107 research outputs found

    A new characterization of symplectic groups C2(3n)

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    We prove that symplectic groups C2(3n), where n = 2k (k ≥ 0) and (32n + 1)=2 is a prime number, can be uniquely determined by the order of the group and the number of elements with the same order

    Muscle co-activation during gait in children with cerebral palsy

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    La paralysie cérébrale (PC) est un trouble non progressif causé par une lésion cérébrale. La PC survient tôt dans la vie et présente une atteinte hétérogène et une altération fonctionnelle. Chez les personnes atteintes de PC, les modifications du Contrôle neuronal et des muscles entraînent des modifications permanentes de la fonction motrice, entraînant des déficits de mouvement. L'une des raisons des patrons de marche atypiques chez les enfants atteints de PC est l'altération l'activation musculaire. Un niveau anormal d'activation simultanée des muscles agonistes et antagonistes des muscles agonistes et antagonistes entourant une même articulation la même articulation empêche une performance de marche optimale chez les enfants atteints de PC. Ce phénomène est connu sous le nom de co-contraction musculaire (CoM) ou de co-activation musculaire (CaM) dans toutes les études. L'identification des schémas musculaires les plus détériorés, à savoir CoM/CaM, chez les enfants atteints de PC est essentielle pour une rééducation efficace de la marche. L'objectif de ce projet de maîtrise était donc de distinguer CoM/CaM chez les enfants atteints de PC de leurs pairs en développement typique (DT) pendant la marche. Cet objectif a été atteint en deux étapes ; Premièrement, nous avons décrit la CoM/CaM chez les personnes atteintes de PC via la réalisation d'une revue de littérature ; Ensuite, nous avons appliqué nos résultats de la première étape à une étude transversale pour comparer CoM/CaM pendant la marche entre des enfants atteints de CP et de DT. Une revue de littérature suivant la méthodologie en 6 étapes du Joanna Briggs Institute a été effectué. Les bases de données ont été consultées à l'aide de mots-clés pertinents. Toutes les études publiées sur CoM/CaM chez les personnes atteintes de PC pendant la marche ont été recueillies. Après un examen de la pertinence des titres et des résumés, un deuxième examen des textes intégraux des sources par deux examinateurs a été appliqué. Enfin, les données ont été extraites des articles inclus (n=21). Ensuite, à l'étape suivante, les principales méthodes utilisées pour quantifier la MCa identifiées à l'étape précédente ont été codées dans Matlab (The Mathworks Inc., Natick, États-Unis) et appliquées à nos données de 12 enfants atteints de CP et 23 enfants TD. Nous avons comparé le CaM moyen de deux groupes de muscles de la cuisse et de la jambe (Rectus Femoris (RF)/Semitendinosus (ST) et Tibialis Anterior (TA)/Lateral gastrocnemius (LG), respectivement) via des tests t non appariés (ou son équivalent non paramétrique). La revue de littérature a suggéré une CaM plus élevée chez les personnes atteintes de PC par rapport à leurs pairs en bonne santé dans toutes les études. Bien qu'il y ait eu une terminologie et des approches méthodologiques incohérentes, nous avons pu discriminer les terminologies (c'est-à-dire CoM et CaM) en fonction des méthodologies de calcul (c'est-à-dire moment et EMG) utilisées par les études. En outre, cette étude nous a permis de résumer les modèles de CaM chez les individus atteints de PC et d'identifier la relation entre certains des paramètres de marche avec CaM. Enfin, les résultats de cette étude ont révélé des informations précieuses concernant les lacunes de la recherche dans ce domaine. La deuxième étude a identifié une augmentation de la CaM pendant la marche (la foulée entière, la phase d’appuie et la phase oscillante) chez les enfants atteints de PC par rapport à leurs pairs TD. Cette augmentation n'a été observée que dans les muscles de la jambe (pendant la phase d’appuie et la phase oscillante) et dans les muscles de la cuisse (pendant la phase oscillante) lorsque nous avons normalisé les signaux d'électromyographie. Les groupes CP et DT n'avaient pas de CaM différent en utilisant l'EMG normalisé pour l'ensemble de la foulée. Cette différence met en évidence l'effet de la normalisation EMG sur les valeurs de CaM. De plus, les enfants avec le niveau II du système de classification de la fonction motrice globale (SCFMG) avaient un CaM plus élevé dans les muscles de la cuisse pendant le swing que ceux avec le niveau I. Dans l'ensemble, ce projet de maîtrise révèle de nouvelles preuves soutenant une plus grande CaM chez les enfants atteints de PC par rapport à DT pendant la marche. Néanmoins, il est important d'étudier la CaM dans différentes phases de marche car elle affecte la comparaison entre les