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The difficulty of observer design for a general class of nonlinear system and the reduction of chattering phenomenon are still challenging tasks in the theory of sliding mode observers. Thus, this paper aims to develop a novel second order sliding mode multiobserver (2SMMO) in order to avoid these problems. Indeed, a decoupled multimodel approach is used to construct the global model of the nonlinear system. Thereafter, the 2SMMO is generated as a finite partial sliding mode observers interpolated by weighting functions. Moreover, the linear matrix inequalities formulation, derived by the Lyapunov stability theory, is employed to establish satisfactory conditions ensuring the convergence of the multiobserver. A numerical simulation and a real application on a chemical reactor are given to illustrate the good performances of the proposed second order sliding mode multiobserver in terms of speed convergence, robustness against the disturbances and chattering phenomenon reduction.

Souissi, MA, Elghoul, Y, Souissi, H, Masmoudi, L, Ammar, A, Hamdi Chtourou, and Souissi, N. The effects of three corrections strategies of errors on the snatch technique in 10–12-year-old children: A randomized controlled trial. J Strength Cond Res37(6): 1218–1224, 2023—Sports movement correction is one of the major problems for motor control and learning. Therefore, the purpose of the present study was to determine which of the 3 strategies, i.e., the self-observation method with direct instructions (SO-DI), self-observation alone (SO), or the direct instruction (DI), would be useful for correcting errors during the snatch technique. Forty-eight children with 2 months of experience were randomly assigned to one of 4 training conditions: SO-DI, SO, DI, or control. In this study, the experience lasted 15 sessions. Subjects completed the test sessions before (T0) and after (T1) 12 training sessions and a retention test session after 2 weeks (T2). The Kinovea version 0.8.15 software was used to measure the kinematic parameters of weightlifting performance. After the training intervention, the data showed that the SO-DI group registered a greater improvement in all kinematic parameters compared with the SO, DI, and control groups, and this benefit was present 2 weeks later in the retention test (e.g., the horizontal displacement of the bar in the first pull with respect to the starting position [T1 vs. T0: +32.57 ± 6.69%, d= 1.87, p< 0.001; T2 vs. T0: 25.07 ± 11.55%, d= 1.32, p< 0.001] and the horizontal displacement of the bar between the receiving position and the reference line [T1 vs. T0: 24.34 ± 29%, d= 1.17, p< 0.01; T2 vs. T0: 25.53 ± 30.4%, d= 0.99, p< 0.01]). The results of the present study could have practical implications for physical education teachers because, even if practice is required to improve the technique, the effectiveness of the learning process is essential to enhance learner self-efficacy and motivation.

The acquisition of the planar images of the same object may be considerably different due to viewpoint dependencies, which influences the shape extraction, hence possibly making the curves partially visible and often accompanied by perspective distortions. In this paper, we propose a new contour alignment system relating to the special affine transformations that contain rotations and stretches, useful for describing planar contours which move in three-dimensional space and which are far enough away from the camera. The registration system that we suggest here includes a first optimization step relating to the dataset concerned. It consists in optimizing the number of correspondence points Nbetween the curves to be registered. This is achieved by minimizing the conditioning of the correspondence matrix which is obtained by matching the re-sampling points by the equi-affine length of the two curves. This correspondence matrix is calculated for all the pairs of curves of the dataset by varying N. After extracting the optimal value of N, the estimation of the special affine transformation between a given couple of curves is realized by the pseudo-inverse of the correspondence matrix in the N0resolution. This approach allows both providing the best accuracy and stabilizing the results of registration. We evaluate and compare our algorithm with other existing methods under different shape variations including noise, missing parts, and articulated deformations. The experiments are conducted on several known datasets.

The recent development towards a battery-powered electric vehicle industry has led to a significant rise in the demand for high-grade Lithium (Li). Global Li is predominately produced from brines (salar or geothermal) and from hard-rocks, while the amount of Li produced from recycling (e.g. from waste batteries) is still negligible, although it is expected to increase in the near future. Li extraction from hard rocks and brines is also associated with environmental issues, such as (i) consumption of a large quantity of reagents, (ii) high water footprint (especially in the case of brines). Therefore, ensuring a clean, stable and sustainable supply of Li is a key point in the European agenda to reach its ambitious climate targets by 2050.

