Contribuições ao estudo das redes complexas: modelo de qualidade

In this work we analyse the implications of using a power law distribution of vertice's quality in the growth dynamics of a network studied by Bianconi anel Barabási. In particular, we start studying the random networks which characterize or are related to some real situations, for instance the tide movement. In this context of complex networks, we investigate several real networks, as well as we define some important concepts in the network studies. Furthermore, we present the first scale-free network model, which was proposed by Barabási et al., and a modified model studied by Bianconi and Barabási, where now the preferential attachment incorporates the different ability (fitness) of the nodes to compete for links. At the end, our results, discussions and conclusions are presented

Plasticidade induzida por treinamento locomotor na medula espinal intacta em ratos: correlatos morfológicos

The locomotion is one of the most important capabilities developed by the animals, whose improvement is dependent on several neural centers, including the spinal cord. This activity promotes a lot of spinal modifications that enable it to adapt and improve their connections. This study aimed to observe the morphological changes occurring in the spinal cord after locomotor training in intact rats. For that we used male Wistar rats, which were submitted to locomotor training in wheel activity in protocols 1, 3 and 7 days (30min/day), and the results were compared to a control group not subjected to exercise. Coronal sections of 40 μm of the lumbosacral spinal cord were subjected to immunohistochemical techniques anti-Egr1, anti-NMDA and anti-SP, to characterize the spinal plasticity related to these substances. Egr1-immunoreactive cells were increased in all laminas, essentially in those more intensely activated by locomotion, laminas IV-X levels L4-S3. All observed sections expressed NMDA-immunoreactivity. Analysis of SP in the spinal dorsal horn resulted no significant variations of this neuropeptide related to locomotion. The results suggest that locomotor training provides synaptic plasticity similar to LTP in all laminas of the lumbosacral spinal cord, in different intensities. However, the SP appears do not participate of this process in the spinal dorsal horn. This work will contribute for consolidating and characterization of synaptic plasticity in the spinal cord

Efeito de três tecnicas de alongamento muscular sobre o torque e atividade eletromiográfica

PURPOSE: To examine the acute effects caused by three techniques for stretching the hamstrings muscle on the active concentric peak torque (PT), passive PT and electromyographic activity (EMG). METHODS: Sixty volunteers (mean ± SD age, 22.6 ± 3 years), height 1.64 ± 0.07m and body weight of 58 ± 8.6kg, were randomly allocated into 4 groups of 15 subjects: Control Group (CG) - 5 minutes at rest, Static Stretching Group (SG) - 2 x 30s; Hold-Relax Group (HRG) - 3 x 6s of isometric contraction of hamstrings interspersed by 10s of hamstrings stretching and agonist Hold-Relax Group (AHRG) - 3 x 6s of isometric contraction of the quadriceps interspersed by 10s of hamstrings stretching. Evaluation has been conducted preand post-intervention, which verified the active concentric PT, passive PT EMG activity of IT. The statistical inference was performed by testing intra and inter, significance level at 5%. RESULTS: After intervention, there was a reduction in passive PT on CG, accompanied by a reduction of EMG activity, and an increase in passive PT on SG and AHRG. There was no change in the active concentric PT, or change in EMG activity. CG showed an increase in angle of the PT active, while the other groups showed no change. CONCLUSION: The results suggest that the shortterm stretching: 1) causes acute increase in passive torque, since the muscle does not perform sub-maximal contraction, 2) does not change in electromyographic activity and active torque, ind ependent of the technique

