<p>The massive number of injuries sustained in trafficaccidents is a growing problem worldwide, especially indeveloping countries. In 1998, more than one million peoplewere killed in traffic accidents worldwide, while about tentimes as many people were injured. Injuries to the centralnervous system and in particular to the headare especiallycritical to human life. This thesis contains five researchpapers looking at head injuries and head protection, proposingnew and more efficient ways of protecting the head, especiallyin traffic accidents.</p><p>In order to define the national dimensions of the patternsof injuries incurred in motorcycle and moped accidents inSweden, a statistical survey was performed on data spanning a13-year period (Paper A). In Sweden, 27,100 individualsreceived in-patient care for motorcycle and moped accidentinjuries between 1987 and 1999. The motorcycle and moped injuryrate reduced in the second half of the study period, so toowere the total number of days of treatment per year. Males hadeight times the incidence of injuries of females. Head injurieswere the single most frequent diagnosis, followed by fracturesof the lower limbs. Concussion was the most frequent headinjury. These statistics clearly show the need for better headinjury prevention systems.</p><p>According to the statistics, the most common type of impactto the head in motorcycle and moped accidents is an obliqueimpact. Oblique impacts generate rotations of the head, whichare a common cause of the most severe head injuries. Thereforea new test rig was constructed to reproduce oblique impacts toa helmeted dummy head, simulating those occurring in real lifeaccidents (Paper B). The new test rig was shown to provideuseful data at speeds of up to 50 km/h and with impact anglesvarying from purely tangential to purely radial. Thisinnovative test rig appears to provide an accurate method formeasuring accelerations in oblique impacts to helmets.</p><p>When testing the performances of motorcycle helmets,discrepancies are usually seen in the test results. In order toevaluate these discrepancies, the finite element method (FEM)was used for simulations of a few oblique helmet impacts (PaperC). Amongthe parameters studied, the coefficients of frictionbetween the impacting surface and the helmet and between thehead and the helmet had the most significant influence on therotational accelerations. Additionally, a thinner andconsequently also weaker shell and a weaker liner, providedbetter protection for the impacts studied.</p><p>Since there are no generally accepted global injurythresholds for oblique impacts to the human head, a study wasdesigned to propose new injury tolerances accounting for bothtranslations and rotations of the head (Paper D). In thatstudy, FE models of (a) a human head, (b) a Hybrid III dummyhead, and (c) the experimental helmet were used. Differentcriteria were proposed for different impact scenarios. Both thetranslational and the rotational effects were found to beimportant when proposing a predictor equation for the strainlevels experienced by the human brain in simulated impacts tothe head.</p><p>In order to reduce the level of head injuries in society andto better understand helmet impacts from different aspect, aballistic impact was also studied (Paper E). The effects ofdifferent helmet shell stiffness and different angles ofimpacts were simulated. In this study, the same FE head modelfrom Paper D was used, however here it was protected with amodel of a composite ballistic helmet. It was concluded thatthe helmet shell should be stiff enough to prevent the insideof the shell from striking the skull, and that the strainsarising in the brain tissue were higher for some obliqueimpacts than for purely radial ones.</p><p>In conclusion, this thesis describes the injury pattern ofmotorcycle and moped accidents in Sweden. This thesis showsthat the injuries sustained from these accidents can bereduced. In order to study both translational as well asrotational impacts, a new laboratory test rig was designed. Byusing the finite element method, it is possible to simulaterealistic impacts to the head and also to predict how severehead injuries may potentially be prevented.</p>

Thesis (Ph. D.)--University of Washington, 2002. / Vita. Includes bibliographical references (leaves 73-84).

Thesis (Ph. D.)--University of Missouri-Columbia, 2003. / Typescript. Vita. Includes bibliographical references (leaves 128-137). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 2003. / Typescript. Vita. Includes bibliographical references (leaves 128-137). Also available on the Internet.

