232 research outputs found

    Monitoring groene grondstoffen

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    Het Platform Groene Grondstoffen heeft een monitoringsmethodiek laten ontwikkelen waarmee het aandeel biomassa dat bijdraagt aan de economie kan worden vastgesteld. Dit rapport beschrijft hoe de monitor is ontwikkeld en waar nog hiaten in de kennis zitten

    Presynaptic Ionotropic Receptors Controlling and Modulating the Rules for Spike Timing-Dependent Plasticity

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    Throughout life, activity-dependent changes in neuronal connection strength enable the brain to refine neural circuits and learn based on experience. In line with predictions made by Hebb, synapse strength can be modified depending on the millisecond timing of action potential firing (STDP). The sign of synaptic plasticity depends on the spike order of presynaptic and postsynaptic neurons. Ionotropic neurotransmitter receptors, such as NMDA receptors and nicotinic acetylcholine receptors, are intimately involved in setting the rules for synaptic strengthening and weakening. In addition, timing rules for STDP within synapses are not fixed. They can be altered by activation of ionotropic receptors located at, or close to, synapses. Here, we will highlight studies that uncovered how network actions control and modulate timing rules for STDP by activating presynaptic ionotropic receptors. Furthermore, we will discuss how interaction between different types of ionotropic receptors may create “timing” windows during which particular timing rules lead to synaptic changes

    Evaluation of the phytoestrogenic activity of Cyclopia genistoides (honeybush) methanol extracts and relevant polyphenols

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    The original publication is available at http://pubs.acs.org/Unfermented C. genistoides methanol extracts of different harvestings and selected polyphenols were evaluated for phytoestrogenic activity by comparing binding to both ER subtypes, transactivation of an ERE-containing promoter reporter, proliferation of MCF-7-BUS and MDA-MB-231 breast cancer cells, and binding to SHBG. The extracts from one harvesting of C. genistoides (P104) bound to both ER subtypes. All extracts transactivated ERE-containing promoter reporters via ERβ but not via ERα. All extracts, except P122, caused proliferation of the estrogen-sensitive MCF-7-BUS cells. Proliferation of MCF-7-BUS cells was ER-dependent as ICI 182,780 reversed proliferation. Physiologically more relevant, extracts antagonized E2-induced MCF-7-BUS cell proliferation. Furthermore, all extracts, except P122, induced proliferation of the estrogen-insensitive MDA-MB-231 cells, suggesting that the extracts are able to induce ER-dependent and ER-independent cell proliferation. Binding to SHBG by extracts was also demonstrated. These results clearly show that C. genistoides methanol extracts display phytoestrogenic activity and act predominantly via ERβ. HPLC and LC-MS analysis, however, suggests that the observed phytoestrogenic activity cannot be ascribed to polyphenols known to be present in other Cyclopia species. © 2007 American Chemical Society.Publishers' versio

    Dynamic impacts of a financial reform of the CAP on regional land use, income and overall growth

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    In this paper we investigate the impacts of abolishing the Common Agricultural Policy (CAP) for the post-2013 European Union (EU) financial perspective and the impacts of re-investing the released funds on research and development (R&D). We apply a linked system of models to analyze the impacts for the EU member states. The linked system consists of five land-use sector models (agriculture, forestry, urban area, tourism and transport infrastructure), which are connected to a macro-econometric model. Additionally, a land cover model is used to disaggregate land use countries to a 1 km² grid. Three scenarios are analysed. In the “baseline” currently decided policies are assumed to be continued until 2025. In the “tax rebate” scenario agricultural support (first pillar) is removed, and the member states’ contributions to EU lowered. In the “R&D investments” scenario agricultural support is also removed, and the released funds are used to increase general R&D efforts in the EU. We find that in both liberalization scenarios, agricultural producer prices drop compared to the baseline. Agricultural production drops too, but less so in the “R&D investment” scenario due to productivity gains resulting from the increased R&D spending. In some countries, the productivity gains totally offset the negative impact of liberalisation on agricultural production. Smaller agricultural production implies less agricultural land use, and the more so in the “R&D Investment” scenario where productivity increases. The fall in agricultural production and prices negatively affects economic activity and households’ purchasing power, but the reduced direct taxation compensates this effect and results in a GDP gain of 0.53% and 0.8 million additional jobs. In “R&D investment” GDP gain reaches 2.57% and yields 2.95 million additional jobs in EU in 2025. The GDP, consumption and employment gains in the “R&D Investment” scenario widely exceed the losses in the agriculture sectors. The analysis indicates that if no external effects of agriculture are considered, then the CAP is an inefficient use of tax money, and that a considerable contribution to reaching the goals of the Lisbon agenda would be achieved if the same amount of money was instead invested in R&D.CAP reform, economical growth, land use, Agricultural and Food Policy, Land Economics/Use,

