ライフサイエンスコーパス: logarithmic

1 original data of 82% for ANFIS, followed by logarithmic 70%, exponential 63% and linear 48% respecti

2 Observed star-to-star variations in logarithmic abundance within an open star cluster--a gra

3 Our approach combines pK(a) (logarithmic acid dissociation constant) calculations fro

4 are more accurately modeled as a function of logarithmic age.

5 Double-logarithmic analysis demonstrates that PR interval incre

6 cessing data normalization options including logarithmic and (Variance Stabilizing Normalization) VSN

7 n is prolonged at high levels throughout the logarithmic and early stationary phase when the preferre

8 pression of the ids operon increased in late logarithmic and early stationary phases and appeared to

9 are not elevated in cells harvested from mid-logarithmic and early stationary phases, suggesting that

10 ulate matter of L cells in tissue culture in logarithmic and plateau phase of growth have been made.

11 egU downregulated yloA expression during the logarithmic and stationary growth phases respectively.

12 s transcription from Pfis well into the late logarithmic and stationary growth phases, demonstrating

13 e H37Rv and a DeltapknK mutant strain during logarithmic and stationary growth phases, we determined

14 rithmic growth or the transition between the logarithmic and stationary growth phases.

15 in rich medium but poorly expressed in late logarithmic and stationary phase.

16 g RNA extracted from cultures growing to the logarithmic and stationary phases.

17 icantly elevated (>3-fold) between the early logarithmic and the late logarithmic/start of stationary

18 ntial: The relaxation is slow, in many cases logarithmic, and can still be observed after many hours.

19 ty of facilitation with neighbors as linear, logarithmic, and unimodal functions is simulated for two

20 he salicylanilides were bactericidal against logarithmic- and stationary-phase cultures of the BI/NAP

21 iptomes were found to be related to those of logarithmic- and stationary-phase planktonic cultures, r

22 The transcriptomes of logarithmic- and stationary-phase Pseudomonas aeruginosa

23 These findings support the notion that a logarithmic, approximately scale-invariant representatio

24 d and empirical regression method based on a logarithmic approximation has been developed to accurate

25 ver time were visibly nonlinear, requiring a logarithmic approximation of the initial reaction rates

26 o 0.21 (inferotemporal RNFL, superonasal VF; logarithmic association) for GDx.

27 o 0.26 (inferotemporal RNFL, superonasal VF; logarithmic association) for HRT II; from 0.02 (temporal

28 o 0.38 (inferotemporal RNFL, superonasal VF; logarithmic association) for OCT; and from 0.03 (tempora

29 Linear and logarithmic associations between RNFL thickness (HRT II,

30 VF, and nasal RNFL, temporal VF; linear and logarithmic associations) to 0.26 (inferotemporal RNFL,

31 the SERS biosensor varies linearly with the logarithmic ATP concentration up to 2.0 nM with a limit

32 bon dioxide deviates significantly from pure logarithmic behavior at concentrations relevant for simu

33 c variation at high dose and deviations from logarithmic behavior at low dose.

34 rting previous research, for both conditions logarithmic binning methods were consistent with Levy fl

35 ere highly targeted specific and linear with logarithmic BoNT/A concentrations in PBS, milk and human

36 ory HGF upregulation, resulting in sustained logarithmic cell killing both in vitro and in xenograft

37 The two-dimensional (2D) logarithmic character of Coulomb interaction between cha

38 been provided over the years, and the basic logarithmic coiling seen in mollusks can be simulated wi

39 The resulting labeled-line code exhibited logarithmic compression obeying the Weber-Fechner law fo

40 That increase was linearly dependent on the logarithmic concentration of ceruloplasmin in blood.

41 hip between the ECL image gray value and the logarithmic concentration of the AFM1 target over a rang

42 d emf changes could still be observed with a logarithmic concentration ratio of 0.05.

