Time Series Analysis: A New Look at Some Old Problems

This dissertation gives a comprehensive report of my doctoral research in time series analysis from summer 2006 to spring 2009. It is comprised of two main efforts: interval estimation for an autoregressive parameter and arc length tests for equivalent ARIMA dynamics. Such problems are traditional in statistics, but three new theorems and several simulations are presented here that help elucidate new ways to handle them

Cholesterol metabolism is altered in Rett syndrome: A study on plasma and primary cultured fibroblasts derived from patients

Rett (RTT) syndrome is a severe neurological disorder that affects almost exclusively females. Several detectable mutations in the X-linked methyl-CpG-binding protein 2 gene (MECP2) are responsible for the onset of the disease. MeCP2 is a key transcription regulator involved in gene silencing via methylation-dependent remodeling of chromatin. Recent data highlight that lipid metabolism is perturbed in brains and livers of MECP2-null male mice. In addition, altered plasma lipid profile in RTT patients has been observed. Thus, the aim of the work is to investigate the protein network involved in cholesterol homeostasis maintenance on freshly isolated fibroblasts and plasma from both RTT and healthy donors. To this end, protein expression of 3-hydroxy-3methyl glutaryl Coenzyme A reductase (HMGR), sterol regulatory element binding proteins (SREBPs), low density lipoprotein receptor (LDLr) and scavenger receptor B-1 (SRB-1) was assessed in cultured skin fibroblasts from unaffected individuals and RTT patients. In addition, lipid profile and the abundance of proprotein convertase subtilisin/kexin type 9 (PCSK9) were analyzed on plasma samples. The obtained results demonstrate that the main proteins belonging to cholesterol regulatory network are altered in RTT female patients, providing the proof of principle that cholesterol metabolism may be taken into account as a new target for the treatment of specific features of RTT pathology

From Home to Community to City: Different Approaches to Environmental Exposure Assessment of Particulate Matter across the Pittsburgh Region

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Assessing Foster Parent Factors That Predict Placement Disruption of Youth in Foster Care

Placement disruption is associated with a range of problematic outcomes for youth in foster care (e.g., externalizing and internalizing difficulties), and stable placements in a safe and supportive environment may buffer negative outcomes associated with placement instability. To best understand factors that are related to placement disruption, the current study aimed to assess if placement disruption was related to foster parent social support, stress, and training experiences above and beyond child and parent demographic variables using a longitudinal, prospective approach. The sample consisted of 32 traditional foster parents (91% female, 9% male) with a mean age of 45.69 years who reported on 64 foster children (54% female, 44% male) with a mean age of 8.20 years. Due to the fact that several foster parents reported on multiple children, only one randomly selected target child report was included in the final analysis resulting in foster parents report on a total of 32 children (53% female, 44% male) with a mean age of 8.41 years. Results suggested that the only variable related to disruption in the current sample was foster parent age. Specifically, older foster parents experienced more placement disruption when compared to younger foster parents. When matching participants based on foster parent age, no relation was observed between disruption status and foster parent social support, stress, and training experiences. Findings from the current study do suggest that for some traditional foster parents, it may not be low training hours, high stress, and low support that accounts for why some placements disrupt. Implications of the current findings as well as directions for future research are discussed

Untangling the relative contribution of maltreatment severity and frequency to type of behavioral outcome in foster youth

Within maltreatment research, type, frequency, and severity of abuse are often confounded and not always specifically documented. The result is that samples are often heterogeneous, and the role of components of maltreatment in predicting outcome is unclear. The purpose of the present study was to identify and test the potential unique role of type, frequency, and severity of maltreatment to elucidate each variable’s role in predicting outcome behavior. Data from 309 youth in foster care (ages 8–22) and their caregivers were collected using the Modified Maltreatment Classification System and the Behavioral Assessment System for Children, 2nd Edition (BASC2), to measure maltreatment exposure and behavioral outcome respectively. A measurement model of the BASC2 was completed to determine model fit within the sample data. A second confirmatory factor analysis (CFA) was completed to determine the unique contributions of frequency and severity of maltreatment across four types of abuse to externalizing, internalizing, and adaptive behavior. The result of the CFA determined good fit of the BASC2 to the sample data after a few modifications. The result of the second CFA indicated that the paths from severity to externalizing behavior and adaptive behavior (reverse loading) were significant. Paths from frequency of abuse were not predictive of behavioral outcome. Maltreatment is a complex construct and researchers are encouraged to avoid confounding components of abuse that may be differentially related to outcome behavior for youth. Untangling the multifaceted nature of abuse is important and may have implications for identifying specific outcomes for youth exposed to maltreatment

