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Supplemental Digital Content is available in the text., Background and Purpose— Due to chronic hypoperfusion, cervical atherosclerosis may promote cerebral collateral circulation. We hypothesized that patients with ischemic stroke due to cervical carotid atherosclerosis have a more extensive collateral circulation and better outcomes than patients with cardioembolism. We tested this hypothesis in a population of patients who underwent endovascular treatment for large vessel occlusion. Methods— From the MR-CLEAN Registry (Multicenter Randomized Controlled Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands), we selected consecutive adult endovascular treatment patients (March 2014 to June 2016) with acute ischemic stroke due to anterior circulation large vessel occlusion and compared patients with cervical carotid artery stenosis >50% to those with cardioembolic etiology. The primary outcome was collateral score, graded on a 4-point scale. Secondary outcomes included the modified Rankin Scale (mRS) score and mortality at 90 days. We performed multivariable regression analyses and adjusted for potential confounders. Results— Of 1627 patients in the Registry, 190 patients with cervical carotid atherosclerosis and 476 with cardioembolism were included. Patients with cervical carotid atherosclerosis were younger (median 69 versus 76 years, P

Background and Purpose— Endovascular treatment (EVT) of patients with acute ischemic stroke because of large vessel occlusion involves complicated logistics, which may cause a delay in treatment initiation during off-hours. This might lead to a worse functional outcome. We compared workflow intervals between endovascular treatment–treated patients presenting during off- and on-hours. Methods— We retrospectively analyzed data from the MR CLEAN Registry, a prospective, multicenter, observational study in the Netherlands and included patients with an anterior circulation large vessel occlusion who presented between March 2014 and June 2016. Off-hours were defined as presentation on Monday to Friday between 17:00 and 08:00 hours, weekends (Friday 17:00 to Monday 8:00) and national holidays. Primary end point was first door to groin time. Secondary end points were functional outcome at 90 days (modified Rankin Scale) and workflow time intervals. We stratified for transfer status, adjusted for prognostic factors, and used linear and ordinal regression models. Results— We included 1488 patients of which 936 (62.9%) presented during off-hours. Median first door to groin time was 140 minutes (95% CI, 110–182) during off-hours and 121 minutes (95% CI, 85–157) during on-hours. Adjusted first door to groin time was 14.6 minutes (95% CI, 9.3–20.0) longer during off-hours. Door to needle times for intravenous therapy were slightly longer (3.5 minutes, 95% CI, 0.7–6.3) during off-hours. Groin puncture to reperfusion times did not differ between groups. For transferred patients, the delay within the intervention center was 5.0 minutes (95% CI, 0.5–9.6) longer. There was no significant difference in functional outcome between patients presenting during off- and on-hours (adjusted odds ratio, 0.92; 95% CI, 0.74–1.14). Reperfusion rates and complication rates were similar. Conclusions— Presentation during off-hours is associated with a slight delay in start of endovascular treatment in patients with acute ischemic stroke. This treatment delay did not translate into worse functional outcome or increased complication rates.

BackgroundCollateral status modified the effect of endovascular treatment (EVT) for stroke in several randomized trials. We assessed the association between collaterals and functional outcome in EVT treated patients and investigated if this association is time dependent.MethodsWe included consecutive patients from the Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in The Netherlands (MR CLEAN) Registry (March 2014–June 2016) with an anterior circulation large vessel occlusion undergoing EVT. Functional outcome was measured on the modified Rankin Scale (mRS) at 90 days. We investigated the association between collaterals and mRS in the MR CLEAN Registry with ordinal logistic regression and if this association was time dependent with an interaction term. Additionally, we determined modification of EVT effect by collaterals compared with MR CLEAN controls, and also investigated if this was time dependent with multiplicative interaction terms.Results1412 patients were analyzed. Functional independence (mRS score of 0–2) was achieved in 13% of patients with grade 0 collaterals, in 27% with grade 1, in 46% with grade 2, and in 53% with grade 3. Collaterals were significantly associated with mRS (adjusted common OR 1.5 (95% CI 1.4 to 1.7)) and significantly modified EVT benefit (P=0.04). None of the effects were time dependent. Better collaterals corresponded to lower mortality (PConclusionIn routine clinical practice, better collateral status is associated with better functional outcome and greater treatment benefit in EVT treated acute ischemic stroke patients, independent of time to treatment. Within the 6 hour time window, a substantial proportion of patients with absent and poor collaterals can still achieve functional independence.