43 between the increments of DeltaR(et) and the logarithmic concentrations of E. coli suspension in the

44 nteraction between charges and the resulting logarithmic confinement is a remarkable inherent propert

45 The area under the logarithmic contrast sensitivity function (AULCSF) was c

46 The linear logarithmic correlation (slope = 1.0) between values of

47 The second linear logarithmic correlation [slope = 0.53 +/- 0.16] between

48 s with two selected aryl radicals revealed a logarithmic correlation between the hydrogen-atom abstra

49 Strong logarithmic correlation between the ratio of ACN content

50 The linear logarithmic correlation between these kinetic parameters

51 A logarithmic correlation was found between the hydrogen-a

52 A logarithmic correlation was observed in a wide range of

53 A superb linear logarithmic correlation, with slope of 1.04 +/- 0.03, is

54 73) and TP content (r=0.979), while negative logarithmic correlations were found between pressing pre

55 : OS hazard ratio, 1.44 per unit increase of logarithmic CRP; 95% CI, 1.30 to 1.59; P < .001; MSS haz

56 MSS hazard ratio, 1.51 per unit increase of logarithmic CRP; 95% CI, 1.36 to 1.68; P < .001).

57 ne in a million yeast cells from low-density logarithmic cultures survive desiccation, while 20-40% o

58 lobal and regional VF sensitivities (both in logarithmic [dB] and 1/Lambert scales [1/L]), were inves

59 d whether decomposition followed a linear or logarithmic decay and, as Shirley cloth is no longer ava

60 re fastest for ermF in slurry-treated soils (logarithmic decay coefficient of -3.5) and for sul1 and

61 or sul1 and sul2 in dry-stack-amended soils (logarithmic decay coefficients of -0.54 and -0.48, respe

62 cture, after all variables were converted to logarithmic decibel scale.

63 ion of a functional reserve results from the logarithmic (decibel) scaling of the visual field.

64 Data best fit with a logarithmic decline (r(2) = 0.20-0.63).

65 st large cities, and accordingly pH showed a logarithmic decline.

66 100 to 10 ng/microL producing an approximate logarithmic decrease of impedance, a low detection limit

67 This model predicts a logarithmic dependence of a protein's diffusion coeffici

68 ristics, including multiple charge carriers, logarithmic dependence of resistance on temperature, ant

69 The model explains a logarithmic dependence of steady-state fitness on the po

70 using one-dimensional models that predict a logarithmic dependence of the unfolding force on the pul

71 re sensitive to cell environment, unlike the logarithmic dependence on H and very small thermal corre

72 t the mean (time-averaged) stress displays a logarithmic dependence on the shear rate for plastic (ir

73 t not so for RED Nernst potential, which has logarithmic dependence on the solution concentration.

74 The response shows a logarithmic dependence spanning over 5 orders of magnitu

75 also adapt and exhibit a slow (approximately logarithmic) dependence on the ligand concentration in t

76 ons from polyelectrolyte models, we observed logarithmic dependences of proton affinity versus salt c

77 e stochastic simulation algorithm (SSA), the logarithmic direct method (LDM) and the next reaction me

78 the neuronal encoding of number is linear or logarithmic divides cognitive neuroscientists working on

79 etic operations and complex functions in the logarithmic domain.

80 inear allometries in both the arithmetic and logarithmic domains.

81 f genes differentially expressed between the logarithmic, early stationary and late stationary growth

82 nonlinearities, thought to reflect intrinsic logarithmic encoding mechanisms, which are later "linear

83 Using the logarithmic equations, it could be shown that a dilution

84 is forecastable, with the square root of the logarithmic error growing linearly with the forecasting

85 y human CD8(+) T-cell clone, which exhibited logarithmic ex vivo growth in the absence of exogenous c

86 While CD8alpha+ and CD11b+ DCs induced logarithmic expansion of naive CD4 and CD8 T cells, with

87 tional Cauchy stress and a recently proposed logarithmic-exponential strain.

88 s angular size and speed, achieved through a logarithmic-exponential transform.

89 e area law cannot be violated by more than a logarithmic factor in the system's size.

90 pulsed ion beams in an electrostatic quadro-logarithmic field.

91 This form of analysis yielded a logarithmic fit characterized by exceptional responsivit

92 In most cases, logarithmic fits were not significantly better than line

93 The platform comes preloaded with logarithmic fold changes from 44 data sets on Mvarphi st

94 or 9 regions, quadratic for 13, cubic for 6, logarithmic for 12, power law for 7, and modified power

95 linear for 9, quadratic for 25, cubic for 2, logarithmic for 6, and power law for 4 using PN data.

