Malaria pathogenesis: Deformability limits of malaria infected erythrocytes

Herricks, Thurston E University of Washington 2007 해외박사(DDOD)

The pathology of severe malaria is poorly understood. Parasite-induced changes in erythrocytes have been suggested to play a role in capillary blockage. While methods for measuring membrane elasticity have been well developed, an investigation into the limits of deformation due to geometric constraints of individual cells has not been performed. Recent developments in microfluidics have allowed for direct measurement of surface area and volume of both infected and uninfected erythrocytes using a method which is independent of membrane elasticity. The volume and surface area are used to calculate a theoretical minimum diameter through which a cell can pass without having to increase its surface area. These microfluidic measurements can accurately predict the size of constrictions which are clogged under physiologically relevant pressures. Observations were then made over the 48 hour asexual lifecycle of Plasmodium falciparum. Such measurements may provide additional insight to the pathology and treatment of severe and complicated malaria.

Service utilization among people with cognitive impairment: Does living alone make a difference?

Herrick, Tamara Harden University of Massachusetts Boston ProQuest Disser 2016 해외박사(DDOD)

For community-dwelling older adults, the effects of living alone and cognitive impairment (CI) on the use of medical services and long-term services and supports were examined. Three questions were addressed: 1) Are people living alone with CI different from people living alone without CI in terms of types of services used? 2) Do people with CI who live alone use different types of services than people with CI who live with others? 3) Are severity of CI and living alone independent predictors of service use? The sample of 2,103 people aged 65 and older was drawn from the 1999 National Long-term Care Survey. Overall, the results provide modest support for each of the hypotheses. Among the respondents that live alone, there were no between-group differences in the type of services used. The finding that CI is not associated with service use was partially supported by the multivariate analysis. This finding holds true for all services except doctor's visits where cognitive impairment was associated with reduced probability of having a doctor's visit in the past month. Among respondents with CI, living alone is positively associated with Home Delivered Meals service. For research question three, multivariate analyses indicated that living alone and CI are independent predictors of service use. Respondents that live alone are less likely to use homemaker services and more likely to use visiting nurse and home delivered meal services. Respondents with moderate to severe cognitive impairment are less likely to report hospitalization in the past 12 months compared to respondents without CI. The findings from this study modestly suggest that living alone is a driving force behind service use and that severity or level of CI does not add to the probability of using long-term support and services. However, it may be that people with CI that live alone do not advocate for themselves to receive the services examined in this study. Previous literature has found that people with CI need support to be safe. The data analyzed here, however, are not capable of measuring self-advocacy. More research is needed that works towards examining this problem using different methodology for data collection.

Exposure to Perfluoroalkyl Compounds and Resultant Effects on Cholesterol in the Mid Ohio River Valley

Herrick, Robert Leroy Leonhardt University of Cincinnati ProQuest Dissertations & 2019 해외박사(DDOD)

Some conjectures about the slopes of modular forms

Herrick, Graham Northwestern University 2005 해외박사(DDOD)

For odd prime numbers p, I present a conjectural formula for the Tp-slopes of classical modular forms of level coprime to p, based on empirical observations. To provide a structural underpinning for the conjecture, I first develop some results about modular forms mod p. In particular, a certain semisimplification of the Hecke module of modular forms mod p decomposes into a direct sum of finitely many cyclic submodules generated in weights ≤2 p + 1 over a noncommutative extension of the Hecke algebra. The forms in each of these submodules all have the same associated Galois representation up to twisting by the cyclotomic character. I attach abstract slope sequences to the forms in these submodules and, provided that the associated Galois representations are locally reducible at p, I conjecture that these abstract slopes agree with the actual slopes associated to classical modular forms with the same associated residual Galois representations.

Syndemic processes among young men who have sex with men (MSM): Pathways toward risk and resilience

Herrick, Amy Laurel University of Pittsburgh 2011 해외박사(DDOD)

