Rozprawy doktorskie na temat „Public understanding of science”

Correct certificate revocation practices are essential to each public-key infrastructure. While there exist a number of protocols to achieve revocation in PKI systems, there has been very little work on the theory behind it: Which different types of revocation can be identified? What is the intended effect of a specific revocation type to the knowledge base of each entity?

As a first step towards a methodology for the development of reliable models, we present a graph-based formalism for specification and reasoning about the distribution and revocation of public keys and certificates. The model is an abstract generalization of existing PKIs and distributed in nature; each entity can issue certificates for public keys that they have confidence in, and distribute or revoke these to and from other entities.

Each entity has its own public-key base and can derive new knowledge by combining this knowledge with certificates signed with known keys. Each statement that is deduced or quoted within the system derives its support from original knowledge formed outside the system. When such original knowledge is removed, all statements that depended upon it are removed as well. Cyclic support is avoided through the use of support sets.

We define different revocation reasons and show how they can be modelled as specific actions. Revocation by removal, by inactivation, and by negation are all included. By policy, negative statements are the strongest, and positive are the weakest. Collisions are avoided by removing the weaker statement and, when necessary, its support.

Graph transformation rules are the chosen formalism. Rules are either interactive changes that can be applied by entities, or automatically applied deductions that keep the system sound and complete after the application of an interactive rule.

We show that the proposed model is sound and complete with respect to our definition of a valid state.

In a postscript, I conclude by urging all researchers within the field of STS to begin to recognize that maintaining the false split between our academic research, undergraduate teaching, university outreach, and community involvement is a failed project. As STS researchers, I believe it is, in fact, our obligation to our local and global communities to adopt an interventionist strategy and to use our work â without apology â for directly political ends. Challenging the technoscientific-political context in which we live always involves a level of real risk â but it is also our only opportunity to achieve real success. Our participation in this challenge is a responsibility to ourselves and to our communities that we must recognize and accept. This participation should not be shunned, but rather applauded.
Master of Science

Since 2010, 2,000 U. S. leaders spent $150 billion on return on investment (ROI) training, yet questions still exist on how to measure the benefits of organizational change. The purpose of this embedded single-case study was to explore how business leaders could use ROI to characterize the benefit of intervention strategies for organizational change. Stakeholder theory and Maslow's hierarchy of needs theory formed the conceptual framework for this study. A purposive sample of 20 civilian personnel managers located at a medical facility for veterans in central Texas participated in semistructured interviews. The 5 primary themes that emerged using thematic analysis were (a) training, (b) leadership, (c) communication, (d) recognition, and (e) consistency. Implications for positive social change include the possibility of organizational leaders applying these findings to develop better intervention strategies. Such interventions could improve processes for stakeholders and create an open dialogue with business leaders within the government sector.

The federal government provides an uncapped reimbursement of state Medicaid spending. In theory, states can use the federal Medicaid funds as a replacement for state funds or the federal funds, which take the form of a matching grant that reduces the relative price of Medicaid, can increase (or stimulate) spending on Medicaid with state-raised tax revenue. In the first dissertation paper, Subsidizing Medicaid Growth: The Impact of the Federal Reimbursement on State Medicaid Programs, I use a state panel data set from 1992 to 2006 to assess the impact of the federal reimbursement on the size of state Medicaid programs. I find that a one point increase in a state's Medicaid reimbursement percentage increases state per capita Medicaid spending between $5 and $16 and increases the percentage of the state's population receiving Medicaid benefits by 0.04 percent to 0.29 percent.

The first paper also utilizes a case study that shows significant growth in Alaska's Medicaid program after its effective federal Medicaid reimbursement increased 50 percent between 1998 and 1999. The large growth in Alaska's Medicaid program after this increase provides evidence that states respond to large increases in the federal Medicaid subsidy in a stimulative manner by increasing spending with state-raised revenue. Overall, the results in the first paper are consistent with the hypothesis that decentralization in the form of intergovernmental matching grants increases the size of government. I also find that states with wealthier and more liberal populations tend to have larger Medicaid programs and that states with Democratic legislatures tend to have more Medicaid beneficiaries than states with Republican legislatures all else equal.