In the present study we investigated the effects of manipulating task difficulty (constant vs. progressive difficulty) and frequency of knowledge of results (KR) on the accuracy and consistency of children’s performance of a novel fine motor coordination task (dart throwing). We assigned 69 right-handed physical education (PE) students (Mage = 10.73, SD= 0.89 years) to progressive (PDG) or constant difficulty (CDG) groups. PDG and CDG were each split into three subgroups who received varying KR frequency (100%KR, 50%KR, and 33%KR), creating a total of six groups. We increased difficulty in the PDG by manipulating the distance to the target (2 m, 2.37 m, and 3.56 m), while distance to the target was constant for CDG throughout the experiment (2.37 m). We conducted performance assessments during familiarization (pre-test), acquisition (post-test), and retention (retention testing) learning phases under both normal condition (NC) and a time pressure condition (TPC). Repeated-measures analysis of variance revealed a significant effect of difficulty manipulation on skill learning under both NC and TPC. Further analyses revealed that skill learning was enhanced by progressive difficulty manipulation. However, learning was not affected by KR frequency changes. Progressive difficulty practice enhanced both accuracy and consistency, specifically at retention testing. These results suggest that motor learning in children may be enhanced by practicing with progressive increases in difficulty. PE teachers are encouraged to gradually introduce difficulty levels in motor learning tasks that require high accuracy.

Polymorphisms within genes encoding the cytokines involved in anti-tuberculosis immunity have been widely studied and sometimes associated with an increased risk of developing the active form of tuberculosis (TB). This study analyzes for the first time the impact of two polymorphisms, namely IFNG+874 T/A and IL10-1082 G/A, in the Algerian population where tuberculosis is moderately endemic.

While augmented feedback (AF) is widely acknowledged to affect motor learning, the effects of mode of feedback on motor learning acquisition, retention, and perceived competence has rarely been studied. The present investigation analyzes the effects of verbal, haptic, and combined (verbal and haptic) feedback when learning a novel gymnastic parallel bars task. Forty-eight physical education students and four expert gymnastics teachers participated in the study. We divided the students into three AF groups (verbal, haptic, and combined) and a no-feedback control group (CG). One gymnastics teacher led the learning sessions, while the others evaluated student performances following familiarization, acquisition, and retention learning phases. All sessions were video recoded, and the experts gave blind assessments according to an adapted gymnastic point code. We recorded task perceived difficulty (PD) and students' perceived self-competency throughout the sessions. A repeated measures analysis of variance revealed a significant effect of AF mode on acquisition and retention such that combined AF was best for learning stability and retention (19.1% improvement for combined vs. 9.9% for haptic and 6.9% for verbal). Similarly, participants in the combined AF group, relative to the verbal and haptic AF groups, also reported lower perceived difficulty and higher perceived self-competency after the retention phase. PE teachers are encouraged to combine verbal and haptic AF when teaching new motor skills.

This paper presents the fault tolerant control (FTC) of a flexible joint robot using singular perturbation method in order to compensate for the lost performance due to the occurrence of actuator fault and the uncertainty. This FTC is based on Lyapunov redesign principle. The singular perturbation method is used to reduce the dynamic model of the flexible joint robot in a fast and slow subsystem. The time scale reduction of the flexible joint model is carried out when their joint stiffness is large enough and the singular perturbation parameter is set to zero. The fault-tolerant control structure in this paper is based on two parts. The first term described the composite control for the system without defect and without uncertainty which represents the sum between slow and fast controllers. While the second term of the fault tolerant command describes additive control designed to compensate for the fault effect of the actuator on the uncertain system. The additive approach is based on the Lyapunov theorem, which guarantees asymptotic stability despite the presence of actuator defects and the parametric uncertainty. The theoretical results are applied on a robot manipulator with a single flexible joint.

Blockchain technology has gained significant attention in the most recent years due to its potential to address related issues to privacy, transparency, and security. In the healthcare industry, it is considered a promising solution to challenges related to data management, medical data privacy, and security. This paper proposes a novel framework for managing electronic medical healthcare records that uses Amazon Web Services (AWS) to create a secure and cost-effective solution. The proposed solution uses a serverless approach to reduce costs and only pay for the compute resources when needed. The framework focuses on improving the security of access to the blockchain network by implementing a multi-level security approach, starting from protecting the Hyperledger and implementing role-based access for end-users who require access to the stored data. The effectiveness of the proposed framework is demonstrated by creating a role-based access matrix for three different user types and performing multiple experiments to validate access for each user type.