Supplemental Digital Content is available in the text., Background and Purpose— Intravenous administration of heparin during endovascular treatment for ischemic stroke may improve outcomes. However, risks and benefits of this adjunctive therapy remain uncertain. We aimed to evaluate periprocedural intravenous heparin use in Dutch stroke intervention centers and to assess its efficacy and safety. Methods— Patients registered between March 2014 and June 2016 in the MR CLEAN Registry (Multicenter Randomized Clinical Trial of Endovascular Treatment of Acute Ischemic Stroke), including all patients treated with endovascular treatment in the Netherlands, were analyzed. The primary outcome was functional outcome (modified Rankin Scale) at 90 days. Secondary outcomes were successful recanalization (extended Thrombolysis in Cerebral Infarction ≥2B), symptomatic intracranial hemorrhage, and mortality at 90 days. We used multilevel regression analysis to evaluate the association of periprocedural intravenous heparin on outcomes, adjusted for center effects and prognostic factors. To account for possible unobserved confounding by indication, we analyzed the effect of center preference to administer intravenous heparin, defined as percentage of patients treated with intravenous heparin in a center, on functional outcome. Results— One thousand four hundred eighty-eight patients from 16 centers were analyzed, of whom 398 (27%) received intravenous heparin (median dose 5000 international units). There was substantial between-center variability in the proportion of patients treated with intravenous heparin (range, 0%–94%). There was no significant difference in functional outcome between patients treated with intravenous heparin and those without (adjusted common odds ratio, 1.17; 95% CI, 0.87–1.56), successful recanalization (adjusted odds ratio, 1.24; 95% CI, 0.89–1.71), symptomatic intracranial hemorrhage (adjusted odds ratio, 1.13; 95% CI, 0.65–1.99), or mortality (adjusted odds ratio, 0.95; 95% CI, 0.66–1.38). Analysis at center level showed that functional outcomes were better in centers with higher percentages of heparin administration (adjusted common odds ratio, 1.07 per 10% more heparin, 95% CI, 1.01–1.13). Conclusions— Substantial between-center variability exists in periprocedural intravenous heparin use during endovascular treatment, but the treatment is safe. Centers using heparin more often had better outcomes. A randomized trial is needed to further study these effects.

Background It is unclear whether intravenous thrombolysis ( IVT ) with alteplase before endovascular treatment ( EVT ) is beneficial for patients with acute ischemic stroke caused by a large vessel occlusion. We compared clinical and procedural outcomes, safety, and workflow between patients treated with both IVT and EVT and those treated with EVT alone in routine clinical practice. Methods and Results Using multivariable regression, we evaluated the association of IVT + EVT with 90‐day functional outcome (modified Rankin Scale), mortality, reperfusion, first‐pass effect, and symptomatic intracranial hemorrhage in the MR CLEAN (Multicenter Randomised Controlled Trial of Endovascular Treatment for Acute Ischemic Stroke in The Netherlands) Registry. Of 1485 patients, 1161 (78%) were treated with IVT + EVT , and 324 (22%) with EVT alone. Patients treated with IVT + EVT had atrial fibrillation less often (16% versus 44%) and had better pre‐stroke modified Rankin Scale scores (pre‐stroke modified Rankin Scale 0: 73% versus 52%) than those treated with EVT alone. Procedure time was shorter in the IVT + EVT group (median 62 versus 68 minutes). Nontransferred IVT + EVT patients had longer door‐to‐groin‐puncture times (median 105 versus 94 minutes). IVT + EVT was associated with better functional outcome (adjusted common odds ratio 1.47; 95% CI : 1.10–1.96) and lower mortality (adjusted odds ratio 0.58; 95% CI : 0.40–0.82). Successful reperfusion, first‐pass effect, and symptomatic intracranial hemorrhage did not differ between groups. Conclusions In this observational study, patients treated with IVT + EVT had better clinical outcomes than patients who received EVT alone. This finding may demonstrate a true benefit of IVT before EVT , but its interpretation is hampered by the possibility of residual confounding and selection bias. Randomized trials are required to properly assess the effect of IVT before EVT .

