scholarly journals Sharpness Recognition Based on Synergy between Bio-inspired Nociceptors and Tactile Mechanoreceptors 

2021 ◽  
Author(s):  
Adel Parvizi-Fard ◽  
Nima Salimi-Nezhad ◽  
Mahmood Amiri ◽  
Egidio Falotico ◽  
Cecilia Laschi
Keyword(s):  
Receptive Fields ◽  
Tactile Sensor ◽  
Feedback Mechanism ◽  
Tactile Feedback ◽  
Temporal Coding ◽  
Control Mechanisms ◽  
Sensory Afferents ◽  
Tactile Stimuli ◽  
Tactile System ◽  
The Impact

Abstract Touch and pain sensations are complementary aspects of daily life that convey crucial information about the environment while also providing protection to our body. Technological advancements in prosthesis design and control mechanisms assist amputees to regain lost function but often they have no meaningful tactile feedback or perception. In the present study, we propose a bio-inspired tactile system with a population of 23 digital afferents: 12 RA-I, 6 SA-I, and 5 nociceptors. Indeed, the functional concept of the nociceptor is implemented on the FPGA for the first time. One of the main features of biological tactile afferents is that their distal axon branches in the skin, creating complex receptive fields. Given these physiological observations, the bio-inspired afferents are randomly connected to the several neighboring mechanoreceptors with different weights to form their own receptive field. To test the performance of the proposed neuromorphic chip in sharpness detection, a robotic system with three-degree of freedom equipped with the tactile sensor indents the 3D-printed objects. Spike responses of the biomimetic afferents are then collected for analysis by rate and temporal coding algorithms. In this way, the impact of the innervation mechanism and collaboration of afferents and nociceptors on sharpness recognition are investigated. Our findings suggest that the synergy between sensory afferents and nociceptors conveys more information about tactile stimuli which in turn leads to the robustness of the proposed neuromorphic system against damage to the taxels or afferents. Moreover, it is illustrated that spiking activity of the biomimetic nociceptors is amplified as the sharpness increases which can be considered as a feedback mechanism for prosthesis protection. This neuromorphic approach advances the development of prosthesis to include the sensory feedback and to distinguish innocuous (non-painful) and noxious (painful) stimuli.

scholarly journals Sharpness recognition based on synergy between bio-inspired nociceptors and tactile mechanoreceptors

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Adel Parvizi-Fard ◽  
Nima Salimi-Nezhad ◽  
Mahmood Amiri ◽  
Egidio Falotico ◽  
Cecilia Laschi
Keyword(s):  
Receptive Fields ◽  
Tactile Sensor ◽  
Feedback Mechanism ◽  
Tactile Feedback ◽  
Temporal Coding ◽  
Control Mechanisms ◽  
Sensory Afferents ◽  
Tactile Stimuli ◽  
Tactile System ◽  
The Impact

AbstractTouch and pain sensations are complementary aspects of daily life that convey crucial information about the environment while also providing protection to our body. Technological advancements in prosthesis design and control mechanisms assist amputees to regain lost function but often they have no meaningful tactile feedback or perception. In the present study, we propose a bio-inspired tactile system with a population of 23 digital afferents: 12 RA-I, 6 SA-I, and 5 nociceptors. Indeed, the functional concept of the nociceptor is implemented on the FPGA for the first time. One of the main features of biological tactile afferents is that their distal axon branches in the skin, creating complex receptive fields. Given these physiological observations, the bio-inspired afferents are randomly connected to the several neighboring mechanoreceptors with different weights to form their own receptive field. To test the performance of the proposed neuromorphic chip in sharpness detection, a robotic system with three-degree of freedom equipped with the tactile sensor indents the 3D-printed objects. Spike responses of the biomimetic afferents are then collected for analysis by rate and temporal coding algorithms. In this way, the impact of the innervation mechanism and collaboration of afferents and nociceptors on sharpness recognition are investigated. Our findings suggest that the synergy between sensory afferents and nociceptors conveys more information about tactile stimuli which in turn leads to the robustness of the proposed neuromorphic system against damage to the taxels or afferents. Moreover, it is illustrated that spiking activity of the biomimetic nociceptors is amplified as the sharpness increases which can be considered as a feedback mechanism for prosthesis protection. This neuromorphic approach advances the development of prosthesis to include the sensory feedback and to distinguish innocuous (non-painful) and noxious (painful) stimuli.

scholarly journals Highly pixelated, untethered tactile interfaces for an on-skin telehaptic system

