@article{UppaluriNaglerStellamannsetal.2011,
  author    = {Uppaluri, Sravanti and Nagler, Jan and Stellamanns, Eric and Heddergott, Niko and Herminghaus, Stephan and Pfohl, Thomas and Engstler, Markus},
  title     = {Impact of Microscopic Motility on the Swimming Behavior of Parasites: Straighter Trypanosomes are More Directional},
  series = {PLoS Computational Biology},
  volume    = {7},
  journal   = {PLoS Computational Biology},
  number    = {6},
  doi       = {10.1371/journal.pcbi.1002058},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-140814},
  pages     = {e1002058},
  year      = {2011},
  abstract  = {Microorganisms, particularly parasites, have developed sophisticated swimming mechanisms to cope with a varied range of environments. African Trypanosomes, causative agents of fatal illness in humans and animals, use an insect vector (the Tsetse fly) to infect mammals, involving many developmental changes in which cell motility is of prime importance. Our studies reveal that differences in cell body shape are correlated with a diverse range of cell behaviors contributing to the directional motion of the cell. Straighter cells swim more directionally while cells that exhibit little net displacement appear to be more bent. Initiation of cell division, beginning with the emergence of a second flagellum at the base, correlates to directional persistence. Cell trajectory and rapid body fluctuation correlation analysis uncovers two characteristic relaxation times: a short relaxation time due to strong body distortions in the range of 20 to 80 ms and a longer time associated with the persistence in average swimming direction in the order of 15 seconds. Different motility modes, possibly resulting from varying body stiffness, could be of consequence for host invasion during distinct infective stages.},
  language  = {en}
}
@article{StellamannsUppaluriHochstetteretal.2014,
  author    = {Stellamanns, Eric and Uppaluri, Sravanti and Hochstetter, Axel and Heddergott, Niko and Engstler, Markus and Pfohl, Thomas},
  title     = {Optical trapping reveals propulsion forces, power generation and motility efficiency of the unicellular parasites Trypanosoma brucei brucei},
  series = {Scientific Reports},
  volume    = {4},
  journal   = {Scientific Reports},
  number    = {6515},
  issn      = {2045-2322},
  doi       = {10.1038/srep06515},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-115348},
  year      = {2014},
  abstract  = {Unicellular parasites have developed sophisticated swimming mechanisms to survive in a wide range of environments. Cell motility of African trypanosomes, parasites responsible for fatal illness in humans and animals, is crucial both in the insect vector and the mammalian host. Using millisecond-scale imaging in a microfluidics platform along with a custom made optical trap, we are able to confine single cells to study trypanosome motility. From the trapping characteristics of the cells, we determine the propulsion force generated by cells with a single flagellum as well as of dividing trypanosomes with two fully developed flagella. Estimates of the dissipative energy and the power generation of single cells obtained from the motility patterns of the trypanosomes within the optical trap indicate that specific motility characteristics, in addition to locomotion, may be required for antibody clearance. Introducing a steerable second optical trap we could further measure the force, which is generated at the flagellar tip. Differences in the cellular structure of the trypanosomes are correlated with the trapping and motility characteristics and in consequence with their propulsion force, dissipative energy and power generation.},
  language  = {en}
}