Kennisdelen met FLIP in de Betuwse Bloem : www.betuweflipt.nl

De Betuwse Bloem staat voor de vijf tuinbouwclusters in het Gelderse Rivierengebied. Het gaat om de paddenstoelensector in de regio Maasdriel, het laanboomcentrum in Opheusden, het fruitcluster in de regio Buren/Geldermalsen en de glastuinbouw (bloemen & planten, groenten) in de Bommelerwaard en de regio Arnhem-Nijmegen. In totaal werken er zo'n 30.000 mensen in de Betuwse tuinbouw. De Betuwse Bloem is een initiatief van ondernemers uit die vijf sectoren, dat ondersteund wordt door de provincie Gelderland en de gemeenten in het gebied, maar ook door diverse intermediaire organisaties en kennisinstellingen, zoals de Wageningen Universiteit en Researchcentrum en Radboud Universiteit Nijmegen. Door meer samenwerking willen de clusters hun gezamenlijk economische positie versterken. Innovatie speelt daarbij een sleutelrol! Om die reden is een project gestart met Transforum, dat gericht is op het toepassen van kennis in een aantal praktische businesscases. Om ervaringen uit te wisselen ontvangen betrokkenen een kleine videocamera (zogenaamde Flip) waarmee ze zelf korte filmpjes kunnen maken en op YouTube plaatsen

Occurrence and diversity of Xanthomonas campestris pv. campestris in vegetable brassica fields in Nepal

Black rot caused by Xanthomonas campestris pv. campestris was found in 28 sampled cabbage fields in five major cabbage-growing districts in Nepal in 2001 and in four cauliflower fields in two districts and a leaf mustard seed bed in 2003. Pathogenic X. campestris pv. campestris strains were obtained from 39 cabbage plants, 4 cauliflower plants, and 1 leaf mustard plant with typical lesions. Repetitive DNA polymerase chain reaction-based fingerprinting (rep-PCR) using repetitive extragenic palindromic, enterobacterial repetitive intergenic consensus, and BOX primers was used to assess the genetic diversity. Strains were also race typed using a differential series of Brassica spp. Cabbage strains belonged to five races (races 1, 4, 5, 6, and 7), with races 4, 1, and 6 the most common. All cauliflower strains were race 4 and the leaf mustard strain was race 6. A dendrogram derived from the combined rep-PCR profiles showed that the Nepalese X. campestris pv. campestris strains clustered separately from other Xanthomonas spp. and pathovars. Race 1 strains clustered together and strains of races 4, 5, and 6 were each split into at least two clusters. The presence of different races and the genetic variability of the pathogen should be considered when resistant cultivars are bred and introduced into regions in Nepal to control black rot of brassicas

In Vitro Bone Formation Associated with Apatite Coated Polylactide

Bone formation onto poly(L-lactide), which was plasma-spray coated with various quantities of hydroxyapatite (0%, 15%, 36% and 100% coverage), was investigated in an in vitro assay. Rat bone marrow cells were grown on the different coatings and the cellular response and elaborated extracellular matrix was examined at the light and electron microscopical level after 1, 2 , 4 and 8 weeks of culture. Proliferation of cells into multilayers was seen on the 0% , 36% and 100% , but not on the 15 % coatings. Coinciding with this was the sparse formation of extracellular matrix on the latter, and its abundant appearance on the former three coatings. Scanning and transmission electron microscopy revealed a mineralized extracellular matrix on the 100% and 36% coatings after 2 and 4 weeks , respectively, and on the 15 % coating after 8 weeks. Mineralization was not observed on uncoated poly(L-lactide). At the interface between hydroxyapatite and the mineralized extracellular matrix, one or more electron dense layers were frequently observed , which showed morphological similarities with structures between these two entities in vivo. The results of this in vitro study show that, in the model used, hydroxyapatite is required to obtain the elaboration of mineralized extracellular matrix on poly(L-lactide)

Influence of Crystal Structure on the Establishment of the Bone-Calcium Phosphate Interface In Vitro