Efeitos da inclinação da esteira na marcha de crianças com síndrome de down

Background: Down syndrome (DS) is a genetic alteration characterized by being a nonprogressive congenital encephalopathy. Children with DS have hypotonia and developmental delays that interfere in the movement`s acquisition for these children. Objective: Analyze the effects of treadmill inclination on angle and spatiotemporal gait characteristics of these individuals. Methodology: We studied 23 subjects of both sexes, with ages ranged between 05 and 11 years, they presented ability to walk on level 5 classified according to the Functional Ambulation Category (FAC). Initially held a subjective evaluation of balance through a questionnaire (Berg Balance Scale-BBS) then the kinematic gait analysis was realized on a treadmill first, without inclination and then, with inclination of 10%, using the motion system analysis Qualisys System. Data analysis was done using BioStat 5.0 attributing significance level of 5%. Normality of data was verified using D'Agostino test and later was applied paired t-test to compare data in two experimental conditions. Results: There was a statistically significant difference in the spatiotemporal variables: reduction in the cadence (from 108.92 ± 39.07 to 99.11 ± 27.51, p <0.04), increase in cycle time (from 1.24 ± 0.27 to 1.36 ± 0.34, p = 0.03 ) and increase in time to take stock (from 0.77 ± 0.15 to 0.82 ± 0.18, p <0.001). Angular variables that showed statistically significant increasing were: the hip in the initial contact (12.23 ± 4.63 to 18.49 ± 5.17, p <0.0001) and max. flexion in balance (12.96±4:32 to 19.50 ± 4.51, p <0.0001 ), knee in the initial contact (15.59 to ± 6.71 to 21.63 ± 6.48, p <0.0001), the ankle in the initial contact (-2.79 ± 9.8 to 2.25 ± 8.79, p <0.0001), max dorsiflexion in stance (4.41 ± 10.07 to 7.13 ± 11.58, p <0.0009), maximum plantar flexion in the pre-assessment of the ankle joint (increase of -6.33 ± 8.77 to -2.69 ± 8.62, p <0.0004).Conclusions: The inclination acts in a positive way for angular and spatiotemporal features gait of children with Down syndrome, demonstrating possible benefit of using this surface in the gait rehabilitation of children with Down Syndrome

O complexo nuclear vestibular do sagui (callithrix jacchus): caracterização citoarquitetônica e neuroquímica

To the vertebrates, maintain body balance against the gravitational field and be able to orient themselves in the environment are fundamental aspects for survival, in which the participation of vestibular system is essential. As part of this system, the vestibular nuclear complex is the first central station that, by integrating many information (visual, proprioceptive), and the vestibular, assumes the lead role in maintaining balance. In this study, the vestibular nuclear complex was evaluated in relation to its cytoarchitecture and neurochemical content of cells and axon terminals, through the techniques of Nissl staining and immunohistochemistry for neuronal specific nuclear protein (NeuN), glutamate (Glu), substance P (SP), choline acetyltransferase (ChAT) (enzyme that synthesizes acetylcholine-Ach) and glutamic acid decarboxylase (GAD) (enzyme that synthesizes gamma-amino butyric acid-GABA). The common marmoset (Callithrix jacchus) was used as experimental animal, which is a small primate native from the Atlantic Forest in the Brazilian Northeast. As results, the Nissl technique, complemented by immunohistochemistry for NeuN allowed to delineate the vestibular nucleus superior, lateral, medial and inferior (or descending) in the brain of the common marmoset. Neurons and terminals immunoreactive to Glu and ChAT and only immunoreactive terminals to SP and GAD were seen in all nuclei, although in varying density. This study confirms the presence in the vestibular nuclei of the common marmoset, of Glu and SP in terminals, probably from the first order neurons of vestibular ganglion, and of GABA in terminals, presumably from Purkinge cells of the cerebellum. Second-order neurons of the vestibular nuclei seem to use Glu and Ach as neurotransmitters, judging by their expressive presence in the cell bodies of these nuclei in common marmosets, as reported in other species

Funcionalidade em pacientes após acidente vascular encefálico: relação com o sono e ritmo de atividade-repouso

