BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//RLASKEY//CALENDEROUS//EN
CALSCALE:GREGORIAN
METHOD:PUBLISH
BEGIN:VEVENT
DTSTAMP:20261020T192948Z
LAST-MODIFIED:20160314T145840Z
DTSTART:20160322T143000Z
DTEND:20160322T153000Z
UID:event1570@bu.edu
URL:http://physics.bu.edu/internal/events/show/1570
SUMMARY:Studies on Helicobacter Pylori Motility: Influence of Cell Morpholo
	gy\, Medium Rheology\, and Swimming Mechanism
DESCRIPTION:Featuring Joseph Hardcastle\n\nPart of the PhD Final Oral Exams
	.\n\nDissertation Committee:  Rama Bansil\, Shyam Erramilli\, Pankaj Mehta\
	, Steve Ahlen\, Kiril Korolev\n\nAbstract:\n\nIn this thesis\, I present a 
	detailed analysis of the role of cell morphology\, solution rheology\, and 
	swimming mechanism has on the motility of Helicobacter Pylori. H. Pylori\, 
	the bacterium that causes gastric ulcers\, has a helical cell shape that ha
	s long been believed to provide an advantage in penetrating the viscous muc
	us layer protecting the stomach lining\, its niche environment. I present r
	esults obtained by performing optical microscopic live cell bacteria tracki
	ng of wild-type H. Pylori and cell shape and flagella mutants of H. Pylori.
	 Bacteria tracking experiments show that helical shaped bacteria swim faste
	r than straight rod-shaped bacteria\, and bacteria with larger number of fl
	agella swim faster. Altering cell shape is found to have a smaller effect o
	n swimming speed than altering the number of flagella a bacterium has. Thes
	e experimental observations are then compared to resistive force theory pre
	dictions. Resistive force theory shows qualitative agreement to our experim
	ental observations\, but overestimates the increase in swimming speed for a
	 helical cell when compared to straight rod cell. In addition to effect of 
	cell morphology on motility\, I explore how motility is altered in differen
	t polymer environments by tracking bacteria in pig gastric mucin\, methylce
	llulose\, and gelatin solutions and gels. Bacteria are found to increase th
	eir swimming speed non-monotonically with increasing polymer concentration\
	, while the number of mobile bacteria is found to decrease with increased p
	olymer concentration. I also present an analysis of the swimming mechanism 
	used by H. Pylori. H. Pylori is found to use a run-reverse swimming mechani
	sm which I model as a random walk. This random walk model fits well to the 
	experimental data and provides a theoretical tool for interpreting H. Pylor
	i's swimming mechanism. Taken together these results provide a detailed des
	cription of the motility of H. Pylori in different media and are applicable
	 to the broad question of how H. Pylori infects and colonizes the mucus lay
	er of the stomach. \n\n![Joseph](/resources/event-image/1570/3dc6108_small)
LOCATION:PRB 365\, 3 Cummington Mall\, 02215
STATUS:CONFIRMED
CLASS:PUBLIC
END:VEVENT
END:VCALENDAR