259 research outputs found

    Energieverbruik bij het bewaren van bijzondere bolgewassen : Allium, Muscari, Zantedeschia en Fritillaria

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    De gewasgroep bijzondere bolgewassen bestaat uit vele tientallen soorten, onder te verdelen in zomer- en voorjaarsbloeiers, en staat qua areaal na tulp en lelie in de boembollensector op de derde plaats. Uit de analyse van het energieverbruik per hectare van de deelnemers aan de MJA-e in de periode 1995-2006 bleek vooral het gasverbruik bij deze gewasgroep erg hoog. Het verdient daarom aanbeveling om met telers van bijzondere bolgewassen te achterhalen wat de achtergronden van de hoge ventilatiedebieten zijn: wat wil men er mee bereiken, welk bewaarklimaat wil men realiseren, welke bewaarziekten of andere problemen wil men voorkomen, etc. Mogelijk leidt dit tot nieuwe inzichten, bv. een ventilatiesturing op basis van RV bij bolgewassen die niet op ethyleen reageren, waardoor de bollensector meer energie kan besparen

    De kracht van het Nederlandse ontwikkelingsbeleid is verdwenen

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    "The Netherlands has lost the strength of its international cooperation". This is stated by Cora van Oosten (Wageningen UR Centre for Development Innovation) and Rob Wildschut (Hivos), in their contribution to the online discussion of Vice Versa. They state that the ideas forming the basis for the new Dutch international cooperation policy are outdated, and have little content. The State's Secretary's most recent letter to the parliament shows a simplistic vision on international cooperation, and should be replaced by a better one, recognizing the achievements made by the international cooperation sector over the past 50 years, showing deeper insight in processes of global development, and real commitment to international solidarity

    Bewaring van lelieplantgoed : energiebesparing door vermindering van de circulatie

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    De veruit belangrijkste energiepost bij de teelt van lelies is het elektraverbruik voor koeling en circulatie tijdens de bewaring van november t/m april. Lelieplantgoed wordt bewaard in palletkisten bij een temperatuur van 2-4 oC in de eerste weken na het rooien tot gemiddeld -0.5 oC in de laatste maanden. Enige ventilatie is nodig voor het afvoeren van CO2 , water en warmte die in de ademhaling geproduceerd worden. Tot enkele jaren geleden werd geadviseerd om één keer per dag de celdeur korte tijd open te zetten om op deze manier te ventileren. Tegenwoordig is in veel leliecellen een PVC-pijpje in de buurt van de verdamper aangebracht om wat verse lucht aan te zuigen. De ventilatiebehoefte van lelies is dus kennelijk erg laag vergeleken met die van tulpenbollen, maar niet exact bekend. Doel van de circulatie is het creëren van een over alle kisten gelijkmatig en gunstig bewaarklimaat tussen de bollen in termen van temperatuur, RV, en CO 2 -gehalte. Voor de circulatie worden in de praktijk normen gehanteerd variërend van 50 tot 300 m3 lucht/uur per m3 leliebollen. Groot nadeel van de circulatie is dat de warmteproductie van de systeemventilatoren ook teruggekoeld moet worden. Doel van dit onderzoek is om voor circulatie en ventilatie tot normen te komen waarmee maximaal op energie wordt bespaard zonder dat dit ten koste gaat van de kwaliteit van het lelieplantgoed. Voor de verminderde circulatie is hierbij ook een vergelijking gemaakt tussen de aan/uit regeling en de frequentieregeling

    Feasibility of sedation and analgesia interruption following cannulation in neonates on extracorporeal membrane oxygenation

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    Purpose: In most extracorporeal membrane oxygenation (ECMO) centers patients are heavily sedated to prevent accidental decannulation and bleeding complications. In ventilated adults not on ECMO, daily sedation interruption protocols improve short- and long-term outcome. This study aims to evaluate safety and feasibility of sedation interruption following cannulation in neonates on ECMO. Methods: Prospective observational study in 20 neonates (0.17-5.8 days of age) admitted for ECMO treatment. Midazolam (n = 20) and morphine (n = 18) infusions were discontinued within 30 min after cannulation. Pain and sedation were regularly assessed using COMFORT-B and visual analog scale (VAS) scores. Midazolam and/or morphine were restarted and titrated according to protocolized treatment algorithms. Results: Median (interquartile range, IQR) time without any sedatives was 10.3 h (5.0-24.1 h). Median interruption duration for midazolam was 16.5 h (6.6-29.6 h), and for morphine was 11.2 h (6.7-39.4 h). During this period no accidental extubations, decannulations or bleeding complications occurred. Conclusions: This is the first study to show that interruption of sedatives and analgesics following cannulation in neonates on ECMO is safe and feasible. Interruption times are 2-3 times longer than reported for adult ICU patients not on ECMO. Further trials are needed to substantiate these findings and evaluate short- and long-term outcomes

