17 research outputs found

    Culture history of the Yahk Mining District

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    Impact of Cigarette Smoke Exposure on Innate Immunity: A Caenorhabditis elegans Model

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    BACKGROUND: Cigarette smoking is the major cause of chronic obstructive pulmonary disease (COPD) and lung cancer. Respiratory bacterial infections have been shown to be involved in the development of COPD along with impaired airway innate immunity. METHODOLOGY/PRINCIPAL FINDINGS: To address the in vivo impact of cigarette smoke (CS) exclusively on host innate defense mechanisms, we took advantage of Caenorhabditis elegans (C. elegans), which has an innate immune system but lacks adaptive immune function. Pseudomonas aeruginosa (PA) clearance from intestines of C. elegans was dampened by CS. Microarray analysis identified 6 candidate genes with a 2-fold or greater reduction after CS exposure, that have a human orthologue, and that may participate in innate immunity. To confirm a role of CS-down-regulated genes in the innate immune response to PA, RNA interference (RNAi) by feeding was carried out in C. elegans to inhibit the gene of interest, followed by PA infection to determine if the gene affected innate immunity. Inhibition of lbp-7, which encodes a lipid binding protein, resulted in increased levels of intestinal PA. Primary human bronchial epithelial cells were shown to express mRNA of human Fatty Acid Binding Protein 5 (FABP-5), the human orthologue of lpb-7. Interestingly, FABP-5 mRNA levels from human smokers with COPD were significantly lower (p = 0.036) than those from smokers without COPD. Furthermore, FABP-5 mRNA levels were up-regulated (7-fold) after bacterial (i.e., Mycoplasma pneumoniae) infection in primary human bronchial epithelial cell culture (air-liquid interface culture). CONCLUSIONS: Our results suggest that the C. elegans model offers a novel in vivo approach to specifically study innate immune deficiencies resulting from exposure to cigarette smoke, and that results from the nematode may provide insight into human airway epithelial cell biology and cigarette smoke exposure

    A Survey of New Temperature-Sensitive, Embryonic-Lethal Mutations in C. elegans: 24 Alleles of Thirteen Genes

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    To study essential maternal gene requirements in the early C. elegans embryo, we have screened for temperature-sensitive, embryonic lethal mutations in an effort to bypass essential zygotic requirements for such genes during larval and adult germline development. With conditional alleles, multiple essential requirements can be examined by shifting at different times from the permissive temperature of 15°C to the restrictive temperature of 26°C. Here we describe 24 conditional mutations that affect 13 different loci and report the identity of the gene mutations responsible for the conditional lethality in 22 of the mutants. All but four are mis-sense mutations, with two mutations affecting splice sites, another creating an in-frame deletion, and one creating a premature stop codon. Almost all of the mis-sense mutations affect residues conserved in orthologs, and thus may be useful for engineering conditional mutations in other organisms. We find that 62% of the mutants display additional phenotypes when shifted to the restrictive temperature as L1 larvae, in addition to causing embryonic lethality after L4 upshifts. Remarkably, we also found that 13 out of the 24 mutations appear to be fast-acting, making them particularly useful for careful dissection of multiple essential requirements. Our findings highlight the value of C. elegans for identifying useful temperature-sensitive mutations in essential genes, and provide new insights into the requirements for some of the affected loci

    An Integrated Strategy to Study Muscle Development and Myofilament Structure in Caenorhabditis elegans

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    A crucial step in the development of muscle cells in all metazoan animals is the assembly and anchorage of the sarcomere, the essential repeat unit responsible for muscle contraction. In Caenorhabditis elegans, many of the critical proteins involved in this process have been uncovered through mutational screens focusing on uncoordinated movement and embryonic arrest phenotypes. We propose that additional sarcomeric proteins exist for which there is a less severe, or entirely different, mutant phenotype produced in their absence. We have used Serial Analysis of Gene Expression (SAGE) to generate a comprehensive profile of late embryonic muscle gene expression. We generated two replicate long SAGE libraries for sorted embryonic muscle cells, identifying 7,974 protein-coding genes. A refined list of 3,577 genes expressed in muscle cells was compiled from the overlap between our SAGE data and available microarray data. Using the genes in our refined list, we have performed two separate RNA interference (RNAi) screens to identify novel genes that play a role in sarcomere assembly and/or maintenance in either embryonic or adult muscle. To identify muscle defects in embryos, we screened specifically for the Pat embryonic arrest phenotype. To visualize muscle defects in adult animals, we fed dsRNA to worms producing a GFP-tagged myosin protein, thus allowing us to analyze their myofilament organization under gene knockdown conditions using fluorescence microscopy. By eliminating or severely reducing the expression of 3,300 genes using RNAi, we identified 122 genes necessary for proper myofilament organization, 108 of which are genes without a previously characterized role in muscle. Many of the genes affecting sarcomere integrity have human homologs for which little or nothing is known

