476 research outputs found

    How Firm Resources and Behavior Impact Firm Performance: An examination of firm resources, competitive actions, and performance

    Get PDF
    In this dissertation, I considered how firm resources, actions and performance may be interrelated. I tested the notion that resources both enable and interact with firm actions to impact performance. Drawing from resource-based and actions-based theory and empirical research, testable hypotheses were developed suggesting that a firm's resources may impact performance potentially in three ways - directly, mediated by actions, and in combination with actions. I examined 1) the extent to which firm resources and actions each directly predict variation in firm performance; 2) the extent to which firm resources predict variation in intervening actions and thereby predict variation in performance; and 3) the extent to which the product of resources and actions in combination predict variation in performance. With a combined dataset of 4,337 actions, gathered through the structured-content analysis of over 16,000 published news articles, and 980 model-years of resources and performance data collected from industry and government sources, 44 foreign and domestic automakers were analyzed over a study period from 1993 to 2000. I find empirical support for key components of their relationships. The analysis shows evidence that firm resources impact performance, both through and with firm actions

    Ly49H signaling through DAP10 is essential for optimal natural killer cell responses to mouse cytomegalovirus infection

    Get PDF
    The activating natural killer (NK) cell receptor Ly49H recognizes the mouse cytomegalovirus (MCMV) m157 glycoprotein expressed on the surface of infected cells and is required for protection against MCMV. Although Ly49H has previously been shown to signal via DAP12, we now show that Ly49H must also associate with and signal via DAP10 for optimal function. In the absence of DAP12, DAP10 enables Ly49H-mediated killing of m157-bearing target cells, proliferation in response to MCMV infection, and partial protection against MCMV. DAP10-deficient Ly49H+ NK cells, expressing only Ly49H–DAP12 receptor complexes, are partially impaired in their ability to proliferate during MCMV infection, display diminished ERK1/2 activation, produce less IFN-γ upon Ly49H engagement, and demonstrate reduced control of MCMV infection. Deletion of both DAP10 and DAP12 completely abrogates Ly49H surface expression and control of MCMV infection. Thus, optimal NK cell–mediated immunity to MCMV depends on Ly49H signaling through both DAP10 and DAP12

    Recurrence of Stachybotrys chartarum during mycological and toxicological study of bioaerosols collected in a dairy cattle shed

    Get PDF
    International audienceAgricultural occupations associated with animal breeding and the processing of animal materials in confinement systems could potentially lead to bioaerosol exposures. Moulds and mycotoxins could be constituents of bioaerosols and should be studied because of their possible involvement in respiratory diseases and cancers. In order to characterize the fungal contamination of the indoor air in a dairy barn, bioaerosols were collected during 20 days in a cattle farm located in Normandy (France). Mycobiota, mycotoxins and the mutagenicity of bioaerosols were studied. The toxigenic ability of Aspergillus flavus group and Aspergillus fumigatus isolates was also evaluated in vitro. The prevalent airborne moulds were from the following potentially toxigenic species: Aspergillus flavus group, Aspergillus fumigatus, Penicillium chrysogenum, Stachybotrys chartarum, and the allergenic species Ulocladium chartarum, Cladosporium cladosporioides. In comparison with harvesting, grain handling or broiler breeding, the concentrations of viable moulds were lower in the cattle shed. Seasonal variations in levels of several species were also observed. This study revealed that aflatoxins were detected in bioaerosols and, for the first time, showed that farmers are possibly exposed to Stachybotrys chartarum during routine barn work. Moreover, the finding of mutagenicity from bioaerosols needs further investigations on bioaerosol composition

    Tetrameric Complexes of Human Histocompatibility Leukocyte Antigen (HLA)-G Bind to Peripheral Blood Myelomonocytic Cells