Goal: Insufficient data is available about safety and efficacy of endovascular treatment (EVT) in patients with minor stroke symptoms because these patients were excluded from most randomized trials. We aimed to compare characteristics, functional outcome, and complications in patients with minor ischemic stroke National Institutes of Health Stroke Scale score ≤5 (NIHSS score ≤5) and moderate to severe ischemic stroke (NIHSS score ≥6) due to intracranial proximal artery occlusion of the anterior circulation who underwent EVT. Materials and Methods: We report patients with an anterior circulation occlusion who were included between March 2014 and June 2016 in the multicenter randomized clinical trial of EVT of acute ischemic stroke in the Netherlands Registry, a prospective, multicenter, observational study for stroke centers that perform EVT in the Netherlands. Minor ischemic stroke was defined as baseline NIHSS score of 5 or less. Primary outcome is the modified Rankin Scale (mRS) score at 90 days. Secondary outcomes include symptomatic intracranial hemorrhage (sICH) and mortality. Findings: Seventy-one (5.5%) patients had a NIHSS score of 5 or less. Functional independence (mRS 0-2 at 90 days) was reached in 75% of these patients, compared to 40% of patients with NIHSS score of 6 or more. sICH occurred in 4% of patients, of which 1% occurred peri-interventionally. Death occurred in 6% of patients. Conclusions: Patients with minor ischemic stroke with an intracranial proximal arterial occlusion of the anterior circulation who underwent EVT have a high chance of favorable outcome and appear to have low occurrence of treatment-related sICH. Therefore, our results encourage the use of EVT for minor ischemic stroke in the absence of effect estimates from controlled studies.

Introduction: Carotid artery dissection (CAD) and atherosclerotic carotid artery occlusion (ACAO) are major causes of a tandem occlusion in patients with intracranial large vessel occlusion (LVO). Presence of tandem occlusions may hamper intracranial access and potentially increases the risk of procedural complications of endovascular treatment (EVT). Our aim was to assess neurological, functional and technical outcome and complications of EVT for intracranial LVO in patients with CAD in comparison to patients with ACAO and to patients without CAD or ACAO.Methods: We analyzed data of the MR CLEAN trial intervention arm and MR CLEAN Registry, acquired in 16 Dutch EVT-centers. Primary outcome was the change in stroke severity by comparing the National Institute of Health Stroke Scale (NIHSS) score at 24-48 h after treatment vs. baseline. Secondary outcomes included reperfusion rate and symptomatic intracranial hemorrhage (sICH). We compared outcomes and complications between patients with CAD vs. patients with ACAO and patients without CAD or ACAO.Results: In total, we identified 74 (4.7%) patients with CAD, 92 (5.9%) patients with ACAO and 1398 (89.4%) patients without CAD or ACAO. Neurological improvement at short-term after EVT in patients with CAD was significantly better compared to ACAO (raw mean -5 vs. mean -1 NIHSS point; p = 0.03) and did not differ compared to patients without CAD or ACAO (-4 NIHSS points; p = 0.62). Rates of successful reperfusion in patients with CAD (47%) was comparable to patients with ACAO (47%; p = 1.00), but was less often achieved compared to patients without CAD or ACAO (58%; p = 0.08). Occurrence of sICH did not differ significantly between CAD patients (5%) and ACAO (11%; p = 0.33) or without CAD/ACAO (6%; p = 1.00).Conclusion: EVT in patients with intracranial LVO due to CAD results in neurological improvement comparable to patients without tandem occlusions. Therefore, carotid artery dissection by itself should not be a contraindication for endovascular treatment in stroke patients with intracranial large vessel occlusion. Although more challenging endovascular procedures are to be suspected in both patients with CAD or ACAO, accurate distinction between CAD and ACAO might influence clinical decision making as better clinical outcome can be expected in patients with CAD.

