Browsing by Subject "LCM"
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Item Techniques for studying the nuclear condition of giant cells induced by Meloidogyne species(Texas A&M University, 2006-04-12) He, BinNematodes of the genus Meloidogyne are known as ??root-knot?? nematodes due to the characteristic knots or galls found on the roots of infected plants. Root-knot nematodes attack over 2000 species of plants and cause over 80 billion dollars lost annually. Giant cells are feeding sites of root-knot nematodes and are enlarged multinuclear cells induced by the nematodes in susceptible host roots and that function to provide nutrients to the nematode. This thesis presents data on two techniques of studying the nuclear condition in giant cells. Colchicine was used to arrest mitosis in giant cells in a previous study. Here we test the effect of colchicine on nematode activity. The results showed that colchicine did not affect nematode egg hatch, juvenile activity, or hatch of eggs produced by treated juveniles. These results confirm that colchicine can be used to arrest mitosis in giant cells without affecting the nematode parasite. A major obstacle to the study of giant cells is collecting tissue samples that are specific to giant cells. Laser capture microdissection (LCM) is a technique that allows one to sample a single giant cell. A focused laser beam was used to collect samples of giant cell cytoplasm from fixed and sectioned tissues. RNA was then extracted from those isolated samples. Using three tomato genes as test samples, specific primers were designed to measure expression level of Rb7, LHA4, and HXK1 gene by Real-Time PCR. Expression of LHA4 and Rb7 increased with time after inoculation, and immature giant cells reached levels that were 3 and 6 times, respectively, that of cortical cells, but which were not different from root meristem cells. Expression of HXK1 did not change with time after inoculation and has the same level of that in root tip and cortical tissues. These data confirmed that the techniques of LCM coupled with RT-real-time PCR can be used to quantitate expression of genes at different stages of giant cell development without contamination from surrounding cells.Item Upriver to Hue and Dong Ha: The U.S. Navy's War in I Corps, Vietnam 1967-1970(2012-02-14) Chavanne, Jonathan BlackshearThe United States Navy's involvement in the Vietnam War, especially its role in the region's inland waterways, has long been an overshadowed aspect of the conflict. Most histories ignore or minimize the Navy's contribution, especially its river patrol or 'brown water' role. Through archival and library research as well as interviews with U.S Navy Vietnam War veterans this thesis demonstrates the vital role played by the brown water navy in the northern provinces of South Vietnam. A key but understudied component of this effort was Task Force Clearwater, an improvised brown water fleet that-along with the maritime logistics campaign that it supported-would prove essential for the successful defense of South Vietnam's northernmost provinces and demonstrate the vital importance of inland naval power. Task Force Clearwater and its supported maritime logistics effort form a little explored component of the U.S. Navy's role in South Vietnam. A brown water task force that proved essential for the successful defense of the northern provinces of I Corps, Clearwater repeatedly demonstrated the vital importance of inland naval power and the critical need for reliable and protected routes of supply. The task force revealed many lessons that had been long understood, forgotten, and then relearned by the U.S. Navy, among them that control of inland waterways was perhaps the most advantageous form of logistical supply in war. Created in part to satisfy the ancient maxim of "keeping the supply lines open", the task force's role broadened with time. In the course of its existence the men and boats of Clearwater would provide not only the tools of war in I Corps but also provide key lessons for the future.