Designed Self‐Assembled β‐Sheet Peptide Fibrils as Templates for Silica Nanotubes

Sol–gel condensation of tetraethoxysilane in the presence of designed self‐assembled β‐sheet peptide fibril templates, followed by template extraction, yields hollow silica nanotubes. The nanotubes are hundreds of nanometers long and possess a central pore of ～ 3.5 nm, determined by the fibril template diameter. The effects of synthesis conditions have been investigated and the resultant silica materials characterized by various techniques. Silica nanostructures with various morphologies have been produced previously using supramolecular organic assemblies as templates. Hollow nano‐ or microtubes, which may have applications in separations, catalysis, nano‐optics, and ‐electronics have been of particular interest. Peptide‐based templates are especially interesting because of their relevance to biological silica microstructure formation. The new fibrillar peptide templates described here have the advantages of prescribed diameter, twist pitch, and handedness, which should impart chirality on the resulting silica nanotubes, providing control of the internal surface architecture by appropriate peptide design.     

The effect of the Müller-Lyer illusion on the planning and control of manual aiming movements.

Two experiments used Müller-Lyer stimuli to test the predictions of the planning-control model (S. Glover, 2002) for aiming movements. In Experiment 1, participants aimed to stimuli that either remained the same or changed upon movement initiation. Experiment 2 was identical except that the duration of visual feedback for online control was manipulated. The authors found that the figures visible during movement planning and online control had additive effects on endpoint bias, even when participants had ample time to use visual feedback to modify their movements (Experiment 2). These findings are problematic not only for the planning-control model but also for A. D. Milner and M. A. Goodale's (1995) two visual system explanation of illusory bias. Although our results are consistent with the idea that a single representation is used for perception, movement planning, and online control (e.g., V. H. Franz, 2001), other work from our laboratory and elsewhere suggests that the manner in which space is coded depends on constraints associated with the specific task, such as the visual cues available to the performer. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Child weighing by the unschooled: a report of a controlled study of growth monitoring over 12 months of Maasai children using direct recording scales

Growth monitoring was developed as a clinic-based programme in the early 1960s, and has spread widely in many countries. The results of weighing children are usually presented in a graphic form, unintelligible to most mothers and difficult for many health workers to interpret. This study suggests that the TALC Direct Recording Scale will allow growth monitoring to be undertaken even by illiterate mothers in the community and reports the results of a trial with a group of illiterate mothers amongst the Maasai of Kenya.