Als door het gebruik van gewasbeschermingsmiddelen in kassen restanten van deze middelen in het nabijgelegen oppervlaktewater terechtkomen, kan dat het waterleven aantasten. Hiermee wordt te weinig rekening gehouden bij de huidige risicobeoordeling van het gebruik van een gewasbeschermingsmiddel voor gewassen die in kassen op substraat, bijvoorbeeld steenwol, worden geteeld. Daarom zijn voor deze toepassingen nieuwe methoden voor de risicobeoordeling ontwikkeld waarin dat wel is ingecalculeerd. Bij de meeste substraatteelten wordt water zoveel mogelijk opnieuw gebruikt. Gedurende dit proces neemt de concentratie van zouten en andere stoffen toe, waardoor zo nu en dan 'vervuild' water moet worden geloosd en vers water moet worden toegevoegd. Ook moeten filters worden schoongespoeld. De nieuwe methoden omvatten scenario's voor vier groepen gewassen (vertegenwoordigd door roos, ficus, tomaat en paprika) waarmee de lozingen en resulterende concentraties in oppervlaktewater door het jaar heen kunnen worden berekend. De indeling in de gewasgroepen is gemaakt op basis van de mate waarin gewassen behoefte aan water hebben en zout verdragen. De mate waarin restanten van gewasbeschermingsmiddelen in het oppervlaktewater komen is onder andere afhankelijk van het teeltsysteem, de wijze van toediening van het gewasbeschermingsmiddel, de mate waarin planten het middel opnemen en de snelheid waarmee het middel in water wordt afgebroken. De methoden zijn ontwikkeld door het RIVM, de onderzoeksinstituten Alterra en Wageningen UR Glastuinbouw en het College voor de toelating van gewasbeschermingsmiddelen en biociden (Ctgb).

Een aantal recente, grote en spraakmakende investeringen geven blijk van het groeiend vertrouwen in de teelt op water. De bedrijven Van Dijck Groenteproducties, De Kruidenaer, Van der Staay-groep, GrowX en eerder al Delicious en Boer/Den Hoedt realiseren grote faciliteiten voor de teelt van kruiden en bladgewassen in gootjes of vijvers, in kassen of als afgesloten meerlagenteelt. Nog niet lang geleden was de stemming een stuk voorzichtiger.

In order to explore the possibilities of a local food system and its effects on the nutrient cycle, a desk study was executed for the urban region Almere, a Dutch city located in the Flevo Polder with about 200,000 inhabitants. This desk study takes this urban perspective as starting point in the search of measures to maintain future food productivity whilst decreasing the demand (and dependence) of external resources. The study focussed on phosphorus (P) as this element is essential for food and feed production while the resources are finite and, it is technically feasible to recover it from the urban waste flows. Three scenarios were distinguished each different in the extent to which the food is produced locally. The first scenario, “Current”, refers to the current situation in which only a small part of the food, estimated at 5% for all food products, is produced and processed locally. In this scenario the reuse from waste is limited and occurs via compost (e.g. kitchen waste) and digestate. In the second scenario, “Hybrid”, the food is as far as possible produced locally except for products that cannot be grown locally (e.g. coffee, tea, exotic fruits). Also a part of the animal feed ingredients (e.g. soybean meal) are still imported. Within the Hybrid scenario two sub-scenarios are distinguished: (a) with a limited P reuse, only via compost/digestate (as in scenario Current) and (b) with a maximal (up to 90%) recovery of P from waste. Finally, in the third scenario, “Self-Sufficient”, all feed ingredients are also grown locally. Only food products that cannot be grown locally are still imported. P recycling from waste is maximal (90%).

Aquaponics combines aquaculture and hydroponic practices. It is a young new agricultural industry, which depends less on primary energy and material inputs than conventional production systems. Potentially, aquaponic systems have a key role to play in food provision. Furthermore, aquaponics tackles challenges such as land, nutrient and water scarcity and reductions in energy use and food miles. Its controlled growing conditions and the expired use of chemicals and pesticides make this technology a promising one. Besides its ecological merits, aquaponic systems save costs on water treatment and fertilizers and benefit from double outputs (fish and crops). Economic viability, however, requires well-defined business models aimed at positioning aquaponic systems in a specific market niche. Given the different price and quality levels of fresh produce globally, aquaponic systems can be more or less successful as a means for (local) fresh food production. This study looks at one of the most challenging situations for positioning a new growing system: the Dutch food industry with its large-scale horticulture, its multiple fishing harbours and agricultural activities and its highly efficient cooled supply chain We address the economic viability of aquaponic systems and describe possible socio-economic scenarios. As compared to rural and peri-urban scenarios, it can be concluded that, under the current Dutch market conditions, the urban scenario seems to be the most promising business concept, producing locally, fresh food, relying on premium prices.

