2,087 research outputs found

    Organizing Multidisciplinary Care for Children with Neuromuscular Diseases

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    The Academic Medical Center (AMC) in Amsterdam, The Netherlands, recently opened the `Children's Muscle Center Amsterdam' (CMCA). The CMCA diagnoses and treats children with neuromuscular diseases. These patients require care from a variety of clinicians. Through the establishment of the CMCA, children and their parents will generally visit the hospital only once a year, while previously they visited on average six times a year. This is a major improvement, because the hospital visits are both physically and psychologically demanding for the patients. This article describes how quantitative modelling supports the design and operations of the CMCA. First, an integer linear program is presented that selects which patients to invite for a treatment day and schedules the required combination of consultations, examinations and treatments on one day. Second, the integer linear program is used as input to a simulation to study to estimate the capacity of the CMCA, expressed in the distribution of the number patients that can be seen on one diagnosis day. Finally, a queueing model is formulated to predict the access time distributions based upon the simulation outcomes under various demand scenarios

    Organizing multidisciplinary care for children with neuromuscular diseases at the Academic Medical Center, Amsterdam:CASE STUDY

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    The Academic Medical Center (AMC) in Amsterdam, The Netherlands, recently opened the ā€˜Childrenā€™s Muscle Center Amsterdamā€™ (CMCA). The CMCA diagnoses and treats children with neuromuscular diseases. The patients with such diseases require care from a variety of clinicians. Through the establishment of the CMCA, children and their parents will generally visit the hospital only once a year, while previously they used to visit on average six times a year. This is a major improvement, because the hospital visits are both physically and psychologically demanding for the patients. This paper describes how quantitative modelling supports the design and operations of the CMCA. First, an integer linear program is presented that selects which patients are to be invited for a treatment day and schedules the required combination of consultations, examinations and treatments on one day. Second, the integer linear program is used as input to a simulation study to estimate the capacity of the CMCA, expressed in terms of the distribution of the number patients that can be seen on one diagnosis day. Finally, a queueing model is formulated to predict the access time distributions based upon the simulation outcomes under various demand scenarios. Its contribution on the case under study is twofold. First, we design highly constrained appointment schedules for multiple patients that require service from multiple disciplinesā€™ resources. Second, we study the effect of the trade-offs between scheduling constraints and access times. As such, the contribution of this case study paper is that it illustrates the value of applying Operations Research techniques in complex healthcare settings, by designing context-specific combinations of mathematical models, thereby improving delivery of the highly-constrained multidisciplinary care

    De proportionaliteitstoets ex art. 7:940 lid 3 BW.

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    Met de zogenoemde proportionaliteitstoets, zoals deze in de laatste volzin van art. 7:940 lid 3 BW is opgenomen, heeft de wetgever een toetsingskader willen bieden om de verzekeringnemer te beschermen tegen een polisconforme, maar niettemin onredelijke opzegging van de overeenkomst (door de verzekeraar). Aan de orde is daarmee de vraag of gebondenheid van de verzekeraar aan de overeenkomst gevergd kan worden. Auteur concludeert dat ā€“ wat zij noemt ā€“ de zuivere proportionaliteitstoets ook zuiver wordt toegepast, maar voelt een duidelijke grens waar opzet tot misleiding vastgesteld is

    Generating crop calendars with Web search data

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    This paper demonstrates the potential of using Web search volumes for generating crop specific planting and harvesting dates in the USA integrating climatic, social and technological factors affecting crop calendars. Using Google Insights for Search, clear peaks in volume occur at times of planting and harvest at the national level, which were used to derive corn specific planting and harvesting dates at a weekly resolution. Disaggregated to state level, search volumes for corn planting generally are an agreement with planting dates from a global crop calendar dataset. However, harvest dates were less discriminatory at the state level, indicating that peaks in search volume may be blurred by broader searches on harvest as a time of cultural events. The timing of other agricultural activities such as purchase of seed and response to weed and pest infestation was also investigated. These results highlight the future potential of using Web search data to derive planting dates in countries where the data are sparse or unreliable, once sufficient search volumes are realized, as well as the potential for monitoring in real time the response of farmers to climate change over the coming decades. Other potential applications of search volume data of relevance to agronomy are also discussed

