Ocean‐bottom seismometers (OBSs) commonly record short‐duration events (SDEs) that could be described by all of these characteristics: (i) duration <1 s, (ii) one single‐wave train with no identified P nor S wave arrivals, and (iii) a dominant frequency usually between 4 and 30 Hz. In many areas, SDEs have been associated with gas‐ or fluid‐related processes near cold seeps or hydrothermal vents, although fish bumps, instrumental, or current‐generated noise have been proposed as possible sources. In order to address some remaining issues, this study presents results from in situ and laboratory experiments combined with observations from two contrasting areas, the Sea of Marmara (Turkey) and the Chilean subduction zone. The in situ experiment was conducted at the European Multidisciplinary Seafloor and water column Observatory‐Molène submarine observatory (near Brest, France) and consisted in continuously monitoring two OBSs with a camera. The images revealed that no fish regularly bumped into the instruments. Laboratory experiments aimed at reproducing SDEs' waveforms by injecting air or water in a tank filled by sand and seawater and monitored with an OBS. Injecting air in the sediments produced waveforms very similar to the observed SDEs, while injecting air in the water column did not, constraining the source of SDEs in the seafloor sediments. Finally, the systematic analysis of two real data sets revealed that it is possible to discriminate gas‐related SDEs from biological or sea state‐related noise from simple source parameters, such as the temporal mode of occurrence, the back azimuth, and the dominant frequency.

We present novel micromagnet array designs for on-chip focusing, programmable transport, and size-selective sorting of superparamagnetic beads. Controlled transport of cancer cells immunolabelled with beads is provided as proof-of-concept.

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Novel partially phosphonated polyethylenimine polymers are developed in order to control the modification of nanoparticle (NP) surfaces. This polymer is built by an accessible one‐step process. The numerous phosphonate functions assume both a strong covalent anchoring on metal oxide NPs and a modulation of electric charges, while amino groups are associated with dispersion preservation and subsequent biofunctionalization. The zwitterionic nanomaterials obtained display a good stability toward pH and ionic strength. According to the selected percentage of phosphonation and the polymer size, zeta potential, and diameter of the particles are controlled.