scholarly journals Comparison of Threshold and Tolerance Nociceptive Withdrawal Reflexes in Horses

Animals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3380
Author(s):  
Selina Mühlemann ◽  
Massimo Leandri ◽  
Åse Ingvild Risberg ◽  
Claudia Spadavecchia
Keyword(s):  
Classical Model ◽  
High Amplitude ◽  
Reflex Activity ◽  
Median Latency ◽  
Behavioral Reactions ◽  
Stimulation Intensity ◽  
Withdrawal Reflex ◽  
Single Burst ◽  
Withdrawal Reflexes ◽  
The Individual

The nociceptive withdrawal reflex (NWR) is used to investigate nociception in horses. The NWR threshold is a classical model endpoint. The aims of this study were to determine NWR tolerance and to compare threshold and tolerance reflexes in horses. In 12 horses, the NWR was evoked through electrical stimulation of the digital nerve and recorded via electromyography from the deltoid. Behavioral reactions were scored from 0 to 5 (tolerance). First, the individual NWR threshold was defined, then stimulation intensity was increased to tolerance. The median NWR threshold was 7.0 mA, whereas NWR tolerance was 10.7 mA. Upon visual inspection of the records, two main reflex components R1 (median latency 44 ms) and R2 (median latency 81 ms) were identified at threshold. Increasing stimulation intensity to tolerance led to a significant increase in the amplitude and duration of R1 and R2, whereas their latency decreased. At tolerance, a single burst of early, high-amplitude reflex activity, with a median latency of 39 ms, was detected in 15 out of 23 stimulations (65%). The results of this study suggest that (1) it is feasible to determine NWR tolerance in horses and (2) high-intensity stimuli initiate ultrafast bursts of reflex activity, which is well known in practice and has now been quantified using the NWR model.

COMPLEXITIES OF PARENTAL UNDERSTANDING OF PHENYLKETONURIA

PEDIATRICS ◽  
1971 ◽  
Vol 48 (2) ◽  
pp. 216-224
Author(s):  
Maarten S. Sibinga ◽  
C. Jack Friedman
Keyword(s):  
Complete Understanding ◽  
Behavioral Reactions ◽  
Behavior Ratings ◽  
Parent Group ◽  
Iq Scores ◽  
Intellectual Status ◽  
Behavioral Score ◽  
The Individual

Parental understanding of phenylketonuria (PKU),investigated through a questionnaire, was evaluated as to completeness and with respect to distortion. Only 19% of 79 parents gave adequately correct answers. The education of the parents was not related to their understanding. Neither the intellectual status of the child with PKU nor its behavioral reactions were found to be related to the individual parent's understanding of the illness. However, the better the understanding of a marital pair, the more intelligent the child was (p < .05) and the higher its behavioral score tended to be (p < .10). Mothers with more complete understanding tended to have brighter sons. Half of the total parent group displayed considerable tendencies to distort in their answers to the questionnaires, education again being unrelated to distortion. Fathers who were more prone to distort had children with lower IQ scores (p < .05) and poorer behavior ratings (p < .10). We believe that effectiveness of communication with parents is, in part, related to the nature of parental thinking. This might be explored independenty, not where it pertains to the child's illness.

Progressive Adaptation of the Soleus H-Reflex With Daily Training at Walking Backward

2003 ◽  
Vol 89 (2) ◽  
pp. 648-656 ◽  
Author(s):  
Cyril Schneider ◽  
Charles Capaday
Keyword(s):  
Motor Program ◽  
High Amplitude ◽  
H Reflex ◽  
Adaptive Plasticity ◽  
Reflex Activity ◽  
Reflex Modulation ◽  
Surprising Result ◽  
Backward Walking ◽  
Rehabilitation Programs ◽  
Daily Training

When untrained subjects walk backward on a treadmill the amplitude of the soleus H-reflex in midswing is equal to or exceeds the value in stance. This is a surprising result because during the swing phase of backward walking the soleus is inactive and its antagonist, the tibialis anterior, is active. We suggested that the high amplitude of the soleus H-reflex in late swing reflects task uncertainties, such as estimating the moment of foot contact with the ground and losing balance. In support of this idea we show that when untrained subjects held on to handrails the unexpected high-amplitude H-reflex during midswing was no longer present. We therefore asked whether daily training at this task without grasping the handrails would adaptively modify the H-reflex modulation pattern. In this event, within 10 days of training for 15 min daily, the anticipatory reflex activity at the beginning of training was gradually abated as the subjects reported gaining confidence at the task. However, when adapted subjects were made to walk backward with their eyes shut, the anticipatory reflex activity in midswing returned immediately. The reflex changes as a result of training were not due to changes in the motor activity or kinematics; they are likely part of the motor program controlling backward walking. This adaptive phenomenon may prove to be a useful model for studying the neural mechanisms of motor learning and adaptive plasticity in humans and may be relevant to rehabilitation programs for neurological patients.

