scholarly journals Neurophysiological Factors Affecting Muscle Innervation Zone Estimation Using Surface EMG: A Simulation Study

Biosensors ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 356
Author(s):  
Chengjun Huang ◽  
Maoqi Chen ◽  
Xiaoyan Li ◽  
Yingchun Zhang ◽  
Sheng Li ◽  
...  
Keyword(s):  
Electrode Array ◽  
Surface Emg ◽  
Emg Activity ◽  
Wave Surface ◽  
Complete Synchronization ◽  
M Wave ◽  
Factors Affecting ◽  
Medium Level ◽  
Muscle Innervation ◽  
The One

Surface electromyography (EMG) recorded by a linear or 2-dimensional electrode array can be used to estimate the location of muscle innervation zones (IZ). There are various neurophysiological factors that may influence surface EMG and thus potentially compromise muscle IZ estimation. The objective of this study was to evaluate how surface-EMG-based IZ estimation might be affected by different factors, including varying degrees of motor unit (MU) synchronization in the case of single or double IZs. The study was performed by implementing a model simulating surface EMG activity. Three different MU synchronization conditions were simulated, namely no synchronization, medium level synchronization, and complete synchronization analog to M wave. Surface EMG signals recorded by a 2-dimensional electrode array were simulated from a muscle with single and double IZs, respectively. For each situation, the IZ was estimated from surface EMG and compared with the one used in the model for performance evaluation. For the muscle with only one IZ, the estimated IZ location from surface EMG was consistent with the one used in the model for all the three MU synchronization conditions. For the muscle with double IZs, at least one IZ was appropriately estimated from interference surface EMG when there was no MU synchronization. However, the estimated IZ was different from either of the two IZ locations used in the model for the other two MU synchronization conditions. For muscles with a single IZ, MU synchronization has little effect on IZ estimation from electrode array surface EMG. However, caution is required for multiple IZ muscles since MU synchronization might lead to false IZ estimation.

Unfilled Training Positions in Germany – Regional and Establishment-Specific Determinants

2019 ◽  
Vol 239 (4) ◽  
pp. 661-701 ◽  
Author(s):  
Sandra Dummert ◽  
Ute Leber ◽  
Barbara Schwengler
Keyword(s):  
Related Factors ◽  
Factors Affecting ◽  
External Conditions ◽  
Western Germany ◽  
Enterprise Level ◽  
Specific Factors ◽  
Regional Factors ◽  
The One ◽  
Training Position ◽  
Quantitative Importance

AbstractThe current situation in the German apprenticeship market is characterized by two contradictory developments. On the one hand, establishments are experiencing increasing problems filling the training positions they offer, and the number of vacant training positions is climbing. On the other hand, the transition into training is still difficult for many young people, and the number of unsuccessful vocational training applicants is rising. Hence, matching supply with demand is becoming increasingly difficult in the German job market for training positions. Using the Linked Employer-Employee dataset (LIAB) from the Institute for Employment Research (IAB), our paper provides a closer examination of the phenomenon of unfilled training positions. It presents an overview of the evolution of vacant training positions in eastern and western Germany and attempts to explain the number of vacancies by investigating the factors responsible for the establishments’ inability to fill their training positions. We assume that training position vacancies are due not only to internal company reasons such as firm size or the wage offer for apprentices but also to external conditions such as general regional factors. Therefore, our analysis also considers the situation on the demand side of the labor market within a region. The results of our multilevel mixed-effects estimations show that in addition to characteristics on the enterprise level, regional determinants also affect the share of vacant apprenticeships. With respect to establishment-related factors, mainly characteristics that describe the attractiveness of the firm prove to be important. With regard to regional-specific factors, we find that the availability of school leavers in a region in addition to the level of regional-sectoral competition impacts the recruiting success of establishments. Our analysis also shows that there are remarkable differences between eastern and western Germany concerning both the quantitative importance of unfilled training positions and the factors affecting them.

