Spelling suggestions: "subject:"publica""
521 |
Application of inertial measurement units for directly measuring occupational exposure to non-neutral postures of the low back and shoulderSchall, Mark Christopher 01 December 2014 (has links)
Epidemiological evidence suggests an association between exposure to non-neutral working postures and work-related musculoskeletal disorders (MSDs) of the low back and shoulder. Accurate and precise quantitative estimation of exposure to non-neutral working postures is, therefore, essential for evaluating worker risk, developing and testing ergonomic interventions, and improving worker health and well-being. Current methods used to directly estimate occupational exposure to non-neutral postures may be obtrusive, often lack sufficient portability for field use, and have limited accuracy and precision when used to measure dynamic or complex motions.
Inertial measurement units (IMUs) are emerging instrumentation devices that measure and report an object's orientation and motion characteristics using multiple electromechanical sensors (i.e., accelerometers, gyroscopes, and/or magnetometers). They have been observed to accurately monitor body kinematics over periods of relatively short duration in comparison to laboratory-based optical motion capture systems. Limited research, however, has been performed comparing exposure information obtained with IMUs to exposure information obtained with other field-capable direct measurement exposure assessment methods. Furthermore, insufficient information on the repeatability of IMU-based estimates over a substantial time period (e.g., a full work shift) and inadequate knowledge regarding the effects of different IMU sensor configurations and processing methods on the accuracy and repeatability of estimates of exposure obtained with IMU systems contributes to a lack of their use in epidemiological field studies.
This thesis was designed to address these issues and expand upon the current scientific literature regarding the use of IMU sensors as direct measurement devices for assessing exposure to non-neutral working postures in the field. Chapter I provides a background and justification for the work. Chapter II presents the findings of a laboratory-based, manual material handling study that was performed to compare estimates of thoracolumbar trunk motion obtained with a commercially available IMU system with estimates of thoracolumbar trunk motion obtained with a field-capable reference system, the Lumbar Motion Monitor (LMM). The effects of alternative sensor configurations and processing methods on the agreement between LMM and IMU-based estimates of trunk motion were also explored. Chapter III presents the results of a study performed to evaluate the accuracy and repeatability of estimates of trunk angular displacement and upper arm elevation obtained with the IMU system examined in Chapter II over the course of an eight-hour work shift in both a laboratory and field-based setting. The effects of alternative sensor configurations and processing methods on the accuracy and repeatability of estimates of trunk angular displacement and upper arm elevation obtained with the IMU system were also studied. Chapter IV presents the results of a randomized, repeated measures intervention that demonstrates the utility of the IMU system examined in Chapters II and III as a direct measurement instrument for comparing "ergonomic" and conventional examination equipment commonly used by ophthalmologists. Finally, Chapter V summarizes the major findings, discusses their practical implications, and provides suggestions for future research.
|
522 |
By measure ofHartman, Kristen A. 01 May 2016 (has links)
A limited variable editioned artist book, by measure of depicts an allegorical conversation between medieval author Christine de Pizan and a contemporary woman. It is, in essence, an exploration of edges in which the characters examine the parameters of identity, both personally and societally designated–how to define/re-define/emphasize/blur them, and what happens in the space where they meet.
|
523 |
Automated reasoning over string constraintsLiang, Tianyi 01 December 2014 (has links)
An increasing number of applications in verification and security rely on or could benefit from automatic solvers that can check the satisfiability of constraints over a rich set of data types that includes character strings. Unfortunately, most string solvers today are standalone tools that can reason only about some fragment of the theory of strings and regular expressions, sometimes with strong restrictions on the expressiveness of their input language (such as, length bounds on all string variables). These specialized solvers reduce string problems to satisfiability problems over specific data types, such as bit vectors, or to automata decision problems. On the other side, despite their power and success as back-end reasoning engines, general-purpose Satisfiability Modulo Theories (SMT) solvers so far have provided minimal or no native support for string reasoning.
This thesis presents a deductive calculus describing a new algebraic approach that allows solving constraints over the theory of unbounded strings and regular expressions natively, without reduction to other problems. We provide proofs of refutation soundness and solution soundness of our calculus, and solution completeness under a fair proof strategy. Moreover, we show that our calculus is a decision procedure for the theory of regular language membership with length constraints.
