The relationships between chemistry, crime, and art are explored in an outreach activity for middle and high school students that investigates a possible art fraud. Students characterize pigment samples via spectroscopy and chemical analysis to determine whether the pigments in a questioned painting are consistent with those used by the alleged artist or are suggestive of a more modern origin. In lieu of actual paint samples, water-soluble dyes and metal salts are used as mock pigments, allowing characterization of colored solutions via UV–visible absorbance spectroscopy. Chemical tests for iron and copper further assist with pigment identification.

The transcription factor D-Pax2 is required for the correct differentiation of several cell types in Drosophila sensory systems. While the regulation of its expression in the developing eye has been well studied, little is known about the mechanisms by which the dynamic pattern of D-Pax2 expression in the external sensory organs is achieved. Here we demonstrate that early activation of D-Pax2 in the sensory organ lineage and its maintenance in the trichogen and thecogen cells are governed by separate enhancers. Furthermore, the initial activation is controlled in part by proneural proteins whereas the later maintenance expression is regulated by a positive feedback loop.

INTRODUCTION-During a coordinated turn, subjects can misperceive tilts. Subjects accelerating in tilting-gondola centrifuges without external visual reference underestimate the roll angle, and underestimate more when backward-facing than when forward-facing. In addition, during centrifuge deceleration, the perception of pitch can include tumble while paradoxically maintaining a fixed perceived pitch angle. The goal of the present research was to test two competing hypotheses: (1) that components of motion are perceived relatively independently and then combined to form a threedimensional perception, and (2) that perception is governed by familiarity of motions as a whole in three dimensions, with components depending more strongly on the overall shape of the motion.

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