A new streptocyanine dye has been doped into monolithic silica gels with different porosities, characterized
by nitrogen adsorption isotherms. Single-molecule tracking with a wide-field fluorescence microscope is used
to determine the diffusivity of the dye in the nanoporous network of the host. The majority of molecules in
the gel with wider pores (22 nm) diffuse freely with an average diffusion coefficient of D = 4.7 × 10-9 cm2
s-1. Most of those in the gel with narrower pores (3 nm) are trapped in regions ranging in size from 50
nmthe positioning accuracy of the setupup to 200 nm. Others are alternately trapped and freely diffusing
with an average D = 3.5 × 10-10 cm2 s-1. The significance of the distribution of diffusion coefficients measured
by single-molecule tracking is discussed. Besides traps, the wide spread of the diffusion coefficients for
individual molecules in both gels reveals pronounced microscopic inhomogeneities.
Turiasauria is a clade of eusauropods with a wide stratigraphic range that could extend from the Bathonian to the lower Aptian including Turiasaurus, Losillasaurus, Zby and putatively, Galveosaurus, Atlasaurus and isolated remains from Middle Jurassic-to-Lower Cretaceous. Some are characterised by the presence of heart-shaped teeth. Several tooth occurrences from the Portuguese Upper Jurassic with this type of morphology (SI: 1.1-1.8) are reported and discussed. If this morphology is regarded as synapomorphic of Turiasauria, the teeth will be tentatively related to this clade. From a sample of 43 teeth, three main morphotypes are described. Three hypotheses might explain the morphological variation: (1) the range of tooth morphologies indicates variation in the jaw, (2) the range of tooth morphologies indicates taxonomic variation or (3) a combination of both. The general wear pattern in morphotypes I and II starts with a distal facet, then the appearance of mesial/apical facet and finally a 'V'-shaped facet. In morphotype III, the wear begins with a mesial facet. The variability observed for Portuguese Upper Jurassic specimens is congruent with the morphological variability along the tooth row shown by other sauropods with spatulate/spoon-shaped teeth and it is considered the most parsimonious hypothesis to explain it.
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