96 Entropy was a logarithmic function of ROI area in normal control tissu

97 verage rate of rise of the first is a simple logarithmic function of target contrast, whereas the sec

98 This is a logarithmic function of the fuel fraction, not of the ab

99 only (EDO) operation, which was modeled as a logarithmic function of VSP.

100 a-gel increased with wind speed, following a logarithmic function so that PSRs are more strongly infl

101 g was not linear and could be modeled with a logarithmic function.

102 nly stopped, stress relaxations occur with a logarithmic functional form over long timescales.

103 ce exists in outcomes between the linear and logarithmic functions, but the unimodal function, which

104 nction when compared with linear, power, and logarithmic functions.

105 The bell-shaped logarithmic GAG dependences fit an obligatory template m

106 ratic GFR equation was developed to estimate logarithmic GFR from the following covariates: 1/SCr, 1/

107 potential of Gram-negative cytoplasm during logarithmic growth (-260 to -280 mV).

108 program that coordinates transitions between logarithmic growth (feast) and growth arrest (famine).

109 diate efficient RP gene transcription during logarithmic growth and dissociate from RP gene promoters

110 rvirulent mucoid switch variant, both during logarithmic growth and during intracellular growth in ma

111 sed with increasing medium osmolarity during logarithmic growth and in stationary phase.

112 tion of reactive oxygen species (ROS) during logarithmic growth and reduced stress signaling via the

113 The drying pressure exhibits a logarithmic growth as a function of the driving rate ove

114 A region of logarithmic growth followed the exponential growth which

115 mpared to expression in the wild type during logarithmic growth in vitro.

116 th RNAPII CTD phosphorylation levels, during logarithmic growth in yeast.

117 ee mRNA transcripts were up-regulated during logarithmic growth of L. casei ATCC 334 on sucrose isome

118 rger genome sizes, predefined databases show logarithmic growth of the number of families per genome,

119 or biphenyl and harvested during either mid-logarithmic growth or the transition between the logarit

120 s regulated by RpoS in stationary but not in logarithmic growth phase (504 were induced and 268 were

121 Secretion continued throughout the logarithmic growth phase and decreased as the culture en

122 It is highly expressed during early logarithmic growth phase in cells growing in rich medium

123 aching maximal levels of 2.5 muM in the late logarithmic growth phase, and both wild-type and pigment

124 els during the transition from stationary to logarithmic growth phase, followed by reproducible oscil

125 Logarithmic growth was observed after a 1-h lag phase.

126 MutL mRNA occur simultaneously during early logarithmic growth when cell densities are low; this bri

127 n resulted in hematogenous dissemination and logarithmic growth within the central nervous system.

128 xpression analysis revealed that, during mid-logarithmic growth, AlgR activated the expression of 58

129 This field is now entering a stage of logarithmic growth, during which chemical innovations co

130 During late-logarithmic growth, QseA activated expression of the LEE

131 Accordingly, during logarithmic growth, Spg5 appears largely dispensable for

132 gen starvation and fail to accumulate during logarithmic growth, when the majority of cells are in G2

133 oducible oscillations in their levels during logarithmic growth, which later decrease during the tran

134 itute an operon and are cotranscribed during logarithmic growth, with transcriptional levels decreasi

135 ctible levels of CL at low osmolarity during logarithmic growth.

136 became associated with mitochondria in late logarithmic growth.

137 -Sobolev inequality for d>/=3, and the sharp Logarithmic Hardy-Littlewood-Sobolev inequality for d =

138 s the McGowan characteristic volume (V), the logarithmic hexadecane-air partition coefficient (L), an

139 prefrontal cortex of the monkey support the logarithmic hypothesis.

140 sent an analysis of these data, which show a logarithmic increase in mean wind speed with height in t

141 the mutation rate and thus yields a similar logarithmic increase in the speed of evolution.

142 we demonstrate with computer simulations the logarithmic increase of displacements with system size:

143 nnels; the electro-oxidized channel showed a logarithmic increase of resistance with decreasing tempe

144 Overall, functional richness follows a logarithmic increase with area, whereas divergence and e

145 During the logarithmic increase, the rapid switch-off of the initia

146 ing of 6 and the final of 22), which reflect logarithmic increasing intensities from 13.5 to 214 Watt

147 hod involves analysis of the distribution of logarithmic intensity of all peaks, including noise and

148 ages into a hierarchy of layers at different logarithmic intensity scales and mapping them to a quasi

149 rease the spatial range of the 2D long-range logarithmic interaction, changing it to predominantly di

150 -dimensional (2D) random Coulomb system with logarithmic interactions.

