143 research outputs found

    Canal blocking strategies for hydrological restoration of degraded tropical peatlands in Central Kalimantan, Indonesia

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    In the 1990s the Government of Indonesia derided to develop one million hectares of peatlands for agriculture in Central Kalimantan on the Island of Borneo. The construction of thousands of kilometres of canals resulted in over-drainage and targets for agricultural production failed. Abandoned, the area has been subject to severe forest and peat fires. Restoration of degraded peatlands normally starts with restoring the water table to rewet the surface in order to control fire and to initiate reforestation. Canal blocking strategies are a potential means for accomplishing this. In a test plot in the Northern part of Block C of the former Mega Rice Project (MRP), a series of dams were constructed and (ground)water tables and subsidence rates were monitored to assess the effects of dam construction on peatland hydrology. The resulting higher water tables did not completely compensate for the negative effects of increased subsidence near the canals. The canals, which are "eating" themselves into the peatland, create depressions in the peatland surface leading to interception of overland- and interflow and increased risk of overtopping of dams during extreme rainfall events. The lessons learned are being used to improve blocking strategies and dam design. The changes in peatland topography caused by drainage, however, need to be better understood in order to further refine strategies for hydrological restoration of degraded peatlands in Indonesia. (C) 2013 Elsevier B.V. All rights reserved

    A large-scale experiment to evaluate control of invasive muskrats

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    The muskrat (Ondatra zibethicus) is an invasive species in Europe. The extensive waterways of the Netherlands provide ideal habitat for muskrats, and a large population established itself after arrival in 1941. A control program was put into effect immediately because muskrat burrowing can compromise the integrity of dikes and, hence, poses a significant public safety risk. The current (2015) annual catch of approximately 89,000 individuals is equivalent to approximately 0.30 muskrats/km of waterway, well above the national objective in spite of decades of effort. The control program is expensive (€35 M annually) and contested by animal rights groups. These factors created the need for a careful evaluation of the full range of control possibilities, from ‘no control’ to ‘extermination.’ As part of this, we experimentally evaluated the validity of a previously published correlation (based on historical data) between catch and effort. We raised or lowered removal effort (2013–2016) in a stratified random sample of 117 5-km × 5-km ‘atlas squares’ from the national grid. We found that catch-per-unit effort (CPUE) decreased after effort was increased, and rose after effort was decreased, by amounts slightly greater than expected based on the correlational data, though confidence intervals enclose zero. As anticipated, CPUE varied consistently and strongly between seasons. The biggest (and unanticipated) effects were those of the catch in the preceding 3 years (‘history’), and surrounding area (‘neighborhood’). Our experiment confirms estimates of intensity of control required to lower muskrat populations. These results will help with more effective allocation of control effort, and better-informed evaluation of the economic costs of various control options

    Burgerschap in het basisonderwijs:Technisch rapport Peil.Burgerschap 2020

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    Ruimte voor verbetering burgerschapscompetentiesHet niveau van burgerschapscompetenties, burgerschapskennis en -houdingen van groep 8-leerlingen blijkt anno 2020 niet onverdeeld gunstig. Zo beantwoordde een kwart van de leerlingen driekwart van de kennisvragen fout. Een kwart de leerlingen beantwoordde ten minste de helft van de kennisvragen goed. Het niveau van burgerschapskennis van leerlingen blijkt vergeleken met 2009 wat lager. De meerderheid van de leerlingen scoort relatief laag op burgerschapshoudingen.Omvangrijk onderzoek in het basisonderwijsDit blijkt uit Peil.burgerschap, een omvangrijk onderzoek, uitgevoerd door de afdeling Pedagogische en Onderwijswetenschappen van de Universiteit van Amsterdam, het Kohnstamm Instituut, het GION van de Rijksuniversiteit Groningen en het Cito. Aan het onderzoek deden 2.237 groep 8-leerlingen mee van 94 basisscholen. Gegevens zijn verzameld onder leerlingen, leerkrachten en schoolleiders. Peil.burgerschap geeft inzicht in de burgerschapscompetenties van leerlingen en het burgerschapsonderwijs aan het einde van het basisonderwijs. Het maakt onderdeel uit van Peil.onderwijs: een serie periodieke onderzoeken onder de regie van de Inspectie van het Onderwijs naar domeinen van onderwijskwaliteit

    Klimaatadaptatie in het landelijk gebied. Verkenning naar wegen voor een klimaatbestendig Nederland

