Exploring the potential of agroforestry integration in arable and dairy farms in the Netherlands - an ex-ante assessment at field and farm level

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The NS3 protein of rice hoja blanca virus suppresses RNA silencing in mammalian cells

The NS3 protein of the tenuivirus rice hoja blanca virus (RHBV) has previously been shown to represent the viral RNA interference (RNAi) suppressor and is active in both plant and insect cells by binding short interfering RNAs (siRNAs) in vitro. Using a firefly luciferase-based silencing assay it is described here that NS3 is also active in mammalian cells. This activity is independent of the inducer molecule used. Using either synthetic siRNAs or a short hairpin RNA construct, NS3 was able to significantly suppress the RNAi-mediated silencing of luciferase expression in both monkey (Vero) and human (HEK293) cells. These results support the proposed mode of action of NS3 to act by sequestering siRNAs, the key molecules of the RNAi pathway conserved in all eukaryotes. The possible applications of this protein in modulating RNAi and investigating the proposed antiviral RNAi response in mammalian cell systems are discussed

Witte lupine voor kalkrijke bodems: Onderzoek over twee jaar naar perspectiefvolle lijnen.

Lupine (Lupinus spp) kan interessant zijn voor zowel biologische als gangbare akkerbouwers die zoeken naar een vlinderbloemig gewas om hun vruchtwisseling te verruimen, niet alleen als veevoer maar ook voor humane voeding. Het doel van dit project was een brede evaluatie van lijnen van witte lupine op hun geschiktheid voor teelt op kalkrijke kleigrond om te beoordelen of er perspectief is voor verdere veredeling voor zowel gangbare als biologische teelt.In dit rapport worden de meest perspectief lijkende lijnen vergeleken over 2012 en 2013 over vier locaties

Brood van natuurakkers: Maatwerk maakt het telen van broodtarwe op natuurakkers mogelijk.

Er is veel gaande op het gebied van natuurbeheer in Nederland. Bezuinigende natuurterrein-beheerorganisaties (TBO’s) zoeken naar nieuwe verdienmodellen. Dit creëert kansen voor bioboeren. Maar er zijn ook vragen over het vinden van de balans tussen natuurdoelen en productie. In het praktijknetwerk “Natuurgrond, Graan en Onkruid” is vooral gekeken naar de mogelijkheden voor de teelt van baktarwe op natuurakkers

Binding of small interfering RNA molecules is crucial for RNA interference suppressor activity of rice hoja blanca virus NS3 in plants

The NS3 protein of rice hoja blanca tenuivirus represents a viral suppressor of RNAi that sequesters small interfering (si)RNAs in vitro. To determine whether this siRNA binding property is the critical determinant for the suppressor activity of NS3, an alanine point mutational analysis was performed and the resulting mutant proteins were tested for both siRNA binding ability and RNAi suppressor activity in plants. Alanine substitutions of lysine residues at position 173-175 resulted in mutant proteins that lost both their affinity for siRNAs and their RNAi suppressor activity in planta. This indicates that siRNA binding of NS3 is indeed essential for the suppressor function of NS3 and that residues at position 173-175 are involved in the siRNA binding and suppressor activit

Thermal behavior of Quantum Cellular Automaton wires

We investigate the effect of a finite temperature on the behavior of logic circuits based on the principle of Quantum Cellular Automata (QCA) and of ground state computation. In particular, we focus on the error probability for a wire of QCA cells that propagates a logic state. A numerical model and an analytical, more approximate, model are presented for the evaluation of the partition function of such a system and, consequently, of the desired probabilities. We compare the results of the two models, assessing the limits of validity of the analytical approach, and provide estimates for the maximum operating temperature.Comment: 15 pages, 7 figures, uses revte

Using a multi-actor approach to getting lupins ‘back on the menu’ in The Netherlands: involving breeders, farmers, food and feed industry and consumers.