    Wildland Fire in Ecosystems Effects of Fire on Cultural Resources and Archaeology

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    This state-of-knowledge review provides a synthesis of the effects of fire on cultural resources, which can be used by fire managers, cultural resource (CR) specialists, and archaeologists to more effectively manage wildland vegetation, fuels, and fire. The goal of the volume is twofold: (1) to provide cultural resource/archaeological professionals and policy makers with a primer on fuels, fire behavior, and fire effects to enable them to work more effectively with the fire management community to protect resources during fuels treatment and restoration projects and wildfire suppression activities; and (2) to provide fire and land management professionals and policy makers with a greater understanding of the value of cultural resource protection and the methods available to evaluate and mitigate risks to CR. The synthesis provides a conceptual fire effects framework for planning, managing, and modeling fire effects (chapter1) and a primer on fire and fuel processes and fire effects prediction modeling (chapter 2). A synthesis of the effects of fire on various cultural resource materials is provided for ceramics (chapter 3), lithics (chapter 4), rock art (chapter 5), historic-period artifacts/materials (chapter 6), and below-ground features (chapter 7). Chapter 8 discusses the importance of cultural landscapes to indigenous peoples and emphasizes the need to actively involve native people in the development of collaborative management plans. The use and practical implications of this synthesis are the subject of the final chapter (chapter 9)

    Report and Recommendations of the Association of Pathology Chairs’ Autopsy Working Group

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    Autopsy has been a foundation of pathology training for many years, but hospital autopsy rates are notoriously low. At the 2014 meeting of the Association of Pathology Chairs, some pathologists suggested removing autopsy from the training curriculum of pathology residents to provide additional months for training in newer disciplines, such as molecular genetics and informatics. At the same time, the American Board of Pathology received complaints that newly hired pathologists recently certified in anatomic pathology are unable to perform an autopsy when called upon to do so. In response to a call to abolish autopsy from pathology training on the one hand and for more rigorous autopsy training on the other, the Association of Pathology Chairs formed the Autopsy Working Group to examine the role of autopsy in pathology residency training. After 2 years of research and deliberation, the Autopsy Working Group recommends the following: Autopsy should remain a component of anatomic pathology training. A training program must have an autopsy service director with defined responsibilities, including accountability to the program director to record every autopsy performed by every resident. Specific entrustable activities should be defined that a resident must master in order to be deemed competent in autopsy practice, as well as criteria for gaining the trust to perform the tasks without direct supervision. Technical standardization of autopsy performance and reporting must be improved. The current minimum number of 50 autopsies should not be reduced until the changes recommended above have been implemented

    Development of an instrument for measuring clinicians' power perceptions in the workplace

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    We report on the development of an instrument to measure clinicians' perceptions of their personal power in the workplace in relation to resistance to computerized physician order entry (CPOE). The instrument is based on French and Raven's six bases of social power and uses a semantic differential methodology. A measurement study was conducted to determine the reliability and validity of the survey. The survey was administered online and distributed via a URL by email to 19 physicians, nurses, and health unit coordinators from a university hospital. Acceptable reliability was achieved by removing or moving some semantic differential word pairs used to represent the six power bases (alpha range from 0.76 to 0.89). The Semantic Differential Power Perception (SDPP) survey validity was tested against an already validated instrument and found to be acceptable (correlation range from 0.51 to 0.81). The SDPP survey instrument was determined to be both reliable and valid. © 2008 Elsevier Inc. All rights reserved
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