The Role of the Dorsolateral Prefrontal Cortex during Sequence Learning is Specific for Spatial Information

Many studies have implicated the dorsolateral prefrontal cortex in the acquisition of skill, including procedural sequence learning. However, the specific role it performs in sequence learning has remained uncertain. This type of skill has been intensively studied using the serial reaction time task. We used three versions of this task: a standard task where the position of the stimulus cued the response; a non-standard task where the color of the stimulus was related to the correct response; and a combined task where both the color and position simultaneously cued the response. We refer to each of these tasks based upon the cues available for guiding learning as position, color and combined tasks. The combined task usually shows an enhancement of skill acquisition, a result of being driven by two simultaneous and congruent cues. Prior to the performance of each of these tasks the function of the dorsolateral prefrontal cortex was disrupted using repetitive transcranial magnetic stimulation. This completely prevented learning within the position task, while sequence learning occurred to a similar extent in both the color and combined tasks. So, following prefrontal stimulation the expected learning enhancement in the combined task was lost, consistent with only a color cue being available to guide sequence learning in the combined task. Neither of these effects was observed following stimulation at the parietal cortex. Hence the critical role played by the dorsolateral prefrontal cortex in sequence learning is related exclusively to spatial cues. We suggest that the dorsolateral prefrontal cortex operates over the short term to retain and manipulate spatial information to allow cortical and subcortical structures to learn a predictable sequence of actions. Such functions may emerge from the broader role the dorsolateral prefrontal cortex has in spatial working memory. These results argue against the dorsolateral prefrontal cortex constituting part of the neuronal substrate responsible for general aspects of implicit or explicit sequence learning.Medicin

Time to reconcile research findings and clinical practice on upper limb neurorehabilitation

The problemIn the field of upper limb neurorehabilitation, the translation from research findings to clinical practice remains troublesome. Patients are not receiving treatments based on the best available evidence. There are certainly multiple reasons to account for this issue, including the power of habit over innovation, subjective beliefs over objective results. We need to take a step forward, by looking at most important results from randomized controlled trials, and then identify key active ingredients that determined the success of interventions. On the other hand, we need to recognize those specific categories of patients having the greatest benefit from each intervention, and why. The aim is to reach the ability to design a neurorehabilitation program based on motor learning principles with established clinical efficacy and tailored for specific patient's needs. Proposed solutionsThe objective of the present manuscript is to facilitate the translation of research findings to clinical practice. Starting from a literature review of selected neurorehabilitation approaches, for each intervention the following elements were highlighted: definition of active ingredients; identification of underlying motor learning principles and neural mechanisms of recovery; inferences from research findings; and recommendations for clinical practice. Furthermore, we included a dedicated chapter on the importance of a comprehensive assessment (objective impairments and patient's perspective) to design personalized and effective neurorehabilitation interventions. ConclusionsIt's time to reconcile research findings with clinical practice. Evidence from literature is consistently showing that neurological patients improve upper limb function, when core strategies based on motor learning principles are applied. To this end, practical take-home messages in the concluding section are provided, focusing on the importance of graded task practice, high number of repetitions, interventions tailored to patient's goals and expectations, solutions to increase and distribute therapy beyond the formal patient-therapist session, and how to integrate different interventions to maximize upper limb motor outcomes. We hope that this manuscript will serve as starting point to fill the gap between theory and practice in upper limb neurorehabilitation, and as a practical tool to leverage the positive impact of clinicians on patients' recovery

Caracterización y modulación de la plasticidad del cerebro humano

Las neuronas son estructuras muy especializadas, resistentes al cambio, integradas en redes distribuidas que experimentan cambios dinámicos a lo largo de la vida. Estos cambios en la conectividad funcional de redes neurales pueden seguirse de cambios estructurales más estables. Por lo tanto, el cerebro está continuamente sometido a una remodelación plástica. La plasticidad no es un estado ocasional del sistema nervioso, sino el estado de normalidad del sistema nervioso durante toda la vida. No es posible comprender el funcionamiento psicológico normal, ni las manifestaciones o consecuencias de la enfermedad, sin considerar el concepto de plasticidad cerebral. Cambios plásticos del sistema nervioso no necesariamente dan lugar a ventajas comportamentales. Por lo tanto, el reto es comprender los mecanismos y las consecuencias de la plasticidad para modularlos, suprimiendo unos y potenciando otros, a fin de promover cambios adaptativos en el cerebro de cada individuo. El comportamiento, la neuroestimulación y las intervenciones dirigidas con neurofármacos pueden modular la plasticidad y promover resultados deseables para cada individuo