Men who have sex with men (MSM) in the US experience great disparities in health outcomes, most notably in HIV. This dissertation will take a look at these disparities and offer a framework for understanding their etiology and for understanding the processes by which these disparities are sustained, propagated and eventually broken down. First, we provide an overview of the literature regarding health disparities among MSM and the current theories that exist to understand where these disparities come from. Specifically, we focus on Syndemics Theory and the Theory of Syndemic Production as the best models for understanding health among MSM. Finally, we suggest a new theoretical model, Cultural Resilience Theory, which can be used to conceptualize health promotion within the syndemic framework. We also test components of Syndemics Theory---interaction and mediation---that until now have functioned as assumed premises with no empirical support for their assertion. Finally, we test Cultural Resilience Theory as a model that can be used in prevention programming to break down syndemic processes among MSM. In the final chapter we look into the practical implications of Cultural Resilience Theory as it applies to the prevention (or abatement) of health disparities among MSM. The findings of this study have great public health significance and important implications for HIV prevention among MSM. First, the synergism analysis is the first to test the assertion that co-occurring psychosocial health conditions interact to increase HIV risk among MSM. These results suggest that there is a synergistic effect present. Likewise, the mediation analysis is the first to test the theory of syndemic production that states that early life adversity impacts HIV outcomes through syndemic processes; an assertion that was supported by these analyses. These two studies further our understanding of how syndemics function within MSM to produce health disparities. Finally, we identify several variables that break down syndemic processes through either their negative association with poor health outcomes, or by buffering the pathways from adversity to HIV risk through syndemics. These results will provide the foundation upon which a culturally tailored Theory of Cultural Resilience among MSM can be developed.

What Do You Notice? What Do You Wonder? A Mixed-Methods Investigation Into Community Science Data Talks

Herrick, Imogen Rose Neilson University of Southern California ProQuest Dissert 2023 해외박사(DDOD)

As social, racial, and environmental justice topics dominate national conversations, STEM teachers must provide learning opportunities that support students to make sense of these problems and co-construct hope for their futures (Calabrese-Barton et al., 2020; Ojala, 2012). Thinking about how teachers can begin to transform their classrooms into places where discussions about inequity, power, environmental justice, and STEM are commonplace, requires the design of innovative opportunities for youth to engage critically with STEM content and acquire skills to transform their current realities and hoped-for future (e.g., Calabrese Barton et al., 2020; Ladson-Billings, 1995; Morales-Doyle, 2017; Rubel, 2017). This dissertation is framed around a potential innovative STEM classroom discourse routine, Community Science Data Talks (CSDTs). The purpose of this study was to examine the potential of CDSTs as a tool for teachers and students to co-construct the learning environment to discuss and learn about local environmental justice issues. The main objective of this study was to investigate if CSDTs could over time stretch teachers' visions of classroom learning and expand students' experiences with local science.This design-based convergent parallel mixed methods case study compares two classrooms in different contexts (i.e., privileged and underserved) to understand what is possible when teachers and students engage in CSDTs. The findings indicate that students across contexts became more proficient in STEM disciplinary practices, had a transformative experiences (e.g., Pugh, 2011), and constructed hope for their futures (e.g., Ojala, 2012). Students constructed hope through different pathways depending on their context. Additionally, the small-scale practice of CSDTs supported teachers in both contexts to experience moments of bearing witness that stretched their pedagogical visions in justice-oriented ways (Hansen, 2017). Overall, these findings indicate that CSDTs are a small-scale justice-centered STEM routine that can provide access for teachers and students to begin working in more transformative ways together (Calabrese Barton et al., 2020; Morales-Doyle, 2017).

Personality Temperament's Influence on Instructional Strategy Type Selection by Nebraska and Iowa High School Band Directors in a Concert Band Setting

Herrick, Matthew D The University of Nebraska - Lincoln 2011 해외박사(DDOD)

The field of education is constantly searching for techniques to efficiently select effective instructional strategies in order to differentiate instruction for students. Why do teachers select the types of instructional strategies they do to promote learning in the music classroom? Most teachers believe a mixture of educational goals, teacher experience, research, student ability, aptitude, interest, and learning style intuitively guide their strategy selection process (Tomlinson et al., 2003). One possible theory is that teachers' personalities are guiding the intuition that selects the instructional strategies. The purpose of this study was to determine if the high school band director's personality temperament significantly influences his/her instructional strategy selection in the context of a high school band rehearsal. Videos of 14 Midwestern high school band directors were coded to determine the instructional strategy types they used. These strategy type selections were analyzed between personality temperaments looking for independent relationships. Significant effects between personality temperament and instructional strategy type selections were found as well as differences in how high school band directors differentiate instruction. It was found all four personality temperaments chose to use Verbal Dictated instructional strategies more than any other instructional strategy type. However, the proportions in which they chose the instructional strategy types differed greatly. The intuitive-thinker personality temperament had the highest percentage in 60% of the instructional strategy types. This means intuitive-thinkers had the greatest differentiation of instruction. Differences in chi-square contributions showed significant differences in each personality temperament's choice of instructional strategy types. For example, sensory-perceivers were more likely to choose behavioral cues than any personality temperament was to choose any instructional strategy type. A person of the intuitive-thinker temperament was less likely to use verbal dictated strategy types than 95% of the other personality temperament-strategy type pairings. Since personality is a preference for behaviors rather than a cause of behavior, the instructor can use categorized instructional strategy types to increase the breadth of instructional choices. Using a wider variety of strategy types statistically improves the chance of finding a strategy to meet the needs of each student.

