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Herzog G. [ Tuning in addictology, the story of a shared musical experience]. Soins Psychiatr 2024; 45:29-32. [PMID: 38527870 DOI: 10.1016/j.spsy.2024.01.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/27/2024]
Abstract
Music can be used as a therapeutic tool with people suffering from complex addictions and traumas. By playing together, the patient and care team create a transitional space conducive to emotional attunement and trust. This shared experience facilitates connection and engagement in the therapeutic relationship, which conveys a sense of security. Music is a powerful tool in the treatment of addiction and trauma. It helps to repair damaged bonds and develop empathy, cooperation and creativity within the care team.
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Affiliation(s)
- Guillaume Herzog
- Pôle centre Marmottan- La Terrasse, GHU Paris psychiatrie et neurosciences Paris Nord, 17/19 rue Armaillé, 75017 Paris, France.
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2
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Coop SH, Yates JL, Mitchell JF. Pre-saccadic Neural Enhancements in Marmoset Area MT. J Neurosci 2024; 44:e2034222023. [PMID: 38050176 PMCID: PMC10860570 DOI: 10.1523/jneurosci.2034-22.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 09/15/2023] [Accepted: 11/20/2023] [Indexed: 12/06/2023] Open
Abstract
Each time we make an eye movement, attention moves before the eyes, resulting in a perceptual enhancement at the target. Recent psychophysical studies suggest that this pre-saccadic attention enhances the visual features at the saccade target, whereas covert attention causes only spatially selective enhancements. While previous nonhuman primate studies have found that pre-saccadic attention does enhance neural responses spatially, no studies have tested whether changes in neural tuning reflect an automatic feature enhancement. Here we examined pre-saccadic attention using a saccade foraging task developed for marmoset monkeys (one male and one female). We recorded from neurons in the middle temporal area with peripheral receptive fields that contained a motion stimulus, which would either be the target of a saccade or a distracter as a saccade was made to another location. We established that marmosets, like macaques, show enhanced pre-saccadic neural responses for saccades toward the receptive field, including increases in firing rate and motion information. We then examined if the specific changes in neural tuning might support feature enhancements for the target. Neurons exhibited diverse changes in tuning but predominantly showed additive and multiplicative increases that were uniformly applied across motion directions. These findings confirm that marmoset monkeys, like macaques, exhibit pre-saccadic neural enhancements during saccade foraging tasks with minimal training requirements. However, at the level of individual neurons, the lack of feature-tuned enhancements is similar to neural effects reported during covert spatial attention.
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Affiliation(s)
- Shanna H Coop
- Brain and Cognitive Sciences, University of Rochester, Rochester 14627-0268, New York
- Center for Visual Science, University of Rochester, Rochester 14627-0268, New York
| | - Jacob L Yates
- Brain and Cognitive Sciences, University of Rochester, Rochester 14627-0268, New York
- Center for Visual Science, University of Rochester, Rochester 14627-0268, New York
- Department of Biology, University of Maryland College Park, College Park, Maryland, 20742-5025
| | - Jude F Mitchell
- Brain and Cognitive Sciences, University of Rochester, Rochester 14627-0268, New York
- Center for Visual Science, University of Rochester, Rochester 14627-0268, New York
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3
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Jaatinen J, Väntänen J, Salmela V, Alho K. Subjectively preferred octave size is resolved at the late stages of cerebral auditory processing. Eur J Neurosci 2023; 58:3686-3704. [PMID: 37752605 DOI: 10.1111/ejn.16150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Revised: 09/06/2023] [Accepted: 09/11/2023] [Indexed: 09/28/2023]
Abstract
Human listeners prefer octave intervals slightly above the exact 2:1 frequency ratio. To study the neural underpinnings of this subjective preference, called the octave enlargement phenomenon, we compared neural responses between exact, slightly enlarged, oversized, and compressed octaves (or their multiples). The first experiment (n = 20) focused on the N1 and P2 event-related potentials (ERPs) elicited in EEG 50-250 ms after the second tone onset during passive listening of one-octave intervals. In the second experiment (n = 20) applying four-octave intervals, musician participants actively rated the different octave types as 'low', 'good' and 'high'. The preferred slightly enlarged octave was individually determined prior to the second experiment. In both experiments, N1-P2 peak-to-peak amplitudes attenuated for the exact and slightly enlarged octave intervals compared with compressed and oversized intervals, suggesting overlapping neural representations of tones an octave (or its multiples) apart. While there were no differences between the N1-P2 amplitudes to the exact and preferred enlarged octaves, ERP amplitudes differed after 500 ms from onset of the second tone of the pair. In the multivariate pattern analysis (MVPA) of the second experiment, the different octave types were distinguishable (spatial classification across electroencephalography [EEG] channels) 200 ms after second tone onset. Temporal classification within channels suggested two separate discrimination processes peaking around 300 and 700 ms. These findings appear to be related to active listening, as no multivariate results were found in the first, passive listening experiment. The present results suggest that the subjectively preferred octave size is resolved at the late stages of auditory processing.
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Affiliation(s)
- Jussi Jaatinen
- Musicology, Faculty of Arts, University of Helsinki, Helsinki, Finland
- Department of Psychology and Logopedics, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Jani Väntänen
- Department of Psychology and Logopedics, Faculty of Medicine, University of Helsinki, Helsinki, Finland
- Psychiatric Assessment and Consultation Clinic, Wellbeing services county of Pirkanmaa, Tampere, Finland
| | - Viljami Salmela
- Department of Psychology and Logopedics, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Kimmo Alho
- Department of Psychology and Logopedics, Faculty of Medicine, University of Helsinki, Helsinki, Finland
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4
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Rotshtein A, Katelnikov D, Pustylnik L, Polin BA. Reliability analysis of man-machine systems using fuzzy cognitive mapping with genetic tuning. Risk Anal 2023; 43:958-978. [PMID: 35689337 DOI: 10.1111/risa.13959] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
This article offers a method for analyzing the reliability of a man-machine system (MMS) and ranking of influencing factors based on a fuzzy cognitive map (FCM). The ranking of influencing factors is analogous to the ranking of system elements the probabilistic theory of reliability. To approximate the dependence of "influencing factors-reliability," the relationship of variable increments is used, which ensures the sensitivity of the reliability level to variations in the levels of influencing factors. The novelty of the method lies in the fact that the expert values of the weights of the FCM graph edges (arcs) are adjusted based on the results of observations using a genetic algorithm. The algorithm's chromosomes are generated from the intervals of acceptable values of edge weights, and the selection criterion is the sum of squares of deviations of the reliability simulation results from observations. The method is illustrated by the example of a multifactor analysis of the reliability of the "driver-car-road" system. It is shown that the FCM adjustment reduces the discrepancy between the reliability forecast and observations almost in half. Possible applications of the method can be complex systems with vaguely defined structures whose reliability depends very much on interrelated factors measured expertly.
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Affiliation(s)
- Alexander Rotshtein
- Department of Industrial Engineering, Jerusalem College of Technology, Jerusalem, Israel
- Department of Information Technology, Vasyl Stus Donetsk National University, Vinnytsia, Ukraine
| | - Denis Katelnikov
- Department of Software Development, Vinnytsia National Technical University, Vinnytsia, Ukraine
| | - Ludmila Pustylnik
- Department of Mechanical Engineering, Afeka College of Engineering, Tel-Aviv, Israel
| | - Brian A Polin
- Department of Industrial Engineering, Jerusalem College of Technology, Jerusalem, Israel
- School of Management, Jerusalem College of Technology, Jerusalem, Israel
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Kim Y, Joo HJ, Chen M, Son B, Burt D, Shi X, Zhang L, Ikonic Z, Tan CS, Nam D. High-Precision Wavelength Tuning of GeSn Nanobeam Lasers via Dynamically Controlled Strain Engineering. Adv Sci (Weinh) 2023:e2207611. [PMID: 37072675 DOI: 10.1002/advs.202207611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 03/09/2023] [Indexed: 05/03/2023]
Abstract
The technology to develop a large number of identical coherent light sources on an integrated photonics platform holds the key to the realization of scalable optical and quantum photonic circuits. Herein, a scalable technique is presented to produce identical on-chip lasers by dynamically controlled strain engineering. By using localized laser annealing that can control the strain in the laser gain medium, the emission wavelengths of several GeSn one-dimensional photonic crystal nanobeam lasers are precisely matched whose initial emission wavelengths are significantly varied. The method changes the GeSn crystal structure in a region far away from the gain medium by inducing Sn segregation in a dynamically controllable manner, enabling the emission wavelength tuning of more than 10 nm without degrading the laser emission properties such as intensity and linewidth. The authors believe that the work presents a new possibility to scale up the number of identical light sources for the realization of large-scale photonic-integrated circuits.
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Affiliation(s)
- Youngmin Kim
- School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - Hyo-Jun Joo
- School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - Melvina Chen
- School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - Bongkwon Son
- School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - Daniel Burt
- School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - Xuncheng Shi
- School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - Lin Zhang
- School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - Zoran Ikonic
- School of Electronic and Electrical Engineering, University of Leeds, Leeds, LS2 9JT, UK
| | - Chuan Seng Tan
- School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - Donguk Nam
- School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
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Grossman Z, Meyerhans A, Bocharov G. An integrative systems biology view of host-pathogen interactions: The regulation of immunity and homeostasis is concomitant, flexible, and smart. Front Immunol 2023; 13:1061290. [PMID: 36761169 PMCID: PMC9904014 DOI: 10.3389/fimmu.2022.1061290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Accepted: 12/28/2022] [Indexed: 01/26/2023] Open
Abstract
The systemic bio-organization of humans and other mammals is essentially "preprogrammed", and the basic interacting units, the cells, can be crudely mapped into discrete sets of developmental lineages and maturation states. Over several decades, however, and focusing on the immune system, we and others invoked evidence - now overwhelming - suggesting dynamic acquisition of cellular properties and functions, through tuning, re-networking, chromatin remodeling, and adaptive differentiation. The genetically encoded "algorithms" that govern the integration of signals and the computation of new states are not fully understood but are believed to be "smart", designed to enable the cells and the system to discriminate meaningful perturbations from each other and from "noise". Cellular sensory and response properties are shaped in part by recurring temporal patterns, or features, of the signaling environment. We compared this phenomenon to associative brain learning. We proposed that interactive cell learning is subject to selective pressures geared to performance, allowing the response of immune cells to injury or infection to be progressively coordinated with that of other cell types across tissues and organs. This in turn is comparable to supervised brain learning. Guided by feedback from both the tissue itself and the neural system, resident or recruited antigen-specific and innate immune cells can eradicate a pathogen while simultaneously sustaining functional homeostasis. As informative memories of immune responses are imprinted both systemically and within the targeted tissues, it is desirable to enhance tissue preparedness by incorporating attenuated-pathogen vaccines and informed choice of tissue-centered immunomodulators in vaccination schemes. Fortunately, much of the "training" that a living system requires to survive and function in the face of disturbances from outside or within is already incorporated into its design, so it does not need to deep-learn how to face a new challenge each time from scratch. Instead, the system learns from experience how to efficiently select a built-in strategy, or a combination of those, and can then use tuning to refine its organization and responses. Efforts to identify and therapeutically augment such strategies can take advantage of existing integrative modeling approaches. One recently explored strategy is boosting the flux of uninfected cells into and throughout an infected tissue to rinse and replace the infected cells.