    Impacts and Uncertainties of +2Ā°C of Climate Change and Soil Degradation on European Crop Calorie Supply

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    Even if global warming is kept below +2Ā°C, European agriculture will be significantly impacted. Soil degradation may amplify these impacts substantially and thus hamper crop production further. We quantify biophysical consequences and bracket uncertainty of +2Ā°C warming on calories supply from ten major crops and vulnerability to soil degradation in Europe using crop modelling. The Environmental Policy Integrated Climate (EPIC) model together with regional climate projections from the European branch of the Coordinated Regional Downscaling Experiment (EURO-CORDEX) were used for this purpose. A robustly positive calorie yield change was estimated for the EU Member States except for some regions in Southern and South-Eastern Europe. The mean impacts range from +30 Gcal haā€“1 in the north, through +25 and +20 Gcal haā€“1 in Western and Eastern Europe, respectively, to +10 Gcal haā€“1 in the south if soil degradation and heat impacts are not accounted for. Elevated CO2 and increased temperature are the dominant drivers of the simulated yield changes in high-input agricultural systems. The growth stimulus due to elevated CO2 may offset potentially negative yield impacts of temperature increase by +2Ā°C in most of Europe. Soil degradation causes a calorie vulnerability ranging from 0 to 80 Gcal haā€“1 due to insufficient compensation for nutrient depletion and this might undermine climate benefits in many regions, if not prevented by adaptation measures, especially in Eastern and North-Eastern Europe. Uncertainties due to future potentials for crop intensification are about two to fifty times higher than climate change impacts

    Pan-European crop modelling with EPIC: Implementation, up-scaling and regional crop yield validation

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    Justifiable usage of large-scale crop model simulations requires transparent, comprehensive and spatially extensive evaluations of their performance and associated accuracy. Simulated crop yields of a Pan-European implementation of the Environmental Policy Integrated Climate (EPIC) crop model were satisfactorily evaluated with reported regional yield data from EUROSTAT for four major crops, including winter wheat, rainfed and irrigated maize, spring barley and winter rye. European-wide land use, elevation, soil and daily meteorological gridded data were integrated in GIS and coupled with EPIC. Default EPIC crop and biophysical process parameter values were used with some minor adjustments according to suggestion from scientific literature. The model performance was improved by spatial calculations of crop sowing densities, potential heat units, operation schedules, and nutrient application rates. EPIC performed reasonable in the simulation of regional crop yields, with long-term averages predicted better than inter-annual variability: linear regression R2 ranged from 0.58 (maize) to 0.91 (spring barley) and relative estimation errors were between +-30% for most of the European regions. The modelled and reported crop yields demonstrated similar responses to driving meteorological variables. However, EPIC performed better in dry compared to wet years. A yield sensitivity analysis of crop nutrient and irrigation management factors and cultivar specific characteristics for contrasting regions in Europe revealed a range in model response and attainable yields. We also show that modelled crop yield is strongly dependent on the chosen PET method. The simulated crop yield variability was lower compared to reported crop yields. This assessment should contribute to the availability of harmonised and transparently evaluated agricultural modelling tools in the EU as well as the establishment of modelling benchmark as a requirement for sound and ongoing policy evaluations in the agricultural and environmental domains

    Affordable nutrient solutions for improved food security as evidenced by crop trials

