23 research outputs found

    The relationship of learning communities to engineering students' perceptions of the freshman year experience, academic performance, and persistence

    Get PDF
    The purpose of this correlational study was to examine the effects of a residential learning community and enrollment in an introductory engineering course to engineering students’ perceptions of the freshman year experience, academic performance, and persistence. The sample included students enrolled in a large, urban, public, research university in the fall semesters of 2005-2007. Students’ perceptions regarding their choice of major, sense of community, the learning environment, academic advising, and competencies required by the Accreditation Board for Engineering and Technology (2009) were operationalized using items from the College of Engineering annual student survey. Incoming characteristics of predicted grade index and level of parental education were incorporated into the study. Structural equation modeling was used to test the goodness-of-fit of the sample data to two hypothesized models that represented competing theories or conceptualizations of the freshman year experience. A hierarchical logistic regression was also conducted to predict re-enrollment in the College of Engineering in the second semester of the sophomore year. Results indicated that neither learning community influenced students’ perceptions of the freshman year experience or sophomore year retention despite historical data that consistently demonstrate the positive effect of the residential learning community on freshman year retention rates. Of the variables considered, only students’ perceptions of the major had a moderate direct effect on both outcomes. Parental education level and academic performance were also significant predictors of persistence. Of particular interest was the finding that students whose parents had not earned a four-year college degree were more than twice as likely to persist in the College of Engineering than their peers who had a least one college-educated parent

    The gut microbial metabolic capacity of microbiome-humanized vs. wild type rodents reveals a likely dual role of intestinal bacteria in hepato-intestinal schistosomiasis

    Get PDF
    Increasing evidence shows that the host gut microbiota might be involved in the immunological cascade that culminates with the formation of tissue granulomas underlying the pathophysiology of hepato-intestinal schistosomiasis. In this study, we investigated the impact of Schistosoma mansoni infection on the gut microbial composition and functional potential of both wild type and microbiome-humanized mice. In spite of substantial differences in microbiome composition at baseline, selected pathways were consistently affected by parasite infection. The gut microbiomes of infected mice of both lines displayed, amongst other features, enhanced capacity for tryptophan and butyrate production, which might be linked to the activation of mechanisms aimed to prevent excessive injuries caused by migrating parasite eggs. Complementing data from previous studies, our findings suggest that the host gut microbiome might play a dual role in the pathophysiology of schistosomiasis, where intestinal bacteria may contribute to egg-associated pathology while, in turn, protect the host from uncontrolled tissue damage

    IRF5 promotes influenza-induced inflammatory responses in human iPSC-derived myeloid cells and murine models.

    Get PDF
    Recognition of Influenza A virus (IAV) by the innate immune system triggers pathways that restrict viral replication, activates innate immune cells, and regulates adaptive immunity. However, excessive innate immune activation can exaggerate disease. The pathways promoting excessive activation are incompletely understood, with limited experimental models to investigate mechanisms driving influenza-induced inflammation in humans. Interferon regulatory factor (IRF5) is a transcription factor that plays important roles in induction of cytokines after viral sensing. In an in vivo model of IAV infection, IRF5 deficiency reduced IAV-driven immune pathology and associated inflammatory cytokine production, specifically reducing cytokine-producing myeloid cell populations in Irf5-/- mice, but not impacting type 1 IFN production or virus replication. Using cytometry by time-of-flight (CyTOF), we identified that human lung IRF5 expression was highest in cells of the myeloid lineage. To investigate the role of IRF5 in mediating human inflammatory responses by myeloid cells to IAV, we employed human induced pluripotent stem cells (hIPSCs) with biallelic mutations in IRF5, demonstrating for the first time iPS-derived dendritic cells (iPS-DCs) with biallelic mutations can be used to investigate regulation of human virus-induced immune responses. Using this technology, we reveal that IRF5 deficiency in human DCs, or macrophages, corresponded with reduced virus-induced inflammatory cytokine production, with IRF5 acting downstream of TLR7 and, possibly, RIG-I after viral sensing. Thus, IRF5 acts as a regulator of myeloid cell inflammatory cytokine production during IAV infection in mice and humans, and drives immune-mediated viral pathogenesis independently of type 1 IFN and virus replication.ImportanceThe inflammatory response to Influenza A virus (IAV) participates in infection control but contributes to disease severity. After viral detection intracellular pathways are activated, initiating cytokine production, but these pathways are incompletely understood. We show that interferon regulatory factor 5 (IRF5) mediates IAV-induced inflammation and, in mice, drives pathology. This was independent of antiviral type 1 IFN and virus replication, implying that IRF5 could be specifically targeted to treat influenza-induced inflammation. We show for the first time that human iPSC technology can be exploited in genetic studies of virus-induced immune responses. Using this technology, we deleted IRF5 in human myeloid cells. These IRF5-deficient cells exhibited impaired influenza-induced cytokine production and revealed that IRF5 acts downstream of Toll-like receptor 7 and possibly retinoic acid-inducible gene-I. Our data demonstrate the importance of IRF5 in influenza-induced inflammation, suggesting genetic variation in the IRF5 gene may influence host susceptibility to viral diseases.This work was supported by The Wellcome Trust. This work was funded by a Wellcome 641 Trust Senior Research Fellowship to Ian Humphreys (207503/Z/17/Z); Medical Research 642 Council, United Kingdom (MR/L018942/1 and MRC Human Immunology Unit Core); 643 Chinese Academy of Medical Sciences (CAMS) Innovation Fund for Medical Sciences 644 (CIFMS), China (grant number: 2018-I2M-2-002). The Wellcome Trust Sanger Institute was 645 the source of the Kolf2 human induced pluripotent cell line which was generated under the 646 Human Induced Pluripotent Stem Cell Initiative funded by a grant from the Wellcome Trust Downloaded from http://jvi.asm.org/ on March 2, 2020 at CAMBRIDGE UNIV27 and Medical Research Council, supported 647 by the Wellcome Trust (WT098051) and the 648 NIHR/Wellcome Trust Clinical Research Facility, and Life Science Technologies 649 Corporation provided Cytotune for reprogramming. We thank the Wellcome Trust Sanger Institute Gene editing pipeline for generation of IRF5-/- 650 iPSCs and the Mass spectrometry 651 Facility at the Weatherall Institute of Molecular Medicine for help with CyTOF experiments