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Affiliation(s)
- Zvi Grossman
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel,Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health (NIH), Bethesda, MD, United States,*Correspondence: Zvi Grossman, ; Andreas Meyerhans, ; Gennady Bocharov,
| | - Andreas Meyerhans
- Infection Biology Laboratory, Department of Medicine and Life Sciences, Universitat Pompeu Fabra, Barcelona, Spain,ICREA, Barcelona, Spain,*Correspondence: Zvi Grossman, ; Andreas Meyerhans, ; Gennady Bocharov,
| | - Gennady Bocharov
- Marchuk Institute of Numerical Mathematics, Russian Academy of Sciences, Moscow, Russia,Institute of Computer Science and Mathematical Modeling, Sechenov First Moscow State Medical University, Moscow, Russia,*Correspondence: Zvi Grossman, ; Andreas Meyerhans, ; Gennady Bocharov,
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Montesinos-López OA, Carter AH, Bernal-Sandoval DA, Cano-Paez B, Montesinos-López A, Crossa J. A Comparison between Three Tuning Strategies for Gaussian Kernels in the Context of Univariate Genomic Prediction. Genes (Basel) 2022; 13:genes13122282. [PMID: 36553547 PMCID: PMC9778581 DOI: 10.3390/genes13122282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 11/15/2022] [Accepted: 11/29/2022] [Indexed: 12/07/2022] Open
Abstract
Genomic prediction is revolutionizing plant breeding since candidate genotypes can be selected without the need to measure their trait in the field. When a reference population contains both phenotypic and genotypic information, it is trained by a statistical machine learning method that is subsequently used for making predictions of breeding or phenotypic values of candidate genotypes that were only genotyped. Nevertheless, the successful implementation of the genomic selection (GS) methodology depends on many factors. One key factor is the type of statistical machine learning method used since some are unable to capture nonlinear patterns available in the data. While kernel methods are powerful statistical machine learning algorithms that capture complex nonlinear patterns in the data, their successful implementation strongly depends on the careful tuning process of the involved hyperparameters. As such, in this paper we compare three methods of tuning (manual tuning, grid search, and Bayesian optimization) for the Gaussian kernel under a Bayesian best linear unbiased predictor model. We used six real datasets of wheat (Triticum aestivum L.) to compare the three strategies of tuning. We found that if we want to obtain the major benefits of using Gaussian kernels, it is very important to perform a careful tuning process. The best prediction performance was observed when the tuning process was performed with grid search and Bayesian optimization. However, we did not observe relevant differences between the grid search and Bayesian optimization approach. The observed gains in terms of prediction performance were between 2.1% and 27.8% across the six datasets under study.
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Affiliation(s)
| | - Arron H. Carter
- Department of Crop and Soil Sciences, Washington State University, Pullman, WA 99164, USA
| | | | - Bernabe Cano-Paez
- Facultad de Ciencias, Universidad Nacional Autónoma de México (UNAM), Mexico City 04510, Mexico
| | - Abelardo Montesinos-López
- Centro Universitario de Ciencias Exactas e Ingenierías (CUCEI), Universidad de Guadalajara, Guadalajara 44430, Mexico
- Correspondence: (A.M.-L.); (J.C.)
| | - José Crossa
- International Maize and Wheat Improvement Center (CIMMYT), El Batan, Texcoco 56237, Mexico
- Hidrociencias, Colegio de Postgraduados, Campus Montecillos, Carretera México-Texcoco Km. 36.5, Montecillo 56230, Mexico
- Correspondence: (A.M.-L.); (J.C.)
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Lu MJ, Li CJ, Ban R, Chen FZ, Hu J, Gao G, Zhou H, Lin P, Zhao WW. Tuning the Surface Molecular Charge of Organic Photoelectrochemical Transistors with Significantly Improved Signal Resolution: A General Strategy toward Sensitive Bioanalysis. ACS Sens 2022; 7:2788-2794. [PMID: 36069701 DOI: 10.1021/acssensors.2c01493] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Nature makes use of molecular charges to operate specific biological synthesis and reactions. Targeting advanced opto-bioelectronic sensors, organic photoelectrochemical transistors (OPECTs), taking advantage of the light fuel substituting an external gate potential, is now debuting and expected to serve as a universal platform for studying the rich light-biomatter interplay for new bioanalytics. Given the ubiquity of charged biomolecules in nature, molecular charge manipulation should underpin a generic route for innovative OPECT regulation and operation, which nevertheless has remained unachieved. Herein, this work manifests the biological tuning of surface charge toward the OPECT biosensor, which was exemplified by a light-sensitive CdS quantum dot (QD) gate electrode interfaced by a smart DNA superstructure with adenosine triphosphate (ATP) responsiveness. Highly negative-charged supramolecular DNA concatemers were self-assembled via sequential hybridization, and the ATP-triggered disassembly of the DNA concatemers would cause a tandem change of the effective gate voltage and transfer characteristics with significantly improved resolution. The present opto-bioelectronic device translates the events of charged molecules into amplified electrical signals and outlines a generic format for the future exploitation of rich biological tunability and light-biomatter interplay for innovative bioanalytics and beyond.
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Affiliation(s)
- Meng-Jiao Lu
- State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China.,School of Chemical Engineering, Guizhou Minzu University, Guiyang 550025, China.,School of Chemistry and Materials Science, Guizhou Education University, Guiyang 550018, China
| | - Cheng-Jun Li
- State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China.,School of Chemical Engineering, Guizhou Minzu University, Guiyang 550025, China
| | - Rui Ban
- School of Chemical Engineering, Guizhou Minzu University, Guiyang 550025, China.,School of Chemistry and Materials Science, Guizhou Education University, Guiyang 550018, China
| | - Feng-Zao Chen
- State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Jin Hu
- State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China.,Shenzhen Key Laboratory of Special Functional Materials & Guangdong Research Center for Interfacial Engineering of Functional Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518060, China
| | - Ge Gao
- State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Hong Zhou
- Shandong Key Laboratory of Biochemical Analysis, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042, China
| | - Peng Lin
- Shenzhen Key Laboratory of Special Functional Materials & Guangdong Research Center for Interfacial Engineering of Functional Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518060, China
| | - Wei-Wei Zhao
- State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
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Rady M, Mahfouz SY. Effects of Concrete Grades and Column Spacings on the Optimal Design of Reinforced Concrete Buildings. Materials (Basel) 2022; 15:4290. [PMID: 35744349 DOI: 10.3390/ma15124290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 06/04/2022] [Accepted: 06/15/2022] [Indexed: 12/04/2022]
Abstract
This paper investigates the effects of concrete grades and column spacings on the optimal design of reinforced concrete (RC) buildings. To this end, cost design optimization was performed for buildings with three different floor systems: flat plates (FS), flat slabs with drop panels (FSDP), and solid slabs (SS). The evolutionary method provided by the Excel solver was used as the optimization algorithm because it can deal with the complex nature of structural design problems. The objective function was the total construction cost of the building, including the costs of concrete, reinforcement bars, labor, and formwork, while still fulfilling the constraints of the Egyptian code of practice (ECP-18). The applicability of the presented algorithm was investigated in a design example, where the tuning of the evolutionary algorithm control parameters was sought, and the best parameters were investigated. Two case studies were employed to study the impacts of changing the column spacing and concrete grades on the optimal cost for each floor system. The results showed that low concrete grades, (i.e., characteristic strength up to 40 MPa) and column spacings up to 5 m are preferred in terms of direct construction costs for low-rise RC residential buildings.
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Abstract
A resonator coupler for subcutaneous implants has been developed with a new impedance matching pattern added to the conventional loop antenna. The tuning element of a concentric metal pad contributes distributed capacitance and inductance to the planar inductive loop and improves resonance significantly. It provides a better qualify factor for resonant coupling and a much lower reflection coefficient for the implant electronics. Practical constraints are taken into account for designs including the requirement of operation within a regulated frequency band and the limited thickness for a monolithic implant. In this work, two designs targeting to operate in the two industrial, scientific, and medical (ISM) bands at 903 MHz and 2.45 GHz are considered. The tuning metal pad improves their resonances significantly, compared to the conventional loop designs. Since it is difficult to tune the implant antenna after implantation, the effects of tissue depth variations due to the individual's surgery and the appropriate implant depths are investigated. Simulations conducted with the dielectric properties of human skin documented in the literature are compared to measurements done with hydrated ground pork as phantoms. Experiments and simulations are conducted to explain the discrepancies in frequency shifts due to the uses of pork phantoms. The design method is thus validated for uses on human skin. A noninvasive localization method to identify the implant under the skin has been examined and demonstrated by both simulations and measurements. It can efficiently locate the subcutaneous implant based on the high quality-factor resonance owing to the tuning elements in both implant and transmitter couplers. The planar resonant coupler for wireless power transfer shows good performance and promise in subcutaneous applications for implants.
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Affiliation(s)
| | | | - J.-C. Chiao
- Electrical and Computer Engineering, Southern Methodist University, Dallas, TX 75205, USA; (S.B.); (K.C.)
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11
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Polyukhov DM, Poryvaev AS, Sukhikh AS, Gromilov SA, Fedin MV. Fine- Tuning Window Apertures in ZIF-8/67 Frameworks by Metal Ions and Temperature for High-Efficiency Molecular Sieving of Xylenes. ACS Appl Mater Interfaces 2021; 13:40830-40836. [PMID: 34423631 DOI: 10.1021/acsami.1c12166] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Separation of structurally similar components from their mixtures is one of the most promising applications of metal-organic frameworks (MOFs). A high efficiency of such molecular sieving requires fine tuning of the MOF structure. In this work, we investigate subtle metal- and temperature-induced changes in window dimensions of zeolitic imidazolate frameworks (ZIF-8(Zn) and ZIF-67(Co)) and apply such structural tuning for efficient separation of xylene isomers (p-, m-, and o-xylenes). The use of Co instead of Zn favorably modifies window geometry: it accelerates the diffusion of all components by a factor of 2-3 while maintaining closely the same separation efficiency as that of ZIF-8(Zn). Outstanding selectivity above 18:1 and faster isolation of demanded p-xylene from the ternary mixture using ZIF-67(Co) have been demonstrated at room temperature, opening new horizons for its energy-efficient xylene separation. More generally, our findings suggest the prospective ways to tune various MOFs for target liquid-state separations.
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Affiliation(s)
| | - Artem S Poryvaev
- International Tomography Center SB RAS, Novosibirsk 630090, Russia
| | | | - Sergey A Gromilov
- Nikolaev Institute of Inorganic Chemistry, Novosibirsk 630090, Russia
| | - Matvey V Fedin
- International Tomography Center SB RAS, Novosibirsk 630090, Russia
- Novosibirsk State University, Novosibirsk 630090, Russia
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12
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Kheradpezhouh E, Tang MF, Mattingley JB, Arabzadeh E. Enhanced Sensory Coding in Mouse Vibrissal and Visual Cortex through TRPA1. Cell Rep 2021; 32:107935. [PMID: 32698003 DOI: 10.1016/j.celrep.2020.107935] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 05/25/2020] [Accepted: 06/29/2020] [Indexed: 01/01/2023] Open
Abstract
Transient receptor potential ankyrin 1 (TRPA1) is a non-selective cation channel, broadly expressed throughout the body. Despite its expression in the mammalian brain, little is known about the contribution of TRPA1 to cortical function. Here, we characterize how TRPA1 affects sensory information processing in two cortical areas in mice: the primary vibrissal (whisker) somatosensory cortex (vS1) and the primary visual cortex (V1). In vS1, local activation of TRPA1 by allyl isothiocyanate (AITC) increases the ongoing activity of neurons and their evoked response to vibrissal stimulation, producing a positive gain modulation. The gain modulation is reversed by TRPA1 inhibitor HC-030031 and is absent in TRPA1 knockout mice. Similarly, in V1, TRPA1 activation increases the gain of direction and orientation selectivity. Linear decoding of V1 population activity confirms faster and more reliable encoding of visual signals under TRPA1 activation. Overall, our findings reveal a physiological role for TRPA1 in enhancing sensory signals in the mammalian cortex.