Soilless cultivation suggests a closed system of water flows, the principal of which are (drip) irrigation evaporation and - in more high-tech systems -condensation water. However, in practice growers discharge water during the process of filter cleaning and also actively discharge water due to high levels of sodium or contamination with chemical or biological components. On average in the Dutch greenhouse situation 2-5% of the annual irrigated water is discharged annually. These discharges lead to pollution of surface water with nutrients as well as (residues of) plant protection products (PPPs). This awareness led in 2008 to the start of a working group that aimed to develop a risk evaluation tool for pesticide authorisation in Europe. The evaluation tool consists of a modelled approach for determining expected concentrations in surface water based on a reference scenario per crop i.e., a description of an actual situation including the technical layout of the glasshouse, the climatological year and the receiving ditch For two currently registered PPPs that are used in spray applications, the annual emission to surface water was calculated using different scenarios. As scenarios, substrate-based rose production and pot plant production were selected in combination with water sources of variable sodium concentrations that commonly occur and are used in The Netherlands. Sodium was found to be the only quantifiable argument for growers for active discharge, and therefore it was used as a leading principle for discharge in the water flow model. Water discharge was found to range from 80 to 700 m3 ha 1 year-1, leading to nitrogen emissions of 17 to 149 kg N ha∗ year-1. The emission of PPPs in these scenarios amounted to 0.02-3% of the total active substance that was applied.

Hydroponic production systems are challenged by root diseases, but can be made less susceptible to infection. While the systems are mostly unchallenged by nematodes, pathogens that can live and spread though water still cause loss of yield. Common diseases would be Phytophthora, Pythium, Fusarium and bacteria such as Erwinias and Pseudomonads. Since horticulture cannot be performed in a sterile environment on a commercial scale, insight in population dynamics of pathogens in aquatic systems as well as plants' resilience need to be understood to lower the risk of infection. This paper addresses a number of biological principles in aquatic ecology that could be used in improving system design processes as well as providing the first data on the population dynamics in chrysanthemum production on deep flow systems in The Netherlands using next generation sequencing (NGS). It was observed that free colonisation of the water leads to highly diverse bacterial populations, while inoculation with water from an established deep flow pond leads to more uniform populations in the long run. Temperature can strongly influence bacterial populations. Addition of benefical micro-organisms leads to increase plant resilience against diseases. It is yet unclear whether such reduced infection is due to direct antagonistic effect, through a plant-endophyte symbiotic relationship or through competition for nutrients (sugars) or physical space. Fungal populations could not be studied since the similarity of DNA-database was too low to draw conclusions.

Als door het gebruik van gewasbeschermingsmiddelen in kassen restanten van deze middelen in het nabijgelegen oppervlaktewater terechtkomen, kan dat het waterleven aantasten. Hiermee wordt te weinig rekening gehouden bij de huidige risicobeoordeling van het gebruik van een gewasbeschermingsmiddel voor gewassen die in kassen op substraat, bijvoorbeeld steenwol, worden geteeld. Daarom zijn voor deze toepassingen nieuwe methoden voor de risicobeoordeling ontwikkeld waarin dat wel is ingecalculeerd.

Er is een risicobeoordeling vereist voor het gebruik van gewasbeschermingsmiddelen in kassen in het kader van de Nederlandse toelatingsprocedure van gewasbeschermingsmiddelen. Het bijbehorende beschermdoel is het aquatische ecosysteem in oppervlaktewater. Voor deze risicobeoordeling dienen de blootstellingsconcentraties in oppervlaktewater te worden bepaald. In de huidige procedure wordt de waterconcentratie berekend analoog aan de emissie van spray drift depositie. Omdat deze aanpak niet wetenschappelijk verdedigbaar is, is een aanpassing van het toegepaste blootstellingscenario nodig. In dit rapport wordt een nieuw blootstellingscenario afgeleid voor gewasbeschermingsmiddelen toegepast in grondgebonden kas-teelten. Het scenario is gebaseerd op state-of-the-art kennis van kas-teelten en de grondgebonden teeltpraktijk in het bijzonder.

