Journal articles: 'Bimodal modulator'

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Tamai, Keiko, Hidekazu Iioka, and Stephanie Doerner. "A bimodal modulator in canonical Wnt signal transduction." Developmental Biology 319, no. 2 (July 2008): 525. http://dx.doi.org/10.1016/j.ydbio.2008.05.210.

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Schulze, Anja, Beatrice Oehler, Nicole Urban, Michael Schaefer, and Kerstin Hill. "Apomorphine Is a Bimodal Modulator of TRPA1 Channels." Molecular Pharmacology 83, no. 2 (December 6, 2012): 542–51. http://dx.doi.org/10.1124/mol.112.081976.

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Iioka, Hidekazu, Stephanie K. Doerner, and Keiko Tamai. "Kaiso is a bimodal modulator for Wnt/β-catenin signaling." FEBS Letters 583, no. 4 (January 21, 2009): 627–32. http://dx.doi.org/10.1016/j.febslet.2009.01.012.

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Zhang, Jiaqi, Yuji Kosugi, Akira Otomo, Yoshiaki Nakano, and Takuo Tanemura. "Active metasurface modulator with electro-optic polymer using bimodal plasmonic resonance." Optics Express 25, no. 24 (November 17, 2017): 30304. http://dx.doi.org/10.1364/oe.25.030304.

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Blanco-Elorrieta, Esti, Karen Emmorey, and Liina Pylkkänen. "Language switching decomposed through MEG and evidence from bimodal bilinguals." Proceedings of the National Academy of Sciences 115, no. 39 (September 11, 2018): 9708–13. http://dx.doi.org/10.1073/pnas.1809779115.

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A defining feature of human cognition is the ability to quickly and accurately alternate between complex behaviors. One striking example of such an ability is bilinguals’ capacity to rapidly switch between languages. This switching process minimally comprises disengagement from the previous language and engagement in a new language. Previous studies have associated language switching with increased prefrontal activity. However, it is unknown how the subcomputations of language switching individually contribute to these activities, because few natural situations enable full separation of disengagement and engagement processes during switching. We recorded magnetoencephalography (MEG) from American Sign Language–English bilinguals who often sign and speak simultaneously, which allows to dissociate engagement and disengagement. MEG data showed that turning a language “off” (switching from simultaneous to single language production) led to increased activity in the anterior cingulate cortex (ACC) and dorsolateral prefrontal cortex (dlPFC), while turning a language “on” (switching from one language to two simultaneously) did not. The distinct representational nature of these on and off processes was also supported by multivariate decoding analyses. Additionally, Granger causality analyses revealed that (i) compared with “turning on” a language, “turning off” required stronger connectivity between left and right dlPFC, and (ii) dlPFC activity predicted ACC activity, consistent with models in which the dlPFC is a top–down modulator of the ACC. These results suggest that the burden of language switching lies in disengagement from the previous language as opposed to engaging a new language and that, in the absence of motor constraints, producing two languages simultaneously is not necessarily more cognitively costly than producing one.

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Eslami, Babak, Daniel Ebeling, and Santiago D. Solares. "Trade-offs in sensitivity and sampling depth in bimodal atomic force microscopy and comparison to the trimodal case." Beilstein Journal of Nanotechnology 5 (July 24, 2014): 1144–51. http://dx.doi.org/10.3762/bjnano.5.125.

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This paper presents experiments on Nafion® proton exchange membranes and numerical simulations illustrating the trade-offs between the optimization of compositional contrast and the modulation of tip indentation depth in bimodal atomic force microscopy (AFM). We focus on the original bimodal AFM method, which uses amplitude modulation to acquire the topography through the first cantilever eigenmode, and drives a higher eigenmode in open-loop to perform compositional mapping. This method is attractive due to its relative simplicity, robustness and commercial availability. We show that this technique offers the capability to modulate tip indentation depth, in addition to providing sample topography and material property contrast, although there are important competing effects between the optimization of sensitivity and the control of indentation depth, both of which strongly influence the contrast quality. Furthermore, we demonstrate that the two eigenmodes can be highly coupled in practice, especially when highly repulsive imaging conditions are used. Finally, we also offer a comparison with a previously reported trimodal AFM method, where the above competing effects are minimized.

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Damircheli, Mehrnoosh, Amir F. Payam, and Ricardo Garcia. "Optimization of phase contrast in bimodal amplitude modulation AFM." Beilstein Journal of Nanotechnology 6 (April 28, 2015): 1072–81. http://dx.doi.org/10.3762/bjnano.6.108.

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Bimodal force microscopy has expanded the capabilities of atomic force microscopy (AFM) by providing high spatial resolution images, compositional contrast and quantitative mapping of material properties without compromising the data acquisition speed. In the first bimodal AFM configuration, an amplitude feedback loop keeps constant the amplitude of the first mode while the observables of the second mode have not feedback restrictions (bimodal AM). Here we study the conditions to enhance the compositional contrast in bimodal AM while imaging heterogeneous materials. The contrast has a maximum by decreasing the amplitude of the second mode. We demonstrate that the roles of the excited modes are asymmetric. The operational range of bimodal AM is maximized when the second mode is free to follow changes in the force. We also study the contrast in trimodal AFM by analyzing the kinetic energy ratios. The phase contrast improves by decreasing the energy of second mode relative to those of the first and third modes.

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Yang, Ruizhen, Bo Huang, Yanting Zhu, Yang Li, Feng Liu, and Jue Shi. "Cell type–dependent bimodal p53 activation engenders a dynamic mechanism of chemoresistance." Science Advances 4, no. 12 (December 2018): eaat5077. http://dx.doi.org/10.1126/sciadv.aat5077.

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Studies of drug resistance mostly characterize genetic mutation, and we know much less about phenotypic mechanisms of drug resistance, especially at a quantitative level. p53 is an important mediator of cellular response to chemotherapy, but even p53 wild-type cells vary in drug sensitivity for unclear reasons. Here, we elucidated a new resistance mechanism to a DNA-damaging chemotherapeutic through bimodal modulation of p53 activation dynamics. By combining single-cell imaging with computational modeling, we characterized a four-component regulatory module, which generates bimodal p53 dynamics through coupled feed-forward and feedback, and found that the inhibitory strength between ATM and Mdm2 determined the differential modular output between drug-sensitive and drug-resistant cancer cell lines. We further showed that the combinatorial inhibition of Mdm2 and Wip1 was an effective strategy to alter p53 dynamics in resistant cancer cells and sensitize their apoptotic response. Our results point to p53 pulsing as a potentially druggable mechanism that mediates chemoresistance.

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Stronks, H. C., J. J. Briaire, and J. H. M. Frijns. "The Temporal Fine Structure of Background Noise Determines the Benefit of Bimodal Hearing for Recognizing Speech." Journal of the Association for Research in Otolaryngology 21, no. 6 (October 26, 2020): 527–44. http://dx.doi.org/10.1007/s10162-020-00772-1.

