408 research outputs found

    Methodological aspects of recent climate change damage cost studies

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    This paper discusses methodological aspects of recent climate change damage studies. Assessing the total and/or marginal damage costs of environmental change is often difficult and it is certainly difficult in the case of climate change. A major obstacle is the uncertainty on the physical impacts of climate change, especially related to extreme events and so-called ‘low-probability high-impact’ scenarios. The subsequent transposition of physical impacts into monetary terms is also a delicate step, given that climate change impacts involve both market and non-market goods and services, covering health, environmental and social values, and that impacts may be distant in time and space. The complexity of climate change cost assessment thus involves several crucial dimensions, including non-market evaluation, risk and uncertainty, baseline definition, equity and discounting, further elaborated in this paper in the course of the overview of the literature and of the overview and evaluation of the key methodological issues.Climate change damage costs, cost of inaction, methodological aspects, risk and uncertainty, discounting, equity

    Gezonde Buxusteelt

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    De Buxusteelt is binnen de boomteelt een grote teelt, bijna 10% van het areaal boomkwekerij. Enkele jaren geleden sloeg de Buxustaksterfte, veroorzaakt door de schimmel Cylindrocladium buxicola(= Cylindrocladium pseudonaviculatum) ernstig toe. In vorige Buxusprojecten die werden gefinancierd door het Productschap Tuinbouw (PT) is veel kennis opgedaan over de biologie van de schimmel, over geschikte gewasbeschermingsmiddelen en zijn effectieve bestrijdingsstrategieën ontwikkeld. Echter, voor een goede beheersing van Cylindrocladium buxicola in Buxus zijn in de praktijk vaak nog veel bespuitingen nodig. Het gebruik van een waarschuwingsmodel kan het aantal bespuitingen omlaag brengen. Daarnaast is gebleken dat de spuittechniek waarmee het binnenste van de plant en de onderkant van de bladeren goed zijn te raken met gewasbeschermingsmiddelen een bepalende factor kan zijn. Naast Cylindrocladium is er ook een andere ziekte in Buxus die steeds meer van zich doet spreken, nl. stambasisrot veroorzaakt door Phytophthora. Op enkele bedrijven is al forse schade geleden door deze ziekte. De vrees is dat Phytophthora snel een nieuwe bedreiging kan worden. In dit project is ervaring opgedaan met een grondbemonsteringstechniek en is een middelentoetsing uitgevoerd. Het doel van dit project is om taksterfte en bladval, veroorzaakt door Cylindrocladium en stambasisrot, veroorzaakt door Phytophthora, duurzaam te beheersen zodat een gezonde Buxusplant kan worden geteeld

    Time to full enteral feeding after necrotizing enterocolitis in preterm-born children is related to neurodevelopment at 2-3 years of age

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    BACKGROUND: Necrotizing enterocolitis (NEC) is associated with poorer neurodevelopment. It is, however, unclear which factors besides surgery affect neurodevelopment in preterm-born children surviving NEC. AIMS: We determined whether time to full enteral feeding (FEFt) and post-NEC complications after NEC were associated with neurodevelopment. STUDY DESIGN: Prospective observational cohort study. SUBJECTS: Two to three year old preterm-born children who survived NEC (Bells stage ≄ 2). We categorized children in two groups, one group shorter and equal and one group longer than the group's median FEFt. Post-NEC complications included recurrent NEC and/or post-NEC stricture. OUTCOME MEASURES: Bayley Scales of Infants and Toddler Development III (Bayley-III) and Child Behavior Checklist (CBCL). Associations between Bayley-III and CBCL scores with FEFt and Post-NEC complications were determined using linear regression analyses, adjusted for severity of illness and potential confounders. RESULTS: We included 44 children, median gestational age of 27.9 [IQR: 26.7-29.3] weeks, birth weight 1148 [IQR: 810-1461] grams. Median FEFt after NEC was 20 [IQR: 16-30] days. Median follow-up age was 25.7 [IQR: 24.8-33.5] months. FEFt > 20 days was associated with lower cognitive and lower motor composite scores of the Bayley-III (B: -8.6, 95% CI -16.7 to -0.4, and B: -9.0, 95% CI, -16.7 to -1.4). FEFt was not associated with CBCL scores. Post-NEC complications (n = 11) were not associated with Bayley-III scores nor with CBCL scores. CONCLUSIONS: Prolonged FEFt after NEC in preterm-born children surviving NEC is associated with lower cognitive and lower motor composite scores at the age of 2-3 years. These results show the importance of limiting the duration of the nil per mouth regimen if and when possible

    Predicting intestinal recovery after necrotizing enterocolitis in preterm infants