151 In this paper, novel quantities based on the logarithmic interspike intervals are proposed as useful

152 Linear semi-logarithmic kinetic plots and molecular weights increasi

153 The low-temperature data follow a logarithmic law, therefore displaying a notable departur

154 coli cells sense the spatial gradient of the logarithmic ligand concentration.

155 for QTL detection than that of the LASSO for logarithmic linear model or the interval mapping based o

156 Logarithmic linearisation of the results evaluated the s

157 dditive mixed models with gamma variance and logarithmic link functions.

158 act RBCs is stable over time, but there is a logarithmic loss of SNO(RBC) with oxyHb desaturation (sl

159 The Logarithmic Mean Divisia Index (LMDI) approach was appli

160 ed from the slopes of the Arrhenius plots of logarithmic mobility vs reciprocal absolute temperature

161 e degradation curve fit (R(2)=0.907-0.979) a logarithmic model.

162 ear and non-linear-regression (quadratic and logarithmic) models.

163 theoretical analysis that predicts that the logarithmic nature of the working domain of the evaporat

164 tude of the previous trial, whereas a static logarithmic nonlinearity predicts trialwise independence

165 als, pesticides and biocides; with logK(ow) (logarithmic octanol-water partitioning coefficient) valu

166 Suggestive loci logarithmic odds (LOD) scores above 2.0 or non-parametri

167 ice and observed highly significant linkage (logarithmic odds [LOD] scores approximately 4.8) for the

168 tter, 91% of patients obtained a UNVA of 0.1 logarithmic of the reading acuity determination (logRAD)

169 This was not possible with linear, logarithmic or exponential methods.

170 ussian as possible, for instance by applying logarithmic or other nonlinear transformations.

171 distribution, which could be corrected using logarithmic or reciprocal transformation.

172 fect on sensitivity to ionizing radiation in logarithmic- or early-stationary-phase cells but was req

173 educed the efficacy (50%) and the potency (5 logarithmic orders) of NAP ethanol antagonism.

174 6 (I6A-NAP) caused a decrease in potency (>2 logarithmic orders) with only a small reduction (<10%) i

175 The "strange kinetics" model with logarithmic oscillations developed by Klafter and co-wor

176 ificantly increased the persister numbers in logarithmic P. aeruginosa PAO1 or PA14 cultures but not

177 The median logarithmic parameter standard errors for the four model

178 is process is regulated: RpoS is degraded in logarithmic phase but becomes stable upon carbon starvat

179 i-analytic methods based on direct or double logarithmic phase expansions, steepest descent approache

180 s more selective when the spirochetes are in logarithmic phase of growth compared to organisms obtain

181 B from a promoter expressed during the early logarithmic phase of growth could complement a ropB dele

182 r alteration in parasite division during the logarithmic phase of growth, an accelerated cell death d

183 protein-bound and free NADH at the early and logarithmic phase of the growth curve and a statisticall

184 he rate of p24 antigen production during the logarithmic phase of viral replication.

185 mRNA level in stationary phase compared with logarithmic phase promastigotes.

186 nia chagasi promastigotes grow in vitro from logarithmic phase to stationary phase.

187 genes are induced at the transition from the logarithmic phase to the stationary phase, and some gene

188 eruginosa PAO1 versus its algR mutant in mid-logarithmic phase, (ii) P. aeruginosa PAO1 versus its al

189 ain the different levels of RpoS observed in logarithmic phase, ammonia starvation, and glucose starv

190 identified as being QS regulated at the mid-logarithmic phase, and 450 genes were identified as bein

191 trifugation of bacterial extracts during mid-logarithmic phase, peaked at the transition to stationar

192 In the logarithmic phase, the bacteria were found to be classic

193 ga expression and Mga protein levels in late-logarithmic-phase cell growth.

194 tarved cells is intermediate between that in logarithmic-phase cells and glucose-starved cells.

195 transcriptome analysis was performed on mid-logarithmic-phase cells grown in rich medium.