An in vitro rat bone marrow cell system was used to examine the interfacial ultrastructure established between various calcium phosphates and mineralized tissue. The investigated calcium phosphates comprised hydroxyapatite (HA), fluorapatite (FA), tricalcium phosphate (TCP), tetracalcium phosphate (TECP) and magnesium whitlockite (MWL). Both scanning and transmission electron microscopy were used to examine the elaborated interface. The time in which a mineralized extracellular matrix was formed on the various materials differed from 2 weeks on HA, TCP and TECP, to 8 weeks on FA. It was only occasionally observed in some areas on MWL, which might have been due to aluminum impurities in the coating. With transmission electron microscopy, three distinct interfacial structures were observed. They differed in the presence or absence of a collagen free, 0. 7 to 0. 8 J.Lm wide, amorphous zone and a 20 to 60 nm thick electron dense layer , interposed between the material surface and the mineralized extracellular matrix. The electron dense layer was considered to be at least partially caused by protein adsorption , which would precede or concur with biological mineralization events , while the amorphous zone was regarded to represent partial degradation of the calcium phosphate surfaces. The results of this study show that plasma sprayed calcium phosphates will display different bone-bonding and biodegradation properties , depending on their chemical composition and crystal structures

Design, manufacturing and testing of a rotorcraft access panel door from recycled carbon fiber reinforced polyphenylenesulfide

An integrally-stiffened access panel for a rotorcraft is selected for detail design, testing and actual flight to demonstrate a novel recycling route for thermoplastic composites. The design, development and validation followed the ‘Building Block approach’. The used material is post-industrial carbon fiber reinforced polyphenylene sulfide waste. This material originates from thermoplastic components of the very same rotorcraft as the panel will be mounted on, improving traceability, logistics and fixing supply and demand. Material data have been gathered from mechanical tests and used to predict the panels strength and stiffness. A critical design detail was selected and tested for validation. This section was included in a manufacturing demo, along with other integrated design features, enabling testing the processability. The final panel design was successfully produced and tested on component level. The re-manufacturing process includes simultaneously applied heat and low-shear mixing, followed by compression molding in an isothermal mold. This offers the possibility to retain long fibers and therefore high mechanical properties at short cycle times. In comparison to the current carbon/epoxy solution, the resulting product is lighter, significantly more cost-effective and made of recycled material (fiber and matrix). The prototype panel is targeted for flight testing on the rotorcraft in 2019.Dutch Organization of Applied Research – SIA, projeto SIA-RAAK 2014-01-72PR

Acute Effects of Delta-9-Tetrahydrocannabinol on Performance Monitoring in Healthy Volunteers

Rationale: The error-related negativity (ERN) is a negative event-related potential that occurs immediately after an erroneous response and is thought to reflect human performance monitoring. Delta-9-Tetrahydrocannabinol (THC) administration in healthy volunteers has been linked to impaired performance monitoring in behavioral studies, but to date no studies have examined the effects of cannabinoids on the ERN. Methods: EEG data from 10 healthy volunteers was recorded during execution of a speeded choice-reaction-time task (Flankers task) after administration of THC or placebo vapor in a double-blind randomized crossover design. Results: The findings of this study show that the ERN was significantly reduced after administration of THC. The behavioral outcomes on the Flankers task showed no indications of drug-induced impairments. Discussion: The diminished ERN reflects impairments in the process of performance monitoring. The task design was not optimized to find behavioral effects. The study shows that cannabinoids impair performance monitoring

An extinction rule for a class of 1D quasicrystals

We study decorated one-dimensional quasicrystal obtained by a non-standard projection of a part of two-dimensional lattice. We focus on the impact of varying relative positions of decorated sites. First, we give general expression for the structure factor. Subsequently we analyze an example of extinction rule.Comment: 5 pages, 2 figures, LaTex2e, to appear in ICQ9 Proceeding (Philosophical Magazine

Limit-(quasi)periodic point sets as quasicrystals with p-adic internal spaces

Model sets (or cut and project sets) provide a familiar and commonly used method of constructing and studying nonperiodic point sets. Here we extend this method to situations where the internal spaces are no longer Euclidean, but instead spaces with p-adic topologies or even with mixed Euclidean/p-adic topologies. We show that a number of well known tilings precisely fit this form, including the chair tiling and the Robinson square tilings. Thus the scope of the cut and project formalism is considerably larger than is usually supposed. Applying the powerful consequences of model sets we derive the diffractive nature of these tilings.Comment: 11 pages, 2 figures; dedicated to Peter Kramer on the occasion of his 65th birthda