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Abstract Cochlear implant (CI) users have more difficulty understanding speech in temporally modulated noise than in steady-state (SS) noise. This is thought to be caused by the limited low-frequency information that CIs provide, as well as by the envelope coding in CIs that discards the temporal fine structure (TFS). Contralateral amplification with a hearing aid, referred to as bimodal hearing, can potentially provide CI users with TFS cues to complement the envelope cues provided by the CI signal. In this study, we investigated whether the use of a CI alone provides access to only envelope cues and whether acoustic amplification can provide additional access to TFS cues. To this end, we evaluated speech recognition in bimodal listeners, using SS noise and two amplitude-modulated noise types, namely babble noise and amplitude-modulated steady-state (AMSS) noise. We hypothesized that speech recognition in noise depends on the envelope of the noise, but not on its TFS when listening with a CI. Secondly, we hypothesized that the amount of benefit gained by the addition of a contralateral hearing aid depends on both the envelope and TFS of the noise. The two amplitude-modulated noise types decreased speech recognition more effectively than SS noise. Against expectations, however, we found that babble noise decreased speech recognition more effectively than AMSS noise in the CI-only condition. Therefore, we rejected our hypothesis that TFS is not available to CI users. In line with expectations, we found that the bimodal benefit was highest in babble noise. However, there was no significant difference between the bimodal benefit obtained in SS and AMSS noise. Our results suggest that a CI alone can provide TFS cues and that bimodal benefits in noise depend on TFS, but not on the envelope of the noise.

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Bindi, Luca, Václav Petříček, Cristian Biagioni, Jakub Plášil, and Yves Moëlo. "Could incommensurability in sulfosalts be more common than thought? The case of meneghinite, CuPb13Sb7S24." Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials 73, no. 3 (May 12, 2017): 369–76. http://dx.doi.org/10.1107/s2052520617002657.

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The structure of meneghinite (CuPb13Sb7S24), from the Bottino mine in the Apuan Alps (Italy), has been solved and refined as an incommensurate structure in four-dimensional superspace. The structure is orthorhombic, superspace groupPnma(0β0)00s, cell parametersa =24.0549 (3),b =4.1291 (6),c =11.3361 (16) Å, modulation vectorq= 0.5433 (4)b*. The structure was refined from 6604 reflections to a finalR= 0.0479. The model includes modulation of both atomic positions and displacement parameters, as well as occupational waves. The driving forces stabilizing the modulated structure of meneghinite are linked to the occupation modulation of Cu and some of the Pb atoms. As a consequence of the Cu/[] and Pb/Sb modulations, three- to sevenfold coordinations of theMcations (Pb/Sb) occur in different parts of the structure. The almost bimodal distribution of the occupation of Cu/[] and Pb/Sb atM5 conforms with the coupled substitution Sb3++ [] → Pb2++ Cu+, thus corroborating the hypothesis deduced previously for the incorporation of copper in the meneghinite structure. The very small departure (∼0.54versus0.50) from the commensurate value of the modulation raises the question of whether other sulfosalts considered superstructures have been properly described, and, in this light, if incommensurate modulation in sulfosalts could be much more common than thought.

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Kessler, David M., Jace Wolfe, Michelle Blanchard, and René H. Gifford. "Clinical Application of Spectral Modulation Detection: Speech Recognition Benefit for Combining a Cochlear Implant and Contralateral Hearing Aid." Journal of Speech, Language, and Hearing Research 63, no. 5 (May 22, 2020): 1561–71. http://dx.doi.org/10.1044/2020_jslhr-19-00304.

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Purpose The purpose of this study was to investigate the relationship between speech recognition benefit derived from the addition of a hearing aid (HA) to the nonimplanted ear (i.e., bimodal benefit) and spectral modulation detection (SMD) performance in the nonimplanted ear in a large clinical sample. An additional purpose was to investigate the influence of low-frequency pure-tone average (PTA) of the nonimplanted ear and age at implantation on the variance in bimodal benefit. Method Participants included 311 unilateral cochlear implant (CI) users who wore an HA in the nonimplanted ear. Participants completed speech recognition testing in quiet and in noise with the CI-alone and in the bimodal condition (i.e., CI and contralateral HA) and SMD in the nonimplanted ear. Results SMD performance in the nonimplanted ear was significantly correlated with bimodal benefit in quiet and in noise. However, this relationship was much weaker than previous reports with smaller samples. SMD, low-frequency PTA of the nonimplanted ear from 125 to 750 Hz, and age at implantation together accounted for, at most, 19.1% of the variance in bimodal benefit. Conclusions Taken together, SMD, low-frequency PTA, and age at implantation account for the greatest amount of variance in bimodal benefit than each variable alone. A large portion of variance (~80%) in bimodal benefit is not explained by these variables. Supplemental Material https://doi.org/10.23641/asha.12185493

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Lighton, J. R. B., L. J. Fielden, and Y. Rechav. "DISCONTINUOUS VENTILATION IN A NON-INSECT, THE TICK AMBLYOMMA MARMOREUM (ACARI, IXODIDAE): CHARACTERIZATION AND METABOLIC MODULATION." Journal of Experimental Biology 180, no. 1 (July 1, 1993): 229–45. http://dx.doi.org/10.1242/jeb.180.1.229.

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We examined and quantified the discontinuous ventilation cycle (DVC) characteristics of unfed nymphs and adults, as well as engorged nymphal and engorged diapausing and non-diapausing female adult life-stages, of the African tortoise tick Amblyomma marmoreum (Koch). All engorged stages ventilated continuously, with little evidence of active spiracular control. Unfed nymphs and adults ventilated discontinuously; at low activity and standard metabolic rate (SMR) levels, mean DVC duration was approximately 0.4 h in nymphs (mean mass 0.7 mg) and 2.8 h in female adults (mean mass 70 mg). SMR, measured as rate of CO2 production (V(dot)CO2; 0.064 mul mg-1 h-1 and 0.019 mul mg-1 h-1, respectively), was almost tenfold lower than that estimated for spiders of equivalent mass. In adults, the DVC was modulated to accommodate changing V(dot)CO2 chiefly by changes in DVC frequency. Modulation of other DVC characteristics was bimodal; at low V(dot)CO2 (below the ‘SMR threshold’), burst volumes were large and not correlated with V(dot)CO2, but the rate of CO2 emission during the burst was modulated by V(dot)CO2. Above the SMR threshold, burst volumes were small and tightly correlated with V(dot)CO2. No fluttering-spiracle phase could be detected, but CO2 bursts were triggered at low volumes above the SMR threshold, suggesting that hypoxia in addition to hypercapnia may initiate the termination of DVCs in the burst phase, rather than initiating the flutter phase as in insects. To explain this bimodal modulation of the DVC by V(dot)CO2 (and hence V(dot)O2) above and below the SMR threshold, we hypothesize that, below the SMR threshold, unfed ixodid ticks - with their very low SMR and large surface area/volume ratio - may obtain significant amounts of O2 by transcuticular or other putative non-spiracular avenues of O2 uptake (larval ticks obtain all their O2 in this way).

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Parsa, Pirooz Victor, Rinaldo David D’Souza, and Sukumar Vijayaraghavan. "Signaling between periglomerular cells reveals a bimodal role for GABA in modulating glomerular microcircuitry in the olfactory bulb." Proceedings of the National Academy of Sciences 112, no. 30 (July 13, 2015): 9478–83. http://dx.doi.org/10.1073/pnas.1424406112.

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In the mouse olfactory bulb glomerulus, the GABAergic periglomerular (PG) cells provide a major inhibitory drive within the microcircuit. Here we examine GABAergic synapses between these interneurons. At these synapses, GABA is depolarizing and exerts a bimodal control on excitability. In quiescent cells, activation of GABAA receptors can induce the cells to fire, thereby providing a means for amplification of GABA release in the glomerular microcircuit via GABA-induced GABA release. In contrast, GABA is inhibitory in neurons that are induced to fire tonically. PG–PG interactions are modulated by nicotinic acetylcholine receptors (nAChRs), and our data suggest that changes in intracellular calcium concentrations triggered by nAChR activation can be amplified by GABA release. Our results suggest that bidirectional control of inhibition in PG neurons can allow for modulatory inputs, like the cholinergic inputs from the basal forebrain, to determine threshold set points for filtering out weak olfactory inputs in the glomerular layer of the olfactory bulb via the activation of nAChRs.