196 c Trypanosoma brucei cells in early and late logarithmic phases and found that approximately 200 mRNA

197 e demonstration of tunable sub-diffusion and logarithmic photon transport in deterministic aperiodic

198 rcinomas is approximately linear on a double logarithmic plot has led to much speculation regarding t

199 Logarithmic plots of the K(i) values versus the empirica

200 linear response of the ECL intensity to the logarithmic potassium concentration between 10 mum and 1

201 compensation effect accounts for the natural logarithmic pre-exponential ln (A/min(-1)) factors of ca

202 not a significant linear predictor but was a logarithmic predictor (p = 0.03) for all-cause mortality

203 ume was a significant (p = 0.001) linear and logarithmic predictor.

204 atical properties of the sampling process on logarithmic (Preston) versus linear (Dewdney) abundance

205 simulated data show that Amordad can support logarithmic query time for identifying similar metagenom

206 r and 50 cells/mL for QCM sensor), a widened logarithmic range of detection (i.e., 3-7 for pili-manno

207 In contrast, logarithmic rate dependence is found in solid-on-solid f

208 Thanks to a steady logarithmic rate of increase in performance for DNA sequ

209 For both measures, a semi-logarithmic reduction in titre was observed as genome si

210 ations by the unmixing method applied to the logarithmic reflectance, leading to an accurate quantifi

211 speed over four decades reveals two distinct logarithmic regimes of the measured modulus and point to

212 Multivariate semi-logarithmic regression analyses were used to determine c

213 0.303]), and rim/disc area [R2 = 0.265]; and logarithmic regression for rim volume [R2 = 0.175]).

214 A logarithmic relationship between a 5-point (0-4) TRS and

215 A logarithmic relationship between the concentration of MB

216 rence risk, overall genetic variance using a logarithmic relative risk scale, the area under the rece

217 r slow relaxations and aging, which predicts logarithmic relaxations, and a particular aging dependen

218 Despite logarithmic replication and phenotypic maturation of DC,

219 nd to background oxygen levels, exhibiting a logarithmic response.

220 s showing a coefficient of variation for the logarithmic result of 2.8 and 7.0%, respectively.

221 curves on either a linear scale (cVL1) or a logarithmic scale (cVL2).

222 mes with intervals that are equidistant on a logarithmic scale between 21 ps and 21 ns.

223 ere the circuit depth is proportional to the logarithmic scale of data size.

224 Student paired t tests based on a logarithmic scale were performed to evaluate the change

225 , from 1.0x10(-10) to 1.0x10(-7)M Fe(III) in logarithmic scale with a detection limit of 2.0x10(-11)M

226 scence quenching efficiency is linear in the logarithmic scale with ATP concentration range from 10 n

227 t alpha-linolenic acid, decrease on a double-logarithmic scale with increasing total phosphorus.

228 dhesion molecule-1 (odds ratio per SD on the logarithmic scale, 1.21; P = .04).

229 and metabolic rate has convex curvature on a logarithmic scale, and is therefore not a pure power law

230 requires that the system senses signal on a logarithmic scale, responding identically to a change in

231 osteric proteins can respond to stimuli on a logarithmic scale.

232 portion with stimulus frequency when cast on logarithmic scales.

233 The observed logarithmic scaling of diffusivity with beta, in close a

234 necessitate a baseline shift at onset and a logarithmic scaling of interspike intervals at offset.

235 dification of the method by extrapolation of logarithmic selectivity coefficients appears to give the

236 .3, and the corresponding electrodes exhibit logarithmic selectivity coefficients for H(+) over K(+)

237 In this work, we present evidence that logarithmic sensing can be implemented with a single pro

238 ealed that the key microscopic mechanism for logarithmic sensing in bacterial chemotaxis is the adapt

239 pulation distributions provides evidence for logarithmic sensing of oxygen, which enhances sensing in

240 o operate in a parameter regime that permits logarithmic sensing.

241 the field to understand the ways in which a logarithmic sensor can be implemented at the molecular l

242 This finding suggests a role as logarithmic sensors for the many allosteric proteins acr

243 a tail that may be approximated by Fisher's logarithmic series.

244 FM and FMI gain progressed in a logarithmic-shaped curve and variation increased with in

245 lous photon transport, including the elusive logarithmic Sinai sub-diffusion in photonic systems for

246 example, recent experimental observations of logarithmic size dependence of electric conductivity of

247 We determine the logarithmic slope of the mass function for substructure

248 In particular, it is possible to observe a logarithmic spatio-temporal evolution of the lamellar cr

249 neurons respond preferentially to linear or logarithmic spectrotemporal amplitudes.

