74 research outputs found

    Charting the Course for Use of Small Unmanned Aerial Systems in Newsgathering

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    News organizations and individual journalists eagerly anticipate safely utilizing Small Unmanned Aerial Systems (sUAS) for newsgathering purposes as lawmakers integrate sUAS into the National Air Space (NAS). For now, these potential users may be flying over an unchartered regulatory landscape while the FAA struggles to complete its administrative rulemaking. In order to better understand how media organizations and individual journalists intend to use sUAS for newsgathering purposes, the National Press Photographers Association (NPPA) developed a survey consisting of twenty-one multiple choice questions, with space for elaboration, and three questions seeking narrative responses. The survey was distributed via email to approximately fifty news organizations and media associations. There were 680 responses, mostly from those identifying themselves as journalists, with the next largest group being news managers. Others responding to the survey include attorneys, academicians, and students. The survey began on February 3, 2014 and remained open until March 13, 2014. The survey answers provide a first-of-its-kind study of this subject. This paper, which was originally presented at the annual meeting of the Association for Unmanned Vehicle Systems International (AUVSI) in Orlando, Florida, in May 2014, introduces the reader to a brief history of manned flight and photography, leading with the natural progression of the two technologies, to sUAS use for newsgathering. The paper explores the ups and downs of current and proposed FAA policies and regulations regarding sUAS use. Other issues addressed include: state legislation as well as some recent incidents and cases involving sUAS. Also examined are some of the proposed requirements found in the FAA\u27s UAS Comprehensive Plan and the FAA Roadmap for Integration of Civil UAS in the NAS. Past privacy debates may be prologue to the present discussion when pondering new rules and legislation. The historical debates between privacy concerns on the one hand and newsgatherers\u27 use of emerging technologies on the other are also examined. The paper also explores haw journalists may better understand and participate in the rulemaking process as well as proposals for striking an appropriate and acceptable balance between First Amendment protected newsgathering activities and privacy concerns

    Origin of myofibroblasts in liver fibrosis

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    Most chronic liver diseases of all etiologies result in progressive liver fibrosis. Myofibroblasts produce the extracellular matrix, including type I collagen, which constitutes the fibrous scar in liver fibrosis. Normal liver has little type I collagen and no detectable myofibroblasts, but myofibroblasts appear early in experimental and clinical liver injury. The origin of the myofibroblast in liver fibrosis is still unresolved. The possibilities include activation of endogenous mesenchymal cells including fibroblasts and hepatic stellate cells, recruitment from the bone marrow, and transformation of epithelial or endothelial cells to myofibroblasts. In fact, the origin of myofibroblasts may be different for different types of chronic liver diseases, such as cholestatic liver disease or hepatotoxic liver disease. This review will examine our current understanding of the liver myofibroblast

    ROS release by PPARβ/δ-null fibroblasts reduces tumor load through epithelial antioxidant response.

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    Tumor stroma has an active role in the initiation, growth, and propagation of many tumor types by secreting growth factors and modulating redox status of the microenvironment. Although PPARβ/δ in fibroblasts was shown to modulate oxidative stress in the wound microenvironment, there has been no evidence of a similar effect in the tumor stroma. Here, we present evidence of oxidative stress modulation by intestinal stromal PPARβ/δ, using a FSPCre-Pparb/d <sup>-/-</sup> mouse model and validated it with immortalized cell lines. The FSPCre-Pparb/d <sup>-/-</sup> mice developed fewer intestinal polyps and survived longer when compared with Pparb/d <sup>fl/fl</sup> mice. The pre-treatment of FSPCre-Pparb/d <sup>-/-</sup> and Pparb/d <sup>fl/fl</sup> with antioxidant N-acetyl-cysteine prior DSS-induced tumorigenesis resulted in lower tumor load. Gene expression analyses implicated an altered oxidative stress processes. Indeed, the FSPCre-Pparb/d <sup>-/-</sup> intestinal tumors have reduced oxidative stress than Pparb/d <sup>fl/fl</sup> tumors. Similarly, the colorectal cancer cells and human colon epithelial cells also experienced lower oxidative stress when co-cultured with fibroblasts depleted of PPARβ/δ expression. Therefore, our results establish a role for fibroblast PPARβ/δ in epithelial-mesenchymal communication for ROS homeostasis

    Genomics of liver fibrosis and cirrhosis

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    Hepatic fibrosis is the response to chronic injury from viral, toxic, metabolic, cholestatic, or autoimmune liver injury. However, only a minority of affected individuals develop advanced fibrosis or cirrhosis, suggesting that modifiers determine the individual risk. Aside from well-established progression factors including gender, duration of exposure to the disease, and ethnicity, unknown host genetic factors are likely to influence disease progression and prognosis. Potential genetic susceptibility loci are single nucleotide polymorphisms in fibrosis-associated genes, point mutations, microsatellites, and haplotype blocks composed of genes pivotal for fibrosis development. However, the study of complex polygenetic diseases poses numerous pitfalls in contrast to the elucidation of monogenetic (i.e., Mendelian) diseases. Many publications on the role of certain genetic variants in modulating the progression of hepatic fibrosis have been limited by inadequate study design and low statistical power. At present, powerful research strategies are being developed that allow the application of knowledge derived from the successful sequencing of the human genome that will help to translate our newly acquired insight into practical improvements for research activities and medical practice

    Genetic polymorphisms of manganese-superoxide dismutase and glutathione-S-transferase in chronic alcoholic pancreatitis

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    Chronic alcohol consumption is a major risk factor for the development of chronic pancreatitis. However, chronic pancreatitis occurs only in a minority of heavy drinkers. This variability may be due to yet unidentified genetic factors. Several enzymes involved in the degradation of reactive oxidants and xenobiotics, such as glutathione-S-transferase P1 (GSTP1) and manganese-superoxide dismutase (MnSOD) reveal functional polymorphisms that affect the antioxidative capacity and may therefore modulate the development of chronic pancreatitis and long-term complications like endocrine and exocrine pancreatic insufficiency. Two functional polymorphisms of the MnSOD and the GSTP1 gene were assessed by polymerase chain reaction and restriction fragment length polymorphism in 165 patients with chronic alcoholic pancreatitis, 140 alcoholics without evidence of pancreatic disease and 160 healthy control subjects. The distribution of GSTP1 and MnSOD genotypes were in Hardy-Weinberg equilibrium in the total cohort. Genotype and allele frequencies for both genes were not statistically different between the three groups. Although genotype MnSOD Ala/Val was seemingly associated with the presence of exocrine pancreatic insufficiency, this subgroup was too small and the association statistically underpowered. None of the tested genotypes affected the development of endocrine pancreatic insufficiency. Polymorphisms of MnSOD and GSTP1 are not associated with chronic alcoholic pancreatitis. The present data emphasize the need for stringently designed candidate gene association studies with well-characterized cases and controls and sufficient statistical power to exclude chance observations
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