    Learning from failure

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    We study decentralized learning in organizations. Decentralization is captured through a symmetry constraint on agents’ strategies. Among such attainable strategies, we solve for optimal and equilibrium strategies. We model the organization as a repeated game with imperfectly observable actions. A fixed but unknown subset of action profiles are successes and all other action profiles are failures. The game is played until either there is a success or the time horizon is reached. For any time horizon, including infinity, we demonstrate existence of optimal attainable strategies and show that they are Nash equilibria. For some time horizons, we can solve explicitly for the optimal attainable strategies and show uniqueness. The solution connects the learning behavior of agents to the fundamentals that characterize the organization: Agents in the organization respond more slowly to failure as the future becomes more important, the size of the organization increases and the probability of success decreases.Game theory

    Determinants of drug absorption in different ECMO circuits

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    Purpose: The aim of this in vitro study was to evaluate potential determinants of drug loss in different ECMO circuits. Methods: Midazolam, morphine, fentanyl, paracetamol, cefazolin, meropenem and vancomycin were injected into three neonatal roller pump, two paediatric roller pump and two clinically used neonatal roller pump circuits, all with a silicone membrane, and two neonatal centrifugal pump circuits with polypropylene hollow-fibre membranes. Serial blood samples were taken from a post-oxygenator site. Drug recovery was calculated as the ratio between the determined and the theoretical maximum concentration. The latter was obtained by dividing dose by theoretical circuit volume. Results: Average drug recoveries at 180 min in three neonatal silicone membrane roller pump circuits were midazolam 0.62%, morphine 23.9%, fentanyl 0.35%, paracetamol 34.0%, cefazolin 84.3%, meropenem 82.9% and vancomycin 67.8%. There was a significant correlation between the lipophilicity of the drug expressed as log P and the extent of drug absorption, p < 0.001. The recovery of midazolam and fentanyl in centrifugal pump circuits with hollow-fibre membrane oxygenator was significantly higher compared to neonatal roller pump circuits with silicone membranes: midazolam 63.4 versus 0.62%, fentanyl 33.8 versus 0.35%, p < 0.001. Oxygenator size and used circuits do not significantly affect drug losses. Conclusions: Significant absorption of drugs occurs in the ECMO circuit, correlating with increased lipophilicity of the drug. Centrifugal pump circuits with hollow-fibre membrane oxygenators show less absorption for all drugs, most pronounced for lipophilic drugs. These results suggest that pharmacokinetics and hence optimal doses of these drugs may be altered during ECMO

    Women's attitude towards prenatal screening for red blood cell antibodies, other than RhD

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    Background: Since July 1998 all Dutch women (± 200,000/y) are screened for red cell antibodies, other than anti-RhesusD (RhD) in the first trimester of pregnancy, to facilitate timely treatment of pregnancies at risk for hemolytic disease of the fetus and newborn (HDFN). Evidence for benefits, consequences and costs of screening for non-RhD antibodies is still under discussion. The screening program was evaluated in a nation-wide study. As a part of this evaluation study we investigated, according to the sixth criterium of Wilson and Jüngner, the acceptance by pregnant women of the screening program for non-RhD antibodies. Methods: Controlled longitudinal survey, including a prenatal and a postnatal measurement by structured questionnaires. Main outcome measures: information satisfaction, anxiety during the screening process (a.o. STAI state inventory and specific questionnaire modules), overall attitude on the screening program. Univariate analysis was followed by standard multivariate analysis to identify significant predictors of the outcome measures. Participants: 233 pregnant women, distributed over five groups, according to the screening result. Results: Satisfaction about the provided information was moderate in all groups. All screen- positive groups desired more supportive information. Anxiety increased in screen- positives during the screening process, but decreased to basic levels postnatally. All groups showed a strongly positive balance between perceived utility and burden of the

    Severe acute respiratory infection caused by swine influenza virus in a child necessitating extracorporeal membrane oxygenation (ECMO), the Netherlands, October 2016.

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    In October 2016, a severe infection with swine influenza A(H1N1) virus of the Eurasian avian lineage occurred in a child with a previous history of eczema in the Netherlands, following contact to pigs. The patient's condition deteriorated rapidly and required life support through extracorporeal membrane oxygenation. After start of oseltamivir treatment and removal of mucus plugs, the patient fully recovered. Monitoring of more than 80 close unprotected contacts revealed no secondary cases
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