scholarly journals Effects of Cultured Adrenal Chromaffin Cell Implants on Hindlimb Reflexes of the6-OHDA Lesioned Rat

1994 ◽  
Vol 5 (2) ◽  
pp. 89-102 ◽  
Author(s):  
Bruce E. Pulford ◽  
Andrea R. Mihajlov ◽  
Howard O. Nornes ◽  
L. Ray Whalen
Keyword(s):  
Spinal Cord ◽  
Glyoxylic Acid ◽  
Reflex Activity ◽  
Emg Activity ◽  
Lumbar Region ◽  
Adrenal Chromaffin Cell ◽  
Electrophysiological Testing ◽  
Withdrawal Reflexes ◽  
6 Hydroxydopamine ◽  
Adrenal Chromaffin

The effects of implantation of cultured adrenal medullary cells on the recovery of neurotransmitter specific reflex activity were studied in the rat spinal cord using electrophysiological testing methods. Cell suspensions of cultured neonatal adrenal medullary chromaffin (AM) cells (which produce catecholamines), or Schwann (Sc) cells (controls) were implanted into the lumbar region of the spinal cord 2 weeks after catecholamine (CA) denervation by intracisternal injection of 6-hydroxydopamine (6-OHDA). All cells were taken from 7 day neonates and cultured for 10 days in the presence of nerve growth factor (NGF). Three months after implantation, the extent of implant-associated recovery of reflex activity was determined by measuring electromyogram (EMG) activity and force associated with the long latency component of the hindlimb withdrawal reflex (which is CA modulated). After the electrophysiological testing, rats were anesthetized, and the spinal cords were rapidly removed and frozen. Spinal cords were sectioned longitudinally, and implanted cells were visualized using glyoxylic acid techniques. Labelled sections were examined to determine cell survival. Results indicate that 1) chromaffin cells survive for 3 months in the segments of the cord into which they have been implanted and 2) rats implanted with AM cells have significantly more forceful withdrawal reflexes than those that received Sc cells or received no implant after lesioning.

Understanding the individual's reactions to the organizational change: a multidimensional approach

2020 ◽  
Vol 33 (5) ◽  
pp. 667-681
Author(s):  
Renata Borges ◽  
Camila Amaro Quintas
Keyword(s):  
Organizational Change ◽  
Evaluation System ◽  
Organizational Readiness ◽  
Equation Modeling ◽  
Multidimensional Approach ◽  
Behavioral Reactions ◽  
Content Type ◽  
Group Pressure ◽  
The Individual ◽  
Reactions To Change

PurposeThe objective of this research is to analyze in a multidimensional perspective the individual responses to organizational change, specifically about the implementation of a new performance evaluation system, investigating some antecedents of the individual reactions to change.Design/methodology/approachCompanies from the education industry were surveyed, and standardized questionnaires were applied. We obtained a sample size of 386 valid responses. The structural equation modeling (SEM) was employed to assess the measurement model and test the hypotheses.FindingsThe results indicate positive reactions to the organizational change, without ambivalent responses. Employees' cognitive and behavioral reactions are influenced by the individuals' anticipation and past similar organizational change and do not depend on the perceived threat to social work life. The influence of group pressure and organizational readiness on cognitive and behavioral reactions differs in the direction that group pressure affects behaviors but not thoughts, and organizational readiness affects thoughts but not behaviors.Research limitations/implicationsLimitations include the inadequate measures of individuals' emotional reaction, preventing this dimension from being tested.Originality/valueThis research provides theoretical contributions as the literature on organizational change lacks a multidimensional view on individuals' reactions to change. The main contribution of this study is to investigate how each of the individual and organizational antecedents of the employees' responses to the change influences the cognitive and behavioral reactions towards the change employing a multidimensional approach.

scholarly journals Geometric-acoustics analysis of singly scattered, nonlinearly evolving waves by circular cylinders

2020 ◽  
Author(s):  
Michael Muhlestein ◽  
Carl Hart
Keyword(s):  
Acoustic Waves ◽  
Nonlinear Distortion ◽  
Nonlinear Evolution ◽  
Scattered Wave ◽  
High Amplitude ◽  
Circular Cylinders ◽  
Ray Theory ◽  
Theoretical Predictions ◽  
Geometric Acoustics ◽  
The Individual