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Ebeling, Daniel, and Santiago D. Solares. "Bimodal atomic force microscopy driving the higher eigenmode in frequency-modulation mode: Implementation, advantages, disadvantages and comparison to the open-loop case." Beilstein Journal of Nanotechnology 4 (March 18, 2013): 198–207. http://dx.doi.org/10.3762/bjnano.4.20.

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We present an overview of the bimodal amplitude–frequency-modulation (AM-FM) imaging mode of atomic force microscopy (AFM), whereby the fundamental eigenmode is driven by using the amplitude-modulation technique (AM-AFM) while a higher eigenmode is driven by using either the constant-excitation or the constant-amplitude variant of the frequency-modulation (FM-AFM) technique. We also offer a comparison to the original bimodal AFM method, in which the higher eigenmode is driven with constant frequency and constant excitation amplitude. General as well as particular characteristics of the different driving schemes are highlighted from theoretical and experimental points of view, revealing the advantages and disadvantages of each. This study provides information and guidelines that can be useful in selecting the most appropriate operation mode to characterize different samples in the most efficient and reliable way.

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Dietz, Christian, Marcus Schulze, Agnieszka Voss, Christian Riesch, and Robert W. Stark. "Bimodal frequency-modulated atomic force microscopy with small cantilevers." Nanoscale 7, no. 5 (2015): 1849–56. http://dx.doi.org/10.1039/c4nr05907g.

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MUIRAS, M. L., P. U. GIACOMONI, and P. TACHON. "Modulation of Bimodal DNA Nicking by H2O2and Ferrous Iron." Annals of the New York Academy of Sciences 663, no. 1 Aging and Cel (November 1992): 447–49. http://dx.doi.org/10.1111/j.1749-6632.1992.tb38697.x.

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Fischer, A., Y. Nakai, L. M. Eubanks, C. M. Clancy, W. H. Tepp, S. Pellett, T. J. Dickerson, E. A. Johnson, K. D. Janda, and M. Montal. "Bimodal modulation of the botulinum neurotoxin protein-conducting channel." Proceedings of the National Academy of Sciences 106, no. 5 (January 21, 2009): 1330–35. http://dx.doi.org/10.1073/pnas.0812839106.

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Guo, Zhi-Ling, Liang-Wu Fu, Hou-Fen Su, Stephanie C. Tjen-A-Looi, and John C. Longhurst. "Role of TRPV1 in acupuncture modulation of reflex excitatory cardiovascular responses." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 314, no. 5 (May 1, 2018): R655—R666. http://dx.doi.org/10.1152/ajpregu.00405.2017.

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We have shown that acupuncture, including manual and electroacupuncture (MA and EA), at the P5–6 acupoints stimulates afferent fibers in the median nerve (MN) to modulate sympathoexcitatory cardiovascular reflexes through central regulation of autonomic function. However, the mechanisms underlying acupuncture activation of these sensory afferent nerves and their cell bodies in the dorsal root ganglia (DRG) are unclear. Transient receptor potential vanilloid type 1 (TRPV1) is present in sensory nerve fibers distributed in the general region of acupoints like ST36 and BL 40 located in the hindlimb. However, the contribution of TRPV1 to activation of sensory nerves by acupuncture, leading to modulation of pressor responses, has not been studied. We hypothesized that TRPV1 participates in acupuncture’s activation of sensory afferents and their associated cell bodies in the DRG to modulate pressor reflexes. Local injection of iodoresiniferatoxin (Iodo-RTX; a selective TRPV1 antagonist), but not 5% DMSO (vehicle), into the P6 acupoint on the forelimb reversed the MA’s inhibition of pressor reflexes induced by gastric distension (GD). Conversely, inhibition of GD-induced sympathoexcitatory responses by EA at P5–6 was unchanged after administration of Iodo-RTX into P5–6. Single-unit activity of Group III or IV bimodal afferents sensitive to both mechanical and capsaicin stimuli responded to MA stimulation at P6. MA-evoked activity was attenuated significantly ( P < 0.05) by local administration of Iodo-RTX ( n = 12) but not by 5% DMSO ( n = 12) into the region of the P6 acupoint in rats. Administration of Iodo-RTX into P5–6 did not reduce bimodal afferent activity evoked by EA stimulation ( n = 8). Finally, MA at P6 and EA at P5–6 induced phosphorylation of extracellular signal-regulated kinases (ERK; an intracellular signaling messenger involved in cellular excitation) in DRG neurons located at C7–8 spinal levels receiving MN inputs. After TRPV1 was knocked down in the DRG at these spinal levels with intrathecal injection of TRPV1-siRNA, expression of phosphorylated ERK in the DRG neuron was reduced in MA-treated, but not EA-treated animals. These data suggest that TRPV1 in Group III and IV bimodal sensory afferent nerves contributes to acupuncture inhibition of reflex increases in blood pressure and specifically plays an important role during MA but not EA.

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Nazaré, Cristina Jordão, and Armando Mónica Oliveira. "Effects of Audiovisual Presentations on Visual Localization Errors: One or Several Multisensory Mechanisms?" Multisensory Research 34, no. 6 (April 20, 2021): 587–621. http://dx.doi.org/10.1163/22134808-bja10048.

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Abstract The present study examines the extent to which temporal and spatial properties of sound modulate visual motion processing in spatial localization tasks. Participants were asked to locate the place at which a moving visual target unexpectedly vanished. Across different tasks, accompanying sounds were factorially varied within subjects as to their onset and offset times and/or positions relative to visual motion. Sound onset had no effect on the localization error. Sound offset was shown to modulate the perceived visual offset location, both for temporal and spatial disparities. This modulation did not conform to attraction toward the timing or location of the sounds but, demonstrably in the case of temporal disparities, to bimodal enhancement instead. Favorable indications to a contextual effect of audiovisual presentations on interspersed visual-only trials were also found. The short sound-leading offset asynchrony had equivalent benefits to audiovisual offset synchrony, suggestive of the involvement of early-level mechanisms, constrained by a temporal window, at these conditions. Yet, we tentatively hypothesize that the whole of the results and how they compare with previous studies requires the contribution of additional mechanisms, including learning-detection of auditory-visual associations and cross-sensory spread of endogenous attention.

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Guan, Shaobo, Yu Liu, Ruobing Xia, and Mingsha Zhang. "Covert attention regulates saccadic reaction time by routing between different visual-oculomotor pathways." Journal of Neurophysiology 107, no. 6 (March 15, 2012): 1748–55. http://dx.doi.org/10.1152/jn.00082.2011.