250 This efficient use of logarithmic spectrotemporal modulations by auditory midb

251 Logarithmic spirals can be fit to the arms with pitch an

252 ometrical model, a new class of self-similar logarithmic spirals observed in a large zone of the para

253 primed the T-cell response before detectable logarithmic spread and were abruptly terminated with min

254 animal) primed the CD4 T-cell response after logarithmic spread was detectable, allowing infection of

255 ) between the early logarithmic and the late logarithmic/start of stationary phases of growth.

256 ased every three sessions from 3 to 1,000 in logarithmic steps.

257 ment in spectrotemporal encoding ability for logarithmic stimuli, with an increase in the mutual info

258 ractal spectra, and additionally demonstrate logarithmic sub-diffusion in the presence of multifracta

259 ensity of MOF-76, which are dependent on the logarithmic tastant concentration, (4) the tastant is id

260 r indications for the hybridization gap with logarithmic temperature dependence (as expected for a Ko

261 The zero-bias conductance peaks show logarithmic temperature dependence and often linear spli

262 n rho, 0.79; P<0.0005): the relationship was logarithmic, the reduction in the impedance with an incr

263 to 48 h of infection but its growth becomes logarithmic thereafter.

264 nhanced wall extension can be described by a logarithmic time function.

265 The logarithmic time-dependence of the variation in crystal

266 ound NADH as cells progress from an early to logarithmic to confluent phase.

267 .2% were significantly changed comparing the logarithmic to stationary growth phase.

268 e concentration as the cells transition from logarithmic to stationary phase, there is a "rebound" of

269 ch later decrease during the transition from logarithmic to stationary phase.

270 cantly decreasing during the transition from logarithmic to stationary-phase growth.

271 istivity upturn with a clear transition from logarithmic- to square-root temperature dependence and d

272 nes was repressed during the transition from logarithmic- to stationary-phase growth, but several wel

273 ential ramp stimuli, a feature that we call "logarithmic tracking."

274 nt with a simple model consisting of a noisy logarithmic transducer followed by a rise-to-threshold a

275 feedforward neural network with function of logarithmic transfer, Levenberg Marquardt algorithm and

276 These simulations show that the logarithmic transform of angular speed occurs between th

277 Weighted subtraction of the logarithmic transform of these images is then performed

278 e shape of the numberline, without requiring logarithmic transform.

279 ained significantly associated with a raised logarithmic transformation (log) of TF (p = 0.04), but t

280 constraint of minimal number of replicates, logarithmic transformation and random error analyses.

281 GO transfer method based on bit-score and a logarithmic transformation of CHI-square (WS-LCHI) perfo

282 Logarithmic transformation of peak BLI tumor signal inte

283 Logarithmic transformation of SD-OCT measurements provid

284 Ordinal least squares regression with a logarithmic transformation of the dependent variable was

285 Logarithmic transformation of the retinal thickness was

286 use the data distribution was highly skewed, logarithmic transformation was performed.

287 achieving normally distributed data through logarithmic transformation.

288 Control lungs had lower average median logarithmic transmission (-0.29 vs -0.18, P = .1) and lo

289 L, reducing the level of Legionella by three logarithmic unit by 2 months postinstallation (T2) until

290 with a much higher sensitivity of 3 mRIU per logarithmic unit of the concentration between 500 pmol L

291 response time of 1 s, a linear range of four logarithmic units, and a medium-term stability of 0.04 m

292 h a F(-)/Cl(-) selectivity of more than five logarithmic units.

293 elationship between normalized R(et) and the logarithmic value of E. coli concentrations was found in

294 ar relationship between impedance change and logarithmic value of H5N1 virus at the concentrations fr

295 0.0001), baseline lesion lumen area (0.019), logarithmic value of the change in high-sensitivity C-re

296 for distinct strains of scrapie, and explain logarithmic variation at high dose and deviations from l

297 uated 3, 6, and 9 months after surgery using logarithmic visual acuity charts.

298 Global associations (linear and logarithmic) were significantly stronger using OCT compa

299 dependently on each of four bands with equal logarithmic width.

300 sponse evoked in the localized population is logarithmic with stimulus amplitude (given a constant fr