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Despite its high-level of robustness and versatility, the human sensorimotor control system regularly encounters and manages various noises, non-linearities, uncertainties, redundancies, and delays. These delays, which are critical to biomechanical stability, occur in various parts of the system and include sensory, signal transmission, CNS processing, as well as muscle activation delays. Despite the relevance of accurate estimation and prediction of the various time delays, the current literature reflects major discrepancy with regards to existing prediction and estimation methods. This scoping review was conducted with the aim of characterizing and categorizing various approaches for estimation of physiological time delays based on PRISMA guidelines. Five data bases (EMBASE, PubMed, Scopus, IEEE and Web of Science) were consulted between the years of 2000 and 2022, with a combination of four related categories of keywords. Scientific articles estimating at least one physiological time delay, experimentally or through simulations, were included. Eventually, 46 articles were identified and analyzed with 20 quantification and 16 qualification questions by two separate reviewers. Overall, the reviewed studies, experimental and analytical, employing both linear and non-linear models, reflected heterogeneity in the definition of time delay and demonstrated high variability in experimental protocols as well as the estimation of delay values. Most of the summarized articles were classified in the high-quality category, where multiple sound analytical approaches, including optimization, regression, Kalman filter and neural network in time domain or frequency domain were used. Importantly, more than 50% of the reviewed articles did not clearly define the nature of the estimated delays. This review presents and summarizes these issues and calls for a standardization of future scientific works for estimation of physiological time-delay.

Neuro mechanical time delay is inevitable in the sensorimotor control of the body due to sensory, transmission, signal processing and muscle activation delays. In essence, time delay reduces stabilization efficiency, leading to system instability (e.g., falls). For this reason, estimation of time delay in patients such as people living with spinal cord injury (SCI) can help therapists and biomechanics to design more appropriate exercise or assistive technologies in the rehabilitation procedure. In this study, we aim to estimate the muscle onset activation in SCI people by four strategies on EMG data. Seven complete SCI individuals participated in this study, and they maintained their stability during seated balance after a mechanical perturbation exerting at the level of the third thoracic vertebra between the scapulas. EMG activity of eight upper limb muscles were recorded during the stability. Two strategies based on the simple filtering (first strategy) approach and TKEO technique (second strategy) in the time domain and two other approaches of cepstral analysis (third strategy) and power spectrum (fourth strategy) in the time–frequency domain were performed in order to estimate the muscle onset. The results demonstrated that the TKEO technique could efficiently remove the electrocardiogram (ECG) and motion artifacts compared with the simple classical filtering approach. However, the first and second strategies failed to find muscle onset in several trials, which shows the weakness of these two strategies. The time–frequency techniques (cepstral analysis and power spectrum) estimated longer activation onset compared with the other two strategies in the time domain, which we associate with lower-frequency movement in the maintaining of sitting stability. In addition, no correlation was found for the muscle activation sequence nor for the estimated delay value, which is most likely caused by motion redundancy and different stabilization strategies in each participant. The estimated time delay can be used in developing a sensory motor control model of the body. It not only can help therapists and biomechanics to understand the underlying mechanisms of body, but also can be useful in developing assistive technologies based on their stability mechanism.

Strength training (ST) induces corticomuscular adaptations leading to enhanced strength. ST alters the agonist and antagonist muscle activations, which changes the motor control, i.e., force production stability and accuracy. This study evaluated the alteration of corticomuscular communication and motor control through the quantification of corticomuscular coherence (CMC) and absolute (AE) and variable error (VE) of the force production throughout a 3 week Maximal Strength Training (MST) intervention specifically designed to strengthen ankle plantarflexion (PF). Evaluation sessions with electroencephalography, electromyography, and torque recordings were conducted pre-training, 1 week after the training initiation, then post-training. Training effect was evaluated over the maximal voluntary isometric contractions (MVIC), the submaximal torque production, AE and VE, muscle activation, and CMC changes during submaximal contractions at 20% of the initial and daily MVIC. MVIC increased significantly throughout the training completion. For submaximal contractions, agonist muscle activation decreased over time only for the initial torque level while antagonist muscle activation, AE, and VE decreased over time for each torque level. CMC remained unaltered by the MST. Our results revealed that neurophysiological adaptations are noticeable as soon as 1 week post-training. However, CMC remained unaltered by MST, suggesting that central motor adaptations may take longer to be translated into CMC alteration.

