Does the phenomenon of Open Educational Resources lead to new didactic model? “It depends”

Didderen, W., & Verjans, S. (2012). Does the phenomenon of Open Educational Resources lead to new didactic model? “It depends”. In R. Jacobi, & N. van der Woert (Eds.), Trend Report Open Educational Resources 2012 (pp. 9-15). Utrecht: SURF Foundation - Special Interest Group Open Educational Resources. Retrieved from https://www.surfspace.nl/artikel/697-trendrapport-open-educational-resources/.This contribution starts with the question of whether there is a direct relationship between OER and didactics. Is there such a thing as “OER didactics”? In the same way as a decade ago the usefulness and need for specific digital didactics were questioned, one can also raise questions regarding specific didactics for OER. Simons (2003) defined digital didactics as “knowledge and expertise regarding the use of ICT to facilitate learning”. A parallel definition of OER didactics would therefore be: “knowledge and expertise regarding the use of OER to facilitate learning”. More generally, one might define specific didactic models as “knowledge and expertise regarding the use of X to facilitate learning”, with X then being replaced by specific tools or technologies, for example online video, virtual worlds, or serious games. The question is then: Is it in fact valuable to think of specific didactic theories, models, or practices specifically for Open Educational Resources? Are OER didactics a specific discipline within digital didactics, or within didactics in general?SURF Foundatio

Leidt het fenomeen Open Educational Resources tot nieuwe didactische modellen? “It depends"

Didderen, W., & Verjans, S. (2012). Leidt het fenomeen Open Educational Resources tot nieuwe didactische modellen? “It depends”. In R. Jacobi, & N. van der Woert (Eds.), Trendrapport Open Educational Resources 2012 (pp. 9-15). Utrecht: SURF Foundation - Special Interest Group Open Educational Resources. Retrieved from https://www.surfspace.nl/artikel/697-trendrapport-open-educational-resources/.Deze bijdrage start vanuit de vraag of er een directe relatie is tussen OER en didactiek. Bestaat er zoiets als een ‘OER-didactiek’? Net zoals een tiental jaren geleden vragen gesteld werden bij het bestaansrecht en de noodzaak van een specifieke digitale didactiek2, kan men dezelfde vragen stellen bij een specifieke OER-didactiek. Simons (2003) definieerde digitale didactiek als “de kennis en kunde met betrekking tot het gebruik van ICT bij het faciliteren van het leren”. Een gelijklopende definitie van OER-didactiek zou dan zijn: de kennis en kunde met betrekking tot het gebruik van OER bij het faciliteren van het leren. Meer in het algemeen zou je specifieke didactische modellen dus kunnen definiëren als “de kennis en kunde met betrekking tot het gebruik van X bij het faciliteren van het leren", waarbij je X dan kan vervangen door specifieke instrumenten of technologieën, zoals online video, virtuele werelden of serious games. De vraag is dan: heeft het denken over specifieke didactische theorieën, modellen of praktijken toegespitst op Open Educational Resources een meerwaarde? Is OER-didactiek een specifieke tak van sport binnen de digitale didactiek, of binnen de didactiek in het algemeen?SURF Foundatio

Effects of metamitron under different relative humidity conditions on the fruit abscission of Malus domestica Borkh. cultivars

