Biology subjects

de Oliveira, L. F.

Publications and source records attributed to de Oliveira, L. F..

3 recordsLinked to original sources

bioRxiv2024

Network vulnerability of cattle movement in Minas Gerais, Brazil, from 2013 to 2022

The aim of this study was to analyze the network vulnerability of cattle movements from 2013 to 2022, in Minas Gerais, Brazil and to identify the spatial spreaders into the network to improve infectious disease control programs by targeted risk-based surveillance and intervention. The vulnerability was calculated considering the graphs diameter and the spatial spreaders with a threshold distance of 300 km, for incoming (IN) and outgoing (OUT) movements. Additionally, a risk-based analysis was performed in the more vulnerable region. The results showed Triangulo Mineiro / Alto Paranaiba with higher vulnerability and many IN spatial spreaders, as well as Vale do Mucuri region with many OUT spatial spreaders. The risk-based analysis revealed betweenness and out degree as the most effective measures to be considered for intervention. Therefore, the vulnerability analysis and the spatial spreader were observed as great tools for risk-based interventions and surveillance. Furthermore, Triangulo Mineiro / Alto Paranaiba and Vale do Mucuri regions were important regions, considering restriction of animal infectious disease spread in Minas Gerais, Brazil.

bioinformatics↗

bioRxiv2024

Greater distal activation of the biceps femoris long head during knee flexion and hip extension tasks reflects differences in peripheral, not central, motor unit properties.

PurposeRecent research has explored region-specific responses within the biceps femoris long head. However, evidence on regional muscle activation remains controversial, primarily because information derived solely from surface electromyograms (sEMG) amplitude does not necessarily provide an accurate estimate of neural drive to the muscle. To address this limitation, this study investigated whether there are proximodistal differences in motor unit properties of the biceps femoris long head during isometric hip extension and knee flexion tasks. MethodsSeventeen resistance-trained males performed isometric knee flexion and hip extension tasks at 20% and 40% of maximal voluntary contraction. High-density sEMG were recorded from proximal and distal regions of the biceps femoris long head and decomposed into individual motor units. Central motor unit properties (mean discharge rate, discharge rate variability, recruitment and de-recruitment thresholds) and action potential properties (amplitude and conduction velocity) were analyzed. Bipolar sEMG amplitude was also calculated for each region to simulate traditional sEMG measurements. ResultsBipolar sEMG amplitude, motor unit action potential amplitude and conduction velocity were significantly greater in the distal region during both tasks. In contrast, no proximodistal differences were observed in central motor unit properties. ConclusionThese findings suggest that increased bipolar sEMG amplitude in the distal region of the biceps femoris long head is driven by motor unit action potential properties rather than differences in central modulation, likely influenced by intra-muscular variations in muscle mechanics and geometry. This emphasizes limitations of relying solely on sEMG amplitude to infer neural control strategies in the biceps femoris long head.

physiology↗

bioRxiv2019

Human Skeletal Muscle has Large Capacity to Increase Carnosine Content in Response to Beta-Alanine Supplementation. A Systematic Review with Bayesian Individual and Aggregate Data E-Max Model and Meta-Analysis

Beta-alanine (BA) supplementation increases muscle carnosine content (MCarn), and is ergogenic in many situations. Currently, many questions on the nature of the Mcarn response to supplementation are open, and the response to these has considerable potential to enhance the efficacy and applications of this supplementation strategy. ObjectiveTo conduct a Bayesian analysis of available data on the Mcarn response to BA supplementation. MethodsA systematic review with meta-analysis of individual and published aggregate data using a dose response (Emax) model was conducted. The protocol was designed according to PRISMA guidelines. A three-step screening strategy was undertaken to identify studies that measured the Mcarn response to BA supplementation. In addition, individual data from 5 separate studies conducted in the authors laboratory were analysed. Data were extracted from all controlled and uncontrolled supplementation studies conducted on healthy humans. Meta-regression was used to consider the influence of potential moderators (including dose, sex, age, baseline Mcarn and analysis method used) on the primary outcome. Results and ConclusionThe Emax model indicated that human skeletal muscle has large capacity for non-linear Mcarn accumulation, and that commonly used BA supplementation protocols may not come close to saturating muscle carnosine content. Neither baseline values, nor sex, appear to influence subsequent response to supplementation. Analysis of individual data indicated that Mcarn is relatively stable in the absence of intervention, and effectually all participants respond to BA supplementation (99.3% response [95%CrI: 96.2 - 100]).

physiology↗