Contraction-induced potentiation of human motor unit discharge and surface EMG activity

1988 ◽  
Vol 20 (4) ◽  
pp. 391-395 ◽  
Author(s):  
SHUJI SUZUKI ◽  
KOJI KAIYA ◽  
SHIROH WATANABE ◽  
ROBERT S. HUTTON
Keyword(s):  
Motor Unit ◽  
Surface Emg ◽  
Emg Activity ◽  
Unit Discharge ◽  
Motor Unit Discharge ◽  
Human Motor

scholarly journals Preliminary synthesis of algorithms for automatic control of automobile continuously variable transmissions with flexible links

2020 ◽  
Vol 1 (4) ◽  
pp. 25-37
Author(s):  
A.E. Yesakov ◽  
◽  
A.V. Kretov ◽  
P.A. Krasavin ◽  
◽  
...  
Keyword(s):  
Automatic Control ◽  
Direct Consequence ◽  
Continuously Variable Transmission ◽  
Factors Affecting ◽  
Flexible Links ◽  
Automatic Control Systems ◽  
High Durability ◽  
Continuously Variable Transmissions ◽  
Variable Transmission ◽  
The One

Variators of different operating principles and designs are of interest as components of automatic transmissions for ground transport and traction machines. At the same time, one of the most popular types of variators are the variators built on the basis of continuously variable transmissions with flexible links. The main reasons for the use of such variators in the transmissions of a number of modern passenger vehicles are, on the one hand, the emergence of flexible link designs with high durability, and, on the other hand, the widespread introduction of programmable electronic devices into automatic control systems for continuously variable transmissions. A direct consequence of the latter circumstance was the need for in-depth research aimed at synthesizing such control algorithms that would make it possible to fully use the advantages inherent in continuously variable transmissions with flexible links and minimize the operational consequences of their shortcomings. This paper makes an attempt to solve the problem of synthesizing the algorithm in a preliminary form, based on the goal of providing the vehicle with the best traction and speed properties. The presence of such an attempt will allow, having set the main parameters of a continuously variable transmission for some reason, to develop the hardware of the automatic control system. In turn, this will make it possible to synthesize a refined algorithm that takes into account the dynamics of the system, errors of meters and signal conversion devices, as well as other factors affecting work pro-cesses. When considering the described problem, various variants of the geometry of the contact surfaces of the continuously variable transmission links were taken into account and the corre-sponding mathematical apparatus were formed. The results of calculations, obtained by computer program that implements these devices, are selectively presented in the materials of the paper.

scholarly journals KINERJA LEMBAGA PERWAKILAN RAKYAT DAERAH (Studi Deskriptif Kualitatif Di DPRD Kota Bengkulu)

2015 ◽  
Vol 1 (2) ◽  
Author(s):  
Harius Eko saputra
Keyword(s):  
Mass Media ◽  
Public Service ◽  
Public Services ◽  
Research Seminar ◽  
Factors Affecting ◽  
The Public ◽  
Current Implementation ◽  
The One ◽  
The Right

Almost every day, in various mass media, especially in newspapers, it is found that there are so many complaints and unsatisfactory opinions from the community, as the customer, towards the current implementation of public service. These complaints and unsatisfactory opinions can describe how bad the quality of the current public service is, which is benefited by the community. It may be the right time for the community to be treated as citizens, who will have rights and give priority to their rights for being served afterwards. They are not anymore being considered as clients who previously have no any choice in choosing and in determining what kind of service that they really want to. There are so many results from research, seminar and writings that are conducted by experts in which their works talk about the implementation of a good and qualified public service. Currently, however, the qualified public service has not yet implemented as should have been. The implementation of public service still acts as however it please to be and only emphasize on its own interest without considering the consumer’s importance as the party that should really be served as well as possible. For this reason, a research, which is done in Service Integrated Unit of the Jember Regency, tries to find out any factors affecting quality of the public services. The main core of the public service implementation is the quality of norm of the service executor. The matter that should be realized is that the executor is the person who should serve for the community, and the community is the one who should be served as well as possible.Keywords: Implementation of public service, legislatif

scholarly journals Analysis of Effect of Bulbous Bow Shape to Ship Resistance in Catamaran Boat

