126 research outputs found

    Sustainable organic plant breeding: Final report - a vision, choices, consequences and steps

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    In general, the characteristics of organic varieties - and by extension of organic plant breeding - differ from that of conventional breeding systems and conventional varieties. Realising an organic plant breeding system and subsequently steering it to meet changing demands is no less than a mammoth task. The many actions to be undertaken can be divided into short-term commercial and scientific activities, and longer or long-term commercial and scientific activities. Action must be taken in the short-term to ensure adequate quantities of organically propagated plants and seed. This is vital in consideration of Regulation 2092/91/EC which states that, as of 1 January 2000, all propagating material used in organic production must be of organic origin. Additional measures are needed to accelerate the development of organically propagated varieties. Within the breeding sector, variety groups should be established to streamline communication in the chain. Variety groups should have a large contingent of farmers, as well as representatives from the trade branch and breeders. Members should communicate intensively with each other, share experiences, and participate in trials and variety assessments. Questions, wishes and bottlenecks could be recorded by variety groups and passed on to other parties in the chain. The practical details of the plant health concept which is at the basis of organic breeding must be worked out (operationalised). This will require scientific research, for example on: root development and mineral absorption efficiency weed suppressive capacity in situ versus ex situ maintenance resistance breeding in combination with cultivation measures seed-transmitted diseases adaptive capacity alternatives for growth stimulants, silver nitrate and silver thiosulfate in the cultivation of cucumbers and pickles Such research should be carried out by academic institutions (such as Wageningen University and Research Centre) in collaboration with Louis Bolk Institute, Stichting Zaadgoed and private companies. A platform should be established to make an inventory of problems and priorities and to develop research proposals. Farmers could contribute their ideas to the platform through the variety groups. Conclusion A plant breeding system for organic production should be based on the organic concept of plant health and on the organic position on chain relationships. As the total land area under organic production is still relatively small, it is unlikely that commercial breeders will make large investments to develop organic breeding programmes without financial support from other parties, i.e. the government. In this early stage, it is vital that the government provides generous funding and plays an active enabling role. We hope that the action plan to stimulate organic plant breeding, as requested by Parliament, will dovetail with the activities described above

    Development of a smart grid simulation environment

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    With the increased integration of renewable energy sources the interaction between energy producers and consumers has become a bi-directional exchange. Therefore, the electrical grid must be adapted into a smart grid which effectively regulates this two-way interaction. With the aid of simulation, stakeholders can obtain information on how to properly develop and control the smart grid.\ud In this paper, we present the development of an integrated smart grid simulation model, using the Anylogic simulation environment. Among the elements which are included in the simulation model are houses connected to a renewable energy source, and batteries as storage devices. With the use of the these elements a neighbourhood model can be constructed and simulated under multiple scenarios and configurations. The developed simulation environment provides users better insight into the effects of running different configurations in their houses as well as allow developers to study the inter-exchange of energy between elements in a smart city on multiple levels

    Over visies en nieuwe wegen: Casestudies van organisatievormen in de biologische veredeling en zaadproductie

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    Onderscheid tussen het biologisch dynamisch circuit en het biologisch klassieke circuit. Het begrip circuit is gebruikt om de samenhang van de initiatieven te verduidelijken. We komen tot de conclusie dat de sociale organisatie van veredelingsactiviteiten, de toegepaste en afgewezen technologieën, en de financiële en juridische constructies samenhang vertonen. De samenhang is voor de twee circuits verschillend. Dit verschil hangt samen met verschil in visies van veredelaars, zaaizaadproducenten en financiers binnen de initiatieven en de daaruitvolgende keuzes ten aanzien van de financiering en toe te passen technologieën

    An Electrochemical Study on the Cathode of the Intermediate Temperature Tubular Sodium-Sulfur (NaS) Battery

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    The development of low-cost energy storage schemes is imminent in light of the ever-growing demand of electricity. Sodium-sulfur (NaS) batteries offer low-cost technology for energy storage applications due to the intrinsically high capacities of elemental sodium and sulfur as well as their abundant resources. Operating this battery technology on the intermediate range (130-200 degrees C) can lead to lower material costs, mitigate thermal management and safety issues and enhance cycle life. Herein, an electrochemical study on the cathode of the IT NaS cell is performed at 150 degrees C and a concentration range of 1.5 to 3 M sodium pentasulfide dissolved in tetraglyme, showing a robust long term performance (42 days of continuous cycling) with a volumetric energy density of 83 Wh L-1. Most importantly, the cell was eligible for a tenfold volume scale-up considerably enhancing its capacity (790 mAh) but in the same time somewhat hindered by mass transport, especially during the end of the discharge process as manifested by electrochemical impedance spectroscopy.</p

    The views of health care professionals about selective decontamination of the digestive tract: An international, theoretically informed interview study

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    Purpose: Selective Decontamination of the Digestive tract (SDD) as a prophylactic intervention improves hospital-acquired infection and survival rates. Uptake of SDD is low and remains controversial. This study applied the Theoretical Domains Framework (TDF) to assess ICU clinicians’ views about SDD in regions with limited or no adoption of SDD. Materials and Methods: Participants were health professionals with ‘decisional authority’ for the adoption of SDD. Semistructured interviews were conducted as the first round of a Delphi study. Views about SDDadoption, delivery and further SDD research were explored. Directed content analysis of interview data identified sub-themes which informed item development for subsequent Delphi rounds. Linguistic features of interview data were also explored. Results: 141 participants provided interview data. Fifty-six sub-themes were identified; 46 were common across regions. Beliefs about consequences was the most widely elaborated theme. Linguistic features of how participants discussed SDD included caution expressed when discussing the risks and benefits and words such as worry, anxiety and fear when discussing potential antibiotic resistance associated with SDD. Conclusions: We identified salient beliefs, barriers and facilitators to SDD adoption and delivery. What participants said about SDD and the way in which they said it demonstrated the degree of clinical caution, uncertainty and concern that SDD evokes
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