Metamitron is an apple (Malus domestica Borkh.) fruit thinner that acts by reducing the photosynthetic capacityof trees. Relativehumiditymayinfluence thinningefficacy; however, thebroadness of this effect is not yet fully understood. Trials were set in Sint-Truiden (Belgium) in 2018 and Lleida and Girona (Spain) in 2019, using 4-year-old cvs. Braeburn and Elstar trees in Belgium, and 16-year-old cv. GoldenReinders trees in Spain. Four treatmentswere implemented at the stage of 12–14mmfruit diameter: (a) CTR—control, trees under natural environmental conditions; (b) HH—high humidity, trees submitted to artificially increased air relative humidity applied for 3 h prior to the beginning of the experiment; (c)MET—trees sprayedwith 247.5mg/Lmetamitron; (d)MET + HH—trees submitted to the combination of increased humidity (HH) and metamitron (MET) application. In Belgium, metamitron absorption by leaves was greater than in Spain. This might be related to morphological characteristics of the leaves which developed under greater natural relative humidity levels in Belgium than in Spain. Compared to MET alone, ‘Braeburn’ and ‘Elstar’ demonstrated significantly greater metamitron absorption, 59% and 84%, respectively, underMET + HH, accompanied by declines in leaf net photosynthesis (10% and 32%, respectively) and sucrose (31% and 26%, respectively). At harvest,MET + HH treatment reduced yield by 24% and 32% in ‘Braeburn’ and ‘Elstar’, respectively, when compared withMET alone. A large reduction (considered over thinning) in the yield of ‘Elstar’ occurred. In contrast,metamitron absorption by ‘Golden Reinders’ usingMET alone was similar toMET + HH; however, there was a slight foliar sugar reduction in the latter treatment. In addition, both treatments enhanced shoot growth and increased fruit abscission with similar improvements in fruit weight and size. In this study, high relative humidity enhanced fruit thinning efficacy under certain circumstances, such as age or genetic predisposal, which left the tree more susceptible to a negative carbohydrate balance. For instance, ‘Braeburn’ and ‘Elstar’ were easier to thin when compared to ‘Golden Reinders’. In addition, this study raises a question that requires further research regarding the impact of HH before and after spraying as well as its effect in combination with higher temperaturesinfo:eu-repo/semantics/publishedVersio

Biebkracht: kenniscreatie in een professionele leeromgeving

Bitter-Rijpkema, M., Manche, A., Didderen, W., Meuleman, I., Verjans, S., Pannekeet, K., & Slot, W. (2011). Biebkracht: kenniscreatie in een professionele leeromgeving. OnderwijsInnovatie, 13(3), 17-24.De Samenwerkende Gelderse Bibliotheken hebben in 2010 Biebkracht.nl gelanceerd als 'e-kennisknooppunt van het Gelders Bibliotheeknetwerk'. Met Biebkracht is een kiem gelegd voor een virtueel kennisnetwerk ter ondersteuning van de professionals in de openbare bibliotheekbranche. Recente inzichten uit het onderzoeksprogramma Learning networks for professionals van CELSTEC van de Open Universiteit vormen mede basis voor het Biebkrachtconcept. In dit artikel een schets van de achtergronden van Biebkracht en een analyse van de eerste ervaringen van gebruikers.Samenwerkende Gelderse Bibliotheken, Biblioservice Gelderland

Metamitron and Shade Effects on Leaf Physiology and Thinning Efficacy of Malus × domestica Borkh

Thinning strategies, namely shade or photosynthetic inhibitors, rely on the reduction of carbon supply to the fruit below the demand, causing fruit abscission. In order to clarify the subject, seven field trials were carried out in Lleida, Girona, and Sint-Truiden (2017 + 2018), using orchards of ‘Golden’ and ‘Gala’ apple trees. At the stage of 9–14-mm fruit diameter, four treatments were implemented: (A) CTR-control, trees under natural environmental conditions; (B) SN-shaded trees, trees above which shading nets reducing 50% of irradiance were installed 24 h after metamitron application date—without application of metamitron—and removed after five days; (C) MET-trees sprayed with 247.5 ppm of metamitron; (D) MET + SN-trees submitted to the combined exposure to metamitron application and shading nets. Low radiation significantly increased metamitron absorption (36–53% in the three locations in 2018) and reduced its degradation. Net photosynthesis and stomatal conductance were strongly reduced in all treatments, with minimum values 2 days after spraying (DAS) and incomplete recovery 10 DAS in MET + SN. All treatments resulted in leaf sucrose and sorbitol decreases, leading to a negative carbon balance. SN and MET + SN promoted the highest thinning efficacy, increasing fruit weight and size, with MET + SN causing over-thinning in some trials. Leaf antioxidant enzymes showed moderate changes in activity increases under MET or MET + SN, accompanied by a rise of glutathione content and a reduction in ascorbate, however without lipid peroxidation. This work shows that environmental conditions, such as cloudy days, must be carefully considered upon metamitron application, since the low irradiance enhances metamitron efficacy and may cause over-thinninginfo:eu-repo/semantics/publishedVersio