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Affiliation(s)
- Ehsan Kheradpezhouh
- Eccles Institute of Neuroscience, John Curtin School of Medical Research, The Australian National University, Canberra, ACT, Australia; The Australian Research Council Centre of Excellence for Integrative Brain Function, Australia.
| | - Matthew F Tang
- Eccles Institute of Neuroscience, John Curtin School of Medical Research, The Australian National University, Canberra, ACT, Australia; The Australian Research Council Centre of Excellence for Integrative Brain Function, Australia; Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
| | - Jason B Mattingley
- The Australian Research Council Centre of Excellence for Integrative Brain Function, Australia; Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia; School of Psychology, The University of Queensland, Brisbane, QLD, Australia; Canadian Institute for Advanced Research (CIFAR), Toronto, ON, Canada
| | - Ehsan Arabzadeh
- Eccles Institute of Neuroscience, John Curtin School of Medical Research, The Australian National University, Canberra, ACT, Australia; The Australian Research Council Centre of Excellence for Integrative Brain Function, Australia
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Ahmed NY, Ranjbar-Slamloo Y, Al Abed AS, Gao L, Sontani Y, RCom-H'cheo-Gauthier A, Arabzadeh E, Dehorter N. Er81 Transcription Factor Fine-Tunes Striatal Cholinergic Interneuron Activity and Drives Habit Formation. J Neurosci 2021; 41:4392-409. [PMID: 33849945 DOI: 10.1523/JNEUROSCI.0967-20.2021] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 03/28/2021] [Accepted: 04/02/2021] [Indexed: 11/21/2022] Open
Abstract
The molecular mechanisms tuning cholinergic interneuron (CIN) activity, although crucial for striatal function and behavior, remain largely unexplored. Previous studies report that the Etv1/Er81 transcription factor is vital for regulating neuronal maturation and activity. While Er81 is known to be expressed in the striatum during development, its specific role in defining CIN properties and the resulting consequences on striatal function is unknown. We report here that Er81 is expressed in CINs and its specific ablation leads to prominent changes in their molecular, morphologic, and electrophysiological features. In particular, the lack of Er81 amplifies intrinsic delayed-rectifier and hyperpolarization-activated currents, which subsequently alters the tonic and phasic activity of CINs. We further reveal that Er81 expression is required for normal CIN pause and time-locked responses to sensorimotor inputs in awake mice. Overall, this study uncovers a new cell type-specific control of CIN function in the striatum which drives habit formation in adult male mice.SIGNIFICANCE STATEMENT Although previous studies have shown that cholinergic interneurons drive striatal activity and habit formation, the underlying molecular mechanisms controlling their function are unknown. Here we reveal that key cholinergic interneuron physiological properties are controlled by Er81, a transcription factor regulating neuronal activity and development in a cell-specific manner. Moreover, our findings uncover a link between the Er81-dependent molecular control of cholinergic interneuron function and habit formation in mice. These insights will contribute to the future enhancement of our understanding of disorders that involve behavioral inflexibility, such as autism and addiction.
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Liu J, Kanold PO. Diversity of Receptive Fields and Sideband Inhibition with Complex Thalamocortical and Intracortical Origin in L2/3 of Mouse Primary Auditory Cortex. J Neurosci 2021; 41:3142-62. [PMID: 33593857 DOI: 10.1523/JNEUROSCI.1732-20.2021] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 01/29/2021] [Accepted: 02/07/2021] [Indexed: 11/21/2022] Open
Abstract
Receptive fields of primary auditory cortex (A1) neurons show excitatory neuronal frequency preference and diverse inhibitory sidebands. While the frequency preferences of excitatory neurons in local A1 areas can be heterogeneous, those of inhibitory neurons are more homogeneous. To date, the diversity and the origin of inhibitory sidebands in local neuronal populations and the relation between local cellular frequency preference and inhibitory sidebands are unknown. To reveal both excitatory and inhibitory subfields, we presented two-tone and pure tone stimuli while imaging excitatory neurons (Thy1) and two types of inhibitory neurons (parvalbumin and somatostatin) in L2/3 of mice A1. We classified neurons into six classes based on frequency response area (FRA) shapes and sideband inhibition depended both on FRA shapes and cell types. Sideband inhibition showed higher local heterogeneity than frequency tuning, suggesting that sideband inhibition originates from diverse sources of local and distant neurons. Two-tone interactions depended on neuron subclasses with excitatory neurons showing the most nonlinearity. Onset and offset neurons showed dissimilar spectral integration, suggesting differing circuits processing sound onset and offset. These results suggest that excitatory neurons integrate complex and nonuniform inhibitory input. Thalamocortical terminals also exhibited sideband inhibition, but with different properties from those of cortical neurons. Thus, some components of sideband inhibition are inherited from thalamocortical inputs and are further modified by converging intracortical circuits. The combined heterogeneity of frequency tuning and diverse sideband inhibition facilitates complex spectral shape encoding and allows for rapid and extensive plasticity.SIGNIFICANCE STATEMENT Sensory systems recognize and differentiate between different stimuli through selectivity for different features. Sideband inhibition serves as an important mechanism to sharpen stimulus selectivity, but its cortical mechanisms are not entirely resolved. We imaged pyramidal neurons and two common classes of interneurons suggested to mediate sideband inhibition (parvalbumin and somatostatin positive) in the auditory cortex and inferred their inhibitory sidebands. We observed a higher degree of variability in the inhibitory sideband than in the local frequency tuning, which cannot be predicted from the relative high homogeneity of responses by inhibitory interneurons. This suggests that cortical sideband inhibition is nonuniform and likely results from a complex interplay between existing functional inhibition in the feedforward input and cortical refinement.
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15
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Trefzer A, Kadam P, Wang SH, Pennavaria S, Lober B, Akçabozan B, Kranich J, Brocker T, Nakano N, Irmler M, Beckers J, Straub T, Obst R. Dynamic adoption of anergy by antigen-exhausted CD4 + T cells. Cell Rep 2021; 34:108748. [PMID: 33567282 DOI: 10.1016/j.celrep.2021.108748] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 09/21/2020] [Accepted: 01/19/2021] [Indexed: 12/11/2022] Open
Abstract
Exhausted immune responses to chronic diseases represent a major challenge to global health. We study CD4+ T cells in a mouse model with regulatable antigen presentation. When the cells are driven through the effector phase and are then exposed to different levels of persistent antigen, they lose their T helper 1 (Th1) functions, upregulate exhaustion markers, resemble naturally anergic cells, and modulate their MAPK, mTORC1, and Ca2+/calcineurin signaling pathways with increasing dose and time. They also become unable to help B cells and, at the highest dose, undergo apoptosis. Transcriptomic analyses show the dynamic adjustment of gene expression and the accumulation of T cell receptor (TCR) signals over a period of weeks. Upon antigen removal, the cells recover their functionality while losing exhaustion and anergy markers. Our data suggest an adjustable response of CD4+ T cells to different levels of persisting antigen and contribute to a better understanding of chronic disease.
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Affiliation(s)
- Anne Trefzer
- Institute for Immunology, Biomedical Center, Medical Faculty, Ludwig-Maximilians-Universität München, 82152 Planegg-Martinsried, Germany
| | - Pallavi Kadam
- Institute for Immunology, Biomedical Center, Medical Faculty, Ludwig-Maximilians-Universität München, 82152 Planegg-Martinsried, Germany
| | - Shu-Hung Wang
- Institute for Immunology, Biomedical Center, Medical Faculty, Ludwig-Maximilians-Universität München, 82152 Planegg-Martinsried, Germany
| | - Stefanie Pennavaria
- Institute for Immunology, Biomedical Center, Medical Faculty, Ludwig-Maximilians-Universität München, 82152 Planegg-Martinsried, Germany
| | - Benedikt Lober
- Institute for Immunology, Biomedical Center, Medical Faculty, Ludwig-Maximilians-Universität München, 82152 Planegg-Martinsried, Germany
| | - Batuhan Akçabozan
- Institute for Immunology, Biomedical Center, Medical Faculty, Ludwig-Maximilians-Universität München, 82152 Planegg-Martinsried, Germany
| | - Jan Kranich
- Institute for Immunology, Biomedical Center, Medical Faculty, Ludwig-Maximilians-Universität München, 82152 Planegg-Martinsried, Germany
| | - Thomas Brocker
- Institute for Immunology, Biomedical Center, Medical Faculty, Ludwig-Maximilians-Universität München, 82152 Planegg-Martinsried, Germany
| | - Naoko Nakano
- Research Institute for Biomedical Sciences, Tokyo University of Science, Chiba 278-0022, Japan
| | - Martin Irmler
- Institute of Experimental Genetics, Helmholtz Zentrum München GmbH, 85764 Neuherberg, Germany
| | - Johannes Beckers
- Institute of Experimental Genetics, Helmholtz Zentrum München GmbH, 85764 Neuherberg, Germany; Chair of Experimental Genetics, Technische Universität München, 85354 Freising, Germany; German Center for Diabetes Research (DZD e. V.), Neuherberg, Germany
| | - Tobias Straub
- Bioinformatics Core Facility, Biomedical Center, Medical Faculty, Ludwig-Maximilians-Universität München, 82152 Planegg-Martinsried, Germany
| | - Reinhard Obst
- Institute for Immunology, Biomedical Center, Medical Faculty, Ludwig-Maximilians-Universität München, 82152 Planegg-Martinsried, Germany.
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16
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Tan L, Tring E, Ringach DL, Zipursky SL, Trachtenberg JT. Vision Changes the Cellular Composition of Binocular Circuitry during the Critical Period. Neuron 2020; 108:735-747.e6. [PMID: 33091339 DOI: 10.1016/j.neuron.2020.09.022] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2020] [Revised: 08/18/2020] [Accepted: 09/16/2020] [Indexed: 02/04/2023]
Abstract
High acuity stereopsis emerges during an early postnatal critical period when binocular neurons in the primary visual cortex sharpen their receptive field tuning properties. We find that this sharpening is achieved by dismantling the binocular circuit present at critical period onset and building it anew. Longitudinal imaging of receptive field tuning (e.g., orientation selectivity) of thousands of neurons reveals that most binocular neurons present in layer 2/3 at critical period onset are poorly tuned and are rendered monocular. In parallel, new binocular neurons are established by conversion of well-tuned monocular neurons as they gain matched input from the other eye. These improvements in binocular tuning in layer 2/3 are not inherited from layer 4 but are driven by the experience-dependent sharpening of ipsilateral eye responses. Thus, vision builds a new and more sharply tuned binocular circuit in layer 2/3 by cellular exchange and not by refining the original circuit.
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Affiliation(s)
- Liming Tan
- Department of Biological Chemistry, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA; Howard Hughes Medical Institute
| | - Elaine Tring
- Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Dario L Ringach
- Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA; Department of Psychology, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - S Lawrence Zipursky
- Department of Biological Chemistry, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA; Howard Hughes Medical Institute
| | - Joshua T Trachtenberg
- Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA.
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17
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Lévêque S, Caraly R. [Not Available]. Soins Pediatr Pueric 2020; 41:19-22. [PMID: 32771202 DOI: 10.1016/j.spp.2020.06.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The use of observation has refined the development of our care practices. Its application in different intervention measures has shown us the importance of focusing on small matters. The value we place on them is for the child. The therapeutics is in this attention. These practices have allowed us to create different specific and adapted measures.
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Affiliation(s)
- Sylvane Lévêque
- Centre médico-psychologique enfant, Centre hospitalier Alpes-Isère, 17 Le Routoir, 38240 Meylan, France.
| | - Rodolphe Caraly
- 82 cours Berriat, 38000 Grenoble, France; Maison des Habitants Centre-ville, 2 rue du Vieux-Temple, 38000 Grenoble, France
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18
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Bartoli E, Bosking W, Foster BL. Seeing Visual Gamma Oscillations in a New Light. Trends Cogn Sci 2020; 24:501-503. [PMID: 32336605 DOI: 10.1016/j.tics.2020.03.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 03/23/2020] [Accepted: 03/30/2020] [Indexed: 10/24/2022]
Abstract
Gamma oscillations have been argued to support visual perception by synchronizing the processing and transfer of information within and across areas of visual cortex. Here, we highlight recent findings implicating the influence of color on visual gamma oscillations and how these observations may relate to local cortical tuning and organization.
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Affiliation(s)
- Eleonora Bartoli
- Department of Neurosurgery, Baylor College of Medicine, Houston, TX, USA
| | - William Bosking
- Department of Neurosurgery, Baylor College of Medicine, Houston, TX, USA
| | - Brett L Foster
- Department of Neurosurgery, Baylor College of Medicine, Houston, TX, USA; Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA.