It is known that sleep plays an important role in the process of motor learning. Recent studies have shown that the presence of sleep between training a motor task and retention test promotes a learning task so than the presence of only awake between training and testing. These findings also have been reported in stroke patients, however, there are few studies that investigate the results of this relationship on the functionality itself in this population. The objective of this study was to evaluate the relationship between functionality and sleep in patients in the chronic stage of stroke. A cross-sectional observational study was conducted. The sample was composed of 30 stroke individuals in chronic phase, between 6 and 60 months after injury and aged between 55 and 75 years. The volunteers were initially evaluated for clinical data of disease and personal history, severity of stroke, through the National Institute of Health Stroke Scale, and mental status, the Mini-Mental State Examination. Sleep assessment tools were Pittsburgh Sleep Quality Index, the Questionnaire of Horne and Ostberg, Epworth Sleepiness Scale, the Berlin questionnaire and actigraphy, which measures were: real time of sleep, waking after sleep onset, percentage of waking after sleep onset, sleep efficiency, sleep latency, sleep fragmentation index, mean activity score. Other actigraphy measures were intraday variability, stability interdiária, a 5-hour period with minimum level of activity (L5) and 10-hour period with maximum activity (M10), obtained to evaluate the activity-rest rhythm. The Functional Independence Measure (FIM) and the Berg Balance Scale (BBS) were the instruments used to evaluate the functional status of participants. The Spearman correlation coefficient and comparison tests (Student's t and Mann-Whitney) were used to analyze the relationship of sleep assessment tools and rest-activity rhythm to measures of functional assessment. The SPSS 16.0 was used for analysis, adopting a significance level of 5%. The main results observed were a negative correlation between sleepiness and balance and a negative correlation between the level of activity (M10) and sleep fragmentation. No measurement of sleep or rhythm was associated with functional independence measure. These findings suggest that there may be an association between sleepiness and xii balance in patients in the chronic stage of stroke, and that obtaining a higher level of activity may be associated with a better sleep pattern and rhythm more stable and less fragmented. Future studies should evaluate the cause-effect relationship between these parameters

Aprendizagem motora baseada em demonstrações de movimento biológico

O objetivo deste estudo foi avaliar o processo de aprendizagem motora de uma habilidade complexa da Ginástica Artística a partir da observação de demonstrações de modelos de pontos de luz e vídeo. Dezesseis participantes divididas em grupos dos respectivos modelos executaram um pré-teste, seguido de 100 tentativas de uma parada de mãos, igualmente distribuídas em blocos de 10 tentativas em dois dias, alternando períodos de demonstração e prática, com um teste de retenção após um dia. Cinemática de braço, tronco e perna das participantes possibilitaram análise da semelhança entre a coordenação de cada participante e do modelo e do tempo de movimento; a performance das participantes também foi avaliada por duas especialistas em Ginástica Artística. Ambas as análises indicaram que os grupos não diferiram. Os resultados são discutidos em termos da hipótese de suficiência de informação nos modelos de movimento biológico particularmente aplicada ao processo de aprendizagem de habilidades motoras complexas.

Síndrome da fragilidade e fatores associados em idosos comunitários do município de Santa Cruz RN

The frailty in the elderly is characterized by decreased physiological reserves, and is associated with increased risk of disability and high vulnerability to morbidity and mortality. This study is part of a multicentric project on Frailty in Elderly Brazilians (REDE FIBRA). Aims: to investigate characteristics, prevalence and associated factors related to frailty. Metodology: We interviewed 391 elderly patients aged 65 years, selected randomly. Data collection was performed using a multidimensional questionnaire containing information about socio-demographic and clinical variables. To characterize the frail elderly, was considered the phenotype proposed by Fried. Data were analyzed using descriptive statistics, bivariate analysis (χ ²) and binary logistic regression. Results: The prevalence of frailty was 17.1%. In the final model of multivariate analysis, was obtained as factors associated with frailty: advanced chronological age (p <0.001), have comorbidity (p <0.035), show dependence on performing basic activities of daily living (p <0.010) and instrumental (p <0.003) and have poor perception of health status (p <0030). Conclusions: The factors associated with frailty suggest a predictive model helping to understand the syndrome, guiding actions that minimize adverse effects on the aging process

Influência da fadiga no comportamento neuromuscular do quadríceps femoral, após reconstrução do ligamento cruzado anterior

Muscle fatigue is a phenomenon that promotes physiological and biomechanical disorders and their changes in healthy subjects have been widely studied and have significant importance for care in preventing injuries, but we do not have many information about its effects in patients after ACL reconstruction. Thus, this study is to analyze the effects of fatigue on neuromuscular behavior of quadriceps after ACL reconstruction. To reach this objective, participants were forty men, twenty healthy (26,90 ± 6,29 years) and twenty after ACL reconstruction (29,75 ± 7,01 years) with a graft of semitendinosus and gracilis tendons, between four to six months after surgery. At first, there was an assessment of joint position sense (JPS) at the isokinetic dynamometer at a speed of 5°/s and target angle of 45° to analyze the absolute error of JPS. Next, we applied the a muscle fatigue protocol, running 100 repetitions of isokinetic knee flexion-extension at 90°/s. Concurrently with this protocol, there was the assessment of muscle performance, as the peak torque (PT) and fatigue index, and electromyographic activity (RMS and median frequency). Finally, we repeated the assessment of JPS. The statistical analysis showed that patients after ACL reconstruction have, even under normal conditions, the amended JPS compared with healthy subjects and that after fatigue, both have disturbances in the JPS, but this alteration is significantly exacerbated in patients after ACL reconstruction. About muscle performance, we could notice that these patients have a lower PT, although there are no differences between the dynamometric and EMG fatigue index. These findings show the necessity about the cares of pacients with ACL reconstruction in respect of the risks of articulate instability and overload in ligamentar graft