Interindividual variability of the modulatory effects of repetitive transcranial magnetic stimulation on cortical excitability

Repetitive transcranial magnetic stimulation (rTMS) appears to have effects on cortical excitability that extend beyond the train of rTMS itself. These effects may be inhibitory or facilitatory and appear to depend on the frequency, intensity, duration and intertrain interval of the rTMS. Many studies assume facilitatory effects of high-frequency rTMS and inhibitory effects of low-frequency rTMS. Nevertheless, the interindividual variability of this modulation of cortical excitability by rTMS has not been systematically investigated. In this study, we applied 240 pulses of rTMS at 90% of the subjects' motor threshold to their motor cortex at different frequencies (1, 10, 15 and 20 Hz) and examined the effects on motor evoked potentials (frequency tuning curve). Although the averaged group data showed a frequency-dependent increase in cortical excitability, each subject had a different pattern of frequency tuning curve, i.e. a different modulatory effect on cortical excitability at different rTMS frequencies. The interindividual variability of these modulatory effects was still high, though less so, when the number of rTMS pulses was increased to 1600. These findings illustrate the degree of variability of the rTMS effects in the human brain.Supported in part by grants from the Cellular Science Research Foundation, Yoshida Science Foundation, Japan North America Medical Exchange Foundation, the Stanley Vada Foundation, the National Alliance for Research and Schizophrenia and Depression, and the National Institute of Mental Health (RO1MH57980)Medicin

Time to reconcile research findings and clinical practice on upper limb neurorehabilitation

The problemIn the field of upper limb neurorehabilitation, the translation from research findings to clinical practice remains troublesome. Patients are not receiving treatments based on the best available evidence. There are certainly multiple reasons to account for this issue, including the power of habit over innovation, subjective beliefs over objective results. We need to take a step forward, by looking at most important results from randomized controlled trials, and then identify key active ingredients that determined the success of interventions. On the other hand, we need to recognize those specific categories of patients having the greatest benefit from each intervention, and why. The aim is to reach the ability to design a neurorehabilitation program based on motor learning principles with established clinical efficacy and tailored for specific patient's needs.Proposed solutionsThe objective of the present manuscript is to facilitate the translation of research findings to clinical practice. Starting from a literature review of selected neurorehabilitation approaches, for each intervention the following elements were highlighted: definition of active ingredients; identification of underlying motor learning principles and neural mechanisms of recovery; inferences from research findings; and recommendations for clinical practice. Furthermore, we included a dedicated chapter on the importance of a comprehensive assessment (objective impairments and patient's perspective) to design personalized and effective neurorehabilitation interventions.ConclusionsIt's time to reconcile research findings with clinical practice. Evidence from literature is consistently showing that neurological patients improve upper limb function, when core strategies based on motor learning principles are applied. To this end, practical take-home messages in the concluding section are provided, focusing on the importance of graded task practice, high number of repetitions, interventions tailored to patient's goals and expectations, solutions to increase and distribute therapy beyond the formal patient-therapist session, and how to integrate different interventions to maximize upper limb motor outcomes. We hope that this manuscript will serve as starting point to fill the gap between theory and practice in upper limb neurorehabilitation, and as a practical tool to leverage the positive impact of clinicians on patients' recovery

Antidepressant Effects of High and Low Frequency Repetitive Transcranial Magnetic Stimulation to the Dorsolateral Prefrontal Cortex

Repetitive transcranial magnetic stimulation(rTMS) has antidepressant effects in patients withmajor depressive disorder. The mechanisms of ac-tion and optimal stimulation parameters remainunclear. To test the hypothesis that rTMS exertsantidepressant effects either by enhancing left dor-solateral prefrontal cortex (DLPFC) excitability orby decreasing right DLPFC excitability, the au-thors studied 45 patients with unipolar recurrentmajor depressive disorder in a double-blind, ran-domized, parallel group, sham-controlled trial. Pa-tients were randomized to receive 1 Hz or 10 HzrTMS to the left DLPFC, 1 Hz to the rightDLPFC or sham TMS. Left 10 Hz and right 1 HzrTMS showed similar significant antidepressanteffects. Other parameters led to no significantantidepressant effectThis study was supported in part by grants from the Spanish Ministerio de Educacion y Cienca (DGICYT), the Milton Fund, the Stanley Vada NAMI Foundation, the National Alliance for Research in Schizophrenia and Depression, and NIMHMedicin