Since 2008, states have experienced significant budgetary pressure; in large part, because of rising Medicaid enrollment due to the recession and weak recovery. Between 2009 and 2011, many states enacted health care provider taxes as a way to bring in additional revenue through the federal Medicaid reimbursement. Provider taxes are generally supported by health care providers since states often give providers an implicit or explicit guarantee of a return of at least as much funding through higher payment rates or supplemental payments. In the second dissertation paper, Impact of Hospital and Nursing Home Taxes on State Medicaid Spending, I assess the impact of the two largest provider taxes, the hospital tax and the nursing home tax, on state Medicaid expenditures using a panel dataset of 42 states from between 2007 and 2011. I find significantly larger Medicaid spending growth for hospitals in states that added hospital taxes and significantly larger Medicaid spending growth for nursing homes in states that added nursing home taxes within the first two years of the enactment of the tax. I also find some evidence that states with hospital taxes were able to increase their total Medicaid spending more than states without hospital taxes during the economic downturn and initial recovery period. This paper also contains evidence that nursing home taxes diverted Medicaid spending from home and community based services to nursing homes.

In the third dissertation paper, Statewide Health Impact of Tennessee's Medicaid Expansion, I utilize a quasi-experimental approach to assess the impact of a large statewide public health insurance expansion on access to health care services, health care utilization, and health outcomes. In 1994, Tennessee expanded its state Medicaid program, called TennCare, by about ten percent of the state's population. Along with a major Medicaid expansion, Tennessee increased government subsidies for individuals to purchase health insurance coverage and emphasized managed care. Using a difference-in-difference methodology with Tennessee's neighboring states as controls, I found that TennCare's impact on utilization was mixed as blood pressure and cholesterol checks increased but regular physician check-ups decreased relative to the surrounding region. Surprisingly, both self-reported health and mortality rates were less favorable in Tennessee relative to the control states after TennCare. Ultimately, the evidence in this paper suggests that health reform built around a significant public insurance expansion is likely to result in minimal, if any, overall health gains measured in the entire population, at least in the short run.

The final dissertation section summarizes the findings from the three dissertation papers, discusses the economic efficiency of the uncapped federal Medicaid reimbursement and state provider taxes, and makes several predictions related to the Medicaid expansion in the Patient Protection and Affordable Care Act.

The purpose of the study was to document how individuals' experiences and understanding of genetics concepts affects their medical experiences. Recently pregnant women were interviewed because they represent a population that needs to comprehend biological and genetic information to understand their health. Three women were designated as science experts (SE) defined as having extensive university level science education and three women were designated as science non-experts (SNE). In general, SEs described a more positive pregnancy experience. Both SEs and SNEs demonstrated a basic understanding of genetic concepts but varied in the application of concepts to personal medical issues. Participants' views and experiences of pre and postnatal tests were linked to their understanding of nature of science components such as recognition that tests have limitations. Results from this study indicate an incomplete understanding of the nature of science among participants may have led to unsatisfactory medical experiences.

The present investigation was developed with the purpose of identifying how the social determinants of health impact individuals' ability to cope with Chagas disease. Identifying coping methods was also a goal of this investigation. Semi-structured interviews were conducted with 15 Latino patients between the ages of 30 and 65 who were being treated for Chagas disease at a university affiliated medical center.

The results of this investigation revealed that individuals infected with Chagas disease are impacted by structural, intermediary, and sociopolitical aspects that affect their living, and working conditions, and make more difficult for them to cope with their illness. Although, concerned professionals are addressing some of these social barriers, there are still many difficulties faced by the population due to lack of attention to the illness and the conditions that cause inequalities in society. Despite the social barriers that individuals with Chagas face, they still thrive by finding ways to cope with their particular situations.

Findings from the study revealed coping strategies used by the participants, some of these include relying on family for support, staying active, believing in God, remaining optimistic, and minimizing or using denial.

From the investigation, several recommendations for practitioners, advocates, and policy makers were developed, as well as recommendations for future studies. Some of the major recommendations are increasing awareness about the illness among policy makers and advocates in order to fully attend to the needs of the population. This would lead to doing more research, investing in the development of better drugs, and providing support to address some of the social needs of the people infected so they can cope better with the illness. Some of the recommendations for future research include increasing the sample size in order to investigate the impact of demographic variables as well as their particular stage of the illness in their ability to cope, and assessing the impact of social determinants using quantitative research methods.