44 research outputs found

    Temporal change in phytoplankton diversity and functional group composition

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    One of the key challenges in managing eutrophication in coastal marine ecosystems is the harmonized cross-border assessment of phytoplankton. Some general understanding of the consequences of shifting nutrient regimes can be derived from the detailed investigation of the phytoplankton community and its biodiversity. Here, we combined long-term monitoring datasets of German and Dutch coastal stations and amended these with additional information on species biomass. Across the integrated and harmonized dataset, we used multiple biodiversity descriptors to analyse temporal trends in the Wadden Sea phytoplankton. Biodiversity, measured as the number of species (S) and the effective number of species (ENS), has decreased in the Dutch stations over the last 20 years, while biomass has increased, indicating that fewer species are becoming more dominant in the system. However, biodiversity and biomass did not show substantial changes in the German stations. Although there were some differences in trends between countries, shifts in community composition and relative abundance were consistent across stations and time. We emphasise the importance of continuous and harmonized monitoring programmes and multi-metric approaches that can detect changes in the communities that are indicative of changes in the environment

    Mentor teachers’ intended intervening during student teachers’ lessons: A vignette study in Dutch primary education

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    This vignette study examined mentor teachers’ intended direction and intensity to intervene during student teachers’ lessons in Dutch primary education and the triggers for their intervening. Based on Fenstermacher's (1986) theory of premises leading to actions, we developed vignettes in which we manipulated trigger type, trigger severity, and student teacher experience. 159 mentor teachers indicated whether and how they would intervene. Results showed that mentor teachers prefer teaching values over mentoring values and intend to intervene quite intensely. We suggest that explicitly emphasising towards mentor teachers that their intervening should serve both pupils and student teachers might improve student teachers’ learning

    Topical rapamycin as a treatment for fibrofolliculomas in Birt-Hogg-Dubé syndrome:a double-blind placebo-controlled randomized split-face trial

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    Background: Birt-Hogg-Dubé syndrome (BHD) is a rare autosomal dominant disorder characterised by the occurrence of benign, mostly facial, skin tumours called fibrofolliculomas, multiple lung cysts, spontaneous pneumothorax and an increased renal cancer risk. Current treatments for fibrofolliculomas have high rates of recurrence and carry a risk of complications. It would be desirable to have a treatment that could prevent fibrofolliculomas from growing. Animal models of BHD have previously shown deregulation of mammalian target of rapamycin (mTOR). Topical use of the mTOR inhibitor rapamycin is an effective treatment for the skin tumours (angiofibromas) in tuberous sclerosis complex, which is also characterised by mTOR deregulation. In this study we aimed to determine if topical rapamycin is also an effective treatment for fibrofolliculomas in BHD. Methods: We performed a double blinded, randomised, facial left-right controlled trial of topical rapamycin 0.1% versus placebo in 19 BHD patients. Trial duration was 6 months. The primary outcome was cosmetic improvement as measured by doctors and patients. Changes in fibrofolliculoma number and size were also measured, as was occurrence of side effects. Results: No change in cosmetic status of fibrofolliculomas was reported in the majority of cases for the rapamycin treated (79% by doctors, 53% by patients) as well as the placebo treated facial sides (both 74%). No significant differences between rapamycin and placebo treated facial halves were observed (p = 1.000 for doctors opinion, p = 0.344 for patients opinion). No significant difference in fibrofolliculoma number or change in size of the fibrofolliculomas was seen after 6 months. Side effects occurred more often after rapamycin treatment (68% of patients) than after placebo (58% of patients; p = 0.625). A burning sensation, erythema, itching and dryness were most frequently reported. Conclusions: This study provides no evidence that treatment of fibrofolliculomas with topical rapamycin in BHD results in cosmetic improvement. Trial Registration: ClinicalTrials.gov NCT00928798</p

    De impact van de versoepeling van het bezoekverbod op bewoners van verpleeghuizen en woonzorgcentra: Een vergelijking tussen mei en juni/juli 2020

