Modeling epidemics: A primer and Numerus Model Builder implementation.

Epidemiological models are dominated by compartmental models, of which SIR formulations are the most commonly used. These formulations can be continuous or discrete (in either the state-variable values or time), deterministic or stochastic, or spatially homogeneous or heterogeneous, the latter often embracing a network formulation. Here we review the continuous and discrete deterministic and discrete stochastic formulations of the SIR dynamical systems models, and we outline how they can be easily and rapidly constructed using Numerus Model Builder, a graphically-driven coding platform. We also demonstrate how to extend these models to a metapopulation setting using NMB network and mapping tools.

Effect of rehabilitation on the somatosensory evoked potentials and gait performance of hemiparetic stroke patients.

BACKGROUND: Gait performance of stroke patients is affected by impaired sensory ability. The purpose of the present study was to determine the relationship between somatosensory-evoked potential (SSEP) parameters and gait performance in hemiparetic stroke patients. METHODS: A convenience sample of 17 hemiparetic stroke patients (mean age 60.11 ± 8.83 years; 10 women; right hemiplegia: 10, left hemiplegia: 7) were recruited for the present study. The Electro Synergy system (Viasys Healthcare; San Diego, CA, USA) was used for SSEP evaluation. The 17 patients were assigned to two groups according to their SSEP results as follows: 8 patients to the normal response group and 9 patients to the abnormal group. All the participants underwent the same rehabilitation exercise programs during 4 weeks, followed by clinical evaluation. A mixed-design analysis of a variance model was used to test for differences in timed up-and-go (TUG) test and 10-meter walking test (10MWT) scores between the two independent groups while the participants were subjected to repeated measures (pretest and posttest). RESULTS: Analysis of variance revealed the main time effect (p< 0.05) and group by time interaction effect (p< 0.05). The post hoc test result confirmed that the normal sensory group showed greater improvement in TUG test and 10MWT scores than the abnormal sensory group (p< 0.05). The TUG test and 10MWT scores in the posttest were greater in the normal sensory group than in the abnormal sensory group. CONCLUSIONS: The present study demonstrated the importance of the clinical contribution of the baseline sensory function of individuals with hemiparetic stroke to their gait performance and recovery after stroke rehabilitation. As anticipated, the individuals who had intact or spared sensory function showed greater improvements in gait speed and performance measures than those who had impaired sensory function.

Best Core Stabilization for Anticipatory Postural Adjustment and Falls in Hemiparetic Stroke.

OBJECTIVES: To compare the effects of conventional core stabilization and dynamic neuromuscular stabilization (DNS) on anticipatory postural adjustment (APA) time, balance performance, and fear of falls in chronic hemiparetic stroke. DESIGN: Two-group randomized controlled trial with pretest-posttest design. SETTING: Hospital rehabilitation center. PARTICIPANTS: Adults with chronic hemiparetic stroke (N=28). INTERVENTIONS: Participants were randomly divided into either conventional core stabilization (n=14) or DNS (n=14) groups. Both groups received a total of 20 sessions of conventional core stabilization or DNS training for 30 minutes per session 5 times a week during the 4-week period. MAIN OUTCOME MEASURES: Electromyography was used to measure the APA time for bilateral external oblique (EO), transverse abdominis (TrA)/internal oblique (IO), and erector spinae (ES) activation during rapid shoulder flexion. Trunk Impairment Scale (TIS), Berg Balance Scale (BBS), and Falls Efficacy Scale (FES) were used to measure trunk movement control, balance performance, and fear of falling. RESULTS: Baseline APA times were delayed and fear of falling was moderately high in both the conventional core stabilization and DNS groups. After the interventions, the APA times for EO, TrA/IO, and ES were shorter in the DNS group than in the conventional core stabilization group (P<.008). The BBS and TIS scores (P<.008) and the FES score (P<.003) were improved compared with baseline in both groups, but FES remained stable through the 2-year follow-up period only in the DNS group (P<.003). CONCLUSIONS: This is the first clinical evidence highlighting the importance of core stabilization exercises for improving APA control, balance, and fear of falls in individuals with hemiparetic stroke.

Reflex-mediated dynamic neuromuscular stabilization in stroke patients: EMG processing and ultrasound imaging.

BACKGROUND: Postural core instability is associated with poor dynamic balance and a high risk of serious falls. Both neurodevelopmental treatment (NDT) and dynamic neuromuscular stabilization (DNS) core stabilization exercises have been used to improve core stability, but the outcomes of these treatments remain unclear. OBJECTIVE: This study was undertaken to examine the therapeutic effects of NDT and DNS core stabilization exercises on muscular activity, core stability, and core muscle thickness. METHODS: Ten participants (5 healthy adults; 5 hemiparetic stroke patients) were recruited. Surface electromyography (EMG) was used to determine core muscle activity of the transversus abdominis/internal oblique (TrA/IO), external oblique (EO), and rectus abdominis (RA) muscles. Ultrasound imaging was used to measure transversus abdominals/internal oblique (TrA/IO) thickness, and a pressure biofeedback unit (PBU) was used to measure core stability during the DNS and NDT core exercise conditions. Data are reported as median and range and were compared using nonparametric Mann - Whitney U test and Wilcoxon signed rank test at p< 0.05. RESULTS: Both healthy and hemiparetic stroke groups showed greater median EMG amplitude in the TrA/IO muscles, core stability, and muscle thickness values during the DNS exercise condition than during the NDT core exercise condition, respectively (p< 0.05). However, the relative changes in the EMG amplitude, core stability, and muscle thickness values were greater during the DNS exercise condition than during the NDT core exercise condition in the hemiparetic stroke patient group (p< 0.05). CONCLUSIONS: Our novel results provide the first clinical evidence that DNS is more effective than NDT in both healthy and hemiparetic stroke subjects to provide superior deep core muscle activation, core stabilization, and muscle thickness. Moreover, such advantageous therapeutic benefits of the DNS core stabilization exercise over the NDT exercise were more apparent in the hemiparetis stroke patients than normal controls.

Intestinal transit and opaque enema study in chagasic mice

Relato de um estudo experimental realizado em camundongos brancos infectados com Trypanosoma cruzi. Foram estudados o trânsito intestinal e morfologia do cólon por meio de raio-X. Na fase subaguda, o trânsito intestinal apresentou-se normal. Nas fases aguda e crônica, havia entretanto, um retardo no tempo de evacuaçäo. Num dos 12 animais, o enema opaco revelou a presença de megacolon