Thermal energy storage using phase change material plays a major role to solve the mismatch between energy demand and supply. In this study, the effect of the inner elliptic tube aspect ratio of a double-pipe latent heat thermal storage unit and its inclination angle is numerically and experimentally investigated. The 3D numerical model is developed using ANSYS FLUENT 17.2 and the finite volume method with the enthalpy-porosity technique under the same mass of PCM and the area of heat transfer while altering the aspect ratio. The predictions of the numerical model were compared favorably with the corresponding experimental results. Temperature distribution, velocity vectors, melt fraction, and total melting times are numerically investigated. Results show that the inclination angle at which minimum melting time takes place depends on the aspect ratio of the inner elliptic tube. The minimum total melting time for aspect ratios of 0.4, 0.6, 0.8, and 1 occurs at inclination angles of 30°, 45°, 75°, and 90° respectively. Furthermore; the optimized condition was with an aspect ratio of 0.4 and an inclination angle of 30°.

This paper presents the design of an additive fault tolerant control for nonlinear time-invariant singularly perturbed systems against actuator faults based on Lyapunov redesign principle. The overall system is reduced into subsystems with fast and slow dynamic behavior using singular perturbation method. The time scale reduction is carried out when the singular perturbation parameter is set to zero, thus avoiding the numerical stiffness due to the interaction of two different dynamics. The fault tolerant controller is computed in two steps. First, a nominal composite controller is designed using the reduced subsystems. Secondly, an additive part is combined with the basic controller to overcome the fault effect. The derived ε - independent controller guarantees asymptotic stability despite the presence of actuator faults. The Lyapunov stability theory is used to prove the stability provided the singular perturbation parameter is sufficiently small. The theoretical results are simulated using a numerical application.

Traumatic isolated rupture of the long head of the biceps (LHB) tendon is an uncommon injury that can result in significant pain and functional impairment. Surgical treatment is often required to restore normal shoulder function.

As laterality of the lower limbs is regarded as a relevant influence on soccer performance, we assessed whether a bilateral training program for both the preferred leg (PL) and non-preferred leg (NPL) would improve soccer players’ lateral asymmetry, agility, and accuracy. Sixty right-foot-dominant young soccer players were randomly assigned to either an experimental group (EXP) that underwent bilateral training or a control group (CONT) that performed their usual training schedule without bilateral exercise. We assessed the players’ lateral asymmetries before and after training on four soccer skill tasks: a zigzag test with and without a ball, a receiving and direct volley-shooting accuracy test, and a passing accuracy test. Results showed post-test versus pre-test performance improvements for the EXP group on the index of technical skills and agility (p< .001). A post-hoc analysis further revealed a pre-test to post-test performance improvement on shooting and passing accuracy with bothlegs only for the EXP group (p< .001). These results support the role of bilateral practice in improving lateral asymmetries, agility, and accuracy.

La pneumonie à SARS-Cov2 est considérée actuellement comme une maladie de système à point de départ respiratoire qui peut influencer le taux des marqueurs cardiaques. L’objectif de ce travail est d’étudier la relation entre le taux de troponine I hypersensible (TnIHS) et la mortalité dans le COVID-19.

In the current study, we examined the effect of an aerobic dance program as part of physical education (PE) classes on aspects of primary school children’s executive functions (EFs) (inhibition, working memory, and cognitive flexibility). Participants were 41 children (21 boys and 20 girls; Mage =10.30, SD= 0.50 years, Mheight = 134.09, SD=3.9 cm; Mweight = 35.61, SD= 7.85 kg) who were divided into an experimental group (EG) and a no-PE control group (CG). The EG followed an aerobic dance intervention as part of their PE program (45 minute sessions two days per week over eight weeks). Participants in both groups performed EF tests before and after the intervention period to evaluate their mental flexibility, inhibition, and working memory. A two-way mixed model repeated measures ANOVA revealed a significant effect of the aerobic dance program on participants’ cognitive flexibility (i.e., on Trails Making Tests B-Atimes and committed errors) (p<0.001), and on Stroop measures of inhibition (corrected number of words and corrected errors) (p<0.001 and p<0.01, respectively), with post-hoc analyses showing an improved performance by the EG in working memory (digit recall score) from pre-test to post-test and in comparsion to the CG (p< 0.001). Thus, this 8-week aerobic dance program promoted EF development among primary school children.

•Type I, type II pneumocytes, and alveolar macrophages were investigated.•Study using light microscopy and transmission electron microscopy.•Large vacuoles in type II pneumocytes were noticed.•Intravascular macrophages in the lungs of 2 months piglets recorded.