Geometric acoustics, or acoustic ray theory, is used to analyze the scattering of high-amplitude acoustic waves incident upon rigid circular cylinders. Theoretical predictions of the nonlinear evolution of the scattered wave field are provided, as well as measures of the importance of accounting for nonlinearity. An analysis of scattering by many cylinders is also provided, though the effects of multiple scattering are not considered. Provided the characteristic nonlinear distortion length is much larger than a cylinder radius, the nonlinear evolution of the incident wave is shown to be of much greater importance to the overall evolution than the nonlinear evolution of the individual scattered waves.

scholarly journals The nociceptive withdrawal reflex does not adapt to joint position change and short-term motor practice

F1000Research ◽  
2013 ◽  
Vol 2 ◽  
pp. 158 ◽  
Author(s):  
Nathan Eckert ◽  
Zachary A Riley
Keyword(s):  
Upper Limb ◽  
Reflex Response ◽  
Short Term ◽  
General Direction ◽  
Nociceptive Withdrawal Reflex ◽  
Withdrawal Reflex ◽  
Motor Practice ◽  
Withdrawal Reflexes ◽  
Sensory Encoding ◽  
Withdrawal Response

The nociceptive withdrawal reflex is a protective mechanism to mediate interactions within a potentially dangerous environment. The reflex is formed by action-based sensory encoding during the early post-natal developmental period, and it is unknown if the protective motor function of the nociceptive withdrawal reflex in the human upper-limb is adaptable based on the configuration of the arm or if it can be modified by short-term practice of a similar or opposing motor action. In the present study, nociceptive withdrawal reflexes were evoked by a brief train of electrical stimuli applied to digit II, 1) in five different static arm positions and, 2) before and after motor practice that was opposite (EXT) or similar (FLEX) to the stereotyped withdrawal response, in 10 individuals. Withdrawal responses were quantified by the electromyography (EMG) reflex response in several upper limb muscles, and by the forces and moments recorded at the wrist. EMG onset latencies and response amplitudes were not significantly different across the arm positions or between the EXT and FLEX practice conditions, and the general direction of the withdrawal response was similar across arm positions. In addition, the force vectors were not different after practice in either the practice condition or between EXT and FLEX conditions. We conclude the withdrawal response is insensitive to changes in elbow or shoulder joint angles as well as remaining resistant to short-term adaptations from the practice of motor actions, resulting in a generalized limb withdrawal in each case. It is further hypothesized that the multisensory feedback is weighted differently in each arm position, but integrated to achieve a similar withdrawal response to safeguard against erroneous motor responses that could cause further harm. The results remain consistent with the concept that nociceptive withdrawal reflexes are shaped through long-term and not short-term action based sensory encoding.

Helicopter Swashplate Design and Analysis Using Semi Compliant Mechanism

2018 ◽  
Author(s):  
Ayse Tekes ◽  
Adeel Khalid ◽  
Niko Giannakakos ◽  
Alexander Bryant
Keyword(s):  
Compliant Mechanism ◽  
High Amplitude ◽  
Plate Motion ◽  
Swash Plate ◽  
Directional Control ◽  
Single Piece ◽  
Model Helicopter ◽  
The Individual ◽  
And Control ◽  
The Mathematical Model

The swashplate of a model helicopter consists of stationary and rotating plates separated by ball bearings. This mechanism enables the swashplate to tilt in all directions and move vertically as one unit. The lower stationary plate is mounted on the main rotor mast and connected to the cyclic and collective controls by a series of pushrods. There are similar pushrods known as pitch links connected to the upper rotating plate. These pitch links are connected to the pitch horns and control the pitch of individual blades. In this study, the pitch links of the model helicopter are replaced by a semi compliant mechanism. This mechanism is directly connected to the pitch horns to control the pitch of the individual blades. The actuation of the bars can be achieved by using high torque stepper or servo motors. These precise low and high amplitude outputs are specifically required for the cyclic and collective controls of the helicopter swashplate. The compliant swashplate mechanism can be fabricated as a single piece using an injection molding technique or by 3D printing. The mechanism is modeled by two similar vector loops in two different planes. The mathematical model of the plate motion and the forces on the mechanism links are developed and simulated using MATLAB and Simulink, and initial results are discussed in this paper. This mechanism would be applied to the helicopter directional control where the plate in the pitch-roll mechanism would serve as the swash plate of the helicopter.