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    Klimaatverandering werkt via hogere temperaturen, veranderingen in neerslagpatronen, veranderingen in frequentie en intensiteit van weersextremen en zeespiegelstijging door op het functioneren van het landgebruik en het watersysteem in het landelijk gebied. De doorwerking van de hierboven genoemde klimaateffecten is complex en verschilt tussen gebieden en verschillende vormen van landgebruik. Klimaatverandering bedreigt sommige functies maar biedt ook nieuwe kansen. Om deze kansen te benutten en de bedreigingen het hoofd te bieden is klimaatadaptatie nodig. Adaptatiemaatregelen in het landelijk gebied kunnen genomen worden binnen de verschillende sectoren en binnen het water-, natuur-, landbouw- en ruimtelijke ordeningsbeleid. Er is een samenhangend pakket van maatregelen nodig. Dit noemen we een integrale adaptatierichting. Deze studie onderzoekt mogelijke adaptatierichtingen voor verschillende landschapstypen; zeekleigebied, veenweide en de hoge zandgronden

    Sepsis at ICU admission does not decrease 30-day survival in very old patients: a post-hoc analysis of the VIP1 multinational cohort study.

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    BACKGROUND: The number of intensive care patients aged ≥ 80 years (Very old Intensive Care Patients; VIPs) is growing. VIPs have high mortality and morbidity and the benefits of ICU admission are frequently questioned. Sepsis incidence has risen in recent years and identification of outcomes is of considerable public importance. We aimed to determine whether VIPs admitted for sepsis had different outcomes than those admitted for other acute reasons and identify potential prognostic factors for 30-day survival. RESULTS: This prospective study included VIPs with Sequential Organ Failure Assessment (SOFA) scores ≥ 2 acutely admitted to 307 ICUs in 21 European countries. Of 3869 acutely admitted VIPs, 493 (12.7%) [53.8% male, median age 83 (81-86) years] were admitted for sepsis. Sepsis was defined according to clinical criteria; suspected or demonstrated focus of infection and SOFA score ≥ 2 points. Compared to VIPs admitted for other acute reasons, VIPs admitted for sepsis were younger, had a higher SOFA score (9 vs. 7, p < 0.0001), required more vasoactive drugs [82.2% vs. 55.1%, p < 0.0001] and renal replacement therapies [17.4% vs. 9.9%; p < 0.0001], and had more life-sustaining treatment limitations [37.3% vs. 32.1%; p = 0.02]. Frailty was similar in both groups. Unadjusted 30-day survival was not significantly different between the two groups. After adjustment for age, gender, frailty, and SOFA score, sepsis had no impact on 30-day survival [HR 0.99 (95% CI 0.86-1.15), p = 0.917]. Inverse-probability weight (IPW)-adjusted survival curves for the first 30 days after ICU admission were similar for acute septic and non-septic patients [HR: 1.00 (95% CI 0.87-1.17), p = 0.95]. A matched-pair analysis in which patients with sepsis were matched with two control patients of the same gender with the same age, SOFA score, and level of frailty was also performed. A Cox proportional hazard regression model stratified on the matched pairs showed that 30-day survival was similar in both groups [57.2% (95% CI 52.7-60.7) vs. 57.1% (95% CI 53.7-60.1), p = 0.85]. CONCLUSIONS: After adjusting for organ dysfunction, sepsis at admission was not independently associated with decreased 30-day survival in this multinational study of 3869 VIPs. Age, frailty, and SOFA score were independently associated with survival

    Cumulative Prognostic Score Predicting Mortality in Patients Older Than 80 Years Admitted to the ICU.

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    OBJECTIVES: To develop a scoring system model that predicts mortality within 30 days of admission of patients older than 80 years admitted to intensive care units (ICUs). DESIGN: Prospective cohort study. SETTING: A total of 306 ICUs from 24 European countries. PARTICIPANTS: Older adults admitted to European ICUs (N = 3730; median age = 84 years [interquartile range = 81-87 y]; 51.8% male). MEASUREMENTS: Overall, 24 variables available during ICU admission were included as potential predictive variables. Multivariable logistic regression was used to identify independent predictors of 30-day mortality. Model sensitivity, specificity, and accuracy were evaluated with receiver operating characteristic curves. RESULTS: The 30-day-mortality was 1562 (41.9%). In multivariable analysis, these variables were selected as independent predictors of mortality: age, sex, ICU admission diagnosis, Clinical Frailty Scale, Sequential Organ Failure Score, invasive mechanical ventilation, and renal replacement therapy. The discrimination, accuracy, and calibration of the model were good: the area under the curve for a score of 10 or higher was .80, and the Brier score was .18. At a cut point of 10 or higher (75% of all patients), the model predicts 30-day mortality in 91.1% of all patients who die. CONCLUSION: A predictive model of cumulative events predicts 30-day mortality in patients older than 80 years admitted to ICUs. Future studies should include other potential predictor variables including functional status, presence of advance care plans, and assessment of each patient's decision-making capacity
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