We have implemented our calculus as a string solver for the theory of (unbounded) strings with concatenation, length, and membership in regular languages, and incorporated it into the SMT solver CVC4 to expand its already large set of built-in theories. This work makes CVC4 the first SMT solver that is able to accept and process a rich set of mixed constraints over strings, integers, reals, arrays and other data types. In addition, our initial experimental results show that, over string problems, CVC4 is highly competitive with specialized string solvers with a comparable input language. We believe that the approach we described in this thesis provides a new idea for string-based formal methods.
|
524 |
Heterogeneous and multiphase chemistry of trace atmospheric gases with mineral dust and other metal containing particlesGankanda, Aruni 01 May 2016 (has links)
Particulate matter in the atmosphere emitted from various natural and anthropogenic sources is important due to their effects on the chemical balance of the atmosphere, the Earth's climate, human health and biogeochemical cycles. Although there have been many studies performed to understand the above effects, there still remains substantial uncertainty associated with processes involved and thus it is difficult for current atmospheric chemistry and climate models to reconcile model results with field measurements. Therefore, it is important to have better agreement between models and observations as the accuracy of future atmospheric chemistry and climate predictions depends on it.
In this research, a greater understanding of the role of mineral dust chemistry was pursued through focused laboratory studies in order to better understand fundamental processes involved. In particular, studies to further understand the photochemistry of adsorbed nitrate, an important inorganic ion associated with particulate matter exposed to gas-phase nitrogen oxides, were conducted using Al2O3, TiO2 and NaY zeolite to represent non-photoactive components, photoactive components and aluminosilicate respectively, present in mineral dust. These studies reveal that photochemistry of nitrate adsorbed on mineral dust is governed by wavelength of light, physicochemical properties of dust particles and adsorption mode of nitrate. Gas phase NO2, NO and N2O are the photolysis products of nitrate on oxide particles under dry conditions. In contrast, nitrate adsorbed on zeolite is converted mainly to adsorbed nitrite upon irradiation. This nitrite yield is decreased with increasing relative humidity. Gas phase N2O is the main photolysis product of nitrate adsorbed in zeolite in the presence of co-adsorbed ammonia. Water adsorbed on semiconducting TiO2 can be photochemically converted to hydroxyl radicals. These hydroxyl radicals can be involved in surface mediated as well as gas phase oxidation reactions in the presence of cyclohexane. Another focus of this dissertation was to investigate the oxidation of sulfur dioxide oxidation in the presence of mineral aerosol, particularly, coal fly ash (FA), γ-Fe2O3 and Arizona test dust (AZTD), a model for mineral dust aerosol. Depending on the temporal evolution of Fe(II), we proposed that S(IV) oxidation in the presence of FA and γ-Fe2O3 initially occurs through a heterogeneous pathway and a homogeneous pathway is also possible over later time scales. S(IV) oxidation in the presence of AZTD appears to be mostly heterogeneous and does not lead to iron dissolution. Overall, these studies suggest that the rate, extent and products of atmospheric S(IV) oxidation can be highly variable and heavily dependent upon the nature of aerosol sources, thereby precluding simple generalizations about this reaction when modeling atmospheric processes involving diverse mineral dust aerosols. With the recent development in nanotechnology, nanoparticles are becoming a major fraction of atmospheric particulate matter. These particles can undergo aging under ambient conditions at any stage of their life cycle. This impacts the fundamental properties of these materials and therefore the behavior in the environment and interactions with biomolecules and biological systems. ZnO and CuO nanoparticles form adsorbed carbonate phases upon exposure to CO2 and water vapor. These carbonates become more solvated as the relative humidity is increased. Presence of carbonate phases on ZnO particles increases their water solubility. Thus, overall the work reported in this dissertation provides insights into heterogeneous and multiphase atmospheric chemical reactions in the presence of mineral aerosol and atmospheric aging of nanoparticles.
|
525 |
The role of protein geranylgeranylation in prostate cancerReilly, Jacqueline Erin 01 December 2014 (has links)
The isoprenoid biosynthetic pathway (IBP) has been highly implicated in a number of cellular malignancies, including proliferation, invasion, and migration. Epidemiological studies have found clinically relevant inhibitors of the IBP, such as the statin family and nitrogenous bisphosphonates, reduce the risk of prostate cancer advancement. In vitro work has implicated statin's and nitrogenous bisphosphonate's inhibition of GGPP and protein geranylgeranylation as the components responsible for their reduction of prostate cancer progression. However, their depletion of nearly all isoprenoid intermediates as well as their organ specificities make understanding the specific role of protein geranylgeranylation in prostate cancer metastasis impossible.