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Covert attention modulates saccadic performance, e.g., the abrupt onset of a task-irrelevant visual stimulus grabs attention as measured by a decrease in saccadic reaction time (SRT). The attentional advantage bestowed by the task-irrelevant stimulus is short-lived: SRT is actually longer ∼200 ms after the onset of a stimulus than it is when no stimulus appears, known as inhibition of return. The mechanism by which attention modulates saccadic reaction is not well-understood. Here, we propose two possible mechanisms: by selective routing of the visuomotor signal through different pathways (routing hypothesis) or by general modulation of the speed of visuomotor transformation (shifting hypothesis). To test them, we designed a cue gap paradigm in which a 100-ms gap was introduced between the fixation point disappearance and the target appearance to the conventional cued visual reaction time paradigm. The cue manipulated the location of covert attention, and the gap interval resulted in a bimodal distribution of SRT, with an early mode (express saccade) and a late mode (regular saccade). The routing hypothesis predicts changes in the proportion of express saccades vs. regular saccades, whereas the shifting hypothesis predicts a shift of SRT distribution. The addition of the cue had no effect on mean reaction time of express and regular saccades, but it changed the relative proportion of two modes. These results demonstrate that the covert attention modification of the mean SRT is largely attributed to selective routing between visuomotor pathways rather than general modulation of the speed of visuomotor transformation.

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Pyschny, Verena, Markus Landwehr, Moritz Hahn, Ruth Lang-Roth, Martin Walger, and Hartmut Meister. "Head Shadow, Squelch, and Summation Effects With an Energetic or Informational Masker in Bilateral and Bimodal CI Users." Journal of Speech, Language, and Hearing Research 57, no. 5 (October 2014): 1942–60. http://dx.doi.org/10.1044/2014_jslhr-h-13-0144.

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Purpose The objective of the study was to investigate the influence of noise (energetic) and speech (energetic plus informational) maskers on the head shadow (HS), squelch (SQ), and binaural summation (SU) effect in bilateral and bimodal cochlear implant (CI) users. Method Speech recognition was measured in the presence of either a competing talker or modulated speech-shaped noise in 10 bimodal and 10 bilateral adult CI users. HS, SQ, and SU effects were calculated. The interfering signals were manipulated with respect to F0 to consider the influence of different speaker voices. Results The effects HS, SQ, and SU differed depending on the type of masker. A detailed analysis of errors was used to dissociate energetic and informational masking effects. The analysis showed a release from energetic than from informational masking. Conclusion Noise interferers are not sufficient to reflect difficulties experienced with speech understanding in noise for bilateral and bimodal CI users.

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Ernst, Matthias, Helen Geen, and Beat H. Meier. "Amplitude-modulated decoupling in rotating solids: A bimodal Floquet approach." Solid State Nuclear Magnetic Resonance 29, no. 1-3 (February 2006): 2–21. http://dx.doi.org/10.1016/j.ssnmr.2005.08.004.

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Lepreux, Gaëtan, Stephan Shuichi Haupt, and Volker Dürr. "Bimodal modulation of background activity in an identified descending interneuron." Journal of Neurophysiology 122, no. 6 (December 1, 2019): 2316–30. http://dx.doi.org/10.1152/jn.00864.2018.

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In the absence of any obvious input, sensory neurons and interneurons can display resting or spontaneous activity. This is often regarded as noise and removed through trial averaging, although it may reflect history-dependent modulation of tuning or fidelity and, thus, be of functional relevance to downstream interneurons. We investigated the history dependence of spontaneous activity in a pair of identified, bimodal descending interneurons of the stick insect, called contralateral ON-type velocity-sensitive interneurons (cONv). The bilateral pair of cONv conveys antennal mechanosensory information to the thoracic ganglia, where it arborizes in regions containing locomotor networks. Each cONv encodes the movement velocity of the contralateral antenna, but also substrate vibration as induced by discrete tapping events. Moreover, cONv display highly fluctuating spontaneous activity that can reach rates similar to those during antennal movement at moderate velocities. Hence, cONv offer a unique opportunity to study history-dependent effects on spontaneous activity and, thus, encoding fidelity in two modalities. In this work, we studied unimodal and cross-modal effects as well as unilateral and bilateral effects, using bilateral recordings of both cONv neurons, while moving one antenna and/or delivering taps to induce substrate vibration. Tapping could reduce spontaneous activity of both neurons, whereas antennal movement reduced spontaneous activity of the contralateral cONv neuron only. Combination of both modalities showed a cooperative effect for some parameter constellations, suggesting bimodal enhancement. Since both stimulus modalities could cause a reduction of spontaneous activity at stimulus intensities occurring during natural locomotion, we conclude that this should enhance neuronal response fidelity during locomotion. NEW & NOTEWORTHY The spontaneous activity in a pair of identified, descending insect interneurons is reduced depending on stimulus history. At rest, spontaneous activity levels are correlated in both interneurons, indicating a common drive from background activity. Whereas taps on the substrate affect both interneurons, antennal movement affects the contralateral interneuron only. Cross-modal interaction occurs, too. Since spontaneous activity is reduced at stimulus intensities encountered during natural locomotion, the mechanism could enhance neuronal response fidelity during locomotion.

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Labuda, Aleksander, Marta Kocuń, Waiman Meinhold, Deron Walters, and Roger Proksch. "Generalized Hertz model for bimodal nanomechanical mapping." Beilstein Journal of Nanotechnology 7 (July 5, 2016): 970–82. http://dx.doi.org/10.3762/bjnano.7.89.

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Bimodal atomic force microscopy uses a cantilever that is simultaneously driven at two of its eigenmodes (resonant modes). Parameters associated with both resonances can be measured and used to extract quantitative nanomechanical information about the sample surface. Driving the first eigenmode at a large amplitude and a higher eigenmode at a small amplitude simultaneously provides four independent observables that are sensitive to the tip–sample nanomechanical interaction parameters. To demonstrate this, a generalized theoretical framework for extracting nanomechanical sample properties from bimodal experiments is presented based on Hertzian contact mechanics. Three modes of operation for measuring cantilever parameters are considered: amplitude, phase, and frequency modulation. The experimental equivalence of all three modes is demonstrated on measurements of the second eigenmode parameters. The contact mechanics theory is then extended to power-law tip shape geometries, which is applied to analyze the experimental data and extract a shape and size of the tip interacting with a polystyrene surface.

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Kawai, Masanobu, and Clifford J. Rosen. "Minireview: A Skeleton in Serotonin’s Closet?" Endocrine Reviews 31, no. 4 (August 1, 2010): 603. http://dx.doi.org/10.1210/edrv.31.4.9989.

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Abstract The serotonin molecule plays a multifunctional role in mammalian homeostasis serving as a neurotransmitter in the central nervous system, a gut-derived mediator of peristalsis, and a circulating hormone that regulates appetite, cardiovascular function, and hemostasis. Recent evidence from the clinic and the bench highlight an unexpected target for serotonin action, the skeleton. Clinically, two classes of drugs, the second generation antipsychotic drugs (SGAs) and selective serotonin reuptake inhibitors (SSRIs), which modulate central and peripheral serotonin signaling, have been shown to alter bone remodeling although the mechanism is not clear. In contrast, genetically engineered mouse models have demonstrated a bimodal control system whereby gut-derived serotonin under the control of the Wnt/Lrp/β-catenin system acts systemically to suppress bone formation, whereas CNS serotonin activated by leptin modulates sympathetic outflow to the skeleton. In this brief review, we will summarize recent findings linking serotonin to the skeleton and discuss future directions for this new but challenging aspect of this multidimensional molecule.

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Kawai, Masanobu, and Clifford J. Rosen. "Minireview: A Skeleton in Serotonin’s Closet?" Endocrinology 151, no. 9 (July 21, 2010): 4103–8. http://dx.doi.org/10.1210/en.2010-0499.