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19
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Fobbs WC, Bariselli S, Licholai JA, Miyazaki NL, Matikainen-Ankney BA, Creed MC, Kravitz AV. Continuous Representations of Speed by Striatal Medium Spiny Neurons. J Neurosci 2020; 40:1679-88. [PMID: 31953369 DOI: 10.1523/JNEUROSCI.1407-19.2020] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 12/20/2019] [Accepted: 01/02/2020] [Indexed: 12/22/2022] Open
Abstract
The striatum is critical for controlling motor output. However, it remains unclear how striatal output neurons encode and facilitate movement. A prominent theory suggests that striatal units encode movements in bursts of activity near specific events, such as the start or end of actions. These bursts are theorized to gate or permit specific motor actions, thereby encoding and facilitating complex sequences of actions. An alternative theory has suggested that striatal neurons encode continuous changes in sensory or motor information with graded changes in firing rate. Supporting this theory, many striatal neurons exhibit such graded changes without bursting near specific actions. Here, we evaluated these two theories in the same recordings of mice (both male and female). We recorded single-unit and multiunit activity from the dorsomedial striatum of mice as they spontaneously explored an arena. We observed both types of encoding, although continuous encoding was more prevalent than bursting near movement initiation or termination. The majority of recorded units did not exhibit positive linear relationships with speed but instead exhibited nonlinear relationships that peaked at a range of locomotor speeds. Bulk calcium recordings of identified direct and indirect pathway neurons revealed similar speed tuning profiles, indicating that the heterogeneity in response profiles was not due to this genetic distinction. We conclude that continuous encoding of speed is a central component of movement encoding in the striatum.SIGNIFICANCE STATEMENT The striatum is a structure that is linked to volitional movements and is a primary site of pathology in movement disorders. It remains unclear how striatal neurons encode motor parameters and use them to facilitate movement. Here, we evaluated two models for this: a "discrete encoding model" in which striatal neurons facilitate movements with brief burst of activity near the start and end of movements, and a "continuous encoding model," in which striatal neurons encode the sensory or motor state of the animal with continuous changes in firing. We found evidence primarily in support of the continuous encoding model. This may have implications for understanding the striatal control of movement, as well as informing therapeutic approaches for treating movement disorders.
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20
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Castello C. [Continuity and work in nurseries]. Soins Pediatr Pueric 2020; 41:28-29. [PMID: 32200968 DOI: 10.1016/j.spp.2019.12.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Continuity of care is a fundamental element in enabling a child to build himself on the psychological level. It is encouraged by professional reflection but can, however, take place at an irregular pace. Meeting with Mathilde Sauvervald, director in training of a day-care centre.
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Affiliation(s)
- Christine Castello
- Établissement public départemental Le Charmeyran, 9 chemin Duhamel, 38700 La Tronche, France.
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21
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Grossman Z. Immunological Paradigms, Mechanisms, and Models: Conceptual Understanding Is a Prerequisite to Effective Modeling. Front Immunol 2019; 10:2522. [PMID: 31749803 PMCID: PMC6848063 DOI: 10.3389/fimmu.2019.02522] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Accepted: 10/10/2019] [Indexed: 12/18/2022] Open
Abstract
Most mathematical models that describe the individual or collective actions of cells aim at creating faithful representations of limited sets of data in a self-consistent manner. Consistency with relevant physiological rules pertaining to the greater picture is rarely imposed. By themselves, such models have limited predictive or even explanatory value, contrary to standard claims. Here I try to show that a more critical examination of currently held paradigms is necessary and could potentially lead to models that pass the test of time. In considering the evolution of paradigms over the past decades I focus on the “smart surveillance” theory of how T cells can respond differentially, individually and collectively, to both self- and foreign antigens depending on various “contextual” parameters. The overall perspective is that physiological messages to cells are encoded not only in the biochemical connections of signaling molecules to the cellular machinery but also in the magnitude, kinetics, and in the time- and space-contingencies, of sets of stimuli. By rationalizing the feasibility of subthreshold interactions, the “dynamic tuning hypothesis,” a central component of the theory, set the ground for further theoretical and experimental explorations of dynamically regulated immune tolerance, homeostasis and diversity, and of the notion that lymphocytes participate in nonclassical physiological functions. Some of these efforts are reviewed. Another focus of this review is the concomitant regulation of immune activation and homeostasis through the operation of a feedback mechanism controlling the balance between renewal and differentiation of activated cells. Different perspectives on the nature and regulation of chronic immune activation in HIV infection have led to conflicting models of HIV pathogenesis—a major area of research for theoretical immunologists over almost three decades—and can have profound impact on ongoing HIV cure strategies. Altogether, this critical review is intended to constructively influence the outlook of prospective model builders and of interested immunologists on the state of the art and to encourage conceptual work.
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Affiliation(s)
- Zvi Grossman
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD, United States.,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
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22
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Dong L, Closson AB, Jin C, Trase I, Chen Z, Zhang JXJ. Vibration-Energy-Harvesting System: Transduction Mechanisms, Frequency Tuning Techniques, and Biomechanical Applications. Adv Mater Technol 2019; 4:1900177. [PMID: 33829079 PMCID: PMC8022913 DOI: 10.1002/admt.201900177] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Indexed: 05/31/2023]
Abstract
Vibration-based energy-harvesting technology, as an alternative power source, represents one of the most promising solutions to the problem of battery capacity limitations in wearable and implantable electronics, in particular implantable biomedical devices. Four primary energy transduction mechanisms are reviewed, namely piezoelectric, electromagnetic, electrostatic, and triboelectric mechanisms for vibration-based energy harvesters. Through generic modeling and analyses, it is shown that various approaches can be used to tune the operation bandwidth to collect appreciable power. Recent progress in biomechanical energy harvesters is also shown by utilizing various types of motion from bodies and organs of humans and animals. To conclude, perspectives on next-generation energy-harvesting systems are given, whereby the ultimate intelligent, autonomous, and tunable energy harvesters will provide a new energy platform for electronics and wearable and implantable medical devices.
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Affiliation(s)
- Lin Dong
- Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, USA
| | - Andrew B Closson
- Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, USA
| | - Congran Jin
- Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, USA
| | - Ian Trase
- Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, USA
| | - Zi Chen
- Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, USA
| | - John X J Zhang
- Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, USA
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23
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Raufer S, Guinan JJ Jr, Nakajima HH. Cochlear partition anatomy and motion in humans differ from the classic view of mammals. Proc Natl Acad Sci U S A 2019; 116:13977-82. [PMID: 31235601 DOI: 10.1073/pnas.1900787116] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Mammals detect sound through mechanosensitive cells of the cochlear organ of Corti that rest on the basilar membrane (BM). Motions of the BM and organ of Corti have been studied at the cochlear base in various laboratory animals, and the assumption has been that the cochleas of all mammals work similarly. In the classic view, the BM attaches to a stationary osseous spiral lamina (OSL), the tectorial membrane (TM) attaches to the limbus above the stationary OSL, and the BM is the major moving element, with a peak displacement near its center. Here, we measured the motion and studied the anatomy of the human cochlear partition (CP) at the cochlear base of fresh human cadaveric specimens. Unlike the classic view, we identified a soft-tissue structure between the BM and OSL in humans, which we name the CP "bridge." We measured CP transverse motion in humans and found that the OSL moved like a plate hinged near the modiolus, with motion increasing from the modiolus to the bridge. The bridge moved almost as much as the BM, with the maximum CP motion near the bridge-BM connection. BM motion accounts for 100% of CP volume displacement in the classic view, but accounts for only 27 to 43% in the base of humans. In humans, the TM-limbus attachment is above the moving bridge, not above a fixed structure. These results challenge long-held assumptions about cochlear mechanics in humans. In addition, animal apical anatomy (in SI Appendix) doesn't always fit the classic view.
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24
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Gardner JL, Liu T. Inverted Encoding Models Reconstruct an Arbitrary Model Response, Not the Stimulus. eNeuro 2019; 6:ENEURO.0363-18.2019. [PMID: 30923743 PMCID: PMC6437661 DOI: 10.1523/eneuro.0363-18.2019] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Revised: 02/25/2019] [Accepted: 03/03/2019] [Indexed: 01/24/2023] Open
Abstract
Probing how large populations of neurons represent stimuli is key to understanding sensory representations as many stimulus characteristics can only be discerned from population activity and not from individual single-units. Recently, inverted encoding models have been used to produce channel response functions from large spatial-scale measurements of human brain activity that are reminiscent of single-unit tuning functions and have been proposed to assay "population-level stimulus representations" (Sprague et al., 2018a). However, these channel response functions do not assay population tuning. We show by derivation that the channel response function is only determined up to an invertible linear transform. Thus, these channel response functions are arbitrary, one of an infinite family and therefore not a unique description of population representation. Indeed, simulations demonstrate that bimodal, even random, channel basis functions can account perfectly well for population responses without any underlying neural response units that are so tuned. However, the approach can be salvaged by extending it to reconstruct the stimulus, not the assumed model. We show that when this is done, even using bimodal and random channel basis functions, a unimodal function peaking at the appropriate value of the stimulus is recovered which can be interpreted as a measure of population selectivity. More precisely, the recovered function signifies how likely any value of the stimulus is, given the observed population response. Whether an analysis is recovering the hypothetical responses of an arbitrary model rather than assessing the selectivity of population representations is not an issue unique to the inverted encoding model and human neuroscience, but a general problem that must be confronted as more complex analyses intervene between measurement of population activity and presentation of data.
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Affiliation(s)
| | - Taosheng Liu
- Department of Psychology, Michigan State University, East Lansing, MI 48824
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25
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Lynch-Aird N, Woodhouse J. Comparison of Mechanical Properties of Natural Gut and Synthetic Polymer Harp Strings. Materials (Basel) 2018; 11:E2160. [PMID: 30388873 DOI: 10.3390/ma11112160] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Revised: 10/25/2018] [Accepted: 10/29/2018] [Indexed: 11/29/2022]
Abstract
The long-term mechanical behaviour of a number of fluorocarbon and gut harp strings has been examined, and the results compared with a previous study of rectified nylon strings. The stretching behaviour of the three materials was studied via different measures of the Young’s modulus; with test time scales on the order of weeks, minutes, and milliseconds. The strings were subjected to cyclic variations in temperature, enabling various aspects of their thermal behaviour to be investigated. The effects of humidity changes on gut strings were also examined. The behaviour of the fluorocarbon strings was found to be similar in many ways to that of the nylon strings, despite their different chemical formulation and significantly higher density. In particular, the faster measures of Young’s modulus were found to show an almost identical strong variation with the applied stress; while the thermal behaviour of both materials was largely determined by the balance between opposing effects associated with thermal contraction and thermal variations in the Young’s modulus. The gut strings showed some similarities of behaviour to the synthetic materials, but also major differences. All three measures of the Young’s modulus remained constant as the applied stress was increased. The gut strings were far more sensitive to changes in humidity than the synthetic materials, although some of the results, especially the thermal tuning sensitivity of the strings when held at constant length, displayed remarkable stability under changing humidity. The observed behaviour suggests very strongly that there is significant coupling between humidity-related changes in the linear density of a gut string and complementary changes in its tension.
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26
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Gim HJ, Choi YS, Li H, Kim YJ, Ryu JH, Jeon R. Identification of a Novel PPAR-γ Agonist through a Scaffold Tuning Approach. Int J Mol Sci 2018; 19:ijms19103032. [PMID: 30287791 PMCID: PMC6213020 DOI: 10.3390/ijms19103032] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 09/27/2018] [Accepted: 10/02/2018] [Indexed: 12/13/2022] Open
Abstract
Peroxisome proliferator-activated receptors (PPARs) are important targets in metabolic diseases including obesity, metabolic syndrome, diabetes, and non-alcoholic fatty liver disease. Recently, they have been highlighted as attractive targets for the treatment of cardiovascular diseases and chronic myeloid leukemia. The PPAR agonist structure is consists of a polar head, a hydrophobic tail, and a linker. Each part interacts with PPARs through hydrogen bonds or hydrophobic interactions to stabilize target protein conformation, thus increasing its activity. Acidic head is essential for PPAR agonist activity. The aromatic linker plays an important role in making hydrophobic interactions with PPAR as well as adjusting the head-to-tail distance and conformation of the whole molecule. By tuning the scaffold of compound, the whole molecule could fit into the ligand-binding domain to achieve proper binding mode. We modified indol-3-ylacetic acid scaffold to (indol-1-ylmethyl)benzoic acid, whereas 2,4-dichloroanilide was fixed as the hydrophobic tail. We designed, synthesized, and assayed the in vitro activity of novel indole compounds with (indol-1-ylmethyl)benzoic acid scaffold. Compound 12 was a more potent PPAR-γ agonist than pioglitazone and our previous hit compound. Molecular docking studies may suggest the binding between compound 12 and PPAR-γ, rationalizing its high activity.