2018 ◽  
Vol 159 ◽  
pp. 02058
Author(s):  
Deddy Chrismianto ◽  
Kiryanto ◽  
Berlian Arswendo Adietya
Keyword(s):  
Fluid Dynamic ◽  
The Body ◽  
Wave System ◽  
Total Resistance ◽  
Factors Affecting ◽  
Ship Resistance ◽  
Bow Wave ◽  
Main Factors ◽  
The One ◽  
Bulbous Bow

Ship resistance is one of the main factors affecting the design of a ship. Catamaran boat is a ship with small wet surface area that able to reduce drag and improve ship power. Generally, a bulbous bow is implemented to reduce wave resistance because the bulbous shape is believed to attenuate the bow wave system. Additionally, the bulbous bow also tends to reduce viscous resistance. When the flow around the body is smooth, the total ship resistance can be reduced significantly if the optimum bulbous bow is obtained. In this study, the main purpose is to get the bulbous bow shape in catamaran boat which produces the smallest ship resistance by using computational fluid dynamic (CFD). Generating the variation of the bulbous bow shapes apply the one-to-one correspondence of the cross section parameter (ABT) and lateral parameter (ABL). The result of investigation shows that application of bulbous bow on catamaran boat can reduce about 11-13% of total resistance of ship.

scholarly journals Transspinal stimulation decreases corticospinal excitability and alters the function of spinal locomotor networks

2019 ◽  
Vol 122 (6) ◽  
pp. 2331-2343 ◽  
Author(s):  
Timothy S. Pulverenti ◽  
Md. Anamul Islam ◽  
Ola Alsalman ◽  
Lynda M. Murray ◽  
Noam Y. Harel ◽  
...  
Keyword(s):  
Evoked Potentials ◽  
Motor Evoked Potentials ◽  
Silent Period ◽  
Surface Emg ◽  
Corticospinal Excitability ◽  
Emg Activity ◽  
Step Cycle ◽  
Healthy Humans ◽  
Descending Volleys ◽  
Period Duration

Locomotion requires the continuous integration of descending motor commands and sensory inputs from the legs by spinal central pattern generator circuits. Modulation of spinal neural circuits by transspinal stimulation is well documented, but how transspinal stimulation affects corticospinal excitability during walking in humans remains elusive. We measured the motor evoked potentials (MEPs) at multiple phases of the step cycle conditioned with transspinal stimulation delivered at sub- and suprathreshold intensities of the spinally mediated transspinal evoked potential (TEP). Transspinal stimulation was delivered before or after transcranial magnetic stimulation during which summation between MEP and TEP responses in the surface EMG was absent or present. Relationships between MEP amplitude and background EMG activity, silent period duration, and phase-dependent EMG amplitude modulation during and after stimulation were also determined. Ankle flexor and extensor MEPs were depressed by suprathreshold transspinal stimulation when descending volleys were timed to interact with transspinal stimulation-induced motoneuron depolarization at the spinal cord. MEP depression coincided with decreased MEP gain, unaltered MEP threshold, and unaltered silent period duration. Locomotor EMG activity of bilateral knee and ankle muscles was significantly depressed during the step at which transspinal stimulation was delivered but fully recovered at the subsequent step. The results support a model in which MEP depression by transspinal stimulation occurs via subcortical or spinal mechanisms. Transspinal stimulation disrupts the locomotor output of flexor and extensor motoneurons initially, but the intact nervous system has the ability to rapidly overcome this pronounced locomotor adaptation. In conclusion, transspinal stimulation directly affects spinal locomotor centers in healthy humans. NEW & NOTEWORTHY Lumbar transspinal stimulation decreases ankle flexor and extensor motor evoked potentials (MEPs) during walking. The MEP depression coincides with decreased MEP gain, unaltered MEP threshold changes, and unaltered silent period duration. These findings indicate that MEP depression is subcortical or spinal in origin. Healthy subjects could rapidly overcome the pronounced depression of muscle activity during the step at which transspinal stimulation was delivered. Thus, transspinal stimulation directly affects the function of spinal locomotor networks in healthy humans.