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The serotonin molecule plays a multifunctional role in mammalian homeostasis serving as a neurotransmitter in the central nervous system, a gut-derived mediator of peristalsis, and a circulating hormone that regulates appetite, cardiovascular function, and hemostasis. Recent evidence from the clinic and the bench highlight an unexpected target for serotonin action, the skeleton. Clinically, two classes of drugs, the second generation antipsychotic drugs (SGAs) and selective serotonin reuptake inhibitors (SSRIs), which modulate central and peripheral serotonin signaling, have been shown to alter bone remodeling although the mechanism is not clear. In contrast, genetically engineered mouse models have demonstrated a bimodal control system whereby gut-derived serotonin under the control of the Wnt/Lrp/β-catenin system acts systemically to suppress bone formation, whereas CNS serotonin activated by leptin modulates sympathetic outflow to the skeleton. In this brief review, we will summarize recent findings linking serotonin to the skeleton and discuss future directions for this new but challenging aspect of this multidimensional molecule.

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Allman, Brian L., and M. Alex Meredith. "Multisensory Processing in “Unimodal” Neurons: Cross-Modal Subthreshold Auditory Effects in Cat Extrastriate Visual Cortex." Journal of Neurophysiology 98, no. 1 (July 2007): 545–49. http://dx.doi.org/10.1152/jn.00173.2007.

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Historically, the study of multisensory processing has examined the function of the definitive neuron type, the bimodal neuron. These neurons are excited by inputs from more than one sensory modality, and when multisensory stimuli are present, they can integrate their responses in a predictable manner. However, recent studies have revealed that multisensory processing in the cortex is not restricted to bimodal neurons. The present investigation sought to examine the potential for multisensory processing in nonbimodal (unimodal) neurons in the retinotopically organized posterolateral lateral suprasylvian (PLLS) area of the cat. Standard extracellular recordings were used to measure responses of all neurons encountered to both separate- and combined-modality stimulation. Whereas bimodal neurons behaved as predicted, the surprising result was that 16% of unimodal visual neurons encountered were significantly facilitated by auditory stimuli. Because these unimodal visual neurons did not respond to an auditory stimulus presented alone but had their visual responses modulated by concurrent auditory stimulation, they represent a new form of multisensory neuron: the subthreshold multisensory neuron. These data also demonstrate that bimodal neurons can no longer be regarded as the exclusive basis for multisensory processing.

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Schendel, Krista, and Lynn C. Robertson. "Reaching Out to See: Arm Position Can Attenuate Human Visual Loss." Journal of Cognitive Neuroscience 16, no. 6 (July 2004): 935–43. http://dx.doi.org/10.1162/0898929041502698.

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Electrophysiological recordings in monkeys have now revealed several brain regions that contain bimodal visuotactile neurons capable of responding to either tactile or visual stimuli placed on or near the hands, arms, and face. These cells have now been found in frontal, parietal, and subcortical areas of the monkey brain, suggesting a cortical network of neurons that preferentially represent near peripersonal space. The degree to which the visual responses of such cells rely on input from the primary visual cortex and the extent to which they may contribute to visual perception is not completely understood. Nonetheless, recent neuropsychological studies suggest that a similar representation of near space may be bimodally coded in humans as well. Given the accumulating evidence for specialized processing of visual stimuli placed near the hands and arms, we hypothesized that arm position may be capable of modulating human visual ability. Here we report the case of WM, who lost his ability to see in his left visual hemifield after sustaining damage to his right primary visual cortex. Interestingly, the placement of WM's left arm into his “blind” field resulted in significantly better detection of left visual field stimuli compared to when his hand was placed in his lap at midline. Moreover, we found this attenuation to be confined to stimuli presented within reaching distance (unless a tool that extended WM's reach was held while he performed the test). These findings are highly consistent with the characteristics of the bimodal visuo-tactile neurons that have been described in monkeys. Thus, it seems that arm position can modulate human visual ability, even after damage to the primary visual cortex. This study provides an exciting bridge between monkey neurophysiology and human visual capacity while also offering a novel approach for improving visual defects acquired via cortical injury.

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Stuckenberg, Maria V., Erich Schröger, and Andreas Widmann. "Modulation of early auditory processing by visual information: Prediction or bimodal integration?" Attention, Perception, & Psychophysics 83, no. 4 (January 27, 2021): 1538–51. http://dx.doi.org/10.3758/s13414-021-02240-1.

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AbstractWhat happens if a visual cue misleads auditory expectations? Previous studies revealed an early visuo–auditory incongruency effect, so-called incongruency response (IR) of the auditory event-related brain potential (ERP), occurring 100 ms after onset of the sound being incongruent to the preceding visual cue. So far, this effect has been ascribed to reflect the mismatch between auditory sensory expectation activated by visual predictive information and the actual sensory input. Thus, an IR should be confined to an asynchronous presentation of visual cue and sound. Alternatively, one could argue that frequently presented congruent visual-cue–sound combinations are integrated into a bimodal representation whereby violation of the visual–auditory relationship results in a bimodal feature mismatch (the IR should be obtained with asynchronous and with synchronous presentation). In an asynchronous condition, an either high-pitched or low-pitched sound was preceded by a visual note symbol presented above or below a fixation cross (90% congruent; 10% incongruent), while in a synchronous condition, both were presented simultaneously. High-pitched and low-pitched sounds were presented with different probabilities (83% vs. 17%) to form a strong association between bimodal stimuli. In both conditions, tones with pitch incongruent with the location of the note symbols elicited incongruency effects in the N2 and P3 ERPs; however, the IR was only elicited in the asynchronous condition. This finding supports the sensorial prediction error hypothesis stating that the amplitude of the auditory ERP 100 ms after sound onset is enhanced in response to unexpected compared with expected but otherwise identical sounds.

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Leo, Fabrizio, Sara Nataletti, and Luca Brayda. "Non-informative vision improves spatial tactile discrimination on the shoulder but does not influence detection sensitivity." Experimental Brain Research 238, no. 12 (October 13, 2020): 2865–75. http://dx.doi.org/10.1007/s00221-020-05944-2.

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Abstract Vision of the body has been reported to improve tactile acuity even when vision is not informative about the actual tactile stimulation. However, it is currently unclear whether this effect is limited to body parts such as hand, forearm or foot that can be normally viewed, or it also generalizes to body locations, such as the shoulder, that are rarely before our own eyes. In this study, subjects consecutively performed a detection threshold task and a numerosity judgment task of tactile stimuli on the shoulder. Meanwhile, they watched either a real-time video showing their shoulder or simply a fixation cross as control condition. We show that non-informative vision improves tactile numerosity judgment which might involve tactile acuity, but not tactile sensitivity. Furthermore, the improvement in tactile accuracy modulated by vision seems to be due to an enhanced ability in discriminating the number of adjacent active electrodes. These results are consistent with the view that bimodal visuotactile neurons sharp tactile receptive fields in an early somatosensory map, probably via top-down modulation of lateral inhibition.

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Kanda, Yuzuki, Miho Okada, Rina Ikarashi, Eri Morioka, Takashi Kondo, and Masayuki Ikeda. "Bimodal modulation of store-operated Ca2+ channels by clozapine in astrocytes." Neuroscience Letters 635 (December 2016): 56–60. http://dx.doi.org/10.1016/j.neulet.2016.10.027.

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Yoo, Young Dong, Su Ran Mun, Chang Hoon Ji, Ki Woon Sung, Keum Young Kang, Ah Jung Heo, Su Hyun Lee, et al. "N-terminal arginylation generates a bimodal degron that modulates autophagic proteolysis." Proceedings of the National Academy of Sciences 115, no. 12 (March 5, 2018): E2716—E2724. http://dx.doi.org/10.1073/pnas.1719110115.

