399 research outputs found

    The Impact of Parameterized Convection on Climatological Precipitation in Atmospheric Global Climate Models

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    This is the author accepted manuscript. The final version is available from Wiley via the DOI in this record.Convective parameterizations are widely believed to be essential for realistic simulations of the atmosphere. However, their deficiencies also result in model biases. The role of convection schemes in modern atmospheric models is examined using Selected Process On/Off Klima Intercomparison Experiment (SPOOKIE) simulations without parameterized convection and forced with observed sea surface temperatures. Convection schemes are not required for reasonable climatological precipitation. However, they are essential for reasonable daily precipitation and restraining extreme daily precipitation that otherwise develops. Systematic effects on lapse rate and humidity are likewise modest compared with the inter-model spread. Without parameterized convection Kelvin waves are more realistic. An unexpectedly large moist Southern Hemisphere storm track bias is identified. This storm track bias persists without convection schemes, as does the double intertropical convergence zone and excessive ocean precipitation biases. This suggests that model biases originate from processes other than convection or that convection schemes are missing key processes.PM, GKV and PGS are funded by the Natural Environment Research Council and Met Office as part of the EuroClim project (grant number NE/M006123/1), ParaCon project (grant number NE/N013123/1) and the Royal Society (Wolfson Foundation). MJW is supported by the Joint UK BEIS/Defra Met Office Hadley Centre Climate Programme number GA01101. SCS acknowledges the Australian Research Council (grant number FL150100035)

    Model Hierarchies for Understanding Atmospheric Circulation

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    This is the final version. Available from Wiley via the DOI in this record.In this review, we highlight the complementary relationship between simple and comprehensive models in addressing key scientific questions to describe Earth’s atmospheric circulation. The systematic representation of models in steps, or hierarchies, connects our understanding from idealized systems to comprehensive models, and ultimately the observed atmosphere. We define three interconnected principles that can be used to characterize the model hierarchies of the atmosphere. We explore the rich diversity within the governing equations in the dynamical hierarchy, the ability to isolate and understand atmospheric processes in the process hierarchy, and the importance of the physical domain and resolution in the hierarchy of scale. We center our discussion on the large scale circulation of the atmosphere and its interaction with clouds and convection, focusing on areas where simple models have had a significant impact. Our confidence in climate model projections of the future is based on our efforts to ground the climate predictions in fundamental physical understanding. This understanding is, in part, possible due to the hierarchies of idealized models that afford the simplicity required for understanding complex systems.Natural Environment Research Council (NERC)US National Science FoundationUS Department of Energy Office of Biological and Environmental ResearchNatural Science and Engineering Research Council of CanadaAustralian Research CouncilSimons FoundationGerman Ministry of Education and Research (BMBF)FONA: Research for Sustainable DevelopmentState Research Agency of Spai

    Laparoscopic sacrohysteropexy and myomectomy for uterine prolapse: a case report and review of the literature

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    <p>Abstract</p> <p>Introduction</p> <p>A large number of hysterectomies are carried out for uterine prolapse, menorrhagia and other symptomatic but benign gynaecological conditions, which has increased interest in new approaches to treat these disorders. These new procedures are less invasive and offer reduced risk and faster recovery.</p> <p>Case presentation</p> <p>Sacrohysteropexy can be carried out instead of vaginal hysterectomy in the treatment of uterine prolapse. It involves using a synthetic mesh to suspend the uterus to the sacrum; this maintains durable anatomic restoration, normal vaginal axis and sexual function. A laparoscopic approach has major advantages over the abdominal route including shorter recovery time and less adhesion formation. We describe a laparoscopic sacrohysteropexy in a 55-year-old Caucasian British woman that was technically difficult. An intramural uterine fibroid was encroaching just above the uterosacral ligament making mesh positioning impossible. This was removed and the procedure completed successfully.</p> <p>Conclusion</p> <p>Posterior wall fibroid is not a contraindication for laparoscopic sacrohysteropexy. This procedure has increasingly become an effective treatment of uterine prolapse in women who have no indication for hysterectomy.</p

    Pulmonary rehabilitation in idiopathic pulmonary fibrosis and COPD: a propensity matched real-world study

