127 research outputs found

    Social revitalisation of urban regions

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    This paper aims to analyse how social revitalisation can contribute to an (economically) attractive urban region and how such policies can be made more effective and efficient. To stimulate re-urbanisation and attract new economic activities and residents, much attention is paid to the concept of ''the attractive city''. Cities are observed to switch their focus from hardware (tangible services) to software (image, quality of life) and orgware (organising capacity). To enhance the effectiveness of social policy is in that context often considered a spearhead for cities. In practice, social policy does not always seem to be carried out effectively. Much money may be spent on solving a problem without effective progress being accomplished. Moreover, the results of social policy are often hard to measure, so that a lack of purpose may not be easy to detect. The paper is based on a comparative research of eight European urban regions.

    Social revitalisation of urban regions

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    This paper aims to analyse how social revitalisation can contribute to an (economically) attractive urban region and how such policies can be made more effective and efficient. To stimulate re-urbanisation and attract new economic activities and residents, much attention is paid to the concept of ''the attractive city''. Cities are observed to switch their focus from hardware (tangible services) to software (image, quality of life) and orgware (organising capacity). To enhance the effectiveness of social policy is in that context often considered a spearhead for cities. In practice, social policy does not always seem to be carried out effectively. Much money may be spent on solving a problem without effective progress being accomplished. Moreover, the results of social policy are often hard to measure, so that a lack of purpose may not be easy to detect. The paper is based on a comparative research of eight European urban regions

    Online automatic tuning and control for fed-batch cultivation

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    Performance of controllers applied in biotechnological production is often below expectation. Online automatic tuning has the capability to improve control performance by adjusting control parameters. This work presents automatic tuning approaches for model reference specific growth rate control during fed-batch cultivation. The approaches are direct methods that use the error between observed specific growth rate and its set point; systematic perturbations of the cultivation are not necessary. Two automatic tuning methods proved to be efficient, in which the adaptation rate is based on a combination of the error, squared error and integral error. These methods are relatively simple and robust against disturbances, parameter uncertainties, and initialization errors. Application of the specific growth rate controller yields a stable system. The controller and automatic tuning methods are qualified by simulations and laboratory experiments with Bordetella pertussis

    Population Structure of Invasive Streptococcus pneumoniae in the Netherlands in the Pre-Vaccination Era Assessed by MLVA and Capsular Sequence Typing

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    The introduction of nationwide pneumococcal vaccination may lead to serotype replacement and the emergence of new variants that have expanded their genetic repertoire through recombination. To monitor alterations in the pneumococcal population structure, we have developed and utilized Capsular Sequence Typing (CST) in addition to Multiple-Locus Variable number tandem repeat Analysis (MLVA)

    Modeling Neisseria meningitidis metabolism: from genome to metabolic fluxes

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    A genome-scale flux model for primary metabolism of Neisseria meningitidis was constructed; a minimal medium for growth of N. meningitidis was designed using the model and tested successfully in batch and chemostat cultures

    DEVELOPMENT OF INACTIVATED POLIO VACCINE FROM ATTENUATED SABIN STRAINS FOR CLINICAL STUDIES AND TECHNOLOGY-TRANSFER PURPOSES

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    Recently, responding to WHO’s call for new polio vaccines, the development of Sabin-IPV (injectable, formalin-Inactivated Polio Vaccine, based on attenuated ‘Sabin’ polio virus strains) was initated at NVI. This activity plays an important role in the WHO polio eradication strategy. The use of Sabin instead of wild-type Salk polio strains will provide additional safety during vaccine production. Initially, the Sabin-IPV production process will be based on the scale-down model of the current, and well-established, Salk-IPV process. In parallel, process development, optimization and formulation research is being carried out to further modernize the process and reduce cost per dose. The lab-scale accelerated process development, product characterization, clinical lot production, and preparations for technology transfer will be discussed. Multivariate data analysis (MVDA) was applied on data from current IPV production (more than 60 Vero cell culture based runs) to extract relevant information, like operating ranges. Subsequently, based on the MVDA analysis, a 3-L scale-down model of the current twin 750-L bioreactors has been setup. Currently, in this lab-scale process, cell and virus culture approximate the large-scale and process improvement studies are in progress. This includes the application of increased cell densities, animal component free media, and DOE optimization in multiple parallel bioreactors. Also, results will be shown from large-scale (to prepare for future technology transfer) generation and testing of Master- and Working virus seedlots, and clinical lot (for phase I studies) production under cGMP conditions. The obtained product was used for immunogenicity studies in rats. It was shown that Sabin-IPV induces a good immune response, and a comparison will be made to regular Salk-IPV. Finally, technology transfer to vaccine manufacturers in low and middle–income countries will take place. For that, an international Sabin-IPV manufacturing course, including practical training at pilot-scale, is being setup