Biebkracht: kenniscreatie in een professionele leeromgeving

De Samenwerkende Gelderse Bibliotheken hebben in 2010 Biebkracht.nl gelanceerd als 'e-kennisknooppunt van het Gelders Bibliotheeknetwerk'. Met Biebkracht is een kiem gelegd voor een virtueel kennisnetwerk ter ondersteuning van de professionals in de openbare bibliotheekbranche. Recente inzichten uit het onderzoeksprogramma Learning networks for professionals van CELSTEC van de Open Universiteit vormen mede basis voor het Biebkrachtconcept. In dit artikel een schets van de achtergronden van Biebkracht en een analyse van de eerste ervaringen van gebruikers

Multitemporal Chlorophyll Mapping in Pome Fruit Orchards from Remotely Piloted Aircraft Systems

Early and precise spatio-temporal monitoring of tree vitality is key for steering management decisions in pome fruit orchards. Spaceborne remote sensing instruments face a tradeoff between spatial and spectral resolution, while manned aircraft sensor-platform systems are very expensive. In order to address the shortcomings of these platforms, this study investigates the potential of Remotely Piloted Aircraft Systems (RPAS) to facilitate rapid, low cost, and flexible chlorophyll monitoring. Due to the complexity of orchard scenery a robust chlorophyll retrieval model on RPAS level has not yet been developed. In this study, specific focus therefore lies on evaluating the sensitivity of retrieval models to confounding factors. For this study, multispectral and hyperspectral imagery was collected over pome fruit orchards. Sensitivities of both univariate and multivariate retrieval models were demonstrated under different species, phenology, shade, and illumination scenes. Results illustrate that multivariate models have a significantly higher accuracy than univariate models as the former provide accuracies for the canopy chlorophyll content retrieval of R2 = 0.80 and Relative Root Mean Square Error (RRMSE) = 12% for the hyperspectral sensor. Random forest regression on multispectral imagery (R2 > 0.9 for May, June, July, and August, and R2 = 0.5 for October) and hyperspectral imagery (0.6 < R2 < 0.9) led to satisfactory high and consistent accuracies for all months.status: Published onlin

Multitemporal Chlorophyll Mapping in Pome Fruit Orchards from Remotely Piloted Aircraft Systems

Early and precise spatio-temporal monitoring of tree vitality is key for steering management decisions in pome fruit orchards. Spaceborne remote sensing instruments face a tradeoff between spatial and spectral resolution, while manned aircraft sensor-platform systems are very expensive. In order to address the shortcomings of these platforms, this study investigates the potential of Remotely Piloted Aircraft Systems (RPAS) to facilitate rapid, low cost, and flexible chlorophyll monitoring. Due to the complexity of orchard scenery a robust chlorophyll retrieval model on RPAS level has not yet been developed. In this study, specific focus therefore lies on evaluating the sensitivity of retrieval models to confounding factors. For this study, multispectral and hyperspectral imagery was collected over pome fruit orchards. Sensitivities of both univariate and multivariate retrieval models were demonstrated under different species, phenology, shade, and illumination scenes. Results illustrate that multivariate models have a significantly higher accuracy than univariate models as the former provide accuracies for the canopy chlorophyll content retrieval of R2 = 0.80 and Relative Root Mean Square Error (RRMSE) = 12% for the hyperspectral sensor. Random forest regression on multispectral imagery (R2 &gt; 0.9 for May, June, July, and August, and R2 = 0.5 for October) and hyperspectral imagery (0.6 &lt; R2 &lt; 0.9) led to satisfactory high and consistent accuracies for all months