Efeitos do treino em esteira com suporte parcial de peso e do método de facilitação neuromuscular proprioceptiva na marcha hemiparética: estudo comparativo

Objective: To compare the effects of the treadmill training with partial body-weight support (TPBWS) and Proprioceptive Neuromuscular Facilitation (PNF) method on gait of subjects with chronic stroke. Design: Quasi-experimental study. Setting: Laboratorial research. Participants: Twenty-three subjects (13 men and 10 women), with a mean age of 56,7 ± 8,0 years and a mean time since the onset of the stroke of 27,7 ± 20,3 months, and able to walk with personal assistance or assistive devices. Interventions: Two experimental groups underwent gait training based on PNF method (PNF group, n=11) or using the TPBWS - Gait Trainer System 2, Biodex, USA (TPBWS group, n=12), for three weekly sessions, during four weeks. Measures: Evaluation of motor function - using the Stroke Rehabilitation Assessment of Movement (STREAM) and the motor subscale of the Functional Independence Measure (motor FIM) -, and kinematic gait analyze with the Qualisys System (Qualisys Medical AB, Gothenburg, Sweden) were carried out before and after the interventions. Results: Increases in the STREAM scores (F=49.189, P<0.001) and in motor FIM scores (F=7.093, P=0.016), as well as improvement in symmetry ratio (F=7.729, P=0.012) were observed for both groups. Speed, stride length and double-support time showed no change after training. Differences between groups were observed only for the maximum ankle dorsiflexion over the swing phase (F=6.046, P=0.024), which showed an increase for the PNF group. Other angular parameters remain unchanged. Conclusion: Improvement in motor function and in gait symmetry was observed for both groups, suggesting similarity of interventions. The cost-effectiveness of each treatment should be considered for your choice

Apoio social e síndrome da fragilidade em idosos residentes na comunidade

Introduction: The frailty in the elderly is the result of a complex interplay between many social and clinical factors involved in its genesis. Although there is an understanding of its association with increased risk of adverse clinical outcomes, still it is unclear whether this syndrome can be aggravated due to lack of social support. So, the objective of this study was to analyze the association between social support and frailty syndrome in elderly community residents. Materials and methods: Observational analytical cross-sectional study, with a sample of 300 elderly living in the city of Natal-RN. Were collected informations about socialdemographic, economics and physical health data. The Social support was assessed by the status of cohabitation; marital status; contact frequency and diversity rate; received and given attendance frequency rate; and Map Minimum Relations of the Elderly. The frailty was assessed using the following criteria: unintentional weight loss, weakness, low physical activity, exhaustion and Slowness. To observe any possible associations, we performed the Pearson chi-square test, the Student t test and multivariate analysis using binary logistic regression, adopting a significance level of 5%. Results: It was observed that there were no associations of frailty with the social support variables, except for housekeeping mode (p = 0.046) of the MMRI. For the sociodemographic, economic, physical health and social support data, only age (p <0.001), sedentary lifestyle (p = 0.002) and poor perceived health (p = 0.001) were the ones that remained in the logistic regression model, with strong association for the presence of frailty. Conclusion: Among the variables related to social support, only to help with housekeeping was significantly associated with frailty. However, more studies need to be developed to characterize the social vulnerability, as well as health services need to recognize the importance of social support as an integral part of care for the elderly

Efeitos da adição de carga no treino de marcha na esteira em indivíduos com Doença de Parkinson: ensaio clínico controlado randomizado