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    The continuing depletion of nutrients from agricultural soils in Sub-Saharan African is accompanied by a lack of substantial progress in crop yield improvement. In this paper we investigate yield gaps for corn under two scenarios: a micro-dosing scenario with marginal increases in nitrogen (N) and phosphorus (P) of 10 kg ha/1 and a larger yet still conservative scenario with proposed N and P applications of 80 and 20 kg/ha respectively. The yield gaps are calculated from a database of historical FAO crop fertilizer trials at 1358 locations for Sub-Saharan Africa and South America. Our approach allows connecting experimental field scale data with continental policy recommendations. Two critical findings emerged from the analysis. The first is the degree to which P limits increases in corn yields. For example, under a micro-dosing scenario, in Africa, the addition of small amounts of N alone resulted in mean yield increases of 8% while the addition of only P increased mean yields by 26%, with implications for designing better balanced fertilizer distribution schemes. The second finding was the relatively large amount of yield increase possible for a small, yet affordable amount of fertilizer application. Using African and South American fertilizer prices we show that the level of investment needed to achieve these results is considerably less than 1% of Agricultural GDP for both a micro-dosing scenario and for the scenario involving higher yet still conservative fertilizer application rates. In the latter scenario realistic mean yield increases ranged between 28 to 85% in South America and 71 to 190% in Africa (mean plus one standard deviation). External investment in this low technology solution has the potential to kick start development and could complement other interventions such as better crop varieties and improved economic instruments to support farmers

    Trends in fall-related hospital admissions in older persons in the Netherlands

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    Background: Fall-related injuries, hospitalizations, and mortality among older persons represent a major public health problem. Owing to aging societies worldwide, a major impact on fall-related health care demand can be expected. We determined time trends in numbers and incidence of fall-related hospital admissions and in admission duration in older adults. Methods: Secular trend analysis of fall-related hospital admissions in the older Dutch population from 1981 through 2008, using the National Hospital Discharge Registry. All fall-related hospital admissions in persons 65 years or older were extracted from this database. Outcome measures were the numbers, and the age-specific and age-adjusted incidence rates (per 10 000 persons) of fall-related hospital admissions in each year of the study. Results: From 1981 through 2008, fall-related hospital admissions increased by 137%. The annual age-adjusted incidence growth was 1.3% for men vs 0.7% for women (P75 years). Although the incidence of fall-related hospital admissions increased, the total number of fall-related hospital days was reduced by 20% owing to a reduction in admission duration. Conclusions: In the Netherlands, numbers of fall-related hospital admissions among older persons increased drastically from 1981 through 2008. The increasing fall-related health care demand has been compensated for by a reduced admission duration. These figures demonstrate the need for implementation of falls prevention programs to control for increases of fall-related health care consumption

    Sorptionā€“desorption of flucarbazone and propoxycarbazone and their benzenesulfonamide and triazolinone metabolites in two soils

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    5 pages, 3 figures, 1 table, 17 references.Sorptionā€“desorption interactions of pesticides with soil determine the availability of pesticides in soil for transport, plant uptake and microbial degradation. These interactions are affected by the physical and chemical properties of the pesticide and soil and, for some pesticides, their residence time in the soil. While sorptionā€“desorption of many herbicides has been characterised, very little work in this area has been done on herbicide metabolites. The objective of this study was to characterise sorptionā€“desorption of two sulfonylaminocarbonyltriazolinone herbicides, flucarbazone and propoxycarbazone, and their benzenesulfonamide and triazolinone metabolites in two soils with different physical and chemical properties. Kf values for all four chemicals were greater in clay loam soil, which had higher organic carbon and clay contents than loamy sand. Kfāˆ’oc ranged from 29 to 119 for the herbicides and from 42 to 84 for the metabolites. Desorption was hysteretic in every case. Lower desorption in themore sorptive system might indicate that hysteresis can be attributed to irreversible binding of the molecules to soil surfaces. These data show the importance of characterisation of both sorption and desorption of herbicide residues in soil, particularly in the case of prediction of herbicide residue transport. In this case, potential transport of sulfonylaminocarbonyltriazolinone herbicidemetabolites would be overpredicted if parent chemical soil sorption values were used to predict transport.Peer reviewe
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