Modelling survival and connectivity of Mnemiopsis leidyi in the south-western North Sea and Scheldt estuaries

Three different models were applied to study the reproduction, survival and dispersal of Mnemiopsis leidyi in the Scheldt estuaries and the southern North Sea: a high-resolution particle tracking model with passive particles, a low-resolution particle tracking model with a reproduction model coupled to a biogeochemical model, and a dynamic energy budget (DEB) model. The results of the models, each with its strengths and weaknesses, suggest the following conceptual situation: (i) the estuaries possess enough retention capability to keep an overwintering population, and enough exchange with coastal waters of the North Sea to seed offshore populations; (ii) M. leidyi can survive in the North Sea, and be transported over considerable distances, thus facilitating connectivity between coastal embayments; (iii) under current climatic conditions, M. leidyi may not be able to reproduce in large numbers in coastal and offshore waters of the North Sea, but this may change with global warming; however, this result is subject to substantial uncertainty. Further quantitative observational work is needed on the effects of temperature, salinity and food availability on reproduction and on mortality at different life stages to improve models such as used here

The effect of three years of TNF alpha blocking therapy on markers of bone turnover and their predictive value for treatment discontinuation in patients with ankylosing spondylitis: a prospective longitudinal observational cohort study

INTRODUCTION: The aim of this study was to investigate the effect of three years of tumor necrosis factor-alpha (TNF-alpha) blocking therapy on bone turnover as well as to analyze the predictive value of early changes in bone turnover markers (BTM) for treatment discontinuation in patients with ankylosing spondylitis (AS). METHODS: This is a prospective cohort study of 111 consecutive AS outpatients who started TNF-alpha blocking therapy. Clinical assessments and BTM were assessed at baseline, three and six months, as well as at one, two, and three years. Z-scores of BTM were calculated to correct for age and gender. Bone mineral density (BMD) was assessed yearly. RESULTS: After three years, 72 patients (65%) were still using their first TNF-alpha blocking agent. In these patients, TNF-alpha blocking therapy resulted in significantly increased bone-specific alkaline phosphatase, a marker of bone formation; decreased serum collagen-telopeptide (sCTX), a marker of bone resorption; and increased lumbar spine and hip BMD compared to baseline. Baseline to three months decrease in sCTX Z-score (HR: 0.394, 95% CI: 0.263 to 0.591), AS disease activity score (ASDAS; HR: 0.488, 95% CI: 0.317 to 0.752), and physician's global disease activity (HR: 0.739, 95% CI: 0.600 to 0.909) were independent inversely related predictors of time to treatment discontinuation because of inefficacy or intolerance. Early decrease in sCTX Z-score correlated significantly with good long-term response regarding disease activity, physical function and quality of life. CONCLUSIONS: Three years of TNF-alpha blocking therapy results in a bone turnover balance that favors bone formation, especially mineralization, in combination with continuous improvement of lumbar spine BMD. Early change in sCTX can serve as an objective measure in the evaluation of TNF-alpha blocking therapy in AS, in addition to the currently used more subjective measures

Discoverabilia in de ontdekkingskontekst

Wetensch. publicatieFaculteit der Sociale Wetenschappe

Vygotsky's legacy: understanding and beyond. An introduction

FSW - Gezinsopvoeding - Ou

To Moscow with Love: Partial Reconstruction of Vygotsky’s Trip to London

The Russian psychologist Lev Vygotsky (1896–1934) left the Soviet Union only once to attend a conference on the education of the deaf in London. So far almost nothing was known about this trip, which took place in a period when Vygotsky was still completely unknown as a psychologist, both inside his own country and abroad. Making use of a newly discovered notebook, it proved possible to partially reconstruct Vygotsky’s journey and stay in London. Vygotsky’s very personal remarks show him to have been a very sensitive and spirited man, who was prey to strong emotions during the conference and afterwards. Rather surprisingly, Vygotsky’s own paper about the education of the deaf was never presented during the conference and the stay in London appears to have had a limited value for his own scientific development

Vrijheid in gebondenheid. Valsiners visie op de ontwikkeling van het kind

Wetensch. publicatieFaculteit der Sociale Wetenschappe

A method for sensitivity analysis to assess the effects of measurement error in multiple exposure variables using external validation data

Measurement error in self-reported dietary intakes is known to bias the association between dietary intake and a health outcome of interest such as risk of a disease. The association can be distorted further by mismeasured confounders, leading to invalid results and conclusions. It is, however, difficult to adjust for the bias in the association when there is no internal validation data

Evaluation of Captured Water Column Technology for Advanced Ultrasonic Sizing Techniques

Ultrasonic (UT) inspection of aircraft engine parts has traditionally been conducted in an immersion water tank. However, experience has shown that the immersion tank is usually large, awkward, and tedious to work with. An alternative method which does not require immersion would increase the time efficiency of the UT inspection. One such method would be to use a captured water column coupling system, which closely approximates the immersion method and eliminates the need for a large immersion tank. The tank would be replaced by a trough or water collection tray to collect the water produced by the low water flow of the captured water column