The capability of reprogramming movement responses following changes in the visual goal has been studied through the double-step paradigm. These studies have shown that: (a) continuous internal feedback-loops correct unconsciously the dynamic errors throughout the movement; (b) proprioceptive information and/or the efference copy have a privileged status among central processes, insuring on-line regulation of the initial motor commands; and (c) generation of the motor program starts after target presentation, and is continuously updated in the direction of the current internal representation of the target, at least until the onset of hand movement. This main corrective process of the initial program appears to be basically independent of visual reafference from the moving hand. However, the agreement with the possibility of a visuomotor loop, based on the comparison of the new updated representation of the target position and on the information from the moving hand, has not determined whether the correcting process is proprioceptive feedback dependent, or whether internal feedback-loops (efferent copies) are responsible for quick corrections of unfolding motor responses. To answer this question, the present experiment investigated the pointing behavior of a deafferented subject, using a double-step paradigm under various conditions of visual feedback and movement initiation. Overall, the present study (a) clearly showed the capacity of the motor system to modify and correct erroneous trajectories on the mere basis of internal feedback-loops and (b) emphasized the crucial role played by the target jump/arm triggering delay and the importance of the eye efferent copy for providing information about the spatial goal of the movement.
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http://dx.doi.org/10.1007/s002210050697 | DOI Listing |
Proc Natl Acad Sci U S A
December 2024
Department of Cell Physiology and Metabolism, Faculty of Medicine, University of Geneva, 1211 Geneva, Switzerland.
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Aier Eye Hospital, Jinan University, Guangzhou, 510071, China.
In the realms of bioengineering and biopharmaceuticals, there exists a critical demand for advanced genetic tools that can interact with specific cell signaling pathways to accurately identify and target various cell types. This research introduces the innovative CRISPR-ADAReader system, which enables precise manipulation of cell activity through sensing target RNA. Featuring both positive and negative feedback loops, the system allows for tailored regulation across different cell types in response to various internal signals, showcasing exceptional programmability, specificity, and sensitivity.
View Article and Find Full Text PDFBiomedicines
November 2024
Department of Anesthesiology and Pain Medicine, Hubei Key Laboratory of Geriatric Anesthesia and Perioperative Brain Health, Wuhan Clinical Research Center for Geriatric Anesthesia, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
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View Article and Find Full Text PDFNurs Child Young People
November 2024
College of Nursing, Midwifery and Healthcare, University of West London, London, England.
Homeostasis can be described as the dynamic process within an organism designed to maintain a relatively constant internal environment that is conducive to the optimal functioning of cells, enzymes and organs. To regulate physiological variables, homeostasis relies on mechanisms called negative and positive feedback loops. However, certain factors can disrupt homeostatic processes, leading to dysregulation and disease.
View Article and Find Full Text PDFOpen Res Eur
November 2024
Faculty of Technology, Policy and Management, Delft University of Technology, Delft, The Netherlands.
European research funding organizations (RFOs) are increasingly experimenting with public engagement in their funding activities. This case study draws attention to the challenges they face in preparing, implementing, and evaluating ethical public engagement in the context of setting funding priorities, formulating calls for proposals, and evaluating project proposals. We discuss challenges related to seven themes: (1) recruiting participants; (2) commitments and expectations; (3) meaningful dialogue and equal engagement; (4) accommodating vulnerability; (5) funding call formulations; (6) lack of expertise in engagement ethics; and (7) uncertainty, resource constraints, and external factors.
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