scholarly journals Pork: profile of the West of Paraná consumers and physical evaluation of chop

2017 ◽  
Vol 38 (6) ◽  
pp. 3563
Author(s):  
Rosana Aparecida da Silva-Buzanello ◽  
Daneysa Lahis Kalschne ◽  
Silmara Maisa Heinen ◽  
Claudete Pertum ◽  
Alexia Francielli Schuch ◽  
...  
Keyword(s):  
Meat Quality ◽  
Storage Conditions ◽  
Absorption Capacity ◽  
Physical Parameters ◽  
Exploratory Research ◽  
Factors Affecting ◽  
Pig Farming ◽  
Consumption Index ◽  
The One ◽  
Processing And Storage

Pork consumption in Brazil is still low despite its productive importance. Relevant issues such as swine breeding, meat quality, and evaluation of aspects and attributes considered important by pork consumers at the time of purchase allows identifying consumer market demands. Moreover, physical parameters evaluation or pork cuts are suggested to certify the meat quality. The aim of this study was to identify the current situation of pig farming and determine the main aspects considered by consumers when buying pork in the Western region of Paraná state, Brazil. Furthermore, the physical properties of five pork chop brands marketed in the region were determined. Initially, an exploratory research was conducted involving ten pig farming sector professionals. This research allowed identifying that professionals understand the factors affecting meat quality and that some municipalities in the region are beyond their absorption capacity for pig production market. A descriptive research involving one hundred pork consumers showed that, although most prefer beef, 41% reported to consume pork 2 to 3 times a week. Pork chops and ribs are the preferred cuts, either fried or roasted. Details such as expiration date and federal inspection register were considered the most important aspects at the time of purchase, while price was the least important one. The meat color was the most mentioned sensory attribute. The physical analyses of five pork chop brands showed no pH difference (p > 0.05), water holding capacity, and cooking loss results, distinctive from the one observed for color (L*, a* and b*) and shearing force, which showed differences among the brands (p ? 0.05). Comparing pH and L*, it can be suggested that two brands showed normal meat characteristics, one DFD meat (pH > 6.0 and L* < 45), and other two brands PSE (pH < 5.8 and L* > 50). The research contributed to identifying features considered important by pork consumers, suggesting strategic actions to achieve greater preference and consumption index. The evaluation of physical parameters showed there is variability involved in pork chop quality as the samples were obtained from commercially different origins and under different processing and storage conditions.

Use of a Shoulder Rest for Playing the Violin Revisited: An Analysis of the Effect of Shoulder Rest Height on Muscle Activity, Violin Fixation Force, and Player Comfort

2019 ◽  
Vol 34 (1) ◽  
pp. 39-46 ◽  
Author(s):  
Laura M Kok ◽  
Jim Schrijvers ◽  
Marta Fiocco ◽  
Barend van Royen ◽  
Jaap Harlaar
Keyword(s):  
Muscle Activity ◽  
Anterior Part ◽  
Activity Patterns ◽  
Deltoid Muscle ◽  
Surface Emg ◽  
Emg Activity ◽  
Linear Regression Models ◽  
Upper Trapezius ◽  
Shoulder Muscles ◽  
Rest Condition

AIMS: For violinists, the shoulder rest is an ergonomic adaptation to reduce musculoskeletal load. In this study, we aimed to evaluate how the height of the shoulder rest affects the violin fixation force and electromyographic (EMG) activity of the superficial neck and shoulder muscles. METHODS: In professional violinists, four different shoulder rest heights during five playing conditions were evaluated. Outcome variables included the jaw-shoulder violin fixation force and bilateral surface EMG of the upper trapezius (mTP), sternocleidomastoid (mSCM), and left anterior part of the left deltoid muscle (mDTA). Playing comfort was subjectively rated on a visual analogue scale (VAS). Linear regression models were estimated to investigate the influence of the shoulder rest height on muscle activity and violin fixation force as well as the muscle activity of the five evaluated muscles on violin fixation force. RESULTS: 20 professional violinists (4 males, 16 females, mean age 29.4 yrs) participated in this study. The shoulder rest condition had a significant effect on playing comfort (p<0.001), with higher shoulder rest conditions associated with decreased subjective playing comfort. The mean violin fixation force for each shoulder rest condition ranged between 2.92 and 3.39 N; higher shoulder rests were related to a higher violin fixation force (p<0.001). CONCLUSION: In this study, violin fixation force and muscle activity of the left mDTA increased while playing with an increasing height of the shoulder rest. As the shoulder rest influences muscle activity patterns and violin fixation force, adjustment of the shoulder rest and positioning of the violin need to be carefully optimized.