2021 ◽  
Author(s):  
Hanbit Jin ◽  
Yunjeong Kim ◽  
Wooseup Youm ◽  
Yulim Min ◽  
Chaehyun Lim ◽  
...  
Keyword(s):  
Dynamic Pressure ◽  
Tactile Sensor ◽  
Tactile Feedback ◽  
Tactile Sensors ◽  
Spatiotemporal Resolution ◽  
Vibrotactile Feedback ◽  
Tactile Stimuli ◽  
Tactile Communication ◽  
Tactile Interfaces ◽  
Short Time

Abstract For highly immersive telehaptic applications, skin-integrated, untethered, and highly pixelated transducer devices that can record and generate tactile stimuli are required. Here, we propose a skin-conformable tactile sensor and actuator array with high spatial resolution of 1.8 mm for realising untethered tactile communication on human skin. The tactile sensors are designed to exhibit ultra-flexibility and bimodal sensitivity to static and dynamic pressure. The actuators are miniaturised to sub-millimetre scale to provide sophisticated, high spatiotemporal resolution tactile feedback over a centimetre square area of the fingertip with the capacity to generate vibrotactile feedback under an external load of up to 529 kPa. Short time Fourier transform analysis showed that our telehaptic system can transmit various types of tactile stimuli, such as the shape of objects and letters, textures of fabrics, and vibration patterns with high fidelity.

scholarly journals 152. Applying A Difference-in-Difference Analysis to Assess Effect of Antimicrobial Stewardship Strategies on Changes in Antimicrobial Use

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S86-S86
Author(s):  
Ann F Chou ◽  
Yue Zhang ◽  
Makoto M Jones ◽  
Christopher J Graber ◽  
Matthew B Goetz ◽  
...  
Keyword(s):  
Antimicrobial Stewardship ◽  
Clinical Pharmacist ◽  
Antibiotic Use ◽  
Feedback Mechanism ◽  
Health Care Facilities ◽  
Antimicrobial Use ◽  
Time Points ◽  
The Difference ◽  
The Impact ◽  
Over Time

Abstract Background About 30–50% of inpatient antimicrobial therapy is sub-optimal. Health care facilities have utilized various antimicrobial stewardship (AS) strategies to optimize appropriate antimicrobial use, improve health outcomes, and promote patient safety. However, little evidence exists to assess relationships between AS strategies and antimicrobial use. This study examined the impact of changes in AS strategies on antimicrobial use over time. Methods This study used data from the Veterans Affairs (VA) Healthcare Analysis & Informatics Group (HAIG) AS survey, administered at 130 VA facilities in 2012 and 2015, and antimicrobial utilization from VA Corporate Data Warehouse. Four AS strategies were examined: having an AS team, feedback mechanism on antimicrobial use, infectious diseases (ID) attending physicians, and clinical pharmacist on wards. Change in AS strategies were computed by taking the difference in the presence of a given strategy in a facility between 2012–2015. The outcome was the difference between antimicrobial use per 1000 patient days in 2012–2013 and 2015–2016. Employing multiple regression analysis, changes in antimicrobial use was estimated as a function of changes in AS strategies, controlling for ID human resources in and organizational complexity. Results Of the 4 strategies, only change in availability of AS teams had an impact on antimicrobial use. Compared to facilities with no AS teams at both time points, antibiotic use decreased by 63.9 uses per 1000 patient days in facilities that did not have a AS team in 2012 but implemented one in 2015 (p=0.0183). Facilities that had an AS team at both time points decreased use by 62.2 per 1000 patient days (p=0.0324). Conclusion The findings showed that AS teams reduced inpatient antibiotic use over time. While changes in having feedback on antimicrobial use and clinical pharmacist on wards showed reduced antimicrobial use between 2012–2015, the differences were not statistically significant. These strategies may already be a part of a comprehensive AS program and employed by AS teams. In further development of stewardship programs within healthcare organizations, the association between AS teams and antibiotic use should inform program design and implementation. Disclosures All Authors: No reported disclosures

Board structure changes after accounting fraud: the case of Schneider Electric

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Benedicte Millet-Reyes ◽  
Nancy Uddin
Keyword(s):  
Corporate Governance ◽  
Internal Control ◽  
Multinational Corporation ◽  
Business Case ◽  
Annual Reports ◽  
Board Structure ◽  
Control Mechanisms ◽  
Accounting Fraud ◽  
Content Type ◽  
The Impact