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The conjugation of amino acids to the protein N termini is universally observed in eukaryotes and prokaryotes, yet its functions remain poorly understood. In eukaryotes, the amino acid l-arginine (l-Arg) is conjugated to N-terminal Asp (Nt-Asp), Glu, Gln, Asn, and Cys, directly or associated with posttranslational modifications. Following Nt-arginylation, the Nt-Arg is recognized by UBR boxes of N-recognins such as UBR1, UBR2, UBR4/p600, and UBR5/EDD, leading to substrate ubiquitination and proteasomal degradation via the N-end rule pathway. It has been a mystery, however, why studies for the past five decades identified only a handful of Nt-arginylated substrates in mammals, although five of 20 principal amino acids are eligible for arginylation. Here, we show that the Nt-Arg functions as a bimodal degron that directs substrates to either the ubiquitin (Ub)-proteasome system (UPS) or macroautophagy depending on physiological states. In normal conditions, the arginylated forms of proteolytic cleavage products, D101-CDC6 and D1156-BRCA1, are targeted to UBR box-containing N-recognins and degraded by the proteasome. However, when proteostasis by the UPS is perturbed, their Nt-Arg redirects these otherwise cellular wastes to macroautophagy through its binding to the ZZ domain of the autophagic adaptor p62/STQSM/Sequestosome-1. Upon binding to the Nt-Arg, p62 acts as an autophagic N-recognin that undergoes self-polymerization, facilitating cargo collection and lysosomal degradation of p62–cargo complexes. A chemical mimic of Nt-Arg redirects Ub-conjugated substrates from the UPS to macroautophagy and promotes their lysosomal degradation. Our results suggest that the Nt-Arg proteome of arginylated proteins contributes to reprogramming global proteolytic flux under stresses.

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Teder-Sälejärvi, W. A., F. Di Russo, J. J. McDonald, and S. A. Hillyard. "Effects of Spatial Congruity on Audio-Visual Multimodal Integration." Journal of Cognitive Neuroscience 17, no. 9 (September 2005): 1396–409. http://dx.doi.org/10.1162/0898929054985383.

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Spatial constraints on multisensory integration of auditory (A) and visual (V) stimuli were investigated in humans using behavioral and electrophysiological measures. The aim was to find out whether cross-modal interactions between A and V stimuli depend on their spatial congruity, as has been found for multisensory neurons in animal studies (Stein & Meredith, 1993). Randomized sequences of unimodal (A or V) and simultaneous bimodal (AV) stimuli were presented to right-or left-field locations while subjects made speeded responses to infrequent targets of greater intensity that occurred in either or both modalities. Behavioral responses to the bimodal stimuli were faster and more accurate than to the uni-modal stimuli for both same-location and different-location AV pairings. The neural basis of this cross-modal facilitation was studied by comparing event-related potentials (ERPs) to the bimodal AV stimuli with the summed ERPs to the unimodal A and V stimuli. These comparisons revealed neural interactions localized to the ventral occipito-temporal cortex (at 190 msec) and to the superior temporal cortical areas (at 260 msec) for both same-and different-location AV pairings. In contrast, ERP interactions that differed according to spatial congruity included a phase and amplitude modulation of visual-evoked activity localized to the ventral occipito-temporal cortex at 100-400 msec and an amplitude modulation of activity localized to the superior temporal region at 260-280 msec. These results demonstrate overlapping but distinctive patterns of multisensory integration for spatially congruent and incongruent AV stimuli.

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Gustison, Morgan L., and Thore J. Bergman. "Divergent acoustic properties of gelada and baboon vocalizations and their implications for the evolution of human speech." Journal of Language Evolution 2, no. 1 (January 1, 2017): 20–36. http://dx.doi.org/10.1093/jole/lzx015.

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Abstract Human speech has many complex spectral and temporal features traditionally thought to be absent in the vocalizations of other primates. Recent explorations of the vocal capabilities of non-human primates are challenging this view. Here, we continue this trend by exploring the spectro-temporal properties of gelada (Theropithecus gelada) vocalizations. First, we made cross-species comparisons of geladas, chacma baboons, and human vowel space area. We found that adult male and female gelada exhaled grunts–a call type shared with baboons—have formant profiles that overlap more with human vowel space than do baboon grunts. These gelada grunts also contained more modulation of fundamental and formant frequencies than did baboon grunts. Second, we compared formant profiles and modulation of exhaled grunts to the derived call types (those not shared with baboons) produced by gelada males. These derived calls contained divergent formant profiles, and a subset of them, notably wobbles and vocalized yawns, were more modulated than grunts. Third, we investigated the rhythmic patterns of wobbles, a call type shown previously to contain cycles that match the 3–8 Hz tempo of speech. We use a larger dataset to show that the wobble rhythm overlaps more with speech rhythm than previously thought. We also found that variation in cycle duration depends on the production modality; specifically, exhaled wobbles were produced at a slower tempo than inhaled wobbles. Moreover, the variability in cycle duration within wobbles aligns with a linguistic property known as ‘Menzerath’s law’ in that there was a negative association between cycle duration and wobble size (i.e. the number of cycles). Taken together, our results add to growing evidence that non-human primates are anatomically capable of producing modulated sounds. Our results also support and expand on current hypotheses of speech evolution, including the ‘neural hypothesis’ and the ‘bimodal speech rhythm hypothesis’.

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Razak, K. A., Z. M. Fuzessery, and T. D. Lohuis. "Single Cortical Neurons Serve Both Echolocation and Passive Sound Localization." Journal of Neurophysiology 81, no. 3 (March 1, 1999): 1438–42. http://dx.doi.org/10.1152/jn.1999.81.3.1438.

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Single cortical neurons serve both echolocation and passive sound localization. The pallid bat uses passive listening at low frequencies to detect and locate terrestrial prey and reserves its high-frequency echolocation for general orientation. While hunting, this bat must attend to both streams of information. These streams are processed through two parallel, functionally specialized pathways that are segregated at the level of the inferior colliculus. This report describes functionally bimodal neurons in auditory cortex that receive converging input from these two pathways. Each brain stem pathway imposes its own suite of response properties on these cortical neurons. Consequently, the neurons are bimodally tuned to low and high frequencies, and respond selectively to both noise transients used in prey detection, and downward frequency modulation (FM) sweeps used in echolocation. A novel finding is that the monaural and binaural response properties of these neurons can change as a function of the sound presented. The majority of neurons appeared binaurally inhibited when presented with noise but monaural or binaurally facilitated when presented with the echolocation pulse. Consequently, their spatial sensitivity will change, depending on whether the bat is engaged in echolocation or passive listening. These results demonstrate that the response properties of single cortical neurons can change with behavioral context and suggest that they are capable of supporting more than one behavior.

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van Leeuwen, Anieke, Sarah A. Budischak, Andrea L. Graham, and Clayton E. Cressler. "Parasite resource manipulation drives bimodal variation in infection duration." Proceedings of the Royal Society B: Biological Sciences 286, no. 1902 (May 8, 2019): 20190456. http://dx.doi.org/10.1098/rspb.2019.0456.

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Over a billion people on earth are infected with helminth parasites and show remarkable variation in parasite burden and chronicity. These parasite distributions are captured well by classic statistics, such as the negative binomial distribution. But the within-host processes underlying this variation are not well understood. In this study, we explain variation in macroparasite infection outcomes on the basis of resource flows within hosts. Resource flows realize the interactions between parasites and host immunity and metabolism. When host metabolism is modulated by parasites, we find a positive feedback of parasites on their own resources. While this positive feedback results in parasites improving their resource availability at high burdens, giving rise to chronic infections, it also results in a threshold biomass required for parasites to establish in the host, giving rise to acute infections when biomass fails to clear the threshold. Our finding of chronic and acute outcomes in bistability contrasts with classic theory, yet is congruent with the variation in helminth burdens observed in human and wildlife populations.

