Inhibitory synchrony as a mechanism for attentional gain modulation

Recordings from area V4 of monkeys have revealed that when the focus of attention is on a visual stimulus within the receptive field of a cortical neuron, two distinct changes can occur: The firing rate of the neuron can change and there can be an increase in the coherence between spikes and the local field potential in the gamma-frequency range (30-50 Hz). The hypothesis explored here is that these observed effects of attention could be a consequence of changes in the synchrony of local interneuron networks. We performed computer simulations of a Hodgkin-Huxley type neuron driven by a constant depolarizing current, I, representing visual stimulation and a modulatory inhibitory input representing the effects of attention via local interneuron networks. We observed that the neuron's firing rate and the coherence of its output spike train with the synaptic inputs was modulated by the degree of synchrony of the inhibitory inputs. The model suggest that the observed changes in firing rate and coherence of neurons in the visual cortex could be controlled by top-down inputs that regulated the coherence in the activity of a local inhibitory network discharging at gamma frequencies.Comment: J.Physiology (Paris) in press, 11 figure

Current-induced vortex dynamics in Josephson-junction arrays: Imaging experiments and model simulations

We study the dynamics of current-biased Josephson-junction arrays with a magnetic penetration depth smaller than the lattice spacing. We compare the dynamics imaged by low-temperature scanning electron microscopy to the vortex dynamics obtained from model calculations based on the resistively-shunted junction model, in combination with Maxwell's equations. We find three bias current regions with fundamentally different array dynamics. The first region is the subcritical region, i.e. below the array critical current I_c. The second, for currents I above I_c, is a "vortex region", in which the response is determined by the vortex degrees of freedom. In this region, the dynamics is characterized by spatial domains where vortices and antivortices move across the array in opposite directions in adjacent rows and by transverse voltage fluctuations. In the third, for still higher currents, the dynamics is dominated by coherent-phase motion, and the current-voltage characteristics are linear.Comment: 10 pages, with eps figures. To appear in Phys. Rev.

Fluctuations in a coupled-oscillator model of the cardiovascular system

We present a model of the cardiovascular system (CVS) based on a system of coupled oscillators. Using this approach we can describe several complex physiological phenomena that can have a range of applications. For instance, heart rate variability (HRV), can have a new deterministic explanation. The intrinsic dynamics of the HRV is controlled by deterministic couplings between the physiological oscillators in our model and without the need to introduce external noise as is commonly done. This new result provides potential applications not only for physiological systems but also for the design of very precise electronic generators where the frequency stability is crucial. Another important phenomenon is that of oscillation death. We show that in our CVS model the mechanism leading to the quenching of the oscillations can be controlled, not only by the coupling parameter, but by a more general scheme. In fact, we propose that a change in the relative current state of the cardiovascular oscillators can lead to a cease of the oscillations without actually changing the strength of the coupling among them. We performed real experiments using electronic oscillators and show them to match the theoretical and numerical predictions. We discuss the relevance of the studied phenomena to real cardiovascular systems regimes, including the explanation of certain pathologies, and the possible applications in medical practice

An investigation into the fabrication parameters of screen-printed capacitive sensors on e-textiles