Teaching acrobatic skills with a minimal amount of repetition is a major challenge for coaches. Biomechanical, statistical or computer simulation tools can help them identify the most determinant factors of performance. Release parameters, change in moment of inertia and segmental momentum transfers were identified in the prediction of acrobatics success. The purpose of the present study was to evaluate the relative contribution of these parameters in performance throughout expertise or optimisation based improvements. The counter movement forward in flight (CMFIF) was chosen for its intrinsic dichotomy between the accessibility of its attempt and complexity of its mastery. Three repetitions of the CMFIF performed by eight novice and eight advanced female gymnasts were recorded using a motion capture system. Optimal aerial techniques that maximise rotation potential at regrasp were also computed. A 14-segment-multibody-model defined through the Rigid Body Dynamics Library was used to compute recorded and optimal kinematics, and biomechanical parameters. A stepwise multiple linear regression was used to determine the relative contribution of these parameters in novice recorded, novice optimised, advanced recorded and advanced optimised trials. Finally, fixed effects of expertise and optimisation were tested through a mixed-effects analysis. Variation in release state only contributed to performances in novice recorded trials. Moment of inertia contribution to performance increased from novice recorded, to novice optimised, advanced recorded, and advanced optimised trials. Contribution to performance of momentum transfer to the trunk during the flight prevailed in all recorded trials. Although optimisation decreased transfer contribution, momentum transfer to the arms appeared. Findings suggest that novices should be coached on both contact and aerial technique. Inversely, mainly improved aerial technique helped advanced gymnasts increase their performance. For both, reduction of the moment of inertia should be focused on. The method proposed in this article could be generalized to any aerial skill learning investigation.

During maximal contractions, the sum of forces exerted by homonymous muscles unilaterally is typically higher than the sum of forces exerted by the same muscles bilaterally. However, the underlying mechanism(s) of this phenomenon, which is known as the bilateral strength deficit, remain equivocal. One potential factor that has received minimal attention is the contribution of body adjustments to bilateral and unilateral force production. The purpose of this study was to evaluate the plantar-flexors in an innovative dynamometer that permitted the influence of torque from body adjustments to be adapted. Participants were identically positioned between two setup configurations where torques generated from body adjustments were included within the net ankle torque (locked-unit) or independent of the ankle (open-unit). Twenty healthy adult males performed unilateral and bilateral maximal voluntary isometric plantar-flexion contractions using the dynamometer in the open and locked-unit mechanical configurations. While there was a significant bilateral strength deficit in the locked-unit (p = 0.01), it was not evident in the open-unit (p = 0.07). In the locked-unit, unilateral torque was greater than in the open-unit (p<0.001) and this was due to an additional torque from the body since the electromyographic activity of the agonist muscles did not differ between the two setups (p>0.05). This study revealed that the mechanical configuration of the dynamometer and then the body adjustments caused the observation of a bilateral strength deficit.

The imposing mass of the trunk in relation to the whole body has an important impact on human motion. The objective of this study is to determine the influence of trunk's natural inclination--forward (FW) or backward (BW) with respect to the vertical--on body kinematics and stance limb kinetics during gait initiation.Twenty-five healthy males were divided based on their natural trunk inclination (FW or BW) during gait initiation. Instantaneous speed was calculated at the center of mass at the first heel strike. The antero-posterior impulse was calculated by integrating the antero-posterior ground reaction force in time. Ankle, knee, hip and thoraco-lumbar (L5) moments were calculated using inverse dynamics and only peaks of the joint moments were analyzed. Among all the investigated parameters, only joint moments present significant differences between the two groups. The knee extensor moment is 1.4 times higher (P<0.001) for the BW group, before the heel contact. At the hip, although the BW group displays a flexor moment 2.4 times higher (P<0.001) before the swing limb's heel-off, the FW group displays an extensor moment 3.1 times higher (P<0.01) during the swing phase. The three L5 extensor peaks after the toe-off are respectively 1.7 (P<0.001), 1.4 (P<0.001) and 1.7 (P<0.01) times higher for the FW group. The main results support the idea that the patterns described during steady-state gait are already observable during gait initiation. This study also provides reference data to further investigate stance limb kinetics in specific or pathologic populations during gait initiation. It will be of particular interest for elderly people, knowing that this population displays atypical trunk postures and present a high risk of falling during this forward stepping.