Our aim in this study was to examine, via technical performance analysis and speed of execution, whether information processing and technical knowledge help explain learning benefits of self-controlled video feedback in children’s weightlifting performance. We randomized 24 children (aged 10 to 12 years) into self-controlled (SC) and yoked (YK) feedback groups. Learners underwent test sessions one week before (pre-test) and one day after (post-test) six weightlifting training sessions. During each test session, we recorded kinematic parameters of snatch performance using Kinovea version 0.8.15 software. After the learning sessions, the SC group improved on most kinematic parameters (e.g., the horizontal displacement of the bar between the first and the second pulls [MDXV= 25.42%, SD= 18.96, p= 0.003) and the maximum height reached by the bar (MHMV= 5.51%, SD= 7.71, p< 0.05)], while the YK group improved only on the DxV (MDXV= 19.08%, SD= 24.68, p< 0.05). In addition, the SC group showed a more advanced phase of cognitive processing compared to the YK group, and the SC group showed a superior improvement in their technical knowledge level (p< 0.001) compared to the YK group (p< 0.05). Thus, key elements to correcting motor errors in children’s weightlifting through self-controlled feedback were improvements in information processing and technical knowledge.

Neisseria gonorrhoeaeculture gave a positive result in 42 of 64 male adults with purulent urethral discharge. The majority of the infections were acquired outside Libya Twenty-seven strains (64.3%) were non-penicillinase producing (NPPNG) and 15 (35.7%) were penicillinase producing (PPNG) by starch paper technique. Antimicrobial susceptibility of the strains to 5 antibiotics was carried out by agar-plate dilution technique. Twenty-three NPPNG strains (54.8%) were susceptible to penicillin with a minimum inhibitory concentration (MIC) of ≤0.5 μg/ml. In 4 strains (9.5%), a high resistance to penicillin (MIC ≥16 μg/ml) appeared to be chromosomally-mediated (CMRNG). All PPNG strains were resistant to penicillin (MIC ≥1 μg/ml). While resistance to erythromycin (MIC ≥ 1 μg/ml) and tetracycline (MIC ≥ 1 μg/ml) was observed in 5 strains, resistance to kanamycin (MIC 32 μg/ml) and spectinomycin (MIC 64 μg/ml) was present in only one strain. Whereas no significant differences were recorded in MICs of erythromycin, tetracycline, kanamycin and spectinomycin between NPPNG and PPNG strains, one PPNG strain was found to be resistant in vitroto all 5 antibiotics.

Schwannomas represent only 5% of all soft tissue tumors. As a variant of this tumor, the plexiform schwannoma is rare accounting for less than 5% of all schwannomas. Herein, we report a rare case of a 49-year-old athlete who suffered from a pain in the posterior aspect of the right leg one year before his presentation. Initially, a radiograph of his right leg showed no abnormality, and so, the emergency physician discharged him on analgesics and anti-inflammatory medications, and rest was advised. The persistent pain obliged the patient to consult our orthopedic department. On examination, we found a firm mass in the proximal medial aspect of his right leg. The neurovascular exam was normal. Sonography of the leg was not conclusive. Therefore, magnetic resonance imaging was performed, and a hemangioma or schwannoma was suspected. The patient underwent surgery in which the entire tumor mass was shelled out in one piece with no damage. The histopathological finding was concomitant with a plexiform schwannoma. Follow-up evaluation, sixteen months later, showed no evidence of recurrence, and the patient has regained his previous level of sportive activities. So, given the case described here, despite the rarity of the schwannoma, it should be taken into consideration as a possible diagnosis in such situation to promote early diagnosis and appropriate treatment.

Almost 2% of all emergency admissions involve an animal bite. While horses bite humans very rarely, their bites are mostly associated with fatalities. Herein, we report the case of a 23-year old bitten by a domestic horse causing a crush injury to his fourth finger with fracture dislocation of the proximal interphalangeal joint. The patient benefited upon arrival at the emergency department from copious irrigation with saline serum, tetanus toxoid, postexposure rabies vaccination, and prophylactic antibiotic therapy. In the operating room, surgical exploration found the ulnar digital pedicle sectioned, the flexor and extensor tendons sectioned and shredded, and the skin shredded. An excisional debridement of devitalized tissue with copious irrigation was performed, and the finger regularized at the level of traumatic amputation with tendon striping followed by coverage of the bone by the radial digital flap with careful clinical and biological monitoring after the surgery. At the last follow-up, the patient revealed no sign of infection, and he returned to his usual activities and has been discharged from care. This wound management, based on a careful examination, a meticulous debridement, and an efficient cleaning with early and targeted antibiotic therapy, might promote good results and avoid dangerous complications.