    Energie- en klimaatmonitor agrosectoren 2011

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    Onderzoek van Agenschap NL en WUR-LEI in opdracht van het ministerie van Economische Zaken, Landbouw en Innovatie (EL&I). Uit de monitor blijkt dat de Nederandse land- en tuinbouwbedrijven meer elektriciteit produceren dan ze zelf verbruiken. De totale bijdrage van deze sectoren aan de in Nederland gebruikte duurzame energie is 44 procent. Ruim de helft van het energieverbruik van de land- en tuinbouwbedrijven zelf (uitgezonderd de glastuinbouw) is afkomstig uit hernieuwbare bronnen

    Contextual determinants associated with children's and adolescents' mental health care utilization:a systematic review

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    Determinants at the contextual level are important for children's and adolescents' mental health care utilization, as this is the level where policy makers and care providers can intervene to improve access to and provision of care. The objective of this review was to summarize the evidence on contextual determinants associated with mental health care utilization in children and adolescents. A systematic literature search in five electronic databases was conducted in August 2021 and retrieved 6439 unique records. Based on eight inclusion criteria, 74 studies were included. Most studies were rated as high quality (79.7%) and adjusted for mental health problems (66.2%). The determinants that were identified were categorized into four levels: organizational, community, public policy or macro-environmental. There was evidence of a positive association between mental health care utilization and having access to a school-based health center, region of residence, living in an urban area, living in an area with high accessibility of mental health care, living in an area with high socio-economic status, having a mental health parity law, a mental health screening program, fee-for-service plan (compared to managed care plan), extension of health insurance coverage and collaboration between organizations providing care. For the other 35 determinants, only limited evidence was available. To conclude, this systematic review identifies ten contextual determinants of children's and adolescents' mental health care utilization, which can be influenced by policymakers and care providers. Implications and future directions for research are discussed PROSPERO ID: CRD42021276033.</p

    Disease- and treatment-associated acquired glucocorticoid resistance

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    The development of resistance to glucocorticoids (GCs) in therapeutic regimens poses a major threat. Generally, GC resistance is congenital or acquired over time as a result of disease progression, prolonged GC treatment or, in some cases, both. Essentially, disruptions in the function and/or pool of the glucocorticoid receptor α (GRα) underlie this resistance. Many studies have detailed how alterations in GRα function lead to diminished GC sensitivity; however, the current review highlights the wealth of data concerning reductions in the GRα pool, mediated by disease-associated and treatment-associated effects, which contribute to a significant decrease in GC sensitivity. Additionally, the current understanding of the molecular mechanisms involved in driving reductions in the GRα pool is discussed. After highlighting the importance of maintaining the level of the GRα pool to combat GC resistance, we present current strategies and argue that future strategies to prevent GC resistance should involve biased ligands with a predisposition for reduced GR dimerization, a strategy originally proposed as the SEMOGRAM–SEDIGRAM concept to reduce the side-effect profile of GCs

    Are BRCA1- and BRCA2-related breast cancers associated with increased mortality?

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    There has been contradictory evidence as to whether BRCA1 associated breast cancers have a poorer prognosis than non-BRCA1 cancers. In this issue of Breast Cancer Research Robson and colleagues provide further evidence for poorer survival in BRCA1 carriers and show that it could be attributed to failure to treat small node-negative grade 3 breast cancers with chemotherapy. There still remains little evidence for a survival difference for BRCA2 related breast cancers. Although the high contralateral breast cancer risk is confirmed by this study there is no real evidence for an increase in ipsilateral recurrence or new primary breast cancers in mutation carriers up to the 10-year point
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