Sound Absorption Properties of Perforated Recycled Polyurethane Foams Reinforced with Woven Fabric

[EN] The acoustic properties of recycled polyurethane foams are well known. Such foams are used as a part of acoustic solutions in different fields such as building or transport. This paper aims to seek improvements in the sound absorption of these recycled foams when they are combined with fabrics. For this aim, foams have been drilled with cylindrical perforations, and also combined with different fabrics. The effect on the sound absorption is evaluated based on the following key parameters: perforation rate (5% and 20%), aperture size (4 mm and 6 mm), and a complete perforation depth. Experimental measurements were performed by using an impedance tube for the characterization of its acoustic behavior. Sound absorption of perforated samples is also studied¿numerically by finite element simulations, where the viscothermal losses were considered; and analytically by using models for the perforated foam and the fabric. Two textile fabrics were used in combination with perforated polyurethane samples. Results evidence a modification of the sound absorption at mid frequencies employing fabrics that have a membrane-type acoustic response.This research was financially supported by the Ministry of Economy and Innovation (MINECO) and the European Union FEDER through project FIS2015-65998-C2-2 and by projects AICO/2016/060 and ACIF/2017/073 by Regional Ministry of Education, Culture and Sport of the Generalitat Valenciana and with the support of European Structural Investment Funds (ESIF-European Union).Atiénzar-Navarro, R.; Rey Tormos, RMD.; Alba, J.; Sánchez Morcillo, VJ.; Picó Vila, R. (2020). Sound Absorption Properties of Perforated Recycled Polyurethane Foams Reinforced with Woven Fabric. Polymers. 12(2):1-18. https://doi.org/10.3390/polym12020401S118122Hamernik, R. P., & Ahroon, W. A. (1998). Interrupted noise exposures: Threshold shift dynamics and permanent effects. The Journal of the Acoustical Society of America, 103(6), 3478-3488. doi:10.1121/1.423056Ramis, J., Alba, J., Del Rey, R., Escuder, E., & Sanchís, V. J. (2010). Nuevos materiales absorbentes acústicos basados en fibra de kenaf. Materiales de Construcción, 60(299), 133-143. doi:10.3989/mc.2010.50809Ramis, J., Del Rey, R., Alba, J., Godinho, L., & Carbajo, J. (2014). A model for acoustic absorbent materials derived from coconut fiber. Materiales de Construcción, 64(313), e008. doi:10.3989/mc.2014.00513Yang, W., Dong, Q., Liu, S., Xie, H., Liu, L., & Li, J. (2012). Recycling and Disposal Methods for Polyurethane Foam Wastes. Procedia Environmental Sciences, 16, 167-175. doi:10.1016/j.proenv.2012.10.023Gama, N., Silva, R., Carvalho, A. P. O., Ferreira, A., & Barros-Timmons, A. (2017). Sound absorption properties of polyurethane foams derived from crude glycerol and liquefied coffee grounds polyol. Polymer Testing, 62, 13-22. doi:10.1016/j.polymertesting.2017.05.042Rey, R. del, Alba, J., Arenas, J. P., & Sanchis, V. J. (2012). An empirical modelling of porous sound absorbing materials made of recycled foam. Applied Acoustics, 73(6-7), 604-609. doi:10.1016/j.apacoust.2011.12.009Chen, S., & Jiang, Y. (2016). The acoustic property study of polyurethane foam with addition of bamboo leaves particles. Polymer Composites, 39(4), 1370-1381. doi:10.1002/pc.24078Delany, M. E., & Bazley, E. N. (1970). Acoustical properties of fibrous absorbent materials. Applied Acoustics, 3(2), 105-116. doi:10.1016/0003-682x(70)90031-9Johnson, D. L., Koplik, J., & Dashen, R. (1987). Theory of dynamic permeability and tortuosity in fluid-saturated porous media. Journal of Fluid Mechanics, 176(-1), 379. doi:10.1017/s0022112087000727Allard, J., & Champoux, Y. (1992). New empirical equations for sound propagation in rigid frame fibrous materials. The Journal of the Acoustical Society of America, 91(6), 3346-3353. doi:10.1121/1.402824Voronina, N. (1994). Acoustic properties of fibrous materials. Applied Acoustics, 42(2), 165-174. doi:10.1016/0003-682x(94)90005-1Umnova, O., Attenborough, K., Shin, H.