Consequently, we have developed a novel library of seven alkyl bisphosphonate ethers found to potently reduce GGDPS with little to no activity against the related FDPS enzyme. Inhibition of GGDPS in three human prostate cancer cell lines reduced GGPP and protein geranylgeranylation without affecting protein farnesylation, translating into a reduction in cell migration and invasion. Interestingly, the GGDPS inhibitors reduced protein geranylgeranylation at lower concentrations in the highly metastatic PC3 cell line as compared to the less metastatic LNCaP and 22Rv1 cell lines. Additionally, the PC3 cell line was found to have higher levels of endogenous IBP intermediates as compared to the less metastatic cells. Translation in vivo using two murine models of human prostate cancer metastasis found a reduction in soft tissue tumor burden that corresponded to a biochemical reduction in protein geranylgeranylation. In conclusion, selective reduction of GGPP and protein geranylgeranylation was sufficient to reduce the metastatic potential of prostate cancer in vitro and in vivo.
|
526 |
Impact of insurance coverage on dental care utilization of Iowa childrenMani, Simi 01 May 2015 (has links)
Objective: To understand the association between dental insurance coverage and dental care utilization in Iowa children.
Methods: The 2010 Iowa Child and Family Household Health Survey (IHHS) data was used to assess the association between dental insurance coverage and dental care utilization in Iowa children. Andersen’s model of health services utilization was used as a framework for determining the predictors of dental care utilization. Chi-square test was used for determining bivariate associations and Logistic regression analysis was used to determine factors associated with dental care utilization.
Results: The results from the multivariable logistic regression model indicate that children with private dental insurance (p<0.001) and 4-9 years of age (p=0.005) were more likely to have a dental visit. Additionally, respondents who were always able to get dental appointments for their child (p<0.001), had a regular source of dental care for the child (p<0.001) and perceived dental need for their child (p<0.001), were more likely to report having a dental check-up for their child in the past 12 months.
Conclusion: Dental insurance was significantly associated with having a dental visit in the past year in Iowa children 4-17 years of age. Some of the other predictors of dental care utilization were: having a regular source of dental care for the child, ease of getting dental appointment for the child, younger child’s age and having perceived dental need for the child.
|
527 |
Mexican-American women and abortion : experiences and reflectionsWelter, Lauren Beth 01 July 2015 (has links)
Because Latinos are the largest, fastest-growing ethnic minority group in the U.S., learning more about their sexual and reproductive experiences and decision-making processes is important. Importantly, although sexuality and abortion are stigmatized in many Latino cultures and conservative religious beliefs specifically oppose abortion, Latinas have the highest birth rates in the U.S. and an estimated one in four pregnancies to Latina women are terminated (Jones, Darroch, &Henshaw, 2002; Jones, Finer, &Singh, 2010). Consequently, nuanced exploration of contradictions in reproductive behaviors and cultural and religious values is critical to supporting women's health and well-being. Seeking to advance the scholarship on the lived experiences of women who undergo elective abortion, this dissertation used Interpretive Phenomenological Analysis and a cultural and religious lens to explore the decision-making processes and phenomenological experiences of four young Mexican-American women who elected to terminate their first pregnancy. Results indicated that the women in this study believed abortion was unique, and more difficult for Mexican-American (and other Latina) women, given cultural and religious norms that specifically prohibit abortion and simultaneously prioritize sexual purity, responsibility, and motherhood for women. The complexity and difficulty inherent in navigating overlapping and oftentimes contradictory sociocultural and religious values are discussed as they relate to the participants' abortion decision and experience. The manuscript concludes with strengths and limitations of the present study, suggestions for future research, and implications for psychologists.