This paper develops a new explanation for user satisfaction with IS. Combining insights from expectation (dis)confirmation theory (ECT) and importance-performance analysis (IPA), we focus on the gaps between the importance of particular IS attributes, and the performance of a system on those attributes, as an explanation for user satisfaction. We identify 12 relevant system attributes and theoretically argue how the gap between importance and performance with regard to these attributes may affect user satisfaction. Our empirical study is based on a survey (N=298) among student users of a newly implemented Student Information System (SIS). The results empirically support the relationship between importance-performance gaps and user satisfaction. For five out of 12 attributes, we find a significant negative influence of a negative gap (i.e., high importance, low performance) on user satisfaction. Our main contribution to the literature is that we provide an integrated perspective on ECT and IPA and empirically validate the relevance of importance-performance gaps for explaining IS user satisfaction. Our second contribution is that we make use of the difference score technique to measure the importance-performance gaps for user satisfaction. Thus, our contribution to the IS literature is both theoretical and methodological.

Het oppervlak aan substraatteelten is de laatste jaren gegroeid tot ongeveer 75% van de beteelde oppervlakte onder glas. De toelatingsbeoordeling van gewasbeschermingsmiddelen, houdt nog geen rekening met deze veranderingen in productiewijze. Dit rapport geeft aan dat daardoor onvoldoende rekening wordt gehouden met spui van recirculatiewater. Het rapport geeft een aanzet tot een aangepaste toelatingsbeoordeling voor deze systemen en beschrijft enkele modellen die hierbij kunnen worden ingezet. De huidige toelatingsbeoordeling gaat uit van een diffuse emissie van gewasbeschermingsmiddelen uit kassen naar het oppervlaktewater, vergelijkbaar met de beoordeling van drift bij spuittoepassingen in open teelten. Uit de studie blijkt dat de emissies bij substraatteelten eerder moeten worden gezien als puntbronnen, waarbij gewasbeschermingsmiddelen onbedoeld worden geloosd bij spuien van het recirculatiewater en het spoelen van filters. Uit het onderzoek blijkt dat emissies van gewasbeschermingsmiddelen in hoge mate worden beinvloed door de kwaliteit van het water dat een teler tot zijn beschikking heeft en de zouttolerantie van het gewas. Bij een voldoende groot bassin voor opvang van regenwater of een andere bron met vergelijkbare waterkwaliteit is er minder noodzaak tot spuien en kunnen emissies tot een minimum worden beperkt.

The management of projects for sustainable innovation is characterised by a variety of intricacies. Facilitators play a central role in dealing with these challenges. Adopting an empirical approach, this chapter discusses the practical approaches and attitudes that facilitators develop to deal with such challenges in the domain of agricultural innovation. To that end, the paper presents a list of four intricacies inherent in running projects that seek to enhance sustainable development, based on the literature: 1) the challenge of combining the ambition of sustainable change with the need for responsiveness in facilitating processes of joint planning and design; 2) the need to develop and use knowledge in a practice-oriented manner in an often science-oriented context; 3) the need to develop an innovative ‘niche’ within a context of vested powers; and 4) the need to reach beyond a project’s duration to ‘anchor’ the dynamics by which its ambitions may be realized in the future. Three cases of managing projects for sustainable (agricultural) innovation are described, highlighting the practical ways in which the respective facilitators in each case deal with the four identified challenges. It is found that attitudes developed by a facilitator differ per project yet that similarities can be identified. Differences can be observed mainly between approaches in facilitating projects that seek to explore the notion of sustainability in terms of guidelines for future practice, and projects that aim at developing concrete implementable designs. Within these two types of projects, facilitators are seen to be engaged in a continual balancing act between two identifiable attitudes: a responsive, serviceable attitude, through which the facilitator seeks to connect with participants and to be responsive to their needs and wishes (called a Learning approach here), and an attitude of leadership, through which the facilitator decides more or less alone on the way the process is to move forward (dubbed here a Leading approach).

Dynamic Pricing (DyP) is a form of Revenue Management in which the price of a (usually) perishable good is changed over time to increase revenue. It is an effective method that has become even more relevant and useful with the emergence of Internet firms and the possibility of readily and frequently updating prices. In this paper a new approach to DyP is presented. We design adaptive dynamic pricing strategies and optimize their parameters with an Evolutionary Algorithm (EA) offline while the strategies can deal with stochastic market dynamics quickly online. We design two adaptive heuristic dynamic pricing strategies in a duopoly where each firm has a finite inventory of a single type of good. We consider two cases, one in which the average of a customer population’s stochastic valuation for each of the goods is constant throughout the selling horizon and one in which the average customer valuation for each good is changed according to a random Brownian motion. We also design an agent-based software framework for simulating various dynamic pricing strategies in agent-based marketplaces with multiple firms in a bounded time horizon. We use an EA to optimize the parameters for each of the pricing strategies in each of the settings and compare the strategies with other strategies from the literature. We also perform sensitivity a analysis and show that the optimized strategies work well even when used in settings with varied demand functions.

