646 research outputs found

    Conditional Facilitation of an Aphid Vector, Acyrthosiphon pisum, by the Plant Pathogen, Pea Enation Mosaic Virus

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    Plant pathogens can induce symptoms that affect the performance of insect herbivores utilizing the same host plant. Previous studies examining the effects of infection of tic bean, Vicia faba L. (Fabales: Fabaceae), by pea enation mosaic virus (PEMV), an important disease of legume crops, indicated there were no changes in the growth and reproductive rate of its primary vector the pea aphid, Acyrthosiphon pisum (Harris) (Hemiptera: Aphididae). Here, we report the results of laboratory experiments investigating how A. pisum responded to PEMV infection of a different host plant, Pisum sativum L., at different stages of symptom development. Aphid growth rate was negatively related to the age of the host plant, but when they were introduced onto older plants with well-developed PEMV symptoms they exhibited a higher growth rate compared to those developing on uninfected plants of the same age. In choice tests using leaf discs A. pisum showed a strong preference for discs from PEMV-infected peas, probably in response to visual cues from the yellowed and mottled infected leaves. When adults were crowded onto leaves using clip-cages they produced more winged progeny on PEMV-infected plants. The results indicate that PEMV produces symptoms in the host plant that can enhance the performance of A. pisum as a vector, modify the production of winged progeny and affect their spatial distribution. The findings provide further evidence that some insect vector/plant pathogen interactions could be regarded as mutualistic rather than commensal when certain conditions regarding the age, stage of infection and species of host plant are met

    Democratic Teacher Education Practices

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    [Living reference work entry] This entry provides an insight into the turbulent and recently disappointing events in the history of Design and Technology (D&T) teacher education in England over the last 150 years. It is a complex journey that needs to include a review of the generic history of teacher education in England, the differing educational needs of children, the changing role of D&T as a school curriculum subject, the requirements for an appropriately trained workforce to meet the economic needs of the country, and how various government educational initiatives and interventions (Gillard 2018) have affected how teachers in general and D&T teachers in particular have been and still are trained today. All these factors are inseparably intertwined. Therefore, this entry discusses them all together in chronological date order

    NOX1-dependent redox signaling potentiates colonic stem cell proliferation to adapt to the intestinal microbiota by linking EGFR and TLR activation

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    The colon epithelium is a primary point of interaction with the microbiome and is regenerated by a few rapidly cycling colonic stem cells (CSCs). CSC self-renewal and proliferation are regulated by growth factors and the presence of bacteria. However, the molecular link connecting the diverse inputs that maintain CSC homeostasis remains largely unknown. We report that CSC proliferation is mediated by redox-dependent activation of epidermal growth factor receptor (EGFR) signaling via NADPH oxidase 1 (NOX1). NOX1 expression is CSC specific and is restricted to proliferative CSCs. In the absence of NOX1, CSCs fail to generate ROS and have a reduced proliferation rate. NOX1 expression is regulated by Toll-like receptor activation in response to the microbiota and serves to link CSC proliferation with the presence of bacterial components in the crypt. The TLR-NOX1-EGFR axis is therefore a critical redox signaling node in CSCs facilitating the quiescent-proliferation transition and responds to the microbiome to maintain colon homeostasis

    Impact of patient characteristics, education and knowledge on emergency room visits in patients with asthma and COPD: a descriptive and correlative study

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    <p>Abstract</p> <p>Background</p> <p>Asthma and COPD are major health problems and an extensive burden for the patient and the health care system. Patient education has been recommended, but the influence on knowledge and health outcomes is not fully examined. Our aims were to compare patient characteristics, education and knowledge in patients who had an emergency room (ER) visit, to explore factors related to disease knowledge, and to investigate patient characteristics, patient education and knowledge in relation to further ER visits over a 12 month period.</p> <p>Methods</p> <p>Eighty-four patients with asthma and 52 with COPD, who had had an ER visit, were included. They were interviewed by telephone 4 to 6 weeks after the ER visit and followed for a year.</p> <p>Results</p> <p>Patients with COPD were older, more sedentary, had had more ER visits the previous year, and had more co morbidity than patients with asthma. About 80% of the patients had received information from health professionals or participated in education/rehabilitation, but a minority (< 20%) reported that their knowledge about how to handle the disease was good. Patients with "good knowledge" were younger, were more likely to have asthma diagnose, and had a higher educational background (p < 0.05). Sixty-seven percent of the patients with COPD had repeated ER visits during the following year versus 42% in asthma (p < 0.05) (adjusted HRR: 1.73 (1.03-2.90)). Patients who had had ER visits the year before inclusion had a higher risk of ER visits the following year (adjusted HRR: 3.83 (1.99-7.38)). There were no significant differences regarding patient education and knowledge between the group with and without further ER visits after adjusting for sex, diagnose, age, and educational background.</p> <p>Conclusion</p> <p>Patients with asthma had a better self reported knowledge of disease management and were less likely to have new exacerbations than patients with COPD. Reported level of knowledge was, however, in it self not a predictor of exacerbations. This indicates that information is not sufficient to reduce the burden of disease. Patient education focused on self-management and behavioral change should be emphasized.</p

