Using this photo   The thumbnail photo (128x192 pixels) on this page may be freely used for personal or academic purposes without prior permission under the Fair Use provisions of US copyright law as long as the photo is clearly credited with © 2009 Sergio Potsch. For other uses, or if you have questions, contact S�rgio Potsch Carvalho-e-Silva spotsch[AT]gmail.com. (Replace the [AT] with the @ symbol before sending an email.)