@article{GhaisariWinklhoferStrauchetal.2017,
  author    = {Ghaisari, Sara and Winklhofer, Michael and Strauch, Peter and Klumpp, Stefan and Faivre, Damien},
  title     = {Magnetosome Organization in Magnetotactic Bacteria Unraveled by Ferromagnetic Resonance Spectroscopy},
  series = {Biophysical journal},
  volume    = {113},
  journal   = {Biophysical journal},
  publisher = {Cell Press},
  address   = {Cambridge},
  issn      = {0006-3495},
  doi       = {10.1016/j.bpj.2017.06.031},
  pages     = {637 -- 644},
  year      = {2017},
  abstract  = {Magnetotactic bacteria form assemblies of magnetic nanoparticles called magnetosomes. These magnetosomes are typically arranged in chains, but other forms of assemblies such as clusters can be observed in some species and genetic mutants. As such, the bacteria have developed as a model for the understanding of how organization of particles can influence the magnetic properties. Here, we use ferromagnetic resonance spectroscopy to measure the magnetic anisotropies in different strains of Magnetosprillum gtyphiswaldense MSR-1, a bacterial species that is amendable to genetic mutations. We combine our experimental results with a model describing the spectra. The model includes chain imperfections and misalignments following a Fisher distribution function, in addition to the intrinsic magnetic properties of the magnetosomes. Therefore, by applying the model to analyze the ferromagnetic resonance data, the distribution of orientations in the bulk sample can be retrieved in addition to the average magnetosome arrangement. In this way, we quantitatively characterize the magnetosome arrangement in both wild-type cells and Delta mamJ mutants, which exhibit differing magnetosome organization.},
  language  = {en}
}
@article{KarwinkelWinklhoferJanneretal.2022,
  author    = {Karwinkel, Thiemo and Winklhofer, Michael and Janner, Lars Erik and Brust, Vera and H{\"u}ppop, Ommo and Bairlein, Franz and Schmaljohann, Heiko},
  title     = {A magnetic pulse does not affect free-flight navigation behaviour of a medium-distance songbird migrant in spring},
  series = {The journal of experimental biology},
  volume    = {225},
  journal   = {The journal of experimental biology},
  number    = {19},
  publisher = {Company of Biologists},
  address   = {Cambridge},
  issn      = {0022-0949},
  doi       = {10.1242/jeb.244473},
  pages     = {7},
  year      = {2022},
  abstract  = {Current evidence suggests that migratory animals extract map information from the geomagnetic field for true navigation. The sensory basis underlying this feat is elusive, but presumably involves magnetic particles. A common experimental manipulation procedure consists of pre-treating animals with a magnetic pulse, with the aim of re-magnetising particles to alter the internal representation of the external field prior to a navigation task. Although pulsing provoked deflected bearings in caged songbirds, analogous studies with free-flying songbirds yielded inconsistent results. Here, we pulsed European robins (Erithacus rubecula) at an offshore stopover site during spring migration and monitored their free-flight behaviour with a regional-scale network of radio-receiving stations. We found no pulse effect on departure probability, nocturnal departure timing departure direction or consistency of flight direction. This suggests either no use of the geomagnetic map by our birds, or that magnetic pulses do not affect the sensory system underlying geomagnetic map detection.},
  language  = {en}
}