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<TITLE>AG Seminar: Bill Sellers "Running with dinosaurs: fossils, physics and physiology" 1st December 2008</TITLE>
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<P><SPAN LANG="en-gb"><FONT SIZE=2 FACE="Arial">*** Apologies for Cross-posting: </FONT></SPAN><A HREF="http://manchester.siggraph.org/"><SPAN LANG="en-gb"><U><FONT COLOR="#0000FF" SIZE=2 FACE="Arial">http://manchester.siggraph.org/</FONT></U></SPAN></A><SPAN LANG="en-gb"><FONT SIZE=2 FACE="Arial"> ***</FONT></SPAN>
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<P><SPAN LANG="en-gb"><FONT SIZE=2 FACE="Arial">Bill Sellers, Integrative Vertebrate Biology, Faculty of Life Sciences, University of Manchester "Running with dinosaurs: fossils, physics and physiology" 1st December 2008, 2-3pm GMT Room 1.10, Kilburn Building The University of Manchester </FONT></SPAN></P>
<P><SPAN LANG="en-us"><FONT SIZE=2 FACE="Arial">Abstract: Traditional techniques for reconstructing gait in fossil dinosaurs either involve complex animatronic machines or stop motion animation techniques. These techniques rely on a good knowledge of the skeletal anatomy and a familiarity with the range of locomotor styles seen in modern animals. These are mixed with a great deal of artistic skill and often produce visually stunning results. However using these approaches it is impossible to say whether the animal could actually have moved as portrayed. The movements used are anatomically possible but in all likelihood if the animal had actually tried to move like this then it would have fallen over. Even had it managed to stay upright it would not have minimised its cost of locomotion as living animals do. These difficulties can be overcome if we include both Newtonian physics and musculoskeletal physiology in conjunction with skeletal anatomy in our reconstructions. To do this we create a computer model of the musculoskeletal system of our target vertebrate fossil. The limbs and body are reconstructed as jointed segments, and the muscles and tendons are force generators that power the movement. </FONT></SPAN></P>
<P><SPAN LANG="en-us"><FONT SIZE=2 FACE="Arial">This requires us to make estimates of various soft tissue parameters which are generally not preserved in the fossil record so we use a combination of phylogenetic and functional bracketing to estimate these values from living animals. The computer model is then imported into a physics simulator which solves the equations of motion so that the model moves appropriately given the forces applied by the muscles, by contact with the ground, and by gravity. Unfortunately such a model will not spontaneously walk or run so we use a genetic algorithm search procedure to find muscle activation patterns that optimise global parameters such as minimising energy cost or maximising speed. </FONT></SPAN></P>
<P><SPAN LANG="en-us"><FONT SIZE=2 FACE="Arial">The end result is the generation of stable gait that is anatomically, physiologically and physically possible. At the same time the gait can represent an objective estimate of the most energetically efficient gait, or alternatively the fastest gait possible for a given animal. </FONT></SPAN></P>
<P><SPAN LANG="en-us"><FONT SIZE=2 FACE="Arial">Sadly current technology does not produce gaits that look as good as the more artistic techniques and this new technique highlights the uncertainty inherent in all attempts at gait reconstruction. However ultimately it is a very powerful approach for the scientific understanding of dinosaur gait and we predict that as the technology advances it will also find a place assisting more artistic reconstructions. </FONT></SPAN></P>
<P><SPAN LANG="en-us"></SPAN><A HREF="http://www.animalsimulation.org"><SPAN LANG="en-us"><U><FONT COLOR="#0000FF" SIZE=2 FACE="Arial">http://www.animalsimulation.org</FONT></U></SPAN></A><SPAN LANG="en-us"></SPAN>