groupes. En outre, ce projet justifie l'importance de la méthodologie (par exemple, le traitement EMG et le calcul CaM) dans les études CaM. Plus précisément, il est fort probable que les résultats changent avec différentes approches de normalisation EMG. De plus, les enfants atteints de SCFMG I et II peuvent éprouver différents niveaux de CaM pendant la phase oscillante. Davantage de comparaisons dans des recherches futures, telles qu'entre les SCFMG I, II et III dans la PC hémiplégique et diplégique pendant les sous-phases de la marche (le contact initial, le « mid-stance »), peuvent fournir de meilleures informations sur les modèles de CaM dans cette population.Cerebral palsy (CP) is a nonprogressive disorder caused by a brain injury. CP occurs early in life, before, during, or after birth, and has heterogeneous involvement and functional impairment. In individuals with CP, changes in neural drive and muscles lead to lifelong changes in motor function, leading to movement deficits. One of the reasons for atypical gait patterns in children with CP is altered muscle activation patterns. An abnormal level of simultaneous activation of agonist and antagonist muscles crossing the same joint prevents optimal gait performance in children with CP. This phenomenon is known as muscle co-contraction (MCo) or muscle co-activation (MCa) across studies. Identification of the most deteriorated muscular patterns, namely, MCo/MCa, in children with CP is vital for effective gait rehabilitation. The objective of this master’s project, therefore, was to distinguish MCo/MCa in children with CP from their typically developing (TD) peers during gait. This objective was achieved through two studies; first, we described MCo/MCa in individuals with CP via the conduction of a scoping review; then, we applied our findings to inform a cross-sectional study to compare MCo/MCa during gait between children with CP and TD. A scoping review following the 6-stage Joanna Briggs Institute methodology was conducted. Databases were searched using relevant keywords. All published studies on MCo/MCa in individuals with CP during gait were collected. After title and abstract relevance screening, a second screening for the full texts of the sources by two reviewers was applied. Finally, data were extracted from the included articles (n=21). Then, leading methods used to quantify MCa identified from the previous study were coded in Matlab (The Mathworks Inc., Natick, USA) and applied to our data from 12 children with CP and 23 TD children. We compared the average MCa of two thigh and shank muscle groups Rectus Femoris (RF)/Semitendinosus (ST) and Tibialis Anterior (TA)/Lateral gastrocnemius (LG), respectively, via unpaired t-tests (or its non-parametric equivalent). According to our scoping review, higher MCa in individuals with CP compared to healthy peers across studies was found. Although there were inconsistent terminology and methodological approaches, we could discriminate terminologies (i.e., MCo and MCa) according to the methodologies in the calculation (i.e., moment and EMG) used by studies. Also, this study enabled us to summarize MCa patterns within individuals with CP and identify the effect of the some of the gait parameters on MCa. Finally, the findings of this study revealed valuable information regarding the research gaps in this area. The second study identified increased MCa around the knee and ankle joints for the following muscles (i.e., RF/ST and TA/LG, respectively) during walking (i.e., entire stride, stance, and swing) in children with CP compared to their TD peers. This increase was seen only in shank muscles (i.e., during stance and swing) and in thigh muscles (i.e., during the swing) when we normalized electromyography (EMG) signals. CP and TD groups did not have different MCa using normalized EMG for the entire stride. This difference highlights the effect of EMG normalization on MCa values. Also, children with Gross Motor Function Classification System (GMFCS) level II had higher MCa around the knee during swing than those with level I. Overall, this master’s project reveals new evidence supporting greater MCa in children with CP compared to TD peers during walking. Nevertheless, it is recommended to investigate MCa within different gait phases as it affects the comparison across groups. Also, this project justifies the importance of methodology (e.g., EMG processing and MCa calculation) in MCa studies. More specifically, it is likely that the results alter with different EMG normalization approaches. Moreover, children with GMFCS I and II can experience various levels of MCa during the swing phase. More comparisons in future research, such as between GMFCS I, II, and III in hemiplegic and diplegic CP during gait sub-phases (i.e., initial stance, mid-stance), can provide better information regarding MCa patterns in this population