Side effects of antiretroviral therapy (ART) can have a negative impact on health-related quality of life threatening long-term retention in HIV care and adherence to ART. The aim of the French community-based survey EVE was to document personal experiences with side effects, the related physician-patient communication, and solutions found to deal with them. Cross-sectional study of women between September 2013 to September 2014. An anonymous online questionnaire included the HIV Symptom Distress Module, which explores 20 symptoms. In all, 301 women on ART participated in the study (median age: 49 years; median duration of ART: 14 years). They reported having experienced a median of 12 symptoms (Q1-Q3: 9-15) during the previous 12 months. Overall, 56% of them reported having found at least a partial solution to dealing with their symptoms. Women reporting financial difficulties were twice less likely to have found solutions to coping with their side effects (AOR: 0.5; 95% CI: 0.3-0.8). Feeling supported by the health-care provider (AOR: 2.1; 95% CI: 1.1-3.9) and being in contact with HIV/AIDS organisations (AOR: 1.9; 95% CI: 1.2-3.2) were positively associated with coping. Seventeen percent reported having modified their ART regimen to improve tolerance, with only 2 in 3 informing their physician afterwards. Reporting financial difficulties and living with more bothersome symptoms increased the risk of ART regimen modification without health-care provider consultation. The EVE study has called attention to the large number of side effects experienced by WLWHIV, only half of whom have found self-care strategies to manage their symptoms. Modification of ART regimen by the women themselves was not uncommon.

Nowadays, billions of lines of code are in the COBOL programming language.This book is an analysis, a diagnosis, a strategy, a MDD method and a tool to transform legacy COBOL into modernized applications that comply with Internet computing, Service-Oriented Architecture (SOA) and the Cloud.

ObjectiveThe aim of this study was to evaluate people living with HIV (PLWH) and HIV specialist prescribers’ perception of discussing antiretroviral therapy (ART) price in PLWH’s care and the acceptability of choosing or switching to various types of less expensive ARTs.DesignCross-sectional surveys (one in a convenience sample of PLWH and one in a voluntary response sample of HIV specialist prescribers).Setting and participantsThe surveys were conducted among PLHW attending an HIV clinic in the North of Paris (cohort of 4922 PLWH in 2016), and HIV specialists working in French HIV clinics (210 across 12 districts/28), between January and June 2016.MethodSelf-administered questionnaires were constructed using data collected during focus groups with PLWH and prescribers. Pretests were carried out to select the questions and items. Descriptive analyses of the 129 complete questionnaires of PLWH and 79 of prescribers are presented.ResultsAmong PLWH, 128/129 were on ART and 54% (69/128) gave a fair estimation of the price of their current regimen. Among prescribers, 24% (19/79) thought that their patients knew this price. Taking into account the price of ART was not perceived as a negative step in the history of French response to HIV epidemic for 53% (68/129) of PLWH and 82% (65/79) of prescribers. Seventy-seven PLWH (60%) would agree to switch to less expensive antiretroviral regimens (as effective and with similar adverse events) if pills were bigger; 42 (33%) if there were more daily doses, and 37 (29%) if there were more pills per dose; prescribers were more circumspect.ConclusionA high proportion of PLWH gave a fair estimate of their ART price and this seemed unexpected by HIV specialists. Consideration of drug prices when choosing ART was perceived as conceivable by PLWH and prescribers if effectiveness and tolerance were also considered.

Is Internet software so different from \"ordinary\" software? This book practically answers this question through the presentation of a software design method based on the State Chart XML W3C standard along with Java. Web enterprise, Internet-of-Things, and Android applications, in particular, are seamlessly specified and implemented from \"executable models.\" Internet software puts forward the idea of event-driven or reactive programming, as pointed out in Boner et al.'s \"Reactive Manifesto\". It tells us that reactiveness is a must. However, beyond concepts, software engineers require effective means with which to put reactive programming into practice. This book's purpose is to outline and explain such means. The lack of professional examples in the literature that illustrate how reactive software should be shaped can be quite frustrating. Therefore, this book helps to fill in that gap by providing in-depth professional case studies that contain comprehensive details and meaningful alternatives. Furthermore, these case studies can be downloaded for further investigation. Internet software requires higher adaptation, at run time in particular. After reading Reactive Internet Programming, the reader therefore will be ready to enter the forthcoming Internet era.