As power markets become liberalised and include more intermittent generation, the trade of reserve energy will become more important. We propose a novel bidding mechanism to integrate power and reserve markets. It facilitates planning for bidding in both markets and adds expressivity to reserve bids\footnote{This work is a part of the IDeaNeD project and sponsored by Agentschap NL, a research funding agency of the dutch ministry of economic affairs, in the IOP-EMVT program. It has also been presented at the AAMAS 2011 conference.

We will demonstrate a prototype exergame aimed at the serious domain of elderly fitness. The exergame incorporates straightforward means to gesture recognition, and utilises a Kinect camera to obtain 2.5D sensory data of the human user.

Recent developments in automated sentiment analysis show a tendency of accounting for various aspects other than word frequencies. One of these aspects is negation. We compare several approaches to accounting for negation in sentiment analysis, differing in their methods of determining the scope of influence of a negation keyword. On a set of English movie review sentences, the best approach turns out to be to consider the first two words, following a negation keyword, to be negated by that keyword. Additionally, we propose to optimize the sentiment modification in case of negation to a value of –1.27 rather than –1.

Recently Semi-Supervised learning algorithms such as co-training are used in many application domains. In co-training, two classifiers based on different views of data or on different learning algorithms are trained in parallel and then unlabeled data that are classified differently by the classifiers but for which one classifier has large confidence are labeled and used as training data for the other. In this paper, a new form of co-training, called Ensemble-Co-Training, is proposed that uses an ensemble of different learning algorithms. Based on a theorem by Angluin and Laird that produces an approximately correct identification with high probability for reliable examples, we propose a criterion for finding a subset of high-confidence predictions and error rate for a classifier in each iteration of the training process. Experiments show that the new method in almost all domains gives better results than the other methods.

Estimation-of-distribution algorithms (EDAs) are optimization algorithms at the frontier of genetic- and evolutionary computation (GEC) research. Characteristic of EDAs is the iteration of selecting promising solutions, estimating a probability distribution from the selected solutions and subsequently generating new solutions by drawing samples from the estimated distribution. Probability distributions provide a principled way of modelling dependencies between problem variables. Contrary to classic GEC methods, this allows EDAs to successfully and automatically identify and exploit problem structures with respect to dependencies between problem variables. EDAs are therefore able to solve a much larger class of problems efficiently without requiring prior knowledge. In this article, we present an EDA for real-valued optimization, benchmark it within the BBOB framework and discuss our findings. The EDA is known as the AdaptedMaximum-Likelihood Gaussian Model Iterated Density-Estimation Evolutionary Algorithm (AMaLGaM-IDEA, or AMaLGaM for short). The BBOB (Black-Box Optimization Benchmarking) framework for real-valued optimization, introduced in 2009, consists of both an experimental setup and an extensive, but carefully chosen, set of functions to be optimized.

Most of the traditional recommendation algorithms are based on TF-IDF, a term-based weighting method. This paper proposes a new method for recommending news items based on the weighting of the occurrences of references to concepts, which we call Concept Frequency-Inverse Document Frequency (CFIDF). In an experimental setup we apply CF-IDF to a set of newswires in which we detect 1; 167 instances of a set of 65 concepts from a domain ontology. The proposed method yields significantly better results with respect to accuracy, recall, and F1 than the TF-IDF method we use as a basis for comparison.

Momenteel wordt een vast percentage van 0.1% gebruikt voor de emissie van gewasbeschermingsmiddelen vanuit kassen naar het oppervlaktewater. Metingsgegevens van waterschappen wijzen erop dat de emissie van gewasbeschermingsmiddelen en biociden naar het oppervlaktewater hoger zijn dan aangenomen wordt in de toelatingsprocedure. Dit rapport onderzoekt of nieuwe benaderingen nodig zijn. De onderzoeksresultaten duiden er op dat de werkelijke emissie sterk verschilt tussen verschillende gewassen, teeltsystemen en toedieningswijzen. Dit zou in de evaluatie van de emissie meegenomen moeten worden.