The validity of practical intelligence measures as constructs in the context of academic and vocational programs in high school

Herrick, Michael John University of Minnesota 2001 해외박사(DDOD)

Practical Intelligence is a construct which postulates that one aspect of human intelligence involves the capacity to use one's mental and decision making abilities for the purpose of achieving success in a particular context. These abilities are manifested in behaviors that take the form of first attempting to adapt to one's environment. If that proves unsuccessful, then attempts to either shape one's environment or select new environments to achieve success are made. One section of the Sternberg Triarchic Ability Test (STAT) claims to measure practical intelligence. This thesis was directed towards describing this theoretical construct of practical intelligence in the context of high schools, developing a self report instrument designed to measure practical intelligence in this context, and conducting statistical tests to determine the construct validity of the instrument. The purpose was to answer two research questions: How is practical intelligence behavior manifested and observed in high schools? Are the Sternberg Triarchic Ability Test and the high school practical intelligence instrument valid measures of practical intelligence for high school students?. The methodology was broken into two phases. Phase I attempted to answer the first research question, and involved focus group interviews with high school students to determine how students manifested practical intelligence behaviors in high school environments. From these descriptions a self report instrument, called the Practical Intelligence High School (PIHS), was created. Phase II of the methodology involved a variety of statistical tests to determine empirical relationships between the STAT, the PIHS, and other variables to determine construct validity of practical intelligence of these instruments. The results document rich descriptions of practical intelligence reported by high school students in terms of adaption, shaping and selecting behaviors used in high school. Also documented are the correlations for the relationships between PIHS and STAT with other variables, including traditional academic intelligence. The findings suggest that the STAT is not a valid measure of practical intelligence and that the adapt and shape aspects of the PIHS may be valid measures of practical intelligence in a high school context.

W-band three-dimensional integrated circuits utilizing silicon micromachining

Herrick, Katherine Juliet The University of Michigan 2000 해외박사(DDOD)

This thesis presents several low-loss micromachined W-band circuit components suitable for integration in a multi-layer silicon environment. Some of these components are micromachined finite ground coplanar waveguides, micromachined circuit combining networks, through-wafer vertical interconnects, and wafer-to-wafer vertical interconnects. In addition, this thesis also includes implementation of these novel architectures into the first 94 GHz micromachined silicon multi-layer transmit module. This transmit module is not only a high-density multi-layer circuit, but an integrated conformal package utilizing thermocompression bonding. The multi-layer silicon environment, with appropriate design and packaging, can provide a solution to the low power problems of conventional monolithic microwave integrated circuits (MMICs) by providing more power per unit area. Although this research effort includes a large fabrication effort, the work is presented with equal weighting on design, simulation, fabrication, and measurement. The strong technology base established through this project forms a legacy for future technology maturation and may also be applied at lower frequencies.

Postsecondary students with disabilities: Predictors of adaptation to college

Herrick, Samantha J The Pennsylvania State University 2011 해외박사(DDOD)

This dissertation presents the findings of an on-line survey-based study designed to examine the predictors of adaptation to college for undergraduate students with disabilities. The survey was relayed to participants via the disability support services offices at 16 colleges or universities in the northeast and mid-west United States. The six week survey administration resulted in 145 usable surveys. This empirical study was designed to examine the relationships between the principle independent variables acceptance of disability and perceived stigma on a college campus on adaptation to college. In addition to the principal variables of research interest, a demographic questionnaire was included in the survey to explore participant characteristics and college-related information on adaptation to college. The on-line survey was comprised of four assessments, a demographic questionnaire, the Postsecondary Student Survey of Disability-Related Stigma (PSSDS), the Acceptance of Disability Scale-Revised (ADSR), and the Student Adaptation to College Questionnaire (SACQ). The results of a hierarchical multiple regression analysis revealed two statistically significant relationships. Among participants in the study pool, students with disabilities with higher GPAs had lower levels of adaptation to college and those with a higher level of acceptance of disability were more adapted to college. Lastly, the exploratory test of mediation revealed that the relationship between acceptance of disability and adaptation to college was significantly mediated by perception of stigma on a college campus. The implications for counseling and disability support services personnel training and practice are discussed, and recommendations are made for future research.