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Affiliation(s)
- Hyo Jin Gim
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Sookmyung Women's University, Cheongpa-ro 47-gil 100, Yongsan-gu, Seoul 04310, Korea.
| | - Yong-Sung Choi
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Sookmyung Women's University, Cheongpa-ro 47-gil 100, Yongsan-gu, Seoul 04310, Korea.
| | - Hua Li
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Sookmyung Women's University, Cheongpa-ro 47-gil 100, Yongsan-gu, Seoul 04310, Korea.
| | - Yoon-Jung Kim
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Sookmyung Women's University, Cheongpa-ro 47-gil 100, Yongsan-gu, Seoul 04310, Korea.
| | - Jae-Ha Ryu
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Sookmyung Women's University, Cheongpa-ro 47-gil 100, Yongsan-gu, Seoul 04310, Korea.
| | - Raok Jeon
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Sookmyung Women's University, Cheongpa-ro 47-gil 100, Yongsan-gu, Seoul 04310, Korea.
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Dong W, Xia A, Raphael PD, Puria S, Applegate B, Oghalai JS. Organ of Corti vibration within the intact gerbil cochlea measured by volumetric optical coherence tomography and vibrometry. J Neurophysiol 2018; 120:2847-2857. [PMID: 30281386 DOI: 10.1152/jn.00702.2017] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
There is indirect evidence that the mammalian cochlea in the low-frequency apical and the more commonly studied high-frequency basal regions function in fundamentally different ways. Here, we directly tested this hypothesis by measuring sound-induced vibrations of the organ of Corti (OoC) at three turns of the gerbil cochlea using volumetric optical coherence tomography vibrometry (VOCTV), an approach that permits noninvasive imaging through the bone. In the apical turn, there was little frequency selectivity, and the displacement-vs.-frequency curves had low-pass filter characteristics with a corner frequency of ~0.5-0.9 kHz. The vibratory magnitudes increased compressively with increasing stimulus intensity at all frequencies. In the middle turn, responses were similar except for a slight peak in the response at ~2.5 kHz. The gain was ~50 dB at the peak and 30-40 dB at lower frequencies. In the basal turn, responses were sharply tuned and compressively nonlinear, consistent with observations in the literature. These data demonstrated that there is a transition of the mechanical response of the OoC along the length of the cochlea such that frequency tuning is sharper in the base than in the apex. Because the responses are fundamentally different, it is not appropriate to simply frequency shift vibratory data measured at one cochlear location to predict the cochlear responses at other locations. Furthermore, this means that the number of hair cells stimulated by sound is larger for low-frequency stimuli and smaller for high-frequency stimuli for the same intensity level. Thus the mechanisms of central processing of sounds must vary with frequency. NEW & NOTEWORTHY A volumetric optical coherence tomography and vibrometry system was used to probe cochlear mechanics within the intact gerbil cochlea. We found a gradual transition of the mechanical response of the organ of Corti along the length of the cochlea such that tuning at the base is dramatically sharper than that at the apex. These data help to explain discrepancies in the literature regarding how the cochlea processes low-frequency sounds.
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Affiliation(s)
- Wei Dong
- VA Loma Linda Healthcare System, Loma Linda, California.,Department of Otolaryngology - Head and Neck Surgery, Loma Linda University Health , Loma Linda, California
| | - Anping Xia
- Department of Otolaryngology - Head and Neck Surgery, Stanford University , Stanford, California
| | - Patrick D Raphael
- Department of Otolaryngology - Head and Neck Surgery, Stanford University , Stanford, California
| | - Sunil Puria
- Eaton-Peabody Laboratories, Massachusetts Eye and Ear Infirmary and Harvard Medical School , Boston, Massachusetts
| | - Brian Applegate
- Department of Biomedical Engineering, Texas A&M University , College Station, Texas
| | - John S Oghalai
- Caruso Department of Otolaryngology - Head and Neck Surgery, University of Southern California , Los Angeles, California
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Walton JP, Dziorny AC, Vasilyeva ON, Luebke AE. Loss of the Cochlear Amplifier Prestin Reduces Temporal Processing Efficacy in the Central Auditory System. Front Cell Neurosci 2018; 12:291. [PMID: 30297983 PMCID: PMC6160587 DOI: 10.3389/fncel.2018.00291] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Accepted: 08/14/2018] [Indexed: 11/24/2022] Open
Abstract
Active mechanical amplification of sound occurs in cochlear outer hair cells (OHCs) that change their length with oscillations of their membrane potential. Such length changes are the proposed cellular source of the cochlear amplifier, and prestin is the motor protein responsible for OHC electromotility. Previous findings have shown that mice lacking prestin displayed a loss of OHC electromotility, subsequent loss of distortion-product otoacoustic emissions, and a 40–60 dB increase in hearing thresholds. In this study we were interested in studying the functional consequences of the complete loss of cochlear amplification on neural coding of frequency selectivity, tuning, and temporal processing in the auditory midbrain. We recorded near-field auditory evoked potentials and multi-unit activity from the inferior colliculus (IC) of prestin (−/−) null and prestin (+/+) wild-type control mice and determined frequency response areas (FRAs), tuning sharpness, and gap detection to tone bursts and silent gaps embedded in broadband noise. We were interested in determining if the moderate to severe sensorineural hearing loss associated with the loss of motor protein prestin would also impair auditory midbrain temporal-processing measures, or if compensatory mechanisms within the brainstem could compensate for the loss of prestin. In prestin knockout mice we observed that there are severe impairments in midbrain tuning, thresholds, excitatory drive, and gap detection suggesting that brainstem and midbrain processing could not overcome the auditory processing deficits afforded by the loss of OHC electromotility mediated by the prestin protein.
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Affiliation(s)
- Joseph P Walton
- Department of Communication Sciences and Disorders, University of South Florida, Tampa, FL, United States.,Department of Chemical and Biomedical Engineering, University of South Florida, Tampa, FL, United States.,Global Center for Hearing and Speech Research, University of South Florida, Tampa, FL, United States
| | - Adam C Dziorny
- Department of Biomedical Engineering, University of Rochester, Rochester, NY, United States
| | - Olga N Vasilyeva
- Department of Neuroscience, The Ernest J. Del Monte Institute for Neuroscience, University of Rochester Medical Center, Rochester, NY, United States
| | - Anne E Luebke
- Department of Biomedical Engineering, University of Rochester, Rochester, NY, United States.,Department of Neuroscience, The Ernest J. Del Monte Institute for Neuroscience, University of Rochester Medical Center, Rochester, NY, United States
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29
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Salelkar S, Somasekhar GM, Ray S. Distinct frequency bands in the local field potential are differently tuned to stimulus drift rate. J Neurophysiol 2018; 120:681-692. [PMID: 29694281 DOI: 10.1152/jn.00807.2017] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Local field potential (LFP) recorded with a microelectrode reflects the activity of several neural processes, including afferent synaptic inputs, microcircuit-level computations, and spiking activity. Objectively probing their contribution requires a design that allows dissociation between these potential contributors. Earlier reports have shown that the primate lateral geniculate nucleus (LGN) has a higher temporal frequency (drift rate) cutoff than the primary visual cortex (V1), such that at higher drift rates inputs into V1 from the LGN continue to persist, whereas output ceases, permitting partial dissociation. Using chronic microelectrode arrays, we recorded spikes and LFP from V1 of passively fixating macaques while presenting sinusoidal gratings drifting over a wide range. We further optimized the gratings to produce strong gamma oscillations, since recent studies in rodent V1 have reported LGN-dependent narrow-band gamma oscillations. Consistent with earlier reports, power in higher LFP frequencies (above ~140 Hz) tracked the population firing rate and were tuned to preferred drift rates similar to those for spikes. Significantly, power in the lower (up to ~40 Hz) frequencies increased transiently in the early epoch after stimulus onset, even at high drift rates, and had preferred drift rates higher than for spikes/high gamma. Narrow-band gamma (50-80 Hz) power was not strongly correlated with power in high or low frequencies and had much lower preferred temporal frequencies. Our results demonstrate that distinct frequency bands of the V1 LFP show diverse tuning profiles, which may potentially convey different attributes of the underlying neural activity. NEW & NOTEWORTHY In recent years the local field potential (LFP) has been increasingly studied, but interpreting its rich frequency content has been difficult. We use a stimulus manipulation that generates different tuning profiles for low, gamma, and high frequencies of the LFP, suggesting contributions from potentially different sources. Our results have possible implications for design of better neural prosthesis systems and brain-machine interfacing applications.
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Affiliation(s)
- Siddhesh Salelkar
- IISc Mathematics Initiative, Department of Mathematics, Indian Institute of Science , Bangalore , India
| | | | - Supratim Ray
- IISc Mathematics Initiative, Department of Mathematics, Indian Institute of Science , Bangalore , India.,Centre for Neuroscience, Indian Institute of Science , Bangalore , India
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30
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Abstract
Circuit operations are determined jointly by the properties of the circuit elements and the properties of the connections among these elements. In the nervous system, neurons exhibit diverse morphologies and branching patterns, allowing rich compartmentalization within individual cells and complex synaptic interactions among groups of cells. In this review, we summarize work detailing how neuronal morphology impacts neural circuit function. In particular, we consider example neurons in the retina, cerebral cortex, and the stomatogastric ganglion of crustaceans. We also explore molecular coregulators of morphology and circuit function to begin bridging the gap between molecular and systems approaches. By identifying motifs in different systems, we move closer to understanding the structure-function relationships that are present in neural circuits.
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Affiliation(s)
| | - Stephen D Van Hooser
- Department of Biology, Brandeis University , Waltham, Massachusetts.,Volen Center for Complex Systems, Brandeis University , Waltham, Massachusetts.,Sloan-Swartz Center for Theoretical Neurobiology, Brandeis University , Waltham, Massachusetts
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31
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Abstract
For the study and application of graphene membranes, it is essential to have means to control their resonance frequency and temperature. Here, we present an on-chip heater platform for local tuning of in-plane tension in graphene mechanical resonators. By Joule heating of a metallic suspension ring we show thermomechanical resonance frequency tuning in a few-layer (FL) graphene nanodrum, which is accompanied by an increase in its quality factor, which we attribute to the increase of the in-plane tension. The in situ control of temperature, in-plane tension, resonance frequency, and quality factor of suspended two-dimensional (2D) nanodrums makes this device a unique platform for investigating the origin of dissipation in these ultrathin structures and can be of fundamental importance for studying the thermal properties of 2D materials. Moreover, by simultaneously controlling the heater and the backgate voltage, we can independently control the resonance frequency and quality factor, which is of great importance for applications in sensors and resonant mechanical filters.
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Affiliation(s)
- Dejan Davidovikj
- Kavli
Institute of Nanoscience, Delft University
of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
- E-mail:
| | - Menno Poot
- Kavli
Institute of Nanoscience, Delft University
of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
- Physik
Department, Technische Universität
München, 85748 Garching, Germany
- Institute
for Advanced Study, Universität München, 85748 Garching, Germany
- E-mail:
| | - Santiago J. Cartamil-Bueno
- Kavli
Institute of Nanoscience, Delft University
of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
| | - Herre S. J. van der Zant
- Kavli
Institute of Nanoscience, Delft University
of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
| | - Peter G. Steeneken
- Kavli
Institute of Nanoscience, Delft University
of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
- Department
of Precision and Microsystems Engineering, Delft University of Technology, Mekelweg 2, 2628 CD Delft, The Netherlands
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32
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DeFranco AL. Multilayer Control of B Cell Activation by the B Cell Antigen Receptor: Following Themes Initiated With Bill Paul. Front Immunol 2018; 9:739. [PMID: 29740430 PMCID: PMC5925841 DOI: 10.3389/fimmu.2018.00739] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Accepted: 03/26/2018] [Indexed: 01/01/2023] Open
Abstract
This article describes the work I did in Bill Paul's lab as a postdoctoral fellow between 1979 and 1983, and to a lesser extent puts that work in the context of other work on B cell activation and antibody responses that was going on in Bill's lab at that time and shortly beforehand, including the discovery of interleukin 4. In addition, this work describes the subsequent and continuing work in my own lab following-up on themes I began during my time working directly with Bill. A particular emphasis was on understanding the biochemical mechanisms of signaling by the B cell antigen receptor (BCR) to the interior of the B cell. Some of the studies from my lab related to the regulation of BCR signaling by Lyn are described in relationship to the lymphocyte tuning hypothesis put forth by Grossman and Paul in 1992 and subsequently.