[EN] The design and development of textile-based capacitive sensors requires the implementation of textile capacitors with a determined capacitance. One of the main techniques to obtain these sensors is the screen-printing of conductive and dielectric inks on textiles. This paper investigates the fabrication parameters that have the most influence when designing and implementing a screen-printed capacitive sensor. In this work, a textile has been used directly as the dielectric part, influencing sensitively the value of the permittivity and the thickness of the dielectric of the capacitor. These are two fundamental parameters for the estimation of its capacitance. The choice of the conductive ink, its viscosity and solid content, as well as printing parameters, such as printing direction, also impact on the manner for obtaining the electrodes of the capacitive sensor. Although the resulting electrodes do not represent an important parameter for the estimation of the capacitance, it determines the selection of fabrics that can be printed. As a result of the investigation, the paper provides a guideline to choose the materials, such as fabrics or inks, as well as the printing parameters, to implement e-textile applications based on projected capacitive technologies. The experiments carried out on different fabrics and inks have provided results with capacities of less than 60 pF, the limit where the sensors based on capacitive technologies are located.The authors disclosed receipt of the following financial support for the research, authorship and/or publication of this article: This work was supported by the Conselleria d'Economia Sostenible, Sectors Productius i Treball, through IVACE (Instituto Valenciano de Competitividad Empresarial) and cofounded by ERDF funding from the European Union (Application no. IMAMCI/2019/1). This work was also supported by the Spanish Government/FEDER funds (RTI2018-100910-B-C43) (MINECO/FEDER).Ferri, J.; Llinares Llopis, R.; Moreno, J.; Lidon-Roger, JV.; Garcia-Breijo, E. (2020). An investigation into the fabrication parameters of screen-printed capacitive sensors on e-textiles. Textile Research Journal. 90(15-16):1749-1769. https://doi.org/10.1177/0040517519901016S174917699015-16Gonçalves, C., Ferreira da Silva, A., Gomes, J., & Simoes, R. (2018). Wearable E-Textile Technologies: A Review on Sensors, Actuators and Control Elements. Inventions, 3(1), 14. doi:10.3390/inventions3010014Mostafalu, P., Tamayol, A., Rahimi, R., Ochoa, M., Khalilpour, A., Kiaee, G., … Khademhosseini, A. (2018). Smart Bandage for Monitoring and Treatment of Chronic Wounds. Small, 14(33), 1703509. doi:10.1002/smll.201703509Shi, H., Zhao, H., Liu, Y., Gao, W., & Dou, S.-C. (2019). Systematic Analysis of a Military Wearable Device Based on a Multi-Level Fusion Framework: Research Directions. Sensors, 19(12), 2651. doi:10.3390/s19122651Kim, K., Jung, M., Jeon, S., & Bae, J. (2019). Robust and scalable three-dimensional spacer textile pressure sensor for human motion detection. Smart Materials and Structures, 28(6), 065019. doi:10.1088/1361-665x/ab1adfFerri, J., Perez Fuster, C., Llinares Llopis, R., Moreno, J., & Garcia‑Breijo, E. (2018). Integration of a 2D Touch Sensor with an Electroluminescent Display by Using a Screen-Printing Technology on Textile Substrate. Sensors, 18(10), 3313. doi:10.3390/s18103313De Vos, M., Torah, R., Glanc-Gostkiewicz, M., & Tudor, J. (2016). A Complex Multilayer Screen-Printed Electroluminescent Watch Display on Fabric. Journal of Display Technology, 12(12), 1757-1763. doi:10.1109/jdt.2016.2613906Lin, X., & Seet, B.-C. (2017). Battery-Free Smart Sock for Abnormal Relative Plantar Pressure Monitoring. IEEE Transactions on Biomedical Circuits and Systems, 11(2), 464-473. doi:10.1109/tbcas.2016.2615603Ejupi, A., & Menon, C. (2018). Detection of Talking in Respiratory Signals: A Feasibility Study Using Machine Learning and Wearable Textile-Based Sensors. Sensors, 18(8), 2474. doi:10.3390/s18082474Polanský, R., Soukup, R., Řeboun, J., Kalčík, J., Moravcová, D., Kupka, L., … Hamáček, A. (2017). A novel large-area embroidered temperature sensor based on an innovative hybrid resistive thread. Sensors and Actuators A: Physical, 265, 111-119. doi:10.1016/j.sna.2017.08.030Komazaki, Y., & Uemura, S. (2019). Stretchable, printable, and tunable PDMS-CaCl2 microcomposite for capacitive humidity sensors on textiles. Sensors and Actuators B: Chemical, 297, 126711. doi:10.1016/j.snb.2019.126711Ng, C. L., & Reaz, M. B. I. (2019). Evolution of a capacitive electromyography contactless biosensor: Design and modelling techniques. Measurement, 145, 460-471. doi:10.1016/j.measurement.2019.05.031Ferri, J., Lidón-Roger, J., Moreno, J., Martinez, G., & Garcia-Breijo, E. (2017). A Wearable Textile 2D Touchpad Sensor Based on Screen-Printing Technology. Materials, 10(12), 1450. doi:10.3390/ma10121450Atalay, O. (2018). Textile-Based, Interdigital, Capacitive, Soft-Strain Sensor for Wearable Applications. Materials, 11(5), 768. doi:10.3390/ma11050768Yongsang Kim, Hyejung Kim, & Hoi-Jun Yoo. (2010). Electrical Characterization of Screen-Printed Circuits on the Fabric. IEEE Transactions on Advanced Packaging, 33(1), 196-205. doi:10.1109/tadvp.2009.2034536Lee, W. J., Park, J. Y., Nam, H. J., & Choa, S.-H. (2019). The development of a highly stretchable, durable, and printable textile electrode. Textile Research Journal, 89(19-20), 4104-4113. doi:10.1177/0040517519828992Chatterjee, K., Tabor, J., & Ghosh, T. K. (2019). Electrically Conductive Coatings for Fiber-Based E-Textiles. Fibers, 7(6), 51. doi:10.3390/fib7060051Gu, J. F., Gorgutsa, S., & Skorobogatiy, M. (2010). Soft capacitor fibers using conductive polymers for electronic textiles. Smart Materials and Structures, 19(11), 115006. doi:10.1088/0964-1726/19/11/115006Khan, S., Lorenzelli, L., & Dahiya, R. S. (2015). Technologies for Printing Sensors and Electronics Over Large Flexible Substrates: A Review. IEEE Sensors Journal, 15(6), 3164-3185. doi:10.1109/jsen.2014.2375203Zhang, Q., Wang, Y. L., Xia, Y., Zhang, P. F., Kirk, T. V., & Chen, X. D. (2019). Textile‐Only Capacitive Sensors for Facile Fabric Integration without Compromise of Wearability. Advanced Materials Technologies, 4(10), 1900485. doi:10.1002/admt.201900485Mukherjee, P. K. (2018). Dielectric properties in textile materials: a theoretical study. The Journal of The Textile Institute, 110(2), 211-214. doi:10.1080/00405000.2018.1473710Sadi, M. S., Yang, M., Luo, L., Cheng, D., Cai, G., & Wang, X. (2019). Direct screen printing of single-faced conductive cotton fabrics for strain sensing, electrical heating and color changing. Cellulose, 26(10), 6179-6188. doi:10.1007/s10570-019-02526-