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    BACKGROUND: The adherence to and clinical efficacy of pulmonary rehabilitation in idiopathic pulmonary fibrosis (IPF), particularly in comparison to people with chronic obstructive pulmonary disease (COPD), remains uncertain. The objectives of this real-world study were to compare the responses of patients with IPF with a matched group of patients with COPD undergoing the same supervised, outpatient pulmonary rehabilitation program, and to determine whether pulmonary rehabilitation is associated with survival in IPF. RESEARCH QUESTION: Do people with IPF improve to the same extent with pulmonary rehabilitation as a matched group of individuals with COPD, and are non-completion of and/or non-response to pulmonary rehabilitation associated with one-year all-cause mortality in IPF? STUDY DESIGN AND METHODS: Using propensity score matching, 163 patients with IPF were matched 1:1 with a control group of 163 patients with COPD referred to pulmonary rehabilitation. We compared between-group pulmonary rehabilitation completion rates and response. Survival status in the IPF cohort was recorded over one-year following pulmonary rehabilitation discharge. Cox proportional-hazards regression explored the association between pulmonary rehabilitation status and all-cause mortality. RESULTS: Similar pulmonary rehabilitation completion rates (IPF: 69%; COPD: 63%; p=0.24) and improvements in exercise response were observed in both groups with no significant mean (95% confidence interval (CI)) between-group differences in incremental shuttle walk (ISW) change (2 (-18 to 22) meters). Pulmonary rehabilitation non-completion (hazard ratio (HR) (95%CI) 5.62 (2.24 to 14.08)) and non-response (HR (95%CI) 3.91 (1.54 to 9.93)) were independently associated with increased one-year all-cause mortality in IPF. INTERPRETATION: Compared with a matched group of patients with COPD, this real-word study demonstrates that patients with IPF have similar completion rates and magnitude of response to pulmonary rehabilitation. In IPF, non-completion of and non-response to pulmonary rehabilitation were associated with increased all-cause mortality. These data reinforce the benefits of pulmonary rehabilitation in patients with IPF

    Change in gait speed and adverse outcomes in patients with idiopathic pulmonary fibrosis: a prospective cohort study.

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    BACKGROUND AND OBJECTIVE: Gait speed is associated with survival in individuals with idiopathic pulmonary fibrosis (IPF). The extent to which four-metre gait speed (4MGS) decline predicts adverse outcome in IPF remains unclear. We aimed to examine longitudinal 4MGS change and identify a cut-point associated with adverse outcome. METHODS: In a prospective cohort study, we recruited 132 individuals newly diagnosed with IPF and measured 4MGS change over 6 months. Death/first hospitalization at 6 months were composite outcome events. Complete data (paired 4MGS plus index event) were available in 85 participants; missing 4MGS data were addressed using multiple imputation. Receiver-Operating Curve plots identified a 4MGS change cut-point. Cox proportional-hazard regression assessed the relationship between 4MGS change and time to event. RESULTS: 4MGS declined over 6 months (mean [95% CI] change: -0.05 [-0.09 to -0.01] m/s; p = 0.02). A decline of 0.07 m/s or more in 4MGS over 6 months had better discrimination for the index event than change in 6-minute walk distance, forced vital capacity, Composite Physiologic Index or Gender Age Physiology index. Kaplan-Meier curves demonstrated a significant difference in time to event between 4MGS groups (substantial decline: >-0.07 m/s versus minor decline/improvers: ≤-0.07 m/s; p = 0.007). Those with substantial decline had an increased risk of hospitalization/death (adjusted hazard ratio [95% CI] 4.61 [1.23-15.83]). Similar results were observed in multiple imputation analysis. CONCLUSION: In newly diagnosed IPF, a substantial 4MGS decline over 6 months is associated with shorter time to hospitalization/death at 6 months. 4MGS change has potential as a surrogate endpoint for interventions aimed at modifying hospitalization/death

    The transferrin receptor CD71 delineates functionally distinct airway macrophage subsets during idiopathic pulmonary fibrosis

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    RATIONALE: Idiopathic pulmonary fibrosis (IPF) is a devastating progressive disease with limited therapeutic options. Airway macrophages (AMs) are key components of the defence of the airways and are implicated in the pathogenesis of IPF. Alterations in iron metabolism have been described during fibrotic lung disease and in murine models of lung fibrosis. However, the role of transferrin receptor-1 (CD71)-expressing AMs in IPF is not known. OBJECTIVES: To assess the role of CD71 expressing AMs in the IPF-lung. METHODS: We utilized multi-parameter flow cytometry, gene expression analysis and phagocytosis/transferrin uptake assays to delineate the role of AMs expressing, or lacking, CD71 in the BAL of patients with IPF or healthy controls. MEASUREMENTS AND MAIN RESULTS: There was a distinct increase in proportions of AMs lacking CD71 in IPF patients in comparison to healthy controls. Levels of BAL transferrin were enhanced in IPF-BAL and furthermore, CD71- AMs had an impaired ability to sequester transferrin. CD71+ and CD71- AMs were phenotypically, functionally and transcriptionally distinct, with CD71- AMs characterised by reduced expression of markers of macrophage maturity, impaired phagocytosis and enhanced expression of pro-fibrotic genes. Importantly, proportions of AMs lacking CD71 were independently associated with worse survival, underlining the importance of this population in IPF and as a potential therapeutic target. CONCLUSIONS: Taken together these data highlight how CD71 delineates AM subsets which play distinct roles in IPF and furthermore, CD71- AMs may be an important pathogenic component of fibrotic lung disease

