18 research outputs found
The Professional Development of School Social Workers
The purpose of this study was to examine the characteristics of continuing professional education, professional development, and other growth activities that most heavily influence the practice of school social workers. It was a qualitative study framed by heuristic inquiry using in depth interviews with twenty participants from two western states. A theoretical model emerged based on three components: the context of practice, contextual learning, and practice behaviors. All three components had the same three attributes: prior learning experiences, outside learning experiences, and the personal qualities of practitioners. Two important findings were that when the participants covered only one school and were funded by multiple sources, they were able to conduct more systemically-oriented interventions than would otherwise have been possible
Growth hormone action predicts age-related white adipose tissue dysfunction and senescent cell burden in mice
The aging process is associated with the development of several chronic diseases. White adipose tissue (WAT) may play a central role in age-related disease onset and progression due to declines in adipogenesis with advancing age. Recent reports indicate that the accumulation of senescent progenitor cells may be involved in age-related WAT dysfunction. Growth hormone (GH) action has profound effects on adiposity and metabolism and is known to influence lifespan. In the present study we tested the hypothesis that GH activity would predict age-related WAT dysfunction and accumulation of senescent cells. We found that long-lived GH-deficient and -resistant mice have reduced age-related lipid redistribution. Primary preadipocytes from GH-resistant mice also were found to have greater differentiation capacity at 20 months of age when compared to controls. GH activity was also found to be positively associated with senescent cell accumulation in WAT. Our results demonstrate an association between GH activity, age-related WAT dysfunction, and WAT senescent cell accumulation in mice. Further studies are needed to determine if GH is directly inducing cellular senescence in WAT or if GH actions on other target organs or alternative downstream alterations in insulin-like growth factor-1, insulin or glucose levels are responsible
Ets1 Induces Dysplastic Changes When Expressed in Terminally-Differentiating Squamous Epidermal Cells
BACKGROUND: Ets1 is an oncogene that functions as a transcription factor and regulates the activity of many genes potentially important for tumor initiation and progression. Interestingly, the Ets1 oncogene is over-expressed in many human squamous cell cancers and over-expression is highly correlated with invasion and metastasis. Thus, Ets1 is believed to mainly play a role in later stages of the oncogenic process, but not early events. METHODOLOGY/PRINCIPAL FINDINGS: To better define the role of Ets1 in squamous cell carcinogenesis, we generated a transgenic mouse model in which expression of the Ets1 oncogene could be temporally and spatially regulated. Upon Ets1 induction in differentiating cells of stratified squamous epithelium, these mice exhibited dramatic changes in epithelial organization including increased proliferation and blocked terminal differentiation. The phenotype was completely reversed when Ets1 expression was suppressed. In mice where Ets1 expression was re-induced at a later age, the phenotype was more localized and the lesions that developed were more invasive. Many potential Ets1 targets were upregulated in the skin of these mice with the most dramatic being the metalloprotease MMP13, which we demonstrate to be a direct transcriptional target of Ets1. CONCLUSIONS/SIGNIFICANCE: Collectively, our data reveal that upregulation of Ets1 can be an early event that promotes pre-neoplastic changes in epidermal tissues via its regulation of key genes driving growth and invasion. Thus, the Ets1 oncogene may be important for oncogenic processes in both early and late stages of tumor development
Averting Enforcement: Strategic Response to the Threat of Environmental Regulation
This paper uses data from the U.S. electric power industry to explore the strategic responses of regulated firms to government enforcement. We focus on the enforcement of New Source Review, a provision of the Clean Air Act that imposes stringent emissions limitations on substantially modified older power plants. Starting in late 1999, the EPA sued the owners of 46 power plants for NSR violations. This paper explores how electric utilities responded to both the perceived threat of future action, and the action itself. We find that the threat of action did have a significant effect on emissions: plants that were likely to be named in the lawsuits (as determined by our discrete choice model of the lawsuit decision) reduced their emissions by about 17 percent on the eve of the lawsuits. After the lawsuits, we find no significant difference between those plants sued and other relatively dirty coal-fired power plants