Feasibility of community level interventions for pre-eclampsia: perspectives, knowledge and task-sharing from Nigeria, Mozambique, Pakistan and India

Hypertensive disorders of pregnancy (HDP), particularly pre-eclampsia and eclampsia, remain one of the leading causes of maternal mortality and are contributory in many foetal/newborn deaths. This editorial discusses a supplement of seven papers which provide the results of the first round of the CLIP (Community Level Interventions for Pre-eclampsia) Feasibility Studies. These studies report a number of enablers and barriers in each setting, which have informed the implementation of a cluster-randomized trial (cRCT) aimed at reducing pre-eclampsia-related, and all-cause, maternal and perinatal mortality and major morbidity using community-based identification and treatment of pre-eclampsia in selected geographies of Nigeria, Mozambique, Pakistan and India. This supplement unpacks the diverse community perspectives on determinants of maternal health, variant health worker knowledge and routine management of HDP, and viability of task sharing for preeclampsia identification and management in select settings. These studies demonstrate the need for strategies to improve health worker knowledge and routine management of HDP and consideration of expanding the role of community health workers to reach the most remote women and families with health education and access to health services.Fil: Kinney, Mary V.. No especifíca;Fil: Smith, Jeffrey Michael. Jhpiego; Estados UnidosFil: Doherty, Tanya. South African Medical Research Council; Sudáfrica. University of the Western Cape; SudáfricaFil: Hermida, Jorge. University Research Company; Estados UnidosFil: Daniels, Karen. South African Medical Research Council; Sudáfrica. University of the Western Cape; SudáfricaFil: Belizan, Jose. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto de Efectividad Clínica y Sanitaria; Argentin