Introduction: The intrinsic gait disorders in individuals with Parkinson's disease (PD) are one of the most disabling motor symptoms. Among the therapeutic approaches used in attempts to improve the motor function, especially the gait pattern of individuals, stands out the treadmill gait training associated with the addition of load. However, there are few findings that elucidate the benefits arising from such practice. Objective: To assess the effects of adding load on the treadmill gait training in individuals with PD. Material and Methods: A controlled, randomized and blinded clinical trial, was performed with a sample of 27 individuals (18 men and 9 women) with PD, randomly assigned to three experimental conditions, namely: treadmill gait training (n=9), treadmill gait training associated with addition of 5% load (n=9) and treadmill gait training associated with addition of 10% load (n=9). All volunteers were assessed, during phase on of Parkinson's medication, regarding to demographic, clinical and anthropometric (identification form) data, level of disability (Hoehn and Yahr Modified Scale), cognitive function (Mini Mental State Examination), clinical functional - in those areas activity of daily living and motor examination (Unified Parkinson's Disease Rating Scale - UPDRS) and gait cinematic analysis was performed through Qualisys Motion Capture System®. The intervention protocol consisted of gait training in a period of 4 consecutive weeks, with three weekly sessions, lasting 30 minutes each. The post-intervention assessment occurred the next day after the last training session, which was performed cinematic analysis of gait and the UPDRS. Data analysis was performed using the software Statistical Package for Social Sciences® (SPSS) 17.0. Results: The age of volunteers ranged from 41 to 75 years old (62,26 ± 9,07) and the time of clinical diagnosis of PD between 2 to 9 years (4,56 ± 2,42). There was a reduction regarding the score from motor exam domain (p=0,005), only when training with the addition of a 5% load. As for the space-time variables there was no significant difference between groups (p>0,120); however, the training with addition of 5% load presented the following changes: increase in stride length (p=0,028), in step length (p=0,006), in time balance of the most affected member (p=0,006) and reduction in support time of the referred member (p=0,007). Regarding angular variables significant differences between groups submitted to treadmill gait training without addition load and with 5% of load were observed in angle of the ankle at initial contact (p=0,019), in plantar flexion at toe-off (p=0,003) and in the maximum dorsiflexion in swing (p=0,005). While within groups, there was a reduction in amplitude of motion of the ankle (p=0,048), the only workout on the treadmill. Conclusion: The treadmill gait training with addition of 5% load proved to be a better experimental condition than the others because it provided greater gains in a number of variables (space-time and angular gait) and in the motion function, becoming a therapy capable of effectively improving the progress of individuals with PD

Influência da adição de carga na marcha em esteira de crianças com paralisia cerebral hemiparética espástica

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Análise da relação entre alterações do padrão do sono e dor lombo-pélvica em mulheres no segundo trimestre gestacional

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Efeitos do treinamento aeróbio sobre sinais precoces do remodelamento do ventrículo esquerdo induzido pelo diabetes Mellitus experimental

Our aim was to investigate the effects of an aerobic training program on adverse and early left ventricle (LV) remodeling, using an experimental model of short-term type 1 diabetes (T1D). Wistar rats were divided in 4 groups: sedentary control (SC), trained control (TC), sedentary diabetic (SD) and trained diabetic (TD). T1D was induced by streptozotocin (45 mg/kg). The training program consisted of 4 weeks running on a treadmill (13 m/min, 60 min/day, 5 days/week). At the end of the experiments, hearts were collected for analysis of morphology and transcriptional profile of LV, by focusing on its remodeling. Deaths were recorded during the 4-week period. We verified high mortality among animals of DS group, whereas it was significantly reduced in DT group. DS group also showed an increase in cross-sectional area of cardiomyocytes and fibrosis. TD group exhibited reduction in measures of cardiac trophism, but with respect to collagen content, it was similar to CS group. Analysis of gene expression related to cardiac remodeling revealed decreased expression of collagen I and III, as well as low expression of MMP-2 in DS group. TD group showed decreased levels of mRNA for MMP-9, and unchanged gene expression of MMP-2 when compared with the CS group. The expression of MMP-2 and TGF-1 were increased in CT group. The ratio between gene expression of collagen I and III was increased in the CT group and decreased in diabetic groups. These results establish early changes of the structure and transcriptional profile of LV myocardium. Moreover, they indicate that aerobic exercise training plays specific protection against mechanisms responsible for cardiac damage observed in T1D