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Affiliation(s)
- Anthony L. DeFranco
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA, United States
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33
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Kolasinski J, Logan JP, Hinson EL, Manners D, Divanbeighi Zand AP, Makin TR, Emir UE, Stagg CJ. A Mechanistic Link from GABA to Cortical Architecture and Perception. Curr Biol 2017; 27:1685-1691.e3. [PMID: 28552355 PMCID: PMC5462622 DOI: 10.1016/j.cub.2017.04.055] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 03/07/2017] [Accepted: 04/26/2017] [Indexed: 11/26/2022]
Abstract
Understanding both the organization of the human cortex and its relation to the performance of distinct functions is fundamental in neuroscience. The primary sensory cortices display topographic organization, whereby receptive fields follow a characteristic pattern, from tonotopy to retinotopy to somatotopy [1]. GABAergic signaling is vital to the maintenance of cortical receptive fields [2]; however, it is unclear how this fine-grain inhibition relates to measurable patterns of perception [3, 4]. Based on perceptual changes following perturbation of the GABAergic system, it is conceivable that the resting level of cortical GABAergic tone directly relates to the spatial specificity of activation in response to a given input [5, 6, 7]. The specificity of cortical activation can be considered in terms of cortical tuning: greater cortical tuning yields more localized recruitment of cortical territory in response to a given input. We applied a combination of fMRI, MR spectroscopy, and psychophysics to substantiate the link between the cortical neurochemical milieu, the tuning of cortical activity, and variability in perceptual acuity, using human somatosensory cortex as a model. We provide data that explain human perceptual acuity in terms of both the underlying cellular and metabolic processes. Specifically, higher concentrations of sensorimotor GABA are associated with more selective cortical tuning, which in turn is associated with enhanced perception. These results show anatomical and neurochemical specificity and are replicated in an independent cohort. The mechanistic link from neurochemistry to perception provides a vital step in understanding population variability in sensory behavior, informing metabolic therapeutic interventions to restore perceptual abilities clinically. GABAergic tone correlates with perceptual acuity in the human somatosensory system This relationship is mediated by the tuning of activity in somatosensory cortex We explain perceptual acuity via the underlying cellular and metabolic processes
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Affiliation(s)
- James Kolasinski
- Oxford Centre for fMRI of the Brain, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK; Cardiff University Brain Research Imaging Centre, School of Psychology, Cardiff University, Cardiff CF24 4HQ, UK; University College, Oxford OX1 4BH, UK.
| | - John P Logan
- Oxford Centre for fMRI of the Brain, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK
| | - Emily L Hinson
- Oxford Centre for fMRI of the Brain, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK; Oxford Centre for Human Brain Activity, Department of Psychiatry, University of Oxford, Oxford OX3 7JX, UK
| | - Daniel Manners
- Oxford Centre for fMRI of the Brain, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK
| | - Amir P Divanbeighi Zand
- Oxford Centre for fMRI of the Brain, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK
| | - Tamar R Makin
- Oxford Centre for fMRI of the Brain, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK
| | - Uzay E Emir
- Oxford Centre for fMRI of the Brain, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK
| | - Charlotte J Stagg
- Oxford Centre for fMRI of the Brain, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK; Oxford Centre for Human Brain Activity, Department of Psychiatry, University of Oxford, Oxford OX3 7JX, UK
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34
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Murofushi T, Tsubota M, Suizu R, Yoshimura E. Is Alteration of Tuning Property in Cervical Vestibular-Evoked Myogenic Potential Specific for Ménière's Disease? Front Neurol 2017; 8:193. [PMID: 28533763 PMCID: PMC5420551 DOI: 10.3389/fneur.2017.00193] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Accepted: 04/20/2017] [Indexed: 01/20/2023] Open
Abstract
OBJECTIVE The aim of this study is to show sensitivity and specificity of cervical vestibular-evoked myogenic potential (cVEMP) tuning property test to Ménière's disease (MD) in comparison with healthy controls (HC) and patients with other vestibular diseases. SUBJECTS Totally 92 subjects (50 women and 42 men, 20-77 years of age) were enrolled in this study. Subjects were composed of 38 definite unilateral MD patients, 11 unilateral benign paroxysmal positional vertigo patients, 14 vestibular migraine patients, 19 unilateral vestibular neuritis patients, and 10 HC. METHODS The subjects underwent cVEMP testing to 500 and 1,000 Hz short tone bursts (125 dBSPL). The corrected amplitudes of the first biphasic responses (p13-n23) (cVEMP) were measured. Then, a tuning property index (the 500-1,000 Hz cVEMP slope) was calculated. RESULTS The area of under the ROC curve (AUC) was 0.75 in comparison with other vestibular disease patients, while AUC was 0.77 in comparison with other vestibular disease patients plus HC. The best cutoff point of the 500-1,000 Hz cVEMP slope was -19.9. Sensitivity of the tuning property test to MD was 0.74, while specificity was 0.76 to other vestibular disease patients. CONCLUSION The tuning property test of cVEMP is useful as a screening test of MD.
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Affiliation(s)
- Toshihisa Murofushi
- Department of Otolaryngology, Teikyo University School of Medicine Mizonokuchi Hospital, Kawasaki, Japan
| | - Masahito Tsubota
- Department of Otolaryngology, Teikyo University School of Medicine Mizonokuchi Hospital, Kawasaki, Japan
| | - Ryota Suizu
- Department of Otolaryngology, Teikyo University School of Medicine Mizonokuchi Hospital, Kawasaki, Japan
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35
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Liu M, Liu Y, Peng Z, Wang S, Wang Q, Mu Q, Cao Z, Xuan L. Organic Solid-State Tri-Wavelength Lasing from Holographic Polymer-Dispersed Liquid Crystal and a Distributed Feedback Laser with a Doped Laser Dye and a Semiconducting Polymer Film. Materials (Basel) 2017; 10:ma10050509. [PMID: 28772869 PMCID: PMC5459077 DOI: 10.3390/ma10050509] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Revised: 04/28/2017] [Accepted: 05/03/2017] [Indexed: 11/25/2022]
Abstract
Organic solid-state tri-wavelength lasing was demonstrated from dye-doped holographic polymer-dispersed liquid crystal (HPDLC) distributed feedback (DFB) laser with semiconducting polymer poly[-methoxy-5-(2′-ethyl-hexyloxy)-1,4-phenylene-vinylene] (MEH-PPV) and laser dye [4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran] (DCM) by a one-step holography technique, which centered at 605.5 nm, 611.9 nm, and 671.1 nm. The temperature-dependence tuning range for the tri-wavelength dye-doped HPDLC DFB laser was as high as 8 nm. The lasing emission from the 9th order HPDLC DFB laser with MEH-PPV as active medium was also investigated, which showed excellent s-polarization characterization. The diffraction order is 9th and 8th for the dual-wavelength lasing with DCM as the active medium. The results of this work provide a method for constructing the compact and cost-effective all solid-state smart laser systems, which may find application in scientific and applied research where multi-wavelength radiation is required.
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Affiliation(s)
- Minghuan Liu
- State Key Laboratory of Applied Optics, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China.
- University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Yonggang Liu
- State Key Laboratory of Applied Optics, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China.
| | - Zenghui Peng
- State Key Laboratory of Applied Optics, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China.
| | - Shaoxin Wang
- State Key Laboratory of Applied Optics, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China.
| | - Qidong Wang
- State Key Laboratory of Applied Optics, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China.
| | - Quanquan Mu
- State Key Laboratory of Applied Optics, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China.
| | - Zhaoliang Cao
- State Key Laboratory of Applied Optics, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China.
| | - Li Xuan
- State Key Laboratory of Applied Optics, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China.
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36
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Lynch-Aird N, Woodhouse J. Mechanical Properties of Nylon Harp Strings. Materials (Basel) 2017; 10:E497. [PMID: 28772858 DOI: 10.3390/ma10050497] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Revised: 04/18/2017] [Accepted: 04/26/2017] [Indexed: 11/17/2022]
Abstract
Monofilament nylon strings with a range of diameters, commercially marketed as harp strings, have been tested to establish their long-term mechanical properties. Once a string had settled into a desired stress state, the Young’s modulus was measured by a variety of methods that probe different time-scales. The modulus was found to be a strong function of testing frequency and also a strong function of stress. Strings were also subjected to cyclical variations of temperature, allowing various thermal properties to be measured: the coefficient of linear thermal expansion and the thermal sensitivities of tuning, Young’s modulus and density. The results revealed that the particular strings tested are divided into two groups with very different properties: stress-strain behaviour differing by a factor of two and some parametric sensitivities even having the opposite sign. Within each group, correlation studies allowed simple functional fits to be found to the key properties, which have the potential to be used in automated tuning systems for harp strings.
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37
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Wang L, Gong S, Yang C, Wen J. An Application of Chalcogenide Alloy Other than Storage Memory Field. Recent Pat Nanotechnol 2017; 11:75-80. [PMID: 27480669 DOI: 10.2174/1872210510666160729092758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Revised: 06/21/2016] [Accepted: 07/13/2016] [Indexed: 06/06/2023]
Abstract
BACKGROUND The necessity to handle mechanical functionality at nanoscale has recently motivated the prosperity of the nanoelectromechanical systems (NEMs). The fabrication of NEMS strongly depends on the so-called "topdown" techniques that are however limited by the resolution of electronbeam lithography. Meanwhile, the size of the NEMS needs to be shrunk continuously in order to further enhance the system performance. As a result, current research interest has been dedicated to "bottomup" techniques or even a hybridization of two aforementioned approaches, leading to the presence of the nanowire-based NEMs. Here, we presented some recent patent for nanowire-based NEMS. METHODS We investigate the resonant frequency and the frequency tuneability of the nanowire-based nanoelectromechanical system using Ge2Sb2Te5 media. By varying the nanowire dimensions, corresponding resonant frequencies and frequency tuneability are calculated using an established mechanical model. RESULTS We theoretically study the frequency tuneability of the nanowire-based NEMs using GST media. The resonant frequencies and the corresponding frequency tuneabilities for different nanowire dimensions are investigated using a developed mechanical model, and a previously established electrothermal model is performed to imitate the frequency tuning behavior of the system along with the phase-change phenomenon. By carefully controlling the amorphous fraction of the active region, a very high resonant frequency can be tuned within an ultra-high adjustable bandwidth. In addition, the merits of the phase-change memories including great scalability, low power consumption, fast transition time, and non-volatility can be also found on the proposed system. These results will open up a route for designing the next generation NEMs, and also pioneer a new application field for the GST media. CONCLUSIONS Today phase-change materials have received a wide range of applications from nonvolatile memories to neuromorphic networks due to its unique combinations of structural, electrical, and thermal properties. However, as the mechanical properties of phase-change materials exhibits a remarkable difference between the amorphous and crystalline phases, the feasibility of continuously changing the resonant frequency of the nanowires based on phase-change materials becomes viable.
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Affiliation(s)
- Lei Wang
- School of Information Engineering, Nanchang Hangkong University, 330063, Nanchang, China
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38
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Abstract
Tuning wind and tidal turbines is critical to maximizing their power output. Adopting a wind turbine tuning strategy of maximizing the output at any given time is shown to be an extremely poor strategy for large arrays of tidal turbines in channels. This 'impatient-tuning strategy' results in far lower power output, much higher structural loads and greater environmental impacts due to flow reduction than an existing 'patient-tuning strategy' which maximizes the power output averaged over the tidal cycle. This paper presents a 'smart patient tuning strategy', which can increase array output by up to 35% over the existing strategy. This smart strategy forgoes some power generation early in the half tidal cycle in order to allow stronger flows to develop later in the cycle. It extracts enough power from these stronger flows to produce more power from the cycle as a whole than the existing strategy. Surprisingly, the smart strategy can often extract more power without increasing maximum structural loads on the turbines, while also maintaining stronger flows along the channel. This paper also shows that, counterintuitively, for some tuning strategies imposing a cap on turbine power output to limit loads can increase a turbine's average power output.
