243 research outputs found

    Runoff Coefficients of High-flow Events in Undisturbed New England Basins

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    The New England region in the Northeast U.S. receives high annual precipitation as rain and snow, which results in floods that endanger people and infrastructure. Owing to the complexity of hydrologic systems, increases in the frequency and intensity of large precipitation events do not always translate into increases in surface runoff measured as event flow at the basin outlet. However, recent studies have recognized positive trends in the frequency and magnitude of high-flow events in New England. For high-flow events of equal or greater than 2-year daily runoff, the runoff coefficients, or the fraction of precipitation converted into surface runoff during an event, were determined for 28 undisturbed New England basins with natural flow conditions. Results indicated that runoff coefficients increase in magnitude and variability with distance from the Atlantic coast toward the north and west. The average runoff coefficient of high-flow events across all basins is 0.90, while there exist many high-flow events with runoff coefficients greater than one. Also, runoff coefficients were generally stationary showing that flood events in undisturbed basins have remained proportional to precipitation inputs, despite increases in extreme precipitation, possibly due to shifts in evapotranspiration, snowpack, and soil moisture. Flood management efforts should continue to focus on large springtime precipitation events, which generate the highest runoff coefficients. Finally, this study can serve as a reference point for future exploration of the flood susceptibility of basins with anthropogenic alterations like dam construction or land use change

    The role of indoleamine 2,3-dioxygenase-aryl hydrocarbon receptor pathway in the TLR4-induced tolerogenic phenotype in human DCs

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    A controlled inflammatory response is required for protection against infection, but persistent inflammation causes tissue damage. Dendritic cells (DCs) have a unique capacity to promote both inflammatory and anti-inflammatory processes. One key mechanism involved in DC-mediated immunosuppression is the expression of tryptophan-metabolizing enzyme indoleamine 2,3-dioxygenase (IDO). IDO has been implicated in diverse processes in health and disease but its role in endotoxin tolerance in human DCs is still controversial. Here we investigated the role of IDO in shaping DCs phenotype and function under endotoxin tolerance conditions. Our data show that TLR4 ligation in LPS-primed DCs, induced higher levels of both IDO isoforms together with the transcription factor aryl-hydrocarbon receptor (AhR), compared to unprimed controls. Additionally, LPS conditioning induced an anti-inflammatory phenotype in DCs - with an increase in IL-10 and higher expression of programmed death ligand (PD-L)1 and PD-L2 - which were partially dependent on IDO. Furthermore, we demonstrated that the AhR-IDO pathway was responsible for the preferential activation of noncanonical NF-κB pathway in LPS-conditioned DCs. These data provide new insight into the mechanisms of the TLR4-induced tolerogenic phenotype in human DCs, which can help the better understanding of processes involved in induction and resolution of chronic inflammation and tolerance

    Depression diagnosis and treatment amongst multimorbid patients: a thematic analysis

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    BACKGROUND: We explored experiences of depression diagnosis and treatment amongst multimorbid patients referred to a metropolitan multidisciplinary outpatient clinic to identify commonalities across this patient group. METHODS: Patients with two or more chronic conditions and a diagnosis of depression participated in semi-structured interviews that were digitally recorded and transcribed. Thematic analysis was performed on the transcriptions. RESULTS: Multimorbid patients attributed depressive symptoms to the loss of 'normal' roles and functionality and struggled to reconcile the depression diagnosis with their sense of identity. Beliefs about themselves and depression affected their receptivity to diagnosis and intervention strategies. These included prescribed interventions, such as psychotherapy or pharmacotherapy, and patient-developed strategies. CONCLUSIONS: Functional and social role losses present a clear context in which GPs should raise the subject of mood, with the situational attribution of depression suggesting that psychotherapy, which is rarely offered, should be prioritised in these circumstances.Melinda N Stanners, Christopher A Barton, Sepehr Shakib and Helen R Winefiel

    The prevalence of depression amongst outpatients with multimorbidity

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    Objectives: Depression may be under-diagnosed and under-treated amongst older adults with multiple chronic illnesses. The current study explores the prevalence of depression diagnosis and Geriatric Depression Scale (GDS) symptoms amongst older multimorbid outpatients, and agreement between GDS scores and doctor-diagnosed depression. Method: Deidentified data from the files of 452 patients aged over 64, with chronic conditions present in two or more organ domains, were extracted from the clinical database of a tertiary referral hospital multidisciplinary outpatient clinic in South Australia between 2005 and 2011. Frequency calculations determined the prevalence of depression diagnosis and GDS categories. Logistic regression, cross-tabulation, kappa and ROC graphs explored relationships between variables. Results: A depression diagnosis had been recorded for 71 (15.7%) patients. Using the recommended cut-off scores for the GDS, 225 (49.8%) patients met criteria for mild-severe depressive symptoms, and 96 (21.3%) met criteria for moderate-severe symptoms. Poor agreement was found between doctor diagnosis of depression and a positive screen for depression using a GDS cut-off score of either 5, k = 0.112 (p = 0.001), or 9, k = 0.189 (p < 0.001), although logistic regression found an association between severity of depression and depression diagnosis, OR = 1.15, p < 0.001 (CI = 1.08 - 1.22). Con-clusion: A much higher proportion of patients with multimorbidities reported threshold level depression symptoms than had a recorded diagnosis of depression, suggesting that although likelihood of diagnosis increases with symptom severity, depression often goes undetected in this population. Depressions’ negative impact on prognosis calls for further investigation of the barriers to screening and diagnosis of depression in multimorbid patients.Melinda Stanners, Christopher Barton, Sepehr Shakib, Helen Winefiel