    Baseline Gut Microbiota Composition Is Associated With Schistosoma mansoni Infection Burden in Rodent Models

    Get PDF
    In spite of growing evidence supporting the occurrence of complex interactions between Schistosoma and gut bacteria in mice and humans, no data is yet available on whether worm-mediated changes in microbiota composition are dependent on the baseline gut microbial profile of the vertebrate host. In addition, the impact of such changes on the susceptibility to, and pathophysiology of, schistosomiasis remains largely unexplored. In this study, mice colonized with gut microbial populations from a human donor (HMA mice), as well as microbiota-wild type (WT) animals, were infected with Schistosoma mansoni, and alterations of their gut microbial profiles at 50 days post-infection were compared to those occurring in uninfected HMA and WT rodents, respectively. Significantly higher worm and egg burdens, together with increased specific antibody responses to parasite antigens, were observed in HMA compared to WT mice. These differences were associated to extensive dissimilarities between the gut microbial profiles of each HMA and WT groups of mice at baseline; in particular, the gut microbiota of HMA animals was characterized by low microbial alpha diversity and expanded Proteobacteria, as well as by the absence of putative immunomodulatory bacteria (e.g. Lactobacillus). Furthermore, differences in infection-associated changes in gut microbiota composition were observed between HMA and WT mice. Altogether, our findings support the hypothesis that susceptibility to S. mansoni infection in mice is partially dependent on the composition of the host baseline microbiota. Moreover, this study highlights the applicability of HMA mouse models to address key biological questions on host-parasite-microbiota relationships in human helminthiases

    Genomics of the Argentinian cholera epidemic elucidate the contrasting dynamics of epidemic and endemic Vibrio cholerae

    Get PDF
    Funder: U.S. Department of Health & Human Services | National Institutes of Health (NIH)Abstract: In order to control and eradicate epidemic cholera, we need to understand how epidemics begin, how they spread, and how they decline and eventually end. This requires extensive sampling of epidemic disease over time, alongside the background of endemic disease that may exist concurrently with the epidemic. The unique circumstances surrounding the Argentinian cholera epidemic of 1992–1998 presented an opportunity to do this. Here, we use 490 Argentinian V. cholerae genome sequences to characterise the variation within, and between, epidemic and endemic V. cholerae. We show that, during the 1992–1998 cholera epidemic, the invariant epidemic clone co-existed alongside highly diverse members of the Vibrio cholerae species in Argentina, and we contrast the clonality of epidemic V. cholerae with the background diversity of local endemic bacteria. Our findings refine and add nuance to our genomic definitions of epidemic and endemic cholera, and are of direct relevance to controlling current and future cholera epidemics

    Understanding and measuring symptoms and health status in asthma COPD overlap: content validity of the EXACT and SGRQ

    No full text
    Abstract Background Asthma-chronic obstructive pulmonary disease overlap (ACO) differs from asthma and chronic obstructive pulmonary disease (COPD) in demographics, phenotypic characteristics and outcomes, yet the patient experience of ACO is poorly characterized. We aimed to understand and compare the patient experience of symptoms and domains of impact in ACO relative to COPD, and assess the content validity of existing patient-reported outcome (PRO) instruments in ACO. Methods This US qualitative, interview study included patients who met American Thoracic Society/European Respiratory Society spirometric criteria for COPD. Additionally, patients with ACO demonstrated reversibility (forced expiratory volume in 1 s [FEV1] increase ≥ 12% and ≥ 200 mL) to albuterol/salbutamol and an FEV1/forced vital capacity ratio < 0.7. Patients took part in concept elicitation (CE) to explore symptoms and impacts of obstructive lung disease. The Exacerbations of Chronic Pulmonary Disease Tool (EXACT), St George’s Respiratory Questionnaire (SGRQ) and a daily wheeze assessment were cognitively debriefed to assess relevance and comprehensiveness. Interviews were analyzed using Atlas.Ti. Concept saturation was evaluated at the symptom level. Results Twenty patients with ACO and 10 patients with COPD were recruited. Patients from both groups indicated that shortness of breath was their most frequent and bothersome symptom. The most frequently reported symptoms in both groups were shortness of breath, cough, wheezing, difficulty breathing, mucus/phlegm, chest tightness, and tiredness, weakness or fatigue. The onset, severity, frequency and duration of symptoms were consistently described across both groups, although a higher proportion of patients with ACO experienced exacerbations versus those with COPD. Impacts on daily living, physical impacts and emotional impacts were commonly described (ACO: 90–100%, COPD: 80–100%). Concept saturation was achieved in both groups. Overall, the EXACT, SGRQ and daily wheeze assessment were well understood and relevant to most patients with ACO or COPD (50–100%) and patients generally found the assessments easy to complete. The PRO instruments adequately captured symptoms described during CE, demonstrating high content validity in ACO and COPD. Conclusions Patients with ACO and COPD experienced similar symptoms and impacts. The EXACT, SGRQ and assessment of wheeze were well understood and captured concepts relevant to patients with ACO
    corecore