http://clipmarks.com/popular/date/2007/6/27/http://rss.clipmarks.com/popular/date/2007/6/27/15Clip, tag and save information that's important to you. Bookmarks save entire pages...Clipmarks save the specific content that matters to you!en-ushttp://clipmarks.com/clipmark/0C9002A8-01B8-415A-9DE0-F4DD08DA4998/<b>clipped by:</b> <a href="http://clipmarks.com/clipper/gzyra/">gzyra</a><br><div border="2" style="margin-top: 10px; border:#000000 1px solid;" width="90%"><div style="background-color:"><div align="center" width="100%" style="padding:4px;margin-bottom:4px;background-color:#666666;overflow:hidden;"><span style="color:#FFFFFF;font-weight:bold;">Clip Source: <a style="color:#FFFFFF;" href="http://www.sciencedaily.com/releases/2007/06/070621161826.htm" title="http://www.sciencedaily.com/releases/2007/06/070621161826.htm">www.sciencedaily.com</a></span></div><div style="padding: 10px;"><div style="text-align:left;">The next time you "catch a yawn" from someone across the room, you're not copying their sleepiness, you're participating in an ancient, hardwired ritual that might have evolved to help groups stay alert as a means of detecting danger. That's the conclusion of University at Albany researchers</div></div><hr size="2" color="#666666" /><div style="padding: 10px;"><div style="text-align:left;">people do not yawn because they need oxygen, since experiments show that raising or lowering oxygen and carbon dioxide in the blood fails to produce the reaction.  Rather, yawning acts as a brain-cooling mechanism. The brain burns up to a third of the calories we consume, and as a consequence generates heat</div></div><hr size="2" color="#666666" /><div style="padding: 10px;"><div style="text-align:left;">yawning enhances the brain’s functioning by increasing blood flow and drawing in cooler air</div></div><hr size="2" color="#666666" /><div style="padding: 10px;"><div style="text-align:left;">Evidence shows that blood vessels in the nasal cavity and face send cool blood to the brain, and by breathing through the nose or by cooling the forehead, the brain is cooled, eliminating the need to yawn</div></div><hr size="2" color="#666666" /><div style="padding: 10px;"><div style="text-align:left;">yawning does not promote sleep but helps mitigate the need to sleep</div></div></div></div><br><div style="margin-bottom: 40px;">Tags: <a href="http://clipmarks.com/tags/biology/" rel="tag">biology</a>, <a href="http://clipmarks.com/tags/evolution/" rel="tag">evolution</a>, <a href="http://clipmarks.com/tags/science/" rel="tag">science</a>, <a href="http://clipmarks.com/tags/human/" rel="tag">human</a></div>http://www.sciencedaily.com/releases/2007/06/070621161826.htmSun, 24 Jun 2007 16:27:01 GMT