    A Sensitive Assay for Virus Discovery in Respiratory Clinical Samples

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    In 5–40% of respiratory infections in children, the diagnostics remain negative, suggesting that the patients might be infected with a yet unknown pathogen. Virus discovery cDNA-AFLP (VIDISCA) is a virus discovery method based on recognition of restriction enzyme cleavage sites, ligation of adaptors and subsequent amplification by PCR. However, direct discovery of unknown pathogens in nasopharyngeal swabs is difficult due to the high concentration of ribosomal RNA (rRNA) that acts as competitor. In the current study we optimized VIDISCA by adjusting the reverse transcription enzymes and decreasing rRNA amplification in the reverse transcription, using hexamer oligonucleotides that do not anneal to rRNA. Residual cDNA synthesis on rRNA templates was further reduced with oligonucleotides that anneal to rRNA but can not be extended due to 3′-dideoxy-C6-modification. With these modifications >90% reduction of rRNA amplification was established. Further improvement of the VIDISCA sensitivity was obtained by high throughput sequencing (VIDISCA-454). Eighteen nasopharyngeal swabs were analysed, all containing known respiratory viruses. We could identify the proper virus in the majority of samples tested (11/18). The median load in the VIDISCA-454 positive samples was 7.2 E5 viral genome copies/ml (ranging from 1.4 E3–7.7 E6). Our results show that optimization of VIDISCA and subsequent high-throughput-sequencing enhances sensitivity drastically and provides the opportunity to perform virus discovery directly in patient material

    Second intravenous immunoglobulin dose in patients with Guillain-Barre syndrome with poor prognosis (SID-GBS):a double-blind, randomised, placebo-controlled trial

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    Background Treatment with one standard dose (2 g/kg) of intravenous immunoglobulin is insufficient in a proportion of patients with severe Guillain-Barre syndrome. Worldwide, around 25% of patients severely affected with the syndrome are given a second intravenous immunoglobulin dose (SID), although it has not been proven effective. We aimed to investigate whether a SID is effective in patients with Guillain-Barre syndrome with a predicted poor outcome. Methods In this randomised, double-blind, placebo-controlled trial (SID-GBS), we included patients (>= 12 years) with Guillain-Barre syndrome admitted to one of 59 participating hospitals in the Netherlands. Patients were included on the first day of standard intravenous immunoglobulin treatment (2 g/kg over 5 days). Only patients with a poor prognosis (score of >= 6) according to the modified Erasmus Guillain-Barre syndrome Outcome Score were randomly assigned, via block randomisation stratified by centre, to SID (2 g/kg over 5 days) or to placebo, 7-9 days after inclusion. Patients, outcome adjudicators, monitors, and the steering committee were masked to treatment allocation. The primary outcome measure was the Guillain-Barre syndrome disability score 4 weeks after inclusion. All patients in whom allocated trial medication was started were included in the modified intention-to-treat analysis. Findings Between Feb 16, 2010, and June 5, 2018, 327 of 339 patients assessed for eligibility were included. 112 had a poor prognosis. Of those, 93 patients with a poor prognosis were included in the modified intention-to-treat analysis: 49 (53%) received SID and 44 (47%) received placebo. The adjusted common odds ratio for improvement on the Guillain-Barre syndrome disability score at 4 weeks was 1.4 (95% CI 0.6-3.3; p=0.45). Patients given SID had more serious adverse events (35% vs 16% in the first 30 days), including thromboembolic events, than those in the placebo group. Four patients died in the intervention group (13-24 weeks after randomisation). Interpretation Our study does not provide evidence that patients with Guillain-Barre syndrome with a poor prognosis benefit from a second intravenous immunoglobulin course; moreover, it entails a risk of serious adverse events. Therefore, a second intravenous immunoglobulin course should not be considered for treatment of Guillain-Barre syndrome because of a poor prognosis. The results indicate the need for treatment trials with other immune modulators in patients severely affected by Guillain-Barre syndrome. Funding Prinses Beatrix Spierfonds and Sanquin Plasma Products. Copyright (C) 2021 Elsevier Ltd. All rights reserved
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