Wschodnie „laboratorium” kontroli konstytucyjności. Recenzja publikacji: Constitutional Courts in Post-Soviet States, red. Jacek Zaleśny

2021 ◽  
Vol 1(162) ◽  
pp. 201-209
Author(s):  
Artur Olechno
Keyword(s):  
Classical Model ◽  
Review Article ◽  
Constitutional Courts ◽  
Hans Kelsen ◽  
The Individual ◽  
Political Scene ◽  
Detailed Presentation

The presented review article is devoted to the monograph Constitutional Courts in Post-Soviet States, edited by Jacek Zaleśny. The researcher points to the originality and topicality of the undertaken subject, correctly selected team of authors, detailed presentation of stages of formation of the model of constitutionality control in selected post-Soviet states, demonstrating their position as distinct from the classical model of Hans Kelsen. We are dealing with a new, eastern “laboratory” of constitutionality control. Its experiments should be followed by both the external legislator and the individual participants of the post-Soviet political scene.

scholarly journals Europe matters … upon closer investigation: a novel approach for analysing individual-level determinants of vote choice across first- and second-order elections, applied to 2019 Italy

2020 ◽  
Vol 50 (3) ◽  
pp. 334-349
Author(s):  
Davide Angelucci ◽  
Lorenzo De Sio ◽  
Aldo Paparo
Keyword(s):  
Classical Model ◽  
Second Order ◽  
Vote Choice ◽  
Order Effects ◽  
Party Change ◽  
European Elections ◽  
Individual Level ◽  
Novel Approach ◽  
Second Order Effects ◽  
The Individual

AbstractAre European Parliament (EP) elections still second-order? In this article, we test the classical model at the individual level in contrast to an alternative ‘Europe matters’ model, by investigating the relative importance of domestic vs. European Union (EU)-related issues among voter-level determinants of aggregate second-order effects, that is, individual party change. We do so by relying on an original, CAWI pre-electoral survey featuring a distinctively large (30) number of both domestic and EU-related, positional and valence issues, with issue attitudes measured according to the innovative ICCP scheme (De Sio and Lachat 2020) which includes issue positions, issue priorities and respondents' assessment of party credibility on both positional and valence goals. Leveraging the concept of ‘normal vote’, we estimate multivariate models of electoral defections from normal voting separately for general and European elections, based on issue party credibility. This allows us to assess: (a) the distinctiveness of the two electoral arenas in terms of issue content; and (b) the relative impact of EU-related and domestic issues on defections of Italian voters. Our findings show that although second-order effects are still relevant in accounting for results in EP elections, vote choice in the latter is also partly due to specific effects of certain policy issues, including some related to the European dimension. This indicates that EP elections have their own political content, for which Europe matters even after controlling for the importance that EU-related issues have acquired in national elections.

Cerebellar Responses Evoked by Nociceptive Leg Withdrawal Reflex as Revealed by Event-Related fMRI

2003 ◽  
Vol 90 (3) ◽  
pp. 1877-1886 ◽  
Author(s):  
A. Dimitrova ◽  
F. P. Kolb ◽  
H.-G. Elles ◽  
M. Maschke ◽  
M. Forsting ◽  
...  
Keyword(s):  
Mossy Fiber ◽  
Anterior Lobe ◽  
Functional Brain Imaging ◽  
Emg Activity ◽  
Medial Malleolus ◽  
Posterior Lobe ◽  
Withdrawal Reflex ◽  
Lateral Posterior ◽  
Crus I ◽  
Withdrawal Reflexes

The aim of the present study was to examine nociceptive leg withdrawal reflex–related areas in the human cerebellum using event-related functional brain imaging (fMRI). Knowledge about cerebellar areas involved in unconditioned limb withdrawal reflex control has some relevance in understanding data of limb withdrawal reflex conditioning studies. Sixteen healthy adult subjects participated. Nociceptive leg withdrawal reflexes were evoked by electrical stimulation of the left tibial nerve behind the medial malleolus. An event-related fMRI paradigm was applied with a total of 30 stimuli being delivered pseudorandomly during 500 consecutive MR scans. Surface electromyographic (EMG) recordings were performed from the left anterior tibial muscle. Only trials with significant reflex EMG activity were used as active events in fMRI statistical analysis. The specified contrasts compared the active event condition with rest. Leg withdrawal reflex–related areas were located within the vermis, paravermis, and lateral posterior cerebellar hemispheres bilaterally. Vermal and paravermal areas in lobules III/IV in the anterior lobe and in lobule VIII in the posterior lobe agree with the cerebellar representation of climbing and mossy fiber hindlimb afferents and voluntary leg movements. They are likely related to efferent modulation of the leg withdrawal reflex and/or sensory processing of afferent inputs from the reflex and/or the noxious stimulus. Additional activation within vermal lobule VI and hemispheral lobules VI/Crus I may be related to other pain-related processes (e.g., facial grimacing, fear, and startlelike reactions).

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