    A direct numerical simulation method for complex modulus of particle dispersions

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    We report an extension of the smoothed profile method (SPM)[Y. Nakayama, K. Kim, and R. Yamamoto, Eur. Phys. J. E {\bf 26}, 361(2008)], a direct numerical simulation method for calculating the complex modulus of the dispersion of particles, in which we introduce a temporally oscillatory external force into the system. The validity of the method was examined by evaluating the storage G(ω)G'(\omega) and loss G"(ω)G"(\omega) moduli of a system composed of identical spherical particles dispersed in an incompressible Newtonian host fluid at volume fractions of Φ=0\Phi=0, 0.41, and 0.51. The moduli were evaluated at several frequencies of shear flow; the shear flow used here has a zigzag profile, as is consistent with the usual periodic boundary conditions

    A randomized phase I study of the safety and immunogenicity of three ascending dose levels of a 3-antigen Staphylococcus aureus vaccine (SA3Ag) in healthy adults

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    Background: Staphylococcus aureus is a common cause of healthcare-acquired morbidity and mortalityand increased healthcare resource utilization. A prophylactic vaccine is being developed that may reducethis disease burden.Methods: Volunteers in good general health aged 50–85 (n = 312) and 18–24 (n = 96) years were random-ized to receive a single intramuscular dose of one of three dose levels of a non-adjuvanted, 3-antigen S.aureus vaccine (SA3Ag) or placebo. SA3Ag antigens included capsular polysaccharides 5 and 8 (CP5 andCP8), each conjugated to cross-reactive material 197 (CRM197), and recombinant clumping factor A (ClfA).Safety, tolerability, and immunogenicity were evaluated.Results: At day 29 post-vaccination, robust immune responses were observed in both age cohorts at allthree SA3Ag dose levels. In the primary analysis population, the 50- to 85-year age stratum, geometricmean-fold-rises in competitive Luminex® immunoassay antibody titers from baseline ranged from 29.2to 83.7 (CP5), 14.1 to 31.0 (CP8), and 37.1 to 42.9 (ClfA), all (P < 0.001) exceeding the pre-defined two-fold rise criteria. Similar rises in opsonophagocytic activity assay titers demonstrated functionality ofthe immune response. Most injection-site reactions were mild in severity and there were no substantial differences (SA3Ag vs. placebo) with regard to systemic or adverse events.Conclusions: In this study of healthy adults aged 50–85 and 18–24 years, SA3Ag elicited a rapid and robustimmune response and was well tolerated, with no notable safety concerns.Michael Nissen, Helen Marshall, Peter Richmond, Sepehr Shakib, Qin Jiang, David Cooper, Denise Rill, James Baber, Joseph Eiden, William Gruber, Kathrin U. Jansen, Emilio A. Emini, Annaliesa S. Anderson, Edward T. Zito, Douglas Girgent

    Технологические особенности процесса антипомпажного регулирования на компрессорных станциях

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    Объект исследования является явление помпажа, возникающее при эксплуатации центробежных компрессоров, а также методы и способы его регулирования. Цель исследования – анализ существующих методов и средств антипомпажного регулирования, поиск оптимальной конструкции регулирующего устройства для предупреждения возникновения помпажа. В процессе исследования проведен анализ нагрузок, действующих на центробежный компрессор. Определены причины возникновения явления помпажа и проанализировано его влияние на работу оборудования.The object of research is the phenomenon of surging that occurs during the operation of centrifugal compressors, as well as methods and methods of its regulation. The purpose of the study is to analyze the existing methods and means of anti-surge control, to find the optimal design of the control device to prevent the occurrence of surging. In the course of the study, the analysis of the loads acting on the centrifugal compressor was carried out. The causes of the surge phenomenon are determined and its impact on the operation of the equipment is analyzed

    Efficacy of a trivalent influenza vaccine against seasonal strains and against 2009 pandemic H1N1: a randomized, placebo-controlled trial

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    Background: Before pandemic H1N1 vaccines were available, the potential benefit of existing seasonal trivalent inactivated influenza vaccines (IIV3s) against influenza due to the 2009 pandemic H1N1 influenza strain was investigated, with conflicting results. This study assessed the efficacy of seasonal IIV3s against influenza due to 2008 and 2009 seasonal influenza strains and against the 2009 pandemic H1N1 strain. Methods: This observer-blind, randomized, placebo-controlled study enrolled adults aged 18–64 years during 2008 and 2009 in Australia and New Zealand. Participants were randomized 2:1 to receive IIV3 or placebo. The primary objective was to demonstrate the efficacy of IIV3 against laboratory-confirmed influenza. Participants reporting an influenza-like illness during the period from 14 days after vaccination until 30 November of each study year were tested for influenza by real-time reverse transcription polymerase chain reaction. Results: Over a study period of 2 years, 15,044 participants were enrolled (mean age ± standard deviation: 35.5 ± 14.7 years; 54.4% female). Vaccine efficacy of the 2008 and 2009 IIV3s against influenza due to any strain was 42% (95% confidence interval [CI]: 30%, 52%), whereas vaccine efficacy against influenza due to the vaccine-matched strains was 60% (95% CI: 44%, 72%). Vaccine efficacy of the 2009 IIV3 against influenza due to the 2009 pandemic H1N1 strain was 38% (95% CI: 19%, 53%). No vaccine-related deaths or serious adverse events were reported. Solicited local and systemic adverse events were more frequent in IIV3 recipients than placebo recipients (local: IIV3 74.6% vs placebo 20.4%, p < 0.001; systemic: IIV3 46.6% vs placebo 39.1%, p < 0.001). Conclusions: The 2008 and 2009 IIV3s were efficacious against influenza due to seasonal influenza strains and the 2009 IIV3 demonstrated moderate efficacy against influenza due to the 2009 pandemic H1N1 strain
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