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    Background: Intestinal recovery after NEC is difficult to predict in individuals. We evaluated whether several biomarkers predict intestinal recovery after NEC in preterm infants. Methods: We measured intestinal tissue oxygen saturation (rintSO2) and collected urinary intestinal-fatty acid binding protein (I-FABPu) levels 0–24 h and 24–48 h after NEC onset, and before and after the first re-feed. We assessed intestinal recovery in two ways: time to full enteral feeding (FEFt; below or equal/above group’s median) and development of post-NEC complications (recurrent NEC/post-NEC stricture). We determined whether the rintSO2, its range, and I-FABPu differed between groups. Results: We included 27 preterm infants who survived NEC (Bell’s stage ≄ 2). Median FEFt was 14 [IQR: 12–23] days. Biomarkers only predicted intestinal recovery after the first re-feed. Mean rintSO2 ≄ 53% combined with mean rintSO2range ≄ 50% predicted FEFt < 14 days with OR 16.7 (CI: 2.3–122.2). The rintSO2range was smaller (33% vs. 51%, p < 0.01) and I-FABPu was higher (92.4 vs. 25.5 ng/mL, p = 0.03) in case of post-NEC stricture, but not different in case of recurrent NEC, compared with infants without complications. Conclusion: The rintSO2, its range, and I-FABPu after the first re-feed after NEC predicted intestinal recovery. These biomarkers have potential value in individualizing feeding regimens after NEC

    Aeroservoelastic design definition of a 20 MW common research wind turbine model

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    Wind turbine upscaling is motivated by the fact that larger machines can achieve lower levelized cost of energy. However, there are several fundamental issues with the design of such turbines, and there is little public data available for large wind turbine studies. To address this need, we develop a 20 MW common research wind turbine design that is available to the public. Multidisciplinary design optimization is used to define the aeroservoelastic design of the rotor and tower subject to the following constraints: blade‐tower clearance, structural stresses, modal frequencies, tip‐speed and fatigue damage at several sections of the tower and blade. For the blade, the design variables include blade length, twist and chord distribution, structural thicknesses distribution and rotor speed at the rated. The tower design variables are the height, and the diameter distribution in the vertical direction. For the other components, mass models are employed to capture their dynamic interactions. The associated cost of these components is obtained by using cost models. The design objective is to minimize the levelized cost of energy. The results of this research show the feasibility of a 20 MW wind turbine and provide a model with the corresponding data for wind energy researchers to use in the investigation of different aspects of wind turbine design and upscaling. Copyright © 2016 John Wiley & Sons, Ltd.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/134256/1/we1970.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/134256/2/we1970_am.pd

    The effect of enteral bolus feeding on regional intestinal oxygen saturation in preterm infants is age-dependent:a longitudinal observational study

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    Background The factors that determine the effect of enteral feeding on intestinal perfusion after preterm birth remain largely unknown. We aimed to determine the effect of enteral feeding on intestinal oxygen saturation (r(int)SO(2)) in preterm infants and evaluated whether this effect depended on postnatal age (PNA), postmenstrual age (PMA), and/or feeding volumes. We also evaluated whether changes in postprandial r(int)SO(2) affected cerebral oxygen saturation (r(c)SO(2)). Methods In a longitudinal observational pilot study using near-infrared spectroscopy we measured r(int)SO(2) and r(c)SO(2) continuously for two hours on postnatal Days 2 to 5, 8, 15, 22, 29, and 36. We compared preprandial with postprandial values over time using multi-level analyses. To assess the effect of PNA, PMA, and feeding volumes, we performed Wilcoxon signed-rank tests or logistic regression analyses. To evaluate the effect on r(c)SO(2), we also used logistic regression analyses. Results We included 29 infants: median (range) gestational age 28.1 weeks (25.1-30.7) and birth weight 1025 g (580-1495). On Day 5, r(int)SO(2) values decreased postprandially: mean (SE) 44% (10) versus 35% (7), P = .01. On Day 29, r(int)SO(2) values increased: 44% (11) versus 54% (7), P = .01. Infants with a PMA >= 32 weeks showed a r(int)SO(2) increase after feeding (37% versus 51%, P = .04) whereas infants with a PMA = 32 weeks when greater volumes of enteral feeding are tolerated. We speculate that at young gestational and postmenstrual ages preterm infants are still unable to increase intestinal oxygen saturation after feeding, which might be essential to meet metabolic demands. Trial registration: For this prospective longitudinal pilot study we derived patients from a larger observational cohort study: CALIFORNIA-Trial, Dutch Trial Registry NTR4153

    Bloedingsziekte in paardenkastanje

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    Samenvatting van de voordracht te houden op 30 november 2005 tijdens de Najaarsvergadering van de KNPV (Koninklijke Nederlandse Plantenziektekundige Vereniging). Onderzoek naar oorzaak en distributie van de paardenkastanjeziekt

    Unification of trap-limited electron transport in semiconducting polymers

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    Electron transport in semiconducting polymers is usually inferior to hole transport, which is ascribed to charge trapping on isolated defect sites situated within the energy bandgap. However, a general understanding of the origin of these omnipresent charge traps, as well as their energetic position, distribution and concentration, is lacking. Here we investigate electron transport in a wide range of semiconducting polymers by current-voltage measurements of single-carrier devices. We observe for this materials class that electron transport is limited by traps that exhibit a Gaussian energy distribution in the bandgap. Remarkably, the electron-trap distribution is identical for all polymers considered: the number of traps amounts to 3 × 1023 traps per m3 centred at an energy of ∌3.6 eV below the vacuum level, with a typical distribution width of ∌0.1 eV. This indicates that the electron traps have a common origin that, we suggest, is most likely related to hydrated oxygen complexes. A consequence of this finding is that the trap-limited electron current can be predicted for any polymer. © 2012 Macmillan Publishers Limited. All rights reserved
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