The first initiatives aimed at increased lupin production in The Netherlands came from two high(er) value chains: the organic sector striving for regional feed production and the food industry looking for alternatives for soy-based products. As regional production is an added value for both market chains, an additional price could be afforded to compensate for the yield gap that developed over the years. Although this proved to be a good starting point for turning the downward spiral for lupins into an upward spiral, the barriers for a successful development turned out to come from many additional angles: a lack of knowledge on successful production among farmers, the absence of agro-chemicals allowed in the cultivation of lupins, the lack of infrastructure for collecting, drying and cleaning the lupins, the fear of food-producers to introduce a new and unknown allergenic ingredient to the production sites and the lack of knowledge among consumers were some of these additional barriers that needed to be addressed. To overcome these barriers, The Louis Bolk Institute started to cooperate with a great number of actors involved. In cooperation with food technologists and foodproducers new lupin based products were developed broadening the market for lupins grown for human consumption. Cooperation with a farmer union ensured that the allowance for necessary agro-chemicals was initiated and political support was organized at a regional and national level. Finally social organizations aimed at stimulating the public and political debate on protein transition were involved to get lupins better known among consumers and politicians as a new and healthy protein source. As a result of the involvement of all these different actors we are slowly seeing a rise in acreage and consumption of lupins in The Netherlands

Spin-dependent transport in metal/semiconductor tunnel junctions

This paper describes a model as well as experiments on spin-polarized tunnelling with the aid of optical spin orientation. This involves tunnel junctions between a magnetic material and gallium arsenide (GaAs), where the latter is optically excited with circularly polarized light in order to generate spin-polarized carriers. A transport model is presented that takes account of carrier capture in the semiconductor surface states, and describes the semiconductor surface in terms of a spin-dependent energy distribution function. The so-called surface spin-splitting can be calculated from the balance of the polarized electron and hole flow in the semiconductor subsurface region, the polarized tunnelling current across the tunnel barrier between the magnetic material and the semiconductor surface, and the spin relaxation at the semiconductor surface. Measurements are presented of the circular-polarization-dependent photocurrent (the so-called helicity asymmetry) in thin-film tunnel junctions of Co/Al2O3/GaAs. In the absence of a tunnel barrier, the helicity asymmetry is caused by magneto-optical effects (magnetic circular dichroism). In the case where a tunnel barrier is present, the data cannot be explained by magneto-optical effects alone; the deviations provide evidence that spin-polarized tunnelling due to optical spin orientation occurs. In Co/τ-MnAl/AlAs/GaAs junctions no deviations from the magneto-optical effects are observed, most probably due to the weak spin polarization of τ-MnAl along the tunnelling direction; the latter is corroborated by bandstructure calculations. Finally, the application of photoexcited GaAs for spin-polarized tunnelling in a scanning tunnelling microscope is discussed.

Dependence of the Frequency of the Kilohertz Quasi-Periodic Oscillations on X-ray Count Rate and Colors in 4U 1608-52

We present new results based on observations carried out with the Rossi X-ray Timing Explorer during the decay of an outburst of the low-mass X-ray binary (LMXB) and atoll source 4U 1608-52. Our results appear to resolve, at least in 4U 1608-52, one of the long-standing issues about the phenomenology of the kilohertz quasi-periodic oscillations (kHz QPOs), namely, the lack of a unique relation between the frequency of the kHz QPOs and the X-ray flux. We show that despite its complex dependence on the X-ray flux, the frequency of the kHz QPOs is monotonically related to the position of the source in the color-color diagram. Our findings strengthen the idea that, as in the case of Z sources, in the atoll sources the X-ray flux is not a good indicator of $\dot M$, and that the observed changes in the frequency of the kHz QPOs in LMXBs are driven by changes in $\dot M$. These results raise some concern about the recently reported detection of the orbital frequency at the innermost stable orbit in 4U 1820-30.Comment: Accepted for publication in The Astrophysical Journal Letters. Uses AAS LaTex v4.0 (5 pages plus 4 postscript figures

Realist Evaluation : an overview

This report summarises the discussions and presentations of the Expert Seminar ‘Realist Evaluation’ with Gill Westhorp, which took place in Wageningen on March 29, 2011. The Expert Seminar was organised by the Wageningen UR Centre for Development Innovation in collaboration with Learning by Design and Context, international cooperation