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Affiliation(s)
- Ross Vennell
- Ocean Physics Group, Department of Marine Science, University of Otago, Dunedin, New Zealand; Cawthron Institute, Nelson, New Zealand
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39
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Salter JM, Williamson D. A comparison of statistical emulation methodologies for multi-wave calibration of environmental models. Environmetrics 2016; 27:507-523. [PMID: 28042255 PMCID: PMC5157755 DOI: 10.1002/env.2405] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Revised: 07/01/2016] [Accepted: 07/06/2016] [Indexed: 05/08/2023]
Abstract
Expensive computer codes, particularly those used for simulating environmental or geological processes, such as climate models, require calibration (sometimes called tuning). When calibrating expensive simulators using uncertainty quantification methods, it is usually necessary to use a statistical model called an emulator in place of the computer code when running the calibration algorithm. Though emulators based on Gaussian processes are typically many orders of magnitude faster to evaluate than the simulator they mimic, many applications have sought to speed up the computations by using regression-only emulators within the calculations instead, arguing that the extra sophistication brought using the Gaussian process is not worth the extra computational power. This was the case for the analysis that produced the UK climate projections in 2009. In this paper, we compare the effectiveness of both emulation approaches upon a multi-wave calibration framework that is becoming popular in the climate modeling community called "history matching." We find that Gaussian processes offer significant benefits to the reduction of parametric uncertainty over regression-only approaches. We find that in a multi-wave experiment, a combination of regression-only emulators initially, followed by Gaussian process emulators for refocussing experiments can be nearly as effective as using Gaussian processes throughout for a fraction of the computational cost. We also discover a number of design and emulator-dependent features of the multi-wave history matching approach that can cause apparent, yet premature, convergence of our estimates of parametric uncertainty. We compare these approaches to calibration in idealized examples and apply it to a well-known geological reservoir model.
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Affiliation(s)
- James M. Salter
- College of Engineering, Mathematics and Physical SciencesUniversity of ExeterExeterU.K.
| | - Daniel Williamson
- College of Engineering, Mathematics and Physical SciencesUniversity of ExeterExeterU.K.
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Martinez D, Metzen MG, Chacron MJ. Electrosensory processing in Apteronotus albifrons: implications for general and specific neural coding strategies across wave-type weakly electric fish species. J Neurophysiol 2016; 116:2909-2921. [PMID: 27683890 PMCID: PMC5224934 DOI: 10.1152/jn.00594.2016] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Accepted: 09/26/2016] [Indexed: 11/22/2022] Open
Abstract
Understanding how the brain processes sensory input to generate behavior remains an important problem in neuroscience. Towards this end, it is useful to compare results obtained across multiple species to gain understanding as to the general principles of neural coding. Here we investigated hindbrain pyramidal cell activity in the weakly electric fish Apteronotus albifrons We found strong heterogeneities when looking at baseline activity. Additionally, ON- and OFF-type cells responded to increases and decreases of sinusoidal and noise stimuli, respectively. While both cell types displayed band-pass tuning, OFF-type cells were more broadly tuned than their ON-type counterparts. The observed heterogeneities in baseline activity as well as the greater broadband tuning of OFF-type cells were both similar to those previously reported in other weakly electric fish species, suggesting that they constitute general features of sensory processing. However, we found that peak tuning occurred at frequencies ∼15 Hz in A. albifrons, which is much lower than values reported in the closely related species Apteronotus leptorhynchus and the more distantly related species Eigenmannia virescens In response to stimuli with time-varying amplitude (i.e., envelope), ON- and OFF-type cells displayed similar high-pass tuning curves characteristic of fractional differentiation and possibly indicate optimized coding. These tuning curves were qualitatively similar to those of pyramidal cells in the closely related species A. leptorhynchus In conclusion, comparison between our and previous results reveals general and species-specific neural coding strategies. We hypothesize that differences in coding strategies, when observed, result from different stimulus distributions in the natural/social environment.
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Affiliation(s)
- Diana Martinez
- Department of Physiology, McGill University, Montreal, Quebec, Canada
| | - Michael G Metzen
- Department of Physiology, McGill University, Montreal, Quebec, Canada
| | - Maurice J Chacron
- Department of Physiology, McGill University, Montreal, Quebec, Canada
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Abstract
The adaptive immune system is expected to protect the host from infectious agents and malignancies, while avoiding robust activation against self-peptides. However, T cells are notoriously inept at protection whenever the pathogen or tumor is persistent in the body for longer periods of time. While this has been thought of as an adaptation to limit the immunopathology from continued effector T-cell responses, it is also likely an extension of the T cell's intrinsic mechanisms which evolved to tolerate self-peptides. Here we deliberate on how the need to tolerate self-peptides might stem from a paradoxical requirement-the utility of such molecules in maintaining a diverse repertoire of pathogen-specific memory T cells in the body. Understanding the mechanisms underlying this intriguing nexus, therefore, has the potential to reveal therapeutic strategies not only for improving immune responses to chronic infections and tumors but also the long-term efficacy of vaccines aimed at cellular immune responses.
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Affiliation(s)
- Nevil J Singh
- Department of Microbiology and Immunology, University of Maryland School of Medicine, 685 W Baltimore St, HSF1, Room 380, Baltimore, MD 21201, USA
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Gjorgjieva J, Evers JF, Eglen SJ. Homeostatic Activity-Dependent Tuning of Recurrent Networks for Robust Propagation of Activity. J Neurosci 2016; 36:3722-34. [PMID: 27030758 PMCID: PMC4812132 DOI: 10.1523/jneurosci.2511-15.2016] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Revised: 01/31/2016] [Accepted: 02/09/2016] [Indexed: 11/21/2022] Open
Abstract
Developing neuronal networks display spontaneous bursts of action potentials that are necessary for circuit organization and tuning. While spontaneous activity has been shown to instruct map formation in sensory circuits, it is unknown whether it plays a role in the organization of motor networks that produce rhythmic output. Using computational modeling, we investigate how recurrent networks of excitatory and inhibitory neuronal populations assemble to produce robust patterns of unidirectional and precisely timed propagating activity during organism locomotion. One example is provided by the motor network inDrosophilalarvae, which generates propagating peristaltic waves of muscle contractions during crawling. We examine two activity-dependent models, which tune weak network connectivity based on spontaneous activity patterns: a Hebbian model, where coincident activity in neighboring populations strengthens connections between them; and a homeostatic model, where connections are homeostatically regulated to maintain a constant level of excitatory activity based on spontaneous input. The homeostatic model successfully tunes network connectivity to generate robust activity patterns with appropriate timing relationships between neighboring populations. These timing relationships can be modulated by the properties of spontaneous activity, suggesting its instructive role for generating functional variability in network output. In contrast, the Hebbian model fails to produce the tight timing relationships between neighboring populations required for unidirectional activity propagation, even when additional assumptions are imposed to constrain synaptic growth. These results argue that homeostatic mechanisms are more likely than Hebbian mechanisms to tune weak connectivity based on spontaneous input in a recurrent network for rhythm generation and robust activity propagation. SIGNIFICANCE STATEMENT How are neural circuits organized and tuned to maintain stable function and produce robust output? This task is especially difficult during development, when circuit properties change in response to variable environments and internal states. Many developing circuits exhibit spontaneous activity, but its role in the synaptic organization of motor networks that produce rhythmic output is unknown. We studied a model motor network, that when appropriately tuned, generates propagating activity as during crawling inDrosophilalarvae. Based on experimental evidence of activity-dependent tuning of connectivity, we examined plausible mechanisms by which appropriate connectivity emerges. Our results suggest that activity-dependent homeostatic mechanisms are better suited than Hebbian mechanisms for organizing motor network connectivity, and highlight an important difference from sensory areas.
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Affiliation(s)
- Julijana Gjorgjieva
- Volen Center for Complex Systems, Brandeis University, Waltham, Massachusetts 02454, Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Cambridge CB3 0WA, United Kingdom,
| | - Jan Felix Evers
- Heidelberg University, Centre for Organismal Studies, Heidelberg D-69120, Germany, Department of Zoology, University of Cambridge, Cambridge CB2 3EJ, United Kingdom, and
| | - Stephen J Eglen
- Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Cambridge CB3 0WA, United Kingdom, Cambridge Computational Biology Institute, University of Cambridge, Cambridge CB3 0WA, United Kingdom
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Bocan KN, Sejdić E. Adaptive Transcutaneous Power Transfer to Implantable Devices: A State of the Art Review. Sensors (Basel) 2016; 16:s16030393. [PMID: 26999154 PMCID: PMC4813968 DOI: 10.3390/s16030393] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Revised: 02/26/2016] [Accepted: 03/11/2016] [Indexed: 11/16/2022]
Abstract
Wireless energy transfer is a broad research area that has recently become applicable to implantable medical devices. Wireless powering of and communication with implanted devices is possible through wireless transcutaneous energy transfer. However, designing wireless transcutaneous systems is complicated due to the variability of the environment. The focus of this review is on strategies to sense and adapt to environmental variations in wireless transcutaneous systems. Adaptive systems provide the ability to maintain performance in the face of both unpredictability (variation from expected parameters) and variability (changes over time). Current strategies in adaptive (or tunable) systems include sensing relevant metrics to evaluate the function of the system in its environment and adjusting control parameters according to sensed values through the use of tunable components. Some challenges of applying adaptive designs to implantable devices are challenges common to all implantable devices, including size and power reduction on the implant, efficiency of power transfer and safety related to energy absorption in tissue. Challenges specifically associated with adaptation include choosing relevant and accessible parameters to sense and adjust, minimizing the tuning time and complexity of control, utilizing feedback from the implanted device and coordinating adaptation at the transmitter and receiver.
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Affiliation(s)
- Kara N Bocan
- Department of Electrical and Computer Engineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, PA 15213, USA.
| | - Ervin Sejdić
- Department of Electrical and Computer Engineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, PA 15213, USA.
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Hammer J, Pistohl T, Fischer J, Kršek P, Tomášek M, Marusič P, Schulze-Bonhage A, Aertsen A, Ball T. Predominance of Movement Speed Over Direction in Neuronal Population Signals of Motor Cortex: Intracranial EEG Data and A Simple Explanatory Model. Cereb Cortex 2016; 26:2863-81. [PMID: 26984895 PMCID: PMC4869816 DOI: 10.1093/cercor/bhw033] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
How neuronal activity of motor cortex is related to movement is a central topic in motor neuroscience. Motor-cortical single neurons are more closely related to hand movement velocity than speed, that is, the magnitude of the (directional) velocity vector. Recently, there is also increasing interest in the representation of movement parameters in neuronal population activity, such as reflected in the intracranial EEG (iEEG). We show that in iEEG, contrasting to what has been previously found on the single neuron level, speed predominates over velocity. The predominant speed representation was present in nearly all iEEG signal features, up to the 600–1000 Hz range. Using a model of motor-cortical signals arising from neuronal populations with realistic single neuron tuning properties, we show how this reversal can be understood as a consequence of increasing population size. Our findings demonstrate that the information profile in large population signals may systematically differ from the single neuron level, a principle that may be helpful in the interpretation of neuronal population signals in general, including, for example, EEG and functional magnetic resonance imaging. Taking advantage of the robust speed population signal may help in developing brain–machine interfaces exploiting population signals.