    Get PDF
    The nonclassical MHC class I molecule human histocompatibility leukocyte antigen (HLA)-G is selectively expressed on fetal trophoblast tissue at the maternal–fetal interface in pregnancy. It has long been suggested that HLA-G may inhibit maternal natural killer (NK) cells through interaction with particular NK cell receptors (KIRs). To investigate interactions of HLA-G, we constructed phycoerythrin-labeled tetrameric complexes of HLA-G refolded with a self-peptide. These HLA-G tetramers failed to bind to NK cells and cells transfected with CD94/NKG2 and killer immunoglobulin-like NK receptors. In contrast, HLA-G tetramers did bind to peripheral blood monocytes, staining a CD16+CD14mid subset with greater intensity. On transfectants, HLA-G tetramers bound to inhibitory immunoglobulin-like transcript (ILT)2 and ILT4 receptors. However, staining in the presence of antibodies reactive with ILT receptors revealed that the interaction of HLA-G tetramers with blood monocytes was largely due to binding to ILT4. These results suggest that the primary role of HLA-G may be the modulation of myelomonocytic cell behavior in pregnancy

    1987: Abilene Christian College Bible Lectures - Full Text

    Get PDF
    THE MIND OF CHRIST Being the Abilene Christian University Annual Bible Lectures 1987 Published by A.C.U. Press 1634 Campus Court Abilene, Texas 7960

    The Role of Innate Immunity in Autoimmunity

    Get PDF
    During the 2004 International Congress of Immunology in Montreal, a panel of experts gathered for an “Ideashop” discussion on the potential role of innate immunity in autoimmunity and the ways in which this might be targeted in future therapies

    Expression of Natural Killer Receptor Alleles at Different Ly49 Loci Occurs Independently and Is Regulated by Major Histocompatibility Complex Class I Molecules

    Get PDF
    Ly49 receptor genes are expressed by subsets of natural killer (NK) cells in an overlapping fashion, accounting for the capacity of NK subsets to attack host cells that have selectively downregulated self–major histocompatibility complex (MHC) class I molecules. It was shown previously that most NK cells express only one or the other allele of a given Ly49 gene, while a smaller population expresses both alleles. However, the methods used to detect monoallelic and biallelic cells were nonquantitative. Here, new allele-specific antibodies were used to provide the first quantitative examination of biallelic and monoallelic expression of Ly49A and Ly49G2. The results demonstrate conclusively that most Ly49A+ and Ly49G2+ NK cells express the corresponding gene in a monoallelic fashion, with a smaller subset expressing both alleles. Unexpectedly, biallelic Ly49A+ NK cells were more numerous than predicted by completely independent allelic expression, suggesting some heterogeneity among NK progenitors in the potential to express a given Ly49 gene. The data also show that cells expressing one allele of Ly49G2 may express Ly49A from the same or opposite chromosome with equal likelihood, indicating that the expressed allele is chosen independently for different Ly49 genes. Finally, the data demonstrate that biallelic expression of Ly49A or Ly49G2 occurs least frequently in mice that express ligands for these receptors (H-2d mice), and most frequently in class I–deficient mice. Thus, biallelic expression of Ly49 genes is regulated by interactions of NK cell progenitors with MHC class I molecules

    Improving Colorectal Cancer Screening in Primary Care Practice: Innovative Strategies and Future Directions

    Get PDF
    Colorectal cancer (CRC) screening has been supported by strong research evidence and recommended in clinical practice guidelines for more than a decade. Yet screening rates in the United States remain low, especially relative to other preventable diseases such as breast and cervical cancer. To understand the reasons, the National Cancer Institute and Agency for Healthcare Research and Quality sponsored a review of CRC screening implementation in primary care and a program of research funded by these organizations. The evidence base for improving CRC screening supports the value of a New Model of Primary Care Delivery: 1. a team approach, in which responsibility for screening tasks is shared among other members of the practice, would help address physicians’ lack of time for preventive care; 2. information systems can identify eligible patients and remind them when screening is due; 3. involving patients in decisions about their own care may enhance screening participation; 4. monitoring practice performance, supported by information systems, can help target patients at increased risk because of family history or social disadvantage; 5. reimbursement for services outside the traditional provider—patient encounter, such as telephone and e-mail contacts, may foster enhanced screening delivery; 6. training opportunities in communication, cultural competence, and use of information technologies would improve provider competence in core elements of screening programs. Improvement in CRC screening rates largely depends on the efforts of primary care practices to implement effective systems and procedures for screening delivery. Active engagement and support of practices are essential for the enormous potential of CRC screening to be realized
    • …
    corecore