinea pig cochlea   65 .") .
Therefore, it is safe to conclude that emilin2 signaling contributes to the
fine structural maturation of the BM throughout development, in addition to
maturation   18 .") . The
present findings also suggest that in the emilin2  −/−  mutant BM development
is arrested, as maturation does not proceed as observed in the BM of wild-type
mice.
T.T., M.K.T. and S.L. designed the research. T.T., M.K.T, M.S., M.T.T. and
S.L. performed experiments, M.S.prepared supplementary Fig.  1
 . S.L. analyzed data and prepared all
other figures and tables in the paper. S.L. wrote the paper with input from
the other authors.