Theoretical basis The impact of corporate governance on internal controls and quality of financial disclosures. Research methodology Analysis of a real financial fraud event for a non-US multinational corporation. The case relies on accessing and analyzing annual reports for the firm, both before and after the fraud. Additional information on industry governance characteristics are provided in the case itself so that students can compare the firm to the industry. Case overview/synopsis This business case is centered on the analysis of Schneider Electric, a French multinational corporation, which had to restate their financial statements in 2011 because of accounting fraud. Following this event, Schneider undertook major changes in their board structure to improve internal control mechanisms. This pedagogical business case familiarizes students with international differences in ownership and board structure and emphasizes potential corporate governance changes after financial statement fraud. Complexity academic level Managerial finance, corporate finance, international finance, auditing. This case is more appropriate for upper-level undergraduate and graduate courses.

scholarly journals Negative feedback in ants: crowding results in less trail pheromone deposition

2013 ◽  
Vol 10 (81) ◽  
pp. 20121009 ◽  
Author(s):  
Tomer J. Czaczkes ◽  
Christoph Grüter ◽  
Francis L. W. Ratnieks
Keyword(s):  
Negative Feedback ◽  
Trail Pheromone ◽  
Distribution Networks ◽  
Feedback Mechanism ◽  
Lasius Niger ◽  
Feedback Signal ◽  
Control Mechanisms ◽  
Negative Feedback Mechanism ◽  
Self Organized ◽  
Fold Reduction

Crowding in human transport networks reduces efficiency. Efficiency can be increased by appropriate control mechanisms, which are often imposed externally. Ant colonies also have distribution networks to feeding sites outside the nest and can experience crowding. However, ants do not have external controllers or leaders. Here, we report a self-organized negative feedback mechanism, based on local information, which downregulates the production of recruitment signals in crowded parts of a network by Lasius niger ants. We controlled crowding by manipulating trail width and the number of ants on a trail, and observed a 5.6-fold reduction in the number of ants depositing trail pheromone from least to most crowded conditions. We also simulated crowding by placing glass beads covered in nest-mate cuticular hydrocarbons on the trail. After 10 bead encounters over 20 cm, forager ants were 45 per cent less likely to deposit pheromone. The mechanism of negative feedback reported here is unusual in that it acts by downregulating the production of a positive feedback signal, rather than by direct inhibition or the production of an inhibitory signal.

scholarly journals Relationship Between Physiological Response Type (RA and SA) and Vibrissal Receptive Field of Neurons Within the Rat Trigeminal Ganglion

2006 ◽  
Vol 95 (5) ◽  
pp. 3129-3145 ◽  
Author(s):  
Steven C. Leiser ◽  
Karen A. Moxon
Keyword(s):  
Trigeminal Ganglion ◽  
Three Dimensional ◽  
Receptive Fields ◽  
Somatosensory System ◽  
Response Type ◽  
Physiological Level ◽  
Somatotopic Organization ◽  
Tactile Stimuli ◽  
Distinct Features ◽  
The Relationship

Cells within the trigeminal ganglion (Vg) encode all the information necessary for the rat to differentiate tactile stimuli, yet it is the least-studied component in the rodent trigeminal somatosensory system. For example, extensive anatomical and electrophysiological investigations have shown clear somatotopic organization in the higher levels of this system, including VPM thalamus and SI cortex, yet whether this conserved schemata exists in the Vg is unknown. Moreover although there is recent interest in recording from vibrissae-responsive cells in the Vg, it is surprising to note that the locations of these cells have not even been clearly demarcated. To address this, we recorded extracellularly from 350 sensory-responsive Vg neurons in 35 Long-Evans rats. First, we determined three-dimensional locations of these cells and found a finer detail of somatotopy than previously reported. Cells innervating dorsal facial features, even within the whisker region, were more dorsal than midline and ventral features. We also show more cells with caudal than rostral whisker receptive fields (RF), similar to that found in VPM and SI. Next, for each vibrissal cell we determined its response type classified as either rapidly (RA) or slowly (SA) adapting. We examined the relationship between vibrissal RF and response type and demonstrate similar proportions of RA and SA cells responding to any whisker. These results suggest that if RA and SA cells encode distinct features of stimuli, as previously suggested, then at the basic physiological level each whisker has similar abilities to encode for such features.

scholarly journals The impact of genetic background and sex on the phenotype of IL-23 induced murine arthritis

2021 ◽  
Author(s):  
Emma Haley ◽  
Mederbek Matmusaev ◽  
Imtiyaz N. Hossain ◽  
Sean Davin ◽  
Tammy M. Martin ◽  
...  
Keyword(s):  
Weight Loss ◽  
Genetic Background ◽  
Skin Inflammation ◽  
Control Mechanisms ◽  
Adult Mice ◽  
Severe Arthritis ◽  
Cytokine Levels ◽  
Clinical Arthritis ◽  
Organ Specific ◽  
The Impact

