18 research outputs found

    Static Traffic Assignment with Queuing: model properties and applications

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    This paper describes the road traffic assignment model Static Traffic Assignment with Queuing (STAQ) that was developed for situations where both static (STA) and dynamic (DTA) traffic assignment models are insufficient: strategic applications on large-scale congested networks. The paper demonstrates how the model overcomes shortcomings in STA and DTA modelling approaches in the strategic context by describing its concept, methodology and solution algorithm as well as by presenting model applications on (small) theoretical and (large) real-life networks. The STAQ model captures flow metering and spillback effects of bottlenecks like in DTA models, while its input and computational requirements are only slightly higher than those of STA models. It does so in a very tractable fashion, and acquires high-precision user equilibria (relative gap < 1E-04) on large-scale networks. In light of its accuracy, robustness and accountability, the STAQ model is discussed as a viable alternative to STA and DTA modelling approaches

    COVID-19 related stigma and healthprotective behaviours among adolescents in the Netherlands:An explorative study

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    The COVID-19 pandemic has forced many governments to impose social distancing measures upon its citizens, including in the Netherlands. Motivating adolescents to adhere to measures such as social distancing can be challenging, since adolescents are relatively more affected by them, while experiencing virtually no personal health benefit. In addition, the COVID-19 pandemic seems to impact the social environment of adolescents in schools, as some media sources have reported bullying and stigmatisation of students with an Asian appearance. This study aims to explore the experiences of adolescents regarding their Health-Protective Behaviour (HPB), as well as the prevalence and expression of stigma towards ethnic minorities within the context of the first wave of COVID-19 pandemic. We performed a cross-sectional mixed-methods study, including two independent online questionnaires. An adapted version of the "HPB"questionnaire (n = 528) and the "Measure of Disease-Related Stigma (MDRS)"questionnaire (n = 380), were administered to Dutch adolescents of 10-16 years old, attending primary or secondary school. Furthermore, 15 interviews were held with eight male and seven female adolescents. All data collection took place between March 17 and April 20, 2020. Results show that adolescents perceive COVID-19 as a threat to other peoples' health, rather than their own, and report adherence to public health measures in the interest of older and more vulnerable members of their community. We found no convincing evidence for widespread misinformation or stigmatising of certain ethnic groups among adolescents related to COVID-19 during this study. Participants acknowledged such behaviour happened in the early stages of the pandemic, before this study was initiated. Adolescents are a vital group for public health researchers to engage with during a pandemic, even when reaching them can be challenging

    Persistence of MERS-CoV-spike-specific B cells and antibodies after late third immunization with the MVA-MERS-S vaccine

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    The Middle East respiratory syndrome (MERS) is a respiratory disease caused by MERS coronavirus (MERS-CoV). In follow up to a phase 1 trial, we perform a longitudinal analysis of immune responses following immunization with the modified vaccinia virus Ankara (MVA)-based vaccine MVA-MERS-S encoding the MERS-CoV-spike protein. Three homologous immunizations were administered on days 0 and 28 with a late booster vaccination at 12 ± 4 months. Antibody isotypes, subclasses, and neutralization capacity as well as T and B cell responses were monitored over a period of 3 years using standard and bead-based enzyme-linked immunosorbent assay (ELISA), 50% plaque-reduction neutralization test (PRNT50), enzyme-linked immunospot (ELISpot), and flow cytometry. The late booster immunization significantly increases the frequency and persistence of spike-specific B cells, binding immunoglobulin G1 (IgG1) and neutralizing antibodies but not T cell responses. Our data highlight the potential of a late boost to enhance long-term antibody and B cell immunity against MERS-CoV. Our findings on the MVA-MERS-S vaccine may be of relevance for coronavirus 2019 (COVID-19) vaccination strategies

    In RA patients without prevalent CVD, incident CVD is mainly associated with traditional risk factors: A 20-year follow-up in the CARRÉ cohort study

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    Objectives: To extend our investigation of cardiovascular diseases (CVD) in rheumatoid arthritis (RA) patients to a follow up of more than 20 years, with a special focus on patients without prevalent CVD. Methods: The CARRÉ study is an ongoing prospective cohort study on CV endpoints in RA patients. Results were compared to those of a reference cohort (n = 2484) enriched for type 2 diabetes mellitus (DM). Hazard ratios (HR) for RA and DM patients compared to non-RA/-DM controls were calculated with cox proportional hazard models, and adjusted for baseline SCORE1 (estimated 10-year CVD mortality risk based on CV risk factors). Results: 238 RA patients, 117 DM patients and 1282 controls, without prevalent CVD at baseline were included. Analysis of events in these patients shows that after adjustment, no relevant ‘RA-specific’ risk remains (HR 1.16; 95%CI 0.88 – 1.53), whereas a ‘DM-specific’ risk is retained (1.73; 1.24 – 2.42). In contrast, adjusted analyses of all cases confirm the presence of an ‘RA-specific’ risk (1.50; 1.19 – 1.89). Conclusions: In RA patients without prevalent CVD the increased CVD risk is mainly attributable to increased presence of traditional risk factors. After adjustment for these factors, an increased risk attributable to RA only was thus preferentially seen in the patients with prevalent CVD at baseline. As RA treatment has improved, this data suggests that the ‘RA-specific’ effect of inflammation is preferentially seen in patients with prevalent CVD. We suggest that with modern (early) treatment of RA, most of the current increased CVD risk is mediated through traditional risk factors

    In RA patients without prevalent CVD, incident CVD is mainly associated with traditional risk factors: A 20-year follow-up in the CARRÉ cohort study