Using Multiple Informants to Assess Child Maltreatment: Condordance Between Case File and Youth Self-Report

This is an Accepted Manuscript of an article published by Taylor & Francis in Journal of Aggression, Maltreatment and Trauma in 2014, available online: http://www.tandfonline.com/10.1080/10926771.2014.933463.To understand the psychosocial implications of child maltreatment, methods used to document prevalence must be clear. Yet, rates of maltreatment found in child self-report are generally inconsistent with data found in case files from state social service agencies. Although self-reports and case file reports of abuse disagree on occurrence of specific events, it is unclear if reporters agree when overall categories of abuse are considered. This study investigated differences between case file and youth report of abuse by examining four types of abuse: physical, sexual, neglect, and psychological, in a within-subjects design using a sample of 97 youth in foster care aged 8 to 22. Case files were coded for the presence of any indication of each type of abuse. Self-report of abuse was also assessed for any indication of each type of abuse. Results indicated that, overall, youth reported more physical and psychological abuse, and younger youth reported more sexual abuse than documented in their file. Implications for research and service provision for maltreated youth are discussed

Longitudinal assessment of self-harm statements of youth in foster care: Rates, reporters, and related factors

Self-harm in youth is a risk factor related to mental health and future morbidity, yet, relatively little is known about the rates and course of self-harm in youth residing in foster care. This study examined self-harm talk in foster youth based on caregiver and child report for 135 children between the ages of 8- and 11-years old. Longitudinal data on course of self-harm talk from both youth and caregivers also are provided. Caregivers identified that 24% of youth participants had disclosed a desire to die or to hurt themselves. Youth self-report revealed that 21% of children indicated a desire for self-harm, and rates of self-harm from both reporters decreased over time. While overall rates were similar across reporters, findings show discrepancies between youth self-report and caregiver report within individuals. Also, caregivers for youth in residential facilities were more likely to report youth self-harm talk than caregivers from foster home settings

Wal-Mart or world-mart? A teaching case study

Abstract This teaching case study aims to draw out discussion in a variety of classes about the responsibilities of large corporations and their role in society. The authors provide a profile and a set of questions about Wal-Mart, the largest corporation in the world. Ultimately, the purpose of the study is to provoke discussions about the marketplace, social welfare, cultural homogenization, labor, and economic structure and agency in the context of expanding global corporate influence in society. JEL classification: A22; P

Indoor air sampling for fine particulate matter and black carbon in industrial communities in Pittsburgh

AbstractImpacts of industrial emissions on outdoor air pollution in nearby communities are well-documented. Fewer studies, however, have explored impacts on indoor air quality in these communities. Because persons in northern climates spend a majority of their time indoors, understanding indoor exposures, and the role of outdoor air pollution in shaping such exposures, is a priority issue. Braddock and Clairton, Pennsylvania, industrial communities near Pittsburgh, are home to an active steel mill and coke works, respectively, and the population experiences elevated rates of childhood asthma. Twenty-one homes were selected for 1-week indoor sampling for fine particulate matter (PM2.5) and black carbon (BC) during summer 2011 and winter 2012. Multivariate linear regression models were used to examine contributions from both outdoor concentrations and indoor sources. In the models, an outdoor infiltration component explained 10 to 39% of variability in indoor air pollution for PM2.5, and 33 to 42% for BC. For both PM2.5 models and the summer BC model, smoking was a stronger predictor than outdoor pollution, as greater pollutant concentration increases were identified. For winter BC, the model was explained by outdoor pollution and an open windows modifier. In both seasons, indoor concentrations for both PM2.5 and BC were consistently higher than residence-specific outdoor concentration estimates. Mean indoor PM2.5 was higher, on average, during summer (25.8±22.7μg/m3) than winter (18.9±13.2μg/m3). Contrary to the study's hypothesis, outdoor concentrations accounted for only little to moderate variability (10 to 42%) in indoor concentrations; a much greater proportion of PM2.5 was explained by cigarette smoking. Outdoor infiltration was a stronger predictor for BC compared to PM2.5, especially in winter. Our results suggest that, even in industrial communities of high outdoor pollution concentrations, indoor activities – particularly cigarette smoking – may play a larger role in shaping indoor exposures