Using 1.0 fb^{-1} of data collected by the Collider Detector at Fermilab (CDF) from Run II of the Fermilab Tevatron, we measure the top-antitop production cross-section in events with two leptons, significant missing transverse energy, and at least jets, at least one of which is identified as a b-jet. As the Run II dataset grows, more stringent tests of Standard Model predictions for the top quark sector are becoming possible. The dilepton channel, where both top quarks decay t-> W b ->l nu b, is of particular interest due to its high purity. Use of an isolated track as the second lepton significantly increases the dilepton acceptance, at the price of some increase in background, particularly from W + jets events where one of the jets is identified as a lepton. To control the increase in background we add to the event selection the requirement that at least one of the jets be identified as a b-jet, reducing the background contribution from all sources. Assuming a branching ratio of BR(W->l nu) = 10.8% and a top mass of m_top = 175 GeV/c^{2} the measured cross-section is sigma = (10.5 +/- 1.8 stat. +/- 0.8 syst. +/- 0.6 lumi.) pb.

This thesis supported the hypothesis that preoperative verbalization enhances the birth experience in primary emergency cesarean delivered women. A T-test was utilized to compare the two groups' responses on each item of a 29 point questionnaire. The questionnaire measured perception of birth in 28 participants who verbalized their feelings preoperatively and 22 participants who did not verbalize preoperatively. The total mean score for all 29 items indicated a favorable perception for the former group. In addition, six specific items were significantly favorable for the group who verbalized. The T-test revealed questionnaire items of significance in the following subgroups: age, duration and intensity of labor, and parity.Ball State UniversityMuncie, IN 47306

The purpose of this study was to describe relationships between husband attendance during cesarean birth and parental perceptions of the cesarean birth and of the neonate. The independent variable was husband attendance during cesarean birth. Dependent variables were parental perceptions as measured by the Parental Perceptions of Cesarean Birth and Neonate Questionnaire. Thirty-five married couples who delivered healthy neonates by cesarean section with regional anesthesia constituted the study and control groups. The 60 parents in the study group were together during cesarean delivery; the 10 parents in the control group were not. Seventy subjects responded to 19 items on a Lilert-type questionnaire and 53 wrote comments about their birth experiences. ANOVA and repeated measures were used to examine data. Both research hypotheses, which were tested at the .05 level off significance, were supported: there was a significant relationship between husband attendance and positive perceptions of both the birth and of the neonate. Presence of the father in surgery had significant effects on perceptions of cesarean birth (p <.01), perceptions of the neonate (p<.01), and perceptions of the time that the neonate was first seen and held by parents (p <.01). Level of education of mother was significantly related to perceptions of the neonate (p <.05). Level of education of father had a significant effect on reported fear for self during cesarean delivery (p <.05). Adequate preparation was significantly related to positive perceptions of cesarean birth (p <.01). The majority of parents of both groups found their birth experiences satisfying, but some would have liked more time together, more contact with infant, more preparation and more comfort for mother. Study results supported the practice of family-centered cesarean birth.Ball State UniversityMuncie, IN 47306

Using 1.0 fb^{-1} of data collected by the Collider Detector at Fermilab (CDF) from Run II of the Fermilab Tevatron, we measure the top-antitop production cross-section in events with two leptons, significant missing transverse energy, and at least jets, at least one of which is identified as a b-jet. As the Run II dataset grows, more stringent tests of Standard Model predictions for the top quark sector are becoming possible. The dilepton channel, where both top quarks decay t-> W b ->l nu b, is of particular interest due to its high purity. Use of an isolated track as the second lepton significantly increases the dilepton acceptance, at the price of some increase in background, particularly from W + jets events where one of the jets is identified as a lepton. To control the increase in background we add to the event selection the requirement that at least one of the jets be identified as a b-jet, reducing the background contribution from all sources. Assuming a branching ratio of BR(W->l nu) = 10.8% and a top mass of m_top = 175 GeV/c^{2} the measured cross-section is sigma = (10.5 +/- 1.8 stat. +/- 0.8 syst. +/- 0.6 lumi.) pb.

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Vegeu vvresum1de1.pdf

At the Los Alamos Neutron Science Center accelerator complex, protons are accelerated to 800 MeV and directed to two tungsten targets, Target 4 at the Weapons Neutron Research facility and the 1L target at the Lujan Center. The Department of Energy requires hazard classification analyses to be performed on these targets and places limits on certain radionuclide inventories in the targets to avoid characterizing the facilities as nuclear facilities. Gadolinium-148 is a radionuclide created from the spallation of tungsten. Allowed isotopic inventories are particularly low for this isotope because it is an alpha-particle emitter with a 75-year half-life. The activity level of Gadolinium-148 is low, but it encompasses almost two-thirds of the total dose burden for the two tungsten targets based on present yield estimates. From a hazard classification standpoint, this severely limits the lifetime of these tungsten targets. The cross section is not well-established experimentally and this is the motivation for measuring the Gadolinium-148 production cross section from tungsten. In a series of experiments at the Weapons Neutron Research facility, Gadolinium-148 production was measured for 600- and 800-MeV protons on tungsten, tantalum, and gold. These experiments used 3 m thin tungsten, tantalum, and gold foils and 10 m thin aluminum activation foils. In addition, spallation yields were determined for many short-lived and long-lived spallation products with these foils using gamma and alpha spectroscopy and compared with predictions of the Los Alamos National Laboratory codes CEM2k+GEM2 and MCNPX. The cumulative Gadolinium-148 production cross section measured from tantalum, tungsten, and gold for incident 600-MeV protons were 15.24.0, 8.310.92, and 0.5910.155, respectively. The average production cross sections measured at 800 MeV were 28.63.5, 19.41.8, and 3.690.50 for tantalum, tungsten, and gold, respectively. These cumulative measurements compared best with Bertini and were within a factor of two to three of CEM2k+GEM2.

Sponge are primitive multi-cellular organisms. They are important sources of secondary metabolites. In the previous studies indicated that the sponges harbor stable symbiotic microbial consortia. The mechanisms for maintenance and transmission of microbial consortia to the next generations are still not fully understood. The sponge, Cinachyrella australinesis, was chosen to further investigate relationship of the symbiotic bacteria within to the host. Fluorescent in situ hybridization ¡]FISH¡^was employed with non-specific ¡]EUB338¡^and specific oligonucleotide probes for bacteria. The sponge was cryo-sectioned¡]1£gm¡^and hybridized with fluorescent probes. The distribution and ratios of the bacteria in the sponge agreed with those of previous studies indicating that the symbiotic bacteria of C. australiensis are stable and endosymbiotic in nature.

Petrographic and Type:variety analyses of Colha ceramics are used to investigate changes in ceramic production technology and organization during the Early and Middle Postclassic. Postclassic sherds from Colha are grouped by petrofabric, surface treatment, and modes. This dissertation focuses on the petrofabric analysis of the ceramic sherds. The groupings are then compared to locally available raw materials. Changes in technological homogeneity, production specialization, and origin will be examined and related to the general economy of Postclassic Colha. / text

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