    A new characterization of the simple groups C4(q), by its order and the largest order of elements

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    We prove that the simple group C4(q), where q > 2 and (q4 + 1)=2 are prime numbers, can be uniquely determined by its order and the largest order of elements

    Modelling physiology of haemodynamic adaptation in short-term microgravity exposure and orthostatic stress on Earth

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    Cardiovascular haemodynamics alters during posture changes and exposure to microgravity. Vascular auto-remodelling observed in subjects living in space environment causes them orthostatic intolerance when they return on Earth. In this study we modelled the human haemodynamics with focus on head and neck exposed to different hydrostatic pressures in supine, upright (head-up tilt), head-down tilt position, and microgravity environment by using a well-developed 1D-0D haemodynamic model. The model consists of two parts that simulates the arterial (1D) and brain-venous (0D) vascular tree. The cardiovascular system is built as a network of hydraulic resistances and capacitances to properly model physiological parameters like total peripheral resistance, and to calculate vascular pressure and the related flow rate at any branch of the tree. The model calculated 30.0 mmHg (30%), 7.1 mmHg (78%), 1.7 mmHg (38%) reduction in mean blood pressure, intracranial pressure and central venous pressure after posture change from supine to upright, respectively. The modelled brain drainage outflow percentage from internal jugular veins is 67% and 26% for supine and upright posture, while for head-down tilt and microgravity is 65% and 72%, respectively. The model confirmed the role of peripheral veins in regional blood redistribution during posture change from supine to upright and microgravity environment as hypothesized in literature. The model is able to reproduce the known haemodynamic effects of hydraulic pressure change and weightlessness. It also provides a virtual laboratory to examine the consequence of a wide range of orthostatic stresses on human haemodynamics

    Investigating the effects of emotional maturity and self--discrepancy on the religious attitude of pre-college adolescent girls in Tehran

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    For downloading the full-text of this article please click here.Background and Objective: Achieve to emotional maturity and lack of self-discrepancy is important factors in people’s religious attitudes. So the aim this study is Investigating the effects of emotional maturity and self-­discrepancy on the religious attitude of pre-college adolescent girls in TehranMethods: The research method is descriptive and correctional. statistical population consists of all pre-college student girls in Tehran. 405 students were selected using Morgan table and multi-stage cluster sampling method. Data collection tools were emotional maturity questionnaire, self-discrepancy questionnaire and religious attitude questionnaire. Collected data has been analyzed using correlation and regression analysis. All ethical issues were observed. Moreover, the authors did not report conflict of interest.Results: This study Investigated that emotional maturity and self-discrepancy variables determined religious attitudes with a factor of 0.10. The emotional maturity factor (beta-0.31) has the greatest impact on religious attitudes (p<0.01), and real-ideal self-­discrepancy with beta 0.11 is the second factor influencing religious attitude in adolescent girls (p<0.05). In this explanation, real-­ought self discrepancy had no significant effect on the religious attitude (p>0.05).Conclusion: The results showed that emotional maturity and self-discrepancy variables play important role in the religious attitude of adolescent girls. Therefore these variables must be considered to promote their religion, and field of necessary education to students such as life skills training should be provided to improve emotional maturity and self-discrepancy.For downloading the full-text of this article please click here.

    Homotopy Analysis Method to determine Magneto Hydrodynamics flow of compressible fluid in a channel with porous walls

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    In this article magnetohydrodynamics (MHD) boundary layer flow of compressible fluid in a channel with porous walls is researched. In this study it is shown that the nonlinear Navier-Stokes equations can be reduced to an ordinary differential equation, using the similarity transformations and boundary layer approximations. Analytical solution of the developed nonlinear equation is carried out by the Homotopy Analysis Method (HAM). In addition to applying HAM into the obtained equation, the result of the mentioned method is compared with a type of numerical analysis as Boundary Value Problem method (BVP) and a good agreement is seen. The effects of the Reynolds number and Hartman number are investigated

    Analytical and Numerical investigation of natural convection in a heated cylinder using Homotopy Perturbation Method

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    Homotopy Perturbation Method (HPM) has been applied to solve a nonlinear heat transfer problem. Natural convection around an isothermal horizontal cylinder was studied. Heat transfer coefficient and specific heat coefficient were assumed to be dependent on temperature. Outcomes were compared with solution of heat transfer equation with constant properties. Solutions of HPM were compared with numerical results for different cases, and variation of Nusselt number was obtained and investigated.

    Burn and Hypertension: How Are They Related?

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    Background: A burn tissue injury is one of the most severe forms of trauma which results in severe life-threatening disturbances. Burn injury has many morbid complications, so it needs a multi-disciplinary care team according to the burn center to reduce its mortality and morbidity. Methods: This article aims to review drawbacks and complications associated with the burning injury including Acute Kidney Injury (AKI), Acute lung injury, Heart Failure, Electrolyte imbalance, intra-abdominal hypertension in children and adult burn patients, and recent challenging treatments. Results: Improved understanding of the pathophysiology of burn-induced complications can contribute to organizing a well-treatment plan, which leads to improved outcomes. Conclusions: Herein, the evidence available on the management of all burn induced-complications is summarized
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