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    Deze factsheet beschrijft de situatie van bewoners in instellingen voor verpleging en verzorging tijdens en na het beëindigen van het landelijke bezoekverbod in 2020. In mei en juni/juli is online vragenlijst onderzoek uitgevoerd naar de gevolgen van sociale isolatie door het nieuwe coronavirus in verpleeghuizen en woonzorgcentra. Voor beide metingen zijn deelnemers (bewoners, familieleden en zorgmedewerkers) onafhankelijk van elkaar geworven. Over het algemeen werd kwaliteit van leven in juni/juli vaker belangrijk gevonden dan veiligheid, en leken deelnemers meer bereid dan in mei om het risico van besmettingen te accepteren door bezoek toe te laten. Hoewel bewoners weer twee tot drie keer per week bezoek konden ontvangen, waren zij niet per se minder eenzaam. Wel werden positieve veranderingen in stemming en gedragsproblemen van bewoners gerapporteerd door familieleden en medewerkers. Ook kwaliteit van leven van bewoners werd beter gewaardeerd dan tijdens het bezoekverbod, maar was nog niet op het niveau als vóór het bezoekverbod. De positieve impact van de versoepeling van het bezoekverbod op bewoners, was al na een relatief korte periode zichtbaar. De resultaten ondersteunen de beslissing geen landelijk bezoekverbod meer in te stellen

    Development and validation of real-time PCR screening methods for detection of cry1A.105 and cry2Ab2 genes in genetically modified organisms

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    Primers and probes were developed for the element-specific detection of cry1A.105 and cry2Ab2 genes, based on their DNA sequence as present in GM maize MON89034. Cry genes are present in many genetically modified (GM) plants and they are important targets for developing GMO element-specific detection methods. Element-specific methods can be of use to screen for the presence of GMOs in food and feed supply chains. Moreover, a combination of GMO elements may indicate the potential presence of unapproved GMOs (UGMs). Primer-probe combinations were evaluated in terms of specificity, efficiency and limit of detection. Except for specificity, the complete experiment was performed in 9 PCR runs, on 9 different days and by testing 8 DNA concentrations. The results showed a high specificity and efficiency for cry1A.105 and cry2Ab2 detection. The limit of detection was between 0.05 and 0.01 ng DNA per PCR reaction for both assays. These data confirm the applicability of these new primer-probe combinations for element detection that can contribute to the screening for GM and UGM crops in food and feed samples

    Laparoscopic ileocolic resection versus infliximab treatment of distal ileitis in Crohn's disease: a randomized multicenter trial (LIR!C-trial)

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    Contains fulltext : 69534.pdf (publisher's version ) (Open Access)BACKGROUND: With the availability of infliximab, nowadays recurrent Crohn's disease, defined as disease refractory to immunomodulatory agents that has been treated with steroids, is generally treated with infliximab. Infliximab is an effective but expensive treatment and once started it is unclear when therapy can be discontinued. Surgical resection has been the golden standard in recurrent Crohn's disease. Laparoscopic ileocolic resection proved to be safe and is characterized by a quick symptom reduction.The objective of this study is to compare infliximab treatment with laparoscopic ileocolic resection in patients with recurrent Crohn's disease of the distal ileum with respect to quality of life and costs. METHODS/DESIGN: The study is designed as a multicenter randomized clinical trial including patients with Crohn's disease located in the terminal ileum that require infliximab treatment following recent consensus statements on inflammatory bowel disease treatment: moderate to severe disease activity in patients that fail to respond to steroid therapy or immunomodulatory therapy. Patients will be randomized to receive either infliximab or undergo a laparoscopic ileocolic resection. Primary outcomes are quality of life and costs. Secondary outcomes are hospital stay, early and late morbidity, sick leave and surgical recurrence. In order to detect an effect size of 0.5 on the Inflammatory Bowel Disease Questionnaire at a 5% two sided significance level with a power of 80%, a sample size of 65 patients per treatment group can be calculated. An economic evaluation will be performed by assessing the marginal direct medical, non-medical and time costs and the costs per Quality Adjusted Life Year (QALY) will be calculated. For both treatment strategies a cost-utility ratio will be calculated. Patients will be included from December 2007. DISCUSSION: The LIR!C-trial is a randomized multicenter trial that will provide evidence whether infliximab treatment or surgery is the best treatment for recurrent distal ileitis in Crohn's disease. TRIAL REGISTRATION: Nederlands Trial Register NTR1150