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Vanni, M. P., J. Provost, C. Casanova, and F. Lesage. "Bimodal modulation and continuous stimulation in optical imaging to map direction selectivity." NeuroImage 49, no. 2 (January 2010): 1416–31. http://dx.doi.org/10.1016/j.neuroimage.2009.09.044.

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Castelnuovo, Manuele, Samir Rahman, Elisa Guffanti, Valentina Infantino, Françoise Stutz, and Daniel Zenklusen. "Bimodal expression of PHO84 is modulated by early termination of antisense transcription." Nature Structural & Molecular Biology 20, no. 7 (June 16, 2013): 851–58. http://dx.doi.org/10.1038/nsmb.2598.

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Solares, Santiago D. "Challenges and complexities of multifrequency atomic force microscopy in liquid environments." Beilstein Journal of Nanotechnology 5 (March 14, 2014): 298–307. http://dx.doi.org/10.3762/bjnano.5.33.

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This paper illustrates through numerical simulation the complexities encountered in high-damping AFM imaging, as in liquid enviroments, within the specific context of multifrequency atomic force microscopy (AFM). The focus is primarily on (i) the amplitude and phase relaxation of driven higher eigenmodes between successive tip–sample impacts, (ii) the momentary excitation of non-driven higher eigenmodes and (iii) base excitation artifacts. The results and discussion are mostly applicable to the cases where higher eigenmodes are driven in open loop and frequency modulation within bimodal schemes, but some concepts are also applicable to other types of multifrequency operations and to single-eigenmode amplitude and frequency modulation methods.

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Akbaba, Sati, Dina Ahmed, Andreas Mock, Thomas Held, Suzan Bahadir, Kristin Lang, Mustafa Syed, et al. "Treatment Outcome of 227 Patients with Sinonasal Adenoid Cystic Carcinoma (ACC) after Intensity Modulated Radiotherapy and Active Raster-Scanning Carbon Ion Boost: A 10-Year Single-Center Experience." Cancers 11, no. 11 (November 1, 2019): 1705. http://dx.doi.org/10.3390/cancers11111705.

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We aimed to evaluate the treatment outcome of primary and postoperative bimodal radiotherapy (RT) including intensity modulated photon radiotherapy (IMRT) and carbon ion radiotherapy (CIRT) for sinonasal adenoid cystic carcinoma (ACC) patients. Medical records of 227 consecutive patients who received either a primary (n = 90, 40%) or postoperative (n = 137, 60%; R2, n = 86, 63%) IMRT with doses between 48 and 56 Gy in 1.8 or 2 Gy fractions and active raster-scanning carbon ion boost with 18 to 24 Gy (RBE, relative biological effectiveness) in 3 Gy (RBE) fractions between 2009 and 2019 up to a median total dose of 80 Gy (EQD2, equivalent dose in 2 Gy single dose fractions, range 71–80 Gy) were reviewed. Results: Median follow-up was 50 months. In univariate and multivariate analysis, no significant difference in local control (LC) could be shown between the two treatment groups (p = 0.33). Corresponding 3-year LC rates were 79% for primary bimodal RT and 82% for postoperative bimodal RT, respectively. T4 stage (p = 0.002) and solid histology (p = 0.005) were identified as independent prognostic factors for decreased LC. Significant worse long-term treatment tolerance was observed for postoperatively irradiated patients with 17% vs. 6% late grade 3 toxicity (p < 0.001). Primary radiotherapy including IMRT and carbon ion boost for dose-escalation results in adequate LC with less long-term grade 3 toxicity compared to postoperative bimodal radiotherapy in sinonasal ACC patients. The high rate of macroscopic tumor disease in the postoperative group makes the interpretation of the beneficial results in LC for primary RT difficult.

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Ong, Jia Hoong, Denis Burnham, Paola Escudero, and Catherine J. Stevens. "Effect of Linguistic and Musical Experience on Distributional Learning of Nonnative Lexical Tones." Journal of Speech, Language, and Hearing Research 60, no. 10 (October 17, 2017): 2769–80. http://dx.doi.org/10.1044/2016_jslhr-s-16-0080.

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Purpose Evidence suggests that extensive experience with lexical tones or musical training provides an advantage in perceiving nonnative lexical tones. This investigation concerns whether such an advantage is evident in learning nonnative lexical tones based on the distributional structure of the input. Method Using an established protocol, distributional learning of lexical tones was investigated with tone language (Mandarin) listeners with no musical training (Experiment 1) and nontone language (Australian English) listeners with musical training (Experiment 2). Within each experiment, participants were trained on a bimodal (2-peak) or a unimodal (single peak) distribution along a continuum spanning a Thai lexical tone minimal pair. Discrimination performance on the target minimal pair was assessed before and after training. Results Mandarin nonmusicians exhibited clear distributional learning (listeners in the bimodal, but not those in the unimodal condition, improved significantly as a function of training), whereas Australian English musicians did not (listeners in both the bimodal and unimodal conditions improved as a function of training). Conclusions Our findings suggest that veridical perception of lexical tones is not sufficient for distributional learning of nonnative lexical tones to occur. Rather, distributional learning appears to be modulated by domain-specific pitch experience and is constrained possibly by top-down interference.

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Zhu, Chunjuan, Guosheng Han, and Feng Jiao. "Dynamical Regulation of mRNA Distribution by Cross-Talking Signaling Pathways." Complexity 2020 (June 17, 2020): 1–11. http://dx.doi.org/10.1155/2020/6402703.

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Gene transcription is a random process in single cells manifested by the observed distribution of mRNA copy numbers in homogeneous cell populations. A central question is to understand how mRNA distribution is modulated under environmental changes. In this work, we initiate a theoretical study on mRNA distribution dynamics for the stochastic transcription model that involves cross-talking signaling pathways to direct gene activation in response to external signals. We first express the distribution in mathematical dynamical formulas under both moderate and high transcriptional upregulations. In each scenario, our further numerical examples display an observed dynamical transition type among three distribution modes for stress genes in yeast. In particular, the intermediate bimodal stage sustains within a certain length of early time and lasts much longer than that generated by the single pathway. This shows the general and robust bimodal transcription regulated by the cross-talk of signaling pathways.

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Majewska, Maria Dorota. "Neurosteroids: Endogenous bimodal modulators of the GABAA receptor mechanism of action and physiological significance." Progress in Neurobiology 38, no. 4 (April 1992): 379–94. http://dx.doi.org/10.1016/0301-0082(92)90025-a.

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Bergan, Joseph F., and Eric I. Knudsen. "Visual Modulation of Auditory Responses in the Owl Inferior Colliculus." Journal of Neurophysiology 101, no. 6 (June 2009): 2924–33. http://dx.doi.org/10.1152/jn.91313.2008.

