Canadian Space Station program

Information on the Canadian Space Station Program is given in viewgraph form. Topics covered include the Mobile Servicing Center (MSC), Space Station Freedom assembly milestones, the MB-3 launch configuration, a new workstation configuration, strategic technology development, the User Development Program, the Space Station Program budget, and Canada's future space activities

The role of the real-time simulation facility, SIMFAC, in the design, development and performance verification of the Shuttle Remote Manipulator System (SRMS) with man-in-the-loop

The SIMFAC has played a vital role in the design, development, and performance verification of the shuttle remote manipulator system (SRMS) to be installed in the space shuttle orbiter. The facility provides for realistic man-in-the-loop operation of the SRMS by an operator in the operator complex, a flightlike crew station patterned after the orbiter aft flight deck with all necessary man machine interface elements, including SRMS displays and controls and simulated out-of-the-window and CCTV scenes. The characteristics of the manipulator system, including arm and joint servo dynamics and control algorithms, are simulated by a comprehensive mathematical model within the simulation subsystem of the facility. Major studies carried out using SIMFAC include: SRMS parameter sensitivity evaluations; the development, evaluation, and verification of operating procedures; and malfunction simulation and analysis of malfunction performance. Among the most important and comprehensive man-in-the-loop simulations carried out to date on SIMFAC are those which support SRMS performance verification and certification when the SRMS is part of the integrated orbiter-manipulator system

Doctor of Philosophy

dissertationUsing a new, representative, longitudinal microdata sample that observes native-born white and black men in 1917 and in 1930 in rich detail, this dissertation investigates the determinants of World War I (WWI) draft probability, the effects of WWI military service on subsequent occupational and geographic mobility, racial variations in the effect of WWI service on labor mobility, and racial variation in Southern out-migrant self-selection during the Great Migration period. Examining how family structure, literacy, occupation, and race affected a man's probability of conscription during WWI, this dissertation finds that inductees were more literate and healthier than the rest of the draft pool. Marriage and having dependents reduced a man's probability of being drafted. Having an agricultural occupation reduced the probability of being drafted for Whites, but not Blacks. Overall, the draft mechanism seems to have functioned as intended and positively selected inductees. This dissertation also finds that the effect of WWI military service varied substantially by race. Service slightly increased the probability of holding a white-collar or skilled blue-collar occupation by 1930, controlling for observed biases in the assignment of veteran status. White veterans who held such jobs before the war were less likely to end up in unskilled labor occupations in 1930. Skilled White soldiers held skilled jobs during the war where they could accumulate experiences transferable to civilian labor markets. Black veterans enjoyed no such protections from downward occupational pressures. WWI service did not offer upward occupational mobility to lowskilled workers or a transition out of agriculture for farmers and farm laborers. White veterans were more likely to make an interstate or interregional geographic move after the war, but Black veterans had the same rates of migration as Black nonveterans. Finally, this study observes black and white Southern out-migrants and nonmigrants before and after migration. Compared with their sending population, Black migrants were more literate and disproportionately from urban areas. Black migrants were more likely to have left from nonfarm occupations in the South and, among nonfarm occupations, professional blacks were more likely to leave. White migrants were more literate than their sending population, but otherwise representative

Challenges for brain repair: insights from adult neurogenesis in birds and mammals

Adult neurogenesis is a widespread phenomenon occurring in many species, including humans. The functional and therapeutic implications of this form of brain plasticity are now beginning to be realized. Comparative approaches to adult neurogenesis will yield important clues about brain repair. Here, we compare adult neurogenesis in birds and mammals. We review recent studies on the glial identity of stem cells that generate new neurons, the different modes of migration used by the newly generated neurons to reach their destinations, and how these systems respond to experimentally induced cell death. We integrate these findings to address how comparative analysis at the molecular level might be used for brain repair

Study of E. coli Hfq's RNA annealing acceleration and duplex destabilization activities using substrates with different GC-contents

Folding of RNA molecules into their functional three-dimensional structures is often supported by RNA chaperones, some of which can catalyse the two elementary reactions helix disruption and helix formation. Hfq is one such RNA chaperone, but its strand displacement activity is controversial. Whereas some groups found Hfq to destabilize secondary structures, others did not observe such an activity with their RNA substrates. We studied Hfq’s activities using a set of short RNAs of different thermodynamic stabilities (GC-contents from 4.8% to 61.9%), but constant length. We show that Hfq’s strand displacement as well as its annealing activity are strongly dependent on the substrate’s GC-content. However, this is due to Hfq’s preferred binding of AU-rich sequences and not to the substrate’s thermodynamic stability. Importantly, Hfq catalyses both annealing and strand displacement with comparable rates for different substrates, hinting at RNA strand diffusion and annealing nucleation being rate-limiting for both reactions. Hfq’s strand displacement activity is a result of the thermodynamic destabilization of the RNA through preferred single-strand binding whereas annealing acceleration is independent from Hfq’s thermodynamic influence. Therefore, the two apparently disparate activities annealing acceleration and duplex destabilization are not in energetic conflict with each other

Healing Justice as Intersectional Feminist Praxis: Well-being Practices for Inclusion and Liberation

Since at least the 1830s, Black feminists in the US have spoken of how oppression harms the spirit and have also expressed the need for Black people to respect themselves in the face of anti-Black racism (Guy-Sheftall, 1995). The recognition that oppression negatively impacts well-being continues today. Research in community health and psychology has demonstrated how Black Americans, Native Americans, and Latinx people have been victims of mass incarceration, state-funded and state-sanctioned violence, and systemic discrimination in schools, workplaces, healthcare, and housing. Due to these conditions, racial and ethnic minorities in the US suffer disproportionately from mental and physical illnesses linked with stress, pollution, and trauma. Intersectionality has been recognized as a vital analytical tool in research, helping scholars, managers, educators, healthcare providers, policy-makers, and more understand the complexities of health risks and healthcare responses; of diversity and inclusion in schools, workplaces, and communities; and of inequalities in every area of social science. At the same time, intersectional activists have insisted on a holistic view of social change that forms the basis of what Reverend angel Kyodo williams calls “transcendent movements” (williams & Owens, 2016, p. 201). The work of well-being, on individual and community levels, has been part of resistance against oppression, exploitation, and prejudice which harm the mind, body, and spirit of those on all sides of oppressive power dynamics. As Ruth King (2018) notes, “racism is a heart disease, and it’s curable!” (p. 9). This essay explores past and present intersectional feminist activism that addresses well-being and the tools to achieve well-being as political strategy. It connects contemporary movements like Black Lives Matter, transformative justice, and mutual aid with a history of work by womanists, U.S. third world feminists, intersectional feminists, and LGBTQIA people of color who have recognized that self-care and community-care are political work and that the work of diversity, inclusion, and well-being is one and the same. This knowledge emphasizes the importance of self-care and community-care in politics, public health, education, and other social change work