    A genome-wide genetic map of NB-LRR disease resistance loci in potato

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    Like all plants, potato has evolved a surveillance system consisting of a large array of genes encoding for immune receptors that confer resistance to pathogens and pests. The majority of these so-called resistance or R proteins belong to the super-family that harbour a nucleotide binding and a leucine-rich-repeat domain (NB-LRR). Here, sequence information of the conserved NB domain was used to investigate the genome-wide genetic distribution of the NB-LRR resistance gene loci in potato. We analysed the sequences of 288 unique BAC clones selected using filter hybridisation screening of a BAC library of the diploid potato clone RH89-039-16 (S. tuberosum ssp. tuberosum) and a physical map of this BAC library. This resulted in the identification of 738 partial and full-length NB-LRR sequences. Based on homology of these sequences with known resistance genes, 280 and 448 sequences were classified as TIR-NB-LRR (TNL) and CC-NB-LRR (CNL) sequences, respectively. Genetic mapping revealed the presence of 15 TNL and 32 CNL loci. Thirty-six are novel, while three TNL loci and eight CNL loci are syntenic with previously identified functional resistance genes. The genetic map was complemented with 68 universal CAPS markers and 82 disease resistance trait loci described in literature, providing an excellent template for genetic studies and applied research in potato

    Mentor teachers: Their perceived possibilities and challenges as mentor and teacher

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    This interview study, including seven case studies of mentor teachers in primary education, explores the possibilities and challenges these mentor teachers perceive when they (sequentially and simultaneously) combine the teacher and mentor roles. Mentor teachers perceive two challenges while simultaneously performing both roles in the same classroom: to transfer (or not) responsibility for the class and pupils to the student teacher and to intervene (or not) in classroom procedures. Mentor teachers felt that being the teacher of the pupils was their primary task, and being a mentor of the student teacher generally was perceived as an aside and additional task

    Mentor teachers : Their perceived possibilities and challenges as mentor and teacher

    No full text
    This interview study, including seven case studies of mentor teachers in primary education, explores the possibilities and challenges these mentor teachers perceive when they (sequentially and simultaneously) combine the teacher and mentor roles. Mentor teachers perceive two challenges while simultaneously performing both roles in the same classroom: to transfer (or not) responsibility for the class and pupils to the student teacher and to intervene (or not) in classroom procedures. Mentor teachers felt that being the teacher of the pupils was their primary task, and being a mentor of the student teacher generally was perceived as an aside and additional task

    Changed sediment composition prevents recovery of macrobenthic community four years after a shoreface nourishment at the Holland coast

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    Sand nourishment is a widespread management strategy to protect sandy coasts against erosion. Nourishments can impact the benthic fauna directly by burial and indirectly by changing environmental conditions such as bottom shear stress and/or sediment composition (grain size distribution). The macrobenthic community in soft-bottom environments is often strongly correlated with sediment composition, however, because of the strong correlation with other environmental conditions, it is difficult to determine the direct effects of sediment composition on the macrobenthic community from field observations. Nourishments can temporarily break this correlation allowing to study the relation between sediment composition and macrobenthic community more or less independent from other environmental factors. In 2017, a shoreface nourishment was constructed at the Holland coast near Callantsoog at a water depth of about 10 m. Because the influence of waves is limited at this depth, the nourishment is not very mobile. Sediment composition and macrobenthos was monitored at the nourished site and two reference locations before (2015 and 2016), and in 2021, four years after nourishment. In 2021, the sediment composition at the nourished site was much coarser (median grain size 330 ± 59 μm) than in the years before nourishment (195 ± 34 μm), while the sediment composition at the reference locations remained comparable over the years. The average number of taxa per sample at the nourishment decreased from 14.1 before nourishment to 3.0 taxa in 2021. Also the average total density at the nourishment location decreased from 12731 ind.m−2 before nourishment to 320 ind.m−2 in 2021. While before nourishment, the composition of the macrobenthic community at the nourished site was comparable to the southern reference location, in 2021 the macrobenthic community was more comparable to the community at the coarser sediments of the northern reference. Clearly, four years after the nourishment, the macrobenthic community has not recovered due to the presence of coarser sediments at the nourished site. Logistic regressions show that most of the dominant species have a negative correlation with median grain size, but some species are more sensitive to changes in sediment composition than others. The sensitivity of the macrobenthos to sediment composition illustrates the importance of using sediments of similar grain size as in the placement area, especially for nourishments in the deeper parts of the shoreface.Environmental Fluid Mechanic
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