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The barn owl's central auditory system creates a map of auditory space in the external nucleus of the inferior colliculus (ICX). Although the crucial role visual experience plays in the formation and maintenance of this auditory space map is well established, the mechanism by which vision influences ICX responses remains unclear. Surprisingly, previous experiments have found that in the absence of extensive pharmacological manipulation, visual stimuli do not drive neural responses in the ICX. Here we investigated the influence of dynamic visual stimuli on auditory responses in the ICX. We show that a salient visual stimulus, when coincident with an auditory stimulus, can modulate auditory responses in the ICX even though the same visual stimulus may elicit no neural responses when presented alone. For each ICX neuron, the most effective auditory and visual stimuli were located in the same region of space. In addition, the magnitude of the visual modulation of auditory responses was dependent on the context of the stimulus presentation with novel visual stimuli eliciting consistently larger response modulations than frequently presented visual stimuli. Thus the visual modulation of ICX responses is dependent on the characteristics of the visual stimulus as well as on the spatial and temporal correspondence of the auditory and visual stimuli. These results demonstrate moment-to-moment visual enhancements of auditory responsiveness that, in the short-term, increase auditory responses to salient bimodal stimuli and in the long-term could serve to instruct the adaptive auditory plasticity necessary to maintain accurate auditory orienting behavior.

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Taffou, Marine, Rachid Guerchouche, George Drettakis, and Isabelle Viaud-Delmon. "Auditory–Visual Aversive Stimuli Modulate the Conscious Experience of Fear." Multisensory Research 26, no. 4 (2013): 347–70. http://dx.doi.org/10.1163/22134808-00002424.

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In a natural environment, affective information is perceived via multiple senses, mostly audition and vision. However, the impact of multisensory information on affect remains relatively undiscovered. In this study, we investigated whether the auditory–visual presentation of aversive stimuli influences the experience of fear. We used the advantages of virtual reality to manipulate multisensory presentation and to display potentially fearful dog stimuli embedded in a natural context. We manipulated the affective reactions evoked by the dog stimuli by recruiting two groups of participants: dog-fearful and non-fearful participants. The sensitivity to dog fear was assessed psychometrically by a questionnaire and also at behavioral and subjective levels using a Behavioral Avoidance Test (BAT). Participants navigated in virtual environments, in which they encountered virtual dog stimuli presented through the auditory channel, the visual channel or both. They were asked to report their fear using Subjective Units of Distress. We compared the fear for unimodal (visual or auditory) and bimodal (auditory–visual) dog stimuli. Dog-fearful participants as well as non-fearful participants reported more fear in response to bimodal audiovisual compared to unimodal presentation of dog stimuli. These results suggest that fear is more intense when the affective information is processed via multiple sensory pathways, which might be due to a cross-modal potentiation. Our findings have implications for the field of virtual reality-based therapy of phobias. Therapies could be refined and improved by implicating and manipulating the multisensory presentation of the feared situations.

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Levy, K. A., Z. D. Brodnik, J. K. Shaw, D. A. Perrey, Y. Zhang, and R. A. España. "Hypocretin receptor 1 blockade produces bimodal modulation of cocaine-associated mesolimbic dopamine signaling." Psychopharmacology 234, no. 18 (June 30, 2017): 2761–76. http://dx.doi.org/10.1007/s00213-017-4673-y.

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Gama, Leonardo R., Guilherme Giovanini, Gábor Balázsi, and Alexandre F. Ramos. "Binary Expression Enhances Reliability of Messaging in Gene Networks." Entropy 22, no. 4 (April 22, 2020): 479. http://dx.doi.org/10.3390/e22040479.

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The promoter state of a gene and its expression levels are modulated by the amounts of transcription factors interacting with its regulatory regions. Hence, one may interpret a gene network as a communicating system in which the state of the promoter of a gene (the source) is communicated by the amounts of transcription factors that it expresses (the message) to modulate the state of the promoter and expression levels of another gene (the receptor). The reliability of the gene network dynamics can be quantified by Shannon’s entropy of the message and the mutual information between the message and the promoter state. Here we consider a stochastic model for a binary gene and use its exact steady state solutions to calculate the entropy and mutual information. We show that a slow switching promoter with long and equally standing ON and OFF states maximizes the mutual information and reduces entropy. That is a binary gene expression regime generating a high variance message governed by a bimodal probability distribution with peaks of the same height. Our results indicate that Shannon’s theory can be a powerful framework for understanding how bursty gene expression conciliates with the striking spatio-temporal precision exhibited in pattern formation of developing organisms.

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Sun, Yao, Zhigang Hu, Dan Zhao, and Kaiyang Zeng. "Mechanical Properties of Microcrystalline Metal–Organic Frameworks (MOFs) Measured by Bimodal Amplitude Modulated-Frequency Modulated Atomic Force Microscopy." ACS Applied Materials & Interfaces 9, no. 37 (September 8, 2017): 32202–10. http://dx.doi.org/10.1021/acsami.7b06809.

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Li, Zhi, Weidong Yu, Tim Li, V. S. N. Murty, and Fredolin Tangang. "Bimodal Character of Cyclone Climatology in the Bay of Bengal Modulated by Monsoon Seasonal Cycle*." Journal of Climate 26, no. 3 (February 1, 2013): 1033–46. http://dx.doi.org/10.1175/jcli-d-11-00627.1.

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Abstract The annual cycle of tropical cyclone (TC) frequency over the Bay of Bengal (BoB) exhibits a notable bimodal character, different from a single peak in other basins. The causes of this peculiar feature were investigated through the diagnosis of a genesis potential index (GPI) with the use of the NCEP Reanalysis I dataset during the period 1981–2009. A methodology was developed to quantitatively assess the relative contributions of four environmental parameters. Different from a conventional view that the seasonal change of vertical shear causes the bimodal feature, it was found that the strengthened vertical shear alone from boreal spring to summer cannot overcome the relative humidity effect. It is the combined effect of vertical shear, vorticity, and SST that leads to the GPI minimum in boreal summer. It is noted that TC frequency in October–November is higher than that in April–May, which is primarily attributed to the difference of mean relative humidity between the two periods. In contrast, more supercyclones (category 4 or above) occur in April–May than in October–November. It is argued that greater ocean heat content, the first branch of northward-propagating intraseasonal oscillations (ISOs) associated with the monsoon onset over the BoB, and stronger ISO intensity in April–May are favorable environmental conditions for cyclone intensification.

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Zhusubaliyev, Z. T., D. S. Kuzmina, and O. O. Yanochkina. "Bifurcation Analysis of Piecewise Smooth Bimodal Maps Using Normal Form." Proceedings of the Southwest State University 24, no. 3 (December 6, 2020): 137–51. http://dx.doi.org/10.21869/2223-1560-2020-24-3-137-151.

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Purpose of reseach. Studyof bifurcations in piecewise-smooth bimodal maps using a piecewise-linear continuous map as a normal form. Methods. We propose a technique for determining the parameters of a normal form based on the linearization of a piecewise-smooth map in a neighborhood of a critical fixed point. Results. The stability region of a fixed point is constructed numerically and analytically on the parameter plane. It is shown that this region is limited by two bifurcation curves: the lines of the classical period-doubling bifurcation and the “border collision” bifurcation. It is proposed a method for determining the parameters of a normal form as a function of the parameters of a piecewise smooth map. The analysis of "border-collision" bifurcations using piecewise-linear normal form is carried out. Conclusion. A bifurcation analysis of a piecewise-smooth irreversible bimodal map of the class Z1–Z3–Z1 modeling the dynamics of a pulse–modulated control system is carried out. It is proposed a technique for calculating the parameters of a piecewise linear continuous map used as a normal form. The main bifurcation transitions are calculated when leaving the stability region, both using the initial map and a piecewise linear normal form. The topological equivalence of these maps is numerically proved, indicating the reliability of the results of calculating the parameters of the normal form.

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Journal articles on the topic 'Bimodal modulator'

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