Keywords: Mexican, Latina, Abortion, Reproductive Health
|
528 |
The development of cationic polymers for non-viral gene delivery systemWongrakpanich, Amaraporn 01 July 2015 (has links)
Gene therapy is the process of delivering genetic material, such as DNA (encoding for an important protein) into a patient’s cells in order to treat a particular disease such as a genetic disorder or heart disease. This process of DNA delivery into cells is known as “transfection” and it is important that the efficiency of transfection be optimized such that a patient can obtain maximum therapeutic benefit from such a treatment. DNA is susceptible to being destroyed by harsh physiological environments prior to reaching its target. This problem can be diminished with the use of vectors that not only protect against harsh conditions but also encourage entry into cells. By mixing 1) DNA with 2) positively charged polymers, “polyplexes” form which protect DNA from degradation and increase transfection efficiency. The development of effective polyplex formulations requires optimization. In the work presented here, it was discovered that when polyplexes contained specific sequences within the DNA called “CpG”, this lowered transfection efficiencies and increased inflammatory responses compared to DNA without CpG, as measured using a mouse lungs model. Thus, DNA composition played an important role in influencing DNA transfection efficiency of polyplexes. Another aspect to take into account is the degree of positive charge of the polymer. We tested a new polymer called poly(galactaramidoamine) or PGAA. We found that this PGAA can form polyplexes with DNA and could be used in gene therapy. At the present time, mechanisms by which the polyplexes get inside and transfect the cells are still unclear. We also introduced a new system called high-content screening to the gene delivery field. This system offers automated measurements of transfection efficiency and cytotoxicity and could be used to reveal the polyplexes trafficking inside cells.
|
529 |
African American male offenders experiences of successful parole/post-release completionVeale, Frances R. B. 01 December 2015 (has links)
With over 2.3 million individuals in a states, federal prison and/or local jail, the United States has the largest prison population in the world. Ninety-five percent of all offenders incarcerated will return to society at some point in their lives; nevertheless, at least two-third recidivate within three years of their parole/post-release and return to prison. The high volume of offenders contributing to the crime rates, enormous prison growth and the budget needed for correctional operation, has led scholars, policymakers, and correctional officials, in addition to society as a whole, to give great attention in discovering and determining ways to break the repetitive cycle of incarceration and recidivism. Once an offender returns to society after incarceration, they face perplexing challenging barriers, and obstacles that impedes upon their ability to resist crime and complete parole supervision. For African American men, these challenging barriers and obstacles are exacerbated, because of their race and gender. Research shows that African American men are disproportionally represented, among the incarceration rates, prison population and are highly susceptible to factors that lead to recidivism.
The purpose of this study sought to gain more in-depth understanding of former African American male offenders’ experiences and perceptions of resisting crime and completing parole/post-release supervision. In particular, this study used qualitative methods to interview six African American men, in order to determine the significant impact which social and personal factors led them to successful parole/post-release supervision completion. The results of this study indicated that African American male offenders have the ability to complete parole/post-release supervision, when provided the opportunity to gain employment, higher levels of education and vocational training, strong support from their family and friend, establish positive social networks, participate in rehabilitative programs. The research further revealed other contributing factors aids in their success as well.
|
530 |
A closer examination of the book-tax difference pricing anomalyHepfer, Bradford Fitzgerald 01 May 2016 (has links)
In this study, I examine whether the pricing of book-tax differences reflects mispricing or a priced risk factor. I provide new evidence that temporary book-tax differences are mispriced by developing portfolios that trade on the information in book-tax differences for future accruals and cash flows. I develop and test predictions on whether book-tax difference mispricing is the value-glamour anomaly in disguise. Both signals of mispricing relate to firm growth and, thus, both may capture mispricing due to over-extrapolation of realized growth to future growth. I find that the book-tax difference pricing anomaly is subsumed by the value-glamour anomaly. Specifically, trading on the information in book-tax differences does not yield incremental returns relative to a value-glamour trading strategy. Hence, mispricing associated with book-tax differences relates more generally to the mispricing of expected growth as extrapolated from past growth.
|
Page generated in 0.0843 seconds