AbstractBackgroundOverexpression of IL-23 in adult mice by means of hydrodynamic tail vein injection of IL-23 minicircles has been reported to result in spondyloarthritis-like disease. The impact of genetic background and sex on the disease phenotype in this model has not been investigated.MethodsWe compared male B10.RIII mice with male C57BL/6 mice, and male with female B10.RIII mice after hydrodynamic injection of IL-23 enhanced episomal vector (EEV) at 8-12 weeks of age. We monitored clinical arthritis scores, paw swelling, and body weight. Animals were euthanized after two weeks and tissues were harvested for histology, flow cytometry and gene expression analysis. Serum cytokine levels were determined by ELISA.FindingsMale B10.RIII mice developed arthritis in the forepaws and feet within 6 days after IL-23 EEV injection; they also exhibited psoriasis-like skin disease, colitis, weight loss, and osteopenia. In contrast to previous reports, we did not observe spondylitis or uveitis. Male C57BL/6 mice injected with IL-23 EEV had serum IL-23 levels comparable with B10.RIII mice and developed skin inflammation, colitis, weight loss, and osteopenia but failed to develop arthritis. Female B10.RIII mice had more severe arthritis than male B10.RIII mice but did not lose weight.ConclusionsSystemic IL-23 overexpression results in spondyloarthritis-like disease in B10.RIII mice. The development of extra-articular manifestations but absence of arthritis in C57BL/6 mice suggests organ-specific genetic control mechanisms of IL-23 driven inflammation. Discrepancies regarding the phenotype of IL-23 induced disease in different labs and the sexual dimorphism observed in this study warrant further exploration.

scholarly journals TET2 mutations as a part of DNA dioxygenase deficiency in myelodysplastic syndromes

2021 ◽  
Author(s):  
Carmelo Gurnari ◽  
Simona Pagliuca ◽  
Yihong Guan ◽  
Vera Adema ◽  
Courtney E Hershberger ◽  
...  
Keyword(s):  
Myelodysplastic Syndromes ◽  
Prognostic Significance ◽  
Age Groups ◽  
Feedback Mechanism ◽  
Dna Demethylation ◽  
Compensatory Mechanisms ◽  
Poor Outcomes ◽  
Relationship Of ◽  
The Impact

Decrease in DNA dioxygease activity generated by TET2 gene family is crucial in myelodysplastic syndromes (MDS). The general down-regulation of 5-hydroxymethylcytosine (5-hmC) argues for a role of DNA demethylation in MDS beyond TET2 mutations, which albeit frequent, do not convey any prognostic significance. We investigated TETs expression to identify factors which can modulate the impact of mutations and thus 5-hmC levels on clinical phenotypes and prognosis of MDS patients. DNA/RNA-sequencing and 5-hmC data were collected from 1,665 patients with MDS and 91 controls. Irrespective of mutations, a significant fraction of MDS patients exhibited lower TET2 expression, while 5-hmC levels were not uniformly decreased. In searching for factors explaining compensatory mechanisms, we discovered that TET3 was up-regulated in MDS and inversely correlated with TET2 expression in wild-type cases. While TET2 was reduced across all age-groups, TET3 levels were increased in a likely feedback mechanism induced by TET2 dysfunction. This inverse relationship of TET2 and TET3 expression also corresponded to the expression of L-2-hydroxyglutarate dehydrogenase, involved in agonist/antagonist substrate metabolism. Importantly, elevated TET3 levels influenced the clinical phenotype of TET2-deficiency whereby the lack of compensation by TET3 (low TET3 expression) was associated with poor outcomes of TET2 mutant carriers.

scholarly journals Neural network models of the tactile system develop first-order units with spatially complex receptive fields

2017 ◽  
Author(s):  
Charlie W. Zhao ◽  
Mark J. Daley ◽  
J. Andrew Pruszynski
Keyword(s):  
Neural Network ◽  
Network Performance ◽  
Receptive Fields ◽  
Network Models ◽  
Network Architectures ◽  
Learning Tools ◽  
Neural Network Models ◽  
First Order ◽  
Wide Range ◽  
Tactile System

AbstractFirst-order tactile neurons have spatially complex receptive fields. Here we use machine learning tools to show that such complexity arises for a wide range of training sets and network architectures, and benefits network performance, especially on more difficult tasks and in the presence of noise. Our work suggests that spatially complex receptive fields are normatively good given the biological constraints of the tactile periphery.

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