Thesis (M.S.)--University of North Texas, May, 2009. / Title from title page display. Includes bibliographical references.

Thesis (M.S.), Eastern Illinois University, 2003. / Includes bibliographical references (leaves 44-48).

Thesis (Ph. D.)--University of Notre Dame, 2003. / Thesis directed by Jeanne D. Day for the Department of Psychology. "December 2003." Includes bibliographical references (leaves 98-106).

Thesis (Ed. D.)--West Virginia University, 2003. / Title from document title page. Document formatted into pages; contains xi, 156 p. Vita. Includes abstract. Includes bibliographical references (p. 130-139).

Introduction: Current treatment recommendations for advanced SCCHN include the use of combined modality therapy (e.g., radiation plus chemotherapy/biologic therapy). The new biologic agent, cetuximab, is considered a primary cost driver for SCCHN management. Cetuximab’s impact, however, has not been factored into SCCHN cost estimates; furthermore, costs have not been delineated for diagnostic, treatment, and end-of-life segments of advanced SCCHN management. We aim to characterize SCCHN segmented and overall costs, before and after cetuximab’s approval. Methods: This was a retrospective analysis of the PharMetrics Choice database. Patients >20 years of age with ICD-9-CM codes suggestive of advanced SCCHN diagnosed between 3/1/2003 and 3/1/2008 were included. Patients were divided into cohorts by diagnosis date: “pre-biologic” and “post-biologic.” Descriptive statistics were used to summarize patient characteristics, monthly and total medical costs, and cost drivers. The Mann-Whitney U test was used to compare costs between segments and cohorts; whereas, least squares regression was used to ascertain the impact of covariates. Results: A total of 365 patients met study criteria. Patients were predominately male (78%), with a median age of 57 years. Median monthly costs were: diagnosis ($2,199), treatment ($4,161), end-of-life ($6,614), and total ($4,167). Total direct medical costs were primarily driven by outpatient costs (23%). Patient age and length of follow-up had a significant impact on total costs, with older age associated with lower costs. When treatment segment was isolated, median monthly costs were lower in the “pre-biologic” as compared to the “post-biologic” era ($3,301 vs. $4,381, p=0.0024); biologic therapy accounted for 4.2% of total cost in the study period. In those patients experiencing all segments of care (“benchmark group”), median monthly costs were: diagnosis ($1,733), treatment ($8,265), end-of-life ($6,614), and total ($7,817). There were no significant differences in monthly medical costs between cohorts for the benchmark group. Conclusions: Median total cost exceeded $4,000/month for SCCHN patients; treatment and end-of-life segments incurred higher costs. Outpatient costs were the biggest cost-driver. Median monthly cost for the treatment segment increased by approximately $1,000 following cetuximab’s approval; however, this difference dissipated when the analysis was limited to those patients who experienced all segments of care. / text

Early childhood—a period of development that research has established as a critical period for establishing a foundation to support later development and well-being—is increasingly likely to take place in multiple contexts. Continuity and discontinuity in children’s exposure to environmental chaos across two important contexts for their early development: (1) the home and (2) the early learning and care (ELC) setting were examined using data from a large representative sample of low-income preschool children attending Head Start in order to determine how children’s exposure to chaos in each context combine to either promote or interfere with their social-emotional and cognitive development over a year of preschool. A series of multi-level models tested whether children’s experiences of chaos, operationalized in three ways: (1) as individual indicators of crowding, lack of routines, and instability in each setting; (2) as a cumulative index of chaos in each setting; and (3) as a profile that incorporated children’s experiences across setting, influenced children’s social-emotional and cognitive development. Both household and classroom chaos predicted children’s development, but children’s experiences in their home environments were the predominant influence, indicating that children who had non-chaotic home environments gained more over the preschool year than did children who had chaotic homes. These findings provide additional support that effective and high-quality early education and care settings must incorporate children’s home and family experiences. / text