The current knowledge concerning effects of polybrominated diphenyl ether (PBDEs) on benthic aquatic organisms is still very limited although they have been widely used as fire retardant additives for 3 decades. This study was conducted to evaluate the toxic effects of BDE-47 and BDE-183, the two common congeners of PBDEs in river sediments, on a benthic oligochaete worms, Monopylephorus limosus. The worms were exposed to BDE-47 or to BDE-183 for two or eight weeks. The survival rates of M. limosus decreased significantly when exposed to 700 ng/g dry soil of BDE-47 or BDE-183 for 8 weeks, but not in groups of 1-1000 ng/g BDE-47 for 2 weeks. A total of forty proteins of M. limosus has been expressed and determined by the two-dimensional gel electrophoresis (2-DE). Through the cluster analysis, it was found that the protein expression in the group of 100 ng/g BDE-47 was similar to 10 ng/g BDE-183. The results indicate that the toxicity of BDE-183 was greater than BDE-47 to M.limosus. Although the survival rate of M. limosus was not significantly affected when exposed to BDE-47 or BDE-183 at concentrations of 1 to 100 ng/g, significant differences in protein expression were found. Thus, the analysis of protein expression is more sensitive to detect the toxicological change in M. limosus than the survival test.

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Sorghum ergot, caused by Claviceps africana Frederickson, Mantle & de Milliano, is a disease that affects non-fertilized ovaries in sorghum male-sterile plants and infects hybrids if there is pollen sterility at flowering time. Sphacelia containing macroconidia could play a role in the survival of the pathogen. This study developed risk assessment models and evaluated environmental conditions affecting viability of macroconidia and transition from sphacelial to sclerotial tissues. Effect of weather on ergot severity was evaluated under natural conditions (in monthly planting dates) in nine sorghum genotypes at College Station, Weslaco, Rio Bravo, and Celaya. Panicles were inoculated daily beginning at flower initiation with a suspension of 1.6 x 106 C. africana conidia ml-1. Weather triad values were used to identify weather parameters correlated with the disease. Ergot severity was statistically greater in A-lines than hybrids because of the possible interference of pollen on some dates. Celaya had the greatest amount of ergot in hybrids. A-line ATx2752 had the lowest average ergot severity throughout years, locations and planting dates, as did the hybrid NC+8R18. Maximum and minimum temperature had a negative correlation with ergot at Rio Bravo, College Station and Weslaco, while at Celaya it was positive. The highest correlation was 7 to 9 days before initiation of flowering, suggesting that cooler temperatures during this period could cause male sterility. A-lines showed the same relationships between ergot and maximum and minimum temperatures after initiation of flowering. Minimum relative humidity had a positive correlation with ergot after initiation of flowering in both sorghum plant types. Sphacelia stored under cool temperatures (-3oC to 7oC) maintained conidial viability, and newly-formed sphacelia located on the sphacelia surface had the highest conidial viability. However, they show a greater viability reduction through time compared with conidia from older sphacelia, showing that conidial maturity can play a role in the survival of the conidia. Sphacelia on plants grown at 10oC, 20oC and 30oC with low relative humidity did not had any sclerotial development up to 4 weeks after formation of sphacelia. However, higher temperatures promoted an increase in the sphacelia dry weight during that time.

Salmonella outbreaks associated with orange juices have been reported in the past. Though there have been studies on the internalization of Salmonella into oranges there is inadequate information on the ability of this pathogen to survive on orange surfaces, become internalized, and survive the low pH internal conditions. The objective of this work was to study the survival of Salmonella gaminara and Salmonella agona on oranges obtained from the field and retail outlets and investigate their attachment and internalization potential. These studies showed that oranges obtained from both the field and retail outlets harbored relatively high concentrations of aerobic heterotrophic bacterial populations. There were significant differences in the survival of Salmonella agona and Salmonella gaminara at 4??C, room temperature (25??C) and 37??C. Survival was highest at 37??C and lowest at 4??C for both Salmonella gaminara and Salmonella agona. Salmonella agona and Salmonella gaminara showed significant differences in recovery when the cells were treated with pH 4.0, 7.0 and 9.5 buffers. The internalization studies suggest that a negative temperature differential favors the internalization of Salmonella cells into the fruit. Significant differences in the internalization of Salmonella into field and market oranges were observed with more internalization in the field oranges as compared to the market oranges. These results suggest that to prevent Salmonella contamination of orange juices adequate pre-harvest protection against pathogen contamination and post-harvest cleaning and disinfection strategies need to be employed.

This study examines the survival of individual subsidiary in an inter-subsidiary perspective within the ever-increasing competitive environment in the Greater China region between Mainland Chinese subsidiaries and Taiwanese subsidiaries. 80 Taiwanese Multinational Enterprises¡¦ (MNEs¡¦) participated in this study and the researcher specifically looked at the two sub-frameworks, data collected were empirically tested. In the first sub-framework, it examines the influences of inter-subsidiary competition for strategic positions on subsidiary survival with respect to its strategic importance, resource asymmetry, and some characteristics of value activities. In the second sub-framework, it examines the influences of competition on knowledge flow positions with respect to knowledge flows and intellectual capital. The results showed that these determinants have different effects on subsidiary survival. Specifically, in the first sub-framework, the strategic importance and advantages of intangible resources enhances a focal subsidiary¡¦s survival, whereas local responsiveness, advantages on physical resources, similarity and mobility of value activities decreases its survival. On the other hand, in the second sub-framework, determinants of knowledge flows specifically on knowledge inflows, knowledge transfer, and absorption capacity of a specific peer subsidiary decreases its survival rate. Further, determinants on intellectual capital such as application capabilities on organizational capital and human capital are seen as positive factors. Finally, this study discusses the implications of inter-subsidiary competition for these factors in determining a focal subsidiary¡¦s survival.

Thesis (Ph. D.)--University of Washington, 2001. / Vita. Includes bibliographical references (leaves 110-114).

Thesis (Ph. D.)--University of Washington, 2001. / Vita. Includes bibliographical references (p. 81-86).

Thesis (Ph. D.)--University of Washington, 2003. / Vita. Includes bibliographical references (p. 141-146).

Thesis (Ph. D.)--University of Chicago, Dept. of Statistics, August 2001. / Includes bibliographical references. Also available on the Internet.

Thesis (Ph. D.)--University of Washington, 2003. / Vita. Includes bibliographical references (p. 158-160).