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    OBJECTIVES: To extend our investigation of cardiovascular diseases (CVD) in rheumatoid arthritis (RA) patients to a follow up of more than 20 years, with a special focus on patients without prevalent CVD. METHODS: The CARRÉ study is an ongoing prospective cohort study on CV endpoints in RA patients. Results were compared to those of a reference cohort (n = 2484) enriched for type 2 diabetes mellitus (DM). Hazard ratios (HR) for RA and DM patients compared to non-RA/-DM controls were calculated with cox proportional hazard models, and adjusted for baseline SCORE1 (estimated 10-year CVD mortality risk based on CV risk factors). RESULTS: 238 RA patients, 117 DM patients and 1282 controls, without prevalent CVD at baseline were included. Analysis of events in these patients shows that after adjustment, no relevant 'RA-specific' risk remains (HR 1.16; 95%CI 0.88 - 1.53), whereas a 'DM-specific' risk is retained (1.73; 1.24 - 2.42). In contrast, adjusted analyses of all cases confirm the presence of an 'RA-specific' risk (1.50; 1.19 - 1.89). CONCLUSIONS: In RA patients without prevalent CVD the increased CVD risk is mainly attributable to increased presence of traditional risk factors. After adjustment for these factors, an increased risk attributable to RA only was thus preferentially seen in the patients with prevalent CVD at baseline. As RA treatment has improved, this data suggests that the 'RA-specific' effect of inflammation is preferentially seen in patients with prevalent CVD. We suggest that with modern (early) treatment of RA, most of the current increased CVD risk is mediated through traditional risk factors

    Seasonal coronavirus–specific B cells with limited SARS-CoV-2 cross-reactivity dominate the IgG response in severe COVID-19

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    Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the cause of coronavirus disease 2019 (COVID-19). Little is known about the interplay between preexisting immunity to endemic seasonal coronaviruses and the development of a SARS-CoV-2–specific IgG response. We investigated the kinetics, breadth, magnitude, and level of cross-reactivity of IgG antibodies against SARS-CoV-2 and heterologous seasonal and epidemic coronaviruses at the clonal level in patients with mild or severe COVID-19 as well as in disease control patients. We assessed antibody reactivity to nucleocapsid and spike antigens and correlated this IgG response to SARS-CoV-2 neutralization. Patients with COVID-19 mounted a mostly type-specific SARS-CoV-2 response. Additionally, IgG clones directed against a seasonal coronavirus were boosted in patients with severe COVID-19. These boosted clones showed limited cross-reactivity and did not neutralize SARS-CoV-2. These findings indicate a boost of poorly protective CoV-specific antibodies in patients with COVID-19 that correlated with disease severity, revealing “original antigenic sin.

    Filamentous fungus-produced human monoclonal antibody provides protection against SARS-CoV-2 in hamster and non-human primate models

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    Monoclonal antibodies are an increasingly important tool for prophylaxis and treatment of acute virus infections like SARS-CoV-2 infection. However, their use is often restricted due to the time required for development, variable yields and high production costs, as well as the need for adaptation to newly emerging virus variants. Here we use the genetically modified filamentous fungus expression system Thermothelomyces heterothallica (C1), which has a naturally high biosynthesis capacity for secretory enzymes and other proteins, to produce a human monoclonal IgG1 antibody (HuMab 87G7) that neutralises the SARS-CoV-2 variants of concern (VOCs) Alpha, Beta, Gamma, Delta, and Omicron. Both the mammalian cell and C1 produced HuMab 87G7 broadly neutralise SARS-CoV-2 VOCs in vitro and also provide protection against VOC Omicron in hamsters. The C1 produced HuMab 87G7 is also able to protect against the Delta VOC in non-human primates. In summary, these findings show that the C1 expression system is a promising technology platform for the development of HuMabs in preventive and therapeutic medicine.</p

    Interferon-α2 Auto-antibodies in Convalescent Plasma Therapy for COVID-19

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    Purpose: To study the effect of interferon-α2 auto-antibodies (IFN-α2 Abs) on clinical and virological outcomes in critically ill COVID-19 patients and the risk of IFN-α2 Abs transfer during convalescent plasma treatment. Methods: Sera from healthy controls, cases of COVID-19, and other respiratory illness were tested for IFN-α2 Abs by ELISA and a pseudo virus–based neutralization assay. The effects of disease severity, sex, and age on the risk of having neutralizing IFN-α2 Abs were determined. Longitudinal analyses were performed to determine association between IFN-α2 Abs and survival and viral load and whether serum IFN-α2 Abs appeared after convalescent plasma transfusion. Results: IFN-α2 neutralizing sera were found only in COVID-19 patients, with proportions increasing with disease severity and age. In the acute stage of COVID-19, all sera from patients with ELISA-detected IFN-α2 Abs (13/164, 7.9%) neutralized levels of IFN-α2 exceeding physiological concentrations found in human plasma and this was associated with delayed viral clearance. Convalescent plasma donors that were anti-IFN-α2 ELISA positive (3/118, 2.5%) did not neutralize the same levels of IFN-α2. Neutralizing serum IFN-α2 Abs were associated with delayed viral clearance from the respiratory tract. Conclusions: IFN-α2 Abs were detected by ELISA and neutralization assay in COVID-19 patients, but not in ICU patients with other respiratory illnesses. The presence of neutralizing IFN-α2 Abs in critically ill COVID-19 is associated with delayed viral clearance. IFN-α2 Abs in COVID-19 convalescent plasma donors were not neutralizing in the conditions tested
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