    GEP100/Arf6 Is Required for Epidermal Growth Factor-Induced ERK/Rac1 Signaling and Cell Migration in Human Hepatoma HepG2 Cells

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    BACKGROUND: Epidermal growth factor (EGF) signaling is implicated in the invasion and metastasis of hepatoma cells. However, the signaling pathways for EGF-induced motility of hepatoma cells remain undefined. METHODOLOGY/PRINCIPAL FINDINGS: We found that EGF dose-dependently stimulated the migration of human hepatoma cells HepG2, with the maximal effect at 10 ng/mL. Additionally, EGF increased Arf6 activity, and ectopic expression of Arf6 T27N, a dominant negative Arf6 mutant, largely abolish EGF-induced cell migration. Blocking GEP100 with GEP100 siRNA or GEP100-△PH, a pleckstrin homology (PH) domain deletion mutant of GEP100, blocked EGF-induced Arf6 activity and cell migration. EGF also increased ERK and Rac1 activity. Ectopic expression GEP100 siRNA, GEP100-△PH, or Arf6-T27N suppressed EGF-induced ERK and Rac1 activity. Furthermore, blocking ERK signaling with its inhibitor U0126 remarkably inhibited both EGF-induced Rac1 activation as well as cell migration, and ectopic expression of inactive mutant form of Rac1 (Rac1-T17N) also largely abolished EGF-induced cell migration. CONCLUSIONS/SIGNIFICANCE: Taken together, this study highlights the function of the PH domain of GEP100 and its regulated Arf6/ERK/Rac1 signaling cascade in EGF-induced hepatoma cell migration. These findings could provide a rationale for designing new therapy based on inhibition of hepatoma metastasis

    Updated fracture incidence rates for the US version of FRAX®

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    # The Author(s) 2009. This article is published with open access at Springerlink.com Summary On the basis of updated fracture and mortality data, we recommend that the base population values used in the US version of FRAX ® be revised. The impact of suggested changes is likely to be a lowering of 10-year fracture probabilities. Introduction Evaluation of results produced by the US version of FRAX ® indicates that this tool overestimates the likelihood of major osteoporotic fracture. In an attempt to correct this, we updated underlying fracture and mortality rates for the model. Methods We used US hospital discharge data from 2006 t

    FRAX (R): Prediction of Major Osteoporotic Fractures in Women from the General Population: The OPUS Study

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    Purposes: The aim of this study was to analyse how well FRAXH predicts the risk of major osteoporotic and vertebral fractures over 6 years in postmenopausal women from general population. Patients and methods: The OPUS study was conducted in European women aged above 55 years, recruited in 5 centers from random population samples and followed over 6 years. The population for this study consisted of 1748 women (mean age 74.2 years) with information on incident fractures. 742 (43.1%) had a prevalent fracture; 769 (44%) and 155 (8.9%) of them received an antiosteoporotic treatment before and during the study respectively. We compared FRAXH performance with and without bone mineral density (BMD) using receiver operator characteristic (ROC) c-statistical analysis with ORs and areas under receiver operating characteristics curves (AUCs) and net reclassification improvement (NRI). Results: 85 (4.9%) patients had incident major fractures over 6 years. FRAXH with and without BMD predicted these fractures with an AUC of 0.66 and 0.62 respectively. The AUC were 0.60, 0.66, 0.69 for history of low trauma fracture alone, age and femoral neck (FN) BMD and combination of the 3 clinical risk factors, respectively. FRAXH with and without BMD predicted incident radiographic vertebral fracture (n = 65) with an AUC of 0.67 and 0.65 respectively. NRI analysis showed a significant improvement in risk assignment when BMD is added to FRAXH. Conclusions: This study shows that FRAXH with BMD and to a lesser extent also without FN BMD predict major osteoporotic and vertebral fractures in the general population
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