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<P><SPAN LANG="en-gb"><FONT SIZE=2 FACE="Arial">Part of the Access Grid enabled ACM University of Manchester Professional SIGGRAPH Chapter Seminar Series: </FONT></SPAN><A HREF="http://manchester.siggraph.org/"><SPAN LANG="en-gb"><U><FONT COLOR="#0000FF" SIZE=2 FACE="Arial">http://manchester.siggraph.org/</FONT></U></SPAN></A><SPAN LANG="en-gb"><FONT SIZE=2 FACE="Arial"> </FONT></SPAN></P>
<P><SPAN LANG="en-gb"><FONT SIZE=2 FACE="Arial">=======</FONT></SPAN>
<BR><SPAN LANG="en-gb"><FONT SIZE=2 FACE="Arial">Access Grid Information: Most of these meeting are Access Grid enabled. Anyone wishing to view a seminar via Access Grid should note the following. Please check the Jabber room shortly before the start of the seminar to find if ScreenStreamer is to be used.</FONT></SPAN></P>
<P><SPAN LANG="en-gb"><FONT SIZE=2 FACE="Arial">Virtual Venue: Access Grid Support Centre Virtual Venue: University of Manchester Room1:10</FONT></SPAN>
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<P><SPAN LANG="en-gb"><FONT SIZE=2 FACE="Arial">Jabber Room: university-of-manchester-(1.10) (sam.ag.manchester.ac.uk)@conference.mcs.anl.gov</FONT></SPAN>
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<P><SPAN LANG="en-gb"><FONT SIZE=2 FACE="Arial">ScreenStreamer</FONT></SPAN>
<BR><SPAN LANG="en-gb"><FONT SIZE=2 FACE="Arial"> * Preferably use ScreenStreamer software - go to </FONT></SPAN><A HREF="http://www.memetic-vre.net/software/ScreenStreamer/ScreenStreamer.php"><SPAN LANG="en-gb"><U><FONT COLOR="#0000FF" SIZE=2 FACE="Arial">http://www.memetic-vre.net/software/ScreenStreamer/ScreenStreamer.php</FONT></U></SPAN></A><SPAN LANG="en-gb"><FONT SIZE=2 FACE="Arial"> and select room "University of Manchester (1.10)" from the AGSC section. Grab the screen feed (by clicking on it) from the screenstreamer window and resize it - more info can be found on </FONT></SPAN><A HREF="http://www.memetic-vre.net/software/ScreenStreamer"><SPAN LANG="en-gb"><U><FONT COLOR="#0000FF" SIZE=2 FACE="Arial">http://www.memetic-vre.net/software/ScreenStreamer</FONT></U></SPAN></A><SPAN LANG="en-gb"><FONT SIZE=2 FACE="Arial">.</FONT></SPAN></P>
<P><SPAN LANG="en-gb"><FONT SIZE=2 FACE="Arial"> * Alternatively, the screenshot (not animated) can be accessed at </FONT></SPAN><A HREF="http://192.150.184.66:7890"><SPAN LANG="en-gb"><U><FONT COLOR="#0000FF" SIZE=2 FACE="Arial">http://192.150.184.66:7890</FONT></U></SPAN></A><SPAN LANG="en-gb"><FONT SIZE=2 FACE="Arial"> (this IP might change for some sessions - please check Jabber). </FONT></SPAN></P>
<P><SPAN LANG="en-gb"><FONT SIZE=2 FACE="Arial">For technical assistance regarding the Access Grid, please contact the Access Grid Support Centre. Non-UK Access Grid nodes are advised to contact the Access Grid Support Centre to check connectivity before the date of the seminar.</FONT></SPAN></P>
<P><SPAN LANG="en-gb"><FONT SIZE=2 FACE="Arial">---</FONT></SPAN>
<BR><SPAN LANG="en-us"><FONT SIZE=2 FACE="Arial">Yours,</FONT></SPAN>
<BR><SPAN LANG="en-gb"><FONT SIZE=2 FACE="Arial">Martin J. Turner<BR>
Visualization Team Leader</FONT></SPAN>
<BR><SPAN LANG="en-gb"><FONT SIZE=2 FACE="Arial">Research Computing Services<BR>
Devonshire House</FONT></SPAN>
<BR><SPAN LANG="en-gb"><FONT SIZE=2 FACE="Arial">The University of Manchester<BR>
Manchester, M13 9PL</FONT></SPAN>
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<P><SPAN LANG="en-gb"><FONT SIZE=2 FACE="Arial">t : +44 (0) 161 275 0613<BR>
m : +44 (0) 7990 918 509<BR>
e : </FONT></SPAN><A HREF="mailto:martin.turner@manchester.ac.uk"><SPAN LANG="en-gb"><U><FONT COLOR="#0000FF" SIZE=2 FACE="Arial">martin.turner@manchester.ac.uk</FONT></U></SPAN></A><SPAN LANG="en-gb"><BR>
<FONT SIZE=2 FACE="Arial">w : </FONT></SPAN><A HREF="http://www.manchester.ac.uk/researchcomputing"><SPAN LANG="en-gb"><U><FONT COLOR="#0000FF" SIZE=2 FACE="Arial">www.rcs.manchester.ac.uk</FONT></U></SPAN></A><SPAN LANG="en-gb"></SPAN>
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