Alves Luiz G A, Scariot Débora B, Guimarães Renato R, Nakamura Celso V, Mendes Renio S, Ribeiro Haroldo V
Departamento de Física, Universidade Estadual de Maringá, Maringá, PR, 87020-900, Brazil.
Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, 60208, United States of America.
PLoS One. 2016 Mar 23;11(3):e0152092. doi: 10.1371/journal.pone.0152092. eCollection 2016.
We report on a diffusive analysis of the motion of flagellate protozoa species. These parasites are the etiological agents of neglected tropical diseases: leishmaniasis caused by Leishmania amazonensis and Leishmania braziliensis, African sleeping sickness caused by Trypanosoma brucei, and Chagas disease caused by Trypanosoma cruzi. By tracking the positions of these parasites and evaluating the variance related to the radial positions, we find that their motions are characterized by a short-time transient superdiffusive behavior. Also, the probability distributions of the radial positions are self-similar and can be approximated by a stretched Gaussian distribution. We further investigate the probability distributions of the radial velocities of individual trajectories. Among several candidates, we find that the generalized gamma distribution shows a good agreement with these distributions. The velocity time series have long-range correlations, displaying a strong persistent behavior (Hurst exponents close to one). The prevalence of "universal" patterns across all analyzed species indicates that similar mechanisms may be ruling the motion of these parasites, despite their differences in morphological traits. In addition, further analysis of these patterns could become a useful tool for investigating the activity of new candidate drugs against these and others neglected tropical diseases.
我们报告了对鞭毛虫原生动物物种运动的扩散分析。这些寄生虫是被忽视的热带疾病的病原体：由亚马逊利什曼原虫和巴西利什曼原虫引起的利什曼病、由布氏锥虫引起的非洲昏睡病以及由克氏锥虫引起的恰加斯病。通过跟踪这些寄生虫的位置并评估与径向位置相关的方差，我们发现它们的运动具有短时瞬态超扩散行为的特征。此外，径向位置的概率分布是自相似的，并且可以用拉伸高斯分布来近似。我们进一步研究了单个轨迹的径向速度的概率分布。在几个候选分布中，我们发现广义伽马分布与这些分布显示出良好的一致性。速度时间序列具有长程相关性，表现出强烈的持续行为（赫斯特指数接近1）。所有分析物种中“通用”模式的普遍性表明，尽管这些寄生虫在形态特征上存在差异，但类似的机制可能在支配它们的运动。此外，对这些模式的进一步分析可能成为研究针对这些以及其他被忽视热带疾病的新候选药物活性的有用工具。
