VTechWorks staff will be away for the winter holidays starting Tuesday, December 24, 2024, through Wednesday, January 1, 2025, and will not be replying to requests during this time. Thank you for your patience, and happy holidays!
 

Patterns of Hemolymph Pressure Related to Tracheal Tube Collapse in the Beetle Pterostichus commutabulis

Simple item page
dc.contributor.authorCox, Lewis Michaelen
dc.contributor.committeechairSocha, John J.en
dc.contributor.committeememberDudek, Daniel M.en
dc.contributor.committeememberWicks, Alfred L.en
dc.contributor.departmentEngineering Science and Mechanicsen
dc.date.accessioned2014-03-14T21:36:22Zen
dc.date.adate2011-06-06en
dc.date.available2014-03-14T21:36:22Zen
dc.date.issued2011-05-04en
dc.date.rdate2011-06-06en
dc.date.sdate2011-05-18en
dc.description.abstractRhythmic collapse and reinflation of tracheal tubes is a form of active ventilation that augments convective gas exchange in multiple orders of insects. The underlying mechanism driving this phenomenon is not known. Among other things, tracheal tube collapse could be caused by either direct impingement of trachea or by a difference of pressure gradients between the intra-tracheal air and the surrounding hemolymph. To determine the relationship between hemolymph pressure and tracheal tube collapse in the ground beetle (Pterostichus commutabulis), we performed direct measurements of hemolymph pressure inside the beetle's prothorax while simultaneously using synchrotron phase contrast imaging to observe morphological changes in the trachea. We observed that a pressure pulse co-occurred with every tube compression observed throughout the body, suggesting that pulses in hemolymph pressure are responsible for tracheal collapse. To assess the effects of the experimental x-ray conditions imposed on the subjects during imaging, hemolymph pressure was also directly measured in the prothorax of beetles less restricted in non-x-ray trials. To compare the pressure patterns in the two experiments, a novel method of identifying and analyzing pressure pulses was developed and applied to the data sets. The comparison provides the first quantitative characterization of a directly measured hemolymph pressure environment, and demonstrates strong similarities in the pressure patterns recorded in both tests. However, pulses occurring during the x-ray experiments exhibited larger average magnitudes. Further video analysis however shows that collapse of the primary tracheal tubes was observed to occur even in the presence of the smallest simultaneously measured pressure pulse (1.01 kPa), suggesting that collapse of the primary tracheal tubes.en
dc.description.degreeMaster of Scienceen
dc.identifier.otheretd-05182011-131013en
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-05182011-131013/en
dc.identifier.urihttp://hdl.handle.net/10919/42719en
dc.publisherVirginia Techen
dc.relation.haspartCox_LM_T_2011.pdfen
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subjectinsect respirationen
dc.subjectTracheal tube collapseen
dc.subjecthemolymph pressureen
dc.titlePatterns of Hemolymph Pressure Related to Tracheal Tube Collapse in the Beetle Pterostichus commutabulisen
dc.typeThesisen
thesis.degree.disciplineEngineering Science and Mechanicsen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.levelmastersen
thesis.degree.nameMaster of Scienceen

Files

Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
Cox_LM_T_2011.pdf
Size:
18.95 MB
Format:
Adobe Portable Document Format
Download

Collections

Masters Theses