    The role of bacteria in the pathogenesis and progression of idiopathic pulmonary fibrosis

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    Rationale:Idiopathic pulmonaryfibrosis (IPF)isa progressivelung disease of unknown cause that leads to respiratory failure and death within 5 years of diagnosis. Overt respiratory infection and immunosuppression carry a high morbidity and mortality, and polymorphisms in genes related to epithelial integrity and host defense predispose to IPF. Objectives: To investigate the role of bacteria in the pathogenesis and progression of IPF. Methods: We prospectively enrolled patients diagnosed with IPF according to international criteria together with healthy smokers, nonsmokers, and subjectswithmoderate chronic obstructive pulmonary disease as control subjects. Subjects underwent bronchoalveolar lavage (BAL), from which genomic DNA was isolated. The V3–V5 region of the bacterial 16S rRNA gene was amplified, allowing quantification of bacterial load and identification of communities by 16S rRNA quantitative polymerase chain reaction and pyrosequencing. Measurements and Main Results: Sixty-five patients with IPF had double the burden of bacteria in BAL fluid compared with 44 control subjects. Baseline bacterial burden predicted the rate of decline in lung volume and risk of death and associated independently with the rs35705950 polymorphism of the MUC5B mucin gene, a proven host susceptibilityfactorfor IPF. Sequencing yielded912,883 high-quality reads from all subjects.WeidentifiedHaemophilus, Streptococcus,Neisseria, and Veillonella spp. to be more abundant in cases than control subjects. Regression analyses indicated that these specific operational taxonomic units as well as bacterial burden associated independently with IPF. Conclusions: IPF is characterized by an increased bacterial burden in BAL that predicts decline in lung function and death. Trials of antimicrobial therapy are needed to determine if microbial burden is pathogenic in the disease

    Modelling forced vital capacity in idiopathic pulmonary fibrosis: optimising trial design.

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    INTRODUCTION: Forced vital capacity is the only registrational endpoint in idiopathic pulmonary fibrosis clinical trials. As most new treatments will be administered on top of standard of care, estimating treatment response will become more challenging. We developed a simulation model to quantify variability associated with forced vital capacity decline. METHODS: The model is based on publicly available clinical trial summary and home spirometry data. A single, illustrative trial setting is reported. Model assumptions are 400 subjects randomised 1:1 to investigational drug or placebo over 52 weeks, 50% of each group receiving standard of care (all-comer population), and a 90-mL treatment difference in annual forced vital capacity decline. Longitudinal profiles were simulated and the impact of varying clinical scenarios evaluated. RESULTS: Power to detect a significant treatment difference was 87-97%, depending on the analysis method. Repeated measures analysis generally outperformed analysis of covariance and mixed linear models, particularly with missing data (as simulated data were non-linear). A 15% yearly random dropout rate led to 0.6-5% power loss. Forced vital capacity decline-related dropout introduced greater power loss (up to 12%), as did subjects starting/stopping standard of care or investigational drug. Power was substantially lower for a 26-week trial due to the smaller assumed treatment effect at week 26 (sample size would need doubling to reach a power similar to that of a 52-week trial). CONCLUSIONS: Our model quantifies forced vital capacity decline and associated variability, with all the caveats of background therapy, permitting robust power calculations to inform future idiopathic pulmonary fibrosis clinical trial design. FUNDING: Galapagos NV (Mechelen, Belgium)

    DNA Methylome Alterations are Associated with Airway Macrophage Differentiation and Phenotype During Lung Fibrosis

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    RATIONALE: Airway macrophages (AMs) are key regulators of the lung environment and are implicated in the pathogenesis of idiopathic pulmonary fibrosis (IPF), a fatal respiratory disease with no cure. However, knowledge of epigenetics of AMs in IPF are limited. METHODS: We undertook DNA methylation profiling using Illumina EPIC (850k) arrays in sorted AMs from Healthy (n=14) and IPF (n=30) donors. Cell-type deconvolution was performed using reference myeloid-cell DNA methylomes. MEASUREMENTS AND MAIN RESULTS: Our analysis revealed epigenetic heterogeneity was a key characteristic of IPF-AMs. DNAm 'clock' analysis indicated epigenetic alterations in IPF-AMs was not associated with accelerated ageing. In differential DNAm analysis, we identified numerous differentially methylated positions (DMPs, n=11) and regions (DMRs, n=49) between healthy and IPF AMs respectively. DMPs and DMRs encompassed genes involved in lipid (LPCAT1) and glucose (PFKFB3) metabolism and importantly, DNAm status was associated with disease severity in IPF. CONCLUSIONS: Collectively, our data identify that changes in the epigenome are associated with development and function of AMs in the IPF lung
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