SUMMARY Quasi-linear field-dependence of remanence provides the foundation for sedimentary relative palaeointensity studies that have been widely used to understand past geomagnetic field behaviour and to date sedimentary sequences. Flocculation models are often called upon to explain this field dependence and the lower palaeomagnetic recording efficiency of sediments. Several recent studies have demonstrated that magnetic-mineral inclusions embedded within larger non-magnetic host silicates are abundant in sedimentary records, and that they can potentially provide another simple explanation for the quasi-linear field dependence. In order to understand how magnetic inclusion-rich detrital particles acquire sedimentary remanence, we carried out depositional remanent magnetization (DRM) experiments on controlled magnetic inclusion-bearing silicate particles (10–50 μm in size) prepared from gabbro and mid-ocean ridge basalt samples. Deposition experiments confirm that the studied large silicate host particles with magnetic mineral inclusions can acquire a DRM with accurate recording of declination. We observe a silicate size-dependent inclination shallowing, whereby larger silicate grains exhibit less inclination shallowing. The studied sized silicate samples do not have distinct populations of spherical or platy particles, so the observed size-dependence inclination shallowing could be explained by a ‘rolling ball’ model whereby larger silicate particles rotate less after depositional settling. We also observe non-linear field-dependent DRM acquisition in Earth-like magnetic fields with DRM behaviour depending strongly on silicate particle size, which could be explained by variable magnetic moments and silicate sizes. Our results provide direct evidence for a potentially widespread mechanism that could contribute to the observed variable recording efficiency and inclination shallowing of sedimentary remanences.

Magnetotactic bacteria (MTB) produce intracellular ferrimagnetic crystals (magnetosomes) consisting of magnetite (Fe 3 O 4 ) or greigite (Fe 3 S 4 ) aligned in chains (e.g., Faivre & Schüler, 2008). These magnetosomes provide MTB a permanent magnetic dipole that orients the bacteria along geomagnetic field lines (magnetotaxis) to navigate toward optimal living conditions . Signatures from MTB can be used to trace Earth surface environmental conditions and biogeochemical cycles (e.g.,

The traditional management of Manske 3B and 4 thumbs is index finger pollicization. Recently, the transfer of composite tissues from the foot to reconstruct the thumb or the carpometacarpal joint has allowed the preservation of a five-digit hand. Concerns remained about the donor site and also the limited functional and cosmetic outcomes that could be achieved. This article challenges the existing dogma in the management of hypoplastic thumbs, that pollicization should always be the reference standard. We describe the evolution of techniques with free vascularized metatarsal transfer, our refinements and our proposal for a new classification system that accommodates these modifications. With increased experience, acceptable outcomes that are comparable with pollicization can be achieved.

Magnetosomes synthesized by magnetotactic bacteria (MTB) are membrane bound magnetic mineral crystals, either magnetite or greigite, arranged in chains with specific morphologies and narrow size ranges (Bazylinski & Frankel, 2004). Magnetosomes can be preserved in sediments as magnetofossils (Kopp & Kirschvink, 2008), which are considered to be excellent paleomagnetic recorders, routinely used for magnetostratigraphic dating (e.g.,