-C., & Cummings, A. (2005). Deduction of tortuosity and porosity from acoustic reflection and transmission measurements on thick samples of rigid-porous materials. Applied Acoustics, 66(6), 607-624. doi:10.1016/j.apacoust.2004.02.005Zhang, C., Li, J., Hu, Z., Zhu, F., & Huang, Y. (2012). Correlation between the acoustic and porous cell morphology of polyurethane foam: Effect of interconnected porosity. Materials & Design, 41, 319-325. doi:10.1016/j.matdes.2012.04.031Chevillotte, F. (2012). Controlling sound absorption by an upstream resistive layer. Applied Acoustics, 73(1), 56-60. doi:10.1016/j.apacoust.2011.07.005Lou, C.-W., Huang, S.-Y., Huang, C.-H., Pan, Y.-J., Yan, R., Hsieh, C.-T., & Lin, J.-H. (2015). Effects of structure design on resilience and acoustic absorption properties of porous flexible-foam based perforated composites. Fibers and Polymers, 16(12), 2652-2662. doi:10.1007/s12221-015-5164-6Lin, J.-H., Chuang, Y.-C., Li, T.-T., Huang, C.-H., Huang, C.-L., Chen, Y.-S., & Lou, C.-W. (2016). Effects of Perforation on Rigid PU Foam Plates: Acoustic and Mechanical Properties. Materials, 9(12), 1000. doi:10.3390/ma9121000Xia, X., Zhang, Z., Zhao, W., Li, C., Ding, J., Liu, C., & Liu, Y. (2017). Acoustic properties of closed-cell aluminum foams with different macrostructures. Journal of Materials Science & Technology, 33(11), 1227-1234. doi:10.1016/j.jmst.2017.07.012ATALLA, N., PANNETON, R., SGARD, F. C., & OLNY, X. (2001). ACOUSTIC ABSORPTION OF MACRO-PERFORATED POROUS MATERIALS. Journal of Sound and Vibration, 243(4), 659-678. doi:10.1006/jsvi.2000.3435Olny, X., & Boutin, C. (2003). Acoustic wave propagation in double porosity media. The Journal of the Acoustical Society of America, 114(1), 73-89. doi:10.1121/1.1534607Sgard, F. C., Olny, X., Atalla, N., & Castel, F. (2005). On the use of perforations to improve the sound absorption of porous materials. Applied Acoustics, 66(6), 625-651. doi:10.1016/j.apacoust.2004.09.008Carbajo, J., Prieto, A., Ramis, J., & Río-Martín, L. (2019). A non-parametric fluid-equivalent approach for the acoustic characterization of rigid porous materials. Applied Mathematical Modelling, 76, 330-347. doi:10.1016/j.apm.2019.05.046Ekici, B., Kentli, A., & Küçük, H. (2012). Improving Sound Absorption Property of Polyurethane Foams by Adding Tea-Leaf Fibers. Archives of Acoustics, 37(4), 515-520. doi:10.2478/v10168-012-0052-1Segura Alcaraz, M. P., Bonet-Aracil, M., Segura Alcaraz, J. G., & Montava Seguí, I. (2017). Sound absorption of textile material using a microfibres resistive layer. IOP Conference Series: Materials Science and Engineering, 254, 072022. doi:10.1088/1757-899x/254/7/072022Pieren, R. (2012). Sound absorption modeling of thin woven fabrics backed by an air cavity. Textile Research Journal, 82(9), 864-874. doi:10.1177/0040517511429604Romero-García, V., Theocharis, G., Richoux, O., & Pagneux, V. (2016). Use of complex frequency plane to design broadband and sub-wavelength absorbers. The Journal of the Acoustical Society of America, 139(6), 3395-3403. doi:10.1121/1.4950708Ingard, K. U., & Dear, T. A. (1985). Measurement of acoustic flow resistance. Journal of Sound and Vibration, 103(4), 567-572. doi:10.1016/s0022-460x(85)80024-9Jayabal, S., & Natarajan, U. (2011). Drilling analysis of coir-fibre-reinforced polyester composites. Bulletin of Materials Science, 34(7), 1563-1567. doi:10.1007/s12034-011-0359-yDel Rey, R., Alba, J., Blanes, M., & Marco, B. (2013). Absorción acústica de cortinas textiles en función del vuelo. Materiales de Construcción, 63(312), 569-580. doi:10.3989/mc.2013.0551