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Affiliation(s)
- Jiří Hammer
- Epilepsy Center, University Medical Center Freiburg, 79106 Freiburg, Germany Neurobiology and Biophysics, Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany Department of Paediatric Neurology, 2nd Faculty of Medicine and Motol University Hospital Department of Neurology, 2nd Faculty of Medicine and Motol University Hospital, Charles University, 150 06 Prague, Czech Republic
| | - Tobias Pistohl
- Neurobiology and Biophysics, Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany Bernstein Center Freiburg, University of Freiburg, 79104 Freiburg, Germany
| | - Jörg Fischer
- Neurobiology and Biophysics, Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany CorTec GmbH, 79110 Freiburg, Germany
| | - Pavel Kršek
- Department of Paediatric Neurology, 2nd Faculty of Medicine and Motol University Hospital
| | - Martin Tomášek
- Department of Neurology, 2nd Faculty of Medicine and Motol University Hospital, Charles University, 150 06 Prague, Czech Republic
| | - Petr Marusič
- Department of Neurology, 2nd Faculty of Medicine and Motol University Hospital, Charles University, 150 06 Prague, Czech Republic
| | - Andreas Schulze-Bonhage
- Epilepsy Center, University Medical Center Freiburg, 79106 Freiburg, Germany Bernstein Center Freiburg, University of Freiburg, 79104 Freiburg, Germany
| | - Ad Aertsen
- Neurobiology and Biophysics, Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany Bernstein Center Freiburg, University of Freiburg, 79104 Freiburg, Germany
| | - Tonio Ball
- Epilepsy Center, University Medical Center Freiburg, 79106 Freiburg, Germany Bernstein Center Freiburg, University of Freiburg, 79104 Freiburg, Germany
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Carse B, Bowers R, Meadows BC, Rowe P. The immediate effects of fitting and tuning solid ankle-foot orthoses in early stroke rehabilitation. Prosthet Orthot Int 2015; 39:454-62. [PMID: 24938770 DOI: 10.1177/0309364614538090] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Accepted: 05/06/2014] [Indexed: 02/03/2023]
Abstract
BACKGROUND Ankle-foot orthoses are known to have a generally positive effect on gait in stroke, however the specifc type of AFO and the time point at which it is provided are highly variable in the currently available literature. OBJECTIVE The objective was to determine the immediate spatiotemporal and kinematic effect of custom-made solid ankle-foot orthoses in early stroke rehabilitation, compared to shod walking. METHODS Five male and three female participants were recruited to the study (n = 8), with a mean age of 57 (16) years who were 3.5 (3) weeks post-stroke. Each received a custom-made solid ankle-foot orthosis to a predefined set of design criteria and tuned using heel wedges to control the shank inclination angle during shod walking. Repeated spatiotemporal and three-dimensional gait measures were taken pre- and immediately post-intervention. STUDY DESIGN A pre-post-test experimental study. RESULTS With the solid ankle-foot orthosis, walking velocity increased from 0.22 (0.2) to 0.36 (0.3) m/s (p < 0.05), overall average step length increased from 0.28 (0.1) to 0.37 (0.1) m (p < 0.05), cadence increased from 45 (19) to 56 (19) steps/min (p < 0.05) and step length symmetry ratio increased from 0.65 (0.2) to 0.74 (0.2) (not significant). No clear changes were observed in the joint kinematics of the hip and knee. CONCLUSION In our small group of early stroke patients who were fitted with a solid ankle-foot orthosis, immediate significant improvements occurred in walking speed, step length and cadence, when compared to walking with shoes only. CLINICAL RELEVANCE This study provides evidence about the immediate effects of custom solid ankle-foot orthoses on gait of early stroke survivors. Ankle-foot orthosis design specifications are fully described for replication. This study suggests that observing global segment orientation may be more useful than joint angles when fitting and tuning ankle-foot orthoses for optimal ankle-foot orthosis/footwear alignment.
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Affiliation(s)
- Bruce Carse
- The Biomedical Engineering Department, University of Strathclyde, Glasgow, UK
| | - Roy Bowers
- The Biomedical Engineering Department, University of Strathclyde, Glasgow, UK
| | | | - Philip Rowe
- The Biomedical Engineering Department, University of Strathclyde, Glasgow, UK
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Cao P, Zhang X, Park I, Najac C, Nelson SJ, Ronen S, Larson PEZ. 1 H- 13 C independently tuned radiofrequency surface coil applied for in vivo hyperpolarized MRI. Magn Reson Med 2015; 76:1612-1620. [PMID: 26597845 DOI: 10.1002/mrm.26046] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Revised: 10/07/2015] [Accepted: 10/20/2015] [Indexed: 01/20/2023]
Abstract
PURPOSE To develop a lump-element double-tuned common-mode-differential-mode (CMDM) radiofrequency (RF) surface coil with independent frequency tuning capacity for MRS and MRI applications. METHODS The presented design has two modes that can operate with different current paths, allowing independent frequency adjustment. The coil prototype was tested on the bench and then examined in phantom and in vivo experiments. RESULTS Standard deviations of frequency and impedance fluctuations measured in one resonator, while changing the tuning capacitor of another resonator, were less than 13 kHz and 0.55 Ω. The unloaded S21 was -36 dB and -41 dB, while the unloaded Q factor was 260 and 287, for 13 C and 1 H, respectively. In vivo hyperpolarized 13 C MR spectroscopy data demonstrated the feasibility of using the CMDM coil to measure the dynamics of lactate, alanine, pyruvate and bicarbonate signal in a normal rat head along with acquiring 1 H anatomical reference images. CONCLUSION Independent frequency tuning capacity was demonstrated in the presented lump-element double-tuned CMDM coil. This CMDM coil maintained intrinsically decoupled magnetic fields, which provided sufficient isolation between the two resonators. The results from in vivo experiments demonstrated high sensitivity of both the 1 H and 13 C resonators. Magn Reson Med 76:1612-1620, 2016. © 2015 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Peng Cao
- Department of Radiology and Biomedical Imaging, University of California at San Francisco, San Francisco, California, USA
| | - Xiaoliang Zhang
- Department of Radiology and Biomedical Imaging, University of California at San Francisco, San Francisco, California, USA
| | - Ilwoo Park
- Department of Radiology and Biomedical Imaging, University of California at San Francisco, San Francisco, California, USA
| | - Chloe Najac
- Department of Radiology and Biomedical Imaging, University of California at San Francisco, San Francisco, California, USA
| | - Sarah J Nelson
- Department of Radiology and Biomedical Imaging, University of California at San Francisco, San Francisco, California, USA
| | - Sabrina Ronen
- Department of Radiology and Biomedical Imaging, University of California at San Francisco, San Francisco, California, USA
| | - Peder E Z Larson
- Department of Radiology and Biomedical Imaging, University of California at San Francisco, San Francisco, California, USA.
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Choi H, Bjornson K, Fatone S, Steele KM. Using musculoskeletal modeling to evaluate the effect of ankle foot orthosis tuning on musculotendon dynamics: a case study. Disabil Rehabil Assist Technol 2015; 11:613-8. [PMID: 25640240 DOI: 10.3109/17483107.2015.1005030] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE This case study examines the influence of an ankle foot orthosis footwear combination (AFO-FC) on musculotendon lengths and gait kinematics and kinetics after right thrombotic stroke resulting in left hemiplegia. METHODS Gait analysis was performed over three visits where the subject walked with an AFO-FC with two shank-to-vertical angle (SVA) alignments, a posterior leaf spring AFO (PLS AFO), and shoes alone. Biomechanical and musculoskeletal modeling was used to evaluate musculotendon lengths, kinematics, and kinetics for each condition. RESULTS The AFO-FC improved walking speed and non-paretic kinematics compared to the PLS AFO and shoes alone. The operating length of the paretic gastrocnemius decreased with the AFO-FC improving knee kinematics in swing, but not stance. As the SVA of the AFO-FC was reduced from 15° to 12°, internal ankle plantar flexor moment increased. CONCLUSIONS Musculoskeletal modeling demonstrated that the AFO-FC altered gastrocnemius operating length during post-stroke hemiplegic gait. Using these tools to evaluate muscle operating lengths can provide insight into underlying mechanisms that may improve gait and guide future AFO-FC design. Implications for Rehabilitation Modeling musculotendon operating lengths during movement has the potential to inform how ankle foot orthoses (AFO) affect tight muscles and improve mobility after stroke. Adjusting shank-to-vertical angle (SVA) of the AFO-footwear combination (AFO-FC) has the potential to improve gait kinematics by controlling length of the pathologic gastrocnemius and maximizing internal ankle plantar flexor moment of individuals with neuromuscular disorders.
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Affiliation(s)
- Hwan Choi
- a Department of Mechanical Engineering and
| | - Kristie Bjornson
- b Department of Pediatrics , University of Washington , Seattle , WA , USA .,c Seattle Children's Research Institute , Seattle , WA , USA , and
| | - Stefania Fatone
- d Prosthetics-Orthotics Center , Northwestern University Feinberg School of Medicine , Chicago , IL , USA
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Keith GA, Rodgers CT, Hess AT, Snyder CJ, Vaughan JT, Robson MD. Automated tuning of an eight-channel cardiac transceive array at 7 tesla using piezoelectric actuators. Magn Reson Med 2014; 73:2390-7. [PMID: 24986525 PMCID: PMC4245186 DOI: 10.1002/mrm.25356] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2013] [Revised: 05/21/2014] [Accepted: 06/17/2014] [Indexed: 11/22/2022]
Abstract
Purpose Ultra-high field (UHF) MR scanning in the body requires novel coil designs due to B1 field inhomogeneities. In the transverse electromagnetic field (TEM) design, maximum B1 transmit power can only be achieved if each individual transmit element is tuned and matched for different coil loads, which requires a considerable amount of valuable scanner time. Methods An integrated system for autotuning a multichannel parallel transmit (pTx) cardiac TEM array was devised, using piezoelectric actuators, power monitoring equipment and control software. The reproducibility and performance of the system were tested and the power responses of the coil elements were profiled. An automated optimization method was devised and evaluated. Results The time required to tune an eight-element pTx cardiac RF array was reduced from a mean of 30 min to less than 10 min with the use of this system. Conclusion Piezoelectric actuators are an attractive means of tuning RF coil arrays to yield more efficient B1 transmission into the subject. An automated mechanism for tuning these elements provides a practical solution for cardiac imaging at UHF, bringing this technology closer to clinical use. Magn Reson Med 73:2390–2397, 2015. © 2014 The Authors. Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Graeme A Keith
- Oxford Centre for Clinical Magnetic Resonance Research, University of Oxford, John Radcliffe Hospital, Oxford, United Kingdom
| | - Christopher T Rodgers
- Oxford Centre for Clinical Magnetic Resonance Research, University of Oxford, John Radcliffe Hospital, Oxford, United Kingdom
| | - Aaron T Hess
- Oxford Centre for Clinical Magnetic Resonance Research, University of Oxford, John Radcliffe Hospital, Oxford, United Kingdom
| | - Carl J Snyder
- Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, Minnesota, USA
| | - J Thomas Vaughan
- Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, Minnesota, USA
| | - Matthew D Robson
- Oxford Centre for Clinical Magnetic Resonance Research, University of Oxford, John Radcliffe Hospital, Oxford, United Kingdom
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Schwarzkopf DS, Anderson EJ, de Haas B, White SJ, Rees G. Larger extrastriate population receptive fields in autism spectrum disorders. J Neurosci 2014; 34:2713-24. [PMID: 24523560 DOI: 10.1523/JNEUROSCI.4416-13.2014] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Previous behavioral research suggests enhanced local visual processing in individuals with autism spectrum disorders (ASDs). Here we used functional MRI and population receptive field (pRF) analysis to test whether the response selectivity of human visual cortex is atypical in individuals with high-functioning ASDs compared with neurotypical, demographically matched controls. For each voxel, we fitted a pRF model to fMRI signals measured while participants viewed flickering bar stimuli traversing the visual field. In most extrastriate regions, perifoveal pRFs were larger in the ASD group than in controls. We observed no differences in V1 or V3A. Differences in the hemodynamic response function, eye movements, or increased measurement noise could not account for these results; individuals with ASDs showed stronger, more reliable responses to visual stimulation. Interestingly, pRF sizes also correlated with individual differences in autistic traits but there were no correlations with behavioral measures of visual processing. Our findings thus suggest that visual cortex in ASDs is not characterized by sharper spatial selectivity. Instead, we speculate that visual cortical function in ASDs may be characterized by extrastriate cortical hyperexcitability or differential attentional deployment.
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50
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Abstract
Due to its limited capacity, visual perception depends on the allocation of attention. The resultant phenomena of inattentional blindness, accompanied by reduced sensory visual cortex response to unattended stimuli in conditions of high perceptual load in the attended task, are now well established (Lavie, 2005; Lavie, 2010, for reviews). However, the underlying mechanisms for these effects remain to be elucidated. Specifically, is reduced perceptual processing under high perceptual load a result of reduced sensory signal gain, broader tuning, or both? We examined this question with psychophysical measures of orientation tuning under different levels of perceptual load in the task performed. Our results show that increased perceptual load leads to both reduced sensory signal and broadening of tuning. These results clarify the effects of attention on elementary visual perception and suggest that high perceptual load is critical for attentional effects on sensory tuning.
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Affiliation(s)
- Moritz Stolte
- Institute of Cognitive Neuroscience, University College London, London, UK
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