Factors affecting L2 phonological awareness in Chinese-Dutch preschoolers

2020 ◽  
Vol 23 (1) ◽  
pp. 109-128
Author(s):  
Han Yuan ◽  
Eliane Segers ◽  
Ludo Verhoeven
Keyword(s):  
Phonological Awareness ◽  
First Language ◽  
Receptive Vocabulary ◽  
Bilingual Children ◽  
Factors Affecting ◽  
Initial Phoneme ◽  
Rhyme Awareness ◽  
Bilingual Group ◽  
The One ◽  
The Relationship

Abstract The present study compared the relationship between Dutch phonological awareness (rhyme awareness, initial phoneme isolation), Dutch speech decoding and Dutch receptive vocabulary in two groups in different linguistic environments: 30 Mandarin Chinese-Dutch bilingual children and 24 monolingual Dutch peers. Chinese vocabulary and phonological awareness were taken into account in the bilingual group. Bilingual children scored below their Dutch monolingual counterparts on all Dutch tasks. In the bilingual group, Dutch rhyme awareness was predicted by Dutch speech decoding, both directly, and indirectly via Dutch receptive vocabulary. When adding Chinese proficiency to the model, Chinese rhyme awareness was found to mediate the relationship between Dutch speech decoding and Dutch rhyme awareness. It can thus be concluded that second language (L2) phonological awareness in Chinese-Dutch kindergartners is affected by their L2 speech and vocabulary level, on the one hand, and their level of phonological awareness in the first language (L1).

The effect of toe-tap exercise on abductor hallucis activity and medial longitudinal arch angle in individuals with pes planus

2020 ◽  
Vol 28 (4) ◽  
pp. 415-422
Author(s):  
Min-Hyeok Kang ◽  
Sang-Min Cha ◽  
Jae-Seop Oh
Keyword(s):  
Repeated Measures ◽  
Plantar Flexion ◽  
Surface Emg ◽  
Rehabilitation Program ◽  
Emg Activity ◽  
Electromyographic Activity ◽  
Medial Longitudinal Arch ◽  
Abductor Hallucis ◽  
Pes Planus ◽  
Longitudinal Arch

BACKGROUND: Active interventions for pes planus, including short-foot exercises (SF) and toe-spread-out exercises (TSO), aim to continuously support the medial longitudinal arch (MLA) by activating the abductor hallucis (AbdH) muscle. However, compensatory movements, such as ankle supination and/or plantar flexion, often occur during these exercises. OBJECTIVE: To examine the effects of a novel exercise, i.e., the toe-tap (TT) exercise on AbdH activity and MLA angle. METHODS: A total of 16 participants with pes planus participated in this study. Participants performed SF, TSO, and TT exercises. Electromyographic activity of the AbdH and MLA angle during three AbdH contraction exercises were recorded using surface EMG system and digital image analysis program, respectively. The differences in outcome measures among the three exercises were analyzed using one-way repeated-measures analysis of variance. RESULTS: The EMG activity of the AbdH was significantly greater during the TT exercise compared to the SF and TSO exercises. The MLA angle was significantly smaller during the TT exercise compared with the SF and TSO exercises. CONCLUSIONS: These findings suggest that the TT exercise could be effective in activating the AbdH and increasing height of the MLA, as part of a sports rehabilitation program for individuals with pes planus.

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