Flexible Hybrid Electrodes for Continuous Measurement of the Local Temperature in Long-Term Wounds

[EN] Long-term wounds need a continuous assessment of different biophysical parameters for their treatment, and there is a lack of affordable biocompatible devices capable of obtaining that uninterrupted flow of data. A portable prototype that allows caregivers to know the local temperature behavior of a long-term wound over time and compare it with different reference zones has been developed. Alternative flexible substrates, screen-printing techniques, polymeric inks, and an embedded system have been tested to achieve potential indicators of the status and evolution of chronic wounds. The final system is formed by temperature sensors attached to a flexible and stretchable medical-grade substrate, where silver conductive tracks have been printed as interconnections with the data-acquisition unit. In addition, a specific datalogger has been developed for this system. The whole set will enable health personnel to acquire the temperature of the wound and its surroundings in order to make decisions regarding the state and evolution of the wound.This research was supported by the Spanish Government/FEDER funds (RTI2018-100910B-C43) (MINECO/FEDER). The work presented also was funded by the Conselleria d'Economia Sostenible, Sectors Productius i Treball, through IVACE (Instituto Valenciano de Competitividad Empresarial). HYBRID II Project-Application No.: IMAMCI/2021/1.Rodes-Carbonell, AM.; Torregrosa-Valls, J.; Guill Ibáñez, A.; Tormos Ferrando, Á.; Juan Blanco, MA.; Cebrián Ferriols, AJ. (2021). Flexible Hybrid Electrodes for Continuous Measurement of the Local Temperature in Long-Term Wounds. Sensors. 21(8):1-24. https://doi.org/10.3390/s21082741S12421

Experimental assessment of ignition characteristics of lubricating oil sprays related to low-speed pre-ignition (LSPI)

This is the author's version of a work that was accepted for publication in International Journal of Engine Research. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published as https://doi.org/10.1177/14680874211013268[EN] Low-speed pre-ignition (LSPI) remains one of the challenges of Direct Injection (DI) Spark Ignition (SI) engines due to its potential to induce a heavy knock. Several mechanisms have been identified in the literature as plausible causes for LSPI. The physical and chemical properties of lubricant oils play a role on some of these causes. The present work aims at getting an independent procedure to determine the proneness of lubricant oils to ignite. To this end, the ignition delay (ID) of different oil formulations is experimentally determined in a constant-pressure flow facility through two different optical techniques: Schlieren and OH* chemiluminescence imaging. The investigation explores the effect of base-stock formulation, oil specification quality level, different additive types content, aging, and oxidation on oil reactivity for several thermodynamic conditions. Differences in ignition delay were found among base stocks, correlating with the American Petroleum Institute (API) group classification. However, no significant differences were found among additive packages previously reported to yield different LSPI occurrences. Hence, differences in reactivity among lubricating oil formulations are not the determining factor explaining their different LSPI occurrences in an engine. Similarly, specific lubricant additive content, aging, and oxidation do not importantly modify the measured ignition delay.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: Part of the experimental hardware used in this work was purchased through funds obtained from IDIFEDER/2018/037 ``Diagnostico optico a alta velocidad para el estudio de procesos termo-fluidodinamicos en sistemas de inyeccion.''Tormos, B.; García-Oliver, JM.; Carreres, M.; Moreno-Montagud, C.; Domínguez, B.; Cárdenas, MD.; Oliva, F. (2022). Experimental assessment of ignition characteristics of lubricating oil sprays related to low-speed pre-ignition (LSPI). International Journal of Engine Research. 23(8):1327-1338. https://doi.org/10.1177/146808742110132681327133823

Monitoring and Prognosis System Based on the ICF for People with Traumatic Brain Injury

The objective of this research is to provide a standardized platform to monitor and predict indicators of people with traumatic brain injury using the International Classification of Functioning, Disability and Health, and analyze its potential benefits for people with disabilities, health centers and administrations. We developed a platform that allows automatic standardization and automatic graphical representations of indicators of the status of individuals and populations. We used data from 730 people with acquired brain injury performing periodic comprehensive evaluations in the years 2006-2013. Health professionals noted that the use of color-coded graphical representation is useful for quickly diagnose failures, limitations or restrictions in rehabilitation. The prognosis System achieves 41% of accuracy and sensitivity in the prediction of emotional functions, and 48% of accuracy and sensitivity in the prediction of executive functions. This monitoring and prognosis system has the potential to: (1) save costs and time, (2) provide more information to make decisions, (3) promote interoperability, (4) facilitate joint decision-making, and (5) improve policies of socioeconomic evaluation of the burden of disease. Professionals found the monitoring system useful because it generates a more comprehensive understanding of health oriented to the profile of the patients, instead of their diseases and injuries